Prediction of repair and maintenance costs of two-wheel tractors in Iran

Predicting of repair and maintenance (R&M) costs of tractors in any mechanized farm is necessary for owners and managers to obtain information on overall maintenance costs in order to control production cost. In this context a study was conducted to predict accumulated R&M costs (Y) of two-wheel drive (2WD) tractors based on total usage hours (X) in Misagh-e- Sabz Agribusiness Company in Iran. Recorded data from the company was used to determine regression models for predicting total R&M costs (as percentage of initial purchase price) based on total usage hours. The statistical results of the study indicated that in order to predict total R&M costs of 2WD tractors with based on usage hours of 2260 h or less the power regression model Y = 0.013 (X/100)1.677 with R2 = 0.976, and to predict total R&M costs of 2WD tractors with based on usage hours of 2260 hours or more the polynomial regression model Y = 0.004 (X/100)2 – 0.181 (X/100) + 4.373 with R2 = 0.998 is strongly suggested. Results of the study also indicated that total R&M costs predicted in this study were lower than those predicted in the previous studies. Cumulative life of 12000 hours, for instance, indicated an total R&M costs equivalent to 40.3% of initial purchase price. The most likely reasons that explain these differences between the predicted results in this study and those predicted in the previous studies probably can be attributed to new tractor technology for production during the last two decades and lower labor wages in Iran

Melatonin Protects Mouse Type A Spermatogonial Stem Cells against Oxidative Stress via The Mitochondrial Thioredoxin System

Objective: Mitochondrial oxidative stress is an important factor in infertility. The mitochondrial thioredoxin systemplays an important role in this condition. N-acetyl-5-methoxy tryptamine (melatonin) plays a role in reducing oxidativestress and apoptosis in spermatogonial stem cells (SSCs). In this study, we explore the probable protective effects ofmelatonin on the mitochondrial thioredoxin system [thioredoxin 2 (Trx2)/Txnip] in SSCs under oxidative stress.Materials and Methods: In this experimental study, SSCs were co-cultured two-dimensionally (2D) with Sertoli cellsin DMEM culture medium that contained 10% fetal bovine serum (FBS), 1% antibiotics, and 10 ng/ml glial cell-derivedneurotrophic factor (GDNF) for 30 days. The cultured cells were subsequently divided into four groups: control; melatonin(250 μM, 24 hours); melatonin (250 μM, 24 hours)+hydrogen peroxide (H2O2, 50 μM, 24 hours); and H2O2 (50 μM, 24hours). Intracellular reactive oxygen species (ROS) production was determined by flow cytometry. Malondialdehyde(MDA) levels were measured by Fluorometry. The expressions of apoptotic and antioxidant genes and nuclear factorerythroid 2-related factor 2 (Nrf2), Trx2, and nicotinamide nucleotide transhydrogenase (NNT) proteins were determinedby quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. Adenosine triphosphate (ATP) levelswere measured by fluorometry.Results: Melatonin reduced H2O2-induced ROS levels and apoptosis in the SSCs. Melatonin also increased mRNAexpression of Nrf2, Trx2, NNT, Sirtuin 3 (Sirt3), and decreased mRNA expression of Txnip, and increased proteinexpressions of Nrf2, Trx2, NNT thereby increasing activity of the mitochondrial thioredoxin system. In addition, melatoninincreased ATP levels.Conclusion: Melatonin increased Trx2 expression through the Nrf2 pathway. This study suggests that melatonin mayprotect SSCs from oxidative stress in diseases related to infertility

Global variation in diabetes diagnosis and prevalence based on fasting glucose and hemoglobin A1c

Fasting plasma glucose (FPG) and hemoglobin A1c (HbA1c) are both used to diagnose diabetes, but these measurements can identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening, had elevated FPG, HbA1c or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardized proportion of diabetes that was previously undiagnosed and detected in survey screening ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the age-standardized proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c was more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global shortfall in diabetes diagnosis and surveillance

Worldwide trends in underweight and obesity from 1990 to 2022: a pooled analysis of 3663 population-representative studies with 222 million children, adolescents, and adults

Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For schoolaged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesit

Global variations in diabetes mellitus based on fasting glucose and haemogloblin A1c

Fasting plasma glucose (FPG) and haemoglobin A1c (HbA1c) are both used to diagnose diabetes, but may identify different people as having diabetes. We used data from 117 population-based studies and quantified, in different world regions, the prevalence of diagnosed diabetes, and whether those who were previously undiagnosed and detected as having diabetes in survey screening had elevated FPG, HbA1c, or both. We developed prediction equations for estimating the probability that a person without previously diagnosed diabetes, and at a specific level of FPG, had elevated HbA1c, and vice versa. The age-standardised proportion of diabetes that was previously undiagnosed, and detected in survey screening, ranged from 30% in the high-income western region to 66% in south Asia. Among those with screen-detected diabetes with either test, the agestandardised proportion who had elevated levels of both FPG and HbA1c was 29-39% across regions; the remainder had discordant elevation of FPG or HbA1c. In most low- and middle-income regions, isolated elevated HbA1c more common than isolated elevated FPG. In these regions, the use of FPG alone may delay diabetes diagnosis and underestimate diabetes prevalence. Our prediction equations help allocate finite resources for measuring HbA1c to reduce the global gap in diabetes diagnosis and surveillance.peer-reviewe

The Effects of Pentoxifylline on Mouse Epididymal Sperm Parameters, Fertilization and Cleavage Rates after Short Time Preservation

