Deadly Taiwan Fireball Caused by Stage Lights: Report

A deadly fireball that ripped through a crowd of young people at a Taiwan water park in June was caused when coloured powder was ignited by stage lights, an investigation reportedly showed Friday.The cornstarch powder had been sprayed over the crowd of hundreds of partygoers at the Formosa Fun Coast water park.It exploded when it came into contact with the lights, whose surface temperatures reached more than 400 degrees Celsius, the Liberty Times reported, citing a fire department investigation.

Eleven people were killed and hundreds were hospitalised, some with third-degree burns covering more than 90 percent of their bodies.The report has been submitted to prosecutors, but officials declined to comment on its content."We will use this report as a reference," Shihlin district prosecutors' office spokeswoman Su Pei-yu told AFP.

"We can't reveal details at the moment as the investigation is still underway."The event, which drew around 1,000 people -- mostly between 18 and 25 years old -- turned into a nightmare when the inferno ripped through the crowd. Horrific video footage showed people running for their lives and screaming as they tried to escape.

Two months on, 42 of the victims are still in critical condition, according to the Ministry of Health and Welfare.The report by the fire department ruled out earlier speculation that the blaze was caused by a cigarette.Three suspects have been released on bail as prosecutors investigate them on charges of offences against public safety and negligence causing deaths.

Six more are being investigated, prosecutors said, including both the chairman and the president of the water park.

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How to Interpret Visual Fields
IntroductionImagine you are assessing a patient with visual difficulties or optic disc swelling. After a bedside visual field examination with waggling fingers and even a red hatpin, you decide that there is an abnormality. After requesting quantified visual field tests, the patient returns with a black and white printout with numbers (eg, Humphrey fields) or coloured lines on a sheet (eg, Goldmann fields). Where is the report you ask? There is none!Static perimetry uses flashing stationary lights. This can be automated (eg, evenly spaced points on a grid) or manual (eg, as a small part of Goldmann test: detailed later). The Humphrey field analyser is by far the most commonly used for automated static perimetry, although there are also other machines such as Octopus and Henson. Later, we describe in detail the interpretation of Humphrey perimetry. oas_tag.loadAd("Middle1"); Kinetic perimetry uses a moving illuminated target and is done either manually (eg, Goldmann) or on an automated machine (eg, Octopus). Goldmann machines are no longer manufactured, being slowly replaced by Octopus machines. Nevertheless, Goldmann remains the most commonly used kinetic perimetry, and so we use this here to illustrate interpretation of kinetic fields. The principles for interpreting Goldmann also apply to results from Octopus machines.It is beyond the scope of this paper to cover the neuroanatomical localisation of visual field defects. Instead we recommend two excellent recent reviews.1 ,2 Skilled interpretation of visual field tests requires a good grasp and application of this prior knowledge.Useful aspects of eye anatomyThe fovea is the area of greatest visual sensitivity, where the cone photoreceptor density is at its highest. The visual sensitivity slopes off further from the fovea. This drop in sensitivity can be visualised as a hill, with the fovea is at the peak (figure 1). Conventional perimetry is carried out under photopic (well lit) conditions, and therefore, rod photoreceptors do not contribute to the findings.The normal field of vision extends to approximately 60 nasally, 90 temporally, 60 superiorly and 70 inferiorly.The blind spot indicates the location of the optic nerve headan area with no photoreceptorsin the temporal part of the visual field.Anything obstructing the travel of light towards the retina may affect the field tests, for example, lens opacity (cataract), ptosis (if not taped away from the pupil) or the rim of a correcting lens (test artefact)Download figure Open in new tab Download powerpoint Figure1 Normal hill of vision.Goldmann field testDuring a Goldmann field test, the patient positions their eye opposite the centre of a white hemispherical bowl (figure 2). The patient fixates upon the central target 33 cm away, while the examiner sits opposite viewing through an eyepiece to ensure good fixation throughout the test. The examiner moves an illuminated white target from the periphery towards the centre, and the patient presses a buzzer to indicate when they first see the target. This is repeated from different directionsallowing the examiner to plot the patient's field of visionusing targets varying in size and brightness. The examiner plots the blind spot and the edges of scotomas in a similar way, with the patient pressing the buzzer to indicate when they first see the light target moving from a blind to a seeing area. The examiner also performs static testinginvolving the brief appearance of the stationary light targetin the four quadrants within the central 20 or so, marking a tick on the chart when the patient sees the target and a cross if they do not.Download figure Open in new tab Download powerpoint Figure2 Goldmann machine. The patient's eye is positioned at the centre of a white hemispheric bowl, with the examiner looking through an eyepiece to ensure good fixation. A white light (indicated by yellow arrow in (A) is brought in from the periphery into the patient's field of vision. The examiner does this by controlling connecting levers (indicated by orange arrows in A and B). The patient presses a buzzer when the light target is seen (blue arrow).The target sizes are labelled with three alphanumeric digits, for example, V4e. The first digit is a Roman numeral (IV), indicating the size of the target, for example, V is equivalent to a target diameter of 9.03 mm. With every drop in number (eg, from V to IV) the diameter halves.The second digit is an Arabic number (14), indicating the brightness of the stimulus: the larger the number the higher the luminance.The third digit is a letter (ae), indicating a finer calibration of luminance. 4e is equivalent to 10-decibel (dB) brightness; each consecutive drop in number represents a 5 dB change and each drop in letter represents a 1 dB change.By convention, the examiner maps three isopters: lines of equal sensitivity to targets of a specified size and luminance. The first isopter, mapping the farthest peripheral vision, requires the largest and brightest target V4e. Another isopter is mapped in the central 30 of vision, and a third isopter is intermediate between these two. The isopter lines therefore show the margins of different visual sensitivity, analogous to the contour lines of a map marking different elevations. This allows us to visualise the hill of vision. The base of the hill represents the area at the periphery with least visual sensitivity, detecting only the largest and brightest target. As we move up towards the peak of the hill, the visual sensitivity increases and the patient sees smaller and dimmer targets.Humphrey field testThe same principles apply to the Humphrey test as to the Goldmann test, but instead with static light stimulation. The machine can also be programmed to perform kinetic tests though we have no experience with this.The illuminated targets appear for 200 ms at predetermined locations on a grid. Humphrey tests are widely used in glaucoma clinics, the most common set up being to test the central 24 (24-2 setting). Some examiners test smaller or wider visual angles; however, the wider the visual angle tested, the more coarse the grid, and hence the greater the likelihood of missing small scotomas. The 24-2 assesses the central 24 with a 54-point grid; 10-2 assesses the central 10 with a 68-point grid; and 30-2 assesses the central 30 with a 76-point grid.The examiner plots the hill of vision based upon the threshold for detecting different target luminance; as visual sensitivity improves towards the fovea, so the detection threshold for the target decreases. Unlike Goldmann, the target size stays the same during the test, with a default size equivalent to Goldmann size III targets. It is rare to need a different default size.The Swedish interactive threshold algorithm (SITA) is the most commonly used test algorithm,3 designed to reduce the time to complete a test; a short test duration limits the likelihood of errors from patient fatigue. SITA starts by determining the visual stimulation thresholds at the four quadrants. If the patient sees the initial stimulus, the examiner reduces its brightness to the level where it is no longer seen. Conversely, if the patient does not see the stimulus, its brightness is increased to find this threshold. The examiner adjusts the initial brightness at adjacent points according to the threshold of its neighbouring point. During the test, the examiner retests some locations to determine reliability (see false-negative errors, below). At completion, the computer generates a statistical analysis, which is compared to an age-matched normal population. Useful aspects of eye anatomyThe fovea is the area of greatest visual sensitivity, where the cone photoreceptor density is at its highest. The visual sensitivity slopes off further from the fovea. This drop in sensitivity can be visualised as a hill, with the fovea is at the peak (figure 1). Conventional perimetry is carried out under photopic (well lit) conditions, and therefore, rod photoreceptors do not contribute to the findings.The normal field of vision extends to approximately 60 nasally, 90 temporally, 60 superiorly and 70 inferiorly.The blind spot indicates the location of the optic nerve headan area with no photoreceptorsin the temporal part of the visual field.Anything obstructing the travel of light towards the retina may affect the field tests, for example, lens opacity (cataract), ptosis (if not taped away from the pupil) or the rim of a correcting lens (test artefact)Download figure Open in new tab Download powerpoint Figure1 Normal hill of vision. Goldmann field testDuring a Goldmann field test, the patient positions their eye opposite the centre of a white hemispherical bowl (figure 2). The patient fixates upon the central target 33 cm away, while the examiner sits opposite viewing through an eyepiece to ensure good fixation throughout the test. The examiner moves an illuminated white target from the periphery towards the centre, and the patient presses a buzzer to indicate when they first see the target. This is repeated from different directionsallowing the examiner to plot the patient's field of visionusing targets varying in size and brightness. The examiner plots the blind spot and the edges of scotomas in a similar way, with the patient pressing the buzzer to indicate when they first see the light target moving from a blind to a seeing area. The examiner also performs static testinginvolving the brief appearance of the stationary light targetin the four quadrants within the central 20 or so, marking a tick on the chart when the patient sees the target and a cross if they do not.Download figure Open in new tab Download powerpoint Figure2 Goldmann machine. The patient's eye is positioned at the centre of a white hemispheric bowl, with the examiner looking through an eyepiece to ensure good fixation. A white light (indicated by yellow arrow in (A) is brought in from the periphery into the patient's field of vision. The examiner does this by controlling connecting levers (indicated by orange arrows in A and B). The patient presses a buzzer when the light target is seen (blue arrow).The target sizes are labelled with three alphanumeric digits, for example, V4e. The first digit is a Roman numeral (IV), indicating the size of the target, for example, V is equivalent to a target diameter of 9.03 mm. With every drop in number (eg, from V to IV) the diameter halves.The second digit is an Arabic number (14), indicating the brightness of the stimulus: the larger the number the higher the luminance.The third digit is a letter (ae), indicating a finer calibration of luminance. 