bluuebunny/crossref_metadata_2025 huggingface dataset:
Extreme lymphoproliferative disease and fatal autoimmune thrombocytopenia in FasL and TRAIL double-deficient mice
Authors: Sedger Lisa M. , Katewa Arna , Pettersen Ann K. , Osvath Sarah R. , Farrell Geoff C. , Stewart Graeme J. , Bendall Linda J. , Alexander Stephen I.
Published: February 2010

To delineate the relative roles of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and Fas ligand in lymphocyte biology and lymphoproliferative disease, we generated mice defective in both molecules. B6.GT mice develop severe polyclonal lymphoproliferative disease because of accumulating CD3+CD4−CD8−B220+ T cells, CD4+ and CD8+ T cells, and follicular B cells, and mice die prematurely from extreme lymphocytosis, thrombocytopenia, and hemorrhage. Accumulating lymphocytes resembled antigen-experienced lymphocytes, consistent with the maximal resistance of B6.GT CD4+ and CD8+ T cell to activation-induced cell death. More specifically, we show that TRAIL contributes to Fas ligand-mediated activation-induced cell death and controls lymphocyte apoptosis in the presence of interferon-γ once antigen stimulation is removed. Furthermore, dysregulated lymphocyte homeostasis results in the production of anti-DNA and rheumatoid factor autoantibodies, as well as antiplatelet IgM and IgG causing thrombocytopenia. Thus, B6.GT mice reveal new roles for TRAIL in lymphocyte homeostasis and autoimmune lymphoproliferative syndromes and are a model of spontaneous idiopathic thrombocytopenia purpura secondary to lymphoproliferative disease.
Treatment outcome of multidrug/extensively drug-resistant tuberculosis in Latvia, 2000–2004
Authors: Leimane V. , Dravniece G. , Riekstina V. , Sture I. , Kammerer S. , Chen M.P. , Skenders G. , Holtz T.H.
Published: February 2010

In the present study, we characterised drug-resistance patterns, compared treatment outcome between extensively and nonextensively drug-resistant tuberculosis (non-XDR-TB) cases, and assessed risk factors for poor outcome in a high-prevalence country that screens all TB patients for first-line anti-TB drug resistance.

We reviewed drug susceptibility test results among all pulmonary TB cases in Latvia diagnosed from 2000–2004, as well as demographic and clinical characteristics, drug-resistance patterns, and treatment outcomes.

During the 5-yr period, 1,027 multidrug-resistant tuberculosis (MDR-TB) cases initiated treatment. Among all cases, the proportion that experienced an outcome of cure or completion increased from 66.2 to 70.2% (p = 0.06 for linear trend). Among the 48 (4.7%) XDR-TB cases, 18 (38%) were cured, four (8%) died, three (6%) defaulted, and treatment failed in 23 (48%). In proportional-hazards analysis, characteristics significantly associated with poor outcome included XDR-TB, being retired, presence of bilateral cavitation, and previous MDR-TB treatment history for those aged ≥55 yrs.

Overall, treatment success among all MDR-TB cases increased over time. Strategies to prevent transmission of XDR-TB and to further improve treatment outcome are crucial for the future of TB control in Latvia.
Healthy hire effect, job selection and inhalation exposure among young adults with asthma
Authors: Olivieri M. , Mirabelli M.C. , Plana E. , Radon K. , Antó J.M. , Bakke P. , Benke G. , D’Errico A. , Henneberger P. , Kromhout H. , Norbäck D. , Torén K. , van Sprundel M. , Villani S. , Wieslander G. , Zock J-P. , Kogevinas M.
Published: February 2010

The aim of the present study was to assess whether asthma onset prior to entering the workforce influences whether a person holds a subsequent job with asthma-related inhalation exposures.

The data of 19,784 adults from the European Community Respiratory Health Survey were analysed. For each respondent, a current or previously held job was linked to a job exposure matrix assigning high, low or no exposure to dust, gases or fumes. Jobs were also categorised according to the risk of exposures related to occupational asthma. Associations between asthma and subsequent occupational exposures were assessed using logistic regression models, with a random intercept for study centre and fixed adjustment for age, sex, type of study sample and smoking status.

Of the respondents, 8% (n = 1,619) reported asthma with onset before completion of full-time education. This population was at decreased risk of having a job with high (odds ratio 0.79; 95% confidence interval 0.68–0.92) or low (0.91; 0.80–1.03) exposure to dust, gases or fumes. The associations were consistent across exposure types (dusts, gases or fumes) and for jobs with a high risk of occupational asthma.

Adults with asthma onset prior to entering the workforce may be less likely to hold jobs involving inhalation exposures.
Tiotropium as a first maintenance drug in COPD: secondary analysis of the UPLIFT® trial
Authors: Troosters T. , Celli B. , Lystig T. , Kesten S. , Mehra S. , Tashkin D.P. , Decramer M.
Published: February 2010

The aim of the present study was investigate the long-term effect of tiotropium as first maintenance respiratory medication in chronic obstructive pulmonary disease (COPD).

