bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of partial melting on the crystallization kinetics of nylon‐1212
Authors: Song Jianbin , Chen Qingyong , Ren Minqiao , Sun Xiaohong , Zhang Huiliang , Zhang Hongfang , Mo Zhishen
Published: September 2005

The isothermal and nonisothermal crystallization kinetics of partially melted nylon‐1212 was investigated with differential scanning calorimetry. Because of partial melting, the pre‐existing crystals changed the crystallization mechanism and had a strong effect on the crystallization process. The Avrami exponent and interfacial free energy of the chain‐folded surface of partially melted nylon‐1212 were higher than those of completely melted nylon‐1212. The work of chain folding was determined to be 5.9 kcal/mol. The activation energy of the isothermal crystallization process was determined to be 399.1 kJ/mol, far higher than that of complete melting. The crystallization rate coefficient and Jeziorny analysis indicated that the ability of nonisothermal crystallization for partially melted nylon‐1212 was enhanced. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3222–3230, 2005
Soy‐oil‐based segmented polyurethanes
Authors: Petrović Zoran S. , Cevallos Maria J. , Javni Ivan , Schaefer Dale W. , Justice Ryan
Published: September 2005

Segmented polyurethanes were prepared from soy polyol, diphenyl methane diisocyanate (MDI), and ethylene glycol or butane diol as chain extenders. Samples were prepared with true hard‐segment concentrations (HSC) of about 0, 10, and 40%. Both the soft MDI–polyol and hard MDI/diol segments are glassy at room temperature. These samples were also crosslinked through the polyfunctional polyol soft segment. Partial crystallinity and phase separation were detected in samples with 40% HSC, on the basis of DSC data. Small‐angle X‐ray scattering shows the existence of phase separation with domain sizes of about 10 nm in the 40% HSC samples, but not in the others. The distribution of domain sizes is considerably broader for the ethylene‐glycol extended system compared with that for the butane‐diol case. Although the presence of hard segments lowers the crosslink density, samples with higher HSC had higher glass transition temperatures, higher strengths, higher moduli, lower swelling, lower elongation at break, and lower impact strengths. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3178–3190, 2005
Electrospinning of polyurethane/organically modified montmorillonite nanocomposites
Authors: Hong Ji Hye , Jeong Eun Hwan , Lee Han Sup , Baik Du Hyun , Seo Seung Won , Youk Ji Ho
Published: September 2005

Polyurethane/organically modified montmorillonite (PU/O‐MMT) nanocomposites were electrospun and the effect of O‐MMT on the morphology and physical properties of the PU/O‐MMT nanofiber mats were investigated for the first time. The average diameters of the PU/O‐MMT nanofibers were ranged from 150 to 410 nm. The conductivities of the PU/O‐MMT solutions were linearly increased with increasing the content of O‐MMT, which caused a decrease in the average diameters of the PU/O‐MMT nanofibers. The as‐electrospun PU and PU/O‐MMT nanofibers were not microphase separated. The exfoliated MMT layers were well distributed within the PU/O‐MMT nanofibers and oriented along the fiber axis. When the PU/O‐MMT nanofibers were annealed, the exfoliated MMT layers hindered the microphase separation of the PU. The electrospinning of PU/O‐MMT nanocomposites resulted in PU nanofiber mats with improved Young's modulus and tensile strength. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3171–3177, 2005
Understanding the effect of skin formation on the removal of solvents from semicrystalline polymers
Authors: Wong Sim‐Siong , Altinkaya Sacide Alsoy , Mallapragada Surya K.
Published: September 2005

