Ecological correlates of sociality in Pemphigus aphids, with a partial phylogeny of the genus

Background: Because the systems of social organisation in the various species of Pemphigus aphids span the continuum from asociality through to advanced sociality (typified by the possession of morphologically specialised soldiers), the genus is an ideal model clade in which to study the influence of ecology on the origins of eusociality. We made detailed study of the ecology of three gall-dwelling species that show clear differences in their levels of social behaviour. To elucidate evolutionary relationships and to attempt to estimate the number of origins of sociality, we also created a phylogeny based on sequences spanning the mitochondrial genes Cytochrome Oxidase I and II for nine species of Pemphigus. Results: P. spyrothecae, a highly social species with aggressive morphologically-specialised soldiers, has the longest galling phase, unsynchronised development of a large number of individuals in a densely-populated gall, and an extended period over which alates emerge. P. populi, a species with no soldiers, has the shortest galling phase, synchronised development of a small number of individuals in a sparsely-populated gall, and an extremely brief emergence period. The ecology of P. bursarius, which has behavioural soldiers that are not morphologically specialised, is intermediate between these two extremes. The galls of P. spyrothecae and P. bursarius form small openings during the course of the season and predation-related mortality is relatively high in these two species. Conversely, predation does not occur during the galling phase of P. populi, which has no soldiers but makes an entirely-sealed gall. The phylogeny allowed us to infer one likely point of origin of basic social defence and two independent origins of enhanced defence. Based on current knowledge of behaviour, the phylogeny also suggests that the defence trait may have been lost at least once. Conclusion: The life-history strategy of P. spyrothecae appears to be geared towards defending the colony against the constant threat of predation that faces the inhabitants of a long-lived, open gall. The life-history strategy of P. populi, on the other hand, is to avoid predation in the closed gall fortress and flee for the secondary host at the earliest opportunity. The life-history strategy of P. bursarius appears to represent a compromise between these strategies

Novel Aerofoils used for Reducing Energy Consumption and Improving Temperature Performance for Multi-Deck Refrigerated Display Cabinets

The paper presents a study of the impact of using air guides attached to the front of the shelves in an open fronted multi-deck refrigerated display cabinet (ODC). A 2D computational fluid dynamics (CFD) model of an ODC was created. The infiltration heat loads with and without the guides were predicted. A higher infiltration heat load without the guides was predicted than when the guides were fitted. The reduction in entrainment was predicted to be 34% equating to an overall reduction in heat load of 24%. Two cabinets were tested with and without the guides to the EN23953 test standard. Adding the air guides reduced the maximum temperature test pack by 0.6ºC as well as reducing the energy consumption by 15%. When the cabinet controller was adjusted so that the maximum pack temperatures were the same for the two tests, the aerofoils reduced energy consumption by 17%

Temperature control in domestic refrigerators and freezers

Temperature control of food in the home is vitally important. In the past decade there have been 15 published surveys of temperatures in domestic refrigerators. The last detailed survey carried out in the UK was in 1991. Refrigerators are now fitted with lower power compressors and thicker insulation to enable them to achieve low energy consumption. Therefore there is a possibility that due to these changes, temperatures in domestic refrigerators have changed. This paper reports results from a survey of currently used domestic refrigerators and compares the results to those obtained in 1991. In addition the paper examines temperatures in domestic freezers. Although freezers pose less of a food safety risk they do contribute to poor food quality and potential waste if the food is not maintained at low enough conditions. None of the surveys published to date examines temperatures in domestic freezers

Mathematical Modelling Of Air Cycle Systems For Combined Heating And Cooling

Air cycle systems produce significant quantities of relatively high grade heat, allowing them to be employed in combined cooking and cooling of suitable food products. A recent study assembled an experimental air cycle apparatus from readily available components from the aircraft air conditioning and food industries. Its design was assisted by development of a mathematical model based on performance characteristics of the main components. It was apparent from the model that the available bootstrap was not capable of balanced operation at the extremes of high and low temperatures required. The model was used to identify and assess modifications to balance the flow. The experimental apparatus was built based on the best option, and test results used to validate the model. The model was then extended in a further study to assess the improvements to system performance likely to result from use of a purpose-built bootstrap and other optimised components (termed ‘ideal’ components)

