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11.
Basilaphelenchus gorganensis n. sp. is described and illustrated from wood and bark of a dead tree from northern Iran. The new species is characterized by female body length (415–559 µm), three‐lined lateral fields, a sclerotized cephalic vestibule and cephalic framework, thin stylet with three elongate backwardly directed knobs, small spherical to oval metacorpus, with small and posteriorly located valve, simple vulva without any flap apparatus, 59‐ to 79‐µm‐long post‐vulval uterine sac, functional rectum and anus and dorsally convex, ventrally concave, usually ventrally bent conical female tail with a sharp tip. Males are common, apparently functional and characterized by well‐curved spicules, three pairs of small caudal papillae and no bursa at tail tip. Molecular phylogenetic inferences using partial sequences of small and large subunit ribosomal RNA genes (SSU and LSU rDNA) from different isolates of the new species revealed it differs from currently sequenced species and belongs to the Tylaphelenchinae clade.  相似文献   
12.
ABSTRACT

The present study was conducted to assess the ability of AquaCrop model in predicting of grain and biological yield of rice genotypes in water management. A two-year field experiment was conducted at the experimental farm of the Iranian Rice Research Institute in Rasht, Iran from 2016 to 2017. The experiment was established in a split-plot design with two irrigation management (continuous submergence and end season water stress) as the main plot, fourth rice genotypes as the sub-plot and three replications. The goodness-of-fit between observed and simulated grain yield and final biomass was assessed by means of the coefficient of determination (R 2), the absolute and normalized root mean square errors (RMSE). The RMSEn of predicting grain yield at calibration and evaluation stages was in the range of 6–12% and 6–8% for biological yield. The results indicated that AquaCrop model is suitable to predict grain yield and biological yield of rice genotypes in northern Iran. AquaCrop model can be used to determine optimization strategies to improve the water consumption of rice genotypes.  相似文献   
13.
Tropical Animal Health and Production - Heat stress can potentially affect most aspects of reproduction in mammals. To our knowledge, no studies have ever been conducted for evaluating the...  相似文献   
14.
Ovulation rate and prolificacy are the most important reproductive traits that have major impact on the efficiency of lamb meat production. Here, we compared the whole genomes of the Romanov sheep, known as one of the high prolific breeds, and four other sheep breeds namely Assaf, Awassi, Cambridge and British du cher, to identify genetic mechanisms underlying prolificacy in sheep. Selection signature analysis revealed 637 and 477 protein‐coding genes under positive selection from FST and nucleotide diversity (Pi) statistics, respectively. Further analysis showed that several candidate genes including LEPR, PDGFRL and KLF5 genes are involved in sheep prolificacy. The identified candidate genes in the selected regions are novel and provide new insights into the genetic mechanisms underlying prolificacy in sheep and can be useful in sheep breeding programmes to develop improved breeds for high reproductive efficiency.  相似文献   
15.
The objective of this study was to investigate the influence of size on salinity tolerance in 1 year old juvenile white sturgeon. Two sizes of sturgeon (10 and 30 g) from the same spawning event (thus reducing confounding effects of genetic make-up and size) and reared in the same environment were exposed to a salinity of 0, 8, 16, 24, or 32 ppt for up to 120 h. Both 10 and 30 g fish exhibited > 93% mortality within 24 h after transfer to 24 or 32 ppt, regardless of whether they were transferred directly from freshwater (FW) or following a 48 h pre-treatment period at 16 ppt. Direct transfer from FW to 16 ppt was associated with 25 to 30% mortality, indicating that these fish have some ability to tolerate large changes in salinity for up to 5 days at this stage. Following exposure to 8 and 16 ppt, an elevation in plasma osmolarity, [Na+], and [Cl?] was observed between 24 and 72 h in both 10 and 30 g sturgeon, but plasma ions and osmolarity in surviving fish at 120 h were not significantly different between groups held at 0, 8, and 16 ppt. Despite being unprepared for either direct or stepwise transfer to salinities of 24 ppt or greater, size confers some ionoregulatory advantage, as mortality occurred more slowly and the degree of ionoregulatory perturbation was less in 30 g than 10 g fish over the course of the exposures. It is not known whether the apparent advantage of size is related to a size-dependent development of ionoregulatory capacity or due to social status which can also influence ionoregulatory capacity, but age and genetic differences did not likely contribute to this size effect.  相似文献   
16.
Major advancement in canola breeding depends on heterotic hybrids that require high general combining ability (GCA) and specific combining ability (SCA) inbred lines. In order to estimate heritability, gene action type, GCA, SCA and heterosis and to identify superior hybrids with wider adaptation to cold, one hundred canola hybrids were produced by crossing 10 lines and 10 testers in a Line?×?Tester mating design. The F1 and F2 generations were sown in α-lattice design in 2012 and 2013 growing seasons under optimum (early October) and late sowing (early November) conditions to be evaluated for days to flowering, days to physiological maturity, number of pods per plant, number of seeds per pod, thousand seed weight, seed yield and leaf electrical conductivity. The combined analysis indicated sufficient genetic diversity in the population and significant difference between two sowing date. The Line?×?Tester analysis presented significant GCA and SCA effects for all studied traits across optimum and late sowing conditions. The main gene action type was found to be non-additive, especially incomplete dominance and over-dominance in both conditions. Narrow-sense heritability ranged from low to moderate whereas broad-sense heritability was recorded more than 60% for all of the studied traits in both generations and conditions. The average heterosis in F2 population for all studied traits was lower than that in F1 representing this fact that heterosis is generally related to the heterozygosity at the population level and poorly correlated with heterozygosity at the individual level.  相似文献   
17.
