Tracking Triploid Mortalities Of Eastern Oysters Crassostrea virginica In The Virginia Portion Of The Chesapeake Bay

Since 2012, aquacultured eastern oysters Crassostrea virginica have been reported by oyster farmers to display mortality approaching 30%, and in some cases 85%, in areas of the lower Chesapeake Bay, VA. Based on accounts from industry, this mortality has typically affected 1-y-old oysters between May and early July, and has tended to occur in triploid oysters, which represent the vast bulk of production in the area. During this period, samples submitted for pathology have not revealed the presence of major pathogens as a cause. In 2015, to gain deeper insight into this mortality and determine whether specific sites, ploidy condition, or genetic lines were affected, oyster seed commercially produced in early 2014 were obtained from four lines, one diploid (2N DEBY) and three triploid (3N DEBY, 3N hANA, and 3N Northern). These lines were deployed in July 2014 at aquaculture farms at five Chesapeake Bay locations: Locklies Creek and Milford Haven on the western shore, and Pungoteague Creek, Nassawadox Creek, and Cherrystone Creek on the Eastern Shore. During this study, mortality was observed to peak in June at most sites, reaching a mean mortality across all tested lines of 17.0% and a cumulative mortality for the study period of 32.0% at Nassawadox Creek, the site most severely affected by mortality that followed the expected early summer mortality pattern. Interval mortality at all sites decreased to under 5% after June, but cumulative levels for the study period reached from 8.8% to 18.6% even at the sites least affected by mortality. This represents a high level of mortality given the documented absence of material involvement by major oyster pathogens such as Hapolosporidium nelsoni and Perkinsus marinus. Infiltration of gill tissues by hemocytes, observed in up to 33% of individuals at Nassawadox Creek coincident with the increase in mortality, was the only pathology observed. Harmful algal blooms were not associated with the mortality, nor were abnormal temperatures or salinities. There was no clear relationship of mortality to oyster genetic heritage, although there was variability in susceptibility among oyster lines and interactions between lines and specific sites. At some locations and in comparison with diploids, triploid oysters appeared to be more susceptible to mortality. Mortality in triploids was coincident with the timing of peak gametogenic development in diploids. Given the lack of involvement by major pathogens and the possible association of mortality with oyster gametogenesis, future work should seek to better understand the suite of environmental stressors potentially impacting cultured oysters in these systems and their interactions with the physiology and energetics of these animals

The depression in visual impairment trial (DEPVIT): trial design and protocol

<b>Background</b> The prevalence of depression in people with a visual disability is high but screening for depression and referral for treatment is not yet an integral part of visual rehabilitation service provision. One reason for this may be that there is no good evidence about the effectiveness of treatments in this patient group. This study is the first to evaluate the effect of depression treatments on people with a visual impairment and co morbid depression.<p></p> <b>Methods/design</b> The study is an exploratory, multicentre, individually randomised waiting list controlled trial. Participants will be randomised to receive Problem Solving Therapy (PST), a ‘referral to the GP’ requesting treatment according to the NICE’s ‘stepped care’ recommendations or the waiting list arm of the trial. The primary outcome measure is change (from randomisation) in depressive symptoms as measured by the Beck’s Depression Inventory (BDI-II) at 6 months. Secondary outcomes include change in depressive symptoms at 3 months, change in visual function as measured with the near vision subscale of the VFQ-48 and 7 item NEI-VFQ at 3 and 6 months, change in generic health related quality of life (EQ5D), the costs associated with PST, estimates of incremental cost effectiveness, and recruitment rate estimation.<p></p> <b>Discussion</b> Depression is prevalent in people with disabling visual impairment. This exploratory study will establish depression screening and referral for treatment in visual rehabilitation clinics in the UK. It will be the first to explore the efficacy of PST and the effectiveness of NICE’s ‘stepped care’ approach to the treatment of depression in people with a visual impairment.<p></p&gt

Stellar archeology: a cosmological view of dwarf galaxies

The origin of dwarf spheroidal galaxies (dSphs) is investigated in a global cosmological context by simultaneously following the evolution of the Milky Way Galaxy and its dwarf satellites. This approach enable to study the formation of dSphs in their proper birth environment and to reconstruct their own merging histories. The proposed picture simultaneously accounts for several dSph and Milky Way properties, including the Metallicity Distribution Functions of metal-poor stars. The observed features are interpreted in terms of physical processes acting at high redshifts.Comment: 8 pages, 5 figures; "Dwarf Galaxies: Keys to Galaxy Formation and Evolution" JENAM 2010 Symposium S

Vignette studies of medical choice and judgement to study caregivers' medical decision behaviour: systematic review

