Controle em tempo real de robôs móveis não-holonômicos

Este documento trata da implementação em tempo real de controladores preditivos para robôs móveis não-holonômicos. É sabido que, conforme o Teorema de Brockett, não é possível se obter uma lei de controle do tipo realimentação de estados suave e invariante no tempo que estabilize um robô móvel não-holonômico em um ponto qualquer. Pode-se contornar o problema utilizando controle preditivo baseado em modelo (MPC). Entretanto, ao se empregar urna função-custo quadrática em relação ao estado do sistema conforme modelo comumente utilizado não se obtém convergência para o ponto de equihbrio desejado. Para tal, funções-custo específicas podem ser consideradas na formulação do MPC. São utilizados controladores MPC também para o problema de rastreamento de trajetória. São revisadas estas estratégias de controle preditivo baseado em modelo aplicadas a robôs móveis, apresentadas novas estratégias e então implementados os diversos controladores em tempo real. Medições de tempo são feitas no sistema em funcionamento para comprovar a aplicabilidade dos controladores propostos.This document deals with the real-time implementation of predictive controllers for non-holonomic mobile robots. According to Brockett's Theorem, it is known that for such· a system a smooth, time invariant state feedback can not be used in order to obtain asymptotic point stability. This issue may be overcome by using model predictive control (MPC). However, by considering a cost function that is quadratic with respect to the system state, according to the usual model considered for the system, one does not obtain convergence to the desired point. With the objective of overcoming this problem, particular cost functions can be used. MPC controlers can also be used with mobile robots for the tracking problem. In this work different MPC strategies are revised, new strategies are presented and the controlers are then implemented in real-time. Time measures are taken on the running controllers so as to assure their applicability

Ebola: an international public health emergency

The outbreak of Ebola in West Africa could become one of the worst infectious-disease-driven humanitarian crises of recent times. With more than 3000 deaths since the first case was confirmed in March 2014, the international community has recognized Ebola as a public health emergency of international concern and a clear threat to global health security. The complexity of dealing with this Ebola outbreak has highlighted the need for traditional actors, such as WHO and the CDC, to embrace the wider health and humanitarian community. The epidemic reinforces the need for nations to investment in health infrastructure and disease surveillance to keep pace with other developments in Africa. If Ebola arrives in high-income and middleincome nations, it should be contained quickly. The crisis shows the importance of sufficient levels of multilateral funding for WHO. The world needs a strong WHO, with the financing and political influence to fulfil its historic mission

The Importance Of Neuronal Plasticity In The Prognosis Of Cases Of Cerebral Ischemia: A Systematic Review

Background: Neuronal plasticity is the capacity that the neurons have to make new connections and enable new ways of transmitting information. Under this context, new methodologies are being addressed in order to measure how important this neuronal capacity is in the process of full recovery of learning in subjects who suffered damage from cerebral ischemia.Methods: A systematic review was performed on the online databases: Medical Literature Analysis and Retrieval System Online (MEDLINE) and Scopus, between 1998 and 2014. The MeSH (Medical Subject Headings) descriptors used in this review were: "neuronal plasticity", "brain ischemia" and "learning". We found 164 articles that, when screened, resulted in 46 articles that met the criteria of evidence and were included in this review.Results: There are several ways available in the literature to increase neuronal plasticity to keep the learning process after bad conformations resulting from cerebral ischemia. We highlighted the most elucidated: those promoted by SMe1EC2 antioxidant, which brings therapeutic benefits when neuronal plasticity is impaired; and Atorvastatin, a statin which facilitates recovery of spatial learning. It is further observed that the body has a number of intrinsic devicessuch as the endogenous compensatory mechanisms that contribute to the development of neuronal plasticity when there is brain damage caused by ischemia.Conclusion: The improvement of neuronal plasticity appears in several studies mapped as a new and still little explored possibility of treatment of damages caused by brain processes of oxygen deprivation. Multiple devices, endogenous and exogenous, that promote an increase in neuronal plasticity, are being elucidated in an attempt to promote the full recovery of the learning process, decreased by brain damage from ischemic processes. Thus, it is pointed the necessity of scientific studies that allows to define and maximize the potentials of the neuronal plasticity

