bluuebunny/crossref_metadata_2025 huggingface dataset:
Sublethal concentrations of the platinum(II) complex [Pt(O,O′‐acac)(γ‐acac)(DMS)] alter the motility and induce anoikis in MCF‐7 cells
Authors: Muscella Antonella , Calabriso Nadia , Vetrugno Carla , Urso Loredana , Fanizzi Francesco Paolo , De Pascali Sandra Angelica , Marsigliante Santo
Published: March 2010

Background and purpose:  We showed previously that a new Pt(II) complex ([Pt(O,O′‐acac)(γ‐acac)(DMS)]) exerted high and fast apoptotic processes in MCF‐7 cells. The objective of this study was to investigate the hypothesis that [Pt(O,O′‐acac)(γ‐acac)(DMS)] is also able to exert anoikis and alter the migration ability of MCF‐7 cells, and to show some of the signalling events leading to these alterations.

Experimental approach:  Cells were treated with sublethal doses of [Pt(O,O′‐acac)(γ‐acac)(DMS)], and the efficiency of colony initiation and anchorage‐independent growth was assayed; cell migration was examined by in vitro culture wounding assay. Gelatin zymography for MMP‐2 and ‐9 activities, Western blottings of MMPs, MAPKs, Src, PKC‐ε and FAK, after [Pt(O,O′‐acac)(γ‐acac)(DMS)] treatment, were also performed.

Key results:  Sub‐cytotoxic drug concentrations decreased the: (i) anchorage‐dependent and ‐independent growth; (ii) migration ability; and (iii) expression and activity of MMP‐2 and MMP‐9. [Pt(O,O′‐acac)(γ‐acac)(DMS)] provoked the generation of reactive oxygen species (ROS), and the activation of p38MAPK, Src and PKC‐ε. p38MAPK phosphorylation, cell anoikis and migration due to [Pt(O,O′‐acac)(γ‐acac)(DMS)] were blocked by PKC‐ε inhibition. Furthermore, Src inhibition blocked the [Pt(O,O′‐acac)(γ‐acac)(DMS)]‐provoked activation of PKC‐ε, while ROS generation blockage inhibited the activation of Src, and also the decrement of phosphorylated FAK observed in detached [Pt(O,O′‐acac)(γ‐acac)(DMS)]‐treated cells.

Conclusions and implications:  Sublethal concentrations of [Pt(O,O′‐acac)(γ‐acac)(DMS)] induced anoikis and prevented events leading to metastasis via alterations in cell migration, anchorage independency, stromal interactions and MMP activity. Hence, [Pt(O,O′‐acac)(γ‐acac)(DMS)] may be a promising therapeutic agent for preventing growth and metastasis of breast cancer.
A series of structurally novel heterotricyclic α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazole‐propionate receptor‐selective antagonists
Authors: Gill MB , Frausto S , Ikoma M , Sasaki M , Oikawa M , Sakai R , Swanson GT
Published: March 2010

Background and purpose: A new class of heterotricyclic glutamate analogues recently was generated by incorporating structural elements of two excitotoxic marine compounds, kainic acid and neodysiherbaine A. Rather than acting as convulsants, several of these ‘IKM’ compounds markedly depressed CNS activity in mice. Here, we characterize the pharmacological profile of the series with a focus on the most potent of these molecules, IKM‐159.

Experimental approach: The pharmacological activity and specificity of IKM compounds were characterized using whole‐cell patch clamp recording from neurons and heterologous receptor expression systems, in combination with radioligand binding techniques.

Key results: The majority of the IKM compounds tested reduced excitatory synaptic transmission in neuronal cultures, and IKM‐159 inhibited synaptic currents from CA1 pyramidal neurons in hippocampal slices. IKM‐159 inhibited glutamate‐evoked whole‐cell currents from recombinant GluA2‐ and GluA4‐containing α‐amino‐3‐hydroxyl‐5‐methyl‐4‐isoxazole‐propionate (AMPA) receptors most potently, whereas kainate and NMDA receptor currents were not reduced by IKM‐159. Antagonism of steady‐state currents was agonist concentration dependent, suggesting that its mechanism of action was competitive, although it paradoxically did not displace [3H]‐AMPA from receptor binding sites. IKM‐159 reduced spontaneous action potential firing in both cultured hippocampal neurons in control conditions and during hyperactive states in anin vitromodel of status epilepticus.

Conclusions and implications: IKM‐159 is an AMPA receptor‐selective antagonist. IKM‐159 and related nitrogen heterocycles represent structurally novel AMPA receptor antagonists with accessible synthetic pathways and potentially unique pharmacology, which could be of use in exploring the role of specific populations of receptors in neurophysiological and neuropathological processes.
The abuse of diuretics as performance‐enhancing drugs and masking agents in sport doping: pharmacology, toxicology and analysis
Authors: Cadwallader Amy B , De La Torre Xavier , Tieri Alessandra , Botrè Francesco
Published: March 2010

Diuretics are drugs that increase the rate of urine flow and sodium excretion to adjust the volume and composition of body fluids. There are several major categories of this drug class and the compounds vary greatly in structure, physicochemical properties, effects on urinary composition and renal haemodynamics, and site and mechanism of action. Diuretics are often abused by athletes to excrete water for rapid weight loss and to mask the presence of other banned substances. Because of their abuse by athletes, diuretics have been included on The World Anti‐Doping Agency's (WADA) list of prohibited substances; the use of diuretics is banned both in competition and out of competition and diuretics are routinely screened for by anti‐doping laboratories. This review provides an overview of the pharmacology and toxicology of diuretics and discusses their application in sports. The most common analytical strategies currently followed by the anti‐doping laboratories accredited by the WADA are discussed along with the challenges laboratories face for the analysis of this diverse class of drugs.
Echocardiographic Assessment of Ductal Anatomy in Premature Infants—Lessons for Device Design
Authors: Trefz Matthew , Wilson Neil , Acton Robert , Hess Donavon J. , Bass John L.
Published: March 2010

