208 research outputs found
Wave-Packet Scattering off the Kink-Solution
We investigate the propagation of a wave--packet in the model. We
solve the time-dependent equation of motion for two distinct initial
conditions: The wave-packet in a trivial vacuum background and in the
background of the kink soliton solution. We extract the scattering matrix from
the wave-packet in the kink background at very late times and compare it with
the result from static potential scattering in the small amplitude
approximation. We vary the size of the initial wave-packet to identify
non-linear effects as, for example, the replacement of the center of the kink.Comment: 15 pages, 7 figures (from 14 eps files), 4 tables, Int. J. Mod. Phys.
A, in prin
KinFit: A factual aerobic sport game with stimulation support
Overweight and obesity is a situation where a person has stacked too much fat that might affect negatively his/her health. Many people skip doing exercises due to several facts related to the encouragement, health-awareness, and time arrangement. Diverse aerobic video games have been proposed to help users in doing exercises. However, we observe some limitations in existing games. For instance, they don't give correct scores while wearing Arabic traditional suits, they don't consider showing immersive realistic scenes, and they don't stimulate users to do exercises and keeping them encouraged to play more. We propose in this paper an aerobic video game that displays real scenes of aerobic coaches and keeps the user notified about doing exercises. It is a kind of serious games that allows users to learn aerobic movements and practice with aerobic coaches. It contains several exercises in which each can be played on normal screen or in fully immersive virtual reality (VR). While the user is playing, he/she can see the playing score with the estimated amount of burned calories. It stores the time when the user plays to remind him/her about doing exercises again. The profound user studies demonstrated the usability and effectiveness of the proposed game. 2018 Kassel University Press GmbH.The authors would like to acknowledge that devices and equipment were provided by the Visual Computing Research Center, Department of Computer Science and Engineering, at Qatar University. This publication was supported by Qatar University Collaborative High Impact Grant QUHI-CENG-18/19-1. The content of this article and its quality are solely the responsibility of the authors and do not necessarily represent the official views of Qatar University.Scopu
Unveiling Significant Shoreline Changes in Lake Michigan After a Record-Setting Water Level Increase using High-Resolution Satellite Images
In this paper, high-resolution multispectral satellite images were used to
uncover a remarkable shoreline transformation in Lake Michigan coastal areas,
driven by a record-setting increase in the water level between 2013 and 2020.
Shoreline change analyses were conducted for eleven different natural beaches
around the lake, unveiling significant variations of shoreline retreat despite
being affected by the same water level increase. The average observed shoreline
retreats between 2013 and 2020 for the beaches ranged between 20 m and 62 m.
When the passive inundation was excluded, the estimated morphological changes
were found to differ significantly from site to site, with some locations
experiencing minimal changes, while others encountered considerable
morphological changes of up to 38m. The examination of the correlation between
the morphological changes and ten hydrodynamic and morphological factors
revealed strong correlations with the offshore slopes and beach width, with
steeply sloping, wide beaches experiencing more erosion. Notably, wave power,
longshore sediment transport divergence, and the number of storms exhibited
moderate correlation with the observed morphological changes. The results of
the shoreline changes and correlation analysis offer valuable insights into the
varied effects of increased water levels on Lake Michigan beaches, including
erosion and passive inundation, while shedding light on the key factors driving
shoreline erosion in this context. These insights can help decision and
policymakers in making informed choices regarding the protection and management
of Lake Michigan coastal areas, particularly in anticipation of future
incidents of water level increase
Efficient Catalytic Production Of Biodiesel Using Nano-sized Sugar Beet Agro-industrial Waste
