446 resultados para exceptionally


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Unusually long (>14 cm) crystalline needles grow from 4-(3-bromopropyloxy)salicylaldehyde 1 presumably as a consequence of Br ... Br interactions; the powdered form of 1 shows one order of magnitude greater SHG activity realtive to urea.

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The problem associated with metal nanoparticle (NP) agglomeration when trying to achieve a high loading amount has been solved by a new method of functionalization of MOFs' pores with terminal alkyne moieties. The alkynophilicity of the Au3+ ions has been utilized successfully for an exceptionally high loading (similar to 50 wt%) of Au-NPs on supported functionalized MOFs.

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Cryptotephras (tephra not visible to the naked eye) form the foundation of the tephrostratigraphic frameworks used in Europe to date and correlate widely distributed geologic, paleoenvironmental and archaeological records. Pyne-O'Donnell et al. (2012) established the potential for developing a similar crypto-tephrostratigraphy across eastern North America by identifying multiple tephra, including the White River Ash (east; WRAe), St. Helens We and East Lake, in a peat core located in Newfoundland. Following on from this work, several ongoing projects have examined additional peat cores from Michigan, New York State, Maine, Nova Scotia and Newfoundland to build a tephrostratigraphic framework for this region. Using the precedent set by recent research by Jensen et al.(in press) that correlated the Alaskan WRAe to the European cryptotephra AD860B, unknown tephras identified in this work were not necessarily assumed to be from "expected" source areas (e.g. the Cascades). Here we present several examples of the preservation of tephra layers with an intercontinental distribution (i.e. WRAe and Ksudach 1), from relatively small magnitude events (i.e. St. Helens layer T, Mono Crater), and the first example of a Mexican ash in the NE (Volcan Ceboruco, Jala pumice). There are several implications of the identification of these units. These far-travelled ashes: (1) highlight the need to consider "ultra" distal source volcanoes for unknown cryptotephra deposits,. (2) present an opportunity for physical volcanologists to examine why some eruptions have an exceptional distribution of ash that is not necessarily controlled by the magnitude of the event. (3) complicate the idea of using tephrostratigraphic frameworks to understand the frequency of eruptions towards aiding hazard planning and prediction (e.g. Swindles et al., 2011). (4) show that there is a real potential to link tropical and mid to high-latitude paleoenvironmental records. Jensen et al. (in press) Transatlantic correlation of the Alaskan White River Ash. Geology. Pyne-O'Donnell et al. (2012). High-precision ultra-distal Holocene tephrochronology in North America. Quaternary Science Reviews, 52, 6-11. Swindles et al. (2011). A 7000 yr perspective on volcanic ash clouds affecting northern Europe. Geology, 39, 887-890.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Vegetal remains are considered labile structures that quickly become decayed in ecosystems. However, certain lignified tissues (woody plants) can largely resist decomposition, becoming sometimes exceptionally well preserved. At the Upper Cretaceous site of ?Lo Hueco? (Cuenca, Spain), those woody remains (trunks and branches) with resinous material in the inner tracheids and parenchyma cells that were buried rapidly under anoxic conditions experienced a low degree of maturation, becoming exceptionally well preserved. Those woody remains deposited under oxic conditions (subaerial or sub-aquatic exposure) were more intensely biodegraded and subsequently carbonified, partially or completely mineralized in gypsum and covered by a ferruginous crust. These two modes of preservation are scarce, with silicification or carbonification processes much more common, and both can be considered as ?exceptional preservation?. Other vegetal remains, such as carbonified leaves, stems and roots, were collected in the site. The different modes of preservation depend directly on: depositional micro-environment (sandy distributary channel, muddy flood plain); and type (trunk, branch, stem, leave, root) and state (presence or absence of resinous material) of the material. The great abundance and diversity of fossils in ?Lo Hueco? identify it as Konzentrat-Lagersta¿tten, sequentially formed by alternated events of flooding and drying depositional events, but the exceptional quality and rarity of determinate vegetal macroremains preservation suggest that certain deposits of this site can be considered as conservation deposits.

