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A laser pulse composed of a fundamental and properly phased second harmonic exhibits an asymmetric electric field that can drive a time-dependent current of photoionized electrons. The current produces an ultrashort burst of terahertz (THz) radiation. When driven by a conventional laser pulse, the THz radiation is emitted into a cone with an angle determined by the dispersion of the medium. Here we demonstrate that the programmable-velocity intensity peak of a spatiotemporally structured, two-color laser pulse can be used to control the emission angle, focal spot, and spectrum of the THz radiation. Of particular interest for applications, a structured pulse with a subluminal intensity peak can drive highly focusable, on-axis THz radiation.

HIV disproportionately impacts many groups, including Black adolescent girls and young women (AGYW) aged 13-24 living in the Deep South. Current prevention efforts have the potential to further exacerbate disparities within this population as HIV pre-exposure prophylaxis (PrEP) remains underutilized by Black AGYW in the South. We conducted in-depth interviews (IDIs) grounded in Andersen's Model of Healthcare Utilization exploring providers' PrEP prescribing practices to Black AGYW in Alabama. Eleven providers completed IDIs exploring providers' PrEP prescription knowledge and experiences. Cross-cutting themes included: (1) Community and provider-level stigmas (including those propagated by legislation) relating to HIV and sexuality limit sexual health discussions with Black AGYW clients; (2) Low PrEP knowledge and comfort with guidelines limits PrEP conversations and reinforces low uptake and prescriptions; (3) Healthcare systems and structural barriers impede PrEP access for youth. Multi-level (structural, community, and provider) barriers to PrEP prescription demands high activation energy for providers to prescribe PrEP. We present recommendations in training in sexual health assessment, updates to PrEP guidelines to accommodate risk assessment appropriate for AGYW, and increased implementation science focused on PrEP prescription for Black AGYW in order to reduce HIV incidence for this population.

In 2015-2016, record temperatures triggered a pan-tropical episode of coral bleaching. In the southern hemisphere summer of March-April 2016, we used aerial surveys to measure the level of bleaching on 1,156 individual reefs throughout the 2,300 km length of the Great Barrier Reef, the world's largest coral reef system. The accuracy of the aerial scores was ground-truthed with detailed underwater surveys of bleaching at 260 sites (104 reefs), allowing us to compare aerial and underwater bleaching data with satellite-derived temperatures and with associated model predictions of bleaching. The severity of bleaching on individual reefs in 2016 was tightly correlated with the level of local heat exposure: the southernmost region of the Great Barrier Reef escaped with only minor bleaching because summer temperatures there were close to average. Gradients in nutrients and turbidity from inshore to offshore across the Great Barrier Reef had minimal effect on the severity of bleaching. Similarly, bleaching was equally severe on reefs that are open or closed to fishing, once the level of satellite-derived heat exposure was accounted for. The level of post-bleaching mortality, measured underwater after 7-8 months, was tightly correlated with the aerial scores measured at the peak of bleaching. Similarly, reefs with a high aerial bleaching score also experienced major shifts in species composition due to extensive mortality of heat-sensitive species. Reefs with low bleaching scores did not change in composition, and some showed minor increases in coral cover. Two earlier mass bleaching events occurred on the Great Barrier Reef in 1998 and 2002, that were less severe than 2016. In 2016, <9% of scored reefs had no bleaching, compared to 42% in 2002 and 44% in 1998. Conversely, the proportion of reefs that were severely bleached (>60% of corals affected) was four times higher in 2016. The geographic footprint of each of the three events is distinctive, and matches satellite-derived sea surface temperature patterns. Our aerial surveys indicate that past exposure to bleaching in 1998 and 2002 did not lessen the severity of bleaching in 2016. This data set of aerial bleaching scores provides a historical baseline for comparison with future bleaching events. No copyright restrictions apply to the use of this data set other than citing this publication., (© 2017 by the Ecological Society of America.)

Objectives: New Zealand has a unique tool, Te Tiriti o Waitangi, the Treaty of Waitangi, for addressing health disparities. Indigenous Māori have compromised health status compared to other groups. This paper investigates ways in which public health units (PHUs) and non-governmental organisations (NGOs) use Te Tiriti o Waitangi in service delivery to Māori., Design: A nationwide telephone survey of primary health providers (n=162) was conducted in 2014-15. Participants were asked about effectiveness and monitoring of their service delivery to Māori., Results: PHUs reported actively working with Māori, and Te Tiriti o Waitangi to reduce health disparities. Direct Māori engagement with development and delivery of programmes was viewed as essential. Strategies included designated PHU staff in positions of responsibility, formal partnerships with Māori, and providing operational and strategic guidance. Some PHUs supported development of cultural competencies. NGO responsiveness to Māori was variable. Some NGOs described prioritising service delivery and programmes for Māori. Others reported the focus of their service was European or other non-Māori ethnicities. Lack of resources or past difficulties engaging with Māori were barriers., Conclusion: Public health has an ethical commitment to reduce health disparities. Advancing Te Tiriti obligations in everyday practice has the potential to address inequalities.

