997 resultados para Inter-element spacing
Resumo:
Cabo Verde é um país ecologicamente frágil e de fracos recursos naturais. A satisfação das necessidades básicas do Homem exige que sejam bem definidas orientações estratégicas de aproveitamento e uma aplicação optimizada dos recursos naturais a favor do desenvolvimento de actividades económicas. Desde a independência, os sucessivos Governos Cabo-verdianos têm-se mostrado preocupados com a questão da preservação dos ecossistemas e com o enquadramento dos organismos vocacionados para a gestão ambiental. Na estratégia expressa nas Grandes Opções para do Desenvolvimento (2002), o ambiente é um dos temas mais importantes. Projecta-se uma sociedade dotada de um sentimento profundo para o ambiente e de uma consciência ecológica desenvolvida sendo as medidas de preservação encaradas de forma sistémica e transversal, pretendendo-se que sejam equitativas. O segundo Plano de Acção Nacional para o Ambiente (PANA II) constitui a concretização destas políticas e define as orientações estratégicas de aproveitamento dos recursos naturais bem como os seus efeitos sobre a gestão sustentável das actividades económicas. É um documento orientador de um processo continuo caracterizado por uma dinâmica própria e que nos próximos 10 anos (2004-2014), servirá de base de trabalho, permitindo um desenvolvimento Cabo-verdiano sustentável e harmonioso, garantindo um ambiente sadio. A elaboração do PANA II foi um processo complexo com o objectivo de assegurar o envolvimento dos parceiros e estabelecer as respectivas interligações entre os vários níveis. Incluído neste processo esteve a elaboração dos nove Planos Ambientais Intersectoriais (PAIS). Esses PAIS incluem as preocupações e planos de todos os ministérios e agências envolvidas em subsectores específicos. Assim resultarão em programas e actividades coerentes, transversais e com uma visão clara sobre o desenvolvimento sustentável. Este documento apresenta os resultados dos trabalhos e planificação dos parceiros no sector Ambiente e Pescas.
Resumo:
Cabo Verde é um país ecologicamente frágil e de fracos recursos naturais. A satisfação das necessidades básicas do Homem exige que sejam bem definidas as orientações estratégicas de aproveitamento e uma aplicação optimizada dos recursos naturais a favor do desenvolvimento de actividades económicas. Desde a independência, os sucessivos Governos Cabo-verdianos têm-se mostrado preocupados com a questão da preservação dos ecossistemas e com o enquadramento dos organismos vocacionados para a gestão ambiental. Na estratégia expressa nas Grandes Opções para o Desenvolvimento (2002), o ambiente é um dos temas mais importantes. Projecta-se uma sociedade dotada de um sentimento profundo para o ambiente e de uma consciência ecológica desenvolvida sendo as medidas de preservação encaradas de forma sistémica e transversal, pretendendo-se que sejam equitativas. O segundo Plano de Acção Nacional para o Ambiente (PANA II) constitui a concretização destas políticas e define as orientações estratégicas de aproveitamento dos recursos naturais bem como os seus efeitos sobre a gestão sustentável das actividades económicas. É um documento orientador de um processo contínuo caracterizado por uma dinâmica própria e que nos próximos 10 anos (2004-2014), servirá de base de trabalho, permitindo um desenvolvimento Cabo-verdiano sustentável e harmonioso, garantindo um ambiente sadio. A elaboração do PANA II foi um processo complexo com o objectivo de assegurar o envolvimento dos parceiros e estabelecer as respectivas interligações entre os vários níveis. Incluída neste processo esteve a elaboração dos nove Planos Ambientais Intersectoriais (PAIS). Esses PAIS incluem as preocupações e planos de todos os ministérios e agências envolvidas em subsectores específicos. Assim resultarão em programas e actividades coerentes, transversais e com uma visão clara sobre o desenvolvimento sustentável. Este documento apresenta os resultados dos trabalhos e planificação dos parceiros no sector Ambiente e Educação, Formação, Informação e Sensibilização.
