Cohomological finiteness conditions for elementary amenable groups

It is proved that every elementary amenable group of type $FP_\infty$ admits a cocompact classifying space for proper actions

PILOT APPRAISAL OF VARIABLES AMONG MEXICAN-AMERICANS FOR SOCIAL NETWORKS ANALYSIS

poster abstractHispanics in the USA often suffer poor oral health. More appropriate solutions may be designed if we move beyond the simplistic interpretation of poor oral outcomes being associated with 1-2 variables, e.g., language; such an approach has failed to provide consistent interpretations, and offers no points for intervention. We propose to examine a constellation of variables interwoven into multilevel strategies under a new(er) paradigm, social network theories (http://cmol.nbi.dk/models/infoflow/infoflow.html). Objectives: To qualitatively identify domains of variables modulating oral health outcomes among 1st-2nd generation MexicanAmerican immigrants. Methods: Through key informant interviews, we ascertained KAB variables in immigrant families originating in Jalisco, Mexico. This community has had a strong, revolving presence for decades in a well-delimited location in Indianapolis, IN, around St. Patrick’s parish. We did not conduct clinical exams but used questions from American national surveys to document health perceptions, availability of dental services/insurance, presence of dental pain and impaired function in adults and children, and family structure and sociodemographic profiles during a Catholic festival (no incentives, no appointments). Data were content-analyzed. Results: Data were collected from 22 parent-child dyads (15 female adults, 7 male; mean age 24±6.3yrs; data from the oldest child and the interviewee). Frequencies of dental emergencies and acute problems varied markedly, with recurrence patterns. A minority exhibited consistent dental attendance, often enabled by public/private dental insurance. Time in the USA varied considerably, with 1st and 2nd generation immigrant parents and children sharing the household. Occupations ranged from manual to clerical, and education from elementary to college among adults. Conclusion: Interviews were feasible and acceptable, and the experience informed future fieldwork considerations. We are using the variables to design a social networks study to characterize the evolution of patterns between families in Indianapolis and among peers living in Jalisco, aiming to measure impacts ascribable to immigration along acculturation spectra

Micron-sized atom traps made from magneto-optical thin films

We have produced magnetic patterns suitable for trapping and manipulating neutral atoms on a $1 \mu$m length scale. The required patterns are made in Co/Pt thin films on a silicon substrate, using the heat from a focussed laser beam to induce controlled domain reversal. In this way we draw lines and "paint" shaped areas of reversed magnetization with sub-micron resolution. These structures produce magnetic microtraps above the surface that are suitable for holding rubidium atoms with trap frequencies as high as ~1 MHz.Comment: 6 pages, 7 figure

Taking the lead on climate change: Modelling and monitoring the fate of an Amazonian frog

Climate change is expected to have important impacts on biodiversity. However, cases showing explicit links between species decline and climate are scarce, mostly because of a lack of baseline data. Tropical ectotherms with narrow altitudinal ranges are particularly sensitive to climate change; for example the frog Pristimantis espedeus may be at risk, with only nine populations known to date in French Guiana, all on isolated massifs. Ecological niche modelling indicated that these populations could disappear by 2070. To facilitate testing of this prediction we conducted a study to design an efficient, cost-effective monitoring protocol, combining occupancy rate estimations using passive acoustic recorders, and abundance estimations using acoustic repeated counts and capture-mark-recapture. We found the passive recorders to be effective, with a detection probability of 0.8. Two recording sessions were sufficient to estimate occupancy rates reliably. A minimum of 57 surveyed sites were required to detect a decline of 15% in occupancy between two consecutive monitoring events. Acoustic repeated counts and capture-mark-recapture yielded similar density estimates (1.6 and 1.8 calling males per 100 m2, respectively). Based on these results we present a protocol based on passive acoustic recording and abundance monitoring to monitor P. espedeus populations

