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The global pandemic caused by coronavirus disease-2019 (COVID-19) disrupted both public and private life for many. Concerning medical students, practical teaching and classrooms were substituted with a virtual curriculum. However, how this new academic environment has affected students' health and lifestyles has yet to be studied. In this study, we surveyed 2,776 students from nine different countries about changes in their university curricula and potential alterations in their daily habits, physical health, and psychological status. We found negative changes across all countries studied, in multiple categories. We found that 99% of respondents indicated changes in their instruction delivery system, with 90% stating a transition to online education, and 93% stating a reduction or suspension of their practical activities. On average, students spent 8.7 hours a day in front of a screen, with significant differences among countries. Students reported worsened studying, sleeping, and eating habits with substantial differences in Latin American countries. Finally, the participants frequently expressed onset and increase in both mental and physical health symptoms: backache, asthenopia, irritability, and emotional instability. Altogether, these results suggest a potential risk in the health and academic performance of future doctors if these new academic modalities are maintained.

Based on the examination of its lectotype (here designated), Westermannia difficilis Dohrn, 1860 (Hemiptera, Heteroptera, Reduviidae, Emesinae, Emesini), currently included in Dohrnemesa Wygodzinsky, 1945, is transferred to the genus Polauchenia McAtee & Malloch, 1925 with the resulting new combination: Polauchenia difficilis (Dohrn, 1860), comb. nov. An updated key to the species of Polauchenia is provided. [ABSTRACT FROM AUTHOR]

Non-parametric statistics and cluster analysis have been found useful to evaluate differences/similarities of PAHs presence/absence in atmospheric settled particles (ASPs) collected on building roofs in Valencia City, Venezuela, as an alternative tool in the study of air pollutants. The sampling focused on variables such as size particles, building heights, location, and sampling months. ASPs were extracted by Soxhlet with dichloromethane. The organic extracts were fractionated by liquid column chromatography, and PAHs were identified by GC-MS. The study used nominal data, and a cluster was built from Jaccard's matrix. The results show three groups: 1 and 2 correspond to not impacted and poorly impacted zone and group 3 is associated with moderate to strongly impacted zone. The results of chi-square test of independence show that height was related to the number of PAHs detected. Non-parametric and multivariate statistical tools are useful to derive conclusions from categorical data of PAHs. [ABSTRACT FROM AUTHOR]

Copyright of Revista Trabajo Social is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Begomoviruses are one of the major pathogens in tomato crops worldwide. In Venezuela, six begomovirus species have been described infecting tomato: Potato yellow mosaic virus ( PYMV), Euphorbia mosaic Venezuela virus (Eu MVV), Merremia mosaic virus (Me MV), Tomato chlorotic leaf distortion virus (To CLDV), Tomato yellow margin leaf curl virus ( TYMLCV) and Tomato yellow leaf curl virus ( TYLCV). In this study, the occurrence of these viruses was analysed by PCR in 338 tomato plants exhibiting virus-like symptoms. Sixty-three per cent of the plants were positive at least to one of the begomoviruses tested. PYMV and TYLCV were the most frequent viruses showing 39.6 and 23.7% occurrence, respectively. Phylogenetic analyses revealed two groups of PYMV isolates from several Caribbean Basin countries. The first group clustered isolates from several countries, including Venezuela, and the second group clustered only Colombian isolates. Due to the high prevalence of PYMV and TYLCV in Venezuela, it is suggested that the surveillance and control strategies currently applied in the country should be focused on these two begomoviruses. [ABSTRACT FROM AUTHOR]

