455 research outputs found
Induced magnetism of carbon atoms at the graphene/Ni(111) interface
We report an element-specific investigation of electronic and magnetic
properties of the graphene/Ni(111) system. Using magnetic circular dichroism,
the occurrence of an induced magnetic moment of the carbon atoms in the
graphene layer aligned parallel to the Ni 3d magnetization is observed. We
attribute this magnetic moment to the strong hybridization between C and
Ni 3d valence band states. The net magnetic moment of carbon in the graphene
layer is estimated to be in the range of per atom.Comment: 10 pages, 3 figure
Complex-Orbital Order in Fe_3O_4 and Mechanism of the Verwey Transition
Electronic state and the Verwey transition in magnetite (Fe_3O_4) are studied
using a spinless three-band Hubbard model for 3d electrons on the B sites with
the Hartree-Fock approximation and the exact diagonalisation method.
Complex-orbital, e.g., 1/sqrt(2)[|zx> + i |yz>], ordered (COO) states having
noncollinear orbital moments ~ 0.4 mu_B on the B sites are obtained with the
cubic lattice structure of the high-temperature phase. The COO state is a novel
form of magnetic ordering within the orbital degree of freedom. It arises from
the formation of Hund's second rule states of spinless pseudo-d molecular
orbitals in the Fe_4 tetrahedral units of the B sites and ferromagnetic
alignment of their fictitious orbital moments. A COO state with longer
periodicity is obtained with pseudo-orthorhombic Pmca and Pmc2_1 structures for
the low-temperature phase. The state spontaneously lowers the crystal symmetry
to the monoclinic and explains experimentally observed rhombohedral cell
deformation and Jahn-Teller like distortion. From these findings, we consider
that at the Verwey transition temperature, the COO state remaining to be
short-range order impeded by dynamical lattice distortion in high temperature
is developed into that with long-range order coupled with the monoclinic
lattice distortion.Comment: 16 pages, 13 figures, 6 tables, accepted for publication in J. Phys.
Soc. Jp
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A systematic review of frameworks for the interrelationships of mental health evidence and policy in low- and middle-income countries
Background: The interrelationships between research evidence and policy-making are complex. Different theoretical frameworks exist to explain general evidence–policy interactions. One largely unexplored element of these interrelationships is how evidence interrelates with, and influences, policy/political agenda-setting. This review aims to identify the elements and processes of theories, frameworks and models on interrelationships of research evidence and health policy-making, with a focus on actionability and agenda-setting in the context of mental health in low- and middle-income countries (LMICs).
Methods: A systematic review of theories was conducted based on the BeHeMOTh search method, using a tested and refined search strategy. Nine electronic databases and other relevant sources were searched for peer-reviewed and grey literature. Two reviewers screened the abstracts, reviewed full-text articles, extracted data and performed quality assessments. Analysis was based on a thematic analysis. The included papers had to present an actionable theoretical framework/model on evidence and policy interrelationships, such as knowledge translation or evidence-based policy, specifically target the agenda-setting process, focus on mental health, be from LMICs and published in English.
Results: From 236 publications included in the full text analysis, no studies fully complied with our inclusion criteria. Widening the focus by leaving out ‘agenda-setting’, we included ten studies, four of which had unique conceptual frameworks focusing on mental health and LMICs but not agenda-setting. The four analysed frameworks confirmed research gaps from LMICs and mental health, and a lack of focus on agenda-setting. Frameworks and models from other health and policy areas provide interesting conceptual approaches and lessons with regards to agenda-setting.
