Identifying trophic variation in a marine suspension feeder:DNA- and stable isotope-based dietary analysis in Mytilus spp.

Accurate field data on trophic interactions for suspension feeders are lacking, and new approaches to dietary analysis are necessary. Polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) was integrated with stable isotope analysis to examine dietary patterns in suspension-feeding Mytilus spp. from seven spatially discrete locations within a semi-enclosed marine bay (Strangford Lough, Northern Ireland) during June 2009. Results of the two methods were highly correlated, reflecting dietary variation in a similar manner. Variation in PCR-DGGE data was more strongly correlated with the principal environmental gradient (distance from the opening to the Irish Sea), while values of dC and dN became progressively enriched, suggesting a greater dependence on animal tissue and benthic microalgae. Diatoms and crustaceans were the most frequently observed phylotypes identified by sequencing, but specific DNA results provided little support for the trophic trends observed in the stable isotope data. This combined approach offers an increased level of trophic insight for suspension feeders and could be applied to other organisms. © 2012 Springer-Verlag Berlin Heidelberg.

Metal Oxide Nanoparticle Mediated Enhanced Raman Scattering and Its Use in Direct Monitoring of Interfacial Chemical Reactions

Metal oxide nanoparticles (MONPs) have widespread usage across many disciplines, but monitoring molecular processes at their surfaces in situ has not been possible. Here we demonstrate that MONPs give highly enhanced (X10(4)) Raman scattering signals from molecules at the interface permitting direct monitoring of their reactions, when placed on top of flat metallic surfaces. Experiments with different metal oxide materials and molecules indicate that the enhancement is generic and operates at the single nanoparticle level. Simulations confirm that the amplification is principally electromagnetic and is a result of optical modulation of the underlying plasmonic metallic surface by MONPs, which act as scattering antennae and couple light into the confined region sandwiched by the underlying surface. Because of additional functionalities of metal oxides as magnetic, photoelectrochemical and catalytic materials, enhanced Raman scattering mediated by MONPs opens up significant opportunities in fundamental science, allowing direct tracking and understanding of application-specific transformations at such interfaces. We show a first example by monitoring the MONP-assisted photocatalytic decomposition reaction of an organic dye by individual nanoparticles.

A direct physiological trade-off between personal and social immunity

1. Recent work shows that organisms possess two strategies of immune response: personal immunity, which defends an individual, and social immunity, which protects other individuals, such as kin. However, it is unclear how individuals divide their limited resources between protecting themselves and protecting others.
2. Here, with experiments on female burying beetles, we challenged the personal immune system and measured subsequent investment in social immunity (antibacterial activity of the anal exudates).
3. Our results show that increased investment in one aspect of personal immunity (wound repair) causes a temporary decrease in one aspect of the social immune response.
4. Our experiments further show that by balancing investment in personal and social immunity in this way during one breeding attempt, females are able to defend their subsequent lifetime reproductive success.
5. We discuss the nature of the physiological trade-off between personal and social immunity in species that differ in the degree of eusociality and coloniality, and suggest that it may also vary within species in relation to age and partner contributions to social immunity.

A Unified Scheduler for Recursive and Task Dataflow Parallelism

Task dataflow languages simplify the specification of parallel programs by dynamically detecting and enforcing dependencies between tasks. These languages are, however, often restricted to a single level of parallelism. This language design is reflected in the runtime system, where a master thread explicitly generates a task graph and worker threads execute ready tasks and wake-up their dependents. Such an approach is incompatible with state-of-the-art schedulers such as the Cilk scheduler, that minimize the creation of idle tasks (work-first principle) and place all task creation and scheduling off the critical path. This paper proposes an extension to the Cilk scheduler in order to reconcile task dependencies with the work-first principle. We discuss the impact of task dependencies on the properties of the Cilk scheduler. Furthermore, we propose a low-overhead ticket-based technique for dependency tracking and enforcement at the object level. Our scheduler also supports renaming of objects in order to increase task-level parallelism. Renaming is implemented using versioned objects, a new type of hyper object. Experimental evaluation shows that the unified scheduler is as efficient as the Cilk scheduler when tasks have no dependencies. Moreover, the unified scheduler is more efficient than SMPSS, a particular implementation of a task dataflow language.

