Pair Production Constraints on Superluminal Neutrinos Revisited

We revisit the pair creation constraint on superluminal neutrinos considered by Cohen and Glashow in order to clarify which types of superluminal models are constrained. We show that a model in which the superluminal neutrino is effectively light-like can evade the Cohen-Glashow constraint.Comment: 5 pages, typo fixed, footnote on sterile neutrinos added, refs. adde

Nitrogen cycling in Sabine Lake

As a part of continuing efforts to investigate nitrogen cycling in Texas estuaries, denitrification, nitrogen fixation, dissimilatory nitrate reduction to ammonium (DNRA), and sediment oxygen demand were measured in Sabine Lake, Texas. Estuarine phytoplankton production can be limited by N availability, and sediments often are an important source of dissolved inorganic N ... . Denitrification transforms combined N to gaseous forms ... . These end-products represent unavailable nutrient sources to most estuarine producers (e.g., phytoplankton and bacteria; Howarth et al. 1988). Thus, denitrification may drive systems toward N limitation (Seitzinger 1990). The purposes of this study were to evaluate the importance of denitrification in nitrogen cycling and examine environmental conditions influencing nitrogen cycling in Sabine Lake. A membrane inlet mass spectrometer (MIMS) for dissolved gas measurement and high performance liquid chromatography (HPLC) system for ammonium isotope measurements were used to quantify denitrification, N-fixation, DNRA, and sediment oxygen demand. Four sampling trips to Sabine Lake were made in June, September, December 2000 and March 2001. Here, we report water column measurements and incubation experiment results.Final report submitted to: The Texas Water Development Board, contract #2000-483-337July 2001Marine Scienc

The complexities of 'otherness': reflections on embodiment of a young White British woman engaged in cross-generation research involving older people in Indonesia

This article has been made available through the Brunel Open Access Publishing Fund.If interviews are to be considered embodied experiences, than the potential influence of the embodied researcher must be explored. A focus on specific attributes such as age or ethnicity belies the complex and negotiated space that both researcher and participant inhabit simultaneously. Drawing on empirical research with stroke survivors in an ethnically mixed area of Indonesia, this paper highlights the importance of considering embodiment as a specific methodological concern. Three specific interactions are described and analysed, illustrating the active nature of the embodied researcher in narrative production and development. The intersectionality of embodied features is evident, alongside their fluctuating influence in time and place. These interactions draw attention to the need to consider the researcher within the interview process and the subsequent analysis and presentation of narrative findings. The paper concludes with a reinforcement of the importance of ongoing and meaningful reflexivity in research, a need to consider the researcher as the other participant, and specifically a call to engage with and present the dynamic nature of embodiment

Discrete Symmetries on the Light Front and a General Relation Connecting Nucleon Electric Dipole and Anomalous Magnetic Moments

We consider the electric dipole form factor, F_3(q^2), as well as the Dirac and Pauli form factors, F_1(q^2) and F_2(q^2), of the nucleon in the light-front formalism. We derive an exact formula for F_3(q^2) to complement those known for F_1(q^2) and F_2(q^2). We derive the light-front representation of the discrete symmetry transformations and show that time-reversal- and parity-odd effects are captured by phases in the light-front wave functions. We thus determine that the contributions to F_2(q^2) and F_3(q^2), Fock state by Fock state, are related, independent of the fundamental mechanism through which CP violation is generated. Our relation is not specific to the nucleon, but, rather, is true of spin-1/2 systems in general, be they lepton or baryon. The empirical values of the anomalous magnetic moments, in concert with empirical bounds on the associated electric dipole moments, can better constrain theories of CP violation. In particular, we find that the neutron and proton electric dipole moments echo the isospin structure of the anomalous magnetic moments, kappa^n ~ - kappa^p.Comment: 25 pages, 1 figure. Published version. Ref. adde

Youth, caregiver, and prescriber experiences of antipsychotic-related weight gain

Objectives. To explore the lived experience of youth, caregivers, and prescribers with antipsychotic medications. Design. We conducted a qualitative interpretive phenomenology study. Youth aged 11 to 25 with recent experience taking antipsychotics, the caregivers of youth taking antipsychotics, and the prescribers of antipsychotics were recruited. Subjects. Eighteen youth, 10 caregivers (parents), and 11 prescribers participated. Results. Eleven of 18 youth, six of ten parents, and all prescribers discussed antipsychotic-related weight gain. Participants were attuned to the numeric weight changes usually measured in pounds. Significant discussions occurred around weight changes in the context of body image, adherence and persistence, managing weight increases, and metabolic effects. These concepts were often inextricably linked but maintained the significance as separate issues. Participants discussed tradeoffs regarding the perceived benefits and risks of weight gain, often with uncertainty and inadequate information regarding the short- and long-term consequences. Conclusion. Antipsychotic-related weight gain in youth influences body image and weight management strategies and impacts treatment courses with respect to adherence and persistence. In our study, the experience of monitoring for weight and metabolic changes was primarily reactive in nature. Participants expressed ambiguity regarding the short- and long-term consequences of weight and metabolic changes

Two dimensionality in quasi one-dimensional cobalt oxides

By means of muon spin rotation and relaxation ($\mu^+$SR) techniques, we have investigated the magnetism of quasi one-dimensional (1D) cobalt oxides $AE_{n+2}$Co$_{n+1}$O$_{3n+3}$ ($AE$=Ca, Sr and Ba, $n$=1, 2, 3, 5 and $\infty$), in which the 1D CoO$_3$ chain is surrounded by six equally spaced chains forming a triangular lattice in the $ab$-plane, using polycrystalline samples, from room temperature down to 1.8 K. For the compounds with $n$=1 - 5, transverse field $\mu^+$SR experiments showed the existence of a magnetic transition below $\sim$100 K. The onset temperature of the transition ($T_{\rm c}^{\rm on}$) was found to decrease with $n$; from 100 K for $n$=1 to 60 K for $n$=5. A damped muon spin oscillation was observed only in the sample with $n$=1 (Ca$_3$Co$_2$O$_6$), whereas only a fast relaxation obtained even at 1.8 K in the other three samples. In combination with the results of susceptibility measurements, this indicates that a two-dimensional short-range antiferromagnetic (AF) order appears below $T_{\rm c}^{\rm on}$ for all compounds with $n$=1 - 5; but quasi-static long-range AF order formed only in Ca$_3$Co$_2$O$_6$, below 25 K. For BaCoO$_3$ ($n$=$\infty$), as $T$ decreased from 300 K, 1D ferromagnetic (F) order appeared below 53 K, and a sharp 2D AF transition occurred at 15 K.Comment: 12 pages, 14 figures, and 2 table