An analysis of structure and properties of a natural cellulosic fiber (Leafiran)

The ever-increasing importance of vegetable natural fibers on the global scale, the comparatively low production of this group of fibers, and the growing fiber imports by the Iranian textile industry have required numerous studies in recent years to be carried out on long natural cellulosic fibers extracted from Typha australis plant leaf. In this study, such tensile properties of the fiber under study as tenacity, modulus, elongation and work of rupture, X-ray and FTIR are investigated by alkali retting at 100 °C for 2 and 4 h. It is found that Leafiran is lignocellulosic with a tenacity approximately 25–40 cN. Tex-1, a linear density of about 4 tex, and a crystallinity of about 60 %, which are all considered to be suitable properties compared to those of other natural cellulosic fibers.     

Effects of flushing and hormonal treatment on reproductive performance of Iranian Markhoz goats

Forty‐eight Iranian Markhoz goats were allocated to six groups (n = 8) to study the effect of flushing and hormonal treatments on reproductive performance. Treatments were divided into two categories including, hormonal treatments and flushing. The goats in each group were fed the same basal ration and received one of the following treatments: Groups A and B – injection of GnRH and equine chorionic gonadotropin (eCG) respectively; Groups C, D and E – a supplement of barley grain, soybean oil and sunflower oil in flushing diets, respectively, were offered and Group F – control (only received basal diet). In the flushing treatments, only the source of energy was different between rations. Both hormonal treatments and flushing treatments improved fertility and kidding rates. Treatment B with 16 and control with seven kids represented the highest and the lowest number of progeny respectively. Among flushing treatments, group C resulted in the highest number of kids being 15. Oestrogen levels in follicular phase increased with the injection of eCG and consumption of barley grain. GnRH injection and consumption of oil sources in the diet increased blood progesterone levels during ovulation and post‐ovulation periods. Under current market conditions, using hormone or flushing can be profitable for Markhoz goats farmers.     

Optimization of microwave assisted extraction for determination of iron and manganese in cereal flour using FAAS: Doehlert design

The present work describes the development by response surface methodology of a method for manganese and iron determination by flame atomic absorption spectrometry (FAAS) in cereal flours, which is based on microwave assisted extraction. The optimization process was performed using two level fractional factorial designs (2^4-1) and Doehlert design matrix. Four variables such as irradiation power, time, temperature and concentration of nitric acid were regarded as factors in the optimization. Results of two level fractional factorial designs with 10 runs for manganese and iron extraction, based on the Pareto chart, demonstrated that the factors irradiation power, time and temperature are statistically significant, and concentration of nitric acid is not significant. Then, a Doehlert design was carried out in order to determine the optimum conditions for the procedure through response surface study. The working conditions were established as a compromise between optimum values found for each analyte. These values were 87.0°C, 573.0 W and 40.0 min, for temperature, irradiation power and time, respectively. The accuracy of the optimized procedure was evaluated by analysis of certified reference material. The procedure proposed was applied for the determination of iron and manganese in cereal flours.     

Effects of Bentonite Application and Urea Fertilization Time on Growth,Development and Nitrate Accumulation in Spinach (Spinacia oleraceae L.)

Under excessive application of nitrogen fertilizer, vegetables can accumulate high levels of nitrate in their vegetative body and, when consumed by living organisms, pose serious health-related risks for humans. Regarding such problems, it is necessary to minimize the accumulation of nitrate in leafy vegetables. Therefore, a pot experiment was conducted to evaluate bentonite levels (0, 20, 40, 60, 80 g/kg soil) application and urea fertilization times (25, 50, 75 days after sowing; at the rate of 0.2 g per pot) on the growth, development and nitrate accumulation of spinach. Results showed that urea fertilization on 25 days after sowing date had the highest effect on the quality, while application of 60 gr bentonite had the highest effect on the improvement of growth parameters of spinach. The lowest nitrate and nitrite accumulation rate was observed at urea fertilization on 50 days after planting and lack of bentonite application, whereas the lowest oxalic acid content was obtained at urea fertilization on 25 days after planting in a soil without bentonite application. The results showed that implementing an appropriate rate of bentonite and urea fertilization times may bring about favorable results for spinach production.     

