From movement to motivation: a proposed framework to understand the antidepressant effect of exercise.

Depression is the leading cause of disability worldwide, exerting a profound negative impact on quality of life in those who experience it. Depression is associated with disruptions to several closely related neural and cognitive processes, including dopamine transmission, fronto-striatal brain activity and connectivity, reward processing and motivation. Physical activity, especially aerobic exercise, reduces depressive symptoms, but the mechanisms driving its antidepressant effects are poorly understood. Here we propose a novel hypothesis for understanding the antidepressant effects of exercise, centred on motivation, across different levels of explanation. There is robust evidence that aerobic exercise decreases systemic inflammation. Inflammation is known to reduce dopamine transmission, which in turn is strongly implicated in effort-based decision making for reward. Drawing on a broad range of research in humans and animals, we propose that by reducing inflammation and boosting dopamine transmission, with consequent effects on effort-based decision making for reward, exercise initially specifically improves 'interest-activity' symptoms of depression-namely anhedonia, fatigue and subjective cognitive impairment - by increasing propensity to exert effort. Extending this framework to the topic of cognitive control, we explain how cognitive impairment in depression may also be conceptualised through an effort-based decision-making framework, which may help to explain the impact of exercise on cognitive impairment. Understanding the mechanisms underlying the antidepressant effects of exercise could inform the development of novel intervention strategies, in particular personalised interventions and boost social prescribing.

Associations between psychological distress in adolescence and menstrual symptoms across life: Longitudinal evidence from the 1970 British Cohort Study.

PURPOSE: This study aimed to investigate the association between psychological distress (PD) at age 16 and menstrual symptoms experienced across women's life. METHODS: Up to 2584 females from the 1970 British Cohort Study, a study of individuals born within one week in 1970, were included. PD at age 16 was measured with the 12-item General Health Questionnaire. Three categories were derived: low PD (<11), moderate PD (11-15), and severe PD (>15). Five menstrual health symptoms were self-reported at each age (16, 30 and 42 years). Binomial logistic regressions examined associations between PD at age 16 and each individual symptom, adjusted for age of menarche, sleep and appetite problems, physical activity levels and socioeconomic position. RESULTS: The most prevalent symptoms were "pain" (61 %), "painful period" (10 %) and "heavy period" (33 %) at ages 16, 30 and 42, respectively. At age 16, those with severe PD were more likely to experience depression (OR: 2.92; 95% CI: 2.31, 3.70)), irritability (1.67; 1.33, 2.11), menstrual pain (1.34; 1.01, 1.80), and headaches (1.29; 1.02, 1.63). A weak association was found between severe PD at age 16 and pre-menstrual tension at age 30 (1.72; 1.01, 2.83). At age 42, those with severe PD at age 16 were more likely to experience pre-menstrual tension (1.89; 1.46, 2.44), painful periods (1.64; 1.27, 2.11), and heavy periods (1.28; 1.00, 1.62). DISCUSSION: Menstruating females with higher levels of PD in adolescence have an increased risk of menstrual symptoms across adolescence, early and mid-adulthood. Our findings suggest the need to consider early-life psychological interventions to improve women's menstrual experiences across their reproductive years.

Is cardiorespiratory fitness associated with cognitive outcomes in mid-adulthood? Findings from the 1958 British birth cohort.

Identifying causal factors to intervene on to delay age-related declines in cognitive function is urgently needed. We examined associations between non-exercise testing cardiorespiratory fitness (NETCRF; estimated using sex, age, body mass index, resting heart rate, and physical activity) at 45 years and cognitive function outcomes (immediate and delayed verbal memory; verbal fluency; visual processing speed) at 50 years in 8130 participants from the 1958 British birth cohort. In unadjusted models, higher NETCRF was associated with better cognitive function across all outcomes. When adjusted for confounding factors, associations disappeared. In this cohort, associations between 45 years NETCRF and 50 years cognitive function likely result from confounding factors.

Associations between sporting physical activity and cognition in mid and later-life: Evidence from two cohorts.

Evidence has linked sporting leisure time physical activity (sporting-LTPA) to healthy cognition throughout adulthood. This may be due to the physiological effects of physical activity (PA), or to other, psychosocial facets of sport. We examined associations between sporting-LTPA and cognition while adjusting for device-measured PA volume devoid of context, both in midlife (N = 4041) participants from the 1970 British Cohort Study and later-life (N = 957) participants from the British Regional Heart Study. Independent of device-measured PA, we identified positive associations between sporting-LTPA and cognition. Sports with team/partner elements were strongly positively associated with cognition, suggesting LTPA context may be critical to this relationship.

