Effect of shifting cultivation on distribution of nutrient elements and carbohydrates within water-stable aggregates in northern Iran

This study attempts to evaluate the nutrient element and carbohydrate distribution within Water-Stable Aggregates (WSA) of two natural ecosystems, native forest and pasturelands, under different land uses. Soil samples were collected from depths of (0-20) cm in Typic Haploxeroll soils. The overall pattern indicated that Mean Weight Diameter (MWD) and WSA were greater in the pasture and forest soils compared with the adjacent cultivated soils and aggregates of > 1.0 mm size were dominant in the uncultivated soils, whereas the cultivated soils comprised aggregates of the size < or = 0.5 mm. Distribution of organic carbon, nitrogen, phosphorus and carbohydrates within the WSA showed preferential enrichment of these parameters in the macroaggregate fraction (4.75-1.0 mm) for the uncultivated soils and microaggregate fraction (> 0.25 mm) for the cultivated soils. Average distribution of total exchangeable bases within WSA showed that cultivation of forest pastureland soils significantly led to reduce in these nutrient in the 4.75-2.0 mm fraction and increase in concentration of these cations in < 0.25 mm fraction. Since smaller aggregates are preferentially removed by erosion, this study emphasizes the need for sustainable soil management practices that they will minimize nutrient loss when forest or pastures lands are converted to cropland.     

Fertilization by refrigerator stored sperm of the Indian major carp, Labeo calbasu (Hamilton, 1822)

This study reports on the spermatological properties, and on the development of a protocol for refrigerator storage (4°C) of Labeo calbasu (Hamilton, 1822) sperm for artificial breeding. Volume, motility, concentration and pH of the freshly collected sperm were 2.21 ± 0.53 (μL g^?1 of fish weight) (mean ± SD), 95 ± 1 (%), 1.93 ± 0.44 × 10⁹ (cells mL^?1) and 7.56 ± 0.17 respectively. Sperm activation was evaluated at different osmolalities of NaCl solution, and motility ceased completely when osmolality of the extender was ≥287 mOsmol kg^?1. Sperm retained motility for 24, 72 and 108 h, after refrigerator storage when sperm were undiluted, suspended in Alsever's solution and suspended in Alsever's solution containing 5% methanol respectively. Fertilization rate of fresh eggs with sperm stored at 4°C in Alsever's solution and Alsever's solution containing 5% methanol was 77% and 60% with a hatching rate of 60% and 43% respectively. The fertilization and hatching success of the stored sperm suggests potential to use refrigeration for transporting genetic material to hatcheries for artificial breeding of L. calbasu in Bangladesh.     

Impact of <Emphasis Type="Italic">Erysiphe alphitoides</Emphasis> on transpiration and photosynthesis in <Emphasis Type="Italic">Quercus robur</Emphasis> leaves

Oak powdery mildew, (Erysiphe alphitoides) causes one of the most common diseases of oaks. We assessed the impact of this pathogen on photosynthesis and water relations of infected leaves using greenhouse-grown oak seedlings. Transpiration of seedlings infected by oak powdery mildew was also investigated. Altogether, E. alphitoides had a low impact on host gas exchange whether at the leaf or whole plant scale. Maximal stomatal conductance of infected leaves was reduced by 20–30% compared to healthy controls. Severely infected seedlings did not experience any detectable change of whole plant transpiration. The reduction in net CO₂ assimilation, A_n, was less than proportional to the fraction of leaf area infected. Powdery mildew reduced both the maximal light-driven electron flux (J_max) and the apparent maximal carboxylation velocity (Vc_max) although Vc_max was slightly more impacted than J_max. No compensation for the infection occurred in healthy leaves of partly infected seedlings as the reduced photosynthesis in the infected leaves was not paralleled by increased A_n levels in the healthy leaves of the seedlings. However, E. alphitoides had a strong impact on the leaf life-span of infected leaves. It is concluded that the moderate effect of E. alphitoides on oak might be related to the small impact on net CO₂ assimilation rates and on tree transpiration; nevertheless, the severe reduction in leaf life-span of heavily infected leaves may lead to decreased carbon uptake over the growth season.     

