Nitrous oxide emission derived from soil organic matter decomposition from tropical agricultural peat soil in central Kalimantan,Indonesia     

Yo Toma  Fumiaki Takakai  Untung Darung  Kanta Kuramochi  Suwido H. Limin  Salampak Dohong 《Soil Science and Plant Nutrition》2013,59(3):436-451

Our previous research showed large amounts of nitrous oxide (N₂O) emission (>200?kg?N?ha^?1?year^?1) from agricultural peat soil. In this study, we investigated the factors influencing relatively large N₂O fluxes and the source of nitrogen (N) substrate for N₂O in a tropical peatland in central Kalimantan, Indonesia. Using a static chamber method, N₂O and carbon dioxide (CO₂) fluxes were measured in three conventionally cultivated croplands (conventional), an unplanted and unfertilized bare treatment (bare) in each cropland, and unfertilized grassland over a three-year period. Based on the difference in N₂O emission from two treatments, contribution of the N source for N₂O was calculated. Nitrous oxide concentrations at five depths (5–80?cm) were also measured for calculating net N₂O production in soil. Annual N fertilizer application rates in the croplands ranged from 472 to 1607?kg?N?ha^?1?year^?1. There were no significant differences in between N₂O fluxes in the two treatments at each site. Annual N₂O emission in conventional and bare treatments varied from 10.9 to 698 and 6.55 to 858?kg?N?ha^?1?year^?1, respectively. However, there was also no significant difference between annual N₂O emissions in the two treatments at each site. This suggests most of the emitted N₂O was derived from the decomposition of peat. There were significant positive correlations between N₂O and CO₂ fluxes in bare treatment in two croplands where N₂O flux was higher than at another cropland. Nitrous oxide concentration distribution in soil measured in the conventional treatment showed that N₂O was mainly produced in the surface soil down to 15?cm in the soil. The logarithmic value of the ratio of N₂O flux and nitrate concentration was positively correlated with water filled pore space (WEPS). These results suggest that large N₂O emission in agricultural tropical peatland was caused by denitrification with high decomposition of peat. In addition, N₂O was mainly produced by denitrification at high range of WFPS in surface soil.  相似文献   

Factors affecting the genetic diversity of a perennial herb Viola grypoceras A. Gray var. grypoceras in urban fragmented forests     

Yuichi Toma  Junichi Imanishi  Masashi Yokogawa  Hiroshi Hashimoto  Ayumi Imanishi  Yukihiro Morimoto  Yuki Hatanaka  Yuji Isagi  Shozo Shibata 《Landscape Ecology》2015,30(8):1435-1447

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Limitation of leaf carbon gain by stomatal and photochemical processes in the top canopy of Macaranga conifera,a tropical pioneer tree     

Ishida A  Toma T  M 《Tree physiology》1999,19(7):467-473

Diurnal changes in gas exchange and chlorophyll fluorescence were measured in the top canopy leaves of the tropical rainforest tree species, Macaranga conifera (Zoll.) Muell. Arg. during a drought year. Maximum values of net photosynthetic rate (P(n), 10 &mgr;mol m(-2) s(-1)) and stomatal conductance (g(s), 0.2 mol m(-2) s(-1)) were found in east-facing leaves in early morning. After 1000 h, both P(n) and g(s) decreased. Minimum daytime values of P(n), g(s), and photosystem II (PSII) quantum yield (DeltaF/F(m)') were found in horizontally fixed leaves. At a given electron transport rate through PSII (ETR), P(n) was higher in early morning than at midday, suggesting a high rate of photorespiration at midday. We tested the hypothesis that the effect of low leaf temperature (T(leaf)) on P(n) is significant in the early morning, whereas the effect of low g(s) on P(n) predominates at midday. In the early morning, when T(leaf) was increased from 32 to 38 degrees C by artificial heating, P(n) at a given ETR decreased 29%, suggesting that the low T(leaf) was associated with a high P(n). When T(leaf) at midday was decreased from 37 to 32 degrees C by artificial cooling, P(n) increased 22%, but P(n) at a given ETR was higher in early morning than at midday, even at the same low T(leaf) (32 degrees C). This suggests that the rate of photorespiration was higher at midday than in early morning because low g(s) at midday caused a reduction in leaf intercellular CO(2) concentration. We conclude that low P(n) at midday was the result of both a reduction in the photochemical process and an increase in stomatal limitation.  相似文献   