Both “illness and temptation of the enemy”: melancholy, the medieval patient and the writings of King Duarte of Portugal (r. 1433–38)

Recent historians have rehabilitated King Duarte of Portugal, previously maligned and neglected, as an astute ruler and philosopher. There is still a tendency, however, to view Duarte as a depressive or a hypochondriac, due to his own description of his melancholy in his advice book, the Loyal Counselor. This paper reassesses Duarte's writings, drawing on key approaches in the history of medicine, such as narrative medicine and the history of the patient. It is important to take Duarte's views on his condition seriously, placing them in the medical and theological contexts of his time and avoiding modern retrospective diagnosis. Duarte's writings can be used to explore the impact of plague, doubt and death on the life of a well-educated and conscientious late-medieval ruler

Eficácia de intervenções imunomoduladoras para o tratamento da Esclerose Lateral Amiotrófica (ELA)

A esclerose lateral amiotrófica (ELA) é uma doença neurodegenerativa que afeta as células nervosas responsáveis pelo controle dos músculos voluntários, resultando em fraqueza muscular e atrofia. Nesse contexto, as intervenções imunomoduladoras têm como objetivo modular a resposta imune do organismo, ao reduzir a inflamação e possibilitar a neuroproteção, a partir do uso de anticorpos monoclonais, inibidores de citocinas e moduladores do sistema imunológico. No entanto, a eficácia de tais intervenções no tratamento da ELA ainda é incerta. Nesse sentido, o presente estudo tem como objetivo analisar a eficácia de intervenções imunomoduladoras para o tratamento da esclerose lateral amiotrófica. Para isso, foram selecionados cinco artigos que abordavam sobre a sua eficácia, por meio de uma estratégia de busca com recorte temporal entre 2017 e 2023, nas bases de dados PubMed (Medline), Cochrane Library e Embase. As intervenções imunomoduladoras, como o uso de inibidores de citocinas, têm demonstrado eficácia no tratamento da esclerose lateral amiotrófica (ELA). Além disso, há evidências de que a inflamação crônica pode estar envolvida em sua patogênese, o que sugere que a modulação do sistema imunológico pode ser uma abordagem terapêutica promissora. Em estudos clínicos recentes, a terapia com inibidores de citocinas mostrou-se capaz de reduzir a progressão da doença e melhorar a qualidade de vida dos pacientes com ELA. Ademais, há evidências que o uso de células-tronco pode melhorar o status funcional em pacientes com a doença. Entretanto, são necessários mais estudos, como ensaios clínicos randomizados e revisões sistemáticas com meta-análises, a fim de ratificar a eficácia das estratégias imunomoduladoras para a patologia

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality

Population and fertility by age and sex for 195 countries and territories, 1950–2017: a systematic analysis for the Global Burden of Disease Study 2017

