جستجوی مقالات مرتبط با کلیدواژه « کلسیم » در نشریات گروه « علوم انسانی »

Biodiversity within ecosystems is intricately linked to a various factor, with soil physicochemical characteristics standing out as pivotal contributors. The soil, particularly in forests, functions as a dynamic habitat supporting a diverse array of organisms, including land snails, which play a significant role in forest ecosystems. This study focuses on unraveling the intricate correlation between the presence of land snails and six key soil parameters: pH, total calcium (Ca), total magnesium (Mg), exchangeable calcium (Ca++), exchangeable magnesium (Mg++), and soil Saturation Moisture percent. These factors are investigated as crucial elements influencing the distribution patterns of land snails.

The research was conducted in the Hyrcanian forests of Iran, specifically targeting three distinct forest regions situated in Kordkoy, Amol, and Tonekabon. These areas were designated as sampling sites during field surveys. To ensure a comprehensive and representative approach, sampling was conducted at three distinct locations within each forest, resulting in a total of 27 sample plots, each measuring 3 m × 3 m for detailed ecological assessment. The identification of snails and the evaluation of biodiversity were enhanced by employing DNA barcoding techniques. Snail abundance and species diversity were measured at each forest site, offering valuable insights into the ecological dynamics of these ecosystems. This quantification process provided a comprehensive understanding of the population density of snails and the variety of species present in each forest location. The analysis of soil factors involved laboratory methods, and Principal Component Analysis (PCA) was utilized to simplify the multidimensional data. It identified important variables for subsequent Canonical Correspondence Analysis (CCA), a sophisticated statistical technique. This comprehensive approach played a pivotal role in unraveling intricate relationships between soil physicochemical factors and the presence of snails. The analysis not only clarified the correlations between environmental variables and species distribution within the forests but also offered profound insights into the nuanced interplay shaping the ecological dynamics of these ecosystems.

A total of 679 snails were collected from the sampling stations, and phylogenetic tree analysis along with species delimitation revealed 37 sequences belonging to 10 Operational Taxonomic Units (OTUs). ANOVA results indicated significant variations in snail abundance among the forests. Following PCA, key factors for CCA were identified, and CCA, utilizing total calcium, total magnesium, and soil saturation moisture percentage as factors, demonstrated a positive correlation with most OTUs and snail abundance. These factors are vital in shaping the distribution and biodiversity of land snails. Land snails need Ca and Mg to restore the shell. Also, areas with moist soil are more favorable habitats for Snails provide.

In conclusion, this research establishes a foundational understanding of the intricate relationship between soil properties and snail communities in sections of the Hyrcanian forests. The insights gained from such studies contribute fundamental information essential for developing a native biodiversity index based on land snails. This index, in turn, holds promise for informing the formulation of effective management strategies aimed at conserving the diverse fauna of land snails within these ecologically vital forest ecosystems.

At the cellular level, the cardioprotective effects of exercise on the heart tissue are different at various ages. The aim of this study is to investigate the changes in angiogenesis (VEGF), tissue hypoxia (HIF-1) and calcium ion flow (Calcineurin) in the heart tissue of immature, mature and old rats following combined training.

Thirty male Wistar rats divided in three age groups of 2 weeks, 8 weeks and 24 months (10 each group) and each age group was divided into two control and exercise training groups (5 each group). In the combined training group, animals performed one day of resistance training and one day of aerobic training for 6 weeks. The amount of overload in the resistance training program was determined based on the body weight of the animals from 30% in the first week to 120% body weight in the last week. For aerobic training, the intensity of training increased from 50% of maximum speed in the first week to 80% in the last week. After 6 weeks of training, sacrificed animals and heart tissue were removed to measure VEGF, HIF-1 and Calcineurin factors by RTPCr method. To analyze data, the statistical method of one-way analysis of variance was used with significance P≤0.05. 

The group of exercise training (8-week) showed higher levels of VEGF gene expression in heart tissue compare to the control group (8-week control) (P=0.020). However, there was no significant difference in VEGF gene expression between training groups in three age groups (P>0.05). Also, there was no significant difference between the control and training groups in each age group and between the training groups in the three age in the expression of cardiac HIF-1 and Calcineurin gene (P>0.05).Discussion and

Exercising at young age has more favorable cellular effects (especially the positive regulation of angiogenesis factor). Therefore, in order to have a good aging period, it was suggested to do regular resistance-aerobic exercises from a young age.

The present study aimed to investigate the interaction effects of vitamin D and calcium, and High-Intensity Circuit Training (HICT) on BDNF and fat percentage of overweight elderly.

