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Background We sought to determine the frequency of asymptomatic SARS-CoV-2 infections, the BNT162b2 mRNA COVID 19 vaccine-related symptoms, and the correlates of immunity in post-vaccination breakthrough infections in a prospective cohort of healthcare workers. Methods We have been conducting a single-center, observational cohort study of healthcare workers. 271 participants were enrolled since August 25, 2020. Testing for SARS-CoV-2 spike (S)-specific IgG antibodies is conducted using a microsphere-based multiplex immunoassay interpolated against an internal standard curve for binding antibody (bAb) units (BAU) and has been performed on serum samples collected at monthly visits between September 2020 to August of 2021, and quarterly since then. Neutralizing antibody titers against wild-type (WT) virus are determined by microneutralization assays and against Delta and Omicron variants by lentiviral pseudovirus neutralization assays. For the first 6 months, participants completed a symptoms questionnaire every day they had any symptoms. Results 12 participants were diagnosed with SARS-CoV-2, with at least mild symptoms. Of 206 participants evaluated for adverse effects after 1st and 2nd vaccine doses, no relationship was observed between vaccine-associated symptom scores and antibody titers 1 month after the 2nd dose. Longitudinal studies demonstrate that anti-S IgG bAbs decrease from a geometric mean (GM) of 1929 BAU/mL at 1 month post-vaccination to a GM of 442 BAU/mL at 6 months post-vaccination (P< 0.001, n=187), and that boosting increases S-specific IgG BAU. While only 5 of 39 participants had detectable anti-Omicron neutralizing activity 1 month after 2 vaccinations, booster vaccination resulted in detectable neutralizing activity for all participants. Conclusion Asymptomatic infection is likely rare, that there is no relationship between vaccine-associated symptom severity and antibody titers 1 month after the 2nd vaccination, and that booster results in better protection against the Omicron variant. Ongoing studies are evaluating serological and cellular immune responses immediately prior to 38 breakthrough infections in an attempt to identify immune correlates of protection and will be reported at the conference. Disclosures John H. Powers, III, MD, Arrevus: Advisor/Consultant|Eicos: Advisor/Consultant|Evofem: Advisor/Consultant|Eyecheck: Advisor/Consultant|Gilead: Advisor/Consultant|GlaxoSmithKline: Advisor/Consultant|OPKO: Advisor/Consultant|Resolve: Advisor/Consultant|Romark: Advisor/Consultant|SpineBioPharma: Advisor/Consultant|UTIlity: Advisor/Consultant|Vir: Advisor/Consultant David Tribble, MD, DrPH, Astra Zeneca: The HJF, in support of the USU IDCRP, was funded to conduct or augment unrelated Phase III Mab and vaccine trials as part of US Govt. COVID19 response Simon Pollett, MBBS, Astra Zeneca: The HJF, in support of the USU IDCRP, was funded to conduct or augment unrelated Phase III Mab and vaccine trials as part of US Govt. COVID19 response Timothy Burgess, MD, MPH, AstraZeneca: The HJF, in support of the USU IDCRP, was funded to conduct or augment unrelated Phase III Mab and vaccine trials as part of US Govt. COVID19 response.