Objective: Echocardiographic analysis of patent ductus arteriosus (PDA), proximal left main pulmonary artery (LPA) and descending thoracic aorta (Ao) dimensions in preterm infants who undergo surgical ligation of the PDA. A discussion for percutaneous ductal occlusion in preterm infants. Methods: Echocardiographic analysis of the LPA diameter, PDA diameter, PDA length, and descending thoracic aorta diameter in 55 preterm infants who underwent surgical ligation of the PDA from 2004 to 2008. Patients were stratified by weight into four groups: those less than 750 g, 751–1,000 g, 1,001–1,250 g, and those greater than 1,250 g. Mean and standard deviation for each structure dimension was calculated in each weight group. Structural dimensions were compared between groups using ANOVA for multiple comparisions. Results: The mean patient weight was 1,018 g (560–2,400 g). The mean ductal length was 4.1 mm (2.5–5.3 mm). The mean ductal diameter was 2.2 mm (1.5–3.6 mm). The mean LPA diameter was 3 mm (1.5–4.5 mm). The mean aortic diameter was 4.3 mm (2.7–7.8 mm). The alpha value for between weight groups for PDA length was 0.21, PDA diameter 0.16, LPA diameter 0.39, and aortic diameter 0.1. Discussion: No statistical significance was seen when comparing structure dimension by weight. This suggests uniform structural dimensions across a broad weight distribution in this patient population. To date, there has been no attempt to standardize dimensions of these vascular structures. The information gathered in this study may be useful in developing an implantable device for ductal occlusion in preterm infants. (ECHOCARDIOGRAPHY 2010;27:575‐579)
Assessment of Residual Viability by Enoximone Echocardiography in Patients with Previous Myocardial Infarction Correlation with Positron Emission Tomographic Studies and Functional Follow‐Up
Authors: Lu Fei , Carlino Mauro , Lu Chunzeng , Landoni Claudio , Lucignani Giovanni , Fragasso Gabriele , Di Bello Vitantonio , Margonato Alberto , Chierchia Sergio L. , Marzilli Mario , Balbarini Alberto
Published: March 2010

Background: The aim of this study was to evaluate enoximone echocardiography (EE) for the identification of residual myocardial viability in postinfarction patients. Findings obtained during EE were compared with those acquired by myocardial uptake of fluorine‐18 fluorodeoxyglucose (18F‐FDG) positron emission tomography (PET) and functional follow‐up results. Methods: Twenty‐five patients underwent EE and PET 18F‐FDG studies. An asynergic segment was considered as having contractile enhancement when the wall motion score decreased by ≥1 grade during EE and was defined as viable if 18F‐FDG uptake score was ≥2 grade on PET. Results: Of 293 dysfunctional segments at baseline, 139 (47%) were viable by PET criteria; 117 (40%) had contractile enhancement induced by enoximone (P = 0.07). Agreement between EE and PET was found in 75% of involved segments (K = 0.46, P < 0.001). The majority of discrepancies (65%, P < 0.01) were mainly due to discordant segments in which PET revealed evidence of 18F‐FDG uptake but EE showed no change in wall motion. In 179 revascularized segments, negative predictive value for functional recovery of both tests reached the same value (89% for both), whereas positive predictive value was 82% for EE and 68% for PET, respectively (P < 0.05). Sensitivity was 85% for EE and 88% for PET (P = ns); specificity was 87% and 70%, respectively (P < 0.01). Conclusions: EE yields a fair concordance with PET study. Compared with PET, despite a similar negative accuracy, EE shows a greater specificity for prediction of function recovery after revascularization. (Echocardiography 2010;27:544‐551)
Twenty‐five years quaternium‐15 in the European baseline series: does it deserve its place there?
Authors: De Groot Anton C. , Coenraads Pieter‐Jan
Published: March 2010

For allergens to be included in the European baseline series, they should have allergy rates of at least 1%. In several studies quaternium‐15 had lower scores. Also, many cases of sensitization are already detected by formaldehyde contact allergy. The aim of this study was to evaluate whether quaternium‐15 deserves continued inclusion in the baseline series on the basis of current criteria: 1% positive reactions, common occurrence in the environment, many relevant reactions. We used the literature survey method in this study. Only the United Kingdom has rates consistently over 1%. The mean for all other countries together and for many individual nations is lower than 1%. At least half of the reactions are already detected by formaldehyde sensitivity, which lowers rates for allergy to quaternium‐15 per se (i.e. not caused or at least detected by formaldehyde sensitivity) to less than 0.6% for all countries except the United Kingdom. Neither common occurrence in the environment nor a high percentage of relevant reactions has been ascertained. It may well be argued that quaternium‐15 does not deserve its place in the European baseline series and could be incorporated in a cosmetic screening series or preservative series instead. In the United Kingdom, routine testing should be continued.
Melatonin attenuates methamphetamine‐induced overexpression of pro‐inflammatory cytokines in microglial cell lines
Authors: Tocharus Jiraporn , Khonthun Chakkrapong , Chongthammakun Sukumal , Govitrapong Piyarat
Published: March 2010

