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

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

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 $0.86\pm 0.03$, 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

Neuropathological Similarities and Differences between Schizophrenia and Bipolar Disorder: A Flow Cytometric Postmortem Brain Study

Recent studies suggest that schizophrenia (SCH) and bipolar disorder (BPD) may share a similar etiopathology. However, their precise neuropathological natures have rarely been characterized in a comprehensive and quantitative fashion. We have recently developed a rapid, quantitative cell-counting method for frozen unfixed postmortem brains using a flow cytometer. In the present study, we not only counted stained nuclei, but also measured their sizes in the gray matter of frontopolar cortices (FPCs) and inferior temporal cortices (ITCs) from patients with SCH or BPD, as well as in that from normal controls. In terms of NeuN(+) neuronal nuclei size, particularly in the reduced densities of small NeuN(+) nuclei, we found abnormal distributions present in the ITC gray matter of both patient groups. These same abnormalities were also found in the FPCs of SCH patients, whereas in the FPCs of BPD patients, a reduction in oligodendrocyte lineage (olig2(+)) cells was much more common. Surprisingly, in the SCH FPC, normal left-greater-than-right asymmetry in neural nuclei densities was almost completely reversed. In the BPD FPC, this asymmetry, though not obvious, differed significantly from that in the SCH FPC. These findings indicate that while similar neuropathological abnormalities are shared by patients with SCH or BPD, differences also exist, mainly in the FPC, which may at least partially explain the differences observed in many aspects in these disorders

Preferência da traça-da-castanha por genótipos de cajueiro-anão e metodologia de avaliação da infestação em campo.

bitstream/item/161378/1/BPD17013.pd

Comparative Analysis of the Subventricular Zone in Rat, Ferret and Macaque: Evidence for an Outer Subventricular Zone in Rodents

The mammalian cerebral cortex arises from precursor cells that reside in a proliferative region surrounding the lateral ventricles of the developing brain. Recent work has shown that precursor cells in the subventricular zone (SVZ) provide a major contribution to prenatal cortical neurogenesis, and that the SVZ is significantly thicker in gyrencephalic mammals such as primates than it is in lissencephalic mammals including rodents. Identifying characteristics that are shared by or that distinguish cortical precursor cells across mammalian species will shed light on factors that regulate cortical neurogenesis and may point toward mechanisms that underlie the evolutionary expansion of the neocortex in gyrencephalic mammals. We immunostained sections of the developing cerebral cortex from lissencephalic rats, and from gyrencephalic ferrets and macaques to compare the distribution of precursor cell types in each species. We also performed time-lapse imaging of precursor cells in the developing rat neocortex. We show that the distribution of Pax6+ and Tbr2+ precursor cells is similar in lissencephalic rat and gyrencephalic ferret, and different in the gyrencephalic cortex of macaque. We show that mitotic Pax6+ translocating radial glial cells (tRG) are present in the cerebral cortex of each species during and after neurogenesis, demonstrating that the function of Pax6+ tRG cells is not restricted to neurogenesis. Furthermore, we show that Olig2 expression distinguishes two distinct subtypes of Pax6+ tRG cells. Finally we present a novel method for discriminating the inner and outer SVZ across mammalian species and show that the key cytoarchitectural features and cell types that define the outer SVZ in developing primates are present in the developing rat neocortex. Our data demonstrate that the developing rat cerebral cortex possesses an outer subventricular zone during late stages of cortical neurogenesis and that the developing rodent cortex shares important features with that of primates

Spatiotemporal expression patterns of Pax6 in the brain of embryonic, newborn, and adult mice

The transcription factor Pax6 has been reported to specify neural progenitor cell fates during development and maintain neuronal commitments in the adult. The spatiotemporal patterns of Pax6 expression were examined in sagittal and horizontal sections of the embryonic, postnatal, and adult brains using immunohistochemistry and double immunolabeling. The proportion of Pax6-immunopositive cells in various parts of the adult brain was estimated using the isotropic fractionator methodology. It was shown that at embryonic day 11 (E11) Pax6 was robustly expressed in the proliferative neuroepithelia of the ventricular zone in the forebrain and hindbrain, and in the floor and the mesencephalic reticular formation (mRt) in the midbrain. At E12, its expression emerged in the nucleus of the lateral lemniscus in the rhombencephalon and disappeared from the floor of the midbrain. As neurodevelopment proceeds, the expression pattern of Pax6 changes from the mitotic germinal zone in the ventricular zone to become extensively distributed in cell groups in the forebrain and hindbrain, and the expression persisted in the mRt. The majority of Pax6-positive cell groups were maintained until adult life, but the intensity of Pax6 expression became much weaker. Pax6 expression was maintained in the mitotic subventricular zone in the adult brain, but not in the germinal region dentate gyrus in the adult hippocampus.There was no obvious colocalization of Pax6 and NeuN during embryonic development, suggesting Pax6 is found primarily in developing progenitor cells. In the adult brain, however, Pax6 maintains neuronal features of some subtypes of neurons, as indicated by 97.1% of Pax6-positive cells co-expressing NeuN in the cerebellum, 40.7% in the olfactory bulb, 38.3% in the cerebrum, and 73.9% in the remaining brain except the hippocampus. Differentiated tyrosine hydroxylase (TH) neurons were observed in the floor of the E11 midbrain where Pax6 was also expressed, but no obvious colocaliztion of TH and Pax6 was detected. No Pax6 expression was observed in TH-expressing areas in the midbrain at E12, E14, and postnatal day 1. These results support the notion that Pax6 plays pivotal roles in specifying neural progenitor cell commitments and maintaining certain mature neuronal fates

Feeding mice with diets containing mercury-contaminated fish flesh from French Guiana: a model for the mercurial intoxication of the Wayana Amerindians

International audienc