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1.
The effects of concurrent cage contamination with Salmonella typhimurium and Eimeria tenella on the establishment of salmonella infection in day-old chickens were investigated. Chickens were divided into five groups: uninfected recipient birds placed in a cage contaminated by donor birds infected with E. tenella and S. typhimurium; E. tenella-infected recipients placed in a cage contaminated by S. typhimurium-infected donors; uninfected recipients placed in a cage contaminated by S. typhimurium-infected donors; E. tenella-infected recipients placed in a cage contaminated by uninfected donors; and uninfected recipients placed in a cage contaminated by uninfected donors. Three identical trials were conducted. Recipient birds were necropsied 4, 7, and 11 days after caging. In the cage where donor birds infected with both organisms had been reared, S. typhimurium counts in feces and number of feces positive for S. typhimurium were significantly (P less than 0.05) greater than those in the other cages on days 0, 4, and 7 after caging. Moreover, in this cage, more chicks died, counts of S. typhimurium in cecal contents were greater, and more birds were positive for S. typhimurium than in the other groups. This suggests that S. typhimurium infection in day-old chickens is enhanced in cages contaminated with E. tenella and S. typhimurium compared with infection in cages contaminated with S. typhimurium alone. 相似文献
2.
Acton L Bruner M Lemen J Tsuneta S Ogawara Y Nishimura J Bentley R Culhane L Canfield R Hudson H Doschek G Hiei E Hirayama T Kosugi T Watanabe T Lang J Makishima K Uchida Y 《Science (New York, N.Y.)》1992,258(5082):618-625
The Japanese Yohkoh satellite is now in orbit observing the sun with a set of x-ray imagers and x-ray and gamma-ray spectrometers. The data from this successful mission provide new information on solar flares and the sun's corona. This paper discusses the Yohkoh observations and presents a sample of the first scientific results from the mission. 相似文献
3.
Inokuma H Yoshizaki Y Matsumoto K Okuda M Onishi T Nakagome K Kosugi R Hirakawa M 《Veterinary parasitology》2004,121(3-4):341-346
A total of 80 free-roaming dogs on Okinawa Island, Japan, were examined for Babesia infection using the polymerase chain reaction (PCR) and sequence analysis. Of 80 samples, 12 were positive in a Babesia genus-specific PCR. Consequent species-specific PCR for B. canis and B. gibsoni revealed that 5 (6.3%) and 7 (8.8%) dogs were infected with B. canis and B. gibsoni, respectively. Sequence analysis of the PCR products revealed that the 18S rRNA gene sequence of B. canis detected from dogs in Okinawa was very close to B. canis vogeli with sequence similarity of 99.94%. 相似文献
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S. H. R. Sadeghi T. Mizuyama S. Miyata T. Gomi K. Kosugi S. Mizugaki Y. Onda 《Journal of Forest Research》2007,12(4):270-277
The reforested headwater watersheds in Japan are very important from the points of view of commercial and environmental aspects.
At the present time, much and varied research is running to assess and understand the hydrologic behavior of these watersheds.
The present study was conducted to evaluate the applicability of the deterministic model MUSLE in the Mie small steeply reforested
watershed. The model was tested and calibrated using accurate continuous suspended sediment data collected during eight storm
events in 2004. Results of the original model simulations for storm-wise sediment yield did not match the observed data, while
the revised version of the model could imitate the observed values well. The results of the study approved the efficient application
of the revised MUSLE in estimating storm-wise sediment yield in the study area with a high level of agreement of beyond 88%,
an acceptable estimation error of some 14% and non-significant difference in mean values. 相似文献
6.
Makita N Kosugi Y Dannoura M Takanashi S Niiyama K Kassim AR Nik AR 《Tree physiology》2012,32(3):303-312
The root systems of forest trees are composed of different diameters and heterogeneous physiological traits. However, the pattern of root respiration rates from finer and coarser roots across various tropical species remains unknown. To clarify how respiration is related to the morphological traits of roots, we evaluated specific root respiration and its relationships to mean root diameter (D) of various diameter and root tissue density (RTD; root mass per unit root volume; gcm(-3)) and specific root length (SRL; root length per unit root mass; mg(-1)) of the fine roots among and within 14 trees of 13 species from a primary tropical rainforest in the Pasoh Forest Reserve in Peninsular Malaysia. Coarse root (2-269mm) respiration rates increased with decreasing D, resulting in significant relationships between root respiration and diameter across species. A model based on a radial gradient of respiration rates of coarse roots simulated the exponential decrease in respiration with diameter. The respiration rate of fine roots (<2mm) was much higher and more variable than those of larger diameter roots. For fine roots, the mean respiration rates for each species increased with decreasing D. The respiration rates of fine roots declined markedly with increasing RTD and increased with increasing SRL, which explained a significant portion of the variation in the respiration among the 14 trees from 13 species examined. Our results indicate that coarse root respiration in tree species follows a basic relationship with D across species and that most of the variation in fine root respiration among species is explained by D, RTD and SRL. We found that the relationship between root respiration and morphological traits provides a quantitative basis for separating fine roots from coarse roots and that the pattern holds across different species. 相似文献
7.
