494 research outputs found

    Generalized Misner-Sharp energy in the generalized Rastall theory

    Full text link
    Employing the unified first law of thermodynamics and the field equations of the generalized Rastall theory, we get the generalized Misner-Sharp mass of spacetimes for which gtt=grr=f(r)g_{tt}=-g^{rr}=-f(r). The obtained result differs from those of the Einstein and Rastall theories. Moreover, using the first law of thermodynamics, the obtained generalized Misner-Sharp mass and the field equations, the entropy of the static spherically symmetric horizons is also addressed in the framework of the generalized Rastall theory. In addition, by generalizing the study to the flat FRW universe, the apparent horizon entropy is also calculated. Considering the effects of applying the Newtonian limit to the field equations on the coupling coefficients of the generalized Rastall theory, our study indicates ii) the obtained entropy-area relation is the same as that of the Rastall theory, and iiii) the Bekenstein entropy is recovered when the generalized Rastall theory reduces to the Einstein theory. The validity of the second law of thermodynamics is also investigated in the flat FRW universe.Comment: 4 pages, accepted by Can. J. Phys (2019

    Core promoter short tandem repeats as evolutionary switch codes for primate speciation

    Get PDF
    Alteration in gene expression levels underlies many of the phenotypic differences across species. Because of their highly mutable nature, proximity to the +1 transcription start site (TSS), and the emerging evidence of functional impact on gene expression, core promoter short tandem repeats (STRs) may be considered an ideal source of variation across species. In a genome-scale analysis of the entire Homo sapiens protein-coding genes, we have previously identified core promoters with at least one STR of ≥6-repeats, with possible selective advantage in this species. In the current study, we performed reverse analysis of the entire Homo sapiens orthologous genes in mouse in the Ensembl database, in order to identify conserved STRs that have shrunk as an evolutionary advantage to humans. Two protocols were used to minimize ascertainment bias. Firstly, two species sharing a more recent ancestor with Homo sapiens (i.e. Pan troglodytes and Gorilla gorilla gorilla) were also included in the study. Secondly, four non-primate species encompassing the major orders across Mammals, including Scandentia, Laurasiatheria, Afrotheria, and Xenarthra were analyzed as out-groups. We introduce STR evolutionary events specifically identical in primates (i.e. Homo sapiens, Pan troglodytes, and Gorilla gorilla gorilla) vs. non-primate out-groups. The average frequency of the identically shared STR motifs across those primates ranged between 0.00005 and 0.06. The identified genes are involved in important evolutionary and developmental processes, such as normal craniofacial development (TFAP2B), regulation of cell shape (PALMD), learning and long-term memory (RGS14), nervous system development (GFRA2), embryonic limb morphogenesis (PBX2), and forebrain development (APAF1). We provide evidence of core promoter STRs as evolutionary switch codes for primate speciation, and the first instance of identity-by-descent for those motifs at the interspecies level. © 2014 Wiley Periodicals, Inc

    Quantifying reputation loss of pipeline operator from various stakeholders perspectives, part 1: prioritization

    Get PDF
    Quantifying reputation loss (RL) due to pipeline damage is commonly generalized based on the owner's definition. This one-way perspective of portraying RL is unfair and unrealistic and consequently miscalculates the impact assessment of pipeline damage; hence, inaccurate risk prediction. It is crucial to develop a model to quantify qualitative RL to avoid unpredicted risk. Thus, this article provides a framework for a procedure to calculate RL by utilizing the factors identified in a previous study. In this paper (Part 1), the prioritization of factors based on the stakeholders' perspectives is presented. The factors were grouped into stakeholder-influenced categories and prioritized by a fuzzy analytic hierarchy process based on the feedback gained from the stakeholders, i.e., investors, customers, employees and the public. The result shows that factor D3, “Accident severity”, was ranked highest by all stakeholders. The priority vector for each factor obtained was assigned as a weight of the factor. The pipeline owner's reputation loss model (RLM) is developed by applying the obtained priority vectors in the subsequent paper (Part 2). The developed model was verified by experts as a comprehensive, clear, objective, practical and moderately reliable model. The model was applied to a case study and eventually produced a lower risk value when compared with the currently used model. It is proven that RL factors can be quantitatively measured and can simultaneously improve pipeline damage impact assessment. Thus, a risk-based inspection schedule can be managed comprehensively

    Influence of stent-induced vessel deformation on hemodynamic feature of bloodstream inside ICA aneurysms

