1,421 research outputs found
How different can h-cobordant manifolds be?
We study the homeomorphism types of manifolds h-cobordant to a fixed one. Our
investigation is partly motivated by the notion of special manifolds introduced
by Milnor in his study of lens spaces. In particular we revisit and clarify
some of the claims concerning h-cobordisms of these manifolds.Comment: 16 pages. Typo corrected and reference adde
Phase Transitions from Saddles of the Potential Energy Landscape
The relation between saddle points of the potential of a classical
many-particle system and the analyticity properties of its thermodynamic
functions is studied. For finite systems, each saddle point is found to cause a
nonanalyticity in the Boltzmann entropy, and the functional form of this
nonanalytic term is derived. For large systems, the order of the nonanalytic
term increases unboundedly, leading to an increasing differentiability of the
entropy. Analyzing the contribution of the saddle points to the density of
states in the thermodynamic limit, our results provide an explanation of how,
and under which circumstances, saddle points of the potential energy landscape
may (or may not) be at the origin of a phase transition in the thermodynamic
limit. As an application, the puzzling observations by Risau-Gusman et al. on
topological signatures of the spherical model are elucidated.Comment: 5 pages, no figure
PARTICIPATORY URBAN SENSING: CITIZENS\u27 ACCEPTANCE OF A MOBILE REPORTING SERVICE
Urban sensing describes the use of today\u27s mobile devices to collectively gather information about environmental issues of public interest. Such information and communication technology (ICT) tools can enhance current e-government practices by enabling citizens to actively participate in urban decision making and service delivery. Yet, it is widely unclear whether there is a link between the citizens? propensity to participate and the use of urban sensing technology. In this study we draw on technology acceptance literature to propose a model for the acceptance of a mobile reporting service, i.e. a sensing tool for reporting urban infrastructure issues to a municipality. The model explains perceived usefulness of urban sensing by the citizen?s degree of environmental awareness and his/her willingness to participate in public affairs. Furthermore, we conceptualize mobile literacy as an important antecedent of perceived ease of use. Empirical tests using data from 200 potential service adopters support these ideas. The findings also suggest that for mobile e-government offerings, perceived privacy risks are not a significant barrier to adoption. These results provide important implications for theory and practice
Relationship between Age-Dependent Body Constitution and Temporomandibular Joint Sounds in Adolescents
To date, risk factors for temporomandibular joint (TMJ) sounds are still not completely understood, and anatomical factors are suspected to influence their occurrence. This study aimed to evaluate the impact of body constitution on temporomandibular joint sounds of adolescents. 10- to 18-year-old participants of the LIFE Child Study were examined for TMJ sounds, and physical parameters such as body height, body weight, and general laxity of joints were measured. Odds ratios (OR) for associations of TMJ sounds and standard deviation scores (SDS) of body height and body weight were calculated by using binary logistic regression, including cofactors such as age and number of hypermobile joints. The OR for TMJ sounds and SDS of body height was 1.28 (95% confidence interval (CI) 1.06; 1.56) in females when the age-adjusted height value was above 0. SDS of body weight indicated significant ORs for TMJ sounds in males with values of 0.81 (95% CI 0.70; 0.94). No correlation was detected for SDS values and TMJ crepitus. Tall female adolescents seem to be more prone to TMJ clicking sounds, while their occurrence seems less likely in male adolescents with higher body weight
Pitfalls in the statistical examination and interpretation of the correspondence between physician and patient satisfaction ratings and their relevance for shared decision making research
BACKGROUND: The correspondence of satisfaction ratings between physicians and patients can be assessed on different dimensions. One may examine whether they differ between the two groups or focus on measures of association or agreement. The aim of our study was to evaluate methodological difficulties in calculating the correspondence between patient and physician satisfaction ratings and to show the relevance for shared decision making research. METHODS: We utilised a structured tool for cardiovascular prevention (arribaâ˘) in a pragmatic cluster-randomised controlled trial. Correspondence between patient and physician satisfaction ratings after individual primary care consultations was assessed using the Patient Participation Scale (PPS). We used the Wilcoxon signed-rank test, the marginal homogeneity test, Kendall's tau-b, weighted kappa, percentage of agreement, and the Bland-Altman method to measure differences, associations, and agreement between physicians and patients. RESULTS: Statistical measures signal large differences between patient and physician satisfaction ratings with more favourable ratings provided by patients and a low correspondence regardless of group allocation. Closer examination of the raw data revealed a high ceiling effect of satisfaction ratings and only slight disagreement regarding the distributions of differences between physicians' and patients' ratings. CONCLUSIONS: Traditional statistical measures of association and agreement are not able to capture a clinically relevant appreciation of the physician-patient relationship by both parties in skewed satisfaction ratings. Only the Bland-Altman method for assessing agreement augmented by bar charts of differences was able to indicate this
Evaluating an implementation strategy in cardiovascular prevention to improve prescribing of statins in Germany: an intention to treat analysis
BACKGROUND: The prescription of statins is an evidence-based treatment to reduce the risk of cardiovascular events in patients with elevated cardiovascular risk or with a cardiovascular disorder (CVD). In spite of this, many of these patients do not receive statins.
