859 research outputs found
Datations Io-U du plus haut niveau marin du dernier interglaciaire sur la côte du Brésil : utilisation du 229Th comme traceur
Serum markers of B-cell activation in pregnancy during late gestation, delivery, and the postpartum period
B cells are vital for the normal evolution of pregnancy due to their humoral and possible regulatory activities. Our group and others have documented that circulating B-cell subsets undergo changes from normal late pregnancy to the postpartum period. However, the underlying mechanisms are poorly understood. Therefore, this study examined the degree of B-cell activation in normal pregnancy by analyzing the levels of serum markers in healthy pregnant women during the third trimester of pregnancy, the day of delivery, and the postpartum period.
METHOD OF STUDY:
A prospective study including pregnant and non-pregnant women attending routine care was undertaken at a hospital clinic. Sociodemographic and clinical data were collected, along with peripheral blood samples. The serum levels of soluble CD23 (sCD23), B-cell-activating factor (BAFF), kappa (κ) and lambda (λ) free light chains (FLC), IgA, IgG, and IgM were quantified.
RESULTS:
Our study included 43 third trimester pregnant and 35 non-pregnant women. In the pregnant women, the median levels of sCD23, BAFF, IgG, and κ FLC were significantly higher during the postpartum period than during the third trimester of pregnancy. Compared to the non-pregnant women, the third trimester pregnant women had higher median BAFF levels and lower sCD23, IgA, IgG, and FLC levels.
CONCLUSION:
Changes in serum markers of B-cell kinetics that occur during pregnancy often persist into the postpartum period and affect the secretion of immunoglobulins from different classes. Further studies are needed to clarify the biological significance of our observations.info:eu-repo/semantics/publishedVersio
Design and business: growing up as a separate couple
This paper addresses the difficulties faced by postgraduate design students (DS) and professional designers (PD) concerning the design, development and implementation of business projects (BP), and of sustainable management (SM). The DS have not previously attended any specific course, either dealing with BP, or having had training in SM. A test administered to 60 DS enabled to picture issues regarding: (i) the sense of discomfort regarding business and management areas, due to lack of skills, and (ii) the special requirements for skills in unfamiliar areas such as production, management, marketing and product stewardship. The study determined that DS perceive the need for educational policies that allow the acquisition of new skills in the referred areas. However, it seems that they are not sensitive to BP/SM scientific’ research importance. Findings point out a direction to curriculum development to bridge Design and Business areas, by overcoming the identified gap.info:eu-repo/semantics/acceptedVersio
Amino Acid Degradation after Meteoritic Impact Simulation
Amino acids are among the most important prebiotic molecules as it is from these precursors that the building blocks of life were formed [1]. Although organic molecules were among the components of the planetesimals making up the terrestrial planets, large amounts of primitive organic precursor molecules are believed to be exogenous in origin and to have been imported to the Earth via micrometeorites, carbonaceous meteorites and comets, especially during the early stages of the formation of the Solar System [1,2]. Our study concerns the hypothesis that prebiotic organic matter, present on Earth, was synthesized in the interstellar environment, and then imported to Earth by meteorites or micrometeorites. We are particularly concerned with the formation and fate of amino acids. We have already shown that amino acid synthesis is possible inside cometary grains under interstellar environment conditions [3]. We are now interested in the effects of space conditions and meteoritic impact on these amino acids [4-6]. Most of the extraterrestrial organic molecules known today have been identified in carbonaceous chondrite meteorites [7]. One of the components of these meteorites is a clay with a composition close to that of saponite, used in our experiments. Two American teams have studied the effects of impact on various amino acids [8,9]. [8] investigated amino acids in saturated solution in water with pressure ranges between 5.1 and 21 GPa and temperature ranges between 412 and 870 K. [9] studied amino acids in solid form associated with and without minerals (Murchison and Allende meteorite extracts) and pressure ranges between 3 and 30 GPa. In these two experiments, the amino acids survived up to 15 GPa. At higher pressure, the quantity of preserved amino acids decreases quickly. Some secondary products such as dipeptides and diketopiperazins were identified in the [8] experiment
