Collective Animal Behavior from Bayesian Estimation and Probability Matching

Animals living in groups make movement decisions that depend, among other factors, on social interactions with other group members. Our present understanding of social rules in animal collectives is based on empirical fits to observations and we lack first-principles approaches that allow their derivation. Here we show that patterns of collective decisions can be derived from the basic ability of animals to make probabilistic estimations in the presence of uncertainty. We build a decision-making model with two stages: Bayesian estimation and probabilistic matching.
In the first stage, each animal makes a Bayesian estimation of which behavior is best to perform taking into account personal information about the environment and social information collected by observing the behaviors of other animals. In the probability matching stage, each animal chooses a behavior with a probability given by the Bayesian estimation that this behavior is the most appropriate one. This model derives very simple rules of interaction in animal collectives that depend only on two types of reliability parameters, one that each animal assigns to the other animals and another given by the quality of the non-social information. We test our model by obtaining theoretically a rich set of observed collective patterns of decisions in three-spined sticklebacks, Gasterosteus aculeatus, a shoaling fish species. The quantitative link shown between probabilistic estimation and collective rules of behavior allows a better contact with other fields such as foraging, mate selection, neurobiology and psychology, and gives predictions for experiments directly testing the relationship between estimation and collective behavior

Population genetics of wild-type CAG repeats in the Machado-Joseph disease gene in Portugal

To gain insights on the molecular mechanisms of mutation that led to the emergence of expanded alleles in the MJD gene, by studying the behavior of wild-type alleles and testing the association of its distribution with the representation of the disease. Methods: The number of CAG motifs in the MJD gene was determined in a representative sample of 1000 unrelated individuals. Associations between the repeat size and the epidemiological representation of MJD were tested. Results: The allelic profi le of the total sample was in the normal range (13–41 repeats), with mode (CAG) 23 . No intermediate alleles were present. Allelic size distribution showed a negative skew. The correlation between the epidemiological representation of MJD in each district and the frequency of small, medium and large normal alleles was not signifi cant. Further correlations performed grouping the districts also failed to produce signifi cant results. Conclusions: The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect refl ection of the frequency of large normal alleles. Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide

Phenotypic redshifts with self-organizing maps: A novel method to characterize redshift distributions of source galaxies for weak lensing

Wide-field imaging surveys such as the Dark Energy Survey (DES) rely on coarse measurements of spectral energy distributions in a few filters to estimate the redshift distribution of source galaxies. In this regime, sample variance, shot noise, and selection effects limit the attainable accuracy of redshift calibration and thus of cosmological constraints. We present a new method to combine wide-field, few-filter measurements with catalogs from deep fields with additional filters and sufficiently low photometric noise to break degeneracies in photometric redshifts. The multi-band deep field is used as an intermediary between wide-field observations and accurate redshifts, greatly reducing sample variance, shot noise, and selection effects. Our implementation of the method uses self-organizing maps to group galaxies into phenotypes based on their observed fluxes, and is tested using a mock DES catalog created from N-body simulations. It yields a typical uncertainty on the mean redshift in each of five tomographic bins for an idealized simulation of the DES Year 3 weak-lensing tomographic analysis of $\sigma_{\Delta z} = 0.007$, which is a 60% improvement compared to the Year 1 analysis. Although the implementation of the method is tailored to DES, its formalism can be applied to other large photometric surveys with a similar observing strategy.Comment: 24 pages, 11 figures; matches version accepted to MNRA

Coronary angiography and angioplasty in diabetic patients

Screening, diagnosis and revascularization of coronary artery disease (CAD) in type 2 diabetes mellitus are major challenges for current clinical practice. Diagnostic (angiography) and therapeutic (angioplasty) cardiac catheterization are important resources for the clinical assessment and management of coronary atherosclerosis. Anatomic peculiarities of CAD in diabetics can be well characterized by angiography, associated or not by intravascular ultrasound. The worse outcome following coronary revascularization procedures, either angioplasty or surgery, in diabetic is one of the main fields of clinical research. In spite of controversies, about one quarter of angioplasty and one third of surgical revascularization procedures are performed in diabetics. Two ongoing, large, randomized, multicentric trials are investigating the best management of CAD in diabetics. The BARI 2D trial is randomizing asymptomatic or mildly symptomatic patients with CAD for either medical therapy or revascularization (angioplasty or surgery, according to the best clinical judgment). The FREEDOM trial is randomizing stable patients with multivessel CAD for either angioplasty with drug eluting stents or surgery, with or without extracorporeal circulation. While the evidences are not available, in order to decide on the best revascularization procedure for individual patients, medical practice has been balanced according to a number of variables. Conditions that favor angioplasty: short lesions, lesions in large vessels, absence of left anterior descending artery disease, previous coronary bypass surgery and high surgical risk due to co-morbidities. Conditions that favor surgery: long lesions, lesions in small vessels, presence of left anterior descending artery disease and need for associated valve surgery.O rastreamento, o diagnóstico e a revascularização da doença arterial coronária (DAC) no diabetes tipo 2 representam enormes desafios para a prática médica. Neste contexto, o cateterismo cardíaco diagnóstico (angiografia) e terapêutico (angioplastia) são recursos fundamentais na avaliação clínica e manejo da aterosclerose coronária. Avaliações das particularidades anatômicas da DAC no diabetes são detalhadamente caracterizadas pela angiografia coronária, associada ou não ao ultra-som intracoronário. Por outro lado, a resposta pior aos procedimentos de revascularização (angioplastia e cirurgia) da DAC nos diabéticos representa umas das áreas de maior investigação clínica contemporânea. A despeito das controvérsias, cerca de um quarto dos pacientes submetidos a angioplastia e um terço dos pacientes submetidos a cirurgia são diabéticos. Dois grandes estudos multicêntricos randomizados, em andamento, investigam o melhor manejo da DAC nos diabéticos. O BARI 2D está randomizando pacientes com DAC assintomáticos ou com sintomas leves para tratamento clínico ou revascularização (angioplastia ou cirurgia, conforme melhor julgamento clínico). O FREEDOM está randomizando pacientes diabéticos estáveis com DAC multiarterial, para angioplastia com stent farmacológico ou cirurgia, com ou sem uso de circulação extra-corpórea. Enquanto as evidências não estão disponíveis, a prática médica atual é balanceada por um conjunto de variáveis na decisão sobre a melhor alternativa de revascularização. Condições que favorecem a angioplastia: estenoses curtas, vasos grandes, ausência de estenose na artéria descendente anterior (ADA), cirurgia de revascularização prévia e risco cirúrgico elevado. Condições que favorecem a indicação de cirurgia: estenoses longas, vasos pequenos, presença de estenose da ADA e cirurgia valvar associada.UNIFESP-EPMSPDM Hospital São Paulo Serviço de Hemodinâmica e Cardiologia IntervencionistaFOR Hospital do Rim e HipertensãoUNIFESP, EPMSPDM Hospital São Paulo Serviço de Hemodinâmica e Cardiologia IntervencionistaSciEL

