Effects of the structure of personal networks in the acquaintances network of a cohort of students in transition from high school to university

En este trabajo se examina la transición normativa de una cohorte de estudiantes de Enseñanza Secundaria de Alcalá de Guadaíra, que empiezan sus estudios universitarios en Sevilla. Se analiza la evolución de la red social de la cohorte de estudiantes junto con los cambios que experimentan en la composición y la estructura de sus redes personales. El seguimiento longitudinal se desarrolla a lo largo de 17 meses en los que los encuestados (n = 57) empiezan a distribuir su tiempo entre la localidad en la que residen y la ciudad en la que estudian, de modo que en su conjunto aumentan la frecuencia de los viajes de ida y vuelta a la capital. Este es uno de los primeros estudios que recoge información de las redes personales de los miembros de una red social completa, combinando ambos indicadores en los análisis. Con el modelo de simulación longitudinal de redes sociales, utilizando el software RSIENA, comprobamos que la intermediación promedio de las redes personales tiene un efecto significativo en la evolución de la red social de los estudiantes que terminan la Enseñanza Secundaria. La intermediación promedio también parece incidir en la tasa de cambio del sentido de comunidad con la ciudad de residencia. Concluimos proponiendo que el desacoplamiento de las relaciones, junto con la competencia entre relaciones múltiples activas, constituyen dos mecanismos clave de los cambios en la estructura de las redes personales en proceso de transición ecológica.In this work the normative transition of a cohort of secondary school students from Alcalá de Guadaíra that start college education in Seville is examined. The evolution of the social network of the cohort of students together with the changes experienced in the composition and structure of their personal networks is analyzed. The longitudinal tracking is developed over 17 months when respondents (n = 57) begin to distribute their time between the town in which they live and the city where they study, so there is an increase in the frequency of commuting to the capital. This is one of the first studies collecting information from the personal networks of the members of a complete social network, and combining both personal and sociocentric indicators in the analysis. With models for the longitudinal analysis of social networks, using the RSIENA software, we found that average betweenness of personal networks has a significant effect on the social network of students completing secondary education. The average betweenness also seems to influence the change rate in the sense of community with the city of residence. We conclude by proposing that the decoupling of relations, as well as active competition between multiple relationships, are two key mechanisms of changes in the structure of personal networks in the process of ecological transition.Ministerio de Educación y Ciencia SEJ2005-2568

A search for water maser emission toward obscured post-AGB star and planetary nebula candidates

Water maser emission at 22 GHz is a useful probe to study the transition between the nearly spherical mass-loss in the AGB to a collimated one in the post-AGB phase. In their turn, collimated jets in the post-AGB phase could determine the shape of planetary nebulae (PNe) once photoionization starts. We intend to find new cases of post-AGB stars and PNe with water maser emission, including water fountains or water-maser-emitting PNe. We observed water maser emission in a sample of 133 objects, with a significant fraction being post-AGB and young PN candidate sources with strong obscuration. We detected this emission in 15 of them, of which seven are reported here for the first time. We identified three water fountain candidates: IRAS 17291-2147, with a total velocity spread of ~96 km/s in its water maser components and two sources (IRAS 17021-3109 and IRAS 17348-2906) that show water maser emission outside the velocity range covered by OH masers. We have also identified IRAS 17393-2727 as a possible new water-maser-emitting PN. The detection rate is higher in obscured objects (14%) than in those with optical counterparts (7%), consistent with previous results. Water maser emission seems to be common in objects that are bipolar in the near-IR (43% detection rate). The water maser spectra of water fountain candidates like IRAS 17291-2147 show significantly less maser components than others (e.g., IRAS 18113-2503). We speculate that most post-AGBs may show water maser emission with wide enough velocity spread (> 100 km/s) when observed with enough sensitivity and/or for long enough periods of time. Therefore, it may be necessary to single out a special group of "water fountains", probably defined by their high maser luminosities. We also suggest that the presence of both water and OH masers in a PN is a better tracer of its youth, rather than the presence of just one of these species.Comment: To be published in Astronomy & Astrophysics. 16 pages, 1 figure (spanning 5 pages). This version includes some minor language corrections and fixes some errors in Table