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Induction of phase 2 detoxication enzymes [e.g., glutathione transferases, epoxide hydrolase, NAD(P)H: quinone reductase, and glucuronosyltransferases] is a powerful strategy for achieving protection against carcinogenesis, mutagenesis, and other forms of toxicity of electrophiles and reactive forms of oxygen. Since consumption of large quantities of fruit and vegetables is associated with a striking reduction in the risk of developing a variety of malignancies, it is of interest that a number of edible plants contain substantial quantities of compounds that regulate mammalian enzymes of xenobiotic metabolism. Thus, edible plants belonging to the family Cruciferae and genus Brassica (e.g., broccoli and cauliflower) contain substantial quantities of isothiocyanates (mostly in the form of their glucosinolate precursors) some of which (e.g., sulforaphane or 4-methylsulfinylbutyl isothiocyanate) are very potent inducers of phase 2 enzymes. Unexpectedly, 3-day-old sprouts of cultivars of certain crucifers including broccoli and cauliflower contain 10–100 times higher levels of glucoraphanin (the glucosinolate of sulforaphane) than do the corresponding mature plants. Glucosinolates and isothiocyanates can be efficiently extracted from plants, without hydrolysis of glucosinolates by myrosinase, by homogenization in a mixture of equal volumes of dimethyl sulfoxide, dimethylformamide, and acetonitrile at −50°C. Extracts of 3-day-old broccoli sprouts (containing either glucoraphanin or sulforaphane as the principal enzyme inducer) were highly effective in reducing the incidence, multiplicity, and rate of development of mammary tumors in dimethylbenz(a)anthracene-treated rats. Notably, sprouts of many broccoli cultivars contain negligible quantities of indole glucosinolates, which predominate in the mature vegetable and may give rise to degradation products (e.g., indole-3-carbinol) that can enhance tumorigenesis. Hence, small quantities of crucifer sprouts may protect against the risk of cancer as effectively as much larger quantities of mature vegetables of the same variety.

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The development of exceptionally potent inhibitors of fatty acid amide hydrolase (FAAH), the enzyme responsible for the degradation of oleamide (an endogenous sleep-inducing lipid), and anandamide (an endogenous ligand for cannabinoid receptors) is detailed. The inhibitors may serve as useful tools to clarify the role of endogenous oleamide and anandamide and may prove to be useful therapeutic agents for the treatment of sleep disorders or pain. The combination of several features—an optimal C12–C8 chain length, π-unsaturation introduction at the corresponding arachidonoyl Δ8,9/Δ11,12 and oleoyl Δ9,10 location, and an α-keto N4 oxazolopyridine with incorporation of a second weakly basic nitrogen provided FAAH inhibitors with Kis that drop below 200 pM and are 102–103 times more potent than the corresponding trifluoromethyl ketones.

