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1.
PLoS Biol ; 14(12): e2000598, 2016 Dec.
Article in English | MEDLINE | ID: mdl-27911892

ABSTRACT

Accumulating evidence indicates high risk of bias in preclinical animal research, questioning the scientific validity and reproducibility of published research findings. Systematic reviews found low rates of reporting of measures against risks of bias in the published literature (e.g., randomization, blinding, sample size calculation) and a correlation between low reporting rates and inflated treatment effects. That most animal research undergoes peer review or ethical review would offer the possibility to detect risks of bias at an earlier stage, before the research has been conducted. For example, in Switzerland, animal experiments are licensed based on a detailed description of the study protocol and a harm-benefit analysis. We therefore screened applications for animal experiments submitted to Swiss authorities (n = 1,277) for the rates at which the use of seven basic measures against bias (allocation concealment, blinding, randomization, sample size calculation, inclusion/exclusion criteria, primary outcome variable, and statistical analysis plan) were described and compared them with the reporting rates of the same measures in a representative sub-sample of publications (n = 50) resulting from studies described in these applications. Measures against bias were described at very low rates, ranging on average from 2.4% for statistical analysis plan to 19% for primary outcome variable in applications for animal experiments, and from 0.0% for sample size calculation to 34% for statistical analysis plan in publications from these experiments. Calculating an internal validity score (IVS) based on the proportion of the seven measures against bias, we found a weak positive correlation between the IVS of applications and that of publications (Spearman's rho = 0.34, p = 0.014), indicating that the rates of description of these measures in applications partly predict their rates of reporting in publications. These results indicate that the authorities licensing animal experiments are lacking important information about experimental conduct that determines the scientific validity of the findings, which may be critical for the weight attributed to the benefit of the research in the harm-benefit analysis. Similar to manuscripts getting accepted for publication despite poor reporting of measures against bias, applications for animal experiments may often be approved based on implicit confidence rather than explicit evidence of scientific rigor. Our findings shed serious doubt on the current authorization procedure for animal experiments, as well as the peer-review process for scientific publications, which in the long run may undermine the credibility of research. Developing existing authorization procedures that are already in place in many countries towards a preregistration system for animal research is one promising way to reform the system. This would not only benefit the scientific validity of findings from animal experiments but also help to avoid unnecessary harm to animals for inconclusive research.


Subject(s)
Animal Experimentation , Animals , Bias , Reproducibility of Results
2.
PLoS One ; 11(12): e0165999, 2016.
Article in English | MEDLINE | ID: mdl-27911901

ABSTRACT

Reproducibility in animal research is alarmingly low, and a lack of scientific rigor has been proposed as a major cause. Systematic reviews found low reporting rates of measures against risks of bias (e.g., randomization, blinding), and a correlation between low reporting rates and overstated treatment effects. Reporting rates of measures against bias are thus used as a proxy measure for scientific rigor, and reporting guidelines (e.g., ARRIVE) have become a major weapon in the fight against risks of bias in animal research. Surprisingly, animal scientists have never been asked about their use of measures against risks of bias and how they report these in publications. Whether poor reporting reflects poor use of such measures, and whether reporting guidelines may effectively reduce risks of bias has therefore remained elusive. To address these questions, we asked in vivo researchers about their use and reporting of measures against risks of bias and examined how self-reports relate to reporting rates obtained through systematic reviews. An online survey was sent out to all registered in vivo researchers in Switzerland (N = 1891) and was complemented by personal interviews with five representative in vivo researchers to facilitate interpretation of the survey results. Return rate was 28% (N = 530), of which 302 participants (16%) returned fully completed questionnaires that were used for further analysis. According to the researchers' self-report, they use measures against risks of bias to a much greater extent than suggested by reporting rates obtained through systematic reviews. However, the researchers' self-reports are likely biased to some extent. Thus, although they claimed to be reporting measures against risks of bias at much lower rates than they claimed to be using these measures, the self-reported reporting rates were considerably higher than reporting rates found by systematic reviews. Furthermore, participants performed rather poorly when asked to choose effective over ineffective measures against six different biases. Our results further indicate that knowledge of the ARRIVE guidelines had a positive effect on scientific rigor. However, the ARRIVE guidelines were known by less than half of the participants (43.7%); and among those whose latest paper was published in a journal that had endorsed the ARRIVE guidelines, more than half (51%) had never heard of these guidelines. Our results suggest that whereas reporting rates may underestimate the true use of measures against risks of bias, self-reports may overestimate it. To a large extent, this discrepancy can be explained by the researchers' ignorance and lack of knowledge of risks of bias and measures to prevent them. Our analysis thus adds significant new evidence to the assessment of research integrity in animal research. Our findings further question the confidence that the authorities have in scientific rigor, which is taken for granted in the harm-benefit analyses on which approval of animal experiments is based. Furthermore, they suggest that better education on scientific integrity and good research practice is needed. However, they also question reliance on reporting rates as indicators of scientific rigor and highlight a need for more reliable predictors.


