Mid-infrared gas sensing using a photonic bandgap fiber

We demonstrate methane sensing based on Fourier transform infrared spectroscopy using a hollow-core photonic bandgap fiber guiding in the mid-infrared and idler pulses from a femtosecond optical parametric oscillator. Transmission measurements are presented for several fibers, and sensing is demonstrated using a fiber whose bandgap overlaps the methane fundamental absorption lines. The gas filling process of the air core is described, and qualitative methane concentrations measurements to 1000 ppm (parts in 10(6)) are reported. Operation down to 50 ppm based on our current experiment is predicted.     

The FDA just says yes

Will a new and, some say, improved FDA improve the conditions, financial and otherwise, of patient care? Many argue that the acceleration of the FDA approval process comes at a high price. As new drugs hit the market faster--and with less proof of their long-term benefits--health care costs are going up, up, up, and society is facing painful rationing decisions.     

Oxygen isotopic abundances in calcium- aluminum-rich inclusions from ordinary chondrites: implications for nebular heterogeneity

The oxygen isotopic compositions of two calcium-aluminum-rich inclusions (CAIs) from the unequilibrated ordinary chondrite meteorites Quinyambie and Semarkona are enriched in 16O by an amount similar to that in CAIs from carbonaceous chondrites. This may indicate that most CAIs formed in a restricted region of the solar nebula and were then unevenly distributed throughout the various chondrite accretion regions. The Semarkona CAI is isotopically homogeneous and contains highly 16O-enriched melilite, supporting the hypothesis that all CAI minerals were originally 16O-rich, but that in most carbonaceous chondrite inclusions some minerals exchanged oxygen isotopes with an external reservoir following crystallization.     

Demonstration of cytoplasmic CD32 (Fc gamma RII) within human lymphocytes following microwave treatment

The effects of a novel prolyl endopeptidase inhibitor (PEP), (S)-2-[[(S)-2-(hydroxyacetyl)-1-pyrrolidinyl]carbonyl]-N-(phenylmethyl)- 1-pyrrolidinecar-boxamide (JTP-4819), on performance of the Morris water maze task and on central cholinergic function were investigated in aged rats. Spatial memory (escape latency, path length, and swimming speed to the platform) was impaired in aged rats performing the Morris water maze task when compared to young rats. Administration of JTP-4819 (1 mg/kg, p.o.) for 14 days improved this memory deficit in aged rats, as shown by the decrease in escape latency and path length. In addition, when JTP-4819 (at doses of 1 and 3 mg/kg, p.o.) was administered for 3 wk, it reversed the age-related increase of ChAT activity in the cerebral cortex and the decrease of 3H-choline uptake in the hippocampus. These data suggest that JTP-4819 ameliorates age-related impairment of spatial memory and partly reverses central cholinergic dysfunction, possibly due to the enhancement of neuropeptide function by inhibition of PEP mediated degradation of substance P, arginine-vasopressin, and thyrotropin-releasing hormone.     

Nicotine dependence symptoms among adolescents with psychiatric disorders: using a Rasch model to evaluate symptom expression across time.

Little is known about the longitudinal course of symptoms of nicotine dependence among adolescents following interventions designed to affect smoking behavior, particularly among high-risk samples. We used an item-response modeling strategy to examine how well nicotine dependence symptoms cohere to a latent construct, the stability of the construct over time, and the sensitivity of the nicotine dependence symptoms to changes in smoking patterns among adolescents with comorbid psychopathology. Assessments occurred prior to cessation treatment delivered within a randomized clinical trial and again at 6 and 12 months after treatment. We used a Rasch item-response modeling approach to examine nicotine dependence as measured by a structured Adolescent Nicotine Dependence Interview (ANDI) and by the Modified Fagerstr?m Tolerance Questionnaire (mFTQ). These analyses provided support for a unidimensional latent measurement model that can be used to organize symptoms of nicotine dependence obtained from ANDI and mFTQ measures. The derived measure showed good construct validity with significant relationships to smoking levels and salivary cotinine levels. The typical symptom patterns and the relative severity of nicotine dependence symptoms remained stable over multiple assessments. Changes in smoking levels were related longitudinally to changes in nicotine dependence, and changes in nicotine dependence were related to changes in motivation to quit and readiness to change smoking behavior. Several behavioral symptoms were sensitive to change in smoking rate over time, whereas core symptoms of physiological dependence did not evidence significant changes. Results suggest that DSM-IV and mFTQ measures of nicotine dependence provide complementary information when assessing nicotine dependence levels among adolescents with psychiatric disorders.     