Abstract: Methamphetamine (METH), the most commonly abused drug, has long been known to induce neurotoxicity. METH causes oxidative stress and inflammation, as well as the overproduction of both reactive oxygen species (ROS) and reactive nitrogen species (RNS). The role of METH‐induced brain inflammation remains unclear. Imbroglio activation contributes to the neuronal damage that accompanies injury, disease and inflammation. METH may activate microglia to produce neuroinflammatory molecules. In highly aggressively proliferating immortalized (HAPI) cells, a rat microglial cell line, METH reduced cell viability in a concentration‐ and time‐dependent manner and initiated the expression of interleukin 1β (IL‐1β), interleukin 6 (IL‐6) and tumor necrosis factor α. METH also induced the production of both ROS and RNS in microglial cells. Pretreatment with melatonin, a major secretory product of the pineal gland, abolished METH‐induced toxicity, suppressed ROS and RNS formation and also had an inhibitory effect on cytotoxic factor gene expression. The expression of cytotoxic factors produced by microglia may contribute to central nervous system degeneration in amphetamine abusers. Melatonin attenuates METH toxicity and inhibits the expression of cytotoxic factor genes associated with ROS and RNS neutralization in HAPI microglia. Thus, melatonin might be one of the neuroprotective agents induced by METH toxicity and/or other immunogens.
Role of Imaging in Prostate Cancer: A Review
Authors: Jeschke S. , Schweigreiter E. , Janetschek G.
Published: March 2010

Imaging is crucial for evaluating the presence and extent of prostate cancer. This review illustrates the role of imaging tools including ultrasound, computed tomography, magnetic resonance imaging, sentinel lymph adenectomy, positron emissions tomography and ohers for optimizing diagnosis and therapeutic concept in prostate cancer patients.
Breast MR‐Imaging of Ductal Carcinoma In Situ: A Systematic Review
Authors: Schmitz A. C. , Smits M. L. J. , Veldhuis W. , Van Der Wall E. , Van Hillegersberg R. , Borel‐Rinkes I. H. M. , Mali W. P. Th. M. , Van Den Bosch M. A. A. J.
Published: March 2010

Magnetic resonance imaging (MRI) of the breast has become a well‐established method for detection of invasive breast carcinoma. However, the role and use of breast MRI for ductal carcinoma in situ (DCIS) has remained controversial. The purpose of this study was to assess the diagnostic performance of breast MRI for detection and characterization of pure DCIS based on the currently published reports. A systematic review was performed in which studies on breast MRI for diagnosis of patients with pure DCIS were selected. A total of 26 articles were finally included, a total of 1051 patients with 1059 lesions. Sensitivity for diagnosis of pure DCIS ranged from 58% to 100%, with an overall of 84%. Sensitivity was highest for high‐grade DCIS (95%). Overall specificity was 74%. The majority of DCIS lesions were characterized as non‐mass‐like enhancement (75%) with a segmental distribution of enhancement (50%). Suspicious kinetic curves were found in 49% of the DCIS cases. A few studies reported on size assessment. This review shows that MRI has a moderate sensitivity for detection of DCIS in general, and a good sensitivity for high‐grade DCIS. The morphologic and kinetic appearance of DCIS can be very variable. Although mammography is the current standard for detection of DCIS, MRI could help improve the ability to diagnose DCIS, especially in high‐grade DCIS.
Purification and expression of a protein elicitor from Alternaria tenuissima and elicitor‐mediated defence responses in tobacco
Authors: Mao J. , Liu Q. , Yang X. , Long C. , Zhao M. , Zeng H. , Liu H. , Yuan J. , Qiu D.
Published: March 2010

A new protein elicitor, PeaT1, was purified from the mycelium of Alternaria tenuissima by column chromatography. PeaT1 was identified as a heat‐stable and acidic protein. It induced systemic acquired resistance to tobacco mosaic virus (TMV) in tobacco plants but did not cause hypersensitive response. The elicitor‐encoding gene was cloned by rapid amplification of cDNA ends method. Sequence analysis revealed that the cDNA is 624 bp in length and the open reading frame encodes for a polypeptide of 207 amino acids with a nascent polypeptide‐associated complex domain. The peaT1 gene was cloned into the expression vector pET‐28a and transformed into Escherichia coli BL21 (DE3). The recombinant elicitor also triggered defence responses in intact tobacco plants. The availability of the pure protein offers the possibility to isolate the corresponding receptor and links it to the downstream signalling pathway.
Sequence similarities between Raspberry leaf mottle virus, Raspberry leaf spot virus and the closterovirus Raspberry mottle virus
Authors: McGavin W.J. , MacFarlane S.A.
Published: March 2010

A sequencing study was performed to determine the relationship between Raspberry mottle virus (RMoV), a newly identified tentative closterovirus found in the United States, and Raspberry leaf mottle virus (RLMV) and Raspberry leaf spot virus (RLSV), which have been known for many years to be components of Raspberry mosaic disease (RMD) in the UK and Europe but which have not been characterised at the molecular level. Cloning and sequencing of cDNAs amplified by reverse transcription‐PCR revealed the presence of closteroviruses with high sequence similarity to RMoV in infected plants from the SCRI Rubus virus collection, as well as in a number of samples collected from RMD‐symptomatic raspberry plants located at different farms in Scotland and England. These results suggest that RMoV, RLMV and RLSV are isolates of the same virus and we propose that they all should be referred to as RLMV, which was the first of these viruses to be described. Many of the field samples were also infected with a second closterovirus isolate, parts of which could be amplified using RLMV‐derived primers. The coat protein amino acid sequences of RLMV and the second virus (PM1) were only 78% identical, even though helicase domain and RNA‐dependent RNA polymerase (RDRP) domain sequences were more than 97% identical between RLMV and PM1.
The Damage Mechanism Route to Better Armor Materials
Authors: Shockey Donald A. , Simons Jeffrey W. , Curran Donald R.
Published: March 2010