Projeto BEEHOPE: conservação da abelha ibérica (Apis mellifera iberiensis) em Portugal
O projeto BEEHOPE, com o título original “Honeybee conservation centres in western Europe - an innovative strategy using sustainable beekeeping to reduce honeybee decline”, foi aprovado no âmbito do 5º concurso transnacional (2013-2014) BiodivErsA/FACCE-JPI na área da biodiversidade. O consórcio internacional que integra o BEEHOPE é constituído por cinco instituições oriundas de França (CNRS/Université de Versailles, CNRS/Université Blaise Pascal, e CNRS/Centre d'Etudes Biologiques de Chizé), Espanha (Universidad del País Vasco) e Portugal (Centro de Investigação de Montanha, Instituto Politécnico de Bragança). Num cenário de ameaças crescentes à integridade genética das subespécies de abelhas nativas da Europa, o objectivo último do BEEHOPE é proteger o fundo genético das populações da linhagem M (A. m. iberiensis e A. m. mellifera) através do estabelecimento de apiários de conservação ao longo de um gradiente que vai desde o Norte de França até ao Sul de Portugal. Estes apiários de conservação terão como missão: (i) servir de base à caraterização da diversidade genética e eco-etológica das abelhas da linhagem da Europa Ocidental (M), (ii) preservar a diversidade genética dessas populações, (iii) constituir uma reserva de diversidade para a indústria apícola e apicultores, (iv) estudar o impacto da abelha domesticada na manutenção da diversidade florística local, e (v) servir de base à utilização da abelha como um bio-coletor e como bio-indicador da qualidade ambiental. Nesta comunicação apresentar-se-ão as atividades desenvolvidas e os primeiros resultados genéticos e eco-etológicos obtidos nos dois apiários Portugueses (Bragança e Algarve) que fazem parte da rede de centros de conservação do BEEHOPE.info:eu-repo/semantics/publishedVersio
Arginase levels and their association with Th17-related cytokines, soluble adhesion molecules (sICAM-1 and sVCAM-1) and hemolysis markers among steady-state sickle cell anemia patients
Sickle cell anemia (SCA) is characterized by a marked endothelial dysfunction, owing to many factors. Arginine metabolism can be related to the inflammatory chronic state presented by patients, playing a key role in their clinical outcome and vascular endothelium. We investigated the serum arginase levels in 50 SCA patients (22 men and 28 women, mean age of 17 ± 10.5 years) and 28 healthy controls. Serum arginase levels were associated with biochemical hemolysis markers and cytokines involved in Th17 response, as well as levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1). Arginase concentrations were higher in SCA patients, compared with controls (p = 0.005), and were significantly and positively associated with total bilirubin (p = 0.004), indirect bilirubin (p = 0.04), and aspartate aminotransferase (AST; p = 0.039) in the SCA patient group. Moreover, arginase was significantly and positively associated with transforming growth factor-beta (TGF-beta; p = 0.008) among SCA patients. sICAM-1 was significantly and positively associated to reticulocytes (p = 0.014) and AST (p = 0.04). sVCAM-1 was likewise associated with lactate dehydrogenase (p = 0.03). These data suggest a new insight into arginase metabolism, as we show here a shift in arginine catabolism, where TGF-beta may induces the arginase pathway instead of the nitric oxide pathway and a possible involvement of the vascular activation and the serum arginase in chronic hemolysis among SCA patients. Additional studies should be carried out in order to investigate the mechanisms by which TGF-beta participates in the metabolism of arginase in SCA patients
Atividade inseticida de estirpes de Bacillus thuringiensis em pragas da soja e do girassol.
