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We study a slender filament beating in a viscous fluid with novel curvature-dependent bending stiffness. Our numerical and experimental investigations reveal that such differential stiffness can sustain planar bending waves far along flexible filaments, in stark contrast to the uniform-stiffness case which requires more sophisticated control. In particular, we establish basal actuation as a viable, parsimonious mechanism for generating high-amplitude planar bending waves. Moreover, the resulting beat patterns closely resemble the power-and-recovery strokes of propulsive biological filaments such as cilia, suggesting extensive applications in robotic and engineered systems.

The material of storage containers affects the shelf life and the chemical composition of food. Artisanal agave spirits, such as mezcal and bacanora, might be filled into low-cost plastic bottles that compromise product quality. We developed an analytical platform to identify the bottle materials of agave spirits, which employs 3D-printed cartridges, and the robotic platform Open LabBot/Open SprayBot for paper-spray ionization mass spectrometry (PS-MS). The bottle material of 102 fresh samples could be identified with a 2 % error. Samples stored for two years at −20 °C in glass vials still were classified correctly in 76 % of the cases. Therefore, the spirits still appear adulterated for a prolonged time after re-bottling into inert containers. The measurement time is about 30 s/sample. Thus, the 3D-PS-MS strategy can be applied for the high-throughput screening for bottle materials of agave spirits and other alcoholic beverages.

Newborn disease screening increases survival, improves quality of life and reduces treatment costs for healthcare systems. Mass spectrometry (MS) is an effective method for metabolic screening. However, conventional analytical methods require biofluid handling and cooling conditions during transport, making the logistics difficult and expensive, especially for remote regions. ’Paper-spray’ (PS) ionization generates a charged solvent spray from samples deposited on paper strips. Therefore, samples can be applied on a suitable matrix and shipped as dried spots to diagnostic laboratories with standard postal or messenger services. We built a robotic platform, the ’Open SprayBot’, to automatically analyze paper-deposited samples via PS-MS and increase the sample throughput. The system is operated via RUMBA32 and Arduino Mega boards. A commercial syringe pump and power supply provide solvent application and electrical current required for PS-MS. The usability of the Open SprayBot was demonstrated by quantifying palmitoyl-l-carnitine, a common biomarker in newborn screening.

Objectives: Despite the widespread availability of COVID-19 vaccines in the United States, vaccine hesitancy remains high among certain groups. This study examined the correlates of being unvaccinated among a sample of students attending a single university (N = 2900) during the spring and summer of 2021, when the campus had been closed for over a year and students were preparing to return to in-person learning. Methods: Students responded to an email invitation and completed electronic surveys. Results: In multivariable logistic regression analyses, students were more likely to be unvaccinated if they were African American, identified with any political affiliation other than Democrat, were undergraduates or international students, had not traveled outside the Los Angeles during the pandemic, and/or had previously been ill with COVID-19. Conclusion: Findings indicate that culturally resonant educational interventions, and possibly vaccine requirements, are needed to promote vaccination among university students.

Abstract Background Attitudes and behaviors towards mask wearing may influence the ability to reduce transmission of COVID-19 and other diseases. Methods University students, staff, and faculty (N = 9653) responded to an email invitation to complete electronic surveys (November 2021 and April 2022). Surveys included 19 items measuring attitudes and behaviors towards mask wearing from the Understanding America Study. Linear mixed models including variables for sex, age group, division, race and ethnicity, political affiliation, and history of COVID-19, were used to estimate the mean difference of the mean score for attitudes and behavior between Time 1 (November 2021) and Time 2 (April 2022). Results Participants were mostly female (62.1%), students (70.6%), White (39.5%) and Asian (34.7%). More than half identified their political affiliation as Democrat (65.5%). Characteristic variable-by-time interactions for difference in mean mask attitude scores difference were significant at Time 1 (T1) and Time 2 (T2) between Black and White participants (B = 0.18 (0.05), 95% CI: 0.07, 0.28, p = 0.001), Asian and White participants (B = 0.07 (0.02), 95% CI: 0.03–0.12, p = 0.001), participants with self-reported history of COVID-19 and no history of COVID-19 (B= -0.13 (0.02), 95% CI: -0.07, -0.18, p

