Aviation fuel and future oil production scenarios

Most aviation fuels are jet fuels originating from crude oil. Crude oil must be refined to be useful and jet fuel is only one of many products that can be derived from crude oil. Jet fuel is extracted from the middle distillates fraction and competes, for example, with the production of diesel.     

Health consequences of reduced daily cigarette consumption

Objective

To determine the risk of dying from specified smoking‐related diseases and from any cause in heavy smoking men and women (⩾15 cigarettes/day), who reduced their daily cigarette consumption by >50%.

Design

A prospective cohort study.

Setting

Three counties in Norway.

Participants

24 959 men and 26 251 women, aged 20–49 years, screened for risk factors of cardiovascular disease in the mid‐1970s, screened again after 3–13 years, and followed up throughout 2003.

Outcomes

Absolute mortality and relative risks adjusted for confounding variables, of dying from all causes, cardiovascular disease, ischaemic heart disease, all smoking‐related cancer and lung cancer.

Results

With sustained heavy smokers as reference, the smokers of both sexes who reduced their daily consumption (reducers) had the following adjusted relative risks (95% confidence interval (CI)): of dying from any cause, 1.02 (0.84 to 1.22); cardiovascular disease, 1.02 (0.75 to 1.39); ischaemic heart disease, 0.96 (0.65 to 1.41); smoking‐related cancer, 0.86 (0.57 to 1.29); and lung cancer, 0.66 (0.36 to 1.21). The difference in cigarette consumption between two examinations was not a significant predictor of death from any of the causes. A follow‐up from a third screening of the subgroup who were reducers at both second and third examinations (sustained reducers) did not have a lower risk than those who were heavy smokers at all three examinations.

Conclusions

Long‐term follow‐up provides no evidence that heavy smokers who cut down their daily cigarette consumption by >50% reduce their risk of premature death significantly. In health education and patient counselling, it may give people false expectations to advise that reduction in consumption is associated with reduction in harm.Does reduced daily cigarette consumption lead to lower mortality from the serious health consequences of cigarette smoking? In other words, does a reduction in consumption bring about reduction in harm?Numerous population studies have given ample evidence that quitting smoking entirely results in a marked reduction in the ill effects of smoking. Up to now, however, only one large prospective study has explored the long‐term effects of unassisted reduced smoking. Godtfredsen et al^1,2,3,4 have pioneered in this field by following up a population of nearly 20 000 men and women living in Copenhagen, Denmark (the Copenhagen Centre for Prospective Population Studies). After mean observation periods ranging from 13.8 to 18 years, they published their results in a series of articles.The aim of this paper is to determine the risk in heavy smokers who reduced their cigarette consumption by at least 50%, named “reducers”, compared with those who continued as heavy smokers. We report on a Norwegian population of 51 210 men and women, aged 20–49 years, who were examined in the mid‐1970s for cardiovascular disease risk factors and were examined again during the next 3–13 years at least once. These people were followed up throughout 2003 for deaths from serious smoking‐related diseases and from all causes. The mean observation period is 21.2 years, maximum 27 years. A subgroup attended three screenings. This gave us the possibility to compare those who were reducers at the two last screenings (sustained reducers) with those who were heavy smokers at all three screenings (sustained heavy smokers).     

Genetic evaluation of claw health traits accounting for potential preselection of cows to be trimmed

