13 research outputs found
Investigating Iranian English Language Teachersâ Practices and Perceptions of Vocabulary Teaching
This study aimed at exploring English language teachersâ practices and perceptions of vocabulary teaching in Iranian private language schools. Using a qualitative research design, four competent language teachers were purposefully selected and their perceptions of vocabulary teaching were investigated from several dimensions. Three qualitative data gathering techniques including interviews, classroom observation, and stimulated recall interviews were utilized to have a thorough understanding of the participantsâ practices and perceptions about vocabulary instruction. Findings revealed that although EFL teachers possessed sufficient knowledge and perspectives with respect to vocabulary teaching strategies, such stated declarative knowledge did not serve the full purposes of vocabulary teaching. Participants typically utilized decontextualized strategies more extensively than contextualized ones in their actual practices indicating that their tendencies are somehow towards traditional approaches in teaching vocabulary. In other words, teachersâ instructional practices did not capture all their stated beliefs. Furthermore, it was found that the implemented policies in English language schools which are greatly towards time economization might be a liable reason cheering teachers to deviate from their real beliefs. Finally, contributing to developmental aspects of language teaching, findings of this particular study possess several implications both for teacher education institutions and stakeholders in private language schools in Iran and other similar contexts
Effects of the inclusion of sunflower hulls in the diet on growth performance and digestive tract traits of broilers and pullets fed a broiler diet from zero to 21 d of age. A comparative study
The effects of including 3% sunflower hulls (SFH) in the diet on growth performance, nutrient retention (TTAR), and gastrointestinal tract (GIT) traits were studied in chicks from zero to 21 d of age. Four treatments that resulted from the combination of 2 chicken lines (female broilers vs. brown pullets) and 2 levels of SFH (zero vs. 3%) were used. The control diet contained 2,980 kcal AMEn/kg, 1.25% digestible Lys, and 8.7% neutral detergent fiber. The experimental diet included 3% SFH at the expense (wt:wt) of the whole diet. Growth performance, TTAR of nutrients, and the AMEn of the diet were greater (P = 0.097 to P < 0.001) in broilers than in pullets. In absolute terms, all the organs of the GIT were heavier (P < 0.001) and the small intestine and cecum were longer (P < 0.001) in broilers than in pullets. At 21 d of age, however, the relative weight (% BW) of all the organs of the GIT (P < 0.001) and the relative length (cm/kg BW) of the small intestine and cecum (P < 0.01) were greater in pullets. Gizzard pH (P < 0.001), total short chain fatty acids concentration in the cecum (P = 0.098), and villus height (P < 0.001) and crypt depth (P < 0.05) of the ileum mucosa were higher in broilers. The inclusion of SFH increased (P < 0.05) the AMEn content of the diet but did not affect bird performance, moisture content of the excreta, or the concentration and profile of fatty acids in the cecum. Dietary SFH increased gizzard weight and reduced gizzard pH (P < 0.001) at both ages. In conclusion, broilers had better growth performance, nutrient retention, and ileum absorptive capacity than pullets. The inclusion of 3% SFH at the expense of the control diet did not have any negative effect on chick performance and, in fact, increased gizzard weight, reduced gizzard pH, and improved the energy content of the diet
Comparison Study on Colonization of hilA Mutant and Parent Strains of Salmonella enteritidis in Vertically Infected Broiler Chickens
Background: Salmonella actively stimulates its own uptake into the epithelial cells by inducing cytoskeleton rearrangements and membrane ruffling triggered by some proteins secreted by Salmonella into the cytosol of the epithelial cells via a type III secretion system (TTSS) encoded by genes of the Salmonella pathogenicity island 1 (SPI-1). hilA is a transcriptional activator encoded on Salmonella Pathogenicity Island 1 (SPI-1) genes.
Methods: To assess the importance of hilA in a simulation modeling of vertical infection and shedding of S. enteritidis in broiler chickens a long-term experiment was designed. Two groups of 200 fertile eggs were inoculated with 20 colony forming units (CFU) of hilA mutant of S. enteritidis or its parent strain just prior to incubation. Thirty five birds of each group were housed in separate rooms. On days 2, 4, 7, 14, 21, 28 and 35 of age, cloacal swabs from live birds as well as samples from internal organs (intestinal tract, liver and spleen) were evaluated by bacteriological or molecular methods.