O controle biológico como tática de manejo integrado de pragas é promissor devido a sua seletividade e sustentabilidade, pois é realizado por diferentes organismos como os insetos parasitóides, predadores e patógenos, destacando-se as bactérias. O presente estudo teve como objetivo avaliar cepas de Bacillus thuringiensis com mortalidade para Spodoptera frugiperda Spodoptera eridania, Spodoptera cosmioides, Chlosyne lacinia saundersii Anticarsia gemmatalis e Pseudoplusia includens. Utilizou-se lagartas de 2° instar e como padrão de comparação a estirpe HD-1 de B. thuringiensis subsp. Kurstaki. Cubos de dieta e pedaços de folhas de girassol e milho foram mergulhados na suspensão das culturas liofilizadas com a concentração desejada para a porcentagem de mortalidade e determinação da CL50. Constatou-se 80% de mortalidade em uma única espécie ou para mais de uma espécie em 21 estirpes. Destacaram-se a Br37, S1450 e HD-1, que causaram mortalidade acima de 80% para todas as espécies testadas. Br78 e S1265, provocaram mortalidade, acima de 82%, nas espécies de S. frugiperda S. eridania, A. gemmatalis e P. includens. O padrão HD-1 apresentou-se virulento para todas as espécies testadas. A CL50 de BR37, BR58 e BR94, variou entre 46,66 ?g de liofilizado/ml e 63,33 ?g/ml para S. eridania, entre 40,00 ?g/ml e 116,66 ?g/ml para S. frugiperda. Das 6 cepas de B. thuringiensis testadas para A.gemmatalis a CL50 variou entre 15,03 ?g/ml a 118,93 ?g/ml. Em C. l. saundersii a variação da CL50 ficou entre 6,54 ?g/ml e 57,77 ?g/ml. Em comparação com o padrão HD-1 a estirpe BR58 para S. eridania manteve a toxicidade, e para S. frugiperda e A. gemmatalis foi de uma vez maior do que em relação ao padrão. Para BR87, S1302, S1269 testadas em C.l. saundersii a toxicidade foi 3,0 vezes maior quando comparada ao padrão HD-1. Os resultados foram satisfatórios observando o potencial de 4 cepas para o controle das espécies acima citadas.SICONBIOL 2011
A study of local adaptation in the Iberian honeybee (Apis mellifera iberiensis) using a reciprocal translocation experiment
In Europe, several translocation experiments suggested that native populations of Apis mellifera are adapted to local climate and flora. However, so far, no study has been conducted on the Iberian honeybee, Apis mellifera iberiensis. The goal of this study was to assess the existence of genotype-environment interaction (GEI), and consequently local adaptation, in the Iberian honeybee. In 2015 two apiaries were set up, each one with 36 colonies (18 of the origin Bragança and 18 of the origin Vila do Bispo), in two latitudinal extremes of Portugal: Bragança (north) and Vila do Bispo (south). Several traits of the 36 colonies were measured for almost 2 years, including: number of brood and pollen cells, honey yield, survival, and Varroa destructor infestation. The analyses were performed using t-Student and Mann-Whitney tests to compare those traits between the two origins in the same apiary and the same origin between the two apiaries. The survival analysis was performed using the Cox proportional hazard model in R. Colonies of the southern origin Vila do Bispo showed a tendency to collect more pollen and consequently they produced a higher number of brood cells, had a higher varroa infestation level and a lower survival rate than colonies of the origin Bragança in both locations. Honey yield was the only trait that showed existence of GEI, and therefore local adaptation, since the local honeybees had a higher honey production in their apiary of origin. Additionally, the differences between the two origins were sharper in more favourable environments where the honeybees can better express their genetic potential. Our findings highlight the importance of protecting local honeybee diversity in a period of increasing selection pressures such as climate change, agricultural land overuse and novel pathogens and parasites.Thisresearchwas funded through the 2013-2014~'BiodivERsA/FACCE-JPI Joint call for research proposals, with the national funders FCT(Portugal), CNRS (France), and MEC(Spain).info:eu-repo/semantics/publishedVersio
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