5,330 research outputs found

    Inverse Low Gain Avalanche Detectors (iLGADs) for precise tracking and timing applications

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    Low Gain Avalanche Detector (LGAD) is the baseline sensing technology of the recently proposed Minimum Ionizing Particle (MIP) end-cap timing detectors (MTD) at the Atlas and CMS experiments. The current MTD sensor is designed as a multi-pad matrix detector delivering a poor position resolution, due to the relatively large pad area, around 1 mm2mm^2; and a good timing resolution, around 20-30 ps. Besides, in his current technological incarnation, the timing resolution of the MTD LGAD sensors is severely degraded once the MIP particle hits the inter-pad region since the signal amplification is missing for this region. This limitation is named as the LGAD fill-factor problem. To overcome the fill factor problem and the poor position resolution of the MTD LGAD sensors, a p-in-p LGAD (iLGAD) was introduced. Contrary to the conventional LGAD, the iLGAD has a non-segmented deep p-well (the multiplication layer). Therefore, iLGADs should ideally present a constant gain value over all the sensitive region of the device without gain drops between the signal collecting electrodes; in other words, iLGADs should have a 100%{\%} fill-factor by design. In this paper, tracking and timing performance of the first iLGAD prototypes is presented.Comment: Conference Proceedings of VCI2019, 15th Vienna Conference of Instrumentation, February 18-22, 2019, Vienna, Austri

    The Influence of Parental Dietary Behaviors and Practices on Children’s Eating Habits

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    Poor dietary habits established during childhood might persist into adulthood, increasing the risk of developing obesity and obesity-related complications such as Type 2 Diabetes Mellitus. It has been found that early modifications in eating habits, especially during childhood, might promote health and decrease the risk of developing diseases during later life. Various studies found a great influence of parental dietary habits on dietary behaviors of their children regardless of demographic characteristics such as gender, age, socioeconomic status and country; however, the exact mechanism is still not clear. Therefore, in this review, we aimed to investigate both parents' and children's dietary behaviors, and to provide evidence for the potential influence of parents' dietary behaviors and practices on certain children's eating habits. Family meals were found to contribute the most in modeling children's dietary habits as they represent an important moment of control and interaction between parents and their children. The parental practices that influenced their children most were role modeling and moderate restriction, suggesting that the increase of parental encouragement and decrease of excessive pressure could have a positive impact in their children's dietary behaviors. This narrative review highlights that parental child-feeding behaviors should receive more attention in research studies as modifiable risk factors, which could help to design future dietary interventions and policies to prevent dietary-related diseases

    Nearby supernova host galaxies from the CALIFA Survey: II. SN environmental metallicity

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    The metallicity of a supernova (SN) progenitor, together with its mass, is one of the main parameters that rules their outcome. We present a metallicity study of 115 nearby SN host galaxies (0.005<z<0.03) which hosted 142 SNe using Integral Field Spectroscopy (IFS) from the CALIFA survey. Using O3N2 we found no statistically significant differences between the gas-phase metallicities at the locations of the three main SN types (Ia, Ib/c and II) all having ~8.50±\pm0.02 dex. The total galaxy metallicities are also very similar and we argue that this is because our sample consists only of SNe discovered in massive galaxies (log(M/Msun)>10 dex) by targeted searches. We also found no evidence that the metallicity at the SN location differs from the average metallicity at the GCD of the SNe. By extending our SN sample with published metallicities at the SN location, we studied the metallicity distributions for all SN subtypes split into SN discovered in targeted and untargeted searches. We confirm a bias toward higher host masses and metallicities in the targeted searches. Combining data from targeted and untargeted searches we found a sequence from higher to lower local metallicity: SN Ia, Ic, and II show the highest metallicity, which is significantly higher than SN Ib, IIb, and Ic-BL. Our results support the picture of SN Ib resulting from binary progenitors and, at least part of, SN Ic being the result of single massive stars stripped of their outer layers by metallicity driven winds. We studied several proxies of the local metallicity frequently used in the literature and found that the total host metallicity allows for the estimation of the metallicity at the SN location with an accuracy better than 0.08 dex and very small bias. In addition, weak AGNs not seen in total spectra may only weakly bias (by 0.04 dex) the metallicity estimate from integrated spectra. (abridged)Comment: 24 pages, 16 Figures, 13 Tables, Accepted in A&

