2,734 research outputs found

    Palaeodiets of Humans and Fauna at the Spanish Mesolithic Site of El Collado

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    The first human stable isotope results from the Spanish Levant, from the Mesolithic (ca. 7500 BP, Mesolithic IIIA phase) site of El Collado (near Oliva, Valencia) provide evidence for the consumption of marine protein by humans, estimated at approximately 25% of the dietary protein for some individuals. Isotopic analysis of human remains from other coastal Mesolithic sites in Europe, particularly along the Atlantic coast, also shows significant consumption of marine foods, but the amount of marine food consumed by the El Collado humans was much less than at those sites. This may be because of a different dietary adaptation or because the Mediterranean is much less productive than the Atlantic

    Intrinsic Moment of Inertia of Membranes as bounds for the mass gap of Yang-Mills Theories

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    We obtain the precise condition on the potentials of Yang-Mills theories in 0+1 dimensions and D0 brane quantum mechanics ensuring the discretness of the spectrum. It is given in terms of a moment of inertia of the membrane. From it we obtain a bound for the mass gap of any D+1 Yang-Mills theory in the slow-mode regime. In particular we analyze the physical case D=3. The quantum mechanical behavior of the theories, concerning its spectrum, is determined by harmonic oscillators with frequencies given by the inertial tensor of the membrane. We find a class of quantum mechanic potential polynomials of any degree, with classical instabilities that at quantum level have purely discrete spectrum.Comment: 12pages, Latex, minor changes, more explanatory comment

    Type O pure radiation metrics with a cosmological constant

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    In this paper we complete the integration of the conformally flat pure radiation spacetimes with a non-zero cosmological constant Λ\Lambda, and τ0\tau \ne 0, by considering the case Λ+ττˉ0\Lambda +\tau\bar\tau \ne 0. This is a further demonstration of the power and suitability of the generalised invariant formalism (GIF) for spacetimes where only one null direction is picked out by the Riemann tensor. For these spacetimes, the GIF picks out a second null direction, (from the second derivative of the Riemann tensor) and once this spinor has been identified the calculations are transferred to the simpler GHP formalism, where the tetrad and metric are determined. The whole class of conformally flat pure radiation spacetimes with a non-zero cosmological constant (those found in this paper, together with those found earlier for the case Λ+ττˉ=0\Lambda +\tau\bar\tau = 0) have a rich variety of subclasses with zero, one, two, three, four or five Killing vectors

    Polarization phenomena in open charm photoproduction processes

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    We analyze polarization effects in associative photoproduction of pseudoscalar (Dˉ\bar{D}) charmed mesons in exclusive processes γ+NYc+Dˉ\gamma+ N\to Y_c +\bar{D}, Yc=Λc+Y_c=\Lambda_c^+, Σc\Sigma_c. Circularly polarized photons induce nonzero polarization of the YcY_c-hyperon with xx- and zz-components (in the reaction plane) and non vanishing asymmetries Ax{\cal A}_x and Az{\cal A}_z for polarized nucleon target. These polarization observables can be predicted in model-independent way for exclusive Dˉ\bar{D}-production processes in collinear kinematics. The T-even YcY_c-polarization and asymmetries for non-collinear kinematics can be calculated in framework of an effective Lagrangian approach. The depolarization coefficients DabD_{ab}, characterizing the dependence of the YcY_c-polarization on the nucleon polarization are also calculated.Comment: 36 pages 13 figure

    Cell-wall chemical-composition analysis of a Saccharum spp. progeny for increased bagasse digestibility

