The von Karman equations, the stress function, and elastic ridges in high dimensions

The elastic energy functional of a thin elastic rod or sheet is generalized to the case of an M-dimensional manifold in N-dimensional space. We derive potentials for the stress field and curvatures and find the generalized von Karman equations for a manifold in elastic equilibrium. We perform a scaling analysis of an M-1 dimensional ridge in an M = N-1 dimensional manifold. A ridge of linear size X in a manifold with thickness h << X has a width w ~ h^{1/3}X^{2/3} and a total energy E ~ h^{M} (X/h)^{M-5/3}. We also prove that the total bending energy of the ridge is exactly five times the total stretching energy. These results match those of A. Lobkovsky [Phys. Rev. E 53, 3750 (1996)] for the case of a bent plate in three dimensions.Comment: corrected references, 27 pages, RevTeX + epsf, 2 figures, Submitted to J. Math. Phy

Psychosocial burden and healthcare disillusionment in recurrent UTI: a large-scale international survey of patient perspectives

ObjectivesRecurrent UTI (rUTI) is a debilitating health condition that is associated with persistent mental, physical, and social burdens. People living with rUTI face inconsistencies in diagnostic testing and fragmented treatment pathways alongside their symptoms, which are likely to add considerably to their illness-related burdens. This study aimed to characterize the factors negatively impacting this population using the qualitative perspectives of people living with the condition.MethodsQualitative data were collected via free-text responses using an online survey hosted by an rUTI patient advocacy website. Female participants with self-reported rUTI (n = 1,983) described the factors that were most salient to their experience of living with the condition. Data were analyzed using a coding reliability approach to thematic analysis.ResultsTwo overarching themes were identified: (1) the patient burden of rUTI, which describes the multifaceted biopsychosocial impact of the illness, and (2) healthcare disillusionment, which describes patient dissatisfaction with healthcare received, both in terms of the treatments offered and communication with healthcare professionals. The patient burden of rUTI encompassed four subordinate themes: facing ongoing uncertainty; symptom salience; sex is not simple anymore; and perceived UTI stigma. Healthcare disillusionment included three subordinate themes: discomfort with frequent antibiotic use; fragmented treatment pathways; and devalued patient perspectives.ConclusionsThe findings demonstrated that ambiguity in the diagnosis of rUTI and inconsistencies in the subsequent treatment pathway are exacerbated by poor patient–clinician communication. The extent of the female-specific burden of rUTI symptoms confirmed the harmful effects of illness-related stigma. This novel qualitative reporting of rUTI symptom burden and life impact highlights the urgent need for increased patient-centered care for those living with rUTI. More effective rUTI management could have a major impact on treatment outcomes and patient-reported psychosocial wellbeing

A Modular Strategy for Fully Conjugated Donor–Acceptor Block Copolymers

A novel strategy for the synthesis of fully conjugated donor–acceptor block copolymers, in a single reaction step employing Stille coupling polymerization of end-functional polythiophene and AA + BB monomers, is presented. The unique donor–acceptor structure of these block copolymers provides a rich self-assembly behavior, with the first example of a fully conjugated donor–acceptor block copolymer having two separate crystalline domains being obtained

Confirmatory structural validation and refinement of the Recurrent Urinary Tract Infection Symptom Scale

AbstractObjectivesTo confirm the structural validity of the Recurrent Urinary Tract Infection Symptom Scale (RUTISS), determining whether a bifactor model appropriately fits the questionnaire's structure and identifying areas for refinement. Used in conjunction with established clinical testing methods, this patient‐reported outcome measure addresses the urgent need to validate the patient perspective.Patients and methodsA clinically and demographically diverse sample of 389 people experiencing recurrent UTI across 37 countries (96.9% female biological sex, aged 18–87 years) completed the RUTISS online. A bifactor graded response model was fitted to the data, identifying potential items for deletion if they indicated significant differential item functioning (DIF) based on sociodemographic characteristics, contributed to local item dependence or demonstrated poor fit or discrimination capability.ResultsThe final RUTISS comprised a 3‐item symptom frequency section, a 1‐item global rating of change scale and an 11‐item general ‘rUTI symptom and pain severity’ subscale with four sub‐factor domains measuring ‘urinary symptoms’, ‘urinary presentation’, ‘UTI pain and discomfort’ and ‘bodily sensations’. The bifactor model fit indices were excellent (root mean square error of approximation [RMSEA] = 0.041, comparative fit index [CFI] = 0.995, standardised root mean square residual [SRMSR] = 0.047), and the mean‐square fit statistics indicated that all items were productive for measurement (mean square fit indices [MNSQ] = 0.64 – 1.29). Eighty‐one per cent of the common model variance was accounted for by the general factor and sub‐factors collectively, and all factor loadings were greater than 0.30 and communalities greater than 0.60. Items indicated high discrimination capability (slope parameters &gt; 1.35).ConclusionThe 15‐item RUTISS is a patient‐generated, psychometrically robust questionnaire that dynamically assesses the patient experience of recurrent UTI symptoms and pain. This brief tool offers the unique opportunity to enhance patient‐centred care by supporting shared decision‐making and patient monitoring

