Probability of Collision of satellites and space debris for short-term encounters: Rederivation and fast-to-compute upper and lower bounds

The proliferation of space debris in LEO has become a major concern for the space industry. With the growing interest in space exploration, the prediction of potential collisions between objects in orbit has become a crucial issue. It is estimated that, in orbit, there are millions of fragments a few millimeters in size and thousands of inoperative satellites and discarded rocket stages. Given the high speeds that these fragments can reach, even fragments a few millimeters in size can cause fractures in a satellite's hull or put a serious crack in the window of a space shuttle. The conventional method proposed by Akella and Alfriend in 2000 remains widely used to estimate the probability of collision in short-term encounters. Given the small period of time, it is assumed that, during the encounter: (1) trajectories are represented by straight lines with constant velocity; (2) there is no velocity uncertainty and the position exhibits a stationary distribution throughout the encounter; and (3) position uncertainties are independent and represented by Gaussian distributions. This study introduces a novel derivation based on first principles that naturally allows for tight and fast upper and lower bounds for the probability of collision. We tested implementations of both probability and bound computations with the original and our formulation on a real CDM dataset used in ESA's Collision Avoidance Challenge. Our approach reduces the calculation of the probability to two one-dimensional integrals and has the potential to significantly reduce the processing time compared to the traditional method, from 80% to nearly real-time

Pseudo-contractions as Gentle Repairs

Updating a knowledge base to remove an unwanted consequence is a challenging task. Some of the original sentences must be either deleted or weakened in such a way that the sentence to be removed is no longer entailed by the resulting set. On the other hand, it is desirable that the existing knowledge be preserved as much as possible, minimising the loss of information. Several approaches to this problem can be found in the literature. In particular, when the knowledge is represented by an ontology, two different families of frameworks have been developed in the literature in the past decades with numerous ideas in common but with little interaction between the communities: applications of AGM-like Belief Change and justification-based Ontology Repair. In this paper, we investigate the relationship between pseudo-contraction operations and gentle repairs. Both aim to avoid the complete deletion of sentences when replacing them with weaker versions is enough to prevent the entailment of the unwanted formula. We show the correspondence between concepts on both sides and investigate under which conditions they are equivalent. Furthermore, we propose a unified notation for the two approaches, which might contribute to the integration of the two areas

Bioactivity of different enriched phenolic extracts of wild fruits from Northeastern Portugal: a comparative study

Arbutus unedo, Prunus spinosa, Rosa micrantha and Rosa canina are good sources of phenolic compounds, including anthocyanins. These compounds have potent antioxidant properties, which have been related to anticancer activity. Herein, the in vitro antioxidant and antitumor properties of enriched phenolic extracts (non-anthocyanin phenolic compounds enriched extract- PE and anthocyanins enriched extract- AE) of the mentioned wild fruits were evaluated and compared. PE gave higher bioactive properties than the corresponding AE. It was observed a high capacity of A. unedo phenolic extract to inhibit lipid peroxidation in animal brain homogenates (EC50 = 7.21 µg/mL), as also a high antitumor potential against NCI-H460 human cell line (non-small lung cancer; GI50 = 37.68 µg/mL), which could be related to the presence of galloyl derivatives (exclusively found in this species). The bioactivity of the studied wild fruits proved to be more related to the phenolic compounds profile than to the amounts present in each extract, and could be considered in the design of new formulations of dietary supplements or functional foods.Foundation for Science and Technology (FCT, Portugal) for PEst-OE/AGR/UI0690/2011, PEst-C/QUI/UI0686/2011, BD/78307/2011 (R. Guimarães), BPD/68344/2010 (R. Calhelha) and researcher contract of L. Barros

A forensic identification case and DPid - can it be a useful tool?