Este documento presenta la evaluación estructural del cuerpo de una aeronave ligera de categoría vla (masa máxima al despegue inferior o igual a 1200 kg), usando software de dinámica computacional de fluidos (cfd) para evaluar el comportamiento aerodinámico de la aeronave y el método de elementos finitos para evaluar su comportamiento estructural. Para su evaluación estructural la aeronave se dividió en cabina, cuerpo y superficies de vuelo (alas y empenaje). Los modelos completos de la aeronave fueron extraídos del modelo cad, elaborado con el software SolidWorks® para cada uno de los subcomponentes de la cabina, el cuerpo y las alas y el empenaje. A partir de los cálculos y simulaciones hechas, se concluyó que la estructura central de la aeronave soporta las fuerzas y momentos aerodinámicos, con valores de esfuerzos por debajo de los valores de fluencia del material y factores de seguridad entre 1.58 y 2.60. Sin embargo, se necesita reforzar la unión del ala al fuselaje para que disminuya el es- fuerzo localizado que se produce en esa zona. A diferencia de otros métodos reportados en la literatura que utilizan programas muy especializados y de altos costos, el procedimiento para evaluar la aerodinámica y la estructura central de una aeronave liviana categoría vla que se desarrolló en este estudio, hizo uso de programas de dominio público, en alrededor de 80 % en el proceso de análisis. This paper shows the structural evaluation of a vla category light aircraft (maximum take-off mass less than or equal to 1200 kg), using computational fluid dynamics (cfd) software to evaluate the aerodynamic behavior of the aircraft and the finite element method to evaluate its structural behavior. For its structural evaluation, the aircraft has been divided into cabin, body, and flight surfaces (wings and empennage). The complete models of the aircraft were extracted from the cad model made using SolidWorks® Software for each of the sub-components of the cockpit, body and wings, and the empennage. From the calculations and simulations performed, it was concluded that the central structure of the aircraft supports the aerodynamic forces and moments adequately, having values below the yield values of the material. However, it is necessary to reinforce the attachment of the wing to the fuselage to reduce the effort produced in that area. Unlike other methods reported in the literature that use very specialized and high-cost programs, the procedure to evaluate the aerodynamics and central structure of a vla category light aircraft that was developed in this study made use of public domain programs, at around 80 % of the analysis proces Este documento apresenta a avaliação estrutural do corpo de uma aeronave leve categoria vla (massa máxima de decolagem menor ou igual a 1200 kg), utilizando software de dinâmica de fluidos computacional (cfd) para avaliar o comportamento aerodinâmico da aeronave e o método de elementos finitos avaliar seu comportamento estrutural. Para sua avaliação estrutural, a aeronave foi dividida em cabine, corpo e superfícies de voo (asas e empenagem). Os modelos completos da aeronave foram extraídos do modelo cad elaborado com o software SolidWorks para cada um dos subcomponentes do cockpit, o corpo e as asas e a empenagem. Com base nos cálculos e simulações realizados, concluiu-se que a estrutura central da aeronave suporta as forças e momentos aerodinâmicos, com valores de tensão abaixo dos valores de escoamento do material e fatores de segurança entre 1,58 e 2,60. No entanto, é necessário reforçar a união da asa à fuselagem para reduzir o estresse localizado produzido nessa área. Diferentemente de outros métodos relatados na literatura que utilizam programas muito especializados e de alto custo, o procedimento de avaliação da aerodinâmica e da estrutura central de uma aeronave leve da categoria vla que foi desenvolvido neste estudo, fez uso de programas de domínio público, em cerca de 80 % processo de análise

The study carried out identifies the metricss of the predictive model obtained through the support vector machine (VSM) algorithm, which will be applied in the satisfaction of the acquisition of professional skills of the students of the Professional Engineering Career. As part of the development, the statistical classification tool is used, during the development of the research, it was identified that the predictive model presents as general metrics an accuracy of 82.1%, a precision of 70.72%, a sensitivity of 91.06% and a specificity of 87.60%. Through this model, it contributes significantly to decision-making in relation to improving satisfaction related to the acquisition of professional skills in engineering students, since decision-making by university authorities will have a scientific basis, to take early and timely actions in relation to the predictive elements.

Background The frequency of asymptomatic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is unclear and may be influenced by how symptoms are evaluated. In this study, we sought to determine the frequency of asymptomatic SARS-CoV-2 infections in a prospective cohort of health care workers (HCWs). Methods A prospective cohort of HCWs, confirmed negative for SARS-CoV-2 exposure upon enrollment, were evaluated for SARS-CoV-2 infection by monthly analysis of SARS-CoV-2 antibodies as well as referral for polymerase chain reaction testing whenever they exhibited symptoms of coronavirus disease 2019 (COVID-19). Participants completed the standardized and validated FLU-PRO Plus symptom questionnaire scoring viral respiratory disease symptom intensity and frequency at least twice monthly during baseline periods of health and each day they had any symptoms that were different from their baseline. Results Two hundred sixty-three participants were enrolled between August 25 and December 31, 2020. Through February 28, 2021, 12 participants were diagnosed with SARS-CoV-2 infection. Symptom analysis demonstrated that all 12 had at least mild symptoms of COVID-19, compared with baseline health, near or at time of infection. Conclusions These results suggest that asymptomatic SARS-CoV-2 infection in unvaccinated, immunocompetent adults is less common than previously reported. While infectious inoculum doses and patient factors may have played a role in the clinical manifestations of SARS-CoV-2 infections in this cohort, we suspect that the high rate of symptomatic disease was due primarily to participant attentiveness to symptoms and collection of symptoms in a standardized, prospective fashion. These results have implications for studies that estimate SARS-CoV-2 infection prevalence and for public health measures to control the spread of this virus.