We aim to test how well modern nonhabitual barefoot people can adapt to barefoot and Minimalist Bare Foot Technology (MBFT) shoes, in regard to gait symmetry. 28 healthy university students (22 females/6 males) were recruited to walk on a 10-meter walkway randomly on barefoot, in MBFT shoes, and in neutral running shoes at their comfortable walking speed. Kinetic and kinematic data were collected using an 8-camera motion capture system. Data of joint angles, joint forces, and joint moments were extracted to compute a consecutive symmetry index. Compared to walking in neutral running shoes, walking barefoot led to worse symmetry of the following: ankle joint force in sagittal plane, knee joint moment in transverse plane, and ankle joint moment in frontal plane, while improving the symmetry of joint angle in sagittal plane at ankle joints and global (hip-knee-ankle) level. Walking in MBFT shoes had intermediate gait symmetry performance as compared to walking barefoot/walking in neutral running shoes. We conclude that modern nonhabitual barefoot adults will lose some gait symmetry in joint force/moment if they switch to barefoot walking without fitting in; MBFT shoe might be an ideal compromise for healthy youth as regards gait symmetry in walking.

Aims:  Epidermal growth factor receptor (EGFR) antagonists are particularly active in non-small cell lung cancer (NSCLC) patients with tumours bearing mutations in the EFGR gene. EGFR mutation prevalence is very low in squamous histology. Response rates using these drugs in patients with KRAS mutations are low, so available KRAS mutation information may aid treatment selection in the second-line setting. Since 2009, patients presenting to this hospital with non-squamous histology have been routinely screened for mutations in both the EGFR and KRAS genes, with results used to inform treatment. We present an analysis of 215 consecutive patients for whom EGFR mutation analysis was informative. Methodology:  EGFR and KRAS mutations were identified using a COLD-PCR technique confirmed with sequencing, which makes no prior assumption about location of specific mutations. Results were correlated with clinical and demographic data from hospital records, where available. Results:  The prevalence of patients with EGFR mutations was 14% and for KRAS mutations it was 27%. Despite the conventional understanding that EGFR and KRAS mutations are mutually exclusive, we identified two dual mutations. Of 29 patients identified with mutated EGFR, there were 3/8/8/10 mutations in exons 18/19/20/21 respectively. Exon 20 mutations were identified in a proportion exceeding many other series because of the unbiased mutation analysis used, and clinical benefit was seen in some of these. Of 23 different EGFR mutations identified, 11 have not previously been described in the literature. Conclusions:  The high prevalence of EGFR, KRAS or both mutations (40%) in this non-squamous population tested in clinical practice supports a policy of routine screening for these mutations in NSCLC., (© 2012 Blackwell Publishing Ltd.)

Purpose: Untreated behavioural and cognitive changes after primary brain tumour (PBT) can result in challenging behaviours (CBs), with limited documentation on treatment approaches. This study explored the feasibility of employing a Behavioural Consultancy approach to manage CBs, targeting individuals with PBT, family and treating staff., Methods: Participants were patients and families of two hospitals and health professionals from cancer/neurological services. A single-case experimental design piloted skill-based training and environmental changes in managing socio-behavioural impairments in a person with a low grade astrocytoma. A half-day workshop to train family members (n = 7) in compensatory strategy use to manage CBs after PBT was piloted. Finally, a 1-day workshop was provided to 43 health professionals in managing CBs after PBT. For both workshops, a pre-post impact evaluation was conducted employing a purpose-designed Strategies Use Measure., Results: All three interventions demonstrated positive results. The single case showed a 71% decrease in the target behaviour (time spent talking) post-intervention. Some attrition to these gains was observed at two follow-up time points (3 and 5 months). Participants from both workshops demonstrated significant post-intervention increases in perceived knowledge of Strategy Use (family members z = 2.03, p < 0.05; health professionals z = 4.95, p < 0.00; Wilcoxon signed-rank test)., Conclusions: These initial studies highlight the potential of employing an integrated multi-tiered intervention based on a Behavioural Consultancy model to manage CBs after PBT.

