329 research outputs found

    In vitro ion chelating, antioxidative mechanism of extracts from fruits and barks of tetrapleura tetraptera and their protective effects against fenton mediated toxicity of metal ions on liver homogenates

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    The aim of the present study was to investigate the antioxidant activity and protective potential of T. tetraptera extracts against ion toxicity. The antioxidant activity of the extracts was investigated spectrophotometrically against several radicals (1,1-diphenyl-2-picrylhydrazyl (DPPH•), 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS•), hydroxyl radical (HO•), and nitric oxide (NO•)), followed by the ferric reducing power, total phenols, flavonoid, and flavonol contents. The effects of the extracts on catalase (CAT), superoxide dismutase (SOD), and peroxidase activities were also determined using the standard methods as well as the polyphenol profile using HPLC. The results showed that the hydroethanolic extract of T. tetraptera (CFH) has the lowest ICvalue with the DPPH, ABTS, OH, and NO radicals. The same extract also exhibited the significantly higher level of total phenols (37.24 ± 2.00 CAE/g dried extract); flavonoids (11.36 ± 1.88 QE/g dried extract); and flavonols contents (3.95 ± 0.39 QE/g dried extract). The HPLC profile of T. tetraptera revealed that eugenol (958.81 ± 00 mg/g DW), quercetin (353.78 ± 00 mg/g DW), and rutin (210.54 ± 00 mg/g DW) were higher in the fruit than the bark extracts. In conclusion, extracts from T. tetraptera may act as a protector against oxidative mediated ion toxicity. © 2015 Bruno Moukette Moukette et al

    A combinatorial smoothness criterion for spherical varieties

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    We suggest a combinatorial criterion for the smoothness of an arbitrary spherical variety using the classification of multiplicity-free spaces, generalizing an earlier result of Camus for spherical varieties of type AA.Comment: 14 pages, 2 table

    Inferring hidden states in Langevin dynamics on large networks: Average case performance

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    We present average performance results for dynamical inference problems in large networks, where a set of nodes is hidden while the time trajectories of the others are observed. Examples of this scenario can occur in signal transduction and gene regulation networks. We focus on the linear stochastic dynamics of continuous variables interacting via random Gaussian couplings of generic symmetry. We analyze the inference error, given by the variance of the posterior distribution over hidden paths, in the thermodynamic limit and as a function of the system parameters and the ratio {\alpha} between the number of hidden and observed nodes. By applying Kalman filter recursions we find that the posterior dynamics is governed by an "effective" drift that incorporates the effect of the observations. We present two approaches for characterizing the posterior variance that allow us to tackle, respectively, equilibrium and nonequilibrium dynamics. The first appeals to Random Matrix Theory and reveals average spectral properties of the inference error and typical posterior relaxation times, the second is based on dynamical functionals and yields the inference error as the solution of an algebraic equation.Comment: 20 pages, 5 figure

    An Algebra of Pieces of Space -- Hermann Grassmann to Gian Carlo Rota

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    We sketch the outlines of Gian Carlo Rota's interaction with the ideas that Hermann Grassmann developed in his Ausdehnungslehre of 1844 and 1862, as adapted and explained by Giuseppe Peano in 1888. This leads us past what Rota variously called 'Grassmann-Cayley algebra', or 'Peano spaces', to the Whitney algebra of a matroid, and finally to a resolution of the question "What, really, was Grassmann's regressive product?". This final question is the subject of ongoing joint work with Andrea Brini, Francesco Regonati, and William Schmitt. The present paper was presented at the conference "The Digital Footprint of Gian-Carlo Rota: Marbles, Boxes and Philosophy" in Milano on 17 Feb 2009. It will appear in proceedings of that conference, to be published by Springer Verlag.Comment: 28 page

    Mediterranean diet and outcomes of assisted reproduction: an Italian cohort study