Characteristics and efficacy of physical activity interventions to improve cardiometabolic and psychosocial outcomes in people living with HIV in sub-Saharan Africa: a protocol for a systematic review.

BACKGROUND: Antiretroviral therapy (ART) has led to an increased lifespan for people living with HIV (PWH). This increased lifespan, coupled with the effects of HIV and adverse effects of ART have resulted in an increasing burden of cardiometabolic disease (CMD) among PWH. Physical activity (PA) has been proposed as an effective strategy to reduce the risk of developing cardiometabolic disease and other health complications in PWH. The aim of this paper is to review the characteristics and efficacy of PA interventions to improve cardiometabolic and psychosocial outcomes among PWH in sub-Saharan Africa. METHODS: The review will follow the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P). Literature searches will be conducted in PubMed, Web of Science (WoS), African Index Medicus, Cumulative Index to Nursing and Allied Health Literature (CINAHL), and Embase. Peer-reviewed publications will be included if they include adults (age 18 or older), PWH in sub-Saharan Africa, and a PA intervention to improve cardiometabolic outcomes and/or psychosocial outcomes. We will include randomized controlled trials and quasi-experimental study designs. Two independent reviewers will screen all abstracts and full-text articles. The study methodological quality (or bias) will be appraised using the Revised tool to assess risk of bias in randomized trials and the Downs and Black checklist. Certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation guidelines. Meta-analyses will be conducted if our results are adequate for meta-analysis. Outcomes will be analyzed as continuous or dichotomous and meta-analyses will be conducted using random effects models with Stata computer software. DISCUSSION: This review will identify and synthesize the current evidence regarding the characteristics and efficacy of PA interventions to improve cardiometabolic and psychosocial outcomes among PWH in sub-Saharan Africa. We also plan to identify the strengths and weaknesses of evaluated interventions. Based on the evidence, recommendations will be made to promote the design and further evaluate the most promising strategies to maximize the efficacy of PA interventions in improving cardiometabolic and psychosocial outcomes in PWH in sub-Saharan Africa. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration ID: CRD42021271937.

Associations between the composition of daily time spent in physical activity, sedentary behaviour and sleep and risk of depression: Compositional data analyses of the 1970 British cohort Study.

BACKGROUND: The benefits of moderate to vigorous physical activity(MVPA) in lowering depression risk are well established, but there is mixed evidence on sleep, sedentary behaviour(SB), and light-intensity physical activity(LIPA). These behaviours are often considered in isolation, neglecting their behavioural and biological interdependences. We investigated how time spent in one behaviour relative to others was associated with depression risk. METHODS: We included 4738 individuals from the 1970 British Cohort study (age 46 wave). Depression status was ascertained using self-reported doctor visits and prescribed anti-depressant use. MVPA, LIPA, SB and sleep were ascertained using thigh-worn accelerometers worn consecutively for 7 days. Compositional logistic regression was used to examine associations between different compositions of time spent in movement behaviours and depression. RESULTS: More time spent in MVPA, relative to SB, sleep or LIPA, was associated with a lower risk of depression. When modelling reallocation of time (e.g. replacing time in one behaviour with another), replacing sleep, SB or LIPA with MVPA time was strongly associated with lower depression risk. Reallocating time between SB, sleep or LIPA had minimal to no effect. LIMITATIONS: Data was cross-sectional, therefore causality cannot be inferred. Accelerometers do not capture SB context (e.g. TV watching, reading) nor separate biological sleep from time spent in bed. CONCLUSIONS: Displacing any behaviour with MVPA was associated with a lower risk of depression. This study provides promising support that increasing MVPA, even in small doses, can have a positive impact on prevention, mitigation and treatment of depression.

Cash Transfers may Increase the No-show Rate for Surgical Patients in Low-resource Settings: A Randomized Controlled Trial.

