581 research outputs found
(R1458) A New Finite Difference Scheme for High-Dimensional Heat Equation
In this research, a new second-order finite difference scheme is proposed to solve two and three- dimensional heat equation. Finite difference equations are determined via a discretization approach in which spatial second order partial derivatives in x and y directions are approximated simultaneously while in the classic method, each spatial partial derivative is replaced by a central finite difference approximation, separately. By this new discretization scheme and also using the forward difference to the first-order time derivative, a finite difference equation is obtained for the parabolic equation. This approach is explicit and similar to other explicit approaches, an interval for the Courant number, r is determined. This region for r is obtained through Fourier stability analysis. The advantage of this approach is that its stability interval is larger than the interval for traditional methods. Numerical experiments are presented to confirm the theoretical results. It is shown that more accurate approximations can be obtained by the new scheme
A sham-controlled trial of acupressure on the quality of sleep and life in haemodialysis patients
Background Sleep disorder in haemodialysis patients can lead to disturbance in their psychosocial function and interpersonal relations, and reduced quality of life. The aim of the present study was to investigate the effect of acupressure on the quality of sleep of haemodialysis patients. Methods In a randomised controlled trial, 108 haemodialysis patients were randomly divided into three groups: true acupressure, placebo acupressure, and no treatment. The two acupressure groups received treatment three times a week for 4 weeks during dialysis. Routine care only was provided for the no treatment group. The main study outcome was sleep quality. Results The total Pittsburgh Sleep Quality Index score decreased significantly from 11.9±3.13 to 6.2±1.93 in the true acupressure group, from 11.3±3.69 to 10.6±3.82 in the sham acupressure group, and from 10.9±4.10 to 10.7±3.94 in the no treatment group. There was a significant difference between groups (p<0.001). Conclusions Acupressure seems to have a positive effect on the sleep quality in haemodialysis patients. Clinical trial registration IRCT201106145864N2
Determinants of childhood obesity in representative sample of children in north east of iran
Childhood obesity has become, a global public health problem, and epidemiological studies are important to identify its determinants in different populations. This study aimed to investigate factors associated with obesity in a representative sample of children in Neishabour, Iran. This study was conducted among 1500 randomly selected 6-12-year-old students from urban areas of Neishabour, northeast of Iran. Then, through a case-control study, 114 obese (BMI � 95 th percentile of Iranian reference) children were selected as the case group and were compared with 102 controls (15 th � BMI 85 th percentile). Factors suggested to be associated with weight status were investigated, for example, parental obesity, child physical activity levels, socio-economic status (SES), and so forth. The analysis was conducted using univariate and multivariate logistic regression (MLR) in SPSS version 16. In univariate logistic regression model, birth weight, birth order, family extension, TV watching, sleep duration, physical activity, parents job, parents education, parental obesity history, and SES were significantly associated with childrens obesity. After MLR analysis, physical activity and parental obesity history remained statistically significant in the model. Our findings showed that physical activity and parental obesity history are the most important determinants for childhood obesity in our population. This finding should be considered in implementation of preventive interventions. Copyright © 2012 Fereshteh Baygi et al
The menopausal age and associated factors in Gorgan, Iran
Background: Considering the physical, emotional and psychological complications of early or delayed menopause on women's life, it is necessary to determine associated factors of menopause age. This study designed to determine menopausal age and associated factors in women of Gorgan, i.e. the capital of Golestan province in the north-east of Iran. Methods: In this cross-sectional study, 804 menopausal women in Gorgan were selected via two-stage sampling method in 2009. The study included only women who had undergone natural menopause and had their last menstrual bleeding at least one year before. Data were gathered through structured questionnaire that included individual characteristics, socioeconomic characteristics, menstrual and fertility characteristics and climacteric complaints. Socioeconomic status was defined using principal component analysis. Data were analyzed with Tstudent's and ANOVA tests using SPSS version 16 (SPSS Inc, Chicago, IL, USA) for Windows. Results: The mean menopause age was 47.6±4.45 years with the median age of 48 years. The mean menopause age in women with first pregnancy before 30 years (47.58±4.47years), without pregnancy (46.26±4.90years) and without delivery (46.30±4.47years) was significantly lower than others (p 0.05). Socioeconomic status was not associated significantly with menopause age (p>0.05). Conclusion: This study illustrated that menstrual and fertility factors have influence on menopausal age while socioeconomic factors were not effective
