27 research outputs found
The Lorentz force between D0 and D6 branes in string and M(atrix) theory
We use different techniques to analyze the system formed by a D0 brane and a
D6 brane (with background gauge fields) in relative motion. In particular,
using the closed string formalism of boosted boundary states, we show the
presence of a term linear in the velocity, corresponding to the Lorentz force
experienced by the D0 brane moving in the magnetic background produced by the
D6 brane. This term, that was missed in previous analyses of this system, comes
entirely from the R-R odd spin structure and is also reproduced by a M(atrix)
theory calculation.Comment: 13 pages, plain LaTeX; some clarifying comments and a reference adde
Статистический анализ производственных процессов
To analyze the synchronization of machine-building production processes, a statistical approach is used on the correctness of the choice of parameters. The accuracy of the parameters is achieved by modeling. This method allows checking how correctly the parameters are selected and whether they ensure uninterrupted operation of production. Statistical analysis of parameters gives information on failures in a particular production unit, on violations of the synchronization of production processes, technological processes. With the help of statistical characteristics, it is possible to evaluate production as a whole. Statistical multidimensional analysis of complex production data allows to analyze the work of individual units, production blocks. The cluster analysis has been carried out by the method of K-medium production process with minimization of the total error probability. A geometric interpretation of the results of cluster analysis of production processes is given in the paper. The influence of factors on the work of production has been determined in the paper. The index factorial method with a different comparison base and different weights has been applied. The hypothesis about the adequacy of the model of production processes has been tested. A statistical analysis of the complex data of the production process has been carried out in the search for optimal solutions in the case of uncertainty and in conditions of risk using the following methods: Bayes, Laplace and Germeyer using the simplex method. The network methods of decision-making have been used in the paper. Statistical methods with the help of mathematical modeling have substantiated the optimal sizes of both individual parts and volumes of local warehouses, so that there were no delays in the transfer of production processes, disruptions in work, downtime of working equipment. In this case, the criterion for the optimality of production volumes can be the minimum of total losses from idle time of individual units and production blocks to the possibility of disruption of the synchronous process modes due to lack of equipment (arising production pockets) or due to long-used outdated units.Для анализа синхронизации процессов машиностроительного производства используется статистический подход о правильности выбора параметров. Точность величин достигается путем моделирования. Данный способ позволяет проверить, насколько правильно выбраны параметры и обеспечивают ли они бесперебойную работу производства. Статистический анализ величин дает информацию о сбоях в том или ином узле производства, о нарушениях синхронизации процессов производства, технологических процессов. С помощью статистических характеристик можно оценить производство в целом. Статистический многомерный анализ сложных данных о производстве позволяет анализировать работу отдельных узлов и блоков производства. Проведен кластерный анализ методом K-средних процессов производства с минимизацией полной вероятности ошибки. Дана геометрическая интерпретация результатов кластерного анализа процессов производства. Определено влияние факторов на работу производства. Применен индексный факторный метод с различной базой сравнения и разными весами. Проведена проверка гипотезы об адекватности модели процессов производства. Выполнен статистический анализ сложных данных процесса производства при поиске оптимальных решений в случае неопределенности и в условиях риска методами Байеса, Лапласа и Гермейера с помощью симплекс-метода. Использованы сетевые методы принятия решений. Статистическими методами посредством математического моделирования провели обоснование оптимальных размеров как отдельных деталей, так и объемов местных складов, чтобы не было опозданий в работе передачи процессов производства, срывов в работе, простоев оборудования. В этом случае критерием оптимальности объемов производства может служить минимум суммарных потерь от простоя отдельных узлов и блоков производства до возможности нарушения режимов синхронного процесса из-за нехватки оборудования (возникших карманов производства) или из-за давно используемых устаревших агрегатов
Competition of nuclear factor-erythroid 2 factors related transcription factor isoforms, Nrf1 and Nrf2, in antioxidant enzyme induction