BACKGROUND: Over two-thirds of the world's population cannot access surgery when needed. Interventions to address this gap have primarily focused on surgical training and ministry-level surgical planning. However, patients more commonly cite cost-rather than governance or surgeon availability-as their primary access barrier. We undertook a randomized, controlled trial (RCT) to evaluate the effect on compliance with scheduled surgical appointments of addressing this barrier through a cash transfer. METHODS: 453 patients who were deemed surgical candidates by a nursing screening team in Guinea, West Africa, were randomized into three study arms: control, conditional cash transfer, and labeled unconditional cash transfer. Patients in the conditional cash transfer group were given a cash transfer to cover their transportation costs once they had been discharged from care. Patients in the unconditional arm were given a cash transfer to cover their transportation costs before they left their homes to get care. Arrival to a scheduled surgical appointment was the primary outcome. The study was performed in conjunction with Mercy Ships. RESULTS: The overall no-show rate was five-fold lower in Guinea than previously published estimates, likely due to changes in the patient selection and retention process, leading to an underpowered study. In a post-hoc analysis, which included non-randomized patients, patients in the control group and the conditional cash transfer group demonstrated no effect from the cash transfer. Patients in the unconditional cash transfer group were significantly less likely to arrive for their scheduled appointment. Subgroup analysis suggested that actual receipt of the unconditional cash transfer, instead of a lapse in the transfer mechanism, was associated with failure to show. CONCLUSION: We find that cash transfers are feasible for surgical patients in a low-resource setting, but that unconditional transfers may have negative effects on compliance. Although demand-side barriers are large for surgical patients in low-resource settings, interventions to address them must be designed with care. CONTEXTE: Plus des deux tiers de la population mondiale n'ont pas accès à la chirurgie lorsqu'ils en ont besoin. Les interventions visant à combler cette lacune ont principalement sur la formation chirurgicale et la planification chirurgicale au niveau ministériel. Cependant, les patients citent plus souvent le coût - plutôt que la gouvernance ou la disponibilité des chirurgiens - comme étant leur principal obstacle à l'accès. Nous avons entrepris un essai contrôlé randomisé (ECR) pour évaluer l'effet sur le respect des rendez-vous chirurgicaux programmés en s'attaquant à cet barrière par un transfert d'argent. MÉTHODES: 453 patients considérés comme des candidats à la chirurgie par une équipe de dépistage infirmière en Guinée, Afrique de l'Ouest, ont été répartis de manière aléatoire dans trois bras d'étude : contrôle, transfert monétaire conditionnel et transfert monétaire non transfert monétaire inconditionnel. Les patients du groupe de transfert monétaire conditionnel ont reçu un transfert d'argent pour couvrir leurs frais de transport une fois qu'ils étaient sortis des soins. Les patients du groupe de transfert inconditionnel recevaient un transfert en espèces pour couvrir leurs frais de transport avant de quitter leur domicile pour recevoir des soins. L'arrivée à un rendez-vous chirurgical programmé était le résultat principal. L'étude a été réalisée en collaboration avec Mercy Ships. RÉSULTATS: Le taux global de non-présentation était cinq fois inférieur en Guinée que les estimations publiées précédemment, probablement en raison de changements dans le processus de sélection et de rétention des patients, ce qui a conduit à une étude insuffisamment puissante. Dans une analyse post-hoc, qui incluait des patients non randomisés, les patients dans le groupe de contrôle et dans le groupe de transfert conditionnel n'ont montré aucun effet du transfert d'argent. Les patients du groupe de transfert d'argent sans condition étaient significativement moins susceptibles d'arriver pour leur rendez-vous prévu. L'analyse des sous-groupes suggère que la réception effective du transfert monétaire inconditionnel plutôt d'un erreur en mécanisme de transfert, était associé à l'absence de rendez-vous. CONCLUSION: Nous constatons que les transferts d'argent sont possibles pour les patients chirurgicaux dans un environnement à faibles ressources, mais que les transferts inconditionnels peuvent avoir des effets négatifs sur l'observance. Bien que les obstacles liés à la demande sont importants pour les patients opérés dans des contextes à faibles ressources, les doivent être conçues avec soin. MOTS-CLÉS: Transferts monétaires, Chirurgie, Chirurgie globale, Guinée, Interventions financières, Utilisation chirurgicale, Essai contrôlé randomisé.

Obesity in early adulthood and physical functioning in mid-life: Investigating the mediating role of c-reactive protein.