Characterization of nutrients uptake and enzymes activity in Khatouni melon (Cucumis melo var. inodorus) seedlings under different concentrations of nitrogen,potassium and phosphorus of nutrient solution

A nutrient solution experiment was done to evaluate effects of different concentrations of nitrogen (N), phosphorus (P) and potassium (K) on leaf mineral concentrations and some enzymes activity of melon seedlings (Cucumismelo var. inodorus subvar. Khatouni). Different levels of these nutrients including 0, 53, 105, 158 and 210?mg L^?1 N; 0, 8, 16, 23 and 31?mg L^?1 P; 0, 59, 118, 176 and 235?mg L^?1 K, all corresponding to 0, 25, 50, 75 and 100% of their concentrations in Hoagland nutrient solution, were applied to plants. The results showed that the highest leaf nitrate reductase (NR) activity was observed at highest N and P levels, whereas the three highest K levels showed the highest NR activity. The highest leaf peroxidase activity was observed at 8?mg L^?1 P, 59?mg L^?1 K and 158?mg L^?1 N. The leaf catalase activity was highest at zero concentration of P, 158?mg L^?1 N and 176?mg L^?1 K; however, catalase activity was decreased by increasing P levels. Leaf protein content showed an increasing trend with increasing N, P and K levels of nutrient solution, while there was no significant difference between 158 and 210?mg L^?1 N. The highest leaf concentrations of N, P, K and Mg were observed at highest nitrogen, potassium and phosphorus levels of nutrient solution, whereas the highest leaf concentration of Ca were obtained at 53 or 105?mg L^?1 N, 176?mg L^?1 K and 23–31?mg L^?1 P. The highest iron concentration of leaves was obtained from 23 to 31?mg L^?1 P, 176?mg L^?1 K and 210?mg L^?1 N.     

Three-dimensional modelling of wood fracture in mode I, perpendicular to the grain direction at fibre level

A coupled experimental and numerical modelling approach was used to investigate the mechanism of softwood fracture at the fibre level. First, a three-dimensional mixed lattice-continuum fracture model was developed to investigate the mechanism of wood fracture, taking into account the porosity of its structure and its heterogeneities at the fibre level. The critical volumes in the specimen where crack propagation was more probable were modelled by a lattice that could show the alternation of earlywood and latewood fibres, and the other regions were considered as the continuum medium. The proposed model was used to investigate the mode I fracture of a small softwood sample in RL orientation. Secondly, a method was developed for microscopic observation of the crack trajectory and investigating the mechanism of initiation and propagation of cracks. This approach was used for microscopic investigation of the fracture behaviour of spruce specimens in mode I and RL orientation. The results of the numerical study were compared with the experimental results. The prepeak and postpeak behaviour of the obtained stress-displacement curve and also the crack opening trajectory in cross-section and longitudinal section in the model and experiments were in good agreement. Both the model and the microscopic observation showed that in mode I fracture and RL orientation, the main trajectory of the crack propagates in the earlywood ring.     

Genetic and Genotype x Environment Interaction Effects for Appearance Quality of Rice

This study was conducted to generate genetic information in rice varieties based on a complete diallel crosses over two years. The results indicated that genotype effect was significant for all traits. Genotype × environment interaction effects were significant only for cooked grain length （CGL） and cooked grain shape （CGSH）. General combining ability （GCA） and specific combining ability （SCA） effects were significant for entire traits, which indicated the important roles of both additive and non-additive gene actions. GCA x environment interaction effects were significant for CGL, CGSH and grain elongation index （GEI）. In the controlling of the inheritance of milled grain shape （GSH）, milled grain width （MGW）, GEI, milled grain length （MGL）, CGSH and cooked grain width （CGW）, the additive gene effects were more important than non-additive one. The average degree of dominance was within the range of partial dominance for all of the traits. The narrow-sense heritability was ranged from 0.65 （GSH） to 0.36 （CGL）. GCA effects were significant for all of the parents in milled grain length and it was significant for some of the parents in other traits. The crosses of Deilmani × IRFAON-215 exhibited significant SCA for GEI. The positive mean of heterosis was observed for CGW. The highest maximum values of heterosis were revealed in GEI, flowed by GSH, MGW and CGW. GCA and MPV were significantly and positively correlated together for all traits.     