Objective The aim of this study was to show DPid as an important tool of potential application to solve cases with dental prosthesis, such as the forensic case reported, in which a skull, denture and dental records were received for analysis. Material and Methods Human identification is still challenging in various circumstances and Dental Prosthetics Identification (DPid) stores the patient’s name and prosthesis information and provides access through an embedded code in dental prosthesis or an identification card. All of this information is digitally stored on servers accessible only by dentists, laboratory technicians and patients with their own level of secure access. DPid provides a complete single-source list of all dental prosthesis features (materials and components) under complete and secure documentation used for clinical follow-up and for human identification. Results and Conclusion If DPid tool was present in this forensic case, it could have been solved without requirement of DNA exam, which confirmed the dental comparison of antemortem and postmortem records, and concluded the case as a positive identification

Análise comparativa da radiopacidade do MTA e cimento Portland nos sistemas radiográficos digitais e convencionais

Introduction: The present study aimed evaluates objectively the radiopacity of MTA and Portland Cement (PC) in conventional and digital radiographic systems. Methods: Five test specimens for each material had been confectioned with 10mm of diameter and 2mm of thickness and exposed on a E/F Kodak Insight film together with a lead plate and step wedge in a focus-film distance of 40cm, device of 70kVp, 8mA and time of exposition of 0,4 and 0,2 second for the conventional and digital system respectively. The optic densities were measured in the radiograph and the values of pixels, in the digital images. For each exposure a graph was made of the measured values versus mmAl, to generate a radiopacity curve of the step wedge steps, obtaining the correspondence in equivalence of mmAl of the studied materials. Results: The statistical test of Mann-Whitney showed statistical significant difference between the radiopacity of MTA and PC, whereas it did not between the gotten results in the radiographical systems. Conclusions: MTA can be used in odontologic clinic because showed radiopacity inside of the standards demanded by specification N○ 57 of the American National Standards/ American Dental Association, whereas PC, not. Therefore, it is necessary the addition of radiopacificators in PC in attempt to increase its radiopacity which is an essential property of odontologic cements.Objetivo: O presente estudo teve como objetivo avaliar a radiopacidade do Agregado de trióxido mineral (MTA) e Cimento Portland (PC) em imagens radiográficas convencionais e digitais a fim de verificar se estão em conformidade com a especificação ANSI / ADA. Materiais e Métodos: Cinco corpos de prova para cada material com 10mm de diâmetro, 1mm de espessura e um penetrômetro foram expostos a 70kVp, 8mA a uma distância foco-filme de 30cm. Os tempos de exposição foram 0,4 e 0,2 s para o filme Insight Kodak e sistema digital CR Kodak 7400, respectivamente. A densidade óptica foi medida na radiografia através de um fotodensitômetro e o valor de pixel foi obtido para as imagens digitais. Um gráfico dos valores obtidos versus mmAl foi elaborado a fim de gerar uma curva de radiopacidade dos degraus do penetrômetro, obtendo a correspondência em equivalência de mmAl dos materiais estudados Um gráfico foi feito para os valores medidos em comparação mmAl, a fim de gerar uma curva de radiopacidade dos passos penetrômetro, obtendo-se a correspondência de equivalência de mmAl dos materiais estudados. Resultados: O teste estatístico de Mann-Whitney mostrou diferença estatística significativa na radiopacidade entre MTA e PC, tanto no sistema convencional (valor p = 0,009) e digital(valor p = 0,009). O mesmo teste também mostrou diferença estatística significativa entre os sistemas convencionais e digitais em ambos os materiais (p = 0,016 valueMTA-e p-valuecp = 0,009). Conclusões: MTA e CP não apresentaram radiopacidade dentro dos padrões exigidos pela especificação N ○ 57 do American National Standards / American Dental Association

Wild Roman chamomile extracts and phenolic compounds: enzymatic assays and molecular modelling studies with VEGFR-2 tyrosine kinase

