58,660 research outputs found
A composição das aluviões do rio Neiva : indicadores do passado
A composição textural das aluviões do rio Neiva mostram que as áreas de fornecimento
sedimentar são fora e dentro do canal. O sector a montante de Panque recebe grande quantidade de
sdimentos provenientes das vertentes, por erosão das rochas com indícios de meteorização em
condições distintas das que originaram as barras de cascalho, quartzítico, ainda conservadas no
leito do canal no sector para jusante. Estas são indicadoras de condições de meteorização mais
quentes e húmidas, semelhantes às que originaram os sedimentos da Formação de Alvarães. No
entanto, a energia da corrente do Neiva tem sido de maior competência que a do sistema fluvial que
originou a Formação de Alvarães.Abstract: The texture attributes of Neiva sediments were studied and compared to the Alvarães
Formation. There were identified two sedimentary sources for Neiva sediments. The Neiva River is
eroding older deposits channel. The actual alluvium is enriched with the quartzite clasts from those
deposits that are mixed with the recent materials eroded from the basin rocks. The recent sediments
are mainly of granite gravels and sands. They are results of different weathering processes. The
quartzite gravels and the Alvarães Formation are indicators of chemical weathering processes at the
source area. The recent material is supplied from the weathering conditions strongly influenced by
the temperate climate. The Alvarães Formation was generated by less competence fluvial streams
then Neiva River
The Wartenberg-Smith Film as Philosophy Debate: Review of Current Controversies in Philosophy of Film
Morfologia e dinâmica fluvial do rio neiva (NW de Portugal)
As sociedades humanas têm ocupado as áreas ribeirinhas, verificando-se um aumento crescente ao longo da história. Por isso, o conhecimento da dinâmica fluvial às diversas escalas a que os processos operam é fundamental para o uso sustentável nestas áreas territoriais. Em termos de configuração morfológica a bacia hidrográfica do rio Neiva é alongada. O Neiva e os seus afluentes formam um padrão de drenagem do tipo retangular com alguns troços do tipo paralelo, influenciada, em termos gerais, pela litologia local e pela direção das fraturas. Ao longo do perfil longitudinal o rio Neiva apresenta diversos tipos de canal, verificando-se a repetição de alguns tipos a partir de Panque, o que coincide com uma rotura de declive importante no perfil longitudinal. O mais frequente é o canal ter leito de cascalho (seixos pequenos e grandes). Na área de cabeceira os controlos dominantes na ação da corrente são o declive do canal e a litologia onde este é modelado. Aí, os blocos no canal possuem sempre alguma matriz com dimensão de seixo e areão. Verifica-se que a percentagem da fração de dimensão areia tende a aumentar para jusante. No estudo da tipologia dos canais usaram-se duas classificações diferentes. Aplicando a proposta por Montgomery & Buffington (1997), no rio Neiva identificam-se canais do tipo A, B, C, D e E. O canal do tipo A (cascade) encontra-se na área próxima da nascente, onde o fluxo é canalizado e corre num canal único mas íngreme e também na zona das Azenhas do Neiva, em regime de fluxo baixo. Em Porrinhoso o canal é do tipo A/B (cascade e step-pool), em Godinhaços e Panque é do tipo B (step-pool). O canal do tipo C (plane-bed) encontra-se em Duas Igrejas e do tipo D (pool-riffle) nos troços de Arcozelo, de Vilar das Almas e de Tregosa. Em Cossourado a classificação atribuída foi do tipo C/D e na zona de Balugães do tipo D/C. Na zona da foz foi classificado como D/E, visto que o leito é arenoso com megaripples e ripples, típicos dos canais do tipo E (dune-ripple), mas, o declive apresentado é frequente nos canais do tipo D assim como as formas não atingem a dimensão de dunas fluviais. A classificação de Rosgen (1994, 1996) não é aplicável ao rio Neiva. Há alguma concordância entre o tipo de canal identificado, segundo os critérios de Rosgen, para a zona da nascente (tipo A) e para as localidades de Porrinhoso e Godinhaços (A/Aa+), com as observações de campo e com os resultados obtidos segundo a classificação de Montgomery & Buffington. Nos outros setores, os valores de entrincheiramento não são consistentes com os restantes critérios. Ainda foi possível obter combinações entre a sinuosidade, largura/profundidade e declive, exceto para os troços observados em Duas Igrejas, Tregosa e Castelo de Neiva. A diversidade morfológica observada no rio Neiva tem valor importante para suporte da biodiversidade, já que, a estrutura dos habitats está intimamente dependente da morfologia e caraterísticas do local, no que diz respeito, por exemplo, à natureza do substrato – rochoso e aluvião. O tipo de estudo apresentado permite compreender a dinâmica do canal à escala espaço-tempo e interpretar os indicadores de estabilidade/instabilidade do canal, de evolução, num curto espaço de tempo. Trata-se de uma abordagem integrada do sistema fluvial, a qual é um suporte para o ordenamento territorial das áreas ribeirinhas, especialmente quando aplicado à gestão ambiental destas.Abstract: Morphology and fluvial dynamic of the Neiva River (Nw of Portugal)
Human societies have occupied riverine areas, and the tendency is increasing throughout history. Therefore, the knowledge of fluvial dynamics and of the process, which operate at different scales, is fundamental to the correct planning of the sustainable use of those land areas. The Neiva River basin is elongated. The Neiva and its tributaries form a drainage pattern of the rectangular type with some sections of the parallel type, influenced, in general terms, by the local lithology and the direction of fractures.
