273 research outputs found

    Necropsy protocol for newborn mice

    Get PDF
    Neonatal mortality is high in laboratory mouse breeding, and causes are poorly understood. Post-mortem analysis of pups is an often overlooked source of information and insight. We present a necropsy protocol for neonatal mice designed for easy practical application by animal technicians.The authors thank all staff at the i3S Animal Facility and the Babraham Institute Biological Support Unit, especially Ana Abreu, Ângela Ribeiro, Urszula Karpinska and Minnie Eve, and the i3S Histology and Electron Microscopy Platform, member of the national infrastructure PPBI - Portuguese Platform of Bioimaging (PPBI-POCI-01-0145-FEDER-022122). This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/CVTWEL/1202/2014 (POCI-01-0145-FEDER-016591)

    Social environment as a cause of litter loss in laboratory mouse: A behavioural study

    Get PDF
    Perinatal mortality is a widespread problem in laboratory mouse breeding and is often manifested by the loss of the entire litter within the first days of life. High mortality is an animal health and welfare concern that violates the 3R principles of reduction and refinement. High pup mortality is often considered “normal” in mouse breeding and the underlying causes are poorly understood. This study investigated the role of the social environment on pup survival and parental behaviour in C57BL/6 mice. Before parturition, multiparous females were allocated to three treatments: single-housing (SH, n=54) or group-housing in trios of two females and a male, with group-housing further divided into trios with (GH1, n=20) or without (GH0, n=35) the presence of another litter. Mouse behaviour was recorded from 24h before to 24h after parturition. Mouse breeding performance (offspring survival and weight) was analysed using logistic and generalized linear models, and behaviours using logistic and multivariable linear models. We confirmed previous findings of high mortality rates for all treatments, but the highest rates were found in GH1 where half of the litters were lost entirely. Social environment had an impact on breeding performance. On the one hand, the presence of adult cagemates in GH0 did not affect litter survival nor pup body weight at 20 days. Adult cagemates shared the work of breeding by performing nest building before and after litter birth, and parental care after birth. GH0 and GH1 dams were less frequently seen performing nest building before and after parturition than SH dams. GH0 and GH1 dams were also less frequently seen inside the nest and performing parental behaviour after parturition than were SH dams. On the other hand, the risks for litter and pup loss were dramatically increased by 2.3 and 1.8 times, respectively, in GH1 compared to GH0. Parturition lasted longer in GH1 than in GH0 treatment. While dam behaviour did not differ between GH1 and GH0, GH1 adult cagemates spent less time performing parental care than did GH0 cagemates. Plausible reasons for the higher mortality in the presence of another litter are insufficient parental care, competition for milk access, poor nest quality, and crushing of newborns by older pups in the nest. This study indicates that being born in a cage where there is already an older litter, so-called reproductive asynchrony, is a major risk factor for litter loss.The authors would like to thank Paula Sofia Vilares Gouveia and Sara Capas Peneda who participated in the behavioural analyses, and all the staff at the Biological Support Unit of the Babraham Institute for their interest and support in the project and the care of the animals. This work was financed by FEDER - Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 - Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/CVT-WEL/1202/2014 (POCI-01- 0145-FEDER-016591)

    Does training method matter? Evidence for the negative impact of aversive-based methods on companion dog welfare

    Get PDF
    Dog training methods range broadly from those using mostly positive punishment and negative reinforcement (aversive-based) to those using primarily positive reinforcement (rewardbased). Although aversive-based training has been strongly criticized for negatively affecting dog welfare, there is no comprehensive research focusing on companion dogs and mainstream techniques, and most studies rely on owner-reported assessment of training methods and dog behavior. The aim of the present study was to evaluate the effects of aversive- and reward-based training methods on companion dog welfare within and outside the training context. Ninety-two companion dogs were recruited from three reward-based schools (Group Reward, n = 42), and from four aversive-based schools, two using low proportions of aversive-based methods (Group Mixed, n = 22) and two using high proportions of aversive-based methods (Group Aversive, n = 28). For evaluating welfare during training, dogs were video recorded for three sessions and six saliva samples were collected, three at home (baseline levels) and three after training (post-training levels). Video recordings were used to examine the frequency of stress-related behaviors (e.g., lip lick, yawn) and the overall behavioral state of the dog (e.g., tense, relaxed), and saliva samples were analyzed for cortisol concentration. For evaluating welfare outside the training context, dogs participated in a cognitive bias task. Results showed that dogs from Group Aversive displayed more stress-related behaviors, were more frequently in tense and low behavioral states and panted more during training, and exhibited higher post-training increases in cortisol levels than dogs from Group Reward. Additionally, dogs from Group Aversive were more 'pessimistic' in the cognitive bias task than dogs from Group Reward. Dogs from Group Mixed displayed more stress-related behaviors, were more frequently in tense states and panted more during training than dogs from Group Reward. Finally, although Groups Mixed and Aversive did not differ in their performance in the cognitive bias task nor in cortisol levels, the former displayed more stress-related behaviors and was more frequently in tense and low behavioral states. These findings indicate that aversive-based training methods, especially if used in high proportions, compromise the welfare of companion dogs both within and outside the training context.The current research study was supported by FCT - Fundação Portuguesa para a Ciência e Tecnologia (Fellowship SFRH/BPD/ 111509/2015) and UFAW - Universities Federation for Animal Welfare (Grant 14-16/17), with grants awarded to ACVC. SP was supported by PIPOL - Regione Friuli Venezia Giulia. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. FCT - Fundação Portuguesa para a Ciência e Tecnologia: https://www.fct.pt/index. phtml.pt UFAW - Universities Federation for Animal Welfare: https://www.ufaw.org.uk/

