Evaluation of hepatitis E virus infection between different production systems of pigs in Brazil

The objectives of this study were to (1) investigate the occurrence of hepatitis E virus (HEV) in pigs from large-scale and family-scale farms, (2) genetically characterize the strains isolated, and (3) study the pathogenesis of swine HEV infection via immunohistochemistry. A total of 50 pigs from 10 farms in Mato Grosso State, Brazil were divided according to type of production system into either large-scale farms (n?=?5) or family-scale farms (n?=?5). Samples of liver, gallbladder, small and large intestines, bile, and feces from the pigs were analyzed by nested PCR with primers targeting the ORF2 region of HEV and by immunohistochemistry. Of the eight HEV-positive samples from pigs of family-scale farms, phylogenetic analysis revealed that seven of the swine HEV isolates clustered with subtype 3b of genotype 3 and one isolate was categorized with subtype 3 f. The HEV antigen was detected mainly in the small intestine samples from family-scale farms, suggesting an early stage HEV infection. HEV was not detected in the samples of pigs from large-scale farms, reinforcing the need for additional studies to evaluate the risk of transmission of HEV to humans from pigs from family-scale farms in Mato Grosso State.     

Mutational analysis of the tyrosine phosphatome in colorectal cancers

Tyrosine phosphorylation, regulated by protein tyrosine phosphatases (PTPs) and kinases (PTKs), is important in signaling pathways underlying tumorigenesis. A mutational analysis of the tyrosine phosphatase gene superfamily in human cancers identified 83 somatic mutations in six PTPs (PTPRF, PTPRG, PTPRT, PTPN3, PTPN13, PTPN14), affecting 26% of colorectal cancers and a smaller fraction of lung, breast, and gastric cancers. Fifteen mutations were nonsense, frameshift, or splice-site alterations predicted to result in truncated proteins lacking phosphatase activity. Five missense mutations in the most commonly altered PTP (PTPRT) were biochemically examined and found to reduce phosphatase activity. Expression of wild-type but not a mutant PTPRT in human cancer cells inhibited cell growth. These observations suggest that the mutated tyrosine phosphatases are tumor suppressor genes, regulating cellular pathways that may be amenable to therapeutic intervention.     

Characterization of Synergy Between Cucumber mosaic virus and Potyviruses in Cucurbit Hosts

ABSTRACT Mixed infections of cucurbits by Cucumber mosaic virus (CMV) and potyviruses exhibit a synergistic interaction. Zucchini squash and melon plants coinfected by the potyvirus Zucchini yellow mosaic virus (ZYMV) and either Fny-CMV (subgroup IA) or LS-CMV (subgroup II) displayed strong synergistic pathological responses, eventually progressing to vascular wilt and plant death. Accumulation of Fny- or LS-CMV RNAs in a mixed infection with ZYMV in zucchini squash was slightly higher than infection with CMV strains alone. There was an increase in CMV (+) strand RNA levels, but no increase in CMV (-) RNA3 levels during mixed infection with ZYMV. Moreover, only the level of capsid protein from LS-CMV increased in mixed infection. ZYMV accumulated to similar levels in singly and mixed infected zucchini squash and melon plants. Coinfection of squash with the potyvirus Watermelon mosaic virus (WMV) and CMV strains increased both the Fny-CMV RNA levels and the LS-CMV RNA levels. However, CMV (-) strand RNA3 levels were increased little or not at all for CMV on coinfection with WMV. Infection of CMV strains (LS and Fny) containing satellite RNAs (WL47-sat RNA and B5*-sat RNA) reduced the accumulation of the helper virus RNA, except when B5*-sat RNA was mixed with LS- CMV. However, mixed infection containing ZYMV and the CMV strains with satellites reversed the suppression effect of satellite RNAs on helper virus accumulation and increased satellite RNA accumulation. The synergistic interaction between CMV and potyviruses in cucurbits exhibited different features from that documented in tobacco, indicating there are differences in the mechanisms of potyvirus synergistic phenomena.     

Confirmation of the spawning area of the striped marlin, Tetrapturus audax, in the so-called core area of the eastern tropical Pacific off Mexico

We report the presence of striped marlin larvae in coastal waters of the mouth of the Gulf of California, collected during seven oceanographic cruises during 1990 to 1993. From 169 sampled stations, 30 produced a total of 68 larvae of 2.4–30.5 mm total length. Most of the larvae were about 3 mm, indicating a recent spawn. The sea surface temperature at the sampled stations ranged from 19.4°C to 32.0°C, but larvae were caught at stations with temperatures between 27.8°C and 31.5°C. These results clarify the existence of a spawning area of striped marlin in the eastern Pacific, located closer to the coast than previously believed, during several months of the year.     

