SIRSi-vaccine dynamical model for the Covid-19 pandemic.

Covid-19, caused by severe acute respiratory syndrome coronavirus 2, broke out as a pandemic during the beginning of 2020. The rapid spread of the disease prompted an unprecedented global response involving academic institutions, regulatory agencies, and industries. Vaccination and nonpharmaceutical interventions including social distancing have proven to be the most effective strategies to combat the pandemic. In this context, it is crucial to understand the dynamic behavior of the Covid-19 spread together with possible vaccination strategies. In this study, a susceptible-infected-removed-sick model with vaccination (SIRSi-vaccine) was proposed, accounting for the unreported yet infectious. The model considered the possibility of temporary immunity following infection or vaccination. Both situations contribute toward the spread of diseases. The transcritical bifurcation diagram of alternating and mutually exclusive stabilities for both disease-free and endemic equilibria were determined in the parameter space of vaccination rate and isolation index. The existing equilibrium conditions for both points were determined in terms of the epidemiological parameters of the model. The bifurcation diagram allowed us to estimate the maximum number of confirmed cases expected for each set of parameters. The model was fitted with data from São Paulo, the state capital of SP, Brazil, which describes the number of confirmed infected cases and the isolation index for the considered data window. Furthermore, simulation results demonstrate the possibility of periodic undamped oscillatory behavior of the susceptible population and the number of confirmed cases forced by the periodic small-amplitude oscillations in the isolation index. The main contributions of the proposed model are as follows: A minimum effort was required when vaccination was combined with social isolation, while additionally ensuring the existence of equilibrium points. The model could provide valuable information for policymakers, helping define disease prevention mitigation strategies that combine vaccination and non-pharmaceutical interventions, such as social distancing and the use of masks. In addition, the SIRSi-vaccine model facilitated the qualitative assessment of information regarding the unreported infected yet infectious cases, while considering temporary immunity, vaccination, and social isolation index.

Effects of Carbon Nanomaterials and Aloe vera on Melanomas-Where Are We? Recent Updates.

Melanoma is an aggressive skin cancer that affects approximately 140,000 people worldwide each year, with a high fatality rate. Available treatment modalities show limited efficacy in more severe cases. Hence, the search for new treatment modalities, including immunotherapies, for curing, mitigating, and/or preventing cancer is important and urgently needed. Carbon nanoparticles associated with some plant materials, such as Aloe vera, have shown appealing antineoplastic activity, derived mainly from the compounds aloin, aloe-emodin, barbaloin acemannan, and octapeptide, thus representing new possibilities as antitumor agents. This systematic review aims to arouse interest and present the possibilities of using Aloe vera combined with carbon-based nanomaterials as an antineoplastic agent in the treatment and prevention of melanoma. Limitations and advances in melanoma treatment using functionalized carbon nanomaterials are discussed here. Moreover, this review provides the basis for further studies designed to fully explore the potential of carbon nanomaterials associated with Aloe vera in the treatment of various cancers, with a focus on melanoma.

Coronavirus and Carbon Nanotubes: Seeking Immunological Relationships to Discover Immunotherapeutic Possibilities.

Since December 2019, the world has faced an unprecedented pandemic crisis due to a new coronavirus disease, coronavirus disease-2019 (COVID-19), which has instigated intensive studies on prevention and treatment possibilities. Here, we investigate the relationships between the immune activation induced by three coronaviruses associated with recent outbreaks, with special attention to SARS-CoV-2, the causative agent of COVID-19, and the immune activation induced by carbon nanotubes (CNTs) to understand the points of convergence in immune induction and modulation. Evidence suggests that CNTs are among the most promising materials for use as immunotherapeutic agents. Therefore, this investigation explores new possibilities of effective immunotherapies for COVID-19. This study aimed to raise interest and knowledge about the use of CNTs as immunotherapeutic agents in coronavirus treatment. Thus, we summarize the most important immunological aspects of various coronavirus infections and describe key advances and challenges in using CNTs as immunotherapeutic agents against viral infections and the activation of the immune response induced by CNTs, which can shed light on the immunotherapeutic possibilities of CNTs.