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We describe an unprecedented radiation of sanguinicolid blood flukes ( Digenea: Sanguinicolidae) from two species of Labridae (Choerodon venustus and C. cauteroma), seven species of Mullidae (Mulloidichthys vanicolensis, Parupeneus barberinoides, P. barberinus, P. bifasciatus, P. cyclostomus, P. indicus and P. multifasciatus) and ten species of Siganidae (Siganus argenteus, S. corallinus, S. doliatus, S. fuscescens, S. lineatus, S. margaritiferus, S. puellus, S. punctatus, S. virgatus and S. vulpinus) from sites off Australia and Palau. The flukes were morphologically similar in having the combination of a long thread-like body, tegumental spines in lateral transverse rows, a vestigial oral sucker bearing concentric rows of fine spines, an H-shaped intestine, a cirrussac, a notch level with the male genital pore, a lateral or post-ovarian uterus, a uterine chamber and separate genital pores. These species are divided into two genera on the basis of testis number. Sanguinicolids from Siganus fuscescens have a single large testis between the intestinal bifurcation and the ovary and are placed in Ankistromeces Nolan & Cribb, 2004. Species from the remaining nine species of Siganidae, Labridae and Mullidae are placed in Phthinomita n. g.; these species have two testes, the anterior testis being large and between the intestinal bifurcation and the ovary whereas the small posterior testis is at the posterior end of the body and appears rudimentary or degenerate and probably non-functional. The second internal transcribed spacer (ITS2) of ribosomal DNA ( rDNA) from 29 host/parasite/location combinations (h/p/l) was sequenced together with that of Ankistromeces mariae Nolan & Cribb, 2004 for comparison. From 135 samples we found 19 distinct genotypes which were interpreted as representing at least that many species. Replicate sequences were obtained for 25 of 30 h/p/l combinations ( including A. mariae); there was no intraspecific variation between replicates sequences for any of these. Interspecific variation ranged from 1 - 41 base differences (0.3 - 12.7% sequence divergence). The 19 putative species were difficult to recognise by morphological examination. We describe 13 new species; we do not describe (= name) six species characterised solely by molecular sequences and three putative species for which morphological data is available but for which molecular data is not. We have neither morphological nor molecular data for sanguinicolids harboured in five hosts species ( Siganus margaritiferus, S. puellus, Choerodon cauteroma, Parupeneus indicus and P. multifasciatus) in which we have seen infections. Where host species were infected in different localities they almost always harboured distinct species. Some host species ( for example, S. argenteus and S. lineatus from Lizard Island) harboured two or three species in a single geographical location. This suggests that, for parts of this system, parasite speciation has outstripped host speciation. Distance analysis of ITS2 showed species from each host family ( Siganidae, Mullidae and Labridae) did not form monophyletic clades to the exclusion of species from other host families. However, a host defined clade was formed by the sequences from sanguinicolids from S. fuscescens.

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This Ph.D. thesis addresses current issues with ichnotaxonomic practice, and characterizes an exceptionally well preserved ichnological assemblage from the Carboniferous Stainmore Formation, Northumberland, United Kingdom. Samples were collected from closely localized float representative of various units throughout the succession, which was deposited in a storm-dominated marine shoreface. Three dominant ichnotaxa were selected for three-dimensional morphological analysis due to their complicated morphology and/or unclear taxonomic status: 1) Dactyloidites jordii isp. nov.; 2) Beaconites capronus, and; 3) Neoeione moniliformis comb. nov. Using serial grinding and photography, these ichnotaxa were ground and modelled in true colour. High-resolution models of three taxa produced in this study are the basis of the first complete three-dimensional consideration of the traces, and forms the basis for refined palaeobiological and ethological analysis of these taxa. Dactyloidites jordii isp. nov. is a stellate to palmate burrow composed of numerous long, narrow rays that exhibit three orders of branching arranged into tiered galleries radiating from a central shaft. It is considered to be the feeding structure produced by a vermiform organism. Beaconites capronus is a winding trace with distinctly chevron-shaped, meniscate backfill demonstrated herein to backfill the vertical shafts associated with its burrows in a comparable fashion to the horizontal portion of the burrow. This lack of a surface connection would result in the trace making organism being exposed to low-oxygen porewater. Coping with this porewater dysoxia could be approached by burrowing organisms in a number of ways: 1) revisiting the sediment-water interface; 2) creating periodic shafts; or 3) employing anaerobic metabolism. Neoeione moniliformis was originally introduced as Eione moniliformis, however, the genus Eione Tate, 1859 is a junior homonym of Eione Rafinesque, 1814. This led to the transfer of Eione moniliformis to Parataenidium. Through careful examination and three-dimensional characterization of topotypes, the transfer to Parataenidium moniliformis is demonstrated herein to be problematic, as Parataenidium refers to primarily horizontal burrows with two distinct layers and Eione moniliformis is composed of one distinct level. As such, the new ichnogenus Neoeione is created to accommodate Neoeione moniliformis.