Shear Viscosity in the O(N) Model

We compute the shear viscosity in the O(N) model at first nontrivial order in the large N expansion. The calculation is organized using the 1/N expansion of the 2PI effective action (2PI-1/N expansion) to next-to-leading order, which leads to an integral equation summing ladder and bubble diagrams. We also consider the weakly coupled theory for arbitrary N, using the three-loop expansion of the 2PI effective action. In the limit of weak coupling and vanishing mass, we find an approximate analytical solution of the integral equation. For general coupling and mass, the integral equation is solved numerically using a variational approach. The shear viscosity turns out to be close to the result obtained in the weak-coupling analysis.Comment: 37 pages, few typos corrected; to appear in JHE

Profile and reproductive roles of seminal plasma melatonin of boar ejaculates used in artificial insemination programs

Melatonin (MLT) is present in seminal plasma (SP) of mammalian species, including pigs, and it is credited with antioxidant properties. This study aims to identify the sources of variation and the role of boar SP MLT on sperm quality and functionality and in vivo fertilizing ability of liquid-stored semen doses used in AI programs. The SP MLT was measured using an ELISA kit in a total of 219 ejaculates collected from 76 boars, and reproductive records of 5,318 AI sows were recorded. Sperm quality was assessed according to motility (computer-aided sperm analysis) and viability (cytometry evaluation). Sperm functionality was assessed according to the cytometric determination of intracellular H2O2 generation, total and mitochondrial O2- production, and lipid peroxidation in liquid AI semen samples stored at 17°C over 144 h. The concentration of SP MLT differed among seasons (P < 0.01) and day length periods (P < 0.001) of the year, demonstrating that the ejaculates collected during the increasing day length period (9.80 ± 1.38 pg/mL, range: 2.75–21.94) had lower SP MLT concentrations than those collected during the decreasing day length period (16.32 ± 1.67 pg/mL, range: 5.02–35.61). The SP MLT also differed (P < 0.001) among boars, among ejaculates within boar, and among portions within the ejaculate, demonstrating that SP from the first 10 mL of sperm-rich ejaculate fraction (SRF) exhibited lower MLT concentrations than post-SRF. The SP MLT was negatively related (P < 0.001) to mitochondrial O2- production in viable sperm. The SP MLT did not differ among AI boars (n = 14) hierarchically grouped according to high and low fertility outcomes. In conclusion, SP MLT concentration in AI boars varies depending on the season of ejaculate collection and differs among boars, ejaculates within boar, and portions within ejaculate. The SP MLT may act at the mitochondrial level of sperm by reducing the generation of O2-. However, this antioxidant role of SP MLT was not reflected in sperm quality or in vivo fertility outcomes of AI semen doses

Direct Constraints on Minimal Supersymmetry from Fermi-LAT Observations of the Dwarf Galaxy Segue 1

The dwarf galaxy Segue 1 is one of the most promising targets for the indirect detection of dark matter. Here we examine what constraints 9 months of Fermi-LAT gamma-ray observations of Segue 1 place upon the Constrained Minimal Supersymmetric Standard Model (CMSSM), with the lightest neutralino as the dark matter particle. We use nested sampling to explore the CMSSM parameter space, simultaneously fitting other relevant constraints from accelerator bounds, the relic density, electroweak precision observables, the anomalous magnetic moment of the muon and B-physics. We include spectral and spatial fits to the Fermi observations, a full treatment of the instrumental response and its related uncertainty, and detailed background models. We also perform an extrapolation to 5 years of observations, assuming no signal is observed from Segue 1 in that time. Results marginally disfavour models with low neutralino masses and high annihilation cross-sections. Virtually all of these models are however already disfavoured by existing experimental or relic density constraints.Comment: 22 pages, 5 figures; added extra scans with extreme halo parameters, expanded introduction and discussion in response to referee's comment

Phase transitions for the Lifshitz black holes

We study possibility of phase transitions between Lifshitz black holes and other configurations by using free energies explicitly. A phase transition between Lifshitz soliton and Lifshitz black hole might not occur in three dimensions. We find that a phase transition between Lifshitz and BTZ black holes unlikely occurs because they have different asymptotes. Similarly, we point out that any phase transition between Lifshitz and black branes unlikely occurs in four dimensions since they have different asymptotes. This is consistent with a necessary condition for taking a phase transition in the gravitational system, which requires the same asymptote.Comment: 19 pages, 7 figures, a revised version to appear in EPJ