4,951 research outputs found
High-order harmonic generation from polyatomic molecules including nuclear motion and a nuclear modes analysis
We present a generic approach for treating the effect of nuclear motion in
the high-order harmonic generation from polyatomic molecules. Our procedure
relies on a separation of nuclear and electron dynamics where we account for
the electronic part using the Lewenstein model and nuclear motion enters as a
nuclear correlation function. We express the nuclear correlation function in
terms of Franck-Condon factors which allows us to decompose nuclear motion into
modes and identify the modes that are dominant in the high-order harmonic
generation process. We show results for the isotopes CH and CD and
thereby provide direct theoretical support for a recent experiment [Baker {\it
et al.}, Science {\bf 312}, 424 (2006)] that uses high-order harmonic
generation to probe the ultra-fast structural nuclear rearrangement of ionized
methane.Comment: 6 pages, 6 figure
Application of p-Multigrid to Discontinuous Galerkin Formulations of the Poisson Equation
We investigate p-multigrid as a solution method for several different discontinuous Galerkin (DG) formulations of the Poisson equation. Different combinations of relaxation schemes and basis sets have been combined with the DG formulations to find the best performing combination. The damping factors of the schemes have been determined using Fourier analysis for both one and two-dimensional problems. One important finding is that when using DG formulations, the standard approach of forming the coarse p matrices separately for each level of multigrid is often unstable. To ensure stability the coarse p matrices must be constructed from the fine grid matrices using algebraic multigrid techniques. Of the relaxation schemes, we find that the combination of Jacobi relaxation with the spectral element basis is fairly effective. The results using this combination are p sensitive in both one and two dimensions, but reasonable convergence rates can still be achieved for moderate values of p and isotropic meshes. A competitive alternative is a block Gauss-Seidel relaxation. This actually out performs a more expensive line relaxation when the mesh is isotropic. When the mesh becomes highly anisotropic, the implicit line method and the Gauss-Seidel implicit line method are the only effective schemes. Adding the Gauss-Seidel terms to the implicit line method gives a significant improvement over the line relaxation method
Contextual Positive Psychology: Policy Recommendations for Implementing Positive Psychology into Schools
There has been a rapid growth in positive psychology, a research and intervention approach that focuses on promoting optimal functioning and well-being. Positive psychology interventions are now making their way into classrooms all over the world. However, positive psychology has been criticized for being decontextualized and coercive, and for putting an excessive emphasis on positive states, whilst failing to adequately consider negative experiences. Given this, how should policy be used to regulate and evaluate these interventions? We review evidence that suggests these criticisms may be valid, but only for those interventions that focus almost exclusively on changing the content of people’s inner experience (e.g., make it more positive) and personality (improving character strength), and overemphasize the idea that inner experience causes action. We describe a contextualized form of positive psychology that not only deals with the criticisms, but also has clear policy implications for how to best implement and evaluate positive education programs so that they do not do more harm than good
The Multi-Fungicide Resistance Status of Aspergillus fumigatus Populations in Arable Soils and the Wider European Environment
The evolution and spread of pan-azole resistance alleles in clinical and environmental isolates of Aspergillus fumigatus is a global human health concern. The identification of hotspots for azole resistance development in the wider environment can inform optimal measures to counteract further spread by minimizing exposure to azole fungicides and reducing inoculum build-up and pathogen dispersal. We investigated the fungicide sensitivity status of soil populations sampled from arable crops and the wider environment and compared these with urban airborne populations. Low levels of azole resistance were observed for isolates carrying the CYP51A variant F46Y/M172V/E427K, all belonging to a cluster of related cell surface protein (CSP) types which included t07, t08, t13, t15, t19, and t02B, a new allele. High levels of resistance were found in soil isolates carrying CYP51A variants TR34/L98H and TR46/Y121F/T289A, all belonging to CSP types t01, t02, t04B, or t11. TR46/Y121F/M172V/T289A/G448S (CSP t01) and TR46/Y121F/T289A/S363P/I364V/G448S (CSP t01), a new haplotype associated with high levels of resistance, were isolated from Dutch urban air samples, indicating azole resistance evolution is ongoing. Based on low numbers of pan-azole resistant isolates and lack of new genotypes in soils of fungicide-treated commercial and experimental wheat crops, we consider arable crop production as a coldspot for azole resistance development, in contrast to previously reported flower bulb waste heaps. This study also shows that, in addition to azole resistance, several lineages of A. fumigatus carrying TR-based CYP51A variants have also developed acquired resistance to methyl benzimidazole carbamate, quinone outside inhibitor and succinate dehydrogenase (Sdh) inhibitor fungicides through target-site alterations in the corresponding fungicide target proteins; beta-tubulin (F200Y), cytochrome b (G143A), and Sdh subunit B (H270Y and H270R), respectively. Molecular typing showed that several multi-fungicide resistant strains found in agricultural soils in this study were clonal as identical isolates have been found earlier in the environment and/or in patients. Further research on the spread of different fungicide-resistant alleles from the wider environment to patients and vice versa can inform optimal practices to tackle the further spread of antifungal resistance in A. fumigatus populations and to safeguard the efficacy of azoles for future treatment of invasive aspergillosis
Designing an implementation intervention with the Behaviour Change Wheel for health provider smoking cessation care for Australian Indigenous pregnant women.
