New variants of SARS-CoV-2, vaccine immune response and the Brazilian reality

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a highly pathogenic β-coronavirus, is the etiologic agent of coronavirus disease 2019 (COVID-19), which gave rise to a difficult to control pandemic, especially in Brazil. Approximately 4,000 mutations have been identified in SARS-CoV-2, with the majority being redundant without having any biological effect on the virus. The aim of the present study was to objectively understand how new SARS-CoV-2 variants can affect vaccine response, in addition to highlighting the current situation in Brazil in the face of the pandemic and considering epidemiological and immunological aspects of COVID-19. The main protective correlate investigated in most vaccines is the neutralizing antibody titer induced by immunizing agents, observed in the pre-clinical phase in animals, whose action is to block the binding of the spike protein to the angiotensin-converting enzyme 2 (ACE2) receptor, preventing infection. Up to the second half of 2021, the variants that are of greatest concern worldwide and require molecular surveillance are Alpha variant (or B.1.1.7 lineage), Beta (or B.1.351 lineage), Gamma (or P1 lineage) and Delta (or B.1.617.2 lineage). Brazil finds itself in a highly unfavorable scenario, with the circulation of variants of concern, mainly Gamma and Delta, with high fatality rates for COVID-19 and low vaccination rate. Given the still latent situation of the COVID-19 pandemic in Brazil, the lack of global planning for action strategies for non-pharmacological prevention measures, there is an imminent risk of the emergence of new variants due to the finding of susceptible hosts and the high proliferative rate of SARS-CoV-2. It is urgent to increase the genotyping of positive samples isolated from infected individuals, the speed of vaccination of the entire population and the unification of non pharmacological preventive measures throughout the country.

Recent Advances in Robot Trajectory Planning in a Dynamic Environment

Background: Trajectory planning is important to research in robotics. As the application environment changes rapidly, robot trajectory planning in a static environment can no longer meet actual needs. Therefore, a lot of research has turned to robot trajectory planning in a dynamic environment. Objective: This paper aims at providing references for researchers from related fields by reviewing recent advances in robot trajectory planning in a dynamic environment. Methods: This paper reviews the latest patents and current representative articles related to robot trajectory planning in a dynamic environment and introduces some key methods of references from the aspects of algorithm, innovation and principle. Results: In this paper, we classified the researches related to robot trajectory planning in a dynamic environment in the last 10 years, introduced and analyzed the advantages of different algorithms in these patents and articles, and the future developments and potential problems in this field are discussed. Conclusion: Trajectory planning in a dynamic environment can help robots to accomplish tasks in a complex environment, improving robots’ intelligence, work efficiency and adaptability to the environment. Current research focuses on dynamic obstacle avoidance, parameter optimization, real-time planning, and efficient work, which can be used to solve robot trajectory planning in a dynamic environment. In terms of the combination of multiple algorithms, multi-sensor information fusion, the combination of local planning and global planning, and multi-robot and multi-task collaboration, more improvements and innovations are needed. It should create more patents on robot trajectory planning in a dynamic environment.

Spatial Signatures of Road Network Growth for Different Levels of Global Planning

We compare the statistical distributions of the geometrical properties of road networks for two representative datasets under different levels of planning: the cities comprising Metropolitan Manila show the conditions under bottom-up self-organized growth, while Brasilia and the Australian Capital Territory centered at Canberra represent the case of strict top-down planning. The distribution of segmented areas of the cities shows a dual power-law behavior, with the larger areas following the ∼1.9 scaling exponent observed in other cities, while the smaller areas show a lower exponent of ∼0.5, believed to be due to practical considerations. While all cities are found to favor the formation of straight road segments, the planned city roads have a preponderance of sinuous roads, with sinuosities approaching π. A simple model based on a nearest-neighbor directed branching coupled with sectional grid formations is proposed to capture the nontrivial statistical features observed.