INTRODUCTION: Obesity in adulthood is associated with reduced physical functioning (PF) at older ages. However, mechanisms underpinning this association are not well understood. We investigated whether and the extent to which C-reactive protein (CRP) mediates the association between early-adult obesity and mid-life PF. METHODS: We used data from 8495 participants in the 1958 British birth cohort study. Body mass index (BMI), CRP and PF were measured at 33, 45 and 50y, respectively. Poor PF was defined as the lowest (sex-specific) 10% on the Short-form 36 Physical Functioning subscale. We accounted for prospectively measured confounders in early-life (e.g., social class at birth) and in mid-adulthood (e.g., 42y comorbidities). We decomposed the total effect of early-adult obesity on mid-life PF into direct and indirect (via CRP) effects, by employing a mediation analysis based on parametric g-computation. RESULTS: The estimated total effect of obesity at 33y on poor PF at 50y, expressed as an odds ratio (OR), was 2.41 (95% CI: 1.89, 3.08). The direct effect of obesity on poor PF (i.e., not operating via CRP), was 1.97 (95% CI: 1.51, 2.56), with an indirect effect of 1.23 (95% CI: 1.10, 1.37). As such, the proportion of the total effect which was mediated by the effect of obesity on CRP at 45y, was 23.27% (95% CI: 8.64%, 37.90%). CONCLUSION: Obesity in early-adulthood was associated with over twice the odds of poor PF in mid-life, with approximately 23% of the obesity effect operating via a downstream effect on CRP. As current younger generations are likely to spend greater proportions of their life course in older age and with obesity, both of which are associated with poor PF, there is an urgent need to identify mechanisms, and thus potential modifiable intermediaries, linking obesity to poor PF.

Comparison of ELISA using recombinant LipL32 and sonicated antigen of leptospira for detecting bovine leptospirosis.

Leptospirosis is one of the most widely distributed zoonosis in the world. Bovine leptospirosis is a serious problem in bovine production, causing reproductive losses. The aim of this work was to compare recombinant LipL32 with sonicated antigen for detecting anti-Leptospira IgG antibodies in bovine serum using ELISA. The Microscopic Agglutination Test (MAT) is used as the gold standard. Sonicated antigen from cultures of Leptospira interrogans serogroup Icterohaemorrhagiae serovar copenhageni (strain M20) was used for the eELISA and rLipL32 for the rELISA. The performance of these assays was evaluated using serum samples from 166 bovines, 69 MAT positive and 97 MAT negative. At the optimal cut-off point recommended by the receiver operating characteristic (ROC) curve analysis, the sensitivity and specificity values were 98.6% and 97.9%, respectively, for eELISA, and 85.5% and 86.6% respectively, for rELISA. The value for the area under the ROC curve was 0.998 (0.994-1.0) (CI 95%) for eELISA and 0.929 (0.891-0.968) (CI 95%) for rELISA. The ROC curves for rLipL32 and sonicated antigen showed statistically significant differences (z = -3.826; p = 0.000). A three-way comparison showed statistically significant differences in the sensitivity and specificity of rELISA and eELISA. Our results showed that eELISA was more specific and sensitive than rELISA. The difference in performance (eELISA-rELISA) was 13.4% (4.03-23.28) (CI 95%) for sensitivity and 11.34 % (4.07-19.56) (CI 95%) for specificity. Our results show that the eELISA has a better diagnostic performance than rELISA for the detection of anti-Leptospira IgG antibodies in bovine serum.

Detección de Leptospira spp. (Spirochaetales: Leptospiraceae) en muestras ambientales de regiones habitadas por poblaciones vulnerables del norte argentino / Leptospira spp. (Spirochaetales: Leptospiraceae) detection in environmental samples from geographical regions inhabited by vulnerable communities in northern Argentina

Resumen La leptospirosis continúa siendo hoy en día un problema para la salud pública, principalmente en poblaciones de bajos recursos socioeconómicos. En este trabajo se presenta la detección de leptospiras patógenas en muestras ambientales (aguas y barros) provenientes de regiones del norte argentino (provincias de Formosa, Salta, Santiago del Estero, Misiones y Chaco) con variadas características climatológicas habitadas por poblaciones vulnerables. De las 89 muestras analizadas, en el 24,7% fue posible detectar molecularmente la presencia de leptospiras patógenas. La prevalencia por tipo de muestra fue de 27,8% para las aguas y 11,8% para los barros. Todas las localidades muestreadas presentaron al menos una muestra positiva a alguna de las pruebas realizadas, por lo que el presente trabajo refleja la necesidad de profundizar los estudios de la leptospirosis en distintas regiones de la Argentina.