Fate of low-molecular-weight organic phosphorus compounds in the P-rich and P-poor paddy soils

Continuous application of organic fertilizers can cause accumulation of organic phosphorus(P) in soil, especially in the lowmolecular-weight organic phosphorus(LMWOP) forms. This organic P pool represents a potentially important source of P for both plants and microorganisms. To understand the effect of long-term fertilization(30 years)(P-rich soil) vs. fallowing(P-poor soil) on the bioavailability and fate of LMWOP in subtropical paddy soils, we determined the sorption and mineralization of 14 C-labeled adenosine, adenosine monophosphate(AMP), adenosine diphosphate(ADP), and adenosine triphosphate(ATP) in each soil. The contents of carbon, nitrogen, and P in the P-rich soil were more than two times greater than those in the P-poor soil. The mineralization rates of the LMWOP compounds were faster in the P-rich soil compared to the P-poor soil, and followed the order AMPADPATP. Using sterilized soil, all forms of adenosine-P were strongly sorbed to the solid phase and reached saturation in a short time, with the adsorbance increasing with the number of phosphate groups. We concluded that the mineralization of LMWOP compounds was repressed slightly by sorption to the solid phase, but only in the short term. Thus, LMWOP compounds serve as readily available sources of C for microorganisms, making P available for themselves as well as for the plants. However, P accumulation and the progressive saturation of the P sorption sites in highly fertile soils may increase the potential risk of P runoff.     

In-vivo evaluation of adjuvants for more effective control of celery leaf-spot (Septoria apiicola) and powdery mildew (Erysiphe graminis) of wheat with fungicides

The effects of seven adjuvants (at 0, 0.5, 1.0 and 2.0 g litre^?1) on the efficacies of four fungicides al 0.5 g litre^?1 were studied in the laboratory for the control of leaf-spot in celery (caused by Septoria apiicola) and powdery mildew on winter wheat (caused by Erysiphe graminis). The most effective fungicides for controlling leaf-spot were: tebuconazole + triadimenol = flutriafol > mancozeb + oxadixyl > prochloraz. However, addition of adjuvant to the fungicides gave a modified pattern of effectiveness. The efficacy of flutriafol was strongly enhanced by addition of all adjuvants, but those of prochloraz and mancozeb+oxadixyl only partially so. The tested adjuvants were mineral oil + surfactant, a polymer/alkoxylated alkyl ether blend, an ethoxylated alkylphenol, an ethoxylated hexitan ester blend, an ethoxylated nonylphenol and an alkylpolysaccharide- based adjuvant mixture. However, the addition of adjuvants to tebuconazole + triadimenol had a negative effect. Of all the adjuvants tested, the nonylphenol ethoxylate and a mixture of mineral oil /surfactant and alkylpolysaccharides gave the highest efficacy with the fungicides, while the mineral oil/surfactant and the alkylpolysaccharides alone were less effective. There was a positive relationship between high concentrations of adjuvants and their effectiveness, but there were some exceptions. The most effective fungicides for control of powdery mildew in wheat were prochloraz, mancozeb + oxadixyl and tebuconazole + triadimenol. There was a linear relationship between the high efficacy of the fungicide and the concentration of adjuvants to control powdery mildew in wheat. The highest concentration of adjuvant (2-0 g litre^?1) gave the highest efficacy for the fungicides.     

The prevalence of medial coronoid process disease is high in lame large breed dogs and quantitative radiographic assessments contribute to the diagnosis

Medial coronoid process disease is a common leading cause of thoracic limb lameness in dogs. Computed tomography and arthroscopy are superior to radiography to diagnose medial coronoid process disease, however, radiography remains the most available diagnostic imaging modality in veterinary practice. Objectives of this retrospective observational study were to describe the prevalence of medial coronoid process disease in lame large breed dogs and apply a novel method for quantifying the radiographic changes associated with medial coronoid process and subtrochlear‐ulnar region in Labrador and Golden Retrievers with confirmed medial coronoid process disease. Purebred Labrador and Golden Retrievers (n = 143, 206 elbows) without and with confirmed medial coronoid process disease were included. The prevalence of medial coronoid process disease in lame large breed dogs was calculated. Mediolateral and craniocaudal radiographs of elbows were analyzed to assess the medial coronoid process length and morphology, and subtrochlear‐ulnar width. Mean grayscale value was calculated for radial and subtrochlear‐ulnar zones. The prevalence of medial coronoid process disease was 20.8%. Labrador and Golden Retrievers were the most affected purebred dogs (29.6%). Elbows with confirmed medial coronoid process disease had short (P < 0.0001) and deformed (～95%) medial coronoid process, with associated medial coronoid process osteophytosis (7.5%). Subtrochlear‐ulnar sclerosis was evidenced in ～96% of diseased elbows, with a significant increase (P < 0.0001) in subtrochlear‐ulnar width and standardized grayscale value. Radial grayscale value did not differ between groups. Periarticular osteophytosis was identified in 51.4% of elbows with medial coronoid process disease. Medial coronoid process length and morphology, and subtrochlear‐ulnar width and standardized grayscale value varied significantly in dogs with confirmed medial coronoid process disease compared to controls. Findings indicated that medial coronoid process disease has a high prevalence in lame large breed dogs and that quantitative radiographic assessments can contribute to the diagnosis.     

