423 research outputs found
El uso de SIG en la zonificación de las áreas protegidas- Apa- Itaúna/Brasil- un caso de estudio
Este artículo trata sobre el uso de Sistemas de Información Geográfica (SIG) como herramienta esencial
en el tratamiento de información que apoyan el desarrollo de una zonificación ambiental. El estudio tiene
como objetivo diagnosticar una zona de interés medioambiental situado en Itaúna/Brasil propuso la creación
de una APA (Área de Protección Ambiental), basados en la cartografía de las características físicas,
ambientales, morfológicas y sociales, así como gestión de riesgos y ocupación de la tierra. Al final, se propone
que la delimitación de la zona y una zonificación modelo, desarrollado con la ayuda directa de los SIG, habida
cuenta de las muchas alternativas que ofrece esta herramienta, por ejemplo, la integración y la manipulación
de varias variables complejas, permitiendo una planificación y espacialmente gestionarse con más eficacia.This article deals about the use of Geographic Information Systems (GIS) as an essential tool in the
treatment of information that support the development of an Environmental Zoning. The study pretend to
diagnose an area of environmental interest located in Itaúna/Brazil and propose the creation of an APA
(Environmental Protection Area), based in mapping of physical, environmental, morphological and social
condition, as well as risk management and occupation of land. At the end it is proposed that the demarcation
of the area and a model zoning, developed with the direct assistance of GIS, given the many alternatives that
this tool provides, for example, integration and manipulation of several complex variables, allowing a planning
and a more efficient space management
Co-evolution of cerebral and cerebellar expansion in cetaceans.
Cetaceans possess brains that rank among the largest to have ever evolved, either in terms of absolute mass or relative to body size. Cetaceans have evolved these huge brains under relatively unique environmental conditions, making them a fascinating case study to investigate the constraints and selection pressures that shape how brains evolve. Indeed, cetaceans have some unusual neuroanatomical features, including a thin but highly folded cerebrum with low cortical neuron density, as well as many structural adaptations associated with acoustic communication. Previous reports also suggest that at least some cetaceans have an expanded cerebellum, a brain structure with wide-ranging functions in adaptive filtering of sensory information, the control of motor actions, and cognition. Here, we report that, relative to the size of the rest of the brain, both the cerebrum and cerebellum are dramatically enlarged in cetaceans and show evidence of co-evolution, a pattern of brain evolution that is convergent with primates. However, we also highlight several branches where cortico-cerebellar co-evolution may be partially decoupled, suggesting these structures can respond to independent selection pressures. Across cetaceans, we find no evidence of a simple linear relationship between either cerebrum and cerebellum size and the complexity of social ecology or acoustic communication, but do find evidence that their expansion may be associated with dietary breadth. In addition, our results suggest that major increases in both cerebrum and cerebellum size occurred early in cetacean evolution, prior to the origin of the major extant clades, and predate the evolution of echolocation
Scaling of Brain Metabolism with a Fixed Energy Budget per Neuron: Implications for Neuronal Activity, Plasticity and Evolution
It is usually considered that larger brains have larger neurons, which consume more energy individually, and are therefore accompanied by a larger number of glial cells per neuron. These notions, however, have never been tested. Based on glucose and oxygen metabolic rates in awake animals and their recently determined numbers of neurons, here I show that, contrary to the expected, the estimated glucose use per neuron is remarkably constant, varying only by 40% across the six species of rodents and primates (including humans). The estimated average glucose use per neuron does not correlate with neuronal density in any structure. This suggests that the energy budget of the whole brain per neuron is fixed across species and brain sizes, such that total glucose use by the brain as a whole, by the cerebral cortex and also by the cerebellum alone are linear functions of the number of neurons in the structures across the species (although the average glucose consumption per neuron is at least 10× higher in the cerebral cortex than in the cerebellum). These results indicate that the apparently remarkable use in humans of 20% of the whole body energy budget by a brain that represents only 2% of body mass is explained simply by its large number of neurons. Because synaptic activity is considered the major determinant of metabolic cost, a conserved energy budget per neuron has several profound implications for synaptic homeostasis and the regulation of firing rates, synaptic plasticity, brain imaging, pathologies, and for brain scaling in evolution
