Effect of Transglutaminase,Citrate Buffer,and Temperature on a Soft Wheat Flour Dough System     

Marcela P. Bagagli  Sahar Jazaeri  Jayne E. Bock  Koushik Seetharaman  Helia H. Sato 《Cereal Chemistry》2014,91(5):460-465

Transglutaminase (TGase) can improve the functional characteristics of proteins by introducing covalent bonds inter‐ or intrachains. Temperature and pH interfere with the protein structure and the catalytic activity of enzymes. Because these three factors can act synergistically, TGase, citrate buffer, and temperature were evaluated for their effects on the rheological and chemical changes in low‐protein wheat flour dough. Dough strength, measured by microextension test, significantly increased with increasing levels of TGase (8 U/g of protein), with changes in pH of the citrate buffer (pH 6.5), and by the effect of interaction between these factors. The same trend was observed in the size‐exclusion HPLC measurements, indicating that these two parameters have the effect of increasing gluten protein aggregation. Temperature had a significant effect on dough extension, measured by microextension test. The changes in secondary structure of gluten protein were investigated by FTIR second‐derivative spectra (amide I region, 1,600–1,700 cm⁻¹) and showed an increase in β‐sheet structures initiated by TGase, citrate buffer pH, and their interaction.  相似文献   

Prevalence of ixodid ticks on cattle and sheep southeast of Iran     

Dehaghi MM  Fathi S  Asl EN  Nezhad HA 《Tropical animal health and production》2011,43(2):459-461

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle and sheep southeast of Iran. A total of 972 ticks were collected from 280 infested cattle and 1,207 ticks were collected from 632 infested sheep during activating seasons of ticks in 2008–2009. The species collected from cattle were Hyalomma marginatum marginatum (50.92%), Hyalomma anatolicum excavatum (25.61%), Hyalomma anatolicum anatolicum (8.12%), Hyalomma asiaticum asiaticum (1.85%), and Rhipicephalus sanguineus (13.47%) while the species collected from sheep were R. sanguineus (36.37%), H. marginatum marginatum (30.65%), H. anatolicum excavatum (19.05%), H. asiaticum asiaticum (10.52%), Hyalomma detritum (3.14%), and Dermacentor marginatus (0.24%). The results show that, H. marginatum marginatum, H. anatolicum excavatum, and R. sanguineus are dominant tick species in the surveyed area.  相似文献   

Serological surveillance reveals widespread influenza A H7 and H9 subtypes among chicken flocks in Egypt     

Manal A. A. Afifi  Magdy F. El-Kady  Sahar A. Zoelfakar  Ahmed Sayed Abddel-Moneim 《Tropical animal health and production》2013,45(2):687-690

Multiple avian influenza viruses’ subtypes are circulating worldwide possessing serious threat to human populations and considered key contributors to the emergence of human influenza pandemics. This study aimed to identify the potential existence of H7 and H9 avian influenza infections circulating among chicken flocks in Egypt. Serum samples were collected from chicken flocks that experienced respiratory distresses and/or variable mortality rates. H7 and H9 virus infections were screened by haemagglutination inhibition assay using chicken erythrocytes. Serum samples were collected from 9 broiler, 12 breeder and 18 layer flocks. Out of 1,225 examined sera, 417 (34 %) from 14 flocks and 605 (49.4 %) from 21 flocks were found positive for H7 and H9, respectively. Prevalence of both H7 and H9 antibodies were higher in layer followed by breeder then broiler flocks. Special consideration should be paid to control influenza viruses in Egypt, as pandemic influenza strains may develop unnoticed given the presence of subclinical infections, and the possibility of re-assortment with the prevailing endemic H5N1 virus strains in Egypt do exist.  相似文献   

An analytical approach for the recovery behavior of cut pile carpet after static loading by mechanical models     

Sahar Jafari  Mohammad Ghane 《Fibers and Polymers》2016,17(4):651-655

In this paper, a viscoelastic model for the recovery behavior of the machine-made carpet has been presented. Different combinations of spring and dashpot systems are usually considered to model the mechanical behavior of textile materials. The initial thickness of the carpet samples was measured using a digital thickness gauge. The samples were then imposed to static loading. Consequently, the thickness of carpet samples after the load removal was measured again by considering the relaxation time at the range of 1 to 30 minutes with the intervals of 2 minutes. Jeffery’s mechanical model, which is combined of spring and dashpot components, was used to model the variation trend of thickness loss percentages for the carpet samples at different relaxation times. Curve fitting based on the least square method was used to adapt the experimental data to the theoretical model. For comparison, the standard linear model was also applied to experimental data. The results showed that there was a reasonably good agreement between the Jeffrey’s model and the experimental data. The results also revealed the linear standard model showed poor regression for the recovery properties of cut pile carpets after static loading. The reason was that the standard linear model was completely elastic, showing no secondary creep. On the other hand, the recovery of cut pile carpers showed some permanent creep that could be explained by Jeffrey’s model.  相似文献   

