Whistler mode waves upstream of Saturn

Whistler mode waves are generated within and can propagate upstream of collisionless shocks. They are known to play a role in electron thermodynamics/acceleration and, under certain conditions, are markedly observed as wave trains preceding the shock ramp. In this paper, we take advantage of Cassini's presence at ~10 AU to explore the importance of whistler mode waves in a parameter regime typically characterized by higher Mach number (median of ~14) shocks, as well as a significantly different interplanetary magnetic field structure, compared to near Earth. We identify electromagnetic precursors preceding a small subset of bow shock crossings with properties which are consistent with whistler mode waves. We find these monochromatic, low-frequency, and circularly polarized waves to have a typical frequency range of 0.2–0.4 Hz in the spacecraft frame. This is due to the lower ion and electron cyclotron frequencies near Saturn, between which whistler waves can develop. The waves are also observed as predominantly right handed in the spacecraft frame, the opposite sense to what is typically observed near Earth. This is attributed to the weaker Doppler shift, owing to the large angle between the solar wind velocity and magnetic field vectors at 10 AU. Our results on the low occurrence of whistler waves upstream of Saturn also underpin the predominantly supercritical bow shock of Saturn

The JCMT Legacy Survey of the Gould Belt: Mapping 13CO and C 18O in Orion A

The Gould Belt Legacy Survey will map star-forming regions within 500 pc, using Heterodyne Array Receiver Programme (HARP), Submillimetre Common-User Bolometer Array 2 (SCUBA-2) and Polarimeter 2 (POL-2) on the James Clerk Maxwell Telescope (JCMT). This paper describes HARP observations of the J= 3 → 2 transitions of 13CO and C18O towards Orion A. The 15 arcsec resolution observations cover 5 pc of the Orion filament, including OMC 1 (including BN–KL and Orion bar), OMC 2/3 and OMC 4, and allow a comparative study of the molecular gas properties throughout the star-forming cloud. The filament shows a velocity gradient of ∼1 km s−1 pc−1 between OMC 1, 2 and 3, and high-velocity emission is detected in both isotopologues. The Orion Nebula and Bar have the largest masses and linewidths, and dominate the mass and energetics of the high-velocity material. Compact, spatially resolved emission from CH3CN, 13CH3OH, SO, HCOOCH3, CH3CHO and CH3OCHO is detected towards the Orion Hot Core. The cloud is warm, with a median excitation temperature of ∼24 K; the Orion Bar has the highest excitation temperature gas, at >80 K. The C18O excitation temperature correlates well with the dust temperature (to within 40 per cent). The C18O emission is optically thin, and the 13CO emission is marginally optically thick; despite its high mass, OMC 1 shows the lowest opacities. A virial analysis indicates that Orion A is too massive for thermal or turbulent support, but is consistent with a model of a filamentary cloud that is threaded by helical magnetic fields. The variation of physical conditions across the cloud is reflected in the physical characteristics of the dust cores. We find similar core properties between starless and protostellar cores, but variations in core properties with position in the filament. The OMC 1 cores have the highest velocity dispersions and masses, followed by OMC 2/3 and OMC 4. The differing fragmentation of these cores may explain why OMC 1 has formed clusters of high-mass stars, whereas OMC 4 produces fewer, predominantly low-mass stars

Religiosity and teen birth rate in the United States

<p>Abstract</p> <p>Background</p> <p>The children of teen mothers have been reported to have higher rates of several unfavorable mental health outcomes. Past research suggests several possible mechanisms for an association between religiosity and teen birth rate in communities.</p> <p>Methods</p> <p>The present study compiled publicly accessible data on birth rates, conservative religious beliefs, income, and abortion rates in the U.S., aggregated at the state level. Data on teen birth rates and abortion originated from the Center for Disease Control; on income, from the U.S. Bureau of the Census, and on religious beliefs, from the U.S. Religious Landscape Survey carried out by the Pew Forum on Religion and Public Life. We computed correlations and partial correlations.</p> <p>Results</p> <p>Increased religiosity in residents of states in the U.S. strongly predicted a higher teen birth rate, with r = 0.73 (p < 0.0005). Religiosity correlated negatively with median household income, with r = -0.66, and income correlated negatively with teen birth rate, with r = -0.63. But the correlation between religiosity and teen birth rate remained highly significant when income was controlled for via partial correlation: the partial correlation between religiosity and teen birth rate, controlling for income, was 0.53 (p < 0.0005). Abortion rate correlated negatively with religiosity, with r = -0.45, p = 0.002. However, the partial correlation between teen birth rate and religiosity remained high and significant when controlling for abortion rate (partial correlation = 0.68, p < 0.0005) and when controlling for both abortion rate and income (partial correlation = 0.54, p = 0.001).</p> <p>Conclusion</p> <p>With data aggregated at the state level, conservative religious beliefs strongly predict U.S. teen birth rates, in a relationship that does not appear to be the result of confounding by income or abortion rates. One possible explanation for this relationship is that teens in more religious communities may be less likely to use contraception.</p

