367 research outputs found

    Adapting to a changing world: Unraveling the role of man-made habitats as alternative feeding areas for Slender-billed Gull (Chroicocephalus genei)

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    Current rates of wildlife habitat loss have placed increasing demands on managers to develop, validate and implement tools aimed at improving our ability to evaluate such impacts on wildlife. Here, we present a case study conducted at the Natural Area of Doñana (SW Spain) where remote sensing and stable isotope (δ13C, δ15N) analyses of individuals were combined to unravel (1) the effect of variations in availability of natural food resources (i.e. from natural marshes) on reproductive performance of a Slender-billed Gull (Chroicocephalus genei) population, and (2) the role of two adjacent, artificial systems (a fish farm and saltmines) as alternate anthropogenic feeding areas. Based on long-term (1983-2004) remote-sensing, we inferred the average extent of flooded area at the marshland (a proxy to natural resource availability) annually. Estimated flooded areas (ranging from extreme drought [ca. 151 ha, 1995] to high moisture [15,049 ha, 2004]) were positively related to reproductive success of gulls (estimated for the 1993-2004 period, and ranging from ca. 0 to 1.7 fledglings per breeding pairs), suggesting that habitat availability played a role in determining their reproductive performance. Based on blood δ13C and δ15N values of fledglings, 2001-2004, and a Bayesian isotopic mixing model, we conclude that saltmines acted as the main alternative foraging habitat for gulls, with relative contributions increasing as the extent of marshland decreased. Although adjacent, anthropogenic systems have been established as the preferred breeding sites for this gull population, dietary switches towards exploitation of alternative (anthropogenic) food resources negatively affected the reproductive output of this species, thus challenging the perception that these man-made systems are necessarily a reliable buffer against loss of natural feeding habitats. The methodology and results derived from this study could be extended to a large suite of threatened natural communities worldwide, thus providing a useful framework for management and conservation

    Glycated haemoglobin (HbA1c ) and fasting plasma glucose relationships in sea-level and high-altitude settings.

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    AIM: Higher haemoglobin levels and differences in glucose metabolism have been reported among high-altitude residents, which may influence the diagnostic performance of HbA1c . This study explores the relationship between HbA1c and fasting plasma glucose (FPG) in populations living at sea level and at an altitude of > 3000 m. METHODS: Data from 3613 Peruvian adults without a known diagnosis of diabetes from sea-level and high-altitude settings were evaluated. Linear, quadratic and cubic regression models were performed adjusting for potential confounders. Receiver operating characteristic (ROC) curves were constructed and concordance between HbA1c and FPG was assessed using a Kappa index. RESULTS: At sea level and high altitude, means were 13.5 and 16.7 g/dl (P > 0.05) for haemoglobin level; 41 and 40 mmol/mol (5.9% and 5.8%; P < 0.01) for HbA1c ; and 5.8 and 5.1 mmol/l (105 and 91.3 mg/dl; P < 0.001) for FPG, respectively. The adjusted relationship between HbA1c and FPG was quadratic at sea level and linear at high altitude. Adjusted models showed that, to predict an HbA1c value of 48 mmol/mol (6.5%), the corresponding mean FPG values at sea level and high altitude were 6.6 and 14.8 mmol/l (120 and 266 mg/dl), respectively. An HbA1c cut-off of 48 mmol/mol (6.5%) had a sensitivity for high FPG of 87.3% (95% confidence interval (95% CI) 76.5 to 94.4) at sea level and 40.9% (95% CI 20.7 to 63.6) at high altitude. CONCLUSION: The relationship between HbA1c and FPG is less clear at high altitude than at sea level. Caution is warranted when using HbA1c to diagnose diabetes mellitus in this setting

    Metronomic oral vinorelbine in previously untreated advanced non-small-cell lung cancer patients unfit for platinum-based chemotherapy: results of the randomized phase II Tempo Lung trial

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    [Background] To assess the efficacy and safety of a metronomic schedule of oral vinorelbine (mVNR) in advanced non-small-cell lung cancer (NSCLC) in patients unfit for platinum-based combination chemotherapy.[Patients and methods] This was a multicenter, prospective, randomized, open-label phase II study in treatment-naive patients with TNM stage IIIB/IV NSCLC. Patients received mVNR at a fixed dose of 50 mg × 3 or standard schedule 60-80 mg/m2 weekly until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS) without grade 4 toxicity (G4PFS; NCI-CTC v4). Main secondary objectives were safety, disease control rate (DCR) without grade 4 toxicity (G4DCR), DCR, PFS, overall survival (OS) and quality of life (QoL).[Results] A total of 167 patients were included, 83 and 84 patients in the mVNR and standard arms, respectively. The median G4PFS was 4.0 months [95% confidence interval (CI): 2.6-4.3] and 2.2 months (95% CI: 1.5-2.9), hazard ration (HR) = 0.63 (95% CI: 0.45-0.88), P = 0.0068 in favor of metronomic arm; G4DCR was 45.8% and 26.8% in the mVNR and standard arms, respectively. Grade 3-4 treatment-related adverse events were less frequent in the mVNR arm (25.3% versus 54.4%) mainly owing to a reduction in all grades (15.7% versus 51.9%) and grade 3-4 neutropenia (10.8% versus 42%). PFS was 4.3 (95% CI: 3.3-5.1) and 3.9 months (95% CI: 2.8-5.2) in mVNR and standard arms, respectively. No difference in median OS was observed. QoL was comparable between arms.[Conclusions] Metronomic oral vinorelbine significantly prolonged median G4PFS in advanced NSCLC patients unfit for platinum combinations as first-line treatment. It was associated with a clear reduction in toxicity and may be considered as an important option in this challenging population.Pierre Fabre Médicament was the Sponsor of the study. The study was funded by Pierre Fabre Médicament. Conduct of the study: Pierre Fabre Médicament with the support of Clinipace clinical research organization (CRO) for the monitoring, of C-Med (CRO) for the data management and statistical analyses.Peer reviewe

