247 research outputs found
Selection of the Most Appropriate Tillage System Based on TOPSIS Model with Emphasize on Impact of Different Tillage Systems on Yield
Among the various agricultural operations, tillage alone accounts for 60% of the energy consumed in agriculture. Other concerns, such as soil compaction, time management, economic issues, porosity reduction, moisture storage capacity, as well as a 25% increase in water and wind erosion, has further fueled efforts to improve tillage methods. In this regard, conservation tillage is more considered by experts. This study was conducted to evaluate important indices of wheat production in different tillage methods. Two plots located in Moghan Agro Co. were selected and were divided into four equal 2.8 hectares. Experiments were performed in randomized complete block design (RCBD) with four tillage systems including conventional, tillage1, tillage2 and direct tillage in which two common wheat cultivars were planted. The results implied that the effect of all four tillage methods was significant at the probability level of 0.001 and the indices such as fuel consumption, efficiency, the number of traffic on farm, land preparation time and its cost per hectare, crop yield, plant density and tiller number were improved using the no-tillage and low tillage2 methods. The results were also re-evaluated using TOPSIS method and the tillage system with CL of 0.98 was selected as the best method. Therefore, direct cultivation can be an appropriate alternative to conventional tillage in sustainable wheat productio
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Prevalence of hepatitis B, hepatitis C, and tuberculosis among people living with HIV in Iran: a systematic review and meta-analysis.
BackgroundUp to now several studies estimate the prevalence of HBV, HCV, and TB among people living with HIV (PLWH) in Iran; however, their results are inconsistent. This study aimed to estimate the overall prevalence of HBV, HVC, and TB among Iranian PLWH.MethodsIn this systematic review and meta-analysis six databases including Medline, Web of Science, Scopus, MagIran, Scientific Information Database (SID), and Barakat Knowledge network system were searched up to October 2023 with no language restriction. All studies estimated the prevalence of HBV, HCV, and TB among PLWH in Iran were included. The random-effects model was used to report the study estimates. Results were reported at a 95% confidence interval (CI).ResultsOut of 1050 retrieved references, 58 articles met the eligibility criteria. Overall among PLWH, HBV prevalence was 13.0% (95% CI: 11.0, 15.0), HCV prevalence was 54% (95% CI: 45.0, 64.0), and TB prevalence was 19% (95% CI: 13.0, 24.0). The results from multivariate meta-regression analysis showed no statistically significant association between HBV and TB prevalence with the year of study, quality of studies, age, gender, and persons who inject drugs (PWID). HCV prevalence was significantly associated with PWID.ConclusionWe found HBV, HCV, and TB infections are common among PLWH in Iran and required to be screened and treated with effective and timely services
Influence of menstrual cycle and salivary ß-estradiol on volatile sulfur compound
BACKGROUND: ß -estradiol is a steroid sex hormone that plays important role in oral physiology. The aim of this study
was to determin the association of the menstrual cycle and salivary ß-estradiol with the production of volatile sulfur
compounds (VSC).
METHODS: In this cross-sectional study, twenty female dental students in good oral and general health were recruited for
evaluation of VSC, salivary flow, ß-estradiol concentration, oral dryness feeling and dysmenorrhea. Data were analyzed
by marginal homogeneity test and xtgee model.
RESULTS: The only covariates that significantly related to VSC were being at the follicular phase (B = -0.21, P = 0.02),
being at the pre-menstrual phase (B = -0.25, P = 0.01), stressfulness (B = 0.02, P = 0.01) and oral dryness feeling
(B = 0.34, P = 0.02). Salivary ß-estradiol was at the level of 59.7 31.2 in those having halitosis (VSC ≥ 75) while in
the others (VSC < 75) it was about 40.8 18.0 (P < 0.009). This difference was not statistically significant in multivariate
analysis.
