A metabarcoding comparison of taxonomic richness and composition between the water column and the benthic boundary layer

Zooplankton monitoring in shelf seas predominantly uses nets that miss the benthic boundary layer (BBL) just above the seabed. However, this boundary between pelagic and benthic assemblages can be faunistically rich, having its own distinct hyperbenthic fauna and acting as a low-light refuge for overwintering or dielly migrating zooplankton. To compare species richness and composition between pelagic and BBL habitats, we sampled a long-term monitoring site in the Western English Channel seasonally. Metabarcoding methods applied to vertical net samples (top 50 m in a �54-m water column) and those from a hyperbenthic sledge generated >100 000 sequences clustered into 294 opera�tional taxonomic units. Of these, 215 were found in the BBL and 170 in the water column. Some key taxa (e.g. mysids) were native to the BBL; by contrast, other delicate taxa (e.g. ctenophores) seemed to avoid the BBL. The major contrasts in plankton composition related to the seasonal cycle rather than to pelagic-BBL differences, suggesting that the basic dynamics of the site are captured by our ongoing long-term weekly resolution monitoring. Overall, metabarcoding approaches, applied to both water column and BBL, provide an independent view of plankton dynamics, and augment existing traditional methods

Congestive Heart Failure Leads to Prolongation of the PR Interval and Atrioventricular Junction Enlargement and Ion Channel Remodelling in the Rabbit.

Heart failure is a major killer worldwide. Atrioventricular conduction block is common in heart failure; it is associated with worse outcomes and can lead to syncope and bradycardic death. We examine the effect of heart failure on anatomical and ion channel remodelling in the rabbit atrioventricular junction (AVJ). Heart failure was induced in New Zealand rabbits by disruption of the aortic valve and banding of the abdominal aorta resulting in volume and pressure overload. Laser micro-dissection and real-time polymerase chain reaction (RT-PCR) were employed to investigate the effects of heart failure on ion channel remodelling in four regions of the rabbit AVJ and in septal tissues. Investigation of the AVJ anatomy was performed using micro-computed tomography (micro-CT). Heart failure animals developed first degree heart block. Heart failure caused ventricular myocardial volume increase with a 35% elongation of the AVJ. There was downregulation of HCN1 and Cx43 mRNA transcripts across all regions and downregulation of Cav1.3 in the transitional tissue. Cx40 mRNA was significantly downregulated in the atrial septum and AVJ tissues but not in the ventricular septum. mRNA abundance for ANP, CLCN2 and Navβ1 was increased with heart failure; Nav1.1 was increased in the inferior nodal extension/compact node area. Heart failure in the rabbit leads to prolongation of the PR interval and this is accompanied by downregulation of HCN1, Cav1.3, Cx40 and Cx43 mRNAs and anatomical enlargement of the entire heart and AVJ

Statistical modeling of ground motion relations for seismic hazard analysis

We introduce a new approach for ground motion relations (GMR) in the probabilistic seismic hazard analysis (PSHA), being influenced by the extreme value theory of mathematical statistics. Therein, we understand a GMR as a random function. We derive mathematically the principle of area-equivalence; wherein two alternative GMRs have an equivalent influence on the hazard if these GMRs have equivalent area functions. This includes local biases. An interpretation of the difference between these GMRs (an actual and a modeled one) as a random component leads to a general overestimation of residual variance and hazard. Beside this, we discuss important aspects of classical approaches and discover discrepancies with the state of the art of stochastics and statistics (model selection and significance, test of distribution assumptions, extreme value statistics). We criticize especially the assumption of logarithmic normally distributed residuals of maxima like the peak ground acceleration (PGA). The natural distribution of its individual random component (equivalent to exp(epsilon_0) of Joyner and Boore 1993) is the generalized extreme value. We show by numerical researches that the actual distribution can be hidden and a wrong distribution assumption can influence the PSHA negatively as the negligence of area equivalence does. Finally, we suggest an estimation concept for GMRs of PSHA with a regression-free variance estimation of the individual random component. We demonstrate the advantages of event-specific GMRs by analyzing data sets from the PEER strong motion database and estimate event-specific GMRs. Therein, the majority of the best models base on an anisotropic point source approach. The residual variance of logarithmized PGA is significantly smaller than in previous models. We validate the estimations for the event with the largest sample by empirical area functions. etc

Traffic-related pollution and asthma prevalence in children. Quantification of associations with nitrogen dioxide.