    Levels of insulin and HOMA-IR in adolescents in Saltillo, Coahuila, Mexico

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    An alarming rise of obesity in adolescents has been observed, placing them at risk of developing resistance to insulin (IR) and its adverse metabolic consequences such as diabetes mellitus type 2 (DM2), metabolic syndrome and cardiovascular disease. Objective: To know the prevalence of obesity, and the levels of glucose, insulin and HOMA-IR and its association with the BMIz, waist circumference and the pubertal stage in a random sample of adolescents. Materials and methods: 292 adolescents between 12 and 15 years (152 female and 140 male), whose anthropometric measurements (weight, height and waist circumference) were taken, body mass index calculated and Z-score determined. Blood glucose and insulin levels were evaluated from a sample of blood and their HOMA-IR was determined. Results: The results showed that 32.5% were obese, 22.3% were overweight and 23.6% showed adolescent central obesity. Glucose levels (p = 0.016), insulin (p = 0.0001) and HOMA-IR (p = 0.0001) showed significant differences in the group with obesity. Values of the three parameters were increased with the stage of puberty. We found significant differences in the levels of glucose (p = 0.0388), insulin (p = 0.0005) and HOMA-IR (p = 0.0001) between the prepubertal and postpubertal stages

    Development of lntraepithelial Cells in the Porcine Small Intestine

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    The number, phenotype, localisation and development of intraepithelial lymphocytes (IEL) from duodenum (Du) and ileum (Il) were studied by immunohistochemistry (IHC) and light and electron microscopy in unweaned (0–7 weeks old) and six months-old pigs. Developmental changes at birth showed that 38% of the total lymphocytes in the villi were IEL, mainly of the CD2+CD4-CD8- double negative (DN) phenotype. That proportion rose to over 50% at week 5 after birth, resembling adult proportion, although still with fewer cells than in adult pigs. CD4+ cells appeared relatively early in life although they were confined to the lamina propria (LP) and CD8+ cells were found only in low numbers. In the villi of adult animals, almost half of the total number of lymphocytes were IEL (49% Du, 52% Il). Over half of these IEL (52% Du, 53% Il) showed the CD2+CD4-CD8+ phenotype and were localized at the epithelium's basement membrane. Numerous (43% Du, 42% Il) DN IEL were found grouped at the enterocyte nucleus level and relatively few (5% in Du and Il) granular IEL were found apically in the epithelium. These proportions were homogeneously maintained along the villi's tip, middle and bottom, suggesting that the IEL may have their origin in the LP. Therefore, the IEL compartment in the porcine intestine develops slowly with age and is actually composed by a heterogeneous population of cells (null, DN and CD8+). These results may explain the increased susceptibility of young animals to disease during the lactation period and should be taken into account when functional studies are carried out with IEL. The quantitative results of this paper established a model for studies on the effect of age, diet, normal flora, infection and oral immunization on the IEL of the gut

    Dynamic semantic ontology generation: a proposal for social robots

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    [Abstract] During a human-robot interaction by dialogue/voice, the robot cannot extract semantic meaning from the words used, limiting the intervention itself. Semantic knowledge could be a solution by structuring information according to its meaning and its semantic associations. Applied to social robotics, it could lead to a natural and fluid human-robot interaction. Ontologies are useful representations of semantic knowledge, as they capture the relationships between objects and entities. This paper presents new ideas for ontology generation using already generated ontologies as feedback in an iterative way to do it dynamically. This paper also collects and describes the concepts applied in the proposed methodology and discusses the challenges to be overcome.Ministerio de Ciencia, Innovación y Universidades; RTI2018-096338-B-I0

    Resistance of cactus pear (Opuntia ficus-indica) against Pseudocercospora opuntiae through β‑1,3‑glucanase activity and polyphenolic compounds in cladodes

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    Black spot disease, caused by the hemibiotrophic fungus Pseudocercospora opuntiae, is one of the main phytosanitary problems of cactus (Opuntia spp.). Through mass selection, one cultivar of Opuntia ficus-indica (L.) Mill. resistant to colonization by P. opuntiae was identified. The ethanolic extract of resistant cladodes showed higher levels of total condensed tannins, flavonoids and polyphenols than those of the susceptible genotypes, generating 93% inhibition of P. opuntiae conidial germination in vitro. The total protein in the resistant genotype showed 300% higher β-1,3-glucanase than the susceptible genotype. This increased activity was able to inhibit germination of conidia by 90%, a similar effect to that of the fungicide Captan® (N‑trichloromethylthio-4-cyclohexene 1,2-dicarboximide). It was shown, for the first time, that the combined action of cactus polyphenols and β-1,3-glucanase contributes significantly to resistance against P. opuntiae. Activity of this enzyme and the phytochemical profile can be used as criteria to predict and detect cactus germplasm with resistance to black spot.Fil: Ochoa, Maria Judith. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; ArgentinaFil: González Flores, L. M.. Instituto Tecnológico de Tlajomulco; MéxicoFil: Cruz Rubio, J. M.. Instituto Tecnológico de Tlajomulco; MéxicoFil: Rivera López, L. A.. Instituto Tecnológico de Tlajomulco; MéxicoFil: Rodriguez, Sergio A.. Universidad Nacional de Santiago del Estero; ArgentinaFil: Nazareno, Mónica Azucena. Universidad Nacional de Santiago del Estero; Argentina. Universidad Nacional de Santiago del Estero. Facultad de Agronomía y Agroindustrias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Gómez Leyva, J. F.. Instituto Tecnológico de Tlajomulco; Méxic