Effect of sex and rearing system on the quality and mineral content of fiber from raeini cashmere goats     

M Shamsaddini-Bafti  M Salehi  A Maghsoudi  AM Tehrani  F Mirzaei  SM Momen 《畜牧与生物技术杂志(英文版)》2012,3(1):20-6

The aim of this study was to compare the quality characteristics and mineral content of the fiber from male and female cashmere goats raised under different management systems. Male and female Raeini cashmere goats (<1.5 years of age, n = 48) were selected from flocks raised at a government breeding station or raised commercially under either rural or nomadic conditions. The staple length, cashmere fiber diameter, coefficient of variation for fiber diameter, percentage of cashmere in a fleece, percentage of guard hair in a fleece and cashmere tenacity averaged 4.6 ±0.1 cm, 18.0 ±0.1 μm, 20.9 ± 0.4%, 66.1 ± 1.5%, 33.8 ± 1.5% and 1.8 ± 0.2 gf/tex, respectively. The sulfur, copper and zinc content of the cashmere averaged 2.8 ± 0.1%, 0.00065 ± 0.00002% and 0.01276 ± 0.00025%, respectively. Rearing method significantly affected staple length, coefficient of variation of fiber diameter, cashmere tenacity and copper content. Males had a higher coefficient of variation of fiber diameter and cashmere tenacity than females (P < 0.05).  相似文献   

A single drought event of 100‐year recurrence enhances subsequent carbon uptake and changes carbon allocation in experimental grassland communities     

Heydar Mirzaei  Juergen Kreyling  Mir Zaman Hussain  Yuelin Li  John Tenhunen  Carl Beierkuhnlein  Anke Jentsch 《植物养料与土壤学杂志》2008,171(5):681-689

Evidence suggests that the expected increase in frequency and magnitude of extreme weather events during climate change will alter plant productivity. Therefore, extreme weather events might also be capable of changing C sequestration and allocation. Here, experimental grassland communities of two species compositions, differing in their diversity, were exposed either to a simulated single drought or to a heavy‐rainfall event. The magnitude of these manipulations imitated the local 100‐year weather extreme according to extreme‐value statistics. Effects on Net Ecosystem CO₂ Exchange (NEE in µmol m^–2 s^–1) as well as aboveground biomass production and leaf‐area index (LAI) were recorded from prior to the manipulations until two months after the manipulations ended. Initial light utilization efficiency and maximum NEE increased after the drought. No change in the respiration was detected and maximum uptake capacity (GPP_max) was 15% higher for the drought‐manipulated plots compared to controls, which indicates an enhanced CO₂ uptake into the systems. The level of diversity was also found to alter the light‐response curves, increasing respiration and maximum NEE to a higher degree than drought in the more diverse compared to the less diverse community. This resulted in an increase of GPP_max by 55%. No significant interactions between species composition and weather manipulations were detected. Interestingly, aboveground biomass production was not significantly affected by weather manipulations, even though LAI increased due to drought. This increase was caused by a decrease in the ratio between reproductive and vegetative growth. The heavy‐rainfall manipulation resulted in no significant effects. Our data suggest that C sequestration can be enhanced by a single weather event. However the importance, long‐term duration, and thresholds or turning points of such effects need to be investigated further as intensification of weather extremes is currently emerging as one of the most important facets of climate change.  相似文献   

Modeling frequency distributions of tree height,diameter and crown area by six probability functions for open forests of <Emphasis Type="Italic">Quercus persica</Emphasis> in Iran     

Mehrdad Mirzaei  Jalal Aziz  Ali Mahdavi  Asma Mohammad Rad 《林业研究》2016,27(4):901-906

The prediction of the distribution of quantitative variables in a forest stand is of great interest to forest managers, for the evaluation of forest resources and scheduling of future silvicultural treatments. The aim of this research was to model the distribution of quantitative variables for Quercus persica in open forests in Iran. To investigate the probability distribution of trees in natural stands, 642 trees were selected for measurement using a systematic random sampling method. Selected trees were measured and data were analyzed. Gamma, beta, normal,lognormal, exponential and Weibull probability distributions were fitted to the height distribution of trees. Variables of distribution functions were estimated using the maximum likelihood estimation method. Actual probability and probability which derived from functions was compared using Kolmogorov–Smirnov and Anderson–Darling tests. Beta, Weibull and Weibull probability distributions explained the distributions of tree height, DBH and crown area.  相似文献   

Effects of supplementation level and particle size of alfalfa hay on growth characteristics and rumen development in dairy calves          下载免费PDF全文