Angiogenesis is a process by which new blood vessels are formed from the pre-existing vasculature, and it is a key process that leads to tumour development. Some studies have recognized phenolic compounds as chemopreventive agents; flavonoids, in particular, seem to suppress the growth of tumor cells modifying the cell cycle. Herein, the antiangiogenic activity of Roman chamomile (Chamaemelum nobile L.) extracts (methanolic extract and infusion) and the main phenolic compounds present (apigenin, apigenin-7-O-glucoside, caffeic acid, chlorogenic acid, luteolin, and luteolin-7-O-glucoside) was evaluated through enzymatic assays using the tyrosine kinase intracellular domain of the Vascular Endothelium Growth Factor Receptor-2 (VEGFR-2), which is a transmembrane receptor expressed fundamentally in endothelial cells involved in angiogenesis, and molecular modelling studies. The methanolic extract showed a lower IC50 value (concentration that provided 50% of VEGFR-2 inhibition) than the infusion, 269 and 301 μg mL(-1), respectively. Regarding phenolic compounds, luteolin and apigenin showed the highest capacity to inhibit the phosphorylation of VEGFR-2, leading us to believe that these compounds are involved in the activity revealed by the methanolic extract.The authors are grateful to strategic projects PEst-OE/AGR/UI0690/2014 and PEst-C/QUI/UI0686/2013-2014 for financial support to the research centres. R. Guimarães, and R. Calhelha thank to FCT, POPH-QREN and FSE for their grants (SFRH/BD/78307/2011 and SFRH/BPD/68344/2010)

Bioactivity and chemical characterization of phenolic and anthocyanin extracts of Arbutus unedo L. wild fruits

Phenolic metabolites are common constituents of fruits and vegetables, and the interest of plant phenolic extracts derives from the evidence of their potent antioxidant activity and their wide range of pharmacologic properties including anticancer, antimicrobial and platelet aggregation inhibition activities. The fruits of Arbutus unedo L. are eaten raw or made in liqueurs (1 ]. In traditional folk medicine, they are reported as having antiseptic, diuretic and laxative effects, being also used to treat arterial hypertension (2) .Moreover, the bark or roots decoctions are used as anti-inflammatory, laxative, carminative, digestive, odontalgic and cardiotonic. In this work, two different enriched phenolic extracts were prepared from A. unedo frutis, in order to evaluate and compare their bioactivity: a phenolic extract without anthocyanins (PE; with phenolic acids, flavones/ols, flavan-3-ols and galloyl derivatives) and a separate anthocyanins extract (AE). A. unedo PE presented the highest antioxidant activity in all the in vitro assays (free radicals scavenging activity, reducing power and lipid peroxidation inhibition), which could be related to the presence of galloyl derivatives. The antiproliferation activity was tested in different human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (PLP2). A. unedo PE also gave the highest antiproliferation inhibition presenting a Gl50 value=38 119/ml for NCI-H460- non-small lung carcinoma cell line, without toxicity for PLP2 (GI 50>400 119/m l). Overall, the results showed that A. unedo fruits may have great potential for food industries as a source of colors and flavors, as well as bioactive molecules such as phenolic compounds for dietary supplements or functional foods