Claw lesions are one of the most important health issues in dairy cattle. Although the frequency of claw lesions depends greatly on herd management, the frequency can be lowered through genetic selection. A genetic evaluation could be developed based on trimming records collected by claw trimmers; however, not all cows present in a herd are usually selected by the breeder to be trimmed. The objectives of this study were to investigate the importance of the preselection of cows for trimming, to account for this preselection, and to estimate genetic parameters of claw health traits. The final data set contained 25,511 trimming records of French Holstein cows. Analyzed claw lesion traits were digital dermatitis, heel horn erosion, interdigital hyperplasia, sole hemorrhage circumscribed, sole hemorrhage diffused, sole ulcer, and white line fissure. All traits were analyzed as binary traits in a multitrait linear animal model. Three scenarios were considered: including only trimmed cows in a 7-trait model (scenario 1); or trimmed cows and contemporary cows not trimmed but present at the time of a visit (considering that nontrimmed cows were healthy) in a 7-trait model (scenario 2); or trimmed cows and contemporary cows not trimmed but present at the time of a visit (considering lesion records for trimmed cows only), in an 8-trait model, including a 0/1 trimming status trait (scenario 3). For scenario 3, heritability estimates ranged from 0.02 to 0.09 on the observed scale. Genetic correlations clearly revealed 2 groups of traits (digital dermatitis, heel horn erosion, and interdigital hyperplasia on the one hand, and sole hemorrhage circumscribed, sole hemorrhage diffused, sole ulcer, and white line fissure on the other hand). Heritabilities on the underlying scale did not vary much depending on the scenario: the effect of the preselection of cows for trimming on the estimation of heritabilities appeared to be negligible. However, including untrimmed cows as healthy caused bias in the estimation of genetic correlations. The use of a trimming status trait to account for preselection appears promising, as it allows consideration of the exhaustive population of cows present at the time a trimmer visited a farm without causing bias in genetic parameters.     

Interactive-adaptive geometrically nonlinear analysis of shell structures

This paper presents an investigation of interactive-adaptive techniques for nonlinear finite element structural analysis. In particular, effective methods leading to reliable automated, finite element solutions of nonlinear shell problems are of primary interest here. This includes automated adaptive nonlinear solution procedures based on error estimation and adaptive step length control, reliable finite elements that account for finite deformations and finite rotations, three-dimensional finite element modeling, and an easy-to-use, easy-to-learn graphical user interface with three-dimensional graphics. A computational environment, which interactively couples a comprehensive geometric modeler, an automatic three-dimensional mesh generator and an advanced nonlinear finite element analysis program with real-time computer graphics and animation tools, is presented. Three examples illustrate the merit and potential of the approaches adopted here and confirm the feasibility of developing fully automated computer aided engineering environments.     

Business opportunities throughUMTS-WLAN networks

This article outlines the economic feasibility of mobile operators that combine nationwide mobility with 3G networks and hot spot coverage withWLANS, WLANS are based onHIPERLAN/2 architecture and theUMTS network exploitswCDMA/FDD technology. The evaluated business scenarios are focused on two different deployment areas, in terms of demographic characteristics and mobile penetration: a large and a small European country. The business case spans 2002 to 2011 withUMTS’ roll-out year in 2002 andWLAN’s in 2004, covering indoor hot-spot areas (stations, airports, stadiums, etc.) where demand is high. The demand for thisUMTS-WLAN roaming case is evaluated based on observations from Europe’s current mobile market and its evolution. Usage scenarios of different service packages corresponding to both residential and business markets have been taken into account. Direct investments and operational costs as well as revenue streams from traffic have been calculated. The methodology and the tool developed inACTS-TERA [1] andIST-TONIC [2] projects have been utilized for this case study. Economic conclusions have been derived, presented and discussed using key profitability factors. Profitability for all scenarios and business profiles has been calculated, presented and discussed. It includes a sensitivity analysis in order to identify the major opportunities and threats, for specific service sets as well as critical parameters and uncertainties. A wide audience from mobile operators and service providers to retail companies interested in entering the 3G market, can exploit this information.     