4e is equivalent to 10-decibel (dB) brightness; each consecutive drop in number represents a 5 dB change and each drop in letter represents a 1 dB change.By convention, the examiner maps three isopters: lines of equal sensitivity to targets of a specified size and luminance. The first isopter, mapping the farthest peripheral vision, requires the largest and brightest target V4e. Another isopter is mapped in the central 30 of vision, and a third isopter is intermediate between these two. The isopter lines therefore show the margins of different visual sensitivity, analogous to the contour lines of a map marking different elevations. This allows us to visualise the hill of vision. The base of the hill represents the area at the periphery with least visual sensitivity, detecting only the largest and brightest target. As we move up towards the peak of the hill, the visual sensitivity increases and the patient sees smaller and dimmer targets. Humphrey field testThe same principles apply to the Humphrey test as to the Goldmann test, but instead with static light stimulation. The machine can also be programmed to perform kinetic tests though we have no experience with this.The illuminated targets appear for 200 ms at predetermined locations on a grid. Humphrey tests are widely used in glaucoma clinics, the most common set up being to test the central 24 (24-2 setting). Some examiners test smaller or wider visual angles; however, the wider the visual angle tested, the more coarse the grid, and hence the greater the likelihood of missing small scotomas. The 24-2 assesses the central 24 with a 54-point grid; 10-2 assesses the central 10 with a 68-point grid; and 30-2 assesses the central 30 with a 76-point grid.The examiner plots the hill of vision based upon the threshold for detecting different target luminance; as visual sensitivity improves towards the fovea, so the detection threshold for the target decreases. Unlike Goldmann, the target size stays the same during the test, with a default size equivalent to Goldmann size III targets. It is rare to need a different default size.The Swedish interactive threshold algorithm (SITA) is the most commonly used test algorithm,3 designed to reduce the time to complete a test; a short test duration limits the likelihood of errors from patient fatigue. SITA starts by determining the visual stimulation thresholds at the four quadrants. If the patient sees the initial stimulus, the examiner reduces its brightness to the level where it is no longer seen. Conversely, if the patient does not see the stimulus, its brightness is increased to find this threshold. The examiner adjusts the initial brightness at adjacent points according to the threshold of its neighbouring point. During the test, the examiner retests some locations to determine reliability (see false-negative errors, below). At completion, the computer generates a statistical analysis, which is compared to an age-matched normal population. Humphrey or Goldmann?The choice may depend upon local availability. The Humphrey is slightly less operator-dependent than the Goldmann and has the advantage of numbers to indicate reliability of the test. The Goldmann tests peripheral fields better, may be more patient-friendly for those who are hesitant on the Humphrey, and is particularly useful for central scotoma, as it is easier to manage fixation losses. As a rule of thumb, when monitoring disease, it is sensible to use the same test as was used previously. Both tests can complement each other, confirming deficit patterns when in doubt.Interpreting the Goldmann field testThe key to interpreting Goldmann visual fields is to keep in mind the normal hill of vision (figure 1) and how it compares with the patient's results. The skill is in identifying patterns and observing any change with repeated tests. This may require experience to be adept, though the following checklist may help (figure 3): Patient name and date of test: a good habit always to check the test belongs to your patient!What is the largest peripheral field (V4e)? This can vary according to age and test response. It normally extends to approximately 60 nasally, 90 temporally, 60 superiorly and 70 inferiorly. Thus, the superior aspect of the field is usually less sensitive than the inferior field, though ptosis could also artefactually reduce it.Is there any distortion to the contours? (Contours are the smaller isopters corresponding to targets that are either smaller or dimmer or both). Is the isopter smooth, as expected for a normal hill of vision?Is there restriction? Examples would be a nasal step in papilloedema or an altitudinal defect in anterior ischaemic optic neuropathy.Are the isopters spaced, as expected for the normal hill of vision? (1) A tiny central field with stacked isoptersvery close to one another as in a steep hillusually denotes functional overlay (figure 7); however, patients with genuine retinal and striate cortex lesions may also have stacked isopters. (2) Isopter lines that cross always indicate unreliable test: isopters cannot cross since this would indicate two different sensitivities at one location. (3) Spiralling isopters suggest functional visual loss and indicate a steady decline in sensitivity during the test.Are there scotomas? It is important to correlate this with the patient's symptoms and clinical (bedside) examination.Is the blind spot size enlarged? This is particularly relevant in papilloedema (figure 5). The normal blind spot size is oval, roughly 10 in diameter, and located 1020 temporally from the central fixation point.Is the central field affected? Was static testing done (indicated with a tick when the patient saw the target)?Is any defect monocular or binocular, when comparing the fields for each eye? If binocular, is the defect homonymous or heteronymous?Any comments written about patient fixation or attention also help. Small pupil size, ptosis and incorrect positioning of a correcting lens may affect the peripheral field.Inadequate correction of refraction error for the viewing distance (33 cm) may affect the central field.Download figure Open in new tab Download powerpoint Figure3 Interpreting the Goldmann visual field.The chart is viewed from the perspective of the patient looking into the test bowl, as if patient is looking into the paper. Suggested checklist to review the Goldmann fields systematically (see text for details):1. Patient name and identification number, date of test.2. The largest isopter, that is, peripheral field.3. The other isoptersany distortion to the contours of the hill of vision? Any scotomas?4. Blind spot.5. Central vision.6. If there is an abnormality, is it monocular or binocular? If binocular, is it homonymous or heteronymous?7. Other, for example, comments about fixation or attention.This is an example of normal Goldmann fields. In contrast, this patient did not perform well on the Humphrey visual fields, with poor reliability and cloverleaf pattern (figure 4).Download figure Open in new tab Download powerpoint Figure4 Interpreting the Humphrey visual field. The charts are viewed from the perspective of the patient looking into the test bowl, as if patient is looking into the paper. Suggested checklist to systematically review Humphrey visual fields (see text for details): 1. Is this the correct test? A. Patient name and identification number B. Date of test C. Left or right eye? D. Test performed degree of visual angle tested test protocol: threshold or screening2. Can I rely on this test? A. False-positive errors B. False-negative errors C. Fixation-loss index D. Gaze-tracking graph 3. Is the test normal? A. Visual sensitivity map B. Total deviation map C. Pattern deviation mapThis patient's test was unreliable: high fixation loss index (and comment from technician, patient advised several times for both eyes (suggesting poor compliance), gaze-tracking graph also showed eye movements (indicated by upward spike from baseline) and high false-negative errors, up to 20% in the left eye. The grey scale visual sensitivity map suggests a clover leaf type pattern (figure 9). This provided the impression that the patient had difficulty with the Humphrey test itself. Clinical examination including visual acuity, colour vision, pupillary examination and visual field to confrontation to red pin was normal. The patient's Goldmann visual field test was normal (figure 3).Download figure Open in new tab Download powerpoint Figure5 Goldmann visual field from papilloedema. This patient has papilloedema from idiopathic intracranial hypertension. Goldmann fields show (1) an enlarged blind spot and (2) inferonasal field restriction.Download figure Open in new tab Download powerpoint Figure6 Goldmann visual fields of a patient with right optic neuropathy. All isopters are restricted but with preserved contours of the hill of vision, giving the appearance of a sunken hill. Compare this with figure 7 showing stacked isopters in a patient with functional visual loss.Download figure Open in new tab Download powerpoint Figure7 Goldmann visual fields of a patient with stacked isopters. This patient has functional overlay of a previous episode of mild optic neuritis affecting the right eye. Compare this with figure 6 of another patient with optic neuropathy. These stacked isopters would represent a hill vision that is too steep to be physiological, that is, the close contours here appear like a cliff drop. Clinical examination with a red target confirmed the presence of a tubular field (figure 8), with the size of visual field remaining unchanged when examined at 1 and 4 m. This is not keeping with the optics of light, whereby at a constant visual angle, the size of the field would appear larger the further away, that is, when examined at 4 m (with a proportionately larger target for acuity), the size of field to confrontation should be larger than on examination at 1 m.Download figure Open in new tab Download powerpoint Figure8 Tunnel vision: functional (ie, tubular field) versus physiological. The optics of light is such that at a constant visual angle, the size of the field appears larger when further away. When examined at 4 m (with a proportionately larger target for acuity), the size of field to confrontation should be larger than on examination at 1 m. Thus, a tubular field, where the size of field is unchanged, suggests functional overlay.Download figure Open in new tab Download powerpoint Figure9 Cloverleaf pattern on Humphrey visual fields. This artefactual visual field defect results from a reduced response rate as the test progresses. The Swedish interactive threshold algorithm (SITA) threshold test starts by determining the initial brightness in the four quadrants using the four points indicated by the arrows. Therefore, if a patient's response deteriorates as the test progresses, for example, because of reduced concentration, the visual field shows a cloverleaf pattern, where the thresholds are low at the four points initially tested and higher for the surrounding points. This pattern commonly occurs in non-organic visual loss