The RNA World is generally thought to have been an important link between purely prebiotic (>3.7 Ga) chemistry and modern DNA/protein biochemistry. One concern about the RNAWorld hypothesis is the geochemical stability of ribose, the sugar moiety of RNA. Prebiotic stabilization of ribose by solutions associated with borate minerals, notably colemanite, ulexite, and kernite, has been proposed as...

Mental-age-matched normal and retarded subjects at mental-age (MA) levels 5.5, 7.5, and 9.5 years received blank-trial discrimination problems designed to expose hypothesis behavior. There was evidence that subjects at all MA levels used hypotheses. Use of feedback indicating that a response was wrong increased significantly with MA, while use of feedback indicating that a response was right in...

in the current study, the effects of ethanol (etoh) on toxicokinetics of methamphetamine (ma) and its metabolite amphetamine (ap) were investigated. a single dose of ma hydrochloride at 15 mg/kg was given intragastrically, either alone (ma group; n = 8) or in conjunction with 3 g/kg etoh (ma+etoh group; n = 8) to rabbits. in placebo group, normal saline only was given (placebo group; n = 4). pl...

Results indicate the presence of significant oxidative damage to the dna of lymphocytes in peripheral blood and ascites from patients with ma, being especially higher in the cells from ascites. The lower tac of ma supernatant may be related to a higher degree of dna damage to tals. The present study suggests that an oxidant–antioxidant imbalance may be one of the mechanisms leading to the dna d...

3 We integrate appealing features of Markowitz’s mean-variance portfolio theory (MVT) 4 and Shefrin and Statman’s behavioral portfolio theory (BPT) into a new mental accounting 5 (MA) framework. Features of the MA framework include an MA structure of portfolios, 6 a definition of risk as the probability of failing to reach the threshold level in each mental 7 account, and attitudes toward risk ...

injecting local anesthetic at the seeking current would be appealing.it would save time and avoid potentially dangerous manipulations of the needle. this study aimed to test the hypotheses that in vertical infraclavicular block, injecting local anesthetic at a seeking current of 0.8 ma would produce the same quality of block as injecting at ≤0.5ma. a total of sixty asa i -iii adult patients sch...

Both mandibular advancement (MA) and stimulation of the genioglossus (GG) have been shown to improve upper airway patency, but neither one achieves the effect of continuous positive airway pressure (CPAP) treatment. In the present study we assessed the combined effect of MA and GG stimulation on the relaxed pharynx in patients with obstructive sleep apnea (OSA). We evaluated responses of upper ...