Effect of Kramecyne on the Inflammatory Response in Lipopolysaccharide-Stimulated Peritoneal Macrophages

Kramecyne is a new peroxide, it was isolated from Krameria cytisoides, methanol extract, and this plant was mostly found in North and South America. This compound showed potent anti-inflammatory activity; however, the mechanisms by which this compound exerts its anti-inflammatory effect are not well understood. In this study, we examined the effects of kramecyne on inflammatory responses in mouse lipopolysaccharide- (LPS-) induced peritoneal macrophages. Our findings indicate that kramecyne inhibits LPS-induced production of tumor necrosis factor (TNF-α) and interleukin- (IL-) 6. During the inflammatory process, levels of cyclooxygenase- (COX-) 2, nitric oxide synthase (iNOS), and nitric oxide (NO) increased in mouse peritoneal macrophages; however, kramecyne suppressed them significantly. These results provide novel insights into the anti-inflammatory actions and support its potential use in the treatment of inflammatory diseases

VISIR-VLT high resolution study of the extended emission of four obscured post-AGB candidates

The onset of the asymmetry of planetary nebulae (PNe) is expected to occur during the late Asymptotic Giant Branch (AGB) and early post-AGB phases of low- and intermediate-mass stars. Among all post-AGB objects, the most heavily obscured ones might have escaped the selection criteria of previous studies detecting extreme axysimmetric structures in young PNe. Since the most heavily obscured post-AGB sources can be expected to descend from the most massive PN progenitors, these should exhibit clear asymmetric morphologies. We have obtained VISIR-VLT mid-IR images of four heavily obscured post-AGB objects barely resolved in previous Spitzer IRAC observations to analyze their morphology and physical conditions across the mid-IR. The VISIR-VLT images have been deconvolved, flux calibrated, and used to construct RGB composite pictures as well as color and optical depth maps that allow us to study the morphology and physical properties of the extended emission of these sources. We have detected extended emission from the four objects in our sample and resolved it into several structural components that are greatly enhanced in the temperature and optical depth maps. They reveal the presence of asymmetry in three young PNe (IRAS 15534-5422, IRAS 17009-4154, and IRAS 18454+0001), where the asymmetries can be associated with dusty torii and slightly bipolar outflows. The fourth source (IRAS 18229-1127), a possible post-AGB star, is better described as a rhomboidal detached shell. The heavily obscured sources in our sample do not show extreme axisymmetric morphologies. This is at odds with the expectation of highly asymmetrical morphologies in post-AGB sources descending from massive PN progenitors. The sources presented in this paper may be sampling critical early phases in the evolution of massive PN progenitors, before extreme asymmetries develop.Comment: 9 pages, 4 figure

Alumina-Based Composites Reinforced with Ductile Particles

Al2O3/Metal composite ceramics were fabricated by the use of mechanical milling and pressureless sintering. Al2O3 + 10 vol.% of La, Mn, Si or Y were mixed and milled during 12 h at 300 rpm in a horizontal mill, then with the powder mixture it was conformed cylindrical samples by uniaxial pressing using 300 MPa. Pressed samples were sintered during 2 h in an electrical furnace at 1500°C. During sintered it was used an argon atmosphere inside the furnace in order to inhibit metal oxidation. XRD results indicate that alumina and metals retain its crystalline structure. Reached density by samples is small and less than 90%. Scanning electron microscopy observations show alumina’s microstructure with very fine and homogeneous distributions of metal particles. Both the Mn and Si are not suitable metals to improve the mechanical properties of alumina, in particular the fracture toughness. Considered rare earth metals such as yttrium and lanthanum, have yielded favorable results in improving the fracture toughness of the alumina. However, it should be made more dense materials with them to better explore this potential