METHODS: We evaluated the impact of a brief educational intervention in cardiovascular prevention in primary care physicians' prescribing behaviour regarding statins beyond their participation in a randomised controlled trial (RCT). For this, prescribing data of all patients >= 35 years who were counselled before and after the study period were analysed (each n > 75000). Outcome measure was prescription of Hydroxymethylglutaryl-CoA Reductase Inhibitors (statins) corresponding to patients' overall risk for CVD. Appropriateness of prescribing was examined according to different risk groups based on the Anatomical Therapeutic Chemical Classification System (ATC codes).
RESULTS: There was no consistent association between group allocation and statin prescription controlling for risk status in each risk group before and after study participation. However, we found a change to more significant drug configurations predicting the prescription of statins in the intervention group, which can be regarded as a small intervention effect.
CONCLUSION: Our results suggest that an active implementation of a brief evidence-based educational intervention does not lead to prescription modifications in everyday practice. Physician's prescribing behaviour is affected by an established health care system, which is not easy to change.Trial registration: ISRCTN71348772
Late Quaternary aeolian dynamics, pedostratigraphy and soil formation in the North European Lowlands â new findings from the Baruther ice-marginal valley
The construction of dunes in central Europe reflects ample sediment supply during the last deglacial hemicycle. A Quaternary inland dune complex in southern Brandenburg, Germany, was studied to determine the duration of recent pedogenesis, from two outcrops, which show buried paleosols. An integrative approach, which combined geomorphological, sedimentological, (paleo-)pedological and chronological methods was used to identify aeolian deposition events, ensuing pedogenesis and anthropogenic remobilization. At the outcrops, which were situated approximately 2 km apart from each other, in total twelve samples of the aeolian sands were dated using optically stimulated luminescence (OSL) and six using 14C dating. Although the dunes have similar morphological features, these forms have a different history of aeolian sand deposition and pedogenesis. At the older dune (Gl 1) the surface soil is a well developed Podzol, whereas soil development of the younger dune (Gl 2) is clearly in an initial state. The two dunes also differ in grain size distribution and in the presence of buried soils, thereby indicating a climatic impact on aeolian remobilization
GPsâ motivation for teaching medical students in a rural areaâdevelopment of the Motivation for Medical Education Questionnaire (MoME-Q)
Background The establishment of a medical education program in the rural area of Siegen is planned to be the first step against a shortage of physicians in this region. General practitioners (GPs) will be extensively involved in this program as Family Medicine (Allgemeinmedizin) will become a core subject in the curriculum nationwide. Based on this situation we aim to figure out GPs motivation to participate in medical education. For this purpose, we had to construct and test a new questionnaire. Methods A survey was conducted among general practitioners (GPs) in the region of Siegen-Wittgenstein regarding their motivation to participate in medical education. For this purpose, the Motivation for Medical Education Questionnaire (MoME-Q), a 24-item questionnaire, was developed. Structural characteristics of GPs, the Maslach Burnout Inventory (MBI) and the Work Satisfaction Questionnaire (WSQ) were used for validation purposes. Results A representative number of GPs took part in the study (53.8%). Although the majority had no connection to a university (86%), 83% can imagine participating in the education of medical students. The items of the MoME-Q load on two factors (commitment and personal benefit). The confirmatory factor analysis shows a good model fit. Subscales of the MoME-Q were able to differentiate between physicians with and without authorization to train GP residents, between practices with and without a specialized practice nurse, and between physicians with and without previous experience in medical education. The MoME-Q subscale âcommitmentâ correlated significantly with all three subscales of the MBI. Correlations were in the medium range around |.30|. Conclusion The MoME-Q seems to be an appropriate tool to assess motivation to participate in medical education of GPs. In our sample, a large number of GPs was motivated to participate in the education of medical students. Future studies with larger number of GPs should be carried out to validate and confirm our findings. Whether the MoME-Q is also appropriate for other specialties should also be shown in further empirical studies
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