A 4-yr, randomised, multicentre, double-blind, parallel-group, placebo-controlled trial (Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT®)) was conducted. Analysis focused on the effect of tiotropiumversusmatching placebo in the 810 (13.5%) COPD patients not on other maintenance treatment (long-acting β-agonists, inhaled corticosteroids, theophyllines or anticholinergics) at randomisation. Spirometry, health-related quality of life (St George’s Respiratory Questionnaire (SGRQ) score), exacerbations of COPD and mortality were also analysed.

403 patients (mean±sdage 63±8 yrs, post-bronchodilator forced expiratory volume in 1 s (FEV1) 53±12% predicted) received tiotropium and 407 (64±8 yrs of age, post-bronchodilator FEV151±12% pred) received placebo. Post-bronchodilator FEV1decline was 42±4 mL·yr−1in the tiotropium group and 53±4 mL·yr−1in the placebo group (p = 0.026). At 48 months, the morning pre-dose FEV1was 134 mL higher in the tiotropium group compared to the placebo group (p<0.001). SGRQ total score declined more slowly in the tiotropium group (difference of 1.05±0.34 units·yr−1; p = 0.002). This was particularly significant for the impact (difference of 1.08±0.37 units·yr−1; p = 0.004) and activity (1.44±0.40 units·yr−1; p<0.001) domains, but not for symptoms (0.26±0.50 units·yr−1; p = 0.6). At 48 months, the difference in total score was 4.6 units (p<0.001) with tiotropium compared to placebo.

In patients with COPD who are not on maintenance therapy, tiotropium is associated with significant benefits in disease progression.
Interleukin-17-producing T-helper cells and related cytokines in human airways exposed to endotoxin
Authors: Glader P. , Smith M.E. , Malmhäll C. , Balder B. , Sjöstrand M. , Qvarfordt I. , Lindén A.
Published: February 2010

Previous studies on mouse models have indicated that interleukin (IL)-17 and IL-17-producing T-helper (Th) cells are important for pulmonary host defence against Gram-negative bacteria. Human correlates to these findings have not yet been demonstrated. The aim of the present study was to determine whether or not IL-17-producing Th cells are present and whether IL-17 and other Th17-associated cytokines are involved in the immunological response to endotoxin in human airways.

Segmental exposure to endotoxin and contralateral exposure to vehicle were performed in the lungs of healthy volunteers, with subsequent bronchoalveolar lavage 12 or 24 h after exposure to study local changes in cytokines and inflammatory cells.

Endotoxin exposure increased concentrations of IL-17, IL-22 and their downstream effector molecules, human β-defensin-2 and IL-8/CXC chemokine ligand 8, in bronchoalveolar lavage fluid. Th cells with the capacity to produce IL-17 were found among the bronchoalveolar lavage cells, and expression of IL-17 mRNA correlated with expression of the transcription factor, retinoic-acid-receptor-related orphan receptor C variant 2. Moreover, endotoxin increased the numbers of neutrophils, macrophages and IL-17-producing T-cells, as well as the concentration of the Th17-regulating cytokines, IL-21 and IL-23.

In conclusion, IL-17-producing Th cells are present, and IL-17, as well as other Th17-associated cytokines, is involved in the immunological response to endotoxin in human airways.
Plasma DNA level in predicting therapeutic efficacy in advanced nonsmall cell lung cancer
Authors: Kumar S. , Guleria R. , Singh V. , Bharti A.C. , Mohan A. , Das B.C.
Published: February 2010

Assessment of total plasma DNA can be a promising noninvasive tool for monitoring the effect of cytotoxic therapies in order to predict therapeutic efficacy at an early stage.

Cell-free plasma DNA levels were quantified before the first, second and third cycle of chemotherapy in 42 patients with advanced nonsmall cell lung cancer and correlated with response to therapy, as assessed by computed tomography following the third chemotherapy cycle.

A significantly lower plasma DNA level, measured before various treatment cycles, was found in patients with remission or stable disease than in those with progression. Higher levels and insufficient decrease in plasma DNA levels during the course of chemotherapy indicated poor outcome. For predicting insufficient therapy response, a sensitivity of 26.9% was achieved at 100% specificity using plasma DNA levels before the first therapy cycle. Prediction of disease progression was achieved with a sensitivity of 35.7% at 100% specificity using plasma DNA levels before the first therapy cycle.

Monitoring of plasma DNA levels during the course of chemotherapy could identify patients who are likely to exhibit an insufficient therapeutic response and disease progression at an early stage. This may help in individualising treatment, and could lead to better management of advanced-stage lung cancer.
Functional conservation between rodents and chicken of regulatory sequences driving skeletal muscle gene expression in transgenic chickens
Authors: McGrew Michael J , Sherman Adrian , Lillico Simon G , Taylor Lorna , Sang Helen
Published: February 2010

Background

Regulatory elements that control expression of specific genes during development have been shown in many cases to contain functionally-conserved modules that can be transferred between species and direct gene expression in a comparable developmental pattern. An example of such a module has been identified at the rat myosin light chain (MLC) 1/3 locus, which has been well characterised in transgenic mouse studies. This locus contains two promoters encoding two alternatively spliced isoforms of alkali myosin light chain. These promoters are differentially regulated during development through the activity of two enhancer elements. The MLC3 promoter alone has been shown to confer expression of a reporter gene in skeletal and cardiac muscle in transgenic mice and the addition of the downstream MLC enhancer increased expression levels in skeletal muscle. We asked whether this regulatory module, sufficient for striated muscle gene expression in the mouse, would drive expression in similar domains in the chicken.

