Janssen effect and the stability of quasi 2-D sandpiles

We present the results of three dimensional molecular dynamics study of global normal stresses in quasi two dimensional sandpiles formed by pouring mono dispersed cohesionless spherical grains into a vertical granular Hele-Shaw cell. We observe Janssen effect which is the phenomenon of pressure saturation at the bottom of the container. Simulation of cells with different thicknesses shows that the Janssen coefficient $\kappa$ is a function of the cell thickness. Dependence of global normal stresses as well as $\kappa$ on the friction coefficients between the grains ($\mu_p$) and with walls ($\mu_w$) are also studied. The results show that in the range of our simulations $\kappa$ usually increases with wall-grain friction coefficient. Meanwhile by increasing $\mu_p$ while the other system parameters are fixed, we witness a gradual increase in $\kappa$ to a parameter dependent maximal value

The effect of Aloe vera extract on humoral and cellular immune response in rabbit

Some plant polysaccharides are well known to possess immunostimulatory effects. Aloe vera possesses confirmed curative or healing actions. The aim of this study was to evaluate the effect of the administration of A. vera plant extract on cellular and humoral immune response in rabbits. 20 healthy male New Zealand white rabbits were randomly divided into five treatment groups: Groups consisted of: 1) control group (normal saline); 2) A. vera control; 3) vaccine control; 4) 50 mg A. vera extract + vaccine; 5) 150 mg A. vera extract + vaccine. The used vaccine was for myxomatosis. Blood samples were obtained at four time points: days 0, 7, 14 and 21 of the study. CD4+ and CD8+ lymphocytes frequency and serum immunoglobulin concentrations were evaluated. According to the results, oral administration of A. vera affected the composition of lymphocyte subsets and serum immunoglobulins positively. These findings demonstrated that A. vera may stimulate both cellular and humoral immune responses after immunization.Key words: Aloe vera, cellular and humoral immune, immunization, rabbits

A Mixture of Regressions Model of COVID-19 Death Rates and Population Comorbidities

As the COVID-19 pandemic spread worldwide, it has become clearer that prevalence of certain comorbidities in a given population could make it more vulnerable to serious outcomes of that disease, including fatality. Indeed, it might be insightful from a health policy perspective to identify clusters of populations in terms of the associations between their prevalent comorbidities and the observed COVID-19 specific death rates. In this study, we described a mixture of polynomial time series (MoPTS) model to simultaneously identify (a) three clusters of 86 U.S. cities in terms of their dynamic death rates, and (b) the different associations of those rates with 5 key comorbidities among the populations in the clusters. We also described an EM algorithm for efficient maximum likelihood estimation of the model parameters

Religious attitudes and spiritual health among elderly inpatient adults in Shahrekord hospitals

Background and Objectives: Human is a multidimensional creature and spiritual domain is the central dimension which has an undeniable effect on gaining health. The most important part of nursing care with family based approach is to help people in achieving optimal level of health. On the other hand, religious attitudes and spiritual health is an important domain of life in ageing period. Therefore, this study was conducted to assess the religious attitudes and spiritual health among elderly inpatients in Shahrekord hospitals. Methods: This descriptive correlational study was conducted in 1392 in Shahrekord hospitals. A total of 308 geriatric patients who were admitted to a surgical ward, were recruited through random sampling. Two sets of questionnaires regarding religious and spiritual health were used as the instruments. After collecting the data, descriptive (frequency, mean, variance, standard deviation) and analytical (independent t test, Pearson correlation) statistics were used by SPSS statistical software. Results: The results showed that 68.8% of patients possessed large religious attitude with an average of 140.68 ±30.14. Spiritual health in 51.3 percent of samples was described to be low while the obtained average score was 86.18 ± 16.61. However, Pearson test showed that there is a positive significant correlation between religious attitudes and spiritual health (r =0.83, P =0.05). Conclusions: The present study revealed that there is a significant relationship between religious attitudes and spiritual health and people with high religious attitudes have high spiritual health

Collection, evaluation and classification of Iranian confectionary sunflower (Helianthus annuus L.) populations using multivaraite statistical techniques