The effect of glassy skin formation on the drying of semicrystalline polymers was investigated with a comprehensive mathematical model developed for multicomponent systems. Polymers with high glass‐transition temperatures can become rubbery at room temperature under the influence of solvents. As the solvents are removed from the polymer, a glassy skin can form and continue to develop. The model takes into account the effects of diffusion‐induced polymer crystallization as well as glassy–rubbery transitions on the overall solvent content and polymer crystallinity. A Vrentas–Duda free‐volume‐based diffusion scheme and crystallization kinetics were used in our model. The polymer–solvent system chosen was a poly(vinyl alcohol) (PVA)–water–methanol system. The drying kinetics of PVA films were obtained by gravimetric methods with swollen films with known water/methanol concentrations. The overall drying behaviors of the polymer system determined by our model and experimental methods were compared and found to match well. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3191–3204, 2005
Crystal structure of a new class of glutathione transferase from the model human hookworm nematode Heligmosomoides polygyrus
Authors: Schuller David J. , Liu Qun , Kriksunov Irina A. , Campbell Alison M. , Barrett John , Brophy Peter M. , Hao Quan
Published: September 2005

The crystal structure of GST Nu2‐2 (HpolGSTN2‐2) from the model hookworm nematode Heligmosomoides polygyrus has been solved by the molecular replacement method and refined to a resolution of 1.71 Å, providing the first structural data from a class of nematode‐specific GSTs. By structural alignment with two Sigma class GSTs, glutathione could be rationally docked into the G‐site of the enzyme. By comparing with all mammalian GST classes, a novel, long, and deep cleft was identified at the H‐site, providing a potential site for ligand binding. This new GST class may support the establishment of infection parasitic nematodes by passively neutralizing chemical toxins derived from host environment. The structure serves as a starting point for structure‐based drug/inhibitor design that would aim to selectively disrupt nematode chemical defenses. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Estimation of prevalence and incidence based on occurrence of health‐related events
Authors: Støvring Henrik , Vach Werner
Published: September 2005

A new method for estimating incidence and prevalence is developed, which only requires observation of occurrence of health‐related events within a given time window. Occurrence data are often easy to collect but estimating incidence and prevalence of a disease from such data is non‐trivial, since the true disease status is not directly observed for all at the beginning of the study period. Our method for overcoming this problem is based on an idea first presented in ‘The waiting time distribution as a graphical approach to epidemiologic measures of drug utilization’ (Epidemiology 1997; 8:666–670). Their fundamental idea is to analyse the waiting time from start of the window to the first event of each individual, and we formalize this by establishing a parametric likelihood which allows ordinary maximum likelihood analysis and explicit modelling of censoring. The developed method is used to analyse incidence and prevalence of hypertension in a Danish cohort of 70+‐year‐olds. A simulation study on the finite sample properties of the method is reported, which indicates that the method gives a quite robust and cost‐effective alternative to ordinary surveys and follow‐up studies for estimating incidence and prevalence. Copyright © 2005 John Wiley & Sons, Ltd.
Assessing uncertainty in reference intervals via tolerance intervals: application to a mixed model describing HIV infection
Authors: Katki Hormuzd A. , Engels Eric A. , Rosenberg Philip S.
Published: September 2005

We define the reference interval as the range between the 2.5th and 97.5th percentiles of a random variable. We use reference intervals to compare characteristics of a marker of disease progression between affected populations. We use a tolerance interval to assess uncertainty in the reference interval. Unlike the tolerance interval, the estimated reference interval does not contains the true reference interval with specified confidence (or credibility). The tolerance interval is easy to understand, communicate and visualize. We derive estimates of the reference interval and its tolerance interval for markers defined by features of a linear mixed model. Examples considered are reference intervals for time trends in HIV viral load, and CD4 per cent, in HIV‐infected haemophiliac children and homosexual men. We estimate the intervals with likelihood methods and also develop a Bayesian model in which the parameters are estimated via Markov‐chain Monte Carlo. The Bayesian formulation naturally overcomes some important limitations of the likelihood model. Published in 2005 by John Wiley & Sons, Ltd.
Adjusted Kaplan–Meier estimator and log‐rank test with inverse probability of treatment weighting for survival data
Authors: Xie Jun , Liu Chaofeng
Published: September 2005