They Treated us Like Employees Not Trainees: Patient Educator Interns’ Experiences of Epistemological Shock

Aim: To explore Patient Educator Interns’ (PEIs’) experiences of learning when entering the working environment. Methods: Semi-structured interviews were conducted with 10 PEIs. Following a narrative type of analysis, case summaries were prepared, compared and interpreted. Results: At the beginning of their internship, PEIs held specific desires and expectations concerning the type of training and work they would experience. These included the expectation of explicit educational activities and specific types of work activities. PEIs’ expectations were frequently not met in reality. Discussion: The findings of the study suggest that new graduates face epistemological shock, which is the challenge of understanding the change from receiving formal instruction at university to learning through participation and engagement in the workplace. Conclusions: Universities could do more to explain to students the differences in learning between university and the workplace, so students better understand the value of participation for learning

Is general relativity `essentially understood' ?

The content of Einstein's theory of gravitation is encoded in the properties of the solutions to his field equations. There has been obtained a wealth of information about these solutions in the ninety years the theory has been around. It led to the prediction and the observation of physical phenomena which confirm the important role of general relativity in physics. The understanding of the domain of highly dynamical, strong field configurations is, however, still quite limited. The gravitational wave experiments are likely to provide soon observational data on phenomena which are not accessible by other means. Further theoretical progress will require, however, new methods for the analysis and the numerical calculation of the solutions to Einstein's field equations on large scales and under general assumptions. We discuss some of the problems involved, describe the status of the field and recent results, and point out some open problems.Comment: Extended version of a talk which was to be delivered at the DPG Fruehjahrstagung in Berlin, 5 March 200

Systematic review of studies generating individual participant data on the efficacy of drugs for treating soil-transmitted helminthiases and the case for data-sharing

Preventive chemotherapy and transmission control (PCT) by mass drug administration is the cornerstone of the World Health Organization (WHO)’s policy to control soil-transmitted helminthiases (STHs) caused by Ascaris lumbricoides (roundworm), Trichuris trichiura (whipworm) and hookworm species (Necator americanus and Ancylostama duodenale) which affect over 1 billion people globally. Despite consensus that drug efficacies should be monitored for signs of decline that could jeopardise the effectiveness of PCT, systematic monitoring and evaluation is seldom implemented. Drug trials mostly report aggregate efficacies in groups of participants, but heterogeneities in design complicate classical meta-analyses of these data. Individual participant data (IPD) permit more detailed analysis of drug efficacies, offering increased sensitivity to identify atypical responses potentially caused by emerging drug resistance

Protective Efficacy of Menthol Propylene Glycol Carbonate Compared to N, N-diethyl-Methylbenzamide Against Mosquito Bites in Northern Tanzania.

The reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. This underscores the need for effective and long lasting arthropod/insect repellents. Despite the reduction in malaria transmission and outcomes in Tanzania, personal protection against mosquito bites is still not well investigated. This study sought to determine the efficacy of menthol propylene glycol carbonate (MR08), Ocimum suave as compared to the gold standard repellent N, N-diethyl-methylbenzamide (DEET), either as a single dose or in combination (blend), both in the laboratory and in the field against Anopheles gambiae s.l and Culex quinquefasciatus. In the laboratory evaluations, repellents were applied on one arm while the other arm of the same individual was treated with a base cream. Each arm was separately exposed in cages with unfed female mosquitoes. Repellents were evaluated either as a single dose or as a blend. Efficacy of each repellent was determined by the number of mosquitoes that landed and fed on treated arms as compared to the control or among them. In the field, evaluations were performed by human landing catches at hourly intervals from 18:00  hr to 01:00  hr. A total of 2,442 mosquitoes were collected during field evaluations, of which 2,376 (97.30%) were An. gambiae s.l while 66 (2.70%) were Cx. quinquefaciatus. MR08 and DEET had comparatively similar protective efficacy ranging from 92% to 100 for both single compound and blends. These findings indicate that MR08 has a similar protective efficacy as DEET for personal protection outside bed nets when used singly and in blends. Because of the personal protection provided by MR08, DEET and blends as topical applicants in laboratory and field situations, these findings suggest that, these repellents could be used efficiently in the community to complement existing tools. Overall, Cx. quinquefasciatus were significantly prevented from blood feeding compared to An. gambiae s.l. The incorporation of these topical repellents for protection against insect bites can be of additional value in the absence or presence of IRS and ITNs coverage. However, a combination of both the physical (bed nets) and the repellent should be used in an integrated manner for maximum protection, especially before going to bed. Additional research is needed to develop repellents with longer duration of protection