225 research outputs found
Human Factors in Highway-Rail Crossing Accidents: The Influence of Driver Decision Style
This paper explores the hypothesis that driver decision-making style influences highway-rail crossing accidents. To investigate this, we have designed an analysis of variance experiment with three independent variables: “driver decision style,” “driver time pressure” and “intersection complexity.” To simulate the driving conditions, we identified and videotaped a number of dangerous crossings in downtown Los Angeles. The tapes represented different environmental complexities and time pressures a driver experiences while crossing an intersection. The tapes were played back to the subject drivers. The subjects were classified according to their decision styles. Dependent measures were designed based on a driver’s decision to cross the intersection. This paper presents the conceptual approach and the experimental design for this research
An Overview of Studies Conducted on Washback, Impact and Validity
This article aimed at presenting a comprehensive overview of three interrelated concepts of washback, impact and validity in language testing and a myriad of studies conducted at different places to investigate the influence of testing on teachers and teaching, textbooks, learners and learning, attitudes toward testing, test preparation behaviors, etc.. Some of these studies present the results of various investigations on the influence of a national English examination on the local English language teaching and learning due to its high-stakes nature in particular countries such as Brazil, China, Hong Kong, Iran, Israel, Japan, Romania, Sri Lanka, and Taiwan. Some others cover a wide range of worldwide investigation on English testing such as the IELTS, TOEFL, and MECC. Moreover, there is a complete report of several important projects appointed by major testing agencies such as Cambridge ESOL and Educational Testing Services (ETS) on washback and impact studies. The article proceeds by reviewing the relevant literature on test validation which is a key concept in language testing domain since it is concerned with test interpretation and use. This domain is characterized and enriched by studies of washback and impact
A new viscoelastic damper for seismic protection of steel building frame
Viscoelastic dampers (VEDs) are widely used to protect structures against earthquake. Conventional VEDs are generally installed within a diagonal brace configuration which provides a stiff structural system and reduces their effectiveness. In addition, the aforementioned configuration is not suitable for retrofitting purpose and violates architectural requirements. In this study, a new type of viscoelastic damper is proposed in order to improve the seismic performance of steel structures and to overcome the drawbacks of the conventional VEDs. In order to evaluate the performance of the proposed VED, dynamic responses of a 3-story scaled down steel frame equipped with the proposed VED were obtained experimentally and numerically under harmonic excitations. In this stage, ABAQUS software was used to establish a detailed finite element analysis. The results obtained were compared with a frame equipped with the conventional VED as well as a moment resisting frame and braced frames. The effects of the size of viscoelastic layer on its dynamic characteristics were also investigated. In addition, a nonlinear time history analysis of a 10-story full scale steel frame was performed using SAP2000 software to demonstrate the effectiveness of the proposed VED for tall buildings. The results of this study showed that the frames equipped with dampers performed better than the braced frames in terms of reduction in the maximum displacement, acceleration and base shear responses of the 3-story moment resisting frame. Compared to the conventional VED, the proposed VED was more effective in reducing displacements, while it was slightly less effective in reduction of accelerations and base shears. It was also found that smaller thickness of the viscoelastic layer decreased displacement responses, however, it increased acceleration and base shear responses. The larger cross-section area of the viscoelastic layer resulted in smaller displacement responses, but larger acceleration and base shear responses. Thus, analysis of the 10-story frame showed that the effectiveness of VEDs for reducing maximum displacement and acceleration responses were strongly dependent on the characteristics of earthquake records. The proposed VED was more effective in reducing responses of the lower floors. Based on the results obtained, the maximum base shear response of the frame equipped with the conventional VED was smaller than the frame equipped with the proposed VED and larger than the bare frame regardless of the characteristics of earthquake records. The results showed that the viscoelastic dampers have more advantage in preventing the formation of plastic hinges in the frames even under severe earthquake. In addition, compared to the conventional VED, the proposed VED resulted in less damage to the structural members due to less plastic hinge formation. Therefore, the implementation of the proposed VED can overcome the deficiency of the VED in seismic protection of structures
Semiotic study of Jami’s Layla and Majnun story on the basis of discourse analysis