Resumo:
Integrative and conjugating elements (ICE) are self-transferable DNAs widely present in bacterial genomes, which often carry a variety of auxiliary genes of potential adaptive benefit. One of the model ICE is ICEclc, an element originally found in Pseudomonas knackmussii B13 and known for its propensity to provide its host with the capacity to metabolize chlorocatechols and 2-aminophenol. In this work, we studied the mechanism and target of regulation of MfsR, a TetR-type repressor previously found to exert global control on ICEclc horizontal transfer. By using a combination of ICEclc mutant and transcriptome analysis, gene reporter fusions, and DNA binding assays, we found that MfsR is a repressor of both its own expression and that of a gene cluster putatively coding for a major facilitator superfamily efflux system on ICEclc (named mfsABC). Phylogenetic analysis suggests that mfsR was originally located immediately adjacent to the efflux pump genes but became displaced from its original cis target DNA by a gene insertion. This resulted in divergence of the original bidirectional promoters into two separated individual regulatory units. Deletion of mfsABC did not result in a strong phenotype, and despite screening a large number of compounds and conditions, we were unable to define the precise current function or target of the putative efflux pump. Our data reconstruct how the separation of an ancestor mfsR-mfsABC system led to global control of ICEclc transfer by MfsR.
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Transposable elements, as major components of most eukaryotic organisms' genomes, define their structural organization and plasticity. They supply host genomes with functional elements, for example, binding sites of the pleiotropic master transcription factor p53 were identified in LINE1, Alu and LTR repeats in the human genome. Similarly, in this report we reveal the role of zebrafish (Danio rerio) EnSpmN6_DR non-autonomous DNA transposon in shaping the repertoire of the p53 target genes. The multiple copies of EnSpmN6_DR and their embedded p53 responsive elements drive in several instances p53-dependent transcriptional modulation of the adjacent gene, whose human orthologs were frequently previously annotated as p53 targets. These transposons define predominantly a set of target genes whose human orthologs contribute to neuronal morphogenesis, axonogenesis, synaptic transmission and the regulation of programmed cell death. Consistent with these biological functions the orthologs of the EnSpmN6_DR-colonized loci are enriched for genes expressed in the amygdala, the hippocampus and the brain cortex. Our data pinpoint a remarkable example of convergent evolution: the exaptation of lineage-specific transposons to shape p53-regulated neuronal morphogenesis-related pathways in both a hominid and a teleost fish.
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Nyssomyia intermedia (Lutz & Neiva) and Nyssomyia neivai (Pinto) are morphologically very close and both present great variation in some structures. The objective of this study is a description of the variation among the females of these species in populations from the States of Minas Gerais and São Paulo. The morphological structures studied were the number of horizontal teeth in the cibarium and the number of rings and the shape of the terminal knob of the spermathecae. The spermatheca rings are significantly more numerous in N. intermedia than in N. neivai and the simple shape of the terminal knob predominated in both species. Regarding the cibarium, eight to eleven teeth have been found in both species, with up to twelve teeth in the latter. The number of horizontal teeth and the shape of the terminal knob of the spermathecae were variable throughout the populations of both species and all structures were polymorphic in the populations studied.
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Purpose: To determine whether the need for retreatment after an initial phase of 3 monthly intravitreal injections of ranibizumab shows an intra-individual regular rhythm and to what degree it varies between different patients. Methods: Prospective study with 42 patients with exudative AMD, treatment naïve. Loading dose of 3 monthly doses of ranibizumab (0,5 mg), followed by a 12 months pro re nata (PRN) regimen according to early exudative signs on HD-OCT Cirrus, Zeiss. The follow-up visits were intensified (week 4, 5, 6, 7, 8, 10, 12, 14, 16, 20, etc after each injection) in order to detect recurrences early, and injection followed within 3 days in cases of subretinal fluid, cysts, or central thickness increase of>50microns. Intervals were calculated between injections for the 12 month follow-up with PRN treatment. Variability was expressed as standard deviation (SD). Results: Visual acuity (VA) improved from a mean ETDRS score of 61.6 (SD 10.8) at baseline to 68.0 (SD 10.2) at month 3 and to 74.7(SD 9.0) at month 12. The 15 patients who have already completed the study showed maintenance of the VA improvement. Central foveal thickness improved from a mean value of 366 microns (baseline) to 253 microns (month 3), well maintained thereafter. Mean number of injections was 8.8 (SD 3.5,range 0-12) per 12 months of follow-up (after 3 doses), with mean individual treatment-recurrence (TR) intervals ranging from 28->365 days (mean 58). Intraindividual variability of TR intervals (SD) was 7.1 days as a mean value (range 1.7¡V22.6). It ranged within 20% of the mean intra-individual interval for 30 (91%) and within 15% for 21 patients (64%). The first interval was within 1 week of the mean intra-individual interval in 64% and within 2 weeks in 89% of patients. Conclusions: The majority of AMD patients showed a relatively stable rhythm for PRN injections of ranibizumab after initial loading phase, associated with excellent functional/anatomical results. The initial interval last loading dose-first recurrence may have a predictive value for further need of treatment, potentially facilitating follow-up and patient care.
