Prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam

We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.1% (134/740) and 71.9% (64/89), respectively. Risk factors for the infection were identified using univariate and multivariate logistic regression analysis. The results revealed that age, sanitary condition and topography were significantly associated with oocyst shedding (P<0.05). Pre-weaned piglets were at the highest risk for infection, followed by post-weaners, sows and finishing pigs. Good sanitary conditions showed positive effects in decreasing oocysts shedding. Topographically, Cryptosporidium was more common in mountainous zone than that in coastal delta zone. There was an association between the occurrence of diarrhea and the level of Cryptosporidium oocyst excretion within infected pigs. This is the first epidemiological investigation of prevalence and risk factors of Cryptosporidium in pigs in Vietnam.     

Prevalence of Fasciola in cattle and of its intermediate host Lymnaea snails in central Vietnam

The aims of this study were to investigate the prevalence of natural Fasciola infections in both the definitive hosts (cattle) and the intermediate hosts (Lymnaea snails) in central Vietnam. A total of 1,075 fecal samples, randomly collected from cattle in Binh Dinh, Khanh Hoa, and Phu Yen provinces, were examined for Fasciola eggs by a sedimentation method. The overall prevalence of Fasciola was 45.3?%. A subset of the animals (235) was also screened for antibodies against Fasciola by an enzyme-linked immunosorbent assay. Overall, 46.3?% of these animals were shedding Fasciola eggs while 87.2?% were Fasciola seropositive. A lower prevalence of Fasciola was observed in calves ??2?years of age (37.6?%) compared to that in cattle >2?years of age (53.7?%) (p?<?0.05). The prevalence in the rainy season (50.8?%) was significantly different to that in the dry season (38.1?%) (p?<?0.05). Of the 3.269 Lymnaea viridis and 1.128 Lymnaea swinhoei examined, 31 (0.95?%) and seven (0.62?%), respectively, were found to be infected with Fasciola. This appears to be the first epidemiological survey of the prevalence of Fasciola in cattle and snails in these three provinces in central Vietnam.     

Forest fires and vegetation during the Holocene in central Yakutia, eastern Siberia

In order to investigate the relationship between vegetation change and fire history in the Siberian boreal forest, fossil pollen and charcoal from two lakes in central Yakutia, eastern Siberia, were analyzed. The vegetation change inferred from the pollen analysis was similar to that found in previous research in the region. Open larch forest covered this region during the late Glacial and early Holocene periods. Later, during the mid-Holocene, Scots pine expanded its range. The low levels of charcoal in the lake deposits represent surface forest fires, suggesting that the present-day surface fire regime has been taking place since at least 6,500 calibrated years before the present (cal yr BP) and that stand-replacing fire has not occurred during the Holocene. Larch and Scots pine forests, which are characterized by surface fire regimes, have been predominant since the early Holocene.     

Effect of increased rainfall on water dynamics of larch (<Emphasis Type="Italic">Larix cajanderi</Emphasis>) forest in permafrost regions,Russia: an irrigation experiment

Sap flow measurements, from July to August 2004, were coupled with micrometeorological, soil moisture, and soil temperature measurements to analyze forest water dynamics in irrigated and undisturbed (control) larch (Larix cajanderi) forest plots in eastern Siberia. Plots were irrigated with 120 mm (20 mm day⁻¹) of water from 17 to 22 July. Sap flow measurements of ten trees at each plot were scaled up to daily stand canopy transpiration (E _c ). Canopy transpiration at the irrigation and control plots was similar before irrigation. Forest evapotranspiration (E _a ) was obtained from Ohta et al. (Agric For Meteorol 148:1941–1953, 2008) while E _a in the irrigation plot was estimated based on the E _{c_irrig}/E _{c_cont} ratio. Rainfall during July–August was 63.4 mm but, after including water from thawing soil layers, the actual water input was 109.9 and 218.5 mm in the control and irrigation plots, respectively. Despite this large difference, a corresponding difference in E _c (and E _a ) was not observed [42.6 (61.5) mm and 46.4 (71.8) mm in control and irrigation plots, respectively]. Daily canopy conductance (g _c ) increased as long as moisture was well supplied in the upper soil layers and evaporative demand was high. Soil moisture and rainfall contribution to E _a was 36.9 and 24.6 mm in the control plot and 34.5 and 37.3 mm in the irrigation plot, respectively. Water supply from soil thawing layers in the control plot and high runoff (105.6 mm) rates in the irrigation plot accounted for the similarity in water dynamics. Under increased precipitation, the forest used less soil water stored from previous growing seasons.     