This paper describes the mechanisms by which brittle materials are penetrated by impacting projectiles, links ballistic performance to fracture behavior, and in turn to microstructure, and suggests a route unexplored previously for achieving better armor materials. Fracture patterns on cross sections through partially penetrated glass and ceramic targets show that deep penetration proceeds by the crushing and subsequent flow of fragments away from the projectile path. Preliminary finite element simulations indicate the likely positive effect of increasing frictional flow resistance of fragments. Tests are envisioned for measuring crush and fragment flow behavior, showing the effects of microstructural variables, guiding mathematical models, and hence leading to a capability to design computationally improved armor materials and structures.
Dielectric, Mechanical, and Thermal Properties of Low‐Permittivity Polymer–Ceramic Composites for Microelectronic Applications
Authors: George Sumesh , Anjana Prabhakaran S. , Sebastian Mailadil T. , Krupka Jerzy , Uma Sreekumar , Philip Jacob
Published: March 2010

A new low‐permittivity polymer–ceramic composite for packaging applications has been developed. The ceramic‐reinforced polyethylene and polystyrene composites were prepared by melt mixing and hot molding techniques. Low‐loss, low‐permittivity Li2MgSiO4 (LMS) ceramics prepared by the solid‐state ceramic route were used as the filler to improve the dielectric properties of the composites. The relative permittivity and dielectric loss were increased with the increase in the ceramic loading at radio and microwave frequencies. The mechanical properties and thermal conductivity of the Li2MgSiO4‐reinforced polymer–ceramic composite were also investigated. The stability of the relative permittivity of polymer–ceramic composites with temperature and frequency was investigated. The experimentally observed relative permittivity, thermal expansion, and thermal conductivity were compared with theoretical models.
Molecular Mechanisms Regulating Rapid Stress Signaling Networks in Arabidopsis
Authors: Walley Justin W. , Dehesh Katayoon
Published: March 2010

As sessile organisms plants must cope with ever changing environmental conditions. To survive plants have evolved elaborate mechanisms to perceive and rapidly respond to a diverse range of abiotic and biotic stresses. Central to this response is the ability to modulate gene expression at both the transcriptional and post‐transcriptional levels. This review will focus on recent progress that has been made towards understanding the rapid reprogramming of the transcriptome that occurs in response to stress as well as emerging mechanisms underpinning the reprogramming of gene expression in response to stress.
Inflammatory bowel disease in the Asia–Pacific area: A comparison with developed countries and regional differences
Authors: AHUJA Vineet , TANDON Rakesh K
Published: March 2010

The Asia–Pacific region has been marked as an area with a low incidence of inflammatory bowel disease (IBD), although confusion always existed as to whether this low incidence was a result of low diagnostic awareness, a high incidence of infective diarrhoea and its diagnostic overlap or a true low incidence. As epidemiological studies from this region are being made available it is clear that the incidence and prevalence rates of IBD in Asia–Pacific region are low compared with Europe and North America. They are however, increasing rapidly. There are substantial variations in the incidence and prevalence rates of IBD in various ethnic groups in Asia. The highest incidence rates are recorded from India, Japan and the Middle East and there exists a genetic predisposition of South Asians (Indians, Pakistanis and Bangladeshis) to ulcerative colitis (UC). It appears that certain racial groups are more prone than others to develop IBD. For instance, Indians in South‐East Asia have higher rates than Chinese and Malays. While there is a host genetic predisposition, environmental factor(s) may be responsible for this difference. The clinical phenotypes and complication rates of Asian IBD resemble those of the Caucasian population in general, but some heterogeneity is observed in different regions of Asia. There is no evidence of a north‐south or an east‐west divide in the Asia–Pacific region. The available studies suggest an increasing incidence of UC in the Asia–Pacific region and hence it is an appropriate time to launch well‐designed epidemiological studies so that etiopathogenetic factors can be identified. There is a male predominance in Crohn's disease in the Asian population. The NOD2/CARD15 gene is not associated with CD in the Japanese, Korean, Chinese and Indian population.
Comparison of immunochemical and guaiac‐based fecal occult blood test in screening and surveillance for advanced colorectal neoplasms: A meta‐analysis
Authors: ZHU Ming Ming , XU Xi Tao , NIE Fang , TONG Jin Lu , XIAO Shu Dong , RAN Zhi Hua
Published: March 2010

OBJECTIVE:  To systematically evaluate whether immunochemical fecal occult blood tests (iFOBT) could improve clinical performance and test accuracy in screening and surveillance for advanced colorectal neoplasms.

METHODS:  Eligible articles were identified by searches of electronic databases. All randomized trials and diagnostic cohort trials directly comparing iFOBT with guaiac‐based FOBT (gFOBT) were included. A statistical analysis was performed using RevMan 4.2.8. A sensitivity, specificity and summary receiver operating characteristic curve was performed using Meta Disc.

