25,521 research outputs found
Measurement of temperature profiles in hot gases by emission-absorption spectroscopy Final report
Measurement of spectral radiances and absorptances in hot gase
Social experience in early ontogeny has lasting effects on social skills in cooperatively breeding cichlids
The early social environment can affect the social behaviour of animals throughout life. We tested whether the presence of adults during early development influences the social behaviour of juveniles later on in the cooperatively breeding cichlid 'Neolamprologus pulcher'. In a split-brood design we raised half of the broods together with parents and with or without brood care helpers, and the other half without adults. During early rearing, fry raised with adults showed more aggressive and submissive behaviour to each other than fish raised with siblings only. After transferring the young to a neutral environment lacking adult conspecifics we tested their social performance in a competitive situation. Either young were assigned the ownership of a shelter or they had no shelter of their own. As shelter owners, fish that had been raised with adults showed more of an energetically cheaper, restrained form of aggression, while as intruders they behaved submissively more often than fish raised without adults. The strength of these treatment effects depended on the opponent's social experience, and contests were terminated earlier only when both opponents had been raised with adults. Our results show that the social-rearing conditions persistently affect the economy and adequacy of individual reactions to social challenges, which is reminiscent of social competence effects known from humans. Remarkably, during the social treatment period brood care involved only protection but no direct interactions between adults and young. We discuss potential mechanisms by which the presence of brood-caring adults may persistently affect social skills in animals
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The circulation and impact of reformist ideas in Germany before the Reformation
Measurement of temperature profiles in hot gases and flames
Computer program was written for calculation of molecular radiative transfer from hot gases. Shape of temperature profile was approximated in terms of simple geometric forms so profile could be characterized in terms of few parameters. Parameters were adjusted in calculations using appropriate radiative-transfer expression until best fit was obtained with observed spectra
Nonequilibrium Quantum Phase Transitions in the Dicke Model
We establish a set of nonequilibrium quantum phase transitions in the Dicke
model by considering a monochromatic nonadiabatic modulation of the atom-field
coupling. For weak driving the system exhibits a set of sidebands which allow
the circumvention of the no-go theorem which otherwise forbids the occurence of
superradiant phase transitions. At strong driving we show that the system
exhibits a rich multistable structure and exhibits both first- and second-order
nonequilibrium quantum phase transitions.Comment: 4 pages, 3 Figures, and supplementary material. This new version
contains corrected typos, new references and new versions of the figures.
Published by Physical Review Letter
Spin-Correlation Coefficients and Phase-Shift Analysis for p+He Elastic Scattering
Angular Distributions for the target spin-dependent observables A,
A, and A have been measured using polarized proton beams at
several energies between 2 and 6 MeV and a spin-exchange optical pumping
polarized He target. These measurements have been included in a global
phase-shift analysis following that of George and Knutson, who reported two
best-fit phase-shift solutions to the previous global p+He elastic
scattering database below 12 MeV. These new measurements, along with
measurements of cross-section and beam-analyzing power made over a similar
energy range by Fisher \textit{et al.}, allowed a single, unique solution to be
obtained. The new measurements and phase-shifts are compared with theoretical
calculations using realistic nucleon-nucleon potential models.Comment: Submitted to Phys. Rev.
Investigation of double beta decay with the NEMO-3 detector
The double beta decay experiment NEMO~3 has been taking data since February
2003. The aim of this experiment is to search for neutrinoless
() decay and investigate two neutrino double beta decay in
seven different isotopically enriched samples (Mo, Se,
Ca, Zr, Cd, Te and Nd). After analysis of
the data corresponding to 3.75 y, no evidence for decay in the
Mo and Se samples was found. The half-life limits at the 90%
C.L. are y and y, respectively.
Additionally for decay the following limits at the 90% C.L.
were obtained, y for Ca, y
for Zr and y for Nd. The
decay half-life values were precisely measured for all investigated isotopes.Comment: 12 pages, 4 figures, 5 tables; talk at conference on "Fundamental
Interactions Physics" (ITEP, Moscow, November 23-27, 2009
Heterozygous mis-sense mutations in Prkcb as a critical determinant of anti-polysaccharide antibody formation
To identify rate-limiting steps in T cell-independent type 2 (TI-2) antibody production against polysaccharide antigens, we performed a genome-wide screen by immunizing several hundred pedigrees of C57BL/6 mice segregating ENU-induced mis-sense mutations. Two independent mutations, Tilcara and Untied, were isolated that semi-dominantly diminished antibody against polysaccharide but not protein antigens. Both mutations resulted from single amino acid substitutions within the kinase domain of Protein Kinase C Beta (PKCβ). In Tilcara, a Ser552>Pro mutation occurred in helix G, in close proximity to a docking site for the inhibitory N-terminal pseudosubstrate domain of the enzyme, resulting in almost complete loss of active, autophosphorylated PKCβI whereas the amount of alternatively spliced PKCβII protein was not markedly reduced. Circulating B cell subsets were normal and acute responses to BCR-stimulation such as CD25 induction and initiation of DNA synthesis were only measurably diminished in Tilcara homozygotes, whereas the fraction of cells that had divided multiple times was decreased to an intermediate degree in heterozygotes. These results, coupled with evidence of numerous mis-sense PRKCB mutations in the human genome, identify Prkcb as a genetically sensitive step likely to contribute substantially to population variability in anti-polysaccharide antibody levels
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