Perceptions about Teaching in Times of COVID-19 Pandemic: Experience of Secondary Education in Chile

<p style="text-align: justify;">The following article is a qualitative study that analyses the perception of parents and high school students regarding teaching in times of Coronavirus disease COVID-19, with the idea of recognizing the facilitators and barriers for the teaching-learning process in the pandemic. The above, in the understanding that due to the sudden appearance of SARS-CoV-2, educational systems around the world had to adapt to virtual teaching, as a result of the confinement to which the population has been subjected during the year 2020 and a good part of the year 2021. The research is based on the interpretative-comprehensive paradigm, with a qualitative methodology, which considered the realization of four focus groups with students and four focus groups with secondary school parents, from two public high schools located in the province of Talca, Maule region, Chile. The findings of the study are related to the adverse effects of the pandemic on student learning, as a result of connectivity difficulties, and the emotional impact on the quality of life of young people and their families. On the other hand, learning at home is related to limited pedagogical strategies and evaluative aspects that do not allow verifying the real learning of the students.</p>

A Review of the Biology, Ecology, and Management of the South American Locust, Schistocerca cancellata (Serville, 1838), and Future Prospects

In the first half of the twentieth century, the South American Locust (SAL), Schistocerca cancellata (Serville, 1838), was a major pest of agriculture in Argentina, Bolivia, Paraguay, Uruguay, and Brazil. From 1954–2014, a preventive management program appeared to limit SAL populations, with only small- to moderate-scale treatments required, limited to outbreak areas in northwest Argentina. However, the lack of major locust outbreaks led to a gradual reduction in resources, and in 2015, the sudden appearance of swarms marked the beginning of a substantial upsurge, with many swarms reported initially in Argentina in 2015, followed by expansion into neighboring countries over the next few years. The upsurge required a rapid allocation of resources for management of SAL and a detailed examination of the improvements needed for the successful management of this species. This paper provides a review of SAL biology, management history, and perspectives on navigating a plague period after a 60-year recession.

COVID-19 AND THE HUMAN EYE – CONJUNCTIVITIS A LONE COVID-19 FINDING - A case-control study

Background: The worldwide sudden appearance and drastic increase in the number of infected cases with the severe acute respiratory syndrome-Coronavirus 2 (SARS-CoV-2) determined the World Health Organization to declare it as a pandemic situation. The ‘Corona Virus Disease 2019’ (COVID-19) has varied clinical manifestations, from asymptomatic to severe cases, and conjunctivitis, seems not only to be one of them, but sometimes found to be lone initial symptom present. Aim and method: The aim was to identify the prevalence of conjunctivitis as the first symptom in COVID-19 patients, in a primary healthcare unit. A retrospective study was conducted analyzing the presenting complains/symptoms and results of COVID-19 confirmatory tests. Results: Out of the 672 cases that were sent for RT-PCR testing only 121 (18%) were found to be positive. Among this 2.67% of patients who had both conjunctivitis and COVID-19, 77.77% of patients had unilateral eye affected while 22.22% had bilateral conjunctivitis of varying degrees. 15 patients diagnosed to have both acute conjunctivitis and COVID-19, presented other symptoms associated with COVID-19 infection. While 3 patients had only acute conjunctivitis during their entire course of COVID-19. Conclusions: Conjunctivitis is a symptom of COVID-19 and maybe the first sign of the infection, until the onset of the classical manifestations, the patient serves to be a viral reservoir. The physicians should not miss unilateral conjunctivitis, as it can be the only presenting complain of the COVID-19 disease at the initial phase, which might worsen if underwent undetected and can aid in the spread of the contagion.

DNA-based quantification of Fusarium oxysporum f. sp. vasinfectum in environmental soils to describe spatial variation in inoculum density

Fusarium wilt of cotton, caused by the soilborne fungal pathogen Fusarium oxysporum f. sp. vasinfectum (FOV), occurs in regions of the United States where cotton (Gossypium spp.) is grown. Race 4 of this pathogen (FOV4) is especially aggressive and does not require the co-occurrence of the root knot nematode (Meloidogyne incognita) to infect cotton. Its sudden appearance in far-west Texas in 2016 after many years of being restricted to California is of great concern, as is the threat of its continued spread through the cotton-producing regions of the United States. The aim of this research was to analyze the spatial variability of FOV4 inoculum density in the location where FOV4 is locally emerging, using quantitative and droplet digital polymerase chain reaction (qPCR and ddPCR) methods. Soil samples collected from a field with known FOV4 incidence in Fabens, Texas were analyzed. Appreciable variation in inoculum density was found to occur at spatial scales smaller than the size of plots involved in cultivar trial research, and was spatially autocorrelated (Moran’s I, Z = 17.73, p < 0.0001). These findings indicate that for cultivar trials, accounting for the spatial distribution of inoculum either by directly quantifying it or through the use of densely-distributed “calibration checks” is important to the interpretation of results.

