372 research outputs found

    More than one dynamic crossover in protein hydration water

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    Studies of liquid water in its supercooled region have led to many insights into the structure and behavior of water. While bulk water freezes at its homogeneous nucleation temperature of approximately 235 K, for protein hydration water, the binding of water molecules to the protein avoids crystallization. Here we study the dynamics of the hydrogen bond (HB) network of a percolating layer of water molecules, comparing measurements of a hydrated globular protein with the results of a coarse-grained model that has been shown to successfully reproduce the properties of hydration water. With dielectric spectroscopy we measure the temperature dependence of the relaxation time of protons charge fluctuations. These fluctuations are associated to the dynamics of the HB network of water molecules adsorbed on the protein surface. With Monte Carlo (MC) simulations and mean--field (MF) calculations we study the dynamics and thermodynamics of the model. In both experimental and model analyses we find two dynamic crossovers: (i) one at about 252 K, and (ii) one at about 181 K. The agreement of the experiments with the model allows us to relate the two crossovers to the presence of two specific heat maxima at ambient pressure. The first is due to fluctuations in the HB formation, and the second, at lower temperature, is due to the cooperative reordering of the HB network

    Experiences of Iranian family caregivers supporting individuals with multiple sclerosis: a qualitative study

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    Family members of patients are often considered informal primary caregivers, particularly for those living with chronic diseases including multiple sclerosis (MS). Caregivers often report increased burden and stress when caring for individuals with chronic care needs. It is important to explore the caregiver experience in the context of MS. The aim of this study is to describe the experiences of family caregivers caring for individuals with Multiple Sclerosis. A purposive sampling method was utilized. A total of eighteen family member caregivers of patients with multiple sclerosis participated in this study. Data were collected through semi-structured and in-depth interviews conducted in the multiple sclerosis society and hospitals of Tabriz in Iran. Data were analyzed using qualitative content analysis assisted by MAXQDA 10 software. Three main categories emerged from interviews about their caregiving experiences. These include1) emotional reactions; 2) caregiver needs; and 3) caregiver expectations. Results of this study demonstrate that family caregivers of individuals with MS show different emotional reactions and have complex needs and expectations from other ‘non-caregiver relatives and society. This study highlights the psychosocial, physical and economic needs of caregivers of individuals with MS and enhances social understanding of this impact of the condition. This may improve the support clinicians provide to family caregivers. There is need to develop targeted interventions that reduce caregiver burden for those caring for individuals with MS

    USCID fourth international conference

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    Presented at the Role of irrigation and drainage in a sustainable future: USCID fourth international conference on irrigation and drainage on October 3-6, 2007 in Sacramento, California.Includes bibliographical references.Based on the shortage of water resources in Iran and the high evapotranspiration rate in Khuzestan region (2044 mm/year), an irrigation system on Estamaran palm tree in the Experimental Farm of Shahid Rajaee of Omidiyeh plain was conducted. This study had two purposes, namely irrigation frequency and suitable depth of irrigation application of the Estamaran palm trees in Omidiyeh region. This study had two objectives. Irrigation frequency was the primary treatment and the evapotranspiration estimating methods was the secondary treatment. Three irrigation levels. i.e. one day long (A1), two day long (A2) and three day long (A3), were used as irrigation frequency. Also the evapotranspiration estimating methods used were, Penman-Montith 100% (B1), Penman-Montith 70% (B2), class A pan 100% (B3) and class A pan 70% (B4). Since this study had three replications, 36 palm trees were selected for this experiment. Cropwat software V.4 for windows, was applied for the evapotranspiration estimating from Penman-Montieth method. Irrigation scheduling was done according to SCS recommendations. Experimental design was according to split plot method in a randomized block. Finally by measuring the different growth indices of palm trees (leaf number, barb number and leaflet length) at a definite time, the best treatment was determined. The results showed that as a whole all the treatments in this experiment did not show a significant difference (up to 5% level) for the indicated indices. However, at the end of 4 month since the beginning of this study, the growth indices of trees in A2B1, A1B2 and A1B1 increased compared to other treatments. The result also indicated that, A1B2 was the best treatment of all. In comparison with the traditional irrigation by local farmers, using A1B2 treatment for all the palm trees (from Aug to Nov), will have 28422.34 m3 water saving in 3.87 hectare per month

    A stack-based chaotic algorithm for encryption of colored images

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    In this paper, a new method is presented for encryption of colored images. This method is based on using stack data structure and chaos which make the image encryption algorithm more efficient and robust. In the proposed algorithm, a series of data whose range is between 0 and 3 is generated using chaotic logistic system. Then, the original image is divided into four subimages, and these four images are respectively pushed into the stack based on next number in the series. In the next step, the first element of the stack (which includes one of the four sub-images) is popped, and this image is divided into four other parts. Then, based on the next number in the series, four sub-images are pushed into the stack again. This procedure is repeated until the stack is empty. Therefore, during this process, each pixel unit is encrypted using another series of chaotic numbers (generated by Chen chaotic system). This method is repeated until all pixels of the plain image are encrypted. Finally, several extensive simulations on well-known USC datasets have been conducted to show the efficiency of this encryption algorithm. The tests performed showthat the proposed method has a really large key space and possesses high-entropic distribution. Consequently, it outperforms the other competing algorithms in the case of securit