Partitioning and purification of polygalacturonases produced by Aspergillus niger URM 5162 using PEG-phosphate in an aqueous two-phase system
Pectinases, or pectinolytic enzymes, are naturally produced by plants, filamentous fungi, bacteria and yeasts. The pectinases are
of great importance to clarify and reduce viscosity in fruit juices, improving and increasing tbe filtration efficiency. When used
in the crushing of grapes or wine must improve juice extraction, reduce the time to clarify and enhance tbe content ofterpenes in
wine. The filamentous fungi most frequently used fur industrial purposes because as much as 90% ofthe enzyme can be excreted
into the culture medium. The partitioning and purification of polygalacturonases (PG) produced by Aspergillus niger URM
5162 were investigated in aqueous two-phase systems (ATPS), furmed by polyetbylene glycol and phosphate salts
(PE(ijlhosphate). To evaluate the effect oftbe 4 independent variables- molar mass ofpolyetbylene glycol (PEG) (400-8000
g1nol MPEG), PEG concentration (12.5-17.5%, w/w- CPEG), phosphate concentration (15-25%, ...W, CPHOS) and pH (6.0, 8.0)
- on the 3 response variables: partition coefficient (K), activity yield (Y) and purification fàctor (PF), a fuctorial design (24) was
used. The endo-polygalacturonases (endo-PG) were prefurentially partitioned in tbe top phase. For endo-PG, the highest values
for the response variables K, Y and PF of 1.23, 74.04% and 8.18, respectively, were obtained for a CPEG of 12.5% (...W), MPEG
of8000 g1nol, and CPHOS of25% (w/w) at pH 6.0. Also, exo-polygalacturonases (exo-PG) were preferentially partitioned in the
top phase. ln tbis case, the highest values ofK (2.40), Y (33.33%), and PF (1.98) were obtained with a MPEG of 8000 g1nol,
CPEG of 12.5% (...W), and CPHOS of25% (...W) at pH 6.0. ln both cases, MPEG had a positive influence on K, Y and PF. The
conditions ofMPEG 8000 g1nol, CPEG of 12.5% (...W), and CPHOS of25% (...W) at pH 6.0 were considered the most suitable
for tbe purification of PG produced by A. niger URM 5162. Furtbermore, MPEG and CPHOS were the most important
independent variables. The PEG/phosphate system is a useful cost-effective altemative for PG purification
Práticas de marketing educacional nas escolas públicas
O presente trabalho tem como objetivo identificar práticas de Marketing Educacional nas escolas públicas.
Tendo por base razões pessoais, profissionais, teóricas e legais que justificam estudos sobre as práticas de Marketing Educacional nas escolas públicas, revê-se a literatura sobre a evolução do marketing (geral) até à emergência do marketing societal e do Marketing Educacional.
Partindo dos normativos legais e da literatura, exploram-se as fontes de informação, a autonomia das escolas, a accountability, o planeamento estratégico e evidências dessas práticas associadas ao Marketing Educacional. Para o efeito, optou-se, metodologicamente, por realizar uma pesquisa quantitativa através de um inquérito por questionário realizado junto dos(as) diretores(as) dos agrupamentos de escolas e escolas não agrupadas de Portugal Continental.
No que respeita aos principais resultados obtidos, é possível concluir que, apesar de haver evidências de predominar a orientação da gestão para a “produção” do serviço educativo, há práticas de Marketing Educacional nas escolas públicas. Contudo, as escolas têm ainda uma consciência míope do que é o Marketing Educacional, pois há défice na identificação e na implementação dessas práticas. Verifica-se que as escolas fazem estudos de suporte a decisões sobre oferta formativa, de avaliação institucional e de satisfação junto dos alunos e restante comunidade educativa. Definem e implementam estratégias não só para cumprir os normativos legais, mas também adequar os serviços aos alunos, tornando-os parte ativa da coprodução do serviço educativo.
Com base nas conclusões e nas opções de concordância do(a)s diretores(as), foi delineado um plano de ação de intervenção de Marketing Educacional.This project aims to identify educational marketing practices in state schools.