Maeda K Kawabata K Mazzali PA Tanaka M Valenti S Nomoto K Hattori T Deng J Pian E Taubenberger S Iye M Matheson T Filippenko AV Aoki K Kosugi G Ohyama Y Sasaki T Takata T 《Science (New York, N.Y.)》2008,319(5867):1220-1223
Core-collapse supernovae (CC-SNe) are the explosions that announce the death of massive stars. Some CC-SNe are linked to long-duration gamma-ray bursts (GRBs) and are highly aspherical. One important question is to what extent asphericity is common to all CC-SNe. Here we present late-time spectra for a number of CC-SNe from stripped-envelope stars and use them to explore any asphericity generated in the inner part of the exploding star, near the site of collapse. A range of oxygen emission-line profiles is observed, including a high incidence of double-peaked profiles, a distinct signature of an aspherical explosion. Our results suggest that all CC-SNe from stripped-envelope stars are aspherical explosions and that SNe accompanied by GRBs exhibit the highest degree of asphericity. 相似文献
8.
Patchy stomatal closure occurs in plants with heterobaric leaves, in which vertical extensions of bundle sheath cells delimit the mesophyll and restrict the diffusion of CO(2). The scale of patchy stomatal behavior was investigated in this study. The distribution of PSII quantum yield (Φ(II)) obtained from chlorophyll fluorescence images was used to evaluate the scale of stomatal patchiness and its relationship with leaf photosynthesis in the sun leaves of 2-year-old saplings of Quercus crispula Blume. Fluorescent patches were observed only during the day with low stomatal conductance. Comparison of numerical simulation of leaf gas exchange and chlorophyll fluorescence images showed that heterogeneous distribution of electron transport rate through PSII (J) was observed following stomatal closure with a bimodal manner under both natural and saturated photosynthetic photon flux densities. Thus, fluorescence patterns can be interpreted in terms of patchy stomatal closure. The mapping of J from chlorophyll fluorescence images showed that the scale of stomatal patchiness was approximately 2.5-fold larger than that of anatomical patches (lamina areas bounded by bundle sheath extensions within lamina). Our results suggest the spatial scale of stomatal patches in Q. crispula leaves. 相似文献
9.
Horiguchi K Fukuta S Yoshida M Kosugi T Naito J Ishida M Harigaya T 《The Journal of reproduction and development》2007,53(4):915-922
Phosphorylated prolactin (PPRL) is considered to be the most quantitatively important post-translationally modified form of prolactin (PRL) in rodents. We recently detected two different types of PPRL in the mouse pituitary gland; one was phosphorylated at serine and the other was phosphorylated at serine/threonine. Furthermore, we showed that there are obvious differences in the ratios between PPRLs and non-phosphorylated PRL in the pituitary gland based on age and sex and that estrogen influences PRL phosphorylation at serine in female mice. In the present study, we examined whether estradiol (E2) increases serine PPRL in the male pituitary gland in the same manner as in the female pituitary gland and examined whether PPRL is released into serum. We first determined the relative amounts of intrapituitary PPRLs in male mice under different pharmacological conditions that increased PRL secretion. The results indicated that treatment with E2 increases serine PPRL. We then performed two-dimensional electrophoresis and immunoblotting analysis after immunoprecipitation with anti-mouse PRL antibody using male and female sera under different pharmacological conditions that increased PRL secretion. The results of this experiment indicated that there were PRLs phosphorylated at serine and serine/threonine in the female serum but not in the male serum. The levels of PPRLs in sera were greatly increased with the E2 treatment for both male and female sera. Furthermore, we examined the effect of E2 on PPRL synthesis in cultured male pituitary glands. In this experiment, we observed increased serine PPRL synthesis and stronger immunohistochemical staining of PRL cells with E2 treatment. These findings suggested that serine PPRL synthesis and secretion were influenced by estrogen. 相似文献
10.
We investigated effects of heterogeneous stomatal behavior on diurnal patterns of leaf gas exchange in 10 tree species. Observations were made in middle and upper canopy layers of potted tropical rainforest trees in a nursery at the Forest Research Institute Malaysia. Measurements were taken from 29 January to 3 February 2010. We measured in situ diurnal changes in net photosynthetic rate and stomatal conductance in three leaves of each species under natural light. In both top-canopy and sub-canopy species, midday depression of net assimilation rate occurred in late morning. Numerical analysis showed that patchy bimodal stomatal behavior occurred only during midday depression, suggesting that the distribution pattern of stomatal apertures (either uniform or non-uniform stomatal behavior) varies flexibly within single days. Direct observation of stomatal aperture using Suzuki's Universal Micro-Printing (SUMP) method demonstrated midday patchy stomatal closure that fits a bimodal pattern in Shorea leprosula Miq., Shorea macrantha Brandis. and Dipterocarpus tempehes V.Sl. Inhibition of net assimilation rate and stomatal conductance appears to be a response to changes in vapor pressure deficit (VPD). Variable stomatal closure with increasing VPD is a mechanism used by a range of species to prevent excess water loss from leaves through evapotranspiration (viz., inhibition of midday leaf gas exchange). Bimodal stomatal closure may occur among adjacent stomata within a single patch, rather than among patches on a single leaf. Our results suggest the?occurrence of patches at several scales within single leaves. Further analysis should consider variable spatial scales in heterogeneous stomatal behavior between and within patches and within single leaves. 相似文献