701 research outputs found
Neural-network simulation of diesel operation under a nonsteady load
© 2016, Allerton Press, Inc.The operation of diesel engines with nonsteady loads is considered. Numerical experiments are based on a model, a neural network, and test-bench data
Key performance indicators in corporate finance
© 2015, Asian Social Science. All rights reserved. The relevance of the study caused by the necessity to assess the impact of KPI system for growth of shareholders welfare and the satisfaction of the interests of other stakeholders. KPI concept suggests widespread use of these factors as measures of internal and external efficiency, as well as an incentive for management to meet the strategic objectives of the company. The article examines the influence of key performance indicators on the value of Russian companies. We used the following tools of econometric research: content analysis and econometric modeling to conduct the study
Alexithymia as a Predictor of Chronic Tension Headaches
© 2016, Springer Science+Business Media New York.Alexithymia as a violation of inter-hemispheric communication which has no visible organic brain changes is now regarded as a predictor of many chronic physical and neurological diseases, but it has not yet been regarded in connection with chronic tension headaches. The authors examined 137 people with tension-type headache (33 men, 84 women) aged 30–50 years (average age 40,75 ± 6,29) in order to clarify a link to alexithymia. The diagnosis of tension headache was conducted according to the International classification of headaches, 3rd edition (beta version). The authors used the original headache diary, Toronto alexithymia scale, Hospital anxiety and depression scale, the measurement of the space under the curve of headache. It was found that the patients with alexithymia have difficulty in describing the place of headaches (the average number of word descriptors at most 1 word), distrust of doctors, abuse of analgesics and tend to use alternative medicine methods. The intensity (p = 0.0001) and the frequency of headaches (p = 0.0028) is significantly higher in patients with alexithymia, and the more common are depression (p = 0.042) and impaired nocturnal sleep (p = 0.001). Patients with chronic tension-type headache associated with sleep disorders, adaptation and symptoms of depression should be considered as alexithymic personalities until the contrary is proved. Physicians should be aware of the fact that alexithymic patients have problems with feelings verbalization, and if patient’s complaints are vague a doctor should use questionnaires, words-descriptors, phrases-descriptors and other auxiliary verbal techniques for accurate diagnosis
Interpretation of the results of thermohydrodynamic studies of vertical wells that operate on multibed deposits
© 2014, Pleiades Publishing, Ltd. A mathematical model for describing thermohydrodynamic processes in a “vertical well-multibed deposit” system was developed. A method for determining the filtration and thermophysical parameters of a multibed deposit and flow rates of interlayers is proposed. The curves of changes in the bottomhole temperature in a vertical borehole that were measured after its startup are used as the initial information
Alexithymia as a Predictor of Chronic Tension Headaches
© 2016, Springer Science+Business Media New York.Alexithymia as a violation of inter-hemispheric communication which has no visible organic brain changes is now regarded as a predictor of many chronic physical and neurological diseases, but it has not yet been regarded in connection with chronic tension headaches. The authors examined 137 people with tension-type headache (33 men, 84 women) aged 30–50 years (average age 40,75 ± 6,29) in order to clarify a link to alexithymia. The diagnosis of tension headache was conducted according to the International classification of headaches, 3rd edition (beta version). The authors used the original headache diary, Toronto alexithymia scale, Hospital anxiety and depression scale, the measurement of the space under the curve of headache. It was found that the patients with alexithymia have difficulty in describing the place of headaches (the average number of word descriptors at most 1 word), distrust of doctors, abuse of analgesics and tend to use alternative medicine methods. The intensity (p = 0.0001) and the frequency of headaches (p = 0.0028) is significantly higher in patients with alexithymia, and the more common are depression (p = 0.042) and impaired nocturnal sleep (p = 0.001). Patients with chronic tension-type headache associated with sleep disorders, adaptation and symptoms of depression should be considered as alexithymic personalities until the contrary is proved. Physicians should be aware of the fact that alexithymic patients have problems with feelings verbalization, and if patient’s complaints are vague a doctor should use questionnaires, words-descriptors, phrases-descriptors and other auxiliary verbal techniques for accurate diagnosis