    Normative and self-perceived orthodontic treatment need of a Peruvian university population

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    BACKGROUND: Previous studies on orthodontic treatment need in young adults have shown that up to 50% had malocclusions that needed orthodontic treatment. The aims of this study were to assess the normative and self-perceived need for orthodontic treatment using the Index of Orthodontic Treatment Need (IOTN) and to determine if the treatment need levels were influenced by sex, age and socio-economic status (SES) in a sample of Peruvian young adults. METHODS: 281 first-year students (157 male and 124 female students) with a mean age of 18.1 +/- 1.6 years were randomly selected and evaluated through the Dental Health Component (DHC) and Aesthetic Component (AC) of the IOTN. Structured interview and clinical examination were used to assess the students. Descriptive statistics and Chi-square tests were used for data analysis with statistical significance set at P < 0.05. RESULTS: An intra-examiner reliability of 0.89 was obtained (weighted Kappa). The percentage of students according to SES was 51.2%, 40.6% and 8.2% corresponding to low, medium and high SES respectively. The percentage of students with DHC grades 4–5 was 29.9% whereas the percentage of students with AC grades 8–10 was 1.8%. There were no significant differences in the distribution of normative and self-perceived orthodontic treatment need based on sex, age and SES comparisons. CONCLUSION: Normative orthodontic treatment need was not matched by a similar level of self-perceived treatment need in these young adults. Sex, age and SES were non-significant factors associated with levels of treatment need

    Prevalence, intensity and extent of Oral Impacts on Daily Performances associated with self-perceived malocclusion in 11-12-year-old children

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    BACKGROUND: To determine the prevalence, intensity and extent of the Oral Impacts on Daily Performances associated with self-perceived malocclusion among Peruvian schoolchildren. METHODS: Eight hundred and five children aged 11 to 12 years attending 4 of 7 randomly selected schools linked to a Health Centre in Lima, Peru, participated in the study. The Spanish (Peru)Child-OIDP was used to assess the prevalence, intensity and extent of oral impacts on 8 daily performances (eating, speaking, teeth cleaning, sleeping, smiling, studying, emotion and social contact). Self-perceived malocclusion included complaints about position of teeth, spacing of teeth and deformity of mouth or face. The prevalence of oral impacts was compared by covariables using the Chi-square test, whereas the intensity and extent of oral impacts were compared by covariables through the Mann-Whitney test. RESULTS: Only 15.5% of children reported impacts associated with self-perceived malocclusion during the last 3 months. Of them, 18.4% reported impacts of severe or very severe intensity and 76.0% reported impacts on only one daily performance. Psychosocial activities such as smiling, emotion and social contact were the most frequently and severely impacted everyday activities. CONCLUSION: Impacts of self-perceived malocclusion primarily affected psychological and social everyday activities. These findings provide further evidence to support the importance of psychological and social components of oral health on children's lives