Results: In most of sampling days colonization and invasion of parent strain S. enteritidis in intestine (especially ceaca) and internal organs of chickens were higher with compared to its hilA mutant but this mutant strain could still colonize in intestinal tract and even invade liver or spleen.
Conclusion: Colonization of hilA mutant of S. enteritidis indicated that hilA gene is only one part of the modulators in Salmonella invasion mechanism. The ability of hilA mutant to multiply and persist in host internal organs including ceaca may promise further research for potential of hilA mutant to prevent the initial colonization of the intestinal tract by a virulent S. enteritidis strai
Hassanzadeh M, Ashrafi I. Identification and characterization of Salmonella isolates from captured house sparrows
Abstract: The objectives of this study were to determine the prevalence of Salmonella in a population of house sparrows, which are commonly found around poultry houses, and to characterize the obtained Salmonella isolates via serotyping, multiplex polymerase chain reaction (PCR), and antibiotic resistance analysis. Samples of visceral organs (gastrointestinal tract, liver, and heart) from 470 house sparrows were subjected to culture and the results show that 18 (3.8%) were positive for Salmonella. Of the 18 Salmonella isolates characterized, the most predominant serovars were Salmonella Typhimurium and S. Enteritidis (9 and 8 cases each, respectively), whereas only 1 serovar belonged to S. Montevideo. All 9 S. Typhimurium serovars were positive for rfbJ, fljB, invA, and fliC genes based on multiplex PCR assay. In the case of S. Enteritidis serovars, PCR generated amplification products for spv and sefA genes, and a random sequence (specific for the genus Salmonella) in all 8 samples. All the Salmonella isolates were sensitive to norfloxacin, flumequine, ampicillin, and sultrim, and 35% were resistant to lincospectin (the most prevalent resistance)
Molecular detection and occurrence of vancomycin resistance genes (van A, B, C1, C2/C3) among Enterococcus species isolated from farm ostriches
Abstract Background Evaluating the prevalence of vancomycin resistance genes (van genes) in enterococcal isolates from foodâproducing animals is an important public health issue because of the possibility of resistance genes spread to human. Objectives The present study aimed to determine the occurrence of vancomycin resistance genes among Enterococcus species obtained from ostrich faecal samples. Methods One hundred and twentyâfive faecal samples of apparently healthy ostriches from five different farms were investigated. Genes encoding vancomycin resistance were studied by multiplexâPCR, and susceptibility to six antibiotics was evaluated by diskâdiffusion method. Results In total, 107 Enterococcus spp. isolates were obtained and confirmed by biochemical and molecular tests. Enterococcus faecium was the prevailing species (56 isolates of 107; 52.3%), followed by E. hirae (24 isolates; 22.4%) and E. gallinarum (12 isolates; 11.2%). Of the 107 recovered isolates, 44% harboured at least a type of van genes. vanA, vanC2/3 and vanC1 were identified in 34 (31.7%), 13 isolates (12.1%) and 4 (3.7%) isolates respectively. Additionally, four isolates (E. gallinarum, E. rafinosus) coâharboured the the vanA and vanC1 or vanA and vanC2/3. Enterococcus faecium and Enterococcus hirae strains with the vanA genotype were the most frequent vanâcarrying enterococci from ostrich faecal samples. Among vanâcarrying enterococcal isolates, 23.4% were phenotypically resistant to vancomycin. This study revealed a relatively high prevalence (44%) of vanâcarrying enterococci in ostrich faecal samples. Conclusions Results of the present study suggest that ostrich faeces could be considered as a reservoir of vancomycin resistance genes, especially vanA containing enterococci that could be potentially transferred to human through the food chain
A refined method for ovule culture in sugar beet (Beta vulgaris L.)
[EN] Induction of gynogenesis through ovule culture is a valuable tool to produce haploid and doubled haploid plants in sugar beet (Beta vulgaris L.). However, there is still large room for refining the method. In this study we investigated the gynogenic response of cultured ovules of three sugar beet genotypes, the effect of the application to inflorescences of different pretreatments with mannitol at 4oC and with 5-azacytidine and 2,4-D, and the effect of the use of different basal culture media and sucrose concentrations. The response was evaluated in terms of percentages of induction of gynogenesis, embryogenesis and callogenesis, as well as of regenerated plants. We showed that a pretreatment with 0.5 M mannitol at 4 degrees C for 4 days, and with 50 mu M 5-AzaC for 1 h, notably improved the percentage of embryogenesis and plant regeneration. Besides, the use of MS basal medium and 60 g/L sucrose was also found beneficial. This study provides new ways to improve the efficiency of haploid induction and plant regeneration through ovule culture in sugar beet, and is potentially applicable to ovule culture in other crops.