Along the longitudinal profile, the Neiva River presents various types of channels, occurring the repetition of certain types after Panque, coinciding with an abrupt change in the longitudinal profile slope. The most common is the channel bed of gravel (small and large pebbles). In the catchment area the controls of the stream are the channel slope and the lithology where it is modeled. There are always some blocks in the channel, with matrix of pebbles and gravels. It is increasing the percentage of the sand sediments in the channel bed towards downstream. In the study of the typology of the channels were used two different classifications. Applying the criteria of Montgomery & Buffington (1997), in the Neiva River were identified the channels types A, B, C, D and E. The type A (cascade) has in the area near the source, where the channel bed towards downstream. In the study of the typology of the channels were used two different classifications. Applying the criteria of Montgomery & Buffington (1997), in the Neiva River were identified the channels types A, B, C, D and E. The type A (cascade) has in the area near the source, where the stream flows in a single steep channel, and also in the area of the Azenhas do Neiva, under low regime. The others are in: Porrinhoso, the channel is of type A/B (cascade and step-pool); Godinhaços and Panque, of type B (step-pool); Duas Igrejas, the C-type channel (plane-bed); type D (pool-riffle) in the areas of Arcozelo, Vilar das Almas and Tregosa; Cossourado, type C/D, and Balugães area, of type D/C; in the mouth area, channel was evaluated as D/E, because the sand bed have megaripples and ripples typical of channel type E (dune-ripple), but the slope type is frequent in D-channels, and landforms do not reach the dimension of river dunes. It was found some correlation between the type of channel identified, according to the classification criteria of Rosgen (1994, 1996), for the source area (type A), and for Porrinhoso and Godinhaços (A / Aa+). There was observed reliability with the field observations and results obtained by the classification of Montgomery & Buffington. In other sectors, the values of entrenchment are not consistent with the other criteria. It was possible to get combinations of the sinuosity, width / depth and slope, except for the sections observed in Duas Igrejas, Tregosa, and Castelo de Neiva. The morphological diversity observed in the Neiva River has important value to support biodiversity, since the structure of habitats is closely dependent on the morphology and characteristics of the place, as regards, for example, the nature of the substrate – rock and alluvium. The type of study presented allows to understand the dynamics of the channel, and interpret the stability / instability of the channel, throughout the space-time. This is an overview of the river system, which is a support for the riparian areas, especially to be applied to the environmental management of these
CULTURAL CONSUMPTION AS PART OF THE COLOMBIAN INCOME 1999-2004
Plenty of people’s consumption is referred to necessary products used every day, and the cultural products are classified as sumptuary groceries used aside the people’s basic necessities. But those cultural consumptions are the ones that cause great difference among people. Those frequent books consumers are more demanded in the labor market and those classic music listeners are clearly different from those who listen tropical music. Towards this phenomenon, understand the Colombian cultural consumption would let us know more about the population and see how prepared it is to face cultural and social changes, because those who consume more cultural products are more prone to cultural transformations.Cultural Consumption, books, video.
Hypothetical, real, and predicted real willingness to pay in open-ended surveys: experimental results
This study reports the results of experiments designed to elicit, within a controlled laboratory environment, hypothetical and real willingness to pay for an environmental educational program using the open-ended question format. By maintaining both the good and the question format constant across the treatments, our experiments overcome the shortcomings of recently reported experimental results, providing a clean test for hypothetical bias in open-ended valuations. Having found a statistically significant difference between the hypothetical and real values, we turn into the question of whether hypothetical valuations may nonetheless provide useful statistical information concerning individuals’ real valuations. This question, which is perhaps the key question in the current state of the debate surrounding the contingent valuation method, is answered affirmatively in this study.experimental methods, contingent valuation methods, calibration methods
The HABP2 G534E polymorphism does not increase nonmedullary thyroid cancer risk in Hispanics.
