The effect of X-ray dust-scattering on a bright burst from the magnetar 1E 1547.0-5408

A bright burst, followed by an X-ray tail lasting ~10 ks, was detected during an XMM-Newton observation of the magnetar 1E 1547.0-5408 carried out on 2009 February 3. The burst, also observed by SWIFT/BAT, had a spectrum well fit by the sum of two blackbodies with temperatures of ~4 keV and 10 keV and a fluence in the 0.3-150 keV energy range of ~1e-5 erg/cm2. The X-ray tail had a fluence of ~4e-8 erg/cm2. Thanks to the knowledge of the distances and relative optical depths of three dust clouds between us and 1E 1547.0-5408, we show that most of the X-rays in the tail can be explained by dust scattering of the burst emission, except for the first ~20-30 s. We point out that other X-ray tails observed after strong magnetar bursts may contain a non-negligible contribution due to dust scattering.Comment: 8 pages, 2 tables and 10 figures; accepted to publication in MNRA

Processos envolvidos no tratamento biologico de efluentes : aplicação de um biorreator de leito recheado

Orientador: Lucia H. Innocentini MeiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuimicaResumo: Foi realizada uma seleção entre 51 cepas de fungos ligninolíticos para descoloração de efluentes fenólicos industriais. A seleção mostrou que a cepa Lentinus edodes UED-2019 remove 73% da cor, 60% da DQO (Demanda Química de oxigênio), 30% da DBO (Demanda Bioquímica de Oxigênio), 70% da massa molecular e 30% de fenóis em 120 horas, sem fonte adicional de carbono. Sob estas condições L. edodes foi mais eficiente que o conhecido Phanerochaete chrysosporium (BKM-F-1767). Observou-se uma pequena remoção de cor devida á adsorção micelial (13%) durante 120 horas em efluente Kraft. Foi avaliada, em escala de bancada, a remoção de cor do efluente E1 em um biorreator de leito recheado modificado (330 ml) operado em estado estacionário, utilizando-se l. edodes imobilizado em nylon e em cavacos de madeira de Eucalyptus grandis. No biorreator, operado durante 120 horas, observou-se 70% de redução de cor, 36% de fenóis e 67% de DQO na imobilização em nylon. Na imobilização nos cavacos encontrou-se 42% de remoção de cor e 26% de redução de fenóis. Esses métodos parecem ser eficientes no processo de descontaminação, representando um grande potencial no tratamento de efluentes industriaisAbstract: A screeting of 51 ligninolytic strains of fungi to examine their ability to decolorized phenolic industrial effluents was carried out. The selection showed that Lentinus edodes UEC-2019 strain removed 73% of color, 60% of COD (Chemical Oxygen Demand), 30% of BOD (Biochemical Oxygen Demand), 70% of molecular mass decrease and 30% phenols in 120 hours, without any additional carbon sources. Under these conditions L. edodes was more efficient than the known Phanerochaete chrysosporium (BKM-F-1767). A little color removal adsorption on the mycelium (13%) was observed during the 120 hours in Kraft mill effluent. The stady-state color removal from the effluent E1 in a bench-scale modified packed-bed bioreactor (330 ml) using L. edodes immobilized in nylon and wood chips of Eucalyptus grandis was evaluated. In a bioreactor, which operated by 120 hours a reduction of 70% of color, 36% of phenols and 67% of COD immobilized in nylon were found, also a 42% of color and 26% of phenols in wood immobilized chips were found. These methods appeared to be an efficient process of decontamination with a great industrial potential in effluent treatmentMestradoCiencia e Tecnologia de MateriaisMestre em Engenharia Químic

On the Effects of Artificial Feeding on Bee Colony Dynamics: A Mathematical Model

This paper proposes a new mathematical model to evaluate the effects of artificial feeding on bee colony population dynamics. The proposed model is based on a classical framework and contains differential equations that describe the changes in the number of hive bees, forager bees, and brood cells, as a function of amounts of natural and artificial food. The model includes the following elements to characterize the artificial feeding scenario: a function to model the preference of the bees for natural food over artificial foodparameters to quantify the quality and palatability of artificial dietsa function to account for the efficiency of the foragers in gathering food under different environmental conditionsand a function to represent different approaches used by the beekeeper to feed the hive with artificial food. Simulated results are presented to illustrate the main characteristics of the model and its behavior under different scenarios. The model results are validated with experimental data from the literature involving four different artificial diets. A good match between simulated and experimental results was achieved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Ministry of Education, BrazilUniversidade Federal de São Paulo (UNIFESP)Univ Fed Sao Paulo, UNIFESP, Rua Talim 330, BR-12231280 Sao Jose Dos Campos, BrazilAeronaut Inst Technol, ITA, Praca Marechal Eduardo Gomes 50, BR-12228900 Sao Jose Dos Campos, BrazilUniv Fed Sao Paulo, UNIFESP, Rua Conceicao 329, BR-09920000 Diadema, BrazilUNIFESP - Universidade Federal de São Paulo, Rua Talim, 330, Sao Jose dos Campos, Brazil, 12231-280UNIFESP - Universidade Federal de São Paulo, Rua Conceicao, 329, Diadema, Brazil, 09920-000Web of Scienc