Phenolic compounds and bioactive properties of wild German and Roman chamomiles

Natural products represent a rich source of biologically active compounds and are an example of molecular diversity, with recognized potential in drug discovery. In the present work, methanolic extracts of Matricaria recutita L. (German chamomile) and Chamaemelum nobile L. (Roman chamomile) and their decoction and infusion (the most consumed preparations of these herbs) were submitted to an analysis of phenolic compounds and bioactivity evaluation. Phenolic compounds were characterized by HPLC-DAD/ESI-MS. The bioactivity of the samples was tested in human tumour cell lines (breast- MCF-7, non-small cell lung- NCI-H460, colon- HCT-15, cervical- HeLa and hepatocellular- HepG2 carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (non-tumour cells, PLP2) [1,2]. Methanolic extracts of both chamomiles presented the highest amount of phenolic compounds compared to decoction and infusion, although varying in their composition. Furthermore, it was observed a decrease in the amount of phenolic compounds in decoction preparations of both samples. The major compounds found were luteolin O-acylhexoside in German chamomile, and 5-O-caffeoylquinic acid and an apigenin derivative in Roman chamomile. Methanolic extract and infusion preparation of both herbs showed inhibitory activity of the growth of HCT-15 and HeLa cell lines, without hepatotoxicity (GI50>400 µg/mL). Roman chamomile methanolic extract presented the highest inhibitory activity for all the cell lines (GI50400 µg/mL), which could indicate that this bioactivity might be related to the compounds (including phenolic compounds) that were not extracted or that were affected by the decoction procedure. Overall, both chamomiles, mainly the methanolic extracts, contain important phytochemicals with bioactive properties to be explored in the medicine, food, and cosmetic industries.The authors are grateful to strategic project PEst-OE/AGR/UI0690/2011 for financial support to CIMO. R. Guimarães, L. Barros and R. Calhelha thanks to FCT, POPH-QREN and FSE for their grants (SFRH/BD/78307/2011, SFRH/BPD/4609/2008 and SFRH/BPD/68344/2010). The GIP-USAL is financially supported by the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063)

Bioactivity and chemical characterization of phenolic and anthocyanin extracts of Arbutus unedo L. wild fruits

Phenolic metabolites are common constituents of fruits and vegetables, and the interest of plant phenolic extracts derives from the evidence of their potent antioxidant activity and their wide range of pharmacologic properties including anticancer, antimicrobial and platelet aggregation inhibition activities. The fruits of Arbutus unedo L. are eaten raw or made in liqueurs (1 ]. In traditional folk medicine, they are reported as having antiseptic, diuretic and laxative effects, being also used to treat arterial hypertension (2) .Moreover, the bark or roots decoctions are used as anti-inflammatory, laxative, carminative, digestive, odontalgic and cardiotonic. In this work, two different enriched phenolic extracts were prepared from A. unedo frutis, in order to evaluate and compare their bioactivity: a phenolic extract without anthocyanins (PE; with phenolic acids, flavones/ols, flavan-3-ols and galloyl derivatives) and a separate anthocyanins extract (AE). A. unedo PE presented the highest antioxidant activity in all the in vitro assays (free radicals scavenging activity, reducing power and lipid peroxidation inhibition), which could be related to the presence of galloyl derivatives. The antiproliferation activity was tested in different human tumour cell lines (breast, lung, colon, cervical and hepatocellular carcinomas), and the hepatotoxicity was evaluated using a porcine liver primary cell culture (PLP2). A. unedo PE also gave the highest antiproliferation inhibition presenting a Gl50 value=38 119/ml for NCI-H460- non-small lung carcinoma cell line, without toxicity for PLP2 (GI 50>400 119/m l). Overall, the results showed that A. unedo fruits may have great potential for food industries as a source of colors and flavors, as well as bioactive molecules such as phenolic compounds for dietary supplements or functional foods

Repercussões da Insuficiência Renal Crônica no Contexto Biopsicossocial de Pessoa em Tratamento Hemodialítico.

