72 research outputs found
Estimation of genetic variation in residual variance in female and male broiler chickens
In breeding programs, robustness of animals and uniformity of end product can be improved by exploiting genetic variation in residual variance. Residual variance can be defined as environmental variance after accounting for all identifiable effects. The aims of this study were to estimate genetic variance in residual variance of body weight, and to estimate genetic correlations between body weight itself and its residual variance and between female and male residual variance for broilers. The data sets comprised 26 972 female and 24 407 male body weight records. Variance components were estimated with ASREML. Estimates of the heritability of residual variance were in the range 0.029 (s.e.50.003) to 0.047 (s.e.50.004). The genetic coefficients of variation were high, between 0.35 and 0.57. Heritabilities were higher in females than in males. Accounting for heterogeneous residual variance increased the heritabilities for body weight as well. Genetic correlations between body weight and its residual variance were 20.41 (s.e.50.032) and 20.45 (s.e.50.040), respectively, in females and males. The genetic correlation between female and male residual variance was 0.11 (s.e.50.089), indicating that female and male residual variance are different traits. Results indicate good opportunities to simultaneously increase the mean and improve uniformity of body weight of broilers by selection
Verandering in crisisinterventie en acute psychiatrie: Amsterdamse consulten in 1983 en 2005.
achtergrond Sinds 1992 stijgt het aantal inbewaringstellingen (ibs'en) in Nederland opvallend. In Amsterdam is er zelfs sprake van een verdrievoudiging. Psychiatrische behandeling in de Amsterdamse klinieken dreigt gedomineerd te worden door dwang. doel Een beeld krijgen van de veranderingen in de acute psychiatrie die hebben bijgedragen aan de stijging van het aantal dwangopnames met ibs. methode Vergelijken van een cohort (n = 460) consulten verricht door de stedelijke crisisdienst in 1983 met een cohort (n = 436) consulten verricht in 2004-2005 op de volgende variabelen: werkwijze van de crisisdienst, kenmerken van de patiënten, diagnose en uitkomst van de consulten. resultaten Vergeleken met 1983 waren er in 2004-2005 meer diensten betrokken bij psychiatrische patiënten in acute situaties in het publieke domein. Het aantal patiënten dat via de politie kwam, verdubbelde. De consulten, die in 1983 uitsluitend werden gedaan op de plek waar de patiënt verbleef, werden in 2004-2005 voor 60% op het bureau van de dienst gedaan. Het aantal patiënten met een psychose in de cohort nam toe van 52,0 naar 63,3%. Er was een toename van ibs opnames (van 16,7 naar 20,0% van de interventies) en een scherpe daling van vrijwillige opnames (van 25,7 naar 7,6%). Het totale aantal opnames na een consult daalde van 42 naar 28%. conclusie De outreachende dienst met een eerstelijnskarakter van 1983 is veranderd in een gespecialiseerde psychiatrische ehbo met een bescheiden outreachende functie. De vrijwillige opname is vrijwel verdwenen bij de crisisdienst. Nader onderzoek naar de kenmerken van de consulten en naar de variabelen die een rol spelen bij het toepassen van dwang is noodzakelijk
Health-related quality of life and fatigue in liver transplant recipients receiving tacrolimus versus sirolimus-based immunosuppression: results from a randomized trial
Background. The impact of different immunosuppression regimes on the health-related quality of life (HRQoL) and the severity of fatigue in liver transplant recipients is largely unknown. We investigated the impact of a sirolimus-based regimen compared with a tacrolimus (TAC)-based regimen on the HRQoL and the severity of fatigue.Methods. In this multicenter, open-label, randomized, controlled trial, 196 patients were randomized 90 d after transplantation to (1) once daily normal-dose TAC or (2) once daily combination therapy of low-dose sirolimus and TAC. HRQoL was measured with the EQ-5D-5L questionnaire, the EQ–visual analog scale, and the severity of fatigue questionnaire Fatigue Severity Score (FSS). The EQ-5D-5L scores were translated to societal values. We examined the HRQoL and the FSS over the course of the study by fitting generalized mixed-effect models.Results. Baseline questionnaires were available for 87.7% (172/196) of the patients. Overall, patients reported the least problems in the states of self-care and anxiety/depression and the most problems in the states of usual activities and pain/discomfort. No significant differences in HrQol and FSS were seen between the 2 groups. During follow-up, the societal values of the EQ-5D-5L health states and the patient’s self-rated EQ–visual analog scale score were a little lower than those of the general Dutch population in both study arms.Conclusions. The HRQoL and FSS were comparable in the 36 mo after liver transplantation in both study groups. The HRQoL of all transplanted patients approximated that of the general Dutch population, suggesting little to no residual symptoms in the long term after transplantation.Transplant surger
Palaeoenvironment of Eocene prodelta in Spitsbergen recorded by the trace fossil Phycosiphon incertum