Subject(s)
Biomedical Research , Models, Biological , Animals , Guidelines as Topic , Humans , Periodicals as Topic , Switzerland
3.
PLoS One ; 10(7): e0134278, 2015.
Article in English | MEDLINE | ID: mdl-26230115

ABSTRACT

European hares of both sexes rely on fat reserves, particularly during the reproduc-tive season. Therefore, hares should select dietary plants rich in fat and energy. However, hares also require essential polyunsaturated fatty acids (PUFA) such as linoleic acid (LA) and alpha-linolenic acid (ALA) to reproduce and survive. Although hares are able to absorb PUFA selectively in their gastrointestinal tract, it is unknown whether this mechanism is sufficient to guarantee PUFA supply. Thus, diet selection may involve a trade-off between a preference for energy versus a preference for crucial nutrients, namely PUFA. We compared plant and nutrient availability and use by hares in an arable landscape in Austria over three years. We found that European hares selected their diet for high energy content (crude fat and crude protein), and avoided crude fibre. There was no evidence of a preference for plants rich in LA and ALA. We conclude that fat is the limiting resource for this herbivorous mammal, whereas levels of LA and ALA in forage are sufficiently high to meet daily requirements, especially since their uptake is enhanced by physiological mechanisms. Animals selected several plant taxa all year round, and preferences did not simply correlate with crude fat content. Hence, European hares might not only select for plant taxa rich in fat, but also for high-fat parts of preferred plant taxa. As hares preferred weeds/grasses and various crop types while avoiding cereals, we suggest that promoting heterogeneous habitats with high crop diversity and set-asides may help stop the decline of European hares throughout Europe.


Subject(s)
Dietary Fats/administration & dosage , Fatty Acids, Unsaturated/administration & dosage , Hares/physiology , Herbivory , Plant Structures/chemistry , Animals
4.
ILAR J ; 55(3): 383-91, 2014.
Article in English | MEDLINE | ID: mdl-25541540

ABSTRACT

The scientific literature of laboratory animal research is replete with papers reporting poor reproducibility of results as well as failure to translate results to clinical trials in humans. This may stem in part from poor experimental design and conduct of animal experiments. Despite widespread recognition of these problems and implementation of guidelines to attenuate them, a review of the literature suggests that experimental design and conduct of laboratory animal research are still in need of refinement. This paper will review and discuss possible sources of biases, highlight advantages and limitations of strategies proposed to alleviate them, and provide a conceptual framework for improving the reproducibility of laboratory animal research.


Subject(s)
Animal Experimentation , Research Design , Animals , Models, Animal , Peer Review, Research , Random Allocation , Reproducibility of Results
5.
Oecologia ; 171(2): 591-600, 2013 Feb.
Article in English | MEDLINE | ID: mdl-23011847

