1,456 research outputs found
Doppler-free two-photon spectrum of the 000 band of the Ă1B1âX1A1 transition in difluorodiazirine, F2CN2
The Doppler-free two-photon excitation spectrum of the vibrationless Ă1B1âImage 1A1 transition of difluorodiazirine (F2CN2) has been recorded with a resolution of 15 MHz using a cw single-mode dye laser coupled to an external concentric resonator. The asymmetric rotor spectrum has been analysed and more than 350 lines randomly selected from all five branches were assigned in order to fit the ground- and excited-state rotational and quartic centrifugal distortion constants. From the rotational constants the rNN and rFF distances in the ground Image 1A1 and excited Ă1B1 state were determined. The geometry change upon excitation is found to be ÎrNN = 3.89(2) pm and ÎrFF = â4.09(2) pm. No perturbation in the rotational structure of the 000 band has been found. This points to a small singlet-triplet coupling matrix element in the small molecule limit
Confirmation of co-denitrification in grazed grassland
peer-reviewedPasture-based livestock systems are often associated with losses of reactive forms of nitrogen (N) to the environment. Research has focused on losses to air and water due to the health, economic and environmental impacts of reactive N. Di-nitrogen (N2) emissions are still poorly characterized, both in terms of the processes involved and their magnitude, due to financial and methodological constraints. Relatively few studies have focused on quantifying N2 losses in vivo and fewer still have examined the relative contribution of the different N2 emission processes, particularly in grazed pastures. We used a combination of a high 15N isotopic enrichment of applied N with a high precision of determination of 15N isotopic enrichment by isotope-ratio mass spectrometry to measure N2 emissions in the field. We report that 55.8âg N mâ2 (95%, CI 38 to 77âg mâ2) was emitted as N2 by the process of co-denitrification in pastoral soils over 123 days following urine deposition (100âg N mâ2), compared to only 1.1âg N mâ2 (0.4 to 2.8âg mâ2) from denitrification. This study provides strong evidence for co-denitrification as a major N2 production pathway, which has significant implications for understanding the N budgets of pastoral ecosystems.The authors are grateful for the funding that was provided through the Research Stimulus Fund Program administered by the Department of Agriculture & Food under the National Development Plan 2007â2013 RSF 07536. The first author is grateful for the funding provided by Teagasc through the Walsh Fellowship Scheme
Religious diversity, empathy, and God images : perspectives from the psychology of religion shaping a study among adolescents in the UK
Major religious traditions agree in advocating and promoting love of neighbour as well as love of God. Love of neighbour is reflected in altruistic behaviour and empathy stands as a key motivational factor underpinning altruism. This study employs the empathy scale from the Junior Eysenck Impulsiveness Questionnaire to assess the association between empathy and God images among a sample of 5993 religiously diverse adolescents (13â15 years old) attending state maintained schools in England, Northern Ireland, Scotland, Wales, and London. The key psychological theory being tested by these data concerns the linkage between God images and individual differences in empathy. The data demonstrate that religious identity (e.g. Christian, Muslim) and religious attendance are less important than the God images which young people hold. The image of God as a God of mercy is associated with higher empathy scores, while the image of God as a God of justice is associated with lower empathy scores
Modelling the habitat of the endangered Carpentarian Grasswren (Amytornis dorotheae): The importance of spatio-temporal habitat availability in a fire prone landscape
Species distribution modelling (SDM), a tool increasingly adopted to quantify geographic range size, often predicts speciesâ distributions as static. However, habitat availability may exhibit spatial and temporal variation when dynamic processes, such as fire, determine suitability. Static SDM approaches may not satisfactorily represent this dynamic process. We investigated the potential use of SDM to quantify dynamic habitat availability by applying the MaxEnt SDM technique to model the habitat of the Carpentarian Grasswren (Amytornis dorotheae), an endangered Australian passerine dependent on long unburnt vegetation in a fire prone system. By adjusting a typical SDM approach to incorporate the dynamic nature of fire, we modelled the spatio-temporal variation of suitable habitat over 12 years and compared it to a static modelling approach. Incorporating fire as a dynamic process increased the importance of the fire variable to models (from 35% permutation importance) and improved model performance, as evaluated by the AUC using cross-validation. Our dynamic model revealed sizeable temporal variation in the area and spatial arrangement of suitable habitat that was not apparent in the static model. This result may partly solve the mystery of why the species occurs as widely separated populations despite the presence of seemingly suitable intervening habitat. In areas where the species is no longer found, habitat availability was less consistent due to frequent fire, and fire refugia was more limited and isolated, when compared to sites with recent records. These results demonstrate that, when compared to a static approach, a dynamic SDM approach can lead to improved understanding of dynamic ecological processes, and their impact on a species
Expansion for the solutions of the Bogomolny equations on the torus
We show that the solutions of the Bogomolny equations for the Abelian Higgs
model on a two-dimensional torus, can be expanded in powers of a quantity
epsilon measuring the departure of the area from the critical area. This allows
a precise determination of the shape of the solutions for all magnetic fluxes
and arbitrary position of the Higgs field zeroes. The expansion is carried out
to 51 orders for a couple of representative cases, including the unit flux
case. We analyse the behaviour of the expansion in the limit of large areas, in
which case the solutions approach those on the plane. Our results suggest
convergence all the way up to infinite area.Comment: 26 pages, 8 figures, slightly revised version as published in JHE
Weight suppression and weight elevation are associated with eating disorder symptomatology in women age 50 and older: Results of the gender and body image study
Objective: Weight suppression (WS), the difference between highest past non-pregnancy weight and current weight, predicts negative outcomes in eating disorders, but the impact of WS and related weight constructs are understudied in nonclinical, midlife populations. We examined WS (current weight < highest weight) and weight elevation (WE), the opposite of WS (current weight > lowest weight) and their associations with eating psychopathology in women aged 50+. Method: Participants were a community-based sample (N = 1,776, M age = 59) who completed demographic and eating psychopathology questions via online survey. WS, WE, and WS Ă WE were tested as predictors of outcome variables; BMI and medical conditions that affect weight were controlled for. Results: Individuals that were higher on WS and WE were most likely to engage in current weight loss attempts, dieting in the past 5 years, and extreme lifetime restriction. Individuals with higher WS were more likely to experience binge eating, greater frequency of weight checking, overvaluation of shape and weight, and lifetime fasting. Individuals with higher WE were more likely to report negative life impacts of eating and dieting. Higher WS and WE each predicted higher levels of skipping meals over the lifetime. Discussion: This novel study investigated WS in midlife women and introduced a new conceptualization of weight change (WE) that may be more relevant for aging populations given that women tend to gain weight with age. The findings implicate the utility of investigating both WS and WE as factors associated with eating psychopathology in midlife women
Final-State Phases in , and Decays
The final-state phases in , and decays
appear to follow a pattern similar to those in , , and decays. Each set of processes is characterized by
three charge states but only two independent amplitudes, so the amplitudes form
triangles in the complex plane. For the first two sets the triangles appear to
have non-zero area, while for the or decays the areas
of the triangles are consistent with zero. Following an earlier discussion of
this behavior for decays, a similar analysis is performed for B decays, and
the relative phases and magnitudes of contributing amplitudes are determined.
