Gravitational synchrotron radiation from cosmic strings

This work studies the gravitational synchrotron radiation emitted from arbitrary cusps of cosmic strings. The results are expressed in terms of four parameters describing the motion of such a cusp. The power spectrum is derived for cusps moving at unit velocity. By using a phenomenological approach the authors also derive the power emitted when the radiation reaction on the cusps is taken into account. In both cases, the synchrotron nature of the radiation produces a power spectrum emitted in a narrow forward cone. If cosmic strings do exist, the radiation emitted by their cusps would seem to be a potential candidate for gravitational-wave detectors

Bacterial lipopolysaccharide potentiates type II collagen-induced arthritis in mice

Collagen-induced arthritis (CIA) is an immunologically relevant animal model of human rheumatoid arthritis. Studies comparing the disease incidence in genetically susceptible male and female DBA/1LacJ mice demonstrated that under low density/low stress housing conditions, female mice had earlier onset (day 35) and higher disease incidence (25%) than the male mice (17% at day 49) when immunized with bovine type II collagen. A single subcutaneous or intraperitoneal injection of bacterial lipopolysaccharide (LPS) 17–24 days after collagen immunization greatly potentiated this standard CIA model in a dose related manner. 20–40 μg of LPS accelerated the onset of disease from day 35 to day 21 and exacerbated the clinical severity score from 0.27 to 2.00 at day 42. A similar administration of 6 μg of recombinant interleukin-β produced a comparable potentiated CIA model. The acute phase protein, serum amyloid P (SAP), was elevated in the serum at day 26 to 440 μg ml−1 for the LPS potentiated CIA mice compared to 65 μg ml−1 in the non-potentiated immunized CIA mice. There was a significant correlation (r = 0.78) between SAP levels and disease expression in the LPS treated CIA mice. The rapidity and uniformity of disease expression in this LPS potentiated CIA model will allow more and different drugs to be evaluated with a smaller number of animals

David Versus Goliath: Strategic Behavior of Small Firms In Consolidated Industries

This study assesses the effect of strategy selection and firm adaptability on small firm performance,  using firm  tenure  as a moderator  variable.  The study  is based  upon interviews with sixteen small firms operating in rapidly changing and consolidating industries. All of the firms in the study pursued a differentiation strategy. Half of the firms  pursued  a  broad product strategy and more than three-quarters pursued a broad service strategy. The study found that small firms adapt by addressing community needs and forming cooperative agreements with other small firms but not larger firms. Variation among the industries studied suggests that the intensity of industry concentration affects firm adaptation decisions. For instance, while the heavily concentrated hardware anti drugstore industries  showed limited adaptation, the unconsolidated bookstore industry showed greater commitment to adaptive strategies. In addition, firm tenure was found to affect the adaptation of the small firms  studied

A Well-Resolved Phylogeny of the Trees of Puerto Rico Based on DNA Barcode Sequence Data

Background: The use of phylogenetic information in community ecology and conservation has grown in recent years. Two key issues for community phylogenetics studies, however, are (i) low terminal phylogenetic resolution and (ii) arbitrarilydefined species pools. Methodology/principal findings: We used three DNA barcodes (plastid DNA regions rbcL, matK, and trnH-psbA) to infer a phylogeny for 527 native and naturalized trees of Puerto Rico, representing the vast majority of the entire tree flora of the island (89%). We used a maximum likelihood (ML) approach with and without a constraint tree that enforced monophyly of recognized plant orders. Based on 50% consensus trees, the ML analyses improved phylogenetic resolution relative to a comparable phylogeny generated with PHYLOMATIC (proportion of internal nodes resolved:constrained ML = 74%, unconstrained ML = 68%, PHYLOMATIC = 52%). We quantified the phylogenetic composition of 15 protected forests in Puerto Rico using the constrained ML and PHYLOMATIC phylogenies. We found some evidence that tree communities in areas of high water stress were relatively phylogenetically clustered. Reducing the scale at which the species pool was defined (from island to soil types) changed some of our results depending on which phylogeny (ML vs. PHYLOMATIC) was used. Overall, the increased terminal resolution provided by the ML phylogeny revealed additional patterns that were not observed with a less-resolved phylogeny. Conclusions/significance: With the DNA barcode phylogeny presented here (based on an island-wide species pool), we show that a more fully resolved phylogeny increases power to detect nonrandom patterns of community composition in several Puerto Rican tree communities. Especially if combined with additional information on species functional traits and geographic distributions, this phylogeny will (i) facilitate stronger inferences about the role of historical processes in governing the assembly and composition of Puerto Rican forests, (ii) provide insight into Caribbean biogeography, and (iii) aid in incorporating evolutionary history into conservation planning

Dietary Supplement Polypharmacy: An Unrecognized Public Health Problem?