    Improving effects of green tea on renal nephrotoxicity

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    Contrast media-induced acute renal damage could lead to renal failure; so, recently much attention has been made on the efficacy of medicinal plants in prevention and treatment of various diseases, especially in kidney and liver complications. Methods: Forty rats were randomly divided into four groups of 10 consisting of control, contrast media, contrast media plus green tea and green tea pretreatment and contrast media group, respectively. After collecting blood samples from lateral tail vein blood urea nitrogen (BUN) and serum creatinine were measured for assessing tubular nephrotoxicity. Findings: In the second group creatinine level was significantly higher than other groups (P ≤ 0.05). Conclusion: Green tea can provide an applicable intervention approach in individuals with a risk for contrast induced acute kidney injury. So, further preclinical investigations are necessary to confirm the efficiency of this herb against various injurious substances to the renal tubular cells

    Ectoparasite infection of Carassius carassius in water resources of west Azerbaijan, Iran

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    Various parasite species were found in Carassius carassius including Diplostomum spathaceum, Dactylogyrus sp.,Gyrodactylus sp. Ichthyophthirius multifiliis and Trichodinia sp . They were found in four rivers in West Azerbaijan Province (North-Western Iran) . A total of 207 live Carassius carassius from four rivers including Aras (72) Zariyneh (42) Nazlo (58) and Barandoz (35) were studied. Parasitological surveys were carried out on gills and external organs. The results showed that Diplostomum spathaceum (70.83%) Dactylogyrus sp. (38.88%) Gyrodactylus sp. ) 22.22%) Ichthyophthirius multifiliis (48.61%) Trichodinia sp. (8.33%) Chilodonella sp. (12.50%) and Argulus sp. (76.19%) were found in fish from Aras Rive so that the result showed, Spathaceum (63.79%) Dactylogyrus sp. (36.20%) Gyrodactylus sp. (25.86%) Ichthyophthirius multifiliis (44.82%) Trichodinia sp. (18.96%) Chilodonella sp. (12.06%) and Argulus sp. (6.89%). Argulus prevalence was greater in Barandoz River while Chilodonella in Zariyneh rud River . In Barandoz River, Diplostomum spathaceum (65.71%) Dactylogyrus sp. (37.14%) Gyrodactylus sp. (22.85%) Ichthyophthirius multifiliis (31.42%) Trichodinia sp. (25.71%) Chilodonella sp. (8.57%) and Argulus sp. (5.71%) were reported, respectively. Finally, in Zariyneh rud river, the followings have been reported: Diplostomum spathaceum (76.19%) Dactylogyrus sp. (21.42%) Gyrodactylus sp. (14.28%) Ichthyophthirius multifiliis (52.38%) Trichodinia sp. (23.80%) Chilodonella sp. (14.28%) and Argulus sp. (7.14%). It should be noted that prevalence , intensity and host parasite relationship will be discussed in details in this article

    Improved battery life for context awareness application in smart-phones

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    The new smart-phones with new operating system and portable sensors support the basis for context awareness systems and applications for handling user activity and user privacy. Nowadays, individuals need new services and real time information anywhere and anytime. Context awareness is an emerging service, which could be able to improve the user experiences in current situation. Context awareness can be considered as location, calendar, user activity and etc. The review of the literature proves that context awareness in mobile phone can be useful and studied as unavoidable service in next generation of smart-phone applications. In this paper, a short review about context awareness in mobile phone is studied, furthermore, we critically analyzed related works of context awareness in smart-phones. The review shows that the most important context in mobile phone is location, which is mostly obtained by using Global Positioning System (GPS) sensor in mobile phones but GPS can significantly increases battery consumption in mobile phones. In this regard, a framework as Improved Battery life in Context Awareness System (IBCS) is proposed to improve battery life and reduce cost of using GPS in context awareness applications based on smart-phones. The review argues the weakness and strength of these studies, and aims to (a) indicate the most important context in mobile phone, (b) reduce the battery consumption of GPS sensor in mobile phone

    Fecundity reproductive cycle of a local population of Gammarus Pulex in Sepidan (Fars Province, Iran)

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    Abstract: Gammarus pulex reproductive was studied in Komehr spring, in Komehr village Fars province, South of Iran. Specimens were collected using a net with 1 mm mesh size. Water temperature, DO, PH, No2, No, Po4, Ec, K, Mg, Total hardens and TDS were measured. Biological parameters including length and wet weight of males and females, number of female having eggs, number of eggs presented in moraspum sac of female, sex ratio, egg size, fecundity and reproductive effort was studied. Mean length of both sex and mean wet weight of males increased in autumn, decreased in spring and increased again in summer. Number of eggs in marsopium sac, female's wet weight, fecundity, and reproductive effort increased from autumn toward summer and egg volume increased in autumn and winter and reduces a little with increasing in egg's number in spring and summer. All reproductive factors showed significant differences throughout the year
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