1,498 research outputs found
Modelos para dados de Sobrevivência com Censura Informativa - Comparação dos Softwares R e Python
Composição automática de músicas utilizando redes neurais recorrentes
O problema de composição musical automática é extensivamente explorado na literatura. Em geral, o objetivo final nesses trabalhos é a composição musical em si, de forma que os modelos utilizados são ajustados para que a música gerada seja adequada em algum sentido. Detalhes técnicos como os impactos que as modificações nos parâmetros têm na composição final são amplamente desconhecidos. Neste trabalho, temos por objetivo estudar o quão sensÃvel é um modelo de rede neural recorrente, baseado em processamento de linguagem natural, construÃdo para composição musical. Para tal tarefa, a mensuração será feita com a perplexidade, uma medida oriunda da teoria da informação. Por fim, as músicas são avaliadas, de forma subjetiva, em relação à musicalidade e à qualidade das peças musicais obtidas.The issue of automatically composed music has received a lot of attention in the literature. In general, the focus is on the composition itself, and models are tuned to produce useful results. Technical details such as the effects that adjustments to the model’s parameters have on the composition, however, are still largely unknown. In this work, we investigate how sensitive is a recurrent neural network model, based on natural language processing, built for music composition. To accomplish this task, we apply a metric from information theory called perplexity. The composed works are then subjectively assessed for musicality and quality
Anterior short correction in thoracic adolescent idiopathic scoliosis with mini-open thoracotomy approach: prospective clinical, radiological and pulmonary function results
Introduction: This is a prospective study of adolescent patients in whom idiopathic thoracic scoliosis was corrected by short anterior fusion through a mini-open thoracotomy approach. Clinical, radiological and pulmonary function results of minimal 2-year (2-6) follow-up are presented. Materials and methods: Consecutive 62 patients with Lenke 1 and 2 curves, having main thoracic scoliosis of up to 75°, were prospectively included. The shoulder imbalance in Lenke 2 patients was less than 20mm. Thoracic scoliosis was corrected by short anterior fusion. The thoracic spine was exposed by an 8-cm mini-open thoracotomy incision. The operation technique and choosing of fusion levels are thoroughly described. Complete 360° discectomies and convex side vertebral endplates osteotomies are essential for deformity corrections with short fusions. Single-rod 5.5-mm titanium implants were used. The age at the time of operation was mean 15.2 years; 56 patients had a single thoracic curve and 6 patients had a double thoracic curve. There were almost equal numbers of patients with lumbar modifier A, B or C. The average length of fusion was 5.5 (4-7) vertebrae. The average length of fusion was 3.5 (2-6) vertebrae shorter than the average curve length. Results: The instrumented thoracic curves improved by 58.3% at 6 weeks and 56.3% at the last follow-up. Apex thoracic vertebral rotation improved by 73.78% at 6 weeks and 76.24% at the last follow-up. The non-instrumented upper thoracic curve improved by 25% in double thoracic scoliosis, where the mid-thoracic curve was selectively fused, and the non-instrumented lumbar curves improved by 33.9% at the last follow-up. The radiological changes from 6 weeks to the last follow-up were statistically not significant. The clinical rib hump improved by 54% at the last follow-up. There were no significant changes in the pulmonary function. FVC% was 81.04% preoperatively, 76.41% at 6 months and 80.38% at the 2-year follow-up. The results of SRS 24 questionnaire improved from a total of 61.40 points preoperatively to 100.50 points at 6 months and 98.62 points at the 2-year follow-up. There were no neurological or thoracotomy related complications, no pseudarthrosis, no implant pullout or breakage. Conclusion: A good deformity correction without loss of correction or adding on, a good cosmetic result and good patient's satisfaction were achieved through shorter than end-to-end thoracic fusions. The radiological residual deformity is acceptable. Anterior correction of thoracic scoliosis with a short spinal fusion is recommended to keep the large part of the spine mobile. A very short fusion, small thoracotomy incision, low-profile implants and complete closure of parietal pleura are keys to prevent reduction in postoperative lung functio
Consistent variation in individual migration strategies of brown skuas
