Visões de ciências de jovens universitários: um estudo de caso sobre a influência dos nichos sociocultural e de pesquisa

Partindo-se de visões sobre ciência e sua filosofia no mundo moderno, este é um estudo de caso que reflete acerca das contribuições dos nichos de pesquisa na construção de uma natureza da ciência dos alunos de Ciências Biológicas Modalidade Médica, um curso de graduação, na Universidade Federal do Rio de Janeiro, que tem por objetivo formar pesquisadores. Foram entrevistados 117 alunos. A análise foi estruturada com base em um questionário fechado que continha questões como “O que é fazer ciência?”, “Como se dá o progresso da ciência?”, “Por que você escolheu esse curso?”. Os resultados mostram as visões de ciência desses alunos: romântica, técnica e social e como essas visões são construídas ao longo da graduação

Empresas e Direitos Humanos: o enfrentamento ao tráfico de pessoas por meio das compras e contratações públicas = Business and Human Rights: combating human trafficking through public procurement and contracting

DOI: https://doi.org/10.46901/revistadadpu.i19.p141-16

Greffage irréversible de polyélectrolytes sur des substrats de silice et de mica et étude des propriétés de surface et de gonflement

Le protocole pour le greffage irréversible du copolymère amphiphile polystyrène-b-poly (acrylate de sodium) PS-b-PANa, sur un substrat de mica et de silice hydrophobe a été développé, en utilisant la méthode de greffage à partir de solution. Les propriétés de surface du bloc chargé ont été évaluées. L’effet de la force ionique sur le gonflement des chaînes a été investigué par ellipsométrie. Les forces d’interaction entre les surfaces recouvertes du copolymère ont été évaluées par la technique SFA. Les profils de force ont démontré être stables et nettement répulsifs en compression et décompression, montrant l’irréversibilité du greffage. Les forces de frottement entre les brosses de PANa sont élevées, mais aucune évidence d’endommagement de la surface n’a été observée. La comparaison entre le comportement à la surface des chaînes de l’acide polyacrylique PAA et celles du PANa, obtenues par deux méthodes de greffage différentes, est également investiguée.A protocol for irreversibly grafting of amphiphilic copolymer polystyrene-b-poly (sodium acrylate) PS-b-PANa onto hydrophobized mica and silica was developed, using the grafting to approach. Surface properties of charge block were evaluated. The swelling of chains and force ionic effect were studied by ellipsometry. The interaction forces and frictional forces were evaluated by SFA technique. Forces profiles were stable and clearly repulsive in loading and receding, indicating an irreversible grafting. High friction forces onto PANa brushes were determinate without evidence of damage at the surface. The comparison between solution behavior of polyacrylic acid, PAA and PANa brushes, obtained via different grafting methods, was equally investigated

Seasonal variation, method of determination of bovine milk stability, and its relation with physical, chemical, and sanitary characteristics of raw milk

The objective of this research was to determine the variation of milk stability evaluated with ethanol, boiling, and coagulation time tests (CTT) to identify milk components related with stability and verify the correlation between the three methods. Bulk raw milk was collected monthly at 50 dairy farms from January 2007 to October 2009 and physicochemical attributes, somatic cell (SCC), and total bacterial counts (TBC) were determined. Milk samples were classified into low, medium, and high stability to ethanol test when coagulation occurred at 72 °GL, between 74 and 78 °GL, and above 78 °GL, respectively. Univariate analysis was performed considering the effects of year, months, and interaction in a completely randomized design. Principal factor analysis and logistic regression were done. There was an interaction between months and years for stability to the ethanol test and coagulation time. All samples were stable at the boiling test. Boiling test was not related to ethanol and coagulation time tests. Coagulation time was weakly but positively correlated with ethanol test. Broken line analysis revealed that milk stability measured with CTT and ethanol tests decreased sharply when SCC attained 790,000 or 106 cell/mL of milk, respectively. Milk stability measured with ethanol test decreased when TBC was higher than 250,000 cfu/mL, while there was no inflexion point between TBC and stability measured with CTT. Milk with high stability presented lower values for acidity, TBC, and SCC but higher values for pH, lactose, protein, and CTT compared with lowstability milk. Due to the execution easiness, single-point cut-off result and low cost, we do not recommend the replacement of ethanol test for boiling or coagulation time test

Should I stay or should I go? Climate change effects on the future of Neotropical savannah bats

AbstractMost extant species are survivors of the last climate change event 20,000 years ago. While past events took place over thousands of years, current climate change is occurring much faster, over a few decades. We modelled the potential distribution area of bat species in the Brazilian Cerrado, a Neotropical savannah, and assessed the potential impacts of climate change up to 2050 in two scenarios. First we evaluated what the impact on the distributions of bat species would be if they were unable to move to areas where climate conditions might be similar to current ones. The novelty of our paper is that, based on least-cost-path analyses, we identified potential corridors that could be managed now to mitigate potential impacts of climate change. Our results indicate that on average, in the future bat species would find similar climate conditions 281 km southeast from current regions. If bat species were not able to move to new suitable areas and were unable to adapt, then 36 species (31.6%) could lose >80% of their current distribution area, and five species will lose more than 98% of their distribution area in the Brazilian Cerrado. In contrast, if bat species are able to reach such areas, then the number of highly impacted species will be reduced to nine, with none of them likely to disappear from the Cerrado. We present measures that could be implemented immediately to mitigate future climate change impacts

The influence of stress factors on the attention levels of nursing professionals

Objective: To identify, according to the reference of nursing professionals, which stress factors have the greatest influence in the attention process; and analyze, which ones generate greater impact in the development of care activities. Method: This is a quantitative, descriptive correlational study where connections among stress, attention and nursing care have been described. Results: 50 nursing professions were evaluated. 54% (n = 27) stated that stress factors interfere on the levels of attention given by nursing professionals in carrying out their care tasks. 55% (n = 15) point that stress factors related to the working environment are the ones that interfere the most on the levels of attention, followed by stressors classified as biological (n = 10) and psychological (n = 02). Conclusion: Stress factors related to the work environment had the greatest influence on attention and are possibly the ones that affect the most the quality of care provided to clients