Estimation and group comparison of survival curves are two very common issues in survival analysis. In practice, the Kaplan–Meier estimates of survival functions may be biased due to unbalanced distribution of confounders. Here we develop an adjusted Kaplan–Meier estimator (AKME) to reduce confounding effects using inverse probability of treatment weighting (IPTW). Each observation is weighted by its inverse probability of being in a certain group. The AKME is shown to be a consistent estimate of the survival function, and the variance of the AKME is derived. A weighted log‐rank test is proposed for comparing group differences of survival functions. Simulation studies are used to illustrate the performance of AKME and the weighted log‐rank test. The method proposed here outperforms the Kaplan–Meier estimate, and it does better than or as well as other estimators based on stratification. The AKME and the weighted log‐rank test are applied to two real examples: one is the study of times to reinfection of sexually transmitted diseases, and the other is the primary biliary cirrhosis (PBC) study. Copyright © 2005 John Wiley & Sons, Ltd.
Pulsatile hemodynamic effects of candesartan in patients with chronic heart failure: The CHARM Program
Authors: Mitchell Gary F. , Arnold J. Malcolm O. , Dunlap Mark E. , O'Brien Terrence X. , Marchiori Gordon , Warner Elaine , Granger Christopher B. , Desai Shashank S. , Pfeffer Marc A.
Published: September 2005

Background:

Abnormal large artery function and increased pulsatile load are exacerbated by excess angiotensin‐II acting through the AT1 receptor and contribute to the pathogenesis and progression of chronic heart failure (CHF).

Aims:

To evaluate effects of the AT1 receptor blocker candesartan (N=30) or placebo (N=34) on pulsatile hemodynamics in participants with CHF in the CHARM program.

Methods and results:

Noninvasive hemodynamics were assessed following 6 and 14 months of treatment and averaged. Using calibrated tonometry and aortic outflow Doppler, characteristic impedance was calculated as the ratio of the change in carotid pressure and aortic flow in early systole. Total arterial compliance was calculated by the diastolic area method. Brachial blood pressure, cardiac output and peripheral resistance did not differ between groups. Lower central pulse pressure in the candesartan group (57±20 vs. 67±17 mmHg, P=0.043) was accompanied by lower characteristic impedance (200±78 vs. 240±74 dyne s/cm5, P=0.039) and higher total arterial compliance (1.87±0.70 vs. 1.47±0.48 ml/mmHg, P=0.008). Similar favorable differences were seen when analyses were stratified for ejection fraction (≤0.40 vs. >0.40) and baseline angiotensin converting enzyme inhibitor use.

Conclusions:

Candesartan has a favorable effect on large artery function in patients with chronic heart failure.
Measuring body composition in chronic heart failure: A comparison of methods
Authors: Uszko‐Lencer Nicole H.M.K. , Bothmer Francien , van Pol Petra E.J. , Schols Annemie M.W.J.
Published: September 2005

Aims:

Fat‐free mass (FFM) is increasingly recognized as a systemic marker of disease severity in chronic organ failure and is an important target for physiologic and pharmacologic interventions to improve functional status. The aim of this study was therefore to evaluate two clinical methods to assess FFM in patients with chronic heart failure (CHF) using deuterium dilution (DEU) as reference and bromide dilution to assess the ratio between intracellular (ICW) and extracellular water (ECW) as potential confounder.

Methods:

Body composition was measured with dual‐energy X‐ray absorptiometry (DXA), bioelectrical impedance analysis (BIA) and DEU in 22 stable patients from our heart failure outpatient clinic and 24 healthy age matched controls.

Results:

FFM values measured by DXA and DEU in patients (r=0.92, SEE: 3.1 kg) and controls (r=0.99, SEE: 1.3 kg) were strongly related. In both patients and controls, the inter method difference increased with higher values of FFM (DXA overestimating DEU). The ICW/ECW ratio was within the normal range and comparable between the groups. In patients, a highly significant correlation coefficient was found (r=0.93, SEE 2.1 p=0.01) between total body water (DEU) and height squared/resistance (Ht2/R). On multiple regression next to Ht2/R, body weight was an independent predictor of FFMDEU (r=0.95, SEE 2.5 kg, p<0.001; TBWdeu=0.528 Ht2/R+(0.182 weight)+8.277).