CONCLUSIONS: The menstrual cycle, stress and oral dryness were the most important determinants of halitosis. The
salivary ß-estradiol level could not explain such relationship as its effect was eliminated considering the other factors.
KEY WORDS: Halitosis, menstrual cycle, ß-estradiol, volatile sulfur compound
Prevention of contrast-associated acute kidney injury in cancer patients undergoing radiologic investigation using contrast media; a short-review to current knowledge
Contrast agents are non-biologically active substances required for various diagnostic imaging procedures. Exposure to contrast materials, predispose some patients to renal disturbances entitled as contrast-associated acute kidney injury. Nephropathy of contrast medium is a deterioration of renal function which happens within 24 to 72 hours after iodinated contrast medium injection. Cancer individuals have several risk factors for contrast-associated acute renal failure, consisting of administration of chemotherapy regimen, which are mainly nephrotoxic, presence of diabetes or chronic renal failure, hypertension, taking of non-steroidal anti-inflammatory drugs, simultaneous use of nephrotoxic drugs, aminoglycosides, cisplatin, cyclosporine A or amphotericin B, increases the risk of contrast-associated acute renal failure. Similarly, age more than 65 years old and anemia is an independent risk factor for contrast-associated acute kidney injury and also timing of CT within 45 days after last chemotherapy and low fluid intake, as the common risk factors in cancer individuals
A Hybrid Ant Colony System and Tabu Search algorithm for the production planning of dynamic cellular manufacturing systems while confronting uncertain costs
Highlights:
• Cellular Manufacturing systems cover a wide range of industries.
• Inflation rate can impose financial harms on cellular manufacturing systems.
• The over-allocation of workers, which usually happens in dynamic systems, causes reduction of the system performance.
• The proposed algorithm in this research can successfully schedule cellular systems to reduce system costs.
Goal:
The main aim is to determine the best trade-off values between in-house manufacturing and outsourcing, and track the impact of uncertain costs on gained schedules. To be more comprehensive, the performance of human resources is restricted and the partial demands are considered uncertain.
Design / Methodology / Approach:
In this paper a new method for minimizing human resource costs, including operating, salary, hiring, firing, and outsourcing in a dynamic cellular manufacturing system is presented where all system costs are uncertain during manufacturing periods and can be affected by inflation rate. For this purpose, a multi-period scheduling model that is flexible enough to use in real industries has been proposed. To solve the proposed model, a hybrid Ant Colony Optimization and the Tabu Search algorithm (ACTS) are proposed and the outcomes are compared with a Branch-and-Bound based algorithm.
Results:
Our findings showed that the inflation rate has significant effect on multi-period system planning. Moreover, utilizing system capability by the operator, for promoting and using temporary workers, can effectively reduce system costs. It is also found that workers’ performance has significant effect on total system costs.
Limitations of the investigation:
This research covers the cellular manufacturing systems.
Practical implications:
The algorithm is applied for 17 series of dataset that are found in the literature. The proposed algorithm can be easily applied in real industries.
