11,332 research outputs found
Mantle geoneutrinos in KamLAND and Borexino
The KamLAND and Borexino experiments have observed, each at ~4 sigma level,
signals of electron antineutrinos produced in the decay chains of thorium and
uranium in the Earth's crust and mantle (Th and U geoneutrinos). Various pieces
of geochemical and geophysical information allow an estimation of the crustal
geoneutrino flux components with relatively small uncertainties. The mantle
component may then be inferred by subtracting the estimated crustal flux from
the measured total flux. To this purpose, we analyze in detail the experimental
Th and U geoneutrino event rates in KamLAND and Borexino, including neutrino
oscillation effects. We estimate the crustal flux at the two detector sites,
using state-of-the-art information about the Th and U distribution on global
and local scales. We find that crust-subtracted signals show hints of a
residual mantle component, emerging at ~2.4 sigma level by combining the
KamLAND and Borexino data. The inferred mantle flux slightly favors scenarios
with relatively high Th and U abundances, within +-1 sigma uncertainties
comparable to the spread of predictions from recent mantle models.Comment: Slight changes and improvements in the text & figures. Results
unchanged. To appear in Phys. Rev.
Geo-neutrinos
We review a new interdisciplinary field between Geology and Physics: the
study of the Earth's geo-neutrino flux. We describe competing models for the
composition of the Earth, present geological insights into the make up of the
continental and oceanic crust, those parts of the Earth that concentrate Th and
U, the heat producing elements, and provide details of the regional settings in
the continents and oceans where operating and planned detectors are sited.
Details are presented for the only two operating detectors that are capable of
measuring the Earth's geo-neutrinos flux: Borexino and KamLAND; results
achieved to date are presented, along with their impacts on geophysical and
geochemical models of the Earth. Finally, future planned experiments are
highlighted
Caracterização geo-ambiental do municÃpio de Porto da Folha (SE).
Localização; Extensão; População; Clima; Geologia; Vegetação; Relevo; Hidrografia; As unidades geo-ambientais; As grandes unidades de solos; Os quadros agrário e agrÃcola; Recomendações e sugestões complementares; Documentos consultados; Anexo: Roteiro metodológico para o zoneamento geo-ambiental a nÃvel de municÃpio no Estado de Sergipe.bitstream/item/143290/1/ID-37391.pd
Clinical case seminar - Hypogonadotropic hypogonadism as a presenting feature of late-onset X-linked adrenal hypoplasia congenita
Mutations in the orphan nuclear receptor DAX-1 cause X-linked adrenal hypoplasia congenita. Affected boys usually present with primary adrenal failure in early infancy or childhood. Impaired sexual development because of hypogonadotropic hypogonadism becomes apparent at the time of puberty. We report adult-onset adrenal hypoplasia congenita in a patient who presented with hypogonadism at 28 yr of age. Although he had no clinical evidence of adrenal dysfunction, compensated primary adrenal failure was diagnosed by biochemical testing. Semen analysis showed azoospermia, and he did not achieve fertility after 8 months of treatment with gonadotropins. A novel Y380D DAX-1 missense mutation, which causes partial loss of function in transient gene expression assays, was found in this patient. This case demonstrates that partial loss-of-function mutations in DAX1 can present with hypogonadotropic hypogonadism and covert adrenal failure in adulthood. Further, an important role for DAX-1 in spermatogenesis in humans is confirmed, supporting findings in the Dax1 (Ahch) knockout mouse
The role of virtual reality in built environment education
This study builds upon previous research on the integration of Virtual Reality (VR) within the built environment curriculum and aims to investigate the role of VR and three-dimensional (3D) computer modelling on learning and teaching in a school of the built environment. In order to achieve this aim, a number of academic experiences were analysed to explore the applicability and viability of 3D computer modelling and VR into built environment subject areas. Although two-dimensional (2D) representations have been greatly accepted by built environment professions and education, 3D computer representations and VR applications, offering interactivity and immersiveness, are not yet widely accepted. The study attempts to understand the values and challenges of integrating visualisation technologies into built environment teaching and investigates tutors’ perceptions, opinions and concerns with respect to these technologies. The study reports on the integration process and considers how 3D computer modelling and VR technologies can combine with, and extend, the existing range of learning and teaching methods appropriate to different disciplines and programme areas
Exposure to Endocrine Disruptors and Nuclear Receptors Gene Expression in Infertile and Fertile Men from Italian Areas with Different Environmental Features