Background: Pentoxifylline (PX) prevents cAMP breakdown by inhibiting the activity of the cAMP-phosphatase and presumably, stimulates sperm motion. Incubation with PX causes hyperactivation of sperm, an important step in achieving fertilization, and leads to changes in membranes associated with sperm capacitation. Objective: The purpose of this study was to examine the effects of pentoxifylline on sperm viability, motility and fertilization rate after mouse sperm preservation. Materials & Methods: Epididymal spermatozoa from adult NMRI mice were collected in T6 medium supplemented with 5% BSA and divided into four control and four experimental groups. The control groups included: (1) Fresh sperm sample (2) Preserved sperm sample at room temperature for 18 hours. (3) Preserved sperm sample at incubator 37°C for 18 hours. (4) Preserved sperm sample at 4°C for 18 hours. Experimental groups were the same groups after treatment with 3mmol/L PX. All the samples were assessed according to World Health Organization Criteria. Oocytes from superovulated NMRI female mice were inseminated in-vitro incubated sperm of all the control and experimental groups. After insemination and washing, the fertilization rate and cleavage rate were assessed by the presence of two pronucleus (2PN) and 2-cell stage embryos. To study the acrosomal reaction of control and treated spermatozoa transmission electron microscopy (TEM) technique was used. Results: The results showed that addition of 3mmol PX to preserved mouse spermatozoa at 4 ºC and 37 ºC could increase the motility rate significantly (P<0.05) and also it could enhance abnormal morphology rate. Significant increase of fertilization rate was seen after preservation of treated sperm at 4 ºC (P<0.05), but there was not seen significant difference regarding cleavage rate comparing treated and non-treated spermatozoa (P>0.05). Studies with electron microscopy showed that addition of PX to the preserved spermatozoa prevent early acrosomal reaction. Conclusion: The results of this study demonstrated that addition of pentoxifylline in mouse sperm samples after short time preservation can enhance the motility and fertilization rate, although it can enhance the abnormal morphology. It also can increase the number of intact sperm after preservation

Protective Effects of Celery (Apium graveloens) Seed Extract on Bleomycin-Induced Pulmonary Fibrosis in Rats

BACKGROUND AND OBJECTIVE: Pulmonary fibrosis is one of the most common side effects of bleomycin which is used as a chemotherapeutic agent. Reactive oxygen species play a key role in the development of pulmonary fibrosis. Celery seed contains a variety of flavonoids which are considered as asantioxidants. This study investigated the effects of celery seed hydroalcoholic extract on bleomycin-induced pulmonary fibrosis in rats. METHODS: This empirical study was conducted on 20 Sprague-Dawley rats weighing from 180 to 150 g. The animals were divided randomly into 5 groups of 4 rats. Groups 1 and 2, respectively, received a single dose of saline or bleomycin (7.5 units per kg) endotracheally. Group 3-5 received different daily doses of celery seed extract (100, 200 and 400 mg/kg) intraperitoneally for one week before and two weeks after the bleomycin. The animals were killed after 21 days and their blood and lungs were collected and tested so as to measure the plasma malondialdehyde, lung hydroxyproline and histopathology test. FINDINGS: The results showed that the index of lung, hydroxyproline and malondialdehyde in the saline normal group were respectively, 2.02±7.27 milligrams of lung per gram of body weight, 0.24±1.78 mg per gram of lung tissue and 0.17±1.48 micromol per liter of plasma. On the other hand, in the group receiving bleomycin, the figures were 0.99±10.1, 1.5±5.75 and 0.23±3.27, respectively. Treatment with extract, especially in groups 4 and 5, significantly reduced these factors compared to the bleomycin group (p<0.05). Furthermore, the results of histology revealed that bleomycin could lead to lung damage and the thickening of the alveolar. CONCLUSION: The results showed that celery seed hydroalcoholic extract has a protective effect on bleomycin-induced pulmonary fibrosis

Factors Affecting Anatomy Learning from the Viewpoints of Medical Students at Basic Sciences Stage

Background Knowledge of anatomy is the basis of medicine and clinical practices. This study aimed to determine factors affecting anatomy learning from the viewpoint of students at Kermanshah University of Medical Sciences. Methods This cross-sectional study enrolled all students at basic sciences stage at the School of Medicine at Kermanshah University of Medical Sciences in 2016 and 2017. A questionnaire was delivered in classrooms by the researchers with the permission of the teachers. Data was analyzed in the SPSS-16 software, employing the Mann-Whitney and Kruskal-Wallis tests. Results Out of 300 questionnaires, 179 were returned, 71 from male students (39.7%) and 108 from female students (60.3%); 116 (64.8%) in the third semester, 31 (17.3%) in the fourth, and 32 (17.9%) in the physiopathology level. Significant differences were found between the viewpoints of male and female students on the following variables: Use of animation, use of moulages, questions based on references, frequent quizzes, classified tests during the term, and the teachers’ patience, indicating the ‘clear expression of teachers’ with a mean of 4.7 ± 0.47 as the main effective factor. There were significant differences between the mean scores for ‘design of questions based on the sources’ (P < 0.05) and also between the views of physiopathology students and third-year students (P < 0.05). Conclusions Lecture-based education without proper audio-visual aids lacks popularity among students, resulting in a waste of time and low levels of student learning. Mentioning the clinical aspects and engaging students in clinical issues to improve learning is paramount