This study was conducted to investigate the impact of water salinity (ECw) and sodicity (SARw) on saturated (Ks) and relative (Kr) hydraulic conductivities in two clay (C) and sandy clay loam (SCL) soils. The results showed that the Ks decreased with increasing SARw, and in all of water quality treatments, the Ks of SCL soil was higher than that of the C soil. Sodicity effect (even at high SARw) on the Kr of clay soil was minimized by high salinity. Although Kr of both soils similarly responded to ECw and SARw, microstructure of clay soil was more sensitive to water quality. Effect of ECw on soil structure was greater than that of SARw. In order to assess the applicability of artificial neural networks (ANNs) in estimating Ks and Kr, two types of FFBP and CFBP ANNs and two training algorithms, namely Levenberg–Marquardt (LM) and Bayesian regulation, were employed with two strategies of uniform threshold and different threshold functions. Multiple linear regressions were also used for Ks and Kr prediction. Based on the ANN results of second strategy, best topology (4–5–4–1) was belonged to CFBP network with LM algorithm, LOGSIG–LOGSIG–TANSIG threshold functions, and values of MAE and R2 are equal to 0.1761 and 0.9945, respectively. Overall, the efficacy of ANNs is much greater than regression method for Ks prediction.  相似文献   
18.
This study was carried out to evaluate milt quality in male Caspian brown trout (Salmo trutta caspius) over the course of the winter spawning season. Milt samples were collected biweekly during December and January. Chemical composition of seminal fluid, sperm production (milt volume, sperm density, spermatocrit,) and sperm motility characteristics (percentage and duration of motility) were measured. Milt volume, sperm density, osmolality, seminal minerals (Ca2+, Mg2+, K+, Na+, Cl?), and total protein gradually decreased over the spawning season. Glucose and triglyceride content of milt did not show significant changes over the spawning season. Milt pH and the percentage and duration of motility were comparatively stable, declining only at the end of the season. Significant positive correlations were found between sperm density and seminal minerals, total protein and spermatocrit; percentage of motile spermatozoa and seminal minerals, total protein; and duration of motility and K+, Cl?, total protein, and pH. Results show that season has a significant influence on milt quality in male Caspian brown trout, with the best milt being available at the beginning of spawning season.  相似文献   
19.
Determining the physical and mechanical properties of soil and its behavior for engineering projects is essential for road construction operations. One of the most important principles in forest road construction, which is usually neglected, is to avoid mixing organic matter with road materials during excavation and embankment construction. The current study aimed to assess the influence of organic matter on the physical properties and mechanical behaviors of forest soil and to analyze the relation between the amount of organic matter and the behavior of forest soil as road material. A typical soil sample from the study area was collected beside a newly constructed roadbed. The soil was mixed with different percentages of organic matter(control treatment, 5, 10, and 15% by mass) and different tests including Atterberg limits, standard compaction, and California bearing ratio(CBR) tests were conducted on these different soil mixtures. The results showed that soil plasticity increased linearly with increasing organic matter.Increasing the organic matter from 0%(control) to 15%resulted in an increase of 11.64% of the plastic limit and 15.22% of the liquid limit after drying at 110 ℃. Also,increasing the organic matter content reduced the soil maximum dry density and increased the optimum moisture content. Increasing the organic matter from 0 to 15% resulted in an increase of 11.0% of the optimum moisture content and a decrease of 0.29 g/cm~3 of the maximum dry density. Organic matter decreased the CBR, which is used as the index of road strength. Adding 15% organic matter to the soil resulted in a decrease of the CBR from 15.72 to 4.75%. There was a significant difference between the two drying temperatures(60 and 110 ℃) for the same organic matter mixtures with lower water content values after drying at 60 ℃. The results revealed the adverse influence of organic matter on soil engineering properties and showed the importance of organic matter removal before excavation and fill construction.  相似文献   
20.
Various classes of medication are currently being used in Polycystic Ovary Syndrome (PCOS) patients including the biguanides and the statins. However, their efficacies are rarely compared. This study aimed to compare efficacy ofa biguanide and a statin in treating PCOS. In a randomized double-blind clinical trial, 400 women with PCOS were recruited within 15 months in Taleghani Hospital. They randomly received either a biguanide (metformin 500 mg three times daily) or a statin (simvastatin 20 mg daily) for three consecutive months. Changes of clinical and laboratory variables were compared. In the biguanide group the serum glucose status (abnormal fasting and non-fasting sugar and insulin levels and percentage of hyperinsulinemic cases) and menstrual abnormalities improved significantly after treatment (p < 0.05). In the statin group the lipid profile status (abnormal total cholesterol, high and low density lipoproteins), C-Reactive Protein (CRP), serum dehydroepiandrosterone sulfate, hyperinsulinemia, severity of acne and menstrual abnormalities improved significantly after treatment (p < 0.05). Comparing the two groups, the improvements in fasting blood sugar and serum insulin levels were significantly better in the biguanide group (p = 0.04 for both parameters); whereas the improvements in serum total cholesterol (p < 0.001), low density lipoprotein (p < 0.001), CRP (p < 0.001) and acne status (p = 0.04) were significantly superior in the statin receivers. Based on these results, each medication is only effective on some aspects of the disease. Overall, the simvastatin was superior to metformin with regard to the number of beneficial effects.  相似文献   
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