845 resultados para Habitat extension
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PURPOSE: To assess the patterns of failure in the treatment of early-stage squamous cell carcinoma of the glottic larynx. PATIENTS AND METHODS: Between 1983-2000, 122 consecutive patients treated for early laryngeal cancer (UICC T1N0 and T2N0) by radical radiation therapy (RT) were retrospectively studied. Male-to-female ratio was 106 : 16, and median age 62 years (35-92 years). There were 68 patients with T1a, 18 with T1b, and 36 with T2 tumors. Diagnosis was made by biopsy in 104 patients, and by laser vaporization or stripping in 18. Treatment planning consisted of three-dimensional (3-D) conformal RT in 49 (40%) patients including nine patients irradiated using arytenoid protection. A median dose of 70 Gy (60-74 Gy) was given (2 Gy/fraction) over a median period of 46 days (21-79 days). Median follow-up period was 85 months. RESULTS: The 5-year overall, cancer-specific, and disease-free survival amounted to 80%, 94%, and 70%, respectively. 5-year local control was 83%. Median time to local recurrence in 19 patients was 13 months (5-58 months). Salvage treatment consisted of surgery in 17 patients (one patient refused salvage and one was inoperable; total laryngectomy in eleven, and partial laryngectomy or cordectomy in six patients). Six patients died because of laryngeal cancer. Univariate analyses revealed that prognostic factors negatively influencing local control were anterior commissure extension, arytenoid protection, and total RT dose < 66 Gy. Among the factors analyzed, multivariate analysis (Cox model) demonstrated that anterior commissure extension, arytenoid protection, and male gender were the worst independent prognostic factors in terms of local control. CONCLUSION: For early-stage laryngeal cancer, outcome after RT is excellent. In case of anterior commissure extension, surgery or higher RT doses are warranted. Because of a high relapse risk, arytenoid protection should not be attempted.
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Aims: The pivotal FREEDOM study evaluated the effi cacy and safety of 3 years' denosumab treatment in women with postmenopausal osteoporosis (PMO).1 Since osteoporosis is a chronic condition requiring long-term therapy, FREEDOM was extended to further elucidate the safety and effi cacy of long-term denosumab administration. We present data from the fi rst 2 years of this extension, representing up to 5 years' continuous exposure to denosumab.Methods: Patients who completed FREEDOM were eligible for the extension. Women continued to receive (long-term group), or started after 3 years' placebo (cross-over group), denosumab 60 mg sc every 6 months and daily calcium and vitamin D. These data refl ect 5 years' (long-term) or 2 years' (cross-over) continuous denosumab treatment. Effi cacy measures include changes in BMD from extension study baseline and bone turnover markers (BTM). P-values are descriptive.Results: Of the 83.0% of subjects who completed FREEDOM, 70.2% (N = 4550) agreed to participate in the extension (long-term: 2343; cross-over: 2207). In the long-term group, there were further signifi cant gains (P < 0.0001) in BMD in years 4 and 5: 1.9% and 1.7% at the lumbar spine to a total of 13.7% from FREEDOM baseline and 0.7% and 0.6% at the total hip to a total of 7.0%. During their fi rst 2 years' denosumab treatment, women in the cross-over group had signifi cant improvements in lumbar spine (7.9%) and total hip BMD (4.1%) (P < 0.0001). Serum C-telopeptide (CTX) was rapidly reduced following denosumab dosing in both groups, with the characteristic attenuation of CTX reduction observed at the end of the dosing interval. A low incidence of new vertebral and nonvertebral fractures was reported for both groups. The denosumab safety profi le did not change over time.Conclusions: Denosumab treatment for up to 5 years in women with PMO remains well tolerated, maintains reduction of BTMs and continues to significantly increase BMD.Reference1. Cummings. NEJM 2009;361:756.