and is equivalent to spiralling on the Goldmann. There will also be a high rate of negative errors. (A) Shows an example where the patient stops responding very early in the test, giving an extreme example of the cloverleaf pattern; (B) shows another example of cloverleaf pattern.Interpreting the Humphrey field testWe suggest the following framework to interpret Humphrey test results (figure 4), structured to answer three questions: 1. Is this the correct test?A. Name and patient number: confirm that the output belongs to your patient!B. Date of test: is this the output of interest? that is, timing in relation to symptoms.C. To which eye does this output correspond? Correlate the results with the history and clinical examination. Beware of fields that are mounted incorrectly: the conventional way of mounting is to place the left chart on the right and vice versa, ie, as if the patient is looking into the chart.D. What test was performed? This is particularly important when comparing to any previous tests.a. What degree of visual angle was tested?Most commonly set to 24-2 (central 24 tested with a 54-point grid). A smaller field with higher concentration of points gives further details of the foveal region. For example, 10-2 assesses the central 10 with a 68-point grid. 30-2 is similar to 24-2 but with an additional 6 and with a corresponding increase in the points tested (76-point grid for 30); thus, this is a longer test with the risk of more patient errors.b. Was it a threshold or a screening test?Screening tests use suprathreshold targets of single luminance and in the past were particularly useful because full threshold tests were time consuming. However, SITA threshold tests have superseded these, reducing test times (equivalent to the time taken for screening tests) without losing sensitivity.2. Can I rely on this test?A. False-positive errorsFalse-positive errors identify trigger happy patients who respond in the absence of light stimulus. They are calibrated according to the patient's overall responses, therefore detecting when responses occur too soon after presenting a stimulus is. A false-positive rate of >15% compromises test results.4B. False-negative errorsA false negative is the failure to respond to a relatively bright suprathreshold target in a region that previously responded to fainter stimuli. A high false-negative index may indicate hesitation or inattentiveness, though a true scotoma may also give false-negative results. However, in a true scotoma, the false-negative error rate is low for the contralateral (normal) eye.4 False-negative error may reduce with repeated testing as the patient gets used to the testing procedure.C. Fixation-loss indexFixation loss is tested by presenting a stimulus at the blind spot. If the patient sees this stimulus, it indicates loss of fixation. Values of >20% can compromise the test.4 However, this number could be artefactually elevated if the blind spot was inaccurately located, or in trigger-happy patients. Tracking of the gaze (below) is better for assessing fixation loss.D. Gaze-tracking graphThe eyes are tracked using video. The gaze tracking graph shows an upward spike when the eyes move and a downward spike when the eyes blink.3. Is the test normal?Three maps are generated with numbers and pictorial representations:A. Visual sensitivity mapThe numbers indicate the threshold of stimulus intensity detected in decibel (dB), with zero corresponding to the brightest intensity. Typical normal values centrally are around 30 dB. Values of 40 dB should not appear in standard test conditions but could occur in patients with high false-positive errors. The visual sensitivity may improve with repeat testing as patients become more familiar with it. The grey scale map is a visual representation of the numbers, with darker areas indicating poorer sensitivity to stimuli.B. Total deviation mapThis shows the deviations of the patient's visual sensitivity compared to an age-matched normal population. The numbers indicate the difference compared to the mean, that is, a negative value indicates less visual sensitivity compared to the mean population. The probability plot gives a visual representation of statistical analysis (t test) of this deviation from the mean; the larger departure from the mean, the darker the symbol.C. Pattern deviation mapThis shows the deviation of the pattern from a normal visual hill, where the peak is at the fovea. The numeric values show any departure from the mean of an age-matched population, and as above, the probability plot is a visual representation of statistical analysis indicating the extent of departure from mean. The pattern deviation adjusts for any shifts in overall sensitivity: for example, a patient with cataract might have a smaller or sunken hill but with normal contour patterns.By statistical chance, patients may have a few scattered dark symbols on the probability map, which may not be of concern. Instead, look for patterns, for example, whether these are around the blind spot, which might indicate a true enlargement. It is important to correlate the test results with the history and clinical examination.The visual sensitivity, total deviation and pattern deviation maps should be viewed together for any discrepancies. It is worth noting the following scenarios: Abnormal grey scale on stimulus intensity map but normal probability plots: lid partially obscuring the superior field.Abnormal total deviation but normal pattern deviation: cataract, small pupils, incorrect correction for refractive error.Abnormal pattern deviation but normal total deviation: a test with high false-positive (trigger happy) patient.Additional information that may help, especially when comparing with previous tests, include pupil diameter (is there a wide variation between tests?), lens modification (was the same correction used?), time taken to do the test (was this particularly long?). The global indices show the mean deviations, which can help to monitor progression, especially in glaucoma.Three summary indices appear on the printout4: The visual field index is a staging index designed to correspond to ganglion cell loss, that is, 100% represents normal fields and 0% represents blind fields.The mean deviation represents the degree of departure of the whole field's average values, from age-adjusted normal values.The pattern SD represents irregularities within the field, for example, of localised field defects. This can be small in completely normal patients or in those with complete blindness.The visual field index and the mean deviation can help to identify progression; the visual field index may be less prone to artefacts from cataract. These values may help to monitor progression, but with caution, since artefacts and test reliability can affect them. Interpreting the Goldmann field testThe key to interpreting Goldmann visual fields is to keep in mind the normal hill of vision (figure 1) and how it compares with the patient's results. The skill is in identifying patterns and observing any change with repeated tests. This may require experience to be adept, though the following checklist may help (figure 3): Patient name and date of test: a good habit always to check the test belongs to your patient!What is the largest peripheral field (V4e)? This can vary according to age and test response. It normally extends to approximately 60 nasally, 90 temporally, 60 superiorly and 70 inferiorly. Thus, the superior aspect of the field is usually less sensitive than the inferior field, though ptosis could also artefactually reduce it.Is there any distortion to the contours? (Contours are the smaller isopters corresponding to targets that are either smaller or dimmer or both). Is the isopter smooth, as expected for a normal hill of vision?Is there restriction? Examples would be a nasal step in papilloedema or an altitudinal defect in anterior ischaemic optic neuropathy.Are the isopters spaced, as expected for the normal hill of vision? (1) A tiny central field with stacked isoptersvery close to one another as in a steep hillusually denotes functional overlay (figure 7); however, patients with genuine retinal and striate cortex lesions may also have stacked isopters. (2) Isopter lines that cross always indicate unreliable test: isopters cannot cross since this would indicate two different sensitivities at one location. (3) Spiralling isopters suggest functional visual loss and indicate a steady decline in sensitivity during the test.Are there scotomas? It is important to correlate this with the patient's symptoms and clinical (bedside) examination.Is the blind spot size enlarged? This is particularly relevant in papilloedema (figure 5). The normal blind spot size is oval, roughly 10 in diameter, and located 1020 temporally from the central fixation point.Is the central field affected? Was static testing done (indicated with a tick when the patient saw the target)?Is any defect monocular or binocular, when comparing the fields for each eye? If binocular, is the defect homonymous or heteronymous?Any comments written about patient fixation or attention also help. Small pupil size, ptosis and incorrect positioning of a correcting lens may affect the peripheral field.Inadequate correction of refraction error for the viewing distance (33 cm) may affect the central field.Download figure Open in new tab Download powerpoint Figure3 Interpreting the Goldmann visual field.The chart is viewed from the perspective of the patient looking into the test bowl, as if patient is looking into the paper. Suggested checklist to review the Goldmann fields systematically (see text for details):1. Patient name and identification number, date of test.2. The largest isopter, that is, peripheral field.3. The other isoptersany distortion to the contours of the hill of vision? Any scotomas?4. Blind spot.5. Central vision.6. If there is an abnormality, is it monocular or binocular? If binocular, is it homonymous or heteronymous?7. Other, for example, comments about fixation or attention.This is an example of normal Goldmann fields. In contrast, this patient did not perform well on the Humphrey visual fields, with poor reliability and cloverleaf pattern (figure 4).Download figure Open in new tab Download powerpoint Figure4 Interpreting the Humphrey visual field. The charts are viewed from the perspective of the patient looking into the test bowl, as if patient is looking into the paper. Suggested checklist to systematically review Humphrey visual fields (see text for details): 1. Is this the correct test? A. Patient name and identification number B. Date of test C. Left or right eye? D. Test performed degree of visual angle tested test protocol: threshold or screening2. Can I rely on this test? A. False-positive errors B. False-negative errors C. Fixation-loss index D. Gaze-tracking graph 3. Is the test normal? A. Visual sensitivity map B. Total deviation map C. Pattern deviation mapThis patient's test was unreliable: high fixation loss index (and comment from technician, patient advised several times for both eyes (suggesting poor compliance), gaze-tracking graph also showed eye movements (indicated by upward spike from baseline) and high false-negative errors, up to 20% in the left eye. The grey scale visual sensitivity map suggests a clover leaf type pattern (figure 9). This provided the impression that the patient had difficulty with the Humphrey test itself. Clinical examination including visual acuity, colour vision, pupillary examination and visual field to confrontation to red pin was normal. The patient's Goldmann visual field test was normal (figure 3).Download figure Open in new tab Download powerpoint Figure5 Goldmann visual field from papilloedema. This