811 research outputs found
Some Siegel modular standard L-values, and Shafarevich–Tate groups
AbstractWe explain how the Bloch–Kato conjecture leads us to the following conclusion: a large prime dividing a critical value of the L-function of a classical Hecke eigenform f of level 1, should often also divide certain ratios of critical values for the standard L-function of a related genus two (and in general vector-valued) Hecke eigenform F. The relation between f and F (Harderʼs conjecture in the vector-valued case) is a congruence involving Hecke eigenvalues, modulo the large prime. In the scalar-valued case we prove the divisibility, subject to weak conditions. In two instances in the vector-valued case, we confirm the divisibility using elaborate computations involving special differential operators. These computations do not depend for their validity on any unproved conjecture
Humans rather than Eurasian lynx (Lynx lynx) shape ungulate browsing patterns in a temperate forest
The recolonization of human-dominated landscapes by large carnivores has been followed with considerable scientific interest; however, little is known about their interactive effect on ungulate foraging behavior. This study compared the risks imposed by humans and lynx on ungulate foraging behavior by examining the effects of browsing intensity (at two spatial scales), diet quality, and tree species selection. We hypothesized that: (1) in areas with high risk imposed by humans and lynx browsing intensity would be reduced; (2) risk effects would interact with habitat visibility at a fine scale, resulting in contrasting browsing patterns in response to humans versus lynx risk; (3) ungulates compensate for the higher costs incurred in high-risk areas by switching to a higher diet quality, and (4) browse a higher proportion of more-preferred tree species. These hypotheses were tested by measuring browsing intensity along 48 transects located at different distances from human settlements within the hunted and nonhunted areas of the Bavarian Forest. Dung samples were collected and analyzed as a proxy of diet quality (C:N ratio, fiber). The spatial patterns of browsing intensity, diet quality, and tree species selection were then linked to lynx risk, hunting intensity, recreation intensity, and distance to human settlements. Our results showed that (1) browsing intensity strongly decreased with increasing recreational activities, whereas it increased with lynx risk; (2) only in close proximity to human settlements tree browsing was higher in dense habitats and (3) a higher diet quality was obtained. (4) We found a stronger avoidance of the less preferred tree species in high-hunting intensity areas. In conclusion, our results indicate that the risk effects of human activities outweigh those of a natural large carnivore. Thus, highlighting the importance of taking those activities into account in predicting the impacts of large carnivores on ungulates and their plant-food choices.publishedVersio
Exposure to challenging behaviours and burnout symptoms among care staff:the role of psychological resources
Background Staff supporting individuals with intellectual disabilities are at risk of burnout symptoms. Evidence suggests an association between exposure to challenging behaviours of individuals with intellectual disabilities and burnout symptoms of staff, but the protective role of staff psychological resources in this relation has been understudied. Method We investigated the association between exposure to challenging behaviours and burnout symptoms of staff and the direct and moderating effects of several psychological resources. Staff (N = 1271) completed an online survey concerning burnout symptoms (subscale Emotional Exhaustion of the Maslach Burnout Inventory), exposure to challenging behaviours and a range of potential psychological resources. We examined main and moderating effects with multilevel analyses. In order to control for the multiple comparisons, P values corrected for false discovery rate (P-FDR) were reported. Results We found a direct relation between exposure to challenging behaviours and increased levels of burnout symptoms in staff (b = .15, t(670) = 4.466, P-FDR <.0001). Perceived supervisor social support (b = -.97, t(627) = -7.562, P-FDR <.0001), staff self-efficacy (b = -.23, t(673) = -3.583, P-FDR <.0001), resilience (b = -.19, t(668) = -2.086, P-FDR <.05) and extraversion (b = -.20, t(674) = -3.514, P-FDR <.05) were associated with reduced burnout symptoms. None of the proposed psychological resources moderated the association between exposure to challenging behaviours and burnout symptoms of staff. Conclusions Of the psychological resources found to be associated with reduced risk of burnout symptoms, staff self-efficacy and access of staff to supervisor social support seem to be the factors that can be influenced best. These factors thus may be of importance in reducing the risk of developing burnout symptoms and improving staff well-being, even though the current study was not designed to demonstrate causal relations between psychological resources and burnout symptoms
Gut microbiota and colonization resistance against bacterial enteric infection