Abstract Leptospirosis remains as a major public health problem nowadays, mainly affecting vulnerable communities with low socioeconomic resources. In this study, the molecular detection of pathogenic leptospires from environmental samples (water and mud) from northern Argentina (Formosa, Salta, Santiago del Estero, Misiones and Chaco provinces) is described. Samples were obtained from regions with varied climatological features, all inhabited by vulnerable communities. From the 89 samples that were analyzed, 24.7% showed molecular evidence of the presence of pathogenic leptospires. Prevalence by sample type was: 27.8% in water samples and 11.8% in mud samples. All the sampled regions showed at least one positive sample. This result highlights the need of further research regarding leptospirosis in different regions of Argentina.

Changes over time in latent patterns of childhood-to-adulthood BMI development in Great Britain: evidence from three cohorts born in 1946, 1958, and 1970.

BACKGROUND: Most studies on secular trends in body mass index (BMI) are cross-sectional and the few longitudinal studies have typically only investigated changes over time in mean BMI trajectories. We aimed to describe how the evolution of the obesity epidemic in Great Britain reflects shifts in the proportion of the population demonstrating different latent patterns of childhood-to-adulthood BMI development. METHODS: We used pooled serial BMI data from 25,655 participants in three British cohorts: the 1946 National Survey of Health and Development (NSHD), 1958 National Child Development Study (NCDS), and 1970 British Cohort Study (BCS). Sex-specific growth mixture models captured latent patterns of BMI development between 11 and 42 years. The classes were characterised in terms of their birth cohort composition. RESULTS: The best models had four classes, broadly similar for both sexes. The 'lowest' class (57% of males; 47% of females) represents the normal weight sub-population, the 'middle' class (16%; 15%) represents the sub-population who likely develop overweight in early/mid-adulthood, and the 'highest' class (6%; 9%) represents those who likely develop obesity in early/mid-adulthood. The remaining class (21%; 29%) reflects a sub-population with rapidly 'increasing' BMI between 11 and 42 years. Both sexes in the 1958 NCDS had greater odds of being in the 'highest' class compared to their peers in the 1946 NSHD but did not have greater odds of being in the 'increasing' class. Conversely, males and females in the 1970 BCS had 2.78 (2.15, 3.60) and 1.87 (1.53, 2.28), respectively, times higher odds of being in the 'increasing' class. CONCLUSIONS: Our results suggest that the obesity epidemic in Great Britain reflects not only an upward shift in BMI trajectories but also a more recent increase in the number of individuals demonstrating more rapid weight gain, from normal weight to overweight, across the second, third, and fourth decades of life.

Use of Chelex-100 for the molecular diagnosis of five animal pathogens / Uso de Chelex-100 para el diagnóstico molecular de cinco patógenos de animales

Abstract Molecular tools have improved conventional veterinary diagnosis. Acid nucleic extraction is a key step for downstream applications. This work aimed to compare the DNA extraction method Chelex-100 resin (M1) with Whatman® cards (M2), phenol-chloroform (M3), or commercial kits (M4), and to determine the most sensitive and inexpensive one for its diagnosis of animal pathogens that, despite their economic or zoonotic relevance, receive little attention. DNA was isolated from urine, organs, semen, blood and intestinal mucous, from the bacteria Leptospira interrogans serovar Pomona Pomona (by M1 and M2), Brucella melitensis (by M1, M3 and M4), and Salmonella ser. Abortusequi (by M1 and M4), and the parasites Leishmania spp. (by M1, M3 and M4), and Eimeria spp. (by M1 and M3), respectively. The sensitivity of each method was assayed by Polymerase Chain Reaction (PCR). The M1 showed similar sensitivity for Salmonella ser. Abortusequi, Leishmania spp., and Eimeria spp., being better for L. interrogans serovar Pomona Pomona and slightly lower for B. melitensis. For the first time, a simple and economic method was successfully employed for extracting DNA from these animal pathogens, especially important in low-resource settings, contributing to the diagnosis of leptospirosis, brucellosis, leishmaniasis, and coccidiosis; as well as to the molecular epidemiology of salmonellosis in stallion from semen samples.