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    XXX Congress of the ISSCT (International Society of Sugar Cane Technologists), Tucumán, from 31 August to 8 September 2019Knowledge of cell-wall composition in sugarcane hybrids could be used for the selection of cultivars with high bagasse digestibility in order to improve sugar release in 2G ethanol production. Cell-wall components of 76 hybrids of a sugarcane cross, their parents and two high-fibre genotypes were analyzed. The Van Soest method was used to determine cellulose, hemicellulose and acid detergent lignin contents (ADL). Spectroscopic acetyl bromide lignin (ABS) was also determined. A correlation analysis was performed with major cell-wall polymers and agronomic traits. Despite the minor differences observed between parental lines’ cell-wall composition, genotypes with high cellulose and low lignin content were identified in the progeny. Differences among them depended on the method used for lignin measurement. The ADL mean was 43% lower than the ABS mean, in agreement with lignin losses during acid detergent treatment previously reported. There was no correlation between ADL and ABS assays. Bagasse of genotypes with higher stalk weights was associated with higher cellulose content and lower ADL content. Saccharification studies are needed to validate lignin assessment methodologies to be used as bioenergy cultivar selection tools.El conocimiento de la composición de la pared celular en híbridos de caña de azúcar puede ser utilizado en la selección de cultivares de elevada digestibilidad del bagazo, orientados a incrementar la liberación de azucares en la producción de etanol 2G. Se analizaron los componentes de la pared celular de 76 híbridos obtenidos de un cruzamiento de caña de azúcar, sus progenitores y dos genotipos de alta fibra. Se utilizó el método de Van Soest para determinar los contenidos de celulosa, hemicelulosa y lignina detergente ácido (LDA); además se determinó el contenido de lignina mediante espectroscopía utilizando brumuro de acetilo (EBA). Se realizó un análisis de correlaciones con los componentes de la pared celular y características agronómicas. A pesar de las diferencias mínimas en la composición de la pared celular observadas entre progenitores, fueron identificados en la progenie genotipos con contenido elevado de celulosa y bajo de lignina. Sin embargo, estos genotipos fueron distintos dependiendo del método empleado en la determinación de lignina. El promedio calculado para LDA fue un 43% más bajo que el promedio de EBA, en coincidencia con pérdidas previamente reportadas en la bibliografía debido al uso del detergente ácido. Se observó una ausencia de correlación entre LDA y EBA, mientras que el peso de tallos estuvo asociado a un contenido mayor de celulosa y menor de LDA. Futuros análisis de sacarificación son necesarios para evaluar la liberación de azúcares de la biomasa y validar los métodos de determinación de lignina como herramientas de selección.La connaissance sur la composition des parois cellulaires des hybrides de canne à sucre pourrait être utilisées dans la sélection de variété à haute digestibilité de la bagasse afin d'améliorer la libération de sucre dans la production d'éthanol 2G. Dans cette étude, les composantes de la paroi cellulaire de 76 hybrides d'une progéniture de canne, leurs progéniteurs et deux génotypes à haute teneur en fibre ont été analysés. La méthode Van Soest a été utilisée pour déterminer la teneur en cellulose, en hémicellulose et en lignine au détergent acide (ADL). Le pourcentage de lignine soluble dans le bromure d'acétyle (ABS) fut déterminé. Les corrélations entre les principaux polymères des parois cellulaires et les caractères agronomiques ont été effectuées. Malgré les différences mineures observées entre la composition de la paroi cellulaire des géniteurs, des génotypes à forte teneur en cellulose et à faible teneur en lignine ont été identifiés dans la progéniture. Les différences entre eux dépendaient de la méthode utilisée pour déterminer la teneur en lignine. La moyenne de l’ADL était inférieure de 43% à la moyenne de l'ABS, en accord avec les pertes en lignine pendant le traitement aux détergents acides. Aucune corrélation n'a été observée entre les dosages ADL et ABS. La bagasse de génotypes ayant un poids de tiges plus élevé était associée à une teneur plus élevée en cellulose et à une teneur plus faible en ADL. D'autres analyses de saccharification sont nécessaires afin d’évaluer la libération de sucre de la biomasse et améliorer la digestibilité de la bagasse dans des génotypes de canne à sucre.EEA FamailláFil: García, José María. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; ArgentinaFil: García, José María. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Acevedo, Alberto. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Suelos; ArgentinaFil: Silva, M.P. University of York. Department of Biology. CNAP; Reino UnidoFil: Gomez, L. University of York. Department of Biology. CNAP; Reino UnidoFil: Erazzú, Luis E. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Famaillá; Argentina

    Correlation between ileal digestibility of amino acids and chemical composition of soybean meals in broilers at 21 days of age

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    The correlations between chemical composition and coefficient of standardized ileal digestibility (CSID) of crude protein (CP) and amino acids (AA) were determined in 22 soybean meal (SBM) samples originated from USA (n = 8), Brazil (BRA; n = 7) and Argentina (ARG; n = 7) in 21-day old broilers. Birds were fed a commercial maize-SBM diet from 1 to 17 days of age followed by the experimental diets in which the SBM tested was the only source of protein (205 g CP/kg) for three days. Also, in vitro nitrogen (N) digestion study was conducted with these samples using the two-step enzymatic method. The coefficient of apparent ileal digestibility (CAID) of the SBM, independent of the origin, varied from 0.820 to 0.880 for CP, 0.850 to 0.905 for lysine (Lys), 0.859 to 0.907 for methionine (Met) and 0.664 to 0.750 for cysteine (Cys). The corresponding CSID values varied from 0.850 to 0.966 for CP, 0.891 to 0.940 for Lys, 0.931 to 0.970 for Met and 0.786 to 0.855 for Cys. The CSID of CP and Lys of the SBM were positively correlated with CP (r = 0.514; P menor que 0.05 and r = 0.370; P = 0.09, respectively), KOH solubility (KOH sol.) (r = 0.696; P menor que 0.001 and r = 0.619; P menor que 0.01, respectively), trypsin inhibitor activity (TIA) (r = 0.541; P menor que 0.01 and r = 0.416; P = 0.05, respectively) and reactive Lys (r = 0.563; P menor que 0.01 and r = 0.486; P menor que 0.05) values, but no relation was observed with neutral detergent fiber and oligosaccharide content. No relation between the CSID of CP determined in vivo and N digestibility determined in vitro was found. The CSID of most key AA were higher for the USA and the BRA meals than for the ARG meals. For Lys, the CSID was 0.921, 0.919 and 0.908 (P menor que 0.05) and for Cys 0.828, 0.833 and 0.800 (P menor que 0.01) for USA, BRA and ARG meals, respectively. It is concluded that under the conditions of this experiment, the CSID of CP and Lys increased with CP content, KOH sol., TIA and reactive Lys values of the SBM. The CSID of most limiting AA, including Lys and Cys, were higher for USA and BRA meals than for ARG meals