RESULTS:  We identified five randomized trials and 11 diagnostic cohort trials. In the randomized trials, the detection rates of advanced colorectal neoplasms with iFOBT or gFOBT were 2.23 percent and 1.24 percent, respectively. The pooled odds ratio (OR) was 1.50 (95% CI 0.94–2.39). In cohort trials, the advanced neoplasm detection rates of iFOBT or gFOBT were 1.44 percent and 0.50 percent (OR 1.99, 95% CI 1.24–3.19) in the average‐risk screened population, and were 8.8 percent and 7.1 percent (OR 1.27, 95% CI 1.01–1.60) in diagnosed patients scheduled for colonoscopy. The sensitivity of iFOBT (0.67, 95% CI 0.61–0.73) was superior to that of gFOBT (0.54, 95% CI 0.48–0.60), as well as the specificities (0.85, 95% CI 0.83–0.87 vs 0.80, 95% CI 0.78–0.82) and positive predictive values (0.41 vs 0.29) in cohort trials of diagnosed patients.

CONCLUSION:  Our review suggests that iFOBT could perform better in increasing the detection rate of advanced colorectal neoplasm than gFOBT and possesses higher sensitivity and specificity in the surveillance of advanced colorectal neoplasm for patients.
Knockdown of hTERT by SiRNA suppresses growth of Capan‐2 human pancreatic cancer cell via the inhibition of expressions of Bcl‐2 and COX‐2
Authors: ZHONG Ying Qiang , XIA Zhong Sheng , FU Yu Ru , ZHU Zhao Hua
Published: March 2010

OBJECTIVE:  To investigate the effects of human telomerase reverse transcriptase (hTERT) on the growth of Capan‐2 human pancreatic cancer cell and apoptosis.

METHODS:  Cell proliferation, apoptosis and cell cycle were analyzed by cell counting and flow cytometry. mRNA and protein expressions of hTERT, Bcl‐2 and cyclooxygenase (COX)‐2 were assessed by real time PCR and Western blot.

RESULTS:  Cell growth was significantly inhibited by 26.39 percent 24 h after hTERT‐small interference RNA (siRNA) transfection (50 nmol/L) with a 100 percent silencing efficiency (P < 0.05). The inhibition rates of cell proliferation were 46.77 percent, 70.61 percent, 84.71 percent and 85.99 percent at 2, 3, 5 and 7 days after transfection, respectively (P < 0.001). Early and late apoptotic cells increased significantly (especially 24 h after transfection) (P < 0.001). The cell cycle was suppressed significantly as manifested by the increase of cells in the G0/G1 phase and the decrease of cells in the S phase and G2/M phase (P < 0.01). The expressions of Bcl‐2 mRNA and COX‐2 mRNA were inhibited significantly 48 h after transfection: the inhibition rates were 86.86 percent and 100 percent, respectively (P < 0.001). Levels of Bcl‐2 protein were downregulated by 58.54 percent and 63.44 percent and the levels of COX‐2 protein were downregulated by 50.06 percent and 82.77 percent at 48 h and 72 h after transfection, respectively.

CONCLUSION:  Knockdown of hTERT by siRNA can inhibit the growth of Capan‐2 cell. The inhibitory effect is associated with the downregulation of Bcl‐2 and COX‐2.
Ensemble forecasting shifts in climatically suitable areas for Tropidacris cristata (Orthoptera: Acridoidea: Romaleidae)
Authors: DINIZ‐FILHO JOSE ALEXANDRE F. , NABOUT JOÃO CARLOS , BINI LUIS MAURICIO , LOYOLA RAFAEL DIAS , RANGEL THIAGO FERNANDO , NOGUES‐BRAVO DAVID , ARAÚJO MIGUEL B.
Published: March 2010

Abstract.  1. The effects of climate change on species’ ranges have been usually inferred using niche‐based models creating bioclimatic envelopes that are projected into geographical space. Here, we apply an ensemble forecasting approach for niche models in the Neotropical grasshopper Tropidacris cristata (Acridoidea: Romaleidae). A novel protocol was used to partition and map the variation in modelled ranges due to niche models, Atmosphere‐Ocean Global Circulation Models (AOGCM), and emission scenarios.

2. We used 112 records of T. cristata and four climatic variables to model the species’ niche using five niche models, four AOGCMs and two emission scenarios. Combinations of these effects (50 cross‐validations for each of the 15 subsets of the environmental variables) were used to estimate and map the occurrence frequencies (EOF) across all analyses. A three‐way anova was used to partition and map the sources of variation.

3. The projections for 2080 show that the range edges of the species are likely to remain approximately constant, but shifts in maximum EOF are forecasted. Suitable climatic conditions tend to disappear from central areas of Amazon, although this depends on the AOGCM and the niche model. Most of the variability around the mapped consensus projections came from using distinct niche models and AOGCMs.

4. Although our analyses are restricted to a single species, they provide new conceptual and methodological insights in the application of ensemble forecasting and variance partition approaches to understand the origins of uncertainty in studies assessing species responses to climate change in the tropics.
Bias due to withdrawal in long‐term randomised trials in COPD: Evidence from the TORCH study
Authors: Vestbo Jørgen , Anderson Julie Anne , Calverley Peter Mark Anthony , Celli Bartolomé , Ferguson Gary Thomas , Jenkins Christine , Yates Julie Carol , Jones Paul Wyatt
Published: March 2010

Introduction:  Randomised controlled trials (RCTs) are considered the least biased method for evaluating drug efficacy and several large long‐term RCTs in chronic obstructive pulmonary disease have been published. These usually include drugs with symptomatic benefits and have significant withdrawal rates.

Objectives:  We aimed at examining bias due to differential withdrawal in the Towards a Revolution in COPD Health (TORCH) trial.