We studied the i-gel™ in 120 anaesthetised children (92 boys, 28 girls; median (IQR [range]) age (3 -7 [0.4 -13]) years and weight 19 (15-26 [7-35]) kg) to assess efficacy and usability. Insertion was successful on the first/second/third attempt in 110/8/1 children and failed in one child. Median (IQR [range]) insertion time was 14 (9-16 [6-200]) s. Manual ventilation was possible in all cases, although excess leak precluded a tidal volume above 7 ml.kg(-1) in three children. Fibreoptic inspection through the i-gel revealed a clear view of the vocal cords in 40 out of 46 cases (87%). Median (IQR [range]) leak pressure was 20 (16-26 [8-30]) cmH(2) O. During maintenance of anaesthesia, 16 manipulations were required in 11 children to improve the airway. One child regurgitated without aspirating. Other complications and side effects were infrequent. The i-gel was inserted without complications, establishing a clear airway and enabling spontaneous and controlled ventilation, in 113 (94%) children., (© 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.)

We studied the i-gel in 100 elective, anaesthetised patients (55:45 male:female, median age 53 years) assessing: ease of use, airway quality, positioning, seal and complications. First insertion attempt was successful in 86 patients, second attempt in 11 patients, and third attempt in three patients. Fifty three manipulations were required in 26 patients (median 1) to achieve a clear airway. Median insertion time was 15 s. During ventilation, expired tidal volume of 7 ml x kg(-1) was achieved in 96 (96%) patients. Median airway leak pressure was 24 cmH(2)O. On fibreoptic examination via the device, vocal cords were visible in 87 patients (91%). During maintenance, six patients (6%) required 12 airway manipulations. There was one episode of regurgitation, without aspiration. Other complications and patient side-effects were mild and few. The i-gel is easily and rapidly inserted, providing a reliable airway in over 90% of cases. Further studies are indicated to assess safety and performance compared to other supraglottic airway devices.

Aims: Evaluation of the pediatric appendicitis score (PAS), in all patients who had an appendicectomy over a one-year period., Methods: Retrospective study of 56 patients aged 4-15 years, who underwent an emergency appendicectomy. PAS was applied and patients were divided according to the PAS protocol into high probability and low probability groups. These results were then correlated with histology., Results: The PAS had sensitivity 0.87, specificity 0.59, positive predictive value 0.83, and negative predictive value 0.67. The negative appendicectomy rate would have been reduced to 17%, but five patients with appendicitis would have been denied early surgical treatment and may have been discharged., Conclusions: The PAS cannot be recommended as it would lead to an unacceptable risk of wrongly discharging or delaying necessary surgery in 13% of patients with appendicitis.

Ethyl formate (EF) in combination with CO2 was tested for control of arthropods commonly infesting California table grapes. In addition, table grape tolerance to EF exposure was evaluated. LC99 estimates were developed for target pests by using a range of EF concentrations (0.04-4.7% EF). Response to treatments varied greatly between species, as well as life stages within species. Western flower thrips, Frankliniella occidentalis (Pergande), and adult and crawler stages of grape mealybug, Pseudococcus maritimus (Ehrhorn), were most susceptible to EF treatments. Least susceptible were grape mealybug eggs; Pacific spider mite, Tetranychus pacificus McGregor; and omnivorous leafroller, Platynota stultana Walsingham. The LC99 for target pests fell within the range of EF concentrations tolerated by table grapes with the exception of 1-, 3-, and 5-d-old omnivorous leafroller pupae.

The purpose of this paper was to investigate the effects of both monocular and dichoptic masking on the frequency doubling (FD) illusion, using both temporal and spatial masks. Monocular spatial tuning effects occurred around the fundamental FD spatial frequency of 0.25 cycles per degree (c/deg), whereas dichoptic spatial frequency tuning effects occurred at the doubled spatial frequency of 0.50 c/deg. Temporal tuning effects were observed at the FD temporal frequency of 25 Hz, in both monocular and dichoptic paradigms. These results suggest that the FD illusion is cortical in origin and is dominated by a flicker component.

We study experimentally the time dependence, steady state behavior and spectra of a dual fiber-laser compound cavity. Theoretically we confirm the CW and spectral characteristics. This particular cavity is formed with two Er-doped fiber amplifiers, each terminated with a fiber Bragg grating, and coupled through a 50/50 coupler to a common feedback and output coupling element. The experiment and theory show that a low Q, high gain symmetric compound cavity extracts nearly 4 times the power of a component resonator. This extraction is maintained even when there is significant difference in the optical pathlengths of the two component elements. Further, our measurements and theory show that the longitudinal modes of the coupled cavity are distinct from the modes of the component cavities and that the coherence is formed on a mode-by-mode basis using these coupled-cavity modes. The time behavior of the compound cavity shows slow fluctuations, on the order of seconds, consistent with perturbations in the laboratory environment.