ABSTRACT

Conservation of migratory wildlife requires knowledge of migratory connectivity between breeding and non-breeding locations. Stable isotopes in combination with geographical isotopic patterns (isoscapes) can provide inferences about migratory connectivity. This study examines whether such an approach can be used to infer wintering areas in sub-Saharan Africa, where we lack such knowledge for many species, but where this method has not been used widely. We measured δ (2)H, δ (13)C and δ (15)N in winter-grown feathers of a breeding Swiss and Spanish population of European hoopoe Upupa epops--a typical Palaearctic-Afrotropical migrant. δ (2)H values predicted that ~70 % of the hoopoes spent the non-breeding season in the western portion of their potential winter range. This was corroborated by a shallow east-west gradient in feather-δ (2)H values of museum specimens from known African origin across the potential winter range and by the recovery of Swiss hoopoes marked with geolocators. Hoopoes categorized as from eastern versus western regions of the wintering range were further delineated spatially using feather δ (13)C and δ (15)N. δ (15)N showed no trend, whereas adults were more enriched in (13)C in the western portion of the range, with eastern adults being in addition more depleted in (13)C than eastern juveniles. This suggests that eastern juveniles may have occupied more xeric habitats than sympatric adults. We demonstrated that stable isotopes, especially δ (2)H, could only very roughly delineate the winter distribution of a trans-Saharan Palaearctic migrant restricted primarily to the Sahelian and savanna belt south of the Sahara. Further refinements of precipitation isoscapes for Africa as well the development of isoscapes for δ (13)C and δ (15)N may improve assignment of this and other migrants.


Subject(s)
Animal Migration , Birds , Conservation of Natural Resources , Africa South of the Sahara , Animals , Carbon Isotopes/analysis , Feathers/chemistry , Hydrogen/analysis , Nitrogen Isotopes/analysis , Seasons
6.
Oecologia ; 168(1): 97-108, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21786022

ABSTRACT

The exchange of individuals among populations can have strong effects on the dynamics and persistence of a given population. Yet, estimation of immigration rates remains one of the greatest challenges for animal demographers. Little empirical knowledge exists about the effects of immigration on population dynamics. New integrated population models fitted using Bayesian methods enable simultaneous estimation of fecundity, survival and immigration, as well as the growth rate of a population of interest. We applied this novel analytical framework to the demography of two populations of long-distance migratory birds, hoopoe Upupa epops and wryneck Jynx torquilla, in a study area in south-western Switzerland. During 2002-2010, the hoopoe population increased annually by 11%, while the wryneck population remained fairly stable. Apparent juvenile and adult survival probability was nearly identical in both species, but fecundity and immigration were slightly higher in the hoopoe. Hoopoe population growth rate was strongly correlated with juvenile survival, fecundity and immigration, while that of wrynecks strongly correlated only with immigration. This indicates that demographic components impacting the arrival of new individuals into the populations were more important for their dynamics than demographic components affecting the loss of individuals. The finding that immigration plays a crucial role in the population growth rates of these two rare species emphasizes the need for a broad rather than local perspective for population studies, and the development of wide-scale conservation actions.


Subject(s)
Animal Migration , Birds , Population Dynamics , Age Factors , Animals , Bayes Theorem , Female , Fertility , Male , Models, Theoretical , Mortality , Population Growth , Switzerland
7.
PLoS One ; 5(10): e13115, 2010 Oct 06.
Article in English | MEDLINE | ID: mdl-20949083

ABSTRACT

Conceived to combat widescale biodiversity erosion in farmland, agri-environment schemes have largely failed to deliver their promises despite massive financial support. While several common species have shown to react positively to existing measures, rare species have continued to decline in most European countries. Of particular concern is the status of insectivorous farmland birds that forage on the ground. We modelled the foraging habitat preferences of four declining insectivorous bird species (hoopoe, wryneck, woodlark, common redstart) inhabiting fruit tree plantations, orchards and vineyards. All species preferred foraging in habitat mosaics consisting of patches of grass and bare ground, with an optimal, species-specific bare ground coverage of 30-70% at the foraging patch scale. In the study areas, birds thrived in intensively cultivated farmland where such ground vegetation mosaics existed. Not promoted by conventional agri-environment schemes until now, patches of bare ground should be implemented throughout grassland in order to prevent further decline of insectivorous farmland birds.


Subject(s)
Birds/physiology , Feeding Behavior , Insecta , Animals , Ecosystem
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