In healthy pregnancies, components of the Renin-Angiotensin system (RAS) are present in the placental villi and contribute to invasion, migration, and angiogenesis. At the same time, soluble fms-like ...tyrosine kinase 1 (sFlt-1) production is induced after binding of ANG-II to its receptor (AT-1R) in response to hypoxia. As RAS plays an essential role in the pathogenesis of COVID-19, we hypothesized that angiogenic marker (sFlt-1) and RAS components (ANG-II and ACE-2) may be related to adverse outcomes in pregnant women with COVID-19; Methods: Prospective cohort study. Primary outcome was severe pneumonia. Secondary outcomes were ICU admission, intubation, sepsis, and death. Spearman's Rho test was used to analyze the correlation between sFlt-1 and ANG-II levels. The sFlt-1/ANG-II ratio was determined and the association with each adverse outcome was explored by logistic regression analysis and the prediction was assessed using receiver-operating-curve (ROC); Results: Among 80 pregnant women with COVID-19, the sFlt-1/ANG-II ratio was associated with an increased probability of severe pneumonia (odds ratio OR: 1.31;
= 0.003), ICU admission (OR: 1.05;
= 0.007); intubation (OR: 1.09;
= 0.008); sepsis (OR: 1.04;
= 0.008); and death (OR: 1.04;
= 0.018); Conclusion: sFlt-1/ANG-II ratio is a good predictor of adverse events such as pneumonia, ICU admission, intubation, sepsis, and death in pregnant women with COVID-19.
Clinical manifestations of coronavirus disease 2019 (COVID-19) in pregnant women are diverse, and little is known of the impact of the disease on placental physiology. Severe acute respiratory ...syndrome coronavirus (SARS-CoV-2) has been detected in the human placenta, and its binding receptor ACE2 is present in a variety of placental cells, including endothelium. Here, we analyze the impact of COVID-19 in placental endothelium, studying by immunofluorescence the expression of von Willebrand factor (vWf), claudin-5, and vascular endothelial (VE) cadherin in the decidua and chorionic villi of placentas from women with mild and severe COVID-19 in comparison to healthy controls. Our results indicate that: (1) vWf expression increases in the endothelium of decidua and chorionic villi of placentas derived from women with COVID-19, being higher in severe cases; (2) Claudin-5 and VE-cadherin expression decrease in the decidua and chorionic villus of placentas from women with severe COVID-19 but not in those with mild disease. Placental histological analysis reveals thrombosis, infarcts, and vascular wall remodeling, confirming the deleterious effect of COVID-19 on placental vessels. Together, these results suggest that placentas from women with COVID-19 have a condition of leaky endothelium and thrombosis, which is sensitive to disease severity.
Extractive metallurgy has recently turned its attention to waste treatment for the recovery of precious metals through innovative metallurgical processes, such as ion flotation. This work studied the ...influence of several chemical and physical factors, such as the concentration of xanthate x, frother agent e, dithiophosphate xl, pH, superficial gas velocity Jg, percentage of gas holdup Eg, bubble diameter (Db) calculated with the drift flux model, and the type of sparger, in the efficiency of silver(I) recovery by the ion flotation technique in sub-aerated cells. The results obtained indicate a 90.7% v/v recovery of silver(I) under conditions of 3.77 × 10−4 M x, 1.25 × 10−4 M e, Jg 0.5 cm/s, Jl 0.19 cm/s, Eg of 4.1% v/v, and Optimal Db of 0.11 cm, with a rigid bubble generator, achieving an apparent flotation kinetics of 4.16 1/min. The use of combinations x–xl achieve a silver(I) recovery of 86.9% with a Jg of 1.0 cm/s. The best recovery efficiencies achieved 93% w/w silver(I) are with pH 8.0, e of 1.25 × 10−4, Jl of 0.19 (cm/s) and a rigid sparger compared to a flexible one.
In recent years, several educational systems have integrated text‐based affective feedback. However, analyses of the educational lexicon from the affectivity perspective are scarce. The provision of ...affective support by these systems is significant because it improves student motivation to learn. This study analyzes the use of a weighted affective lexicon in tutoring systems to improve student motivation. First, based on the suggestions of 166 undergraduate students, this study constructed and evaluated an educational lexicon in Spanish. Additionally, after considering the assessment of another group of 185 undergraduate students, this study provides an interpretation of words/phrases on a valence and arousal scale. The authors carried out a comprehensive analysis to categorize the words/phrases. Furthermore, this study integrates an affective lexicon in a tutoring system. Finally, this paper presents a review of the impacts of this system on the motivation of its potential users. The authors believe that the results of the present study will support the development of a highly adopted Intelligent Tutoring Systems (ITSs), which will benefit prospective users.
People who have dementia (PwD) experience deteriorating executive functions, in particular their working memory, and therefore find it hard to complete multistep tasks or activities of daily living. ...There is no doubt that during the pandemic, PwD and their caregivers were particularly vulnerable, often isolated which affected their mental and physical health. Their ability to live independently was hampered, fomenting depression in the PwD and burnout on informal caregivers. Information technology can support dementia care improving the quality of life of PwD and easing the burden on caregivers. There is an increasing demand to support informal caregivers and improve their well-being by making dementia challenges less severe. This study uses qualitative techniques to design a model with technological strategies based on semi-structured interviews applied to seven informal caregivers from two different countries. Based on these interviews we developed design insights for implementing solutions to help informal caregivers take care of their PwD at home using conversational agents. We hope that the findings presented in this study will help researchers, and developers design solutions that can support PwD and informal caregivers.