Familial nonmedullary thyroid cancer (NMTC) has not been clearly linked to causal germline variants, despite the large role that genetic factors play in risk. Recently, HABP2 G534E (rs7080536A) has been implicated as a causal variant in NMTC. We have previously shown that the HABP2 G534E variant is not associated with TC risk in patients from the British Isles. Hispanics are the largest and the youngest minority in the United States and NMTC is now the second most common malignancy in women from this population. In order to determine if the HABP2 G534E variant played a role in NMTC risk among Hispanic populations, we analyzed 281 cases and 1105 population-matched controls from a multicenter study in Colombia, evaluating the association through logistic regression. We found that the HABP2 G534E variant was not significantly associated with NMTC risk (P=0.843) in this Hispanic group. We also stratified available clinical data by multiple available clinicopathological variables and further analyzed the effect of HABP2 on NMTC presentation. However, we failed to detect associations between HABP2 G534E and NMTC risk, regardless of disease presentation (P≥0.273 for all cases). Therefore, without any significant associations between the HABP2 G534E variant and NMTC risk, we conclude that the variant is not causal of NMTC in this Hispanic population
Marine forests of the Mediterranean-Atlantic Cystoseira tamariscifolia complex show a southern Iberian genetic hotspot and no reproductive isolation in parapatry
Climate-driven range-shifts create evolutionary opportunities for allopatric divergence and subsequent contact, leading to genetic structuration and hybrid zones. We investigate how these processes influenced the evolution of a complex of three closely related Cystoseira spp., which are a key component of the Mediterranean-Atlantic seaweed forests that are undergoing population declines. The C. tamariscifolia complex, composed of C. tamariscifolia s.s., C. amentacea and C. mediterranea, have indistinct boundaries and natural hybridization is suspected. Our aims are to (1) infer the genetic structure and diversity of these species throughout their distribution ranges using microsatellite markers to identify ancient versus recent geographical populations, contact zones and reproductive barriers, and (2) hindcast past distributions using niche models to investigate the influence of past range shifts on genetic divergence at multiple spatial scales. Results supported a single, morphologically plastic species the genetic structure of which was incongruent with a priori species assignments. The low diversity and low singularity in northern European populations suggest recent colonization after the LGM. The southern Iberian genetic hotspot most likely results from the role of this area as a climatic refugium or a secondary contact zone between differentiated populations or both. We hypothesize that life-history traits (selfing, low dispersal) and prior colonization effects, rather than reproductive barriers, might explain the observed genetic discontinuities.Pew Charitable Trusts (USA); MARINERA, Spain [CTM2008-04183-E/MAR]; FCT (Portugal) [FCT-BIODIVERSA/004/2015, CCMAR/Multi/04326/2013, SFRH/BPD/107878/2015, SFRH/BPD/85040/2012]; FPU fellowship of the Spanish Ministry of Education; European Community ASSEMBLE visiting grant [00399/2012]; University of Cadi
MAPA de aptidão agrícola das terras da área do Polo Acre I. Área de Rio Branco - Estado do Acre.
Equipe técnica: Tarcísio Ewerton Rodrigues, João Marcos Lima da Silva, Moacir Azevedo Valente, Sandra Maria Neiva Sampaio Antonio Guilherme Soares Campos
Biomimetic implant surface functionalization with liquid L-PRF products: in vitro study
Abstract
Objective:
Platelet-rich fibrin (PRF) clots and membranes are autologous blood concentrates widely used in oral surgical procedures; less is known, however, about the liquid formulations of such products. The aim of this in vitro study is to assess the behavior of different implant surfaces when in contact with two liquid leucocyte- and platelet-rich fibrin (L-PRF) products.
Methods:
Six commercial pure titanium discs, of 9.5 mm diameter and 1.5 mm thickness, were used. Three of these samples had a micro/nano-rough surface; three were machined. Three different protocols were tested. Protocols involved the immersion of the samples in (1) a platelets, lymphocytes, and fibrinogen liquid concentrate (PLyF) for 10 minutes, (2) an exudate obtained from L-PRF clots rich in fibronectin and vitronectin for 5 minutes, and (3) the fibronectin/vitronectin exudate for 2 minutes followed by immersion in the PLyF concentrate for further 8 minutes. After these treatments, the samples were fixed and observed using a scanning electron microscope (SEM).
Results:
Under microscopic observation, (1) the samples treated with the PLyF concentrate revealed a dense fibrin network in direct contact with the implant surface and a significant number of formed elements of blood; (2) in the samples treated with the fibronectin/vitronectin exudates, only a small number of white and red blood cells were detectable; and (3) in samples exposed to the combined treatment, there was an apparent increase in the thickness of the fibrin layer. When compared to the machined surface, the micro/nano-rough samples showed an overall increased retention of fibrin, leading to a thicker coating.
Conclusions:
Liquid L-PRF products promote the formation of a dense fibrin clot on micro/nano-rough implant surfaces in vitro. The adjunctive treatment of surfaces with the fibronectin/vitronectin exudate could provide support to contact of the fibrin with the surface, though it is not essential for the clot formation. Further studies are necessary to better elucidate the properties and benefits of liquid L-PRF products
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