Biofilm formation behaviour of marine filamentous cyanobacterial strains in controlled hydrodynamic conditions

Marine biofouling has severe economic impacts and cyanobacteria play a significant role as early surface colonizers. Despite this fact, cyanobacterial biofilm formation studies in controlled hydrodynamic conditions are scarce. In this work, computational fluid dynamics was used to determine the shear rate field on coupons that were placed inside the wells of agitated 12-well microtiter plates. Biofilm formation by three different cyanobacterial strains was assessed at two different shear rates (4 and 40 s-1 ) which can be found in natural ecosystems and using different surfaces (glass and perspex). Biofilm formation was higher under low shear conditions, and differences obtained between surfaces were not always statistically significant. The hydrodynamic effect was more noticeable during the biofilm maturation phase rather than during initial cell adhesion and optical coherence tomography showed that different shear rates can affect biofilm architecture. This study is particularly relevant given the cosmopolitan distribution of these cyanobacterial strains and the biofouling potential of these organisms.This work was financially supported by project UID/EQU/ 00511/2019 – Laboratory for Process Engineering, Environment, Biotechnology and Energy – LEPABE funded by national funds through FCT/MCTES (PIDDAC) and by the CVMAR+i – Industrial Innovation and Marine Biotechnology Valorisation, funded by INTERREG V A Espanha Portugal (POCTEP) [0302_CVMAR_I_1_P]. The authors also acknowledge support from the EU COST Actions iPROMEDAI (TD1305) and ENBA (CA15216), and M.J.R. acknowledges a PhD grant from FCT (SFRH/BD/140080/2018)

Correlation Between NT-proBNP Values and Changes in Functional Capacity in Patients with Chronic Heart Failure

OBJECTIVE: We set out to evaluate whether changes in N-terminal pro-brain natriuretic peptide (proBNP) can predict changes in functional capacity, as determined by cardiopulmonary exercise testing (CPET), in patients with chronic heart failure (CHF) due to dilated cardiomyopathy (DCM). METHODS: We studied 37 patients with CHF due to DCM, 81% non-ischemic, 28 male, who performed symptom-limited treadmill CPET, with the modified Bruce protocol, in two consecutive evaluations, with determination of proBNP after 10 minutes rest prior to CPET. The time between evaluations was 9.6+/-5.5 months, and age at first evaluation was 41.1+/-13.9 years (21 to 67). RESULTS IN THE FIRST AND SECOND EVALUATIONS RESPECTIVELY WERE: NYHA functional class >II 51% and 16% (p<0.001), sinus rhythm 89% and 86.5% (NS), left ventricular ejection fraction 24.9+/-8.9% and 26.6+/-8.6% (NS), creatinine 1.03+/-0.25 and 1.09+/-0.42 mg/dl (NS), taking ACE inhibitors or ARBs 94.5% and 100% (NS), beta-blockers 73% and 97.3% (p<0.001), and spironolactone 89% and 89% (NS). We analyzed the absolute and percentage variation (AV and PV) in peak oxygen uptake (pVO2--ml/kg/min) and proBNP (pg/ml) between the two evaluations. RESULTS: (1) pVO2 AV: -17.4 to 15.2 (1.9+/-5.7); pVO2 PV: -56.1 to 84% (11.0+/-25.2); proBNP AV: -12850 to 5983 (-778.4+/-3332.5); proBNP PV: -99.0 to 379.5% (-8.8+/-86.3); (2) The correlations obtained--r value and p value [r (p)]--are shown in the table below; (3) We considered that a coefficient of variation of pVO2 PV of >10% represented a significant change in functional capacity. On ROC curve analysis, a proBNP PV value of 28% showed 80% sensitivity and 79% specificity for pVO2 PV of >10% (AUC=0.876, p=0.01, 95% CI 0.75 to 0.99). CONCLUSIONS: In patients with CHF due to DCM, changes in proBNP values correlate with variations in pVO2, as assessed by CPET. However, our results suggest that only a proBNP PV of >28% predicts a significant change in functional capacity