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    Background: Detrimental lifestyle habits have been indicated as potential causes of reduced fertility. Recently studies have suggested an association between healthy diets and increased live birth rates after assisted reproduction techniques. However, the issue remains under debate, and evidence is still accumulating. Objective: The objective of the study was to study the relationship between a Mediterranean diet and outcomes of assisted reproduction techniques in subfertile couples in an Italian population. Study Design: This was a prospective cohort study, conducted in an Italian fertility clinic. Couples undergoing in vitro fertilization were interviewed on the day of oocyte retrieval to obtain information on personal and health history, lifestyle habits, and diet. Adherence to a Mediterranean diet was evaluated using a Mediterranean diet score. Relative risks and 95% confidence intervals for embryo transfer, clinical pregnancy, and live birth were calculated. Potential confounders were included in the equation model. Results: Among 474 women (mean age, 36.6 years, range, 27\u201345), 414 (87.3%) performed embryo transfer, 150 (31.6%) had clinical pregnancies, and 117 (24.7%) had live births. In a model including the potential confounders (age, leisure physical activity, body mass index, smoking, daily calorie intake, and previous failed in vitro fertilization cycles), findings showed that the Mediterranean diet score was not significantly associated with in vitro fertilization outcomes. Adjusted analyses were performed in strata of age, previous assisted reproduction technique cycles, and reasons for infertility, with consistent findings. The only exception was observed in women >35 years old with an intermediate Mediterranean diet score, who showed a lower risk of not achieving clinical pregnancy (adjusted relative risk, 0.84, 95% confidence interval, 0.71\u20131.00, P = .049). Conclusion: No clear association was observed between adherence to a Mediterranean diet and successful in vitro fertilization

    Intrinsic surface depression of the order parameter under mixed (s+id)-wave pair symmetry and its effect on the critical current of high-Tc SIS Josephson junctions

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    An intrinsic gap depression at the Superconductor-Insulator interface due to the very short value of the coherence length in High-Tc Superconductors [HTSs] is considered, in the framework of a mixed (s+id)-wave pair symmetry for the order parameter ranging from pure s to pure d-wave. This gap depression acts as the main physical agent causing the relevant reduction of IcRn(T) values with respect to BCS expectations in HTS SIS Josephson junctions. Good agreement with various experimental data is obtained with both pure s-wave and pure d-wave symmetries of the order parameter, but with amounts of gap depression depending on the pair symmetry adopted. Regardless of the pair symmetry considered, these results prove the importance of the surface order-parameter depression in the correct interpretation of the Ic(T)Rn(T) data in HTS SIS junctions. In a case of planar YBCO-based junction the use of the de Gennes condition allowed us to tentatively obtain an upper limit for the amount of d-wave present in the order parameter of YBCO.Comment: 11 pages REVTeX file, 6 PostScript figures, to be published in J. Superconductivit

    Probing T-cell response by sequence-based probabilistic modeling

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    With the increasing ability to use high-throughput next-generation sequencing to quantify the diversity of the human T cell receptor (TCR) repertoire, the ability to use TCR sequences to infer antigen-specificity could greatly aid potential diagnostics and therapeutics. Here, we use a machine-learning approach known as Restricted Boltzmann Machine to develop a sequence-based inference approach to identify antigen-specific TCRs. Our approach combines probabilistic models of TCR sequences with clone abundance information to extract TCR sequence motifs central to an antigen-specific response. We use this model to identify patient personalized TCR motifs that respond to individual tumor and infectious disease antigens, and to accurately discriminate specific from non-specific responses. Furthermore, the hidden structure of the model results in an interpretable representation space where TCRs responding to the same antigen cluster, correctly discriminating the response of TCR to different viral epitopes. The model can be used to identify condition specific responding TCRs. We focus on the examples of TCRs reactive to candidate neoantigens and selected epitopes in experiments of stimulated TCR clone expansion

    Ancient and modern mitogenomes from Central Argentina: New insights into population continuity, temporal depth and migration in South America