Excessive and inappropriate use of medications, or ‘polypharmacy’, has been recognized as a public health problem. In addition, there is growing use of dietary supplements in the United States; however, little is known about the patterns of supplement use. Recent reports in the literature of cases of excessive or inappropriate use of herbal dietary supplements leading to the term ‘polyherbacy’. The clinical vignettes described in this article highlight the need for further research on the nature and extent of multiple and inappropriate dietary supplement use or ‘dietary supplement polypharmacy’. Clinical interviewing and population surveys both address this issue in complementary ways, and provide a further understanding of dietary supplement use patterns

The role of intrinsic efficacy in determining response to a β2-agonist in acute severe asthma

SummaryBackgroundCurrent guidelines recommend repeated doses of albuterol for the emergency treatment of acute asthma. However, approximately one-third of patients show little or no initial response to this partial β2-agonist.MethodsWe conducted a randomized, double-blind, proof-of-concept study to investigate whether a full β2-agonist, isoproterenol, offers a therapeutic advantage in adults presenting with acute severe asthma (FEV1<50%) who fail to respond to an initial treatment of the partial β2-agonist, albuterol. Study subjects were randomized to receive a 2-h continuous nebulization of either albuterol (7.5mg/h) (n=10, mean FEV1=37% predicted) or isoproterenol (7.5mg/h) (n=9, mean FEV1=33% predicted). Respiratory symptoms, vital signs and pulmonary function measures were collected.ResultsSubjects from both treatment groups had similar baseline characteristics. The percent improvements from baseline FEV1 at 60 and 120min were significantly higher in subjects receiving isoproterenol than those receiving albuterol (44 vs. 17% and 63 vs. 24%, respectively, P<0.05). The change in symptoms measured by the modified Borg score was also significantly greater in subjects receiving isoproterenol (P<0.01). Both treatments were well tolerated, though the mean increase in pulse rate at 60 and 120min (21 vs. 1 and 23 vs. 6beats/min, respectively, P<0.05) and the mean change in serum potassium at 120min (−0.52 vs. −0.07meq/L, P<0.05) from baseline were significantly greater in the isoproterenol group.ConclusionsOur data suggest that in subjects presenting with acute severe asthma who fail to show an initial response to albuterol, the use of a β2-agonist of higher intrinsic efficacy can be more effective in improving lung function and symptoms

A modeling tool to evaluate regional coral reef responses to changes in climate and ocean chemistry

This is the published version.We developed a spreadsheet-based model for the use of managers, conservationists, and biologists for projecting the effects of climate change on coral reefs at local-to-regional scales. The COMBO (Coral Mortality and Bleaching Output) model calculates the impacts to coral reefs from changes in average SST and CO2 concentrations, and from high temperature mortality (bleaching) events. The model uses a probabilistic assessment of the frequency of high temperature events under a future climate to address scientific uncertainties about potential adverse effects. COMBO offers data libraries and default factors for three selected regions (Hawai’i, Great Barrier Reef, and Caribbean), but it is structured with user-selectable parameter values and data input options, making possible modifications to reflect local conditions or to incorporate local expertise. Preliminary results from sensitivity analyses and simulation examples for Hawai’i demonstrate the relative importance of high temperature events, increased average temperature, and increased CO2 concentration on the future status of coral reefs; illustrate significant interactions among variables; and allow comparisons of past environmental history with future predictions

Circular holonomy in the Taub-NUT spacetime

Parallel transport around closed circular orbits in the equatorial plane of the Taub-NUT spacetime is analyzed to reveal the effect of the gravitomagnetic monopole parameter on circular holonomy transformations. Investigating the boost/rotation decomposition of the connection 1-form matrix evaluated along these orbits, one finds a situation that reflects the behavior of the general orthogonally transitive stationary axisymmetric case and indeed along Killing trajectories in general.Comment: 9 pages, LaTeX iopart class, no figure

A randomized controlled trial testing the efficacy of a brief cannabis universal prevention program among adolescents in primary care

Aims To examine the efficacy of a brief intervention delivered by a therapist ( TBI ) or a computer ( CBI ) in preventing cannabis use among adolescents in urban primary care clinics. Design A randomized controlled trial comparing: CBI and TBI versus control. Setting Urban primary care clinics in the U nited S tates. Participants Research staff recruited 714 adolescents (aged 12–18 years) who reported no life‐time cannabis use on a screening survey for this study, which included a baseline survey, randomization (stratified by gender and grade) to conditions (control; CBI ; TBI ) and 3‐, 6‐ and 12‐month assessments. Measurements Using an intent‐to‐treat approach, primary outcomes were cannabis use (any, frequency); secondary outcomes included frequency of other drug use, severity of alcohol use and frequency of delinquency (among 85% completing follow‐ups). Findings Compared with controls, CBI participants had significantly lower rates of any cannabis use over 12 months (24.16%, 16.82%, respectively, P  < 0.05), frequency of cannabis use at 3 and 6 months ( P  < 0.05) and other drug use at 3 months ( P  < 0.01). Compared with controls, TBI participants did not differ in cannabis use or frequency, but had significantly less other drug use at 3 months ( P  < 0.05), alcohol use at 6 months ( P  < 0.01) and delinquency at 3 months ( P  < 0.01). Conclusions Among adolescents in urban primary care in the U nited S tates, a computer brief intervention appeared to prevent and reduce cannabis use. Both computer and therapist delivered brief interventions appeared to have small effects in reducing other risk behaviors, but these dissipated over time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106949/1/add12469.pd

Gravitomagnetism in the Kerr-Newman-Taub-NUT spacetime

We study the motion of test particles and electromagnetic waves in the Kerr-Newman-Taub-NUT spacetime in order to elucidate some of the effects associated with the gravitomagnetic monopole moment of the source. In particular, we determine in the linear approximation the contribution of this monopole to the gravitational time delay and the rotation of the plane of the polarization of electromagnetic waves. Moreover, we consider "spherical" orbits of uncharged test particles in the Kerr-Taub-NUT spacetime and discuss the modification of the Wilkins orbits due to the presence of the gravitomagnetic monopole.Comment: 12 pages LaTeX iopart style, uses PicTex for 1 Figur