38 research outputs found

    Gross intestinal morphometry and allometry in primates

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    Although it is generally assumed that among mammals and within mammal groups, those species that rely on diets consisting of greater amounts of plant fiber have larger gastrointestinal tracts (GIT), statistical evidence for this simple claim is largely lacking. We compiled a dataset on the length of the small intestine, caecum, and colon in 42 strepsirrhine, platyrrhine, and catarrhine primate species, using specimens with known body mass (BM). We tested the scaling of intestine length with BM, and whether dietary proxies (percentage of leaves and a diet quality index) were significant covariates in these scaling relationships, using two sets of models: one that did not account for the phylogenetic structure of the data, and one that did. Intestine length mainly scaled geometrically at exponents that included 0.33 in the confidence interval; Strepsirrhini exhibited particularly long caeca, while those of Catarrhini were comparatively short. Diet proxies were only significant for the colon and the total large intestine (but not for the small intestine or the caecum), and only in conventional statistics (but not when accounting for phylogeny), indicating the pattern occurred across but not within clades. Compared to terrestrial Carnivora, primates have similar small intestine lengths, but longer large intestines. The data on intestine lengths presented here corroborate recent results on GIT complexity, suggesting that diet, as currently described, does not exhaustively explain GIT anatomy within primate clades

    Long-lived self-renewing bone marrow-derived macrophages displace embryo-derived cells to inhabit adult serous cavities

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    Peritoneal macrophages are one of the most studied macrophage populations in the body, yet the composition, developmental origin and mechanisms governing the maintenance of this compartment are controversial. Here we show resident F4/80(hi)GATA6(+) macrophages are long-lived, undergo non-stochastic self-renewal and retain cells of embryonic origin for at least 4 months in mice. However, Ly6C(+) monocytes constitutively enter the peritoneal cavity in a CCR2-dependent manner, where they mature into short-lived F4/80(lo)MHCII(+) cells that act, in part, as precursors of F4/80(hi)GATA6(+) macrophages. Notably, monocyte-derived F4/80(hi) macrophages eventually displace the embryonic population with age in a process that is highly gender dependent and not due to proliferative exhaustion of the incumbent embryonic population, despite the greater proliferative activity of newly recruited cells. Furthermore, although monocyte-derived cells acquire key characteristics of the embryonic population, expression of Tim4 was impaired, leading to cumulative changes in the population with age

    The Upper and Lower Visual Field of Man: Electrophysiological and Functional Differences

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    Concentração plasmática do hormônio adrenocorticotrófico de parturientes submetidas a método não farmacológico de alívio da ansiedade e dor do parto Concentración de la hormona adrenocorticotrófica en parturientas sometidas a un método no farmacológico de alivio de ansiedad y el dolor durante el parto Corticotrophin hormone serum levels of parturients submitted to nonpharmacologic anxiety and pain relief method during labor

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    Objetivo: analisar os níveis séricos do hormônio adrenocorticotrófico (ACTH) e a correlação entre esses níveis, a ansiedade e a dor na parturição. Dezessete parturientes (grupo controle - GC) receberam assistência de enfermagem de rotina, e dezenove (grupo experimental - GE) foram estimuladas e orientadas a realizar técnicas de respiração e relaxamento. Os níveis plasmáticos do ACTH, o traço e estado de ansiedade e a intensidade de dor foram avaliados. Os níveis de ACTH foram baixos no início do trabalho de parto, com pico no final e regressão no pós-parto imediato, sem diferença estatisticamente significativa entre os grupos. A redução do ACTH com alívio parcial do estresse do GE, sugere a interferência das técnicas de respiração e relaxamento. Os níveis do ACTH, não se correlacionaram à ansiedade e à dor, em ambos os grupos.<br>La finalidad de este estudio fue analizar los niveles séricos de la hormona adrenocorticotrófica (ACTH), la correlación entre esos niveles, la ansiedad y el dolor en el parto. Diecisiete parturientas (grupo control - GC) recibieron atención de enfermería de rutina y diecinueve (grupo experimento - GE) fueron preparadas y orientadas a realizar técnicas de respiración y relajación. Los niveles de la ACTH, el trazo y estado de ansiedad y la intensidad del dolor fueron evaluados. Los niveles de la ACTH fueron bajos en el inicio del trabajo de parto, con elevación en el final y regresión en el postparto inmediato, sin diferencia estadísticamente significativa entre los grupos. La reducción de la ACTH con alivio parcial del stress del GE, sugiere la interferencia de las técnicas de respiración y relajación. Los niveles de la ACTH no se correlacionaron ni con la ansiedad ni con el dolor, en ambos grupos.<br>This study aimed to analyze the plasma ACTH levels and the correlation between the ACTH levels and pain and anxiety during the parturition. Seventeen parturients received routine nursing care (control group - CG) and nineteen (Experimental Group - EG) were stimulated and guided to perform respiration and relaxation techniques. ACTH levels, pain intensity and state-trait anxiety were evaluated. ACTH levels were lower at the beginning of labor, peaked at the end and decreased again in the immediate postpartum period. There was no significant statistical difference between the groups. Lower ACTH levels and partial stress relief in the EG suggest the interference of breathing and relaxation techniques; ACTH levels did not show any correlation with anxiety or pain in any of both groups

    Am I who I say I am? Unobtrusive self-representation and personality recognition on Facebook

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    <div><p>Across social media platforms users (sub)consciously represent themselves in a way which is appropriate for their intended audience. This has unknown impacts on studies with unobtrusive designs based on digital (social) platforms, and studies of contemporary social phenomena in online settings. A lack of appropriate methods to identify, control for, and mitigate the effects of self-representation, the propensity to express socially responding characteristics or self-censorship in digital settings, hinders the ability of researchers to confidently interpret and generalize their findings. This article proposes applying boosted regression modelling to fill this research gap. A case study of paid Amazon Mechanical Turk workers (n = 509) is presented where workers completed psychometric surveys and provided anonymized access to their Facebook timelines. Our research finds indicators of self-representation on Facebook, facilitating suggestions for its mitigation. We validate the use of LIWC for Facebook personality studies, as well as find discrepancies with extant literature about the use of LIWC-only approaches in unobtrusive designs. Using survey data and LIWC sentiment categories as predictors, the boosted regression model classified the Five Factor personality model with an average accuracy of 74.6%. The contribution of this work is an accurate prediction of psychometric information based on short, informal text.</p></div
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