The gut microbiome is critical in providing resistance against colonization by exogenous microorganisms. The mechanisms via which the gut microbiota provide colonization resistance (CR) have not been fully elucidated, but they include secretion of antimicrobial products, nutrient competition, support of gut barrier integrity, and bacteriophage deployment. However, bacterial enteric infections are an important cause of disease globally, indicating that microbiota-mediated CR can be disturbed and become ineffective. Changes in microbiota composition, and potential subsequent disruption of CR, can be caused by various drugs, such as antibiotics, proton pump inhibitors, antidiabetics, and antipsychotics, thereby providing opportunities for exogenous pathogens to colonize the gut and ultimately cause infection. In addition, the most prevalent bacterial enteropathogens, including Clostridioides diflicile, Salmonella enterica serovar Typhimurium, enterohemorrhagic Escherichia coli, Shigella flexneri, Campylobacter jejuni, Vibrio cholerae, Yersinia enterocolitica, and Listeria monocytogenes, can employ a wide array of mechanisms to overcome colonization resistance. This review aims to summarize current knowledge on how the gut microbiota can mediate colonization resistance against bacterial enteric infection and on how bacterial enteropathogens can overcome this resistance.Molecular basis of bacterial pathogenesis, virulence factors and antibiotic resistanc
Combining quantum and classical density functional theory for ion-electron mixtures
We combine techniques from quantum and from classical density functional
theory (DFT) to describe electron-ion mixtures. For homogeneous systems, we
show how to calculate ion-ion and ion-electron correlation functions within
Chihara's quantum hypernetted chain approximation, which we derive within a DFT
formulation. We also sketch out how to apply the DFT formulation to
inhomogeneous electron-ion mixtures, and use this to study the electron
distribution at the liquid-solid interface of Al.Comment: to be published in J. Non-Cryst. Solids, LAM 11 special issu
Nitrogen transfer between herbivores and their forage species
Herbivores may increase the productivity of forage plants; however, this depends on the return of nutrients from faeces to the forage plants. The aim of this study was to test if nitrogen (N) from faeces is available to forage plants and whether the return of nutrients differs between plant species using (15)N natural abundance in faeces and plant tissue. To investigate the effect of grazing on N transfer, we carried out a grazing experiment in wet and mesic tundra on high Arctic Spitsbergen using barnacle geese (Branta leucopsis) as the model herbivore. N inputs (from faeces) increased with grazing pressure at both the wet and mesic sites, with the greatest N input from faeces at the wet site. The delta(15)N ratio in plant tissue from grazed plots was enriched in mosses and the dwarf shrub species, reflecting the delta(15)N signature of faeces-derived N, but no such pattern was observed in the dominant grasses. This study demonstrates that the delta(15)N signature of faeces and forage species is a useful tool to explore how grazing impacts on N acquisition. Our findings suggest that plant species which acquire their N close to the soil surface (e.g. mosses) access more of the N from faeces than species with deeper root systems (e.g. grasses) suggesting a transfer of N from the preferred forage species to the mosses and dwarf shrubs, which are less preferred by the geese. In conclusion, the moss layer appears to disrupt the nitrogen return from herbivores to their forage species
The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake : a randomized controlled trial
Purpose To examine the cost effectiveness of dietary advice to increase protein intake on 6-month change in physical functioning among older adults. Methods In this multicenter randomized controlled trial, 276 community-dwelling older adults with a habitual protein intake = 1.2 g/kg aBW/d (PROT, n = 96), Intervention 2; similar advice and in addition advice to consume protein (en)rich(ed) foods within half an hour after usual physical activity (PROT + TIMING, n = 89), or continue the habitual diet with no advice (CON, n = 91). Primary outcome was 6-month change in 400-m walk time. Secondary outcomes were 6-month change in physical performance, leg extension strength, grip strength, body composition, self-reported mobility limitations and quality of life. We evaluated cost effectiveness from a societal perspective. Results Compared to CON, a positive effect on walk time was observed for PROT; - 12.4 s (95%CI, - 21.8 to - 2.9), and for PROT + TIMING; - 4.9 s (95%CI, - 14.5 to 4.7). Leg extension strength significantly increased in PROT (+ 32.6 N (95%CI, 10.6-54.5)) and PROT + TIMING (+ 24.3 N (95%CI, 0.2-48.5)) compared to CON. No significant intervention effects were observed for the other secondary outcomes. From a societal perspective, PROT was cost effective compared to CON. Conclusion Dietary advice to increase protein intake to >= 1.2 g/kg aBW/d improved 400-m walk time and leg strength among older adults with a lower habitual protein intake. From a societal perspective, PROT was considered cost-effective compared to CON. These findings support the need for re-evaluating the protein RDA of 0.8 g/kg BW/d for older adults.Peer reviewe
Shoulder pain due to cervical radiculopathy: an underestimated long-term complication of herpes zoster virus reactivation?