AbstractAlthough the Nrf2 (nuclear factor-erythroid 2 p45 subunit-related factor 2) regulated expression of multiple antioxidant and cytoprotective genes through the electrophile responsive element (EpRE) is well established, interaction of Nrf2/EpRE with Nrf1, a closely-related transcription factor, is less well understood. Due to either proteolysis or alternative translation, Nrf1 has been found as proteins of varying size, p120, p95, and p65, which have been described as either activators of EpRE or competitive inhibitors of Nrf2. We investigated the effect of Nrf1 on EpRE-regulated gene expression using the catalytic and modifier subunits of glutamate cysteine ligase (GCLC and GCLM) as models and explored the potential role of Nrf1 in altering their expression in aging and upon chronic exposure to airborne nano-sized particulate matter (nPM). Nrf1 knockout resulted in the increased expression of GCLC and GCLM in human bronchial epithelial (HBE1) cells. Overexpression Nrf2 in combination with either p120 or p65 diminished or failed to further increase the GCLC- and GLCM-EpRE luciferase activity. All known forms of Nrf1 protein, remained unchanged in the lungs of mice with age or in response to nPM. Our study shows that Nrf1 could inhibit EpRE activity in vitro, whereas the precise role of Nrf1 in vivo requires further investigations. We conclude that Nrf1 may not be directly responsible for the loss of Nrf2-dependent inducibility of antioxidant and cytoprotective genes observed in aged animals
THE OUTCOME OF PSYCHIATRIC REHABILITATION TREATMENT DEPENDS ON AFFECTIVE STATE AT THE TIME OF ADMISSION
Background: In Austria, new approaches of rehabilitation programs focus on the prevention of mental illness and offer
treatment not only for acute psychiatric patients, but also for those who are at risk of developing a mental disorder or have
recovered from one.The aim of this study was to determine the effects of a psychiatric rehabilitation program on individuals with
different mood states.
Subjects and methods: 600 patients with a history of affective disorder were tested at the time of admission to an Austrian
inpatient psychiatric rehabilitation center. Data of extreme groups - patients who were depressed (n=59; BDI-II <9 and HAMD <8)
or euthymic (n=59; BDI 19) at the time of therapy start - were analyzed. The participants completed the Maslach
Burnout Inventory - General Survey, the Symptom Checklist - Revised and the Stress Coping Questionnaire at the beginning and the
end of the 6-weeks rehabilitation program.
Results: After 6 weeks, both groups showed significantly less psychiatric symptoms (BDI-II, HAMD, SCL-90, and negative coping
strategies (SVF). Importantly, work-related stress symptoms (“burnout” symptoms) improved significantly in the euthymic group.
Conclusions: Euthymic patients seem to be able to focus on work-related stress symptoms including reduced emotional
exhaustion through treatment, while currently depressed patients primarily benefit by an improvement in general psychiatric
symptomatology. The results indicate the crucial role of mood state validated with standardized psychological questionnaires BDI-II
and HAMD at time of admission to such programs. These findings could have implications on treatment decisions for psychiatric
patients and assist in making a forecast concerning ability to recover and treatment prognosis
Hair cortisol, allostatic load, and depressive symptoms in Australian Aboriginal and Torres Strait Islander people
Chronic stress and adversity are associated with poor mental health and are thought to contribute to the existing mental health gap between Aboriginal and Torres Strait Islander people and other Australians. Hair cortisol and allostatic load (AL) are indices of sustained stress and may be mediators of the effects of stress on health. The aim of this study was to examine the relationship between hair cortisol, AL, and depressive symptoms. This cross-sectional study comprised 329 Aboriginal and Torres Strait Islander adolescents and adults recruited at two health screening programs operating in three communities in north Queensland. We measured hair cortisol and calculated an AL index from 10 biomarkers. We assessed depressive symptoms with a version of the Patient Health Questionnaire-9 adapted for Aboriginal and Torres Strait Islander people (aPHQ-9). We found differences in cortisol and AL between the screening programs and communities, which were not explained by depressive symptoms. Overall aPHQ-9 scores were unrelated to hair cortisol (p = .25 and p = .94) and AL (p = .30 and p = .88) when age, gender and smoking were taken into account. However, anhedonia (p = .007) and insomnia (p = .006) sub-scores were each significantly associated with AL in one study site. Our present data did not demonstrate overall associations of stress biomarkers and multisystem dysregulation with depressive symptoms, which suggests that the relationship between cumulative stress and depression may be better explained by other factors in this population. The specific association between anhedonia and insomnia with AL indicates that chronic multisystem dysregulation plays a role in these features of depression in this population
Hair glucocorticoids in adults with intellectual disabilities and depressive symptoms pre- and post-bright light therapy:First explorations