Quantum Acoustics with Surface Acoustic Waves

It has recently been demonstrated that surface acoustic waves (SAWs) can interact with superconducting qubits at the quantum level. SAW resonators in the GHz frequency range have also been found to have low loss at temperatures compatible with superconducting quantum circuits. These advances open up new possibilities to use the phonon degree of freedom to carry quantum information. In this paper, we give a description of the basic SAW components needed to develop quantum circuits, where propagating or localized SAW-phonons are used both to study basic physics and to manipulate quantum information. Using phonons instead of photons offers new possibilities which make these quantum acoustic circuits very interesting. We discuss general considerations for SAW experiments at the quantum level and describe experiments both with SAW resonators and with interaction between SAWs and a qubit. We also discuss several potential future developments.Comment: 14 pages, 12 figure

The transcriptional response of Caenorhabditis elegans to ivermectin exposure identifies novel genes involved in the response to reduced food intake

We have examined the transcriptional response of Caenorhabditis elegans following exposure to the anthelmintic drug ivermectin (IVM) using whole genome microarrays and real-time QPCR. Our original aim was to identify candidate molecules involved in IVM metabolism and/or excretion. For this reason the IVM tolerant strain, DA1316, was used to minimise transcriptomic changes related to the phenotype of drug exposure. However, unlike equivalent work with benzimidazole drugs, very few of the induced genes were members of xenobiotic metabolising enzyme families. Instead, the transcriptional response was dominated by genes associated with fat mobilization and fatty acid metabolism including catalase, esterase, and fatty acid CoA synthetase genes. This is consistent with the reduction in pharyngeal pumping, and consequential reduction in food intake, upon exposure of DA1316 worms to IVM. Genes with the highest fold change in response to IVM exposure, cyp-37B1, mtl-1 and scl-2, were comparably up-regulated in response to short–term food withdrawal (4 hr) independent of IVM exposure, and GFP reporter constructs confirm their expression in tissues associated with fat storage (intestine and hypodermis). These experiments have serendipitously identified novel genes involved in an early response of C. elegans to reduced food intake and may provide insight into similar processes in higher organisms

The Hot (Invisible?) Hand: Can Time Sequence Patterns of Success/Failure in Sports Be Modeled as Repeated Random Independent Trials?

The long lasting debate initiated by Gilovich, Vallone and Tversky in is revisited: does a “hot hand” phenomenon exist in sports? Hereby we come back to one of the cases analyzed by the original study, but with a much larger data set: all free throws taken during five regular seasons () of the National Basketball Association (NBA). Evidence supporting the existence of the “hot hand” phenomenon is provided. However, while statistical traces of this phenomenon are observed in the data, an open question still remains: are these non random patterns a result of “success breeds success” and “failure breeds failure” mechanisms or simply “better” and “worse” periods? Although free throws data is not adequate to answer this question in a definite way, we speculate based on it, that the latter is the dominant cause behind the appearance of the “hot hand” phenomenon in the data

Long-Term Follow-Up of a High School Alcohol Misuse Prevention Program's Effect on Students' Subsequent Driving

