9,625 research outputs found
The role of geology in a sustainable society: perceptions of university students
Geology has been at the service of an instrumental view of nature contributing to its exploitation, and helping providing the raw materials needed for economic development, frequently with high ecological impacts. However, Environmental Geology and Geoconservation are fields more concerned with environmental protection and its preservation. At the same time, Geology is responsible for a certain ambiguity of values, choosing the hammer as a symbol but focusing its action on the field, which helps to generate a sense of reverence for Earth. Based on these ideas, a questionnaire was applied to 36 master students who will teach Geology (20) or will exercise other professions related with it (16), in order to ascertain how respondents characterize the work of geologists related to nature, and see their opinion about the contribution of this science to a fairer and more sustainable society. The general results show that the students identify more with a less exploiting view of this science and prefer to highlight its role for a fairer and more sustainable society especially concerning a more sustainable exploitation of Earth resources and rising of awareness of geohazards. This can support the idea of paradigm changing in Geosciences, adding an element of caution to our actions instead of helping the mutilation of the planet.info:eu-repo/semantics/publishedVersio
Aprendizagem organizacional como estratégia para a gestão do conhecimento na Embrapa Informática Agropecuária.
Resumo: O objetivo deste artigo é analisar e compreender como elementos circunscritos à estrutura e cultura organizacional, apontados por pesquisadores da Embrapa Informática Agropecuária, uma das 47 unidades de pesquisa da Empresa Brasileira de Pesquisa Agropecuária ? Embrapa, servem como fatores pessoais e institucionais favorecedores da aprendizagem organizacional e da construção de conhecimento na empresa. Para alcance deste objetivo adotou-se como procedimento metodológico a análise de conteúdo realizada com dados coletados em uma investigação de doutorado de abordagem qualitativa, concluÃda em 2008. Os resultados mostram que os fatores indicados pelos sujeitos da pesquisa propulsionam as condições favoráveis para se promover a aprendizagem organizacional e a construção de conhecimentos podendo servir de base para que a Embrapa Informática Agropecuária revise e reajuste suas polÃticas e práticas de gestão internas.GECIC 2012
Clear as daylight: analysis of diurnal raptor pellets for small mammal studies
Claro como el agua: análisis de las egagrópilas de aves rapaces diurnas para los estudios sobre pequeños mamÃferos
Los métodos no invasivos se investigan y se aplican cada vez más en los estudios de comunidades de pequeños mamÃferos, ya que son más rentables en cuanto a sus costos y evitan los problemas relacionados con la conservación y el bienestar animal. Sin embargo, las egagrópilas de aves rapaces diurnas rara vez se han utilizado para estos fines. En este trabajo se evaluó el potencial que tienen las egagrópilas del aguilucho lagunero (Circus aeruginosus) como un método no invasivo para estudiar las comunidades de pequeños mamÃferos, mediante la comparación de los resultados con los obtenidos en las trampas de tipo Sherman y las de caÃda (pitfall). Los tres métodos se utilizaron simultáneamente en un complejo formado por tierras agrÃcolas y humedales en el noroeste de Portugal. Las estimaciones de la riqueza, la diversidad, la uniformidad y la abundancia de especies y la proporción de cada una de ellas dentro de la comunidad mostraron diferencias significativas entre los tres métodos. Nuestros resultados sugieren que la utilización de las egagrópilas del aguilucho lagunero es más eficaz para inventariar las especies de pequeños mamÃferos que cualquiera de los dos tipos de trampas, al mismo tiempo que evita la muerte involuntaria de animales asociada con el muestreo de pequeños mamÃferos no voladores. Además, el análisis de las egagrópilas fue el método más rentable. Entre los dos métodos de captura, la muerte involuntaria de animales fue mayor en las trampas de caÃda que en las trampas de tipo Sherman. Se discuten las ventajas y los inconvenientes de los tres métodos tanto desde una perspectiva técnica como conservacionista.Non–invasive approaches are increasingly investigated and applied in studies of small mammal assemblages because they are more cost–effective and bypass conservation and animal welfare issues. However, pellets of diurnal raptors have rarely been used for these purposes. We evaluated the potential of marsh harrier pellets (Circus aeruginosus) as a non–invasive method to sample small mammal assemblages, by comparing the results with those