Production and fate of the G ring arc particles due to Aegaeon (Saturn LIII)

The G ring arc hosts the smallest satellite of Saturn, Aegaeon, observed with a set of images sent by Cassini spacecraft. Along with Aegaeon, the arc particles are trapped in a 7:6 corotation eccentric resonance with the satellite Mimas. Due to this resonance, both Aegaeon and the arc material are confined to within sixty degrees of corotating longitudes. The arc particles are dust grains which can have their orbital motions severely disturbed by the solar radiation force. Our numerical simulations showed that Aegaeon is responsible for depleting the arc dust population by removing them through collisions. The solar radiation force hastens these collisions by removing most of the 10$~\mu$m sized grains in less than 40 years. Some debris released from Aegaeon's surface by meteoroid impacts can populate the arc. However, it would take 30,000 years for Aegaeon to supply the observed amount of arc material, and so it is unlikely that Aegaeon alone is the source of dust in the arc

The mixed capacitated arc routing problem with non-overlapping routes

Real world applications for vehicle collection or delivery along streets usually lead to arc routing problems, with additional and complicating constraints. In this paper we focus on arc routing with an additional constraint to identify vehicle service routes with a limited number of shared nodes, i.e. vehicle service routes with a limited number of intersections. This constraint leads to solutions that are better shaped for real application purposes. We propose a new problem, the bounded overlapping MCARP (BCARP), which is defined as the mixed capacitated arc routing problem (MCARP) with an additional constraint imposing an upper bound on the number of nodes that are common to different routes. The best feasible upper bound is obtained from a modified MCARP in which the minimization criteria is given by the overlapping of the routes. We show how to compute this bound by solving a simpler problem. To obtain feasible solutions for the bigger instances of the KARP heuristics are also proposed. Computational results taken from two well known instance sets show that, with only a small increase in total time traveled, the model BCARP produces solutions that are more attractive to implement in practice than those produced by the MCARP modelinfo:eu-repo/semantics/submittedVersio

Respostas morfofisiológica da dinâmica foliar de curauá (Ananas erectifolius L.B. Sm.) ao regime hídrico, sob cultivo em sistemas agroflorestais.

Dada as diferentes funções que a água sobre as exerce plantas e as diferentes condições aonde a planta vem sendo cultivada, o trabalho teve como objetivo avaliar respostas morfofisiológica da dinâmica foliar de curauá ao regime hídrico, sob cultivo em sistemas agroflorestais

Macrofauna do solo em estágios sucessionais de alteração da paisagem na região do distrito da BR-163, oeste do Pará.

A macrofauna do solo apresenta alta diversidade e rápida capacidade de reprodução, sendo considerada excelente bioindicadora, e suas propriedades ou funções indicam e determinam a qualidade ou o nível de degradação do solo..

Cultural adaptation and psychometric validation of the Portuguese breakthrough pain assessment tool with cancer patients

Breakthrough cancer pain (BTcP) is a transient exacerbation of pain that occurs over persistent, stable, and adequately controlled cancer background pain. It is prevalent and bears severe consequences to patients' quality-of-life. The effective management of BTcP depends on fast and reliable (re)assessment. The Breakthrough pain Assessment Tool (BAT) is one of the most concise and reliable self-report instruments adapted to clinical contexts so far, showing good psychometric qualities in the United Kingdom, the Netherlands, and South Korea. As to promote the effective management of BTcP in Portuguese-speaking communities this study, first aimed to culturally adapt and validate the Portuguese version of the BAT (BAT-Pt). Second, and most importantly, it sought to provide novel evidence on its criterion validity by investigating its association with measures of psychological distress, which has not been yet investigated. The BAT was translated into European Portuguese, using the back-translation method, and culturally adapted. Its psychometric properties (factor structure, internal consistency, construct and criterion validity) were analyzed in a cross-sectional multicenter study, with a sample of 65 cancer patients (49.2% women) recruited from eight hospitals in mainland Portugal (a priori power analysis determined a minimum sample of 50). Health professionals collected patients' clinical information, assessed their functional disability (ECOG Performance Status) and the adequacy of pain control. In addition to the Portuguese version of the BAT (BAT_Pt), patients completed the Portuguese versions of the Brief Pain Inventory, the Hospital Anxiety and Depression Scale, a Distress Thermometer and answered questions about the adequacy of pain control. The BAT-Pt was very well accepted by experts and patients. As hypothesized, a Principal Axis Factor Analysis revealed two underlying factors accounting for 55.2% of the variance: (1) Pain Severity and Impact of BTcP and (2) Duration of BTcP and Medication Inefficacy. Two items (on episode frequency and medication efficacy) were analyzed separately given their lower/cross loadings. The BAT-Pt showed good internal consistency overall (?=0.79) and for each sub-scale, namely, Pain Severity and Impact of BTcP (n=5 items; ?=0.86) and Duration of BTcP and Medication Inefficacy (n=2 items; rsb=0.62).info:eu-repo/semantics/acceptedVersio

