191 research outputs found

    Rotational excitation of interstellar benzonitrile by helium atoms

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    Interstellar aromatic molecules such as polycyclic aromatic hydrocarbons and polycyclic nitrogen and oxygen bearing molecules are thought to be abundant in the interstellar medium. In this class of molecules, benzonitrile (cc-C6_6H5_5CN) plays an important role as a proxy for benzene. It has been detected through rotational emission in several astrophysical sources and is one of the simplest N-bearing polar aromatic molecules. Even in the cold ISM, the population of the rotational levels of benzonitrile might not be at equilibrium. Consequently, modeling its detected emission lines requires a prior computation of its quenching rate coefficients by the most abundant species in the ISM (He or H2_2). In this paper, we focus on the excitation of c-C6_6H5_5CN by collision with He. We compute the first potential energy surface (PES) using the explicitly correlated coupled cluster method in conjunction with large basis sets. The PES obtained is characterized by a potential well depth of -97.2 cm1^{-1} and an important anisotropy. Scattering computations of the rotational (de-)excitation of c-C6_6H5_5CN by He atoms are performed by means of the coupled states approximation that allow to obtain collisional rates for rotational states up to jj = 9 and temperatures up to 40 K. These rate coefficients are then used to examine the effect of C6_6H5_5CN excitation induced by collisions with para-H2_2 in molecular clouds by carrying out simple radiative transfer calculations of the excitation temperatures and show that non-equilibrium effects can be expected for H2_2 densities up to 105^5-106^6 cm3^{-3}

    Antimicrobial, antioxidant and phytochemical investigation of Balanites aegyptiaca (L.) Del. edible fruit from Sudan

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    The methanol extract of the fruit (edible mesocarp) of Balanites aegyptiaca (L.) Del., a popular plant from Sudan, widely employed in Sudanese folk medicine was screened for antimicrobial, antioxidant and some active phytochemical compounds. The extract showed the presence of saponin, terpenoids, phenolic compounds and alkaloids. The methanolic extract of the fruits extracted from B. aegyptiaca exhibited a strong antioxidant activity in the DPPH assay and a potent capacity in preventing linoleic acid oxidation. Methanol extracts (50 and 100 mg/ml) were tested on several microbial strains using agar-well diffusion, minimum inhibitory concentration (MIC), minimum bacterial concentration (MBC) and minimum fungal concentration (MFC) methods. These experiments were performed on ten bacterial strains (five Gram-positives and five Gram-negatives) and four fungal strains. Methanol extracts, particularly at concentration of 100 mg/ml was found to be active against all bacterial and fungal strains and it was comparable to standard antibiotics Gentamicin and Amphotericin B. These findings support some of the traditional applications of the fruit of B. aegyptiaca against microbial aliments. It is therefore recommended that further studies regarding fractionation, separation and purification of these active antimicrobial compounds are required, in addition to toxicological evaluation in vivo.Key words: Balaneties aegyptiaca, antibacterial, antifungal, phytochemical, antioxidant, methanol extract

    Collisional excitation of propyne (CH3_3CCH) by He atoms

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    A detailed interpretation of the detected emission lines of environments in which propyne (or methyl acetylene, CH3_3CCH) is observed requires a knowledge of its collisional rate coefficients with the most abundant species in the interstellar medium, He or H2_2. We present the first three-dimensional potential energy surface (3D-PES) for the CH3_3CCH-He molecular complex, study the dynamics of the collision, and report the first set of rate coefficients for temperatures up to 100 K for the collisional excitation of the lowest 60 ortho rotational levels and 60 para rotational levels of CH3_3CCH by He atoms. We computed the 3D-PES with the explicitly correlated coupled-cluster with single-, double-, and perturbative triple-excitation method, in conjunction with the augmented correlation-consistent triple zeta basis set (CCSD(T)-F12a/aug-cc-pVTZ). The 3D-PES was fitted to an analytical function. Scattering computations of pure rotational (de-)excitation of CH3_3CCH by collision with He atoms were performed and the state-to-state cross sections were computed using the close coupling method for total energies up to 100 cm1^{-1} and with the coupled states approximation at higher energy for both ortho and para symmetries of CH3_3CCH. The PES obtained is caracterized by a large anisotropy and a potential well depth of 51.04 cm1^{-1}. By thermally averaging the collisional cross sections, we determined quenching rate coefficients for kinetic temperatures up to 100 K. A strong even Δj\Delta j propensity rule at almost all collision energies exists for CH3_3CCH-He complex. To evaluate the impact of rate coefficients in the analysis of observations, we carried out non-LTE radiative transfer computations of the excitation temperatures and we demonstrate that LTE conditions are typically not fulfilled for the propyne molecule.Comment: Accepted in A&

    Short communication: Influence of vitamins C and E on sperm motility of rabbit bucks

