Is post-trabeculectomy hypotony a risk factor for subsequent failure? A case control study

BACKGROUND: Ocular hypotony results in an increased break down of the blood-aqueous barrier and an increase in inflammatory mediator release. We postulate that this release may lead to an increased risk of trabeculectomy failure through increased bleb scarring. This study was designed to try to address the question if hypotony within one month of trabeculectomy for Primary Open Angle Glaucoma (POAG), is a risk factor for future failure of the filter. METHODS: We performed a retrospective, case notes review, of patients who underwent trabeculectomy for POAG between Jan 1995 and Jan 1996 at our hospital. We identified those with postoperative hypotony within 1 month of surgery. Hypotony was defined as an intraocular pressure (IOP) < 8 mmHg or an IOP of less than 10 mmHg with choroidal detachment or a shallow anterior chamber. We compared the survival times of the surgery in this group with a control group (who did not suffer hypotony as described above), over a 5 year period. Failure of trabeculectomy was defined as IOP > 21 mmHg, or commencement of topical antihypertensives or repeat surgery. RESULTS: 97 cases matched our inclusion criteria, of these 38 (39%) experienced hypotony within 1 month of surgery. We compared the survival times in those patients who developed hypotony with those who did not using the log-rank test. This data provided evidence of a difference (P = 0.0492) with patients in the hypotony group failing more rapidly than the control group. CONCLUSION: Early post-trabeculectomy hypotony (within 1 month) is associated with reduced survival time of blebs

Operator theory and function theory in Drury-Arveson space and its quotients

The Drury-Arveson space $H^2_d$, also known as symmetric Fock space or the $d$-shift space, is a Hilbert function space that has a natural $d$-tuple of operators acting on it, which gives it the structure of a Hilbert module. This survey aims to introduce the Drury-Arveson space, to give a panoramic view of the main operator theoretic and function theoretic aspects of this space, and to describe the universal role that it plays in multivariable operator theory and in Pick interpolation theory.Comment: Final version (to appear in Handbook of Operator Theory); 42 page

Detection of early age-related macular degeneration using novel functional parameters of the focal cone electroretinogram

The focal cone electroretinogram is a sensitive marker for macular disease, but have we unlocked its full potential? Typically assessment of waveform parameters is subjective and focuses on a small number of locations (e.g. the a-wave). This study evaluated the discriminatory and diagnostic potential of 4 conventional and 15 novel, objectively determined, parameters in patients with early Age-related Macular Degeneration. Focal cone electroretinograms were recorded in 54 participants with early Age-related Macular Degeneration (72.9±8.2 years) and 54 healthy controls (69±7.7 years). Conventional a and b wave amplitudes and implicit times were measured and compared to novel parameters derived from both the 1st and 2nd derivatives and the frequency-domain power spectrum of the electroretinogram.Statistically significant differences between groups were shown for all conventional parameters, the majority of 1st and 2nd derivative parameters and the power spectrum at 25 and 30 Hz. Receiver operating characteristics showed that both conventional and 1st and 2nd derivative implicit times had provided the best diagnostic potential. A regression model showed a small improvement over any individual parameter investigated. The non-conventional parameters enhanced the objective evaluation of the focal electroretinogram, especially when the amplitude was low. Furthermore, the novel parameters described here allow the implicit time of the electroretinogram to be probed at points other than the peaks of the a and b waves. Consequently these novel analysis techniques could prove valuable in future electrophysiological investigation, detection and monitoring of Age-related Macular Degeneration

Scrapheap Challenge: A novel bulk-bone metabarcoding method to investigate ancient DNA in faunal assemblages

Highly fragmented and morphologically indistinct fossil bone is common in archaeological and paleontological deposits but unfortunately it is of little use in compiling faunal assemblages. The development of a cost-effective methodology to taxonomically identify bulk bone is therefore a key challenge. Here, an ancient DNA methodology using high-throughput sequencing is developed to survey and analyse thousands of archaeological bones from southwest Australia. Fossils were collectively ground together depending on which of fifteen stratigraphical layers they were excavated from. By generating fifteen synthetic blends of bulk bone powder, each corresponding to a chronologically distinct layer, samples could be collectively analysed in an efficient manner. A diverse range of taxa, including endemic, extirpated and hitherto unrecorded taxa, dating back to c.46,000 years BP was characterized. The method is a novel, cost-effective use for unidentifiable bone fragments and a powerful molecular tool for surveying fossils that otherwise end up on the taxonomic “scrapheap”

Acupuncture and chiropractic care for chronic pain in an integrated health plan: a mixed methods study

