The rational reconstruction of the research program on classic rationalism: Locke and the empiricist approach

This article intends to rationally reconstruct Locke`s theory of knowledge as incorporated in a research program concerning the nature and structure of the theories and models of rationality. In previous articles we argued that the rationalist program can be subdivided into the classical rationalistic subprogram, which includes the knowledge theories of Descartes, Locke, Hume and Kant, the neoclassical subprogram, which includes the approaches of Duhem, Poincare and Mach, and the critical subprogram of Popper. The subdivision results from the different views of rationality proposed by each one of these subprograms, as well as from the tools made available by each one of them, containing theoretical instruments used to arrange, organize and develop the discussion on rationality, the main one of which is the structure of solution of problems. In this essay we intend to reconstruct the assumptions of Locke`s theory of knowledge, which in our view belongs to the classical rationalistic subprogram because it shares with it the thesis of the identity of (scientific) knowledge and certain knowledge.

Phylogeography of the cactophilic species Drosophila gouveai: demographic events and divergence timing in dry vegetation enclaves in eastern Brazil

Aim The aim of this study was to assess the causal mechanisms underlying populational subdivision in Drosophila gouveai, a cactophilic species associated with xeric vegetation enclaves in eastern Brazil. A secondary aim was to investigate the genetic effects of Pleistocene climatic fluctuations on these environments. Location Dry vegetation enclaves within the limits of the Cerrado domain in eastern Brazil. Methods We determined the mitochondrial DNA haplotypes of 55 individuals (representing 12 populations) based on sequence data of a 483-bp fragment from the cytochrome c oxidase subunit II (COII) gene. Phylogenetic and coalescent analyses were used to test for the occurrence of demographic events and to infer the time of divergence amongst genetically independent groups. Results Our analyses revealed the existence of two divergent subclades (G1 and G2) plus an introgressed clade restricted to the southernmost range of D. gouveai. Subclades G1 and G2 displayed genetic footprints of range expansion and segregated geographical distributions in south-eastern and some central highland regions, east and west of the Parana River valley. Molecular dating indicated that the main demographic and diversification events occurred in the late to middle Pleistocene. Main conclusions The phylogeographical and genetic patterns observed for D. gouveai in this study are consistent with changes in the distribution of dry vegetation in eastern Brazil. All of the estimates obtained by molecular dating indicate that range expansion and isolation pre-dated the Last Glacial Maximum, occurring during the late to middle Pleistocene, and were probably triggered by climatic changes during the Pleistocene. The current patchy geographical distribution and population subdivision in D. gouveai is apparently closely linked to these past events.

Genetic population structure of the catadromous perciform: Macquaria novemaculeata (Percichthyidae)

Genetic population structure in the catadromous Australian bass Macquaria novemaculeata was investigated using samples from four locations spanning 600 km along the eastern Australian coastline. Both allozymes and mtDNA control region sequences were examined. Population subdivision estimates based on allozymes revealed low levels of population structuring (G(st)=0.043, P<0.05). However, mtDNA indicated moderate levels of geographic population structure (G(st)=0.146, P<0.01). Phylogenetic analysis of mtDNA control region sequences (mean sequence divergence 1.9%) indicated little phylogeographic structuring. Results suggested that genotypic variation within each river population, while bring affected primarily by genetic drift, was also prevented from more significant divergence by homogenizing levels of gene flow-synonymous with a one-dimensional stepping-stone model of population structure. The catadromous life history of Macquaria novemaculeata was considered to br influential on the pattern of population structure displayed. Results were compared to the few population genetic studies involving catadromous fishes, indicating that catadromy alone is unlikely to be a good predictor of population structure. A more comprehensive suite of biological characteristics than simple life-history traits must be considered fully to allow reliable predictive models of population structure to be formulated. (C) 1997 The Fisheries Society of the British Isles.