Genetic and Genotype × Environment Interaction Effects for Appearance Quality of Rice

This study was conducted to generate genetic information in rice varieties based on a complete diallel crosses over two years. The results indicated that genotype effect was significant for all traits. Genotype × environment interaction effects were significant only for cooked grain length (CGL) and cooked grain shape (CGSH). General combining ability (GCA) and specific combining ability (SCA) effects were significant for entire traits, which indicated the important roles of both additive and non-additive gene actions. GCA x environment interaction effects were significant for CGL, CGSH and grain elongation index (GEI). In the controlling of the inheritance of milled grain shape (GSH), milled grain width (MGW), GEI, milled grain length (MGL), CGSH and cooked grain width (CGW), the additive gene effects were more important than non-additive one.The average degree of dominance was within the range of partial dominance for all of the traits. The narrow-sense heritability was ranged from 0.65 (GSH) to 0.36 (CGL). GCA effects were significant for all of the parents in milled grain length and it was significant for some of the parents in other traits. The crosses of Deilmani × IRFAON-215 exhibited significant SCA for GEI. The positive mean of heterosis was observed for CGW. The highest maximum values of heterosis were revealed in GEI, flowed by GSH, MGW and CGW. GCA and MPV were significantly and positively correlated together for all traits.     

Multilocus Sequence Typing for Molecular Epidemiology of Stenotrophomonas maltophilia Clinical and Environmental Isolates from a Tertiary Hospital in West of Iran

Background: Stenotrophomonas maltophilia is an opportunistic bacterium, contributing to different hospital-acquired infections and can be acquired from different hospital setting sources. Epidemiological study of S. maltophilia in the hospital also demonstrates the intrahospital distribution of certain strains of bacteria in healthcare facilities. The aim of the current study was to identify the molecular epidemiology of S. maltophilia isolates from clinical and environmental sources within a hospital. Methods:A total of 400 samples (clinical and environmental) were collected from the different settings of hospital. Following the standard biochemical testing and 23S rRNA genotyping, the molecular typing of S. maltophilia isolates was determined using the MLST technique. Also, the frequencies of zot and entF virulence genes among S. maltophilia isolates were examined by PCR technique. Results:Based on the biochemical testes and PCRs targeting 23S rRNA gene, 22 S. maltophilia isolates were identified. The MLST analysis demonstrated that these isolates were assigned to 14 ST, and 6 out of 14 STs were common among clinical and environmental samples. All 22 isolates were identified in the PubMLST database. The PCR screening demonstrated that none of 22 S. maltophilia isolates had zot virulence gene, while the entF gene with the 59% frequency was observed in 13 out of 22 isolates. Among these 13 isolates, 6 STs were common in clinical and environmental isolates. Conclusion:Our study showed the clonal relatedness between clinical and environmental sources of the S. maltophilia isolates in a hospital. Further studies are required to understand the epidemic situation of this pathogen in the clinic and the environment. Key Words: Environment, Multilocus sequence typing, Stenotrophomonas maltophilia     

Study of Genetic Diversity of Pear Genotypes and Cultivars (<Emphasis Type="Italic">Pyrus communis</Emphasis> L.) Using Inter<Emphasis Type="Italic">-</Emphasis>Simple Sequence Repeat Markers (ISSR)

ISSR molecular marker was used to investigate genetic diversity of ‘Dare Gazi’ genotypes of Mashhad Esteghlal orchard and its relationship with other commercial and native cultivars of pear. Among ‘Dare Gazi’ genotypes of Mashhad Esteghlal orchard 23 genotypes were selected base on difference in tree vigor, leaf color, shape and color of fruit and also 33 other commercial and native pear cultivars from Esteghlal orchard and other Mashhad commercial orchards were studied. A total number of 230 DNA fragments were obtained using 11 primers of which 225 were polymorphic. On average, each primer produced 20.9 bands. Dice similarity coefficient ranged from 0.27 (between ‘Dom Kaj’ and Asian pear) to 1 (between ‘Dare Gazi’ 1 and 2 genotypes). Sample cluster dendrogram indicated that 56 genotypes were divided into 12 distinct clusters. The dendogram generated on the principle of Unweight Pair Wise Method using Arithmetic Average (UPGMA) was constructed by Dice coefficient and the genotypes were grouped into 12 clusters. ‘Dare Gazi’ genotypes did not show 100% similarity due to seed propagation or mutation, as ‘Dare Gazi’ 3 and 18 genotypes had the lowest similarity coefficient (0.64). Asian pears were placed in a separate group from European pears. And ‘Dare Gazi’ genotypes from different orchards were grouped separately, but all of them are called as ‘Dare Gazi’ pear for convenience. ISSR molecular marker can well identify the genetic variability among genotypes and cultivars and found suitable for grouping them.