Heating of galactic gas by dark matter annihilation in ultracompact minihalos

The existence of substructure in halos of annihilating dark matter would be expected to substantially boost the rate at which annihilation occurs. Ultracompact minihalos of dark matter (UCMHs) are one of the more extreme examples of this. The boosted annihilation can inject significant amounts of energy into the gas of a galaxy over its lifetime. Here we determine the impact of the boost factor from UCMH substructure on the heating of galactic gas in a Milky Way-type galaxy, by means of N-body simulation. If $1\%$ of the dark matter exists as UCMHs, the corresponding boost factor can be of order $10^5$. For reasonable values of the relevant parameters (annihilation cross section $3\times10^{-26} ~\textrm{cm}^3~ \textrm{s}^{-1}$, dark matter mass 100 GeV, 10% heating efficiency), we show that the presence of UCMHs at the 0.1% level would inject enough energy to eject significant amounts of gas from the halo, potentially preventing star formation within $\sim$1 kpc of the halo centre.Comment: 14 pages, 3 figure

Health Related Quality of Life in Persons with Type 2 Diabetes in a Rural Community Served by a Critical Access Hospital

Purpose Type 2 diabetes poses significant health concerns and severe complications can result. The prevalence of type 2 diabetes is greater in rural than urban areas with rural populations exhibiting higher blood glucose (A1C). The purpose of this study was to determine whether health related quality of life (QOL) varies by gender and diabetes control (A1C) in rural persons with type 2 diabetes. Subjects We surveyed 615 persons with type 2 diabetes who receive care at a critical access hospital that serves a seven county rural area in a Midwestern state. Methods This study was a cross-sectional mail survey including a questionnaire assessing demographic characteristics, health related quality of life (QOL) using the diabetes specific QOL tool, D-39, which covers five dimensions of a persons’ life: energy and mobility, diabetes control, anxiety and worry, social burden, and sexual functioning. We analyzed associations between A1C levels and survey responses using descriptive statistics and Spearman correlations. Results We received a 42% response rate with an even distribution of males and females. The median age for females was 76 years, males was 72 years and the majority were white (95%). The average years since diagnosis was 13.4 years (11 years for males and 9.5 for females). Spearman correlations were computed for D-39 subscales, overall perceived severity and QOL, and A1C. Positive correlations exist between overall perceived severity and the QOL dimensions of diabetes control (p\u3c.001), anxiety and worry (p\u3c.001), social burden (p\u3c.001), sexual functioning (p\u3c.001), and energy and mobility (p\u3c.001). Overall QOL rating is positively correlated with anxiety and worry (p=.011), social burden (p=.002) and energy and mobility (p\u3c.001). Hemoglobin A1C is positively correlated with the dimensions of diabetes control (p\u3c.001), anxiety and worry (p=.006), social burden (p\u3c.001), and sexual functioning (p=.030). When comparing the subscale dimension means between gender there is a significant difference only in reports of the sexual functioning dimension (p\u3c.001). Additional gender differences are related to perceived severity. When at low perceived severity females have a lower A1C and at high values of perceived severity males have a lower A1C. Conclusions Since diabetes control is largely due to self-management, it is important to consider the associations between the QOL dimensions, diabetes control (A1C) and gender. These results could be important for implementing successful intervention strategies for glycemic control (a potential mediator between diabetes and QOL) in rural critical access hospitals. Clinical Relevance Although gender is commonly reported in published studies about diabetes, differences have not been routinely analyzed. A better understanding of the relationship of perceived QOL and the impact on diabetes control and gender differences can assist the physical therapist in their role in providing optimal care for older adults with type 2 diabetes in rural communities

The Effect of Various Pasture-based Systems of Milk Production on Animal Performance in the Northeast Region of Ireland

