The effects of the anorectics benzphetamine, chlorphentermine, clortermine, mazindol, phendimetrazine, and phenmetrazine on food intake were compared to the effects of d-amphetamine in rhesus monkeys ...given daily access to food pellets. The ability of these compounds to maintain intravenous self-administration under a fixed-ratio 10 schedule was also determined in rhesus monkeys. All drugs reduced food intake in a dose-related manner. d-Amphetamine was the most potent. Mazindol, chlorphentermine, phenmetrazine, and phendimetrazine were approximately 1/5 to 1/9 as potent as d-amphetamine while benzphetamine and clortermine were 1/14 and 1/20 as potent, respectively. Benzphetamine, mazindol, and phenmetrazine were self-administered above saline levels and were approximately equipotent. Chlorphentermine and clortermine were not self-administered and phendimetrazine was self-administered by only one of four monkeys at one dose. Thus, although all of the compounds were effective anorectics, chlorphentermine, clortermine, and phendimetrazine did not function as positive reinforcers. Since the ability of a drug to function as a positive reinforcer is related to its dependence potential, these three compounds might be less subject to abuse when used therapeutically. Within the group of 3 compounds that was self-administered, benzphetamine was relatively more potent as a positive reinforcer than as an anorectic. Therefore, this drug might be a less desirable compound for therapeutic use.
Lasing from population inversion is demonstrated from gas contained in a hollow-core kagome structured photonic crystal fiber. Laser pulses in the mid-IR (3.1-3.2 μm) were generated by optically ...pumping at λ ~ 1.5 μm.
Lasing from HCN gas contained in HC-PCF is observed for the first time. Mid-IR pulses (3.15 and 3.09 μm) were generated by optically pumping at 1.54 μm. A 12 C 2 H 2 -filled gas laser is also studied ...quantitatively.
A method for splicing hollow-core photonic bandgap fiber to step-index fiber using a commercial arc fusion splicer has been developed. These splices compare favorably with commercially available ...splices for nonlinear optical interactions with gases.
The idea that foods rich in fat and sugar may be addictive has generated much interest, as well as controversy, among both scientific and lay communities. Recent research indicates that fatty and ...sugary food in-and-of itself is not addictive. Rather, the food and the context in which it is consumed interact to produce an addiction-like state. One of the contexts that appears to be important is the intermittent opportunity to consume foods rich in fat and sugar in environments where food is plentiful. Animal research indicates that, under these conditions, intake of the fatty sugary food escalates across time and binge-type behavior develops. However, the mechanisms that account for the powerful effect of intermittency on ingestive behavior have only begun to be elucidated. In this review, it is proposed that intermittency stimulates appetitive behavior that is associated with uncertainty regarding what, when, and how much of the highly palatable food to consume. Uncertainty may stimulate consumption of optional fatty and sugary treats due to differential firing of midbrain dopamine neurons, activation of the stress axis, and involvement of orexin signaling. In short, uncertainty may produce an aversive state that bingeing on palatable food can alleviate, however temporarily. "Food addiction" may not be "addiction" to food at all; it may be a response to uncertainty within environments of food abundance.
Abstract
The prevalence of bacteria, parasite and viral pathogens in 3875 patients with diarrhea in community and hospital settings from March 1997 through August 1999 in Jakarta, Indonesia was ...determined using routine bacteriology and molecular assay techniques. Bacterial pathogens isolated from hospital patients were, in decreasing frequency, Vibrio cholerae O1, Shigella flexneri, Salmonella spp. and Campylobacter jejuni, while S. flexneri, V. cholerae O1, Salmonella spp. and C. jejuni were isolated from the community patients. V. cholerae O1 was isolated more frequently (P<0.005) from the hospital patients than the community patients. Overall, bacterial pathogens were isolated from 538 of 3875 (14%) enrolled cases of diarrhea. Enterotoxigenic Escherichia coli were detected in 218 (18%) of 1244 rectal swabs. A small percentage of enterohemorrhagic E. coli (1%) and of Clostridium difficile (1.3%) was detected. Parasitic examination of 389 samples resulted in 43 (11%) positives comprising Ascaris lumbricoides (1.5%), Blastocystis hominis (5.7%), Giardia lamblia (0.8%), Trichuris trichiura (2.1%) and Endolimax nana (0.5%). Rotavirus (37.5%), adenovirus (3.3%) and Norwalk-like virus (17.6%) were also detected. Antimicrobial resistance was observed among some isolates. Bacterial isolates were susceptible to quinolones, with the exception of some isolates of C. jejuni which were resistant to ciprofloxacin, nalidixic acid and norfloxacin. Data obtained from this community- and hospital-based study will enable the Indonesian Ministry of Health to plan relevant studies on diarrheal diseases in the archipelago.
We demonstrate what we believe is the first hollow fiber gas laser based on population inversion. A single-cell-defect Kagome fiber with a core diameter of about 40 microns was filled with a few torr ...of acetylene ( 12 C 2 H 2 ). Acetylene has absorption transitions in the attractive telecommunication C band region and recently lasing was observed at about 3 microns from a gas cell when optically pumped. Pumping the gas filled fiber (1.65 m) with micro Joule pulses from a 5-ns OPO resulted in the emission of two laser lines at 3123.2 nm and 3162.4 nm. The pump (-1521 nm) was in the guiding regions of the fiber (loss ~ 0.75 dB/m) while the laser output occurred in weakly guided modes (~ 20 dB/m). This laser combines attractive features of both fiber and gas lasers, such as the confinement of the pump and laser over long interaction lengths in a compact configuration, the many possible emission wavelengths of various gases, high damage threshold, and the potential for coherent beam combining of mutually incoherent pump sources. While this first laser demonstration used a pulsed pump, the gas filled fiber laser is particularly attractive for pumping with CW laser sources.
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