Masculinity, racism, social support, and colorectal cancer screening uptake among African American men: A systematic review

Colorectal cancer (CRC) is highly preventable when CRC screening is utilized, yet CRC screening completion among African American men is relatively low and their mortality rates remain 50% higher juxtaposed to their White counterparts. Since a growing body of literature indicates masculinity, racism, and social support each have strong influences on CRC screening uptake, this systematic review examined the connections between these three sociocultural factors and CRC screening uptake among African American men. Potential studies were retrieved from MEDLINE, CINAHL, EMBASE, and PsycINFO. Cited reference searching for the final sample was employed to identify and assess additional studies for inclusion using Scopus. The methodological quality of the reviewed evidence was also evaluated. Nineteen studies met inclusion/exclusion criteria. Thirteen studies employed nonexperimental research designs; a quasi-experimental design was present in four, and two utilized experimental designs. Studies were published between 2000 and 2014; the majority between 2009 and 2013. Social support was most frequently addressed (84%) while masculinity and racism were equally studied with paucity (11%) for their influence on CRC screening. After evaluating conceptual and methodological characteristics of the studies, 42% fell below average in quality and rigor. The need for increased attention to the sociocultural correlates of CRC screening for African American men are highlighted in this systematic review, and important recommendations for research and practice are provided. Alongside a call for more rigorous research, further research examining the influence of masculinity and racism on CRC screening completion among African American men is warrante

Completeness and Incompleteness of Synchronous Kleene Algebra

Synchronous Kleene algebra (SKA), an extension of Kleene algebra (KA), was proposed by Prisacariu as a tool for reasoning about programs that may execute synchronously, i.e., in lock-step. We provide a countermodel witnessing that the axioms of SKA are incomplete w.r.t. its language semantics, by exploiting a lack of interaction between the synchronous product operator and the Kleene star. We then propose an alternative set of axioms for SKA, based on Salomaa's axiomatisation of regular languages, and show that these provide a sound and complete characterisation w.r.t. the original language semantics.Comment: Accepted at MPC 201

Glucose enhancement of memory is modulated by trait anxiety in healthy adolescent males

Glucose administration is associated with memory enhancement in healthy young individuals under conditions of divided attention at encoding. While the specific neurocognitive mechanisms underlying this ‘glucose memory facilitation effect’ are currently uncertain, it is thought that individual differences in glucoregulatory efficiency may alter an individual’s sensitivity to the glucose memory facilitation effect. In the present study, we sought to investigate whether basal hypothalamic–pituitary–adrenal axis function (itself a modulator of glucoregulatory efficiency), baseline self-reported stress and trait anxiety influence the glucose memory facilitation effect. Adolescent males (age range = 14–17 years) were administered glucose and placebo prior to completing a verbal episodic memory task on two separate testing days in a counter-balanced, within-subjects design. Glucose ingestion improved verbal episodic memory performance when memory recall was tested (i) within an hour of glucose ingestion and encoding, and (ii) one week subsequent to glucose ingestion and encoding. Basal hypothalamic–pituitary–adrenal axis function did not appear to influence the glucose memory facilitation effect; however, glucose ingestion only improved memory in participants reporting relatively higher trait anxiety. These findings suggest that the glucose memory facilitation effect may be mediated by biological mechanisms associated with trait anxiety

Derivation and validation of a simple, accurate and robust prediction rule for risk of mortality in patients with Clostridium difficile infection.