Sentimientos de adolescentes con Diabetes Mellitus delante del proceso de vivir con la enfermedad

Qualitative research conducted in a diabetes service in the countryside of the state of Ceará, Brazil, with 11 teenagers with diabetes mellitus. The study aimed to understand the experience of adolescents facing the process of living with diabetes. Data were collected in 2007 May and June, through semi-structured interviews. It was observed that the teenager faces difficulties since the moment of diagnosis, especially because their food habits and lifestyles need to change, triggering feelings like fear, insecurity and anger. Over time, they incorporate the necessary changes to treatment and care, and begin to see the disease as normal. One concludes that it is necessary to understand teenagers, their behaviors, fears and desires and support them in the different areas of this experience.Investigación cualitativa, llevada a cabo en un servicio de diabetes del interior del estado de Ceará, Brasil, con 11 adolescentes con diabetes mellitus. El objetivo fue comprender la experiencia del adolescente delante del proceso de vivir con diabetes. Los datos fueron recolectados entre mayo y junio de 2007 a través de entrevistas semi estructuradas. Se observó que el adolescente enfrenta dificultades desde el momento del diagnóstico, sobre todo en el plan alimentar y cambios en el estilo de vida, desencadenando sentimientos como miedo, inseguridad e ira. Con el tiempo, incorporan los cambios necesarios al tratamiento y atención, y llegan a ver la enfermedad como algo normal. En conclusión, que es necesario entender los adolescentes, sus comportamientos, miedos y deseos, y apoyarlos en las diferentes áreas de esta experiencia.Pesquisa de natureza qualitativa, realizada em um serviço de diabetes do interior do Ceará com 11 adolescentes portadores de diabetes mellitus. O estudo objetivou compreender a experiência do adolescente frente ao processo de viver com o diabetes. Os dados foram coletados nos meses de maio e junho de 2007 por meio de entrevista semiestruturada. Constatou-se que o adolescente enfrenta dificuldades desde o momento do diagnóstico, principalmente no plano alimentar e nas mudanças no estilo de vida, desencadeando sentimentos como medo, insegurança e revolta. Com o passar do tempo, incorporam as mudanças necessárias ao tratamento e cuidados; e passam a ver a doença de forma normal. Conclui-se que é necessário compreender os adolescentes, seus comportamentos, medos e anseios e apoiá-los nos diversos âmbitos dessa experiência.Secretaria Municipal de Saúde de Pio IX-PI Programa de Saúde da FamíliaUniversidade Federal do Ceará Faculdade de Farmácia Odontologia e Enfermagem Departamento de EnfermagemUniversidade Federal de São Paulo (UNIFESP) Programa de Pós-Graduação em Saúde ColetivaUNIFESP, Programa de Pós-Graduação em Saúde ColetivaSciEL

Study of Bc+B_c^+ decays to the K+K−π+K^+K^-\pi^+ final state and evidence for the decay Bc+→χc0π+B_c^+\to\chi_{c0}\pi^+

A study of $B_c^+\to K^+K^-\pi^+$ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0 $\mathrm{fb}^{-1}$ collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of $7$ and $8$ TeV. Evidence for the decay $B_c^+\to\chi_{c0}(\to K^+K^-)\pi^+$ is reported with a significance of 4.0 standard deviations, resulting in the measurement of $\frac{\sigma(B_c^+)}{\sigma(B^+)}\times\mathcal{B}(B_c^+\to\chi_{c0}\pi^+)$ to be $(9.8^{+3.4}_{-3.0}(\mathrm{stat})\pm 0.8(\mathrm{syst}))\times 10^{-6}$. Here $\mathcal{B}$ denotes a branching fraction while $\sigma(B_c^+)$ and $\sigma(B^+)$ are the production cross-sections for $B_c^+$ and $B^+$ mesons. An indication of $\bar b c$ weak annihilation is found for the region $m(K^-\pi^+)<1.834\mathrm{\,Ge\kern -0.1em V\!/}c^2$, with a significance of 2.4 standard deviations.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-022.html, link to supplemental material inserted in the reference

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

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

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