Thirty-two healthy older women were randomly divided into four Training + Supplementation, Training + Placebo, Supplementation, and Control groups. The training protocol performed three sessions per week for eight weeks. The Supplementation groups consumed 1,000 mg of calcium-effervescent tablet daily and 50,000 IU of vitamin D per week.

The results showed that the body fat percentage in the Training + Supplementation group decreased significantly compared with Supplementation (p = 0.001), Control (p = 0.001), and Training + Placebo (p = 0.045) groups. Moreover, the fat percentage in the Training + Placebo group decreased significantly compared with the Control group (p = 0.001). However, there were no significant differences between the Training + Placebo and Supplementation groups in body fat percentage. Moreover, there was a significant decrease in fat percentage in the Supplementation group compared with the Control group (p = 0.047). BDNF in the Training + Supplementation group had a significant increase compared with the Supplementation (p = 0.002) and Control (p = 0.001) groups but had no significant difference compared with the Training + Placebo (p = 0.085) group. Moreover, there was a significant increase in BDNF in the Training + Placebo group compared with Control (p = 0.003) and Supplementation (p = 0.01) groups. In contrast, no significant difference was observed between Supplementation and Control (p = 0.985) groups.  

Overall, the interaction of training and supplementation showed a significant decrease in the body fat percentage and a significant increase in BDNF in overweight elderly.

Vitamin D deficiency is associated with an increase in plasma parathyroid hormone levels, which leads to an increase in negative and destructive effects on the organism and a decrease in muscle function. The present study was conducted with the aim of the effect of vitamin D supplementation on the hormonal and functional changes of elite deaf national team female futsal players.

For this purpose,16 female football players deaf national team (age 26.20±3 years,height 155.15±3 cm, weight 56.68±2 kg and BMI 23.61±1 kg/m2)were selected and were randomly divided into two groups supplementation (n=8) and placebo (n=8). Subjects took vitamin D and placebo 120 minutes before the activity in a double-blind manner. Subjects were tested for maximal leg strength, anaerobic and aerobic capacity, speed, agility and 5cc of fasting blood from the anticubital vein before and after the tests. The training program included of continuous, plyometric, resistance and specific training. Statistical analysis was done by one-way analysis of covariance (P≤0.05).

According to the results of ANCOVA, there was a significant difference between the mean residual scores of vitamin D, leg strength and ergojump in groups (P≤0.05). There was no significant difference between the mean scores of aerobic power, speed, parathyroid, Calcium (P≥0.05). Findings indicate an increase in serum vitamin D (19.58 ng/ml) in supplementation group than control (P≤0.05).

The most favorable result of the current research is that the optimal level of vitamin D is vital for the optimal functioning of skeletal muscle. Therefore, maintaining (OH)D-25 levels can accelerate recovery for muscle power generation during intense exercise. Athletes should be evaluated throughout the year and supplemental assistance should be provided in case of problems.

The purpose of this study was to investigate the effect of 12 weeks of moderate -intensity aerobic exercise on lumbar spine & femoral neck bone mineral density (BMD) and serum levels of calcium & phosphorus in sedentary postmenopausal women 55-70 years old. The statistical population was all healthy and sedentary postmenopausal women 55-70 years old in Urmia city. Therefore, 20 healthy and sedentary postmenopausal women with having an average [age (60.12±2.12 yr), height (156.71±6.17 cm), weight (72.47±10.28 kg), and BMI (29.46±3.24 kg.m2)] voluntarily & bona fide participated in this study and then subjects were randomly divided into two the Exercise (11 women) and Control (9 women) groups. Exercise group performed of twelve weeks walking & jogging moderate-intensity aerobic exercise 65-70% maximal heart rate, three sessions per week and per session 50-60 (min) in the morning, but the Control group participated in no intervention. Twenty-four hours before and after the 12-week training program in order to measure bone density and serum markers in the Exercise & Control groups were taken densitometry and blood samples, respectively. Evaluation of the lumbar spine and femoral neck BMD were measured by DXA machine and serum levels of calcium and phosphorus by Auto analyzer & Biotechnical Instrument Italy machines, respectively. Data analysis included descriptive and inferential (ANCOVA test) statistics using SPSS-23 software and a significance level of P≥0.05 was considered. The results showed that there was no significant difference between lumbar spine & femoral neck BMD and T Score lumbar spine and femoral neck of Exercise group compared to the Control group after 12 weeks of moderate -intensity aerobic exercise (P>0.05). Also, no significant difference was found serum levels of calcium and phosphorus (P>0.05). Furthermore, the inter-group results showed no significant difference in any of the variables (P>0.05). The results in the study suggest that 12 weeks of moderate -intensity exercise such as walking & jogging program (W-WJMIEP-R) had no effect on bone density and serum levels of calcium and phosphorus in postmenopausal women.