End of Project ReportThe potential of Irish soils to grow grass throughout the year and success in utilizing grass are key factors affecting output and profitability of dairy production systems (Shalloo et al., 2004). In the Northeast region of Ireland, the potential grazing season is shortened due to impeded land drainage, topography, high rainfall and northerly aspect. The main focus of the Ballyhaise research programme is to develop more sustainable production systems suitable to the limitations of the region with a specific focus on grass growth and utilization. Progress in these technologies will improve the competitiveness of dairying in the Northeast region. We are also now faced with a new economic environment with market forecasts predicting a steady decline in dairy product prices for Irish dairy farmers while input prices continue to increase. It has been shown from previous studies that dairy farmers need to expand and/or increase the efficiency of their dairy operation to maintain their real farm incomes over the coming years (Breen and Hennessey, 2003). It is likely that land purchase price will continue to be high in future years. Firstly, dairy farmers can continue at their current level of production and efficiency, and suffer a decline in farm profit as milk price falls. It is likely that greater amounts of milk quota will become available in the coming years; therefore many dairy farmers will have the option to increase production. Expansion opportunities will be limited by the key constraints such as labour supply and cost, capital cost, milk quota availability and price and availability of land around the milking parlour. Labour efficient work practices will have to be adopted on farms to allow one operator to manage a greater number of cows. The objective of this experiment was to examine the effect of two divergent pasture-based systems of milk production on animal performance over a two-year period and to subsequently describe the optimum system for dairy farmers in the Northeast region both now and into the future

Long-term Impacts of Partial Afforestation on Water and Salt Dynamics of an Intermittent Catchment under Climate Change

Soil salinization is a major environmental issue in arid and semi-arid regions, and has been accelerated in some areas by removal of native vegetation cover. Partial afforestation can be a practical mitigation strategy if efficiently integrated with farms and pastures. Using an integrated surface-subsurface hydrological model, this study evaluates the water and salt dynamics and soil salinization conditions of a rural intermittent catchment in the semi-arid climate of southeast Australia subjected to four different partial afforestation configurations under different climate change scenarios, as predicted by several general circulation models. The results show that the locations of afforested areas can induce a retarding effect in the outflow of groundwater salt, with tree planting at lower elevations showing the steadier salt depletion rates. Moreover, except for the configuration with trees planted near the outlet of the catchment, the streamflow is maintained under all other configurations. It appears that under both Representative Concentration Pathways considered (RCP 4.5 and RCP 8.5), the Hadley Centre Global Environmental Model represents the fastest salt export scheme, whereas the Canadian Earth System Model and the Model for Interdisciplinary Research on Climate represent the slowest salt export scheme. Overall, it is found that the location of partial afforestation generally plays a more significant role than the climate change scenarios

New Combinations: Changing Technologies and Infrastructures and the Business Organizations That Will Deal with Them.

This tale is somewhat unique. It is probably one of the few panels, or the only panel in which there is a certain level of agreement. In fact, every one in this room probably has the basic agreement with this panel, that changes in regulation and changes in policy that we are struggling with are driven by changes in technology. This panel has been put together to look at changes in technology. It has three overall goals. The first is, as you heard one of the panels this morning talk about, to talk about technology itself to try to gain some type of understanding. As regulators or practitioners of law in the area, it is hard to be effective without some type of understanding of just what the technology is that we are supposed to be regulating or trying to give people advice concerning. The second area that this panel will hopefully inform us on is how technology continues to change. Many times we look back and see how technological changes have occurred, and how they have forced us to change. However, there is little consideration for the fact that these technologies continue to change and there will be other challenges or maybe even solutions to current problems that will result from that change in technology. And the final area we hope to provide information on is, as technology changes and as it causes regulators to address new issues, how the utilities, are themselves very different, and have been changed and shaped by this changing technology. This group, I think, can demonstrate very well how the conversion of the different technologies have shaped most of the companies and people who are on the panel

Magnetic White Dwarfs from the SDSS II. The Second and Third Data Releases

Fifty-two magnetic white dwarfs have been identified in spectroscopic observations from the Sloan Digital Sky Survey (SDSS) obtained between mid-2002 and the end of 2004, including Data Releases 2 and 3. Though not as numerous nor as diverse as the discoveries from the first Data Release, the collection exhibits polar field strengths ranging from 1.5MG to ~1000MG, and includes two new unusual atomic DQA examples, a molecular DQ, and five stars that show hydrogen in fields above 500MG. The highest-field example, SDSSJ2346+3853, may be the most strongly magnetic white dwarf yet discovered. Analysis of the photometric data indicates that the magnetic sample spans the same temperature range as for nonmagnetic white dwarfs from the SDSS, and support is found for previous claims that magnetic white dwarfs tend to have larger masses than their nonmagnetic counterparts. A glaring exception to this trend is the apparently low-gravity object SDSSJ0933+1022, which may have a history involving a close binary companion.Comment: 20 pages, 4 figures Accepted for publication in the Astronomical Journa