Comparative single‐dose pharmacokinetics of orally administered florfenicol in rainbow trout (Oncorhynchus mykiss,Walbaum, 1792) at health and experimental infection with Streptococcus iniae or Lactococcus garvieae

This study evaluates changes in the pharmacokinetic behavior of a single oral dose of florfenicol in rainbow trouts experimentally infected with Lactococcus garvieae or Streptococcus iniae. One hundred and fifty fish were randomly divided into three equal groups: 1—healthy fish, 2—fish inoculated with S. iniae (2.87 × 10⁷ CFU/ml, i.p.), and 3—fish inoculated with L. garvieae (6.8 × 10⁵ CFU/ml, i.p.). Florfenicol was administered to all groups at 15 mg/kg by oral gavage. Blood sampling was performed at 0, 2, 3, 6, 8, 12, 24, 48, 72, and 120 hr after drug administration to each group, and plasma concentration of florfenicol was assayed by HPLC method. The MICs of florfenicol were 1.2 μg/ml and 5 μg/ml against L. garviae and S. iniae, respectively. Healthy fish showed higher values for most of the PK/PD parameters as compared to fish infected with L. garvieae which was reversed in fish infected with S. iniae. Fish infected with L. garvieae showed decreased relative bioavailability accompanied by increased volume of distribution at steady‐state (Vd_ss) and total body clearance (Cl_B)_. Infection with S. iniae increased the peak concentration of drug after administration (Cmax) and decreased elimination half‐life (T_{1/2 β})_, central compartment volume (V_c), and Vd_ss. In conclusion, infection with these bacteria can affect the pharmacokinetic behavior of florfenicol in rainbow trouts as shown by decreased bioavailability and increased total body clearance and volume of distribution in L. garvieae infection and decreased volume of distribution accompanied by increased Cmax in S. iniae‐infected fish.     

Evaluation of growth inhibitory and apoptosis inducing activity of human calprotectin on the human gastric cell line (AGS)

BACKGROUND: Calprotectin is cytotoxic agent that its anti-tumor effects are governed through suppression of topoisomerase II; a key enzyme in apoptosis. In previous studies, cytotoxicity and apoptotic effects of calprotectin are shown on different cancer cell lines, but not human gastric cancer cell lines. In the present study, cytotoxicity and apoptotic effects of calprotectin on human gastric adenocarcinoma cancer cell line (AGS) were evaluated. METHODS: The AGS cells were exposed to the different concentrations of calprotectin for 24, 48 and 72 hours. Cell proliferation was assessed using dimethylthiazol diphenyl tetrazolium bromide assay and dye exclusion tests. For evaluation of cytotoxic mechanism in calprotectin on AGS cells, flow cytometric analysis was performed. RESULTS: Our results revealed that calprotectin induces growth inhibition of AGS in a dose- and time-dependent manner. Results of this investigation showed that sensitivity of AGS cells to cytotoxic effect of human calprotectin was highly remarkable. In addition, growth inhibitory effect of this cytotoxic agent mostly was governed through induction of apoptosis in the AGS cells. CONCLUSION: These findings indicated that calprotectin induces growth inhibition and apoptosis in the AGS cells.     

Thermal degradation studies of poly(o-anisidine) doped with 5-sulfosalicylic acid

Thermal decomposition of the solid state of poly(o-anisidine) (POAN) base (POAN-EB) and salt [doped with 5-sulfosalicylic (SSA) acid] (SSA-doped POAN) forms has been studied by thermogravimetric analysis (TGA) and differential thermal analysis (DTA) under non-isothermal conditions. The potential (PE) and optimum molecular geometric (OMG) energies of the repeating unit (tetramer form) of investigated matrix were calculated using molecular mechanics (MM+) calculations. These calculations (PE= −3.48×10⁹ and OMG=−122.72 kJ mol⁻¹) indicate that the optimum molecular geometric structure of this matrix is highly stable. The empirical formula of the doped polymer is best represented by [POAN-2SSA.n/6H₂O] and substantiate by elemental analysis and MM+ calculations. The full polymer decomposition and degradation were found to occur in three stages during the temperature increase. The decomposition activation energy (E _d) of both POAN base (POAN-EB) and its doped (SSA-doped POAN) were calculated by employing different approximations. The heating rate of decomposition and the frequency factor (k _o ) as well as kinetic parameters were calculated for doped or base form of this matrix. A remarkable heating rate dependence of the decomposition rate of the SSA-doped POAN matrix was observed.