Framework for Assessing Online Shopping Use Under the Digital Transformation of the Economy in a Post-Pandemic Era

The sudden appearance of COVID-19 has positively ameliorated digital presence generally as well as B2C e-shopping transactions. This situation attracts researchers' interest to unravel the effect of COVID-19 vis-à-vis various e-commerce activities. Recent studies have already shown a direct impact of the pandemic on many businesses, especially B2C transactions. However, its moderation effect and its effect as a control variable were scarcely traced in the literature. Hence, the chapter explains and proposes a framework for assessing online shopping use under the digital transformation in a post-pandemic era, including both a moderating and a control effect of the COVID-19 pandemic. Building on the TAM theoretical model, the proposed framework added risk factors and channel credibility as additional independent variables and the COVID-19 pandemic as both a moderating and a control variable, respectively. Using existing literature, the authors establish relationships among variables and conceptualise both the moderating and control effects of the COVID-19 pandemic, respectively.

Cytologic and histologic features of COVID-19 post-vaccination lymphadenopathy

In this study, we present six cases of axillary or supraclavicular lymphadenopathies in the days following to the Pfizer-BioNTech vaccine’s first dose and its study for fine-needle aspiration cytology (two patients), biopsy with a gross needle (two patients), and the evolution of two other patients. Cytological smears and histological sections reveal reactive nodes, predominantly T, CD8, and the presence of atypia with striking mitosis. Differential diagnosis with viral lymphadenopathies and lymphoma is important, so the clinical correlation, in a vaccination context, sudden appearance, and progressive decrease in days of the adenopathy, is essential. In this article, we have studied the cytohistological manifestations of post-Pfizer-BioNTech vaccination lymphadenopathy and discussed its differential diagnosis.

Simulation of the Vibrations Produced to the Human Body During Operation of the Bucket Wheel Excavators. A Case Study of ERc 1400-30/7 Type Excavator

The paper deals with the analysis of the dynamic response over time of the excavator boom during operation. For a start, we determined the variation in time of the forces acting on the rotor shaft, due to the excavation. These forces have high values and a slow variation over time, which depends on the rotation speed of the bucket wheel and the number of buckets installed on it. A virtual model of the BWE boom was proposed, for which the dynamic response in time due to the excavation forces was determined, for a point in the main cabin of the BWE. A virtual sensor has been attached to this point corresponding to seat of the operator. The simulation of the dynamic response over time was performed taking into account a global damping of 2% of the critical damping. The simulation was performed both for the excavation of a homogeneous material and for the case of a shock (a sudden appearance of an inclusion of hard material during the cutting of the homogeneous material).

COVID 19 Pneumonia and a Rare Form of Fungal Peritonitis in a Patient Survivor on Peritoneal Dialysis

Peritoneal dialysis (PD) related peritonitis is usually caused by bacteria, but viruses and fungi could also affect the peritoneal membrane and cause cloudy effluent with negative bacterial cultures. We present a case of a PD patient who survived fungal peritonitis caused by Geotrichum klebahnii (March 2015) and COVID-19 pneumonia (April 2021) with peritonitis probably caused by the SARS-CoV-2 virus. The fungal peritonitis followed one episode of exit-site infection and two episodes of bacterial peritonitis treated with a wide-spectrum antibiotic. The patient’s PD catheter was removed immediately upon the diagnosis of fungal peritonitis, and an antifungal treatment was continued for 3 weeks after catheter removal. The new peritoneal catheter was reinserted 8 weeks after complete resolution of peritonitis, and the patient continued treatment with PD. The patient developed severe Covid-19 pneumonia with a sudden appearance of cloudy peritoneal effluent. There was no bacterial or fungal growth on the effluent culture. A PCR test for SARS-CoV-2 in peritoneal effluent was not performed. The peritoneal effluent became transparent with the resolution of the severe symptoms of Covid-19 pneumonia.

Aperiodic EEG activity masks the dynamics of neural oscillations during loss of consciousness from propofol

EEGs are known to provide biomarkers for consciousness. Although EEG correlates of loss of consciousness (LOC) are often ascribed to changes in neural synchrony, mounting evidence suggests that some changes result from asynchronous neural activity. By combining EEG recordings of humans undergoing propofol administration with biophysical modelling, we present here a principled decomposition of EEG changes during LOC into synchronous and asynchronous sources. Our results reveal that IPSP decay rate and mean spike rate shape aperiodic EEG features, and that propofol's effects on these parameters largely explain the changes in EEG spectra following propofol infusion. We further show that traditional spectral EEG analysis likely conflates these effects with changes in rhythmic activity, thereby masking the true dynamics of neural synchrony. We conclude that the well-documented propofol-induced alpha rhythm in fact appears before LOC, and that the moment of LOC is uniquely correlated with the sudden appearance of a delta rhythm.