Abstract Background Mistrust in science and scientists may adversely influence the rate of COVID-19 vaccination and undermine public health initiatives to reduce virus transmission. Methods Students, staff and faculty responded to an email invitation to complete an electronic survey. Surveys included 21-items from the Trust in Science and Scientists Inventory questionnaire. Responses were coded so higher scores indicated a higher trust in science and scientists, A linear regression model including sex, age group, division, race and ethnicity, political affiliation, and history of COVID-19, was used to determine variables significantly associated with trust in science and scientists scores at the p

Insects are good examples of ground locomotion because they can adapt their gait pattern to propel them in any direction, over uneven terrain, in a stable manner. Nevertheless, replicating such locomotion skills to a legged robot is not a straightforward task. Different approaches have been proposed to synthesize the gait patterns for these robots; each approach exhibits different restrictions, advantages, and priorities. For the purpose of this document, we have classified gait pattern generators for multi-legged robots into three categories: precomputed, heuristic, and bio-inspired approaches. Precomputed approaches rely on a set of precalculated motion patterns obtained from geometric and/or kinematic models that are performed repeatedly whenever necessary and that cannot be modified on-the-fly to adapt to the terrain changes. On the other hand, heuristic and bio-inspired approaches offer on-line adaptability, but parameter-tuning and heading control can be difficult. In this document, we present the K3P algorithm, a real-time kinematic gait pattern generator conceived to command a legged robot. In contrast to other approaches, K3P enables the robot to adapt its gait to follow an arbitrary trajectory, at an arbitrary speed, over uneven terrain. No precomputed motions for the legs are required; instead, K3P modifies the motion of all mechanical joints to propel the body of the robot in the desired direction, maintaining a tripod stability at all times. In this paper, all the specific details of the aforementioned algorithm are presented, as well as different simulation results that validate its characteristics.

Despite the efficacy and widespread availability of COVID-19 vaccines, vaccine uptake has been relatively low in U.S. Hispanic communities, especially among adolescents. This study examined vaccination status among 444 high school students in predominantly Hispanic neighborhoods of Los Angeles County, California in May-June 2022 (mean age = 15.74 years, 55% female, 93% Hispanic). Guided by Protection Motivation Theory, we hypothesized that the odds of being fully vaccinated (at least 2 vaccine doses) would be significantly associated with higher levels of perceived severity, perceived vulnerability, response efficacy, and self-efficacy. 79% of the respondents were fully vaccinated. Binary logistic regression analyses found that response efficacy (belief in the effectiveness of the COVID-19 vaccine) and self-efficacy to get vaccinated were significantly associated with the likelihood of being fully vaccinated. Perceived severity of COVID-19 and perceived vulnerability to COVID-19 were not associated with the likelihood of being fully vaccinated. Results indicate that health communications are needed to convince Hispanic adolescents and their parents that the COVID-19 vaccine is effective, and outreach efforts are needed to remove barriers to vaccination among this population.

IntroductionSevere acute respiratory syndrome virus 2 (SARS-CoV-2) has caused over million deaths worldwide, with more than 61,000 deaths in Chile. The Chilean government has implemented a vaccination program against SARS-CoV-2, with over 17.7 million people receiving a complete vaccination scheme. The final target is 18 million individuals. The most common vaccines used in Chile are CoronaVac (Sinovac) and BNT162b2 (Pfizer-Biotech). Given the global need for vaccine boosters to combat the impact of emerging virus variants, studying the immune response to SARS-CoV-2 is crucial. In this study, we characterize the humoral immune response in inoculated volunteers from Chile who received vaccination schemes consisting of two doses of CoronaVac [CoronaVac (2x)], two doses of CoronaVac plus one dose of BNT162b2 [CoronaVac (2x) + BNT162b2 (1x)], and three doses of BNT162b2 [BNT162b2 (3x)].MethodsWe recruited 469 participants from Clínica Dávila in Santiago and the Health Center Víctor Manuel Fernández in the city of Concepción, Chile. Additionally, we included participants who had recovered from COVID-19 but were not vaccinated (RCN). We analyzed antibodies, including anti-N, anti-S1-RBD, and neutralizing antibodies against SARS-CoV-2.ResultsWe found that antibodies against the SARS-CoV-2 nucleoprotein were significantly higher in the CoronaVac (2x) and RCN groups compared to the CoronaVac (2x) + BNT162b2 (1x) or BNT162b2 (3x) groups. However, the CoronaVac (2x) + BNT162b2 (1x) and BNT162b2 (3x) groups exhibited a higher concentration of S1-RBD antibodies than the CoronaVac (2x) group and RCN group. There were no significant differences in S1-RBD antibody titers between the CoronaVac (2x) + BNT162b2 (1x) and BNT162b2 (3x) groups. Finally, the group immunized with BNT162b2 (3x) had higher levels of neutralizing antibodies compared to the RCN group, as well as the CoronaVac (2x) and CoronaVac (2x) + BNT162b2 (1x) groups.DiscussionThese findings suggest that vaccination induces the secretion of antibodies against SARS-CoV-2, and a booster dose of BNT162b2 is necessary to generate a protective immune response. In the current state of the pandemic, these data support the Ministry of Health of the Government of Chile’s decision to promote heterologous vaccination as they indicate that a significant portion of the Chilean population has neutralizing antibodies against SARS-CoV-2.