BACKGROUND: Depressive symptoms and stress are common in adults with intellectual disabilities. Our aim was to explore long‐term biological stress levels, assessed by hair cortisol (HairF) and cortisone (HairE) concentrations, in adults with intellectual disabilities and depressive symptoms and to investigate the effects of bright light therapy (BLT) on hair glucocorticoids. METHOD: Scalp hair samples (n = 14) were retrospectively examined at baseline and post‐BLT (10.000 and 300 lux). Liquid chromatography–tandem mass spectrometry was used to measure hair glucocorticoids. RESULTS: A significant correlation was found between baseline HairF and depression scores (r = .605, p = .028). Post‐intervention HairE levels were significantly increased ([95% CI: 11.2–17.4 pg/mg], p = .003), in particular after dim light (300 lux) ([95% CI: 10.0–18.3 pg/mg], p = .020). CONCLUSIONS: This study showed that retrospectively examining biological levels of stress in adults with intellectual disabilities seems a potentially promising and objective method to gain insight in the stress level of adults with intellectual disabilities
The contribution of rat studies to contemporary knowledge of Major Depressive Disorder: Results from citation analysis
Funding: This study was financed by Animalfree Research—Switzerland, a grant from the Johns Hopkins Center for Alternatives to Animal Testing (CAAT) and by Portuguese National Funds through FCT—Fundação para a Ciência e a Tecnologia, within the CFCUL Unit funding UIDB/00678/2020. TM thanks partial support by CEAUL (funded by FCT—Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2019). FP thanks FCT/MCTES for the financial support to CESAM (UIDP/50017/2020 and UIDB/50017/2020), through national funds. Open access publication costs were covered by Animalfree Research-Switzerland and by funding provided by the Ketty and Leif Hjordt Foundation.Major depressive disorder (MDD) is the most severe depression type and one of the leading causes of morbidity worldwide. Animal models are widely used to understand MDD etiology, pathogenesis, and treatment, but the efficacy of this research for patients has barely been systematically evaluated. Such evaluation is important given the resource consumption and ethical concerns incurred by animal use. We used the citation tracking facilities within Web of Science and Scopus to locate citations of original research papers on rats related to MDD published prior to 2013—to allow adequate time for citations—identified in PubMed and Scopus by relevant search terms. Resulting citations were thematically coded in eight categories, and descriptive statistics were calculated. 178 publications describing relevant rat studies were identified. They were cited 8,712 times. More than half (4,633) of their citations were by other animal studies. 794 (less than 10%) were by human medical papers. Citation analysis indicates that rat model research has contributed very little to the contemporary clinical understanding of MDD. This suggests a misuse of limited funding hence supporting a change in allocation of research and development funds targeting this disorder to maximise benefits for patients.Publisher PDFPeer reviewe
Examining the Relationship Between Hair Cortisol With Stress-Related and Transdiagnostic Subclinical Measures
Background: Hair cortisol concentrations (HCC) provide a retrospective examination of long-term cortisol production as a measure of the hypothalamic-pituitary-adrenal (HPA) axis functioning, one of the major neural systems implicated in mediating the effects of stress on mental illness. However, evidence about the relationship between HCC with stressors and symptoms is scattered. In the present study, we aimed to examine the association between HCC and a wide range of stress-related and transdiagnostic subclinical measures in a sample of non-clinical young adults with a wide distribution of schizotypy. Methods: A total sample of 132 non-clinical young adults recruited at college and technical schools oversampled for schizotypy scores were assessed on distal and proximal stressful experiences, appraisals of stress, traits and symptoms of the affective, psychosis and dissociation spectrums, as well as stress-buffering measures, and provided 3 cm-hair samples. Results: No significant associations were found between HCC and any of the stress-related and subclinical measures. Only suspiciousness and disorganization showed a trend for a positive association with HCC but the magnitude was small. Conclusions: The present findings support previous studies indicating an overall lack of concordance between a broad range of stress-related and (sub)clinical phenotypic measures with hair cortisol. This study examined for the first time the relationship of HCC with the non-clinical expression of the psychosis spectrum, that is, schizotypy, which complements previous studies on clinical high risk and established psychosis and offers a promising strategy for studying possible HPA dysfunctions characterizing the subclinical psychosis continuum without the confounds associated to clinical psychosis
Mathematical statistics
This educational and methodological manual is intended for university students studying mathematical statistics; it can be used by graduate students, undergraduates, engineers to calculate statistical data of any structure. The manual includes theoretical questions for preparing for the exam, tasks for classes and independent work, a typical calculation for mathematical statistics, as well as tables of function values, that are necessary for solving tasks. The manual contains a brief description of access to the software tools of the STATISTICA system, which is designed for statistical data processing in the Windows environment