Political parties: extent and nature
The political party is a means of connecting the political process with society and it helps to improve the political system. In addition, a central feature of any democracy is political party which serve as a vehicle through which citizens can come together freely to define their political and policy aspirations and campaign for public office. In fact political parties have developed alongside democracy, and it is commonly assumed that democracy cannot survive without them. This article is an overview from the extent and nature of the political party in any society
Developing Disposable EEG Cap for Infant Recordings at the Neonatal Intensive Care Unit
Long-term EEG monitoring in neonatal intensive care units (NICU) is challenged with finding solutions for setting up and maintaining a sufficient recording quality with limited technical experience. The current study evaluates different solutions for the skin–electrode interface and develops a disposable EEG cap for newborn infants. Several alternative materials for the skin–electrode interface were compared to the conventional gel and paste: conductive textiles (textured and woven), conductive Velcro, sponge, super absorbent hydrogel (SAH), and hydro fiber sheets (HF). The comparisons included the assessment of dehydration and recordings of signal quality (skin interphase impedance and powerline (50 Hz) noise) for selected materials. The test recordings were performed using snap electrodes integrated into a forearm sleeve or a forehead band along with skin–electrode interfaces to mimic an EEG cap with the aim of long-term biosignal recording on unprepared skin. In the hydration test, conductive textiles and Velcro performed poorly. While the SAH and HF remained sufficiently hydrated for over 24 h in an incubator-mimicking environment, the sponge material was dehydrated during the first 12 h. Additionally, the SAH was found to have a fragile structure and was electrically prone to artifacts after 12 h. In the electrical impedance and recording comparisons of muscle activity, the results for thick-layer HF were comparable to the conventional gel on unprepared skin. Moreover, the mechanical instability measured by 1–2 Hz and 1–20 Hz normalized relative power spectrum density was comparable with clinical EEG recordings using subdermal electrodes. The results together suggest that thick-layer HF at the skin–electrode interface is an effective candidate for a preparation-free, long-term recording, with many advantages, such as long-lasting recording quality, easy use, and compatibility with sensitive infant skin contact. Keywords: aEEG; NICU; SAH; HFPeer reviewe
Assessing the level of CO2 emission in Iran via the econometric approach
The main objective of this study is to investigate the production of carbon dioxide and its effective factors on CO2 emission in Iran and other parts of the world. The results show that by increasing the population and to meet their needs, it is necessary to increase the production of fossil fuels, in the less-developed or developing countries. Also in developing countries by increase in the gross domestic product (GDP), expenditure in these countries arises. Since there is no suitable infrastructure for optimal use of resources properly. In Iran, the rate of CO2 emission arises by increased population and GDP. However, in developed countries, due to the high technology available to the society and government, the amount of CO2 emission is decreasing or under the control. In order to create suitable infrastructure for proper management of resources and expenditure, as well as to reduce CO2 emission, long-term planning is suggested to be drawn. Hence, transferring the technology to the country and domesticating it, will help in this trend. Furthermore, cooperation with successful countries in the field of reduction and control of CO2 emission and using experiences of successful countries facilitated this trend
Optimisation des réacteurs microfluidiques microbiens en contrôlant la croissance et l'homogénéité du biofilm
Les biofilms microbiens soit des communautés multicellulaires formées de bactéries, adhérant à une surface, entourés d'une couche de polymère extracellulaire (EPS). Parce qu'ils sont naturels, les biofilms bactériens sont de plus en plus étudiés et utilisés pour des applications en biocatalyse, en autoréparation et en tant que systèmes pouvant fonctionner efficacement dans des conditions ambiantes. La structure du biofilm est également importante, car elle peut protéger les bactéries sous les contraintes physiques, chimiques et biologiques rencontrées lors de l'opération du bioréacteur. Parmi les principaux facteurs entrant dans la régulation du développement du biofilm et de ses propriétés à maturité, on trouve les conditions hydrodynamiques et les concentrations d'éléments nutritifs appliquées. La microfluidique connait une popularité croissante parmi la communauté de recherche sur les biofilms