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Leaders must scan the internal and external environment, chart strategic and task objectives, and provide performance feedback. These instrumental leadership (IL) functions go beyond the motivational and quid-pro quo leader behaviors that comprise the full-range-transformational, transactional, and laissez faire-leadership model. In four studies we examined the construct validity of IL. We found evidence for a four-factor IL model that was highly prototypical of good leadership. IL predicted top-level leader emergence controlling for the full-range factors, initiating structure, and consideration. It also explained unique variance in outcomes beyond the full-range factors; the effects of transformational leadership were vastly overstated when IL was omitted from the model. We discuss the importance of a "fuller full-range" leadership theory for theory and practice. We also showcase our methodological contributions regarding corrections for common method variance (i.e., endogeneity) bias using two-stage least squares (2SLS) regression and Monte Carlo split-sample designs.
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Our objective is to evaluate the habitat preference of freshwater snails in relation to environmental factors and the presence of the competitor snail Melanoides tuberculatus. In the first phase, snails was collected at 12 sites. This sampling sites presented a degree of organic input. In the second phase 33 sampling sites were chosen, covering a variety of lotic and lentic environments. The snail species found at Guapimirim, state of Rio de Janeiro, displayed a marked habitat preference, specially in relation to the physical characteristics of each environment. Other limiting factors for snail distribution at the studied lotic environments were the water current velocity and the amount of organic matter, mainly to Physa marmorata, M. tuberculatus, and Biomphalaria tenagophila. The absence of interactions between M. tuberculatus and another snails could be associated to the distinct spatial distribution of those species and the instability of habitats. This later factor may favor the coexistence of M. tuberculatus with B. glabrata by reduction of population density. In areas of schistosomiasis transmission some habitat modification may add to the instability of the environment, which would make room for the coexistence of M. tuberculatus and Biomphalaria spp. In this way, some of the usual measures for the control of snail hosts would prevent the extinction of populations of Biomphalaria spp. by M. tuberculatus in particular habitats.
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The Eukaryotic Promoter Database (EPD) is an annotated non-redundant collection of eukaryotic POL II promoters, experimentally defined by a transcription start site (TSS). There may be multiple promoter entries for a single gene. The underlying experimental evidence comes from journal articles and, starting from release 73, from 5' ESTs of full-length cDNA clones used for so-called in silico primer extension. Access to promoter sequences is provided by pointers to TSS positions in nucleotide sequence entries. The annotation part of an EPD entry includes a description of the type and source of the initiation site mapping data, links to other biological databases and bibliographic references. EPD is structured in a way that facilitates dynamic extraction of biologically meaningful promoter subsets for comparative sequence analysis. Web-based interfaces have been developed that enable the user to view EPD entries in different formats, to select and extract promoter sequences according to a variety of criteria and to navigate to related databases exploiting different cross-references. Tools for analysing sequence motifs around TSSs defined in EPD are provided by the signal search analysis server. EPD can be accessed at http://www.epd. isb-sib.ch.
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Aim, Location Although the alpine mouse Apodemus alpicola has been given species status since 1989, no distribution map has ever been constructed for this endemic alpine rodent in Switzerland. Based on redetermined museum material and using the Ecological-Niche Factor Analysis (ENFA), habitat-suitability maps were computed for A. alpicola, and also for the co-occurring A. flavicollis and A. sylvaticus. Methods In the particular case of habitat suitability models, classical approaches (GLMs, GAMs, discriminant analysis, etc.) generally require presence and absence data. The presence records provided by museums can clearly give useful information about species distribution and ecology and have already been used for knowledge-based mapping. In this paper, we apply the ENFA which requires only presence data, to build a habitat-suitability map of three species of Apodemus on the basis of museum skull collections. Results Interspecific niche comparisons showed that A. alpicola is very specialized concerning habitat selection, meaning that its habitat differs unequivocally from the average conditions in Switzerland, while both A. flavicollis and A. sylvaticus could be considered as 'generalists' in the study area. Main conclusions Although an adequate sampling design is the best way to collect ecological data for predictive modelling, this is a time and money consuming process and there are cases where time is simply not available, as for instance with endangered species conservation. On the other hand, museums, herbariums and other similar institutions are treasuring huge presence data sets. By applying the ENFA to such data it is possible to rapidly construct a habitat suitability model. The ENFA method not only provides two key measurements regarding the niche of a species (i.e. marginality and specialization), but also has ecological meaning, and allows the scientist to compare directly the niches of different species.