Persistent postural-perceptual dizziness
© 2017, Media Sphera, All rights reserved. Objective. To study persistent postural perceptual dizziness (PPPD) in outpatients with benign paroxysmal positional vertigo (BPPV) and patients with presbiataxia (PAt). Material and methods. Eighty-four patients with PPPD, including 14 with Meniere’s disease (MD), 19 with BPPV, 17 with a history of ischemic stroke (IS) in the vertebrobasilar system and 34 with Pat, were examined. For the diagnosis of anxiety, the original 15-point questionnaire with the Likert Scale structure was used. Patients received anvifen (aminophenylbutyric acid hydrochloride) in dose of 250 mg 3 times a day for 6 weeks. Results and conclusion. The most common trigger of PPPD was sleep deprivation. The highest level of anxiety was identified in the PAt group (19,5±2,89). There was a good effect of the drug: it reduced anxiety in all patients studied. The quality of sleep was improved as well. The authors recommend anvifen as the drug of choice in patients with PPPD during vestibular rehabilitation and cognitive-behavioral therapy
Key performance indicators in internal control
© Medwell Journals, 2017. This study describes some of the approaches to the problem of establishing an effective system of internal financial control structures aimed at rational use of material, labor and financial resources in the conditions of crisis in the global economy. In the study in particular, we hypothesized about the need to use key performance indicators in the internal financial control system. The KPI system is integrated in the modern concept of corporate finance in particular VBM. In this regard in the study, we constructed an econometric model of the relationship between financial performance and economic value added for the purpose of identifying which particular KPI may serve as reference points for the internal financial control department
Optimization of the expression, purification and polymerase activity reaction conditions of recombinant human PrimPol
© 2017 Boldinova et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Human PrimPol is a DNA primase/polymerase involved in DNA damage tolerance and prevents nuclear genome instability. PrimPol is also localized to the mitochondria, but its precise function in mitochondrial DNA maintenance has remained elusive. PrimPol works both as a translesion (TLS) polymerase and as the primase that restarts DNA replication after a lesion. However, the observed biochemical activities of PrimPol vary considerably between studies as a result of different reaction conditions used. To reveal the effects of reaction composition on PrimPol DNA polymerase activity, we tested the polymerase activity in the presence of various buffer agents, salt concentrations, pH values and metal cofactors. Additionally, the enzyme stability was analyzed under various conditions. We demonstrate that the reaction buffer with pH 6–6.5, low salt concentrations and 3 mM Mg 2+ or 0.3–3 mM Mn 2+ cofactor ions supports the highest DNA polymerase activity of human PrimPol in vitro. The DNA polymerase activity of PrimPol was found to be stable after multiple freeze-thaw cycles and prolonged protein incubation on ice. However, rapid heat-inactivation of the enzyme was observed at 37ºC. We also for the first time describe the purification of human PrimPol from a human cell line and compare the benefits of this approach to the expression in Escherichia coli and in Saccharomyces cerevisiae cells. Our results show that active PrimPol can be purified from E. coli and human suspension cell line in high quantities and that the activity of the purified enzyme is similar in both expression systems. Conversely, the yield of full-length protein expressed in S. cerevisiae was considerably lower and this system is therefore not recommended for expression of full-length recombinant human PrimPol
Thermohydrodynamic studies of vertical wells with hydraulic fracturing of a reservoir
© 2017, Pleiades Publishing, Ltd.A mathematical model to describe thermohydrodynamic processes in the system “oil reservoir–hydraulic fracture” is developed. A method for determining filtration and thermophysical parameters of the reservoir and fracture is proposed. Curves of the change of the downhole temperature and pressure are used as initial information
Determination of the Parameters of the Hole Bottom Zone of a Vertical Well from the Results of Thermodynamic Investigations
© 2016, Springer Science+Business Media New York.A computational algorithm for estimating the parameters of the hole bottom zone from the results of measuring pressure and temperature at the bottom hole of a vertical well is suggested. The ambiguity of determining the permeability and of the hole bottom zone radius depending on the original information is shown
- …