Upcycling Pears with Physiopathy Into Soft Solid Foods Intended for People with Swallowing Difficulties: Formulation, Rheology and Tribology Studies

A key circular economy concept for food loss reduction is upcycling. In this work, soft-solid food preparations were designed for people with swallowing difficulties, formulated with wasted physiophatic pears, which do not enter the market for fresh consumption. Proteins (whey, spirulina and pea) were added in formulation of pear purees to ensure a better nutritional intake. Enzyme treatments and structuration by means of a thickener carbossimetilcellulose (CMC) allowed ranging the perceived texture between mildly thick up to extremely thick texture, according to the international classification for Dysphagia Diet Standardisation. Nutritional functionality was considered (protein and polyphenols content, antioxidant activity). In addition to rheological properties evaluation (flow behaviour, thixotropy, viscoelasticity), tribological aspects were assessed. he combination of proteins, thickening agent, eventually enzyme pectinase activity could establish positive interactions in terms of the viscosity. Together with the increase in the viscosity of purees, the thickener caused a considerable increase in thixotropy recovery, a weakening of the gel-like dispersion and a drastic increase in mucoadhesiviness. The overall results are a preliminary to the industrial manufacturing of specific textured pear purees

Mechanistic aspects of biosynthesis of silver nanoparticles by several Fusarium oxysporum strains

Extracellular production of metal nanoparticles by several strains of the fungus Fusarium oxysporum was carried out. It was found that aqueous silver ions when exposed to several Fusarium oxysporum strains are reduced in solution, thereby leading to the formation of silver hydrosol. The silver nanoparticles were in the range of 20–50 nm in dimensions. The reduction of the metal ions occurs by a nitrate-dependent reductase and a shuttle quinone extracellular process. The potentialities of this nanotechnological design based in fugal biosynthesis of nanoparticles for several technical applications are important, including their high potential as antibacterial material

How we do it: the Zurich Microsurgery Lab technique for placenta preparation

BACKGROUND Perfused placentas provide an excellent and accessible model for microvascular dissection, microsuturing and microanastomosis training - particularly in the early microsurgical learning curve. This way, a significant amount of live animals can be spared. METHOD We present the Zurich Microsurgery Lab protocol, detailing steps for obtaining, selecting, cleaning, flushing, cannulating, and preserving human placentas - as well as microsurgical training examples - in a tried-and-true, safe, cost-effective, and high-yield fashion. CONCLUSION Our technique enables highly realistic microsurgical training (microdissection, microvascular repair, microanastomosis) based on readily available materials. Proper handling, preparation, and preservation of the perfused placenta models is key

Segmentation techniques of brain arteriovenous malformations for 3D visualization: a systematic review

BACKGROUND Visualization, analysis and characterization of the angioarchitecture of a brain arteriovenous malformation (bAVM) present crucial steps for understanding and management of these complex lesions. Three-dimensional (3D) segmentation and 3D visualization of bAVMs play hereby a significant role. We performed a systematic review regarding currently available 3D segmentation and visualization techniques for bAVMs. METHODS PubMed, Embase and Google Scholar were searched to identify studies reporting 3D segmentation techniques applied to bAVM characterization. Category of input scan, segmentation (automatic, semiautomatic, manual), time needed for segmentation and 3D visualization techniques were noted. RESULTS Thirty-three studies were included. Thirteen (39%) used MRI as baseline imaging modality, 9 used DSA (27%), and 7 used CT (21%). Segmentation through automatic algorithms was used in 20 (61%), semiautomatic segmentation in 6 (18%), and manual segmentation in 7 (21%) studies. Median automatic segmentation time was 10 min (IQR 33), semiautomatic 25 min (IQR 73). Manual segmentation time was reported in only one study, with the mean of 5-10 min. Thirty-two (97%) studies used screens to visualize the 3D segmentations outcomes and 1 (3%) study utilized a heads-up display (HUD). Integration with mixed reality was used in 4 studies (12%). CONCLUSIONS A golden standard for 3D visualization of bAVMs does not exist. This review describes a tendency over time to base segmentation on algorithms trained with machine learning. Unsupervised fuzzy-based algorithms thereby stand out as potential preferred strategy. Continued efforts will be necessary to improve algorithms, integrate complete hemodynamic assessment and find innovative tools for tridimensional visualization

Microporous Organic Polymers: Synthesis, Characterization, and Applications

The presence of a certain degree of porosity in polymers is a feature that provides them with unique properties and with opportunities to be exploited in a number of technologically important applications [...