Differential immunoreactivity of glucocorticoid receptors and vasopressin in neurons of the anterior and medial parvocellular subdvisions of the hypothalamic paraventricular nucleus

arginine-vasopressin in the parvocellular neurons of the hypothalamic paraventricular nucleus is known to play an important role in the control of the hypothalamo-pituitary-adrenal axis. In the present study, we verify plasma corticosterone levels, the distribution of glucocorticoid receptor- and arginine-vasopressin-positive neurons, and the co-localization of both glucocorticoid receptors and arginine-vasopressin in neurons in the anterior and medial parvocellular subdivisions of the paraventricular nucleus after manipulations of the hypothalamus-pituitary-adrenal axis. Normal, sham surgery, and adrenalectomized male rats were subjected to intraperitoneal injections of saline or dexamethasone to measure plasma corticosterone levels by a radioimmunoassay. We also examined arginine-vasopressin and glucocorticoid receptor immunofluorescence in sections from the paraventricular nucleus. Our results showed that the immunoreactivity of arginine-vasopressin neurons increased in the anterior parvocellular subdivision and decreased in the medial parvocellular subdivision from adrenalectomized rats treated with dexamethasone. On the other hand, we showed that the immunoreactivity of glucocorticoid receptors increased in the anterior and medial parvocellular subdivisions of these same animals. However, the immunoreactivity of glucocorticoid receptors is higher in the medial parvocellular than anterior parvocellular subdivision. The co-localization of arginine-vasopressin and glucocorticoid receptors was found only in the medial parvocellular subdivision. These findings indicate that glucocorticoids have direct actions on arginine-vasopressin-positive neurons in the medial parvocellular but not anterior parvocellular subdivision. There is a differentiated pattern of arginine-vasopressin-positive neuron expression between the anterior and medial parvocellular subdivisions. (C) 2010 Elsevier Inc. All rights reserved.

Glomerular Nucleus of the Weakly Electric Fish, Gymnotus sp.: Cytoarchitecture, Histochemistry, and Fiber Connections-Insights from Neuroanatomy to Evolution and Behavior

The present study provides a detailed description of morphological and hodological aspects of the glomerular nucleus in the weakly electric fish Gymnotus sp., and explores the evolutionary and functional implications flowing from this analysis. The glomerular nucleus of Gymnotus shows numerous morphological similarities with the glomerular nucleus of percomorph fish, although cytoarchitectonically simpler. In addition, congruence of the histochemical acetylcholinesterase (AChE) distribution with cytoarchitectonic data suggests that the glomerular nucleus, together with the ventromedial cell group of the medial subdivision of the preglomerular complex (PGm-vmc) rostrally, and the subglomerular nucleus (as identified by Maler et al. [1991] J Chem Neuroanat 4:1-38) caudally, may form a distinct longitudinally organized glomerular complex. Our results show that an important source of sensory afferents to the glomerular nucleus originates in the pretectal and electrosensorius nuclei. The glomerular nucleus in turn projects to the hypothalamus (inferior lobe and anterior hypothalamus), to the anterior tuberal nucleus, and to the medial region of the preglomerular nucleus (PGm). These data suggest that visual and electrosensory information reach the glomerular nucleus and are relayed to the hypothalamus and, via PGm, to the pallium. Such connections are similar to those of the glomerular nucleus in percomorphs and the posterior pretectal nucleus in osteoglossomorph, esocids, and salmonids, where they comprise one component of a visual processing pathway. In Gymnotiform fish, however, the pretectal region that projects to the glomerular nucleus is dominated by electrosensory input (visual input is minor), which is consistent with the dominant role of electroreception in these fish. J. Comp. Neurol. 519:1658-1676, 2011. (c) 2011 Wiley-Liss, Inc.

Hypothalamic oxytocin neurons modulate hypophagic effect induced by adrenalectomy

Glucocorticoids have major effects on food intake, as demonstrated by the decrease of food intake following adrenalectomy (ADX); however, the mechanisms leading to these effects are not well understood. Oxytocin (OT) has been shown to reduce food intake. We evaluated the effects of glucocorticoids on OT neuron activation and OT mRNA expression in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei induced by feeding. We also evaluated the effect of pretreatment with OT-receptor antagonist ([d(CH2)5,Tyr(Me)2,Orn8]-vasotocin, OVT) on food intake in ADX rats. Fos/OT neurons in the posterior parvocellular subdivision of the PVN were increased after refeeding, with a higher number in the ADX group, compared with sham and ADX+corticosterone (B) groups, with no difference in the medial parvocellular and magnocellular subdivisions of the PVN. ADX increased OT mRNA expression in the PVN both in fasting and refeeding condition, compared with sham and ADX+B groups. In the SON, refeeding increased the number of Fos/OT neurons, with a higher number in the ADX+B group. In fasted condition, OT mRNA expression in the SON was increased in ADX and ADX+B, compared with sham group. Pretreatment with OVT reversed the ADX-induced hypophagia, with no difference between sham and ADX+B animals. The present results show that glucocorticoid withdrawal induces a higher activation of PVN OT neurons in response to feeding, and an increase of OT mRNA expression in the PVN and OT-receptor antagonist reverses the anorexigenic effect induced by ADX These data indicate that PVN OT neurons might mediate the hypophagic effect induced by adrenalectomy. (C) 2009 Elsevier Inc. All rights reserved.