    PM speciation and sources in Mexico during the MILAGRO-2006 Campaign

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    International audienceLevels of PM10, PM2.5 and PM1 and chemical speciation of PM10 and PM2.5 were measured during the MILAGRO campaign (1st to 31st March 2006, but extended in some cases until 6th April) at four urban, one suburban, two rural background and two rural sites, with different degree of industrial influence, in the Mexico City Metropolitan Area (MCMA) and adjacent regions. PM10 and PM2.5 daily levels varied between 50?56?g/m3 and 24?46?g/m3 at the urban sites, 22?35?g/m3 and 13?25?g/m3 at the rural sites, and 75?g/m3 and 31?g/m3 at the industrial hotspot, lower than those recorded at some Asian mega-cities and similar to those recorded at other Latin American cities. At the urban sites, hourly PM2.5 and PM1 concentrations showed a marked impact of road traffic emissions (at rush hours), with levels of coarse PM remaining elevated during daytime. At the suburban and rural sites different PM daily patterns were registered according to the influence of the pollution plume from MCMA, and also of local soil resuspension. The speciation studies showed that mineral matter accounted for 25?27% of bulk PM10 at the urban sites and a higher proportion (up to 43%) at the suburban and rural sites. This pattern is repeated in PM2.5, with 15% at urban and 28% at suburban and rural sites. Carbonaceous compounds accounted for a significant proportion at the urban and industrial sites (32?46% in PM10, and 51?55% in PM2.5), markedly reduced at the suburban and rural sites (16?23% in PM10, and 30% in PM2.5). The secondary inorganic aerosols accounted for 10?20% of bulk PM10 at urban, suburban, rural and industrial sites, with a higher proportion (40%) at the industrial background site. A relatively high proportion of nitrate in rural sites was present in the coarse fraction. Typically anthropogenic elements (As, Cr, Zn, Cu, Pb, Sn, Sb, Ba, among others) showed considerably high levels at the urban sites; however levels of particulate Hg and crustal trace elements (Rb, Ti, La, Sc, Ga) were generally higher at the suburban site. Principal component analysis identified three major common factors: crustal, regional background and road traffic. Moreover, some specific factors were obtained for each site

    Impacto del uso de diversos materiales como capa de transporte de huecos en una celda solar de perovskita

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    En varios trabajos se ha investigado la incidencia de las características de la capa de Perovskita en la eficiencia en la celda. Hay estudios que comparan el desempeño de diversos materiales para la capa llamada “ETL-Electron Transport Layer”. En este trabajo analizamos como son afectados los parámetros que caracterizan a una celda solar de Perovskita, empleando distintas alternativas para la capa llamada “HTL-Hole Transport Layer”. Empleamos el simulador SCAPS-1D (Solar Cells Capacitance Simulator). Hemos hallado una fuerte dependencia del rendimiento de la celda con la diferencia entre el máximo de la banda de Valencia de la Perovskita y el de la capa HTL, y con los dopajes de ambas capas. Rendimientos del 28% se obtienen para lo que hemos denominado condición de bandas planas en la interface HTL- Perovskita. La movilidad de los portadores en la HTL solo disminuye el rendimiento cuando es muy baja. El alto rendimiento calculado demuestra la potencialidad de esta tecnología.The characteristics of the perovskyte layer and its influence on the efficiency of perovskyte solar cells have been investigated recently in several research works. There are also many published studies in which the performance of different materials for the electron transport layer (ETL) in these devices is compared. In this paper, the main parameters of perovskyte solar cells are analyzed by considering different materials for the hole transport layer (HTL). The study is carried out theoretically by applying the device simulation code SCAPS-1D. We have found a strong dependence of the cell efficiency on the energy difference between the top of the valence band in the perovskyte and the HTL, and on the doping level in both layers. Efficiencies in the order of 28% have been obtained for a flatband condition at the interface perovskyte-HTL. The carrier mobilities at the HTL have been shown to degrade the efficiency only for very low mobility values. The high efficiency calculated demonstrates the promising potentiality of this technology.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism

    Impacto del uso de diversos materiales como capa de transporte de huecos en una celda solar de perovskita

    Get PDF
    En varios trabajos se ha investigado la incidencia de las características de la capa de Perovskita en la eficiencia en la celda. Hay estudios que comparan el desempeño de diversos materiales para la capa llamada “ETL-Electron Transport Layer”. En este trabajo analizamos como son afectados los parámetros que caracterizan a una celda solar de Perovskita, empleando distintas alternativas para la capa llamada “HTL-Hole Transport Layer”. Empleamos el simulador SCAPS-1D (Solar Cells Capacitance Simulator). Hemos hallado una fuerte dependencia del rendimiento de la celda con la diferencia entre el máximo de la banda de Valencia de la Perovskita y el de la capa HTL, y con los dopajes de ambas capas. Rendimientos del 28% se obtienen para lo que hemos denominado condición de bandas planas en la interface HTL- Perovskita. La movilidad de los portadores en la HTL solo disminuye el rendimiento cuando es muy baja. El alto rendimiento calculado demuestra la potencialidad de esta tecnología.The characteristics of the perovskyte layer and its influence on the efficiency of perovskyte solar cells have been investigated recently in several research works. There are also many published studies in which the performance of different materials for the electron transport layer (ETL) in these devices is compared. In this paper, the main parameters of perovskyte solar cells are analyzed by considering different materials for the hole transport layer (HTL). The study is carried out theoretically by applying the device simulation code SCAPS-1D. We have found a strong dependence of the cell efficiency on the energy difference between the top of the valence band in the perovskyte and the HTL, and on the doping level in both layers. Efficiencies in the order of 28% have been obtained for a flatband condition at the interface perovskyte-HTL. The carrier mobilities at the HTL have been shown to degrade the efficiency only for very low mobility values. The high efficiency calculated demonstrates the promising potentiality of this technology.Tema 4: Energía solar, conversión fotovoltaica.Facultad de Arquitectura y Urbanism
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