Terrain irregularities in natural environments present mobility challenges for autonomous robots and vehicles. Loosely consolidated sandy slopes flow unpredictably when perturbed, often leading to locomotion failure. Systematic experiments with various robot morphologies on flowable terrains feature open‐loop quasistatic gait strategies that remodel the terrain to aid locomotor kinematics. On a sloped terrain of granular media near the critical angle, a laboratory‐scale rover robot induces a flow via a localized fluidization gait to remodel local terrain and succeed in locomotion. A Bayesian optimization machine learning approach that modulates this gait strategy then finds a pattern of selectively fluidizing and solidifying terrain to climb slopes rapidly. In a biped walker robot, a cleated foot design dynamically manipulates the stress fields of flowable slopes. The deeply submerged cleats remodel the shear response of the material by creating jammed regions behind them which then improve forward progression by reducing slip when compared to a flat foot. The “robophysics” approach of systematic experiments exploring terrain reconfiguration combined with future machine learning models of flowable terrain evolution can augment gait discovery for future robots.

This paper presents an agent-based model employing a stochastic optimization search that attempts to find an optimal solution to the online bicycle rebalancing problem for general bike-sharing systems. The algorithm receives the initial and final global state configuration of the system. The main objective of the study is to find the minimum cost path from the initial to the final state. Each agent of the model has four behavioral options that search the optimal configuration; at each iteration, it selects one of these options based on random thresholds and shares the temporary solution found with neighboring agents to improve their search process. The algorithm presents a high exploratory behavior of the search space, which helps to find an approximation away from the local optimal configuration. Additionally, the exchanges between agents allow a consensus on the solutions found. The algorithm has been tested with two different generated configurations using as a basis a real dataset extracted from a functional bike-sharing system collected in 2019. The results show a positive evolution originating from the emerging effect of stochastic selection and interaction between agents. [ABSTRACT FROM AUTHOR]

Objective: This study examined characteristics associated with being unvaccinated among a sample of university staff and faculty prior to university campus reopening for in-person learning in 2021. Methods: Staff and faculty responded to an email invitation to complete an online survey. Survey questions included demographic data (race/ethnicity, age, sex), COVID-19 knowledge and behaviors, employment specific data including division and subdivision (healthcare vs. non-healthcare related division); and self-reported vaccination status. A multivariable logistic regression analysis was performed to determine significant characteristics associated with the likelihood of being unvaccinated for COVID-19. Results: Participants identifying as Asian and Asian American (aOR = 1.44, 95% CI: 1.06, 1.96), Hispanic/Latinx (aOR = 1.73, 95% CI: 1.21, 2.49) or Multicultural/Other (aOR = 1.72, 95% CI: 1.24, 2.38) had greater odds of being unvaccinated compared to Non-Hispanic White participants. Other characteristics associated with greater likelihood of being unvaccinated included working as a university staff member (vs. faculty) (aOR = 1.69, 95% CI: 1.24. 2.30), decrease in income (aOR = 1.34, 95% CI:1.05, 1.71), inability to work remotely (aOR = 1.48, 95% CI:1.13, 1.93) and not traveling outside of the Los Angeles area (aOR = 1.46, 95% CI: 1.16, 1.83). Political affiliation as an Independent (aOR = 1.39, 95% CI:1.04, 1.85) or as something else (aOR = 3.84, 95% CI: 2.72, 5.41) were more likely to be unvaccinated compared to participants identifying as Democrat. Conclusions: Several factors associated with racial and social disparities may delay the uptake of COVID-19 vaccination. This study highlights the need for targeted educational interventions to promote vaccination among university staff and faculty.

