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61.
Canids are natural reservoirs of Leishmania infantum and have been promoted as experimental hosts to decipher the pathogenesis of human visceral leishmaniasis (VL). In this study, the presence of IgG antibodies as well as the presence of mononuclear leukocytes reactive to different cysteine proteinases (CPs) were examined in 13 L. infantum-infected dogs (six with symptoms, seven asymptomatic). Cysteine proteinases which belong to papain-like enzymes known as clan CA are the most studied CPs of parasite protozoa. These molecules are expressed by the intracellular stages of the parasite and could be immunogenic. We studied Type II CP (CPA) and Type I CP (CPB) with its long C-terminal extension (CTE) which could be highly immunogenic. We showed that the level of antibodies reactive to rCPA is low in both symptomatic and asymptomatic dogs. In contrast, when CPB and CTE were used as antigens, the level of total IgG (with IgG2 superior to IgG1) reached higher values in asymptomatic dogs than in dogs with VL. While the peripheral blood mononuclear cell (PBMC) reactivity was significant when cultured in the presence of freezed/thawed (F/T) lysate, it remained low in presence of CP although always higher for PBMC recovered from asymptomatic dogs. We showed the importance of CPB and CTE in particular as a target of immune response and their potential use for serodiagnosis in asymptomatic dogs.  相似文献   
62.
The relationships between a number of agronomic practices, Fusarium root rot (FRR) measurements and yield variables were characterized at different growth stages in 122 commercial bean fields in Zanjan, Iran. Mean FRR incidence, severity and index differed among growth stages and years. A lower FRR index at growth stage R9 and higher yields were detected in Red beans compared to Pinto and White beans. FRR severity affected the number of pods and seeds per plant. Despite the lack of an impact of initial drought on FRR and yield factors, FRR levels were higher following frequent irrigations at 2–3 days intervals than at longer intervals at R6-7. The highest FRR index at R6-7 (51.9%) and incidence at R9 (69.1%) were associated with the densest category of plant populations. Yield components differed significantly between the levels of plant density at R9. FRR levels at V3 were lower for June plantings than for May-second-week plantings. Lower FRR ratings and higher yields were detected at a seeding depth of 0–5 cm in comparison to 10–20 cm. At R9, FRR levels on beans following maize were lower than those following barley, bean, tomato or wheat. At V3, FRR severity was greater in fields that received 50–500 kg/ha of urea compared to non-fertilized fields. Greater mean FRR index at R6-7 and lower yield levels were associated with the greatest weed density compared to weed-free fields. This new information benefits the systematic understanding of interactions between bean yield, FRR and various agronomic variables at large-scale.  相似文献   
63.
The gaseous BeH2 molecule has been synthesized by means of an electrical discharge inside a high-temperature furnace and identified with infrared emission spectroscopy. The antisymmetric stretching mode nu3 has been detected near 2179 reciprocal centimeters. The BeH2 molecule has a linear, symmetric structure with an r0 BeH bond length of 1.333761(2) angstroms.  相似文献   
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65.
In this paper, laccase enzyme was immobilized onto zinc ferrite nanoparticle and the characteristics of enzyme immobilized nanoparticle (EIN) were evaluated by Fourier transform infrared (FTIR) and scanning electronic microscope (SEM). Enzymatic decolorization of dyes using EIN from single and binary systems was studied. Direct red 31 (DR31) and Acid blue 92 (AB92) were used as model dyes. The effects of several parameters such as EIN dosage, pH, and dye concentration on decolorization of dyes from single and binary systems were evaluated. The optimized amount of EIN, reaction time, and pH for decolorization of dyes from single and binary systems were 0.2 g (for DR31) and 0.3 g (for AB92), 40 min, and 3 in single systems and 0.2 g (for DR31 and AB92), 40 min, and 3 in binary systems, respectively. Dye decolorization kinetics followed Michaelis-Menten model. The results showed that enzymatic process using EIN was effective method to decolorize dyes from single and binary systems.  相似文献   
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67.
