214 research outputs found

    On the Unit Graph of a Noncommutative Ring

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    Let RR be a ring (not necessary commutative) with non-zero identity. The unit graph of RR, denoted by G(R)G(R), is a graph with elements of RR as its vertices and two distinct vertices aa and bb are adjacent if and only if a+ba+b is a unit element of RR. It was proved that if RR is a commutative ring and \fm is a maximal ideal of RR such that |R/\fm|=2, then G(R)G(R) is a complete bipartite graph if and only if (R, \fm) is a local ring. In this paper we generalize this result by showing that if RR is a ring (not necessary commutative), then G(R)G(R) is a complete rr-partite graph if and only if (R, \fm) is a local ring and r=R/m=2nr=|R/m|=2^n, for some nNn \in \N or RR is a finite field. Among other results we show that if RR is a left Artinian ring, 2U(R)2 \in U(R) and the clique number of G(R)G(R) is finite, then RR is a finite ring.Comment: 6 pages. To appear in Algebra Colloquiu

    A practice-inspired mindset for researching the psychophysiological and medical health effects of recreational dance (dance pport)

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    “Dance” has been associated with many psychophysiological and medical health effects. However, varying definitions of what constitute “dance” have led to a rather heterogenous body of evidence about such potential effects, leaving the picture piecemeal at best. It remains unclear what exact parameters may be driving positive effects. We believe that this heterogeneity of evidence is partly due to a lack of a clear definition of dance for such empirical purposes. A differentiation is needed between (a) the effects on the individual when the activity of “dancing” is enjoyed as a dancer within different dance domains (e.g., professional/”high-art” type of dance, erotic dance, religious dance, club dancing, Dance Movement Therapy (DMT), and what is commonly known as hobby, recreational or social dance), and (b) the effects on the individual within these different domains, as a dancer of the different dance styles (solo dance, partnering dance, group dance; and all the different styles within these). Another separate category of dance engagement is, not as a dancer, but as a spectator of all of the above. “Watching dance” as part of an audience has its own set of psychophysiological and neurocognitive effects on the individual, and depends on the context where dance is witnessed. With the help of dance professionals, we first outline some different dance domains and dance styles, and outline aspects that differentiate them, and that may, therefore, cause differential empirical findings when compared regardless (e.g., amount of interpersonal contact, physical exertion, context, cognitive demand, type of movements, complexity of technique and ratio of choreography/improvisation). Then, we outline commonalities between all dance styles. We identify six basic components that are part of any dance practice, as part of a continuum, and review and discuss available research for each of them concerning the possible health and wellbeing effects of each of these components, and how they may relate to the psychophysiological and health effects that are reported for “dancing”: (1) rhythm and music, (2) sociality, (3) technique and fitness, (4) connection and connectedness (self-intimation), (5) flow and mindfulness, (6) aesthetic emotions and imagination. Future research efforts might take into account the important differences between types of dance activities, as well as the six components, for a more targeted assessment of how “dancing” affects the human body

    Optimizing linear alkyl benzene sulfonate removal using fenton oxidation process in taguchi method

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    Linear alkyl benzene sulfonate (LAS), which is the most common used anionic surfactant in detergents manufacturing, can discharge onto water resources through wastewater and causes change in taste and odor, disruption in water treatment processes, aquatics death, and oxygen transfer limitation. Accordingly, this article investigates to optimize LAS removal using Fenton oxidation process in Taguchi Method for the first time. LAS removal using Fenton oxidation was perused experimentally in a lab-scale reactor

    A microfluidic approach to rapid sperm recovery from heterogeneous cell suspensions