Results

We have observed that a conserved downstream MLC enhancer is present in the chicken MLC locus. We found that the rat MLC1/3 regulatory elements were transcriptionally active in chick skeletal muscle primary cultures. We observed that a single copy lentiviral insert containing this regulatory cassette was able to drive expression of a lacZ reporter gene in the fast-fibres of skeletal muscle in chicken in three independent transgenic chicken lines in a pattern similar to the endogenous MLC locus. Reporter gene expression in cardiac muscle tissues was not observed for any of these lines.

Conclusions

From these results we conclude that skeletal expression from this regulatory module is conserved in a genomic context between rodents and chickens. This transgenic module will be useful in future investigations of muscle development in avian species.
Mutations in epidermal growth factor receptor and K-ras in Chinese patients with colorectal cancer
Authors: Yunxia Zuo , Jun Cao , Guanshan Zhu , Yachao Lu , Xueke Zhou , Jin Li
Published: February 2010

Background

Mutations of EGFR and K-ras are biomarkers for predicting the efficacy of targeting agents in non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC). Data on the gene mutation status of EGFR and K-ras in Chinese patients with CRC are limited.

Methods

EGFR mutations in exon 18-21 and K-ras mutations in exon 1 and 2 were detected in tumor samples from 101 Chinese patients with CRC by polymerase chain reaction-single strand conformational polymorphism. The relationship between patients' characteristics and survival time and gene mutation status were analyzed using the Statistical Package for the Social Sciences.

Results

Only two samples (2.0%) had EGFR mutations in exon 18 or 21, and 33 of 101 samples (32.7%) had K-ras mutations in codon 12, 13, 45, 69, or 80. Univariate analysis suggested that differentiation might be correlated with K-ras mutations (p = 0.05), which was confirmed by a logistic regression model (p = 0.04). The median overall survival (OS) and median survival after metastasis were 44.0 and 18.0 months, respectively, in the mutant K-ras group, and 53.3 and 19.0 months, respectively, in the wild K-ras group. K-ras mutation was not an independent prognostic factor for OS or survival after metastasis (p = 0.79 and 0.78, respectively).

Conclusions

In Chinese patients with CRC, EGFR mutations were rare, and K-ras mutations were similar to those of Europeans. New mutations in codons 45, 69, and 80 were found in the Chinese population. Poor differentiation was an independent factor related to K-ras mutations.
Association between gefitinib and hemorrhagic cystitis and severely contracted bladder: a case report
Authors: Arakawa Maki , Nakamura Kogenta , Yamada Yoshiaki , Rosser Charles J , Tobiume Motoi , Saito Hiroko , Hasegawa Takaaki , Honda Nobuaki
Published: February 2010

Background

Gefitinib remains an excellent treatment option for patients with a variety of cancers, including non small cell lung cancer (NSCLC). However, clinicians must be aware of the potential of gefitinib to cause an inflammatory reaction in the skin, lungs and bladder.

Case Presentation

We present a case on hemorrhagic cystitis and severaly contracted bladder in a patient with NSCLC on gefitinib.

Conclusions

Further studies are needed to substantiate the association of gefitinib therapy with hemorrhagic cystitis and contracted bladder.
A novel method for sample preparation of fresh lung cancer tissue for proteomics analysis by tumor cell enrichment and removal of blood contaminants
Authors: De Petris Luigi , Pernemalm Maria , Elmberger Göran , Bergman Per , Orre Lotta , Lewensohn Rolf , Lehtiö Janne
Published: February 2010

Background

In-depth proteomics analyses of tumors are frequently biased by the presence of blood components and stromal contamination, which leads to large experimental variation and decreases the proteome coverage. We have established a reproducible method to prepare freshly collected lung tumors for proteomics analysis, aiming at tumor cell enrichment and reduction of plasma protein contamination. We obtained enriched tumor-cell suspensions (ETS) from six lung cancer cases (two adenocarcinomas, two squamous-cell carcinomas, two large-cell carcinomas) and from two normal lung samples. The cell content of resulting ETS was evaluated with immunocytological stainings and compared with the histologic pattern of the original specimens. By means of a quantitative mass spectrometry-based method we evaluated the reproducibility of the sample preparation protocol and we assessed the proteome coverage by comparing lysates from ETS samples with the direct lysate of corresponding fresh-frozen samples.

Results

Cytological analyses on cytospin specimens showed that the percentage of tumoral cells in the ETS samples ranged from 20% to 70%. In the normal lung samples the percentage of epithelial cells was less then 10%. The reproducibility of the sample preparation protocol was very good, with coefficient of variation at the peptide level and at the protein level of 13% and 7%, respectively. Proteomics analysis led to the identification of a significantly higher number of proteins in the ETS samples than in the FF samples (244 vs 109, respectively). Albumin and hemoglobin were among the top 5 most abundant proteins identified in the FF samples, showing a high contamination with blood and plasma proteins, whereas ubiquitin and the mitochondrial ATP synthase 5A1 where among the top 5 most abundant proteins in the ETS samples.