Based on personal, professional, theoretical and legal reasons that justify studies on Educational Marketing practices in state schools, we'll be reviewing the literature on the evolution of marketing, and of general marketing until the emergence of Educational Marketing.
Starting from legal requirements and literature, we will explore information sources, school autonomy, accountability, strategic and practical evidence associated with Educational Marketing. For this purpose, it was decided, as far as methodology is concerned, to carry out a quantitative research through a survey with the School Directors/headmasters of the school groupings and schools in mainland Portugal.
Concerning the main results obtained, it is possible to conclude that, although there is evidence of a predominant management orientation towards the “production” of the educational service, it is undeniable that there are Educational Marketing practices in state schools. However, schools still have a short-sighted awareness of what Educational Marketing is, as there is a deficit in identifying and implementing these practices. In fact, schools carry out surveys that support decisions on training courses, institutional assessment and satisfaction among students and the rest of the educational community. They define and implement strategies not only to comply with legal regulations, but also to adapt services to students, making them an active part of the co-production of the educational service.
Based on the headmasters' conclusions and agreement options, an Educational Marketing action plan was outlined.
KEYWORDS: Educational Marketing
Effects of beta-alanine supplementation on brain homocarnosine/carnosine signal and cognitive function: an exploratory study
Objectives: Two independent studies were conducted to examine the effects of 28 d of beta-alanine supplementation at 6.4 g d-1 on brain homocarnosine/carnosine signal in omnivores and vegetarians (Study 1) and on cognitive function before and after exercise in trained cyclists (Study 2). Methods: In Study 1, seven healthy vegetarians (3 women and 4 men) and seven age- and sex-matched omnivores undertook a brain 1H-MRS exam at baseline and after beta-alanine supplementation. In study 2, nineteen trained male cyclists completed four 20-Km cycling time trials (two pre supplementation and two post supplementation), with a battery of cognitive function tests (Stroop test, Sternberg paradigm, Rapid Visual Information Processing task) being performed before and after exercise on each occasion. Results: In Study 1, there were no within-group effects of beta-alanine supplementation on brain homocarnosine/carnosine signal in either vegetarians (p = 0.99) or omnivores (p = 0.27); nor was there any effect when data from both groups were pooled (p = 0.19). Similarly, there was no group by time interaction for brain homocarnosine/carnosine signal (p = 0.27). In study 2, exercise improved cognitive function across all tests (P0.05) of beta-alanine supplementation on response times or accuracy for the Stroop test, Sternberg paradigm or RVIP task at rest or after exercise. Conclusion: 28 d of beta-alanine supplementation at 6.4g d-1 appeared not to influence brain homocarnosine/ carnosine signal in either omnivores or vegetarians; nor did it influence cognitive function before or after exercise in trained cyclists
Global and regional brain metabolic scaling and its functional consequences
Background: Information processing in the brain requires large amounts of
metabolic energy, the spatial distribution of which is highly heterogeneous
reflecting complex activity patterns in the mammalian brain.
Results: Here, it is found based on empirical data that, despite this
heterogeneity, the volume-specific cerebral glucose metabolic rate of many
different brain structures scales with brain volume with almost the same
exponent around -0.15. The exception is white matter, the metabolism of which
seems to scale with a standard specific exponent -1/4. The scaling exponents
for the total oxygen and glucose consumptions in the brain in relation to its
volume are identical and equal to , which is significantly larger
than the exponents 3/4 and 2/3 suggested for whole body basal metabolism on
body mass.
Conclusions: These findings show explicitly that in mammals (i)
volume-specific scaling exponents of the cerebral energy expenditure in
different brain parts are approximately constant (except brain stem
structures), and (ii) the total cerebral metabolic exponent against brain
volume is greater than the much-cited Kleiber's 3/4 exponent. The
neurophysiological factors that might account for the regional uniformity of
the exponents and for the excessive scaling of the total brain metabolism are
discussed, along with the relationship between brain metabolic scaling and
computation.Comment: Brain metabolism scales with its mass well above 3/4 exponen
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