Methods:  We did an observational study nested in the TORCH trial, a placebo‐controlled trial of salmeterol/fluticasone propionate combination (SFC) therapy in chronic obstructive pulmonary disease. We included 3057 patients randomly allocated to placebo or SFC in the analyses. We examined rates of withdrawal from the study and analysed change in effect parameters over time and in relation to withdrawal, as well as medication uptake after withdrawal.

Results:  There was differential withdrawal with a significantly higher withdrawal rate from the group allocated to placebo than to SFC, 44% compared with 34%. Regardless of treatment group, withdrawal was associated with worse baseline lung function and more frequent exacerbations, leading to selection of a study population in better health than those originally recruited. As a result, annualized exacerbation rates in the first 6 months of the study compared with the last 6 months of the study decreased from 6.8 to 0.9 in the placebo group and from 3.0 to 0.8 in the SFC group. Also, use of medications under test in the study was frequent in patients after withdrawal.

Conclusion:  Significant bias may occur in long‐term RCTs of registered medications with symptomatic benefits as a result of differential withdrawal.

Please cite this paper as: Vestbo J, Anderson JA, Calverley PMA, Celli B, Ferguson GT, Jenkins C, Yates JC, Jones PW. Bias due to withdrawal in long‐term randomised trials in COPD: Evidence from the TORCH study. Clin Respir J 2011; 5: 44–49.
Do Privatization IPOs Outperform in the Long Run?
Authors: Choi Seung‐Doo , Lee Inmoo , Megginson William
Published: March 2010

This paper investigates the long‐run stock returns of privatization initial public offering (IPO) firms using a sample of 241 privatization IPOs from 42 countries during the period 1981‐2003. We compare one‐, three‐, and five‐year holding period returns of privatization IPOs to those of the domestic stock market indices and to size and size‐ and book‐to‐market equity ratio (BM)‐matched firms from the same countries. Consistent with previous studies, we find that privatization IPOs significantly outperform their domestic stock markets in the long run. However, they show less consistent abnormal long‐term stock performance relative to their size or size‐ and BM‐matched benchmark firms.
Managing News Coverage around Initial Public Offerings
Authors: Ho Chia‐Cheng , Huang Chi‐Ling , Lin Chien‐Ting , Lin George Y.C.
Published: March 2010

We examine opportunistic behavior of initial public offering (IPO) firms in Taiwan where they are required to disclose their own earnings forecasts and are unrestricted in releasing news around the offerings. We find that prior to the offerings, IPO firms tend to report higher earnings, disclose inflated earnings forecasts, and manage more good news. News management, however, emerges as the most predominant factor in aftermarket stock prices. In particular, IPO firms have a strong preference for releasing good news related to strategy/policy that may simply provide a vision of a firm's future. Furthermore, the news releases are often forward‐looking when they are positive about the firms but tend to be realized when they are negative. IPO firms also tend to engage in more window dressing activities before a larger sale of IPO shares from existing shareholders or a larger decline in insiders' holdings. Our analysis shows that managerial optimism cannot fully account for their behavior.
Overinvestment and the Operating Performance of SEO Firms
Authors: Fu Fangjian
Published: March 2010

Prior studies have documented that firms' operating performance deteriorates following seasoned equity offerings (SEOs). This paper proposes and empirically tests the hypothesis that this poor performance is the result of managers' overinvestment. I find that, subsequent to the offering, SEO firms tend to invest more heavily than nonissuing control firms that are in the same industry and have enough financial slack and similar investment opportunities. More importantly, I find a negative correlation between postissue investment and operating performance, controlling for investment opportunities and preissue performance. Overinvestment results in a reduction in asset productivity and is more severe for firms with relatively fewer investment opportunities.
Mutual Fund Incentive Fees: Determinants and Effects
Authors: Drago Danilo , Lazzari Valter , Navone Marco
Published: March 2010

We investigate the how and why of performance fee provisions in a free contracting environment such as the Italian mutual fund market until 2006. We find weak support for the hypothesis that these provisions emerge as an economically efficient solution in a rational asset management industry plagued by asymmetric information. They appear to emerge mainly as the product of strategic pricing by asset managers wishing to ease market competition, leverage on investors' sentiment, and hedge their cost structure. Alternatively, fears that managers may opportunistically alter funds' investment policies to maximize the option value embedded in the incentive provisions appear unjustified.
Do Tax Law Changes Influence Ex‐Dividend Stock Price Behavior? Evidence from 1926 to 2005
Authors: Whitworth Jeff , Rao Ramesh P.
Published: March 2010

We test the Elton and Gruber model of ex‐dividend stock pricing over a period spanning all US tax law changes since 1926. Our results indicate that price drop ratios (ΔP/D) and ex‐day returns are related to dividend and capital gains tax rates in the theorized manner. Consistent with tax clienteles, we also find that ex‐day price movements of higher dividend yield stocks are driven more by corporate tax rates, while lower yield stocks are more influenced by personal rates. Finally, we demonstrate that the positive relationship between ΔP/D and the dividend yield becomes stronger as the tax differential |td− tcg| widens.
Chinese Yellow Wine and Red Wine Inhibit Matrix Metalloproteinase‐2 and Improve Atherosclerotic Plaque in LDL Receptor Knockout Mice
Authors: Guo Hangyuan , Liu Longbin , Shi Yafei , Sun Aijing , Xu Fukang , Chi Jufang , Huang Dilai
Published: March 2010