Metrics based on information entropy applied to evaluate complexity of landscape patterns.

Landscape is an ecological category represented by a complex system formed by interactions between society and nature. Spatial patterns of different land uses present in a landscape reveal past and present processes responsible for its dynamics and organisation. Measuring the complexity of these patterns (in the sense of their spatial heterogeneity) allows us to evaluate the integrity and resilience of these complex environmental systems. Here, we show how landscape metrics based on information entropy can be applied to evaluate the complexity (in the sense of spatial heterogeneity) of patches patterns, as well as their transition zones, present in a Cerrado conservation area and its surroundings, located in south-eastern Brazil. The analysis in this study aimed to elucidate how changes in land use and the consequent fragmentation affect the complexity of the landscape. The scripts CompPlex HeROI and CompPlex Janus were created to allow calculation of information entropy (He), variability (He/Hmax), and López-Ruiz, Mancini, and Calbet (LMC) and Shiner, Davison, and Landsberg (SDL) measures. CompPlex HeROI enabled the calculation of these measures for different regions of interest (ROIs) selected in a satellite image of the study area, followed by comparison of the complexity of their patterns, in addition to enabling the generation of complexity signatures for each ROI. CompPlex Janus made it possible to spatialise the results for these four measures in landscape complexity maps. As expected, both for the complexity patterns evaluated by CompPlex HeROI and the complexity maps generated by CompPlex Janus, the areas with vegetation located in a region of intermediate spatial heterogeneity had lower values for the He and He/Hmax measures and higher values for the LMC and SDL measurements. So, these landscape metrics were able to capture the behaviour of the patterns of different types of land use present in the study area, bringing together uses linked to vegetation with increased canopy coverage and differentiating them from urban areas and transition areas that mix different uses. Thus, the algorithms implemented in these scripts were demonstrated to be robust and capable of measuring the variability in information levels from the landscape, not only in terms of spatial datasets but also spectrally. The automation of measurement calculations, owing to informational entropy provided by these scripts, allows a quick assessment of the complexity of patterns present in a landscape, and thus, generates indicators of landscape integrity and resilience.

Evidence of genomic information and structural restrictions of HIV-1 PR and RT gene regions from individuals experiencing antiretroviral virologic failure.

OBJECTIVES: This study analyzed Protease-PR and Reverse Transcriptase-RT HIV-1 genomic information entropy metrics among patients under antiretroviral virologic failure, according to the numbers of virologic failures or resistance mutations. METHODS: For this purpose, we used genomic sequences from PR and RT of HIV-1 from a cohort of chronic patients followed up at São Paulo Hospital. RESULTS: Informational entropy proportionally increases with the number of antiretroviral virologic failures in PR and RT (p < .001). Affected regions of PR were related to catalytic and structural functions, such as Fulcrum (K20) Flap (M46) and Cantilever (A71). In RT, this occurred at Fingers (E44) and Palm (K219). Informational entropy increases according to the number of resistance mutations in PR and RT (p < .001). Higher PR entropy was proportional to the resistance mutation numbers in Fulcrum (L10), Active site (L24) Flap (M46), Cantilever (L63) and near Interface (L90). In RT, they related to regions responsible for protein stability such as Fingers (T39) and Palm (L100). CONCLUSIONS: The antiretroviral selective pressure affects HIV genomic informational entropy at the PR and RT regions, leading to the emergence of more unstable virions. Mapping the three-dimensional structure in these HIV-1 proteins is relevant to designing new antiretroviral targeting resistant strains.

Brumadinho: entre a prudência e a probabilidade, a tragédia / Brumadinho: between prudence and probability, tragedy