Sign-semantic analysis checks the relationship between language signs in the Dialogue system and beyond Sentence. This analysis shows that a sign associated with other discourse signs follow up what process with a special meaning. In the meantime, checking the elements that underlie the formation of meaning is crucial. Effective tools to analyze the sign-semantics include many elements such as: Internal and external forms of discourse, the dynamic word of dialogue, the role of effective verbs in the discourse, the word stress process, actors, types of actions, relationship of elements in succession and juxtaposition Axis, etc. In this study, we have tried to find some of the elements of meaning in the story of Layla and Majnun narrative Jami. And we check these elements show: first: signs of a discourse on the story pass what process to the forming Semantic structure. Secondly, we explored the types of discourse in this story. Third, we check the structure of narrative text to achieve the superstructure or essence. Methods based on classification and discourse analysis and semantic elements in the story of Layla and Majnun. In the process of discourse analysis we take full advantage of the mode of Sha’iry in the book Fundamentals of modern semantics. For this purpose, the general framework of analysis is classified in four chains. Leili and Majnoon of meaning elements such as inside and outside of verbal language factors, the word dynamic, active persuasion, the value of the word, of discourse factors, stress the word, the word value, verbs effective role in the dialogue, the process of succession and juxtaposition of word and so on in the form of the four chains were studied. Leili and Majnoon of Jami’s sign-semantic analysis in four analytical chain in the context of this study achieved the following results: 1) The basic narrative in the story of Layla and Majnun, based on the change from the unbalanced situation (separation) to the balanced (Joiner). 2) The dominant discourse in the story of Layla and Majnun of induction or prescriptive discourse. Persuasion activity in a few steps and two villages to assist the hero and create an obstacle to hero, from both the opposition and anti-agent agent takes place. In this regard, the sensory-perceptual and sensory-motor causes create cognitive structure in hero. Three "effective actions"_ desire, ability and knowledge_ play a decisive role in the process of action of story elements. The agent knows that he has the ability of union with the object value. Here we are faced with two current knowledge and ability. Since the beginning of the story, asking a subject raises challenges and pave the way for future events in the story. Hero catches up in every possible way to attain the object's value. Don'ts barrier of traditional social and tribal prejudices is against the will of the subject. The protagonist in the conflict between the desire and the traditional social norms, not the fate of the story. Prejudices tribal and clan relations cause to preventing of Lily's father to her marriage to Majnoon. Here we face to "ought verb". So two "effective verbs” "want" and "ought" are central verbs in the story of Layla and Majnun. 3) Subjective factor is In the case of discharge with true love and union with separation (injury). Discourse and functioning with secondary factors story for the purpose of disjunction of separation and union with true love and takes place
Symptomatic reinfection with COVID-19: A case-report study in Iran
Coronavirus disease 2019 (COVID-19) resulted in a worldwide concern. The role of the immunity system and memory cells in this disease and their ability in preventing a secondary infection is a controversial issue. Here we presented a case of reinfection with this virus eight months after the first episode. A twenty-one-year-old man was referred to our local hospital on 19 February 2020 with symptoms of viral infection. COVID-19 infection was confirmed by RT-PCR. He got hospitalized for 5 days. Eight months later on 4 October 2020, he was again referred with symptoms of viral infection and para-clinical tests confirmed COVID-19 infection. He got hospitalized for 6 days in the second episode. Although the immunity system plays important role in COVID-19 infection through the presence of memory cells it doesn’t guarantee permanent immunity to this virus. Reinfection with COVID-19 is possible and has been reported in some other studies.
Effect of metformin and folic acid on plasma homocysteine level in type 2 diabetic patients
Hyperhomocysteinemia is associated with an increased risk of cardiovascular disease in diabetic patients. The aim of this study was to evaluate effects of metformin and folic acid on plasma homocysteine level in diabetic patients. In this clinical trial 47 new cases of type 2 diabetes were randomized to two groups. We treated patients in trial group with metformin and 1 mg folic acid, whereas patients in control group treated with metformin and placebo for 16 weeks. There was no significant difference in plasma homocysteine level and glycosylated hemoglobin (HbA1c) between two groups at the start of study. After 16 weeks plasma homocysteine level in the trial group did not change. In contrast plasma homocysteine level increased in the placebo group. There was significant difference in mean plasma homocysteine level between two groups (P-value < 0.01). This difference was highly significant in males (P-value < 0.0001). Correlation between glycosylated hemoglobin and plasma homocysteine level at start and end of study was not significant. This finding indicated that metformin increases plasma homocysteine level in diabetic patients especially males, whereas administration of folic acid with metformin can prevent this process
The Expression and Function of Nitric Oxide Synthase Enzyme in Atorvastatin Effects on Morphine-Induced Dependence in Mice
