1,189 research outputs found

    Wearable electric potential sensing: a new modality sensing hair touch and restless leg movement

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    Electric potential sensors (EPS) are classified as capacitive sensors with the ability to measure small variations in electric potential or electric field remotely and accurately. Here we show how a low cost single chip version of EPS can be integrated into a wearable device such as smart watch to provide relevant information about habitual movements specifically, hair touching and scratching as well as leg movement. This new modality could be used in consumer care product research such as studying the quality of shampoos and to study restless leg syndrome remotely without the need of wearing additional sensors. In both scenarios, a single sensor was worn on the wrist, similar to a smart watch, with the sensing electrode pointing away from the body (i.e. no skin contact)

    In vitro pancreatic carcinogenesis

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    Studies in our laboratories have indicated that pancreatic cancer originates not only from pancreatic ductal/ductular cells but also from within the Langerhans' islets, probably from reserve (precursor, stem) cells. To identify, enrich and characterize these cells, we established a long-term hamster islet culture and studied their growth, differentiation and response to the pancreatic carcinogen, N-nitrosobis(2-oxopropyl)amine (BOP). One group of cultured islets was treated in vitro with BOP (KL5B group) and the other group of islets served as an untreated control (KL5N group). During the early culture days, in both groups all cultured islets showed a progressive loss of endocrine cells and replacement by ductular, acinar and intermediary cells. However, all these cells disappeared after 35 days in culture and gave room to undifferentiated cells, which we believe represent stem cells. No differences were found between KL5N and KL5B cells with regard to cell growth and differentiation until day 35, when the growth of the KL5B cells accelerated and the cells underwent increasing pleomorphism and atypia. At day 133, KL5B cells but not KL5N cells showed colony formation in soft agar and formed invasive, poorly differentiated adenocarcinomas of the ductal type when transplanted into hamsters. All of these tumors showed mutation of the K-ras gene and extensive chromosomal damage. We concluded that like ductal/ductular cells, certain cell populations within islets are responsive to the carcinogenic effect of BOP. We could not ascertain whether these cells present a preexisting (stem, reserve) cell population within the islets or transdifferentiated islet cell

    Change in bone mineral density in post menopausal women with rheumatoid arthritis

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    Introduction: Low bone mass is a serious complication of post menopausal women with rheumatoid arthritis. We determined the Change in Bone Mineral Density in postmenopausal women with rheumatoid arthritis. Methods: This retrospective cohort study was carried out on consecutive postmenopausal women with rheumatoid arthritis who were referred to the Azar 5th teaching hospital affiliated to Golestan University of Medical Sciences, North of Iran in 2009. The required data were gathered from the patients' medical records. The data were analyzed using SPSS software and statistical tests. Results: We studied 98 postmenopausal women with rheumatoid arthritis. Mean number of years since menopause and mean duration of disease were 9.39 and 5.13 respectively. T Score mean in femoral neck and lumbar spines was -1.45±1.26 and -2.45±1.44 respectively. The overall prevalence of osteoporosis at both the lumbar spine and femoral neck was 13.3. We have found a significant correlation between age, duration of disease, duration of menopause and bone mineral density (P-Value<0.01). Conlusion: Our results indicate a negative effect of age, number of years since menopause and duration of disease on bone mineral density. So, BMD should be measured in high risk women prior to the implementation of any treatment or prevention program

    Determining the best drought tolerance indices using Artificial Neural Network (ANN): Insight into application of intelligent agriculture in agronomy and plant breeding

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    In the present study, efficiency of the artificial neural network (ANN) method to identify the best drought tolerance indices was investigated. For this purpose, 25 durum genotypes were evaluated under rainfed and supplemental irrigation environments during two consecutive cropping seasons (2011–2013). The results of combined analysis of variance (ANOVA) revealed that year, environment, genotype and their interaction effects were significant for grain yield. Mean grain yield of the genotypes ranged from 184.93 g plot–1 under rainfed environment to 659.32 g plot–1 under irrigated environment. Based on the ANN results, yield stability index (YSI), harmonic mean (HM) and stress susceptible index (SSI) were identified as the best indices to predict drought-tolerant genotypes. However, mean productivity (MP) followed by geometric mean productivity (GMP) and HM were found to be accurate indices for screening drought tolerant genotypes. In general, our results indicated that genotypes G9, G12, G21, G23 and G24 were identified as more desirable genotypes for cultivation in drought-prone environments. Importantly, these results could provide an evidence that ANN method can play an important role in the selection of drought tolerant genotypes and also could be useful in other biological contexts

