The impact of climate change on maize yields in the United States and China   总被引：1，自引：0，他引：1  

Xiang LiTaro Takahashi  Nobuhiro SuzukiHarry M. Kaiser 《Agricultural Systems》2011,104(4):348-353

This study analyzes the impacts of climate change on maize yields using an econometric model that incorporates climate, economic, and technology variables. The major finding is climate change will not universally cause negative impacts of maize yields in the United States and China. The results of a simulation of climate change on maize yields over the period 2008-2030 show that a combination of changes in temperature and precipitation can either bring positive or negative effects on maize yields. Furthermore, variation in regional climatic and economic conditions makes the impacts of climatic change on maize yields substantially different in different regions. In this research, the impacts of climate change on maize yields are not simply examined by climate factors. Economic and technology adaptation effects on maize yields are also incorporated. Thus, even with significant changes in climate conditions that alter the maize crop’s growing environment and affect crop yields, a decrease in maize supply due to a decrease in maize yields would lead to an increase in the maize price, which in turn would induce farmers to add more investments in production inputs to raise yields. Thus, the decrease in actual yields may not be as dramatic as predicted in only climate factor considered cases. In this research, findings gained from the study can be used for early-staged policymaking decisions and advanced problem prevention programs. To ensure the continuous increase in maize yields in the future, further studies and research, as well as efficient environmental policies and actions are required.  相似文献   

Ciguatoxin: isolation and chemical nature   总被引：5，自引：0，他引：5  

P J Scheuer  W Takahashi  J Tsutsumi  T Yoshida 《Science (New York, N.Y.)》1967,155(767):1267-1268

Ciguatoxin, the agent responsible for ciguatera, a disease produced in humans from ingestion of certain fishes, has been isolated from specimens of the moray eel, Gymnothorax javanicus. The toxin is apparently a lipid containing quaternary nitrogen, hydroxyl, and carbonyl functions.  相似文献   

Growth of the collembolan Folsomia candida Willem in soil supplemented with glucose   总被引：1，自引：0，他引：1  

Satoshi Kaneda  Nobuhiro Kaneko   《Pedobiologia》2004,48(2):165-170

Freely available glucose improves the conditions for soil microorganisms which are utilized as food by Collembola. We examined the effects of glucose application on collembolan (Folsomia candida Willem) growth and on several biotic and abiotic soil parameters (microbial biomass, soil respiration, qCO₂, dissolved organic carbon, inorganic nitrogen, and Olson-P) in an artificial system without predatory pressure on Collembola. Glucose addition increased soil respiration and qCO₂, and decreased nutrient levels in the soil. Collembolan growth increased with increasing glucose doses. We conclude that the availability of carbon substrates can sustain collembolan growth via an improvement of microbial growth conditions.  相似文献   

Detection and confirmation of toxoplasma oocysts in the soil.     

S Ito  K Tsunoda  Y Tsutsumi  T Matsui  H Nishikawa 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1975,37(6):549-554

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Fine surface structure of bovine acrosome-intact and reacted spermatozoa observed by atomic force microscopy     

Saeki K  Sumitomo N  Nagata Y  Kato N  Hosoi Y  Matsumoto K  Iritani A 《The Journal of reproduction and development》2005,51(2):293-298

The atomic force microscope (AFM) provides nanometer resolution, topographic data of the natural surface structure of materials. We studied the topology of the surface structure of bovine sperm heads during the acrosome reaction by AFM. In addition, we numerically analyzed the areas of the median sagittal plane of the sperm heads. Bovine frozen-thawed spermatozoa were washed, capacitated by heparin, and incubated with lysophosphatidylcholine (LPC) to induce the acrosome reaction, smeared on a cover glass, air-dried, and observed with AFM using the dynamic force (tapping) mode. AFM analysis of spermatozoa showed the clear surface structure of acrosomes, equatorial segments, postacrosomal regions and necks. Although AFM images of spermatozoa capacitated by heparin had complete acrosomes, most spermatozoa treated with LPC had no acrosomal caps as shown by AFM. These observations coincided with those obtained by light microscopy after staining with naphthol yellow S and erythrosin B. Furthermore, numerical analysis of AFM images indicated that areas of the median sagittal plane of the anterior portions of acrosome-reacted sperm heads (2679 +/- 616 pixels) were approximately 40% less than those of intact heads (4535 +/- 174 pixels, P<0.05). These results indicate that AFM can usefully observe and numerically analyze the fine surface structures of bovine spermatozoa.  相似文献   

Hardening by annealing and softening by deformation in nanostructured metals     

Huang X  Hansen N  Tsuji N 《Science (New York, N.Y.)》2006,312(5771):249-251

We observe that a nanostructured metal can be hardened by annealing and softened when subsequently deformed, which is in contrast to the typical behavior of a metal. Microstructural investigation points to an effect of the structural scale on fundamental mechanisms of dislocation-dislocation and dislocation-interface reactions, such that heat treatment reduces the generation and interaction of dislocations, leading to an increase in strength and a reduction in ductility. A subsequent deformation step may restore the dislocation structure and facilitate the yielding process when the metal is stressed. As a consequence, the strength decreases and the ductility increases. These observations suggest that for materials such as the nanostructured aluminum studied here, deformation should be used as an optimizing procedure instead of annealing.  相似文献   

Mode of inheritance in fruit acidity in apple analysed with a mixed model of a major gene and polygenes using large complex pedigree     

Hiroshi Iwanami  Shigeki Moriya  Nobuhiro Kotoda  Naozumi Mimida  Sae Takahashi‐Sumiyoshi  Kazuyuki Abe 《Plant Breeding》2012,131(2):322-328

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Meiosis-specific noncoding RNA mediates robust pairing of homologous chromosomes in meiosis     

Ding DQ  Okamasa K  Yamane M  Tsutsumi C  Haraguchi T  Yamamoto M  Hiraoka Y 《Science (New York, N.Y.)》2012,336(6082):732-736

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Empirical Percentile Growth Curves with Z-scores Considering Seasonal Compensatory Growths for Japanese Thoroughbred Horses     

Tomoaki ONODA  Ryuta YAMAMOTO  Kyohei SAWAMURA  Harutaka MURASE  Yasuo NAMBO  Yoshinobu INOUE  Akira MATSUI  Takeshi MIYAKE  Nobuhiro HIRAI 《Journal of Equine Science》2013,24(4):63-69

Percentile growth curves are often used as a clinical indicator to evaluate variations of children’s growth status. In this study, we propose empirical percentile growth curves using Z-scores adapted for Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Individual horses and residual effects were included as random effects in the growth curve equation model and their variance components were estimated. Based on the Z-scores of the estimated variance components, empirical percentile growth curves were constructed. A total of 5,594 and 5,680 body weight and age measurements of male and female Thoroughbreds, respectively, and 3,770 withers height and age measurements were used in the analyses. The developed empirical percentile growth curves using Z-scores are computationally feasible and useful for monitoring individual growth parameters of body weight and withers height of young Thoroughbred horses, especially during compensatory growth periods.  相似文献   

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?     

Alejandro M. S. Mayer  Abimael D. Rodríguez  Orazio Taglialatela-Scafati  Nobuhiro Fusetani 《Marine drugs》2013,11(7):2510-2573

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.  相似文献