Background: Population estimates underpin demographic and epidemiological research and are used to track progress on numerous international indicators of health and development. To date, internationally available estimates of population and fertility, although useful, have not been produced with transparent and replicable methods and do not use standardised estimates of mortality. We present single-calendar year and single-year of age estimates of fertility and population by sex with standardised and replicable methods. Methods: We estimated population in 195 locations by single year of age and single calendar year from 1950 to 2017 with standardised and replicable methods. We based the estimates on the demographic balancing equation, with inputs of fertility, mortality, population, and migration data. Fertility data came from 7817 location-years of vital registration data, 429 surveys reporting complete birth histories, and 977 surveys and censuses reporting summary birth histories. We estimated age-specific fertility rates (ASFRs; the annual number of livebirths to women of a specified age group per 1000 women in that age group) by use of spatiotemporal Gaussian process regression and used the ASFRs to estimate total fertility rates (TFRs; the average number of children a woman would bear if she survived through the end of the reproductive age span [age 10–54 years] and experienced at each age a particular set of ASFRs observed in the year of interest). Because of sparse data, fertility at ages 10–14 years and 50–54 years was estimated from data on fertility in women aged 15–19 years and 45–49 years, through use of linear regression. Age-specific mortality data came from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2017 estimates. Data on population came from 1257 censuses and 761 population registry location-years and were adjusted for underenumeration and age misreporting with standard demographic methods. Migration was estimated with the GBD Bayesian demographic balancing model, after incorporating information about refugee migration into the model prior. Final population estimates used the cohort-component method of population projection, with inputs of fertility, mortality, and migration data. Population uncertainty was estimated by use of out-of-sample predictive validity testing. With these data, we estimated the trends in population by age and sex and in fertility by age between 1950 and 2017 in 195 countries and territories. Findings: From 1950 to 2017, TFRs decreased by 49\ub74% (95% uncertainty interval [UI] 46\ub74–52\ub70). The TFR decreased from 4\ub77 livebirths (4\ub75–4\ub79) to 2\ub74 livebirths (2\ub72–2\ub75), and the ASFR of mothers aged 10–19 years decreased from 37 livebirths (34–40) to 22 livebirths (19–24) per 1000 women. Despite reductions in the TFR, the global population has been increasing by an average of 83\ub78 million people per year since 1985. The global population increased by 197\ub72% (193\ub73–200\ub78) since 1950, from 2\ub76 billion (2\ub75–2\ub76) to 7\ub76 billion (7\ub74–7\ub79) people in 2017; much of this increase was in the proportion of the global population in south Asia and sub-Saharan Africa. The global annual rate of population growth increased between 1950 and 1964, when it peaked at 2\ub70%; this rate then remained nearly constant until 1970 and then decreased to 1\ub71% in 2017. Population growth rates in the southeast Asia, east Asia, and Oceania GBD super-region decreased from 2\ub75% in 1963 to 0\ub77% in 2017, whereas in sub-Saharan Africa, population growth rates were almost at the highest reported levels ever in 2017, when they were at 2\ub77%. The global average age increased from 26\ub76 years in 1950 to 32\ub71 years in 2017, and the proportion of the population that is of working age (age 15–64 years) increased from 59\ub79% to 65\ub73%. At the national level, the TFR decreased in all countries and territories between 1950 and 2017; in 2017, TFRs ranged from a low of 1\ub70 livebirths (95% UI 0\ub79–1\ub72) in Cyprus to a high of 7\ub71 livebirths (6\ub78–7\ub74) in Niger. The TFR under age 25 years (TFU25; number of livebirths expected by age 25 years for a hypothetical woman who survived the age group and was exposed to current ASFRs) in 2017 ranged from 0\ub708 livebirths (0\ub707–0\ub709) in South Korea to 2\ub74 livebirths (2\ub72–2\ub76) in Niger, and the TFR over age 30 years (TFO30; number of livebirths expected for a hypothetical woman ageing from 30 to 54 years who survived the age group and was exposed to current ASFRs) ranged from a low of 0\ub73 livebirths (0\ub73–0\ub74) in Puerto Rico to a high of 3\ub71 livebirths (3\ub70–3\ub72) in Niger. TFO30 was higher than TFU25 in 145 countries and territories in 2017. 33 countries had a negative population growth rate from 2010 to 2017, most of which were located in central, eastern, and western Europe, whereas population growth rates of more than 2\ub70% were seen in 33 of 46 countries in sub-Saharan Africa. In 2017, less than 65% of the national population was of working age in 12 of 34 high-income countries, and less than 50% of the national population was of working age in Mali, Chad, and Niger. Interpretation: Population trends create demographic dividends and headwinds (ie, economic benefits and detriments) that affect national economies and determine national planning needs. Although TFRs are decreasing, the global population continues to grow as mortality declines, with diverse patterns at the national level and across age groups. To our knowledge, this is the first study to provide transparent and replicable estimates of population and fertility, which can be used to inform decision making and to monitor progress. Funding: Bill & Melinda Gates Foundation