To investigate the effects of agronomic practices and farmer demographics on levels of weed infestation in chickpea fields, a survey was conducted during 2015 in Sanjabi district, Kermanshah, Iran. Two sets of data were collected: (a) weed sampling from the selected chickpea fields, and (b) questionnaire recording of farmer demographics and agronomic management. The farmers were asked about their residence status (resident or migrant), occupation (farming only, farming plus a second job), experience and education levels, as well as seedbed preparation, sowing date and method, source of seed supply, crop cultivar, sowing seed rate, weed control operation and crop rotation history. The results showed that weed species composition was similar across the studied fields. The use of a row crop planter, a sowing rate of 45 kg ha‐1, and weed control resulted in 30.2, 23.03 and 34.2% reductions in weed infestation compared with hand sowing, a sowing rate of 30 kg ha‐1 and lack of weed control, respectively. Weed density decreased with increasing farmer experience and decreased by 33.0% and 23.5% in chickpea fields of resident farmers and owners whose sole occupation was agriculture. We found that 89.5% of the most experienced farmers adopted weed control operations and most resident landowners (77.4%) opted for crop planter (77.4%) and weed control (90.3%) compared to migrant farmers (50 and 68.5%, respectively). More landowners who were exclusively farmers performed weed control (90.6%) than owners who had a second job (67.9%).  相似文献   
68.
The present study on the sediment production in natural forests was carried out on an 13,284 ha area,ocated in Guilan Province, in the north of Iran. This area is under intensive management. We first analyzed the physi- sal factors of the area. Then, the amount of road construction, afforestation and harvested wood volume, as well as the harvesting method in the region were determined for the years between 1993 and 2010. The results show that the aver- age annual amount of sediment production in the entire region, over this 18-year period, has increased annually at a rate of 3.54 t.km-2 (R2 = 0.56) at a confidence level of 95%. Operations management and management methods used in :his forest area has affected the amount of sediment production. Clear cutting and extensive harvesting methods in the region caused an increase in the amount of sediment production, as indicated by a coefficient of determination of 0.71, mplying that forest management may be considered effective and in harmony with the environment.  相似文献   
69.
The use of polyphosphates as a partial replacement of salt in different meat products to improve water holding capacity yield and retard oxidative rancidity has been noticed for many years. Therefore, in this study, effects of polyphosphates dip treatment in 5% solution with three different compounds of phosphate—including tetrasodium pyrophosphate (TSPP), sodium tripolyphosphate (STPP), and a mixture of them on kutum (Rutilus frisii kutum) fillets stored in ice was investigated for 18 days. Phosphate pretreatments showed desirable modal effects on fillets. In particular, the use of TSPP and the mixture of TSPP and STPP solutions were found to delay the fish fillet color changes and improved textural characteristics. An increase in water holding capacity accompanied with a decrease in hardness was observed in samples pretreated with polyphosphates. In total, the results indicated that dipping kutum fillets in polyphosphates solution was the most effective method to improve the quality properties of fillets during ice storage when compared with other phosphate-treated groups.  相似文献   
70.
In order to shed light on the role of Iran in apple evolution and domestication, we chose to investigate the relationships of a collection of 159 accessions of wild and domesticated apples including Iranian indigenous apple cultivars and landraces, selected wild species, and old apple scion and rootstock cultivars from different parts of the world. The majority of the wild species belonged to M. sieversii, which is widely believed to be the main maternal wild ancestor of domestic apples, from Kazakhstan and M. orientalis, which is one of the probable minor ancestors of domestic apples, from Turkey and Russia located on the east and west of Iran, respectively. The accessions were assigned into six arbitrary populations for the purpose of generating information on genetic parameters. Nine simple sequence repeat (SSR) loci selected from previous studies in apple were screened over DNA extracted from all the accessions. Results showed that all SSR loci displayed a very high degree of polymorphism with 11–25 alleles per locus. In total, there were 153 alleles across all loci with an average of 17 alleles per locus. The SSR allelic data were then used for estimation of population genetic parameters, including genetic variation statistics, F-statistics, gene flow, genetic identity, genetic distance and then cluster analysis using POPGENE 1.32 software. The F-statistics and gene flow in particular, showed that there was more intra-population than between population variation. The genetic identity and genetic distance estimates, and the dendrogram generated from the un-weighted pair group arithmetic average (UPGMA) method of cluster analysis showed that the Iranian cultivars and landraces were more closely related to M. sieversii from Central Asia (east of Iran) and M. orientalis native to Turkey and Russia than to other accessions of Malus species. Also, the old apple cultivars from different parts of the world have a closer genetic relationship to M. sieversii, M. orientalis and the Iranian apples, than to other wild species. Based on these results, we suggest that the Iranian apples may occupy an intermediate position between the domesticated varieties and wild species. We propose that Iran could be one of the major players in apples’ domestication and transfer from Central Asia to the western countries.  相似文献   
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