Some constraints on neutral heavy leptons from flavor-conserving decays of the Z boson

Small neutrino masses can arise in some grand unified models or superstring theories. We consider a model with an enhanced fermion sector containing Dirac neutral heavy leptons. The dependence on the mass and mixing parameters of these new fermions is investigated for several measurable quantities. We study the flavor-conserving leptonic decays of the Z boson and universality breaking in these decays. We also consider the W boson mass dependence on neutral heavy lepton parameters.Comment: 20 pages, Revtex 3.0, 6 uuencoded and compressed postscript figures included. Compressed postscript file of paper, including figures, also available by anonymous ftp at ftp://ftp.physics.carleton.ca/pub/theory/gour/ocipc9411.ps.Z . Accepted for publication in Phys. Rev. D

Protracted treatment with corticosterone reduces breeding success in a long-lived bird

Determining the physiological mechanisms underpinning life-history decisions is essential for understanding the constraints under which life-history strategies can evolve. In long-lived species, where the residual reproductive value of breeders is high, adult survival is a key contributor to lifetime reproductive success. We therefore expect that when adult survival is compromised during reproduction, mechanisms will evolve to redirect resources away from reproduction, with implications for reproductive hormones, adult body mass, nest attendance behaviour and breeding success. We investigated whether manipulating corticosterone, to simulate exposure to an environmental stressor, affected the secretion of prolactin and breeding success in the black-legged kittiwake Rissa tridactyla. We used implanted Alzet® osmotic pumps to administer corticosterone to incubating kittiwakes at a constant rate over a period of approximately eight days. Manipulated birds were compared with sham implanted birds and control birds, which had no implants. There was no significant difference in the body mass of captured individuals at the time of implantation and implant removal. Corticosterone-implanted males showed lower nest attendance during the chick rearing period compared to sham-implanted males; the opposite pattern was found in females. Corticosterone treated birds showed a marginally significant reduction in breeding success compared to sham-implanted individuals, with all failures occurring at least one week after implant removal. However, prolactin concentrations at implant removal were not significantly different from initial values. We were unable to measure the profile of change in corticosterone during the experiment. However, our results suggest a delayed effect of elevated corticosterone on breeding success rather than an immediate suppression of prolactin concentrations causing premature failure

Phenomenology of neutral heavy leptons

We continue our previous work on the flavour-conserving leptonic decays of the Z boson with neutral heavy leptons (NHL's) in the loops by considering box, vertex, and self-energy diagrams for the muon decay. By inclusion of these loops (they contribute to the input parameter M_W) we can probe the full parameter space spanned by the so-called flavour-conserving mixing parameters ee_(mix), \mu\mu_(mix), \tau\tau_(mix) in a superstring-inspired model of neutrino mass. We compare the results of our analysis with the existing work in this field and conclude that flavour-conserving decays have certain advantages over traditionally considered flavour-violating ones.Comment: submitted to Phys. Rev. D, 30 pages, 9 figures (ps), REVTE

A dedicated electric oven for characterization of thermoresistive polymer nanocomposites

AbstractThe construction, characterization and control of an electric oven dedicated to the study of thermoresistive polymer nanocomposites is presented. The oven is designed with a heating plate capable of reaching 300°C with a resolution of 0.3°C and an area of uniform temperature of 3.8cm×2.5cm. The temperature is regulated by means of a discrete proportional–integral–derivative controller. A heat transfer model comprising three coupled non-linear differential equations is proposed to predict the thermal profiles of the oven during heating and cooling, which are experimentally verified. The oven is used for thermoresistive characterization of polymer nanocomposites manufactured from a polysulfone polymer and multiwall carbon nanotubes