Published onlineJournal ArticleResearch Support, Non-U.S. Gov'tBACKGROUND: Clostridium difficile infection poses a significant healthcare burden. However, the derivation of a simple, evidence based prediction rule to assist patient management has not yet been described. METHOD: Univariate, multivariate and decision tree procedures were used to deduce a prediction rule from over 186 variables; retrospectively collated from clinical data for 213 patients. The resulting prediction rule was validated on independent data from a cohort of 158 patients described by Bhangu et al. (Colorectal Disease, 12(3):241-246, 2010). RESULTS: Serum albumin levels (g/L) (P = 0.001), respiratory rate (resps /min) (P = 0.002), C-reactive protein (mg/L) (P = 0.034) and white cell count (mcL) (P = 0.049) were predictors of all-cause mortality. Threshold levels of serum albumin ≤ 24.5 g/L, C- reactive protein >228 mg/L, respiratory rate >17 resps/min and white cell count >12 × 10(3) mcL were associated with an increased risk of all-cause mortality. A simple four variable prediction rule was devised based on these threshold levels and when tested on the initial data, yield an area under the curve score of 0.754 (P < 0.001) using receiver operating characteristics. The prediction rule was then evaluated using independent data, and yield an area under the curve score of 0.653 (P = 0.001). CONCLUSIONS: Four easily measurable clinical variables can be used to assess the risk of mortality of patients with Clostridium difficile infection and remains robust with respect to independent data.This work was funded by University of Exeter, Systems Biology Initiative, a small grants fund from the RD&E NHS Trust and The National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula (PenCLAHRC). This article presents independent research funded by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care (CLAHRC) for the South West Peninsula. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health in England

Elastin is Localised to the Interfascicular Matrix of Energy Storing Tendons and Becomes Increasingly Disorganised With Ageing

Tendon is composed of fascicles bound together by the interfascicular matrix (IFM). Energy storing tendons are more elastic and extensible than positional tendons; behaviour provided by specialisation of the IFM to enable repeated interfascicular sliding and recoil. With ageing, the IFM becomes stiffer and less fatigue resistant, potentially explaining why older tendons become more injury-prone. Recent data indicates enrichment of elastin within the IFM, but this has yet to be quantified. We hypothesised that elastin is more prevalent in energy storing than positional tendons, and is mainly localised to the IFM. Further, we hypothesised that elastin becomes disorganised and fragmented, and decreases in amount with ageing, especially in energy storing tendons. Biochemical analyses and immunohistochemical techniques were used to determine elastin content and organisation, in young and old equine energy storing and positional tendons. Supporting the hypothesis, elastin localises to the IFM of energy storing tendons, reducing in quantity and becoming more disorganised with ageing. These changes may contribute to the increased injury risk in aged energy storing tendons. Full understanding of the processes leading to loss of elastin and its disorganisation with ageing may aid in the development of treatments to prevent age related tendinopathy

Consenting to health record linkage: evidence from a multi-purpose longitudinal survey of a general population

Background: The British Household Panel Survey (BHPS) is the first long-running UK longitudinal survey with a non-medical focus and a sample covering the whole age range to have asked for permission to link to a range of administrative health records. This study determines whether informed consent led to selection bias and reflects on the value of the BHPS linked with health records for epidemiological research. Methods. Multivariate logistical regression is used, with whether the respondent gave consent to data linkage or not as the dependent variable. Independent variables were entered as four blocks; (i) a set of standard demographics likely to be found in most health registration data, (ii) a broader set of socio-economic characteristics, (iii) a set of indicators of health conditions and (iv) information about the use of health services. Results: Participants aged 16-24, males and those living in England were more likely to consent. Consent is not biased with respect to socio-economic characteristics or health. Recent users of GP services are underrepresented among consenters. Conclusions: Whilst data could only be linked for a minority of BHPS participants, the BHPS offers a great range of information on people's life histories, their attitudes and behaviours making it an invaluable source for epidemiological research. © 2012 Knies et al; licensee BioMed Central Ltd