Properties Of Different Groups Research Articles

Psychometric evaluation and validation of Urdu Social Rank Scale for women with infertility in Pakistan.

Infertility negatively affects nearly all aspects of women's life and is a source of demotion in the rank/status of women that they have achieved after marriage. This social rank/status demotion due to infertility may result in depression and several other psychopathologies. No extant instrument is available to measure the phenomenon of social rank in women with infertility in Pakistan. The aim of the current study was to evaluate the psychometric properties and validate the Social Rank Scale for women experiencing infertility in Pakistan. This study was conducted in four phases. The data were collected from women with primary infertility who visited hospitals all over Pakistan from 2016 to 2018. Social Rank Scale for Women with Infertility (SRS-WI) comprising of two scales, the Social Comparison Scale for Women with Infertility (SCS-WI) and the Submissive Behavior Scale for Women with Infertility (SBS-WI), was developed. The factor structure of 37 items of SCS-WI and of 21 items of SBS-WI was determined through exploratory factor analysis (EFA) on a sample of 215 women with primary infertility with an age range of 20-45 years (Mage = 31.03; SD = 6.18). Principal component analysis with varimax rotation method yielded a three-factor solution for SCS-WI, and 32 items were retained for SCS-WI that accounted for 62.38% variance. For SBS-WI, a uni-factor solution was obtained, and 20 items were retained for SBS-WI, which collectively accounted for 42.01% variance. The factor structure for both scales was confirmed via confirmatory factor analysis among a sample of 210 participants with good model fit indices. The study provides acceptable psychometric properties of the SRS-WI in Pakistan. Testing of psychometric properties in different groups of samples would justify the generalized use of the instrument.

Математическое моделирование рекомендательной системы и обработка данных телекоммуникационной компании с помощью моделей машинного обучения

The purpose of the study is to develop data modeling methods for projecting recommender algorithms using doubly stochastic autoregressive models of random processes and checking their adequacy by applying machine learning algorithms to cluster users in a simulated data set and predict probabilities of interest. Research methods. The article discusses the methods used in the construction of recommender systems. At the same time, the problem of modeling user behavior using a doubly stochastic model is considered. This model is proposed for generating artificial data. The doubly stochastic model allows generating non-stationary processes, thus creating users with different probabilistic properties in different groups of objects of interest. After that, artificially created users (and their activity) are clustered based on a modified K-means algorithm. The main modification is the need for automatic pre-estimation of the number of clusters, and not its choice by a person. Next, the behavior of representatives of each user group for new events is modeled. Based on the generated information and training data, the problem of predictiing and ranking the services offered is solved. At the same time, at the first stage, the use of regression models is sufficient to assign users to a group and form offers for this user. Results of the study. On the training data in 2 clusters, high determination indices were achieved, which indicates approximately 90% of the explained variance when using the proposed doubly stochastic model. Particular attention is paid to the work of modern recommender systems on the example of the Disco system developed by Yandex. In addition, pre-processing and preliminary analysis of data from the real sector was performed, namely, the data of a telecommunications company are being studied. For the purpose of issuing relevant proposals for communication services, a test recommender system has been developed. Conclusion. Thus, the main results of the work include a mathematical model that simulates the reaction of users to various services, as well as a logistic regression model used to predict the probability of a user's interest in a new service. Based on predicted probabilities, it is not difficult to rank new proposals. Approbation on the synthesized data showed the high efficiency of the model.

Optical properties of sea buckthorn drinks as the main physical characteristic of their quality

The hue and color intensity are referred to optical properties of soft drinks made from fruit and berry raw materials that are crucial for control of their quality and identification. In addition, a natural color of raw materials is attractive for consumers since it provides a more appealing natural appearance to the drink. Sea buckthorn drinks are prone to browning during storage due to the specific chemical composition of berries, which necessitates the control of their optical properties. The study aimed to investigate optical properties of different groups of sea buckthorn drinks during storage, namely clarified juice and dry wine material made from sea buckthorn of the Chuiskaya variety, and to establish the possibility of using some calculated parameters that characterize the drink color in techno-chemical control practices. Optical properties of drink samples were determined with a UV-1800 spectrophotometer, and the values obtained were used to calculate the parameters of intensity, hue, and yellowness. It is shown that physical methods can be used to control optical properties of sea buckthorn drinks in order to objectively assess the color as one of the basic organoleptic parameters of drink quality. It is established that the results of optical analysis are consistent with visual assessment of the sea buckthorn drink samples during storage, which opens up prospects for implementation of this research method in the laboratories of enterprises involved in processing of sea buckthorn to produce various groups of drinks.