Purpose: This study investigated the in vitro dehydration performance of silicone hydrogel and conventional hydrogel contact lens materials., Methods: In vitro dehydration was assessed using a gravimetric method. The mass loss over time of Focus Night&Day, PureVision, Optima, Acuvue and Proclear Compatibles was measured as the ambient temperature increased from room temperature to 34 degrees C under varying airflow and humidity conditions., Results: Dehydration data demonstrated a typical ogival form. The results were best fitted with a double exponential, non-linear regression model, which accounted for at least 99% of the variance. Regardless of material, increased airflow had a greater impact on dehydration rate than increased humidity (P<0.05). Relative dehydration amounts were strongly correlated with initial water content (r(2)=0.92), with higher water content materials dehydrating to a greater extent., Conclusions: In vitro dehydration studies of conventional and novel silicone-containing hydrogel materials indicated that evaporation rates from materials are predominantly water content related, with only subtle differences between materials of similar water contents being seen. Environmental conditions have a significant impact on in vitro dehydration, with increased airflow having a greater impact than reduced humidity on increasing dehydration rates. In vitro dehydration is closely related to bulk water diffusion rates and, as a result of their low water content, silicone-containing hydrogel materials exhibit low levels of dehydration compared with high water content hydrogel contact lens materials. Further, in vivo studies are necessary to see if the in vitro dehydration behaviour of silicone hydrogel materials is predictive of in-eye performance.

Purpose: This study characterized ocular symptoms typical of dry eye in an unselected optometric clinical population in the United States and Canada., Methods: Self-administered dry eye questionnaires, one for non-contact lens wearers (dry eye questionnaire) and one for contact lens wearers (contact lens dry eye questionnaire), were completed at six clinical sites in North America. Both questionnaires included categoric scales to measure the prevalence, frequency, diurnal severity, and intrusiveness of nine ocular surface symptoms. The questionnaires also asked how much these ocular symptoms affected daily activities and contained questions about computer use, medications, and allergies. The examining doctors, who were masked to questionnaire responses, recorded a nondirected dry eye diagnosis for each patient, based on their own diagnostic criteria., Results: The dry eye questionnaires were completed by 1,054 patients. The most common ocular symptom was discomfort, with 64% of non--contact lens wearers and 79% of contact lens wearers reporting the symptom at least infrequently. There was a diurnal increase in the intensity of many symptoms, with symptoms such as discomfort, dryness, and visual changes reported to be more intense in the evening. The 22% percent of non-contact lens wearers and 15% of contact lens wearers diagnosed with dry eye (most in the mild to moderate categories) reported symptoms at a greater frequency than those not diagnosed with dry eye., Conclusions: Our results show that symptoms of ocular irritation and visual disturbances were relatively common in this unselected clinical population. The intensity of many ocular symptoms increased late in the day, which suggested that environmental factors played a role in the etiology of the symptoms.

Objectives: Although alcohol is known to play a key part in accidents, no UK study has assessed alcohol concentrations in a comprehensive sample of accident and emergency (A&E) attenders. This study set out to do this, and examine the relation between alcohol concentrations and the severity, type and circumstances of presentation, and the sociodemographic characteristics of patients., Methods: A survey was conducted of all new A&E attenders (aged 10 years or over). Two 24 hour periods for each day of the week were covered in 6, 7 or 11 hour sessions over a two month period. Alcohol concentrations were assessed from saliva samples using a disposable device. Data were collected from 638 attenders, of whom 544 provided saliva samples; the remainder refused or were unable to participate., Results: Positive saliva alcohol readings were obtained in 22% of attenders (95%CI 19% to 26%); this increased to 25% if others were included (for example, those who refused to participate but were judged to be intoxicated). Alcohol was associated with 94% of incidents of self harm, 54% of non-specific/multiple complaints, 47% of collapses, 50% of assaults, and 50% of patients admitted to hospital. Higher concentrations of alcohol were found from Friday to Sunday, between midnight and 0900, and in patients aged 41 to 60. Among people with positive alcohol results, those attending with a companion had higher concentrations than those attending alone. There were no significant differences between men and women in alcohol concentrations., Discussion: These findings show that alcohol use is an important factor in A&E attendance, but it should not be assumed that there is a causal relation between alcohol use and injury. Several accident related and sociodemographic variables were predictive of alcohol use before attending. The overall level of prediction was too weak to permit accurate identification of drinkers for screening purposes, but routine alcohol concentration assessments may be justified in the high risk groups identified in this study. A&E departments may be convenient and fruitful settings for brief interventions with early problem drinkers.

