Moments of von Mises and Fisher distributions and applications

The von Mises and Fisher distributions are spherical analogues to the Normal distribution on the unit circle and unit sphere, respectively. The computation of their moments, and in particular the second moment, usually involves solving tedious trigonometric integrals. Here we present a new method to compute the moments of spherical distributions, based on the divergence theorem. This method allows a clear derivation of the second moments and can be easily generalized to higher dimensions. In particular we note that, to our knowledge, the variance-covariance matrix of the three dimensional Fisher distribution has not previously been explicitly computed. While the emphasis of this paper lies in calculating the moments of spherical distributions, their usefulness is motivated by their relationship to population statistics in animal/cell movement models and demonstrated in applications to the modelling of sea turtle navigation, wolf movement and brain tumour growth

Barriers and facilitators to uptake and retention of inner-city ethnically diverse women in a postnatal weight management intervention: a mixed-methods process evaluation within a feasibility trial in England.

OBJECTIVES: To understand the barriers and facilitators to uptake and retention of postnatal women randomised to a commercial group weight management intervention using the COM-B (capability, opportunity, motivation and behaviour) behaviour change model. DESIGN: Concurrent mixed-methods (qualitative dominant) process evaluation nested within a feasibility randomised controlled trial, comprising questionnaires and interviews at 6 and 12 months postbirth. SETTING: One National Health Service maternity unit in an inner city area in the south of England. PARTICIPANTS: 98 postnatal women with body mass indices>25 kg/m2 (overweight/obese) at pregnancy commencement. INTERVENTION: Twelve-week Slimming World (SW) commercial group weight management programme, commencing anytime from 8 to 16 weeks postnatally. PRIMARY AND SECONDARY OUTCOME MEASURES: Data regarding uptake and retention from questionnaires and interviews conducted 6 and 12 months postbirth analysed thematically and mapped to the COM-B model. RESULTS: Barriers to SW uptake mostly concerned opportunity issues (eg, lack of time or childcare support) though some women also lacked motivation, not feeling that weight reduction was a priority, and a few cited capability issues such as lacking confidence. Weight loss aspirations were also a key factor explaining retention, as were social opportunity issues, particularly in relation to factors such as the extent of group identity and relationship with the group consultant; and physical opportunity such as perceived support from and fit with family lifestyle. In addition, barriers relating to beliefs and expectations about the SW programme were identified, including concerns regarding compatibility with breastfeeding and importance of exercise. Women's understanding of the SW approach, and capability to implement into their lifestyles, appeared related to level of attendance (dose-response effect). CONCLUSIONS: Uptake and retention in commercial weight management programmes may be enhanced by applying behaviour change techniques to address the barriers impacting on women's perceived capability, motivation and opportunity to participate. TRIAL REGISTRATION NUMBER: ISRCTN39186148

Optimal exercise intensity for individuals with impaired glucose tolerance

Upośledzona tolerancja glukozy (IGT, impaired glucose tolerance) jest stanem przejściowym między normoglikemią a cukrzycą. U co trzeciego nieleczonego chorego z powyższym zaburzeniem metabolicznym w ciągu 10 lat rozwinie się cukrzyca typu 2. U pacjentów z IGT uzasadnionym postępowaniem wydaje się wdrażanie metod mających na celu przywrócenie normoglikemii lub hamowanie postępu cukrzycy. Opublikowane w ostatnim czasie zalecenia Centers for Disease Control and Prevention oraz American College of Sports Medicine sugerują, że systematyczny wysiłek fizyczny o umiarkowanym natężeniu korzystnie wpływa na stan zdrowia chorych z IGT. Zdaniem autorów powyższych zaleceń każdy Amerykanin w ciągu doby powinien wykonywać wysiłek o umiarkowanym nasileniu trwający w sumie 30 minut. Obecnie obowiązujące zalecenia oparte są głównie na danych epidemiologicznych. Istnieje niewiele danych pochodzących z badań klinicznych, świadczących, że właśnie taki wysiłek istotnie obniża stężenie glukozy. Wydaje się, że konieczny byłby intensywniejszy wysiłek, aby poprawić tolerancję glukozy oraz działanie insuliny. Mimo że wysiłek o większym nasileniu wydaje się kluczem do poprawy homeostazy glukozy, to jednak mógłby powodować mechaniczne i oksydacyjne uszkodzenie prowadzące do przejściowego upośledzenia działania insuliny i tolerancji glukozy. Dlatego też u chorych z IGT optymalny wysiłek fizyczny oznacza wysiłek o wyważonej intensywności.Impaired glucose tolerance (IGT) is a transitory state between normoglycemia and frank diabetes. One in three individuals with IGT will develop type 2 diabetes within 10 years if left untreated. A strong rationale exists for the implementation of strategies designed to reverse or stabilize the deterioration in glucose homeostasis in individuals with IGT. Recent physical activity guidelines from the Centers for Disease Control and Prevention and the American College of Sports Medicine have suggested that intermittent moderate-intensity exercise is beneficial and can improve the health status of these individuals. Specifically, the guidelines recommend that every American should accumulate 30 min of moderate- intensity physical activity per day. The current guidelines are based predominantly on epidemiological data, and very little clinical evidence exists that this level of physical activity can significantly improve glycemic status. More intense exercise prescriptions would appear to be needed to improve glucose tolerance and insulin action. Although higher exercise intensity is a key determinant for improvements in glucose homeostasis, it may produce mechanical and oxidative damage that can result in transitory impairments in insulin action and glucose tolerance. Therefore, the optimal exercise inten-sity for an individual with IGT appears to lie between these two extremes