Аналіз можливостей вибору та адаптації алгоритмів чисельної реалізації диференціальних динамічних моделей

The paper analyzes possibilities of selection and adaptation of computational algorithms in the implementation of differential dynamic models, i.e. in solving ordinary differential equations. The limited resources of computer-integrated systems determine the requirements for the computing and control systems’ performance, which indicates the urgency of target selection or adaptation of numerical methods for solving equations of dynamics objects. The process of improving numerical methods has a long history and does not stop until now. The growing complexity of the studied dynamic objects has led to the development of implicit methods for dynamics’ numerical analysis, but research shows that the use of implicit methods is justified, if we assume the use of a significant step of integrating the source system. In addition, it is found that the available results on the formalization of power methods for solving algebraic equations in the integration step and their adaptation in computer use are still insufficient to address their use in the study of complex dynamic objects. The integration step upper limit indicates the inexpediency of using high-order Runge-Kutta methods for the purposes of modeling the dynamics of the studied systems in real time. Accordingly, with regard to quadrature methods, the problem of formalizing the construction is not solved in general. Thus, the task of selecting the optimal method can be formulated as follows: to determine the numerical method for the modeled object’s dynamics equations’ integration, for which the required speed of the control system can be achieved, and the error of solving the dynamics equations does not exceed the specified value. The analysis of the properties of different groups of numerical methods is carried out, which makes it possible to conclude that in choosing the best method the initial set of the required methods should be formed based on the single-step methods of the Runge-Kutta type and the quadrature methods no higher than the fourth order. In implementing stationary modes, the initial group of methods should also include the multi-step methods — explicit and the «forecast-correction» type

Separation of Components in the Group Analysis of the Organic Matter of Peat: A Review

Methods and conditions for the separation of different groups of organic matter in the group analysis of peat, which have been developed and improved in different countries over more than 100 years, are analyzed. Data on the influence of the type of extractant, temperature, pH, extraction time, and other factors on the yield and properties of different groups of organic matter from peat are presented. It is shown that the separation of some organic matter components can significantly change the yield, molecular structure, and properties of other components. The degrees of changes in components with the use of different group analysis methods are different. To eliminate these disadvantages, it is necessary to search for instrumental techniques for the quantitative measurement of the concentrations of the main components in the organic matter of peat instead of extraction methods.

Influence of Various Hydrocarbon Groups on the Effectiveness and Environmental Characteristics of Anti-Collapse Agent for Drilling Fluids

With the country’s increasing requirements on environmental performance of drilling fluid treatment agents, which the traditional anti-collapse agent design has been unable to meet, research on environmentally-friendly anti-collapse agent molecular design is becoming increasingly important. This paper studies the effect of different types of groups on the anti-collapse characteristics and environmental protection performance of anti-collapse agents. The core immersion test and linear expansion test were used to evaluate the anti-collapse properties of different groups. The experimental results show that the anti-collapse properties of different groups of the same carbon chain length decrease in the following order: amino group > amide group > hydroxy group > carboxyl group. The anti-collapse properties of different amino groups of organic amines change in the following order: primary amine > secondary amine > tertiary amine. At the same time, the potassium dichromate method, the dilution and inoculation method, and the luminescent bacteria method were used to measure the COD value, BOD value, and EC50 value of the anti-collapse agents with different groups, and the experimental results show that the biodegradability decreases in the following order: hydroxyl group > carboxyl group > amide group > amino group. Biological toxicity decreases in the following order: hydroxyl group > amide group > carboxyl group > amino group. The biodegradability value of different amino groups of organic amines increases in the following order: primary amine secondary amine > tertiary amine.

INITIAL DATA FOR ANALYSIS OF ELECTROMECHANICAL SYSTEM THE INTERCONNECTED STANDS

For continuous rolling mills one of the most important technical issues is to configure the speed interrelated stands line. The basic law when setting speed rolling of the group of sequentially connected mill stands is the constancy of the volume of rolled metal S1*V1=S2*V2=S3*V3=...=SiVi . Setting the desired coherent frequencies of rotation of the rolls carried by the mill operator with the drive control specific panel. The electric drive system driven Converter (TP) – DC motor (D) with independent excitation allows operation in two zones (nн>n>n0), which gives the possibility of rapid adjustment of speed of rolling, in violation of the law of constancy of volume rolled. Construction properties of different groups of stands (roughing, intermediate, finishing) can have a considerable effect on the dynamic interaction and, as a consequence, loads on the interconnected Electromechanical systems stands. To assess the interaction of Electromechanical systems of interconnected mill stands it is recommended to first conduct a research on mathematical models to identify the most loaded units with their further study on a real mill using the methods of thermal and vibration field.