Introduction: chronic renal failure is considered an important public health problem since both the disease and the treatment have profound impacts on the entire life context of the affected person. Objective: to understand the repercussions of chronic renal failure in the biopsychosocial context of patients undergoing hemodialysis. Methodology: this is a descriptive, qualitative study developed in a regional reference hospital for the treatment of hemodialysis in the State of Bahia, Brazil. Twenty people with chronic renal failure undergoing hemodialysis took part in the study; all of them were over 18 years old. The data collection was carried out in December 2019 through a semi-structured interview. Subsequently, the data were systematized through Content Analysis. Results: the study showed that renal failure brings multidimensional repercussions to the patients due to the difficulties in entering the world market, difficulties related to food and water restrictions, limitations related to leisure and the physical activity practices, and the impact on sexuality. However, despite the limitations caused by the disease, patients showed themselves resilient in highlighting the importance of the treatment to guarantee their quality of life. Conclusion: the study points to the need of building specific policies aimed at reducing the impact caused by chronic renal failure since it is a chronic and irreversible disease that requires permanent treatment. Furthermore, the findings confirm the need for individualized assessment and the provision of holistic and humanized care by health professionals as a way to minimize the impact of the illness.Introducción: La insuficiencia renal crónica es considerada un importante problema de salud pública, ya que tanto la enfermedad como el tratamiento tienen profundos impactos en todo el contexto de vida de la persona afectada. Objetivo: Comprender las repercusiones de la insuficiencia renal crónica en el contexto biopsicosocial de personas en hemodiálisis. Metodología: Se trata de un estudio descriptivo, cualitativo, desarrollado en un hospital regional de referencia para el tratamiento de hemodiálisis en el Estado de Bahía, Brasil. En el estudio participaron 20 personas con insuficiencia renal crónica, mayores de 18 años, sometidas a hemodiálisis. La recolección de datos se realizó durante el mes de diciembre de 2019, a través de una entrevista semiestructurada. Posteriormente, los datos fueron sistematizados mediante análisis de contenido. Resultados: Se demostró que la insuficiencia renal trae repercusiones multidimensionales para las personas, debido a las dificultades para ingresar al mundo laboral, dificultades relacionadas con las restricciones alimentarias y hídricas, limitaciones relacionadas con el ocio y la práctica de actividad física e impactos en el ejercicio de la sexualidad. Sin embargo, a pesar de las limitaciones provocadas por la enfermedad, las personas se mostraron resilientes al resaltar la importancia del tratamiento para garantizar su calidad de vida. Conclusión: El estudio apunta a la necesidad de construir políticas específicas orientadas a reducir los impactos provocados por la insuficiencia renal crónica, por ser una enfermedad crónica e irreversible, que necesita tratamiento permanente. Además, los hallazgos confirman la necesidad de una evaluación individualizada y la provisión de atención integral y humanizada por parte de profesionales de la salud que les brindan atención, como una forma de minimizar los impactos de la enfermedad.Introdução: a insuficiência renal crônica é considerada um importante problema de saúde pública, uma vez que tanto a doença quanto o tratamento provocam impactos profundos em todo o contexto de vida da pessoa acometida. Objetivo: compreender as repercussões da insuficiência renal crônica no contexto biopsicossocial de pacientes em tratamento hemodialítico. Metodologia: trata-se de um estudo descritivo, qualitativo, desenvolvido em um hospital referência regional para o tratamento de hemodiálise no Estado da Bahia, Brasil. Participaram do estudo 20 pessoas com insuficiência renal crônica, com idade superior a 18 anos, em tratamento hemodialítico. A coleta dos dados foi realizada durante o mês de dezembro de 2019 através de uma entrevista semiestruturada. Posteriormente, os dados foram sistematizados através da Análise de Conteúdo. Resultados: evidenciou-se que a insuficiência renal traz repercussões multidimensionais para os pacientes, devido às dificuldades de inserção no mundo do trabalho, dificuldades relacionadas às restrições alimentares e hídricas, limitações relacionadas ao lazer e a prática de atividade física e impactos no exercício da sexualidade. Entretanto, apesar das limitações provocadas pela doença, os pacientes mostraram-se resilientes ao destacarem a importância do tratamento para garantia de sua qualidade de vida. Conclusão: o estudo aponta para necessidade de construção de políticas específicas voltadas para redução dos impactos provocados pela Insuficiência Renal Crônica, uma vez que se trata de uma doença crônica e irreversível, com necessidade de tratamento permanente. Além disso, os achados ratificam a necessidade de avaliação individualizada e oferta de uma assistência holística e humanizada por parte dos profissionais de saúde como forma de minimizar os impactos do adoecimento