    Get PDF
    One of the effective treatment options for intracranial aneurysms is stent-assisted coiling. Though, previous works have demonstrated that stent usage would result in the deformation of the local vasculature. The effect of simple stent on the blood hemodynamics is still uncertain. In this work, hemodynamic features of the blood stream on four different ICA aneurysm with/without interventional are investigated. To estimate the relative impacts of vessel deformation, four distinctive ICA aneurysm is simulated by the one-way FSI technique. Four hemodynamic factors of aneurysm blood velocity, wall pressure and WSS are compared in the peak systolic stage to disclose the impact of defamation by the stent in two conditions. The stent usage would decrease almost all of the mentioned parameters, except for OSI. Stenting reduces neck inflow rate, while the effect of interventional was not consistent among the aneurysms. The deformation of an aneurysm has a strong influence on the hemodynamics of an aneurysm. This outcome is ignored by most of the preceding investigations, which focused on the pre-interventional state for studying the relationship between hemodynamics and stents. Present results show that the application of stent without coiling would improve most hemodynamic factors, especially when the deformation of the aneurysm is high enough

    Delineating the antigenotoxic and anticytotoxic potentials of 4-methylimidazole against ethyl methanesulfonate toxicity in bone marrow cell of swiss albino mice

    Get PDF
    4-Methylimidazole (4-MEI) is mostly used in beverages and coloring food, dark beers and common brands of cola drinks, which may contain more than 100 μg of this compound per 12-ounce serving. This study was aimed to investigate the antigenotoxic and anticytotoxic effects of 4-MEI (100, 130 and 160 mg/kg) against ethyl methanesulfonate (240 mg/kg) using chromosome aberrations (CAs) and Mitotic index (MI) tests in bone marrow cells of Swiss Albino Mice at 12 h and 24 h treatment periods. So, the t-test was used for the statistical analysis. In this research, 4-MEI at all concentrations for 12 h treatment period reduced chromosomal aberrations and at 130 and 160 mg/kg concentrations for 24 h treatment period increased chromosomal aberrations induced by EMS (240 mg/kg), but th ese reductions and increases were not significant. Also, intraperitoneal injection of 4-MEI at doses of 100, 130 and 160 mg/kg combined with EMS (240 mg/kg) showed that the mitotic index was decreased at 100 and 130 mg/kg for 12h and 130 mg/kg for 24 h treatment periods, when compared to positive sample (EMS), but did not show any statistically difference from the EMS treated group. It can be concluded that 4-MEI might not be antigenotoxic and protective effects in bone marrow cells of Swiss Albino Mice, because 4-MEI could not reduce the chromosomal aberrations induced by EMS

    Scorpion envenomation in Bagh-E Malek, Iran –a 5 year study

    Get PDF
    Scorpionism is a major health problem in many tropical countries including Iran. The aim of this study was to describe the epidemiological and demographic information among whom stung by scorpions in Bagh-E Malek, Iran. In this retrospective cross-sectional study the information were gathered through evaluation of the records of stung patients referring to Shahid Tabatabai hospital of Bagh-E Malek April 2008 to April 2012. A total of 132 cases stung by scorpion were recorded including 3115 males (43%) and 4121 females (57%).Approximately 42.1 percent of the sting cases occurred in the summer followed by spring with 35.9% of stings. About 59.8% of stings happened in people by the age of 15-44 years old. Most of the stings happened in exposed extremities (78.5%) with most of it in upper limbs (41.8%). The scorpions’ species were unknown but 60.4% of them were yellow, 34.0% black and 5.6% were “other colors”. Since the highest rate of scorpionism cases were reported in rural areas (74.2%), it is suggested that the main focus should be considered for education of rural people, especially women who play a major role in the family. Additionally, evaluation of residential houses and surrounding environment and giving information on method of cleaning up the environment from the equipment and the factors from which scorpion may use as shelter, can also be effective in reducing the incidence of Scorpionism.Keywords: Scorpion sting; Epidemiology; Bagh-E Malek; Ira

    Evaluation of different dietary protein and energy levels on growth performance and body composition of narrow clawed crayfish (Astacus leptodactylus)

