3,338 research outputs found
Violência entre pares na adolescência: Um estudo com estudantes no início e no final do 3.º ciclo do ensino básico
Resumo: Este estudo propõe-se caraterizar comportamentos de violência entre pares, em função do nível de escolaridade, género e variáveis socioafetivas. Os participantes incluem uma amostra de 80 estudantes do 3.º ciclo do ensino básico (7.º – 9.º anos), avaliados com o QEVE, em dois momentos (7.º e 9.º anos). Os resultados demonstram que: i) as condutas de vitimação e agressão mais frequentes são a exclusão social e a agressão verbal; ii) a taxa de vitimação diminui do 7.º para o 9.º ano, enquanto a taxa de agressão mantém-se estável; iii) os rapazes encontram-se mais envolvidos em situações de bullying físico do que as raparigas; iv) o sentimento face à escola (i.e., gostar da escola) e a perceção de ter amigos revelam-se aspetos protetores especialmente importantes das condutas de vitimação e agressão entre os alunos do nível de escolaridade mais baixo. Estes resultados sugerem uma intervenção educativa diferenciada e orientada para a literacia socioemocional, destacando o papel dos pares na prevenção da violência escolar
Arranque de operação e granulação de biomassa num reactor UASB aplicado ao tratamento de águas residuais da indústria cervejeira
O presente trabalho foca o arranque e início de operação de um reactor
anaeróbio de leito de lamas de fluxo ascendente UASB (Upflow Anaerobic Sludge
Blanket) aplicado ao tratamento das águas residuais da indústria cervejeira Unicer S.A.
Os estudos efectuados incidiram sobre o desempenho do reactor UASB e o fenómeno da
granulação. Os ensaios permitiram obter o desenvolvimento de grânulos, se bem que a
evolução nesse sentido tenha sido relativamente morosa, cerca de 6 meses. A actividade
dos grânulos permitiu suportar a aplicação de cargas orgânicas elevadas, na ordem dos
20 kgCQO/m³.dia, com eficiências de remoção de matéria orgânica, em termos de CQO,
próximas dos 80%. A velocidade de sedimentação dos grânulos atingiu valores de 40-50
m/h e o SVI 10 mL/g. Os polissacáridos e proteínas extracelulares foram monitorizadas
durante uma parte do trabalho experimental. Contudo, não se detectou qualquer
alteração significativa na concentração de polímeros, apesar do significativo aumento da
concentração de sólidos voláteis na biomassa
Utilização de raios X na avaliação de danos causados por caruncho em sementes de feijão-caupi
In Brazil, the cowpea [Vigna unguiculata (L.) Walp], is important in the Northeast Region, where it is typically grown on family farms. The importance of the damage caused to the seed quality of this species by stored pests has been described in various studies. Using X-ray, it is possible to see the internal seed structures and identify possible changes and damage. The objective of this study was to identify the damage caused by the weevil [Callosobruchus maculatus (Fabr.)] by analyzing X-ray and evaluate its relationship to the physiological quality of the cowpea seed. Three cultivars were used (IPA-206, BRS-Pajeu and BRS-Potengi) and two lines (L 281.005 and L ESP 10). The samples were exposed to X-ray and germination test to determine the cause-effect relationship between weevil damage and seed germination. X-ray images were evaluated to determine damage severity and location in the seed. Seed damage classified as severe, located in the embryonic axis or in the cotyledons, resulted in abnormal seedlings or dead seeds. The X-ray test, therefore, is efficient for evaluating weevil damage in cowpea seeds and the damage caused to be associated with any resulting adverse germination effects.No Brasil, o feijão-caupi [Vigna unguiculata (L.) Walp], tem destaque na Região Nordeste, sendo uma cultura típica da agricultura familiar. A importância