Conclusion: Our systematic review identified frameworks on evidence and policy interrelations that differ in their elements and processes. No framework fulfilled all inclusion criteria. Four actionable frameworks are applicable to mental health and LMICs, but none specifically target agenda-setting. We have identified agenda-setting as a research theory gap in the context of mental health knowledge translation in LMICs. Frameworks from other health/policy areas could offer lessons on agenda-setting and new approaches for creating policy impact for mental health and to tackle the translational gap in LMICs
Higher incidence of perineal community acquired MRSA infections among toddlers
<p>Abstract</p> <p>Background</p> <p>A six-fold increase in pediatric MRSA infections, prompted us to examine the clinical profile of children with MRSA infections seen at Mercy Children's Hospital, Toledo, Ohio and to characterize the responsible strains.</p> <p>Methods</p> <p>Records were reviewed of pediatric patients who cultured positive for MRSA from June 1 to December 31, 2007. Strain typing by pulsed field gel electrophoresis (PFT) and DiversiLab, SCC<it>mec </it>typing, and PCR-based <it>lukSF-PV </it>gene (encodes Panton-Valentine leukocidin), arginine catabolic mobile element (ACME) and <it>cap</it>5 gene detection was performed.</p> <p>Results</p> <p>Chart review of 63 patients with MRSA infections revealed that 58(92%) were community acquired MRSA (CAMRSA). All CAMRSA were skin and soft tissue infections (SSTI). Twenty five (43%) patients were aged < 3 yrs, 19(33%) aged 4-12 and 14(24%) aged 13-18. Nineteen (76%) of those aged < 3 yrs had higher incidence of perineal infections compared to only 2(11%) of the 4-12 yrs and none of the 13-18 yrs of age. Infections in the extremities were more common in the older youth compared to the youngest children. Overall, there was a significant association between site of the infection and age group (Fisher's Exact p-value < 0.001). All CAMRSA were USA300 PFT, clindamycin susceptible, SCC<it>mec </it>type IVa and <it>lukSF-PV gene </it>positive. Nearly all contained ACME and about 80% were <it>cap</it>5 positive. Of the 58 USA300 strains by PFT, 55(95%) were also identified as USA300 via the automated repetitive sequence-based PCR method from DiversiLab.</p> <p>Conclusions</p> <p>CAMRSA SSTI of the perineum was significantly more common among toddlers and that of the extremities in older children. The infecting strains were all USA300 PFT. Further studies are needed to identify the unique virulence and colonization characteristics of USA300 strains in these infections.</p
Enhanced Crystal Field Splitting and Orbital Selective Coherence by Strong Correlations in V_2O_3
We present a study of the paramagnetic metallic and insulating phases of
vanadium sesquioxide by means of the th order muffin-tin orbital
implementation of density functional theory combined with dynamical mean-field
theory. The transition is shown to be driven by a correlation-induced
enhancement of the crystal field splitting within the manifold, which
results in a suppression of the hybridization between the and
bands. We discuss the changes in the effective quasi-particle band
structure caused by the correlations and the corresponding self-energies. At
temperatures of about 400 K we find the orbitals to display coherent
quasi-particle behavior, while a large imaginary part of the self-energy and
broad features in the spectral function indicate that the orbitals
are still far above their coherence temperature. The local spectral functions
are in excellent agreement with recent bulk sensitive photoemission data.
Finally, we also make a prediction for angle-resolved photoemission experiments
by calculating momentum-resolved spectral functions.Comment: Paper I will appear in condmat in two week
Persistence of Integration in the Face of Specialization: How Firms Navigated the Winds of Disintegration and Shaped the Architecture of the Semiconductor Industry
Interspecific comparisons of C\u3csub\u3e3\u3c/sub\u3e turfgrass for tennis use: I. Wear tolerance and carrying capacity under actual match play
Previous studies in the evaluation of wear tolerance have been conducted using wear simulators. Research to investigate wear tolerance of C3 turfgrasses under actual playing conditions and their carrying capacity is limited. Three grass tennis courts (replicates) maintained as official size (single) courts were constructed. Eight species and cultivars were randomized within the three courts (blocks): (1) ‘Keeneland’ Kentucky bluegrass (KB, Poa pratensis L.), (2) ‘Rubix’ KB, (3) ‘Villa’ velvet bentgrass (VBG, Agrostis canina L.), (4) ‘Puritan’ colonial bentgrass (CL, Agrostis capillaris L.), (5) ‘007’ creeping bentgrass (CB, Agrostis stolonifera L.), (6) fine fescue (FF, Festuca spp.) mixture, (7) ‘Karma’ perennial ryegrass (PR, Lolium