    Get PDF
    Nine practical diets containing increasing percentages of crude protein (CP) and energy (30%, 35%, 40% and 300kcal/100g, 370kcal/100g and 450kcal/100g) were fed to narrow clawed crayfish (mean individual weight=17±2.3 g) during an 8 week feeding trial. Weight Gain, Feed conversion ratio (FCR), Protein Efficiency Ratio (PER), Net Protein Utilization (NPU), Daily Food Consumption (DFC) and body composition of tail-muscle meat of narrow clawed crayfish were determined. At the conclusion of the experiment, comparing the growth parameters in response to interaction between protein and energy levels demonstrated that dietary number 2 (30/370) resulted in higher WG, NPU, PER, and the lowest FCR whereas dietary number 3 (30:450) showed higher SGR and DFC. Comparison of the body composition results indicates the greatest amount of protein absorption in diet number 2 (30/370). Results from this study indicate that narrow clawed crayfish can be fed a practical diet containing 30% protein and 370 Kcal/100gr. Reducing CP levels in narrow clawed crayfish diets may help reduce operating costs and thereby increase producers’ profits

    Study of chemical and physical behavior cotton fabrics treated by corona discharge after several laundering

    Get PDF
    Cotton fabric because of finishing process has shrinkage behavior after laundering and for improving this problem, chemical agents utilize for anti-shrinkage. This temporary finishing can reduce shrinkagebut has many environmental problems. Corona discharge treatment has been used for cotton fabric, other fibers and polymers. This treatment can reduce costs and environmental impacts. In this study, cotton fabric was treated by corona discharge instrument at 2 - 40 passages and fabrics were washed with laundering method. After four times laundering, shrinkage behavior of corona discharge treated fabric as compared with un-treated fabric decrease. After 10 passages of corona discharge treatment,water, dye absorption and shrinkage are modified but after 14 passages, despite of shrinkage improvement, dyeing properties decrease

    Ultrasound - guided access during percutaneous nephrolithotomy: Entering desired calyx with appropriate entry site and angle

    Get PDF
    Objectives: To evaluate the success of ultrasonography directed renal access in entering the target calyx from proper entry site and in the direction of renal pelvis during percutaneous nephrolithotomy (PCNL). Materials and Methods: PCNL cases who were operated on by one fellow from May- June 2014 were included in this study. A vertically placed ultrasound probe on the patient flank in prone position was used to identify the preselected target calyx. Needle was advanced through needle holder and fluoroscopy was used to document the entered calyx, site and angle of entry. Results: Successful entering to the target calyx was achieved in 43 cases (91). Successful entry with appropriate entry site and angle was observed in 34 cases (72). Reasons for failure were minimal hydronephrosis, upper pole access and high lying kidneys. Conclusions: Although it is feasible to access a preselected calyx by ultrasonography guidance during PCNL, but entry to the calyx from the appropriate site and direction is another problem and needs more experience. In cases of minimal hydronephrosis, superior pole access or high lying kidneys, ultrasonography is less successful and should be used with care

    Thermal error modelling of a gantry-type 5-axis machine tool using a Grey Neural Network Model

    Get PDF
    This paper presents a new modelling methodology for compensation of the thermal errors on a gantry-type 5-axis CNC machine tool. The method uses a “Grey Neural Network Model with Convolution Integral” (GNNMCI(1, N)), which makes full use of the similarities and complementarity between Grey system models and artificial neural networks (ANNs) to overcome the disadvantage of applying either model in isolation. A Particle Swarm Optimisation (PSO) algorithm is also employed to optimise the proposed Grey neural network. The size of the data pairs is crucial when the generation of data is a costly affair, since the machine downtime necessary to acquire the data is often considered prohibitive. Under such circumstances, optimisation of the number of data pairs used for training is of prime concern for calibrating a physical model or training a black-box model. A Grey Accumulated Generating Operation (AGO), which is a basis of the Grey system theory, is used to transform the original data to a monotonic series of data, which has less randomness than the original series of data. The choice of inputs to the thermal model is a non-trivial decision which is ultimately a compromise between the ability to obtain data that sufficiently correlates with the thermal distortion and the cost of implementation of the necessary feedback sensors. In this study, temperature measurement at key locations was supplemented by direct distortion measurement at accessible locations. This form of data fusion simplifies the modelling process, enhances the accuracy of the system and reduces the overall number of inputs to the model, since otherwise a much larger number of thermal sensors would be required to cover the entire structure. The Z-axis heating test, C-axis heating test, and the combined (helical) movement are considered in this work. The compensation values, calculated by the GNNMCI(1, N) model were sent to the controller for live error compensation. Test results show that a 85% reduction in thermal errors was achieved after compensation
    corecore