Investigating dark matter substructure with pulsar timing: I. Constraints on ultracompact minihalos

Small-scale dark matter structure within the Milky Way is expected to affect pulsar timing. The change in gravitational potential induced by a dark matter halo passing near the line of sight to a pulsar would produce a varying delay in the light travel time of photons from the pulsar. Individual transits produce an effect that would either be too rare or too weak to be detected in 30-year pulsar observations. However, a population of dark matter subhalos would be expected to produce a detectable effect on the measured properties of pulsars if the subhalos constitute a significant fraction of the total halo mass. The effect is to increase the dispersion of measured period derivatives across the pulsar population. By statistical analysis of the ATNF pulsar catalogue, we place an upper limit on this dispersion of $\log \sigma_{\dot{P}} \leq -17.05$. We use this to place strong upper limits on the number density of ultracompact minihalos within the Milky Way. These limits are completely independent of the particle nature of dark matter.Comment: 9 pages, 5 figues, includes erratum published in MNRA

The Introductory Communication Course: Results of A National Survey

Data for this survey were gathered from a national sample of institutions of higher education by means of a questionnaire mailed in November of 1987. The questionnaire and a cover letter signed by the president of the Association for Communication Administration were sent to all 2-year colleges and all 4-year and graduate institutions which have an affiliation with the Speech Communication Association or the Association for Communication Administration. In each case they were addressed to the executive officer of the relevant communication department and requested data relevant to the 1987-88 academic year. The instrument used in this survey is a revision of the initial questionnaire used in a 1985 survey of communication departments. We received responses from 421 institutions, an increase from the 373 we received on the earlier survey. These responses were distributed over four types of institutions: 76 from two-year colleges; 101 from four-year colleges without master’s degrees in many fields; 139 from four-year colleges offering master’s degrees in many fields; 139 from four-year colleges offering PhD degrees in many fields. The number of responses in each category are sufficient to allow reasonable comparisons and generalizations from the data

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

Miscarriage, stillbirth and congenital malformation in the offspring of UK veterans of the first Gulf war.

OBJECTIVES: To assess whether the offspring of UK veterans of the first Gulf war are at increased risk of fetal death or congenital malformation. METHOD: This was a retrospective reproductive cohort study of UK Gulf war veterans and a demographically similar comparison group who were in service at the time but were not deployed to the Gulf. Reproductive history was collected by means of a validated postal questionnaire between 1998 and 2001. RESULTS: In all, 27 959 pregnancies reported by men and 861 pregnancies reported by women were conceived after the first Gulf war and before November 1997. The risk of reported miscarriage was higher among pregnancies fathered by Gulf war veterans than by non-Gulf war veterans (OR = 1.4, 95% CI: 1.3, 1.5). Stillbirth risk was similar in both groups. Male Gulf war veterans reported a higher proportion of offspring with any type of malformation than the comparison cohort (OR = 1.5, 95% CI: 1.3, 1.7). Examination by type of malformation revealed some evidence for increased risk of malformations of the genital system, urinary system (renal and urinary tract), and 'other' defects of the digestive system, musculo-skeletal system, and non-chromosomal (non-syndrome) anomalies. These associations were weakened when analyses were restricted to clinically confirmed conditions. There was little or no evidence of increased risk for other structural malformations, specific syndromes, and chromosomal anomalies. Among female veterans, no effect of Gulf war service was found on the risk of miscarriage. The numbers of stillbirths and malformations reported by women were too small to allow meaningful analyses. CONCLUSION: We found no evidence for a link between paternal deployment to the Gulf war and increased risk of stillbirth, chromosomal malformations, or congenital syndromes. Associations were found between fathers' service in the Gulf war and increased risk of miscarriage and less well-defined malformations, but these findings need to be interpreted with caution as such outcomes are susceptible to recall bias. The finding of a possible relationship with renal anomalies requires further investigation. There was no evidence of an association between risk of miscarriage and mothers' service in the gulf

Delineating Novel Signature Patterns of Altered Gene Expression in Schizophrenia Using Gene Microarrays

Schizophrenia is a complex and devastating brain disorder that affects 1% of the population and ranks as one of the most costly disorders to afflict humans. This disorder typically has its clinical onset in late adolescence or early adulthood, presenting as a constellation of delusions and hallucinations (positive symptoms); decreased motivation, emotional expression, and social interactions (negative symptoms); and impaired learning and memory (cognitive symptoms). The etiology of schizophrenia is unknown, but appears to be multifaceted, with genetic and epigenetic developmental factors all implicated. A convergence of observations from clinical, neuroimaging, and anatomical studies has implicated the dorsal prefrontal cortex as a major locus of alterations in schizophrenia

ATV safety

The Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311.Biosystems and Agricultural Engineerin

Two Out of Three Ain’t Bad: 3 Year Progress Report of Multi-Species Non-Invasive Montioring of Forest Carnivores in the Southwest Crown of the Continent

The Southwestern Crown of the Continent is a 1.5 million acre landscape in western Montana that has been the focus of collaborative forest restoration since 2010. Monitoring the effects on forest carnivores of forest restoration efforts can aid land management decisions significantly. A multi-party working group initiated field work to collect baseline information regarding the distribution and relative abundance of forest carnivores across the Southwestern Crown. In the winters of 2012-2014, we employed non-invasive detection methods, including systematic grid-based snowtrack surveys (with backtracking to obtain genetic samples), combined with baited DNA snares and camera traps, to detect target species, including lynx (Lynx canadensis), wolverine (Gulo gulo), and fisher (Pekania pennanti). We surveyed 82 of the 129 5 x 5 mile grid cells in the study area, resulting in 3,366 miles of track surveys, and 274+ bait stations.  We detected lynx in 35 cells and wolverine in 38 cells. The number of cells where lynx were detected was consistent between survey years, while the number of wolverine detection cells increased each survey year.  We did not detect any fisher in the study area.  Genetics have identified at least 18 individual lynx (13 M, 5 F) and 15 individual wolverines (6 M, 9 F).  The combination of two detection methods improved our ability to detect species, including non-target species, compared with either method alone. Our methods could be deployed more widely in Montana