57 research outputs found
Efficient Approaches for Enclosing the United Solution Set of the Interval Generalized Sylvester Matrix Equation
In this work, we investigate the interval generalized Sylvester matrix
equation and develop some
techniques for obtaining outer estimations for the so-called united solution
set of this interval system. First, we propose a modified variant of the
Krawczyk operator which causes reducing computational complexity to cubic,
compared to Kronecker product form. We then propose an iterative technique for
enclosing the solution set. These approaches are based on spectral
decompositions of the midpoints of , , and
and in both of them we suppose that the midpoints of and
are simultaneously diagonalizable as well as for the midpoints of
the matrices and . Some numerical experiments are given to
illustrate the performance of the proposed methods
Relationship between Students’ Critical Thinking and Self-efficacy Beliefs in Ferdowsi University of Mashhad, Iran
AbstractNowadays, critical thinking and motivational factors affecting it, such as self-efficacy have been heavily regarded by higher education systems. This descriptive-correlation study aimed to investigate the relationship between students’ self-efficacy and critical thinking in Ferdowsi University of Mashhad, Iran. A random sample of 216 students completed Sherer et al.’s (1982) General Self-efficacy Scale and the California Critical Thinking Skills Test- Form B (1994). Finding showed a significantly positive relationship between students’ self-efficacy and critical thinking (r= 0.21, p< 0.001). Hence, self-efficacy as motivational factor should be considered for developing learners’ critical thinking skills
Assessment of microbiological quality of potable water distributed in buses of Karandish terminal
Background: Due to the lack of proper rail road and air transportation, most commutes in Iran
are carried out by buses. In most cases, the water in the busses is used for passengers for
drinking usage. Although this kind of water source has provided convince for the travelers, it
could be a great risk in disease outbreak. The aim of this study is to determine the water
quality in commuting buses of Shiraz Karandish terminal in winter 2011. Methods: The study
is of descriptive-cross-sectional type. 48 samples were collected through quota sampling
The mediating role of success mechanism in work in the influence of positive personality traits on self-leadership with emphasis on the moderating role of active personality.
هدف این پژوهش، بررسی نقش میانجی مکانیسم کامیابی در کار در تاثیرگذاری ویژگیهای شخصیتی بر خود رهبری با تاکید بر نقش تعدیلگر شخصیت فعال میباشد. پژوهش حاضر از نظر هدف کاربردی و از نظر ماهیت و روش، توصیفی ـ همبستگی است. جامعه آماری (300 نفر) کارکنان کارخانه سپاهان باطری بوده که با روش تصادفی ساده و از طریق فرمول کوکران (169 نفر) انتخاب شدند. از پرسشنامههای اسنایدر و همکاران (1996)، اشریر و کارور (1985) که شامل ویژگیهای شخصیتی مثبت، پرسشنامه گرسیا و همکاران (2012) در خود رهبری، پرسشنامه پورث و همکاران (2012) در مکانیسم کامیابی در کار و همچنین پرسشنامه جانسن و همکاران (2017) در شخصیت فعال، استفاده شد. روایی و پایایی پرسشنامهها حاکی از آن بود که ابزارهای اندازهگیری از روایی (همگرا و واگرا) و پایایی (بار عاملی، ضریب پایایی مرکب، ضریب آلفای کرونباخ)، خوبی برخوردار هستند. نتایج حاصل از آزمون فرضیهها توسط نرمافزار SMART-PLS و با استفاده از آماره آزمون t و ضرایب مسیر (β)، نشان دهنده آن است که ویژگیهای شخصیتی مثبت بر مکانیسم کامیابی در کار و بر خودرهبری تأثیر دارد، مکانیسم کامیابی در کار بر خود رهبری تأثیر دارد، در نهایت نقش میانجی مکانیسم کامیابی در کار و نقش تعدیلگری شخصیت فعال تأیید شدند. با این اوصاف مدیران باید بتواند به منظور افزایش خود رهبری به ویژگیهای شخصیتی مثبت کارکنان توجه کنند. بدین منظور نیز میتوانند از مکانیسم کامیابی در کار به عنوان نقش میانجی در جهت این افزایش بهره جویند. هرچند باید مواظب کاهش سطح شخصیت فعال باشند چرا که منجر به کاهش این نوع رابطه میشود
A generalized preconditioned MHSS method for a class of complex symmetric linear systems
Based on the MHSS (Modified Hermitian and skew-Hermitian splitting) and preconditioned MHSS methods, we will present a generalized preconditioned MHSS method for solving a class of complex symmetric linear systems. The new method (GPMHSS) is essentially a two-parameter iteration method where the iterative sequence is unconditionally convergent to the unique solution of the linear system. A parameter region of the convergence for our method is provided. An efficient preconditioner is presented for the actual implementation of the new method. Some numerical results are given to show its effectiveness
Antioxidant and anticholinesterase properties of Echinometra mathaei and Ophiocoma erinaceus venoms from the Persian Gulf
Introduction: The Persian Gulf is home to a diverse range of marine life, including various species of fish, crustaceans, mollusks, and echinoderms. This study investigates the potential therapeutic properties of venoms from echinoderms in the Persian Gulf, specifically their ability to inhibit cholinesterases (Acetylcholinesterase and butyrylcholinesterase) and act as antioxidants.Methods: Four venoms from two echinoderm species, including the spine, gonad, and coelomic fluids of sea urchins, as well as brittle star venoms, were analyzed using various methods, including LD50 determination, protein analysis, antioxidant assays, GC-MS for secondary metabolite identification, and molecular docking simulations.Results and discussion: The study’s results revealed the LD50 of the samples as follows: 2.231 ± 0.09, 1.03 ± 0.05, 1.12 ± 0.13, and 6.04 ± 0.13 mg/mL, respectively. Additionally, the protein levels were 44.037 ± 0.002, 74.223 ± 