Conclusion

The method is feasible and reproducible. We could obtain a fair enrichment of cells but the major benefit of the method was an effective removal of contaminants from red blood cells and plasma proteins resulting in larger proteome coverage compared to the direct lysis of frozen samples. This sample preparation method may be successfully implemented for the discovery of lung cancer biomarkers on tissue samples using mass spectrometry-based proteomics.
Species-independent bioassay for sensitive quantification of antiviral type I interferons
Authors: Kuri Thomas , Habjan Matthias , Penski Nicola , Weber Friedemann
Published: February 2010

Background

Studies of the host response to infection often require quantitative measurement of the antiviral type I interferons (IFN-α/β) in biological samples. The amount of IFN is either determined via its ability to suppress a sensitive indicator virus, by an IFN-responding reporter cell line, or by ELISA. These assays however are either time-consuming and lack convenient readouts, or they are rather insensitive and restricted to IFN from a particular host species.

Results

An IFN-sensitive, Renilla luciferase-expressing Rift Valley fever virus (RVFV-Ren) was generated using reverse genetics. Human, murine and avian cells were tested for their susceptibility to RVFV-Ren after treatment with species-specific IFNs. RVFV-Ren was able to infect cells of all three species, and IFN-mediated inhibition of viral reporter activity occurred in a dose-dependent manner. The sensitivity limit was found to be 1 U/ml IFN, and comparison with a standard curve allowed to determine the activity of an unknown sample.

Conclusions

RVFV-Ren replicates in cells of several species and is highly sensitive to pre-treatment with IFN. These properties allowed the development of a rapid, sensitive, and species-independent antiviral assay with a convenient luciferase-based readout.
Inferring genetic interactions via a nonlinear model and an optimization algorithm
Authors: Chen Chung-Ming , Lee Chih , Chuang Cheng-Long , Wang Chia-Chang , Shieh Grace S
Published: February 2010

Background

Biochemical pathways are gradually becoming recognized as central to complex human diseases and recently genetic/transcriptional interactions have been shown to be able to predict partial pathways. With the abundant information made available by microarray gene expression data (MGED), nonlinear modeling of these interactions is now feasible. Two of the latest advances in nonlinear modeling used sigmoid models to depict transcriptional interaction of a transcription factor (TF) for a target gene, but do not model cooperative or competitive interactions of several TFs for a target.

Results

An S-shape model and an optimization algorithm (GASA) were developed to infer genetic interactions/transcriptional regulation of several genes simultaneously using MGED. GASA consists of a genetic algorithm (GA) and a simulated annealing (SA) algorithm, which is enhanced by a steepest gradient descent algorithm to avoid being trapped in local minimum. Using simulated data with various degrees of noise, we studied how GASA with two model selection criteria and two search spaces performed. Furthermore, GASA was shown to outperform network component analysis, the time series network inference algorithm (TSNI), GA with regular GA (GAGA) and GA with regular SA. Two applications are demonstrated. First, GASA is applied to infer a subnetwork of human T-cell apoptosis. Several of the predicted interactions are supported by the literature. Second, GASA was applied to infer the transcriptional factors of 34 cell cycle regulated targets in S. cerevisiae, and GASA performed better than one of the latest advances in nonlinear modeling, GAGA and TSNI. Moreover, GASA is able to predict multiple transcription factors for certain targets, and these results coincide with experiments confirmed data in YEASTRACT.

Conclusions

GASA is shown to infer both genetic interactions and transcriptional regulatory interactions well. In particular, GASA seems able to characterize the nonlinear mechanism of transcriptional regulatory interactions (TIs) in yeast, and may be applied to infer TIs in other organisms. The predicted genetic interactions of a subnetwork of human T-cell apoptosis coincide with existing partial pathways, suggesting the potential of GASA on inferring biochemical pathways.
Oxygen- and capacity-limitation of thermal tolerance: a matrix for integrating climate-related stressor effects in marine ecosystems
Authors: Pörtner H.-O.
Published: February 2010

