فهرست مطالب r .mazaheri

Experiences from previous wars have shown that the science of geomorphology plays an important role in the implementation of offensive and defensive plans, the selection of settlement areas, the dispersion and the ready points. Therefore, geomorphological factors play an important role in adopting effective measures for passive defense. This study aims to investigate the geomorphological features of the coasts of Abadan district from the perspective of passive defense to identify the geomorphological strengths and weaknesses of the region. Preparing the SWOT method for application in the passive defense studies requires refining the basic concepts, as the basic concepts in passive defense studies are different from other fields of study. In passive defense studies, threats and opportunities of the external environment should be considered separately and differentiated from their internal counterparts. For example, a weakness can be considered an opportunity from another point of view, or a phenomenon that is considered strength from another point of view may be a weakness. The results show that vegetation as a whole has a positive effect on passive defense in the region. According to the geomorphological map of the region, the Arvand River is a flood plain and a part of it is a tidal wetland (Shalaheh and Khosrowabad villages). This tidal section is used to irrigate the palm-groves. The whole area is flat and there is a view of the facilities and personnel for the military, in both the Iranian and Iraqi sides. Some elevated features are created artificially in some areas but there are no naturally elevated geomorphological forms. The valleys and plains are less exposed to floods.

Heat stress (HS) compromises efficient animal production and although difficult to accurately quantify, the economic impact on the global livestock industries is likely greater than $100 billion annually (Baumgard and Rhoads 2013). The economic decline in the dairy industry is primarily associated with lowered milk production, reduced growth, compromised milk quality, reduced reproduction, increased metabolic disorders and poor immune function. Dry matter intake per kilogram live weight was lower and the maintenance requirements of sheep were higher at high ambient temperatures (Marai et al. 2007). Pair-feeding study in dairy cows indicated that during heat stress, reduced dry matter intake accounted for only 35- 50% of the decreased in milk production (Wheelock et al. 2009). A variety of amelioration strategies for HS are available and can be implemented alone or in a coordinated manner that include physical modifications to the environment, management adaptations, genetic selection, and dietary modifications. Nutritional strategies are among the easiest and cheapest to alleviate the negative effects of HS. Nutritional tactics used during HS generally focus on enhancing the energy density of the diet and decreasing the ration forage based on the reduction of incremental heat (Mahjoubi et al. 2016). Providing gluconeogenic substrates or supplements that metabolized into glucose precursors may increase productivity during the heat stress (Baumgard and Rhoads 2012). The objective of this study was to evaluate the heat stress effects and also glucogenic supplement during heat stress on performance, heat stress indices and blood metabolites of fattening Makoei lambs.

In this experiment, 10 male Makuei lambs with 3 months age and average live weight of 32 ± 3.2 kg in 2 treatments and 5 repeat per treat at two experimental periods were used. 10 days before beginning of period 1, the lambs were adapted to 2×1 meter individual cage and experimental diets. Lambs received water and feed individually. Feed was delivered to the animals as a total mixed ration and offered in the morning (8:00) and evening (16:00). Diet was formulated to meet or exceed NRC (2007) recommendations (Table 1) using the Small Ruminant Nutrition System. In period 1 that lasted 10 d, lambs at thermal neutral (TN) condition (24.5±3.2 °C and temperature-humidity index [THI] of 66.1 ± 2.5) and heat stress (HS) (33-41°C and THI of more than 83) were fed ad libitum. In period 2 (lasted 10 d) the lambs of HS condition continued to ad libitum feeding and lambs in TN condition pair fed (feed intake reduced according to HS group feed intake in period 1) to eliminated the confounding effects of unequal nutrient intake. Both groups received 10 gr/d of a top-dressed glucogenic product (GL-Part 100®) in two equal meals. All production and blood data were collected daily through both periods. Three thermostat-regulated heaters were used to generate the heat load and 2 fans were utilized to evenly distribute the heat load within the room and fans were angled to prevent hot air blowing directly on the animals. In the beginning of the experiment and at the end of each experimental period, lambs were weighed before morning feeding. During each period, DMI and water intake were recorded daily and body temperature indices were obtained at 1400 h. Blood samples were collected during both periods from the jugular vein (5 mL in collection tubes containing of sodium heparin) before and 4 h after morning feeding on d 3 and 8 in P1, and d 3, 8 in P2. Blood was centrifuged at 2000 x g for 15 min to obtain plasma and then, stored at -20°C for later analysis.

HS significantly reduced DMI in both periods than TN group (P<0.05). Glucogenic supplement in period 2 significantly increased DMI than period 1 (P<0.01). Glucogenic supplement increased average daily gain and feed efficiency significantly (P<0.05). HS significantly increased rectal temperature in both periods, but Glucogenic supplement did not effect on body temperature. At a.m. feeding in both periods, blood glucose concentration of HS group significantly lower than TN lams (P<0.05). After feeding, HS did not affect any of the blood parameters (Mahjoubi et al., 2016), But Glucogenic supplement affected NEFA blood concentration significantly (P<0.05). Lower blood urea nitrogen in glucogenic supplementation treatments was probably due to a higher supply of glucose precursors and a less need for muscle tissue degradation to supply glucose precursors, leading to increased nitrogen efficiency (Donkin et al., 2009). After feeding, no increase in blood glucose after glucogenic supplementation was interesting because we expected that glucose precursor consumption would increase blood glucose concentration after feeding. The results differ on the effects of using glucose precursor supplements. Glucose precursor supplementation numerically increased blood insulin levels compared to the first period, which may be another reason for the lack of increased blood glucose in lambs after glucogenic supplementation. Differences in the type and composition of glucose precursor supplements, how much they are used in the diet and the physiological stages of livestock are the reasons for the differences in the results of different researchers.