Será possível, em algum momento no futuro, explicar com exatidão o que aconteceu no caso do rompimento da barragem de Brumadinho? Apesar de, muitas vezes, se utilizar a palavra exatidão no mundo da engenharia, sabe-se que, em muitos casos, trata-se de um eufemismo. A arte da engenharia consiste em projetar, construir, implementar e gerenciar diferentes tipos de sistemas que podem trazer consequências tanto positivas como negativas para os trabalhadores, para a sociedade, para o meio ambiente. Aconteceu um evento ou uma sequência de eventos que levou ao rompimento. A engenharia de barragens de rejeitos conhece e é capaz de controlar todos os eventos passiveis de acontecer e que, articulados, podem levar ao rompimento? Há dois caminhos: primeiro, o conhecimento total; a engenharia conheceria tudo e seria capaz de projetar de modo a evitar, com certeza, todos os eventos nocivos. Segundo: a engenharia não conhece a totalidade dos fenômenos, mas sabe que, fazendo como sempre se fez (com o conhecimento empírico) e com margens de segurança grandes, a probabilidade de rompimento se aproxima de zero. Ninguém projeta uma barragem para que ela se rompa. Mas se projeta uma barragem sem dominar na totalidade os eventos que podem ocorrer. Quando se conhece a totalidade da situação, o que deve ser feito para evitar o rompimento é 100% conhecido ­ e precificado. Entretanto, isso nunca acontece, a probabilidade de ocorrência de eventos nunca é completamente conhecida, eles não são determinísticos e a incerteza é um fato.

Will it be possible, sometime in the future, to exactly explain what happened in the dam failure in Brumadinho? Although word "exactness" is often used within the world of engineering, it is often known to be an euphemism. The engineering art consists in projecting, building, implementing and managing different types of systems which might have both positive and negative consequences for workers, society and the environment. Some event or series of events culminated in the dam failure. Is tailings dam engineering aware of and able to control all possible events which together might cause a failure? There are two possible paths: one involves absolute knowledge ­ engineering has absolute knowledge of everything and is able to design projects in a way to avoid any harmful event. According to the other, while engineering does not have absolute knowledge of all the phenomena, its traditional know-how (empirical knowledge) and wide margins of safety make the odds of dam failure come close to zero. No one projects a dam just to fail. But dams are projected without absolute control of all possible events. When the entire situation is known, all that should be done to avoid failures is 100% known ­ and the price fixed. However, this never happens, the probability of the occurence of events are never completely known, they are not deterministic and uncertainty is always a fact.

Brumadinho: between prudence and probability, tragedy.

Will it be possible, sometime in the future, to exactly explain what happened in the dam failure in Brumadinho? Although word "exactness" is often used within the world of engineering, it is often known to be an euphemism. The engineering art consists in projecting, building, implementing and managing different types of systems which might have both positive and negative consequences for workers, society and the environment. Some event or series of events culminated in the dam failure. Is tailings dam engineering aware of and able to control all possible events which together might cause a failure? There are two possible paths: one involves absolute knowledge - engineering has absolute knowledge of everything and is able to design projects in a way to avoid any harmful event. According to the other, while engineering does not have absolute knowledge of all the phenomena, its traditional know-how (empirical knowledge) and wide margins of safety make the odds of dam failure come close to zero. No one projects a dam just to fail. But dams are projected without absolute control of all possible events. When the entire situation is known, all that should be done to avoid failures is 100% known - and the price fixed. However, this never happens, the probability of the occurence of events are never completely known, they are not deterministic and uncertainty is always a fact.

Será possível, em algum momento no futuro, explicar com exatidão o que aconteceu no caso do rompimento da barragem de Brumadinho? Apesar de, muitas vezes, se utilizar a palavra exatidão no mundo da engenharia, sabe-se que, em muitos casos, trata-se de um eufemismo. A arte da engenharia consiste em projetar, construir, implementar e gerenciar diferentes tipos de sistemas que podem trazer consequências tanto positivas como negativas para os trabalhadores, para a sociedade, para o meio ambiente. Aconteceu um evento ou uma sequência de eventos que levou ao rompimento. A engenharia de barragens de rejeitos conhece e é capaz de controlar todos os eventos passiveis de acontecer e que, articulados, podem levar ao rompimento? Há dois caminhos: primeiro, o conhecimento total; a engenharia conheceria tudo e seria capaz de projetar de modo a evitar, com certeza, todos os eventos nocivos. Segundo: a engenharia não conhece a totalidade dos fenômenos, mas sabe que, fazendo como sempre se fez (com o conhecimento empírico) e com margens de segurança grandes, a probabilidade de rompimento se aproxima de zero. Ninguém projeta uma barragem para que ela se rompa. Mas se projeta uma barragem sem dominar na totalidade os eventos que podem ocorrer. Quando se conhece a totalidade da situação, o que deve ser feito para evitar o rompimento é 100% conhecido ­ e precificado. Entretanto, isso nunca acontece, a probabilidade de ocorrência de eventos nunca é completamente conhecida, eles não são determinísticos e a incerteza é um fato.