of sampling using Sherman live–traps and pitfalls. The three methods were applied simultaneously in an agricultural–wetland complex in NW Portugal. Estimates of species richness, diversity, evenness, abundance, and proportion of each species within the assemblage showed significant differences between the three methods. Our results suggest that the use of marsh harrier pellets is more effective in inventorying small mammal species than either of the two kinds of traps, while also avoiding any involuntary fatalities associated with the sampling of small non–volant mammals. Moreover, the analysis of pellets was the most cost–effective method. Comparison of the two trapping methodologies showed involuntary fatalities were higher in pitfalls than in Sherman traps. We discuss the advantages and flaws of the three methods, both from technical and conservational perspectives.Claro como el agua: análisis de las egagrópilas de aves rapaces diurnas para los estudios sobre pequeños mamÃferos
Los métodos no invasivos se investigan y se aplican cada vez más en los estudios de comunidades de pequeños mamÃferos, ya que son más rentables en cuanto a sus costos y evitan los problemas relacionados con la conservación y el bienestar animal. Sin embargo, las egagrópilas de aves rapaces diurnas rara vez se han utilizado para estos fines. En este trabajo se evaluó el potencial que tienen las egagrópilas del aguilucho lagunero (Circus aeruginosus) como un método no invasivo para estudiar las comunidades de pequeños mamÃferos, mediante la comparación de los resultados con los obtenidos en las trampas de tipo Sherman y las de caÃda (pitfall). Los tres métodos se utilizaron simultáneamente en un complejo formado por tierras agrÃcolas y humedales en el noroeste de Portugal. Las estimaciones de la riqueza, la diversidad, la uniformidad y la abundancia de especies y la proporción de cada una de ellas dentro de la comunidad mostraron diferencias significativas entre los tres métodos. Nuestros resultados sugieren que la utilización de las egagrópilas del aguilucho lagunero es más eficaz para inventariar las especies de pequeños mamÃferos que cualquiera de los dos tipos de trampas, al mismo tiempo que evita la muerte involuntaria de animales asociada con el muestreo de pequeños mamÃferos no voladores. Además, el análisis de las egagrópilas fue el método más rentable. Entre los dos métodos de captura, la muerte involuntaria de animales fue mayor en las trampas de caÃda que en las trampas de tipo Sherman. Se discuten las ventajas y los inconvenientes de los tres métodos tanto desde una perspectiva técnica como conservacionista
Contamination of resin-matrix composites on chairside handling using latex or nitrile gloves: an in vitro study
The aim of this study was to evaluate the efect of diferent gloves and clinical environment on the contamination of resinmatrix composites for restorative dentistry. Specimens of nano-hybrid resin-matrix composite (n=6) were divided in groups regarding the handling with (A) clinical spatula; (B) latex gloves; (C) latex or (D) nitrile gloves with human saliva; (E) latex or (F) nitrile gloves with human blood. After light curing, groups of specimens were analyzed by optical microscopy at magnifcation ranging from x30 up to x500 and by scanning electron microscopy at diferent magnifcation ranging from x50 up to x8000. Handling of resin-matrix composites with unpowdered nitrile gloves or clinical spatulas avoided the presence of contaminants. However, agglomerates of the resin-matrix composite itself became entrapped leading to a heterogenous morphological aspect. SEM images revealed the presence of corn-derived starch released from the powdered gloves. Also, the formation of micro-spaces (voids) occurred after handling with powdered latex gloves. Specimens handled with both type of gloves contaminated with saliva showed a conditioning layer composed of glycoproteins rolls and compounds including calcium-based chlorides, phosphates, and carbonates. Also, blood products were transferred from the contaminated gloves to the resin-matrix composites after handling. Thus, resin-matrix composite restorations are susceptible to contamination with debris from powdered gloves. Also, saliva or blood debris become adsorbed and entrapped in the resin-matrix composites during clinical handling leading to the presence of defects such macro- and micro-scale voids or contaminant agglomerates.info:eu-repo/semantics/publishedVersio
Alta freqüência da mutação Q318X em pacientes com hiperplasia adrenal congênita por deficiência da 21-hidroxilase no nordeste do Brasil
