109 research outputs found

    The perception of same gender coaches by Iranian skaters and its influence on sport achievement motivation and commitment

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    Aim: To examine the relationship between the perception of same gender coaches by male and female Iranian skaters and their sport achievement motivation and commitment. Participants: Fifty two female and forty two male skaters, age range 13 to 18 years, from the province of Isfahan in Iran. Materials: The following 3 questionnaires, tested for reliability and validity for the Iranian population and adapted for Farsi, were used: i) Pelletier, Fortier, Vallerand and Briere (2001) Interpersonal Behaviour Scale to measure social support of trainers, ii) Gill and Deeter (1988) Sport Orientation Questionnaire (SOQ) to measure achievement motivation, and iii) Scanlan, Simons, Carpenter, Schmidt and Keeler (1993) Sport Commitment Model to measure sport commitment. Procedure: The questionnaires were administered to participants in person by the first author after training sessions in sport stadiums. Results: There was a significant positive correlation between perceived coaches' social support and sport achievement motivation and commitment for both male and female participants. However, on all of the above measures females scored significantly more positive ratings than their male counterparts. Results of regression analyses conducted separately for males and females showed that relatedness support is the strongest predictor for sport achievement motivation and commitment for males, whereas autonomy support was the strongest predictor for sport commitment amongst females. Implications: These findings are of particular interest in understanding the impact of perceived coaching support for young male and female athletes, especially if coached exclusively by the same gender. Keywords: Same gender, coaches social support, achievement motivation, sport commitment, skating

    Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System

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    Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produce novel natural-synthetic hybrid polymers. We have studied structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning. Properties of these hybrids polymers are compared with extant chitosan containing hybrids synthesized by electrospinning. Molecular interactions and orientation in the fibers are analyzed by infrared and Raman spectroscopies respectively, morphology by scanning electron microscopy and thermophysical properties by thermogravimetric analysis and differential scanning calorimetry. Addition of PET to Ch + S systems results in improved thermal stability at elevated temperatures

    Investigation of breeding and culture in Iranian cichlid (Iranocichla hormuzensis) as endemic and ornamental species

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    Iranian Cichlid is an invaluable ornamental species which is domesticated in Iran and called Iranocichla hormuzensis scientifically, is living in the Hormoz zone, Shahou River (between Bandar Abbas and Haji Abad). The first phase of the research project started in September of 2012 and lasted about 18 months, focused on adapting the wild cichlids to cope with the aquarium environment. Therefore, about 63 male and female of Iranian cichlids collected from the natural habitat, Shahou River, then moved to the nearest city, Bandar Abbas to and released in aquariums which were filled by water of River where they were living. After few days they moved to “innovative aquaculture technologies research station” and reared in 100 liter glass tanks to monitor their behaviors. By initial days, the Cichlids seemed to be stressed out significantly, they were flashing, hitting them to the aquarium, trying to jump out and get discolored due to strange environment. By days, the stressful treats decreased and the experiments coped with the new environment. At the next step, schools of 5-7 fish organized to pear up. The mortality rate collected daily and accidental biometry recorded fortnightly. The rearing temperature adjusted and was stable at 37˚C. Finally, the Cichlids were completely adopted and prepared for mating and breeding

    Blend electrospinning of dye-functionalized chitosan and poly(ε-caprolactone) : towards biocompatible pH-sensors

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    Fast-response and easy-to-visualize colorimetric nanofibrous sensors show great potential for visual and continuous control of external stimuli. This makes them applicable in many fields, including wound management, where nanofibers serve as an optimal support material. In this paper, fast responding and user-friendly biocompatible, halochromic nanofibrous sensors are successfully fabricated by incorporating the halochromic dyes Methyl Red and Rose Bengal inside a chitosan/poly(e-caprolactone) nanofibrous matrix. The commonly applied dye-doping technique frequently suffers from dye-leaching, which not only reduces the sensor's sensitivity over time but can also induce adverse effects. Therefore, in this work, dye-immobilization is accomplished by covalent dye-modification of chitosan before blend electrospinning. It is shown that efficient dye-immobilization with minimal dye-leaching is achieved within the biomedical relevant pH-region, without significantly affecting the halochromic behavior of the dyes. This is in contrast to the commonly applied dye-doping technique and other dye-immobilization strategies stated in literature. Moreover, the nanofibers show high and reproducible pH-sensitivity by providing an instantaneous color change in response to change in pH in aqueous medium and when exposed to acidic or basic gases. The results stated within this work are of particular interest for natural (bio) polymers for which covalent modification combined with electrospinning provides a universal method for versatile dye-functionalization of large area nanofibrous membranes with proper dye-immobilization