The concept of oxygen- and capacity-dependent thermal tolerance in aquatic ectotherms has successfully explained climate-induced effects of rising temperatures on species abundance in the field. Oxygen supply to tissues and the resulting aerobic performance characters thus form a primary link between organismal fitness and its role and functioning at the ecosystem level. The thermal window of performance in water breathers matches their window of aerobic scope. Loss of performance reflects the earliest level of thermal stress, caused by hypoxaemia and the progressive mismatch of oxygen supply and demand at the borders of the thermal envelope. Oxygen deficiency elicits the transition to passive tolerance and associated systemic and cellular stress signals like hormonal responses or oxidative stress as well as the use of protection mechanisms like heat shock proteins at thermal extremes. Thermal acclimatization between seasons or adaptation to a climate regime involves shifting thermal windows and adjusting window widths. The need to specialize on a limited temperature range results from temperature-dependent trade-offs at several hierarchical levels, from molecular structure to whole-organism functioning, and may also support maximized energy efficiency. Various environmental factors like CO2 (ocean acidification) and hypoxia interact with these principal relationships. Existing knowledge suggests that these factors elicit metabolic depression supporting passive tolerance to thermal extremes. However, they also exacerbate hypoxaemia, causing a narrowing of thermal performance windows and prematurely leading the organism to the limits of its thermal acclimation capacity. The conceptual analysis suggests that the relationships between energy turnover, the capacities of activity and other functions and the width of thermal windows may lead to an integrative understanding of specialization on climate and, as a thermal matrix, of sensitivity to climate change and the factors involved. Such functional relationships might also relate to climate-induced changes in species interactions and, thus, community responses at the ecosystem level.
What are the physiological and immunological responses of coral to climate warming and disease?
Authors: Mydlarz Laura D. , McGinty Elizabeth S. , Harvell C. Drew
Published: February 2010

Coral mortality due to climate-associated stress is likely to increase as the oceans get warmer and more acidic. Coral bleaching and an increase in infectious disease are linked to above average sea surface temperatures. Despite the uncertain future for corals, recent studies have revealed physiological mechanisms that improve coral resilience to the effects of climate change. Some taxa of bleached corals can increase heterotrophic food intake and exchange symbionts for more thermally tolerant clades; this plasticity can increase the probability of surviving lethal thermal stress. Corals can fight invading pathogens with a suite of innate immune responses that slow and even arrest pathogen growth and reduce further tissue damage. Several of these responses, such as the melanin cascade, circulating amoebocytes and antioxidants, are induced in coral hosts during pathogen invasion or disease. Some components of immunity show thermal resilience and are enhanced during temperature stress and even in bleached corals. These examples suggest some plasticity and resilience to cope with environmental change and even the potential for evolution of resistance to disease. However, there is huge variability in responses among coral species, and the rate of climate change is projected to be so rapid that only extremely hardy taxa are likely to survive the projected changes in climate stressors.
Diversity, decoys and the dilution effect: how ecological communities affect disease risk
Authors: Johnson P. T. J. , Thieltges D. W.
Published: February 2010

Growing interest in ecology has recently focused on the hypothesis that community diversity can mediate infection levels and disease (‘dilution effect’). In turn, biodiversity loss — a widespread consequence of environmental change — can indirectly promote increases in disease, including those of medical and veterinary importance. While this work has focused primarily on correlational studies involving vector-borne microparasite diseases (e.g. Lyme disease, West Nile virus), we argue that parasites with complex life cycles (e.g. helminths, protists, myxosporeans and many fungi) offer an excellent additional model in which to experimentally address mechanistic questions underlying the dilution effect. Here, we unite recent ecological research on the dilution effect in microparasites with decades of parasitological research on the decoy effect in macroparasites to explore key questions surrounding the relationship between community structure and disease. We find consistent evidence that community diversity significantly alters parasite transmission and pathology under laboratory as well as natural conditions. Empirical examples and simple transmission models highlight the diversity of mechanisms through which such changes occur, typically involving predators, parasite decoys, low competency hosts or other parasites. However, the degree of transmission reduction varies among diluting species, parasite stage, and across spatial scales, challenging efforts to make quantitative, taxon-specific predictions about disease. Taken together, this synthesis highlights the broad link between community structure and disease while underscoring the importance of mitigating ongoing changes in biological communities owing to species introductions and extirpations.
Avian distributions under climate change: towards improved projections
Authors: La Sorte F. A. , Jetz W.
Published: February 2010

Birds are responding to recent climate change in a variety of ways including shifting their geographic ranges to cooler climates. There is evidence that northern-temperate birds have shifted their breeding and non-breeding ranges to higher latitudes, and tropical birds have shifted their breeding ranges to higher altitudes. There is further evidence these shifts have affected migration strategies and the composition and structure of communities. Projections based on correlative distributional models suggest many birds will experience substantial pressures under climate change, resulting in range contraction and shifts. Inherent limitations of correlative models, however, make it difficult to develop reliable projections and detailed inference. Incorporating a mechanistic perspective into species distribution models enriches the quality of model inferences but also severely narrows the taxonomic and geographic relevance. Mechanistic distributional models have seen increased applications, but so far primarily in ectotherms. We argue that further development of similar models in birds would complement existing empirical knowledge and theoretical projections. The considerable data already available on birds offer an exciting basis. In particular, information compiled on flight performance and thermal associations across life history stages could be linked to distributional limits and dispersal abilities, which could be used to develop more robust and detailed projections. Yet, only a broadening of taxonomic scale, specifically to appropriately represented tropical diversity, will allow for truly general inference and require the continued use of correlative approaches that may take on increasingly mechanistic components. The trade-off between detail and scale is likely to characterize the future of global change biodiversity research, and birds may be an excellent group to improve, integrate and geographically extend current approaches.
Global warming and the Arctic: a new world beyond the reach of the Grinnellian niche?
Authors: MacDonald G. M.
Published: February 2010