The dorsomedial visual areas in New World and Old World monkeys: homology and function

The extrastriate cortex near the dorsal midline has been described as part of an 'express' pathway that provides visual input to the premotor cortex. This pathway is considered important for the integration of sensory information about the visual field periphery and the skeletomotor system, especially in relation to the control of arm movements. However, a better understanding of the functional contributions of different parts of this complex has been hampered by the lack of data on the extent and boundaries of its constituent visual areas. Recent studies in macaques have provided the first detailed view of the topographical organization of this region in Old World monkeys. Despite differences in nomenclature, a comparison of the visuotopic organization, myeloarchitecture and connections of the relevant visual areas with those previously studied in New World monkeys reveals a remarkable degree of similarity and helps to clarify the subdivision of function between different areas of the dorsomedial complex. A caudal visual area, named DM or V6, appears to be important for the detection of coherent patterns of movement across wide regions of the visual field, such as those induced during self-motion. A rostral area, named M or V6A, is more directly involved with visuomotor integration. This area receives projections both from DM/V6 and from a separate motion analysis channel, centred on the middle temporal visual area (or V5), which detects the movement of objects in extrapersonal space. These results support the suggestion, made earlier on the basis of more fragmentary evidence, that the areas rostral to the second visual area in dorsal cortex are homologous in all simian primates. Moreover, they emphasize the importance of determining the anatomical organization of the cortex as a prerequisite for elucidating the function of different cortical areas.

Comparative phylogeography of three rainforest-restricted lizards from mid-east Queensland

Several small isolates of rainforest situated on the central eastern coast of Australia are home to a rich herpetofauna, including four endemic species of leaftail geckos (Phyllurus spp.) and two skinks (Eulamprus spp.). To examine the extent and geographic pattern of historical subdivision among isolates, we assayed mtDNA variation in two species endemic to rainforests of this region (Phyllurus ossa and Eulamprus amplus) and, for comparison, a more widespread and less specialised lizard, Carlia rhomboidalis. There is a clear genetic signature of historical changes in population size and distribution in P. ossa that is consistent with Pleistocene (or earlier) rainforest contraction and subsequent expansion. Although more pronounced in the gecko, phylogeographic structure was congruent between E. amplus and P. ossa. In contrast to the saxicolous, rainforest-restricted P. ossa and E. amplus, the rainforest-generalist species, C. rhomboidalis, does not display strong geographic population structure. The differences in genetic population structure exhibited by the three species are consistent with species-specific differences in ecology.

Reconciling paleodistribution models and comparative phylogeography in the Wet Tropics rainforest land snail Gnarosophia bellendenkerensis (Brazier 1875)

Comparative phylogeography has proved useful for investigating biological responses to past climate change and is strongest when combined with extrinsic hypotheses derived from the fossil record or geology. However, the rarity of species with sufficient, spatially explicit fossil evidence restricts the application of this method. Here, we develop an alternative approach in which spatial models of predicted species distributions under serial paleoclimates are compared with a molecular phylogeography, in this case for a snail endemic to the rainforests of North Queensland, Australia. We also compare the phylogeography of the snail to those from several endemic vertebrates and use consilience across all of these approaches to enhance biogeographical inference for this rainforest fauna. The snail mtDNA phylogeography is consistent with predictions from paleoclimate modeling in relation to the location and size of climatic refugia through the late Pleistocene-Holocene and broad patterns of extinction and recolonization. There is general agreement between quantitative estimates of population expansion from sequence data (using likelihood and coalescent methods) vs. distributional modeling. The snail phylogeography represents a composite of both common and idiosyncratic patterns seen among vertebrates, reflecting the geographically finer scale of persistence and subdivision in the snail. In general, this multifaceted approach, combining spatially explicit paleoclimatological models and comparative phylogeography, provides a powerful approach to locating historical refugia and understanding species' responses to them.