patient has papilloedema from idiopathic intracranial hypertension. Goldmann fields show (1) an enlarged blind spot and (2) inferonasal field restriction.Download figure Open in new tab Download powerpoint Figure6 Goldmann visual fields of a patient with right optic neuropathy. All isopters are restricted but with preserved contours of the hill of vision, giving the appearance of a sunken hill. Compare this with figure 7 showing stacked isopters in a patient with functional visual loss.Download figure Open in new tab Download powerpoint Figure7 Goldmann visual fields of a patient with stacked isopters. This patient has functional overlay of a previous episode of mild optic neuritis affecting the right eye. Compare this with figure 6 of another patient with optic neuropathy. These stacked isopters would represent a hill vision that is too steep to be physiological, that is, the close contours here appear like a cliff drop. Clinical examination with a red target confirmed the presence of a tubular field (figure 8), with the size of visual field remaining unchanged when examined at 1 and 4 m. This is not keeping with the optics of light, whereby at a constant visual angle, the size of the field would appear larger the further away, that is, when examined at 4 m (with a proportionately larger target for acuity), the size of field to confrontation should be larger than on examination at 1 m.Download figure Open in new tab Download powerpoint Figure8 Tunnel vision: functional (ie, tubular field) versus physiological. The optics of light is such that at a constant visual angle, the size of the field appears larger when further away. When examined at 4 m (with a proportionately larger target for acuity), the size of field to confrontation should be larger than on examination at 1 m. Thus, a tubular field, where the size of field is unchanged, suggests functional overlay.Download figure Open in new tab Download powerpoint Figure9 Cloverleaf pattern on Humphrey visual fields. This artefactual visual field defect results from a reduced response rate as the test progresses. The Swedish interactive threshold algorithm (SITA) threshold test starts by determining the initial brightness in the four quadrants using the four points indicated by the arrows. Therefore, if a patient's response deteriorates as the test progresses, for example, because of reduced concentration, the visual field shows a cloverleaf pattern, where the thresholds are low at the four points initially tested and higher for the surrounding points. This pattern commonly occurs in non-organic visual loss and is equivalent to spiralling on the Goldmann. There will also be a high rate of negative errors. (A) Shows an example where the patient stops responding very early in the test, giving an extreme example of the cloverleaf pattern; (B) shows another example of cloverleaf pattern. Interpreting the Humphrey field testWe suggest the following framework to interpret Humphrey test results (figure 4), structured to answer three questions: 1. Is this the correct test?A. Name and patient number: confirm that the output belongs to your patient!B. Date of test: is this the output of interest? that is, timing in relation to symptoms.C. To which eye does this output correspond? Correlate the results with the history and clinical examination. Beware of fields that are mounted incorrectly: the conventional way of mounting is to place the left chart on the right and vice versa, ie, as if the patient is looking into the chart.D. What test was performed? This is particularly important when comparing to any previous tests.a. What degree of visual angle was tested?Most commonly set to 24-2 (central 24 tested with a 54-point grid). A smaller field with higher concentration of points gives further details of the foveal region. For example, 10-2 assesses the central 10 with a 68-point grid. 30-2 is similar to 24-2 but with an additional 6 and with a corresponding increase in the points tested (76-point grid for 30); thus, this is a longer test with the risk of more patient errors.b. Was it a threshold or a screening test?Screening tests use suprathreshold targets of single luminance and in the past were particularly useful because full threshold tests were time consuming. However, SITA threshold tests have superseded these, reducing test times (equivalent to the time taken for screening tests) without losing sensitivity.2. Can I rely on this test?A. False-positive errorsFalse-positive errors identify trigger happy patients who respond in the absence of light stimulus. They are calibrated according to the patient's overall responses, therefore detecting when responses occur too soon after presenting a stimulus is. A false-positive rate of >15% compromises test results.4B. False-negative errorsA false negative is the failure to respond to a relatively bright suprathreshold target in a region that previously responded to fainter stimuli. A high false-negative index may indicate hesitation or inattentiveness, though a true scotoma may also give false-negative results. However, in a true scotoma, the false-negative error rate is low for the contralateral (normal) eye.4 False-negative error may reduce with repeated testing as the patient gets used to the testing procedure.C. Fixation-loss indexFixation loss is tested by presenting a stimulus at the blind spot. If the patient sees this stimulus, it indicates loss of fixation. Values of >20% can compromise the test.4 However, this number could be artefactually elevated if the blind spot was inaccurately located, or in trigger-happy patients. Tracking of the gaze (below) is better for assessing fixation loss.D. Gaze-tracking graphThe eyes are tracked using video. The gaze tracking graph shows an upward spike when the eyes move and a downward spike when the eyes blink.3. Is the test normal?Three maps are generated with numbers and pictorial representations:A. Visual sensitivity mapThe numbers indicate the threshold of stimulus intensity detected in decibel (dB), with zero corresponding to the brightest intensity. Typical normal values centrally are around 30 dB. Values of 40 dB should not appear in standard test conditions but could occur in patients with high false-positive errors. The visual sensitivity may improve with repeat testing as patients become more familiar with it. The grey scale map is a visual representation of the numbers, with darker areas indicating poorer sensitivity to stimuli.B. Total deviation mapThis shows the deviations of the patient's visual sensitivity compared to an age-matched normal population. The numbers indicate the difference compared to the mean, that is, a negative value indicates less visual sensitivity compared to the mean population. The probability plot gives a visual representation of statistical analysis (t test) of this deviation from the mean; the larger departure from the mean, the darker the symbol.C. Pattern deviation mapThis shows the deviation of the pattern from a normal visual hill, where the peak is at the fovea. The numeric values show any departure from the mean of an age-matched population, and as above, the probability plot is a visual representation of statistical analysis indicating the extent of departure from mean. The pattern deviation adjusts for any shifts in overall sensitivity: for example, a patient with cataract might have a smaller or sunken hill but with normal contour patterns.By statistical chance, patients may have a few scattered dark symbols on the probability map, which may not be of concern. Instead, look for patterns, for example, whether these are around the blind spot, which might indicate a true enlargement. It is important to correlate the test results with the history and clinical examination.The visual sensitivity, total deviation and pattern deviation maps should be viewed together for any discrepancies. It is worth noting the following scenarios: Abnormal grey scale on stimulus intensity map but normal probability plots: lid partially obscuring the superior field.Abnormal total deviation but normal pattern deviation: cataract, small pupils, incorrect correction for refractive error.Abnormal pattern deviation but normal total deviation: a test with high false-positive (trigger happy) patient.Additional information that may help, especially when comparing with previous tests, include pupil diameter (is there a wide variation between tests?), lens modification (was the same correction used?), time taken to do the test (was this particularly long?). The global indices show the mean deviations, which can help to monitor progression, especially in glaucoma.Three summary indices appear on the printout4: The visual field index is a staging index designed to correspond to ganglion cell loss, that is, 100% represents normal fields and 0% represents blind fields.The mean deviation represents the degree of departure of the whole field's average values, from age-adjusted normal values.The pattern SD represents irregularities within the field, for example, of localised field defects. This can be small in completely normal patients or in those with complete blindness.The visual field index and the mean deviation can help to identify progression; the visual field index may be less prone to artefacts from cataract. These values may help to monitor progression, but with caution, since artefacts and test reliability can affect them. ConclusionWe present these simplified checklists to help neurologists to interpret Humphrey and Goldmann visual fields. We emphasise the importance of correlating these visual field outputs with careful patient history and clinical examination. Increased exposure to perimetry and its application in the clinical setting will help build up skills in its interpretation. For readers interested in deepening their understanding of fields and its nuances, we suggest further reading from the reference list.46 Key pointsPerimetry results give a pictorial representation of the patient's hill of vision; keep the normal hill in mind when reviewing these tests.Correlate perimetry results with the clinical history and examination (including examination to confrontation), as the tests often have artefacts.Watch out for patient performance effect, for example, high false-positive or false-negative errors, cloverleaf pattern (static perimetry) or spiralling of fields (kinetic fields).Perimetry results change if anything obstructs the travel of light towards the retina (eg cataract).Static and kinetic perimetry complement one another; consider the other if the first is unexpectedly normal or abnormal. ReferencesCooper SA, Metcalfe RA. Assess and interpret the visual fields at the bedside. Pract Neurol 2009;9:32434. doi:10.1136/jnnp.2009.193920OpenUrlAbstract/FREE Full TextHickman SJ. Neurological visual field defects. Neuro-ophthalmology 2011;35:24250. doi:10.3109/01658107.2011.616980OpenUrlBengtsson B, Olsson J, Heijl A, et al. A new generation of algorithms for computerized threshold perimetry, SITA. Acta Ophthalmol Scand 1997;75:36875. doi:10.1111/j.1600-0420.1997.tb00392.xOpenUrlPubMedWeb of ScienceHeijl A, Patella VM, Bengtsoon B. The field analyzer primer: effective perimetry. 2012, Carl Zeiss Meditec.Barton JJS, Benatar M. Field of vision: a manual and atlas of perimetry. Current Clinical Neurology series. New Jersey: Humana Press, 2003.Carl Zeiss Meditec, Inc. Humphrey Field Analyzer Manual Book II-i series system software version 5.1. 2012, Carl Zeiss Meditec. FootnotesContributors SHW wrote the first draft of the manuscript; GTP reviewed and made revisions to the manuscript.Competing interests None declared.Provenance and peer review Commissioned; externally peer reviewed. This paper was reviewed by Mark Lawden, Leicester, UK.