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The work by Koglin et al. (Koglin, N., Kostopoulos, D., Reichmann, T., 2009. Geochemistry, petrogenesis and tectonic setting of the Samothraki mafic Suite, NE Greece: Trace-element, isotopic and zircon age constraints. Tectonophysics 473, 53-68. doi: 10.1016/j.tecto.2008.10.028), where the authors have proposed to nullify the scenario presented by Bonev and Stampfli (Bonev, N., Stampfli, G., 2008. Petrology, geochemistry and geodynamic implications of Jurassic island arc magmatism as revealed by mafic volcanic rocks in the Mesozoic low-grade sequence, eastern Rhodope, Bulgaria. Lithos 100, 210-233) is here Put under discussion. The arguments for this proposal are reviewed in the light of available stratigraphic and radiometric age constraints, geochemical signature and tectonics of highly relevant Jurassic ophiolitic suites occurring immediately north of the Samothraki mafic suite. Our conclusion is that the weak arguments and the lack of knowledge on the relevant constraints from the regional geologic information make inconsistent the Proposal and the model of these authors. (C) 2009 Elsevier B.V. All rights reserved.
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The neuro-peptide hormone oxytocin regulates several reproductive mechanisms in mammals, such as uterine contractions during parturition and milk ejection in the lactating mammary gland. Oxytocin may also influence behavior and behavioral strategies, e.g. pair bonding, social recognition, maternal behavior, trust building, or anxiety. Teasing oestrous mares by a stallion provokes the release of oxytocin. We therefore tested whether such elevated oxytocin levels reveal possible mate preferences as determined in typical preference tests.
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This paper investigates the role of employee referrals in the labor market.Using an original data set, I find that industries that pay wage premia andhave characteristics associated with high-wage sectors rely mainly on employeereferrals to fill jobs. Moreover, unemployment rates are higher in industries which use employee referrals more extensively. This paper develops an equilibrium matching model which can explain these empirical regularities. Inthis model, the matching process sorts heterogeneous firms and workers into two distinct groups: referrals match "good" jobs to "good" workers, while formalmethods (e.g., newspaper ads and employment agencies) match less-attractive jobs to disadvantaged workers. Thus, well-connected workers who learn quickly aboutjob opportunities use referrals to jump job queues, while those who are less well placed in the labor market search for jobs through formal methods. The split of firms and workers between referrals and formal search is, however, not necessarily efficient. Congestion externalities in referral search imply that unemployment would be closer to the optimal rate if firms and workers 'at themargin' searched formally.