Oceanic interchange and nonequilibrium population structure in the estuarine dependent Indo-Pacific tasselfish, Polynemus sheridani

We assayed mtDNA haplotype [300 base pairs (bp) control region] geography and genealogy in the Indo-Pacific tasselfish, Polynemus sheridani from its contiguous estuarine distribution across northern Australia (n = 169). Eight estuaries were sampled from three oceanographic regions (Timor Sea, Gulf of Carpentaria and the Coral Sea) to assess the impact of Pleistocene sea level changes on the historical connectivity among P. sheridani populations. Specifically, we investigated the genetic consequences of disruption to Indian-Pacific Ocean connectivity brought about by the closure of the Torres Strait. Overall there was significant population subdivision among estuaries (F-ST = 0.161, (Phi(ST) = 0.187). Despite a linear distribution, P. sheridani did not show isolation by distance over the entire sampled range because of genetic similarity of estuaries greater than 3000 km apart. However, significant isolation by distance was detected between estuaries separated by less than 3000 km of coastline. Unlike many genetic studies of Indo-Pacific marine species, there was no evidence for an historical division between eastern and western populations. Instead, phylogeographical patterns were dominated by a starlike intraspecific phylogeny coupled with evidence for population expansion in both the Gulf of Carpentaria and the Coral Sea but not the Timor Sea. This was interpreted as evidence for recent west to east recolonization across of northern Australia following the last postglacial marine advance. We argue that although sufficient time has elapsed postcolonization for populations to approach gene flow-drift equilibrium over smaller spatial scales (< 3000 km), the signal of historical colonization persists to obscure the expected equilibrium pattern of isolation by distance over large spatial scales (> 3000 km).

Grid structure impact in sparse point representation of derivatives

In the Sparse Point Representation (SPR) method the principle is to retain the function data indicated by significant interpolatory wavelet coefficients, which are defined as interpolation errors by means of an interpolating subdivision scheme. Typically, a SPR grid is coarse in smooth regions, and refined close to irregularities. Furthermore, the computation of partial derivatives of a function from the information of its SPR content is performed in two steps. The first one is a refinement procedure to extend the SPR by the inclusion of new interpolated point values in a security zone. Then, for points in the refined grid, such derivatives are approximated by uniform finite differences, using a step size proportional to each point local scale. If required neighboring stencils are not present in the grid, the corresponding missing point values are approximated from coarser scales using the interpolating subdivision scheme. Using the cubic interpolation subdivision scheme, we demonstrate that such adaptive finite differences can be formulated in terms of a collocation scheme based on the wavelet expansion associated to the SPR. For this purpose, we prove some results concerning the local behavior of such wavelet reconstruction operators, which stand for SPR grids having appropriate structures. This statement implies that the adaptive finite difference scheme and the one using the step size of the finest level produce the same result at SPR grid points. Consequently, in addition to the refinement strategy, our analysis indicates that some care must be taken concerning the grid structure, in order to keep the truncation error under a certain accuracy limit. Illustrating results are presented for 2D Maxwell's equation numerical solutions.

Sei whale (Balaenoptera borealis) ecology and management in the North Atlantic

Tese de Doutoramento em Ciências do Mar, especialidade em Ecologia Marinha.

Prospecção de recursos hidrominerais e geotérmicos na Orla Ocidental Portuguesa: os casos das Termas dos Cucos e de Monte Real