Research on an Obstacle Avoidance Method for UAV

With the continuous development of UAV technology, UAV has been widely used in various industries. In the flight process of UAV, UAV often changes the given path because of obstacles (including static nonliving body and moving living body). According to the properties of obstacles and the characteristics of UAV, standard Kalman filter is used for nonmaneuvering targets, and sigma point Kalman filter is used for maneuvering targets. In the aspect of obstacle avoidance, the minimum search method is used to get the initial population of local programming. Then, the improved genetic algorithm is run. Combined with the predicted obstacle features, the local planning path can be obtained. Finally, the local planning path and global planning path are combined to generate the planning path with new obstacles. At the end of the paper, the obstacle avoidance strategies of static and moving obstacles are simulated. The simulation results show that this method has fast convergence speed and good feasibility and can flexibly deal with the obstacle avoidance and local path planning of various new obstacles.

Multi-Destination Path Planning Method Research of Mobile Robots Based on Goal of Passing through the Fewest Obstacles

In order to effectively solve the inefficient path planning problem of mobile robots traveling in multiple destinations, a multi-destination global path planning algorithm is proposed based on the optimal obstacle value. A grid map is built to simulate the real working environment of mobile robots. Based on the rules of the live chess game in Go, the grid map is optimized and reconstructed. This grid of environment and the obstacle values of grid environment between each two destination points are obtained. Using the simulated annealing strategy, the optimization of multi-destination arrival sequence for the mobile robot is implemented by combining with the obstacle value between two destination points. The optimal mobile node of path planning is gained. According to the Q-learning algorithm, the parameters of the reward function are optimized to obtain the q value of the path. The optimal path of multiple destinations is acquired when mobile robots can pass through the fewest obstacles. The multi-destination path planning simulation of the mobile robot is implemented by MATLAB software (Natick, MA, USA, R2016b) under multiple working conditions. The Pareto numerical graph is obtained. According to comparing multi-destination global planning with single-destination path planning under the multiple working conditions, the length of path in multi-destination global planning is reduced by 22% compared with the average length of the single-destination path planning algorithm. The results show that the multi-destination global path planning method of the mobile robot based on the optimal obstacle value is reasonable and effective. Multi-destination path planning method proposed in this article is conducive to improve the terrain adaptability of mobile robots.

Digital Currencies and Relevant Policy Analysis

The paper collates the relations of digital currencies with the past forms of currencies, studies the operating mechanism of digital currencies, analyzes the influence of digital currencies on the financial order and economic pattern, and probes into how to drive the reform of global monetary system with pragmatic and innovative efforts. The paper highlights: First, the evolution and development of currency reflects the mankind’s social and economic development level. Second, digital currency born with the advances of technology does not change the content of credit money. The credit money-to-digital currency shift must respect the operating mechanism of money and ensure that the physical market and the money market are balanced or roughly balanced. Third, with a complicated influence on the social economy, digital currency is unlikely to change the global monetary system and the international economic pattern easily. Fourth, the work of encouraging financial innovation and improving overall financial infrastructure should come with strengthened efforts to develop sound rules governing the market order in the context of digital economy, by guarding against the risks from “excessive monopoly” and “decentralization”. Fifth, the paper calls for linking “trust, confidence and credit” of the human society organically with such intrinsic values as global development, global planning and global resources, and also leveraging such values to actively approach the “Earth-based” monetary system and its replacement of the “gold standard”, the “silver standard” and the sovereign credit based monetary system which have been in long use.

Global View Of A Sustainable Society And Its Stability

It is often said, and at present it is probably true that famine and poverty in some parts of the world are a problem of distribution rather than one of production of the necessities of life. The improvement of our distribution system, however, does not only solve an acute problem of regional deprivation, but also creates regional interdependence. Thus, with present day transcontinental trade the questions related to sustainability become global issues. The whole world is an interconnected network. Is there some "invisible hand" which guides local actions in a direction beneficial to the whole or does this connectedness necessitate deliberate global planning?A similar question arises when we look far ahead in time. Many people have a blind trust in the future and are unconcerned with questions of long term sustainability of human civilization. Those who believe in science and technology respond to warnings of global sustenance problems: "The engineers will invent something that will solve our problems." Those with a religious bent say: "Why worry about tomorrow? 'He' who has provided for us in the past will do so in the future." How useful is this fatalistic stance today? Given the knowledge we possess, are we not responsible for irreversible damages to the Planet which will burden future generations? Is mankind capable of consciously choosing its future path?This paper analyses the state of the World and the stability of the processes in it. We take a global and long term perspective. The basic tool used is a balance equation for material, cultural, biological, social and ecological substances. Conditions for sustainable, dynamic equilibria are derived and presented in per capita values in order to facilitate intuitive comprehension. Possible contributions to sustainability of the natural sciences and engineering and of the social sciences and the humanities are outlined. In conclusion some desirable and some accidental paths to sustainability are given.