The objective of this study was to identify the results of the learning management system (LMS) functionality, and its relationship in the perception of electronic engineering students. The results serve as a basis for continuous improvement for the higher institution, because these systems are tools that have the purpose of improving the performance and retention of the student in the virtual teaching-learning process. Initially, the reliability of the data collected was determined using Cronbach's Alpha, obtaining a consistency coefficient of 0.868. After processing the data in the SPSS software, using the 5-level Likert scale, it was determined that the indicators that present a better perception are related to the design and ease of navigation. However, 21.4% do not fully agree with the functionality, due to the technical problems presented when downloading the study material. The effect generated by the optimal functionality of the LMS is 70.87% satisfaction in students. The Chi square test validated the cause-effect relationship, with a significance of 0.000, between the functionality of the LMS, on the perception of the students. It determined that the indicators with a greater relationship refer to design, availability (connectivity) and ease of communication and interaction with the teacher and their peers.

Antibodies against SARS-CoV-2 decay but persist six months post-vaccination, with lower levels of neutralizing titers against Delta than wild-type. Only 2 of 227 vaccinated healthcare workers experienced outpatient symptomatic breakthrough infections despite 59 of 227 exhibiting serological evidence of exposure to SARS-CoV-2 as defined by development of anti-nucleocapsid protein antibodies.

Background The relationship between postvaccination symptoms and strength of antibody responses is unclear. The goal of this study was to determine whether adverse effects caused by vaccination with the Pfizer/BioNTech BNT162b2 vaccine are associated with the magnitude of vaccine-induced antibody levels. Methods We conducted a single-center, observational cohort study consisting of generally healthy adult participants that were not severely immunocompromised, had no history of coronavirus disease 2019, and were seronegative for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein before vaccination. Severity of vaccine-associated symptoms was obtained through participant-completed questionnaires. Testing for immunoglobulin G antibodies against SARS-CoV-2 spike protein and receptor-binding domain was conducted using microsphere-based multiplex immunoassays performed on serum samples collected at monthly visits. Neutralizing antibody titers were determined by microneutralization assays. Results Two hundred six participants were evaluated (69.4% female, median age 41.5 years old). We found no correlation between vaccine-associated symptom severity scores and vaccine-induced antibody titers 1 month after vaccination. We also observed that (1) postvaccination symptoms were inversely correlated with age and weight and more common in women, (2) systemic symptoms were more frequent after the second vaccination, (3) high symptom scores after first vaccination were predictive of high symptom scores after second vaccination, and (4) older age was associated with lower titers. Conclusions Lack of postvaccination symptoms after receipt of the BNT162b2 vaccine does not equate to lack of vaccine-induced antibodies 1 month after vaccination., We found no correlation between BNT162b2-associated symptom severity and vaccine-induced antibody titers 1 month after vaccination. Adverse effects inversely correlated with age and weight, whereas symptom severity after first vaccination was predictive of that after second vaccination.

This study analyzed the perception of Mechanical Engineering and Systems Engineering students in the process of evaluating teacher performance in online teaching due to the COVID-19 pandemic. This was descriptive-correlational research. The results showed that the Systems Engineering students performed a better perception with the class session management factor and low qualification to the didactic strategies factor. Likewise, the Pearson correlation test indicated a significant relationship (0.000) between the specific factors on the overall performance factor. The topic factor has the greatest strength on the qualification of the overall performance factor, with a constant Pearson's correlation of 0.964. The Mechanical Engineering students showed a better perception with the class session planning factor and low qualification to the didactic strategies factor. Likewise, the Pearson correlation test indicated a significant relationship (0.000) between the specific factors on the overall performance factor. The didactic strategies factor being the one that has the greatest strength on the qualification of the overall performance factor, with a correlation constant Pearson's of 0.983.

This article aims to carry out a descriptive analysis of the performance of teachers qualified as researchers, in the distance education environment according to the student's perspective. The results will be a frame of reference for university authorities on the path of continuous improvement of virtual education. When carrying out the research, a general qualification of the teaching performance of 14.20 was determined, established the highest grade equal to 20, it can be indicated that there is a good performance of the teacher in the virtual education environment. In addition, the results show that the highest evaluation corresponds to the indicator management of the group and fulfillment of the objectives, which is directly related to the administration of the class, while the lowest rating is for the indicator "Teacher effectiveness so that their students acquire relevant knowledge, skills and attitudes”, which is directly related to the didactic strategies used, that is, to the use of technological tools that today are more than just an option. Finally, it can be noted that of the total of 17 teaching, 23.5% present a very good performance, 35.3% present a good performance and 41.2% present a regular performance.

