46 research outputs found

    Sequential sampling of overwintered sunn pest, Eurygaster integriceps (Het.: Scutelleridae) in rainfed wheat fields in Borujerd, Iran

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    The sunn pest, Eurygaster integriceps Puton, is the most important pest of wheat and barley in most wheat producing regions of Iran, including Lorestan province. The pest overwinters under bushes in mountains and returns to wheat fields in the next spring. Study of spatial distribution of overwintered sunn pest (OSP) in rainfed wheat fields using two quadrate sizes (50 à 50 cm2 = 0.25 m2 and 70.71 à 70.71 cm2 = 0.5 m2) and their conformity with negative binomial distribution, showed a dispersion pattern of aggregation. In this study, a sequential sampling plan (Waldâs method) was presented by use of 1.5 OSP/m2 as an action threshold and 1.05 OSP/m2 as the safety level, and estimating the common K (Kc) for the both sizes of quadrates in 2004 and 2005. Two sizes of quadrates were used as sample units to estimate densities and dispersion patterns of the pest populations. The decision lines, y = 0.32x ± 7.62 andy = 0.63x ± 7.44 were calculated for 0.25 and 0.5 m2 quadrates, respectively. The operating characteristic (OC) and average sample number (ASN) curves indicated that low numbers of samples are required for control decision making when the population densities are either low (less than 0.22 and 0.44 OSP/q for small and large quadrates, respectively) or high (more than 0.45 and 0.89 OSP/q for small and large quadrates, respectively). However, the number of samples required will be high when the population density is nearly medium and at the point of inflection of OC curve (0.32 and 0.63 OSP/q for small and large quadrates, respectively)

    Ph3P Catalyzed Synthesis of Alkyl 2-(4-Oxopyridin-1(4H)-yl)acrylates by Nucleophilic Addition to Alkyl Propiolates

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    4-Hydroxypyridine undergoes a smooth reaction with alkyl propiolates in the presence of triphenylphosphine to produce and β-substituted alkyl acrylate products. When the reaction was performed with 4-hydroxyquinoline only  α-substituted alkyl acrylates were obtained.Keywords: 4-hydroxypyridine, 4-hydroxyquinoline, Alkyl Acrylates, Alkyl Propiolates, Triphenylphosphin

    On the almost quasi-Yamabe solitons

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    The Effects of Toxic Heavy Metals Lead, Cadmium and Copper on the Epidemiology of Male and Female Infertility

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    Infertility is a major problem in modern society that affects a significant number of couples around the world. Heavy metals and a number of other factors have been causally linked to infertility. The aim of this study was to determine the effect of heavy metals lead, cadmium, and copper on the epidemiology of male and female infertility. Searches for articles published from 1982 to 2020 using related keywords such as male and female infertility and heavy metals were performed in scientific databases PubMed, Google Scholar, Science Direct, and others. The results showed that, in recent years, the number of infertile individuals has increased. Various environmental, occupational, and genetic factors have been described as potential causes. Heavy metals lead, cadmium, and copper cause infertility in couples through various mechanisms, such as changes in sperm motility factors, decreased semen quality, or effects on the egg. Exposure to physical phenomena such as radiation (ionized or microwave) and heat; stress and mental disorders; chemicals from cigarettes, respiratory pollutants (lead), insecticides and pesticides; anesthetic gases; and mercury and cytotoxic drugs may also contribute to the onset of infertility

    Validation of the 2010 American College of Rheumatology preliminary diagnostic criteria for fibromyalgia in an Iranian population

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    The aim of this study was to validate the 2010 American College of Rheumatology (ACR) preliminary criteria for fibromyalgia (FM) in an Iranian population. In this multicenter prospective study, we enrolled 168 FM patients and 110 controls. All participants underwent dolorimetry examination by study assessors and completed a questionnaire containing variables of both the ACR 2010 preliminary and ACR 1990 criteria. We compared the performance of the ACR 2010 criteria with the expert diagnosis as well as the ACR 1990 criteria. Receiver operator characteristic analyses and Youden index were used to evaluate the test characteristics of a set of different cutoff points for two subcomponents of ACR 2010 criteria including widespread pain index (WPI) and symptom severity (SS) scale. Considering expert diagnosis as the gold standard, the ACR 2010 criteria showed comparable specificity with ACR 1990 (92.8 vs. 88.3 , P = 0.073), but lower sensitivity (58.9 vs. 71.4 , P = 0.003) and a tendency for lower accuracy (72.4 vs. 78.4 , P = 0.105). Applying the ACR 1990 criteria as the gold standard, we observed a trend toward an increase in overall accuracy (72.4 vs. 79.1 , P = 0.064). Optimal test characteristics were achieved for WPI C6 and SS scale score C4 and improved sensitivity and accuracy of ACR 2010 criteria when compared to expert, 76.1 and 81.7, respectively. The preliminary ACR 2010 criteria performed less desirably in terms of sensitivity in our set of Iranian patients. Selecting lower cutoff points as WPI C6 and SS scale score C4 improved the diagnostic values of the criteria. © Springer-Verlag Berlin Heidelberg 2013
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