Effects of caffeine injection in paradoxical sleep window on memory in rat

زمینه و هدف: برخی محققین عقیده دارند که پس از یادگیری برخی اعمال، میزان خواب REM در دوره هایی خاص افزایش می‌یابد و در طی برخی از این دوره‌ها پردازش و تثبیت حافظه صورت می‌گیرد. این دوره‌های خاص به عنوان پنجره‌های خواب متناقض مطرح گردیده‌اند. این پژوهش با هدف بررسی نقش آگونیست ها و آنتاگونیست‌های آدنوزینی و استیل کولینی در پنجره‌های خواب متناقض و تاثیر آن ها بر حافظه انجام شد. روش‌ بررسی: در این مطالعه تجربی موش‌های صحرایی نر تحت آموزش فعال دو طرفه یک جلسه 100 تریالی قرار گرفتند. آن دسته از حیواناتی که به مرز70 یادگیری رسیدند به 6 گروه دارویی و 2 گروه دارو-محرومیت تقسیم شدند. در بخش دارویی به ترتیب به هر یک از گروه ها سالین، کافئین ( mg/kg25)، آدنوزین ( mg/kg7)، آدنوزین ( mg/kg50)، فیزوستیگمین (mg/kg1/0) و اسکوپولامین ( mg/kg5) به صورت درون صفاقی تزریق گردید. در بخش دارو- محرومیت حیوانات گروه اول در دوره 4-1 ساعت پس از یادگیری از خواب REM محروم شدند و به حیوانات گروه دوم علاوه بر محرومیت، کافئین ( mg/kg25) تزریق گردید. میزان حافظه در تمام گروه ها یک هفته بعد مورد آزمایش قرار گرفت. یافته‌ها: تزریق کافئین باعث تقویت حافظه گردید (05/0

Reducing Consumed Energy while Drilling an Oil Well through a Deep Rig Time Analysis

As time goes by, increase in world energy demand forces oil and gas companies to drill deeper in order to produce more oil and gas for balancing world’s offer and demand. This requires drilling layers with various characteristics and dealing with more drilling problems as drilling progresses. Reduction of drilling problems can help drillers to reduce their cost effectively. Rig time break down of more than 300 wells in one south west Iranian oil field has been analysed to determine effective parameters on non-productive time amount. Results show that the most common drilling problems always have been experienced by drilling engineers are Equipment failure, stuck pipe and lost circulation which expose huge expenses to the oil companies. Several factors while drilling will govern how severe mud loss and stuck pipe would occur. These actually make analytical modelling of lost circulation or pipe sticking to somehow complicated. Hereby, employing artificial intelligence can be a leeway with proven capability and accuracy. In this research, operational parameters in Maroun oilfields are introduced to artificial neural networks to predict lost circulation severity, stuck pipe position and stuck pipe severity before happening. Results are well-matched with reality. Key words: Energy; Drilling problems; Lost circulation; Stuck pipe; Rig time analysi

The Relationship Between Biomechanical-Anthropometrical Parameters and the Force Exerted on the Head When Heading Free Kicks in Soccer

Background: Soccer is a contact sport in which the players are frequently faced with the risk of injury. It has been shown that the force exerted on the head during heading can be as much as 500–1200 Newton (N). Objectives: The main objective of this study was to determine whether there was any relationship between the force exerted on the head and several biomechanical and anthropometrical parameters related to heading free kicks. Patients and Methods: A total of 16 semi-professional soccer players with at least 5 years experience participated in this study. The mean age, height, and weight of the study participants were 21.36 ± 5.67, 178 ± 5.99 cm, and 70.55 ± 8.55 kg, respectively. To measure the force exerted on the heads of the players, a pressure gauge was installed on their foreheads. Each participant was asked to defend the ball using the heading technique three times. A camera with a sampling frequency of 150 frames per second was used to record the moment of impact between the ball and head during each heading event. For each participant and replicate, the ball and head velocity (m/s) as well as the angular body changes (degrees) were calculated using MATLAB and AutoCAD softwares, respectively. Descriptive statistics, including means and standard deviations were used to describe the data. Pearson correlation coefficient (alpha = 0.05) was used to examine potential relationships between the variables of interest. Results: Significant correlations existed between the force exerted on the head during heading, participant age, body mass, body fat percentage, and head perimeter (P < 0.05). Conclusions: The study revealed the significance of anthropometric variables related to heading, such as age and head perimeter. Therefore, it was concluded that these variables should be considered when teaching and practicing the heading technique with players of different ages and anthropometric sizes

Modelling of three-axis Hall effect sensors based on integrated magnetic concentrator

In this paper, we develop computational model to analyze the magnetic concentrating effect of integrated magnetic concentrator (IMC) on surrounding external magnetic field. We present an IMC-based three-axis Hall sensor model that enables to measure both inclination angles and absolute strength of a random external magnetic field. An IMC changes surrounding parallel magnetic components into perpendicular components, and therefore allows the horizontal Hall plates to measure both the strength and inclination angles of parallel external magnetic fields. We develop a finite element method (FEM) based model in COMSOL Multiphysics for the three-axis Hall sensor. Key factors influencing IMC’s magnetic concentrating effect, including material property and sensor structure, are investigated and discussed using the developed model. Comparing to traditional IMC-based three-axis angular sensors, a reference permanent magnet is no longer needed in the sensor. A measurement accuracy of 0.8 and 1.2 degrees are achieved respectively for the angles of α and θ of external magnetic field