Purpose
To evaluate if herpes zoster virus (HZV) reactivation may be considered in the aetiology of cervical radiculopathy.
Methods
The study group was composed of 110 patients (52 M-58F;mean age ± SD:46.5 ± 6.12; range:40-73) with a clinical diagnosis of cervical radiculopathy. Patients with signs of chronic damage on neurophysiological studies were submitted to an X-ray and to an MRI of the cervical spine in order to clarify the cause of the cervical radiculopathy and were investigated for a possible reactivation of HZV; HZV reactivation was considered as “recent” or “antique” if it occurs within or after 24 months from the onset of symptoms, respectively. Data were submitted to statistics.
Results
Thirty-eight patients (34,5%,16 M-22F) had a history of HZV reactivation: four (2 M-2F) were “recent” and 34 (14 M-20F) were “antique”. In 68 of 110 participants (61,8%,30 M-38F), pathological signs on X-ray and/or MRI of the cervical spine appeared; in the remaining 42 (38,2%,22 M-20F) X-ray and MRI resulted as negative. Among patients with HZV reactivation, seven (18,4%) had a “positive” X-ray-MRI while in 31 (81,6%) the instrumental exams were considered as negative. The prevalence of “antique” HZV reactivations was statistically greater in the group of patients with no pathological signs on X-ray/MRI of the cervical spine with respect to the group with a pathological instrumental exam (p < 0.01).
Conclusions
It may be useful to investigate the presence of a positive history of HZV reactivation and to consider it as a long-term complication of a cervical root inflammation especially in patients in which X-ray and MRI of the cervical spine did not show pathological findings
Survival of molar teeth in need of complex endodontic treatment:Influence of the endodontic treatment and quality of the restoration
Objectives: The objective of this retrospective practice-based study was to evaluate the survival of molar teeth and endodontic success after complex endodontic treatment up to 89 months. Methods: Endodontically (Endodontic Treatment Classification (ETC) scores II and III) treated first and second molars treated between January 2011-October 2017 within a referral setting were included. Open apices, combined surgical treatment, ETC score I, patients 2 were excluded. Cumulative survival estimates and Cox regression analysis were performed for tooth survival and endodontic healing according to the Glossary of Endodontic Terms. Restoration quality was assessed using the FDI criteria. Alpha was set at 0.05. Results: 279 endodontically treated molars in 245 patients were included for survival analysis and 268 molars for endodontic success. After 89 months, the cumulative survival was 91.7 % [95 % CI: 86.8 %?94.9 %]. Absence of adjacent teeth and deviance in root canal morphology significantly decreased the probability of tooth survival. Cumulative endododontic healing rates after 48 and 89 months were 82.2 % [95 %CI: 75.7 %?87.1 %] and 51.1 [95 % CI: 20.2 %?75.5 %] respectively. Deviance in root canal morphology and inadequate coronal seal significantly decreased the probability of endodontic healing. Indirect restorations obtained higher esthetic and biological FDI scores, however no difference between direct and indirect restorations was found concerning the functional FDI score. Conclusions: After 89 months, cumulative survival of molars in need of complex endodontic treatment was 91.7 % [95 % CI: 86.8 %?94.9 %]. Clinical significance: Within daily clinical practice, the dilemma of performing a complex endodontic (re)treatment or to explore other treatment options for molar teeth in need of reintervention is still urgent. Tooth survival of molar teeth with complex endodontic (re)treatment seems satisfactory up to 89 months
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