Ambient nitrogen dioxide is a widely available measure of traffic-related air pollution and is inconsistently associated with the prevalence of asthma symptoms in children. The use of this relationship to evaluate the health impact of policies affecting traffic management and traffic emissions is limited by the lack of a concentration-response function based on systematic review and meta-analysis of relevant studies. Using systematic methods, we identified papers containing quantitative estimates for nitrogen dioxide and the 12 month period prevalence of asthma symptoms in children in which the exposure contrast was within-community and dominated by traffic pollution. One estimate was selected from each study according to an a priori algorithm. Odds ratios were standardised to 10 μg/m(3) and summary estimates were obtained using random- and fixed-effects estimates. Eighteen studies were identified. Concentrations of nitrogen dioxide were estimated for the home address (12) and/or school (8) using a range of methods; land use regression (6), study monitors (6), dispersion modelling (4) and interpolation (2). Fourteen studies showed positive associations but only two associations were statistically significant at the 5 % level. There was moderate heterogeneity (I(2) = 32.8 %) and the random-effects estimate for the odds ratio was 1.06 (95 % CI 1.00 to 1.11). There was no evidence of small study bias. Individual studies tended to have only weak positive associations between nitrogen dioxide and asthma prevalence but the summary estimate bordered on statistical significance at the 5 % level. Although small, the potential impact on asthma prevalence could be considerable because of the high level of baseline prevalence in many cities. Whether the association is causal or indicates the effects of a correlated pollutant or other confounders, the estimate obtained by the meta-analysis would be appropriate for estimating impacts of traffic pollution on asthma prevalence

Evaluating Retinal Function in Age-Related Maculopathy with the ERG Photostress Test

PURPOSE. To evaluate the diagnostic potential of the electroretinogram (ERG) photostress test and the focal cone ERG in age-related maculopathy (ARM). METHODS. The cohort comprised 31 patients with ARM and 27 age-matched control subjects. The ERG photostress test was used to monitor cone adaptation after intense light adaptation. Focal 41- and 5-Hz cone ERGs were recorded monocularly (central 20°) to assess steady state retinal function. Univariate analysis identified electrophysiological parameters that differed between groups, and receiver operating characteristic (ROC) curves were constructed to assess their diagnostic potential. Logistic regression analysis determined the diagnostic potential of a model incorporating several independent predictors of ARM. RESULTS. The rate of recovery of the ERG photostress test was reduced (recovery was slower) in subjects with ARM. The parameter exhibited good diagnostic potential (P = 0.002, area under ROC curve = 0.74). The implicit times of the 5-Hz (a-wave, P = 0.002; b-wave, P < 0.001) and the 41-Hz (P < 0.001) focal cone ERGs were increased, and the 41-Hz focal cone ERG amplitude (P = 0.003) and focal to full-field amplitude ratio (P = 0.001) were reduced in the ARM group. Logistic regression analysis identified three independent predictors of ARM, including the rate of recovery of the ERG photostress test. CONCLUSIONS. Early ARM has a marked effect on the kinetics of cone adaptation. The clinical application of the ERG photostress test increases the sensitivity and specificity of a model for the diagnosis of ARM. Improved assessment of the functional integrity of the central retina will facilitate early diagnosis and evaluation of therapeutic interventions

Getting into hot water:sick guppies frequent warmer thermal conditions

Ectotherms depend on the environmental temperature for thermoregulation and exploit thermal regimes that optimise physiological functioning. They may also frequent warmer conditions to up-regulate their immune response against parasite infection and/or impede parasite development. This adaptive response, known as ‘behavioural fever’, has been documented in various taxa including insects, reptiles and fish, but only in response to endoparasite infections. Here, a choice chamber experiment was used to investigate the thermal preferences of a tropical freshwater fish, the Trinidadian guppy (Poecilia reticulata), when infected with a common helminth ectoparasite Gyrodactylus turnbulli, in female-only and mixed-sex shoals. The temperature tolerance of G. turnbulli was also investigated by monitoring parasite population trajectories on guppies maintained at a continuous 18, 24 or 32 °C. Regardless of shoal composition, infected fish frequented the 32 °C choice chamber more often than when uninfected, significantly increasing their mean temperature preference. Parasites maintained continuously at 32 °C decreased to extinction within 3 days, whereas mean parasite abundance increased on hosts incubated at 18 and 24 °C. We show for the first time that gyrodactylid-infected fish have a preference for warmer waters and speculate that sick fish exploit the upper thermal tolerances of their parasites to self medicate

A randomised controlled trial and cost-effectiveness evaluation of "booster" interventions to sustain increases in physical activity in middle-aged adults in deprived urban neighbourhoods

