Effects of different dietary selenium sources (sodium selenite,selenomethionine and nanoselenium) on growth performance,muscle composition,blood enzymes and antioxidant status of common carp (Cyprinus carpio)

This experiment was conducted to compare the effects of different sources of selenium (Se) on growth, muscle Se concentration, muscle proximate composition, blood enzymes and antioxidant status of common carp, Cyprinus carpio. Organic Se (selenomethionine, SeMet), inorganic Se (sodium selenite, Na₂SeO₃), or nanoselenium were each added to the basal diet at 0.7 mg Se kg^?1 diet. Four groups of fish with an average weight of 9.69 ± 0.12 g were fed one of the experimental diets for 8 weeks. Nano‐Se diet resulted in better growth performance (P < 0.05). Fish fed with Se‐supplemented diets showed a higher (P < 0.05) Se content in the muscle and liver tissues. Fish fed nano‐Se had the highest liver glutathione peroxidase, superoxide dismutase and catalase activities (P < 0.05). Liver malondialdehyde level was significantly (P < 0.05) lower in fish fed on SeMet and nano‐Se diets as compared to control. The carp fed on nano‐Se diet had the lowest values of aspartate transaminase and alanine transaminase. Lactate dehydrogenase activity was significantly lower in fish fed on SeMet and nano‐Se diets. This study shows that nano‐Se acts more efficiently on growth performance and antioxidant defence system of common carp than organic and inorganic sources of Se.     

Inducing salt tolerance in strawberry (Fragaria × ananassa Duch) plants by acetate application

Abstract

Acetate, can be considered as an appropriate interface for increasing tolerance to salinity stress in strawberries. Strawberry plants were exposed to different treatments including control (Hoagland solution), salinity (40?mM NaCl), acetic acid (AA) (1?mM), acetic acid (1?mM) + salinity (AAS), ammonium acetate (AA) (1?mM), ammonium acetate (AM) (1?mM) + salinity (AMS), ammonium carbonate (AC) (0.5?mM), and ammonium carbonate (0.5?mM) + salinity (ACS) and put them in hydroponic system. The results indicated that salinity reduced shoot dry weight about 80.12% when compared with untreated control plants. That in comparison to acetate treatments, this reduction was 47.13 and 48.77% in AAS and AMS, respectively. Leaf area was decrease 59% in salinity treatment but this reduction was 14% in AAS. The AAS and AMS were most effective in increasing fruit yields (35.93 and 52.16?g per plant, respectively) in comparison to salinity treatment alone (27.23?g per plant) condition. In saline conditions, the highest amount of soluble carbohydrate was observed in AMS treatment (9.67?mg g^?1 DW) that there was no significant difference with AAS treatment. Increase in Na⁺ and Cl^? accumulation in shoots and decreased in K⁺ in saline condition were observed. The highest amount of potassium was observed in acetate treatments. The present results have demonstrated that acetate could improve tolerance to the salinity, yield and plants growth in strawberry. But, in comparison to AA and AM treatments, better results were observed in AA treatment in both salinity and non-salinity conditions.     

Determination of antibiotic resistance pattern and virulence genes in Escherichia coli isolated from bovine with subclinical mastitis in southwest of Iran

The aims of the present study were to investigate the prevalence of some virulence genes and also determine the antimicrobial resistance pattern of E. coli isolated from bovine with subclinical mastitis. The milk of 502 cows was collected from 8 dairy herds in the southwest of Iran. Conventional biochemical tests were used for identification of E. coli at the species level. Antimicrobial susceptibility patterns of E. coli isolates were determined by disc agar diffusion method and polymerase chain reaction (PCR) was used for detection of seven virulence genes including f17A, afaE-8, afaD-8, eaeA, cnf1, cnf2, and iucD. Seventy (13.94%) isolates of E. coli were identified in 502 milk samples. The highest rate of resistance was observed against tetracycline (18.6%), while none of the isolates were resistant to streptomycin. Eight (11.5%) out of 70 E. coli isolates carried at least one of the virulence genes. The afaD-8 was the most prevalent gene detected in 5 (7.1%) isolates. The afaE-8, iucD, and eaeA were detected in 3, 3, and 2 isolates respectively. Low prevalence of virulence factors may be indicating that most of the E. coli isolates originated from the commensal flora of cows and enter to the udders via environment contamination with feces.