dos danos causados por pragas de armazenamento em sementes da referida espécie, em relação à sua qualidade, tem sido evidenciada em vários trabalhos. Através de imagens de raios X é possível visualizar as estruturas internas da semente, identificando possíveis alterações e danificações. Dessa forma, esse trabalho teve o objetivo de identificar os danos causados por caruncho (Callosobruchus maculatus) e sua relação com a qualidade fisiológica das sementes de feijão-caupi, por intermédio da análise de raios X. Foram utilizadas três cultivares (IPA-206, BRS-Pajeu e BRS-Potengi) e duas linhagens (L 281.005 e L ESP 10). As amostras foram submetidas ao teste de raios X e ao teste de germinação, a fim de determinar a relação de causa e efeito entre os danos provocados pelo caruncho e a germinação das sementes. Nas avaliações das imagens de raios X foi considerada a severidade e a localização dos danos na semente. Para os danos classificados como severos, localizados no eixo embrionário e, ou nos cotilédones, as sementes originaram plântulas anormais ou as sementes estavam mortas. Portanto, o teste de raios X é eficiente para a avaliação de danos causados por caruncho em sementes de feijão-caupi, permitindo relacionar os eventuais danos com os prejuízos causados à germinação.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)CNP
Fibulae from an Iron Age Site in Portugal
Castro de Pragança is located in Estremadura province, on the Portuguese Western coast. Although most of the metal artifacts found in the site can be dated to Copper and Bronze Ages, an unusual set of nine fibulae was recovered. They can be dated to the period from the Iron Age until the Roman conquest. Nondestructive micro-EDXRF elemental analyses showed that five of the fibulae are made of bronze (Cu-Sn alloy), while four fibulae have a polymetallic character and are made both of bronze and iron. This fact indicates exceptionally important archaeological and technological issue
Analysis of intact prophages in genomes of paenibacillus larvae, an important pathogen for bees
Paenibacillus larvae is a highly contagious spore-forming bacteria, responsible for the American
Foulbrood (AFB) disease, lethal to honeybee brood. Integrated in bacterial genomes, prophages are
often able to provide new genes or to alter phenotypic characteristics of bacteria. The potential role
of prophages in the performance of P. larvae has been studied.
A total of 55 intact prophage genomes from 11 P. larvae strains were annotated and analysed. The
main focus was to infer the influence of their genes with some type of virulence trait (e.g.: toxins),
or functions such as antibiotic resistance, metabolic function, germination/sporulation or transporter
of nutrients, which could improve bacterial fitness. We also aimed at understanding if specific
traits were provided to a given genotype (ERIC I-V).
A total of 67 putative genes with different functions were identified. Some were present in all genotypes,
as for example, genes encoding phosphomannomutase, HicB and MazE antitoxins, while others
were exclusive from a specific genotype. In ERIC I, were found genes encoding a DNA internalization
protein or an enhancin-like toxin, in ERIC II, genes responsible for a SocA antitoxin or a DNA
mismatch repair protein, in ERIC III, a gene for a lipid phosphatase, in ERIC IV, genes encoding proteins
associated to ironsulfur uptake and nitrogen fixation and in ERIC V, genes for an aromatic acid
exporter family protein, for an epsilon-toxin type B or for an epithelial and chitin-binding protein.
Although several prophage-derived genes are closely linked to metabolic processes, only ERIC V
strains appear to have a competitive advantage since prophages contained multiple genes that could contribute to a more aggressive infection.