Open Access Publishing in Business Research: The Authors’ Perspective

Open access (OA) publishing is now accepted as an integral part of the emerging trends within scholarly communication. Business librarians, like their subject specialist colleagues in other disciplines, are increasingly called upon to interpret scholarly communication trends to their faculty. This study surveys 1,293 business faculty from American schools of business accredited by the Association to Advance Collegiate Schools of Business. Issues explored include business faculty publishing practices within the discipline and how these affect academic advancement, obtaining articles for their own research, electronic publishing, self-archiving, and their perceptions about OA publishing generally.With support from the Emerald Publishing Research Award 2009

Direct reaction measurements with a 132Sn radioactive ion beam

The (d,p) neutron transfer and (d,d) elastic scattering reactions were measured in inverse kinematics using a radioactive ion beam of 132Sn at 630 MeV. The elastic scattering data were taken in a region where Rutherford scattering dominated the reaction, and nuclear effects account for less than 8% of the cross section. The magnitude of the nuclear effects was found to be independent of the optical potential used, allowing the transfer data to be normalized in a reliable manner. The neutron-transfer reaction populated a previously unmeasured state at 1363 keV, which is most likely the single-particle 3p1/2 state expected above the N=82 shell closure. The data were analyzed using finite range adiabatic wave calculations and the results compared with the previous analysis using the distorted wave Born approximation. Angular distributions for the ground and first excited states are consistent with the previous tentative spin and parity assignments. Spectroscopic factors extracted from the differential cross sections are similar to those found for the one neutron states beyond the benchmark doubly-magic nucleus 208Pb.Comment: 22 pages, 7 figure

Pumped-Up SU(1,1) interferometry

Although SU(1,1) interferometry achieves Heisenberg-limited sensitivities, it suffers from one major drawback: Only those particles outcoupled from the pump mode contribute to the phase measurement. Since the number of particles outcoupled to these “side modes” is typically small, this limits the interferometer’s absolute sensitivity. We propose an alternative “pumped-up” approach where all the input particles participate in the phase measurement and show how this can be implemented in spinor Bose-Einstein condensates and hybrid atom-light systems—both of which have experimentally realized SU(1,1) interferometry. We demonstrate that pumped-up schemes are capable of surpassing the shot-noise limit with respect to the total number of input particles and are never worse than conventional SU(1,1) interferometry. Finally, we show that pumped-up schemes continue to excel—both absolutely and in comparison to conventional SU(1,1) interferometry—in the presence of particle losses, poor particle-resolution detection, and noise on the relative phase difference between the two side modes. Pumped-up SU(1,1) interferometry therefore pushes the advantages of conventional SU(1,1) interferometry into the regime of high absolute sensitivity, which is a necessary condition for useful quantum-enhanced devices

Protection Against a Bovine Viral Diarrhea Virus (BVDV) Type 1 Challenge in Calves Vaccinated with a Bovine Herpesvirus-1 (BHV-1)-BVDV Recombinant

A recently developed recombinant bovine herpesvirus 1 (BHV-1) virus containing the envelope protein gp53 of bovine viral diarrhea virus (BVDV) type 1, BHV-1 (v1V31), was assessed for its ability to protect against BVDV in calves. Four calves were vaccinated intranasally with the recombinant BHV-1-BVDV vaccine and did not exhibit any clinical signs following vaccination. The vaccine virus was recovered from all vaccinated calves on days 8 through 10 and the replication appeared to be restricted to nasal passages. Twenty-eight days after vaccination, the four vaccinated and four control calves were challenged with the type 1 BVDV, strain NY-1. All calves had slight temperature elevations but the clinical signs were more severe in the control calves. The platelet counts were significantly depressed in the control calves. Prior to challenge, neither group had BVDV serum neutralizing antibody. The vaccinated calves developed higher serum antibody levels 2 months following challenge, indicating a secondary immune response. Necropsy was performed six weeks following infection. No latent BHV-1 virus was detected from the trigeminal ganglion of any of the vaccinated calves. The recombinant BHV-1 virus vaccine containing a single BVDV protein provided partial protection against BVDV infection

The Dark Side of ROTSE-III Prompt GRB Observations

We present several cases of optical observations during gamma-ray bursts (GRBs) which resulted in prompt limits but no detection of optical emission. These limits constrain the prompt optical flux densities and the optical brightness relative to the gamma-ray emission. The derived constraints fall within the range of properties observed in GRBs with prompt optical detections, though at the faint end of optical/gamma flux ratios. The presently accessible prompt optical limits do not require a different set of intrinsic or environmental GRB properties, relative to the events with prompt optical detections.Comment: ApJ accepted. 20 pages in draft manuscript form, which includes 6 pages of tables and 2 figure