Ichnological, sedimentological and geochemical analyses were conducted on the Eocene Frysjaodden Formation in order to interpret palaeoenvironment prodelta sediments in the Central Basin of Spitsbergen. Phycosiphon incertum is the exclusive ichnotaxon showing differences in size, distribution, abundance and density, and relation to laminated/bioturbated intervals. Large P. incertum mainly occur dispersed, isolated and randomly distributed throughout the weakly laminated/non-laminated intervals. Small P. incertum occur occasionally in patches of several burrows within laminated intervals or as densely packed burrows in thin horizons in laminated intervals or constituting fully bioturbated intervals that are several centimetres thick. Ichnological changes are mainly controlled by oxygenation, although the availability of benthic food cannot be discarded. Changes in oxygenation and rate of sedimentation can be correlated with the registered variations in the Bouma sequence of the distal turbiditic beds within prodeltal shelf sediments.Funding for this research was provided by Project CGL2012-33281 (Secretaría de Estado de Investigación, Desarrollo e Innovación, Spain), Project RYC-2009-04316 (Ramón y Cajal Programme) and Projects RNM-3715 and RNM-7408 and Research Group RNM-178 (Junta de Andalucía). The authors benefited from a bilateral agreement between the universities of Granada and Oslo, supported by the University of Granada
Quantified health and cost effects of faster endovascular treatment for large vessel ischemic stroke patients in the Netherlands
Background: The effectiveness of endovascular treatment (EVT) for large vessel occlusion (LVO) stroke severely depends on time to treatment. However, it remains unclear what the value of faster treatment is in the years after index stroke. The aim of this study was to quantify the value of faster EVT in terms of health and healthcare costs for the Dutch LVO stroke population. Methods: A Markov model was used to simulate 5-year follow-up functional outcome, measured with the modified Rankin Scale (mRS), of 69-year-old LVO patients. Post-treatment mRS was extracted from the MR CLEAN Registry (n=2892): costs per unit of time and Quality-Adjusted Life Years (QALYs) per mRS sub-score were retrieved from follow-up data of the MR CLEAN trial (n=500). Net Monetary Benefit (NMB) at a willingness to pay of €80 000 per QALY was reported as primary outcome, and secondary outcome measures were days of disability-free life gained and costs. Results: EVT administered 1 min faster resulted in a median NMB of €309 (IQR: 226;389), 1.3 days of additional disability-free life (IQR: 1.0;1.6), while cumulative costs remained largely unchanged (median: -€15, IQR: -65;33) over a 5-year follow-up period. As costs over the follow-up period remained stable while QALYs decreased with longer time to treatment, which this results in a near-linear decrease of NMB. Since patients with faster EVT lived longer, they incurred more healthcare costs. Conclusion: One-minute faster EVT increases QALYs while cumulative costs remain largely unaffected. Therefore, faster EVT provides better value of care at no extra healthcare costs
The quantitative genetics of phenotypic variation in animals
Considerable attention has been paid to estimating genetic variability in quantitative traits and to how it is maintained and changed by selection in natural and domesticated populations, but rather little attention has been paid to how levels of environmental and phenotypic variance are influenced. We review recent estimates, showing there is substantial genetic variation in levels of environmental and phenotypic variation. We review evolutionary forces that can affect the level of environmental variation, and find that most models lead to a predicted reduction. We thus argue that its maintenance is a consequence of factors such as the intrinsic cost of homogeneity, phenotypic plasticity to variable environments, or mutants that increase variance. We show how to construct a selection index to predict the magnitude of changes in variance as a result of artificial selection, and consider the opportunities for artificial selection to increase uniformit
Foliar aggressiveness of Phytophthora infestans in three potato growing regions in the Netherlands
Heritable Environmental Variance Causes Nonlinear Relationships Between Traits: Application to Birth Weight and Stillbirth of Pigs
There is recent evidence from laboratory experiments and analysis of livestock populations that not only the phenotype itself, but also its environmental variance, is under genetic control. Little is known about the relationships between the environmental variance of one trait and mean levels of other traits, however. A genetic covariance between these is expected to lead to nonlinearity between them, for example between birth weight and survival of piglets, where animals of extreme weights have lower survival. The objectives were to derive this nonlinear relationship analytically using multiple regression and apply it to data on piglet birth weight and survival. This study provides a framework to study such nonlinear relationships caused by genetic covariance of environmental variance of one trait and the mean of the other. It is shown that positions of phenotypic and genetic optima may differ and that genetic relationships are likely to be more curvilinear than phenotypic relationships, dependent mainly on the environmental correlation between these traits. Genetic correlations may change if the population means change relative to the optimal phenotypes. Data of piglet birth weight and survival show that the presence of nonlinearity can be partly explained by the genetic covariance between environmental variance of birth weight and survival. The framework developed can be used to assess effects of artificial and natural selection on means and variances of traits and the statistical method presented can be used to estimate trade-offs between environmental variance of one trait and mean levels of others
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