     

Values,technologies, and epistemology

The aim of this paper is to make possible dialogue between those who claim that technologies are coded with social, political, or ethical values and those who argue that they are value-neutral. To demonstrate the relevance of this bridge-building project, the controversy regarding agrifood biotechnology will be used as a case study. Drawing on work by L. H. Nelson about the nature of human knowledge-building enterprises and E. F. Kittay’s account of the relationally-constituted self, the argument will be made that all technologies embody the values of the communities that created them. Zahra Meghani is an assistant professor in the Department of Philosophy at the University of Rhode Island. Her research interests are philosophy of technology, feminist theory (especially feminist epistemology and feminist philosophy of science), normative ethics, practical ethics (especially health care ethics), disability issues, and political theory.     

Rutin from different parts of Capparis spinosa growing wild in Khuzestan/Iran

A qualitative and quantitative analysis of rutin from leaves, fruits and flowers of Capparis spinosa growing wild in Khuzestan was achieved. After soxhelet extraction of fats in diethyl ether, rutin was extracted by maceration using 50% EtOH. The ethanol extracts of these parts were separated by preparative TLC on silica gel precoated plate with a mixture of butanol: acetic acid (4:1, by volume) as the developing solvent. The spots were visualized under ultraviolet light (254 nm). Rutin was qualified by comparison of its R(f) value with that of standard. UV/Vis spectrum of separated rutin was also compared with those of standards and showed characteristic wavelengths at 260 and 360 nm. Purified rutin was quantified by UV/Vis spectrophotometric determination at 360 nm. The calibration curve was linear in the range of 0.156-2.5 microg mL(-1) with detection limit of 0.0731 microg mL(-1). The purity of extracted rutin from leave, flower and fruit determined by high performance liquid chromatography were 90.41, 87.25 and 64.56%, respectively. The amounts of rutin in leaves, fruits and flowers were 61.09, 6.03 and 43.72 mg per 100 g of dried powder, respectively. By analyzing the spiked samples of leave, flower and fruit the recovery of the UV/Vis method was in the range of 102-107.6%.     

The effect of different biochars on the growth and water use efficiency of fenugreek (Trigonella foenum-graecum L.)

In two identical pot trials, we investigated the effect of different biochars on the growth and water use efficiency (WUE) of fenugreek (Trigonella foenum-graecum L.) grown with and without water stress. Plants were grown in pots with and without biochar. Rice husk (RH), standard rice husk (SRH), standard wheat straw (SWS) or standard oilseed rape straw (SOS) biochars were added at a rate of 2% by weight. Irrigation was reduced from 80% of field capacity to 40% in half of the pots to create water stress when 50% of the plants flowered. No significant interaction was observed between irrigation and biochar treatments. Water stress resulted in smaller plants (11.5%), fewer pods (16.1%) and reduced 100-seed weight (12.6%), seed yield (20.1%) and plant dry weight (55.0%). All standard biochars increased plant dry weight in a range of 18%−25% compared with the controls. There was no significant effect of biochar on the number of pods and seed weight. Only RH, SWS and SOS biochar increased the number of seeds pod⁻¹ by 9.0%−14.5% compared with the controls regardless of water stress. RH and SOS biochars increased seed yield by 16.7 and 21.6%, respectively. RH, SWS and SOS biochar increased the WUE by 17.3%, 10.1% and 16.2% regardless of water stress, respectively. Based on the experiment, we recommend farmers to add biochar whatever type they have available. However, RH and SOS seem to be better than the others are, as they seem to be able to increase seed yield and WUE considerably.     

