284 research outputs found

    A Fast, Memory-Efficient Alpha-Tree Algorithm using Flooding and Tree Size Estimation

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    The alpha-tree represents an image as hierarchical set of alpha-connected components. Computation of alpha-trees suffers from high computational and memory requirements compared with similar component tree algorithms such as max-tree. Here we introduce a novel alpha-tree algorithm using 1) a flooding algorithm for computational efficiency and 2) tree size estimation (TSE) for memory efficiency. In TSE, an exponential decay model was fitted to normalized tree sizes as a function of the normalized root mean squared deviation (NRMSD) of edge-dissimilarity distributions, and the model was used to estimate the optimum memory allocation size for alpha-tree construction. An experiment on 1256 images shows that our algorithm runs 2.27 times faster than Ouzounis and Soille's thanks to the flooding algorithm, and TSE reduced the average memory allocation of the proposed algorithm by 40.4%, eliminating unused allocated memory by 86.0% with a negligible computational cost

    Do nanoparticle physico-chemical properties and developmental exposure window influence nano ZnO embryotoxicity in Xenopus laevis?

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    The growing global production of zinc oxide nanoparticles (ZnONPs) suggests a realistic increase in the environmental exposure to such a nanomaterial, making the knowledge of its biological reactivity and its safe-by-design synthesis mandatory. In this study, the embryotoxicity of ZnONPs (1\u2013100 mg/L) specifically synthesized for industrial purposes with different sizes, shapes (round, rod) and surface coatings (PEG, PVP) was tested using the frog embryo teratogenesis assay-Xenopus (FETAX) to identify potential target tissues and the most sensitive developmental stages. The ZnONPs did not cause embryolethality, but induced a high incidence of malformations, in particular misfolded gut and abdominal edema. Smaller, round NPs were more effective than the bigger, rod ones, and PEGylation determined a reduction in embryotoxicity. Ingestion appeared to be the most relevant exposure route. Only the embryos exposed from the stomodeum opening showed anatomical and histological lesions to the intestine, mainly referable to a swelling of paracellular spaces among enterocytes. In conclusion, ZnONPs differing in shape and surface coating displayed similar toxicity in X. laevis embryos and shared the same target organ. Nevertheless, we cannot exclude that the physico-chemical characteristics may influence the severity of such effects. Further research efforts are mandatory to ensure the synthesis of safer nano-ZnO-containing products

    Project of an advanced ISOL facility for exotic beams at LNL

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    Abstract In the framework of the European program to define a second generation Radioactive Ion Beam facility, LNL are proposing the construction in the next five–seven years of a specialized national facility for RIB originated by fission fragments produced by secondary neutrons. It consists on a two-accelerator ISOL-type facility to provide intense neutron-rich radioactive ion beams of highest quality, in the range of masses between 80 and 160. The conceptual design is based on a high intensity 50 MeV (100 kW) proton linac as driver and on the availability of the heavy-ion accelerator ALPI as post accelerator. The estimated neutron yield is 2×1014 n/s at 0°, high enough to satisfy the demand for an advanced RIB facility. An intense R&D program on different items is actually in progress in collaboration with other Laboratories and University groups and is moving in a European context

    Estimativa da biomassa da parte aérea em pastagem de Urochloa decumbens com o uso de um sensor proximal de refletância do dossel.

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    As gramíneas forrageiras tropicais, como a Urochloa (syn. Brachiaria) decumbens, são as mais utilizadas na bovinocultura extensiva e intensiva do Brasil. A U. decumbens é altamente aclimatada, principalmente em área de Cerrado, sendo considerada boa alternativa para a cria, recria e engorda de bovinos

    Análise espaço-temporal da incidência da radiação fotossinteticamente ativa em sistema silvipastoril sob manejo do componente arbóreo.