Behavioural and physiological responses of heifer calves to acute stressors: long-term consistency and relationship with adult reactivity to milking

The present study investigated the long-term consistency of individual differences in dairy cattles’ responses in tests of behavioural and hypothalamo–pituitary–adrenocortical (HPA) axis reactivity, as well as the relationship between responsiveness in behavioural tests and the reaction to first milking. Two cohorts of heifer calves, Cohorts 1 (N = 25) and 2 (N = 16), respectively, were examined longitudinally from the rearing period until adulthood. Cohort 1 heifers were subjected to open field (OF), novel object (NO), restraint, and response to a human tests at 7 months of age, and were again observed in an OF test during first pregnancy between 22 and 24 months of age. Subsequently, inhibition of milk ejection and stepping and kicking behaviours were recorded in Cohort 1 heifers during their first machine milking. Cohort 2 heifers were individually subjected to OF and NO tests as well as two HPA axis reactivity tests (determining ACTH and/or cortisol response profiles after administration of exogenous CRH and ACTH, respectively) at 6 months of age and during first lactation at approximately 29 months of age. Principal component analysis (PCA) was used to condense correlated response measures (to behavioural tests and to milking) within ages into independent dimensions underlying heifers’ reactivity. Heifers demonstrated consistent individual differences in locomotion and vocalisation during an OF test from rearing to first pregnancy (Cohort 1) or first lactation (Cohort 2). Individual differences in struggling in a restraint test at 7 months of age reliably predicted those in OF locomotion during first pregnancy in Cohort 1 heifers. Cohort 2 animals with high cortisol responses to OF and NO tests and high avoidance of the novel object at 6 months of age also exhibited enhanced cortisol responses to OF and NO tests at 29 months of age. Measures of HPA axis reactivity, locomotion, vocalisation and adrenocortical and behavioural responses to novelty were largely uncorrelated, supporting the idea that stress responsiveness in dairy cows is mediated by multiple independent underlying traits. Inhibition of milk ejection and stepping and kicking behaviours during first machine milking were not related to earlier struggling during restraint, locomotor responses to OF and NO tests, or the behavioural interaction with a novel object. Heifers with high rates of OF and NO vocalisation and short latencies to first contact with the human at 7 months of age exhibited better milk ejection during first machine milking. This suggests that low underlying sociality might be implicated in the inhibition of milk ejection at the beginning of lactation in heifers.

Development and Validation of a PulseNet Standardized Protocol for Subtyping Isolates of Cronobacter Species

Cronobacter (formerly known as Enterobacter sakazakii) is a genus comprising seven species regarded as opportunistic pathogens that can be found in a wide variety of environments and foods, including powdered infant formula (PIF). Cronobacter sakazakii, the major species of this genus, has been epidemiologically linked to cases of bacteremia, meningitis in neonates, and necrotizing enterocolitis, and contaminated PIF has been identified as an important source of infection. Robust and reproducible subtyping methods are required to aid in the detection and investigation, of foodborne outbreaks. In this study, a pulsed-field gel electrophoresis (PFGE) protocol was developed and validated for subtyping Cronobacter species. It was derived from an existing modified PulseNet protocol, wherein XbaI and SpeI were the primary and secondary restriction enzymes used, generating an average of 14.7 and 20.3 bands, respectively. The PFGE method developed was both reproducible and discriminatory for subtyping Cronobacter species.

The influence of market deregulation on fast food consumption and body mass index:A cross-national time series analysis

Objective
To investigate the effect of fast food consumption on mean population body mass index (BMI) and explore the possible influence of market deregulation on fast food consumption and BMI.

Methods
The within-country association between fast food consumption and BMI in 25 high-income member countries of the Organisation for Economic Co-operation and Development between 1999 and 2008 was explored through multivariate panel regression models, after adjustment for per capita gross domestic product, urbanization, trade openness, lifestyle indicators and other covariates. The possible mediating effect of annual per capita intake of soft drinks, animal fats and total calories on the association between fast food consumption and BMI was also analysed. Two-stage least squares regression models were conducted, using economic freedom as an instrumental variable, to study the causal effect of fast food consumption on BMI.