Conclusion:

DXA and DEU are appropriate and interchangeable laboratory methods for assessment of FFM in clinically stable heart failure patients, however, overestimation of FFMDXA should be considered. BIA is a suitable clinical alternative for diagnostic purposes.
Heart failure and sleep apnoea: To sleep perchance to dream
Authors: Ferreira Susana , Winck João , Bettencourt Paulo , Rocha‐Goncalves Francico
Published: September 2005

Heart failure and sleep apnoea are major health problems with an increasingly recognized association; evidence suggests that sleep apnoea may play a role in the progression of heart failure. However, confounding factors such as obesity, hypertension and coronary heart disease make this relationship uncertain and an independent correlation remains unproven.

Diagnosis of sleep apnoea is suboptimal, as it is often asymptomatic and polysomnography is expensive and time‐consuming. A simple and reliable screening protocol is required. All heart failure patients should be considered to be at high risk of sleep apnoea, as this association might be linked to adverse outcome. Continuous positive airway pressure has shown some beneficial effects, but long‐term outcome and improvement in survival remains to be demonstrated.

Despite recent advances in the understanding of the complex relationship between heart failure and sleep apnoea, there are a number of areas requiring further investigation, which may have important implications for the management and prognosis of a significant number of patients.
Benefits of coronary revascularisation in diabetic and non‐diabetic patients with ischaemic cardiomyopathy: Role of myocardial viability
Authors: Rizzello Vittoria , Poldermans Don , Biagini Elena , Schinkel Arend F.L. , Boersma Eric , Elhendy Abdou , Sozzi Fabiola B. , Maat Alexander , Roelandt Jos R.T.C. , Bax Jeroen J.
Published: September 2005

Background:

Diabetes mellitus in patients with coronary artery disease is associated with poor outcome. In this study, the relation between myocardial viability, diabetes, coronary revascularisation and outcome was evaluated.

Methods:

129 patients (31 diabetic, 98 non‐diabetic) with ischaemic cardiomyopathy underwent dobutamine stress echocardiography to assess myocardial viability. Patients with ≥4 viable segments were defined as viable and patients with <<4 viable segments as nonviable. Left ventricular ejection fraction (LVEF) was assessed before and 9–12 months post‐revascularisation. At the same time‐points, LV volumes were measured to evaluate LV remodelling. Finally, cardiac events were noted during 5‐year follow‐up.

Results:

The extent of viable myocardium was comparable between diabetic and non‐diabetic patients. After revascularisation, LVEF increased ≥5% in 44% of diabetic and in 40% of non‐diabetic patients. LVEF only improved in patients with viable myocardium. Ongoing LV remodelling occurred in 36% and 35% of diabetic and non‐diabetic patients respectively, and was related to non‐viability, whereas viability protected against ongoing LV remodelling, both in diabetic and non‐diabetic patients. Viability was the only predictor of survival after revascularisation.

Conclusions:

Diabetic, viable patients with ischaemic LV dysfunction exhibit improvement in LVEF post‐revascularisation with prevention of ongoing LV remodelling, similar to non‐diabetic patients. Myocardial viability was also the only predictor of long‐term outcome.
Accumulation of risk markers predicts the incidence of sudden death in patients with chronic heart failure
Authors: Watanabe Jun , Shinozaki Tsuyoshi , Shiba Nobuyuki , Fukahori Kohei , Koseki Yoshito , Karibe Akihiko , Sakuma Masahito , Miura Masahito , Kagaya Yutaka , Shirato Kunio
Published: September 2005

Background:

Sudden death is common in chronic heart failure (CHF). Risk stratification is the first step for primary prevention.

Aim:

To evaluate the use of risk markers for estimating sudden death risk.

Methods and results:

We prospectively examined 680 stable patients with CHF. Risk markers were evaluated using the Cox's proportional hazard model in a stepwise manner. Ejection fraction <30%, left ventricular end‐diastolic diameter >60 mm, brain natriuretic peptide >200 pg/ml, non‐sustained ventricular tachycardia, and diabetes were significantly associated with increased risk of sudden death. When the number of risk markers were included as co‐variables, only “number of risk markers ≥3” entered the model (hazard ratio 8.95, 95% confidence interval 4.57–17.52), while the effects of individual markers did not enter the model. The annual mortality from sudden death was 11% in patients with 3 or more risk markers and 1.4% in patients with 2 or less.

