1,634 research outputs found
Control of the Light Interaction in a Semiconductor Nanoparticle Dimer Through Scattering Directionality
11 págs.; 4 figs.; 1 tab.Dimers of nanoparticles are very interesting for several devices due to the possibility of obtaining intense light concentrations in the gap between them. A dynamic control of this interaction to obtain either the maximum or minimum light through interferential effects could be also relevant for a multitude of devices such as chemical sensors or all-optical devices for interchip/intrachip communications. Semiconductor nanoparticles satisfying Kerker conditions present an anisotropic scattering distribution with a minimum in either the forward or the backward direction and prominent scattering in the contrary direction. The reduction or enhancement of the electromagnetic field in a certain direction can minimize or maximize the interaction with neighboring nanoparticles. In this paper, we consider a dimer of nanoparticles such that each component satisfies each one of the Kerker conditions. Depending on the arrangement of the nanoparticles with respect to the impinging light direction, we can produce a minimum or a maximum of the electric field between them, reducing or maximizing the interferential effects. The strong dependence of the directional conditions with external conditions, such as the incident wavelength, can be used to dynamically control the light concentration in the gap. Ó 2016 IEEEThis work was supported in part by the Ministerio
de EconomÃa y Competitividad of Spain under Grant TEC2013—50138—EXP and Grant
TEC2013-47342-C2-2-R, by the RD Program of the Comunidad de Madrid under Grant SINFOTON
S2013/MIT—2790, and by COST Action IC1208.Peer Reviewe
The impact of hydroxychloroquine treatment on pregnancy outcome in women with antiphospholipid antibodies
Factors influencing wild chimpanzee (Pan troglodytes verus) relative abundance in an agriculture-swamp matrix outside protected areas
This study was funded by a grant from the Arcus Foundation No. G-PGM-1508-1368 to TH; PA was supported by the MINECO and the Universidad de Castilla-La Mancha (UCLM) through a 'Ramón y Cajal' contract (RYC-2012-11970), and Tacugama Chimpanzee Sanctuary provided logistical support. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. We are grateful to the Ministry of Agriculture, Forestry and Food Security of the Sierra Leone Government for granting us permission to conduct this research. This work would not have been possible without the collaboration of the people in the study communities. We also thank the outreach and management teams at the Tacugama Chimpanzee Sanctuary, in particular David Momoh, Joseph Marah, Konkofa Marah, Yirah Koroma, Bockarie Kanneh and Natalia Casado, for their assistance in the field. We are also extremely grateful to Dr. Raj Amin, Institute of Zoology in London, for providing the camera trap analysis software and to Jasper Gilardi for his help with processing camera trap images. Finally, we would also like to thank the two anonymous reviewers who provided useful suggestions for improving the quality of this manuscript.Human population growth and anthropogenic activities are exacerbating pressures on biodiversity globally. Land conversion is aggravating habitat fragmentation and non-human primates are increasingly compelled to live in forest-agricultural mosaics. In Sierra Leone, more than half of the wild chimpanzee population (Pan troglodytes verus) occurs outside protected areas and competes for resources with farmers. Our study area, in the Moyamba district in south-western Sierra Leone, is practically devoid of forest and is dominated by cultivated and fallow fields, swamps and mangroves. In this region, traditional slash-and-burn agriculture modifies annually the landscape, sparing swamps and mangroves and semi-domesticated oil palms (Elaeis guineensis). This study aimed to explore ecological and anthropogenic factors influencing chimpanzee relative abundance across this highly degraded and human-impacted landscape. Between 2015 and 2016, we deployed 24 camera traps systematically across 27 1.25x1.25 km grid cells. Cameras were operational over a period of 8 months. We used binomial iCAR models to examine to what extent anthropogenic (roads, settlements, abandoned settlements and human presence) and habitat variables (swamps, farmland and mangroves) shape chimpanzee relative abundance. The best model explained 43.16% of the variation with distance to roads and swamps emerging as the best predictors of chimpanzee relative abundance. Our results suggest that chimpanzees avoid roads and prefer to maintain proximity to swamps. There was no significant effect of settlements, abandoned settlements, mangroves or human presence. It appears that chimpanzees do not avoid areas frequented by people; although, our findings suggest temporal avoidance between the two species. We highlight the importance of studying chimpanzee populations living in anthropogenic habitats like agricultural-swamp matrixes to better understand factors influencing their distribution and inform conservation planning outside protected areas
