Symmetric space description of carbon nanotubes

Using an innovative technique arising from the theory of symmetric spaces, we obtain an approximate analytic solution of the Dorokhov-Mello-Pereyra-Kumar (DMPK) equation in the insulating regime of a metallic carbon nanotube with symplectic symmetry and an odd number of conducting channels. This symmetry class is characterized by the presence of a perfectly conducting channel in the limit of infinite length of the nanotube. The derivation of the DMPK equation for this system has recently been performed by Takane, who also obtained the average conductance both analytically and numerically. Using the Jacobian corresponding to the transformation to radial coordinates and the parameterization of the transfer matrix given by Takane, we identify the ensemble of transfer matrices as the symmetric space of negative curvature SO^*(4m+2)/[SU(2m+1)xU(1)] belonging to the DIII-odd Cartan class. We rederive the leading-order correction to the conductance of the perfectly conducting channel and its variance Var(log(delta g)). Our results are in complete agreement with Takane's. In addition, our approach based on the mapping to a symmetric space enables us to obtain new universal quantities: a universal group theoretical expression for the ratio Var(log(delta g)/ and as a byproduct, a novel expression for the localization length for the most general case of a symmetric space with BC_m root system, in which all three types of roots are present.Comment: 23 pages. Text concerning symmetric space description augmented, table and references added. Version to be published on JSTA

Refusal to enrol in Ghana's National Health Insurance Scheme: is affordability the problem?

BACKGROUND: Access to health insurance is expected to have positive effect in improving access to healthcare and offer financial risk protection to households. Ghana began the implementation of a National Health Insurance Scheme (NHIS) in 2004 as a way to ensure equitable access to basic healthcare for all residents. After a decade of its implementation, national coverage is just about 34% of the national population. Affordability of the NHIS contribution is often cited by households as a major barrier to enrolment in the NHIS without any rigorous analysis of this claim. In light of the global interest in achieving universal health insurance coverage, this study seeks to examine the extent to which affordability of the NHIS contribution is a barrier to full insurance for households and a burden on their resources. METHODS: The study uses data from a cross-sectional household survey involving 2,430 households from three districts in Ghana conducted between January-April, 2011. Affordability of the NHIS contribution is analysed using the household budget-based approach based on the normative definition of affordability. The burden of the NHIS contributions to households is assessed by relating the expected annual NHIS contribution to household non-food expenditure and total consumption expenditure. Households which cannot afford full insurance were identified. RESULTS: Results show that 66% of uninsured households and 70% of partially insured households could afford full insurance for their members. Enroling all household members in the NHIS would account for 5.9% of household non-food expenditure or 2.0% of total expenditure but higher for households in the first (11.4%) and second (7.0%) socio-economic quintiles. All the households (29%) identified as unable to afford full insurance were in the two lower socio-economic quintiles and had large household sizes. Non-financial factors relating to attributes of the insurer and health system problems also affect enrolment in the NHIS. CONCLUSION: Affordability of full insurance would be a burden on households with low socio-economic status and large household size. Innovative measures are needed to encourage abled households to enrol. Policy should aim at abolishing the registration fee for children, pricing insurance according to socio-economic status of households and addressing the inimical non-financial factors to increase NHIS coverage

Does the National Health Insurance Scheme provide financial protection to households in Ghana?

BACKGROUND: Excessive healthcare payments can impede access to health services and also disrupt the welfare of households with no financial protection. Health insurance is expected to offer financial protection against health shocks. Ghana began the implementation of its National Health Insurance Scheme (NHIS) in 2004. The NHIS is aimed at removing the financial barrier to healthcare by limiting direct out-of-pocket health expenditures (OOPHE). The study examines the effect of the NHIS on OOPHE and how it protects households against catastrophic health expenditures. METHODS: Data was obtained from a cross-sectional representative household survey involving 2,430 households from three districts across Ghana. All OOPHE associated with treatment seeking for reported illness in the household in the last 4 weeks preceding the survey were analysed and compared between insured and uninsured persons. The incidence and intensity of catastrophic health expenditures (CHE) among households were measured by the catastrophic health payment method. The relative effect of NHIS on the incidence of CHE in the household was estimated by multiple logistic regression analysis. RESULTS: About 36% of households reported at least one illness during the 4 weeks period. Insured patients had significantly lower direct OOPHE for out-patient and in-patient care compared to the uninsured. On financial protection, the incidence of CHE was lower among insured households (2.9%) compared to the partially insured (3.7%) and the uninsured (4.0%) at the 40% threshold. The incidence of CHE was however significantly lower among fully insured households (6.0%) which sought healthcare from NHIS accredited health facilities compared to the partially insured (10.1%) and the uninsured households (23.2%). The likelihood of a household incurring CHE was 4.2 times less likely for fully insured and 2.9 times less likely for partially insured households relative to being uninsured. The NHIS has however not completely eliminated OOPHE for the insured and their households. CONCLUSION: The NHIS has significant effect in reducing OOPHE and offers financial protection against CHE for insured individuals and their households though they still made some out-of-pocket payments. Efforts should aim at eliminating OOPHE for the insured if the objective for establishing the NHIS is to be achieved