The levels of CO2 in the atmosphere have already far exceeded values attained at any other time over at least the past 650,000 years. Temperature increases due to rising greenhouse gases will be amplified in Arctic and subarctic regions, and winter warming will be enhanced relative to summer warming. Climate in large areas of high latitudes may have no analogue in current climates or those of the recent geological past. Experimental field manipulations and laboratory studies indicate that plants will exhibit complex responses in photosynthesis, growth rates, phenology and reproductive functioning due to this combination of increasing temperatures, changing seasonality and increasing levels of CO2. The resulting changes in the abundance, distribution, growth rates and production of fruit and phenology of plant species will in turn impact animal populations. In predicting what the future biota of the ‘New Arctic’ will be like and developing appropriate conservation strategies, Grinnellian niche-based approaches are likely to be insufficient, and experimental ecological studies of organism response to specific anticipated changes in climate are crucial.
Voronoi-diagram-based linking of contour-parallel tool paths for two-and-a-half-dimensional closed-pocket machining
Authors: Hinduja S , Mansor M S A , Owodunni O O
Published: February 2010

Contour-parallel tool paths for machining milling features are formed by linking the offsets. Determination of links between offsets and the sequence in which the offsets should be traversed is a major problem. Results of efforts to link tool paths from academic researchers and developers of commercial computer-aided manufacturing (CAM) systems have shortcomings which include the fact that the linking strategies (a) are not based on clear geometric principles, (b) are not optimal, (c) do not consider technological factors such as the amount of slotting, overmilling, mode of cutting, and (d) are either not gouge-free or use tool retractions to avoid gouging. To overcome these shortcomings, this paper presents a linking algorithm which employs segments on the Voronoi diagram as links. The technological factors, hitherto ignored in previous research are considered and their optimality is ensured by employing guidelines which were mostly developed through observations of tool paths generated from a general test bed. Multiple solutions obtained after pruning out unfeasible solutions can be evaluated by users using geometrical (total tool path length) and technological (amount of overmilling, slotting, etc.) considerations or a combination of the criteria. The implementation of the algorithm is tested by generating tool paths for two two-and-a-half-dimensional (2½D) milled features. When compared with those obtained from some commercial CAM systems, they are shorter by 5 to 31 per cent.
Machining Performance and Surface Integrity of SiC Ceramic Machined Using Electrical Discharge Milling and the Mechanical Grinding Compound Process
Authors: Ji R J , Liu Y H , Zhang Y Z , Li H , Cheng X D
Published: February 2010

A new combined process that integrates electrical discharge milling and mechanical grinding is presented. The process is able effectively to machine a large surface area on SiC ceramic with a good surface quality and low cost. The effects of machining conditions on the material removal rate, relative electrode wear ratio, and surface roughness were investigated. The surface microstructures machined by the new process were observed by a scanning electron microscope (SEM), an X-ray diffraction, and an energy dispersive spectrometer. The SEM micrographs show that the surfaces machined at rough machining mode and semi-finish machining mode are characterized by an uneven fusing structure, globules of debris, shallow craters, and micropores; the surface machined at finish machining mode is smooth, and covered by fewer little craters and pockmarks.
Excimer Laser Machining of Bisphenol a Polycarbonate under Closed Immersion Filtered Water with Varying Flow Velocities and the Effects on the Etch Rate
Authors: Dowding C F , Lawrence J
Published: February 2010

Until now, progress in laser ablation micromachining has been significantly limited with respect to feature miniaturization and output yield by ablation-generated debris. Gas-jetting techniques have proven to be inadequate and vacuum environments are unwieldy in an industrial setting. To this end, a controlled geometry for both the optical interfaces of a flowing liquid film can be provided by a closed flowing thick-film filtered water immersion technique. This ensures repeatable machining conditions and allows control of liquid flow velocity. To investigate the impact of this technique on etch rate, bisphenol A polycarbonate samples have been machined using KrF excimer laser radiation passing through a medium of filtered water flowing at a number of flow velocities that are controllable by modifying liquid flowrate. A mean increase in etch rate of 8.5 per cent when using a turbulent flow velocity regime immersed ablation over ablation in ambient air was recorded. However, use of laminar flow velocities resulted in a mean loss of 26.6 per cent in etch rate compared to ablation in ambient air. Plotting the recorded etch rate achieved with respect to flow velocity gives support for previously proposed flow—plume interactions: the primary cause of a 37 per cent variance in etch rate over a 72 per cent change in laminar flow velocity was a shift in the ratio between the refresh rate of liquid volume over the feature and laser repetition rate. The small variance of etch rate achieved by modification of turbulent regime flow velocity indicates that laser etching provided the dominating contribution to the total etch rate measured. This work demonstrates that this technique developed for ablation debris control does not reduce the efficiency of laser etching with respect to that achieved with established gas media laser ablation machining. Therefore, this process shows great promise for industrial implementation development.
Parametric identification of fractional-order systems using a fractional Legendre basis
Authors: Ghanbari M , Haeri M
Published: February 2010