Originality / Value:
The authors confirm that the current research and its results are original and have not been published before. The proposed algorithm is useful to schedule cellular manufacturing systems and analyse various production conditions
A high-order nonlinear Schrödinger equation with the weak non-local nonlinearity and its optical solitons
Abstract The present paper explores a high-order nonlinear Schrodinger equation in a non-Kerr law media with the weak non-local nonlinearity describing solitons' propagation through nonlinear optical fibers. To this end, the real and imaginary parts of the model are firstly extracted using a wave variable transformation. The modified Kudryashov method and symbolic computations are then adopted to successfully retrieve optical solitons of the model. The results presented in the current study demonstrate the great performance of the modified Kudryashov method in handling high-order nonlinear Schrodinger equations
HIV prevalence and related risk behaviours among female sex workers in Iran: results of the national biobehavioural survey, 2010
Objectives To determine the prevalence of HIV and related behavioural risks among Iranian female sex workers (FSW) via the first national biobehavioural surveillance survey. Methods In 2010, 1005 FSW were approached and 872 recruited using facility-based sampling from 21 sites in 14 cities in Iran. We collected dried blood samples and conducted face-to-face interviews using a standardised questionnaire. Data were weighted based on the response rate and adjusted for the clustering effect of the sampling site. Adjustment was performed by weighting based on the sampling fraction of each site using a prior estimate of its total size of the FSW population. Results The prevalence of HIV infection (95% CI) was 4.5% (2.4 to 8.3) overall, 4.8% (2.2 to 9.8) among those who had reported a history of drug use and 11.2% (5.4 to 21.5) among those who had a history of injection drug use. The frequencies of condom use in the last sexual act with paying clients and non-paying partners were 57.1% and 36.3%, respectively. Any drug use was reported by 73.8% of participants, and among this subgroup, 20.5% had a history of injection drug use. Conclusions The prevalence of HIV was considerable among FSW particularly those who had a history of drug injection. A combination of prevention efforts addressing unsafe sex and injection are needed to prevent further transmission of HIV infection
Meta-analysis of Smoking Prevalence in Iran
Background: There are numerous studies and documents regarding the prevalence of smoking in Iran. Thus, to provide suitable information for decision-making and policy-making in this regard, the prevalence of smoking in Iran was evaluated using the meta-analysis of the results of the existing researches. Methods: Data were collected by searching the keywords cigarette, smoking, tobacco, and nicotine in English databases, searching their Persian equivalents in Persian Databases, and in non-electronic resources. After studying the titles and texts of collected articles, the repeated and irrelevant cases were excluded. Cases which had the inclusion criteria of this meta-analysis were entered into the Stata software. According to heterogeneity results, random effect model was used to estimate the prevalence of smoking. Findings: In initial studies and non-communicable surveillance system, 274992 Iranian adults were studied regarding daily smoking. Among initial studies, smoking prevalence varied from 12.3% to 38.5% in men, and from 0.6% to 9.8% in women. Based on the meta-analysis of initial studies and risk factors of non-communicable disease surveillance system, smoking prevalence was estimated 21.7% and 19.8% in men and 3.6% and 0.94% in women, respectively. Moreover, smoking prevalence in all subjects was estimated 13.9% according to the meta-analysis of the initial study. Conclusion: The findings of this meta-analysis revealed that a significant part of the general population over 15 years of age, and one fifth of Iranian male adults smoke. Thus, concerning causal relationship confirmed between smoking and most diseases, if suitable guidelines are not employed the diseases related to this factor will increase in Iran. Keywords: Cigarette, Prevalence, Iran, Structured review, Meta-analysi
A review of methods to estimate the visibility factor for bias correction in network scale-up studies
Network scale-up is an indirect size estimation method, in which participants are questioned on sensitive behaviors of their social network members. Therefore, the visibility of the behavior affects the replies and estimates. Many attempts to estimate visibility have been made. The aims of this study were to review the main methods used to address visibility and to provide a summary of reported visibility factors (VFs) across populations. We systematically searched relevant databases and Google. In total, 15 studies and reports that calculated VFs were found. VF calculation studies have been applied in 9 countries, mostly in East Asia and Eastern Europe. The methods applied were expert opinion, comparison of NSU with another method, the game of contacts, social respect, and the coming-out rate. The VF has been calculated for heavy drug users, people who inject drugs (PWID), female sex workers (FSWs) and their clients, male who have sex with male (MSM), alcohol and methamphetamine users, and those who have experienced extra-/pre-marital sex and abortion. The VF varied from 1.4% in Japan to 52.0% in China for MSM; from 34.0% in Ukraine to 111.0% in China for FSWs; and from 12.0% among Iranian students to 57.0% in Ukraine for PWID. Our review revealed that VF estimates were heterogeneous, and were not available for most settings, in particular the Middle East and North Africa region, except Iran. More concrete methodologies to estimate the VF are required
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