Despite the low representativeness on P. larvae strains diversity, we definitely contribute to leveraging studies in a subject with recent and short knowledge.info:eu-repo/semantics/publishedVersio
Analysis of intact prophages in genomes of Paenibacillus larvae: An important pathogen for bees
The Supplementary materials for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2022.903861/full#supplementary-materialPaenibacillus larvae is the etiological agent of American Foulbrood (AFB), a highly contagious and worldwide spread bacterial disease that affects honeybee brood. In this study, all complete P. larvae genomes available on the NCBI database were analyzed in order to detect presence of prophages using the PHASTER software. A total of 55 intact prophages were identified in 11 P. larvae genomes (5.0±2.3 per genome) and were further investigated for the presence of genes encoding relevant traits related to P. larvae. A closer look at the prophage genomes revealed the presence of several putative genes such as metabolic and antimicrobial resistance genes, toxins or bacteriocins, potentially influencing host performance. Some of the coding DNA sequences (CDS) were present in all ERIC-genotypes, while others were only found in a specific genotype. While CDS encoding toxins and antitoxins such as HicB and MazE were found in prophages of all bacterial genotypes, others, from the same category, were provided by prophages particularly to ERIC I (enhancin-like toxin), ERIC II (antitoxin SocA) and ERIC V strains (subunit of Panton-Valentine leukocidin system (PVL) LukF-PV). This is the first in-depth analysis of P. larvae prophages. It provides better knowledge on their impact in the evolution of virulence and fitness of P. larvae, by discovering new features assigned by the viruses.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. HR was supported by FCT through the grant SFRH/BD/128859/2017 and COVID/BD/151856/2021.info:eu-repo/semantics/publishedVersio
Defence mechanisms of infertile couples vs. fertile couples
Los mecanismos de defensa (DM) fueron investigados en las parejas infértiles (n = 60) a la espera de su primera consulta de infertilidad, haciendo uso del inventario de mecanismos de defensa (DMI). Cuando se comparó con los resultados de las parejas fértiles (n = 60), mujeres y hombres infértiles demostraron una tendencia significativa a evitar el uso de mecanismos de defensa que permitan la expresión de impulsos agresivos, así como una tendencia al uso excesivo de mecanismos de defensa que permiten la racionalización y la negación de situaciones frustrantes. Estos datos parecen indicar la presencia de rigidez defensiva en las parejas afectadas por estrés reproductivo, mientras que en las parejas en común la flexibilidad defensiva es de esperar.Defence mechanisms (DM) were investigated in infertile couples (n = 60) waiting for their first infertility consultation, making use of the Defense Mechanisms Inventory (DMI). When compared with results of fertile couples (n = 60), infertile men and women showed a significant trend to avoid the use of defence mechanisms that enable the expression of aggressive impulses as well as a tendency to overuse defence mechanisms that enable the rationalization and negation of frustrating situations. Such data seem to indicate the presence of defensive inflexibility in couples affected by reproductive stress, while in common couples defensive flexibility is to be expected.peerReviewe
Spent coffee grounds for biodiesel production and other applications
This work evaluates the possibility of using spent coffee grounds (SCG) for biodiesel production and other applications. An experimental study was conducted with different solvents showing that lipid content up to 6 wt% can be obtained from SCG. Results also show that besides biodiesel production, SCG can be used as fertilizer as it is rich in nitrogen, and as solid fuel with higher heating value (HHV) equivalent to some agriculture and wood residues. The extracted lipids were characterized for their properties of acid value, density at 15 °C, viscosity at 40 °C, iodine number, and HHV, which are negatively influenced by water content and solvents used in lipid extraction. Results suggest that for lipids with high free fatty acids (FFA), the best procedure for conversion to biodiesel would be a two-step process of acid esterification followed by alkaline transesterification, instead of a sole step of direct transesterification with acid catalyst. Biodiesel was characterized for its properties of iodine number, acid value, and ester content. Although these quality parameters were not within the limits of NP EN 14214:2009 standard, SCG lipids can be used for biodiesel, blended with higher-quality vegetable oils before transesterification, or the biodiesel produced from SCG can be blended with higher-quality biodiesel or even with fossil diesel, in order to meet the standard requirements
Meiotic wave adds extra asymmetry to the development of female chicken gonads
Development of female gonads in the chicken is asymmetric. This asymmetry affects gene expression, morphology, and germ cell development; consequently only the left ovary develops into a functional organ, whereas the right ovary remains vestigial. In males, on the other hand, both gonads develop into functional testes. Here, we revisited the development of asymmetric traits in female (and male) chicken gonads between Hamburger Hamilton stage 16 (HH16) and hatching. At HH16, primordial germ cells migrated preferentially to the left gonad, accumulating in the left coelomic hinge between the gut mesentery and developing gonad in both males and females. Using the meiotic markers SYCP3 and phosphorylated H2AFX, we identified a previously undescribed, pronounced asymmetryc meiotic progression in the germ cells located in the central, lateral, and extreme cortical regions of the left female gonad from HH38 until hatching. Moreover, we observed that-in contrast to the current view-medullary germ cells are not apoptotic, but remain arrested in pre-leptotene until hatching. In addition to the systematic analysis of the asymmetric distribution of germ cells in female chicken gonads, we propose an updated model suggesting that the localization of germ cells-in the left or right gonad; in the cortex or medulla of the left gonad; and in the central part or the extremities of the left cortex-has direct consequences for their development and participation in adult reproduction
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