M. Mirzaei  M. Khorvash  G. R. Ghorbani  M. Kazemi‐Bonchenari  A. Riasi  A. Nabipour  J. J. G. C. van den Borne 《Journal of animal physiology and animal nutrition》2015,99(3):553-564

The aim of this study was to assess the effects of particle size (PS) of alfalfa hay on growth characteristics and rumen development in dairy calves at two levels of alfalfa supplementation. Fifty newborn dairy calves (42.7 ± 2.2 kg BW) were used in a 2 × 2 factorial arrangement with the factors supplementation level (low, 8%; or high, 16% on DM basis) and PS (medium, 2.92 mm; or long, 5.04 mm as geometrical means) of alfalfa hay. In addition, a control group without alfalfa hay was used. Hence, treatments were: control (C); low level with medium PS (LM); low level with long PS (LL); high level with medium PS (HM) or high level with long PS (HL). Growth performance of alfalfa‐fed calves did not differ from control calves, but alfalfa supplementation decreased corneum thickness of the rumen wall. In alfalfa‐fed calves, post‐weaning starter intake was greater for LL calves than for LM calves. During the entire rearing period, starter intake was 26–32% higher for LL and HM calves than for LM calves. Pre‐weaning average daily gain was higher for LL and HM calves than for HL calves, but this effect was not persistent over the entire rearing period. Final body weight decreased from 86 to 79 kg when the level of long PS alfalfa hay increased from 8 to 16%, but increased from 78 to 87 kg when the level of medium PS alfalfa increased from 8 to 16%. Regardless of PS and level, morphometric characteristics of rumen wall were generally similar among alfalfa feeding groups, but corneum thickness decreased from 8.7 to 6.1 μm with greater PS at the low level. These results indicate that adequate, but not excessive, physical stimulation is required for appropriate rumen development and growth performance of dairy calves.  相似文献   

Light transmission and the fine structure of poly(methyl methacrylate) nanofibers and films     

Maryam Mirzaei Sheshkol  Sedigheh Borhani  Mostafa Youssefi 《Fibers and Polymers》2017,18(12):2361-2367

In this paper, the structure and optical properties of poly(methyl methacrylate) (PMMA) nanofibers and films were investigated. Differential scanning calorimetery (DSC) and Wide-Angle X-ray scattering (WAXS) results confirmed the amorphous structure of both nanofibers and films. Low angle X-ray diffraction (LA-XRD) revealed the presence of voids and/or particles with the spacing of 128.4 Å within the nanofibers. From the Porod plots, a three-dimensional surface fractal for the nanofibers and a mass fractal structure for the films were derived. By the interpretation of Small Angle X-ray scattering (SAXS), the shape and size of the particles in the samples were assessed. It was concluded that the particles shape within the nanofibers and the films were globular, with the radius of gyration of 8.5 nm for the nanofibers and 16.5 nm for the films. The nanofiber mat showed less light transparency when compared with the film. This phenomenon could be attributed to the difference in the physical shape, as well as scattering of the light by the voids or particles within the nanofibers.  相似文献   

Zinc deficiency in winter oilseed rape (Brassica napus L.) is counteracted by N fertilization     

Dr Hossein Sabahi  Saeid Soufizadeh  Reza Mirzaei Talarposhti 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(4):317-325

Abstract

A two-year experiment was conducted on oilseed rape in 2004–2005 and 2005–2006 in north Iran. Treatments were 0, 50, 100, and 150 kg N ha^?1 as urea (F₀ to F₁₅₀, respectively), 100 kg N ha^?1 as urea +50 kg N ha^?1 as manure (F₁₀₀M₅₀), 50 kg N ha^?1 as urea +100 kg N ha^?1 as manure (F₅₀M₁₀₀), and 150 kg N ha^?1 as manure (M₁₅₀). Results indicated that seed yield in M₁₅₀ was significantly lower than in F₁₅₀ in both years. Seed protein content in the inorganic fertilization system (F₁₅₀) was significantly higher than in the organic (M₁₅₀) and integrated systems (F₁₀₀M₅₀ and F₅₀M₁₀₀). Seed oil content, however, was higher in the organic treatment than in the inorganic treatment. Less N uptake in F₁₀₀M₅₀ compared with F₁₅₀ in the first year and in F₅₀M₁₀₀ compared with F₁₅₀ in the second year did not result in similar differences in grain yield. Owing to the low content of soil-available Zn, the association between Zn and N concentration in shoot in the inorganic treatments was low. In spite of a significant increase in soil-available Zn under the organic and integrated treatments, no significant increase was observed in Zn concentration of shoot in these treatments compared with F₁₅₀. It appears that the excessive availability of P in M₁₅₀, F₅₀M₁₀₀, and F₁₀₀M₅₀ has reduced either Zn uptake or its translocation from root to shoot. Overall, it could be concluded that in order to increase Zn uptake under manure application in a Zn-deficient soil, N availability should increase.  相似文献