Our previous study found that Chinese yellow wine could inhibit the production of homocysteine (HCY) induced extracellular matrix metalloproteinase‐2 (MMP‐2) in the cultured rat vascular smooth muscle cells. Little is known about the relationship between Chinese yellow wine and atherosclerosis or MMP‐2 in vivo. Thirty‐two LDL Receptor knockout mice on a high‐fat and l‐methionine diet developed plasma hyperhomocysteinemia and atherosclerosis. They were randomly divided into yellow wine group (n = 8), red wine group (n = 8), ethanol group (n = 8), and control group (n = 8), they were sacrificed after 14 weeks. There were no significant differences with plasma total cholesterol (TC), triglyceride (TG), high‐density lipoprotein cholesterol (HDL‐C), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) levels in the four groups. Plasma HCY was significantly decreased in the yellow wine group compared to the other three groups (P < 0.01). Yellow wine and red wine groups significantly reduced the atherosclerosis lesion area compared to ethanol and control groups (P < 0.001). However, there was no significant discrepancy between the yellow wine group and red wine group. Compared to the control group and ethanol group, the production of MMP‐2 reduced 26.8% and 23.6% in the aortic sinus and the activation of MMP‐2 reduced 32.6% and 27.3% in the aortic arch in the yellow wine group; the production of MMP‐2 reduced 25.7% and 22.4% in the aortic sinus and the activation of MMP‐2 reduced 30.2% and 26.6% in the aortic arch in the red wine group. These results suggest that Chinese yellow wine and red wine can inhibit MMP‐2 and improve atherosclerosis, and maybe both Chinese yellow wine and red wine have beneficial effects on cardiovascular disease by inhibiting MMP‐2.
Portal vein thrombosis in Egyptian patients with liver cirrhosis: Role of methylenetetrahydrofolate reductase C677T gene mutation
Authors: Gabr Mamdouh Ahmed , Bessa Sahar Saad El‐Din , El‐Zamarani Enas Arafa
Published: March 2010

Aim:  The pathogenesis of non‐malignant portal vein thrombosis (PVT) in cirrhotic patients is not clearly defined. This case‐control study aimed to investigate the role of methylenetetrahydrofolate reductase (MTHFR) C677T gene mutation in the pathogenesis of PVT in Egyptian cirrhotic patients.

Methods:  Plasma homocysteine was measured and MTHFR C677T gene mutation was detected in 76 cirrhotic patients (21 with PVT, 55 without PVT) and 20 healthy controls.

Results:  The frequency of CC genotype (wide type) in cirrhotic patients with PVT was lower than controls and cirrhotics without PVT. However, the frequency of TT genotype (homozygous mutation) was elevated in cirrhotic patients with PVT as compared to controls and those without PVT. Cirrhotic patients with PVT had significantly higher homocysteine than those without PVT. Cirrhotic patients with TT genotype are at a significant risk for PVT (odds ratio = 7.7, 95% confidence interval, 1.50–42.81) when compared with CC genotype. Moreover, subjects carrying TT genotype had a higher homocysteine than those carrying CC genotype.

Conclusions:  The TT genotype of MTHFR is associated with an increased risk of PVT in Egyptian cirrhotic patients. Hyperhomocysteinemia could be considered as a relatively new risk factor for PVT in cirrhotic patients and plasma homocysteine should be investigated particularly in patients with PVT of unexplained etiology. The important clinical implication is that the readily available therapy of folate, vitamin B6 and B12 supplementation may reduce homocysteine and prevent further thrombotic complications in cirrhotic patients carrying the TT genotype.
Shakedown Analysis of Nuclear Components Using Linear and Nonlinear Methods
Authors: Vlaicu Dan
Published: March 2010

A cyclically loaded structure made of elastic-plastic material is considered as an elastic shakedown if plastic straining occurs in the first few cycles and the sequent response is wholly elastic. In this paper, the finite element method is used to develop upper and lower bound limits for the elastic shakedown of structures under periodic loading conditions. Linear methods using elastic compensation approach and the residual stress method derived from Melan’s theorem are used to generate the lower bound limit for the shakedown load, while the upper bound is found through a method derived from Koiter’s theorem. Furthermore, the results are compared with cycle-by-cycle method based on nonlinear material properties.
Three-Dimensional Stress State Around Corrosive Cavities on Pressure Vessels
Authors: Abdulaliyev Z. , Ataoglu S. , Bulut O. , Kayali E. S.
Published: March 2010

Internal surfaces of pressure vessels used in many industrial sectors are subjected to corrosive effects leading to cavities. In this study, corrosive cavities on investigated pressure vessels are classified according to their shapes and dimensions. Distribution of stress was experimentally investigated around regions of different types of cavities using three-dimensional photoelastic models. An empirical expression is proposed to determine where maximum stress occurs in type of ellipsoidal cavity in the case of uniaxial loading. The obtained results show quite high stress levels around the cavity regions in pressure vessels, which increase the risk of crack formation.
Computation of Working Life Consumption of a Steam Turbine Rotor
Authors: Mitrović Dejan , Zivkovic Dragoljub
Published: March 2010

Fatigue is one of the most important aging effects of power plant components. Information about fatigue helps in assessing structural degradation of the component and so assists in planning in-service inspection and maintenance. In this paper, we present a computation method that can be used to estimate the working life consumption of a steam turbine rotor. In the method, creep and low cycle material damage were considered. The calculations are based on the Palmgren–Miner hypothesis of linear damage accumulation. The computation was done utilizing the Microsoft Excel software package and the VISUAL BASIC for application programming language. As a reference, we used the MAN-339 MW steam turbine installed in the “Kosovo-B” power plant station in Obilic. This method can be implemented to other parts of the power plant that will result in better organization of the maintenance and ultimate enhancement of the reliability and availability of the plant.
Influence of Cooling Rate on Predicted Weld Residual Stress Buildup in a Thick-Walled Piping Intersection
Authors: Jiang Wei , Yahiaoui Kadda
Published: March 2010