BACKGROUND: Vignette studies of medical choice and judgement have gained popularity in the medical literature. Originally developed in mathematical psychology they can be used to evaluate physicians' behaviour in the setting of diagnostic testing or treatment decisions. We provide an overview of the use, objectives and methodology of these studies in the medical field. METHODS: Systematic review. We searched in electronic databases; reference lists of included studies. We included studies that examined medical decisions of physicians, nurses or medical students using cue weightings from answers to structured vignettes. Two reviewers scrutinized abstracts and examined full text copies of potentially eligible studies. The aim of the included studies, the type of clinical decision, the number of participants, some technical aspects, and the type of statistical analysis were extracted in duplicate and discrepancies were resolved by consensus. RESULTS: 30 reports published between 1983 and 2005 fulfilled the inclusion criteria. 22 studies (73%) reported on treatment decisions and 27 (90%) explored the variation of decisions among experts. Nine studies (30%) described differences in decisions between groups of caregivers and ten studies (33%) described the decision behaviour of only one group. Only six studies (20%) compared decision behaviour against an empirical reference of a correct decision. The median number of considered attributes was 6.5 (IQR 4-9), the median number of vignettes was 27 (IQR 16-40). In 17 studies, decision makers had to rate the relative importance of a given vignette; in six studies they had to assign a probability to each vignette. Only ten studies (33%) applied a statistical procedure to account for correlated data. CONCLUSION: Various studies of medical choice and judgement have been performed to depict weightings of the value of clinical information from answers to structured vignettes of care givers. We found that the design and analysis methods used in current applications vary considerably and could be improved in a large number of cases

A probable stellar solution to the cosmological lithium discrepancy

The measurement of the cosmic microwave background has strongly constrained the cosmological parameters of the Universe. When the measured density of baryons (ordinary matter) is combined with standard Big Bang nucleosynthesis calculations, the amounts of hydrogen, helium and lithium produced shortly after the Big Bang can be predicted with unprecedented precision. The predicted primordial lithium abundance is a factor of two to three higher than the value measured in the atmospheres of old stars. With estimated errors of 10 to 25%, this cosmological lithium discrepancy seriously challenges our understanding of stellar physics, Big Bang nucleosynthesis or both. Certain modifications to nucleosynthesis have been proposed, but found experimentally not to be viable. Diffusion theory, however, predicts atmospheric abundances of stars to vary with time, which offers a possible explanation of the discrepancy. Here we report spectroscopic observations of stars in the metalpoor globular cluster NGC 6397 that reveal trends of atmospheric abundance with evolutionary stage for various elements. These element-specific trends are reproduced by stellar-evolution models with diffusion and turbulent mixing. We thus conclude that diffusion is predominantly responsible for the low apparent stellar lithium abundance in the atmospheres of old stars by transporting the lithium deep into the star.Comment: 10 pages, 3 two-panel figures, 2 tables, includes all Supplementary Information otherwise accessible online via www.nature.co

Effect of rehabilitation worker input on visual function outcomes in individuals with low vision: study protocol for a randomised controlled trial

BACKGROUND: Visual Rehabilitation Officers help people with a visual impairment maintain their independence. This intervention adopts a flexible, goal-centred approach, which may include training in mobility, use of optical and non-optical aids, and performance of activities of daily living. Although Visual Rehabilitation Officers are an integral part of the low vision service in the United Kingdom, evidence that they are effective is lacking. The purpose of this exploratory trial is to estimate the impact of a Visual Rehabilitation Officer on self-reported visual function, psychosocial and quality-of-life outcomes in individuals with low vision. METHODS/DESIGN: In this exploratory, assessor-masked, parallel group, randomised controlled trial, participants will be allocated either to receive home visits from a Visual Rehabilitation Officer (n = 30) or to a waiting list control group (n = 30) in a 1:1 ratio. Adult volunteers with a visual impairment, who have been identified as needing rehabilitation officer input by a social worker, will take part. Those with an urgent need for a Visual Rehabilitation Officer or who have a cognitive impairment will be excluded. The primary outcome measure will be self-reported visual function (48-item Veterans Affairs Low Vision Visual Functioning Questionnaire). Secondary outcome measures will include psychological and quality-of-life metrics: the Patient Health Questionnaire (PHQ-9), the Warwick-Edinburgh Mental Well-being Scale (WEMWBS), the Adjustment to Age-related Visual Loss Scale (AVL-12), the Standardised Health-related Quality of Life Questionnaire (EQ-5D) and the UCLA Loneliness Scale. The interviewer collecting the outcomes will be masked to the group allocations. The analysis will be undertaken on a complete case and intention-to-treat basis. Analysis of covariance (ANCOVA) will be applied to follow-up questionnaire scores, with the baseline score as a covariate. DISCUSSION: This trial is expected to provide robust effect size estimates of the intervention effect. The data will be used to design a large-scale randomised controlled trial to evaluate fully the Visual Rehabilitation Officer intervention. A rigorous evaluation of Rehabilitation Officer input is vital to direct a future low vision rehabilitation strategy and to help direct government resources. TRIAL REGISTRATION: The trial was registered with ( ISRCTN44807874 ) on 9 March 2015