Vehicular networks is a key technology for efficiently communicating both user’s devices and cars for timely information regarding safe driving conditions and entertaining applications like social ...media, video streaming, and gaming services, among others. In view of this, mobile communications making use of cellular resources may not be an efficient and cost-effective alternative. In this context, the implementation of light-fidelity (LiFi) in vehicular communications could be a low-cost, high-data-rate, and efficient-bandwidth usage solution. In this work, we propose a mathematical analysis to study the average throughput in a road intersection equipped with a traffic light that operates as a server, which is assumed to have LiFi communication links with the front lights of the vehicles waiting for the green light. We further assume that the front vehicle (the car next to the traffic light) is able to communicate to the car immediately behind it by using its own tail lights and the front lights of such vehicle, and so on and so forth. The behavior of the road junction is modeled by a Markov chain, applying the Queueing theory with an M/M/1 system in order to obtain the average queue length. Then, Little’s theorem is applied to calculate the average waiting delay when the red light is present in the traffic light. Finally, the mathematical expression of the data throughput is derived.
The Autistic Spectrum Disorder is a cognitive disorder that affects the cognitive and motor skills; due that, users cannot perform digital and fine motor tasks. It is necessary to create software ...applications that adapt to the abilities of these users. In recent years has been an increase in the research of the use of technology to support autistic users to develop their communication skills and to improve learning. However, the applications’ usability for disable users is not assessed objectively as the existing models do not consider interaction operators for disable users. This article focuses on identifying the operations that can easily be performed by autistic users following the metrics of KML-GOMS, TLM and FLM. In addition, users of typical development were included in order to do a comparison between both types of users. The experiment was carried out using four applications designed for autistic users. Participants were subjects divided in two groups: level 1 and level 2 autistic users, and a group of users of typical development. During the experimentation, users performed a use case for each application; the time needed to perform each task was measured. Results show that the easiest operations for autistic users are K (Keystroke), D (Drag), Initial Act (I) and Tapping (T).
In recent years, the development of mobile applications for people within the autism spectrum has proliferated to help enhance skills that could be diminished in users with this condition. However, ...the usability of these applications does not appear to be the focus of development because users with autism can have difficulty with fine motor skills. This article focuses on evaluating the optimal drag distance and the sizes of the interaction elements for users with Autism Spectrum Disorder. To accomplish this goal, a case study was conducted that involved 20 users with Autism Spectrum Disorder and 30 users with typical development, using a prototype generated and two applications for commercial use on 7-in. tablets. For both developed applications, a slight variation can be observed between the different groups of participants. In the interaction with Proyect@ Habilidades, the application has pictograms of 65 pixels and it has a maximum trailing distance of 340 pixels. Moreover, in Proyect@ Retratos, where there is a minimum deviation between users with levels of autism 1 and 2, it also has pictograms of 65 pixels but with a drag distance of 110 pixels. For this reason, according to the results, we suggest that in order to obtain better results in the interaction with applications aimed at users diagnosed with autism spectrum disorders, the applications should have pictograms of a range of 65 pixels with a drag interaction between 110 and 340 pixels. Considering in context a 7-in. tablet with a resolution of 1280 × 800 pixels.
Scrum is one of many agile frameworks and is considered the most popular and widely adopted. Although Scrum presents several advantages, process and final product quality continue to be Scrum’s main ...challenges. The quality assessment should be an essential activity in the software development process. Several authors have attempted to improve the quality of Scrum projects, changing some aspects of the framework, such as including new quality practices, a quality role, and quality processes. However, the quantification of quality is still a challenge. For that reason, the authors proposed a framework called Scrumlity, which was defined in a previous study. This framework proposes a change to Scrum, including a quality role and some artifacts to evaluate quality through a complete execution of a Sprint. In this study, the authors add a User Story Quality assessment to the framework. The User Story Quality Assessment includes over 250 analyzed User Stories. Results obtained after this experiment indicate the importance of executing a User Story Quality Assessment and that Scrum Team members are willing to accept adding this to the framework.
The genus Aeromonas is a group of bacteria that is widely distributed in water bodies and belongs to the normal intestinal microbiota of aquatic and terrestrial animals. In the present work, rainbow ...trout fingerlings were experimentally infected by an immersion bath with different Aeromonas species. Subsequently, the behavior of the infected groups was observed and recorded. Infected fingerlings were evaluated by histopathology. The highest percentages of hyperpigmentation (18.88%) and inappetence (47.7%) were observed in fish infected with A. salmonicida, while abnormal swimming (83.33%) was recorded in fish infected with A. bestiarum. In histopathological findings, the highest percentages were observed in the olfactory epithelium (50.0%) for A. lusitana and A. salmonicida (41.1%)-infected fish. While, in the nervous system, the cerebral hemispheres (31.1%) in A. media-infected fish and the oblongata medulla (40.0%) in the A. bestiarum-infected fish presented the highest percentages. Meanwhile, A. salmonicida and A. bestiarum have the highest pathogenicity and virulence based on the histopathological findings in the olfactory epithelium and nervous system. Due to the proximity of the olfactory epithelium with the nervous tissue, it is possible that the infection generated by the Aeromonas species and the histopathological findings in the nervous tissue are reflected in different behavioral changes that suggest differences in the pathogenicity and virulence of the bacteria.
PDF
