排序方式： 共有96条查询结果，搜索用时 31 毫秒
31.
Hiva Alipour Mina Sharbatoghli Poopak Eftekhari Yazdi Abdolhossein Shahverdi Mohamad Taghi Daneshzadeh Masoud Afshani Seied Jalal Mirian Hormoz Hamidi Ahmad Reza Mohammadi Mojtaba Rezazadeh Valojerdi 《Journal of Equine Veterinary Science》2013
The primary goal of this project was to establish a protocol to freeze the sperm of the Caspian miniature horse in an attempt to start an intensive artificial insemination program to effectively increase the population of this breed, which has been listed as “Critical Rare Breed” by the American Livestock Breed Conservancy and is in danger of extinction. Commercially available equine freezing medium (EquiPRO CyoGuard Complete egg-yolk extender) was used for the initial setup of two different freeze protocols: slow and fast. The fast-freeze protocol had slightly better postthaw results and was used for a fertility demonstration. Five mares of proven fertility, aged 3 to 12 years, were used in the fertility trials, two of which resulted in pregnancy. This is the first report of pregnancy in the Caspian miniature horse using frozen semen, and the results seem to be a promising start to an extensive program to help this endangered breed, although further research on freezing protocols and conditions for this process are necessary to further improve the survival of semen and pregnancy rate. 相似文献
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Elham Sadat Yazdi Almodarresi Javad Mokhtari Seyed Mohammad Taghi Almodarresi Mahdi Nouri Ali Shams Nateri 《Fibers and Polymers》2013,14(7):1196-1202
Conventional theory for color matching is Kubelka-Munk, but it fails in some situations. New intelligent procedures such as neural networks could learn the behavior of a complex system and produce accurate prediction. This paper investigates the ability of MLP (multiple layer perceptron) neural network for color matching of cotton fabric. Three reactive dyes, namely Levafix Red CA, Levafix Yellow CA and Levafix Blue CA were used for experiments. The dyed samples were scanned and L * a * b * histogram were extracted. Different neural networks were trained and tested using L * a * b * histogram of fabric’s images and also L * a * b * values (D65, 10°) of fabrics. The results were encouraging. For neural networks including the L * a * b * histogram in input vector, colorants and their concentration were predicted with a mean square error (MSE) less than 10?5 and an average value of color difference (CMC (1:2)) less than 1.5 for approximately 80 % of testing data. 相似文献
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I. Esfandiarpoor Borujeni Mohammad H. Salehi N. Toomanian J. Mohammadi R.M. Poch 《CATENA》2009,79(1):18-26
Landscapes are considered to be complex systems that are hierarchically structured and spatially scale-dependent. Geopedology allows a systematic approach in geomorphic analysis for soil mapping that extrapolates the results obtained at sample areas up to similar units. This paper examines the influence of sampling intervals on the accuracy of geopedological results in the Borujen region, Central Iran. After a primary interpretation of the study area on air photos (1:20 000), a geomorphic unit that encompassed the maximum surface of the sample area (and also the study area) was selected and was surveyed at three different scales: 500, 250 and 125 m intervals. The credibility of generalization of the results of the geopedological approach for the studied unit was tested by comparison with three profiles in a similar unit outside the sample area, named the validation area. Although the type of mapping unit in the sample area and the validation area was the same (complex) at the three different scales, the dominant soil in the validation area was different in comparison with the sample area at 125 and 250 m intervals. The results indicate that the geopedological approach to soil mapping is better carried out in reconnaissance or exploratory surveys. Comparison of soil types between the unit in the sample area and the validation area at three scales indicated that by increasing the taxonomic accuracy, the hidden aspects of the soils may be more identifiable. Therefore, although the geopedological approach tries to distinguish more homogeneous soil mapping units, it still is not able to fully define and represent the variability and apparent chaotic nature of the soils. We recommend further investigations on different techniques of stratifying the landscape in order to better analyze and understand the soil forming processes and soil variability and to improve sampling and mapping approaches. 相似文献
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In this study a newly laser treatment method for surface modification of nanofibers is introduced. The new method is based
on different infrared absorption of materials. Surface modification of Clay-PAN composite nanofibers was performed using selective
laser etching approach with CO2 pulsed laser in order to increase surface area of nanofibers. The surface structure of resulted nanofibers is characterized
using field emission scanning electron microscope and the results show characteristic modification of the surface topography
of laser treated nanofibers. The modified surface structure of nanofibers was studied and analyzed for different laser pulse
numbers and laser fluence. The results show that nanofiber surface modification strongly depends on the number of CO2 laser pulses and frequency of modified sites on the surface of nanofibers increasing with increasing the pulse fluence. This
new technique is highly selective and can also compete with conventional techniques for nanofibers surface modification. 相似文献
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Arefeh Ghoddusi Bahar Nayeri Fasaei Taghi Zahraei Salehi Hesameddin Akbarein 《Zoonoses and public health》2019,66(6):587-596