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The occurrence of OsHV-1, a herpes virus causing mass mortality in the Pacific oyster Crassostrea gigas was investigated with the aim to select individuals with different susceptibility to the infection. Naïve spat transferred to infected areas and juveniles currently being grown at those sites were analyzed using molecular and histology approaches. The survey period distinguishes itself by very warm temperatures reaching up to 3.5°C above the average. The virus was not detected in the virus free area although a spread of the disease could be expected due to high temperatures. Overall mortality, prevalence of infection and viral load was higher in spat confirming the higher susceptibility in early life stages. OsHV-1 and oyster mortality were detected in naïve spat after 15 days of cohabitation with infected animals. Although, infection was associated with mortality in spat, the high seawater temperatures could also be the direct cause of mortality at the warmest site. One stock of juveniles suffered an event of abnormal mortality that was significantly associated with OsHV-1 infection. Those animals were infected with a previously undescribed microvariant whereas the other stocks were infected with OsHV-1 μVar. Cell lesions due to the infection were observed by histology and true infections were corroborated by in situ hybridization. Survivors from the natural outbreak were exposed to OsHV-1 μVar by intramuscular injection and were compared to naïve animals. The survival rate in previously exposed animals was significantly higher than in naïve oysters. Results derived from this study allowed the selection of animals that might possess interesting characteristics for future analysis on OsHV-1 resistance.

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The purpose of this paper is to assess aspects of the British Government's attempts to use sporting participation as a vehicle to re-integrate socially disadvantaged, excluded and 'at-risk' youth into mainstream society. A number of organisations, policy-makers, commentators, and practitioners with a stake in the 'sport and social inclusion agenda' were interviewed. General agreement was found on a number of points: that the field was overly crowded with policies, programmes and initiatives; that the field worked in a 'bottom-up' way, with the most significant factor determining success being effective local workers with good networks and cultural access; that the dichotomising rhetoric of inclusion/exclusion was counter-productive; that the notion of the 'at-risk youth' was problematic and unhelpful; and that they all now dealt with a marketplace, where 'clients' had to be enrolled in their own reformation. There was also disagreement on a number of points: that policy acts as a relatively accurate template for practice, as opposed to the argument that it was simply regarded as a cluster of suggestions for practice; that policy was exceptionally piecemeal in its formulation and application, as opposed to regarding policy as necessarily targeted and dispersed; and that the inclusion agenda was largely politically driven and transitory, as opposed to the optimistic view that it had become ingrained in local practice. Finally, the paper examines some issues that are the most likely points of contribution by researchers in the area: that more research needs to be done on the processes of identity formation associated with participation in sport; that more effective programme evaluation needs to be done for such forms of governmental intervention to work properly; and that the relationship between different kinds of physical activity and social and personal change needs to be more thoroughly theorised.

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The indoline dyes D102, D131, D149, and D205 have been characterized when adsorved on fluorine-doped tin oxide (FTO) and TiO2 electrode surfaces. Adsorption from 50:50 acetonitrile - tert-butanol onto flourine-doped tin oxide (FTO) allows approximate Langmuirian binding constants of 6.5 x 10(4), 2.01 x 10(3), 2.0 x 10(4), and 1.5 x 10(4) mol-1 dm3, respectively, to be determined. Voltammetric data obtained in acetonitrile/0.1 M NBu4PF6 indicate reversible on-electron oxidation at Emid = 0.94, 0.91, 0.88, and 0.88 V vs Ag/AgCI(3 M KCI), respectively, with dye aggregation (at high coverage) causing additional peak features at more positive potentials. Slow chemical degradation processes and electron transfer catalysis for iodine oxidation were observed for all four oxidezed indolinium cations. When adsorbed onto TiO2 nanoparticle films (ca. 9nm particle diameter and ca.3/um thickness of FTO0, reversible voltammetric responses with Emid = 1.08, 1.156, 0.92 and 0.95 V vs Ag/AgCI(3 M KCI), respectively, suggest exceptionally fast hole hopping diffusion (with Dapp > 5 x 10(-9) m2 s-1) for adsorbed layers of four indoline dyes, presumably due to pie-pie stacking in surface aggregates. Slow dye degradation is shown to affect charge transport via electron hopping. Spectrelectrochemical data for the adsorbed indoline dyes on FTO-TiO2 revealed a red-shift of absorption peaks after oxidation and the presence of a strong charge transfer band in the near-IR region. The implications of the indoline dye reactivity and fast hole mobility for solar cell devices are discussed.