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Lutzomyia (Nyssomyia) whitmani s.l.is the main vector of cutaneous leishmaniasis in state of Mato Grosso, but little is known about environmental determinants of its spatial distribution on a regional scale. Entomologic surveys of this sand fly species, conducted between 1996 and 2001 in 41 state municipalities, were used to investigate the relationships between environmental factors and the presence of the species, and to develop a spatial model of habitat suitability. The relationship between averaged CDC light trap indexes and 15 environmental and socio-economic factors were tested by logistic regression (LR) analysis. Spatial layers of deforestation tax and the Brazilian index of gross net production (IGNP) were identified as significant explanatory variables for vector presence in the LR model, and these were then overlaid with habitat maps. The highest habitat suitability in 2001 was obtained for the heavily deforested areas in the Central-North, South, East, and Southwest of Mato Grosso, particularly in municipalities with lower IGNP values.
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Two endangered tetraonids, the capercaillie (Tetrao urogallus) and the hazel grouse (Bonasa bonasia rupestris), are sympatric throughout part of their distribution range in central Europe. Precise information on their specific habitat requirements is needed if the coexistence of both species in exploited forests is to be maintained. We quantified winter habitat selection for both species in the upper part (1100-1600 m) of the Jura mountains (Switzerland). No preference for altitude or exposure could be detected. Capercaillie preferred open forests (including grazed forests) with a sparse canopy dominated by spruce (Picea abies) and fir (Abies alba), and avoided dense undercanopy and understorey, especially when dominated by spruce and beech (Fagus sylvatica). By contrast, hazel grouse preferred feeding sites with a dense understorey of rowan (Sorbus aucuparia), willow (Salix sp.), beech and spruce. These preferences can be related to the feeding habits and predator avoidance behaviour of both species. Coexistence thus requires a mosaic distribution of habitat types, with a matrix of open forests (30% canopy cover) where fir is favoured, and understorey kept sparse (20%). Group-cuts of mature trees should allow regeneration patches, where a dense understorey (50% cover) should provide suitable habitats for hazel grouse
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A study was carried out to determine the distribution and habitat preferences of several species of the genus Biomphalaria. Samples were taken at 350 freshwater locations in Cuba. Three species of Biomphalaria (Biomphalaria havanensis, Biomphalaria helophila and Biomphalaria pallida) were recorded based on their distribution. Of the three species, B. havanensis has the weakest distribution because it was identified in only one locality. The other species, B. helophila and B. pallida, are abundant in rivers and dams and have large populations in Cuba. However, the only species that appears to occur in ecosystems shared with thiarids is B. pallida, possibly due to recent introduction of thiarids, but always in fewer numbers. Here we discuss the possibility of these species to act as intermediary hosts of Schistosoma mansoni in Cuba over the basis of occurrence in natural and anthropic habitats.