2021 05 25
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2019 Audi A7 to Debut at NAIAS - News.
The all-new 2019 Audi A7 will make its US debut at the North American International Auto Show in Detroit next week. The German luxury automaker is looking to build on the success of the first generation with this new generation of the A7, which the manufacturer claims "exemplifies the prologue design language, featuring a more precise, modern exterior and interior, as well as the next generation of lighting innovations from Audi."Although sedan cars on the whole are finding buyers pretty hard to come by in America and elsewhereat the moment, the Sportback body style of the A7 and others is still proving popular. The combination of a coupe-like silhouette and four doors might not be as overtly practical as that of a similar-size crossover SUV, but it's a look and format where buyersappear happy to accept a little compromise in order to have it. However, Audi is still doing what it can to make this new A7 as practical as possible without ruining its form in any way, as this new model has more interior volume, more comfortable seating for rear seat passengers, and more head and legroom than its predecessor.Interior lighting also seems to be a strong theme with the new A7, with contour lights lining the center console and door trims that precisely trace the cabin's architecture and subtly highlight the increased space. Even the Audi's quattro badge in the instrument panel is illuminated, which some could see as a little gimmicky, but it certainly does add to the theatrical lighting of the cabin.Of course, no new luxury car can hope to make it these days without being awash with the latest and most advanced technology, and the new A7 will feature the same advanced infotainment system that recently made its debut in the A8.
2021 05 25
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Seven Magnificent Castle Stays to Cure Your Royal Family Fever
If you didnt get an invite to the royal baby shower or wedding, dont fret! the global leader in connecting travellers with the widest choice of incredible places to stay, delved into its more than 1.6 million properties in over 128,000 destinations across the globe to present seven magnificent castle stays fit for royalty, but on a commoners budget. nIf you are looking for an ancient castle that has transformed into a charming hotel, then the Castello Di Pavone is the place to stay. Surrounded by a tropical garden, all rooms mix traditional furnishing with modern amenities, offering a truly unique setting steeped in history. The property features a number of dining halls, small and large, and each one has unique features that will you bring you back in time such as chandeliers and beamed ceilings. nWith a magical setting inside a 9th-century castle, the Parador de Cardona is straight out of fairy tale. Offering panoramic views over the Catalonian countryside, and interiors faithful to the Cardona's history with medieval styling, vaulted ceilings, stone walls and gorgeous courtyards, youll be treated like a king or queen. Guests will be spellbound with the delicious and authentic Catalonian specialties, before retreating to a charming bedroom with canopy beds and the beautiful furnishing highlighted by theatrical lighting and rich fabrics. nGiven the iconic Bavarian-style of The Castle Hotel, you might think you were in the hills of Germanys Black Forest. But youre actually only a few steps away from Xinghai Square the largest city square in the world. Offering high-end accommodation and the royal treatment every guest deserves. Surrounded by lush forests, this luxurious property features elegantly decorated rooms and offers the royal treatment at the spa and indoor pool. nSet in the striking woodlands of Galway County with the beautiful backdrop of the 12 Bens Mountain Range, this luxury castle overlooks its impressive salmon fishery on its large private estate. Nature lovers can enjoy a variety of outdoor activities fit for a royal, such as pony trekking, woodcock shooting or just relaxing walk by the lake and the river to admire the local wildlife. nThis impressive castle overlooking the St Brides Bay will transport guests to a mystical time. Dating back to the 12th century, Roch Castle is standing proudly on a rocky outcrop high above the Pembrokeshire landscape. Guests can enjoy a unique sense of history combined with a romantic getaway as each room is luxuriously decorated offering a modern feeling with beautiful views of the British coast and countryside. nSituated in Old Quebec, this heritage property boasts views of the St. Lawrence River and the Old fortified City. Being a landmark on its own right, guests can make themselves at home in the luxurious, European-style rooms as well as spa facilities to relax and rejuvenate after an exciting day exploring upper and lower town districts of Quebec City. nFor something a little less ordinary during your trip in India, choose to rest your head at the RAAS Devigarh. Housed in an 18th-century palace in the village of Delwara, this heritage property is nestled amidst the Aravalli Hills and has a picture-perfect mountain backdrop. Guests can have a quiet read in the library or relax in their spacious suite adorned with grand furnishings and intricately carved archways.