Findings
After adjustment for covariates, each 1-unit increase in annual fast food transactions per capita was associated with an increase of 0.033 kg/m2 in age-standardized BMI (95% confidence interval, CI: 0.013–0.052). Only the intake of soft drinks – not animal fat or total calories – mediated the observed association (β: 0.030; 95% CI: 0.010–0.050). Economic freedom was an independent predictor of fast food consumption (β: 0.27; 95% CI: 0.16–0.37). When economic freedom was used as an instrumental variable, the association between fast food and BMI weakened but remained significant (β: 0.023; 95% CI: 0.001–0.045).

Conclusion
Fast food consumption is an independent predictor of mean BMI in high-income countries. Market deregulation policies may contribute to the obesity epidemic by facilitating the spread of fast food.

Enrichment of low-abundance proteins from bovine and porcine serum samples for proteomic studies

One of the main applications of serum proteomics is the identification of new biomarkers for animal disease or animal production. However, potential obstacles to these studies are the poor performance of affinity serum depletion methods based on human antigens when using animal samples, and loss of minor serum components bound to albumin and other proteins. In the present study, we have analyzed the efficiency and reproducibility of the ProteoMiner® beads with bovine and porcine serum samples, and compared to a traditional immunoaffinity-based albumin and IgG depletion system specific for human samples. The ProteoMiner kit is based on the use of a combinatorial peptide binding library and intends to enrich low-abundance proteins.

Low-power DWT-based quasi-averaging algorithm and architecture for epileptic seizure detection

In this paper, we have developed a low-complexity algorithm for epileptic seizure detection with a high degree of accuracy. The algorithm has been designed to be feasibly implementable as battery-powered low-power implantable epileptic seizure detection system or epilepsy prosthesis. This is achieved by utilizing design optimization techniques at different levels of abstraction. Particularly, user-specific critical parameters are identified at the algorithmic level and are explicitly used along with multiplier-less implementations at the architecture level. The system has been tested on neural data obtained from in-vivo animal recordings and has been implemented in 90nm bulk-Si technology. The results show up to 90 % savings in power as compared to prevalent wavelet based seizure detection technique while achieving 97% average detection rate. Copyright 2010 ACM.

An efficacy and mechanism evaluation study of Levosimendan for the Prevention of Acute oRgan Dysfunction in Sepsis (LeoPARDS): Protocol for a randomized controlled trial

Background

Organ dysfunction consequent to infection (‘severe sepsis’) is the leading cause of admission to an intensive care unit (ICU). In both animal models and early clinical studies the calcium channel sensitizer levosimendan has been demonstrated to have potentially beneficial effects on organ function. The aims of the Levosimendan for the Prevention of Acute oRgan Dysfunction in Sepsis (LeoPARDS) trial are to identify whether a 24-hour infusion of levosimendan will improve organ dysfunction in adults who have septic shock and to establish the safety profile of levosimendan in this group of patients.

This is a multicenter, randomized, double-blind, parallel group, placebo-controlled trial. Adults fulfilling the criteria for systemic inflammatory response syndrome due to infection, and requiring vasopressor therapy, will be eligible for inclusion in the trial. Within 24 hours of meeting these inclusion criteria, patients will be randomized in a 1:1 ratio stratified by the ICU to receive either levosimendan (0.05 to 0.2 μg.kg^-1.min^-1 or placebo for 24 hours in addition to standard care. The primary outcome measure is the mean Sequential Organ Failure Assessment (SOFA) score while in the ICU. Secondary outcomes include: central venous oxygen saturations and cardiac output; incidence and severity of renal failure using the Acute Kidney Injury Network criteria; duration of renal replacement therapy; serum bilirubin; time to liberation from mechanical ventilation; 28-day, hospital, 3 and 6 month survival; ICU and hospital length-of-stay; and days free from catecholamine therapy. Blood and urine samples will be collected on the day of inclusion, at 24 hours, and on days 4 and 6 post-inclusion for investigation of the mechanisms by which levosimendan might improve organ function. Eighty patients will have additional blood samples taken to measure levels of levosimendan and its active metabolites OR-1896 and OR-1855. A total of 516 patients will be recruited from approximately 25 ICUs in the United Kingdom.