Reproduction of adenoviral gizzard erosion by the horizontal transmission of fowl adenovirus serotype 1   总被引：1，自引：0，他引：1  

Ono M  Okuda Y  Shibata I  Sato S  Okada K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2007,69(10):1005-1008

The horizontal transmission ability of fowl adenovirus (FAV) serotype 1 99ZH strain, isolated from chickens exhibiting gizzard erosion, was investigated. Twelve 13-day-old specific pathogen-free chickens were inoculated orally with 10(6) TCID(50)/0.05 ml of the strain. An in-pen contact group (chickens in the same pen with inoculated chickens), hedge contact group (chickens in a pen connected with pens housing inoculated chickens), non-contact group (chickens in a separate pen placed at a distance of 70 cm from the connected pens), human exposure group (chickens in the next room and attended last every day) and negative control group were examined. Each group consisted of 11 or 12 uninoculated chickens. Gizzard lesions were grossly or histologically observed from 10 days after exposure (DAE) in the in-pen contact group, and from 15 DAE in the hedge contact and non-contact groups. The FAV gene was detected by polymerase chain reaction performed on cloacal swabs taken on 5 and 13 DAE from chickens in both contact groups, and on 20 and 26 DAE from those in the non-contact group. Serum neutralizing antibodies against FAV serotype 1 were detected in chickens from 13 and 26 DAE in both contact groups and in the non-contact group, respectively. In the human exposure and negative control groups, no infection was observed. We conclude that FAV-99ZH strain spreads rapidly through direct contact with inoculated chickens, and slowly through non-contact transmission, and that adenoviral gizzard erosion is reproduced by this horizontal transmission.  相似文献   

Trial of immunization against classical porcine plague by use of the principle of interferential vaccines     

C Pilet  B Toma 《Bulletin de l'Académie vétérinaire de France》1967,40(4):197-202

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Dynamics of Nucleic Acids and Total Proteins in the Thymus and the Bursa of Fabricius of Chickens with Rous Sarcoma     

V. Toma  R. Giurgea  M. Borßa  S. Ilyes 《Zoonoses and public health》1976,23(7):536-541

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FC-47 Comparison of four different types of stain in ear cytology     

L.Cornegliani  S.Toma  P.Persico  C.Noli 《Veterinary dermatology》2004,15(S1):35-37

Swab cytology is one of the most useful and rapid methods to assess the presence of external infections in ear canals. Smears are generally stained with Romanowsky-type stains, with or without prior heat fixation. The aim of this study was to compare four different ways of staining ear cytology swab samples. Eight animals with ceruminous or purulent otitis externa were selected. Cotton swabs were introduced in a total of 12 ear canals, and four cytologic samples on four different slides were obtained from each swab. Glass slides were air-dried and randomly identified with the number of the ear canal and the letters A, B, C or D. Slides marked with A were heat-fixed and stained with Dip Quick^®; slides marked with B were stained without heat fixation. Slides marked with C were heat-fixed and dipped in the blue colour only; slides marked with D were stained in the blue colour only without prior heat fixation. Ten high-power fields (oil immersion) were evaluated for each slide, and keratinocytes, yeasts, bacteria and neutrophils were counted. A statistical comparison was performed with parametric (Student's t -test applied after verifying the normal distribution of the data) and nonparametric tests (Wilcoxson's and signs' tests). There were no significant differences between the four staining methods ( P  ≤ 0.05). The authors conclude that heat fixation does not improve the cytological evaluation of ear swab samples and propose a one-step dip in the blue colour only as a rapid method of staining cytological samples from ear canals.
Funding: Self-funded.  相似文献   

Evaluation of greenhouse gas emissions in a Miscanthus sinensis Andersson-dominated semi-natural grassland in Kumamoto,Japan     

Yo Toma  Toshihiko Yamada  Fabián G. Fernández  Aya Nishiwaki  Ryusuke Hatano  J. Ryan Stewart 《Soil Science and Plant Nutrition》2016,62(1):80-89