Carbon-containing catalysts for the hydroprocessing of oil fractions: A review

Over the last 20 years, carbon-containing catalysts prepared using carbonized aluminum oxide and various carbon-based materials as carriers, along with metal carbides as active components, have been widely studied in the hydroprocessing of oil fractions. In this work, the properties of different groups of carbon-containing catalysts are discussed. The difficulties of using carbon-based carriers caused by their need for chemical pretreatment (oxidation and leaching), and the application of water–organic infiltrating solutions to form active catalyst components in finely dispersed form, is shown.

Cardiogenic shock: can the well-forgotten old become the new?

Cardiogenic shock (CS) is considered to be the most severe variant of acute heart failure. It occurs against the background of myocardial infarction or non-coronary myocardial disease with the loss of 40-50% contractile ability by the left ventricular mass and acute heart overload of another genesis. The marked decrease of blood pressure is accompanied by generalized impairment of microcirculation in all organs. The acting recommendations for emergency assistance suggest to recover blood perfusion pressure in ischemic tissues by inotropic drugs vasopressors, crystalloids that eliminate hypovolemia. However, the recovery of hemodynamic parameters using these medicines is accompanied by increased load on the myocardium and causes only a slight temporary increase of blood pressure. Death rapidly occurs in almost 100% of cases because offast heart energy depletion There is no doubt that stable recovery of hemodynamic in CS is not possible without sustainable recovery of myocardial contractility. The effective discharge of myocardium by drugs should not be accompanied by deterioration of blood supply to peripheral organs. Taking into account the literature data and pharmacological properties of different groups of drugs, there is every reason to believe that nitroglycerin may be the drug of choice for the treatment of cardiogenic shock. It reduces myocardium preload without impairment of microcirculation in the peripheral organs. This conclusion is preliminary and requires verification in randomized trials.

Opportunities and prospects of the phytotherapy of different forms of mastopathy

Taking into consideration the frequency of breast pathology and limited possibilities of pharmacological treatment, question of medicinal plants connectivity to complex therapy is very relevant. In order to identify prospects of herbal treatment of mastopathy, the article analyzes key aspects of pathogenesis of mastopathy various forms, which may be affected by phytopreparations. The literature on this issue gives pharmacological properties of different groups of gonadotropin plants based on their impact on different pathogenetic changes in women, that occur in this disease and generalize comprehensive approach on the formation of lines and principles of phytotherapy in this condition using groups of plants with different pharmacological properties. It is determined, that in some situations, herbalism not possible or permissible, but generally it is strictly necessary and, in fact, it is the only effective therapeutic method, also relatively safe with proper selection of combinations and under doctor's control, who is a specialist in phytotherapy. This testifies prospects of herbal medicine in mastopathy.

Revisión de estudios de la Escala de Ansiedad y Depresión Hospitalaria (HAD) en muestras españolas.

<em>Introduction:</em><strong> </strong>The Hospital Anxiety and Depression Scale (HADS, Zigmond and Snaith, 1983) has become a popular clinical instrument designed to assess anxiety and depression. Evidence of HADS’ good screening properties applied to several samples has been found. HADS seems to be as good screening properties as other tools. Different studies in Spanish sample tested its psychometric properties, including also their cut-offs points, specificity and sensitivity. Our <em>aim </em>is to unify the results of studies in Spanish population specifying guidelines regarding their applicability and interpretation of their cut-off points. <em>Material and method</em>: bibliographic review. <em>Results:</em><strong> </strong>15 articles were selected, a) HADS confirms its optimal psychometric properties in different groups, b) HADS shows some variability in proposed cut-off points for different groups, c) A number of items shown weak factor loading and item-test. <em>Discussion:</em> These items should be reconsidered for new proposals of a shortened final scale. We suggest attending at distress total scale.

Development of a Measure to Assess Healthcare Providers’ Implementation of Patient‐Centered Care

Patient-centered care (PCC) is a vaguely defined element of high-quality care, which precludes its consistent and precise operationalization. A conceptualization of PCC was derived from the literature and guided the development of an instrument to assess implementation of PCC by healthcare providers. The items of the instrument capture specific activities that reflect three components of PCC: holistic, collaborative, and responsive care. This paper reports on the measure's content and construct validity and reliability. Content validity was evaluated in a sample of 11 nurse practitioners who rated the relevance of each items' content in reflecting the respective component of PCC. The content validity index (CVI) was estimated. Construct validity and internal consistency reliability were examined in a survey of 149 nurse practitioners employed in acute care institutions, using factor analysis and the KR-20 coefficient, respectively. The CVIs were 100% for the three subscales assessing the holistic, collaborative, and responsive care components of PCC. The items in each subscale loaded on one factor. The KR-20 coefficients were .66, .70, and .42, respectively. Overall, the majority (>70%) of respondents indicated performance of the activities comprising the three components of PCC. The PCC measure demonstrated acceptable psychometric properties. The low variance in responses, which is anticipated for instruments assessing fidelity of intervention implementation, accounts for the low reliability coefficients. Additional testing of the measure's psychometric properties in different groups of healthcare providers is warranted. The measure can be used to monitor healthcare providers' implementation of PCC in their usual practice.