This trial will test the efficacy of levosimendan to reduce acute organ dysfunction in adult patients who have septic shock and evaluate its biological mechanisms of action.

Environmental filtering vs. resource-based niche partitioning in diverse soil animal assemblages

Terrestrial invertebrates constitute most of described animal biodiversity and soil is a major reservoir of this diversity. In the classical attempt to understand the processes supporting biodiversity, ecologists are currently seeking to unravel the differential roles of environmental filtering and competition for resources in niche partitioning processes: these processes are in principle distinct although they may act simultaneously, interact at multiple spatial and temporal scales, and are often confounded in studies of soil communities. We used a novel combination of methods based on stable isotopes and trait analysis to resolve these processes in diverse oribatid mite assemblages at spatial
scales at which competition for resources could in principle be a major driver. We also used a null model approach based on a general neutral model of beta diversity. A large and significant fraction of community variation was explainable in terms of linear and periodic spatial structures in the distribution of organic C, N and soil structure: species were clearly arranged along an environmental, spatially structured gradient. However, competition related trait differences did not map onto the distances separating species along the environmental gradient and neutral models provided a satisfying approximation of beta diversity patterns. The results represent the first robust evidence
that in very diverse soil arthropod assemblages resource-based niche partitioning plays a minor role while environmental filtering remains a fundamental driver of species distribution.

AgriSense: Multichannel disposable sensors for animal health disease diagnostics

Rapid and sensitive detection of viral infections associated with Bovine Respiratory Disease (BRD) in live animals is recognized as key to minimizing the impact of this disease. ELISA-based testing is limited as it typically relies on the detection of a single viral antibody subtype within an individual test sample and testing is relatively slow and expensive. We have recently initiated a new project entitled AgriSense to develop a novel low-cost and label-free, integrated bimodal electronic biosensor system for BRD. The biosensor system will consist of an integrated multichannel thin-film-transistor biosensor and an electrochemical impedance spectroscopy biosensor, interfaced with PDMS-based microfluidic sample delivery channels. By using both sensors in tandem, nonspecific binding biomolecules must have the same mass to charge ratio as the target analyte to elicit equivalent responses from both sensors. The system will target simultaneous multiplexed sensing of the four primary viral agents involved in the development of BRD: bovine herpesvirus-1 (BHV-1), bovine parainfluenza virus-3 (BPIV-3), bovine respiratory syncytial virus (BRSV), and bovine viral diarrhea (BVD). Optimized experimental conditions derived through model antigen-antibody studies will be applied to the detection of serological markers of BRD-related infections based on IgG interaction with a panel of sensor-immobilized viral proteins. This rapid, “cowside” multiplex sensor capability presents a major step forward in disease diagnosis, helping to ensure the integrity of the agri-food supply chain by reducing the risk of disease spread during animal movement and transport.

The ones that come ready made:The identification and use of Sus tusks as tools at prehistoric cave sites in Malaysia

Evidence for osseous technologies has featured in excavation reports from Southeast Asia for almost a century and from archaeological deposits as old as 43,000 years BP. However, in contrast to the significance that is placed on this technology in other parts of the world, until recently, Southeast Asian assemblages have drawn only very limited attention. Concentrating on evidence from Malaysia, the current paper examines one element of this inventory of tools: the deliberate modification of pig canines and the means by which such alteration can be distinguished from patterns of natural tooth wear. Particular attention is paid to the bearded pig (Sus barbatus), as it is one of the two species of wild boar in Malaysia whose tusks are most likely to have been used by prehistoric toolmakers. Reference is also made to wider, regional ethnographic examples of known tusk implements and their accredited uses to further assist in the identification process. Distinguishing criteria for worked tusk are formulated according to the type and extent of modification. These criteria are then applied to archaeological specimens recovered from two prehistoric cave sites in Malaysia, Gua Bintong and Niah Cave.