Characterization of confectionary sunflower germplasm resources is critical to their efficient collection and management as well as for breeding programs. Thirty six (36) confectionary sunflower populations originating from different regions of Northwest Iran were characterized using 15 agro-morphological traits. Among the studied traits, high coefficients of variation were observed for harvest index (48.36), seed yield (42.07) and petiole length (41.63). Cluster analysis using Ward's method classified the 36 populations into four groups. A large number of genotypes was placed in cluster III (16 genotypes) followed by cluster I (13), cluster IV (4) and cluster II (3). Clusters I, III and VI include genotypes from different sources indicating no association between clustering pattern and eco-geographical distribution of genotypes. The maximum inter-cluster distance of 9.03 was observed between clusters II and VI indicating the possibility of high heterosis if individuals from these two clusters are cross-bred. Principal component analysis resulted in the first four components with Eigen value greater than one accounting for 78% of the total variation. The results of PCA were closely in line with those of cluster analysis. These results can now be used by breeders to develop high yielding sunflower hybrids.Key words: Cluster analysis, confectionary sunflower, genetic variability, principal component analysis

A Pareto Front Approach to Bi-objective of Distillation Column Operation Using Genetic Algorithm

In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using Genetic algorithm. First, the simulation of a distillation column is performed by using the shortcut results and irreversibility in each tray is obtained. The area beneath the exergy loss profile is used as Irreversibility Index for exergy criteria. Then, two targets optimization algorithm (SA, Simulated Annealing) is used to maximize recovery and minimize irreversibility index in a column by six different variables (Feed Condition, Reflux Rate, Number of theoretical stage, Feed Trays (Feed Splitting, three variables)). SA uses one objective function for the purpose or alters two targets optimization to one target optimization. Then, GA optimization algorithm is used for two targets optimization except Pareto set which is used instead of objective function; finally, the results are compared with SA results. Then, one pump-around is considered to obtain better results (OPT2). Irreversibility index criterion is compared with exergetic efficiency, constant and variable feed composition splitters are considered.Key words: Exergy analysis; Irreversibility index; Genetic algorithm; Process optimization; Distillation colum

A comparative analysis of classifiers in cancer prediction using multiple data mining techniques

In recent years, application of data mining methods in health industry has received increased attention from both health professionals and scholars. This paper presents a data mining framework for detecting breast cancer based on real data from one of Iran hospitals by applying association rules and the most commonly used classifiers. The former were adopted for reducing the size of datasets, while the latter were chosen for cancer prediction. A k-fold cross validation procedure was included for evaluating the performance of the proposed classifiers. Among the six classifiers used in this paper, support vector machine achieved the best results, with an accuracy of 93%. It is worth mentioning that the approach proposed can be applied for detecting other diseases as well

A multi-period location-allocation model for nursing home network planning under uncertainty

This paper proposes a multi-period location- allocation problem arising in nursing home network planning. We present a strategic model in which the improvement of service accessibility through the planning horizon is appropriately addressed. Unlike previous research, the proposed model modifies the allocation pattern to prevent unacceptable deterioration of the accessibility criterion. In addition, the problem is formulated as a covering model in which the capacity of facilities as well as the demand elasticity are considered. The uncertainty in demands within each time period is captured by adopting a distributionally robust approach. The model is then applied to a real case study for nursing home planning network in Shiraz city, Iran

Microfluidics as efficient technology for the isolation and characterization of stem cells.

The recent years have been passed with significant progressions in the utilization of microfluidic technologies for cellular investigations. The aim of microfluidics is to mimic small-scale body environment with features like optical transparency. Microfluidics can screen and monitor different cell types during culture and study cell function in response to stimuli in a fully controlled environment. No matter how the microfluidic environment is similar to in vivo environment, it is not possible to fully investigate stem cells behavior in response to stimuli during cell proliferation and differentiation. Researchers have used stem cells in different fields from fundamental researches to clinical applications. Many cells in the body possess particular functions, but stem cells do not have a specific task and can turn into almost any type of cells. Stem cells are undifferentiated cells with the ability of changing into specific cells that can be essential for the body. Researchers and physicians are interested in stem cells to use them in testing the function of the body's systems and solving their complications. This review discusses the recent advances in utilizing microfluidic techniques for the analysis of stem cells, and mentions the advantages and disadvantages of using microfluidic technology for stem cell research