perenne L.), and (8) ‘Wicked’ PR. Injury at the baseline was measured by counting healthy grass on four dates in 2017 and 2019 using an intersect grid. Carrying capacity at the baseline was derived as hours of play to sustain 90, 80, 70, and 60% grass cover. After 6 wk of actual tennis play involving \u3e120 participating players in 2017 and 2019, KB and PR were superior to other C3 turfgrass for wear tolerance and carrying capacity. These two species exhibited four times the carrying capacity of FF species and nearly 60% more carrying capacity than bentgrass (BG) species. Species of BG afforded higher shoot density and better traction than KB and PR, with VBG exhibiting the best traction, and FF and PR exhibiting the poorest traction. In 2017, greater cell wall content increased wear tolerance and carrying capacity. Velvet bentgrass was as good as KB and PR in overall wear tolerance and carrying capacity under actual match play
Research-policy partnerships - experiences of the Mental Health and Poverty Project in Ghana, South Africa, Uganda and Zambia
Background: Partnerships are increasingly common in conducting research. However, there is little published evidence about processes in research-policy partnerships in different contexts. This paper contributes to filling this gap by analysing experiences of research-policy partnerships between Ministries of Health and research organisations for the implementation of the Mental Health and Poverty Project in Ghana, South Africa, Uganda and Zambia. Methods: A conceptual framework for understanding and assessing research-policy partnerships was developed and guided this study. The data collection methods for this qualitative study included semi-structured interviews with Ministry of Health Partners (MOHPs) and Research Partners (RPs) in each country. Results: The term partnership was perceived by the partners as a collaboration involving mutually-agreed goals and objectives. The principles of trust, openness, equality and mutual respect were identified as constituting the core of partnerships. The MOHPs and RPs had clearly defined roles, with the MOHPs largely providing political support and RPs leading the research agenda. Different influences affected partnerships. At the individual level, personal relationships and ability to compromise within partnerships were seen as important. At the organisational level, the main influences included the degree of formalisation of roles and responsibilities and the internal structures and procedures affecting decision-making. At the contextual level, political environment and the degree of health system decentralisation affected partnerships. Conclusions: Several lessons can be learned from these experiences. Taking account of influences on the partnership at individual, organisation and contextual/system levels can increase its effectiveness. A common understanding of mutually-agreed goals and objectives of the partnership is essential. It is important to give attention to the processes of initiating and maintaining partnerships, based on clear roles, responsibilities and commitment of parties at different levels. Although partnerships are often established for a specific purpose, such as carrying out a particular project, the effects of partnership go beyond a particular initiative
Occurrence of Corynebacterium striatum as an emerging antibiotic-resistant nosocomial pathogen in a Tunisian hospital
Corynebacterium striatum is a nosocomial opportunistic pathogen increasingly associated with a wide range of human infections and is often resistant to several antibiotics. We investigated the susceptibility of 63 C. striatum isolated at the Farhat-Hached hospital, Sousse (Tunisia), during the period 2011?2014, to a panel of 16 compounds belonging to the main clinically relevant classes of antimicrobial agents. All strains were susceptible to vancomycin, linezolid, and daptomycin. Amikacin and gentamicin also showed good activity (MICs90 = 1 and 2 mg/L, respectively). High rates of resistance to penicillin (82.5%), clindamycin (79.4%), cefotaxime (60.3%), erythromycin (47.6%), ciprofloxacin (36.5%), moxifloxacin (34.9%), and rifampicin (25.4%) were observed. Fifty-nine (93.7%) out of the 63 isolates showed resistance to at least one compound and 31 (49.2%) were multidrug-resistant. Twenty-nine resistance profiles were distinguished among the 59 resistant C. striatum. Most of the strains resistant to fluoroquinolones showed a double mutation leading to an amino acid change in positions 87 and 91 in the quinolone resistance-determining region of the gyrA gene. The 52 strains resistant to penicillin were positive for the gene bla, encoding a class A ?-lactamase. Twenty-two PFGE patterns were identified among the 63 C. striatum, indicating that some clones have spread within the hospital
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