A cobertura sedimentar da região Oeste portuguesa é constituída por uma série possante de sedimentos com uma variedade de fácies com idades compreendidas entre o Triásico Superior e o actual. Estes sedimentos foram depositados numa bacia alongada com direcção NNE‐SSW. A tectónica desta cobertura sedimentar é condicionada pelas falhas tardi‐Variscas que afectaram o substrato e pelo complexo evaporítico depositado na base das séries sedimentares. Séries evaporíticas espessas de idade Hetangiana formaram numerosas estruturas diapíricas. Na região Oeste de Portugal existem diversas nascentes minerais e termais usadas para hidroterapia. Esta tese tem por objectivo estudar as concessões hidrominerais das Termas dos Cucos e das Termas de Monte Real (Portugal Central), bem como as suas áreas envolventes. Estas actividades hidroterapêuticas são muito relevantes em termos sócio‐económicos para os concelhos de Torres Vedras e Leiria. Os estudos contemplados nesta tese (que incluíram trabalho de campo no domínio da geotectónica, geomorfologia e hidrogeologia) permitiram delinear modelos hidrogeológicos conceptuais, apoiados, ainda, pela re‐interpretação de estudos geofísicos e hidrogeológicos prévios. A caracterização destas áreas foi suportada por inventários hidrogeológicos, tendo sido determinante para o projecto dos furos de captação, incluindo localização e profundidade. Todos os dados compilados foram representados cartograficamente numa base de Sistemas de Informação Geográfica (SIG).

Geotecnia urbana da zona ribeirinha de Vila Nova de Gaia: criação de uma base de dados SIG geotécnica

O presente trabalho apresenta os resultados dos estudos geotécnicos e de uma base de dados da zona ribeirinha de Vila Nova de Gaia, com o objectivo de compreender melhor os aspectos geotécnicos em ambiente urbano numa área sensível com um registo histórico de instabilidade de taludes rochosos. Além disso, os escassos estudos científicos recentes de natureza geológica e geotécnica em Vila Nova de Gaia justificam o estudo exploratório da geotecnia urbana da zona ribeirinha de Vila Nova de Gaia. A importância de Vila Nova de Gaia como a terceira maior cidade portuguesa e como centro de intensa actividade económica e cultural despoleta uma constante necessidade de expansão. O aumento da densidade populacional acarreta a realização de projectos complexos de engenharia, utilizando o subsolo para a construção e, com frequência, em terrenos com características geotécnicas desfavoráveis. As cidades de Vila Nova de Gaia e do Porto foram sendo edificadas ao longo de encostas numa plataforma litoral caracterizada por uma vasta área aplanada, inclinando ligeiramente para Oeste. Esta plataforma foi cortada pelo Rio Douro num vale encaixado de vertentes abruptas, nas quais se localizam as zonas ribeirinhas das duas cidades. Este trabalho envolveu, inicialmente, uma caracterização topográfica, morfoestrutural, geotectónica e geomecânica da área de estudo e, numa fase posterior, o desenvolvimento duma base de dados geotécnica. Todos os dados geológicos e geotécnicos locais e os estudos geotécnicos levados a cabo in situ pelas diversas empresas e instituições foram representados cartograficamente numa base apoiada pelos Sistemas de Informação Geográfica (SIG). Esta metodologia inter‐disciplinar foi de grande valor para um melhor conhecimento dos riscos geológico‐geotécnicos ao longo das margens do Rio Douro. De facto, a cartografia geotécnica da zona ribeirinha de Vila Nova de Gaia deve constituir uma ferramenta importante para uma previsão mais rigorosa de futuras instabilidades de taludes e um bom instrumento para a gestão do espaço urbano.

Avaliação geológica e geotécnica do maciço da Pedreira de S. Domingos n.º 2 (Armamar)

Neste trabalho, apresentam-se e discutem-se os resultados da aplicação da técnica de amostragem linear de descontinuidades em faces expostas do maciço rochoso da pedreira granítica de S. Domingos Nº 2 (Fontelo, Armamar; N de Portugal). É, igualmente, utilizada informação sobre a rede de fracturação regional, obtida através da análise morfoestrutural de mapas topográficos e mapas geológicos. São ainda referidos os métodos utilizados no tratamento dos dados de terreno com o objectivo de definir as famílias de descontinuidades e de caracterizar estatísticamente a sua atitude, espaçamento e extensão. Os resultados obtidos são comparados, à mega escala e macro-escala, no sentido de averiguar a presença de um padrão de fracturação com dimensão multiescala. Esta abordagem foi refinada através da aplicação de Sistemas de Informação Geográfica. A aplicação desta técnica para a caracterização da compartimentação do maciço poderá contribuir para aperfeiçoar a gestão sustentável do georrecurso da pedreira de S. Domingos Nº 2 (Fontelo). O controlo geomecânico do desmonte do maciço rochoso é salientado com o intuito de uma abordagem de geo-engenharia integrada dos maciços rochosos.