2,481 research outputs found
Testicular Thermal Damage and Infertility from Laptop Use
Today, more laptop computers are being used on a daily basis than ever before. One of the health risks associated with extended, repeated use by men is that of testicular damage, or reduced spermatogenesis due to increased temperatures in the groin region. Naturally, the scrotum is maintained 2oC below standard body temperature. However, the combination of increased temperature due to leg positioning to support a laptop on the thighs, and the potential for temperatures of 60oC to be reached on the bottom, outer surface of the device [11] present a health risk. Although temperatures of 50oC are more common, they still contribute to a rise of approximately 0.6oC in addition to a 2.1oC increase which is already due to leg positioning alone. The direct contact between the thigh and testicles is a significant factor in this increase in temperature, as well as the laptop heat generation. In the future, potential methods of reducing heat conduction into the body may be mitigated by additional heat sinks, or fans which may reduce the effects of extended periods of laptop use
Método proximal para problemas de desigualdad variacional: caso no monótono
En el presente artículo introducimos un algoritmo de punto proximal inexacto usando distancias proximales para resolver el problema de desigualdad variacional cuando el operador involucrado en el modelo es pseudo-monótono y cuasi-monótono. Bajo algunas hipótesis naturales probamos que la sucesión generada por el método es convergente en el caso pseudo-monótono y débilmente convergente en el caso cuasi-monótono. Este enfoque extiende los resultados de Auslender, Teboulle y Ben-Tiba [1] y Brito et al.[3]
Recent and Rapid Radiation of the Highly Endangered Harlequin Frogs (Atelopus) into Central America Inferred from Mitochondrial DNA Sequences
Populations of amphibians are experiencing severe declines worldwide. One group with the most catastrophic declines is the Neotropical genus Atelopus (Anura: Bufonidae). Many species of Atelopus have not been seen for decades and all eight Central American species are considered “Critically Endangered”, three of them very likely extinct. Nonetheless, the taxonomy, phylogeny, and biogeographic history of Central American Atelopus are still poorly known. In this study, the phylogenetic relationships among seven of the eight described species in Central America were inferred based on mitochondrial DNA sequences from 103 individuals, including decades-old museum samples and two likely extinct species, plus ten South American species. Among Central American samples, we discovered two candidate species that should be incorporated into conservation programs. Phylogenetic inference revealed a ladderized topology, placing species geographically furthest from South America more nested in the tree. Model-based ancestral area estimation supported either one or two colonization events from South America. Relaxed-clock analysis of divergence times indicated that Atelopus colonized Central America prior to 4 million years ago (Ma), supporting a slightly older than traditional date for the closure of the Isthmus. This study highlights the invaluable role of museum collections in documenting past biodiversity, and these results could guide future conservation efforts
What it’s like to be a _____: Why it’s (often) unethical to use VR as an empathy nudging tool
In this article, we apply the literature on the ethics of choice-architecture (nudges) to the realm of virtual reality (VR) to point out ethical problems with using VR for empathy-based nudging. Specifically, we argue that VR simulations aiming to enhance empathic understanding of others via perspective-taking will almost always be unethical to develop or deploy. We argue that VR-based empathy enhancement not only faces traditional ethical concerns about nudge (autonomy, welfare, transparency), but also a variant of the semantic variance problem that arises for intersectional perspective-taking. VR empathy simulations deceive and manipulate their users about their experiences. Despite their often laudable goals, such simulations confront significant ethical challenges. In light of these goals and challenges, we conclude by proposing that VR designers shift from designing simulations aimed at producing empathic perspective-taking to designing simulations aimed at generating sympathy. These simulations, we claim, can avoid the most serious ethical issues associated with VR nudges, semantic variance, and intersectionalit
Analysis of potentials and costs of storage of CO2 in the Utsira aquifer in the North Sea:Final report for the FENCO ERA-NET project
Propiedades estructurales, fisicoquímicas y emulsionantes de la pectina obtenida por extracción acuosa de la cascara de la pitaya roja (Hylocereus polyrhizus)
Pectin was obtained from red pitaya peels (RPP) by aqueous extraction. SEM analysis showed irregular and rough particles, with some micro-fractures surface. The yield (11.59/100 g d.b.) and Gal A content (54.36 ± 1.03%) were slightly lower than that reported for other conventional pectin sources. The RPP pectin presented high thermal stability (310.74 °C) and a high degree of esterification (60.35±1.35%) which classifies it as a high methoxyl pectin. Also, the emulsifying activity and emulsifying stability of RPP pectin were comparable or higher than that reported for other pectin sources and could be attributed to the small inherent protein content detected. The high RPP pectin/oil volume ratio increased both the emulsifying activity and emulsion stability, which is a desired property. Therefore, the results showed that the RPP pectin has an adequate balance between physicochemical characteristics and functional properties that make it a potentially suitable substitute of commercial pectins for applications in the industry, particularly in the formation and stabilization of emulsions. In addition, the results obtained in this work justify the fact of taking advantage of, maximizing, and giving an added value to the peel of the red pitaya fruit in order to develop a process to produce pectin. In this way, help the rural communities where this fruit is cultivated to improve their environment and quality of life.This work aimed to carry out a straightforward aqueous extraction of pectin from red pitaya peels (RPP), in a drive to promote the circular economy of the settlements where the fruit of this endemic species grows. The average pectin yield was 11.59 g/100 g dry basis, the degree of esterification was 60.35±1.35% (classified as high methoxyl), the galacturonic acid content was 54.36±1.03%, and the protein content of 5.86 ± 0.25%. The RPP pectin was analyzed in terms of physicochemical, functional, and structural features. The FTIR spectrum confirmed that the unveiled pectin structure was consistent with that reported for commercial pectins from different botanical sources. Pectin aqueous dispersions exhibited power-law shear thinning behaviour. Corn oil (10 mL) in 150 mL aqueous pectin solutions (0.12, 0.15, 0.30, 0.60 and 0.90%, w/v) emulsions exhibited increasing emulsifying activity and emulsifying stability with increased pectin concentration. It was concluded that the RPP pectin is an alternative potential new source of pectin for use in the formation and stabilization of oil-in-water food emulsions.A la Universidad Autónoma del Estado de México por financiar este artículo mediante el proyecto con clave 6160/2020/CI
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