36 research outputs found
The role of receptivity in the courtship behavior of Podocnemis erythrocephala in captivity
The courtship behavior of Podocnemis erythrocephala (Red-headed Amazon River Turtle) in captivity was studied to examine female receptivity and male response to female rejection. We observed 20 females and 39 males in 150 sessions (3–6 h/day for a total of 450 h). In 36% of the trials, there was no interaction between males and females, and 20% of the trials resulted in copulations. All males introduced into tanks approached females, and eventually there was aggression among the males. In 48% of the experiments, females also searched for or approached males. When males initially approached females, they either accepted the male’s advances (14%), rejected the male passively (38%), or rejected the male aggressively (48%). In 86% of the cases where males were rejected, 4% attempted to approach females again, and in 51% they were ultimately successful
Inflammatory responses and intestinal injury development during acute Trypanosoma cruzi infection are associated with the parasite load
Reproductive indices in natural nests of giant Amazon river turtles Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) in the Environmental Protection Area Meanders of the Araguaia river
SPATIAL DISTRIBUTION OF LYMNAEIDAE (MOLLUSCA, BASOMMATOPHORA), INTERMEDIATE HOST OF Fasciola hepatica LINNAEUS, 1758 (TREMATODA, DIGENEA) IN BRAZIL
Accuracy versus precision in boosted top tagging with the ATLAS detector
Abstract
The identification of top quark decays where the top quark has a large momentum transverse to the beam axis, known as top tagging, is a crucial component in many measurements of Standard Model processes and searches for beyond the Standard Model physics at the Large Hadron Collider.
Machine learning techniques have improved the performance of top tagging algorithms, but the size of the systematic uncertainties for all proposed algorithms has not been systematically studied.
This paper presents the performance of several machine learning based top tagging algorithms on a dataset constructed from simulated proton-proton collision events measured with the ATLAS detector at √
s
= 13 TeV.
The systematic uncertainties associated with these algorithms are estimated through an approximate procedure that is not meant to be used in a physics analysis, but is appropriate for the level of precision required for this study.
The most performant algorithms are found to have the largest uncertainties, motivating the development of methods to reduce these uncertainties without compromising performance.
To enable such efforts in the wider scientific community, the datasets used in this paper are made publicly available.</jats:p
Ex vivo Expansion of CD56(+) NK and NKT-like Lymphocytes from Peripheral Blood Mononuclear Cells of Patients with Ovarian Neoplasia
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Methods for ex vivo expansion of natural killer (NK) cells have allowed obtaining enough numbers of human NK cells for clinical trials. However, the evaluation of these methods has been mostly limited to haematological malignancies. This study aimed at evaluating a method for selective expansion of NK cells when applied in peripheral blood mononuclear cells (PBMC) of patients with ovarian neoplasia. PBMC from 13 volunteer patients with ovarian neoplasia, seven benign and six malignant tumours, were cultured in Cell-Gro medium supplemented with anti-CD3 (9-10 initial days), IL-2 and foetal bovine serum for 21 days. The resulting effector cells were evaluated for their phenotype, cytotoxicity and cytokine secretion. PBMC cultures resulted in multiple populations (NK, NKT and T) of effector cells, enriched with CD56(+) lymphocytes. NK cells from patients with benign and malignant ovarian neoplasia were expanded 139.6 +/- 63.4 and 82.7 +/- 25.3-fold, respectively, being the largest lymphocyte subtype among CD56(+) population. Effector cells expanded from patients with malignant ovarian neoplasia had higher proportion of T lymphocytes and altered cytokine production patterns, characterized by lower INF-gamma, TNF-alpha and higher IL-4, compared with patients with benign ovarian neoplasia. Effector cells were cytotoxic against K562 and OVCAR3 cell lines. Cytotoxicity was significantly higher (P < 0.05) using magnetically separated CD56(+) effector cell fractions compared with CD56-deprived ones. The present study demonstrates the feasibility of the culture system employed to generate effector cells, enriched with CD56(+) lymphocytes, from PBMC of patients with ovarian neoplasia. NK cells were the largest lymphocyte subtype among the CD56(+) population and the main variable among the final effector cell preparation affecting target cell killing.743244252Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [2006/04600-2