Forest structure depends both on extrinsic factors such as climate and on intrinsic properties such as community composition and diversity. Here, the authors use a dataset of stand structural complexity based on LiDAR measurements to build a global map of structural complexity for primary forests, and find that precipitation variables best explain global patterns of forest structural complexity.

This article presents the results of the analysis of the studies of the operation of a modified IEEE-13 distribution feeder, which was built to scale in the laboratory at Universidad del Norte. In this article, we show the cases of the operating regimes of the modified IEEE-13, before the different levels of wind energy penetration. The modified IEEE-13 distribution feeder was built taking into account that each of the scaled modules and their generator-load will work under the conditions of the Universidad del Norte laboratory. An experimental methodology was used to compare the results obtained in the actual scaled model with the results of the simulations in specialized programs. The conclusions of the article show the wind energy that can be injected into an electrical system with conventional power generation so that it can maintain its operation complying with the current regulatory framework.

This paper summarizes the impact of soil/dirt in solar-panel performance in the Colombian Caribbean Region. The corresponding experiment compares the performance of two identical solar panels, which are subjected to different scenarios. The objective of this research is, to categorize or establish on site solar-radiation ranges in order to estimate the actual solar-panel efficiency compared to 1000 W/m2. The maximum power point is calculated using an I vs V transfer function approximation. The soiling related maximum-power-point impact analysis is carried out with a complete Multivariate Analysis of Variance (ANOVA) considering three fundamental factors: dirt/particles, solar radiation and day. According to experimental results, the soiling effect in the solar-panel efficiency reduction has been estimated as up to 6% during times of the day with the maximum solar radiation; while for lower radiations, the effect decreases exponentially becoming negligible on the available electric power. Thus, empirically it is shown that the effect of dirt/particles is significant from a clean solar-panel to one with light accumulation, but such a negative effect rapidly diminishes as accumulation changes from light to heavy. Therefore, it is suggested that once some dirt accumulates on a panel, a cleaning procedure can wait until the particle accumulation becomes heavy. Thus, this study can become a tool that solar-power-plant operators can employ to estimate the trade-off between photovoltaic-system power efficiency and its financial viability.

Accurate temperature measurements are needed to monitor and reduce energy use and greenhouse gas emissions in building, industrial, and other processes. This paper describes a temperature sensor instrument, named TempSense, developed for classroom demonstrations of thermal phenomena. The instrument can monitor, record, and visualize data from multiple temperature sensors using a K-type amplifier and thermocouples. It has an accuracy of ±2 deg C from -200 to +700 deg C and an accuracy of ±6 deg C from –270 to +1372 deg C. The instrument uses a USB bridge and the Python language to interface with open-source thermocouple amplifiers without the need for byte-level programming. Its design allows novice experimenters to inspect the build and operation and even customize it to their needs. TempSense can be extended via Python libraries to provide internet communication, visualization, and analysis.

This article states that human rights have evolved from an state’s responsibility focused on the safekeeping of the public sphere to a preoccupation to safeguard the private space. This essay develops the discussion about the relevance of an international regulation to certify of given entrepreneurial processes and how they could help stability and international peace. It points out that many private enterprises and companies related to security issues, make relevant investments in fragile governability or in undergoing armed conflict zones, and the fact that their intervention may foster or diminish conflicts. The war scenarios present the most complex problems due to the general complexity of observing the International Humanitarian Law, as well as for the difficulty to repair damages due to private companies actions. Finally the article summarize the juridical discussion around “mercenarism” and the dilemma set by the regulation or the prohibition of the private military and security enterprises.