Osteoporosis is a metabolic bone disease that dramatically reduces bone density. Therefore, the purpose of this study was to investigate the effect of moderate intensity aerobic training on serum levels of vitamin D, parathyroid hormone, calcium, and phosphorous in sedentary postmenopausal women.
This investigation was in the form of a semi-experimental with two experimental & control groups. Twenty sedentary postmenopausal women with having an average [age (60.12±2.12 yr) and BMI (29.46±3.24 kg.m2)] voluntarily & bona fide participated in this study. Then subjects were randomly divided into two the exercise (10 women) and control (10 women) groups. Exercise group performed of 12 weeks walking & jogging moderate-intensity aerobic training 65-70% maximal heart rate reserve, three sessions per week, and per session 50-60 (min), but the control group participated in no intervention. Twenty-four hours before and after of 12 weeks training program were taken blood samples for fasting in order to measure serum indices of vitamin D, parathyroid hormone, calcium, and phosphorous in the exercise & control groups. Data analysis included descriptive and inferential (paired samples t-test & ANCOVA test) statistics using SPSS-23 software and a significance level of P≥0.05 was considered.
The results between-groups showed that serum levels of vitamin D, calcium, and phosphorus were not significantly different (P>0.05), while serum levels of parathyroid hormone significantly increased (P≥0.05).
The results in the study suggest that 12 weeks of moderate-intensity aerobic training 65-70% maximal heart rate reserve such as walking & jogging program (W-WJMIEP-R) serum levels of vitamin D, calcium and phosphorus does not affect, while parathyroid hormone increases that Probably due to the duality of it effects to improve bone mass in sedentary women 50-70 years old.

Nowadays, osteoporosis is one of the risk factors for public health. Studies conducted on the role of physical activities in bone density have revealed that physical activities have important effects on the development and maintenance of bone mass. But there is doubt about the type and intensity of exercise which induces maximum anabolic effect on bone. This study aimed to study the effect of six weeks of aerobic training on bone growth markers (serum levels of alkaline phosphate, calcium and phosphorus) in 11-12-year-old girls. In this study, 20 girls (11-12 years old) were randomly assigned two groups: experimental (n=10, mean age 11.3±0.48 years, weight 41.80±7 kg, height 144±0.06 cm) and control (n=10, mean age 11.4±0.51 years, weight 43.70±4.7 kg, height 147±0.05 cm). The experimental group participated in an aerobic training program for six weeks (three sessions per week, each session 45-60 min. with 70-75% HRR) while the control group had no training. Before and after the training protocol (after 12 hours of fasting), 5cc blood was takenfrom subject's antecubital vein in order to estimate bone markers. Findings were investigated using descriptive and inferential statistics (dependent t test to compare pretest and posttest in each group and independent t test to study the differences between the two groups at p<0.05 using spss software version 19). The results indicated that six weeks of aerobic training significantly increased the serum concentration of alkaline phosphate (P=0.00) in the experimental group. But the serum levels of calcium and phosphorus did not significantly change in this group. In the control group, serum level of alkaline phosphate increased, but this increase was not significant. As a result, it can be said that aerobic activities at growth age may be effective factors to increase bone density in adolescents.

Reconstructing of environment and livelihood in ancient sites is an important subject in archaeological studies. Researchers use several methods for palaeodiet studies. One of these methods survey nutrition in use determines rate concentration of chemical element in ancient skeletal. Parthian people which ruled in Iran since 238 BC for 224 AD, when extended their power from east to the west by occupying new territory , found different civilization with their food consuming patterns. Elemental analysis of teeth of human skeletal from sites and graves of this period gave valuable information about nutrition in this period. In this article we want the found information about paleodiet in Parthian period in use PIXE manner. We have selected the teeth under study, from several Parthian sites in Iran, Shian, Valiran, Kharand, Gandab and nakhle Ibrahimi. We emphasis on these elements; Fe, Ca, Sr, Zn and P. In this research we gathered information about the variety in food in Parthian period. 

This study attempted to examine the social structure of the communities in Parthian period, based on the nutritional situation of the people of that time. Realizing the nutritional status of the communities, this article analyzes the elemental data of human skeleton remained from the graves of the Parthian period in the ancient area of Valiran in Damavand. The difference in the amount of the elements in human skeleton indicates the differences in the nutritional status of people under the investigation and dietary differences, suggested the differences in their social situations. In written sources, there was little about the social situation of Parthian period in the communities. Though Parthian social structure was tribal, and the complexity is not much, the archaeological study of social status in this period has had certain complexities. This study that was based on analyzing data gathered from chemical elements of ancient skeletons of Parthian period, tried to provide us with useful information about their social status.