en raison de sa capacité à mieux contrôler ces paramètres en fonction de d'autres propriétés physicochimiques importantes et même le taux de croissance. Dans ce travail, nous nous appuyons sur les travaux antérieurs de notre groupe pour résoudre deux principales limites. Tout d'abord, la tendance des biofilms à contaminer les canaux et les tubes en amont peut éroder les spécifications précises des conditions expérimentales dans les positions en aval d'où des mesures analytiques sont réalisées. La premiere partie ce travail, nous présentons un dispositif microfluidique qui varie la vitesse d'écoulement en amont pour arrêter la croissance vers l'arrière et la contamination de l'entrée pour les expériences de longue durée. Le deuxième point d'intérêt est lié à des facteurs qui provoquent une hétérogénéité dans les modèles de croissance du biofilm. On a noté que les bulles formées pendant et après l'inoculation augmentaient la croissance locale du biofilm et réduisaient l'uniformité et l'homogénéité globale. Ce mémoire étudie également les effets des bulles sur le taux de croissance et le développement secondaire du biofilm
Developing Disposable EEG Cap for Infant Recordings at the Neonatal Intensive Care Unit
Long-term EEG monitoring in neonatal intensive care units (NICU) is challenged with finding solutions for setting up and maintaining a sufficient recording quality with limited technical experience. The current study evaluates different solutions for the skin–electrode interface and develops a disposable EEG cap for newborn infants. Several alternative materials for the skin–electrode interface were compared to the conventional gel and paste: conductive textiles (textured and woven), conductive Velcro, sponge, super absorbent hydrogel (SAH), and hydro fiber sheets (HF). The comparisons included the assessment of dehydration and recordings of signal quality (skin interphase impedance and powerline (50 Hz) noise) for selected materials. The test recordings were performed using snap electrodes integrated into a forearm sleeve or a forehead band along with skin–electrode interfaces to mimic an EEG cap with the aim of long-term biosignal recording on unprepared skin. In the hydration test, conductive textiles and Velcro performed poorly. While the SAH and HF remained sufficiently hydrated for over 24 h in an incubator-mimicking environment, the sponge material was dehydrated during the first 12 h. Additionally, the SAH was found to have a fragile structure and was electrically prone to artifacts after 12 h. In the electrical impedance and recording comparisons of muscle activity, the results for thick-layer HF were comparable to the conventional gel on unprepared skin. Moreover, the mechanical instability measured by 1–2 Hz and 1–20 Hz normalized relative power spectrum density was comparable with clinical EEG recordings using subdermal electrodes. The results together suggest that thick-layer HF at the skin–electrode interface is an effective candidate for a preparation-free, long-term recording, with many advantages, such as long-lasting recording quality, easy use, and compatibility with sensitive infant skin contact. Keywords: aEEG; NICU; SAH; HFPeer reviewe
Explanation of Experiences and Emotional Reactions in Women Victims of Infidelity: A Qualitative Study
Introduction: Infidelity as one of the main causes for divorce has very deleterious effects on family, mental health, and feelings of the victims. The purpose of this study was to identify and explain emotional experiences and reactions of women victims of infidelity.
Method: In this interpretative study with phenomenology method, study population consisted of women victims of infidelity in Shemiranat, Tehran City, Iran, in 2016. 18 women of 22-64 years who were victims of the infidelity were selected through purposive sampling and were investigated by a semi-structured interview. The data were analyzed using a thematic analysis method.
Results: The data analysis resulted in two main themes, 12 subthemes, and 61 initial concepts. As the first theme, ‘maladaptive emotional reactions’ consisted of subthemes as the feelings of separation from life (including feelings of sadness, frustration, and desire for death), separation from oneself (including inadequacy, and sense of abandonment), anger, hatred, cruelty, vulnerability, emotional confusion, fear and anxiety, numbness, and coldness. The second main theme was ‘adaptive emotional reactions’ consisting of subthemes as feelings of self-worth (including one’s own and spouse), compassion (including toward the spouse, and toward the rival), and attachment to the spouse (interest in the spouse, sense of their ownership, and their forgiveness).
Conclusion: The results showed that infidelity was a phenomenon not experienced similarly by all women victims. Based on social constructivists, different perceptions of women victims causing different patterns of reactions to infidelity in them. Given the fact that the findings have been elicited out of a native study, they may play a vital role in developing the intervention packages.
Keywords: Extramarital sex behavior, Adultery, Affair, Extramarital relations, Emotional aspects, Affective aspect
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