Search

This paper evaluates the stress changes and settlements following dissipation of local, 3D excess pore pressure fields induced by controlled blasting. Field data gathered during a blasting experiment in medium dense sand deposits at the Port of Portland, Oregon, were used to validate the numerical simulations. The field measurements included cone penetration tests, excess pore pressure (ue), dissipation, and ground surface and subsurface settlements. The proposed numerical framework consisted of a 2D finite-element approach using a critical state–based hypoplasticity constitutive soil model capable of reproducing changes in void ratio, thus capturing soil densification to study soil arching mechanisms as a result of the dissipation of the local ue field. The soil parameters were calibrated to match laboratory test results performed on reconstituted specimens of medium dense sand and intact specimens of medium stiff silt obtained at the project site. The methodology was validated using the field measurements in terms of changes in tip resistance, shear wave velocities, and distribution of ground surface and subsurface volumetric strains and displacements. The field measurements and numerical results were used to draw conclusions regarding the variability of the postdissipation stress field within the blasted area due to soil arching. The main variables contributing to the development of liquefaction-induced soil arching as a result of controlled blasting were analyzed in a parametric study. The effects of the extent of the blasting zone as a function of the width-to-height ratio (W/H) and blasting intensity quantified with the excess pore pressure ratio (ru) were investigated. Results of the parametric study include the identification of significant reductions in mean effective stresses occurring within the blasting zone for small W/H ratios regardless of the input ru. A discussion regarding blast-induced cone tip resistance (qt) changes with time to explain qt reductions through the lens of case histories and implications for soil arching concludes this study. [ABSTRACT FROM AUTHOR]

Although many studies have focused on aggression or visual-spatial cognition effects of video games, the problem-solving aspects have been largely ignored. This study sought to expand the existing literature on video game effects by focusing on a rarely-tested outcome: creative production. As a game with few rules and a high amount of player freedom, "Minecraft" exemplifies a game that fosters players' abilities for creative expression. This experimental study included 352 undergraduates and it compared the effect of playing "Minecraft" on creativity measures compared to watching a TV show (passive control), a driving game (game control), and playing "Minecraft" with specific instructions (an instructional control). A within-subjects analysis found a significant correlation between trait creativity and game play habits. Between-groups experimental analyses showed that players randomly assigned to play "Minecraft" without instruction demonstrated significantly higher scores on post-game creativity measures compared to those who played "Minecraft" with instructions to "be creative," those who played a driving game, or those who watched a television show. Results indicate that effects are not solely predicted by game mechanics, but also by the way the player plays.

In this research, we employ the potent technique of Lie group analysis to derive analytical solutions for the (3+1)-extended Kadomtsev-Petviashvili (3D-EKP) equation. The systematic application of this method enables the identification of Lie point symmetries associated with the equation, leading to the derivation of an optimal system of one-dimensional subalgebras relevant to the equation. This optimal system is utilized to obtain several invariant solutions. The Lie group method is subsequently applied to the reduced governing equations derived from the given equation. We complement our findings with Mathematica simulations illustrating some of the obtained solutions. Furthermore, a direct approach is used to investigate local conservation laws. Importantly, our study addresses a gap in the exploration of the 3D-EXP equation using group theoretic methods, making our findings novel in this context. [ABSTRACT FROM AUTHOR]