Purpose: To assess the tear film, ocular surfaces, and symptoms of ocular discomfort in a presbyopic population before and after contact lens wear., Methods: A total of 150 presbyopes (49% were previous soft contact lens wearers) participated in a clinical trial in which they wore either monovision (single vision Acuvue lenses) or Acuvue Bifocal contact lenses. Clinical measurements of tear film, biomicroscopy, and corneal sensitivity as well as subjective ratings using the Dry Eye Questionnaire were collected at the initial visit and repeated after 6 months. Comparisons were made between age groups (40 to 51 years and 52 to 71 years) and genders before and after contact lens wear. Associations between objective and subjective tests were sought., Results: After 6 months of contact lens wear, clinical signs had worsened by less than one-half of a grade, and tear break up time (TBUT) worsened by 3 s. Only TBUT was lower for the older age group. Females had less bulbar hyperemia, more sensitive eyes, more lissamine green staining, and lower TBUT and phenol red thread measurements (all p < 0.04). Twenty-eight percent experienced dryness before contact lens wear, but this figure increased to 68% when wearing contact lenses. There were no age differences, but almost twice as many females as males reported dryness. Reporting symptoms of dryness was associated with gender, corneal sensitivity, and type of corneal staining., Conclusions: These results provide a representation of the ocular surface condition and symptoms of ocular discomfort in the middle-aged population and seem similar to reports of younger populations. Wearing contact lenses seems to influence dry eye symptoms more than age or gender. Therefore, presbyopes should not be excluded from consideration for contact lens fitting.

Ocular microtremor (OMT) is a fine high frequency tremor of the eyes caused by extra-ocular muscle activity stimulated by impulses emanating in the brain stem. Several studies have shown that the frequency of this tremor is reduced in patients whose consciousness is reduced by anaesthesia or head injury. Therefore, OMT may possibly be used to determine depth of anaesthesia. Twenty-two unpre-medicated subjects undergoing surgery with general anaesthesia were studied. OMT activity was measured at admission using the open eye piezoelectric strain gauge technique. Anaesthesia was induced with propofol using a target controlled infusion delivery system (Diprifusor). OMT activity was then recorded at predicted plasma propofol concentrations of 1, 2, 3 and 5 microg ml(-1). The patient's level of consciousness (response to command or stimulation) was assessed after each OMT measurement. OMT activity was reduced progressively at predicted plasma concentrations of propofol of I and 2 microg ml(-1) and then plateaued between 3 and 5 microg ml(-1). There was a significant difference between the last awake OMT recording and the first recording at loss of consciousness (P < 0.001). OMT recording holds promise as a practical indicator of the depth of anaesthesia.

This report describes the new optical imaging technique of optical coherence tomography (OCT). OCT is capable of high-resolution, micrometer-scale, cross-sectional imaging of biological tissue. The OCT for ophthalmic application uses 843-nm, near-infrared light, which produces a longitudinal resolution of 10 to 20 microm and a penetration depth of a few millimeters. The scans are displayed in a false color representation scale on which warm colors represent areas of high optical reflectivity and cool colors represent areas of minimal or no reflectivity. A cross-sectional view similar to a histology section is obtained. The cornea, iris, and lens may be visualized as well as the retina and optic nerve. OCT has been used to investigate several ocular diseases. These include macular disease, genetic retinal disease, retinal detachment and retinoschisis, choroidal tumors, optic nerve disorders, and glaucoma.

Purpose: To investigate the repeatability of three anterior segment clinical grading scales: 1) verbal descriptors scale (VDS), 2) photographic matching scale (PS), and 3) continuous matching scale (CS)., Methods: Five optometrists graded 30 slides each of 3-9-o'clock staining, bulbar redness, and palpebral conjunctival roughness twice, separated by at least a day. VDS and PS were five-point scales (0-4) with half grades permitted. The CS was a 5-second, 240-frame video movie generated using morphing software. PS and CS grading was done with references presented on a computer screen., Results: Averaged across observers, the test-retest intraclass correlation, correlation coefficient of concordance, and Pearson's r ranged from 0.95 to 0.99 (all p < 0.001). Coefficients of repeatability using CS to grade all three ocular conditions ranged between 0.31 and 0.49. The corresponding PS and VDS coefficients of repeatability ranged between 0.37 and 0.49; PS generally had better repeatability than VDS., Conclusions: Each of the clinical grading scales was reliable. The coefficients of repeatability showed that bulbar redness and palpebral conjunctival roughness were graded with higher precision using CS.