Conclusions:

Rather than particular risk markers, the number of accumulated risk markers was a more powerful predictor for sudden death in patients with CHF. The number of risk markers could be useful for risk stratification of sudden death.
Heterotopic ischemic pain attenuates somatosensory evoked potentials induced by electrical tooth stimulation: Diffuse noxious inhibitory controls in the trigeminal nerve territory
Authors: Fujii Keiko , Motohashi Katsunori , Umino Masahiro
Published: September 2005

The purpose of this study was to determine whether the late component of somatosensory evoked potentials (SEP) induced by electrical tooth stimulation and pain intensity are inhibited by heterotopic ischemic stimulation. The tourniquet pressure with 50 mmHg greater than the individual's systolic pressure was applied to the left upper arm for 10 min as ischemic conditioning stimulation. The late component of SEP and visual analogue scale (VAS) were recorded at 4 times and both were significantly decreased when ischemic conditioning stimulation was applied. The maximum reductions in SEP amplitude and the VAS value were 26.1% and 21.2%, respectively, during ischemic conditioning stimulation. After‐effect was observed 5 min after removal of the conditioning stimulation. The present study revealed that heterotopic ischemic stimulation attenuated the late component of SEP induced by electrical tooth stimulation, triggering diffuse noxious inhibitory controls (DNIC) and after‐effects in the trigeminal nerve territory. It was also suggested that the DNIC effect differs, depending on the intensity, kind, and quality of the test and conditioning stimuli.
How can elongation factors EF‐G and EF‐Tu discriminate the functional state of the ribosome using the same binding site?
Authors: Sergiev Petr V. , Bogdanov Alexey A. , Dontsova Olga A.
Published: September 2005

Elongation factors EF‐G and EF‐Tu are structural homologues and share near‐identical binding sites on the ribosome, which encompass the GTPase‐associated centre (GAC) and the sarcin‐ricin loop (SRL). The SRL is fixed structure in the ribosome and contacts elongation factors in the vicinity of their GTP‐binding site. In contrast, the GAC is mobile and we hypothesize that it interacts with the alpha helix D of the EF‐Tu G‐domain in the same way as with the alpha helix A of the G′‐domain of EF‐G. The mutual locations of these helices and GTP‐binding sites in the structures of EF‐Tu and EF‐G are different. Thus, the orientation of the GAC relative to the SRL determines whether EF‐G or EF‐Tu will bind to the ribosome.
Analysis of glycoside hydrolase family 98: Catalytic machinery, mechanism and a novel putative carbohydrate binding module
Authors: Rigden Daniel J.
Published: September 2005

Glycoside hydrolases (GHs) are diverse enzymes of biotechnological and medical importance. Bioinformatics contributes to our understanding of GH structure and function in various ways, including dissection of their typically modular structures and detection of the distant evolutionary relationships between families that often allow for prediction of catalytic sites. Here these twin strands are applied to the recently described GH98 family, the founder member of which is a blood group glycotope‐cleaving endo‐β‐galactosidase of potential medical importance from Clostridium perfringens. Three domains can be discerned including a central catalytic TIM barrel domain in which putative catalytic residues can be assigned. Distant homologies and domain contexts suggest that the N‐terminal domain is a novel carbohydrate binding module.
Ex situ conservation status of an endangered Yangtze finless porpoise population (Neophocaena phocaenoides asiaeorientalis) as measured from microsatellites and mtDNA diversity
Authors: Xia Junhong , Zheng Jinsong , Wang Ding
Published: September 2005