Background: Atorvastatin exerts neuroprotective effects on the treatment of central nervous system disorders. Morphine analgesic tolerance and dependence remain as major concerns in medicine. Nitric oxide (NO) pathway mediates the development of opioid analgesic tolerance and dependence, as well as atorvastatin neuroprotection. Objectives: The present study aimed to assess the possible involvement of the NO/cGMP pathway in the process of the effects of atorvastatin on morphine physical dependence. Methods: Dependence was induced by repetitive injection of morphine sulfate. Naloxone was injected at the dose of 4 mg/kg on the last day of the experiment to assess withdrawal signs. Animals received atorvastatin (1, 5,10, and 20 mg/kg, orally). Nitric oxide synthase (NOS) inhibitors and ODQ were injected before protective dose of atorvastatin. The gene expression of NOS isoforms was evaluated by real-time PCR. Thereafter, the hippocampal levels of cGMP and nitrite were measured. Results: Treatment with atorvastatin 10 mg/kg significantly attenuated naloxone-induced withdrawal behaviours. The administration of L-NAME, aminoguanidine, and ODQ before atorvastatin enhanced its effects. The treatment with atorvastatin significantly decreased the nitrite and cGMP levels as well as NOS gene expression in the hippocampus of dependent animals. Conclusions: It can be concluded that atorvastatin, possibly, through inducible NOS, could alleviate morphine dependence and withdrawal signs
Prevalence, causes, and complications of acute kidney transplant rejection: survey in a single center
Backgrounds: Kidney transplantation has become a preferred surgical approach for several renal disorders. To acquire required information in basis of acute transplant rejection and its complications, it is important to determine rejection prevalence and its potential causes.Methods: In present retrospective study, during a 37-year survey, 2250 patients received conventional kidney transplantation. The patients who had suffered graft loss, death, and nephrectomy of transplanted kidney during the first month after transplantation enrolled the study and all required data recorded in designed questionnaire. Results: Of 2557 patients underwent kidney transplantation, 86 (3.36%) patients were suffered acute graft loss during the first month after transplantation, that 43 (50%) were males and 43 (50%) were females. Mean age of the patients with acute graft loss was 40.09±14.09. The most common underlying cause for acute graft loss in our study were as follows: acute rejection of transplanted kidney (34.9%), renal vein thrombosis (17.5%), heart infarction (13.9%), idiopathic (6.9%). Of 86 patients, thirty-three patients underwent nephrectomy subsequent to rejection, however, fifty-three patients well responded to medical treatment. In our study the amount of acute nephrectomy during the first month after transplantation was 38.4% (33 patients) which constituted 1.2% of the total graft losses.Conclusion: Renal vein thrombosis is the most common underlying reason for graft loss in kidney transplantation patients, and 1st week of the transplantation is the most probable postoperative time for graft rejection
A Post-Marketing Surveillance Study to Evaluate the Safety Profile of AlvotereⓇ (Docetaxel) in Iranian Patients Diagnosed with Different Types of Cancers Receiving Chemotherapy
Background
Docetaxel is a clinically well established antimitotic chemotherapy medication. Labeled docetaxel indications are breast cancer, gastric cancer, head and neck cancer, non–small cell lung cancer, and prostate cancer.
Objective
This is a Phase IV study to evaluate the safety profile of docetaxel (Alvotere; NanoAlvand, Iran) in Iranian patients diagnosed with different types of cancers receiving chemotherapy regimens with docetaxel.
Methods
Patients who received Alvotere as a part of their chemotherapy regimen were enrolled in this Phase IV, observational, multicenter, open-label study. Alvotere was administrated as a single agent or in combination with other chemotherapy agents. Safety parameters in each cycle were assessed, and the related data were recorded in booklets.
Findings
A total of 411 patients with different types of cancers were enrolled from 25 centers in Iran. The most common malignancies among participants were breast cancer (49.88%), followed by gastric cancer (22.63%). Participants’ mean age was 53.33 years, and the mean total dose used in each cycle was 132 mg. According to the results, 341 patients experienced at least 1 adverse event, that the most common was alopecia (41.12%). In total, 92 (22.38%) patients had at least 1 adverse event of grade 3 or 4, and 25 (6.08%) patients showed 54 serious adverse events, which the causality assessment for all was possibly related to Alvotere. There was a significant difference between men and women in the incidence of skin and subcutaneous tissue disorders (55.63% in women vs 41.73% in men; P = 0.009). Also, the incidence of gastrointestinal disorders, nervous system disorders, skin and subcutaneous tissue disorders, hepatic enzymes increase, and fluid retention was significantly higher (P < 0.05) in patients receiving anthracyclines in their chemotherapy regimens.
Conclusions
The findings of this open-label, observational, multicenter, postmarketing surveillance showed that Alvotere appears to have an acceptable safety profile in Iranian cancer patients receiving chemotherapeutic regimens. (Curr Ther Res Clin Exp. 2022; 82:XXX–XXX) © 2022 Elsevier HS Journals, Inc
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