1,720,957 research outputs found
Modulation of behavior in zebrafish, Danio rerio, according to female reproductive status and visual and chemical cues
No full textZebrafish, Danio rerio, is one of the most studied vertebrate models. However, there are stillmany aspects of its reproductive behavior to be elucidated. The aim of this work was to clarify whether males and females of this species display different behaviors according to sexual status, and the kind of cues they were exposed to (visual and/or chemical). Females in two different sexual status, pre- (PreS) or post-spawning (PostS), were exposed to single males cues (visual or chemical) or complementary cues (visual and chemical together). PreS females spent more time near the male’s compartment than PostS when they were exposed to complementary cues, but no differences were found when only one cue was present. Males showed a higher proximity to females when they were exposed to visual, and both cues together, but no difference was found according to females’ reproductive status. When no barrier was present, males and PreS females spent more time swimming together than males with PostS females. These results showed that females’ reproductive status, and the kind of cues to which females and males are exposed to, can modulate behaviors related to reproduction. Particularly, both cues together (visual and chemical) arenecessary to trigger different behaviors in females according to their reproductive status.Fil: Cavallino, Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Valchi, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Morandini, Leonel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; ArgentinaFil: Pandolfi, Matias. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Biodiversidad y Biología Experimental y Aplicada. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Biodiversidad y Biología Experimental y Aplicada; Argentin
Endocannabinoid system in pregnancy
Full text linkThe endocannabinoid system (eCS), is a complex system, comprising the main endogenous ligands anandamide and 2-arachidonoyl glycerol, the cannabinoid receptors CB1 and CB2 and the biosynthetic and degrading enzymes. Cumulative evidence shows that the eCS plays an important role in reproduction, from egg fertilization to parturition. Therefore, alterations in this system, either by recreation/therapeutic use of cannabis or deregulation of the endogenous cannabinoids, might lead to adverse pregnancy outcomes, including retardation in embryo development, poor blastocyst implantation, inhibition of decidualization, miscarriage and compromised placentation. Nevertheless, the molecular mechanisms by which the eCS participates in different stages of pregnancy remain poorly understood. In this review, we will examine the evidence from animal and human studies to support the role of the eCS in implantation, early-to-late pregnancy and placentation as well as the difficulties of targeting this system for treatment of female infertility.Fil: Correa, Fernando Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Wolfson, Manuel Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Valchi, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Aisemberg, Julieta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Franchi, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentin
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Aging-associated inflammation in testes of Syrian hamsters
No full textAging constitutes a universal, multi-factorial, progressive and irreversible process. Although the aging process may vary among different tissues, it is usually associated to a chronic inflammatory condition. Relevant to male reproductive aging, we have previously shown an inverse association between longevity and testicular pro-inflammatory state in mouse models with delayed (Ames dwarf Prop1-/- and growth hormone releasing hormone‐knockout mice) or accelerated (growth hormone‐transgenic mice) aging.Fil: Valchi, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Calandra, Ricardo Saul. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; ArgentinaFil: Frungieri, Monica Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Matzkin, Maria Eugenia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental. Fundación de Instituto de Biología y Medicina Experimental. Instituto de Biología y Medicina Experimental; Argentina. Universidad de Buenos Aires. Facultad de Medicina; ArgentinaReunión Conjunta de Sociedades de Biociencias: LXII Reunión Anual de la Sociedad Argentina de Investigación Clínica; LIII Reunión anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular; LXV Reunión Anual de la Sociedad Argentina de Inmunología; Reunión de la Sociedad Argentina de Andrología; XLVI Reunión Anual de la Sociedad Argentina de Biofísica; XIX Reunión Anual de la Sociedad Argentina de Biología; XLIX Reunión Anual de la Sociedad Argentina de Farmacología Experimental ; Reunión Anual de la Sociedad Argentina de Fisiología; Reunión de la Sociedad Argentina de Hematología; XXIX Reunión Anual de la Sociedad Argentina de ProtozoologíaBuenos AiresArgentinaSociedad Argentina de Investigación ClínicaSociedad Argentina de Investigación Bioquímica y Biología MolecularSociedad Argentina de InmunologíaSociedad Argentina de AndrologíaSociedad Argentina de BiofísicaSociedad Argentina de BiologíaSociedad Argentina de Farmacología ExperimentalSociedad Argentina de FisiologíaSociedad Argentina de HematologíaSociedad Argentina de Protozoologí
Comparative spermatozoa ultrastructure of neotropical grass frogs (genus Leptodactylus) with comments on anuran reproductive modes and phylogeny
No full textThe sperm cell ultrastructure provides important insights into fertilization mechanism and phylogenetic relationships. However, it has rarely been included in phylogenetic analysis of anurans. This work aims to characterize the ultrastructure of the mature spermatozoa in the genus Leptodactylus, to relate the observed variations with the different reproductive strategies and define characters to optimize in a previously published cladogram of this genus. We studied 24 species distributed into four groups: L. fuscus, L. latrans, L. melanonotus and L. pentadactylus where morphological characters were coded and optimized using the parsimony method. The analyzed spermatozoa have three conspicuous regions: head, middle zone and tail. Regarding the head, a short and thin acrosomal vesicle is observed in species of the groups L. fuscus and L. pentadactylus, but it is long and thick in most of the studied species of the groups L. latrans and L. melanonotus. Furthermore, nuclear lacunae are observed in most species. In relation to the middle zone, an organelle-free cytoplasmic region was observed in species of the groups L. fuscus, L. latrans and L. melanonotus, but it was absent in species of the L. pentadactylus group. Most of the studied species showed a mitochondrial collar and cytoplasmic canal. Finally, in the tail all of the species have an axoneme, an undulating membrane, and an axial fiber, but only some have a juxtaxonemal fiber. Results show the thick acrosomal vesicle as a synapomorphy of the clade L. latrans + L. melanonotus. The presence of nuclear lacunae and the absence of a sub-acrosomal cone optimizes as a putative synapomorphy of Leptodactylidae. In conclusion, we observed a relationship between reproductive strategies and spermatozoa morphology, which also supports the phylogenetic relationships in this genus.Fil: Valchi, Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Biología de Anfibios; ArgentinaFil: Ponssa, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Farías, Alejandro. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Biología de Anfibios; ArgentinaFil: Volonteri, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto de Diversidad y Evolución Austral; ArgentinaFil: Hermida, Gladys Noemí. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Biodiversidad y Biología Experimental. Laboratorio de Biología de Anfibios; Argentin
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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