As expected, HS reduced DMI than TN lambs, but glucogenic supplemented lambs have more DMI than lambs in period 1. Dietary glucose precursors improved feed efficiency at HS. These results showed that in HS the efficiency of converting dietary nutrients into tissue accretion was enhanced as glucose precursors fed. Also, HS significantly increased rectal temperature in both periods. At a.m. feeding in both periods, blood glucose concentration of HS group significantly was lower than TN lams. But glucogenic supplementation significantly affected NEFA blood concentration. In overall, improvement of some important functional and metabolic indices in lambs fed with glucogenic supplement in HS condition can indicate the beneficial effects of this nutritional strategy on lambs during HS, but this needs more research to prove.

The purpose of the present descriptive-survey study is development and validation of teaching - learning process instrument in smart schools in educational system of the Islamic Republic of Iran.

The research tool i.e. the researcher-made questionnaire was designed and implemented based on research background. First, the theoretical foundations and research background in this field were studied And three dimensions of indicators, components and tools were extracted and designed in the form of scale items. In the next step, to evaluate the validity of this scale, item analysis method was used and all items had the required validity more than 0.4. In addition, the reliability of the scale was determined and confirmed by Cronbach's alpha. then The designed questionnaire was provide after validation to statistical sample of 216 teachers of smart schools in Gorgan randomly selected based on the sample size formula in the academic year of 1395-1396. who were. Finally, The results were analyzed using descriptive and inferential statistical methods. Friedman test and one-sample t-test statistical techniques were used to analyze statistical data.

The results of this study show that the teaching and learning indicators in smart schools have the greatest impact on creating a dynamic and attractive environment for students' creativity and the least amount is related to the promotion of the assessment of high levels of thinking, knowledge and skills. In terms of teaching and learning components of intelligent schools, the highest level of influences is on teachers' familiarity with IT skills and the least amount on the promotion of critical thinking and students’ self-directedness. Also, regarding teaching and learning tools, smart schools have had the greatest impact on hybrid technology (film, image, etc.), and the least amount of influence on the production of blogs and educational sites.

Smart schools are one of the most important achievements in the development of information technology in order to fundamentally change the educational system. Technology can be used as a powerful tool to improve the quality and efficiency of education, but it should be noted that the combination of information and communication technology with education and learning system is a multifaceted and complex process. According to the findings of the present study, in examining the infrastructure of smart schools, quantitative and qualitative aspects of indicators, components and effective tools of smartening up process should be considered. Undoubtedly, development of smart schools in the country will not be successful regardless of the attitude of the authorities, parents, students and most importantly teachers to this technology. In other words, to succeed in this, determining the factors affecting a positive attitude to technology-based learning is of particular importance because a positive attitude increases motivation and better acceptance of technology as well as active participation in the related activities. Moreover, With a scientific and technological view of the current situation of the country's educational system and producing various electronic content and empowering teachers in the field of information technology it is possible with a long term planning to provide a dynamic ground and bring about structural developments in all dimensions for the educational environment and the teaching-learning process in smart schools. In knowledge-based societies, the development of smart schools is welcomed as a way to train creative and entrepreneurial force and is considered as a way of sustainable development. According to this principle, the entry of our country into this field can provide the ground for increasing and sustainable development.  

Tooth brushing is a common oral health habit worldwide. Therefore hygiene of toothbrushes can play an effective role in maintaining oral health. Several factors can affect microbial contamination of toothbrushes. The aim of this study was to investigate the effectiveness of chlorhexidine 0.2% solution on toothbrush decontamination.Method and materials: In this experimental study, a total of 84 sterile, similar toothbrushes were given to 42 individuals in two seperate sessions. In the first session, subjects washed their brushes in the usual way after brushing their teeth. In the second session, the brushes were put in a solution of chlorhexidine 0.2% following their application by the subjects. At the end of each session, toothbrush heads were detached under sterile conditions and were put in the phosphated buffer solution (PBS) before being sent to the laboratory for microbial culture. The collected data were analyzed using Wilcoxon test with a confidence rate 0.95.

There was a statistically significant difference in bacterial contamination on toothbrush heads between the two sessions (P value = 0.009). In the first session (simple rinsing) 21.4% of toothbrushes were contaminated while in the second session (using chlorhexidine 0.2%) only 2.4% of samples were contaminated.

The results of this study revealed that chlorhexidine 0.2% reduces bacterial contamination on toothbrushes. This solution is easily available and is also helpful for other oral purposes.