<p>Abstract</p> <p>Background</p> <p>Substantial recent research examines the efficacy of many types of complementary and alternative (CAM) therapies. However, outcomes associated with the "real-world" use of CAM has been largely overlooked, despite calls for CAM therapies to be studied in the manner in which they are practiced. Americans seek CAM treatments far more often for chronic musculoskeletal pain (CMP) than for any other condition. Among CAM treatments for CMP, acupuncture and chiropractic (A/C) care are among those with the highest acceptance by physician groups and the best evidence to support their use. Further, recent alarming increases in delivery of opioid treatment and surgical interventions for chronic pain--despite their high costs, potential adverse effects, and modest efficacy--suggests the need to evaluate real world outcomes associated with promising non-pharmacological/non-surgical CAM treatments for CMP, which are often well accepted by patients and increasingly used in the community.</p> <p>Methods/Design</p> <p>This multi-phase, mixed methods study will: (1) conduct a retrospective study using information from electronic medical records (EMRs) of a large HMO to identify unique clusters of patients with CMP (e.g., those with differing demographics, histories of pain condition, use of allopathic and CAM health services, and comorbidity profiles) that may be associated with different propensities for A/C utilization and/or differential outcomes associated with such care; (2) use qualitative interviews to explore allopathic providers' recommendations for A/C and patients' decisions to pursue and retain CAM care; and (3) prospectively evaluate health services/costs and broader clinical and functional outcomes associated with the receipt of A/C relative to carefully matched comparison participants receiving traditional CMP services. Sensitivity analyses will compare methods relying solely on EMR-derived data versus analyses supplementing EMR data with conventionally collected patient and clinician data.</p> <p>Discussion</p> <p>Successful completion of these aggregate aims will provide an evaluation of outcomes associated with the real-world use of A/C services. The trio of retrospective, qualitative, and prospective study will also provide a clearer understanding of the decision-making processes behind the use of A/C for CMP and a transportable methodology that can be applied to other health care settings, CAM treatments, and clinical populations.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01345409">NCT01345409</a></p

Latanoprost treatment for open angle glaucoma. The United Kingdom Glaucoma Treatment Study: a multicentre, randomised, placebo-controlled clinical trial

BACKGROUND: Treatment of open-angle glaucoma (OAG) aims to prevent vision loss by lowering intraocular pressure (IOP), yet there has been no previous placebo-controlled medical treatment trial assessing vision function preservation. Observation periods in previous (unmasked) trials assessing visual function have typically been at least 5 years. The aim of this study was to assess vision preservation by latanoprost treatment compared to placebo. METHODS In this randomised, triple-masked, placebo-controlled trial, patients with newly-diagnosed OAG were enrolled at 10 UK centres (tertiary referral centres, teaching hospitals, and district general hospitals) between Feb 2007 and Mar 2010. Eligible patients were randomly allocated (1:1) to receive either latanoprost 0·005% or placebo eye drops, provided in identical bottles, once daily to both eyes. Randomization was in permuted blocks stratified by participating centre. The primary hypothesis was that latanoprost treatment reduces incident visual field (VF) deterioration, compared with placebo, by 50% over 2 years. The primary outcome was VF deterioration: 3 locations in the Pattern Deviation Glaucoma Change Probability maps worse than baseline in 2 consecutive VFs, present in 2 consecutive VF pairs. The primary analysis was VF survival in the intention-to-treat population. The trial was terminated in July 2011 on the recommendation of the independent data monitoring committee following an interim analysis. Trial registration number: ISRCTN96423140. FINDINGS: 516 patients were randomised and data on all subjects with post-allocation data (461) were analysed. 18 serious adverse events were reported, none attributable to the study drug. Baseline mean (SD) IOP was 19·6 (4·6) mmHg and 20·1 (4·8) mmHg, and IOP reduction at 24 months 3·8 (4·0) mmHg and 0·9 (3·8) mmHg, in the latanoprost and placebo groups, respectively. Incident VF deterioration (95% CI) by 24 months was 15·0% (10·8, 20·0) in the latanoprost group and 24·8% (19·5, 30·7) in the placebo group (P=0·007). VF survival was significantly longer in the latanoprost group: at 24 months, adjusted hazard ratio (HR) 0·44 (0·28, 0·69) (P=0·0003). The difference between treatment groups was evident after only 12 months, HR 0·47 (0·23, 0·95) (P=0·035). INTERPRETATION: This is the first placebo-controlled trial to demonstrate VF preservation with an IOP-lowering agent in OAG. The study design enabled a relatively short observation period. FUNDING: Pfizer Inc.; UK National Institute for Health Research Biomedical Research Centre