Predatory arthropod community composition in apple orchards: Orchard management, landscape structure and sampling method

Studies on predatory arthropods in agricultural areas seldom include Diptera other than hoverflies, partly because common sampling methods are less effective for capturing species that easily fly off when disturbed. To study the effect from this bias when describing the predator community, we compared traditional beat sampling of branches and suction sampling for describing the community of predatory arthropods in Swedish apple orchards, both organic orchards and orchards using integrated pest management (IPM). Our results indicate that the proportion of both predatory dipterans and parasitic hymenopterans increase dramatically when using suction sampling (Diptera: 32% vs. 20%, Hymenoptera: 25% vs. 7%). In fact, predatory dipterans were the most abundant predatory group when using suction sampling, in contrast to beat sampling where spiders were the most abundant group. One group of predatory flies that was particularly rich in both species and individuals in the surveyed apple orchards was dance flies in the family Hybotidae. Even though the bias of sampling method was evident, it was encouraging that the method choice did not affect the conclusions concerning management on predatory arthropod communities. With both methods, dipteran and coleopteran predators were more abundant in organic apple orchards whereas opilionids were more abundant in orchards managed according to IPM. The inclusion of landscape variables further indicated effects of landscape diversity and of deciduous forest cover, but the response varied in sign between predatory groups. Whereas both Coleoptera and Heteroptera were more abundant in orchards surrounded by more complex landscapes (high landscape diversity and/or high deciduous forest cover), spiders, opilionids and dipterans were rather less abundant in these orchards. To conclude, our study points to the potential importance of predatory dipterans in apple orchards, and we highly recommend future studies of arthropod predators in apple and other crops to actively include predatory Diptera

Biglycan neo-epitope (BGN(262)), a novel biomarker for screening early changes in equine osteoarthritic subchondral bone

Objective: Native biglycan (BGN), which can undergo proteolytic cleavage in pathological conditions, is well known to be involved in bone formation and mineralization. This study aimed to delineate the specific cleavage fragment, a neo-epitope for BGN (BGN(262)), in synovial fluid (SF) from young racehorses in training, osteoarthritic (OA) joints with subchondral bone sclerosis (SCBS), and chip fracture joints.Design: A custom-made inhibition ELISA was developed to quantify BGN(262) in SF. Cohort 1: A longitudinal study comprising 10 racehorses undergoing long-term training. Cohort 2: A cross-sectional study comprising joints from horses (N = 69) with different stages of OA and radiographically classified SCBS. Cohort 3: A cross-sectional study comprising horses (N = 9) with chip fractures. Receiver operating characteristic (ROC) curve analysis was performed (healthy joints vs chip joints) to evaluate BGN(262) robustness.Results: Cohort 1: SF BGN(262) levels from racehorses showed a statistical increase during the first 6 months of the training period. Cohort 2: BGN(262) levels were significantly higher in the SF from severe SCBS joints. Cohort 3: SF BGN(262) levels in chip fracture joints showed a significant increase compared to normal joints. The ROC analysis showed an AUC of 0.957 (95% C.I 0.868-1.046), indicating good separation between the groups.Conclusions: The data presented show that BGN(262) levels increase in SF in correlation with the initiation of training, severity of SCBS, and presence of chip fractures. This suggests that BGN262 is a potential predictor and a novel biomarker for early changes in subchondral bone (SCB), aiming to prevent catastrophic injuries in racehorses. (c) 2022 The Author(s). Published by Elsevier Ltd on behalf of Osteoarthritis Research Society International. This is an open access article under the CC BY license (http://creativecommons.org/ licenses/by/4.0/)