Increasing greenhouse gas emissions from anthropogenic activities continue to be a mounting problem worldwide. In the semi-natural Miscanthus sinensis Andersson; grasslands of Aso, Kumamoto, Japan, which have been managed for thousands of years, we measured soil methane (CH₄) and nitrous oxide (N₂O) emissions before and after annual controlled burns. We estimated annual soil carbon (C) accumulation, and CH₄ and N₂O emissions induced by biomass burning in 2009 and 2010, to determine the impacts of this ecosystem and its management on global warming. Environmental factors affecting soil CH₄ and N₂O fluxes were unknown, with no effect of annual burning observed on short-term soil CH₄ and N₂O emissions. However, deposition of charcoal during burning may have enhanced CH₄ oxidation and N₂O consumption at the study site, given that emissions (CH₄: ?4.33 kg C ha^?1 yr^?1, N₂O: 0.17 kg N ha^?1 yr^?1) were relatively lower than those measured in other land-use types. Despite significant emission of CH₄ and N₂O during yearly burning events in early spring, the M. sinensis semi-natural grassland had a large annual soil C accumulation, which resulted in a global warming potential of ?4.86 Mg CO₂eq ha^?1 yr^?1. Consequently, our results indicate that long-term maintenance of semi-natural M. sinensis grasslands by annual burning can contribute to the mitigation of global warming.  相似文献   

Assessment of Lung Ultrasound B‐Lines in Dogs with Different Stages of Chronic Valvular Heart Disease          下载免费PDF全文

T. Vezzosi  T. Mannucci  A. Pistoresi  F. Toma  R. Tognetti  E. Zini  O. Domenech  E. Auriemma  S. Citi 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2017,31(3):700-704

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Usninsäure aus jugoslawischen Flechten und ihre antibiotische Wirksamkeit     

F. Benzinger  P. Tomašić  M. Zaveršek 《Plant foods for human nutrition (Dordrecht, Netherlands)》1960,7(4):371-383

Zusammenfassung Es wurde L-Usninsäure aus jugoslawischen Flechten in reiner Form isoliert. Der Schmelzpunkt der Substanz (zwei Proben) ist bei . Die Elementarmikroanalyse sowie die qualitativen Reaktionen entsprechen auch der reinen L-Usninsäure. Ein drittes isoliertes Präparat hatte den Schmp. bei 196° und . Das Präparat mit dem Schmp. 204° wurde auf seine bakteriostatische Wirksamkeit verwendet, und zwar in fein pulverisierter Form in einer Blut-Agar-Nährlösung suspendiert (Rinnenmethode), sowie mit der Routinemethode der Diskuse. Ein Lösungsvermittler für die sehr schwer in Wasser lösliche Usninsäure wurde nicht angewendet.Die Methode der Suspendierung in dem Nährmedium ist etwas empfindlicher, aber weniger praktisch. L-Usninsäure wirkt in vitro bakteriostatisch auf Mikroorganismen der Kugelform und zeigt so eine Ähnlichkeit mit Penicillin. Sie entwickelt eine Wirksamkeit gegenüber Streptokokken, Staphylokokken und Pneumokokken. Auf grampositive Bacillen zeigt sie in Suspensions-Konzentrationen von 0,25, 0,5 und 1,0% keine Wirksamkeit, was mit der sehr schweren Löslichkeit der Substanz in Wasser im Zusammenhang stehen wird.Die Wirkungsweise der Usninsäure steht am nächsten dem Penicillin, obwohl dieselbe schwächer ist als beim letzteren.Gegen Penicillin resistente Stämme zeigten sich als empfindlich auf Usninsäure.Die Versuche werden fortgesetzt.

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Summary L-usninic acid was isolated in pure form from lichens of Jugoslavia. The melting point of the substance (two samples) lies at . The elementary microanalysis and the qualitative reactions are in accordance with the pure L-usninic acid. A third isolated preparation showed the melting point 196° C, and . The preparation (melting point 204°) was tested on the bacteriostatic effet, specifically pulverized suspended in a blood-agar-culture solution (Rinnen-method) (channel-method), as well as with the routine method of the discuse. A medium to rise the solubility in water of the very little soluble usninic acid was not used.The method of suspending this acid in the culture solution is somewhat more sensitive, but less usefull. L-usninic acid has in vitro a bacteriostatic effect on spherical microorganisms in resemblance with penicilline. It is effective against streptococci, staphylococci and pneumococci. On Gram-positive bacillae the usninic acid has no effect in concentrations of 0,25 0,5 and 1,0 % of the suspensions, probably in consequence of its very small solubility.The effectiveness of the usninic acid is analogous to that of the penicilline, but weaker than the last-named. Stocks resistant against penicilline showed sensible against usninic acid.The researches will be continued.

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