Numerical investigation of the influence of texture,surface drip emitter discharge rate and initial soil moisture condition on wetting pattern size

Knowledge of the dimensions of the wetted zone formed under point source surface drip irrigation is essential to the design of cost-effective and efficient irrigation systems. Numerical simulations were carried out with Hydrus-2D/3D to investigate the influence of emitter discharge rates and initial soil moisture conditions on the wetting pattern dimensions of a series of soils with varying textures. Numerical simulations of simple 2D soil tank irrigation experiments were also conducted on two soil types. Based on the simulation results, the parameters of the Schwartzman and Zur model were refined. The results showed a small influence of discharge rates >1 L h^?1 on the size of the wetting pattern. The only major difference was observed for the rates lower than 0.5 L h^?1, where the largest wetting patterns were observed. Higher initial soil water content caused larger wetting pattern sizes in all directions. When compared to the 2D tank experimental results, Hydrus-2D/3D predicted the wetting pattern dimensions with a relatively small root mean square error not exceeding 2.6 cm. The numerical data obtained for a wide range of textures provided the opportunity to refine the parameters of the Schwartzman and Zur model, which, when compared to experimental data from the literature, provided good estimates of wetting pattern dimensions. This suggests that this simple model, for which the only soil parameter required is the saturated hydraulic conductivity, could provide a valuable and practical tool for irrigation design.     

Molecular investigation of hard ticks (Acari: Ixodidae) and fleas (Siphonaptera: Pulicidae) as potential vectors of rickettsial and mycoplasmal agents

The aim of the present study was twofold. First, in general, to reveal new aspects of the potential vector role of ixodid ticks and fleas by screening large numbers of specimens with recently developed molecular biological methods. Second, to evaluate the occurrence of vector-borne infectious agents in a geographical context. Altogether 3442 unfed hard ticks (Ixodes ricinus, Dermacentor marginatus, D. reticulatus, Haemaphysalis inermis, H. concinna, H. punctata) and 939 fleas of cats and dogs (Ctenocephalides felis, C. canis, Pulex irritans) were collected in Hungary. DNA was extracted and analyzed in pools for representatives of the orders Rickettsiales and Mycoplasmatales.H. inermis was newly identified as the most important potential vector for Rickettsia helvetica in the study region. A novel Rickettsia genotype (designated ‘Candidatus R. hungarica’) was also detected in the same tick species, with a maximum of 95.8% gltA gene sequence identity to known rickettsiae. In addition, P. irritans tested positive for Rickettsia sp. RF2125, which has not been previously described in Europe. The human pathogen R. felis and the feline pathogen ‘Candidatus Mycoplasma turicensis’ were shown for the first time to occur in Central-Eastern Europe. Further novel findings include the presence of Spiroplasma spp. in D. marginatus and fleas. In conclusion, this molecular study extends the geographic range and vector spectrum of several arthropod-borne agents, some of which have zoonotic potential.     

Heat Shock Protein Regulation in Rainbow Trout,Oncorhynchus mykiss,is Altered by Dietary Soybean Meal Inclusion and Anti‐Phopholipase A2 Antibody

Heat shock proteins (Hsps) can promote integrity of damaged intestinal epithelial tissues. The aim of this study was to determine the effects of a commercially available anti‐phospholipase A₂ antibody on growth, feed efficiency, Hsp expression, and intestinal health of rainbow trout fed diets containing high levels of soybean meal (SBM). Six practical‐type diets (45% protein; 15% fat) were formulated to contain 0, 17.5, or 35% SBM with and without antibody. Each diet was fed to three replicate tanks of fish (20 fish/tank; initial weight 21 g) for 9 wk. RNA was isolated from liver and intestinal tissues (n = 3/tank) to detect alterations in Hsp 27, Hsp 70, and Hsp 90 expression. Fish fed a diet containing 35% SBM had decreased growth and intestinal damage. Hsp 27 and Hsp 90 mRNA was elevated in fish fed 35% SBM. Fish fed 35% SBM with antibody had lower Hsp 90 mRNA expression than fish without antibody. These data indicate that feeding rainbow trout high levels of SBM alters the expression of some Hsps and anti‐phospholipase A₂ antibody supplementation does not normalize growth or prevent distal enteritis in fish fed 35% SBM.     

Growth of Atlantic Salmon,Salmo salar,Fed Diets Containing Barley Protein Concentrate

A 16-week feeding trial was conducted with juvenile Atlantic salmon (123 g/fish initial weight) to determine the effects of adding either 11% or 22% barley protein concentrate (BPC) to the diet compared to salmon fed a reference diet (0% BPC) containing mostly fishmeal. The fish were stocked into twelve 0.264 m³ tanks, providing 40 fish per tank with an average density of 18.55 kg/m³. Temperature was maintained at ?12°C and salinity at ?2 ppt using ground water during the study. There were no significant differences in specific growth rate (0.62 basal, 0.60 11% BPC, 0.72 22% BPC), feed conversion (1.06, 1.37, 1.09), weight gain (124.3 g, 113.5 g, 155.3 g), proximate composition of the salmon for lipid (8.4%, 7.8%, 9.8%), protein (17.3%, 17.1%, 18.6%), moisture (71.4%, 72.3%, 69.4%), and ash (6.5%, 6.1%, 6.9%) among any of the treatment groups. Salmon fed the diet containing 22% barley protein concentrate, however, had significantly greater energy retention (34%) compared to the fish fed the other diets (23%–28%). The results of this study indicate that barley protein concentrate is an acceptable feed ingredient for Atlantic salmon that should provide performance similar to fishmeal at inclusion rates below 22%.     