Key message This study provides new ways to improve the efficiency of haploid induction and plant regeneration through ovule culture in sugar beet.Sohrabi, S.; Abdollahi, MR.; Mirzaie-Asl, A.; Koulaei, HE.; Aghaeezadeh, M.; SeguĂ-Simarro, JM. (2021). A refined method for ovule culture in sugar beet (Beta vulgaris L.). Plant Cell Tissue and Organ Culture (PCTOC). 146(2):259-267. https://doi.org/10.1007/s11240-021-02065-82592671462Abdollahi MR, Rashidi S (2018) Production and conversion of haploid embryos in chickpea (Cicer arietinum L.) anther cultures using high 2, 4-D and silver nitrate containing media. Plant Cell Tiss Organ Cult 133:39â49Aflaki F, Pazuki A, Gurel S, Stevanato P, Biancardi E, Gurel E (2017) Doubled haploid sugar beet: an integrated view of factors influencing the processes of gynogenesis and chromosome doubling. International Sugar Journal 119:884â895Ardebili SH, Shariatpanahi ME, Amiri R, Emamifar M, Oroojloo M, Nematzadeh G, Sadat Noori SA, Heberle-Bors E (2011) Effect of 2, 4-D as a Novel Inducer of Embryogenesis in Microspores of Brassica napus L. Czech J Genet Plant Breed 47:114â122BaraĆski R (1996) In vitro gynogenesis in red beet (Beta vulgaris L.): effects of ovule culture conditions. Acta Soc Bot Pol 65:57â60Bohanec B (2009) Doubled Haploids via Gynogenesis. In: Touraev AF, Forster BP, Jain SM (eds) Advances in Haploid Production in Higher Plants. Springer, pp 35â46Chen JF, Cui L, Malik AA, Mbira KG (2011) In vitro haploid and dihaploid production via unfertilized ovule culture. Plant Cell Tiss Organ Cult 104:311â319Corral-MartĂnez P, SeguĂ-Simarro JM (2012) Efficient production of callus-derived doubled haploids through isolated microspore culture in eggplant (Solanum melongena L.). Euphytica 187(1):47â61Corral-MartĂnez P, SeguĂ-Simarro JM (2014) Refining the method for eggplant microspore culture: effect of abscisic acid, epibrassinolide, polyethylene glycol, naphthaleneacetic acid, 6-benzylaminopurine and arabinogalactan proteins. Euphytica 195(3):369â382De Greef W, Jacobs M (1979) In vitro culture of the sugarbeet: description of a cell line with high regeneration capacity. Plant Sci Lett 17:55â61Fraga HP, Vieira LN, Caprestano CA, Steinmacher DA, Micke GA, Spudeit DA, Pescador R, Guerra MP (2012) 5-Azacytidine combined with 2,4-D improves somatic embryogenesis of Acca sellowiana (O. Berg) Burret by means of changes in global DNA methylation levels. Plant Cell Rep 31:2165â2176Grzybkowska D, MoroĆczyk J, WĂłjcikowska B, Gaj MD (2018) Azacitidine (5-AzaC)-treatment and mutations in DNA methylase genes affect embryogenic response and expression of the genes that are involved in somatic embryogenesis in Arabidopsis. Plant Growth Regul 85:243â256GĂŒrel S, GĂŒrel E, Kaya Z (2000) Doubled haploid plant production from unpollinated ovules of sugar beet (Beta vulgaris L.). Plant Cell Rep 19:1155â1159GĂŒrel S, GĂŒrel E, Kaya Z, Erdal M, GĂŒler E (2003) Effects of antimitotic agents on haploid plant production from unpollinated ovules of sugar beet (Beta vulgaris L.). Biotechnol Biotechnol Equip 17:97â101Hassani M, Heidari B, Dadkhodaie A, Stevanato P (2018) Genotype by environment interaction components underlying variations in root, sugar and white sugar yield in sugar beet (Beta vulgaris L.). Euphytica 214:79Klimek-Chodacka M, Baranski R (2013) Comparison of haploid and doubled haploid sugar beet clones in their ability to micropropagate and regenerate. Electron J Biotechnol 16:1â10Leljak-LevaniÄ D, Bauer N, MihaljeviÄ S, Jelaska S (2004) Changes in DNA methylation during somatic embryogenesis in Cucurbita pepo L. Plant Cell Rep 23:120â127Li H, Soriano M, Cordewener J, Muiño JM, Riksen T, Fukuoka H, Angenent GC, Boutilier K (2014) The histone deacetylase inhibitor Trichostatin A promotes totipotency in the male gametophyte. Plant Cell 26(1):195â209Lipavska