A longitudinal study on perceived health in cardiovascular patients. The role of conscientiousness, subjective wellbeing and cardiac self-efficacy
Cardiovascular disease (CVD) is the world’s most prevalent chronic disease and the leading chronic cause of morbidity. There are several psychosocial factors associated with quality of life during CVD. Our main objectives were to analyze the roles of conscientiousness, subjective wellbeing and self-efficacy beliefs. The sample comprised 514 patients (mean age 63.57 years) who were assessed twice over a nine-month interval. At Time 1, participants answered a questionnaire assessing conscientiousness, perceived subjective wellbeing (positive and negative affect, life satisfaction), cardiac self-efficacy and health-related quality of life (HRQoL). The same variables (except for conscientiousness) were re-assessed at Time 2. Results showed that conscientiousness had a positive relation with subjective wellbeing, cardiac self-efficacy, and HRQoL at Time 1. Moreover, cardiac self-efficacy at Time 1 had a positive longitudinal effect on HRQoL at Time 2, while controlling for autoregressive effects. Mediation analyses indicated that the relationship between conscientiousness and HRQoL was mediated by positive affect and cardiac self-efficacy. These results suggest the usefulness of psychosocial interventions aimed at promoting positive affect and self-efficacy beliefs among CVD patients
First-line eradication rates comparing two shortened non-bismuth quadruple regimens against Helicobacter pylori: an open-label, randomized, multicentre clinical trial
OBJECTIVES: Helicobacter pylori eradication remains a challenge. Non-bismuth-based quadruple regimens (NBQR) have shown high eradication rates (ER) elsewhere that need to be locally confirmed. The objective of this study was to compare the first-line ER of a hybrid therapy (20 mg of omeprazole twice daily and 1 g of amoxicillin twice daily for 10 days, adding 500 mg of clarithromycin twice daily and 500 mg of metronidazole every 8 h for the last 5 days; OA-OACM) with that of a 10 day concomitant regimen consisting of taking all four drugs twice daily every day (including 500 mg of metronidazole every 12 h; OACM). A 10 day arm with standard triple therapy (OAC; 20 mg of omeprazole/12 h, 1 g of amoxicillin/12 h and 500 mg of clarithromycin/12 h) was included. PATIENTS AND METHODS: Three hundred consecutive patients were randomized (1: 2: 2) into one of the three following regimens: (i) OAC (60); (ii) OA-OACM (120); and (iii) OACM (120). Eradication was generally confirmed by a [(13)C]urea breath test at least 4 weeks after the end of treatment. Adverse events and compliance were assessed. EudraCT: 2011-006258-99. RESULTS: ITT cure rates were: OAC, 70.0% (42/60) (95% CI: 58.3-81.7); OA-OACM, 90.8% (109/120) (95% CI: 85.6-96.0); and OACM, 90.0% (107/119) (95% CI: 84.6-95.4). PP rates were: OAC, 72.4% (42/58) (95% CI: 60.8-84.1); OA-OACM, 93.9% (108/115) (95% CI: 89.5-98.3); and OACM, 90.3% (102/113) (95% CI: 84.8-95.8). Both NBQR significantly improved ER compared with OAC (P < 0.01), but no differences were seen between them. Mean compliance was elevated [98.0% (SD = 9.8)] with no differences between groups. There were more adverse events in the quadruple arms (OACM, 65.8%; OA-OACM, 68.6%; OAC, 46.6%; P < 0.05), but no significant differences between groups in terms of severity were seen. CONCLUSIONS: Hybrid and concomitant regimens show good ER against H. pylori infection with an acceptable safety profile. They clearly displace OAC as first-line regimen in our area
Living with chronic migraine: a qualitative study on female patients' perspectives from a specialised headache clinic in Spain
OBJECTIVES: The aim of this study was to explore the views and experiences of a group of Spanish women suffering from chronic migraine (CM).
SETTING: Headache clinic at a university hospital in Madrid (Spain).
PARTICIPANTS: Purposeful sampling of patients that attended a specialised headache clinic for the first time between June 2016 and February 2017 was performed. The patients included were females aged 18–65 and with positive diagnoses of CM according to the International Classification of Headache disorders (third edition, beta version), with or without medication overuse. Accordingly, 20 patients participated in the study with a mean age of 38.65 years (SD 13.85).
DESIGN: Qualitative phenomenological study.
METHODS: Data were collected through in-depth interviews, researchers’ field notes and patients’ drawings. A thematic analysis was performed following appropriate guidelines for qualitative research.