Seabirds show remarkable variability in migration strategies among individuals and populations. In this study, we analysed 47 migrations of 28 brown skuas Catharacta antarctica lonnbergi breeding on King George Island in the Maritime Antarctic. Brown skuas from this population used a large area during the non-breeding period north of 55°S, including parts of the Patagonian Shelf, Argentine Basin and South Brazil Shelf, areas which are characterised by high levels of marine productivity. However, individual birds utilised only a subset of these areas, adopting 1 of 4 distinct migration strategies to which they were highly faithful between years, and showed high repeatability in departure and arrival dates at the breeding ground. Although they spent the majority of the non-breeding season within a particular region, almost all individuals used the same area in the late winter, exploiting its seasonal peak in productivity. Overall, these results indicate consistent individual variation in migration strategies that may reflect a combination of genetic control and individual experience, but with considerable flexibility to shift distribution in response to prevailing environmental conditions
Adjuvant Radiotherapy in the Treatment of Invasive Intraductal Papillary Mucinous Neoplasm of the Pancreas: an Analysis of the Surveillance, Epidemiology, and End Results Registry
Background: Management and outcomes of patients with invasive intraductal papillary mucinous neoplasm (IPMN) of the pancreas are not well established. We investigated whether adjuvant radiotherapy (RT) improved cancer-specific survival (CSS) and overall survival (OS) among patients undergoing surgical resection for invasive IPMN. Methods: The Surveillance, Epidemiology, and End Results (SEER) registry was used in this retrospective cohort study. All adult patients with resection of invasive IPMN from 1988 to 2007 were included. CSS and OS were analyzed using Kaplan-Meier curves. Unadjusted and propensity-score-adjusted Cox proportional-hazards modeling were used for subgroup analyses. Results: 972 patients were included. Adjuvant RT was administered to 31.8% (n=309) of patients. There was no difference in overall median CSS or OS in patients who received adjuvant RT (5-year CSS: 26.5months; 5-year OS: 23.5months) versus those who did not (CSS: 28.5months, P=0.17; OS: 23.5months, P=0.23). Univariate predictors of survival were lymph node (LN) involvement, T4-classified tumors, and poorly differentiated tumor grade (all P<0.05). In the propensity-score-adjusted analysis, adjuvant RT was associated with improved 5-year CSS [hazard ratio (HR): 0.67, P=0.004] and 5-year OS (HR: 0.73, P=0.014) among all patients with LN involvement, though further analysis by T-classification demonstrated no survival differences among patients with T1/T2 disease; patients with T3/T4-classified tumors had improved CSS (HR: 0.71, P=0.022) but no difference in OS (HR: 0.76, P=0.06). Conclusion: On propensity-score-adjusted analysis, adjuvant RT was associated with improved survival in selected subsets of patients with invasive IPMN, particularly those with T3/T4 tumors and LN involvemen
Genome-scale analysis identifies paralog lethality as a vulnerability of chromosome 1p loss in cancer.
Functional redundancy shared by paralog genes may afford protection against genetic perturbations, but it can also result in genetic vulnerabilities due to mutual interdependency1-5. Here, we surveyed genome-scale short hairpin RNA and CRISPR screening data on hundreds of cancer cell lines and identified MAGOH and MAGOHB, core members of the splicing-dependent exon junction complex, as top-ranked paralog dependencies6-8. MAGOHB is the top gene dependency in cells with hemizygous MAGOH deletion, a pervasive genetic event that frequently occurs due to chromosome 1p loss. Inhibition of MAGOHB in a MAGOH-deleted context compromises viability by globally perturbing alternative splicing and RNA surveillance. Dependency on IPO13, an importin-β receptor that mediates nuclear import of the MAGOH/B-Y14 heterodimer9, is highly correlated with dependency on both MAGOH and MAGOHB. Both MAGOHB and IPO13 represent dependencies in murine xenografts with hemizygous MAGOH deletion. Our results identify MAGOH and MAGOHB as reciprocal paralog dependencies across cancer types and suggest a rationale for targeting the MAGOHB-IPO13 axis in cancers with chromosome 1p deletion
Catchment Soil Properties Affect Metal(loid) Enrichment in Reservoir Sediments of German Low Mountain Regions
Sediment management is a fundamental part of reservoir operation, but it is often complicated by metal(loid) enrichment in sediments. Knowledge concerning the sources of potential