Telemedicina: Situação em Portugal

Introdução: A telemedicina é hoje reconhecida pela OMS como uma ferramenta para melhorar o acesso e a qualidade dos cuidados de saúde. Apesar das vantagens aparentes é uma tecnologia recente e está longe de constituir uma prática de rotina na vida clínica diária. Objectivo: Conhecer a situação actual em Portugal relativamente à telemedicina, nomeadamente: quais as Unidades de Saúde com instalações de telemedicina e áreas em que se desenvolve esta actividade; número de serviços anuais e evolução; dificuldades e obstáculos dos profissionais e Instituições; perspectivas futuras Metodologia: A recolha dos dados foi efectuado através de: inquérito enviados às ARS do Norte, Centro, Lisboa e Vale do Tejo, Alentejo, Algarve e IGIF; entrevista com algumas instituições relativa aos serviços em funcionamento; pesquisa bibliográfica e na Internet Resultados: Dos 6 inquéritos enviados foram recebidos 5, provenientes da ARS Norte, Centro, Lisboa e Vale do Tejo, Algarve e Alentejo. Foram efectuadas entrevistas: H S. João, CHVila Nova de Gaia, CHVale do Sousa e H Pediátrico de Coimbra. Obtivemos informações relativas aos equipamentos instalados e serviços actualmente em funcionamento, em todo o país, destacando- se o funcionamento nas áreas da cardiologia, imagiologia e dermatologia. Não havia registo do número de teleconsultas e transmissão de exames excepto no que se refere à ARS Alentejo. Das dificuldades e obstáculos encontrados salientamos a falta de adesão dos profissionais e instituições; custos do funcionamento do sistema; ausência de definição funcional dos profissionais envolvidos (falta de remuneração dos actos médicos e acumulação de funções); ausência de uma estratégia nacional. Quanto às perspectivas futuras, de um modo geral, os objectivos das ARS incluem: a ligação dos centros de saúde e hospitais, e petrechamento com um equipamento básico de Telemedicina em conformidade com as actividades e tipos de consulta a realizar; o desenvolvimento de projectos no âmbito do INTERREG III. Comentários: O desafio que as organizações tem que enfrentar é a mudança estrutural provocada pela modernização dos processos e métodos de trabalho, «o hospital virtual», e a diluição das barreiras entre os Cuidados Primários e os Diferenciados. A telemedicina exige novas formas de gestão e de medição de desempenho das instituições; esta actividade deve ser equiparada às outras normalmente desenvolvidas nas unidades de saúde. Introduction: Telemedicine is recognized by the WHO as a tool for improvement of access and the quality of health care. However it is not yet a routine procedure in health services. Objective: to assess the utilization of telemedicine in Portugal, namely: health care services equipped with telemedicine, and services provided; annual services and evolution; difficulties and obstacles from professionals and institutions; future trends Methodology: data was obtained through a questionnaire sent to the five Regional Administrations of Health and the Financial Department of Health, interviews with some of the professionals practising Telemedicine and research in the web Results: We received five questionnaires from the Regional Administrations of Health, and collected data from the following Hospitals: S. João, Vila Nova de Gaia, Vale do Sousa e Coimbra Children’s Hospital. We obtained information of the institutions practising telemedicine, and the type of services. Cardiology, radiology and dermatology were the services more frequently provided. The number of teleconsultations or transmitted studies was not registered, except in Alentejo. The more common difficulties to implement this technology were: clinical and providers acceptance; lack of integration into the health care mainstream (the costs of teleconsultations are not reimbursed); equipment and operational costs; absence of a national strategy. Future trends include the equipment of telemedicine stations in Primary and Hospital care and the development of projects in cooperation with Spain (INTERREG III). Comments: Organizations face the challenge of a structural change due to the new technologies (telemedicine and health informatics) and the disappearance of barriers between primary and hospital care. Institutional, organizational and national policies must face new realities to introduce telemedicine into the mainstream of health, including assessment of health outcomes