Measurement of cognitive bias and cortisol levels to evaluate the effects of space restriction on captive collared peccary (Mammalia, Tayassuidae)

We use the judgement-bias paradigm to evaluate whether space restriction in metabolism pens affects the emotional state of collared peccary (Pecari tajacu) during a nutritional experiment. We trained individual adult males to ‘go’ to a specific location within 30 s when a positive auditory cue (whistle; CS+) was given in order to receive cassava root pieces as a reward, and to ‘no-go’ when a negative cue (caxixi percussion instrument; CS−) was sounded to avoid punishment (jet of water) and no reward. An ‘ambiguous’ auditory cue (a drumstick hitting an aluminum plate; CSA) was presented to probe decision-making under ambiguity. Individuals were subjected to five 8-day housing conditions in the order: H1 (control-no space restriction-metabolism pen and additional area), H2 space restriction without environmental enrichment (metabolism pen only), H3 (control-no space restriction), H4 (space restriction with environmental enrichment), and H5 (control-no space restriction). On the eighth day of each housing condition, each animal was exposed to 10 judgement bias trials of each of the three cue types: CS+, CS−, and CSA. We recorded whether animals showed the ‘go’ or ‘no-go’ response after each type of cue and collected fecal samples to assess fecal glucocorticoid metabolite concentrations. Peccaries learnt to discriminate CS+ and CS− and maintained this discrimination during the five housing conditions tested. The response to the ambiguous cue (CSA) varied according to the housing condition. During H1, the peccaries made a similar proportion of ‘go’ responses to all three types of cue (Ps > 0.07). During H2 and H3, ‘go’ responses to CSA and CS− cues occurred in similar proportions (Ps > 0.70), but peccaries showed more go responses to CS+ (Ps < 0.03) indicating that they were responding to CSA as if it were more likely to predict the waterjet than food. During H4 and H5, peccaries again made a similar proportion of ‘go’ responses to all three types of cue, as in H1. During H2 and H3, fecal glucocorticoid metabolite concentrations were higher than during the other tests (208.0 ± 16.4 vs. 141.6 ± 25.9 ngg−1 dry feces, Ps < 0.03). Our results suggest that space restriction may induce physiological stress and influence judgement bias and affective state in peccaries, and that these effects may be offset by environmental enrichment. However, the possibility of a general habituation to the housing conditions across time cannot be ruled out

Limiting temperature from a parton gas with power-law tailed distribution

We combine Tsallis distributed massless partons to an effective thermal prehadron spectrum by folding. A limiting temperature and a mass spectrum combined of three exponentials emerge from this procedure. Meson and baryon resonance spectra have different polynomial prefactors.Comment: 4 pages, 2 figures, revtex4 style, v2 more reference

Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV

A search for a Higgs boson decaying into two photons is described. The analysis is performed using a dataset recorded by the CMS experiment at the LHC from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross section of the standard model Higgs boson decaying to two photons. The expected exclusion limit at 95% confidence level is between 1.4 and 2.4 times the standard model cross section in the mass range between 110 and 150 GeV. The analysis of the data excludes, at 95% confidence level, the standard model Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The largest excess of events above the expected standard model background is observed for a Higgs boson mass hypothesis of 124 GeV with a local significance of 3.1 sigma. The global significance of observing an excess with a local significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is estimated to be 1.8 sigma. More data are required to ascertain the origin of this excess.Comment: Submitted to Physics Letters

Measurement of isolated photon production in pp and PbPb collisions at sqrt(sNN) = 2.76 TeV

Isolated photon production is measured in proton-proton and lead-lead collisions at nucleon-nucleon centre-of-mass energies of 2.76 TeV in the pseudorapidity range |eta|<1.44 and transverse energies ET between 20 and 80 GeV with the CMS detector at the LHC. The measured ET spectra are found to be in good agreement with next-to-leading-order perturbative QCD predictions. The ratio of PbPb to pp isolated photon ET-differential yields, scaled by the number of incoherent nucleon-nucleon collisions, is consistent with unity for all PbPb reaction centralities.Comment: Submitted to Physics Letters