The newly discovered glymphatic system: the missing link between physical exercise and brain health?

Dementias are responsible for the most frequent neurodegenerative diseases and the seventh leading cause of death worldwide. As a result, there is a growing effort by the neuroscientific community to understand the physiopathology of neurodegenerative diseases, including how to alleviate the effects of the cognitive decline by means of non-pharmacological therapies (e.g., physical exercise). Studies have shown that exercise can improve aspects of brain health related to cognition. However, there still needs to be more knowledge regarding the mechanisms controlling these relationships, and a newly discovered cleansing system in the brain, named the glymphatic system, can be the missing link in this mechanism. The objective of this paper is to review recent findings regarding the potential impacts of physical exercise on the glymphatic system and its implications for the onset of neurodegenerative diseases. Additionally, considering the close interplay between exercise and sleep quality, we aim to explore how sleep patterns may intersect with exercise-induced effects on glymphatic function, further elucidating the complex relationship between lifestyle factors and brain health

ClaimChain: Improving the Security and Privacy of In-band Key Distribution for Messaging

The social demand for email end-to-end encryption is barely supported by mainstream service providers. Autocrypt is a new community-driven open specification for e-mail encryption that attempts to respond to this demand. In Autocrypt the encryption keys are attached directly to messages, and thus the encryption can be implemented by email clients without any collaboration of the providers. The decentralized nature of this in-band key distribution, however, makes it prone to man-in-the-middle attacks and can leak the social graph of users. To address this problem we introduce ClaimChain, a cryptographic construction for privacy-preserving authentication of public keys. Users store claims about their identities and keys, as well as their beliefs about others, in ClaimChains. These chains form authenticated decentralized repositories that enable users to prove the authenticity of both their keys and the keys of their contacts. ClaimChains are encrypted, and therefore protect the stored information, such as keys and contact identities, from prying eyes. At the same time, ClaimChain implements mechanisms to provide strong non-equivocation properties, discouraging malicious actors from distributing conflicting or inauthentic claims. We implemented ClaimChain and we show that it offers reasonable performance, low overhead, and authenticity guarantees.Comment: Appears in 2018 Workshop on Privacy in the Electronic Society (WPES'18

Histopathological Features of Dental Pulp in Teeth with Different Levels of Chronic Periodontitis Severity

Purpose. To evaluate the histopathological condition of the pulp in teeth with different levels of chronic periodontitis in humans. Methods. Twenty-five single-root nondecayed teeth were divided into three groups as follows: group 1, clinical attachment level (CAL) 3 to 4 mm and alveolar bone loss (BL) from 4 to 6 mm without reaching the tooth apex; group 2, CAL ≥ 5 mm and BL > 6 mm without reaching the tooth apex; group 3, CAL ≥ 5 mm and BL > 6 mm up to the tooth apex. Histological analyses were accomplished after laboratorial processing. Results. The mean of CAL was 3.2 ± 0.7 mm in group 1, 7.6 ± 2.0 mm in group 2, and 12.1 ± 2.8 mm in group 3, while for BL it was 4.8 ± 0.9 mm, 7.6 ± 2.2 mm, and 11.9 ± 2.1 mm, respectively. Histopathological data in the pulpal chambers were similar among the three groups showing normal aspects, and, the radicular pulps showed variable levels of reactive dentin, fibrosis, dystrophic mineralizations, atrophy, and mononuclear inflammatory infiltrate. Conclusions. Gradual progression of the chronic periodontitis led to changes in the histopathological aspects of the radicular pulp with progressive involvement

New optimization techniques for PlonK’s arithmetization

PlonK is a universal and updatable zk-SNARK for general circuit satisfiability that allows a verifier to check the validity of a certain NP statement very efficiently, optionally in zero-knowledge. PlonK requires that the NP relation of interest be expressed as a system of so-called PlonK constraints. Such conversion is complex and can be implemented in various ways, having a great impact on the prover complexity (which is typically linearithmic in the number of PlonK constraints). We propose several general results for simplifying PlonK constraint systems, which produce more compact but equivalent systems and can lead to significant performance improvements. We also develop an automated optimizer of constraints, based on our techniques, that can be used to construct very compact and less error-prone constraint systems, favoring a more auditable circuit design. Finally, we demonstrate the potential of our techniques by implementing optimized constraint systems for the Poseidon hash, obtaining the most compact representations in the Turbo-PlonK model with minimal custom gates. En route, we devise a novel optimization idea for implementing Poseidon partial rounds and show that it can be applied to both simplifying SNARK circuits and achieving performance improvements in CPU implementations of the Poseidon hash