Environmental pollution from microplastics (MPs), an anthropogenically mediated menace to the biosphere, is a global concern. This research conducted a bibliometric analysis of MPs in soil and terrestrial ecosystems using R software and biblioshiny to analyze descriptive statistics, author contributions, documents, and conceptual structures. The Scopus database was selected, and various keywords optimized the search. An analysis of research trends divided the timeline into three periods: period I (2012-2018), period II (2019-2021), and period III (2022). Results showed Wang J. as the author with the highest h-index, while Science of the Total Environment had an h-index of 43. In period I, research focused on MPs and plastic pollution, raising questions about their impacts on terrestrial ecosystems. Research found that MPs negatively affected soil organisms by decreasing growth rates and causing weight loss. In period II, research diversified, exploring interactions between MPs and heavy metals, bioaccumulation, phytotoxicity, soil pollution, and gut microbiota. Research revealed that MPs could influence heavy metal uptake by plants and affect bacterial community structures in soil. In period III, research emphasized oxidative stress, a common ecotoxicity response in plants and animals. MPs induced oxidative stress, leading to reactive oxygen species (ROS) buildup. Polyethylene MPs were more toxic to plant seedlings than polystyrene and polypropylene, causing significant oxidative stress. Similarly, oxidative stress impacts on soil organisms were highlighted when exposed to MPs and pesticides. Research in this area is expected to continue growing, aiding in delineating distinct research paths, particularly focusing on oxidative stress, bioaccumulation, and heavy metals. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of crude oil (CO) on plant height, number of total leaves, and basal diameter for 27 weeks, and at week 27 on leaf area, number of total roots, root length, root dry matter, aerial dry matter, bacterial population, actinomycetes, arbuscular mycorrhizal fungy (AMF), and total petroleum hydrocarbons (TPH) removal to propose indices as a basis for toxicity protocols and phytoremediation technologies using Jatropha curcas L. A microtunnel experiment was established for 27 weeks to evaluate the effect of seven doses of oil on the plant. CO inhibited the height and number of leaves, a longer time in the adaptation phase and a shorter time in the linear phase, compared to the control. The basal diameter showed adaptation in the linear phase in all treatments and was stimulated by the first four doses of CO at weeks 19 to 27. Plant height, total leaves, and dry matter, at week 27, were inhibited by CO, with relative toxicity indexes < 1, but leaf area, basal diameter, total roots, and root length were stimulated, with RTI ≥ 1. The population of heterotrophic and hydrocarbonoclastic bacteria, hydrocarbonoclastic fungi, and AMF were stimulated by CO, but the only highly significant positive correlation was between TPH removal and the percentage of hyphae, arbuscules, vesicles, and AMF. The highest removal was in soil with 4 g/kg CO. We conclude that J. curcas is adapted to low oil concentrations. We suggest its use in toxicity and phytoremediation protocols of clay soil contaminated with CO in the Mexican humid tropics. [ABSTRACT FROM AUTHOR]

Objective: To characterize the physicochemical and nutritional compounds of meal made from shrimp (Farfantepenaeus aztecus L.) exoskeleton, obtained through hot air dehydration processes, in order to value new products and applications, according to their nutritional components. Design/Methodology/Approach: Shrimp producers from Alvarado, Veracruz, were interviewed using a quantitative approach with a descriptive scope. Likewise, shrimp (Farfantepenaeus aztecus L.) shells were dehydrated and powdered to transform them into meal. The proximate chemical composition was analyzed to determine its nutritional composition and its macro and micronutrients, as well as to identify the deficiencies or excesses of certain nutrients. The general public and local ranchers were surveyed and interviewed to establish the opinions, preferences, and behaviors of consumers regarding meal by-products, in order to evaluate their market acceptance. Results: In Alvarado, Veracruz, 2.5 tons of shrimp shell are wasted. The meal obtained from these shells has a high protein (45.40%) and mineral content, which includes Ca (11.17%), Na (6.86%), Fe (237 mg/Kg-1), and Zn (77 mg/Kg-1). Therefore, this nutrient content guarantees the quality of the protein input that is acquired and the food that is provided. Study Limitations/Implications: Access to outdated statistical information, resulting from the COVID-19 pandemic, hindered the collection of relevant data. Likewise, the lack of interest of the producers in monitoring the project and the limited participation and knowledge of the workers represented a significant challenge to the progress of the study. Findings/Conclusions: The meal under study contained nutritional elements, making it a product with high nutritional quality that could add value to shrimp waste and that has potential applications in the food industry, in the production of fertilizers, and in the formulation of balanced feed for animals. Consequently, it would contribute to the reduction of pollution in the Alvarado lagoon system. [ABSTRACT FROM AUTHOR]

Copyright of Revista del Museo de Antropología is the property of Museo de Antropologia - IDACOR 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.)