The prediction of the outcome from coma is of considerable importance to the patients, their relatives and attendant medical staff, and yet current clinical methods lack sensitivity and specificity. Objective investigations can enhance the accuracy of such predictions and are an important adjuvant when reaching decisions to continue or terminate life support. Of the neurophysiological methods available, electroencephalography and short-latency somatosensory evoked potentials have proved the most useful in the clinical setting. These tests are good predictors of an adverse outcome; however, they tell us only about the ongoing cerebral activity and integrity of the primary somatosensory pathways, respectively. The presence of long-latency event-related potentials has been shown to be a useful predictor of a favourable neurological outcome, and thus their use complements other neurophysiological techniques. Their potential application in clinical practice is reviewed., (Copyright 2000 S. Karger AG, Basel)

Purpose: The aim of this study was to compare the cardio-respiratory differences between rowing ergometry and treadmill exercise in beta-blocked men participating in exercise rehabilitation soon after myocardial infarction (postMI)., Methods: Eleven males all receiving beta-blockade medication were measured for oxygen consumption (VO2), respiratory exchange ratio (RER), and rating of perceived exertion (RPE) at individualized submaximal exercise target heart rates (THR) during 6 min of exercise on each of a motorized treadmill and a rowing ergometer 2-6 wk (4.9 +/- 1.4) postMI., Results: The mean THR of the group, predetermined from an exercise ECG stress test, was 107 +/- 16 beats x min(-1). No significant difference was found between rowing versus treadmill VO2 (19.4 +/- 3.2 vs 19.7 +/- 4.2 mL x kg(-1) x min(-1); P = 0.53) or RPE (12.6 +/- 1 vs 12.7 +/- 1; P = 0.72). RER was significantly greater (P = 0.02) during rowing (0.99 +/- 0.07) compared with treadmill exercise (0.94 +/- 0.07)., Conclusion: Exercising at a specified submaximal THR during rowing versus treadmill exercise in beta-blocked men participating in very early cardiac rehabilitation represents the same VO2 and RPE. A significantly greater RER was, however, apparent during rowing compared with treadmill exercise; thus, agreement was shown with previous studies on healthy individuals where rowing ergometry was less metabolically efficient than treadmill exercise. The results suggest that establishing a THR from a standard treadmill stress test soon after MI is not only suitable for walking/treadmill exercise but also in setting exercise intensity for rowing ergometry.

Purpose: To determine whether lens dehydration correlates with discomfort, dryness, and noninvasive tear break-up time in symptomatic and asymptomatic contact lens wearers and whether dehydration of the two lens types varies., Method: Twenty hydrogel contact lens wearers with dryness-related symptoms and 20 asymptomatic wearers wore an Etafilcon A lens (Acuvue; Vistakon, Inc., Jacksonville, Florida) in one eye and an Omafilcon A lens (Proclear; Biocompatibles, Norfolk, Virginia) in the contralateral eye for 7 h in a randomized, double-masked study. Lens water content was measured before and after 7 h of lens wear and prelens noninvasive tear film break-up time (NIBUT) was measured immediately after insertion and after 5 h of lens wear. Subjective comfort and dryness were rated at 0, 1, 3, 5, and 7 h of lens wear., Results: The symptomatic group had significantly reduced prelens NIBUT, decreased comfort, and increased dryness, but there was no difference between lenses for these variables. The Omafilcon A lenses dehydrated significantly less than the Etafilcon A lenses, but there was no significant difference in lens dehydration between two subject groups., Conclusion: No correlation was found between lens dehydration and subjective dryness and comfort. Symptomatic hydrogel contact lens wearers with decreased wearing time had measurably decreased comfort, increased dryness ratings, and reduced NIBUT.

There is an evident need to measure the comprehensive burden of morbidity experienced by survivors of brain tumours in childhood. To this end, a questionnaire based on the Health Utilities Index mark 2 (HUI2) and mark 3 (HUI3) systems was completed independently for a cohort of such children by their parents, by a nurse, by physicians and by a selected group of the children themselves. Each of the HUI2 and HUI3 systems consists of a multi-attribute health status classification scheme linked to a preference function which provides utility scores for levels within single attributes (domains of health) and for global health states. All eligible families (n = 44) participated. Even cognitively impaired children of at least 9.5 years of age could complete the questionnaire. The greatest burden of morbidity, occurring in two-thirds of children, was in the attribute of cognition. Surprisingly, almost one-third of children experienced pain. Global health status was lowest in children who underwent radiotherapy before the age of 5 years and the corresponding utility scores were related inversely to the volume irradiated. Children with demonstrable disease had lower scores than those in whom disease was not evident. There was a high level of agreement (intraclass correlation coefficients > 0.5) on formal assessment of inter-rater reliability for global health-related quality of life utility scores. The usefulness of measures of health status and health-related quality of life, in children surviving brain tumours, has been demonstrated by this study.