Advances in Carbon Nanotubes for Malignant Melanoma: A Chance for Treatment.

Malignant melanoma is an aggressive skin cancer with limited therapeutic options. Cancer is the second largest cause of death in society and one of the most difficult diseases to treat. Advances in biotechnology have enabled the current use of nanotechnology via the application of nanomaterials, especially as drug delivery systems for the transportation of very small particles. In this context, carbon nanotubes, with a potential role in the diagnosis and treatment of melanoma, are still an emerging research field. Their properties have been extensively studied for the use of antineoplastics drugs, as well as for DNA and RNA interference for the treatment of cancer. However, the most important challenge in nanomedicine is to decrease the toxicity and increase the biocompatibility of the nanomaterials used to transport therapeutic molecules. In this sense, this article addresses the recent advances in the use of carbon nanotubes in melanoma therapy and highlights the opportunities and challenges in this area. The advances and challenges involving these topics are essential to the success of nanoconjugate systems, and studies improving the comprehension of these nanosystems contribute to the development of specific antitumor therapies.

Impact of antiretroviral resistance and virological failure on HIV-1 informational entropy.

Objectives: The present study investigated the relationship between genomic variability and resistance of HIV-1 sequences in protease (PR) and reverse transcriptase (RT) regions of the pol gene. In addition, we analysed the resistance among 651 individuals presenting antiretroviral virological failure, from 2009 to 2011, in the state of São Paulo, Brazil. Methods: The genomic variability was quantified by using informational entropy methods and the relationship between resistance and replicative fitness, as inferred by the residual viral load and CD4+ T cell count. Results: The number of antiretroviral schemes is related to the number of resistance mutations in the HIV-1 PR (α = 0.2511, P = 0.0003, R2 = 0.8672) and the RT (α = 0.7892, P = 0.0001, R2 = 0.9141). Increased informational entropy rate is related to lower levels of HIV-1 viral loads (α = -0.0121, P = 0.0471, R2 = 0.7923), lower levels of CD4+ T cell counts (α = -0.0120, P = 0.0335, R2 = 0.8221) and a higher number of antiretroviral resistance-related mutations. Conclusions: Less organized HIV genomes as inferred by higher levels of informational entropy relate to less competent host immune systems, lower levels of HIV replication and HIV genetic evolution as a consequence of antiretroviral resistance.

Advances in carbon nanotubes for malignant melanoma: a chance for treatment

Malignant melanoma is an aggressive skin cancer with limited therapeutic options. Cancer is the second largest cause of death in society and one of the most difficult diseases to treat. Advances in biotechnology have enabled the current use of nanotechnology via the application of nanomaterials, especially as drug delivery systems for the transportation of very small particles. In this context, carbon nanotubes, with a potential role in the diagnosis and treatment of melanoma, are still an emerging research field. Their properties have been extensively studied for the use of antineoplastics drugs, as well as for DNA and RNA interference for the treatment of cancer. However, the most important challenge in nanomedicine is to decrease the toxicity and increase the biocompatibility of the nanomaterials used to transport therapeutic molecules. In this sense, this article addresses the recent advances in the use of carbon nanotubes in melanoma therapy and highlights the opportunities and challenges in this area. The advances and challenges involving these topics are essential to the success of nanoconjugate systems, and studies improving the comprehension of these nanosystems contribute to the development of specific antitumor therapies.