Resumen Las técnicas moleculares han contribuido a mejorar el diagnóstico veterinario tradicional y la extracción de ácidos nucleicos es determinante. El objetivo de este trabajo fue comparar el método de extracción de ADN Chelex-100 (M1) con papel Whatman (M2), fenol-cloroformo (M3) o kits comerciales (M4), y determinar un método sensible y de bajo costo para el diagnóstico de patógenos de animales económica o zoonóticamente relevantes y que reciben poca atención. A partir de orina, órganos, semen, sangre y mucosa intestinal se extrajo el ADN de las bacterias Leptospira interrogans serovar Pomona Pomona (con M1 y M2), Brucella melitensis (con M1, M3 y M4), Salmonella ser. Abortusequi (M1 y M4), y de los parásitos Leishmania spp. (M1, M3 y M4) y Eimeria spp. (M1 y M3), respectivamente. La sensibilidad de los protocolos fue analizada por PCR. El método M1 demostró una sensibilidad similar para S. Abortusequi, Leishmania spp. y Eimeria spp., siendo mejor para L. interrogans y levemente menor para B. melitensis. Por primera vez se usó exitosamente en estos patógenos veterinarios un método simple y económico para extraer ADN, especialmente importante en laboratorios de bajos recursos económicos, contribuyendo al diagnóstico de leptospirosis, brucelosis, leishmaniasis y coccidiosis, así como también a la epidemiología molecular de salmonelosis en muestras de semen de caballos.

Cross-sectional associations of device-measured sedentary behaviour and physical activity with cardio-metabolic health in the 1970 British Cohort Study.

AIMS: This study aimed to examine the cross-sectional associations of thigh accelerometry-assessed sedentary behaviour and moderate-to-vigorous physical activity (MVPA) with cardio-metabolic health markers and prevalent diabetes in a population sample of middle-aged British adults. METHODS: Participants (n = 4892) from the age-46-to-48 wave of the 1970 British Cohort Study were fitted with a waterproofed activPAL3 micro device. Total/prolonged sedentary time, breaks and MVPA were the main exposures. We dichotomized prolonged sedentary time and MVPA based on the corresponding median, generating four combinations as categorical exposures. Outcomes comprised of diabetes and seven cardio-metabolic health markers. We used logistic regression and generalized linear models to examine independent/joint associations, conducting a minimally adjusted model including demographics and contextual covariates, and further adjusted for total sedentary time and/or MVPA as applicable. RESULTS: Each set of 10 sedentary breaks and 1 h of prolonged sedentary time were associated with HbA1c (mmol/mol) [B = -0.18 (-0.33, -0.03) and 2.35 (1.01, 3.69), respectively]. Each set of 10 sedentary breaks and 1 h of MVPA were favourably associated with diabetes [adjusted odds ratio (AOR): 0.80 (0.71, 0.99) and 0.42 (0.26, 0.67), respectively]. Joint analyses showed that only the low MVPA × long sedentary time combination had significantly higher odds for diabetes than the referent high MVPA × short sedentary time combination [AOR: 1.89 (1.17, 3.03)]. CONCLUSIONS: Each set of additional 10 sedentary breaks per day was associated with 20% lower odds for diabetes. A low physical activity level combined with long sedentary time might synergistically deteriorate cardio-metabolic health.

Publisher Correction: Control of electron-electron interaction in graphene by proximity screening.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Control of electron-electron interaction in graphene by proximity screenings.

Electron-electron interactions play a critical role in many condensed matter phenomena, and it is tempting to find a way to control them by changing the interactions' strength. One possible approach is to place a studied system in proximity of a metal, which induces additional screening and hence suppresses electron interactions. Here, using devices with atomically-thin gate dielectrics and atomically-flat metallic gates, we measure the electron-electron scattering length in graphene and report qualitative deviations from the standard behavior. The changes induced by screening become important only at gate dielectric thicknesses of a few nm, much smaller than a typical separation between electrons. Our theoretical analysis agrees well with the scattering rates extracted from measurements of electron viscosity in monolayer graphene and of umklapp electron-electron scattering in graphene superlattices. The results provide a guidance for future attempts to achieve proximity screening of many-body phenomena in two-dimensional systems.

Principal component analysis of seven skin-ageing features identifies three main types of skin ageing.