Adolescent definitions of change in smoking behavior: an investigation.

Although adolescent smoking cessation has received increased research attention, little information exists as to how adolescents define change efforts for smoking behaviors. This issue is of particular importance because surveys routinely incorporate items assessing smoking cessation, yet how adolescents interpret such items is unclear. The present study investigated definitions of smoking behavior change efforts among adolescents. A total of 94 adolescent smokers-of average age 16.7 years (SD = 1.0), 56% female, and 71% White-were asked to define the terms quit, stop, and cut down smoking. Responses to the three questions were categorized using content analysis. Definitions of quit and stop were categorized as (a) stop permanently, (b) stop temporarily, (c) stop except in certain situations, and (d) reduce smoking (for quit only). Definitions of cut down were categorized as (a) reduce the number of cigarettes, (b) smoke less in a time frame, (c) reduce smoking occasions, and (d) smoke less. Three trained raters sorted responses into each of the categories. Definitions of quit and stop were most frequently categorized in the stop permanently category (86% and 75%, respectively). Definitions of cut down were distributed across categories, with 51% categorized as smoke less, 25% smoking less in a time frame, and 25% reducing number of cigarettes. Different definitions of stop were related to smoking history and motivation to quit, although the other two terms were not related to adolescent individual characteristics. Findings highlight the importance of using clearly defined questionnaire items when assessing adolescent smoking change efforts.     

A standardized menu for Goal Attainment Scaling in the care of frail elders

The traditional anion gap [AG = Na-Cl-(total CO2)] mean value of 12 mEq/L was established during the 1970s with analyzer methods that are no longer used widely. No studies have systematically compared mean AG values from analyzers in current use. We used data from healthy subjects obtained from 27 clinical laboratories, 5 manufacturers, and 8 publications to compute mean AG values from 1970s analyzers and 8 current analyzers. We also compared mean AG values by evaluating Na, Cl, and total CO2 data from the College of American Pathologists Chemistry Surveys (1990-1996). Data from healthy subjects showed that overall mean AG values of the 9 analyzers ranged from 5.9 to 12.4 mEq/L. The pooled (i.e., average) AG SD was 2.3 mEq/L. We then used the data of the Surveys and the mean value from 1 analyzer to compute predicted mean values for the other 7 current analyzers. Almost all mean AG values predicted from the Surveys agreed (within 1.5 mEq/L) with mean values from healthy subjects. These results show that mean values of analyzers vary widely, indicating that analytic bias strongly influences the AG. The results should be a useful guide for the AG measurements that can be expected from different analyzers.     

Nursing in the NHS: the executive nurse director

The advent of trusts within the NHS brought a new dimension to the role of nurses in management, in that each trust must appoint an executive nurse director to sit on the trust board. The function and potential function of this role is, I believe, pivotal to the development of clinical services within the NHS.     

New tools for phenotypic analysis in Candida albicans: the WAR1 gene confers resistance to sorbate

Availability of the complete sequence of the Candida albicans genome allows for global gene analysis. We designed a gene deletion method to facilitate such studies. First, we constructed C. albicans strains that are both Deltaura3 and Deltatrp1. Second, we designed a system that relies on in vitro recombination, using the Gateway((R)) technology, for efficient generation of deletion cassettes. They are generated in two steps: (a) upstream and downstream DNA fragments of the chromosomal region to be deleted are amplified by PCR and introduced into two separate entry vectors; (b) the second step involves a quadruple recombination event including the two entry vectors, a plasmid bearing a marker of interest and a destination vector, in order to generate a plasmid containing the deletion cassette. The deletion plasmid contains very rare restriction sites for convenient excision of the knockout cassette. Selection in C. albicans can be performed with one of the following markers: the C. albicans URA3 gene, a modified S. cerevisiae TRP1 gene or the mycophenolic acid resistance (MPA(R)) gene. Upon integration into the genome, these markers can be removed by the use of 5-fluoroorotic acid (URA3), 5-fluoroanthranilic acid (TRP1) or the FLP recombinase (MPA(R)). Using this approach, we show that removal of the C. albicans orf19.1035 gene results in sensitivity to the weak acid sorbate, while its overexpression increases resistance to this compound. We named it WAR1, in analogy to its S. cerevisiae orthologue.