OBJETIVES: Deficiency of 21-hydroxylase is the most common form of congenital adrenal hyperplasia (CAH-21OH). The aim of this study was to determine, by allele-specific PCR, the frequency of microconversions of the CYP21A2, in sixteen patients with the classical forms and in 5 patients with the nonclassical (NC) form of CAH-21OH and correlate genotype with phenotype. METHODS: Genotypes were classified into 3 mutation groups (A, B and C), based on the degree of enzymatic activity. Screening for 7 microconversions by allele-specific PCR diagnosed 74.3% (n=26) of the 35 unrelated alleles. RESULTS: The most frequent mutations were Q318X (25.7%), V281L (17.1%), I2 Splice (14.3%), I172N (14.3%), and R356W (14.3%). Genotype was identified in 57.1% of the patients. We observed correlation between genotype and phenotype in 91.7% of the cases. CONCLUSION: The highest frequency for Q318X (25.7%) when compared to other studies may reflect individual sample variations in this Northeastern population.OBJETIVOS: Deficiência de 21-hidroxilase é a forma mais comum de hiperplasia adrenal congênita (CAH-21OH). O objetivo deste estudo foi determinar, por PCR alelo-especÃfica, a freqüência de microconversões no CYP21A2, em 16 pacientes com a forma clássica e em cinco pacientes com a forma não-clássica (NC) de CAH-21OH e correlacionar o genótipo com o fenótipo. MÉTODOS: Genótipo foi classificado em três grupos de mutações (A, B e C), baseado no grau de atividade enzimática. A técnica de PCR alelo-especÃfico diagnosticou 74,3% (n = 26) dos 35 alelos não relacionados. RESULTADOS: As mutações mais freqüentes foram Q318X (25,7%), V281L (17,1%), I2 Splice (14,3%), I172N (14,3%) e R356W (14,3%). O genótipo foi identificado em 57,1% dos pacientes. Houve correlação genótipo-fenótipo em 91,7% dos casos. CONCLUSÃO: A mais alta freqüência da mutação Q318X (25,7%) comparada a outros estudos pode refletir variações individuais desta população do nordeste.Fapitec (FAP - Foundation for Support to Research of Sergipe [Fundep] 02/2002)Federal University of Sergipe - Medicine Post-Graduation Cente
Spherical and rod shaped mesoporous nanosilicas for cancer- targeted and photosensitizers delivery in photodynamic therapy
Mesoporous silica nanoparticles (MSNPs) have attracted much attention in many biomedical applications. One of the fields in which smart functional nanosystems have found wide application is cancer treatment. Here, we present new silica nanoparticle-based systems which have been explored as efficient vehicles to transport and deliver photosensitizers (PSs) into tumor tissues during photodynamic therapy (PDT). In this work, we report the preparation, characterization, and in vitro studies of distinct shaped MSNPs grafted with S-glycoside porphyrins (Pors). The ensuing nanomaterials were fully characterized, and their properties as third-generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UM-UC-3, were examined. The best uptake results were obtained for MSNP-PS2, while MSNP-PS1 showed the lowest cellular uptake among the nanocarriers tested, but revealed the best phototoxicity in both cancer cells. Overall, the phototoxicity was higher with MSNPs than with mesoporous silica nanorods (MSNRs) and higher uptake and phototoxicity were consistently observed in UM-UC-3 rather than in HT-1376 cancer cellpublishe
Correlation between objective and subjective assessment of noise barriers
There are several international standards that define the way to evaluate the
attenuation capacity of noise reducing devices, by single-number quantities
representing airborne sound insulation and insertion loss. These two
single-value ratings define the quality and performance of acoustic barriers,
the former being related to intrinsic and the latter to both intrinsic and
extrinsic acoustic characteristics of the devices. However, not many studies
can be found on whether these objective parameters correlate to the perception
of annoyance reduction. The aim of the present work is to analyze the adequacy
of these objective ratings to indicate the performance of noise barriers, by
comparing their values with the perception of annoyance reduction. For this
purpose, ninety individuals of two different nationalities (Spanish and
Portuguese) were asked to rate the perceived annoyance reduction in a listening
experimental test, in which they were exposed, under controlled conditions, to
several environmental noises and acoustic screened stimuli simulated by audio
filters. The obtained results show a high correlation between objective ratings
and subjective annoyance perception, with a better correlation being observed
for insertion loss single-number parameter than for the airborne sound
insulation single-number rating. Furthermore, significant differences were
found depending on the gender and nationality of the respondents. The results,
from this ongoing research work, may be of great interest for future acoustic
barriers design
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