Assessing the Value of Recreational Divers for Censusing Elasmobranchs

BACKGROUND: Around the world, researchers are using the observations and experiences of citizens to describe patterns in animal populations. This data is often collected via ongoing sampling or by synthesizing past experiences. Since elasmobranchs are relatively rare, obtaining data for broad-scale trend analysis requires high sampling effort. Elasmobranchs are also relatively large and conspicuous and therefore it may be possible to enlist recreational divers to collect data on their occurrence and relative abundance from daily dive activities. For this, however, a good understanding of the value of data collected by recreational divers is essential. METHODOLOGY/PRINCIPAL FINDINGS: Here, we explore the value of recreational divers for censusing elasmobranchs using a diverse set of data sources. First, we use a simulation experiment to explore detection rates of the roving diver technique, used by recreational divers, across a range of fish densities and speeds. Next, using a field survey, we show that inexperienced recreational divers detect and count elasmobranchs as well as experienced recreational divers. Finally, we use semi-structured interviews of recreational dive instructors to demonstrate the value of their recollections in terms of effort and their descriptions of spatial and temporal distributions of sharks in Thailand. CONCLUSIONS/SIGNIFICANCE: Overall, this study provides initial ground-work for using recreational divers for monitoring elasmobranch populations. If used appropriately, citizen-collected data may provide additional information that can be used to complement more standardized surveys and to describe population trends across a range of spatial and temporal scales. Due to the non-extractive nature of this data, recreational divers may also provide important insight into the success of conservation initiatives, such as shark sanctuaries and no-take zones

A reporting format for leaf-level gas exchange data and metadata

Leaf-level gas exchange data support the mechanistic understanding of plant fluxes of carbon and water. These fluxes inform our understanding of ecosystem function, are an important constraint on parameterization of terrestrial biosphere models, are necessary to understand the response of plants to global environmental change, and are integral to efforts to improve crop production. Collection of these data using gas analyzers can be both technically challenging and time consuming, and individual studies generally focus on a small range of species, restricted time periods, or limited geographic regions. The high value of these data is exemplified by the many publications that reuse and synthesize gas exchange data, however the lack of metadata and data reporting conventions make full and efficient use of these data difficult. Here we propose a reporting format for leaf-level gas exchange data and metadata to provide guidance to data contributors on how to store data in repositories to maximize their discoverability, facilitate their efficient reuse, and add value to individual datasets. For data users, the reporting format will better allow data repositories to optimize data search and extraction, and more readily integrate similar data into harmonized synthesis products. The reporting format specifies data table variable naming and unit conventions, as well as metadata characterizing experimental conditions and protocols. For common data types that were the focus of this initial version of the reporting format, i.e., survey measurements, dark respiration, carbon dioxide and light response curves, and parameters derived from those measurements, we took a further step of defining required additional data and metadata that would maximize the potential reuse of those data types. To aid data contributors and the development of data ingest tools by data repositories we provided a translation table comparing the outputs of common gas exchange instruments. Extensive consultation with data collectors, data users, instrument manufacturers, and data scientists was undertaken in order to ensure that the reporting format met community needs. The reporting format presented here is intended to form a foundation for future development that will incorporate additional data types and variables as gas exchange systems and measurement approaches advance in the future. The reporting format is published in the U.S. Department of Energy's ESS-DIVE data repository, with documentation and future development efforts being maintained in a version control system

Effects of a brief worksite stress management program on coping skills, psychological distress and physical complaints : a controlled trial

Objectives: To examine the effects of single-session, small-group stress management program on knowledge about stress, coping skills, and psychological and physical distress. Methods: A total of 300 employees from a company in western Japan were invited to participate in the study. Those who consented to enter the study were assigned to an intervention (n=149) or waiting list control group (n=151). Participants in the intervention group received a small-group stress management program. The program was primarily aimed at increasing knowledge about stress and improving coping skills. To investigate the intervention effect, change scores in outcome variables were calculated by subtracting the scores at pre-intervention from those at post-intervention (8 weeks after the pre-intervention survey). Next, the difference in the scores between groups was examined using analyses of covariance (ANCOVA) with the pre-intervention score as the covariate. Results: Favorable intervention effects were found on knowledge about stress and on coping skills (P < 0.001 and P=0.012, respectively) and adverse effects on psychological distress (P=0.022). However, this adverse effect on psychological distress did not exist among those who initially perceived higher levels of job control. Conclusion: The single-session stress management program was effective on improving knowledge about stress, and coping skills, where job control moderated the effect of the program on psychological distress