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Stable isotopes of carbonates (delta(13)C(carb), delta(18)O(carb)), organic matter (delta(13)C(org), delta(15)N(org)) and major, trace and rare earth element (REE) compositions of marine carbonate rocks of Late Permian to Early Triassic age were used to establish the position of the Permian-Triassic boundary (PTB) at two continuous sections in the Velebit Mountain, Croatia. The chosen sections - Rizvanusa and Brezimenjaca - are composed of two lithostratigraphic units, the Upper Permian Transitional Dolomite and the overlying Sandy Dolomite. The contact between these units, characterized by the erosional features and sudden occurrence of ooids and siliciclastic grains, was previously considered as the chronostratigraphic PTB. The Sandy Dolomite is characterized by high content of non-carbonate material (up to similar to 30 wt.% insoluble residue), originated from erosion of the uplifted hinterland. A relatively rich assemblage of Permian fossils (including Geinitzina, Globivalvulina, Hemigordius, bioclasts of gastropods, ostracods and brachiopods) was found for the first time in Sandy Dolomite, 5 m above the lithologic boundary in the Rizvanusa section. A rather abrupt negative delta(13)C(carb) excursion in both sections appears in rocks showing no recognizable facies change within the Sandy Dolomite, -2 parts per thousand at Rizvanusa and -1.2 parts per thousand at Brezimenjaca, 11 m and 0.2 m above the lithologic contact, respectively. This level within the lower part of the Sandy Dolomite is proposed as the chemostratigraphic PTB. In the Rizvanusa section, the delta(13)C(org) values decline gradually from similar to-25 parts per thousand in the Upper Permian to similar to-29 parts per thousand in the Lower Triassic. The first negative delta(13)C(org) excursion occurs above the lithologic contact, within the uppermost Permian deposits, and appears to be related to the input of terrigenous material. The release of isotopically light microbial soil-biomass into the shallow-marine water may explain this sudden decrease of delta(13)C(org) values below the PTB. This would support the hypothesis that in the western Tethyan realm the land extinction, triggering a sudden drop of woody vegetation and related land erosion, preceded the marine extinction. The relatively low delta(15)N(org) values at the Permian-Triassic (P-Tr) transition level, close to approximate to 0 parts per thousand, and a secondary negative delta(13)C(org) excursion of -0.5 parts per thousand point to significant terrestrial input and primary contribution of cyanobacteria. The profiles of the concentrations of redox-sensitive elements (Ce, Mn, Fe, V), biogenic or biogenic-scavenged elements (P, Ba, Zn, V), Ce/Ce* values, and normalized trace elements, including Ba/Al, Ba/Fe, Ti/Al, Al/(Al + Fe + Mn) and Mn/Ti show clear excursions at the Transitional Dolomite-Sandy Dolomite lithologic boundary and the chemostratigraphic P-Tr boundary. The stratigraphic variations indicate a major regression phase marking the lithologic boundary, transgressive phases in the latest Permian and a gradual change into shallow/stagnant anoxic marine environment towards the P-Tr boundary level and during the earliest Triassic. (C) 2010 Elsevier B.V. All rights reserved.
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Coagulation factor V (FV) deficiency is characterised by variable bleeding phenotypes and heterogeneous mutations. To add new insights into the FV genotype-phenotype relationship, we characterised the R1698W change in the A3 domain, at the poorly investigated interface with the A2 domain. The FV R1698W mutation was responsible for a markedly reduced expression level (10% of FV-WT) and specific activity in thrombin generation (0.39). Interestingly, the FVa1698W showed rapid activity decay upon activation due to increased dissociation rate between the heavy and light chains. The importance of the size and charge of the residue at position 1698 was investigated by three additional recombinant mutants, FVR1698A, FVR1698Q, and FVR1698E. FVR1698A and FVR1698Q expression (30 and 45% of FV-WT), specific activity (both 0.57) and stability were all reduced. Noticeably, FVR1698E showed normal activity and stability despite poor expression (10% of FV-WT). These data indicate the essential role of R1698 for normal biosynthetic process and support local flexibility for positively or negatively charged residues to produce stable and functional A3-A2 domain interactions. Their experimental alteration produces a gradient of FV defects, which help to interpret the wide spectrum of phenotypes in FV-deficient patients.
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We report the study of a large American family displaying autosomal dominant retinitis pigmentosa with reduced penetrance, a form of hereditary retinal degeneration. Although the inheritance pattern and previous linkage mapping pointed to the involvement of the PRPF31 gene, extensive screening of all its exons and their boundaries failed in the past to reveal any mutation. In this work, we sequenced the entire PRPF31 genomic region by both the classical Sanger method and ultrahigh throughput (UHT) sequencing. Among the many variants identified, a single-base substitution (c.1374+654C>G) located deep within intron 13 and inside a repetitive DNA element was common to all patients and obligate asymptomatic carriers. This change created a new splice donor site leading to the synthesis of two mutant PRPF31 isoforms, degraded by nonsense-mediated mRNA decay. As a consequence, amounts of PRPF31 mRNA derived from the mutant allele were very reduced, with no evidence of mutant proteins being synthesized. Our results indicate that c.1374+654C>G causes retinitis pigmentosa via haploinsufficiency, similar to the vast majority of PRPF31 mutations described so far. We discuss the potential of UHT sequencing technologies in mutation screening and the continued identification of pathogenic splicing mutations buried deep within intronic regions.