    Aluminium incorporation in AlGaN/GaN heterostructures: a comparative study by ion beam analysis and X-ray diffraction

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    The Al content in AlxGa1 − xN/GaN heterostructures has been determined by X-ray diffraction (XRD) and contrasted with absolute measurements from ion beam analysis (IBA) methods. For this purpose, samples with 0.1bxb0.3 grown by metal organic chemical vapour deposition on sapphire substrates have been studied. XRD and IBA corroborate the good epitaxial growth of the AlGaN layer, which slightly deteriorates with the incorporation of Al for xN0.2. The assessment of Al incorporation by XRD is quite reliable regarding the average value along the sample thickness. However, XRD analysis tends to overestimate the Al fraction at low contents, which is attributed to the presence of strain within the layer. For the highest Al incorporation, IBA detects a certain Al in-depth compositional profile that should be considered for better XRD data analysis

    Vegetación de la Sierra Madre Occidental, México: una síntesis

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    The Sierra Madre Occidental (SMO) is the largest mountain range in Mexico, extending along more than 1200 km from northeastern Sonora (30°35' N) ca at the US-Mexico border to northern Jalisco (21°00' N) on western Mexico. It includes part of the states of Sonora, Chihuahua, Durango, Zacatecas, as well as small areas of Sinaloa, Nayarit, Jalisco, and Aguascalientes. Of major ecological and economical importance, with a high biological and cultural diversity, this cordilleran complex is not yet well known. For this area, information about the different vegetation types, their elevational ranges, and the climates influencing them, is presented, as is a map showing the geographical distribution of the vegetation types. The area encompasses a confluence of Madrean, Xerophytic Madrean, and Tropical ecosystems. The Madrean region, with temperate and semi-cold climates, includes five vegetation types: pine forest, mixed-conifer forest, pine-oak forest, oak forest and temperate mesophytic forest, as well as communities of primary and secondary chaparral and montane meadow vegetation. The Xerophytic Madrean region, at foothills and eastern branches of the cordillera, has temperate or semi-cold dry climates and a vegetation of oak or pine-oak woodland and evergreen Juniperscrub, with transitions toward the grassland and xerophytic scrub areas of the Mexican high plateau or even to the subtropical scrub at the southern area of the Madrean Archipelago subregion. The Tropical region, entering the SMO through the deep canyons on the western flanks, has warm, semi-warm, and dry-warm climates and a prevalence of tropical deciduous forest and subtropical scrub, with small areas of tropical semideciduous forest. The high species richness of this range can be exemplified with the three physiognomically dominant genera: 24 species of Pinus (46% of the Mexican total), 54 species of Quercus (34%), and 7 species ofArbutus (100%).La Sierra Madre Occidental (SMO) es el complejo montañoso más grande de México, extendiéndose por casi 1200 km desde el noreste de Sonora (30°35' N) hasta el norte de Jalisco (21°00' N). A pesar de su gran importancia ambiental y económica, es todavía deficientemente conocida. Se presenta una sinopsis de los tipos de vegetación, con datos sobre la superficie que ocupan las comunidades reconocidas, intervalos de elevación y climas donde se localizan, así como un mapa. En la zona confluyen tres regiones, albergando ecosistemas templados y semifríos (región Madrense), semiáridos (Madrense-Xerófila) y cálido-secos (Tropical), respectivamente. La región Madrense, en el macizo de la sierra, incluye bosque de pino, bosque mixto de coníferas, bosque de pino-encino, bosque de encino y manchones de bosque mesófilo de montaña, además de comunidades como chaparral (primario y secundario) y vegetación de claros de bosque. La región Madrense-Xerófila, en el piedemonte norte y oriental y estribaciones al oriente de la sierra, presenta bosque bajo abierto (de encino o de pino-encino), matorral perennifolio y zonas de ecotonía hacia pastizal y matorral xerófilo, además de ecotonías con matorral subtropical hacia el sur del Archipiélago Madrense. En la región Tropical, a lo largo de la base occidental de la sierra e ingresando a esta a través de las barrancas y quebradas, predomina bosque tropical caducifolio y matorral subtropical, con pequeñas áreas de bosque tropical subcaducifolio. La alta diversidad de la SMO se ejemplifica con los tres géneros dominantes fisonómicamente en la vegetación: 24 especies de Pinus (46% del total nacional), 54 de Quercus (34%) y 7 de Arbutus (100%)
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