This paper addresses the use of agro-industrial residue as a promising heterogeneous catalyst for the efficient production of biodiesel. That is, CaO-rich Sugarbeet agro-industrial waste (smashed down to nano-size) shows superb catalytic activity for biodiesel production via transesterification process employing sunflower oil and methanol. Physicochemical properties of the proposed catalyst are probed by TGA–DTG, XRF, XRD, FT-IR, SEM, BET, and CO2-TPD techniques. Biodiesel conversion (%) of Ca. 93% is achieved under the optimal conditions (catalyst loading of 1 wt%, methanol/oil molar ratio of 4.5:1, refluxed at 75 °C for 60 min). The relatively short reaction time indicates the enhanced kinetics of the process using the proposed agro-industrial residue which imparts its economic feasibility. Also, the proposed CaO-rich residue can be reused twice while retaining its catalytic activity. The thus-produced biodiesel fuel compiles the ASTM D6751 and EN-14214 specifications
Herbal Medicine for Cardiovascular Diseases: Efficacy, Mechanisms, and Safety
Cardiovascular diseases (CVDs) are a significant health burden with an ever-increasing
prevalence. They remain the leading causes of morbidity and mortality worldwide. The use
of medicinal herbs continues to be an alternative treatment approach for several diseases
including CVDs. Currently, there is an unprecedented drive for the use of herbal
preparations in modern medicinal systems. This drive is powered by several aspects,
prime among which are their cost-effective therapeutic promise compared to standard
modern therapies and the general belief that they are safe. Nonetheless, the claimed
safety of herbal preparations yet remains to be properly tested. Consequently, public
awareness should be raised regarding medicinal herbs safety, toxicity, potentially lifethreatening
adverse effects, and possible herb–drug interactions. Over the years,
laboratory data have shown that medicinal herbs may have therapeutic value in CVDs
as they can interfere with several CVD risk factors. Accordingly, there have been many
attempts to move studies on medicinal herbs from the bench to the bedside, in order to
effectively employ herbs in CVD treatments. In this review, we introduce CVDs and their
risk factors. Then we overview the use of herbs for disease treatment in general and CVDs
in particular. Further, data on the ethnopharmacological therapeutic potentials and
medicinal properties against CVDs of four widely used plants, namely Ginseng, Ginkgo
biloba, Ganoderma lucidum, and Gynostemma pentaphyllum, are gathered and reviewed.
In particular, the employment of these four plants in the context of CVDs, such as
myocardial infarction, hypertension, peripheral vascular diseases, coronary heart disease,
cardiomyopathies, and dyslipidemias has been reviewed, analyzed, and critically
discussed. We also endeavor to document the recent studies aimed to dissect the
cellular and molecular cardio-protective mechanisms of the four plants, using recently
reported in vitro and in vivo studies. Finally, we reviewed and reported the results of the recent clinical trials that have been conducted using these four medicinal herbs with
special emphasis on their efficacy, safety, and toxicity.This work has been made possible thanks to grants (Ager S.O.S.) and (fondo di Ateneo per la ricerca 2019) to GP and Qatar University grant (IRCC-2019-007) to GN and GP
Parental awareness regarding pediatric antibiotic use in Madinah, Saudi Arabia
Purpose: To determine the level of awareness of antibiotic use in children in Madinah, Saudi Arabia, and to identify factors associated with parental decisions regarding it.
Methods: Using a multiple-choice-question-based questionnaire survey, 1256 forms were distributed to visitors of major shopping malls in Madinah City to obtain socio-demographic and antibiotics knowledgebased data from October 2017 to January 2018. Differences in scores between and within groups on knowledge of parents about antibiotics were determined.
Results: Most participants (67 %) had good basic knowledge of antibiotics: 69 and 40 % of respondents were aware of their side effects and antibacterial resistance, respectively. Participants in high age groups (> 46 years old) have a significantly higher mean knowledge score (55.4 ± 20.1, p < 0.05) than those in younger groups. Educational status increased the mean knowledge score by approximately 60 %, with the most educated group having a mean score of 61.2 ± 16.4 (p < 0.05).
Conclusion: These results reveal the importance of awareness campaigns on antibiotic use and the role of healthcare professionals in the education of patients and parents on correct use of antibiotics, as well as the significance of antibacterial resistance.
Keywords: Antibiotics misuse, Pediatrics, Patient education, Antibacterial resistanc
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