This paper deals with the identification of fractional-order systems through orthogonal rational functions. Fractional systems are characterized by their non-exponential aperiodic multimodes; therefore, fractional orthogonal rational functions provide better approximating models with fewer parameters. In spite of the fact that the Laguerre-based model is simple, it is, to some extent, deficient at high frequencies. Motivated by this objective, the use of a Legendre basis which has progressive pole locations and can be expected to perform better at high frequencies is studied.
Takagi-Sugeno fuzzy-model-based control of hyperchaotic Chen system with norm-bounded uncertainties
Authors: Huang X , Cao J , Li Y
Published: February 2010

In this paper, control of hyperchaotic Chen system is investigated under the existence of norm-bounded parameter uncertainties. A Takagi-Sugeno fuzzy model is employed to represent the hyperchaotic Chen system and the parallel distributed compensation technique is applied to design the time-delayed fuzzy state feedback controller. Based on Lyapunov stability theory, a sufficient delay-dependent or delay-independent stability criterion is given in term of linear matrix inequalities (LMIs) to guarantee the stability of the closed-loop system. The two sets of feedback gain matrices can be simultaneously obtained by solving a group of LMIs. Numerical simulation results demonstrate the effectiveness of the proposed method.
Robust contact force controller for slip prevention in a robotic gripper
Authors: O'Toole M , Bouazza-Marouf K , Kerr D , Vloeberghs M
Published: February 2010

Grasping a soft or fragile object requires the use of minimum contact force to prevent damage or deformation. Without precise knowledge of object parameters, real-time feedback control must be used with a suitable slip sensor to regulate the contact force and prevent slip. Furthermore, the controller must be designed to have good performance characteristics to rapidly modulate the fingertip contact force in response to a slip event. In this paper, a fuzzy sliding mode controller combined with a disturbance observer is proposed for contact force control and slip prevention. The controller is based on a system model that is suitable for a wide class of robotic gripper configurations. The robustness of the controller is evaluated through both simulation and experiment. The control scheme was found to be effective and robust to parameter uncertainty. When tested on a real system, however, chattering phenomena, well known to sliding mode research, was induced by the unmodelled suboptimal components of the system (filtering, backlash, and time delays), and the controller performance was reduced.
Robust regulation with H∞ control of linear two-time-scale systems: A new modelling approach
Authors: Karimi H R
Published: February 2010

This paper considers the problem of robust multi-objective
Structure-Specified H∞ Loop Shaping Control for Balancing of Bicycle Robots: A Particle Swarm Optimization Approach
Authors: Bui T T , Parnichkun M , Le C H
Published: February 2010

The Particle swarm optimization (PSO) approach is an efficient meta-heuristic search method that can be used to solve the multi-objective and non-convex optimization problems that are normally generated when designing structure-specified H∞ loop shaping controllers. In this study, PSO is used to design the controllers able to balance a bicycle robot, with a model-based systematic procedure for the controller design being proposed. Simulation and experimental results are presented that show that superior robustness and efficiency properties were obtained using the structure-specified H∞ loop shaping controllers compared to those obtained using the proportional plus derivative as well as conventional H∞ loop shaping ones. In comparison with the solutions obtained based on genetic algorithms, the use of PSO has a better efficiency in term of the computational time.
Improving diesel mixture preparation by optimization of orifice arrangements in a group-hole nozzle
Authors: Moon S , Matsumoto Y , Nishida K , Gao J
Published: February 2010

The factors affecting the free and wall-impinging spray characteristics of closely spaced micro-orifices (group-hole nozzles) are investigated to determine the optimal orifice arrangement for improved in-cylinder air utilization. To determine the optimized arrangement of the nozzles, different types of group-hole nozzles with different intervals and angles between the orifices have been studied. The spray tip penetration and fuel evaporation were analysed using a laser absorption scattering technique for non-axisymmetric sprays. In the case of a free spray, the spray tip penetration of the group-hole nozzle increased as the included angle and the distance between orifices decreased. The shortest spray tip penetration was observed when the two jets injected by a group-hole nozzle began to separate, but the periphery of each jet still touched. On the contrary, fuel evaporation deteriorated when the distance and angle between the two orifices decreased since the severe collision/coalescence of the two jets hindered evaporation. In the case of a wall-impinging spray, the spray tip penetration of the group-hole nozzle was strongly related to the distance χ between the arbitrary centres of each jet at the impingement wall. Maximum spray tip penetration of the group-hole nozzle was observed at a specific range of χ. In this range, the strong momentum regions of the jets began to meet just after wall impingement, therefore collision/coalescence before wall impingement was minimized and the interaction between the two wall-impinging jets was maximized. The fuel evaporation in the wall-impinging spray also improved at a distance of χ for maximum tip penetration. The mechanism causing this phenomenon is discussed in terms of near-field spray interaction and wall-impinging jet interaction after wall impingement.
Combustion control for waste-heat recovery system in internal combustion engine vehicles: Increase in exhaust-gas heat by combustion phasing and its effect on thermal efficiency factors
Authors: Shudo T , Toshinaga K
Published: February 2010