Ploidy variation of hardy kiwifruit (Actinidia arguta) resources and geographic distribution in Japan

Survey on the wild genetic resources of hardy kiwifruit (Actinidia arguta) in Japan was conducted to determine the ploidy variation and its geographic distribution. Among the 127 wild plants collected from different geographic locations, 15 plants were diploid, 87 were tetraploid, and 22 were hexaploid. Additionally, 2 plants were heptaploid and one plant was octaploid. The tetraploid plants were distributed all over the country, whereas the diploid and hexaploid plants were geographically localized, in the warm Pacific hill areas of the south western part and in the deep-snow region of the mid-northern part of Honshu, respectively. The diploid plants could be clearly distinguished from other plants with ploidy variation by the morphological characteristics of the leaf and fruit. Hexaploid plants showed a relatively larger L/D ratio of the leaf blade, a greenish petiole, and pubescence on the petiole and lower leaf vein, whereas the tetraploid plants exhibited a reddish petiole and callose hairs on the vein of the lower leaf surface. Fruit shape of the tetraploid plants varied largely, from round to ellipsoidal, whereas that of the hexaploid plants was mostly ellipsoidal. These results indicate that the hexaploid plants of A. arguta as well as the diploid and tetraploid ones, naturally grow in a certain size of population in the restricted region of Japan.     

Effects of isoprothiolane on cell growth of cultured bovine mammary epithelial cells.

This study was performed to investigate the effects of isoprothiolane on cell growth and the production of interleukin (IL)-1 and IL-6 by bovine mammary epithelial cells in vitro. Isoprothiolane increased proliferation of mammary epithelial cells in a dose-dependent manner at the concentration of 0.05 to 5 microM when cultured either with or without serum-supplemented medium. In contrast, isoprothiolane (0.0005-5 microM) significantly inhibited the production of IL-1 and IL-6 by mammary epithelial cells. Moreover, the cytokines, IL-1alpha, IL-1beta, IL-6, and tumor necrosis factor (TNF)-alpha tended to inhibit the proliferation of mammary epithelial cells in a dose-dependent manner. These results indicated that isoprothiolane regulated mammary epithelial cell growth in vitro possibly by modulating the production of cytokines.     

Effect of Gaseous Acetic Acid on Dough Rheological and Breadmaking Properties

Breads baked from wheat flours (protein contents 14.1–16.5% at 14.0% mb) that were pretreated with 2–3 mL of gaseous acetic acid per kg of wheat flour, showed maximum bread height and specific volume (cm³/g). Flour-water suspension and the crumb pH values were gradually decreased with increased amounts of acetic acid. Gas generation and dough expansion tests with bread dough showed that the addition of the same amount of acetic acid, which achieved maximum specific volume, also showed the highest rate of gas generation and dough expansion. However, increasing acetic acid decreased these values. Scanning electron microscope (Cryo-SEM) observation showed that the bread dough made from the same acetic acid-treated flour indicated continuum and no cracks in the dough matrix. Evaluation of mixograms showed the decrease of mixing stability with increased acetic acid levels. Viscosity and water binding capacity of flour-water suspensions were sharply increased by the addition of acetic acid at pH 5.0–3.5.     

Breaking the dormancy of rice seeds with various dormancy levels using steam and high temperature treatments in a steam nursery cabinet

This study aimed to determine the appropriate steam treatment conditions, using a steam nursery cabinet, to break the dormancy of Japanese rice cultivar seeds exhibiting various dormancy levels. The influence of the temperature and duration of the steam treatments on the germination percentage and germination rate was investigated. In highly dormant ‘Takanari’ seeds, the steam treatment at 40 °C for 7 d increased the germination percentage and decreased the 50% germination time (T_50S; based on seed number); this treatment was as effective as the dry heat treatment at 50 °C for 7 d. For the medium dormant ‘Moeminori’ and ‘Hitomebore’ seeds, the steam treatment at 40 °C for 5 d decreased T_50S sufficiently and more effectively than did the dry heat treatment at 50 °C for 7 d. For the slightly dormant ‘Moeminori’ seeds, the steam treatment at temperatures ranging from 24 °C to 40 °C for 7 d decreased T_50S without a corresponding decrease in germination percentage to <90%. For the non-dormant ‘Moeminori’ and ‘Takanari’ seeds, the same steam treatments had no, or a little if any, useful effect on the germination percentage and T_50S. Therefore, we concluded that, for the highly dormant seeds, steam treatment at 40 °C for 7 d was appropriate. Moreover, for less dormant seeds, steam treatment at 40 °C for 5 d was appropriate, and the steam treatment was not necessary for the non-dormant seeds.