705 research outputs found
On Complexity for Higher Derivative Gravities
Using "complexity=action" proposal we study complexity growth of certain
gravitational theories containing higher derivative terms. These include
critical gravity in diverse dimensions. One observes that the complexity growth
for neutral black holes saturates the proposed bound when the results are
written in terms of physical quantities of the model. We will also study
effects of shock wave to the complexity growth where we find that the presence
of massive spin-2 mode slows down the rate of growth.Comment: 18 pages, 3 figures, journal versio
Assessment of changes in biochemical parameters associated with kidney function in patients with multiple sclerosis while taking the drug
زمینه و هدف: بیماری مولتیپل اسکلروزیس، یکی از شایع ترین بیماری های مغز و اعصاب محسوب می گردد. هدف از این مطالعه، بررسی تغییرات پارامترهای بیوشیمیایی مرتبط با عملکرد کلیه شامل اوره، اوریک اسید و کراتینین در بیماران مبتلا به ام اس در حین مصرف دارو و مقایسه آن ها با گروه کنترل است. روش بررسی: در این مطالعه، سطح سرمی اوره، اوریک اسید و کراتینین در 52 بیمار مبتلا به ام اس اندازه گیری شد و با 52 فرد سالم که از نظر سنی و جنسی و BMI با گروه بیمار هماهنگ بودند، مقایسه گردید. در نهایت داده ها با استفاده از روش تی تست، شاخص های میانگین و انحراف معیار توسط نرم افزار SPSS تحلیل شدند. یافته ها: میانگین سطح سرمی اوره در گروه بیمار و سالم به ترتیب 58/4±38/14 و 33/4±86/13 میلی گرم بر دسی لیتر مشاهده شد. میانگین غلظت اسید اوریک در گروه بیمار 99/0±66/4 و در گروه سالم 06/1±64/4 میلی گرم بر دسی لیتر و میانگین غلظت کراتینین نیز در گروه بیمار و سالم به ترتیب 10/0±85/0 و 11/0±78/0 میلی گرم بر دسی لیتر به دست آمد. نتیجه گیری: یافته های این تحقیق نشان داد که سطح سرمی اوره، اسید اوریک و کراتینین هیچ تفاوت آماری معنی داری بین گروه بیمار و کنترل نداشت
A study on the ethical components of nursing practice (moral distress, ethical sensitivity, ethical decision)
This paper is an applied research in terms of objective and a descriptive research in terms of method. Having prepared the research plan, a questionnaire was designed based on goals and hypotheses of the research and was sent to the statistical universe. Also this paper is a field research in terms of data collection. As regards theoretical bases of the research, library data collection method has been applied. So, the required data has been gathered by referring to the related references, books, libraries and so on. To design a questionnaire and gather the opinions of the statistical universe members, field study method and researcher-made questionnaire have been used. The statistical universe comprises nurses and head of ICU and head nurses of Najmieh Hospital in Tehran. The respondents were selected by random sampling method. Also to estimate sample size, Morgan table was applied. The statistical universe consists of 65 members and according to the table, 56 questionnaires were determined for the research. So 60 questionnaires were sent and 58 ones were returned. Face and content validity of the research tool were approved by experts. The test reliability was estimated 0.777 by calculating Cronbach's alpha coefficient. In this paper, factor analysis based on partial least squares structural equations method has been applied to analyze more important factors and coefficients, estimate independent variables coefficients and even determine effectiveness of each independent variable on each other and determine appropriateness of the questions and their coefficients in explaining the related index. The main result of this paper presents a proper model for the relation of effective variables on nurse performance by using regression model. © IDOSI Publications, 2014
Rats with hippocampal lesion show impaired learning and memory in the ziggurat task: A new task to evaluate spatial behavior
Spatial tasks are widely used to determine the function of limbic system structures in rats. The present study used a new task designed to evaluate spatial behavior, the ziggurat task (ZT), to examine the performance of rats with widespread hippocampal damage induced by N-methyl-d-aspartic acid (NMDA). The task consisted of an open field containing 16 identical ziggurats (pyramid shaped towers) arranged at equal distances. One of the ziggurats was baited with a food reward. The task required rats to navigate through the open field by using a combination of distal and/or proximal cues in order to locate the food reward. The ability to acquire and recall the location of the goal (baited) ziggurat was tested in consecutive training sessions of eight trials per day for 10 days. The location of the goal ziggurat was changed every second day, requiring the rats to learn a total of five different locations. Several parameters, including latency to find the target, distance traveled, the number of visits to non-baited ziggurats (errors), and the number of returns were used as indices of learning and memory. Control rats showed a significant decrease in distance traveled and reduced latency in locating the goal ziggurat across trials and days, suggesting that they learned and remembered the location of the goal ziggurat. Interestingly, the hippocampal-damaged group moved significantly faster, and traveled longer distances compared to the control group. Significant differences were observed between these groups with respect to the number of errors and returns on test days. Day 11 served as probe day, in which no food reward was given. The controls spent more time searching for the food in the previous training quadrant compared to the hippocampal group. The findings demonstrate that the ZT is a sensitive and efficient dry task for measuring hippocampus-dependent spatial performance in rats requiring little training and not associated with some of the disadvantages of water tasks. © 2007 Elsevier B.V. All rights reserved