Salmonella enterica is a common food‐borne pathogen with occasional multidrug resistance (MDR). Salmonella genomic island (SGI1) is a horizontally transmissible genomic island, containing an MDR gene cluster. All Salmonella serotypes are public health concern, although there is an additional concern associated with those that harbour SGI1. In Iran, there are no data on the presence of SGI1 variants in Salmonella isolates. The present study was conducted to identify MDR‐ and SGI1‐carrying Salmonella strains isolated from various sources and to compare their genetic relatedness between human and animal sources. In total, 242 Salmonella isolates collected from chicken, cattle, and humans from 2008 through 2014 were studied. The isolates were tested for resistance to 14 antimicrobials via the disc diffusion method. They were also tested for the presence of SGI1 variants via PCR, and genetic relatedness was evaluated based on pulsed‐field gel electrophoresis (PFGE). Resistance to at least one antimicrobial agent was observed in 132 (54%) Salmonella isolates (n = 242), while more than 40% of the isolates showed MDR. Based on PCR analysis, eight variants of SGI1, including SGI1, SGI1‐B, SGI1‐C, SGI1‐D, SGI1‐F, SGI1‐I, SGI1‐J and SGI1‐O, were found in both human and animal isolates. Statistical analysis revealed no significant difference in the prevalence of SGI1 variants between human and animal isolates (p > 0.05). Macrorestriction PFGE analysis of the isolates with the same SGI1 variant and resistance patterns revealed genetic relatedness ranging from 70% to 100% among human and animal isolates. According to our review, this is the first documentation of SGI1 in Salmonella isolates in Iran. The presence of similar SGI1 variants in both humans and animals, along with their related PFGE patterns, suggests that food‐producing animals may be a source of MDR Salmonella isolates in Iran. 相似文献
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ABSTRACTThe effects of combined infrared-vacuum drying parameters, including infrared power (300–400 W), pressure (5–25 kPa) and time (0–140 min) on the drying kinetics of grapefruit slices were investigated. Both the infrared lamp power and vacuum pressure influenced the drying time of grapefruit slices. The regression results showed that the quadratic model satisfactorily described the drying behavior with highest R and lowest SE values. The effective moisture diffusivity increases as power increases and range between 5.83 × 10–10 and 2.13 × 10–9 m2/s. The color scale parameters, including redness (a*), yellowness (b*) and lightness (L*) values of dried grapefruit slices increased during drying. The rise in infrared power has a negative effect on the color change intensity (?E) and with increasing in infrared radiation power it was increased. Different kinetic models were used to fit the experimental data and the results revealed that the power model was the most suitable to describe the ?E. 相似文献
39.
Bakhshi B Pourshafie MR Navabakbar F Tavakoli A Shahcheraghi F Salehi M Faradjzadegan Z Zahraei SM 《Iranian Biomedical Journal》2008,12(3):159-165
Background: The virulence of a pathogenic Vibrio cholerae is dependent on a discrete set of genetic determinants. In this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of V. cholerae. Methods: The antibiotic resistance profiles of the isolates were determined using standard disk diffusion assay. PCR assay was performed to analyze the presence of toxin genes of ctx, zot and ace. The composition of cholera toxin encoding element (CTX) region flanking of the V. cholerae isolates was also analyzed. Results: All of the clinical isolates (100%) showed a complete set of virulence genes and also the attachment site of the filamentous bacteriophage CTXphi. None of the environmental isolates contained the virulence genes and the attachment site of the CTXphi. Analysis of the flanking regions including the toxin-linked cryptic element and repeat in toxin genes revealed their integrity in the clinical isolates while in the environmental isolates they were absent or contained incomplete sequences. Comparison of the antibiotic resistance assay of the environmental and clinical isolates showed a significant difference in the resistance profiles of the isolates obtained from the two sites. High rates of resistance to co-trimoxosol, streptomycin and chloramphenicol were found with clinical isolates. Conclusion: The absence of all virulence determinants in the environmental strains may suggest that certain ecological features must be present for V. cholerae to acquire a complete set of virulence determinants and to turn them into pathogenic strains. 相似文献
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Effects of monensin and increasing crude protein in early lactation on performance of dairy cows 总被引：1，自引：0，他引：1
Ghorbani B Ghoorchi T Amanlou H Zerehdaran S 《Pakistan journal of biological sciences: PJBS》2008,11(13):1669-1675
Twenty-four Holstein dairy cows were used to evaluate the singular and combined effects of different level of crude protein and monensin treatments during the early lactation on digestion and milk yield of dairy cows. The experiment was designed as completely randomized with a 3x2 factorial arrangement of treatments. The factors were three Concentrations of CP supplement (19.5, 21.4 and 23.4% of dry matter) and two levels of monensin (0 and 350 mg per cow per day). This experiment consist of three periods and each period was 3 week in length. Monensin did not affect DMI, milk yield, lactose and SNF but it reduced milk fat and protein percentage. Monensin premix significantly decreased rumen ammonia but rumen pH and microbial protein synthesis was not affected by monensin treatment. Although, Monensin treatment increased apparent digestibility of DM, NDF, ADF, CP, but they were not significantly. Increasing dietary CP, improved milk and protein production, but did not alter the other components of milk. Digestibility of NDF, ADF, CP were improved by increasing dietary CP. Increasing diet CP from 19.5 to 21.4% did not significantly increase ruminal ammonia, but increasing to 23.4% have significant effect on it. There was a linear relationship between level of crud protein in the diet and urine volume excretion. Microbial protein synthesis was affected by increasing CP level; on this way maximum protein synthesis was achieved in 21.4% CP. 相似文献