Global View Of A Sustainable Society And Its Stability

It is often said, and at present it is probably true that famine and poverty in some parts of the world are a problem of distribution rather than one of production of the necessities of life. The improvement of our distribution system, however, does not only solve an acute problem of regional deprivation, but also creates regional interdependence. Thus, with present day transcontinental trade the questions related to sustainability become global issues. The whole world is an interconnected network. Is there some "invisible hand" which guides local actions in a direction beneficial to the whole or does this connectedness necessitate deliberate global planning?A similar question arises when we look far ahead in time. Many people have a blind trust in the future and are unconcerned with questions of long term sustainability of human civilization. Those who believe in science and technology respond to warnings of global sustenance problems: "The engineers will invent something that will solve our problems." Those with a religious bent say: "Why worry about tomorrow? 'He' who has provided for us in the past will do so in the future." How useful is this fatalistic stance today? Given the knowledge we possess, are we not responsible for irreversible damages to the Planet which will burden future generations? Is mankind capable of consciously choosing its future path?This paper analyses the state of the World and the stability of the processes in it. We take a global and long term perspective. The basic tool used is a balance equation for material, cultural, biological, social and ecological substances. Conditions for sustainable, dynamic equilibria are derived and presented in per capita values in order to facilitate intuitive comprehension. Possible contributions to sustainability of the natural sciences and engineering and of the social sciences and the humanities are outlined. In conclusion some desirable and some accidental paths to sustainability are given.

Global short-term forecasting of COVID-19 cases

The continuously growing number of COVID-19 cases pressures healthcare services worldwide. Accurate short-term forecasting is thus vital to support country-level policy making. The strategies adopted by countries to combat the pandemic vary, generating different uncertainty levels about the actual number of cases. Accounting for the hierarchical structure of the data and accommodating extra-variability is therefore fundamental. We introduce a new modelling framework to describe the pandemic’s course with great accuracy and provide short-term daily forecasts for every country in the world. We show that our model generates highly accurate forecasts up to seven days ahead and use estimated model components to cluster countries based on recent events. We introduce statistical novelty in terms of modelling the autoregressive parameter as a function of time, increasing predictive power and flexibility to adapt to each country. Our model can also be used to forecast the number of deaths, study the effects of covariates (such as lockdown policies), and generate forecasts for smaller regions within countries. Consequently, it has substantial implications for global planning and decision making. We present forecasts and make all results freely available to any country in the world through an online Shiny dashboard.

Mathematical modeling of the trajectory of a ship as a control object in local planning

In the article proposes the decomposition of the global planning task in local planning. It is proposed to combine the segment method and the sector method of division of the circle to construct the ship’s trajectory in local planning. Corrective coefficients were selected for the correct geometry of the turning trajectory, combining the segment method and the sector method of constructing the ship’s trajectory. The article uses formulas of spherical trigonometry; the trajectory of the turn depends on the rudder angle, which in turn depends on the turning ability of the vessel under the given conditions. In determining the value of the angle of the rudder, the control device must take into account the ship’s turning ability in the conditions set, the value of the angle of the turn and the constrained water area. The combination of all factors allows to differentiate the ship’s turning ability such as: high HG, middle MD or low LW with regard to passage area. The ME shifting operating modes matrix proposed in the article works as a filter of modes of operation and is completely dependent on the readings of pressure, temperature and vibration sensors. The ship’s trajectory is constructed using calculations in MS Excel and graphic simulations in the MATLAB environment.