What is the relationship between physical activity and chronic pain in older adults? A systematic review and meta-analysis protocol

INTRODUCTION: Chronic pain is highly prevalent in older adults and can cause functional limitations, negatively affecting health and quality of life. Physical activity is a non-pharmacological approach used to prevent chronic pain as it promotes the release of endogenous opioids that block pain sensitivity. Therefore, we developed a systematic review protocol to analyse the relationship between physical activity and the occurrence and intensity of chronic pain in older adults. METHODS AND ANALYSES: The systematic review will search PubMed, Scopus and Embase databases. The inclusion criteria will be observational studies that had primary chronic pain as an outcome, including persistent and intermittent pain. The population will include older adults from the community, living in a long-stay institution, or in outpatient follow-up. There will be no restriction regarding the year of publication and articles published in Portuguese, English and Spanish will be analysed. Effect or impact measures will be quantified, including OR, HR, prevalence ratio, incidence ratio and relative risk with their 95% CIs. If the data allow, a meta-analysis will be performed. The results may help understand the impact of physical activity as a potential protection factor against the occurrence of pain later in life as well as promote strategic prevention plans and public policies that encourage this practice in older adults. ETHICS AND DISSEMINATION: Ethical approval is not required. The results will be disseminated via submission for publication to a peer-reviewed journal when complete. PROSPERO REGISTRATION NUMBER: CRD42021282898

Modelo de sistema operacional básico para ensino na Ciência da Computação

A inclusão de atividades práticas no ensino de Sistemas Operacionais facilita a aprendizagem, porém incorpora novos desafios à disciplina, por exemplo, desenvolver novos sistemas operacionais. Propõe-se neste artigo um modelo de referência de núcleo de sistema operacional básico, que contribui para estudantes compreenderem mais claramente aspectos relacionados ao desenvolvimento prático de sistemas operacionais. Para tanto apresenta-se o Modelo de Sistema Operacional Básico (MSOB), desenvolvido em linguagem de alto nível, que serve como modelo de referência para o desenvolvimento de sistemas operacionais. Os resultados alcançados com sua aplicação revelaram aumento da compreensão nos estudantes, com impacto positivo no ensino prático de Sistemas Operacionais

Desenvolvimento de interface de dispositivos móveis para utilização com uma plataforma múltipla de dados / Mobile device interface development for use with a multiple data platform

Essa pesquisa aborda o desenvolvimento de um modelo de interface aplicado a sistemas desenvolvidos para a internet ou desktop, que apresentam dificuldades de acesso e apresentação aos dados em dispositivos móveis. Ainda existem sistemas que trabalham em ambientes sem considerar acesso por dispositivos móveis, deste modo, prejudicando o acesso aos dados desses sistemas, proporcionando dificuldades de uso e fazendo ocorrer até a desistência no uso desse aplicativos nesses dispositivos. Tendo em vista que, a importância desses dispositivos no acesso a dados tem se tornado crescente, isso faz com que haja necessidade de adaptações desses sistemas para esses ambientes. O padrão de interface proposto é baseado na arquitetura Model-View-Controller, e foi concebida para se adaptar a quaisquer tipos de dispositivos móveis

A reduction in CD90 (THY-1) expression results in increased differentiation of mesenchymal stromal cells

Background: Mesenchymal stromal cells (MSCs) are multipotent progenitor cells used in several cell therapies. MSCs are characterized by the expression of CD73, CD90, and CD105 cell markers, and the absence of CD34, CD45, CD11a, CD19, and HLA-DR cell markers. CD90 is a glycoprotein present in the MSC membranes and also in adult cells and cancer stem cells. The role of CD90 in MSCs remains unknown. Here, we sought to analyse the role that CD90 plays in the characteristic properties of in vitro expanded human MSCs. Methods: We investigated the function of CD90 with regard to morphology, proliferation rate, suppression of T-cell proliferation, and osteogenic/adipogenic differentiation of MSCs by reducing the expression of this marker using CD90-target small hairpin RNA lentiviral vectors. Results: The present study shows that a reduction in CD90 expression enhances the osteogenic and adipogenic differentiation of MSCs in vitro and, unexpectedly, causes a decrease in CD44 and CD166 expression. Conclusion: Our study suggests that CD90 controls the differentiation of MSCs by acting as an obstacle in the pathway of differentiation commitment. This may be overcome in the presence of the correct differentiation stimuli, supporting the idea that CD90 level manipulation may lead to more efficient differentiation rates in vitro