Background: Systematic reviews have identified a range of brief interventions which increase physical activity in previously sedentary people. There is an absence of evidence about whether follow up beyond three months can maintain long term physical activity. This study assesses whether it is worth providing motivational interviews, three months after giving initial advice, to those who have become more active. Methods/Design: Study candidates (n = 1500) will initially be given an interactive DVD and receive two telephone follow ups at monthly intervals checking on receipt and use of the DVD. Only those that have increased their physical activity after three months (n = 600) will be randomised into the study. These participants will receive either a "mini booster" (n = 200), "full booster" (n = 200) or no booster (n = 200). The "mini booster" consists of two telephone calls one month apart to discuss physical activity and maintenance strategies. The "full booster" consists of a face-to-face meeting with the facilitator at the same intervals. The purpose of these booster sessions is to help the individual maintain their increase in physical activity. Differences in physical activity, quality of life and costs associated with the booster interventions, will be measured three and nine months from randomisation. The research will be conducted in 20 of the most deprived neighbourhoods in Sheffield, which have large, ethnically diverse populations, high levels of economic deprivation, low levels of physical activity, poorer health and shorter life expectancy. Participants will be recruited through general practices and community groups, as well as by postal invitation, to ensure the participation of minority ethnic groups and those with lower levels of literacy. Sheffield City Council and Primary Care Trust fund a range of facilities and activities to promote physical activity and variations in access to these between neighbourhoods will make it possible to examine whether the effectiveness of the intervention is modified by access to community facilities. A one-year integrated feasibility study will confirm that recruitment targets are achievable based on a 10% sample.Discussion: The choice of study population, study interventions, brief intervention preceding the study, and outcome measure are discussed

Electrophysiological study of local/global processing in Williams syndrome

Persons with Williams syndrome (WS) demonstrate pronounced deficits in visuo-spatial processing. The purpose of the current study was to examine the preferred level of perceptual analysis in young adults with WS (n = 21) and the role of attention in the processing of hierarchical stimuli. Navon-like letter stimuli were presented to adults with WS and age-matched typical controls in an oddball paradigm where local and global targets could appear with equal probability. Participants received no explicit instruction to direct their attention toward a particular stimulus level. Behavioral and event-related potential (ERP) data were recorded. Behavioral data indicated presence of a global precedence effect in persons with WS. However, their ERP responses revealed atypical brain mechanisms underlying attention to local information. During the early perceptual analysis, global targets resulted in reduced P1 and enhanced N150 responses in both participant groups. However, only the typical comparison group demonstrated a larger N150 to local targets. At the more advanced stages of cognitive processing, a larger P3b response to global and local targets was observed in the typical group but not in persons with WS, who instead demonstrated an enhanced P3a to global targets only. The results indicate that in a perceptual task, adults with WS may experience greater than typical global-to-local interference and not allocate sufficient attentional resources to local information

Lung carcinoma with hypertrophic osteoarthropathy in a teenager

Hypertrophic osteoarthropathy (HOA) characterised by arthralgia, clubbing and periosteal proliferation of long bones, is rarely encountered in children and adolescents. Whereas in adults over 80% of cases are associated with malignancy, in children the majority of cases are due to non-neoplastic causes such as cystic fibrosis, bilary atresia and congenital heart disease. Up to 5% of adults with lung cancer demonstrate signs of HOA. However, lung cancer is extremely uncommon in children and young people. Here we report a case of lung adenocarcinoma in an 18 year old male associated with HOA present both at diagnosis and at subsequent disease progression

Water quality and planktonic microbial assemblages of isolated wetlands in an agricultural landscape

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Wetlands 31 (2011): 885-894, doi:10.1007/s13157-011-0203-6.Wetlands provide ecosystem services including flood protection, water quality enhancement, food chain support, carbon sequestration, and support regional biodiversity. Wetlands occur in human-altered landscapes, and the ongoing ability of these wetlands to provide ecosystem services is lacking. Additionally, the apparent lack of connection of some wetlands, termed geographically isolated, to permanent waters has resulted in little regulatory recognition. We examined the influence of intensive agriculture on water quality and planktonic microbial assemblages of intermittently inundated wetlands. We sampled 10 reference and 10 agriculturally altered wetlands in the Gulf Coastal Plain of Georgia. Water quality measures included pH, alkalinity, dissolved organic carbon, nutrients (nitrate, ammonium, and phosphate), and filterable solids (dry mass and ash-free dry mass). We measured abundance and relative size distribution of the planktonic microbial assemblage (< 45 μm) using flow cytometry. Water quality in agricultural wetlands was characterized by elevated nutrients, pH, and suspended solids. Autotrophic microbial cells were largely absent from both wetland types. Heterotrophic microbial abundance was influenced by nutrients and suspended matter concentration. Agriculture caused changes in microbial assemblages forming the base of wetland food webs. Yet, these wetlands potentially support important ecological services in a highly altered landscape.Funding was provided by the Joseph W. Jones Ecological Research Center.2012-07-2