Policies and Programs for Prevention and Control of Diabetes in Iran: A Document Analysis
Trend analysis in 2005 to 2011 showed high growth in diabetes prevalence in Iran. Considering the high prevalence of diabetes in the country and likely to increase its prevalence in the future, the analysis of diabetes-related policies and programs is very important and effective in the prevention and control of diabetes. Therefore, the aim of the study was an analysis of policies and programs related to prevention and control of diabetes in Iran in 2014. This study was a policy analysis using deductive thematic content analysis of key documents. The health policy triangle framework was used in the data analysis. PubMed and ScienceDirect databases were searched to find relevant studies and documents. Also, hand searching was conducted among references of the identified studies. MAXQDA 10 software was used to organize and analyze data. The main reasons to take into consideration diabetes in Iran can be World Health Organization (WHO) report in 1989, and high prevalence of diabetes in the country. The major challenges in implementing the diabetes program include difficulty in referral levels of the program, lack of coordination between the private sector and the public sector and the limitations of reporting system in the specialized levels of the program. Besides strengthening referral system, the government should allocate more funds to the program and more importance to the educational programs for the public. Also, Non-Governmental Organizations (NGOs) and the private sector should involve in the formulation and implementation of the prevention and control programs of diabetes in the future
Seismic velocity deviation log: An effective method for evaluating spatial distribution of reservoir pore types
Velocity deviation log (VDL) is a synthetic log used to determine pore types in reservoir rocks based on a combination of the sonic log with neutron-density logs. The current study proposes a two step approach to create a map of porosity and pore types by integrating the results of petrographic studies, well logs and seismic data. In the first step, velocity deviation log was created from the combination of the sonic log with the neutron-density log. The results allowed identifying negative, zero and positive deviations based on the created synthetic velocity log. Negative velocity deviations (below − 500 m/s) indicate connected or interconnected pores and fractures, while positive deviations (above + 500 m/s) are related to isolated pores. Zero deviations in the range of [− 500 m/s, + 500 m/s] are in good agreement with intercrystalline and microporosities. The results of petrographic studies were used to validate the main pore type derived from velocity deviation log. In the next step, velocity deviation log was estimated from seismic data by using a probabilistic neural network model. For this purpose, the inverted acoustic impedance along with the amplitude based seismic attributes were formulated to VDL. The methodology is illustrated by performing a case study from the Hendijan oilfield, northwestern Persian Gulf. The results of this study show that integration of petrographic, well logs and seismic attributes is an instrumental way for understanding the spatial distribution of main reservoir pore types
Fluoride Concentration in Drinking Water Resources; North of Iran
Abstract Aims: Fluoride is one of the anions present in soil and water, and determining its level in drinking water is vital for preventing dental and bone diseases in societies. This research aimed to determine fluoride concentrations in drinking water sources of rural and urban areas of Babol City, Iran. Instrument & Methods: This descriptive cross-sectional study was conducted in Babol City, Iran, in 2014. 384 water samples were taken from 43 wells and 3 springs in the rural areas, and from 20 wells, 3 water reservoirs, and the water distribution system in the urban areas. Fluoride concentrations of water samples were measured with a model DR2000 spectrophotometer using the standard SPADNS method. Data were entered to SPSS 16 software and were analyzed by ANOVA test. Findings: The mean fluoride concentrations in the water samples of the deep wells were higher compared to those of the springs (p=0.01). The mean fluoride concentrations in the plains areas were higher compared to the mountainous regions (p=0.02). The mean fluoride concentrations in the wells of the urban areas, in the urban reservoirs, and in the urban water distribution system were 0.40±0.14, 0.39±0.15, and 0.40±0.15mg/l, respectively (p=0.07). Fluoride concentrations in water in urban areas during various seasons varied from 0.31 to 0.45mg/l (p=0.06). Conclusion: Fluoride concentrations in all drinking water sources in urban and rural areas of Babol are less than the ranges recommended by WHO and Iranian national standards
Success Rate and Complications of Internal Jugular Vein Catheterization With and Without Ultrasonography Guide
Background: Central venous catheterization (CVC) is an important procedure in emergency departments (EDs). Despite existence of ultrasonography (US) devices in every ED, CVC is done using anatomical landmarks in many EDs in Iran.