H, Vreugdenhil D (1996) Uptake of mannitol from the media by in vitro grown plants. Plant Cell Tiss Organ Cult 45:103â107Lux H, Herrmann L, Wetzel C (1990) Production of haploid sugar beet (Beta vulgaris L.) by culturing unpollinated ovules. Plant Breed 104:177â183Murashige T, Skoog F (1962) A revised medium for rapid growth and bio assays with tobacco tissue cultures. Physiol Plant 15:473â497Nagl N, Mezei S, KovaÄev L, VasiÄ D, ÄaÄiÄ N (2004) Induction and micropropagation potential of sugar beet haploids. Genetika 36:187â194Nowaczyk L, Nowaczyk P, Olszewska D, Niklas-Nowak A (2015) Effect of 2,4-dichlorophenoxyacetic acid pretreatment of Capsicum spp. donor plants on the anther culture efficiency of lines selected by capsaicinoid content. Biotechnologia 96:179â183Osorio-Montalvo P, SĂĄenz-Carbonell L, De-la-Peña C (2018) 5-Azacytidine: a promoter of epigenetic changes in the quest to improve plant somatic embryogenesis. Int J Mol Sci 19:3182Parra-Vega V, Renau-Morata B, Sifres A, SeguĂ-Simarro JM (2013) Stress treatments and in vitro culture conditions influence microspore embryogenesis and growth of callus from anther walls of sweet pepper (Capsicum annuum L.). Plant Cell Tissue Organ Cult 112(3):353â360Pazuki A, Aflaki F, GĂŒrel E, ErgĂŒl A, GĂŒrel S (2017) A robust method for haploid sugar beet in vitro proliferation and hyperhydricity reduction. Folia Hortic 29:241â250Pazuki A, Aflaki F, GĂŒrel E, ErgĂŒl A, GĂŒrel S (2018a) Gynogenesis induction in sugar beet (Beta vulgaris) improved by 6-benzylaminopurine (BAP) and synergized with cold pretreatment. Sugar Tech 20:69â77Pazuki A, Aflaki F, GĂŒrel S, ErgĂŒl A, GĂŒrel E (2018b) Production of doubled haploids in sugar beet (Beta vulgaris): an efficient method by a multivariate experiment. Plant Cell Tiss Organ Cult 132:85â97Pazuki A, Aflaki F, Gurel S, Ergul A, Gurel E (2018c) The effects of proline on in vitro proliferation and propagation of doubled haploid sugar beet (Beta vulgaris). Turk J Bot 42:280â288Salas P, Prohens J, SeguĂ-Simarro JM (2011) Evaluation of androgenic competence through anther culture in common eggplant and related species. Euphytica 182(2):261â274SeguĂ-Simarro JM (2016) Androgenesis in solanaceae. In: GermanĂ MA, Lambardi M (eds) In vitro embryogenesis, vol 1359. Methods in Molecular Biology. Springer Science + Business Media, New York, pp 209â244Shariatpanahi ME, Bal U, Heberle-Bors E, Touraev A (2006) Stresses applied for the re-programming of plant microspores towards in vitro embryogenesis. Physiol Plant 127:519â534Testillano PS (2019) Microspore embryogenesis: targeting the determinant factors of stress-induced cell reprogramming for crop improvement. J Exp Bot 70(11):2965â2978Tomaszewska-Sowa M (2010) Cytometric analyses of sugar beet (Beta vulgaris L.) plants regenerated from unfertilized ovules cultured in vitro. Electron J Pol Agric Univ 13:1â10Yamamoto N, Kobayashi H, Togashi T, Mori Y, Kikuchi K, Kuriyama K, Tokuji Y (2005) Formation of embryogenic cell clumps from carrot epidermal cells is suppressed by 5-azacytidine, a DNA methylation inhibitor. J Plant Physiol 162:47â54Yaseen M, Ahmad T, Sablok G, Standardi A, Hafiz IA (2013) Role of carbon sources for in vitro plant growth and development. Mol Biol Rep 40:2837â284
Effects of dietary on antioxidant status, lipid profile, immune response and performance characteristics of broiler chickens reared under high ambient temperature
Objective Spirulina has been recognized formerly as a filamentous spiral-shaped blue-green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat-exposed broilers. Methods Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at 36°C for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didnât meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis
Evaluation of biochemical parameters and productive performance of japanese quail in response to the replacement of soybean meal with canola meal
The present study was conducted to evaluation the different levels canola meal (CM) replacement by soybean meal (SBM) in Japanese quails diets on productive performance, egg quality trails and blood parameters including blood protein, minerals concentration, liver enzymes and thyroid hormones. In this study, 160 of Japanese quails in second laying phase from 46 to 56 weeks of age were divided in four treatments with four replicates and 10 quail in each per replicate, on a completely randomized design (CRD).Treatments consisted:T1) control (without CM), T2, T3 and T4) replacing 30, 60 and 90% of SBM with CM respectively. The results were shown no significant variation in body weight between treatments in initial and end of the experiment (p > 0.05). There was significant decrease in feed intake by increasing level of CM (p 0.05). However, the egg shell thickness showed significantly decreased with increasing levels of canola meal in the diet  (p < 0.05). According to this study results, 30% replacement of SBM by CM in the diet (contained 10% CM) has no adverse effect on quailâs performance.
Intestinal carbohydrase activity and sodium-glucose transporter expression in layers fed diets containing wheat and rice brans supplemented with phytase
The effect of diets containing wheat and rice brans with or without phytase supplementation on performance, intestinal carbohydrase activities and mRNA expression of sodium-glucose transporter-1 (SGLT-1) in layers was studied. A total of 96 23-wk-old Hy-line W-36 were allocated in a completely randomized experimental design at random with 6 treatments and 4 replicate cages of 4 birds each. A control diet was used in this experiment and then it was formulated to contain 10% wheat bran and 15% rice bran. Then phytase (2 g kg-1; 1000 FTU kg-1) was added to each diet. Feed intake, egg mass, feed conversion ratio, shell weight, shell thickness and Haugh units were not influenced by brans or phytase supplementation (p > 0.05). But egg production decreased in rice bran treatments (p < 0.05). In the jejunum, adding of phytase to control and diet containing wheat bran increased the concentration of sucrase (p †0.01). Also, addition of phytase to control diet increased (p †0.001) the mRNA expression of SGLT-1 in the duodenum. It was concluded that feeding layers with diets containing 10% wheat bran were practically feasible without compromising production performance, egg shell quality, and endogenous carbohydrase activity.
The effects of protein, amino acid, and dietary electrolyte balance on broiler chicken performance and blood parameters under heat stress
ABSTRACT The effect of crude protein (CP), amino acid (AA), and dietary electrolyte balance (DEB) were evaluated on blood parameters, carcass traits, and broiler performance under heat stress (29-34°C). A total of 540 male chickens (Ross 308) were allocated to 12 diets with factorial arrangement 2 à 2 à 3, using a completely randomized design with three replicates of 15 chickens in grower (13 to 26 days) and finisher (27 to 42 days) periods. and 120, 220, and 320 mEq kg-1 DEB. The level of 21% CP increased body weight gain (BWG) and decreased feed conversion ratio (FCR) at grower period (p < 0.05). In contrast, 20% CP level decreased BWG and increased FCR at finisher period (p < 0.05). Further, 20% CP level reduced blood sodium and blood electrolyte balance (p < 0.05). The highest blood electrolyte balance was achieved by DEB 320 mEq kg-1 diet (p < 0.05). Broiler response to DEB in heat stress depended on the age of bird, length of exposure to high temperature and CP level of the diet. Under heat stress (29-34°C), the 21% CP level at grower period and 17% CP level at finisher period improved broiler BWG and FCR