Alcohol-related injuries, particularly motor vehicle, are an important cause of adolescent mortality. School-based alcohol prevention programs have not been evaluated in terms of driving outcomes. This study examined the effects on subsequent driving of a high school-based alcohol prevention program. Methods : The Alcohol Misuse Prevention Study included a randomized test of the effectiveness of an alcohol misuse prevention curriculum conducted among 4635 10th-grade students. Students were assigned to intervention ( n = 1820) or control ( n = 2815) groups and were followed for an average of 7.6 years after licensure, which typically occurred during or shortly after 10th grade. Outcomes examined included alcohol-related and other serious offenses, and at-fault, single-vehicle, and alcohol-related crashes. Results : Only serious offenses (which included alcohol-related) had a significant treatment effect (statistically marginal) after we adjusted for sex, age, race, alcohol use/misuse, family structure, presence of prelicense offenses, age of driver licensure, and parental attitudes toward teen drinking. The effect was found only during the first year of licensure (estimated adjusted relative risk = 0.80, confidence interval = 0.63–1.01). Two first-year serious offense interactions were found. The positive effect was strongest among the largest subgroup of students, those who were drinking less than one drink per week on average before the curriculum, compared with those who drank more than one drink per week ( p = 0.009). The effect was also stronger for the small subgroup of students whose parents had not expressed disapproval of teens’ drinking, compared with those whose parents had disapproved ( p = 0.004). Conclusions : These findings suggest that a high school-based alcohol prevention program can positively affect subsequent driving, particularly that of students who do not use alcohol regularly. The results highlight the need to start prevention efforts early and extend them beyond the initial exposure to driving. Programs should incorporate the differing backgrounds of the students.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65493/1/j.1530-0277.2001.tb02227.x.pd

Emergent global patterns of ecosystem structure and function from a mechanistic general ecosystem model

Anthropogenic activities are causing widespread degradation of ecosystems worldwide, threatening the ecosystem services upon which all human life depends. Improved understanding of this degradation is urgently needed to improve avoidance and mitigation measures. One tool to assist these efforts is predictive models of ecosystem structure and function that are mechanistic: based on fundamental ecological principles. Here we present the first mechanistic General Ecosystem Model (GEM) of ecosystem structure and function that is both global and applies in all terrestrial and marine environments. Functional forms and parameter values were derived from the theoretical and empirical literature where possible. Simulations of the fate of all organisms with body masses between 10 µg and 150,000 kg (a range of 14 orders of magnitude) across the globe led to emergent properties at individual (e.g., growth rate), community (e.g., biomass turnover rates), ecosystem (e.g., trophic pyramids), and macroecological scales (e.g., global patterns of trophic structure) that are in general agreement with current data and theory. These properties emerged from our encoding of the biology of, and interactions among, individual organisms without any direct constraints on the properties themselves. Our results indicate that ecologists have gathered sufficient information to begin to build realistic, global, and mechanistic models of ecosystems, capable of predicting a diverse range of ecosystem properties and their response to human pressures

An unbiased survey of 500 nearby stars for debris disks: A JCMT legacy program

We present the scientific motivation and observing plan for an upcoming detection survey for debris disks using the James Clerk Maxwell Telescope. The SCUBA‐2 Unbiased Nearby Stars (SUNS) survey will observe 500 nearby main‐sequence and subgiant stars (100 of each of the A, F, G, K, and M spectral classes) to the 850 μm extragalactic confusion limit to search for evidence of submillimeter excess, an indication of circumstellar material. The survey distance boundaries are 8.6, 16.5, 22, 25, and 45 pc for M, K, G, F, and A stars, respectively, and all targets lie between the declinations of −40° to 80°. In this survey, no star will be rejected based on its inherent properties: binarity, presence of planetary companions, spectral type, or age. The survey will commence in late 2007 and will be executed over 390 hr, reaching 90% completion within 2 years. This will be the first unbiased survey for debris disks since the Infrared Astronomical Satellite. We expect to detect ~125 debris disks, including ~50 cold disks not detectable in current shorter wavelength surveys. To fully exploit the order of magnitude increase in debris disks detected in the submillimeter, a substantial amount of complementary data will be required, especially at shorter wavelengths, to constrain the temperatures and masses of discovered disks. High‐resolution studies will likely be required to resolve many of the disks. Therefore, these systems will be the focus of future observational studies using a variety of observatories, including Herschel, ALMA, and JWST, to characterize their physical properties. For nondetected systems, this survey will set constraints (upper limits) on the amount of circumstellar dust, of typically 200 times the Kuiper Belt mass, but as low as 10 times the Kuiper Belt mass for the nearest stars in the sample (≈2 pc)