Gene expression profiling in brain of mice exposed to the marine neurotoxin ciguatoxin reveals an acute anti-inflammatory, neuroprotective response

<p>Abstract</p> <p>Background</p> <p>Ciguatoxins (CTXs) are polyether marine neurotoxins and potent activators of voltage-gated sodium channels. This toxin is carried by multiple reef-fish species and human consumption of ciguatoxins can result in an explosive gastrointestinal/neurologic illness. This study characterizes the global transcriptional response in mouse brain to a symptomatic dose of the highly toxic Pacific ciguatoxin P-CTX-1 and additionally compares this data to transcriptional profiles from liver and whole blood examined previously. Adult male C57/BL6 mice were injected with 0.26 ng/g P-CTX-1 while controls received only vehicle. Animals were sacrificed at 1, 4 and 24 hrs and transcriptional profiling was performed on brain RNA with Agilent whole genome microarrays. RT-PCR was used to independently validate gene expression and the web tool DAVID was used to analyze gene ontology (GO) and molecular pathway enrichment of the gene expression data.</p> <p>Results</p> <p>A pronounced 4°C hypothermic response was recorded in these mice, reaching a minimum at 1 hr and lasting for 8 hrs post toxin exposure. Ratio expression data were filtered by intensity, fold change and p-value, with the resulting data used for time course analysis, K-means clustering, ontology classification and KEGG pathway enrichment. Top GO hits for this gene set included acute phase response and mono-oxygenase activity. Molecular pathway analysis showed enrichment for complement/coagulation cascades and metabolism of xenobiotics. Many immediate early genes such as Fos, Jun and Early Growth Response isoforms were down-regulated although others associated with stress such as glucocorticoid responsive genes were up-regulated. Real time PCR confirmation was performed on 22 differentially expressed genes with a correlation of 0.9 (Spearman's Rho, p < 0.0001) with microarray results.</p> <p>Conclusions</p> <p>Many of the genes differentially expressed in this study, in parallel with the hypothermia, figure prominently in protection against neuroinflammation. Pathologic activity of the complement/coagulation cascade has been shown in patients suffering from a chronic form of ciguatera poisoning and is of particular interest in this model. Anti-inflammatory processes were at work not only in the brain but were also seen in whole blood and liver of these animals, creating a systemic anti-inflammatory environment to protect against the initial cellular damage caused by the toxin.</p

The reliability and validity of three non-radiological measures of thoracic kyphosis and their relations to the standing radiological Cobb angle

UnlabelledHyperkyphosis is implicated in a mounting list of negative outcomes, including higher mortality. Hyperkyphosis research is hindered due to difficulties inherent in its measurement. By showing that three clinical measures of kyphosis are suitable for use in large scale, longitudinal, hyperkyphosis studies, we will facilitate much needed research in this field.IntroductionThe objective of this study is to describe the reliability of three non-radiological kyphosis measures (Debrunner kyphosis angle, flexicurve kyphosis index, and flexicurve kyphosis angle) and their validity compared to the Cobb angle and to approximate a Cobb angle from non-radiological kyphosis measures.MethodsWe analyzed data from 113 participants aged ≥ 60 years with kyphosis angle ≥ 40°. Cobb angle was measured on a standing lateral thoracolumbar radiograph using bounds at T4 and T12. Non-radiological measures of kyphosis were made three times by a single rater and a 4th time by a blinded second rater.ResultsIntra- and inter-rater reliabilities for non-radiological assessments were high (intra-class correlations of 0.96 to 0.98) and did not differ from each other. Pearson correlations, estimating validity, ranged from 0.62 to 0.69 and did not differ. The Debrunner angle was close to the Cobb angle, with scaling factor of 1.067 and an offset of 5°. The Flexicurve kyphosis angle had to be scaled by 1.53 to obtain the equivalent Cobb angle. The scaling factor for the Flexicurve kyphosis index to Cobb angle was 315, with an offset of 5°. Compared to the measured Cobb angle, Cobb angles predicted using the non-radiological measures had similar magnitude errors (standard deviations of the differences ranging between 10.24 and 11.26).ConclusionsEach non-radiological measurement had similar reliability and validity. Low cost, ease of use, and robustness to variations in spine contour argue for the Flexicurve in longitudinal kyphosis assessments. The approximate conversion factors provided will permit translation of non-radiological measures to Cobb angles