2021 05 25
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Best ADJ MOD QW100 Modular Series LED PAR Light
Best ADJ MOD QW100 Modular Series LED PAR LightBuy Link: CLICK HEREADJ MOD QW100 Modular Series LED PAR Light Product Description:ADJ MOD QW100 Modular Series LED PAR Light. The ADJ Lighting Modular Series LED Pars allow lighting designers more flexibility when it comes to features, plus more power to create brilliant washes for stages, installations or mobile events. DJ ADJ. DJ, DJ Lighting, PAR Lights. Price: 469.95 USD. Sale Price: 349.99 USD.The ADJ MOD QW100 Modular Series LED PAR Light is certainly that and will be a great buy. For this price, the ADJ MOD QW100 Modular Series LED PAR Light is highly recommended and is a popular choice with lots of people.Buy it NowBuy ADJ MOD QW100 Modular Series LED PAR Light is a post from: Musical Instruments RELATED QUESTION How do I find cheap and reliable e-cigarette suppliers in China? Importing Electronic Cigarettes from ChinaElectronic cigarettes are one of the few products that could be considered a home grown product in China. Since the first units rolled off the assembly lines in Shenzhen about 10 years ago, the electronic cigarettes have presented itself as a serious alternative to smokers that still want to take a puff now and then.However, e-cigarettes are still a topic of high level controversy, and regulations are still on the drawing board in both the US and EU. The product is also lethal if not manufactured according to the relevant safety standards. Keep reading and we explain why. Electronic Cigarette Manufacturers in China Theres only one place in the world to go if youre looking for electronics, the Guangdong province. Roughly 87% of the Electronic cigarettemanufacturers based here. Of these, the majority isbased in Shenzhen, a city bordering Hong Kong. But there are also quite a few suppliers located in Dongguan, Huizhou and Zhongshan all of which are also based in Guangdong province. The industry jump started in 2010 and 2011 when hundreds of new suppliers starting manufacturing and trading (thats two different things) electronic cigarettes. This was before most western government had yet reacted to the influx of this, still controversial, product. Ill get to that in a bit.A lot of suppliers caught on this trend and started trading electronic cigarettes, rather than manufacturing the product themselves. If you browse a site youll quickly notice that most suppliers are mere traders, with very little registered capital (ranging from RMB 30,000 to 100,000). Stay away from these suppliers. They cant offer a better price. They can rarely offer smaller volumes and certainly not smaller volumes of electronic cigarettes that are compliant with EU andUS product certification standards. What they can offer is an extra, non-transparent, layer between you and the actual manufacturer. A manufacturer you know nothing about. Components and Product Specifications Theres no universal definition of good quality. Instead, you need to know what defines good quality. As with every product, there are certain features and parameters thatdefines the quality standardof an electronic cigarette. To begin with, there are 4 main categories of electroniccigarettes:1. Rechargeable Electronic Cigarettes 2. Disposable Electronic Cigarettes (Non-Rechargeable) 3. E-Go Electronic Cigarettes 4. Personal Vaporizers Product specifications vary between the different types of electronic cigarettes. For example, you dont need to bother with E-liquid cartridges if youre purchasing Disposable Electronic Cigarettes. But there are still a number of common quality factors that buyers should take into consideration when selecting a product: Cartridge Puffs: 200 500 Cartridge Capacity: 1.X ml Child-proof spring switch: Yes / No Body material: Mouthpiece material: LED: Yes / No Charger type: USB Battery Capacity: XXX mAh Weight: XXg Working voltage: 3.X 3.X VBatteryMost suppliers can offer batteries of different capacities. Its a critical component, since the number of puffs is limited not only by the E-liquid, but also the battery capacity. The relation between the battery capacity and the number of puffs is something like this: 650mah: 600-650 puffs 900mah: 800-850 puffs 1100mah:1000-1050 puffs Theres also a limit to the battery life. However, the battery shall be rechargeable at least 300 times. Charger Most suppliers offer both USB chargers and Power socket chargers. Id go for the USB charger. The voltage in a power socket is much higher than the voltage in a USB socket (around 5 V). An overloaded power socket charger can cause personal injury and outbreak of fire. Ive seen it happen. On the other hand, an overcharged USB is likely to result in little more than a voltage drop or cut. That wont kill anyone or burn down a house.E-liquidsThe E-liquid, or E-juice, is the active substance in the electronic cigarettes and usually contains the following: Propylene glycol Vegetable glycerin Nicotine Flavorings However, theres no set standard of what substances E-liquid shall contain, not to mention the content of each substance. This is also a current topic of debate among regulators around the world, particularly in the European Union and United States.In the European Union, the legal situation is more fragmented. So far, theres no EU wide product safety standard that applies specifically to electronic cigarettes. However, EU states have implemented their own regulations. As of today, its legal to import and sell electronic cigarettes and liquids with nicotine in the following EU countries: United Kingdom Germany Italy Poland Ireland Latvia Lithuania Still, electronic cigarettes are still a topic of debate and further regulations are to be expected. This post could be outdated two weeks from now, so make sure youread up on the current regulationsbefore you import electronic cigarettes or e-liquids from China.In Australia, electronic cigarettes are regulated on a state level. Recently, Western Australia banned imports and sales of electronic cigarettes of all kinds. While imports are still legal for personal use, Australian importers better stay away from electronic cigarettes altogether. Product Certification Requirements Even though regulations specifically for electronic cigarettes are still on the drawing board, in both Europe and America, that is not saying that product certification standards dont apply to the hardware. Electronic cigarettes are subject to certification standards regulating electronic products. These include the following:European Union RoHS (Assembled product & individual components) CE (Assembled product & individual components) REACH (Mouthpiece & plastic case) Need a helping hand? When you order a Starting Package we source Electronic cigarette suppliers able to show previous compliance, and guide you step-by-step through the whole ordering process. There are several reported casesof e-cigarettes exploding and catching fire. Keep in mind the importer is always held responsible, in case a product causes personal injury or property damage. Ensuring product certification compliance is always critical when importing from China.
2021 05 25
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Review: Spellbinding Performance As Symphony Conductor Combines Russian Music and Ballet
The Edmonton Symphony Orchestras chief conductor, Alexander Prior, has a deep grounding in Russian music. Despite having a Scottish twang to his accent, his mother is Russian and he studied at the St. Petersburg Conservatory, graduating with distinction at the age of 17.In his first season in his new post, he has already shown his affinity to Russian music in his approach to such works as Tchaikovskys Symphony No. 5 and Rachmaninovs Symphony No. 2. Last Thursday evening, he turned to the Russian tradition of ballet in front of a packed and enthusiastic Winspear audience.When composers wish to have their ballet music heard in a concert hall, they usually rework the music into a concert suite where the overall shape is better designed for the different circumstance. Indeed, Prokofiev turned the music from one of his masterpieces, the ballet Romeo and Juliet, into no less than three different orchestral suites, all of which are heard today.Priors approach was a little different. Instead of playing one of the suites, he devoted the entire first half of the concert to excepts chosen directly from Prokofievs ballet. All the best-known music was there, ending with Juliets death, but the order will have been different for those used to the suites rather than the ballet.This was a spellbinding performance, too. Prior took the music often heard with a veneer of neo-romantic lyricism back to its roots in 20th Century Soviet Russia. There was little sentimentality here. Instead there were incisive rhythms, a steel-like edge to the poster-paint orchestral colours, a huge sound in the climatic moments (in a couple of places the huge orchestral swells reminded one of Sibelius).This was Prokofiev played closer to the grit of Shostakovich, at times almost inexorable, mechanistic in its inevitability (as, indeed, is Shakespeares story). The exciting fast and furious scurry of Tybalts Death, for example, would be difficult to do with dancers, but really worked here on the Winspear stage.It was achieved by really precise playing and cleanness of sound emphasizing how at times the score is almost chamber-like. The brass managed something of a Russian snarl, the woodwind were, as usual, notable, though the orchestration was taken from the suites rather than from the full ballet. One wished that the orchestra did have more strings, though, for both here and in the Tchaikovsky that followed, the extra weight and sheen a large body of strings gives was missing, as if powered by a four-cylinder engine albeit a powerful and efficient one rather than the heft of a six-cylinder.After such a compelling performance, Tchaikovskys The Nutcracker, which filled the second half, didnt have quite such panache, and indeed the orchestra was at times less precise.Again, Prior eschewed the concert suite that Tchaikovsky made from the ballet score, and instead the orchestra gave us the whole of Act I. This was an interesting idea, as Act I contains most of the main action of the plot, up to the point where the Nutcracker becomes a Prince. It includes the battle between the toys and the mice, and ends with Waltz of the Snowflakes.It doesnt include the famous dance of the Sugar Plum Fairy, but much of the best-known music is there.It was interesting to be able to concentrate just on the actual ballet music, without the dancers. For it highlighted features one doesnt notice in the suite again, the often-sparse orchestration, or the unexpected affinities: the almost British feel of the childrens gallop and parents entry, or the echoes of Beethovens Wellingtons Victory.Prior also brought out some of the darker colours of the score, especially in some of the climaxes, in a way that again one might not encounter in the theatre.The ballet was not completely forgotten, however, for in the final number the Waltz of the Snowflakes the orchestra was joined by members of the Edmonton School of Ballet, very effectively choreographed, especially given the limited space available to them at the front of the stage. Some theatrical lighting effects added to the atmosphere, as they had in the quiet ending of the Prokofiev.Perhaps most interesting of all, we were able to hear the wordless chorus that goes with this Act I closing tableau. Its not in the suite, and it is often substituted by an instrument in ballet performance, and thus is rarely heard. Here it was sung by the Cantilon Chamber Choir, who well repaid their patience at having to wait right until the very end of the concert to sing.The ESO and Prior will be playing more Russian music on May 27 (Glinkas Russian and Ludmilla Overture), in a concert that sees the orchestra shift to Beethoven (here the Fifth Symphony), leading up to their performances of the Ninth Symphony on June 1 and 2.Edmonton Symphony Orchestra Russian BalletsOrganization: Edmonton Symphony OrchestraConductor: Alexander PriorFeaturing: Cantilon Chamber Choir and the Edmonton School of BalletWhere: WinspearWhen: Thursday, May 17