The study of effectiveness of social capital, organizational capital and knowledge on entrepreneurship

In this research, we studied the effectiveness of internal and external social capital and organizational capital (two subcategories of intellectual capital) and also different types of presented knowledge in the organization, by counting tacitness or explicitness or even complexity, on entrepreneurship and innovation of firms. The result of study shows that social capital (inside organizational and outside organizational) have positive effect on innovation and organizational capital also by having positive effect on social capital have indirect effect on innovation. Also, the effect of knowledge tacitness exists under social capital high level conditions, and it shows the positive relation with fundamental innovations. Knowledge complexity also applies positive effect on radical innovations

The study of effectiveness of social capital, organizational capital and knowledge on entrepreneurship

In this research, we studied the effectiveness of internal and external social capital and organizational capital (two subcategories of intellectual capital) and also different types of presented knowledge in the organization, by counting tacitness or explicitness or even complexity, on entrepreneurship and innovation of firms. The result of study shows that social capital (inside organizational and outside organizational) have positive effect on innovation and organizational capital also by having positive effect on social capital have indirect effect on innovation. Also, the effect of knowledge tacitness exists under social capital high level conditions, and it shows the positive relation with fundamental innovations. Knowledge complexity also applies positive effect on radical innovations

The study of effectiveness of social capital, organizational capital and knowledge on entrepreneurship

In this research, we studied the effectiveness of internal and external social capital and organizational capital (two subcategories of intellectual capital) and also different types of presented knowledge in the organization, by counting tacitness or explicitness or even complexity, on entrepreneurship and innovation of firms. The result of study shows that social capital (inside organizational and outside organizational) have positive effect on innovation and organizational capital also by having positive effect on social capital have indirect effect on innovation. Also, the effect of knowledge tacitness exists under social capital high level conditions, and it shows the positive relation with fundamental innovations. Knowledge complexity also applies positive effect on radical innovations

Neural Microprobe Device Modelling for Implant Micromotions Failure Mitigation

Brain micromotion is a major contributor to the failure of implantable neural interfaces. Brain micromotions and tissue damage can be effectively reduced in two ways: (i) miniaturization of the implantable device footprint and (ii) choosing flexible materials for the device substrate. To meet these requirements, in this work we perform two sets of modelling using finite element method in COMSOL Multiphysics. First, we model the performance of different materials ranging from stiff (e.g. Silicon) to very soft (e.g. PDMS) with different sizes to find the optimal dimension and material for the microprobe. For the device size optimization, the main degree of freedom is thickness, while the minimum shank width and length depend on the recording sites and the target recording point, respectively. Modelling devices with different thicknesses (50 − 200 μm) and fixed shank width (100 μm) based on different substrates, we show that the Polyimide-based microprobe exhibits a safety factor of 5 to 15 and maximum von mises stress of 248–770 MPa. Further, simulations indicate that the Polyimide-based microprobe of 50 μm thickness, exhibiting safety factor of 5 and stress of 248 MPa, provides the optimal solution in terms of size and material. Second, to analyse the device shape factor, we model different layouts based on the obtained optimal design and find that the optimal layout features von mises stress of 134.123 MPa, which is versatile and suitable to be used as microprobe especially for the brain micromotion effects mitigation purpose

Depression in mothers of children with thalassemia or blood malignancies: a study from Iran

BACKGROUND: Several studies have found that parents of children with chronic diseases or disabilities have higher depression scores than control parents. Mothers usually take on the considerable part of the extra care and support that these children need and thus are at markedly increased risks of suffering from psychological distress and depression. The main aim of the present study was to investigate if mothers of children with thalassemia or blood malignancies have higher scores of depression compared with a group of control mothers. METHODS AND MATERIALS: In this cross – sectional study, 294 mothers were recruited in three groups and assessed using the Beck Depression Inventory (BDI): mothers of children with thalassemia, mothers of children with blood malignancies and a control group. SPSS version 11.5 with chi square, ANOVA, linear and logistic regression were used for statistical analysis. RESULTS: The only variable bearing a statistically significant relationship with the depression score of mothers was the child's disease: for thalassemia with OR of 2.17 (95% CI = 1.16–4.0, P = 0.015), for blood malignancies with OR of 2.71 (95% CI = 1.48–4.99, P = 0.001). DISCUSSION AND CONCLUSION: The results of this study can contribute to the development of a screening program for decreasing depression burden and promoting quality of life for mothers of children with thalassemia or blood malignancies

Design and Fabrication of Robot-Manufactured Joints for a Curved-Folded Thin-Shell Structure Made from CLT

The prototype presented in this chapter utilizes the technique of curved folding for the design of a thin-shell structure built from curved cross-laminated timber panels (CLT). The curved-folded geometry allows for a span of 13.5 m, at a shell thickness of only 77 mm. The construction requires curved line CLT joints, which are difficult to address with state-of-the-art jointing techniques for CLT. Inspired by traditional woodworking joinery, we have designed connections for the integrated attachment of curved CLT panels, utilizing digital geometry processing tools to combine the advantages of traditional joinery techniques with those of modern automation technology