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    O sistema silvipastoril (Integração Pecuária-Floresta) produz diversos serviços ambientais e pode contribuir para uma maior eficiência da pecuária, amenizando variações climáticas, melhorando o conforto térmico animal e agregando valor aos produtos à longo prazo, ressaltando a importância da presença de árvores de maneira equilibrada em um sistema pastoril

    Estimativa do índice de área foliar em pastagem extensiva a partir de um sensor proximal de refletância do dossel.

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    O conhecimento das propriedades e parâmetros biofísicos do solo e planta são importantes para o manejo adequado de insumos utilizados nas pastagens. Um parâmetro importante é o índice de área foliar (IAF), descrito como a razão entre a área foliar do dossel e a unidade de superfície projetada no solo (m² m-²), diretamente relacionado com estrutura do dossel e potencial de evapotranspiração, permitindo a simulação do efeito de variações climáticas sobre o potencial produtivo das pastagens

    First measurements of the ^16O(e,e'pn)^14N reaction

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    This paper reports on the first measurement of the ^16O(e,e'pn)^14N reaction. Data were measured in kinematics centred on a super-parallel geometry at energy and momentum transfers of 215 MeV and 316 MeV/c. The experimental resolution was sufficient to distinguish groups of states in the residual nucleus but not good enough to separate individual states. The data show a strong dependence on missing momentum and this dependence appears to be different for two groups of states in the residual nucleus. Theoretical calculations of the reaction using the Pavia code do not reproduce the shape or the magnitude of the data.Comment: 10 pages, 11 figures, 2 tables, Accepted for publication in EPJ

    Contemporary Trends of Systemic Neoadjuvant and Adjuvant Intravesical Chemotherapy in Patients With Upper Tract Urothelial Carcinomas Undergoing Minimally Invasive or Open Radical Nephroureterectomy: Analysis of US Claims on Perioperative Outcomes and Health Care Costs

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    Introduction: New evidence indicates that minimally invasive surgery (MIS) (laparoscopic or robotic-assisted [LNU, RANU]) reaches oncologic equivalence compared with Open Radical Nephroureterectomy (ORNU) for high-risk upper-tract urothelial carcinoma (UTUC). Recently, European Association of Urology (EAU) Guidelines suggested implementing neoadjuvant chemotherapy (NAC) to standard treatment to improve oncologic outcomes of high-risk UTUC. We aimed (1) To explore contemporary trends of MIS for RNU in the United States and to compare perioperative outcomes and costs with that of ORNU. (2) To determine the trends of NAC and postoperative intravesical chemotherapy (PIC) administration for high-risk UTUC and to assess their contribution to perioperative outcomes and costs. Patients and methods: The Optum Clinformatics Data Mart de-identified database was queried from 2003 to 2018 to retrospectively examine patients who had undergone LNU/RANU or ORNU with or without NAC and PIC. We evaluated temporal adoption trends, complications, and health care cost analyses. We obtained descriptive statistics and utilized multivariable regression modeling to assess outcomes. Results: A total of n = 492 ORNU and n = 1618 LNU/RANU procedures were reviewed. The MIS approach was associated with a statistically significant lower risk of intraoperative complications (adjusted Odds Ratio [aOR], 0.48, 95% CI:0.24-0.96), risk of hospitalization costs (aOR: 0.62, 95% CI:0.49-0.78), and shorter hospital stay (aOR: 0.20, 95% CI:0.15-0.26) when compared to ORNU. Overall, adoption of NAC and PIC accounted for only n = 81 and n < 37 cases respectively. The implementation of NAC and higher number of cycles were associated with an increased probability of any complication rate (aOR: 2.06, 95% CI:1.26-3.36) and hospital costs (aOR: 2.12, 95% CI:1.33-3.38). Conclusion: MIS has become the approach of choice for RNU in the US. Although recommended by guidelines, neither NAC nor postoperative bladder instillation of chemotherapy has been routinely incorporated into the clinical practice of patients with UTUC
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