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In order to successfully deploy multicast services in QoS-aware networks, pricing architectures must take into account the particular characteristics of multicast sessions. With this objective, we propose a charging scheme for QoS multicast services, assuming that the unicast cost of each interconnecting link is determined and that such cost is expressed in terms of quality of service (QoS) parameters. Our scheme allows determining the cost distribution of a multicast session along a cost distribution tree (CDT), and basing such distribution in those pre-existing unicast cost functions. The paper discusses in detail the main characteristics of the problem in a realistic interdomain scenario and how the proposed scheme would contribute to its solution
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To classify mosquito species based on common features of their habitats, samples were obtained fortnightly between June 2001-October 2003 in the subtropical province of Chaco, Argentina. Data on the type of larval habitat, nature of the habitat (artificial or natural), size, depth, location related to sunlight, distance to the neighbouring houses, type of substrate, organic material, vegetation and algae type and their presence were collected. Data on the permanence, temperature, pH, turbidity, colour, odour and movement of the larval habitat's water were also collected. From the cluster analysis, three groups of species associated by their degree of habitat similarity were obtained and are listed below. Group 1 consisted of Aedes aegypti. Group 2 consisted of Culex imitator, Culex davisi, Wyeomyia muehlensi and Toxorhynchites haemorrhoidalis separatus. Within group 3, two subgroups are distinguished: A (Psorophora ferox, Psorophora cyanescens, Psorophora varinervis, Psorophora confinnis, Psorophora cingulata, Ochlerotatus hastatus-oligopistus, Ochlerotatus serratus, Ochlerotatus scapularis, Culex intrincatus, Culex quinquefasciatus, Culex pilosus, Ochlerotatus albifasciatus, Culex bidens) and B (Culex maxi, Culex eduardoi, Culex chidesteri, Uranotaenia lowii, Uranotaenia pulcherrima, Anopheles neomaculipalpus, Anopheles triannulatus, Anopheles albitarsis, Uranotaenia apicalis, Mansonia humeralis and Aedeomyia squamipennis). Principal component analysis indicates that the size of the larval habitats and the presence of aquatic vegetation are the main characteristics that explain the variation among different species. In contrast, water permanence is second in importance. Water temperature, pH and the type of larval habitat are less important in explaining the clustering of species.
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BACKGROUND: Extension of retinoblastoma cells into the posterior chamber is a criterion for group E according to the international classification of intraocular retinoblastoma. Currently, the anterior extension of retinoblastoma is based on the presence of tumour cells in the anterior chamber assessed by biomicroscopy. AIM: To determine the value of ultrasound biomicroscopy (UBM) in the assessment of posterior chamber involvement in advanced retinoblastoma. METHODS: Retrospective review of all retinoblastoma cases enucleated at the Jules Gonin Eye Hospital from January 1996 to December 2009 for which UBM (35 MHz) evaluation was available. The patients' records were reviewed for patient and tumour features and histopathological findings. UBM findings were compared with histopathological features. RESULTS: UBM documentation was available in 31 cases. Retinoblastoma was detected by UBM in the posterior chamber in 18 cases and was absent in 13 cases while histopathological analysis demonstrated its presence in the posterior chamber in 22 cases and its absence in 9 cases. Among the 18 UBM-positive cases, 7 had biomicroscopic detectable involvement of the anterior chamber. There was a significant correlation between echodensities consistent with retinoblastoma on UBM in the posterior chamber and histopathological tumorous involvement of the posterior chamber (p=0.0001). The sensitivity of UBM in the assessment of posterior chamber invasion by retinoblastoma was 81% and the specificity was 100%. CONCLUSION: In selected cases of advanced retinoblastoma, UBM appears to represent a valuable tool in the precise evaluation of anterior extension of disease, with good sensitivity and specificity for the assessment of posterior chamber involvement. UBM may provide useful criteria governing the indication for enucleation.
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Every year, autochthonous cases of Plasmodium vivax malaria occur in low-endemicity areas of Vale do Ribeira in the south-eastern part of the Atlantic Forest, state of São Paulo, where Anopheles cruzii and Anopheles bellator are considered the primary vectors. However, other species in the subgenus Nyssorhynchus of Anopheles (e.g., Anopheles marajoara) are abundant and may participate in the dynamics of malarial transmission in that region. The objectives of the present study were to assess the spatial distribution of An. cruzii, An. bellator and An. marajoara and to associate the presence of these species with malaria cases in the municipalities of the Vale do Ribeira. Potential habitat suitability modelling was applied to determine both the spatial distribution of An. cruzii, An. bellator and An. marajoara and to establish the density of each species. Poisson regression was utilized to associate malaria cases with estimated vector densities. As a result, An. cruzii was correlated with the forested slopes of the Serra do Mar, An. bellator with the coastal plain and An. marajoara with the deforested areas. Moreover, both An. marajoara and An. cruzii were positively associated with malaria cases. Considering that An. marajoara was demonstrated to be a primary vector of human Plasmodium in the rural areas of the state of Amapá, more attention should be given to the species in the deforested areas of the Atlantic Forest, where it might be a secondary vector.