BACKGROUND: Indigenous smoking rates are up to 80% among pregnant women: prevalence among pregnant Australian Indigenous women was 45% in 2014, contributing significantly to the health gap for Indigenous Australians. We aimed to develop an implementation intervention to improve smoking cessation care (SCC) for pregnant Indigenous smokers, an outcome to be achieved by training health providers at Aboriginal Medical Services (AMS) in a culturally competent approach, developed collaboratively with AMS. METHOD: The Behaviour Change Wheel (BCW), incorporating the COM-B model (capability, opportunity and motivation for behavioural interventions), provided a framework for the development of the Indigenous Counselling and Nicotine (ICAN) QUIT in Pregnancy implementation intervention at provider and patient levels. We identified evidence-practice gaps through (i) systematic literature reviews, (ii) a national survey of clinicians and (iii) a qualitative study of smoking and quitting with Aboriginal mothers. We followed the three stages recommended in Michie et al.'s "Behaviour Change Wheel" guide. RESULTS: Targets identified for health provider behaviour change included the following: capability (psychological capability, knowledge and skills) by training clinicians in pharmacotherapy to assist women to quit; motivation (optimism) by presenting evidence of effectiveness, and positive testimonials from patients and clinicians; and opportunity (environmental context and resources) by promoting a whole-of-service approach and structuring consultations using a flipchart and prompts. Education and training were selected as the main intervention functions. For health providers, the delivery mode was webinar, to accommodate time and location constraints, bringing the training to the services; for patients, face-to-face consultations were supported by a booklet embedded with videos to improve patients' capability, opportunity and motivation. CONCLUSIONS: The ICAN QUIT in Pregnancy was an intervention to train health providers at Aboriginal Medical Services in how to implement culturally competent evidence-based practice including counselling and nicotine replacement therapy for pregnant patients who smoke. The BCW aided in scientifically and systematically informing this targeted implementation intervention based on the identified gaps in SCC by health providers. Multiple factors impact at systemic, provider, community and individual levels. This process was therefore important for defining the design and intervention components, prior to a conducting a pilot feasibility trial, then leading on to a full clinical trial
One hundred and twelve infected arthroplasties treated with ‘DAIR’ (debridement, antibiotics and implant retention): antibiotic duration and outcome
Partition function of two- and three-dimensional Potts ferromagnets for arbitrary values of q>0
A new algorithm is presented, which allows to calculate numerically the
partition function Z_q of the d-dimensional q-state Potts models for arbitrary
real values q>0 at any given temperature T with high precision. The basic idea
is to measure the distribution of the number of connected components in the
corresponding Fortuin-Kasteleyn representation and to compare with the
distribution of the case q=1 (graph percolation), where the exact result Z_1=1
is known.
As application, d=2 and d=3-dimensional ferromagnetic Potts models are
studied, and the critical values q_c, where the transition changes from second
to first order, are determined. Large systems of sizes N=1000^2 respectively
N=100^3 are treated. The critical value q_c(d=2)=4 is confirmed and
q_c(d=3)=2.35(5) is found.Comment: 4 pages, 4 figures, RevTe
Lowering Cardiovascular Disease Risk for People with Severe Mental Illnesses in Primary Care: A Focus Group Study.