Background The Prospective Assessment of SARS-CoV-2 Seroconversion (PASS) study is following over 200 healthcare workers who have received the Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine. A major aim of the study is to determine whether baseline antibody titers against the seasonal human coronaviruses are associated with altered levels of vaccine-induced antibody responses to SARS-CoV-2. Methods Serial serum samples obtained pre-vaccination and 1 month after the second dose were tested for IgG antibodies against the full pre-fusion spike protein and the receptor binding domain (RBD) of SARS-CoV-2, as well as the full pre-fusion spike proteins of OC43, HKU1, 229E, and NL63. Antibodies were measured using highly sensitive and specific multiplex assays based on Luminex-xMAP technology. Results Preliminary analyses of the first 103 subjects in whom we have 1 month post-vaccination serum demonstrate development of high IgG geometric mean titers (GMT) to both the full spike protein (GMT: 13,685, 12,014-15,589, 95% CI) and the RBD (GMT: 19,448, 17,264-21,908, 95% CI) of SARS-CoV-2 after the 2nd vaccine dose. Preliminary analysis demonstrates no association between baseline antibody titers against spike protein of OC43 and antibody titers against SARS-CoV-2 spike protein (Pearson’s r-value= 0.13, P-value= 0.21) or RBD (Pearson’s r-value= 0.09, P-value= 0.36) one month after vaccination. Future analyses will evaluate whether there is an association with baseline seasonal coronavirus antibody titers and either SARS-CoV-2 neutralization titers or anti-SARS-CoV-2 spike protein titers at 6 months after vaccination. Conclusion These preliminary results suggest that baseline antibody responses to seasonal coronaviruses neither boost nor impede SARS-CoV-2 vaccine-induced antibody responses. Longitudinal sampling will enable assessment of vaccine durability and determination of whether baseline seasonal coronavirus antibody levels are associated with altered duration of detectable COVID-19 vaccine-induced antibody responses. Disclosures Simon Pollett, MBBS, Astra Zeneca (Other Financial or Material Support, HJF, in support of USU IDCRP, funded under a CRADA to augment the conduct of an unrelated Phase III COVID-19 vaccine trial sponsored by AstraZeneca as part of USG response (unrelated work)) David Tribble, M.D., DrPH, Astra Zeneca (Other Financial or Material Support, HJF, in support of USU IDCRP, funded under a CRADA to augment the conduct of an unrelated Phase III COVID-19 vaccine trial sponsored by AstraZeneca as part of USG response (unrelated work))

Background. Bacteria endophytes, harmless symbiotic organisms that promote plant growth and development, have been considered useful tools for ecosystem restauration. Goals . The present study characterized bacteria endophytes isolated from Lemna gibba plants (collected in the “chinampera area” of Xochimilco canals over two seasons) according to the amount of indole acetic acid production. Methods . Twelve phytobacteria species were found; eight in plants collected through the drought season belonging to the genera Achromobacter, Bacillus, Deinococcus, Enterococcus, and four in plants collected during the rainy season of the genus Serratia. Results . According to their indole acetic acid production, four of the phytobacteria isolated from plants collected in the dry season were characterized as low producers and four as high producers. All the organisms obtained from plants gathered during the rainy season were classified as high producers. Conclusions. The presence of endophytic bacteria producing large amounts of indole acetic acid in Lemna gibba plants suggests that these organisms could promote plant development and act as potential bioinoculants.

This article aims to describe the design of an automatic control system for the automated management of motor drives through Simocode pro; and determine the effect from the quantitative point of view on the performance of the filling and dispatch process of chemical inputs from the perspective of dispatch time and the amount of input spilled in the tank filling stage. For this, the programming of the programmable logic controller was carried out using the simatic step 7 software, then the distributed control system (DCS Siemens S410) was programmed, using the PCS7 V8.1 software, where the control logic and simocode pro integration is carried out through the profibus protocol, which is monitored from an human-machine interface (HMI) interface. Once the control system was implemented, it was possible to reduce the operating time from 60 minutes on average to 35 minutes, which reflects an improvement of 41.66%; this in turn generates an increase in the number of tank filling by 62.84%. Likewise, it is possible to reduce the amount of chemical inputs spilled in the filling stage; this improvement represents 88.60%.