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    [EN] The objective of the study is to investigate the effect of vitamin C and E supplementation on rabbit sperm motility. Forty INAT breed bucks aged 8.5 mo were divided into 2 groups: control group (C) and treated group (T) receiving vitamins C (1 g/L) and E (1 g/L) incorporated in the drinking water. Semen was collected using an artificial vagina over 6 wk (C, total ejaculates=81; T, total ejaculates=76). The massal motility (MM) was evaluated in the fresh and raw semen. Then, the individual motility at 0 (IM0), 2 (IM2) and 4 h (IM4) after semen collection was determined in diluted semen and conserved at +4°C for the 2 groups. MM was higher in T than in C group (P=0.0012). However, the individual motilities IM0, IM2 and IM4 did not vary between the 2 groups. In conclusion, the supplementation of vitamins C and E in the drinking water for rabbit influenced only the MM in both fresh and raw semen.Najjar Ben Maâtoug, A.; Ben Saïd, S.; Najjar, T.; Kalamoun, S.; Ben Khalifa, N.; Ben Aïchae, E.; Ben Mrad, M. (2013). Short communication: Influence of vitamins C and E on sperm motility of rabbit bucks. World Rabbit Science. 21(1):45-48. doi:10.4995/wrs.2013.1174.SWORD454821

    The Human Papillomavirus E6 Oncogene Represses a Cell Adhesion Pathway and Disrupts Focal Adhesion through Degradation of TAp63β upon Transformation

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    Cervical carcinomas result from cellular transformation by the human papillomavirus (HPV) E6 and E7 oncogenes which are constitutively expressed in cancer cells. The E6 oncogene degrades p53 thereby modulating a large set of p53 target genes as shown previously in the cervical carcinoma cell line HeLa. Here we show that the TAp63β isoform of the p63 transcription factor is also a target of E6. The p63 gene plays an essential role in skin homeostasis and is expressed as at least six isoforms. One of these isoforms, ΔNp63α, has been found overexpressed in squamous cell carcinomas and is shown here to be constitutively expressed in Caski cells associated with HPV16. We therefore explored the role of p63 in these cells by performing microarray analyses after repression of endogenous E6/E7 expression. Upon repression of the oncogenes, a large set of p53 target genes was found activated together with many p63 target genes related to cell adhesion. However, through siRNA silencing and ectopic expression of various p63 isoforms we demonstrated that TAp63β is involved in activation of this cell adhesion pathway instead of the constitutively expressed ΔNp63α and β. Furthermore, we showed in cotransfection experiments, combined with E6AP siRNA silencing, that E6 induces an accelerated degradation of TAp63β although not through the E6AP ubiquitin ligase used for degradation of p53. Repression of E6 transcription also induces stabilization of endogenous TAp63β in cervical carcinoma cells that lead to an increased concentration of focal adhesions at the cell surface. Consequently, TAp63β is the only p63 isoform suppressed by E6 in cervical carcinoma as demonstrated previously for p53. Down-modulation of focal adhesions through disruption of TAp63β therefore appears as a novel E6-dependent pathway in transformation. These findings identify a major physiological role for TAp63β in anchorage independent growth that might represent a new critical pathway in human carcinogenesis

    Male oxidative stress infertility (MOSI): proposed terminology and clinical practice guidelines for management of idiopathic male infertility

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    Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

    Male Oxidative Stress Infertility (MOSI):proposed terminology and clinical practice guidelines for management of idiopathic male infertility

    Get PDF
    Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

    SIGMORPHON 2021 Shared Task on Morphological Reinflection: Generalization Across Languages

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    This year's iteration of the SIGMORPHON Shared Task on morphological reinflection focuses on typological diversity and cross-lingual variation of morphosyntactic features. In terms of the task, we enrich UniMorph with new data for 32 languages from 13 language families, with most of them being under-resourced: Kunwinjku, Classical Syriac, Arabic (Modern Standard, Egyptian, Gulf), Hebrew, Amharic, Aymara, Magahi, Braj, Kurdish (Central, Northern, Southern), Polish, Karelian, Livvi, Ludic, Veps, Võro, Evenki, Xibe, Tuvan, Sakha, Turkish, Indonesian, Kodi, Seneca, Asháninka, Yanesha, Chukchi, Itelmen, Eibela. We evaluate six systems on the new data and conduct an extensive error analysis of the systems' predictions. Transformer-based models generally demonstrate superior performance on the majority of languages, achieving >90% accuracy on 65% of them. The languages on which systems yielded low accuracy are mainly under-resourced, with a limited amount of data. Most errors made by the systems are due to allomorphy, honorificity, and form variation. In addition, we observe that systems especially struggle to inflect multiword lemmas. The systems also produce misspelled forms or end up in repetitive loops (e.g., RNN-based models). Finally, we report a large drop in systems' performance on previously unseen lemmas.Peer reviewe

    Male Oxidative Stress Infertility (MOSI): Proposed Terminology and Clinical Practice Guidelines for Management of Idiopathic Male Infertility

    Get PDF
    Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm’s potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

    A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa

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