0.025, 469.97 ± 0.02, and 104.407 ± 0.025 μg/mL, respectively. SDS-PAGE and total protein studies indicated that at least part of the venom was proteinaceous. Furthermore, the study found that the brittle star samples exhibited significantly higher antioxidant activity compared to other samples, including the standard ascorbic acid, at all tested concentrations. GC-MS analysis identified 12, 23, 21, and 25 compounds in the samples, respectively. These compounds had distinct chemical and bioactive structures, including alkaloids, terpenes, and steroids.Conclusion: These venoms displayed strong cholinesterase inhibitory and antioxidant activities, likely attributed to their protein content and the presence of alkaloids, terpenes, and steroids. Notably, the alkaloid compound C7 was identified as a promising candidate for further research in Alzheimer’s disease therapy. In conclusion, echinoderms in the Persian Gulf may hold significant potential for discovering novel therapeutic agents
Study of the Epidemiology and Use of Condoms in Vulnerable Women Referring to Damage Reduction Centers in Shiraz During 2015-2016
Background and aims: Female sex workers (FSWs) play an essential role in the transmission of HIV and are considered critical groups compared to the public groups of society and their customers. Therefore, this study was conducted to investigate the status of sexual intercourse among prostitutes in Shiraz in 2015-2016. Methods: This is a cross-sectional study conducted on 162 prostitutes referred to Shiraz transitional damage reduction centers and the information was gathered through a checklist. Results: The results showed that the mean age at the first vaginal intercourse was 16.57±3.65. In 62.3 of people, the main reason for prostitution was the need for money to help the family. It was also found that 39.5 of prostitutes had anal sex, and more than 95 of them did not use condoms during sex. There was also a statistically significant relationship (P<0.01) between the age of sexual intercourse and education level. Conclusion: The results of this study demonstrated that prostitutes initiated the first sexual intercourse at a very young age, and increase in the education level postponed the first sexual intercourse. Otherwise stated, the first sexual intercourse can be delayed by increasing the level of education
Large Volume Paracentesis in Patients with Liver Cirrhosis Temporarily Diminishes Blood Cell Count
Background: Large-volume paracentesis is the preferred treatment for patients with severe and refractory ascites. Several complications were reported during therapeutical paracentesis. However, there are very few published studies on the change in blood cell count after paracentesis. This study aimed to evaluate any changes in blood cell counts after ascites fluid drainage. Methods: This study was conducted on patients with severe ascites and chronic liver disease who underwent large-volume paracentesis at Namazi Hospital, in Shiraz, Iran, between March 2021 and February 2022. A data gathering form containing the patient’s medical history, cause of cirrhosis, ascites fluid volume, as well as routine tests including primarily sodium, potassium, and basal creatinine, was filled out. Before and after the surgery, the total blood cell count was measured. Before the procedure, adjustment was made in the case of coagulopathy and albumin deficiency. The effect of factors such as the volume of drained fluid, splenomegaly, antibiotics, and steroid use was assessed on the changes in the number of blood cells. Using the JAMOVI 2.3.9 software, a paired t test and multiple regression were applied for statistical analysis (P0.001).Conclusion: The findings of the present study showed that children with tense ascites who had large-volume paracentesis might experience a sharp drop in blood cell count after the procedure, which was a transient physiological condition
Determining the Concentration of Particulate Matters and Microbiological Quality of Indoor Air in Intensive Care Units of Kashan Hospital, Iran
Introduction: Maintaining hospital air quality is very important, especially in intensive care units (ICUs), where patients undergo invasive procedures. Therefore, the present study was conducted with the aim of determining the relationship between particulate matters (PMs) and bioaerosols in pediatric ICU (PICU), neonatal ICU (NICU), and ICU open heart (ICU OH) of Shahid Beheshti Hospital in Kashan.
Materials and Methods: This cross-sectional study was conducted for six consecutive months, i.e., autumn and winter of 2021. PM samples were taken using a Grimm Dust Monitor and microbial samples were taken using a Quick Take 30 sampler. Kolmogorov-Smirnov test was used for analysis and then ANOVA and LSD were used for further tests.
Results: The maximum and minimum PM10 concentrations in the PICU and ICU OH were 59.19 and 9.71 μg/m3, respectively; and the maximum and minimum PM2.5 concentrations were 20.23 μg/m3 in the NICU and 4.69 μg/m3 in PICU. The mean PM concentration and the number of bacterial and fungal colonies were consistent with the WHO and EPA guidelines. Gram-positive Staphylococcus were the most abundant bacteria (90.96%). The most abundant fungi were Aspergillus (54.23%), Penicillium (15.64%), and Cladosperium (12.17%) species. There was also no significant relationship between PMs and bioaerosols.
Conclusion: The mean concentrations of PMs and bioaerosols match with the guidelines, which can be attributed to more observance of health protocols and restrictions on the movement of people into ICUs due to the COVID-19 outbreak
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