Global temperature modes shed light on the Holocene temperature conundrum.

Reconstructions of the global mean annual temperature evolution during the Holocene yield conflicting results. One temperature reconstruction shows global cooling during the late Holocene. The other reconstruction reveals global warming. Here we show that both a global warming mode and a cooling mode emerge when performing a spatio-temporal analysis of annual temperature variability during the Holocene using data from a transient climate model simulation. The warming mode is most pronounced in the tropics. The simulated cooling mode is determined by changes in the seasonal cycle of Arctic sea-ice that are forced by orbital variations and volcanic eruptions. The warming mode dominates in the mid-Holocene, whereas the cooling mode takes over in the late Holocene. The weighted sum of the two modes yields the simulated global temperature trend evolution. Our findings have strong implications for the interpretation of proxy data and the selection of proxy locations to compute global mean temperatures.

Synthesis of 4-thia-[6-(13)C]lysine from [2- (13)C]glycine: access to site-directed isotopomers of 2-aminoethanol, 2-bromoethylamine and 4-thialysine.

4-Thialysine (S-(2-aminoethyl)-L: -cysteine) is an analog of lysine. It has been used as an alternative substrate for lysine in enzymatic reactions. Site-directed isotopomers are often needed for elucidation of mechanism of reactions. 4-Thialysine can be synthesized by reacting cysteine with 2-bromoethylamine, an important reagent in chemical-modification rescue (CMR) of proteins. Here, we present the synthesis of 4-thia-[6-(13)C]lysine, one of the isotopomers of 4-thialysine, from commercially available starting material [2-(13)C]glycine via formation of five intermediates including 2-amino[2-(13)C]ethanol and 2-bromo[1-(13)C]ethylamine. The compounds were characterized using various spectroscopic techniques. Moreover, we discuss that our strategy would provide access to site-directed isotopomers of 2-aminoethanol, 2-bromoethylamine and 4-thialysine. Biological activity of 4-thia-[6-(13)C]lysine was tested in the enzymatic reaction of lysine 5,6-aminomutase.

Comparison of prevalence between self-reported erectile dysfunction and erectile dysfunction as defined by five-item International Index of Erectile Function in Taiwanese men older than 40 years.

OBJECTIVES: To conduct a cohort study in men older than 40 years in Taiwan to evaluate the prevalence of erectile dysfunction (ED) by self-report and the use of the abridged, five-item version of the International Index of Erectile Function (IIEF-5). METHODS: From July to August 2003, 990 Taiwanese men older than 40 years of age completed a telephone survey designed to assess ED prevalence and sexual functioning. ED was identified through respondent self-report and investigator assessment using the IIEF-5 instrument. Data were analyzed using the analysis of variance test, t test, and chi-square test, with Yates' correction or Fisher's method. RESULTS: The prevalence of self-reported ED was 13.1%, with 26.2% of this subgroup subsequently deemed to not have ED by IIEF-5 assessment. Among the subgroup of men self-reported to not have ED, 18.8% were found to have ED by IIEF-5 assessment. In total, 26.0% of respondents had ED by IIEF-5 assessment. The ED prevalence increased with age and a history of chronic illness. The frequency of sexual contact and sexual satisfaction were also reduced in the respondents with ED. CONCLUSIONS: The prevalence of self-reported ED in Taiwanese men older than 40 years of age was 13.1% compared with 26.0% using the IIEF-5 assessment. Estimates of ED prevalence in the general population should not rely on self-reporting alone because it is likely to underestimate the true prevalence of ED.