303 research outputs found

    Shade as enrichment : testing preferences for shelter in two model fish species

    Get PDF
    N.A.R.J. was supported by an Fisheries Society of the British Isles studentship, F.M.J. by the St Andrews School of Biology and H.C.S.-J. by the John Templeton Foundation.We compared preferences shown by zebrafish Danio rerio and three‐spined stickleback Gasterosteus aculeatus for shelter provided by above‐tank shade and artificial plants. Zebrafish showed no preference for either shelter, whereas sticklebacks showed a preference for both shelter types over open areas and for shade over plants. Our results suggest shade may be used as enrichment for captive fish and re‐emphasise the importance of species‐specific welfare considerations.PostprintPeer reviewe

    Der Handel von Kreditrisiken: eine neue Dimension des Kapitalmarktes

    Get PDF
    This paper makes an attempt to present the economics of credit securitization in a non-technical way, starting from the description and the analysis of a typical securitization transaction. The paper sketches a theoretical explanation for why tranching, or nonproportional risk sharing, which is at the heart of securitization transactions, may allow commercial banks to maximize their shareholder value. However, the analysis makes also clear that the conditions under which credit securitization enhances welfare, are fairly restrictive, and require not only an active role of the banking supervisiory authorities, but also a price tag on the implicit insurance currently provided by the lender of last resort. Klassifikation: D82, G21, D74. February 16, 2005

    Transducers for the determination of the pressure and shear stress distribution at the stump-socket interface of trans-tibial amputees

    Get PDF
    Recent developments in prosthetic socket design have created renewed interest in monitoring the stress distribution at the socket-residual limb interface. Although a few devices for measuring pressure can be found in the literature, none are capable of measuring reliably in areas of high curvature, such as the important area at the patellar tendon bar. Furthermore, few devices can record shear stress, thought to be critical in causing tissue damage. In order to address these issues two new transducers have been designed and evaluated. One design allows the simultaneous recording of the normal and shear stresses at various points of the socket walls, while the other is capable of measuring the three components of the force applied on the patellar tendon. The latter design incorporates a feature that permits displacement of the patellar tendon bar, in order to study the effect of various amounts of indentation of the tendon on the stress distribution around the residual limb. Both transducers were calibrated using dead weights and special jigs to ensure accurate loading conditions. Under laboratory bench conditions the normal-shear force transducer showed: 2.03 per cent full scale output (FSO) hysteresis error for shear stress direction, 1.65 per cent FSO for normal direction; 99.56 per cent FSO overall accuracy for shear direction, and within 99.64 per cent FSO for normal direction; and for the patellar tendon transducer 1.53 per cent FSO hysteresis error for shear direction, 1.85 per cent FSO for shear stress direction; 99.65 per cent FSO overall accuracy for shear direction, and 99.58 per cent FSO for normal direction. During an amputee walking trial the transducers showed 92 per cent to 97 per cent repeatability. The two new transducers were used in conjunction with two other types of transducers, previously designed at the University of Strathclyde, in a series of tests on ten trans-tibial amputees. Sample results for walking activities and a summary of maximum stresses recorded are presented

    The state of the Martian climate

    Get PDF
    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

    Mapping immune variation and var gene switching in naive hosts infected with Plasmodium falciparum

    Get PDF
    Falciparum malaria is clinically heterogeneous and the relative contribution of parasite and host in shaping disease severity remains unclear. We explored the interaction between inflammation and parasite variant surface antigen (VSA) expression, asking whether this relationship underpins the variation observed in controlled human malaria infection (CHMI). We uncovered marked heterogeneity in the host response to blood challenge; some volunteers remained quiescent, others triggered interferon-stimulated inflammation and some showed transcriptional evidence of myeloid cell suppression. Significantly, only inflammatory volunteers experienced hallmark symptoms of malaria. When we tracked temporal changes in parasite VSA expression to ask whether variants associated with severe disease rapidly expand in naive hosts, we found no transcriptional evidence to support this hypothesis. These data indicate that parasite variants that dominate severe malaria do not have an intrinsic growth or survival advantage; instead, they presumably rely upon infection-induced changes in their within-host environment for selection

    Defining the Effect of the 16p11.2 Duplication on Cognition, Behavior, and Medical Comorbidities.

    Get PDF
    IMPORTANCE: The 16p11.2 BP4-BP5 duplication is the copy number variant most frequently associated with autism spectrum disorder (ASD), schizophrenia, and comorbidities such as decreased body mass index (BMI). OBJECTIVES: To characterize the effects of the 16p11.2 duplication on cognitive, behavioral, medical, and anthropometric traits and to understand the specificity of these effects by systematically comparing results in duplication carriers and reciprocal deletion carriers, who are also at risk for ASD. DESIGN, SETTING, AND PARTICIPANTS: This international cohort study of 1006 study participants compared 270 duplication carriers with their 102 intrafamilial control individuals, 390 reciprocal deletion carriers, and 244 deletion controls from European and North American cohorts. Data were collected from August 1, 2010, to May 31, 2015 and analyzed from January 1 to August 14, 2015. Linear mixed models were used to estimate the effect of the duplication and deletion on clinical traits by comparison with noncarrier relatives. MAIN OUTCOMES AND MEASURES: Findings on the Full-Scale IQ (FSIQ), Nonverbal IQ, and Verbal IQ; the presence of ASD or other DSM-IV diagnoses; BMI; head circumference; and medical data. RESULTS: Among the 1006 study participants, the duplication was associated with a mean FSIQ score that was lower by 26.3 points between proband carriers and noncarrier relatives and a lower mean FSIQ score (16.2-11.4 points) in nonproband carriers. The mean overall effect of the deletion was similar (-22.1 points; P < .001). However, broad variation in FSIQ was found, with a 19.4- and 2.0-fold increase in the proportion of FSIQ scores that were very low (≤40) and higher than the mean (>100) compared with the deletion group (P < .001). Parental FSIQ predicted part of this variation (approximately 36.0% in hereditary probands). Although the frequency of ASD was similar in deletion and duplication proband carriers (16.0% and 20.0%, respectively), the FSIQ was significantly lower (by 26.3 points) in the duplication probands with ASD. There also were lower head circumference and BMI measurements among duplication carriers, which is consistent with the findings of previous studies. CONCLUSIONS AND RELEVANCE: The mean effect of the duplication on cognition is similar to that of the reciprocal deletion, but the variance in the duplication is significantly higher, with severe and mild subgroups not observed with the deletion. These results suggest that additional genetic and familial factors contribute to this variability. Additional studies will be necessary to characterize the predictors of cognitive deficits
    corecore