2021 05 25
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Brighter and More Efficient Solid-State Lighting Using Laser Diodes
Solid-state lighting in the form of Light Emitting Diodes (LEDs) converts electrical energy into visible light with greater efficiency and less heat loss when compared to incandescent or fluorescent lights.Above a certain current, however, LEDs become less efficient and convert less of their electrical energy into light. This is a condition known as droop, which makes the use of LEDs in high-power applications difficult. The next generation of solid-state lighting may use laser diodes, which overcome some of the LEDs limitations by operating at higher power and optical intensities, but are about the same size.As lasers are brighter than LEDs, they require fewer diodes for an equivalent light source, which makes the device cheaper and more compact.White Light SourcesLEDs and laser diodes share one characteristic they are monochromatic, or emit a single color of light. To create white light from either source, we use one of two methods.The first method combines the primary colors red, green and blue to create white light.The second method of creating white light uses either a blue or ultra-violet diode along with phosphors to down convert the higher frequency light into a range of lower frequencies. By blending phosphors in the right combination, we can get something that looks like white light.Phosphor Driven White Solid-State LightingThere are several complications affecting our ability to blend phosphors to get white light.Firstly, as a diodes color output can degrade with age or drift with temperature, its necessary to use complex optics and electronics to actively monitor and control color output. LEDs can be coated with phosphors to generate white light, but the heat they generate can degrade phosphors over time.As phosphor-coated LEDs generate visible light sources, we need optics to diffuse the light beam.If we separate the phosphor from the LED, however, it overcomes these issues. Philips currently uses this remote phosphor design, which won the L Prize in 2011, a competition run by the US Department of Energy to encourage lighting manufacturers to develop high-quality, high-efficiency solid-state lighting products.Laser Diodes for Remote Phosphor DesignIn a recent paper, Kristin A. Denault and a research team at the Solid-State Lighting and Energy Center and Materials Department, UC Santa Barbara tested the lighting output of a remote phosphor design using laser diodes. The group tested color output using a blue laser to produce a cool white light with a CCT of 4,400 K and a near UV laser to produce warm white light with a CCT of 2,700 K.The UCSB team also used their data to calculate the maximum efficacy for blue laser diodes, a measure of how well a light source can potentially produce visible light. This calculation allows the group to gauge the possible capabilities of future laser based white light devices. They found a maximum efficacy of 78 lm/W for the blue laser diode which is comparable to a luminous efficacy of LEDs currently on the market. Improvements in wall plug efficiency to 75% could increase this number to 200 lm/W, bringing it in line with the Department of Energys goal for solid-state lighting and making laser diodes a viable high-power solid-state lighting candidate for the future.Solid-State Lighting: The FutureLaser diodes and LEDs both suffer limitations when it comes to high power lighting. LEDs suffer from efficiency droop, a problem first reported in 1999 where light output decreases if the current is increased beyond a critical point.Laser diodes problems stem from their low wall plug efficiency, currently around 30% but an increase to 75% would make laser diodes an attractive high power lighting option.Technological advances are overcoming the problems of both devices. A recent paper by Rensselaer Polytechnic Institute researchers has identified the mechanism behind droop a phenomenon known as electron leakage due to the slight differences in the movement of charge carriers through a semiconducting material results in energy loses.The group believes their findings could lead to the development of new semiconductor structures that will lead to more efficient devices.A fundamental factor limiting wall-plug efficiency of laser diodes is the material properties of the semiconductor itself. Each material contributes a certain electrical resistance, optical loss and thermal resistance researchers are making improvements all the time. Though laser diodes are currently less efficient than LEDs, they have the potential to go beyond where LEDs are currently.When asked about the future of laser diode lighting and its comparison to LEDs, Denault, co-author of the study on laser-diodes for solid-state lighting, told Decoded Science, I think that as laser diode technology improves and people begin to be aware of the benefits of using laser diodes as an excitation source in solid-state white lighting, more applications and advantages will become apparent. ResourcesDenault, K. A. , Cantore, M. , Nakamura, S. , DenBaars, S. P. , & Seshadri, R. Efficient and stable laser-driven white lighting. (2013). AIP Advances. Accessed August 18, 2013.Meyaard, D. S., Lin, G.-B., Cho, J., Fred Schubert, E., Shim, H., Han, S.-H., Sun Kim, Y. Identifying the cause of the efficiency droop in GaInN light-emitting diodes by correlating the onset of high injection with the onset of the efficiency droop. (2013). Applied Physics Letters. Accessed August 18, 2013.Xu, Y., Chen, L., Li, Y., Song, G., Wang, Y., Zhuang, W., & Long, Z. Phosphor-conversion white light using InGaN ultraviolet laser diode. (2008). Applied Physics Letters. Accessed August 18, 2013. Future Lighting Solutions. Remote Phosphor. (2013). Accessed August 18, 2013. Lighting Research Center, What is an LED? (2003). Accessed August 18, 2013.Originally published at on August 18, 2013 RELATED QUESTION What is proffesional led stage lighting? When you're putting on an occasion, whether it is an unassuming school play or a party, stage lighting rental is an unquestionable requirement. Lighting is a main thrust of your production, giving brightening, center, detail and modifying the view of the group of audience. There is nothing that so vitally passes on an inclination superior to a decent lighting system, and with boundless inventive potential, will serve as an immense advantage for your creation. Focus, position and hanging: Conventional stage lighting must be set up because of these three contemplations. Focus refers to where the light will point; position alludes to where the light will start from; hanging refers to the real demonstration of hanging the light. Shading, force and example (assuming any) should be considered next. Types of stage lighting : Ellipsoidal - these lights are the conventional stage lights and thought to be the most critical. They are centering lights, the appearance in front of an audience of which can be adjusted by screens and channels. Fresnel - these lights are utilized for shading washes on the stage. Standard Jars - these lights are the sort you will see in even the dingiest of bars. Continuously a strong choice, standard jars can get hammered, are sturdy and simple to transport. Follow spots - these are spotlights used to pursue somebody around a phase. Obviously, there are increasingly choices accessible for stage lighting with the consistent progress of innovation. Presently you have the fundamentals; here are a couple of more alternatives: LEDs - these Professional LED Stage Lighting are useful for centered pillars and have been gradually supplanting conventional globules in stage lighting. Dizzies - these lights are round circles with a few Drove lights (more often than not of varying hues) covering the surface. The circle pivots in an assortment of bearings and examples, making a whirling, confounding example, consequently the name. Gels - this term alludes to the hues given to lights. They function as shading channels, and should work in congruity with the shade of the light itself to accomplish the craved impact. Once you have got your types of lighting down, you'll have to consider where to place them. Here's an essential summary of lighting positions: Front - This is utilized for the most part for perceivability and shading impacts. Side - can be utilized to awesome impact to complement activity. Back - Additionally utilized for impact. This kind of lighting can make the dream of profundity on a phase, or notwithstanding to silhouette a man totally.
2021 05 25
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Best ADJ MOD QA60 Modular Series LED PAR Light
Best ADJ MOD QA60 Modular Series LED PAR LightBuy Link: CLICK HEREADJ MOD QA60 Modular Series LED PAR Light Product Description:ADJ MOD QA60 Modular Series LED PAR Light. The ADJ Lighting Modular Series LED Pars allow lighting designers more flexibility when it comes to features, plus more power to create brilliant washes for stages, installations or mobile events. DJ ADJ. DJ, DJ Lighting, PAR Lights. Price: 419.95 USD. Sale Price: 299.99 USD.The ADJ MOD QA60 Modular Series LED PAR Light is certainly that and will be a great buy. For this price, the ADJ MOD QA60 Modular Series LED PAR Light is highly recommended and is a popular choice with lots of people.Buy it NowBuy ADJ MOD QA60 Modular Series LED PAR Light is a post from: Musical Instruments RELATED QUESTION How do I find cheap and reliable e-cigarette suppliers in China? Importing Electronic Cigarettes from ChinaElectronic cigarettes are one of the few products that could be considered a home grown product in China. Since the first units rolled off the assembly lines in Shenzhen about 10 years ago, the electronic cigarettes have presented itself as a serious alternative to smokers that still want to take a puff now and then.However, e-cigarettes are still a topic of high level controversy, and regulations are still on the drawing board in both the US and EU. The product is also lethal if not manufactured according to the relevant safety standards. Keep reading and we explain why. Electronic Cigarette Manufacturers in China Theres only one place in the world to go if youre looking for electronics, the Guangdong province. Roughly 87% of the Electronic cigarettemanufacturers based here. Of these, the majority isbased in Shenzhen, a city bordering Hong Kong. But there are also quite a few suppliers located in Dongguan, Huizhou and Zhongshan all of which are also based in Guangdong province. The industry jump started in 2010 and 2011 when hundreds of new suppliers starting manufacturing and trading (thats two different things) electronic cigarettes. This was before most western government had yet reacted to the influx of this, still controversial, product. Ill get to that in a bit.A lot of suppliers caught on this trend and started trading electronic cigarettes, rather than manufacturing the product themselves. If you