    Physiological responses of two rice (Oryza sativa L.) genotypes to chilling stress at seedling stage

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    In this study, quantitative changes of dry matter, proline and total soluble protein in shoot and root, stomatal conductance (gs), total chlorophyll, chlorophyll stability index (CSI) and soil and plant analyzer development (SPAD) number of latest fully-expanded leaves were determined in an Iranian coldsensitive rice genotype (Hoveizeh) in comparison to an international check genotype (IRCTN34, coldtolerant). The hydroponic experiment was arranged in a completely randomized design with three replications under the growth chamber condition under a controlled environment of 29/22°C (day/night) and 12 h light photoperiod. Then, the treatment plants were exposed to 15/10°C (day/night) cold stress for two weeks and control plants were kept at 29/22°C (day/night). Dry matter accumulation decreased with chilling stress in the two genotypes, with decreases been more pronounced in Hoveizeh genotype. Our results showed that cold treatment increased accumulation of total soluble protein (only in coldtolerant genotype) and proline in rice seedlings, while it decreased the content of chlorophyll, stomatal conductance, total soluble protein (only in cold-sensitive genotype) and dry matter. The results indicated that higher contents of protein and chlorophyll under stress were associated with tolerance to chilling.Key words: Abiotic stress, cold, total soluble protein, proline, total chlorophyll, stomatal conductance

    Comparison of Intelligent Systems, Artificial Neural Networks and Neural Fuzzy Model for Prediction of Gas Hydrate Formation Rate

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    The main objective of this study was to present a novel approach for predication of gas hydrate formation rate based on the Intelligent Systems. Using a data set including about 470 data obtained from flow tests in a mini-loop apparatus, different predictive models were developed. From the results predicted by these models, it can be pointed out that the developed models can be used as powerful tools for prediction of gas hydrate formation rate with total errors of less than 4%

    Emergence and patterning dynamics of mouse-definitive endoderm

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    The segregation of definitive endoderm (DE) from bipotent mesendoderm progenitors leads to the formation of two distinct germ layers. Dissecting DE commitment and onset has been challenging as it occurs within a narrow spatiotemporal window in the embryo. Here, we employ a dual Bra/Sox17 reporter cell line to study DE onset dynamics. We find Sox17 expression initiates in vivo in isolated cells within a temporally restricted window. In 2D and 3D in vitro models, DE cells emerge from mesendoderm progenitors at a temporally regular, but spatially stochastic pattern, which is subsequently arranged by self-sorting of Sox17 + cells. A subpopulation of Bra-high cells commits to a Sox17+ fate independent of external Wnt signal. Self-sorting coincides with upregulation of E-cadherin but is not necessary for DE differentiation or proliferation. Our in vivo and in vitro results highlight basic rules governing DE onset and patterning through the commonalities and differences between these systems

    Developing a Questionnaire for Iranian Women's Attitude on Medical Ethics in Vaginal Childbirth

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    Background: Vaginal delivery is one of the challenging issues in medical ethics. It is important to use an appropriate instrument to assess medical ethics attitudes in normal delivery, but the lack of tool for this purpose is clear. Objectives: The aim of this study was to develop and validate a questionnaire for the assessment of women’s attitude on medical ethics application in normal vaginal delivery. Patients and Methods: This methodological study was carried out in Iran in 2013 - 2014. Medical ethics attitude in vaginal delivery questionnaire (MEAVDQ) was developed using the findings of a qualitative data obtained from a grounded theory research conducted on 20 women who had vaginal childbirth, in the first phase. Then, the validation criteria of this tool were tested by content and face validity in the second phase. Exploratory factor analysis was used for construct validity and reliability was also tested by Cronbach’s alpha coefficient in the third phase of this study. SPSS version 13 was used in this study. The sample size for construct validity was 250 females who had normal vaginal childbirth. Results: In the first phase of this study (tool development), by the use of four obtained categories and nine subcategories from grounded theory and literature review, three parts (98-items) of this tool were obtained (A, B and J). Part A explained the first principle of medical ethics, part B pointed to the second and third principles of medical ethics, and part J explained the fourth principle of medical ethics. After evaluating and confirming its face and content validity, 75 items remained in the questionnaire. In construct validity, by the employment of exploratory factor analysis, in parts A, B and J, 3, 7 and 3 factors were formed, respectively; and 62.8%, 64% and 51% of the total variances were explained by the obtained factors in parts A, B and J, respectively. The names of these factors in the three parts were achieved by consideration of the loading factor and medical ethics principles. The subscales of MEAVDQ showed significant reliability. In parts A, B and J, Cronbach’s alpha coefficients were 0.76, 0.72 and 0.68, respectively and for the total questionnaire, it was 0.72. The results of the test–retest were satisfactory for all the items (ICC = 0.60 - 0.95). Conclusions: The present study showed that the 59-item MEAVDQ was a valid and reliable questionnaire for the assessment of women’s attitudes toward medical ethics application in vaginal childbirth. This tool might assist specialists in making a judgment and plan appropriate for women in vaginal delivery management