Thin-film microextraction

The properties of a thin sheet of poly(dimethylsiloxane) (PDMS) membrane as an extraction phase were examined and compared to solid-phase microextraction (SPME) PDMS-coated fiber for application to semivolatile analytes in direct and headspace modes. This new PDMS extraction approach showed much higher extraction rates because of the larger surface area to extraction-phase volume ratio of the thin film. Unlike the coated rod formats of SPME using thick coatings, the high extraction rate of the membrane SPME technique allows larger amounts of analytes to be extracted within a short period of time. Therefore, higher extraction efficiency and sensitivity can be achieved without sacrificing analysis time. In direct membrane SPME extraction, a linear relationship was found between the initial rate of extraction and the surface area of the extraction phase. However, for headspace extraction, the rates were somewhat lower because of the resistance to analyte transport at the sample matrix/headspace barrier. It was found that the effect of this barrier could be reduced by increasing either agitation, temperature, or surface area of the sample matrix/headspace interface. A method for the determination of PAHs in spiked lake water samples was developed based on the membrane PDMS extraction coupled with GC/MS. A linearity of 0.9960 and detection limits in the low-ppt level were found. The reproducibility was found to vary from 2.8% to 10.7%.     

Theoretical investigation of the signal-to-noise ratio in fluorescence lifetime imaging

We deduce the signal-to-noise ratio for fluorescence lifetime imaging when using frequency-domain methods. We assume mono-exponential decay and quantum-noise-limited performance. The results are compared with Monte Carlo simulations with good agreement. We also compare our results with previous investigations of time-domain methods for fluorescence lifetime imaging. For a given number of detected photons, we find that frequency-domain and time-domain methods are equally good. The correct choice of detection technique and its parameters is important for obtaining good results.     

The structural basis of MHC control of collagen-induced arthritis; binding of the immunodominant type II collagen 256-270 glycopeptide to H-2Aq and H-2Ap molecules

The Aq major histocompatibility complex (MHC) class II molecule is associated with susceptibility to murine collagen-induced arthritis (CIA), whereas the closely related H-2Ap molecule is not. To understand the molecular basis for this difference, we have analyzed the ability of H-2Aq and H-2Ap molecules (referred to as Aq and Ap) to bind and present collagen type II (CII)-derived glycosylated and non-glycosylated peptides. T cell clones specific for the immunodominant CII 256-270 peptide and restricted to both Aq and Ap molecules were identified. When these clones were incubated with CII protein and either Aq- or Ap-expressing antigen-presenting cells (APC), only Aq-expressing APC were able to induce stimulation. With the use of A(beta) transgenic mice this could be shown to be solely dependent on the MHC class II molecule itself and to be independent of other MHC- or non-MHC genes. Peptide binding studies were performed using affinity-purified MHC class II molecules. The CII 256-270 peptide bound with lower affinity to the Ap molecule than to the Aq molecule. Using a set of alanine-substituted CII 256-270 peptides, MHC class II and T cell receptor (TCR) contacts were identified. Mainly the side chains of isoleucine 260 and phenylalanine 263 were used for binding both the Aq and Ap molecule, i.e. the peptide was orientated similarly in the binding clefts. The major TCR contact amino acids were lysine 264, which can be posttranslationally modified, and glutamic acid 266, which is the only amino acid in the heterologous peptide which differs from the mouse sequence. Glycosylation at positions 264 and 270 of the CII 256-270 peptide did not change the anchor positions used for binding to the Aq or Ap molecules. The autologous form of the peptide (with aspartic acid at position 266) bound with lower affinity to the Aq molecule as compared with the heterologous peptide. The variable affinity displayed by the immunodominant CII 256-270 peptide for different MHC class II molecules, the identification of MHC and TCR contacts and the significance of glycosylation of these have important implications for the understanding of the molecular basis for inherited MHC class II-associated susceptibility to CIA and in turn, for development of novel treatment strategies in this disease.     

Sex-role stereotypes and clinical judgments of mental health.

Gave a sex-role stereotype questionnaire consisting of 122 bipolar items to 79 actively functioning clinicians with 1 of 3 sets of instructions: to describe a healthy, mature, socially competent (a) adult, sex unspecified, (b) a man, or (c) a woman. It was hypothesized that clinical judgments about the characteristics of healthy individuals would differ as a function of sex of person judged, and that these differences would parallel sterotypic sex-role differences. A 2nd hypothesis predicted that behaviors and characteristics judged healthy for an adult, sex unspecified, which are presumed to reflect an ideal standard of health, will resemble behaviors judged healthy for men, but not for women. Both hypotheses were confirmed. (21 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)