Welded, thick-walled piping intersections are widely used in many engineering applications including the offshore and nuclear power industries. These components are often fabricated by multipass welding, which inevitably introduces undesirable residual stresses. In this paper, weld-induced residual stresses in a thick-walled piping intersection were predicted using a validated, full three dimensional, sequentially coupled thermomechanical finite element modeling technique. The moving heat source was simulated by imposing body heat flux onto the newly activated elements progressing along the circumferential weld path around the intersection during each pass. The effect of cooling rate on the final residual stress state, especially at critical areas where the peak residual stresses are located, was then investigated by applying different convective heat transfer coefficients to the exposed piping intersection surfaces. It was found that the magnitudes and overall spatial distributions of residual stresses were very sensitive to cooling rate. Residual stresses on the outer surfaces of the component can be significantly reduced by external cooling. On the other hand, cooling the inner surfaces can dramatically convert residual stresses from tensile to compressive in these regions. The results and modeling technique presented in this paper show that residual stress profiles in multipass welded complex geometries can be efficiently optimized through convenient cooling rate control.
Mechanical Behavior of Random Fiber Composite Perforated Plates
Authors: Eggen Michael , Mantell Susan C. , Davidson Jane H.
Published: March 2010

The mechanical behavior of perforated, chopped fiber reinforced polymer plates is measured in three point bend tests to determine if an equivalent elastic modulus can be applied to fiber filled perforated plates despite local areas of reduced stiffness surrounding each hole. Experimental values of the scaled effective elastic modulus E∗/E are obtained for a range of perforation geometries in unfilled and glass fiber reinforced polyamide 6,6 and polycarbonate thin plates. Data for nonreinforced and chopped fiber reinforced plates are indistinguishable and agree well with a finite element model for linear elastic isotropic materials. No compensation for the reduction in modulus near the perforations is required in the finite element model. It is also concluded that the equivalent elastic modulus approach is suitable for the prediction of bending deformation of machined random fiber composite plates.
Fitness-for-Service Assessment of Hydrocarbon Storage Tanks
Authors: Ahmad F. , Hossain M. M. , Seshadri R.
Published: March 2010

Storage tanks are widely used in the industry to store hydrocarbon products. Corrosion damage is considered to be a serious threat to the structural integrity of the industrial storage tanks if it occurs on the primary pressure containment boundary. Therefore, fitness-for-service (FFS) assessment of these structures is performed periodically in order to ensure the operational safety and structural integrity. In this paper, evaluation methods are proposed for FFS assessment of storage tanks undergoing corrosion damage. The proposed methods are shown to give reasonably accurate and conservative assessment of the remaining strength factor. The methods are demonstrated through an example and the results are verified by inelastic finite element analysis.
CFD Analysis of Thermally Stratified Flow and Conjugate Heat Transfer in a PWR Pressurizer Surgeline
Authors: Jo Jong Chull , Kang Dong Gu
Published: March 2010

Temperature gradients in the thermally stratified fluid flowing through a pipe may cause undesirable excessive thermal stresses at the pipe wall in the axial, circumferential, and radial directions, which can eventually lead to damages such as deformation, support failure, thermal fatigue, cracking, etc., to the piping systems. Several nuclear power plants have so far experienced such unwelcome mechanical damages to the pressurizer surgeline, feedwater nozzle, high pressure safety injection lines, or residual heat removal lines at a pressurized water reactor (PWR). In this regard, determining with accuracy the transient temperature distributions in the wall of a piping system subjected to internally thermal stratification is the essential prerequisite for the assessment of the structural integrity of such a piping system. In this study, to realistically predict the transient temperature distributions in the wall of an actual PWR pressurizer surgeline with a complex geometry of three-dimensionally bent piping, three-dimensional transient computational fluid dynamics (CFD) calculations involving the conjugate heat transfer analysis are performed for the PWR pressurizer surgeline subjected to either out- or in-surge flows using a commercial CFD code. In addition, the wall temperature distributions obtained by taking into account the existence of wall thickness are compared with those by neglecting it to identify some requirements for a realistic and conservative thermal analysis from a safety viewpoint.
High-current, low-cost field emission triode using a reticulated vitreous carbon cathode
Authors: Carpenter Arthur C. , Hunt Charles E.
Published: March 2010

A simple, macroscale field-emission triode was assembled using a single 3.8 mm diameter Ar+-ion irradiated reticulated vitreous carbon (RVC) cathode. The irradiation process results in random carbon nanostructures on the surface of the RVC, providing effective, low-field emission sites. The use of RVC results in a self-ballasting cathode. The grid electrode further increases local field enhancement on the cathode surface, increasing the extracted current over what is produced in diode mode. The anode electric field required to produce 0.1 μA/cm2 was measured to decrease from 0.9 to 0.65 V/μm with 300 V applied to the grid electrode. With 2.1 V/μm, and 300 V applied to the grid, the limits of our power supply were reached, and a current density of 16.0 mA/cm2 and a current of 1.82 mA from a single cathode were measured. Semiconductorlike emission properties, showing three regions of operation, were observed. In region III the cathode emits from a large number of sites, producing a total beam that is readily focused to a small spot size with ordinary electron optics. This low-cost, robust configuration, machined without microfabrication processes or lithography, makes very-high total current in single field-emission triodes possible.