    Photoemission study and band alignment of GaN passivation layers on GaInP heterointerface

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    III-V semiconductor-based photoelectrochemical (PEC) devices show the highest solar-to-electricity or solar-to-fuel conversion efficiencies. GaInP is a relevant top photoabsorber layer or a charge-selective contact in PEC for integrated and direct solar fuel production, due to its tunable lattice constant, electronic band structure, and favorable optical properties. To enhance the stability of its surface against chemical corrosion which leads to decomposition, we deposit a GaN protection and passivation layer. The n-doped GaInP(100) epitaxial layers were grown by metalorganic chemical vapor deposition on top of GaAs(100) substrate. Subsequently, thin 1-20 nm GaN films were grown on top of the oxidized GaInP surfaces by atomic layer deposition. We studied the band alignment of these multi-junction heterostructures by X-ray and ultraviolet photoelectron spectroscopy. Due to the limited emission depth of photoelectrons, we determined the band alignment by a series of separate measurements in which we either modified the GaInP(100) surface termination or the film thickness of the grown GaN on GaInP(100) buffer layers. On n-GaInP(100) surfaces prepared with the well-known phosphorus-rich (2x2)/c(4x2) reconstruction we found up-ward surface band bending (BB) of 0.34 eV, and Fermi level pinning due to the present surface states. Upon oxidation, the surface states are partially passivated resulting in a reduction of BB to 0.12 eV and a valence band offset (VBO) between GaInP and oxide bands of 2.0 eV. Between the GaInP(100) buffer layer and the GaN passivation layer, we identified a VBO of 1.8 eV. The corresponding conduction band offset of -0.2 eV is found to be rather small. Therefore, we evaluate the application of the GaN passivation layer as a promising technological step not only to reduce surface states but also to increase the stability of the surfaces of photoelectrochemical devices

    A study on the abundance and species diversity of cynipid wasps (Hym.: Cynipidae) in West Azerbaijan province, Iran

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    The induced galls by oak gall wasps were collected from various oak forests of Iranian province of West Azerbaijan in the regions of Ghabre-Hossein, Mir-Abad, Vavan, Shalmash, Rabat and Dar-Ghabr during from April to November 2009. The optimum number of samples was found to be 40 oak trees. In each tree, as a sampling unit, all of the existing galls were counted. The species richness of oak gall wasps in the West Azerbaijan province was measured and the parameters such as Simpsonâs, Shannonâs H', and Sorensen similarity indexes were calculated. In this study, 35 species of oak gall wasps on the oak tree species of Quercus infectoria, Q. brantii and Q. libani were identified. Most galls were observed on Q. infectoria. All of the collected oak gall wasp species belonged to the genera Andricus Hartig, Cynips L., Neuroterus Hartig, Biorhiza Westwood, Pseudoneuroterus Kinsey, Chilaspis Mayr and Aphelonyx Mayre. The genus Andricus included 23 species of oak gall wasps. The highest Simpson and Shannon indexes were recorded for the spring galls of Mir-Abad and for the fall galls of Ghabre-Hossein and Dar-Ghabr regions. The Sorensen similarity index reached its peak for the spring galls (sexual generation of oak gall wasps) of Ghabre-Hossein and Mir-Abad and for the fall galls (asexual generation of oak gall wasps) of Ghabre-Hossein and Dar-Ghabr. The distribution of oak species and subspecies, and geographical and climatic aspects are believed to be among the key factors for the species diversity of oak gall wasps
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