Internal levels of selected endocrine disruptors (EDs) (i.e., perfluorooctane sulfonate (PFOS), perfluorooctanoic acid (PFOA), di-2-ethylhexyl-phthalate (DEHP), mono-(2-ethylhexyl)-phthalate (MEHP), and bisphenol A (BPA)) were analyzed in blood/serum of infertile and fertile men from metropolitan, urban and rural Italian areas. PFOS and PFOA levels were also evaluated in seminal plasma. In peripheral blood mononuclear cells (PBMCs) of same subjects, gene expression levels of a panel of nuclear receptors (NRs), namely estrogen receptor α (ERα) estrogen receptor β (ERβ), androgen receptor (AR), aryl hydrocarbon receptor (AhR), peroxisome proliferator-activated receptor γ (PPARγ) and pregnane X receptor (PXR) were also assessed. Infertile men from the metropolitan area had significantly higher levels of BPA and gene expression of all NRs, except PPARγ, compared to subjects from other areas. Subjects from urban areas had significantly higher levels of MEHP, whereas subjects from rural area had higher levels of PFOA in both blood and seminal plasma. Interestingly, ERα, ERβ, AR, PXR and AhR expression is directly correlated with BPA and inversely correlated with PFOA serum levels. Our study indicates the relevance of the living environment when investigating the exposure to specific EDs. Moreover, the NRs panel in PBMCs demonstrated to be a potential biomarker of effect to assess the EDs impact on reproductive health
Cathodoluminescence, Raman and scanning electron microscopy with energy dispersion system mapping to unravel the mineralogy and texture of an altered Ca-Al-rich inclusion in Renazzo CR2 carbonaceous chondrite
An altered fluffy type A Ca-Al-rich inclusion in the CR2 Renazzo carbonaceous chondrite was examined by combined Raman, scanning electron microscopy with energy dispersion system (SEM-EDS) and cathodoluminescence (CL) mapping. Blue CL at 450 nm and orange emission at 600 nm were related to anorthite and calcite, respectively. Raman spectra were highly fluorescent, and only the stronger peaks of anorthite, clinopyroxene and calcite were observed. Raman-induced fluorescence emission was measured using the 632-nm Raman laser source, up to 850 nm, and used to chart the mineral phases. A fluorescence structured peak at 690 nm, split in three subpeaks at 678, 689 and 693 nm, was found; it is likely related to the fluorescence emission of Cr3+ from a fassaitic pyroxene in anorthite. Secondary pyroxene in the Wark–Lovering rim does not show the peak at 690 nm; the different fluorescence emission from the secondary rim and the pyroxene patches within anorthite could be a marker to spot the primary pyroxene. From combined imaging, the events in the altered chondrite could be sequenced. Starting from a pristine assemblage of spinel and melilite, with little fassaite, several alteration episodes occurred. Alteration in secondary anorthite, which could be mapped by the blue CL emission at 450 nm, was followed by alkalization, with rims of sodalite and nepheline, and subsequent formation of secondary clinopyroxene, encircling the inclusion. Widespread calcite alteration, present also in the matrix between chondrules, was the last recorded event
Recovery of n-3 polyunsaturated fatty acids and conjugated linoleic acids in ripened cheese obtained from milk of cows fed different levels of extruded flaxseed
Abstract The aim of the study was to investigate whether the addition of extruded flaxseed (EF) in dairy cow diets had an effect on milk fat and individual fatty acids (FA) recovery in cheese after 90 d of ripening. Eighteen Holstein-Friesian cows, divided into 3 experimental groups (6 cows/group), were fed 3 isonitrogenous and isoenergetic diets with 0 (CTR), 500 (EF500), or 1,000g/d (EF1000) of EF in 3 subsequent periods (2 wk/each), following a 3×3 Latin square design. Dry matter intake (DMI) and milk yield were recorded daily. Individual milk samples were collected on d 7 and 13 of each period to determine proximate and FA composition. Eighteen cheese-making sessions (2 for each group and period) were carried out, using a representative pooled milk sample obtained from the 6 cows of each group (10L). At 90 d of ripening, cheeses were analyzed for proximate and FA composition. Cheese yield was computed as the ratio between the weights of ripened cheese and processed milk. Recoveries of fat, individual FA, and grouped FA were computed as the ratio between the corresponding weights in cheese and in milk. Inclusion of EF did not affect DMI, milk yield, or milk composition. Compared with CTR, the 2 diets containing EF increased the proportion of C18:3n-3 and total n-3 FA, in both milk and cheese. Cheese yield and cheese fat percentage did not differ among diets. Likewise, milk fat recovery in cheese was comparable in the 3 treatments and averaged 0.85. The recoveries of individual FA were, for the most part, not dissimilar from fat recovery, except for short-chain saturated FA (from 0.38 for C4:0 to 0.80 for C13:0), some long-chain saturated FA (0.56 and 0.62 for C20:0 and C21:0, respectively), and for C18:3n-6 (1.65). The recovery of saturated FA was lower than that of monounsaturated FA, whereas recovery of polyunsaturated FA was intermediate. Compared with medium- and long-chain FA, short-chain FA were recovered to a smaller extent in cheese. No differences in recovery were found between n-6 and n-3 FA. In conclusion, FA have different recoveries during cheese-making, with lower values for the short-chain compared with long-chain FA, and for saturated FA compared with unsaturated FA. The addition of EF in dairy cow diets did not influence cheese yield or fat recovery in cheese, irrespective of the inclusion level. The experiment confirmed that feeding cows with EF represents a successful strategy for improving the FA profile of dairy products, through an increase of n-3 FA
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