    Design and anticancer properties of new water-soluble ruthenium–cyclopentadienyl complexes

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    Ruthenium complexes are emerging as one of the most promising classes of complexes for cancer therapy. However, their limited aqueous solubility may be the major limitation to their potential clinical application. In view and to contribute to the progress of this field, eight new water-soluble Ru(II) organometallic complexes of general formula [RuCp(mTPPMS)n(L)] [CF3SO3], where mTPPMS = diphenylphosphane-benzene-3-sulfonate, for n = 2, L is an imidazole-based ligand (imidazole, 1-benzylimidazole, 1-butylimidazole, (1-(3 aminopropyl)imidazole), and (1-(4-methoxyphenyl)imidazole)), and for n = 1, L is a bidentate heteroaromatic ligand (2-benzoylpyridine, (di(2-pyridyl)ketone), and (1,2-(2-pyridyl)benzo-[b]thiophene)) were synthesized and characterized. The new complexes were fully characterized by NMR, FT-IR, UV–vis., ESI-HRMS, and cyclic voltammetry, which confirmed all the proposed molecular structures. The antiproliferative potential of the new Ru(II) complexes was evaluated on MDAMB231 breast adenocarcinoma, A2780 ovarian carcinoma, and HT29 colorectal adenocarcinoma cell lines, showing micromolar (MDAMB231 and HT29) and submicromolar (A2780) IC50 values. The interaction of complex 6 with human serum albumin (HSA) and fatty-acid-free human serum albumin (HSAfaf) was evaluated by fluorescence spectroscopy techniques, and the results revealed that the ruthenium complex strongly quenches the intrinsic fluorescence of albumin in both cases.info:eu-repo/semantics/publishedVersio

    PTRF acts as an adipokine contributing to adipocyte dysfunctionality and ectopic lipid deposition

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    Adipose tissue (AT) expands under obesogenic conditions. Yet, when the growth exceeds a certain limit, AT becomes dysfunctional and surplus lipids start depositing ectopically. Polymerase I and transcription release factor (PTRF) has been proposed as a mechanism leading to a dysfunctional AT by decreasing the adipogenic potential of human adipocyte precursors. However, whether or not PTRF can be secreted by the adipocytes into the bloodstream is not yet known. For this work, PTRF presence was investigated in plasma. We also produced a recombinant PTRF (rPTRF) and examined its impact on the functional interactions between the adipocyte and the hepatocyte in vitro. We demonstrated that PTRF can be found in human plasma, and is at least in part, carried by exosomes. In vitro treatment with rPTRF increased the hypertrophy and senescence of 3T3-L1 adipocytes. In turn, those rPTRF-treated adipocytes increased lipid accumulation in hepatocytes. Lastly, we found a positive correlation between circulating PTRF and the concentration of PTRF in the visceral fat depot. All these findings point toward the presence of an enlarged and dysfunctional visceral adipose tissue which secretes PTRF. This circulating PTRF behaves as an adipokine and may partially contribute to the well-known detrimental effects of visceral fat accumulation

    Obtaining a class of Type O pure radiation metrics with a cosmological constant, using invariant operators

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    Using the generalised invariant formalism we derive a class of conformally flat spacetimes whose Ricci tensor has a pure radiation and a Ricci scalar component. The method used is a development of the methods used earlier for pure radiation spacetimes of Petrov types O and N respectively. In this paper we demonstrate how to handle, in the generalised invariant formalism, spacetimes with isotropy freedom and rich Killing vector structure. Once the spacetimes have been constructed, it is straightforward to deduce their Karlhede classification: the Karlhede algorithm terminates at the fourth derivative order, and the spacetimes all have one degree of null isotropy and three, four or five Killing vectors.Comment: 29 page
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