    Fibers for hearts: A critical review on electrospinning for cardiac tissue engineering

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    Cardiac cell therapy holds a real promise for improving heart function and especially of the chronically failing myocardium. Embedding cells into 3D biodegradable scaffolds may better preserve cell survival and enhance cell engraftment after transplantation, consequently improving cardiac cell therapy compared with direct intramyocardial injection of isolated cells. The primary objective of a scaffold used in tissue engineering is the recreation of the natural 3D environment most suitable for an adequate tissue growth. An important aspect of this commitment is to mimic the fibrillar structure of the extracellular matrix, which provides essential guidance for cell organization, survival, and function. Recent advances in nanotechnology have significantly improved our capacities to mimic the extracellular matrix. Among them, electrospinning is well known for being easy to process and cost effective. Consequently, it is becoming increasingly popular for biomedical applications and it is most definitely the cutting edge technique to make scaffolds that mimic the extracellular matrix for industrial applications. Here, the desirable physico-chemical properties of the electrospun scaffolds for cardiac therapy are described, and polymers are categorized to natural and synthetic.Moreover, the methods used for improving functionalities by providing cells with the necessary chemical cues and a more in vivo- like environment are reported

    Epithelial Dysplasia in Oral Cavity

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    Among oral lesions, we encounter a series of malignant epithelial lesions that go through clinical and histopathologic processes in order to be diagnosed. Identifying these processes along with the etiology knowledge of these lesions is very important in prevention and early treatments. Dysplasia is the step preceding the formation of squamous cell carcinoma in lesions which have the potential to undergo dysplasia. Identification of etiological factors, clinical and histopathologic methods has been the topic of many articles. This article, reviews various articles presenting oral cavity dysplasia, new clinical methods of identifying lesions, and the immunohistochemical research which proposes various markers for providing more precise identification of such lesions. This article also briefly analyzes new treatment methods such as tissue engineering

    Data from: Regeneration of glycocalyx by heparan sulfate and sphingosine 1-phosphate restores inter-endothelial communication

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    Vasculoprotective endothelium glycocalyx (GCX) shedding plays a critical role in vascular disease. Previous work demonstrated that GCX degradation disrupts endothelial cell (EC) gap junction connexin (Cx) proteins, likely blocking interendothelial molecular transport that maintains EC and vascular tissue homeostasis to resist disease. Here, we focused on GCX regeneration and tested the hypothesis that vasculoprotective EC function can be stimulated via replacement of GCX when it is shed. We used EC with [i] intact heparan sulfate (HS), the most abundant GCX component; [ii] degraded HS; or [iii] HS that was restored after enzyme degradation, by cellular self-recovery or artificially. Artificial HS restoration was achieved via treatment with exogenous HS, with or without the GCX regenerator and protector sphingosine 1- phosphate (S1P). In these cells we immunocytochemically examined expression of Cx isotype 43 (Cx43) at EC borders and characterized Cx-containing gap junction activity by measuring interendothelial spread of gap junction permeable Lucifer Yellow dye. With intact HS, 60% of EC borders expressed Cx43 and dye spread to 2.88 ± 0.09 neighboring cells. HS degradation decreased Cx43 expression to 30% and reduced dye spread to 1.87± 0.06 cells. Cellular self-recovery of HS restored baseline levels of Cx43 and dye transfer. Artificial HS recovery with exogenous HS partially restored Cx43 expression to 46% and yielded dye spread to only 1.03 ± 0.07 cells. Treatment with both HS and S1P, recovered HS and restored Cx43 to 56% with significant dye transfer to 3.96 ± 0.23 cells. This is the first evidence of GCX regeneration in a manner that effectively restores vasculoprotective EC communication
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