BACKGROUND: People with severe mental illnesses die early from cardiovascular disease. Evidence is lacking regarding effective primary care based interventions to tackle this problem. AIM: To identify current procedures for, barriers to, and facilitators of the delivery of primary care based interventions for lowering cardiovascular risk for people with severe mental illnesses. METHOD: 75 GPs, practice nurses, service users, community mental health staff and carers in UK GP practice or community mental health settings were interviewed in 14 focus groups which were audio-recorded, transcribed and analysed using Framework Analysis. RESULTS: Five barriers to delivering primary care based interventions for lowering cardiovascular risk in people with severe mental illnesses were identified by the groups: negative perceptions of people with severe mental illnesses amongst some health professionals, difficulties accessing GP and community-based services, difficulties in managing a healthy lifestyle, not attending appointments, and a lack of awareness of increased cardiovascular risk in people with severe mental illnesses by some health professionals. Identified facilitators included involving supportive others, improving patient engagement with services, continuity of care, providing positive feedback in consultations and goal setting. CONCLUSION: We identified a range of factors which can be incorporated in to the design, delivery and evaluation of services to reduce cardiovascular risk for people with severe mental illnesses in primary care. The next step is determining the clinical and cost effectiveness of primary care based interventions for lowering cardiovascular risk in people with severe mental illnesses, and evaluating the most important components of such interventions
Long-Term Use of Nonsteroidal Anti-inflammatory Drugs Decreases the Risk of Cutaneous Melanoma: Results of a United States Case–Control Study
Experimental and observational studies continue to demonstrate conflicting results regarding the role of several commonly used drugs as melanoma chemopreventive agents. This case–control study was designed to assess the associations between cutaneous melanoma (CM) and exposure to nonsteroidal anti-inflammatory drugs (NSAIDs) and statins in current users. A total of 400 CM and 600 eligible age- and gender-matched community-based controls were prospectively recruited and interviewed. We assessed participants’ demographic characteristics, CM risk factors, and current and previous use of medications. Multivariable conditional logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for associations between NSAIDs and/or aspirin (ASA), statin exposure, and CM risk. Half of the subjects were men (mean age 60 years). After adjusting for confounders, use of any type of NSAIDs for more than 5 years significantly reduced the risk of melanoma development compared with the low-exposure group (adjusted OR=0.57; 95% CI=0.43–0.77). Subgroup analyses showed that the observed risk reduction was primarily driven by continuous ASA use (>5 years adjusted OR=0.51, 95% CI=0.35–0.75). No significant protective effect was observed with statin exposure (OR=0.97, 95% CI=0.73–1.29). Long-term use of NSAIDs, especially ASA, is associated with a significantly decreased risk of CM development. Clinical intervention studies are warranted to further investigate the potential role of ASA and other NSAIDs as chemopreventive agents for CM.JID JOURNAL CLUB ARTICLE: For questions, answers, and open discussion about this article, please go to http://www.nature.com/jid/journalclu
Epidemiological studies of pan-azole resistant Aspergillus fumigatus populations sampled during tulip cultivation show clonal expansion with acquisition of multi-fungicide resistance as potential driver
Pan-azole resistant isolates are found in clinical and environmental Aspergillus fumigatus (Af) populations. Azole resistance can evolve in both settings, with Af directly targeted by antifungals in patients and, in the environment, Af unintendedly exposed to fungicides used for material preservation and plant disease control. Resistance to non-azole fungi-cides, including methyl benzimidazole carbamates (MBCs), quinone outside inhibitors (QoIs) and succinate dehydrogenase inhibitors (SDHIs), have recently been reported. These fungicide groups are not used in medicine but can play an important role in further spread of pan-azole resistant genotypes. We investigated the multi-fungicide resistance status and genetic diversity of Af populations sampled from tulip field soils, tulip peel waste and flower compost heaps using fungicide sensitivity testing and a range of genotyping tools, including STRAf typing and sequencing of fungicide resistant alleles. Two major clones were present in the tulip bulb population. Comparisons with clinical isolates and literature data revealed that several common clonal lineages of TR34/L98H and TR46/Y121F/T289A strains that have expanded successfully in the environment have also acquired resistance to MBC, QoI and/or SDHI fungicides. Strains carrying multiple fungicide resistant alleles have an advantage in environments where residues of multiple fungicides belonging to different modes of action are presen
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