3,161 research outputs found

    DNA extraction from museum specimens of parasitic Hymenoptera.

    Get PDF
    At the same time that molecular researchers are improving techniques to extract DNA from museum specimens, this increased demand for access to museum specimens has created tension between the need to preserve specimens for maintaining collections and morphological research and the desire to conduct molecular analyses. To address these concerns, we examined the suitability of non-invasive DNA extraction techniques on three species of parasitic Hymenoptera (Braconidae), and test the effects of body size (parasitoid species), age (time since collection), and DNA concentration from each extract on the probability of amplifying meaningful fragments of two commonly used genetic loci. We found that age was a significant factor for determining the probability of success for sequencing both 28S and COI fragments. While the size of the braconid parasitoids significantly affected the total amount of extracted DNA, neither size nor DNA concentration were significant factors for the amplification of either gene region. We also tested several primer combinations of various lengths, but were unable to amplify fragments longer than ~150 base pairs. These short fragments of 28S and COI were however sufficient for species identification, and for the discovery of within species genetic variation

    Is the UK productivity slowdown unprecedented?

    Get PDF
    We estimate trend UK labour productivity growth using a Hodrick-Prescott filter method. We use the results to compare downturns where the economy fell below its pre-existing trend. We find that the current productivity slowdown has resulted in productivity being 19.7 per cent below the pre-2008 trend path in 2018. This is nearly double the previous worst productivity shortfall ten years after the start of a downturn. On this criterion the slowdown is unprecedented in the past 250 years. We conjecture that this reflects a combination of adverse circumstances, namely, a financial crisis, a weakening impact of ICT and impending Brexit

    The Effect of Excuses on Customers\u27 Perceptions of Service Agents rollowing Service Delays

    Get PDF
    The purpose of this study is twofold. The first purpose is to determine whether a service agent, using impression, management techniques, can change the attributions customers make and thereby reduce or even eliminate the negative emotions experienced by customers who are forced to wait longer than they had expected. The second purpose is to determine whether the subjects attend to information contained in the accounts provided by the service agent, or whether an excuse script is activated and verbal content ignored. In other words, are accounts offered for a delay subject to Langer et al.\u27s (1978) concept of mindlessness

    SCALABLE CAPABILITY-BASED AUTHORIZATION FOR HIGH-PERFORMANCE PARALLEL FILE SYSTEMS

    Get PDF
    As the size and scale of supercomputers continues to increase at an exponential rate the number of users on a given supercomputer will only grow larger. A larger number of users on a supercomputer places a greater importance on the strength of information security. Nowhere is this requirement for security more apparent than the file system, as users expect their data to be protected from accidental or deliberate modification. In spite of the ever-increasing demand for more secure file system access the majority of parallel file systems do not implement a robust security protocol for fear it will negatively impact the performance and scalability of the file system. We provide a capability-based security protocol for use in high-performance parallel file systems that is capable of meeting the performance and scalability requirements of current and future supercomputers. We develop a reference implementation for the Parallel Virtual File System and show its performance characteristics using several microbenchmarks. Our test results show that capability-based security is capable of protecting access to parallel file system objects, in some cases with little overhead

    A Review of Alt-Right Gangs: A Hazy Shade of White by Shannon E. Reid and Matthew Valasik

    Get PDF
    No abstract available

    Small-scale intraspecific life history variation in herbivorous spider mites (Tetranychus pacificus) is associated with host plant cultivar.

    Get PDF
    Life history variation is a general feature of arthropod systems, but is rarely included in models of field or laboratory data. Most studies assume that local processes occur identically across individuals, ignoring any genetic or phenotypic variation in life history traits. In this study, we tested whether field populations of Pacific spider mites (Tetranychus pacificus) on grapevines (Vitis vinifera) display significant intraspecific life history variation associated with host plant cultivar. To address this question we collected individuals from sympatric vineyard populations where either Zinfandel or Chardonnay were grown. We then conducted a "common garden experiment" of mites on bean plants (Phaseolus lunatus) in the laboratory. Assay populations were sampled non-destructively with digital photography to quantify development times, survival, and reproductive rates. Two classes of models were fit to the data: standard generalized linear mixed models and a time-to-event model, common in survival analysis, that allowed for interval-censored data and hierarchical random effects. We found a significant effect of cultivar on development time in both GLMM and time-to-event analyses, a slight cultivar effect on juvenile survival, and no effect on reproductive rate. There were shorter development times and a trend towards higher juvenile survival in populations from Zinfandel vineyards compared to those from Chardonnay vineyards. Lines of the same species, originating from field populations on different host plant cultivars, expressed different development times and slightly different survival rates when reared on a common host plant in a common environment

    Does Hydrotherapy Impact Behaviours Related to Mental Health and Well-Being for Children with Autism Spectrum Disorder? A Randomised Crossover-Controlled Pilot Trial

    Get PDF
    Background: Children diagnosed with Autism Spectrum Disorder (ASD) are less physically active than typically developing children due to reduced socialisation and delayed gross-motor skills, negatively impacting social, emotional and physical well-being. This study aimed to determine whether hydrotherapy influences behaviours which impact mental health and well-being in children with ASD. Methods: A within-subjects, randomised crossover-controlled pilot trial was used over 8 weeks. Children aged 6–12 years and diagnosed with ASD (n = 8) were randomly allocated to Group 1 (n = 4) or Group 2 (n = 4). All children participated in hydrotherapy intervention from either weeks 1 to 4 or weeks 5 to 8. The Child Behaviour Checklist (CBCL) measured behaviour changes impacting mental health and well-being, administered at weeks 0, 4 and 8. Results: No observable differences were found in CBCL subscales between Group 1 or 2 at baseline (week 0). Paired-samples t-tests revealed significant improvements post-intervention: Anxious/Depressed subdomain (p = 0.02) and the Internalising Problems Domain Summary (p = 0.026), with large effect size (d = 1.03 and d = 1.06 respectively). Thought Problems (p = 0.03) and Attention Problems (p = 0.01) both significantly improved post-intervention. The Total Problems score significantly improved post-intervention (p = 0.018) with a large effect size (d = 1.04). Conclusion: Hydrotherapy may enhance behaviours impacting mental health and well-being of children with ASD and could be considered a beneficial therapy option
    corecore