Copyright of Revista Iberoamericana de Ciencia, Tecnologia y Sociedad is the property of Centro de Estudios sobre Ciencia, Desarrollo y Educacion Superior and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this article we report a new cassava (Manihot esculenta Crantz) bacterial disease in Venezuela. The disease has been observed in different Venezuelan regions since 2001. Leaves of the collected samples showed angular water-soaked lesions on the leaf lamina, which became later necrotic with a chlorotic halo. Advanced disease stages induce an early senescence of leaves leaving the stem bare. Bacteria isolated formed small beige, glistening, smooth colonies with regular margins within 24 h incubation at 30°C on LB agar or semi-selective threhalose agar. All isolates were Gram negative, facultative anaerobic with several peritrichious flagella observed under the Electron Microscope. The bacterium was identified as Enterobacter cloacae by biochemical assays, but 16S rRNA gene sequence analysis did not allow discrimination between E. cloacae and Pantoea agglomerans. Other PCR based identification methods such as ERIC and GIRRN-LIRRN ribotyping, and hsp60 sequence identified the strains as E. cloacae. Pathogenicity test on cassava plants reproduced the disease symptoms and allowed the reisolation of E. cloacae from the infected tissues. This is the first report of a disease caused by E. cloacae on cassava and it may have an impact on cassava seed production. [ABSTRACT FROM AUTHOR]

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important pest due to its capacity for producing strong infestations and transmitting plant viruses. The New World putative species of B. tabaci complex (NW) is the indigenous whitefly of the Americas, but only the invasive Middle East-Asia Minor 1 putative species of B. tabaci complex (MEAM1), commonly referred to as the 'B biotype' was identified in a limited scope sampling in Venezuela. Similarly to MEAM1 invasions elsewhere, in this South American country there has been an increase in the geographic range and abundance of B. tabaci, and in the number of viruses that it transmits since the late 1980s. We estimated the diversity of B. tabaci to elucidate their role in the epidemiology of geminiviruses in Venezuela. Thirteen microsatellite loci were screened in samples collected from 19 localities in ten major agricultural states. A Bayesian clustering method (Structure) grouped the samples into two genetic groups. Control samples from whiteflies NW and MEAM1 and partial sequencing of the mitochondrial cytochrome oxidase I gene showed that our samples of B. tabaci populations from Venezuela fall within NW and MEAM1 groups. In this survey, MEAM1 was predominant over NW whitefly in a proportion of 35:1. No evidence was observed for gene flow between indigenous and invader whitefly. Altogether, our results stress the urgency for controlling the proliferation of the invasive whitefly. [ABSTRACT FROM AUTHOR]

To evaluate the acceptance and long-term use of insecticide-treated (IT) materials for dengue vector control. In 2007, IT jar covers and/or curtains (PermaNet®) were distributed under routine conditions to 4101 households (10 clusters) in Venezuela and to 2032 households (22 clusters) in Thailand. The use of IT tools was measured at distribution (uptake), at 5/6 months (short-term use) and at 18/22 months (continued use) after distribution. Determinants of use were assessed with logistic regression analysis. The uptake of IT curtains was 76.7% in Venezuela and 92.3% in Thailand. It was associated with being a resident for >5 years (OR Venezuela 3.0 95% CI 2.0-4.4; OR Thailand 3.5 95% CI 1.7-7.3) and with pre-intervention use of ordinary curtains (OR Venezuela 2.2 95% CI 1.4-3.6). The continued use decreased significantly to 38.4% of households in Venezuela and 59.7% in Thailand and was, conditional on short-term use, only determined by the perceived effectiveness of IT curtains (OR Venezuela 13.0 95%CI 8.7-19.5; OR Thailand 4.9 95% CI 3.1-7.8). Disease knowledge and pre-intervention perception of mosquito nuisance were not associated with IT curtains' uptake or use. The uptake of IT jar covers in Venezuela was 21.5% and essentially determined by the presence of uncovered jars in the household (OR 32.5 95% CI 14.5-72.6). Their continued use, conditional on short-time use, was positively associated with the household use of Abate® (OR 7.8 95% CI 2.1-28.9). The use of IT curtains rapidly declines over time. Continued use is mainly determined by the perceived effectiveness of the tool. This poses a real challenge if IT curtains are to be introduced in dengue control programmes. [ABSTRACT FROM AUTHOR]