Composição florística de espécies oportunistas em agroecossistema de paricá e curauá.

O trabalho foi realizado no Campo Experimental Tramontina, Aurora do Pará-PA com objetivo de verificar a composição florística de plantas oportunistas em um agroecossistema de paricá (Schizolobium pararyba var. amazonicum (Huber ex Ducke) Barneby) e curauá (Ananas comosus var. erectifolius (L.B.Sm.) Coppens & F.Leal) visando contribuir quanto à conservação de recursos genéticos vegetais. Para isso foram coletadas, herborizadas e inventariadas todas as espécies invasoras ocorrentes em 20 parcelas de 4m x 4m instaladas em uma área total de 5.702,5m² seguindo delineamento experimental inteiramente ao acaso. Os dados do levantamento florístico foram analisados através da freqüência, abundância, hábitos, forma de vida, duração de ciclo, índices de riqueza e diversidade. Foi aplicada uma redução categórica, entre espécies do grupo herbáceo e não-herbáceo. Foram identificadas 70 espécies, pertencentes a 53 gêneros distribuídos em 25 famílias, com maior número de espécies para Fabaceae. A maioria das espécies apresentou um ciclo de vida perene (58 espécies) com os hábitos arbustivos perenes (18 espécies), herbáceos perenes (17 espécies) e herbáceos anuais (10 espécies), lianas (7 espécies) e espécies arbóreas (6 espécies). Foram evidenciados, 04 agrupamentos com um grau de similaridade mínima de 30% em função da freqüência e abundância. Para Paspalum conjugatum (Poaceae) (46,59%) a diversidade foi elevada (H?=3,847), sendo que os valores de diversidade (H?) apresentaram distinção (p<0.05) entre os agrupamentos

Avaliação do capim-marandu sob déficit hídrico em casa de vegetação, no período de estabelecimento.

O objetivo deste trabalho foi avaliar o perfilhamento e a produção de biomassa do capim-marandu no período de estabelecimento, sob influência do déficit hídrico. Realizou-se o experimento em casa-de-vegetação na Embrapa Pecuária Sudeste, sob delineamento em blocos completos casualizados com arranjo fatorial 3x3+1. Os tratamentos referiram-se à suspensão da irrigação em diferentes épocas do estabelecimento (semeadura, germinação e perfilhamento primário) até que o solo apresentasse teor de água equivalente a 75, 50 e 25% da capacidade de armazenamento de água disponível no solo (CAD), além da testemunha que não sofreu restrição hídrica. As avaliações de número de perfilhos surgidos por vaso foram realizadas semanalmente, por cinco semanas, a partir do início do perfilhamento. Uma coleta de biomassa foi realizada aproximadamente 30 dias após o término do último tratamento, período em que o solo foi mantido próximo a capacidade de campo. O perfilhamento e a produção de biomassa do capim-marandu são reduzidos quando o déficit hídrico é suficiente para que o teor de água no solo atinja 25%CAD, durante a fase de estabelecimento, independente da época em que ocorra a escassez hídrica

A case report

Benign transient hyperphosphatasemia of infancy and early childhood is a self-limiting condition characte-rized by transiently increased serum alkaline phosphatase in the absence of liver, kidney or metabolic bone diseases. It is often accidentally found in children under five years old and it might be associated with a variety of underlying clinical disorders. Its pathophysiology remains unclear. Herein, we report a case of a 4-year-old girl with a 1-year history of persistent oligoarticular Juvenile Idiopathic Arthritis, who was found to have transient hyperphosphatasemia during a periodic check-up. This clinical case underlines the importance of promptly recognizing this benign condition, which avoids unnecessary extensive investigations.publishersversionpublishe