This study assessed the repeatability of the Nikon NRK-8000, the Nidek KM-800 and the Bausch and Lomb keratometer. In addition, the comparability of the Nikon NRK-8000 and the Nidek KM-800 are evaluated relative to the Bausch and Lomb keratometer. Measurements were taken with all three techniques on two separate occasions with a test-retest separation of at least 24 hr. The right eyes of 30 normal subjects were used. Repeatability and comparability statistics and plots were generated using matrix representations of dioptric power. The Nidek KM-800 coefficient of repeatability values were found to be 0.345, 0.187, and 0.321 in the vertical, torsional, and horizontal meridians while the Nikon NRK-8000 values were 0.346, 0.232, and 0.276 respectively.

Osteopenia has been reported in children surviving acute lymphoblastic leukaemia, apparently as a consequence of therapy. It has been suggested that cranial irradiation may play a crucial role in this disorder. To explore that possibility, survivors of brain tumours in childhood, all of whom had received radiotherapy, were examined for evidence of bone mineral loss. 19 children were assessed, on average at 7 years after treatment. Measurements of growth velocities, plain radiography of the skeleton, bone densitometry, health-related quality of life and physical activity were undertaken. Growth hormone (GH) deficiency had been detected in 6 children and 5 had received GH replacement, for a minimum of more than 3 years. 9 children were radiographically osteopenic (including the 5 who had received GH). Z scores for bone mineral density (BMD) were negative in the majority of children. Health-related quality of life was less and pain more frequent in those with low BMD scores. Pain was correlated negatively with both free-time activity and seasonal activity (P < 0.01). Osteopenia is a common sequel of therapy in children with brain tumours. Those with osteopenia have more pain and more compromised, health-related quality of life than those who are not osteopenic, and pain significantly limits physical activity. The pathogenesis of osteopenia in these children is still uncertain, but is likely to be multifactorial.

This study assessed the repeatability of various methods of measuring tear break-up time (TBUT) with and without soft contact lenses (CLs). TBUT was measured on 22 subjects with the tearscope, videokeratoscope and slit-lamp before and after 30 min of soft CL wear, and immediately after CL removal. Slit-lamp corneal TBUT was measured with fluorescein and without fluorescein while wearing CLs. TBUT was measured three times on the right eye only, using each technique in randomised order. TBUT measurements on CLs were repeated a second day. TBUT measurements were highly variable under all conditions and our results indicated a lack of correlation between techniques. The videokeratoscope was the least repeatable; while the tearscope was the most repeatable technique.

Objective: To collect questionnaire data from patients in a large clinical population that would allow for an estimate of the prevalence of self-reported symptoms of dry eyes., Methods: A 13-point questionnaire (The Canada Dry Eye Epidemiology Study, CANDEES) was mailed to all optometric practices in Canada in October 1994, with the request that it be completed by 30 successive nonselected patients., Results: Four hundred fifty sets of questionnaires (total, 13,517) were analyzed (a 15.7% return rate) from patients aged from < 10 years to > 80 years; 55% were in the 21- to 50-year age group; 60.7% were female; and 24.3% were contact lens wearers. A total of 28.7% reported dry eye symptoms, of whom 24.2% reported concurrent dry mouth, 24.5% had worse symptoms in the morning, 30.3% reported concurrent lid problems, and 35.7% reported a history of allergies. Of the 3716 patients reporting symptoms, 62 (1.6%) were in the "severe" category and 290 (7.8%) were in the "constant but moderate" category. Contact lens wear, concurrent allergies, dry mouth, lid problems, or use of medications increased the chance of a patient reporting dry eye symptoms., Conclusions: The prevalence of patients reporting any level of symptoms of dry eyes was approximately 1 in 4; severe symptoms were reported by 1 in 225 patients.

This study assessed the repeatability of the Nikon NRK-8000, the Nidek AR-1000, and subjective refraction. In addition, the accuracy of the Nikon and the Nidek were evaluated in comparison to subjective refraction. Measurements were taken with all 3 techniques on 2 separate occasions with a test-retest separation of at least 24 h. The right eyes of 30 normal subjects were used. Repeatability and accuracy statistics and plots were generated using matrix representations of dioptric power. Subjective refraction was the most repeatable method, with the coefficient of repeatability (COR) found to be 0.611, 0.224, and 0.490 in the vertical, torsional, and horizontal meridians. The autorefractors' COR was found to range from 0.712 to 0.826 for the vertical and horizontal meridians, whereas the torsional meridian ranged from 0.224 to 0.319.