This paper shows the development of a virtual environment for a mobile robotic system with the ability to recognize basic voice commands, which are oriented to the recognition of a valid command of bring or take an object from a specific destination in residential spaces. The recognition of the voice command and the objects with which the robot will assist the user, is performed by a machine vision system based on the capture of the scene, where the robot is located. In relation to each captured image, a convolutional network based on regions is used with transfer learning, to identify the objects of interest. For human-robot interaction through voice, a convolutional neural network (CNN) of 6 convolution layers is used, oriented to recognize the commands to carry and bring specific objects inside the residential virtual environment. The use of convolutional networks allowed the adequate recognition of words and objects, which by means of the associated robot kinematics give rise to the execution of carry/bring commands, obtaining a navigation algorithm that operates successfully, where the manipulation of the objects exceeded 90%. Allowing the robot to move in the virtual environment even with the obstruction of objects in the navigation path. [ABSTRACT FROM AUTHOR]

A semiempirical method to determine ground deformations and vibrations induced by impact pile driving in sandy soil conditions is presented in this study. Field data during installation of precast prestressed concrete piles with impact hammers were obtained in terms of ground deformations and peak particle velocities. Semiempirical equations are proposed using a combination of field measurements and numerical analyses to consider the following triggering factors for the ground response due to impact pile driving operations: (1) rated energy of the hammer, (2) scaled distance from the pile, (3) pre-drilling depth, and (4) relative void ratio, which is closely related to the relative density. The numerical component of this framework was developed adopting a continuous pile driving modeling approach coupled with the Updated Lagrangian approach to deal with large deformations and an advanced constitutive soil model (i.e., hypoplasticity for sands enhanced with the intergranular strain concept) capable of reproducing changes in soil void ratios during pile installation. The model parameters were adopted by computationally matching published nonlinear shear modulus degradation curves of the granular layers. A highly disturbed zone close to the pile was computed arising from pile driving-induced soil liquefaction causing large variations in computed void ratios. It was concluded that even if vibration levels are below typical vibration limits defined by regulatory agencies, large levels of ground deformations can still occur. The proposed method is validated in terms of ground vibrations and deformations induced by impact pile driving using field measurements, published vibration attenuation curves, and vibration-induced ground surface settlement prediction methods. [ABSTRACT FROM AUTHOR]

The antifungal activity of palindromic peptide RWQWRWQWR and its derivatives was evaluated against clinical isolates of Candida albicans and C. auris. Also, Bidens pilosa ethanolic extracts of leaves and stem were evaluated. Furthermore, combinations of peptide, extract, and/or fluconazole (FLC) were evaluated. The cytotoxicity of peptides and extracts in erythrocytes and fibroblasts was determined. The original palindromic peptide, some derivative peptides, and the ethanolic extract of leaves of B. pilosa exhibited the highest activity in some of the strains evaluated. Synergy was obtained between the peptide and the FLC against C. auris 435. The combination of the extract and the original palindromic peptide against C. albicans SC5314, C. auris 435, and C. auris 537 decreased the minimal inhibitory concentrations (MICs) by a factor of between 4 and 16. These mixtures induced changes in cell morphology, such as deformations on the cell surface. The results suggest that the combination of RWQWRWQWR and B. pilosa extract is an alternative for enhancing antifungal activity and decreasing cytotoxicity and costs and should be considered to be a promising strategy for treating diseases caused by Candida spp. [ABSTRACT FROM AUTHOR]

Copyright of Roca: Revista Científico-Educacional de la Provincia de Granma is the property of Universidad de Granma, Departamento Editorial 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.)

Hypopigmented skin lesions are frequent motive for consultation in the childhood. Several dermatological diseases are expressed by macules of whitish coloration and the lichen striatus is one of them; it is an autolimited, inflammatory and acquired dermatosis that has benign course and unknown etiology. The histological image is considered few specific; it is necessary to carry out clinical and histological approach. A case of a 9-year-old schoolgirl who presented papulous and pruriginous lesions with whitish coloration in the shape of linear plaques, located in the left hemithorax and left forearm is presented. Rev.cienc.biomed. 2013;4(2):335-338