Revenue risk management, risk aversion and the use of Livestock Gross Margin for Dairy Cattle insurance

The Livestock Gross Margin Insurance for Dairy Cattle is a federally reinsured insurance program that enables US dairy producers to establish minimum levels of milk income net of feed cost. Given the structure of this program there are an infinite number of possible contract designs based on the choice of deductible level and proportion of production insured. Adding to this complexity, producers vary in their risk preferences, which affect the incentive to insure their margin. It is unclear as to how producers may adopt this program for revenue risk management. This paper investigates the interplay between producer risk preferences, contract design and the subsidization of premium in determining program coverage. We undertook this analysis within an expected utility framework. Optimal contracts under different rates of constant relative rate of risk aversion and subsidies were analyzed using a nonlinear optimization model. We found that total optimal coverage increased significantly with the level of risk of aversion at lower deductibles but as deductible level increased, the level of risk aversion had a lesser impact on total optimal coverages. As expected, at the same deductible and risk aversion levels, inclusion of a premium subsidy increased the total optimal coverage.     

Quantitative methods for estimating foliar uptake of zinc from suspension‐based Zn chemicals

The present study developed methods for quantifying foliar Zn uptake from suspension‐based Zn chemicals of low solubility, which were ZnO (particle size: 0.15^–1.34 μm) and a newly synthesized Zn hydroxide nitrate crystal (Zn‐HNC) (50^–100 nm thickness and 0.2^–1 μm lateral dimension). Recently matured leaves of citrus (Citrus aurantium L. cv. Valencia), capsicum (Capsicum annume L. cv. Giant Bell), and/or tomato (Solanum lycopersicum L. cv. Roma) were in vitro–treated with microdroplets (5 μL per droplet) of Zn‐HNC‐ and ZnO‐suspension solutions on the adaxial surface and incubated under controlled conditions for up to 72 h. Leaf‐washing protocols were compared, including: dilute ethanol (3%), dilute nitric acid (2%), and their combination. The methods for quantifying Zn uptake were: (1) whole‐leaf loading by which droplets of the Zn suspension solutions were loaded onto central regions of both left and right sides of leaf blades and (2) half‐leaf loading by which soluble‐Zn (ZnSO₄) droplets were loaded onto only one side of leaf blades while the other was used as the background Zn control. Foliar‐surface characteristics of the plant species affected the effectiveness of the washing methods. The dilute nitric acid (2%; ± 3% ethanol) was required to remove residue particles of the ZnO and Zn‐HNC suspensions from foliar surfaces of capsicum and tomato (highly trichomatic), but the residue Zn chemicals on citrus leaves (nontrichomatic and highly waxy) were similarly and effectively removed by the three washing methods. For quantifying Zn uptake by the leaves, the half‐leaf loading method showed its advantages over the whole‐leaf loading method, because it did not stringently require similar background Zn concentrations in the control and treated leaves at the start and had little risks of secondary absorption of soluble Zn in the washing solution.     

Spatio-temporal dynamics of gross rainfall partitioning and nutrient fluxes in shaded-cocoa (<Emphasis Type="Italic">Theobroma cocoa</Emphasis>) systems in a tropical semi-deciduous forest

Land-use change from forest to cocoa agroforestry and other tree-based farming systems alters the structure of forest stands and influences the magnitude of canopy water fluxes and subsequent bio-element inputs to the forest floor. The partitioning of incident rainfall (IR) into throughfall (TF), stemflow (SF) and canopy interception loss (IL_C) and their associated nutrient element concentrations and fluxes was examined along a replicated chrono-sequence: forest, 3, 15 and 30-year-old smallholder shaded-cocoa systems in Ashanti Region, Ghana. Mean annual precipitation during the 2-year observational period (2007 and 2008) was 1376.2 ± 93.8 mm. TF contributed between 76.5–90.4%, and SF between 1.4–1.7% of the annual IR to the forest floor. There were significant differences in IR, TF and SF chemistry. While TF and SF were enriched in phosphorus (1.33–5.67-fold), potassium (1.1–5.69 fold), calcium (1.35–2.65 fold) and magnesium (1.4–2.68 fold) relative to IR, total N (NH₄ ⁺+NO₃ ^?) declined (0.5–0.91) of IR values in TF and SF in forest and shaded cocoa systems. Incident rainfall was significantly more acidic than TF and SF in both forest and shaded-cocoa systems. Mean annual total N, P, K, Ca and Mg inputs to the forest floor through IR were 5.7, 0.14, 13.6, 9.43 and 5.6 kg ha^?1year^?1 respectively. Though an important source of available nutrients for plant growth, incident rainfall provides only a small percentage of the annual nutrient requirements. With declining soil fertility and pervasive low cocoa yields, possible effects of the reported nutrient fluxes on nutrient budgets in cocoa systems merit further investigation. Against the background of increased TF and decreased IL_C following forest conversion to shaded-cocoa, it is also recommended that more studies be carried out on rainfall partitioning and its impact on ground water recharge as a way of establishing its influence on the availability of moisture for agriculture in these systems.     