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    The isolation of sperm cells from background cell populations and debris is an essential step in all assisted reproductive technologies. Conventional techniques for sperm recovery from testicular sperm extractions stagnate at the sample processing stage, where it can take several hours to identify viable sperm from a background of collateral cells such as white bloods cells (WBCs), red blood cells (RBCs), epithelial cells (ECs) and in some cases cancer cells. Manual identification of sperm from contaminating cells and debris is a tedious and time-consuming operation that can be suitably addressed through inertial microfluidics. Microfluidics has proven an effective technology for high-quality sperm selection based on motility. However, motility-based selection methods cannot cater for viable, non-motile sperm often present in testicular or epididymal sperm extractions and aspirations. This study demonstrates the use of a 3D printed inertial microfluidic device for the separation of sperm cells from a mixed suspension of WBCs, RBCs, ECs, and leukemic cancer cells. This technology presents a 36-fold time improvement for the recovery of sperm cells (> 96%) by separating sperm, RBCS, WBCs, ECs and cancer cells into tight bands in less than 5 min. Furthermore, microfluidic processing of sperm has no impact on sperm parameters; vitality, motility, morphology, or DNA fragmentation of sperm. Applying inertial microfluidics for non-motile sperm recovery can greatly improve the current processing procedure of testicular sperm extractions, simplifying the fertility outcomes for severe forms of male infertility that warrant the surgery

    Performance evaluation of green roofs in urban runoff reduction

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    Urbanism directly affects the hydrological cycle. One of the ways to manage runoffs in urban areas that is considered nowadays is green roof creation. Green roof is mainly created in humid and semi-humid areas, and efficiency of green roofs in arid and semi-arid areas has attracted less attention. In the current study, to evaluate the effect of green roof in arid and semi-arid to reduce runoff, an experimental green roof without vegetation was designed in Behbahan city of Khuzestan province in Iran. The city has an arid and semi-arid climate. Experimental Green roof was studied during 7 months. During the study, the data regarding the height of rainfall, soil moisture in different soil layers of the experimental green roof as well as the amount of output runoff were measured. The results showed that the amount of moisture in the surface layer of soil is severely affected by rainfall. The average surface soil moisture has been about 20.5 % and in the deep and middle layers has been 24.8 and 24.1, respectively. In addition, regarding runoff reduction and delays in creating runoff, the results showed that in the observed rain events, in average, 92.2 percent of volume of rainfall has been kept in soil, and has not been converted into runoff. Due to arid and semi-arid climate of the target area and high-intensity of rainfall, green roof can reduce a considerable percentage of runoff

    Performance of Common Clustering Methods in Segmenting Vascular Pathologies in Capsule Endoscopy Images

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    This work was supported by the program Industria del Coneixement of the Catalan Government.Noorda, RA.; Naranjo Ornedo, V.; Pons, V. (2017). Performance of Common Clustering Methods in Segmenting Vascular Pathologies in Capsule Endoscopy Images. International Journal of Computer Assisted Radiology and Surgery. 12(1):S22-S23. https://doi.org/10.1007/s11548-017-1588-3SS22S2312

    Investigation of the effect of educational program based on the health belief model on preventing behaviors exposure to polluted air among pregnant women

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    BACKGROUND AND OBJECTIVE: Air pollution creates a wide range of acute and chronic effects in pregnant mothers. This study was carried out to determine the effect of education using Health Belief Model on improving the prevention of exposure to polluted air in pregnant women. METHODS:This quasi-experimental study was carried out in two cross-sectional and interventional sections. In the cross-sectional study, 208 pregnant women were randomly selected and data were collected based on Health Belief Model questionnaire (sensitivity, severity, benefits, barriers, practice guidance and perceived self-efficacy, while calculating the scores of each section based on 100). In the intervention study, a total of 114 pregnant women (6 to 24 weeks) were selected by multistage sampling and randomly divided into two groups of case and control. The intervention was performed according to the Health Belief Model and the subjects were followed for three months and then the data were collected and analyzed. RESULTS: The variables of external action, sensitivity and barriers, predicted a total of 25% of behavioral changes. In the intervention study, the mean awareness score of mothers in the intervention group increased significantly from 43.18±15.50 before the intervention to 71.39±16.68 after the intervention and the mean performance score increased significantly form 73.14±11.29 to 84.75±8.54 (p<0.001). CONCLUSION: The results of this study showed that the implementation of training program based on Health Belief Model with emphasis on predictive behaviors can be effective in reducing exposure to air pollution in pregnant women
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