Metabolism of [14C]cymoxanil in grapes,potatoes and tomatoes

Foliar-applied [¹⁴]cymoxanil, 1-(2-cyano-2-methoxyimino-[2-¹⁴C]acetyl)-3-ethylurea was rapidly metabolised in grapes, tomatoes and potatoes, Furthermore, the metabolism of this fungicide was unusual in that the metabolites were found to be naturally occurring compounds, with glycine as the major metabolite. Significant levels of radioactivity were found in other amino-acids, sugars, starch, fatty acids and lignin, indicating incorporation of carbon-14 via the various metabolic pathways.     

Aerobic bacterial flora of the vagina and prepuce of California sea lions (Zalophus californianus) and investigation of associations with urogenital carcinoma

To investigate the association between genital bacterial infection and urogenital carcinoma in California sea lions (Zalophus californianus), vaginal and preputial swabs for bacterial isolation were taken from 148 free-ranging and 51 stranded California sea lions including 16 animals with urogenital carcinoma. Cytological examination of vaginal or preputial smears showed a majority (65.5%, 57/87) of animals examined had mild or no inflammation. Aerobic bacteria were isolated from 116 (78.4%) wild sea lions and 100% of stranded animals. A total of 403 isolates were identified representing 51 unique bacterial species. The median number of isolates per animal increased with age in the wild group, but there was no difference in the number of isolates per animal between wild and stranded adults. The most common bacteria isolated from the wild sea lions were Psychrobacter phenylpyruvicus (39 isolates), non-hemolytic Streptococcus (35 isolates), Corynebacterium spp. (30 isolates), and Escherichia coli (20 isolates). More bacterial species were isolated from stranded animals than wild animals (33 versus 26) and there was significantly less growth of P. phenylpyruvicus, Corynebacterium spp., and Moraxella-like spp. in the stranded animals. Beta-hemolytic Streptococcus was the only bacterium significantly associated with urogenital carcinomas in California sea lions, but only in females.     

Proliferation of peripheral blood mononuclear cells from healthy piglets after mitogen stimulation as indicators of disease resilience

Disease resilience refers to the productivity of an animal under disease. Given the high biosecurity of pig nucleus herds, traits that can be measured on healthy pigs and that are genetically correlated with disease resilience, that is, genetic indicator traits, offer a strategy to select for disease resilience. Our objective was to evaluate mitogen stimulation assays (MSAs) on peripheral blood mononuclear cells (PBMCs) from young healthy pigs as genetic indicators for disease resilience. Data were from a natural disease challenge in which batches of 60 or 75 naïve Yorkshire × Landrace piglets were introduced every 3 wk into a continuous flow barn that was seeded with multiple diseases. In this environment, disease resilience traits, including growth, treatment, and mortality rates, were recorded on 3,136 pigs that were genotyped with a high-density marker panel. PBMCs from 882 of these pigs from 19 batches were isolated from whole blood collected prior to the disease challenge and stimulated with five mitogens: concanavalin A (ConA), phytohemagglutinin (PHA), pokeweed mitogen (PWM), lipopolysaccharide (LPS), and phorbol myristate acetate (PMA). The proliferation of cells was evaluated at 48, 72, and 96 h and compared with unstimulated samples (rest count). Heritabilities of cell proliferation were estimated using a model with batch as a fixed effect and covariates of entry age; rest count; complete blood count proportions of lymphocytes, monocytes, eosinophils, and basophils; and pen, litter, and animal genetics as random effects. Heritability estimates were highest for response to ConA (0.30 ± 0.09, 0.28 ± 0.10, 0.17 ± 0.10, and 0.25 ±0.10 at 48, 72, and 96 h after stimulation and for area under the curve across the three time points, respectively). Estimates were in a similar range for response to PHA and PMA but low for PWM and LPS. Responses to ConA, PHA, and PMA were moderately genetically correlated with several disease resilience traits and in the expected direction, but individual estimates were not significantly different from zero due to large SEs. In conclusion, although validation is needed, MSAss, in particular based on ConA, show promise as genetic indicator traits for disease resilience.     

地表状况对泥沙和化学运移影响的研究

研究土壤侵蚀过程可以为开发当代基于过程的土壤侵蚀预报模型提供理论和方法支持。位于印第安那州西拉菲特的ＵＳＤＡ -ＡＲＳ国家土壤侵蚀研究实验室 (ＮＳＥＲＬ)是全美进行土壤侵蚀过程研究和开发土壤侵蚀预报模型的中心。本报告将重点介绍ＮＳＥＲＬ关于地表状况 (也就是糙