Evaluation of competition and light estimation indices for predicting diameter growth in mature boreal mixed forests

A series of conventional distance-independent and distance-dependent competition indices, a highly flexible distance-dependent crowding index, and two light resource estimation indices were compared to predict individual tree diameter growth of five species of mature trees from natural-origin boreal mixed forests. The crowding index was the superior index for most species and ecosites. However, distance-independent indices, such as basal area of competing trees, were also effective. Distance-dependent light estimation indices, which estimate the fraction of seasonal photosynthetically-active radiation available to each tree, ranked intermediate to low. Determining separate competition indices for each competitor species accounted for more variation than ignoring species or classifying by ecological groups. Species’ competitive ability ranked (most competitive to least): paper birch ≈ white spruce ≈> trembling aspen > lodgepole pine > balsam poplar. Stratification by ecosite further improved model performance. However, the overall impact of competition on mature trees in these forests appears to be small.     

Reproductive characteristics of the fishery important temperate demersal berycid Centroberyx gerrardi indicate greater reproductive output in regions of upwelling

The reproductive biology of Centroberyx gerrardi (Günther) was investigated across ~2,000 km of its southern Australian distribution, encompassing different jurisdictions and varying environmental features. Greater gonad mass and prevalence of spawning fish, along with lower ratios of lengths at maturity:maximum lengths and ages at maturity:maximum ages, were identified at the western‐most (Capes) and eastern‐most (Great Australian Bight; GAB) regions. Across the study region, spawning peaks in summer/autumn, when water temperatures are warmest. Regional differences in potential “reproductive output,” while not consistent with the eastward decline in mean monthly water temperature, may instead be related to summer upwelling in the Capes and GAB, driving greater oceanic productivity prior to peak spawning, supporting larval survival. In autumn, the prevailing southward and eastward flowing, downwelling Leeuwin Current (LC) strengthens, providing a dispersal mechanism along the west and south Australian coasts, but limiting upwelling effects. Predicted changes in environmental conditions and their potential impacts on C. gerrardi are discussed, in particular how these factors may affect recruitment to stocks and fisheries, requiring a better understanding of source‐sink relationships for this species. As environmental changes occur, management strategies to sustain fish resources must adapt to spatially variable and changing reproductive output and be collaborative across jurisdictions.     

Prevalence and risk factors of mycobacterial infections in farm and trade cattle in southwestern Nigeria

We evaluated the prevalence of mycobacterial infections (i.e., Mycobacterium bovis and non-tuberculous mycobacteria [NTM]) and their associated risk factors among cattle herds and trade cattle in southwestern Nigeria. Through cross-sectional study design, cattle herds from three locations were screened using the single intradermal comparative cervical tuberculin test based on two diagnostic standards; more than 4 mm (? 4 mm) and more than 2 mm (? 2 mm) cut-off points. Abattoir study involved screening trade cattle for tuberculous lesions. Overall, 515 cattle from 45 herds were screened. Using >?4 mm, animal level and herd prevalence of 11.7 and 46.7% were recorded, respectively. Applying the ? 2 mm cut-off, animal level and herd prevalence increased to 31.1 and 60.0%, respectively. Significantly, using the ? 2 mm cut-off, cattle in medium size herds/extensive management system (OR?=?1.6; 95% CI 1.1–2.5) and Sokoto Gudali (OR?=?2.3; 95% CI 1.4–3.8) were more at risk of being positive reactors, while Rahaji (OR?=?0.3; 95% CI 0.1–0.7) breeds of cattle and cows in the peri-urban area (OR?=?0.4; 95% CI 0.2–0.9) were less at risk of being positive reactors. Again, M. avium reactor of 21.7% was observed. In the abattoir, 1797 cattle were examined with 126 lesions suggestive of tuberculosis (TB). Culture/molecular analyses confirmed 2.2% M. bovis and 0.9% NTM infections. Risk factors associated with bovine TB among trade cattle were sex (OR?=?4.0; 95% CI 1.2–13.5) and age (OR?=?0.3; 95% CI 0.1–0.9). We confirm 11.7% prevalence of mycobacterial infections among populations of cattle screened with breed and herd size being major risk factors.