Advances in carbon nanotubes for malignant melanoma: a chance for treatment

Malignant melanoma is an aggressive skin cancer with limited therapeutic options. Cancer is the second largest cause of death in society and one of the most difficult diseases to treat. Advances in biotechnology have enabled the current use of nanotechnology via the application of nanomaterials, especially as drug delivery systems for the transportation of very small particles. In this context, carbon nanotubes, with a potential role in the diagnosis and treatment of melanoma, are still an emerging research field. Their properties have been extensively studied for the use of antineoplastics drugs, as well as for DNA and RNA interference for the treatment of cancer. However, the most important challenge in nanomedicine is to decrease the toxicity and increase the biocompatibility of the nanomaterials used to transport therapeutic molecules. In this sense, this article addresses the recent advances in the use of carbon nanotubes in melanoma therapy and highlights the opportunities and challenges in this area. The advances and challenges involving these topics are essential to the success of nanoconjugate systems, and studies improving the comprehension of these nanosystems contribute to the development of specific antitumor therapies.

Auto-organização psíquica / Psychical self-organization

Sermos animados por um 'a mais de tensão' difere o humano do não-humano na perspectiva psicanalítica, situação que cria um dinamismo no qual emerge a realidade psíquica. Ao tomar os estímulos corporais como pura dispersão, sem formarem de início um conjunto estruturado e ao enfatizar a existência de uma semântica mental apoiada na sexualidade, apontamos que Freud traçou um paralelo entre dois domínios diferentes: ciências mentais e ciências do cérebro, incorporando precocemente preceitos de complexidade às suas teorias. Neste artigo, tentamos mostrar que a articulação entre as noções de pulsão e de inconsciente, a qual coloca a gênese da significação em território não-controlável, possibilitando a compreensão da emergência do psiquismo como um processo de auto-organização de um cérebro sensível às condições iniciais. Perturbações pequenas são amplificadas na flutuação global e essa idéia pode contribuir para a compreensão das modernas perspectivas de estudo da mente (AU)

Development of one experimental module to study the modulation of the propagation velocity of chemical excitation waves in gel by weak external force (gravity).

Biological and chemical systems in which the pattern of flow of energy and matter imposes self-organization can be seen as examples of excitable media. One property of such media is the presence of excitation waves. The Belouzov-Zabotinsky(B-Z) reaction system and the retinal spreading depression wave are examples of experimental models of excitable media in which the influence of gravity can be studied. In this paper we describe one especial module constructed to test the influence of gravity in gels of the B-Z system. In the gel condition, convection effects are minimized. The results will be directly comparable to retinal experiments programmed by the same group and complete a series of investigations of systematic comparison of the modulation of chemical and biological excitation waves by weak external forces.

Auto-organização psíquica / Psychical self-organization

Sermos animados por um "a mais de tensäo" difere o humano do näo-humano na perspectiva psicanalítica, situaçäo que cria um dinamismo no qual emerge a realidade psíquica. Ao tomar os estímulos corporais como pura dispersäo, sem formarem de início um conjunto estruturado e ao enfatizar a existência de uma semântica mental apoiada na sexualidade, apontamos que Freud traçou um paralelo entre dois domínios diferentes: ciências mentais e ciências do cérebro, incorporando precocemente preceitos de complexidade às suas teorias. Neste artigo, tentamos mostrar que a articulaçäo entre as noçöes de pulsäo e de inconsciente, a qual coloca a gênese da significaçäo em território näo-controlável, possibilitando a compreensäo da emergência do psiquismo como um processo de auto-organizaçäo de um cérebro sensível às condiçöes iniciais. Perturbaçöes pequenas säo amplificadas na flutuaçäo global e essa idéia pode contribuir para a compreensäo das modernas perspectivas de estudo da mente

Auto-organização e complexidade: o problema do desenvolvimento do ciclo vigília-sono / Self-organization and complexity: the problem of sleep-wake cycle development

Neste artigo tenta-se estabelecer algumas interpretações teóricas para os conceitos de auto-organização e complexidade em sistemas biológicos, utilizando-se idéias originárias da Teoria da Informação e da Teoria dos Sistemas Dinâmicos. Além disso, apresenta-se um exemplo de aplicação dos métodos propostos ao problema da caracterização do grau de organização do ciclo vigília-sono em bebês.

This article is a trial on stablishing some theoretical formalisms for the concepts of self-organizing and complex biological systems, using ideas from Information Theory and Dynamical Systems Theory. As an example the organization of the sleep-wake cycle in babies is studied, applying the methods proposed.