    All the pups we cannot see: Cannibalism masks perinatal death in laboratory mouse breeding but infanticide is rare

    Get PDF
    Perinatal mortality is a major issue in laboratory mouse breeding. We compared a counting method using daily checks (DAILY_CHECK) with a method combining daily checks with detailed video analyses to detect cannibalisms (VIDEO_TRACK) for estimating the number of C57BL/6 pups that were born, that died and that were weaned in 193 litters from trios with (TRIOOVERLAP) or without (TRIO-NO_OVERLAP) the presence of another litter. Linear mixed models were used at litter level. To understand whether cannibalism was associated with active killing (infanticide), we analysed VIDEO_TRACK recordings of 109 litters from TRIO-OVERLAP, TRIONO_OVERLAP or SOLO (single dams). We used Kaplan-Meier method and logistic regression at pup level. For DAILY_CHECK, the mean litter size was 35% smaller than for VIDEO_TRACK (p < 0.0001) and the number of dead pups was twice lower (p < 0.0001). The risk of pup loss was higher for TRIO-OVERLAP than TRIO-NO_OVERLAP (p < 0.0001). A high number of pup losses occurred between birth and the first cage check. Analyses of VIDEO_TRACK data indicated that pups were clearly dead at the start of most of the cannibalism events and infanticide was rare. As most pups die and disappear before the first cage check, many breeding facilities are likely to be unaware of their real rates of mouse pup mortality.Funding: This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT—Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project PTDC/CVT-WEL/1202/2014 (POCI-01-0145-FEDER-016591). This work was financed by FEDER?Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020?Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT?Funda??o para a Ci?ncia e a Tecnologia/Minist?rio da Ci?ncia, Tecnologia e Ensino Superior in the framework of the project PTDC/CVT-WEL/1202/2014 (POCI-01-0145-FEDER-016591). The authors would like to thank the staff at the Biological Support Unit of the Babraham Institute, and more particularly Marc Wiltshire, Mike Regan, Paul Symonds and Urszula Karpinska, for their interest and support in the project and the care of the animals

    Morphological asymmetry and broiler welfare

    Get PDF
    Health status, feed conversion ratio, and mortality are long known broiler chicken production indicators. However, further parameters are required by today's demanding meat markets, as these indicators are not sufficiently accurate to determine flock overall welfare. Morphological asymmetry has been pointed as an alternative welfare indicator as it reflects the ability of the bird to cope with the challenges that rearing conditions may impose. This study aimed at evaluating the possibility of using morphological asymmetry as a welfare indicator. Broilers from 28 to 42 days of age were used in the trial. Birds were randomly selected in a commercial poultry farm and transported to the laboratory. They walked over the force measurement platform in order to determined their feet force as a percentage of body weight. The following body parts of the live birds were measured by two different operators using a digital caliper: tarsometatarsus length, outertoe length, midtoe length, and backtoe length. In the corresponding carcasses, the following traits were measured: wattle width, eye length, and first secondary feather length. Data were submitted to statistical analyses and no correlation was found between specific feet trait measurements and walking ability. Considering the time budget involved in measuring morphological asymmetry, this procedure did not appear to be a practically feasible welfare indicator.209213Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

    Get PDF
    We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

    Get PDF
    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

    Get PDF
    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

    Get PDF
    A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN
    corecore