سابقه و هدف: آب هوای یک منطقه در دوره بلندمدت را اقلیم گویند. شناسایی طبقه‌بندی اقلیمی از دیرباز مورد توجه متخصصان هواشناسی بوده است. محققان با به کارگیری روش ­های مختلف استفاده متغیرهای همچون بارش دما، زمین مناطق همگن طبقه ­بندی کرده‌اند نتایج پهنه‌بندی ارزیابی کمبود منابع مقیاس­ های کوچک بزرگ منظور پیش‌بینی اقدامات عملی برای کنترل خشکی آسیب‌پذیر به‌کار برده‌اند. هدف این تحقیق به‌‌روزرسانی تحل...

Phytolith remains of rice (Oryza sativa L.) recovered from the Shangshan site in the Lower Yangtze of China have previously been recognized as the earliest examples of rice cultivation. However, because of the poor preservation of macroplant fossils, many radiocarbon dates were derived from undifferentiated organic materials in pottery sherds. These materials remain a source of debate because o...

Very soon after the discovery of radioactivity, measurements of the heavy radioactive elements existing in nature were undertaken to determine the age of rocks (Rutherford 1904), but only when Professor Willard Libby in an evening lecture during the first United Nations Conference on the Peaceful Uses of Atomic Energy in Geneva in 1955 described how he and his research team had evolved the carb...

Biosignal Research Center, Kobe University, Kobe 657-8501, Japan, Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, UK, Department of Neurophysiology, Gunma University Graduate School of Medicine, Maebashi, Gunma 371-8511, Japan, Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan, Department of C...

Sea surface reservoir ages must be known to establish a common chronological framework for marine, continental, and cryospheric paleoproxies, and are crucial for understanding ocean-continent climatic relationships and the paleoventilation of the ocean. Radiocarbon dates of planktonic foraminifera and tephra contemporaneously deposited over Mediterranean marine and terrestrial regions reveal th...

Sudan I is generally considered mutagenic based on various in vitro and in vivo tests and is carcinogenic in the rat. Dose-response modelling of the data for hepatocellular adenomas in male rats gave a BMDL(10) of 7.3mg/kg-bw/day. Sudan I is an unauthorised substance that might be present in food intermittently. The great variability and uncertainties in the human exposure data which are countr...

Kinetic measurements were made with cortisone reductase (20-dihydrocortisone-NAD(+) oxidoreductase, EC 1.1.1.53) and a series of substrates which differed in shape, size and electronic character in the region adjacent to C-11, C-14 and C-18. Structural changes at C-11 in these substrates resulted in up to 660-fold changes in the apparent K(m) value, up to 200-fold changes in the apparent V(max....

The cause of a large increase of atmospheric methane concentration during the Younger Dryas-Preboreal abrupt climatic transition (approximately 11,600 years ago) has been the subject of much debate. The carbon-14 (14C) content of methane (14CH4) should distinguish between wetland and clathrate contributions to this increase. We present measurements of 14CH4 in glacial ice, targeting this transi...

Although this paper is self-contained, it logically follows our discussion, begun several years ago in N1706 and continued in N1891, of a feature oft-requested for C++: an opaque typedef , sometimes termed a strong typedef . The earlier of those works was presented to WG21 on 2004-10-20 during the Redmond meeting, and the later work was presented during the Berlin meeting on 2005-04-06. Both pr...