BACKGROUND: The underlying phenotypic correlations between wrinkles, pigmented spots (PS), telangiectasia and other related facial-ageing subphenotypes are not well understood. OBJECTIVES: To analyse the underlying phenotypic correlation structure between seven features for facial ageing: global wrinkling, perceived age (PA), Griffiths photodamage grading, PS, telangiectasia, actinic keratosis (AK) and keratinocyte cancer (KC). METHODS: This was a cross-sectional study. Facial photographs and a full-body skin examination were used. We used principal component analysis (PCA) to derive principal components (PCs) of common variation between the features. We performed multivariable linear regressions between age, sex, body mass index, smoking and ultraviolet radiation exposure and the PC scores derived from PCA. We also tested the association between the main PC scores and 140 single-nucleotide polymorphisms (SNPs) previously associated with skin-ageing phenotypes. RESULTS: We analysed data from 1790 individuals with complete data on seven features of skin ageing. Three main PCs explained 73% of the total variance of the ageing phenotypes: a hypertrophic/wrinkling component (PC1: global wrinkling, PA and Griffiths grading), an atrophic/skin colour component (PC2: PS and telangiectasia) and a cancerous component (PC3: AK and KC). The associations between lifestyle and host factors differed per PC. The strength of SNP associations also differed per component with the most SNP associations found with the atrophic component [e.g. the IRF4 SNP (rs12203592); P-value = 1·84 × 10-22 ]. CONCLUSIONS: Using a hypothesis-free approach, we identified three major underlying phenotypes associated with extrinsic ageing. Associations between determinants for skin ageing differed in magnitude and direction per component. What's already known about this topic? Facial ageing is a complex phenotype consisting of different features including wrinkles, pigmented changes, telangiectasia and cancerous-related growths; it is not clear how these phenotypes are related to each other and to other phenotypes. A few studies have described two main clinical phenotypes for photoageing, namely hypertrophic ageing and atrophic ageing, which have been based solely on the clinical assessment of photoageing characteristics. What does this study add? We are the first to use epidemiology data to identify three main components associated with photoageing, namely a hypertrophic component (global wrinkling; perceived age; Griffiths grading) and atrophic component (pigmented spots; telangiectasia) and a cancer component (actinic keratosis; keratinocyte cancer). Association analysis showed different effects and direction of environmental determinants and genetic associations with the three components, with the most significant gene variants associations found for the atrophic component.

Epidemiology and determinants of facial telangiectasia: a cross-sectional study.

BACKGROUND: Telangiectasia or red veins are one of the prominent features of facial skin ageing. To date, there are few studies investigating the determinants of telangiectasia. OBJECTIVES: We investigated lifestyle and physiological factors associated with facial telangiectasia in a large prospective Dutch cohort study. METHODS: Telangiectasia was quantified digitally from standardized facial photographs of 2842 North European participants (56.8% female, median age 66.9) from the Rotterdam Study, collected in 2010-2013. Effect estimates from multivariable linear regressions are presented as the percentage difference in the mean value of telangiectasia area per unit increase of a determinant (%Δ) with corresponding 95% CI. RESULTS: Significant determinants were older age [1.7%Δ per year (95% CI 1.4, 2.0)], female sex [18.3%Δ (95% CI 13.2, 23.6)], smoking [current versus never 38.4%Δ (95% CI 30.3, 47.0); former versus never 11.6%Δ (95% CI 6.6, 16.9)], a high susceptibility to sunburn [10.2%Δ (95% CI 5.4, 15.3)] and light skin colour [pale versus white-to-olive 31.4%Δ (95% CI 19.7, 44.1]; white vs. white-to-olive 9.2%Δ (95% CI 2.8, 16.0)]. CONCLUSIONS: In this large cohort study, we confirmed known and described new determinants of facial telangiectasia.

Comparación de métodos de extracción de ADN simples y económicos para el diagnóstico molecular de leptospirosis animal

La leptospirosis bovina es una importante enfermedad zoonótica cuyo diagnóstico molecular está ampliamente divulgado. Sin embargo, no existe un método único de extracción de ADN para leptospiras patógenas a partir de muestras clínicas. En este trabajo se utilizó orina bovina contaminada con cultivo de L. interrogans serovar Pomona Pomona para analizar el mejor método comparando: M1.) resina Chelex-100, M2.) papel FTA Whatman y M3.) hervido de la muestra (protocolo casero). De estas tres técnicas, la primera (M1) presentó la mayor sensibilidad al realizar la PCR de diagnóstico, detectándose hasta 2x102 leptospiras/mL. La metodología aquí planteada resultó tener buen rendimiento para la detección de leptospiras en muestras clínicas animales, aunque es necesario su validación con mayor número y diversidad de muestras.

