675 research outputs found

    A seismic-driven 3D model of rock mechanical facies: An example from the Asmari reservoir, SW Iran

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    Asmari Formation is one of the most prolific and important hydrocarbon reservoirs in Iran. This formation in the Cheshmeh-Khosh oilfield shows mixed carbonate-siliciclastic lithology and its elastic modulus changes are correlatable with facies changes. To address these changes, we investigated the relation between sedimentary environment (facies) and texture with various elastic moduli. The Young's modulus shows higher correlation with the facies changes. Data from three wells are analyzed and used for the construction of rock mechanical facies. Based on elastic properties, facies and texture changes as well as petrophysical characteristics seven rock mechanical facies (RMFs) are recognized in the studied formation. To predict RMFs at inter-well spaces more efficiently and capturing the lateral formation property variationsa 3D rock mechanical facies model is constructed based on seismic attributes. In this method, RMFs are correlatable between the studied wells and mappable by seismic attribute in the field scale. Finally, the distribution of RMFs and their related properties is investigated in the studied field

    Intense physical activity is associated with cognitive performance in the elderly

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    Numerous studies have reported positive impacts of physical activity on cognitive function. However, the majority of these studies have utilised physical activity questionnaires or surveys, thus results may have been influenced by reporting biases. Through the objective measurement of routine levels of physical activity via actigraphy, we report a significant association between intensity, but not volume, of physical activity and cognitive functioning. A cohort of 217 participants (aged 60–89 years) wore an actigraphy unit for 7 consecutive days and underwent comprehensive neuropsychological assessment. The cohort was stratified into tertiles based on physical activity intensity. Compared with individuals in the lowest tertile of physical activity intensity, those in the highest tertile scored 9%, 9%, 6% and 21% higher on the digit span, digit symbol, Rey Complex Figure Test (RCFT) copy and Rey Figure Test 30-min recall test, respectively. Statistically, participants in the highest tertile of physical activity intensity performed significantly better on the following cognitive tasks: digit symbol, RCFT copy and verbal fluency test (all P<0.05). The results indicate that intensity rather than quantity of physical activity may be more important in the association between physical activity and cognitive function

    Comparison of auditory steady-state responses with conventional audiometry in older adults

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    Behavioral measures, such as pure-tone audiometry (PTA), are commonly used to determine hearing thresholds, however, PTA does not always provide reliable hearing information in difficult to test individuals. Therefore, objective measures of hearing sensitivity that require little-to-no active participation from an individual are needed to facilitate the detection and treatment of hearing loss in difficult to test people. Investigation of the reliability of the auditory steady-state response (ASSR) for measuring hearing thresholds in older adults is limited. This study aimed to investigate if ASSR can be a reliable, objective measure of frequency specific hearing thresholds in older adults. Hearing thresholds were tested at 500 Hz, 1000 Hz, 2000 Hz, and 4000 Hz in 50 participants aged between 60 and 85 years old, using automated PTA and ASSR. Hearing thresholds obtained from PTA and ASSR were found to be significantly correlated (p \u3c .001) in a cohort consisting of participants with normal hearing or mild hearing loss. ASSR thresholds were significantly higher as compared to PTA thresholds, but for the majority of cases the difference remained within the clinically acceptable range (15 dB). This study provides some evidence to suggest that ASSR can be a valuable tool for estimating objective frequency-specific hearing thresholds in older adults and indicate that ASSR could be useful in creating hearing treatment plans for older adults who are unable to complete behavioral PTA. Further research on older adults is required to improve the methodological features of ASSR to increase consistency and reliability, as well as minimize some of the limitations associated with this technique

    The effect of magnesium on bioactivity, rheology and biology behaviors of injectable bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane nanocomposite-paste for small bone defects repair

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    Injectable bioactive glass-based pastes represent promising biomaterials to fill small bone defects thus improving and speed up the self-healing process. Accordingly, injectable nanocomposite pastes based on bioactive glass-gelatin-3-glycidyloxypropyl trimethoxysilane (GPTMS) were here synthesized via two different glasses 64SiO2. 27CaO. 4MgO. 5P2O5 (mol.%) and 64SiO2.31CaO. 5P2O5 (mol.%). In particular, the effects of MgO on bioactivity, rheology, injectability, disintegration resistance, compressive strength and cellular behaviors were investigated. The results showed that the disintegration resistance and compressive strength of the composite were improved by the replacement of MgO; thus, leading to an increase in the amount of storage modulus (G′) from 26800 to 43400 Pa, equal to an increase in the viscosity of the paste from 136 × 103 to 219 × 103 Pa s. Since the release rate of ions became more controllable, the formation of calcite was decreased after immersion of the Mg bearing samples in the SBF solution. Specimens’ cytocompatibility was firstly verified towards human osteoblasts by metabolic assay as well as visually confirmed by the fluorescent live/dead staining; finally, the ability of human fibroblasts to penetrate within the pores of 3D composites was verified by a migration assay simulating the devices repopulation upon injection in the injured site