The upwelling system off the southern Caribbean coast is probably the main source of the nutrients that support biological productivity in the oligotrophic Caribbean Sea. Subtropical underwater (SUW) that forms the subsurface salinity maximum in the Caribbean Sea is the main source of upwelled waters in this system. Profiles of salinity and temperature with depth derived from four oceanographic cruises and Argo floats showed that upwelled waters have a salinity that is ~0.11 g kg−1 lower than the SUW in the central Caribbean Sea and a seasonal variation of approximately 0.09 g kg−1 that reflects the rainy/dry seasons. In addition, the SUW is ~50 m shallower on the continental shelf slope (~100 m) compared to the depth of the SUW in the central Caribbean Sea. The origin of these modified SUW was analyzed using the Mercator numerical model, which reproduces the main vertical characteristics of the subsurface salinity maximum. The modeled data showed that SUW upwelling off of the La Guajira Peninsula and Venezuela arrive into the system via an intense Caribbean Coastal Undercurrent (CaCU, mean speed ~0.28 m s−1). This current is formed in front of the Nicaragua platform from the divergence of subsurface water flow at the salinity maximum depth. The lower salinity observed in the upwelled waters may be the result of intense vertical mixing processes that could occur when the SUW are transported by the CaCU below the Panama-Colombia Gyre (PCG) region before reaching the upwelling zones. The mixing processes—involving double diffusion and mechanical turbulence driven by vertical shear of horizontal currents—were analyzed using the Turner Angle and the Thorpe scale, respectively. Below a depth of 200 m, double diffusion by salt fingers (diffusivities > 5 x 10−5 m2 s−1) was the main process of salt diffusion, generating a downward salt flux of >2 x 10−2 g kg−1 m d−1 between the SUW and the North Atlantic Central Waters (NACW). Above a depth of 100 m, mechanical turbulent diffusion generates a salt flux towards the surface ranging 0.5–4 x 10−2 g kg−1 m d−1, where double diffusion by salt finger is not possible. The diluted SUW is subsequently transported by the CaCU, connecting—at the subsurface level—the PCG region with the upwelling zones off of Colombia and Venezuela. As well as modifying the salt content of the coastal SUW, these mixing processes may also alter the nutrient content of upwelling waters, the ecosystem effects of which are still unknown. • The Subtropical underwater (SUW) upwells front of the southern Caribbean coast. • SUW upwelled off Colombian coast has lower salinity than in the central Caribbean. • SUW arrived to upwelling zones via the Caribbean Coastal Undercurrent (CaCU). • The CaCU formed front Nicaragua transports SUW bellow the Panama-Colombia gyre (PCG). • Intense mixing processes in PCG reduce the salinity of the SUW and upwelling waters. [ABSTRACT FROM AUTHOR]

The article discusses the Pectobacterium carolovonim which known to be the cause of the plant disease bell pepper soft rot in Venezuela including observing the soft rot symptoms, manifestation of infected plants and bacterial strains which include the gram-negative rods and motile.

The cocoa husk is a by-product of the cocoa industry with a high content of phytochemical and nutritional compounds. It has a typical chocolate flavor and smell that can be used in the production of food products. As a general objective, it was proposed to optimize the process for obtaining the infusion type aqueous extract from the husk of the roasted cocoa bean. A micromorphological and microbiological evaluation of the scale was carried out. Then the experiment was designed (11 experimental runs) where the best infusion type extract was selected taking into account the variables sensory quality and total polyphenol content, using the response surface methodology. The main results were that the cocoa husk presents different structural characters: cavities or pockets of fat or oils, different types of vessels, sclerenchymal and sclereid fibers, reserve parenchyma with pentagonal cells, presence of proteins and starch grains. The performance optimization obtained quadratic models that described the behavior of the sensory quality, the total content of polyphenols and the best conditions for obtaining them (0.1 g/mL). The negative correlation between the total polyphenol variables and sensory quality was verified, fulfilling from the relation 0.08 with a higher intensity. The selected infusion presented 2.3% of total solids, acceptable sensory quality, total polyphenols of 1098.3 mg (AGE)/L of extract and chromatic coordinates that correspond to a medium brown color. This study constitutes the basis for expanding the application of this by-product in food production. [ABSTRACT FROM AUTHOR]