Bovine leptospirosis is an important zoonotic disease whose molecular diagnosis is widely reported. However, there is not a unique method of extraction of DNA for pathogenic leptospires using clinical samples. In this study, bovine urine was contaminated with pure culture of L. interrogans serovar Pomona Pomona in order to compare three of them: M1.) Chelex-100 resin, M2.) FTA Whatman paper and M3.) boiling of the sample (in-house protocol), being the first one the most sensitive when used in diagnostic PCR, detecting up to 2x102 leptospiras/mL. The methodology proposed in this study turned out to have good performance for the detection of leptospires in animal clinical samples, although it should be applied to a greater number of samples and in different stages of the pathology.

Surgical decision-making in infants with suspected UPJ obstruction: stakeholder perspectives.

INTRODUCTION: Although there are significant demographic and clinical variations in treatment decisions for infants with high-grade hydronephrosis concerning for ureteropelvic junction obstruction (UPJO), there has been little research on the roles of parents and surgeons in the surgical decision-making (DM) process. OBJECTIVE: The purpose of this study was to understand parents' and surgeons' perceived roles in the surgical DM process for infants with high-grade hydronephrosis. STUDY DESIGN: Semistructured interviews were conducted with pediatric urologists from three regionally diverse tertiary referral sites and parents of infants diagnosed and treated for unilateral Society for Fetal Urology grade 3 or 4 hydronephrosis at one tertiary pediatric urology practice. Purposive sampling was used to ensure adequate representation of parents based on treatment choice, patient gender, race/ethnicity, and distance from the practice. Survey domains included (1) discussions about diagnosis and treatment options, (2) factors guiding treatment choice, and (3) participants' role in the DM process. Transcribed data and field notes were analyzed using a team-based, inductive grounded theory qualitative approach. RESULTS: Thirteen physicians and 32 parents were interviewed between November 2016 and November 2017. Parents and surgeons agreed that the surgeon was best equipped to guide treatment decisions because of their clinical knowledge and experience. Parents reported that their trust in the surgeon was the primary factor in their decisions. Surgeons reported tailoring discussions with parents to not only educate them about treatment options but also to develop an ongoing relationship with parents. Both parents and surgeons reported being satisfied with their roles in the DM process. DISCUSSION: This study suggests that parental trust in the surgeon and surgeon recommendations drive DM. This may be due to a lack of explicit discussion of options or of parental values and preferences for care. Limited discussions may also impact parental understanding of risks and potential complications. These findings are similar to those of prior studies in adults and children considering elective surgery. CONCLUSIONS: In this study, parents and surgeons reported that surgeon recommendations, rather than parent preferences, guide treatment choices for infants with suspected UPJO. Both parents and surgeons are satisfied with a physician-driven approach to DM, suggesting that, in situations where the perceived risk is low and parental knowledge is limited, parents may find a physician-led approach beneficial. Data gleaned from this study will be used to inform future quantitative studies evaluating factors guiding surgeon recommendations for treatment and their associations with underlying treatment variation.

Association of objectively measured physical activity with brain structure: UK Biobank study.

BACKGROUND: Physical activity may be beneficial for cognition but mechanisms are unclear. We examined the association between objectively assessed physical activity and brain volume, with a focus on the hippocampus region. METHODS: We used data from UK Biobank (n = 5272; aged 55.4 ± 7.5 years; 45.6% men) collected through 2013-2016. Participants wore the Axivity AX3 wrist-worn triaxial accelerometer for 7 days to assess habitual physical activity. Structural magnetic resonance imaging was performed using a standard Siemens Skyra 3T running VD13A SP4 to obtain images of the brain. RESULTS: There was an association between physical activity (per SD increase) and grey matter volume after adjustment for a range of covariates, although this association was only detected in older adults (>60 years old). We also observed associations of physical activity with both left (B = 0.52, 95% CI, 0.01, 1.03; P = 0.046) and right hippocampal volume (B = 0.59, 95% CI, 0.08, 1.10; P = 0.024) in covariate-adjusted models. CONCLUSION: In summary, physical activity may play a role in the prevention of neurodegenerative diseases.