The significance of recent results on \ob \to D^{(*)0} \bar{K}^{(*)0} is
noted. Open theoretical and experimental questions are indicated.Comment: 16 pages, LaTeX, 3 figures, to be submitted to Phys. Rev. D.
References added; comments on new experimental results and analysi
Unscreened Hartree-Fock calculations for metallic Fe, Co, Ni, and Cu from ab-initio Hamiltonians
Unscreened Hartree-Fock approximation (HFA) calculations for metallic Fe, Co,
Ni, and Cu are presented, by using a quantum-chemical approach. We believe that
these are the first HFA results to have been done for crystalline 3d transition
metals. Our approach uses a linearized muffin-tin orbital calculation to
determine Bloch functions for the Hartree one-particle Hamiltonian, and from
these obtains maximally localized Wannier functions, using a method proposed by
Marzari and Vanderbilt. Within this Wannier basis all relevant one-particle and
two-particle Coulomb matrix elements are calculated. The resulting
second-quantized multi-band Hamiltonian with ab-initio parameters is studied
within the simplest many-body approximation, namely the unscreened,
self-consistent HFA, which takes into account exact exchange and is free of
self-interactions. Although the d-bands sit considerably lower within HFA than
within the local (spin) density approximation L(S)DA, the exchange splitting
and magnetic moments for ferromagnetic Fe, Co, and Ni are only slightly larger
in HFA than what is obtained either experimentally or within LSDA. The HFA
total energies are lower than the corresponding LSDA calculations. We believe
that this same approach can be easily extended to include more sophisticated
ab-initio many-body treatments of the electronic structure of solids.Comment: 11 papes, 7 figures, 5 table
Cosmic Ray Energy Spectra and Mass Composition at the Knee - Recent Results from KASCADE -
Recent results from the KASCADE experiment on measurements of cosmic rays in
the energy range of the knee are presented. Emphasis is placed on energy
spectra of individual mass groups as obtained from an two-dimensional unfolding
applied to the reconstructed electron and truncated muon numbers of each
individual EAS. The data show a knee-like structure in the energy spectra of
light primaries (p, He, C) and an increasing dominance of heavy ones (A > 20)
towards higher energies. This basic result is robust against uncertainties of
the applied interaction models QGSJET and SIBYLL which are used in the shower
simulations to analyse the data. Slight differences observed between
experimental data and EAS simulations provide important clues for further
improvements of the interaction models. The data are complemented by new limits
on global anisotropies in the arrival directions of CRs and by upper limits on
point sources. Astrophysical implications for discriminating models of maximum
acceleration energy vs galactic diffusion/drift models of the knee are
discussed based on this data.Comment: 8 pages, 7 figures, to appear in Nuclear Physics B, Proceedings
Supplements, as part of the volume for the CRIS 2004, Cosmic Ray
International Seminar: GZK and Surrounding
Eating disorder recovery in men: A pilot study
Objective: This pilot study examined the validity of a comprehensive definition of recovery (physical, behavioral, and cognitive recovery indices) for the first time in men. Method: Men with an eating disorder history were recruited from former patients at eating disorder centers, university campuses, and fitness centers/gyms. At baseline and a 12-month follow-up, data were collected via online surveys, diagnostic interviews, and measured weight and height from men with an eating disorder history (n = 36) and men with no eating disorder history (n = 27). Results: Of the men with an eating disorder history, 15 met criteria for an eating disorder, 7 met criteria for partial recovery, and 5 for full recovery. Men who met criteria for full recovery did not differ significantly from men with no eating disorder history and had significantly lower levels of broad eating pathology, thinness and restricting expectancies, body shame, difficulties in stopping thoughts about body, food, or exercise, and male body attitudes related to muscularity and body fat than men with an eating disorder. Men meeting criteria for full recovery had higher levels of body acceptance and intuitive eating than men who met criteria for partial recovery or an eating disorder. In terms of predictive validity, of those fully recovered at baseline, 60% also met full recovery criteria at follow-up. Discussion: Preliminary findings suggest that a comprehensive definition of recovery applies to men. Although research with larger samples is needed, this research provides some optimism for the potential of recovery in men
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