Patterned expression of ion channel genes in mouse dorsal raphe nucleus determined with the Allen Mouse Brain Atlas

The dorsal raphe nucleus (DR) is the major source of serotonin (5-hydroxytryptamine, 5-HT) in the forebrain and dysfunction of this midbrain structure is implicated in affective disorders. The DR is composed of several types of 5-HT and non-5-HT neurons and their excitable-membrane properties are heterogeneous and overlapping. In order to understand how these properties may be generated, we examined the mRNA expression patterns of voltage- and ligand-gated ion channels in the DR using the Allen Mouse Brain Atlas. Since DR cytoarchitecture is organized with respect to the midline, we sought to identify genes that were expressed in a pattern with respect to the midline, either enriched or depleted, rather than those that were homogenously expressed throughout the DR. Less than 10% of the screened genes for voltage-gated ion channels showed patterned expression within the DR. Identified genes included voltage-gated sodium channel beta subunits, potassium channels, P/Q-, N-type calcium channels, as well as the alpha2/delta-1 calcium channel. Several voltage-gated chloride channels were also identified, although these may function within intracellular compartments. Of the ligand-gated ion channels examined, 20% showed patterned expression. These consisted primarily of glutamate and GABA-A receptor subunits. The identified genes likely contribute to unique excitable properties of different groups of neurons in the DR and may include novel pharmacologic targets for affective disorders.

Estimation of mechanical properties of articular cartilage with MRI – dGEMRIC, T2 and T1 imaging in different species with variable stages of maturation

Magnetic resonance imaging (MRI) is one of the most potential methods for non-invasive diagnosis of cartilage disorders. Several methods have been established for clinical use; T(1) relaxation time imaging with negatively charged contrast agent (delayed gadolinium enhanced MRI of cartilage, dGEMRIC) has been shown to be sensitive to proteoglycan (PG) content while T(2) relaxation time has been demonstrated to express properties of the collagen fibril network. The use of native T(1) relaxation time has received less attention. In the present study, magnetic resonance (MR) parameters of different types of patellar cartilage were studied with respect to the mechanical properties of the tissue. The general usefulness of the parameters to predict mechanical properties was investigated using cartilage from different species and stages of maturation. dGEMRIC, T(2) and native T(1) relaxation times of healthy mature human, juvenile porcine and juvenile bovine articular cartilage samples were measured at 9.4T at 25 degrees C. Mechanical properties (Young's modulus and dynamic modulus) of the samples were measured in unconfined compression using a material testing device. The relationships between MRI and mechanical parameters and potential differences between different types of tissues were tested statistically. Significant, but varying relationships were established between T(1) or T(2) relaxation time and mechanical properties, depending on tissue type. The values of mechanical parameters were in line with the results previously reported in the literature. Unexpectedly, dGEMRIC showed no statistically significant association with the mechanical properties. Variation in the assumption of native T(1) value did not induce significant differences in the calculated contrast agent concentration, and consequently did not affect prediction of mechanical properties. For patellae, a complex variation in the relationships between T(2) and mechanical properties in different groups was revealed. The results support the conclusion that juvenile animal tissue, exhibiting a highly complex collagenous architecture, may not always serve as a realistic model for mature human tissue with a typical three-zone network organization, and other than bulk metrics are required for the analysis of cartilage T(2). As the multilayered collagen network can strongly control the mechanical characteristics of juvenile tissue, it may mask the mechanical role of PGs and explain why dGEMRIC could not predict mechanical parameters in patellar cartilage.

Insect gonadotropic peptide hormones: some recent developments

Gonadotropic peptides are a new generation of peptide hormone regulators of insect reproduction. They have been isolated from ovaries, oviducts, or brains of insects. The subject of this paper is insect peptides that exert stimulatory or inhibitory effects on ovarian development and oocyte maturation. On the basis of the literature data and the results of our investigations, the structure and biological properties of different groups of peptides are presented.

Sources of heterogeneity in distributions with ordered categorical variables

The chi-squared statistic is used to test the homogeneity for several groups in a contingency table. However, it may be inappropriate to apply the test when ordinal categories are involved. If it can be assumed that the ordinal categorical variables are realizations of underlying continuous random variables, then it is possible to study the properties of different groups in a relative sense. Assuming that the distributions of the continuous variables are in the same family and that the thresholds that define the categories are invariant across groups, we propose a procedure to test homogeneity and to address the sources of heterogeneity in different groups. An example based on a real data set is used to demonstrate the practical applicability of the suggested method.