Kinetics of nutrient release from different organic residues using a laboratory system

Organic residues play a vital role in maintaining soil fertility in arid and semi-arid regions. Knowledge of the nutrient release from organic residues will help in optimizing nutrient efficiency in agricultural crop production systems. This study was conducted to assess the continuous release of phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg) from eight different organic residues (sheep manure, beet, waste material, rape, poultry manure, sunflower, potato and garlic) using successive extractions with distilled water. The residues were shaken for 1 h and equilibrated for longer intervals (1, 3.5, 18, 42, 72, 192, 768, 1248, 1608, 1968 and 2328 h) with successive extractions. Cumulative nutrient release curves by different organic residues versus time showed an initial rapid phase followed by a slow phase. The average percentage of nutrients released and the average release rate of nutrients found using a power model was different and were in the order K > P > Ca > Mg and Ca > Mg > P > K, respectively. According to MINTEQ software, the partitioning of total P between HPO₄ ^2? and H₂PO₄ ^? is sensitive to the type of organic residue. On average (pooled over all extractions), between 13% (rape) to 40% (poultry) and 27% (poultry manure) to 79% (beet) of total P in aqueous solutions present as HPO₄ ^2? and H₂PO₄ ^?, respectively. Among the various organic residues and in the first stage of release, sunflower residue, beet residue, poultry manure and garlic residue had the highest rate constant for Ca, Mg, P and K, respectively, indicating the high potential availability of these nutrients in the early stage of application to soils.     

Effect of Drought Stress and Different Levels of Nitrogen and Potassium Fertilizers on the Accumulation of Osmolytes and Chlorophyll in Rice (Oryza sativa L.)

Gesunde Pflanzen - Management of plant nutrition using fertilizers is an approach to deal with drought and to increase water productivity in paddies. The aim of this study, therefore, was to...     

Exploring changes in middle-school student lunch consumption after local school food service policy modifications

OBJECTIVE: This study assessed the impact of changes in school food policy on student lunch consumption in middle schools. METHODS: Two years of lunch food records were collected from students at three middle schools in the Houston, Texas area. During the first year, no changes occurred in the school food environment. After that school year was completed, chips and dessert foods were removed from the snack bars of all schools by the Food Service Director. Students recorded the amount and source of food and beverage items consumed. Point-of-service purchase machines provided a day-by-day electronic data file with food and beverage purchases from the snack bars during the 2-year period. Independent t-tests and time series analyses were used to document the impact of the policy change on consumption and sales data between the two years. RESULTS: In general, student consumption of sweetened beverages declined and milk, calcium, vitamin A, saturated fat and sodium increased after the policy change. Snack chips consumption from the snack bar declined in year 2; however, consumption of snack chips and candy from vending increased and the number of vending machines in study schools doubled during the study period. Ice cream sales increased significantly in year 2. CONCLUSIONS: Policy changes on foods sold in schools can result in changes in student consumption from the targeted environments. However, if all environments do not make similar changes, compensation may occur.     

Food-purchasing patterns for home: a grocery store-intercept survey

OBJECTIVES: To identify the most common frequency of food-purchasing patterns and relate this pattern to characteristics of individuals and families.DESIGN: A customer-intercept survey was conducted in the greater Houston area, Texas, USA, in 2002. The frequency of food shopping at supermarkets, convenience stores and restaurants to buy food for eating at home was assessed.SUBJECTS: A total of 823 adults (78.5% female; mean age 37.4 years) who went to any of several grocery or convenience stores, including European, Hispanic and African Americans, and Asian/Pacific Islanders.RESULTS: Major food-shopping patterns were a weekly big trip with a few small trips (34.9%), biweekly big trips with a few small trips (21.9%), no big shopping trips (15.4%), a weekly big trip without small trips (13.9%), a monthly big trip (8.3%), and biweekly big trips without small trips (6.4%). While 61.1% of participants never went to convenience stores to buy fruit and vegetables (F&V) for eating at home, 67% went to restaurants for F&V. African American families shopped for food least frequently, while Asian American families shopped for food most frequently. Educational level was negatively associated with the use of convenience stores and positively associated with take-away from restaurants.CONCLUSIONS: There is substantial variability in the frequency of food shopping. Future research on food shopping should incorporate this variable.