"Antecedentes. Los endófitos bacterianos que habitan dentro de las plantas sin causar daño y promueven su crecimiento y desarrollo se han considerado herramientas útiles para la restauración de los ecosistemas. Objetivos. En el presente estudio se caracterizaron fitobacterias endófitas aisladas de plantas de Lemna gibba, colectadas en la zona chinampera de los canales de Xochimilco en dos temporadas, con base en la comparación de su producción de ácido indolacético. Métodos. Se evaluaron 12 fitobacterias en total; ocho aisladas de las plantas L. gibba colectadas en la temporada de sequía pertenecientes a los géneros Achromobacter, Bacillus, Deinococcus, Enterococcus, Pseudomonas y Rahnella. Las variedades restantes (pertenecientes al género Serratia) se obtuvieron de plantas colectadas en la temporada de lluvias. Resultados. De acuerdo con la producción de ácido indolacético, de las fitobacterias colectadas en la temporada de sequía, cuatro se clasificaron como bajas productoras y cuatro como altas productoras. Por otra parte, todos los organismos que se recolectaron en la temporada de lluvias se clasificaron como altos productores. Conclusiones. La presencia de fitobacterias endófitas altas productoras de ácido indolacético en Lemna gibba sugiere que son promotoras potenciales del desarrollo de dichas plantas y también que actúan como bioinoculantes potenciales."

Plant-associated bacteria that inhabit the rhizosphere may influence the plant growth by their contribution to the endogenous pool of phytohormones and by the activity of ACC deaminase to decrease the ethylene concentration. The aim of this study was to analyse the root length growth by the promoting effect of indole acetic acid producers phytobacteria with ACC deaminase activity, on inoculated seeds of Lens esculenta as synergistic effect on root elongation. In this study, although the roots of L. esculenta seedlings do not show a significant promotion, these phytobacteria could be recommended to treat plants analyzing their added inoculum to increase plant biomass and retard the effect of ethylene on cultures supplied with Tryptophan and ACC.

Xochimilco’s lacustrine zone is a network of channels that, along with the chinampas, conform a unique ecosystem which has served as source of aquatic resources. Duckweeds are small free-floating monocotyledon aquatic plants classified as macrophytes that serve as nutrient pumps and reduce eutrophication effects. Recently, there are number of new studies related to the aquatic plant-microbial interaction focused on the direct functional analysis that investigate plant microbe interactions at full biological hierarchy. The aim of this study was to compare the auxin in vitro production efficiency of the endophyte phytobacteria isolated from Lemna gibba L. plants collected nearby the Xochimilco aquatic agrosystem. There were 17 isolates obtained from the L. gibba plants collected in the dry season and 14 isolates for the rainy season. The environmental conditions and seasonal characteristics determined the number and identity of the isolated endophyte phytobacteria in L. gibba plants according to the several apparent differences in the water quality. This work contributes to the knowledge of the phytobacteria diversity in aquatic plants, particularly in Lemnaceae species; here the majority of the isolates have been characterized as higher indole acetic acid producers, recommended as candidates for their use as biofertilizers. Key words: Plant growth-promoting bacteria, biofertilizers, Lemna gibba , Xochimilco.

espanolEn las obras tardias de Martin Heidegger puede advertirse una dificultad de distincion entre dos aspectos fundamentales de su pensamiento: pensar y poetizar. No resultan muy claras las distinciones que el mismo filosofo establece, por ejemplo: “asi y todo, no podemos decidir aqui de manera definitiva si la poesia es, en lo propio, una forma de pensamiento o si el pensamiento es, en lo propio, una forma de poesia” (Heidegger, 2002, p. 140). Es bastante «oscura» la relacion entre estos dos modos del decir, mas aun cuando el mismo filosofo aleman deja en claro que estos dos «vecinos» se encuentran bajo una «luminosa» diferencia. Por ello, surge la pregunta: ?que tan clara tiene el mismo Heidegger la diferencia entre pensar y poetizar cuando reconoce una «oscuridad» en la relacion, pero afirma una «luminosidad» en la diferencia? EnglishIn Martin Heidegger’s later works, one can notice a difficulty in distinguishing between two fundamental aspects of his thought: thinking and poetizing. The distinctions that the philosopher himself establishes are not very clear, for example: “even so, we cannot decide here definitively if poetry is, in itself, a form of thought or if thought is, in itself, a form of poetry” (Heidegger, 2002, p. 140). The relationship between these two modes of saying is quite «dark», even more so when the same German philosopher makes it clear that these two «neighbors» are under a «luminous» difference. Therefore, the question arises: how clear is Heidegger himself the difference between thinking and poetizing when he recognizes a «darkness» in the relationship, but affirms a «luminosity» in the difference?