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    The inverted triangle shape of South America places Argentina territory as a geographical crossroads between the two principal peopling streams that followed either the Pacific or the Atlantic coasts, which could have then merged in Central Argentina (CA). Although the genetic diversity from this region is therefore crucial to decipher past population movements in South America, its characterization has been overlooked so far. We report 92 modern and 22 ancient mitogenomes spanning a temporal range of 5000 years, which were compared with a large set of previously reported data. Leveraging this dataset representative of the mitochondrial diversity of the subcontinent, we investigate the maternal history of CA populations within a wider geographical context. We describe a large number of novel clades within the mitochondrial DNA tree, thus providing new phylogenetic interpretations for South America. We also identify several local clades of great temporal depth with continuity until the present time, which stem directly from the founder haplotypes, suggesting that they originated in the region and expanded from there. Moreover, the presence of lineages characteristic of other South American regions reveals the existence of gene flow to CA. Finally, we report some lineages with discontinuous distribution across the Americas, which suggest the persistence of relic lineages likely linked to the first population arrivals. The present study represents to date the most exhaustive attempt to elaborate a Native American genetic map from modern and ancient complete mitochondrial genomes in Argentina and provides relevant information about the general process of settlement in South America.This work was supported by Agencia Nacional de Promoción de la Investigación, el Desarrollo Tecnológico y la Innovación (PICT 2007-1549, PICT 2012-711 and PICT 2015-3155), Secretaría de Ciencia y Tecnología (Universidad Nacional de Córdoba), Ministerio de Ciencia y Tecnología de la Provincia de Córdoba (PID 2018-79) and Consejo Nacional de Investigaciones Científicas y Técnicas (2015-11220150100953CO). M.P. is a postdoctoral fellow and A.G., R.N., J.M.B.M, C.M.B., M.F. and D.A.D. are research career members of CONICET, Argentina

    An homoplasmic large deletion in mtDNA control region: case report

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    We report a new case of a large, homoplasmic Control Region deletion in human mitochondrial DNA. A missing 154 bp fragment spanning positions 16154?16307 was found in an apparently healthy blood donor from Salta (NW Argentina) whose maternal lineage was attributable to Native American haplogroup D1. The same mutation, to the best of our knowledge, has been independently reported before only twice, in both homoplasmic and heteroplasmic states.Fil: Motti, Josefina María Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Alfaro, E. L.. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; ArgentinaFil: Dipierri, Jose Edgardo. Universidad Nacional de Jujuy. Instituto de Biología de la Altura; ArgentinaFil: Muzzio, Marina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Ramallo, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Santos, María Rita. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Irwin, J. A.. Armed Forces Dna Identification Laboratory; Estados UnidosFil: Scheible, M.. Armed Forces Dna Identification Laboratory; Estados UnidosFil: Saunier, J. L.. Armed Forces Dna Identification Laboratory; Estados UnidosFil: Coble, M. B.. Armed Forces Dna Identification Laboratory; Estados UnidosFil: Bailliet, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; ArgentinaFil: Bravi, Claudio Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Multidisciplinario de Biología Celular. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Multidisciplinario de Biología Celular. Universidad Nacional de La Plata. Instituto Multidisciplinario de Biología Celular; Argentin

    Continental Origin for Q Haplogroup Patrilineages in Argentina and Paraguay

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    Haplogroup Q originated in Eurasia around 30,000 years ago. It is present in Y-chromosomes from Asia and Europe at rather low frequencies. Since America is undoubtedly one of the continents where this haplogroup is highly represented, it has been defined as one of the founding haplogroups. Its M3 clade has been early described as the most frequent, with Pan-American representation. However, it was also possible to find several other haplogroup Q clades at low frequencies. Numerous mutations have been described for haplogroup Q, allowing the analysis of its variability and the assignment of its geographic origin. We have analyzed 442 samples belonging to haplogroup Q of unrelated men from Argentina and Paraguay, but this work is specifically referred to 27 Q (xM3) lineages. We tested 3 SNPs by APLP, 3 for RFLP, 15 SNPs by Sanger sequencing, and 17 STRs. Our approach allowed us to identify 5 sub-haplogroups. Q-M3 and Q-CTS2730/Z780 are undoubtedly autochthonous lineages and represent the most frequent sub-haplogroups. With significant representation in self-defined aboriginal populations, their autochthonous status has been previously described. The aim of present work is to identify the continental origin of the remaining Q lineages. Thus, we analyzed the STR haplotypes for the samples of our series and compared them with haplotypes described by other authors for the rest of the world. Even when haplogroup Qs have been extensively studied in America, some of them could have their origin in post Columbian human migration from Europe and Middle East
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