Utilizing exhaust-gas heat can be effective to improve the overall thermal efficiency of engine vehicles. However, the exhaust-gas heat and temperature at light loads may be insufficient for some exhaust-gas heat recovery systems. Exhaust-gas heat is largely influenced by the combustion phase, and a retardation of spark timing could increase exhaust-gas heat considerably. The current work evaluates the effect of a large retardation of spark-ignition timing on the exhaust-gas temperature and heat at steady operating conditions and at vehicle driving mode conditions. The relationships between the exhaust heat and thermal efficiency factors such as cooling-loss fraction, degree of constant volume, and pumping-loss fraction are also analysed in detail. The results show that a combination of spark retardation and intake throttle opening can increase exhaust-gas heat with minimum deteriorations in engine efficiency. The minimum deterioration in efficiency is attributed to reductions in cooling and pumping losses, while the degree of constant volume is decreased by the retarded combustion phase.
Studies on the characteristics of orange oil—diethyl ether in a direct injection diesel engine
Authors: Purushothaman K , Nagarajan G
Published: February 2010

This paper describes an experimental study concerning the feasibility of using orange oil obtained from orange peel. The combustion, performance, and emission characteristics of a direct-injection (DI) diesel engine were studied using orange oil and diethyl ether (DEE). DEE was inducted as an ignition improver through the induction manifold, and orange oil was injected into the engine through a conventional fuelling device as a primary fuel. The test results indicate that the performance of the orange oil—DEE fuel was better than that of diesel fuel. The peak cylinder pressure and heat release rate were found to be higher for the orange oil—DEE fuel than those of diesel fuel. The hydrocarbon and carbon monoxide emission levels in the engine exhaust increased with orange oil—DEE compared with those of diesel fuel. The smoke and NO x emissions were lower with orange oil—DEE compared with diesel fuel. It is concluded that a diesel engine operated using orange oil—DEE gives simultaneous reduction in NO x and smoke emissions with better performance.
Baclofen: Hiccups
Authors: Generali Joyce A. , Cada Dennis J.
Published: February 2010

This Hospital Pharmacy feature is extracted from Off-Label Drug Facts, a quarterly publication available from Wolters Kluwer Health. Off-Label Drug Facts is a practitioner-oriented resource for information about specific drug uses that are unapproved by the US Food and Drug Administration. This new guide to the literature enables the health care professional or clinician to quickly identify published studies on off-label uses and determine if a specific use is rational in a patient care scenario. A summary of the most relevant data is provided, including background, study design, patient population, dosage information, therapy duration, results, safety, and therapeutic considerations. References direct the reader to the full literature for more comprehensive information before patient care decisions are made. Direct questions or comments regarding Off-Label Drug Uses to jgeneral@kumc.edu .
The Impact of a Pharmacist's Participation on Hospitalists' Rounds
Authors: Patel Reena , Butler Kimberly , Garrett Deidra , Badger Naadede , Cheoun Diane , Hallman Laura
Published: February 2010

Background

Expanding the role of pharmacists in the hospital setting has the potential to positively impact the quality of patient care and provide cost savings. Previous studies have shown that integrating pharmacists into rounding teams can enhance patient care through interventions at the point of assessment and prescribing. This study examines these potential benefits at a community hospital that does not have formal hospitalist rounds and in which the pharmacists must make recommendations via written communication.

Objective

The primary objective was to identify the number of interventions and to determine how to optimally utilize a pharmacist for a group of 19 hospitalists. Secondary objectives included estimating pharmacist time invested and cost savings.

Methods

Initially, methods in this study included reviewing patient medication profiles and informally rounding with the hospitalists. Interventions were performed at the time of rounding. After 2 weeks of rounding, methods were altered to improve the efficiency of the pharmacist's time. Patient profiles were reviewed and interventions were performed by written communication.

Results

A total of 386 patients were reviewed, with 117 interventions discovered. Fifty-eight verbal interventions were made during rounds with a 93% acceptance rate. Fifty-nine written interventions were made in the second part of the study with a 76% acceptance rate. The pharmacist spent an average of 10 minutes reviewing each patient profile, which resulted in a savings of $16 per hour of time invested. An actual cost savings of $3,900 was produced by 64 of the interventions, and the potential cost savings of the remaining 53 interventions exceeded $100,000.

Conclusion

Opportunities for pharmacist interventions exist within a hospitalists' team and the potential benefits to patient care, along with the actual and potential cost savings, should justify creating collaborations between pharmacists and hospitalists.
Policy-Related Degree Options for Pharmacists Interested in Careers in the Health Care Field
Authors: Fink Joseph L. , Talbert Jeffery , Blumenschein Karen
Published: February 2010

Policies exist at many levels and impact the practice of pharmacy in a wide variety of ways. Some pharmacists may seek advanced education related to policy development and assessment. In this article, policy is defined and the various ways the term is used with regard to the profession are reviewed with selected examples provided. Sources of information about policy-related degree programs offered both by educational units primarily focusing on pharmacy and units outside the specialty area are emphasized along with points to consider in making a decision. Examples of career opportunities are provided and questions to consider are presented.
Recent Publications on Medications and Pharmacy
Authors: Sterling Jacyntha A.
Published: February 2010

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest regarding a broad scope of topics are abstracted monthly.