browse a site youll quickly notice that most suppliers are mere traders, with very little registered capital (ranging from RMB 30,000 to 100,000). Stay away from these suppliers. They cant offer a better price. They can rarely offer smaller volumes and certainly not smaller volumes of electronic cigarettes that are compliant with EU andUS product certification standards. What they can offer is an extra, non-transparent, layer between you and the actual manufacturer. A manufacturer you know nothing about. Components and Product Specifications Theres no universal definition of good quality. Instead, you need to know what defines good quality. As with every product, there are certain features and parameters thatdefines the quality standardof an electronic cigarette. To begin with, there are 4 main categories of electroniccigarettes:1. Rechargeable Electronic Cigarettes 2. Disposable Electronic Cigarettes (Non-Rechargeable) 3. E-Go Electronic Cigarettes 4. Personal Vaporizers Product specifications vary between the different types of electronic cigarettes. For example, you dont need to bother with E-liquid cartridges if youre purchasing Disposable Electronic Cigarettes. But there are still a number of common quality factors that buyers should take into consideration when selecting a product: Cartridge Puffs: 200 500 Cartridge Capacity: 1.X ml Child-proof spring switch: Yes / No Body material: Mouthpiece material: LED: Yes / No Charger type: USB Battery Capacity: XXX mAh Weight: XXg Working voltage: 3.X 3.X VBatteryMost suppliers can offer batteries of different capacities. Its a critical component, since the number of puffs is limited not only by the E-liquid, but also the battery capacity. The relation between the battery capacity and the number of puffs is something like this: 650mah: 600-650 puffs 900mah: 800-850 puffs 1100mah:1000-1050 puffs Theres also a limit to the battery life. However, the battery shall be rechargeable at least 300 times. Charger Most suppliers offer both USB chargers and Power socket chargers. Id go for the USB charger. The voltage in a power socket is much higher than the voltage in a USB socket (around 5 V). An overloaded power socket charger can cause personal injury and outbreak of fire. Ive seen it happen. On the other hand, an overcharged USB is likely to result in little more than a voltage drop or cut. That wont kill anyone or burn down a house.E-liquidsThe E-liquid, or E-juice, is the active substance in the electronic cigarettes and usually contains the following: Propylene glycol Vegetable glycerin Nicotine Flavorings However, theres no set standard of what substances E-liquid shall contain, not to mention the content of each substance. This is also a current topic of debate among regulators around the world, particularly in the European Union and United States.In the European Union, the legal situation is more fragmented. So far, theres no EU wide product safety standard that applies specifically to electronic cigarettes. However, EU states have implemented their own regulations. As of today, its legal to import and sell electronic cigarettes and liquids with nicotine in the following EU countries: United Kingdom Germany Italy Poland Ireland Latvia Lithuania Still, electronic cigarettes are still a topic of debate and further regulations are to be expected. This post could be outdated two weeks from now, so make sure youread up on the current regulationsbefore you import electronic cigarettes or e-liquids from China.In Australia, electronic cigarettes are regulated on a state level. Recently, Western Australia banned imports and sales of electronic cigarettes of all kinds. While imports are still legal for personal use, Australian importers better stay away from electronic cigarettes altogether. Product Certification Requirements Even though regulations specifically for electronic cigarettes are still on the drawing board, in both Europe and America, that is not saying that product certification standards dont apply to the hardware. Electronic cigarettes are subject to certification standards regulating electronic products. These include the following:European Union RoHS (Assembled product & individual components) CE (Assembled product & individual components) REACH (Mouthpiece & plastic case) Need a helping hand? When you order a Starting Package we source Electronic cigarette suppliers able to show previous compliance, and guide you step-by-step through the whole ordering process. There are several reported casesof e-cigarettes exploding and catching fire. Keep in mind the importer is always held responsible, in case a product causes personal injury or property damage. Ensuring product certification compliance is always critical when importing from China.
2021 05 25
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Best ADJ Pocket Pro Pearl Stage Light
Best ADJ Pocket Pro Pearl Stage LightBuy Link: CLICK HEREADJ Pocket Pro Pearl Stage Light Product Description:ADJ Pocket Pro Pearl Stage Light. The ADJ Pocket Pro Pearl, in all white color exterior housing, is truly a transformed fixture from the base up. ADJ listened to what customers wanted in a compact and affordable Spot moving head. DJ ADJ. DJ, DJ Lighting, Moving Lights. Price: 439. 95 USD. Sale Price: 319. 99 USD. The ADJ Pocket Pro Pearl Stage Light is certainly that and will be a great buy. For this price, the ADJ Pocket Pro Pearl Stage Light is highly recommended and is a popular choice with lots of people.Buy it NowBuy ADJ Pocket Pro Pearl Stage Light is a post from: Musical Instruments. RELATED QUESTION What is proffesional led stage lighting? When you're putting on an occasion, whether it is an unassuming school play or a party, stage lighting rental is an unquestionable requirement. Lighting is a main thrust of your production, giving brightening, center, detail and modifying the view of the group of audience. There is nothing that so vitally passes on an inclination superior to a decent lighting system, and with boundless inventive potential, will serve as an immense advantage for your creation. Focus, position and hanging: Conventional stage lighting must be set up because of these three contemplations. Focus refers to where the light will point; position alludes to where the light will start from; hanging refers to the real demonstration of hanging the light. Shading, force and example (assuming any) should be considered next. Types of stage lighting : Ellipsoidal - these lights are the conventional stage lights and thought to be the most critical. They are centering lights, the appearance in front of an audience of which can be adjusted by screens and channels. Fresnel - these lights are utilized for shading washes on the stage. Standard Jars - these lights are the sort you will see in even the dingiest of bars. Continuously a strong choice, standard jars can get hammered, are sturdy and simple to transport. Follow spots - these are spotlights used to pursue somebody around a phase. Obviously, there are increasingly choices accessible for stage lighting with the consistent progress of innovation. Presently you have the fundamentals; here are a couple of more alternatives: LEDs - these Professional LED Stage Lighting are useful for centered pillars and have been gradually supplanting conventional globules in stage lighting. Dizzies - these lights are round circles with a few Drove lights (more often than not of varying hues) covering the surface. The circle pivots in an assortment of bearings and examples, making a whirling, confounding example, consequently the name. Gels - this term alludes to the hues given to lights. They function as shading channels, and should work in congruity with the shade of the light itself to accomplish the craved impact. Once you have got your types of lighting down, you'll have to consider where to place them. Here's an essential summary of lighting positions: Front - This is utilized for the most part for perceivability and shading impacts. Side - can be utilized to awesome impact to complement activity. Back - Additionally utilized for impact. This kind of lighting can make the dream of profundity on a phase, or notwithstanding to silhouette a man totally.
2021 05 25
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Best ADJ Encore FR150Z Stage Light
Best ADJ Encore FR150Z Stage LightBuy Link: CLICK HEREADJ Encore FR150Z Stage Light Product Description:ADJ Encore FR150Z Stage Light. Part of the Encore stage lighting series, the ADJ Encore FR150Z lighting fixture is equipped with an 8-inch Fresnel lens and powered by a 130W LED engine. DJ ADJ. DJ, DJ Lighting, Spotlights. Price: 779.95 USD. Sale Price: 569.99 USD.The ADJ Encore FR150Z Stage Light is certainly that and will be a great buy. For this price, the ADJ Encore FR150Z Stage Light is highly recommended and is a popular choice with lots of people.Buy it NowBuy ADJ Encore FR150Z Stage Light is a post from: Musical Instruments RELATED QUESTION What is proffesional led stage lighting? When you're putting on an occasion, whether it is an unassuming school play or a party, stage lighting rental is an unquestionable requirement. Lighting is a main thrust of your production, giving brightening, center, detail and modifying the view of the group of audience. There is nothing that so vitally passes on an inclination superior to a decent lighting system, and with boundless inventive potential, will serve as an immense advantage for your creation. Focus, position and hanging: Conventional stage lighting must be set up because of these three contemplations. Focus refers to where the light will point; position alludes to where the light will start from; hanging refers to the real demonstration of hanging the light. Shading, force and example (assuming any) should be considered next. Types of stage lighting : Ellipsoidal - these lights are the conventional stage lights and thought to be the most critical. They are centering lights, the appearance in front of an audience of which can be adjusted by screens and channels. Fresnel - these lights are utilized for shading washes on the stage. Standard Jars - these lights are the sort you will see in even the dingiest of bars. Continuously a strong choice, standard jars can get hammered, are sturdy and simple to transport. Follow spots - these are spotlights used to pursue somebody around a phase. Obviously, there are increasingly choices accessible for stage lighting with the consistent progress of innovation. Presently you have the fundamentals; here are a couple of more alternatives: LEDs - these Professional LED Stage Lighting are useful for centered pillars and have been gradually supplanting conventional globules in stage lighting. Dizzies - these lights are round circles with a few Drove lights (more often than not of varying hues) covering the surface. The circle pivots in an assortment of bearings and examples, making a whirling, confounding example, consequently the name. Gels - this term alludes to the hues given to lights. They function as shading channels, and should work in congruity with the shade of the light itself to accomplish the craved impact. Once you have got your types of lighting down, you'll have to consider where to place them. Here's an essential summary of lighting positions: Front - This is utilized for the most part for perceivability and shading impacts. Side - can be utilized to awesome impact to complement activity. Back - Additionally utilized for impact. This kind of lighting can make the dream of profundity on a phase, or notwithstanding to silhouette a man totally.
2021 05 25
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