RESULTS: Five main themes describing the significance of suffering emerged: (a) the shame of suffering from an invisible condition; (b) treatment: between need, scepticism and fear; (c) looking for physicians’ support and sincerity and fighting misconceptions; (d) limiting the impact on daily life through self-control; and (e) family and work: between understanding and disbelief. The disease is experienced as an invisible process, and the journey to diagnosis can be a long and tortuous one. Drug prescription by the physician is greeted with distrust and scepticism. Patients expect sincerity, support and the involvement of their doctors in relation to their disease. Pain becomes the main focus of the patient’s life, and it requires considerable self-control. The disease has a strong impact in the work and family environment, where the patient may feel misunderstood.
CONCLUSIONS: Qualitative research offers insight into the way patients with CM experience their disease and it may be helpful in establishing a more fruitful relationship with these patients
Relationship Between Sexual Activity, Contraceptive Utilization and Biopsychosocial Characteristics Among Homeless Shelter Adolescents.
Objective: To determine whether biopsychosocial factors are associated with sexual activity and contraceptive utilization among homeless shelter adolescents. Methods: A retrospective study of 440 adolescents at a shelter in Pennsylvania between February 2015 and September 2019 was conducted. The cohort was evaluated to determine what relationship age, gender identity, substance use, and trauma history have with sexual activity and contraceptive utilization. Results: Sexual activity was significantly related to age (mean 15.8+1.4 years in sexually active vs. 14.7+1.6 years in abstinent youth, p\u3c0.001); remote history of self-harm behavior (relative risk ratio (RR) 1.23 [95% CI 1.03-1.46]; p=0.02), history of aggressive behavior (RR 1.21 [95% CI 1.01-1.46]; p=0.04), history of trauma (RR 1.24 [95% CI 1.04-1.48]; p=0.03), and substance use (RR 2.27 [95%CI 1.86-2.77]; p\u3c0.001). There were 55.7% sexually active females vs. 42.50% males reporting contraception use (p=0.01). After adjustment, older age and substance use remained significantly associated with sexual activity (adjusted odds ratio (AOR) 1.58 [95% CI 1.36-1.83]; p\u3c0.001 and AOR 5.18 [95% CI 3.28-8.18]; p\u3c0.001, respectively). Conclusions: Females self-reported sexual activity using contraception more than males. After adjustment, older age and substance use were associated with sexual activity. By better understanding the impact these factors can have on contraceptive utilization, informed policy and practice interventions can be developed and implemented to help increase safe sex practices in spaces where homeless adolescents access healthcare
Nuclear Vav3 is required for polycomb repression complex-1 activity in B-cell lymphoblastic leukemogenesis
Acute B-cell lymphoblastic leukemia (B-ALL) results from oligo-clonal evolution of B-cell progenitors endowed with initiating and propagating leukemia properties. The activation of both the Rac guanine nucleotide exchange factor (Rac GEF) Vav3 and Rac GTPases is required for leukemogenesis mediated by the oncogenic fusion protein BCR-ABL. Vav3 expression becomes predominantly nuclear upon expression of BCR-ABL signature. In the nucleus, Vav3 interacts with BCR-ABL, Rac, and the polycomb repression complex (PRC) proteins Bmi1, Ring1b and Ezh2. The GEF activity of Vav3 is required for the proliferation, Bmi1-dependent B-cell progenitor self-renewal, nuclear Rac activation, protein interaction with Bmi1, mono-ubiquitination of H2A(K119) (H2AK119Ub) and repression of PRC-1 (PRC1) downstream target loci, of leukemic B-cell progenitors. Vav3 deficiency results in de-repression of negative regulators of cell proliferation and repression of oncogenic transcriptional factors. Mechanistically, we show that Vav3 prevents the Phlpp2-sensitive and Akt (S473)-dependent phosphorylation of Bmi1 on the regulatory residue S314 that, in turn, promotes the transcriptional factor reprogramming of leukemic B-cell progenitors. These results highlight the importance of non-canonical nuclear Rho GTPase signaling in leukemogenesis.This project was funded by the National Institutes of Health Grants R01-CA273016 (N.N.N. and J.A.C.) and U54-DK126108 (J.A.C.), the Leukemia & Lymphoma Society of North America (J.A.C and N.N.N.; and N.N.N. and J.A.C.), and William Lawrence & Blanche Hughes Foundation (J.A.C. and N.N.)
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