    Investigation of Natural Effective Gamma Dose Rates case study: Ardabil Province in Iran

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    Gamma rays pose enough energy to form charged particles and adversely affect human health. Since, the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined, natural background gamma dose rates and corresponding annual effective doses were determined for selected cities of Ardabil province from 2009 to 2010. Outdoor gamma dose rates were measured using an Ion Chamber Survey Meter in 105 locations in selected districts. Average absorbed dose for Ardabil, Sar-Ein, Germy, Neer, Shourabil Recreational Lake, and Kosar were determined as 265, 219, 344, 233, 352, and 358 nSvh-1, respectively. Although dose rates recorded for Germi and Kosar are comparable with some areas with high natural radiation background, however, the dose rates in other districts are well below the levels reported for such locations. Average annual effective dose due to indoor and outdoor gamma radiation for Ardabil province was estimated to be 1.73 (1.35-2.39) mSv, which is on average 2 times higher than the world population weighted average

    Personality characteristics are independently associated with prospective memory in the laboratory, and in daily life, among older adults

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    Prospective memory (PM) can deteriorate with age and adversely influence health behaviours. Research suggests that personality is related to PM in healthy young adults, but we know little about the role of personality in the PM amongst older adults. Community-dwelling older adults (N=152) completed the NEO Five-Factor Inventory-3 and PM measures. After adjusting for demographics and general cognition, higher neuroticism and lower levels of openness were independently associated with lower objectively-measured time- and event-based PM. Lower conscientiousness was the only personality predictor of self-reported everyday PM failures. Findings indicate that personality plays a role in PM functioning in the laboratory and daily life

    Rural residency has a protective effect and marriage is a risk factor for NAFLD

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    Background: Non-alcoholic fatty liver disease (NAFLD) is considered the leading cause of liver disease worldwide. Although many previous studies have evaluated the potential risk factors of NAFLD, few studies have determined the effect of residency or marriage status on NAFLD. Objectives: We aim to evaluate whether residency and marriage status increased the risk factors for NAFLD. Materials and Methods: We utilized data from 5,052 participants, 18 years and older, from a cohort study conducted using 6,140 participants in northern Iran. The population was divided into 16 subgroups according to sexandage; the age groupshadan interval of 10 years. We randomly selected the subjects from each subgroup in proportion to the size of each subpopulation group. Logistic regression analyses were conducted on NAFLD as an outcome of marriage status, residency (rural vs. urban), and other potential risk factors. Results: We found that NAFLD had an inverse association with rural living in men (OR = 0.513, 0.422 - 0.622, P value < 0.001) and women (OR = 0.431, 0.345 - 0.539, P value < 0.001). Furthermore, we determined that NAFLD had a direct association with marriage status for men (OR = 2.770, 2.004 - 3.831, P value < 0.001) and women (OR = 1.241, 1.033 - 1.490, P value = 0.0209). Conclusions: While rural living has a protective effect on NAFLD, marriage may be a potential risk factor for this condition. © 2016, Kowsar Corp

    A qualitative approach to identify barriers to multi-professional teamwork among medical professors at Iranian teaching hospitals

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    Background: In some cases of diseases, such as infectious, neurological and chronic ones prevention and treatment is complex. Therefore, a single medical specialty alone cannot effectively manage treatment of patients due to health care needs of them and complexities of treatment. Instead, a team composed of different healthcare disciplines with effective, continuous, and organized communication must follow up various aspects of patient care. In this regard, the present qualitative study aimed to shed light on the experiences of clinical teachers of multi-professional teamwork barriers within Iranian teaching hospitals. Methods: In this qualitative research, the experiences of medical clinical teachers of multi-professional teamwork barriers within teaching hospitals were explained. Sampling was theoretical and the data were collected from experienced clinical teachers and medical students studying at several Universities of Medical Sciences through semi-structured interviews and observation, which were continued until data saturation. Fifteen clinical teachers and five medical students participated in the study. The interviews were analyzed using conventional content analysis. Results: Three main categories were extracted. The first category was �enhancing the culture of interdisciplinary education� included �paving the way for an interdisciplinary culture�, �enhancing teamwork culture�, and �having a general view of medical sciences instead of specialization�. The second category was �barriers of interdisciplinary education� included �influence of the dominant culture of specialization in society�, �poor interdisciplinary education infrastructure�, and �individualism as a value of society�. And the third category was �consequences of specialization� included �medical sciences education under the shadow of specialization�, �possibility to harming patients�, and �distrust of society in the services provided by the 1st and 2nd level centers�. Conclusion: It seems that attitudinal barriers, teamwork difficulties, and the culture of individualism are evident in Iran; more, roles of the healthcare team and the status of each member is not clear. Designing interactive curriculum and arranging clinical settings to facilitate exchange of ideas among clinical teachers and students of different disciplines, is a step forward to achieving a common value concept, language, and common perception, and establishing cooperation and understanding among disciplines involved, which leads to further understanding of the professional responsibilities of other disciplines. © 2021, The Author(s)
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