Background: Although nurse educators and nurse managers have disagreed about which clinical competencies are necessary for new graduates to begin working in critical care, the competencies are in need of revision and reassessment., Objectives: To validate a list of beginning-level competencies and to compare baccalaureate nurse educators' and critical care nurse manager's current perceptions of beginning clinical competencies for new baccalaureate graduates in critical care settings., Methods: An expert panel of nurses from across the United States critiqued a questionnaire about which clinical competencies were considered relevant to critical care nursing practice. The revised questionnaire, containing 105 clinical competencies, was mailed to a randomly selected sample across the United States. Forty-one baccalaureate nurse educators and 41 critical care nurse managers completed the mail survey questionnaire (94% response rate) by rating the necessity ("essential," "desired," or "not required") of the clinical competencies for new baccalaureate nurses., Results: A high degree of agreement was generally seen between nurse educators and nurse managers on the necessity ratings of the 105 competencies. The majority of nurse educators and nurse managers rated 81 of the 105 competencies as either "essential" or "desirable." Only five competencies showed considerable disagreement between nurse educators and nurse managers, and none of these competencies were rated "essential" by more than a few raters in either group., Conclusions: The agreement between nurse educators and nurse managers supports a competency list for baccalaureate nursing curricula and hospital inservice programs to integrate new graduates into critical care.

Background: Visiting policies have been liberalized in ICUs, but the process and outcome of policy modifications have not been well described., Objectives: To describe the process by which nurses in one critical care unit modified visiting from a restricted to a liberalized (i.e., modified open) policy, and to evaluate the nurses' perceptions about visiting before and after the policy was liberalized., Methods: A group of ICU/coronary care unit nurses met to discuss changes in their unit's visiting policy. Before the change was initiated, nurses (N = 36) in the unit were informally surveyed regarding their perceptions and attitudes about visiting. After a 3-month trial of liberalized visiting, in which visiting hours were increased at the discretion of the nursing staff, nurses (N = 32) were surveyed using a questionnaire about their beliefs, attitudes, level of satisfaction, and perceptions of their actual visiting policy., Results: Nurses confirmed that the visiting policy had become liberalized, and they believed that liberalized visiting had positive effects on patients' emotional well-being. Nurses had more positive attitudes about the effects of liberalized visiting on families than on patients and unit function. Most nurses were satisfied with liberalized visiting. However, attitudes differed about how liberalized visiting affected patients' physiological responses or the unit function., Conclusions: Effective implementation of liberalized visiting depends on assessment of the following: nurses' beliefs, attitudes, and satisfaction about a change toward a more open visiting policy; staff involvement in determining the policy; and nurse manager and clinical nurse specialist support.

We evaluated the effect of +3.25 dioptres of optical blur on the discrimination of motion direction in random dot cinematograms. Dot displacement between frames varied from 2.1 to 63' of visual angle while the temporal interval was held constant. Optical blur worsened discrimination in three normal subjects at displacements below 16', but improved discrimination at displacements of 21' or more. In a second experiment, two subjects viewed equivalent velocity stimuli constructed with different combinations of temporal interval and spatial displacement. Results showed that the effect of blur was specific to displacement and not velocity. Furthermore, varying the dot density of the display showed that the effect of blur correlated with dot displacement and not the probability of dot mismatches. Since optical blur attenuates high spatial frequencies, this suggests that high spatial frequencies are important for motion perception when dot displacements are less than 16' to 21', but reduce motion perception at larger dot displacements. The use of random dot cinematograms in populations must take into account stimulus displacement and optical causes of reduced spatial acuity.

We performed functional imaging with a conventional 1.5-T magnetic resonance scanner in 9 normal subjects. We used a gradient-echo technique to examine changes in signal between periods when subjects viewed a stationary black-and-white grating, a moving grating, and when they followed a moving spot. We located image pixels with significant differences between the viewing conditions. In 7 subjects, these occurred in the lateral occipitotemporal cortex, a region previously identified as a putative human homologue of the motion-sensitive middle temporal area (MT, or V5) of monkeys. Signal intensity was greater during pursuit of the moving dot than during viewing of the moving grating with the eyes still, despite the fact that the moving grating generated more retinal image motion. In contrast, signal intensity in striate cortex was least during pursuit of the moving dot. These findings suggest that the lateral occipitotemporal cortex has extraretinal signals during pursuit. Such signals may include attentional input, corollary eye movement information, or even a pursuit command. Extraretinal signals suggest that the lateral occipitotemporal cortex may contain a human homologue not only of MT but also of other components of the monkey V5 complex, such as the medial superior temporal area.

Factors associated with the attempted length, disturbance, effectiveness, and nap supplementation of sleep were analyzed in 97 patients recovering from cardiac surgery a few days before hospital discharge. Patients rated sleep for the prior night and factors that impaired their sleep after transfer from the critical care unit. The group averaged little sleep, with moderate disturbance and effectiveness and low nap supplementation. The disturbance, effectiveness, and attempted length of sleep were associated with an inability to perform their usual routine before sleep, inability to get comfortable, pain, noises, procedural care, and an unfamiliar bed. Patients encounter difficulties with sleep, even near discharge from the hospital. Interventions should be tested to mitigate specific factors that affect selected dimensions of sleep.