Objectives: This study aimed to compare the traditional landmark method vs. US-guided method of CVC placement in terms of complications and success rate.
Patients and Methods: In this randomized controlled trial, patients who were candidate for internal jugular vein catheterization, and referred to Baqiyatallah Hospital ED were randomly allocated into US-guided CVC and anatomical landmarks guided CVC groups. Central vein access time, number of attempts, success rate, and complications in each group were evaluated. Mann-Whitney U, chi-square and Fisher exact tests along with Pearson and Spearman correlation coefficients were used to analyze the data.
Results: Out of 100 patients, 56 were male and 44 were female. No significant differences were found between the US-guided and traditional landmark methods of CVC insertion in terms of age, gender, BMI, and site of catheter insertion. The mean access time was significantly lower in the US-guided group (37.12 ± 17.33 s vs. 63.42 ± 35.19 s, P < 0.001). The mean number of attempts was also significantly lower in the US-guided group (1.12 ± 0.3 vs. 1.58 ± 0.64 times, P < 0.001). Eighty-eight percent of patients in the US-guided group were catheterized in the first attempt, while 50% of patients in the traditional landmark group were catheterized in the second or more attempts (P < 0.001). The success rate was 100% in the US-guided group, while it was 88% in the landmark group (P = 0.013). Moreover, the rate of complications was significantly lower in the US-guided group (4% vs. 24%, P = 0.004).
Conclusions: The US-guided method for CVC placement was superior to the traditional landmark method in terms of access time, number of attempts, success rate, and fewer complications
Indicators Affecting the Urban Resilience with a Scenario Approach in Tehran Metropolis
Urban resilience refers to the capacity of an urban system to fully recover from unforeseen calamities. This study aims to assess the physical resilience indicators used to measure urban resilience in Tehran, the political and economic capital of Iran, and to pinpoint the most significant direct and indirect influences on urban resilience. The research process divided into two parts. The environmental scanning approach (reviewing papers and published sources, interviewing specialists, and monitoring conferences) and the literature review were employed in the first part to compile a database of the key information on the elements impacting physical resilience. The most significant factors impacting physical resilience over the next ten years were requested to be identified by specialists and intellectuals in the second part. Finally, the MicMac program was used to analyze the data after 29 variables were specified in Delphi. In light of the trace-analysis-dependence diagram, which depicts the instability of the influential factors and the persistence of their impact on other variables, the results demonstrate that Tehran’s physical resilience is in an unstable condition. According to the results, the factors that have the maximum impact on other variables are granularity drivers, emergency evacuation capacity, rescue and security spaces (emergency, fire station, and police station), impermeability, rate of the amendment and retrofitting measures in the buildings of each zone, building age, and the compatibility of land uses. The variables that are most susceptible to change from other variables include the distribution status of dangerous land uses, the quality of the buildings, the rate of historically vulnerable buildings, the vulnerability of internal and external roads, the rate of improvements and retrofitting measures in buildings in each zone, as well as historically vulnerable historical buildings
Short term doxycycline treatment induces sustained improvement in myocardial infarction border zone contractility.
Decreased contractility in the non-ischemic border zone surrounding a MI is in part due to degradation of cardiomyocyte sarcomeric components by intracellular matrix metalloproteinase-2 (MMP-2). We recently reported that MMP-2 levels were increased in the border zone after a MI and that treatment with doxycycline for two weeks after MI was associated with normalization of MMP-2 levels and improvement in ex-vivo contractile protein developed force in the myocardial border zone. The purpose of the current study was to determine if there is a sustained effect of short term treatment with doxycycline (Dox) on border zone function in a large animal model of antero-apical myocardial infarction (MI). Antero-apical MI was created in 14 sheep. Seven sheep received doxycycline 0.8 mg/kg/hr IV for two weeks. Cardiac MRI was performed two weeks before, and then two and six weeks after MI. Two sheep died prior to MRI at six weeks from surgical/anesthesia-related causes. The remaining 12 sheep completed the protocol. Doxycycline induced a sustained reduction in intracellular MMP-2 by Western blot (3649±643 MI+Dox vs 9236±114 MI relative intensity; p = 0.0009), an improvement in ex-vivo contractility (65.3±2.0 MI+Dox vs 39.7±0.8 MI mN/mm2; p<0.0001) and an increase in ventricular wall thickness at end-systole 1.0 cm from the infarct edge (12.4±0.6 MI+Dox vs 10.0±0.5 MI mm; p = 0.0095). Administration of doxycycline for a limited two week period is associated with a sustained improvement in ex-vivo contractility and an increase in wall thickness at end-systole in the border zone six weeks after MI. These findings were associated with a reduction in intracellular MMP-2 activity
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