Physiologically Based Pharmacokinetic Modeling of Nanoceria Systemic Distribution in Rats Suggests Dose- and Route-Dependent Biokinetics

Background: Cerium dioxide nanoparticles (nanoceria) are increasingly being used in a variety of products as catalysts, coatings, and polishing agents. Furthermore, their antioxidant properties make nanoceria potential candidates for biomedical applications. To predict and avoid toxicity, information about their biokinetics is essential. A useful tool to explore such associations between exposure and internal target dose is physiologically based pharmacokinetic (PBPK) modeling. The aim of this study was to test the appropriateness of our previously published PBPK model developed for intravenous (IV) administration when applied to various sizes of nanoceria and to exposure routes relevant for humans. Methods: Experimental biokinetic data on nanoceria (obtained from various exposure routes, sizes, coatings, doses, and tissues sampled) in rats were collected from the literature and also obtained from the researchers. The PBPK model was first calibrated and validated against IV data for 30 nm citrate coated ceria and then recalibrated for 5 nm ceria. Finally, the model was modified and tested against inhalation, intratracheal (IT) instillation, and oral nanoceria data. Results: The PBPK model adequately described nanoceria time courses in various tissues for 5 nm ceria given IV. The time courses of 30 nm ceria were reasonably well predicted for liver and spleen, whereas the biokinetics in other tissues were not well captured. For the inhalation, IT instillation, and oral exposure routes, re-optimization was difficult due to low absorption and, hence, low and variable nanoceria tissue levels. Moreover, the nanoceria properties and exposure conditions varied widely among the inhalation, IT instillation, and oral studies, making it difficult to assess the importance of different factors. Conclusion: Overall, our modeling efforts suggest that nanoceria biokinetics depend largely on the exposure route and dose

Landscape planning and stress.

Introduction In the history of humankind, stress has certainly always been a part of life, as it is caused by, for example, death, starvation and plague. During recent decades, however, people have more frequently reported illnesses caused by stress, and they often report experiencing lingering periods in which they cannot control their everyday life. To a greater extent than before, ill-health problems are affecting professionals, who report long periods of sick leave. This is particularly true of West- The distance to public urban open green spaces seems to be of decisive importance, as is access to a garden, in the form of a private garden or a green yard immediately adjacent to, for instance, an apartment building. People do not usually compensate for lack of green environments in their own residential area with more visits to public parks or urban forests. According to our results, laying out more green areas close to apartment houses, and making these areas more accessible, could make for more restorative environments. Outdoor areas that provide environments free from demands and stress, and that are available as part of everyday life, could have significant positive effects on the health of town-dwellers in Sweden. This may also apply to other Western societies

Self-injury in youths who lost a parent to cancer: nationwide study of the impact of family-related and health-care-related factors.

BACKGROUND: Self-injury, a manifestation of severe psychological distress, is increased in cancer-bereaved youths. Little is known about the potential influence on the risk for self-injury of factors that could be clinically relevant to and modifiable by the health-care professionals involved in the care of the dying parent. METHODS: In a nationwide population-based anonymous study, 622 (73.1%) youths (aged 18-26) who, 6 to 9 years earlier at ages 13 to 16, had lost a parent to cancer answered study-specific questions about self-injury and factors related to the family and parental health care. RESULTS: Univariable analyses showed that the risk for self-injury was increased among cancer-bereaved youths who reported poor family cohesion the years before (relative risk [RR], 3.4, 95% confidence interval [CI], 2.5-4.6) and after the loss (RR, 3.3, 95% CI, 2.4-4.4), distrust in the health care provided to the dying parent (RR, 1.7, 95% CI, 1.2-2.4), perceiving poor health-care efforts to cure the parent (RR 1.5, 95% CI, 1.1-2.1) and poor efforts to prevent suffering (RR, 1.6, 95% CI, 1.1-2.4), that at least one of their parents had been depressed or had troubles in life (RR, 1.5, CI, 1.1-2.1) and believing 3 days before the loss that the treatment would probably cure the parent (RR, 1.6, CI, 1.1-2.3). In the total multivariable models, only poor family cohesion before and after the loss remained statistically significantly associated with self-injury. CONCLUSION: Poor family cohesion before and after the loss of a parent to cancer is associated with an increased risk of self-injury in teenage children

Efficient application of a browsing repellent: Can associational effects within and between plants be exploited?

publishedVersio