contaminants is therefore of important significance. To address this issue, the concentrations and
the mobile fractions of metal(loid)s were determined in the sediments and the respective catchment
areas of six reservoirs. The results indicate that reservoirs generally have a high potential for contaminated sediment accumulation due to preferential deposition of fine particles. The median values
of the element-specific enrichment factor (EF) demonstrates slight enrichments of arsenic (EF: 3.4),
chromium (EF: 2.8), and vanadium (EF: 2.9) for reservoir sediments. The enrichments of cadmium
(EF: 8.2), manganese (EF: 3.9), nickel (EF: 4.8), and zinc (EF: 5.0) are significantly higher. This is
enabled by a diffuse element release from the soils into the impounded streams, which is particularly
favored by soil acidity. Leaching from the catchment soils partially enriches elements in stream
sediments before their fine-grained portions in particular are deposited as reservoir sediment. We
assume that this effect is of high relevance especially for reservoirs impounding small streams with
forested catchments and weakly acid buffering parent material of soil formation
Modified risk-stratified sequential treatment (subcutaneous rituximab with or without chemotherapy) in B-cell Post-transplant lymphoproliferative disorder (PTLD) after Solid organ transplantation (SOT): the prospective multicentre phase II PTLD-2 trial
The prospective multicentre Phase II PTLD-2 trial (NCT02042391) tested modified risk-stratification in adult SOT recipients with CD20-positive PTLD based on principles established in the PTLD-1 trials: sequential treatment and risk-stratification. After rituximab monotherapy induction, patients in complete remission as well as those in partial remission with IPI < 3 at diagnosis (low-risk) continued with rituximab monotherapy and thus chemotherapy free. Most others (high-risk) received R-CHOP-21. Thoracic SOT recipients who progressed (very-high-risk) received alternating R-CHOP-21 and modified R-DHAOx. The primary endpoint was event-free survival (EFS) in the low-risk group. The PTLD-1 trials provided historical controls. Rituximab was applied subcutaneously. Of 60 patients enrolled, 21 were low-risk, 28 high-risk and 9 very-high-risk. Overall response was 45/48 (94%, 95% CI 83-98). 2-year Kaplan-Meier estimates of time to progression and overall survival were 78% (95% CI 65-90) and 68% (95% CI 55-80) - similar to the PTLD-1 trials. Treatment-related mortality was 4/59 (7%, 95% CI 2-17). In the low-risk group, 2-year EFS was 66% (95% CI 45-86) versus 52% in the historical comparator that received CHOP (p = 0.432). 2-year OS in the low-risk group was 100%. Results with R-CHOP-21 in high-risk patients confirmed previous results. Immunochemotherapy intensification in very-high-risk patients was disappointing
Molecular phylogeny and taxonomic revision of the sportive lemurs (Lepilemur, Primates)
BACKGROUND: The number of species within the Malagasy genus Lepilemur and their phylogenetic relationships is disputed and controversial. In order to establish their evolutionary relationships, a comparative cytogenetic and molecular study was performed. We sequenced the complete mitochondrial cytochrome b gene (1140 bp) from 68 individuals representing all eight sportive lemur species and most major populations, and compared the results with those obtained from cytogenetic studies derived from 99 specimens. RESULTS: Interspecific genetic variation, diagnostic characters and significantly supported phylogenetic relationships were obtained from the mitochondrial sequence data and are in agreement with cytogenetic information. The results confirm the distinctiveness of Lepilemur ankaranensis, L. dorsalis, L. edwardsi, L. leucopus, L. microdon, L. mustelinus, L. ruficaudatus and L. septentrionalis on species level. Additionally, within L. ruficaudatus large genetic differences were observed among different geographic populations. L. dorsalis from Sahamalaza Peninsula and from the Ambanja/Nosy Be region are paraphyletic, with the latter forming a sister group to L. ankaranensis. CONCLUSION: Our results support the classification of the eight major sportive lemur taxa as independent species. Moreover, our data indicate further cryptic speciation events within L. ruficaudatus and L. dorsalis. Based on molecular data we propose to recognize the sportive lemur populations from north of the Tsiribihina River, south of the Betsiboka River, and from the Sahamalaza Peninsula, as distinct species
Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea
Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t
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