This paper presents a useful model to determine the washing periods and to indicate the pollution levels of electrical insulators. The behavior of leakage current, which is one indicator of the presence of pollutants on the insulator surfaces, was characterized through a regression model. We quantitatively examine the behavior of leakage current and the way electrical components are polluted. The data for environmental variables and leakage current in an electrical substation are analyzed and a model is identified that well represents the leakage current behavior on the insulators. Through this model, some predictions of the pollution effect can be made using analysis tools that enable the identification of the effects of leakage current on the entire network. This method can be used to obtain leakage current models on electrical substations located in highly polluted zones.

This article describes that the military right comes from the constitutional regulation of the use of force. This regulation imposes a particular duty of obedience to the military, that is guarded at the same time, by the military disciplinary right and the military penal code. It informs that although military justice is not forbidden by the international right of the Human Rights, is considered as a regulation of restricted application. Also details, the valid requisites presented by the international right for the military justice, and how jurisprudence of the Inter American system had influenced the reform of the military penal jurisdiction in the continent.

This article delimits the borders de of the associative crime, by using as the main study case the Tarantino’s film “Pulp Fiction” (1994). By means of the analysis and cinematographic interpretation, the main characteristics that shape the “organized crime” are described and illustrated: the existence of a solid organization, the criminal profitable ends and the employment of violence as a criminal method.

Introduction A broad range of stakeholders have called for randomised evidence on the potential clinical benefits and harms of proton therapy, a type of radiation therapy, for patients with breast cancer. Radiation therapy is an important component of curative treatment, reducing cancer recurrence and extending survival. Compared with photon therapy, the international treatment standard, proton therapy reduces incidental radiation to the heart. Our overall objective is to evaluate whether the differences between proton and photon therapy cardiac radiation dose distributions lead to meaningful reductions in cardiac morbidity and mortality after treatment for breast cancer.Methods We are conducting a large scale, multicentre pragmatic randomised clinical trial for patients with breast cancer who will be followed longitudinally for cardiovascular morbidity and mortality, health-related quality of life and cancer control outcomes. A total of 1278 patients with non-metastatic breast cancer will be randomly allocated to receive either photon or proton therapy. The primary outcomes are major cardiovascular events, defined as myocardial infarction, coronary revascularisation, cardiovascular death or hospitalisation for unstable angina, heart failure, valvular disease, arrhythmia or pericardial disease. Secondary endpoints are urgent or unanticipated outpatient or emergency room visits for heart failure, arrhythmia, valvular disease or pericardial disease. The Radiotherapy Comparative Effectiveness (RadComp) Clinical Events Centre will conduct centralised, blinded adjudication of primary outcome events.Ethics and dissemination The RadComp trial has been approved by the institutional review boards of all participating sites. Recruitment began in February 2016. Current version of the protocol is A3, dated 08 November 2018. Dissemination plans include presentations at scientific conferences, scientific publications, stakeholder engagement efforts and presentation to the public via lay media outlets.Trial registration number NCT02603341

The human respiratory syncytial virus (hRSV) is the main etiologic agent of severe lower respiratory tract infections that affect young children throughout the world, associated with significant morbidity and mortality, becoming a serious public health problem globally. Up to date, no licensed vaccines are available to prevent severe hRSV-induced disease, and the generation of safe-effective vaccines has been a challenging task, requiring constant biomedical research aimed to overcome this ailment. Among the difficulties presented by the study of this pathogen, it arises the fact that there is no single animal model that resembles all aspects of the human pathology, which is due to the specificity that this pathogen has for the human host. Thus, for the study of hRSV, different animal models might be employed, depending on the goal of the study. Of all the existing models, the murine model has been the most frequent model of choice for biomedical studies worldwide and has been of great importance at contributing to the development and understanding of vaccines and therapies against hRSV. The most notable use of the murine model is that it is very useful as a first approach in the development of vaccines or therapies such as monoclonal antibodies, suggesting in this way the direction that research could have in other preclinical models that have higher maintenance costs and more complex requirements in its management. However, several additional different models for studying hRSV, such as other rodents, mustelids, ruminants, and non-human primates, have been explored, offering advantages over the murine model. In this review, we discuss the various applications of animal models to the study of hRSV-induced disease and the advantages and disadvantages of each model, highlighting the potential of each model to elucidate different features of the pathology caused by the hRSV infection.