The Yangtze finless porpoise, Neophocaena phocaenoides asiaeorientalis, is an endangered small cetacean that occurs only in the middle and lower reaches of the Yangtze River of China. The establishment of a breeding population of the porpoise in Tian-e-Zhou Baiji National Natural Reserve represents the first attempt at ex situ conservation efforts for a cetacean species. With the goal of effective protection, management, and monitoring of this preserved population, we examined its genetic diversity using 930 bp of mtDNA control region sequences and 13 polymorphic microsatellite loci. A very low level of genetic variation (h = 0.6010 ± 0.0029 s.d.; π = 0.0007 ± 0.0000002 s.d.) in the mtDNA control region sequences and a moderate genetic diversity (Ho = 0.5740 ± 0.2575 s.d.) in the microsatellites were detected in the population. It is necessary to introduce more individuals with representative genetic variations into the reserve in order to form a larger and healthier group structure for long-term survival of the population. Successful establishment of the Yangtze finless porpoise population in the Reserve also provides a useful model for an ex situ conservation programme for other rare and endangered species.
The application of qualitative risk assessment methodology to prioritize issues for fisheries management
Authors: Fletcher W.J.
Published: September 2005

Implementing more holistic forms of fisheries management (e.g. Ecologically Sustainable Development (ESD), Ecosystem-Based Fisheries Management) usually increases the number and scope of impacts requiring assessment. This study examined the effectiveness of a qualitative risk assessment process, developed as part of a National ESD framework, for prioritizing issues across the seven most valuable Western Australian commercial fisheries. Structured stakeholder workshops were used to identify issues across three ecological areas: retained species (i.e. target and by-product), non-retained (i.e. discarded and protected) species, and the broader ecosystem for each fishery. The risk associated with each issue was assessed using one of five sets of consequence criteria specifically developed to cover fishery-related impacts. The risk scores, for which suitably detailed justifications were written, determined the level of reporting and management required for each issue. Despite an additional 96 “non-target species issues” being identified at the workshops from a total of 115 issues, of the 27 issues requiring explicit management actions, just six new issues were added by this process. In addition, it identified where modifications of some of the existing arrangements were necessary. Finally, the system significantly improved stakeholder involvement and therefore acceptance of the outcomes. Given this success, risk assessment has now been applied to all Western Australia's export fisheries and to the development or review of many other systems, thereby improving the entire management process.
What's behind GM food trade disputes?
Authors: JACKSON LEE ANN , ANDERSON KYM
Published: September 2005

Over the past decade, the United States (US) and the European Union (EU) have implemented widely divergent regulatory systems to govern the production and consumption of genetically modified (GM) agricultural crops. In the US, many GM varieties have been commercially produced and marketed, while in the EU few varieties have been approved: a de facto moratorium limited EU production, import and domestic sale of most GM crops from late 1998 to April 2004, and since then strict labelling regulations and a slow approval process are having a similar effect. The EU policies have substantially altered trade flows and led in September 2003 to the WTO establishing a WTO Dispute Settlement panel to test the legality of European policy towards imports of GM foods. This paper seeks to better understand the economic forces behind the different regulatory approaches of the US and the EU. It uses a model of the global economy (GTAP) to examine empirically how GM biotechnology adoption would affect the economic welfare of both adopting and non-adopting countries in the absence of alternative policy responses to this technology, and in their presence. These results go beyond earlier empirical studies to indicate effects on real incomes of farm households, and suggest the EU moratorium on GM imports helps EU farmers even though it requires them to forego the productivity boost they could receive from the new GM biotechnology.
The role of the WTO in achieving equity and efficiency in international markets for agricultural products
Authors: MACLAREN DONALD
Published: September 2005

The fundamental objective of the negotiations on agriculture that are taking place in the Doha Round is to establish a new set of rules, which will correct current distortions and prevent future distortions in international markets for agricultural products while taking into account non-trade concerns and special and differential treatment. A summary of the chronology of the very slow progress to date in the negotiations is provided. This rate of progress is explained through considering the weights the different groups of governments are giving to removing trade distortions, on the one hand, and to non-trade concerns and special and differential treatment, on the other. Some results from the economic theory of distortions and welfare are used to explain the conditions under which the twin pursuits of non-trade concerns domestically and fairness internationally are compatible. These results are contrasted with the realities of the current negotiations on the agriculture component of the ‘July 2004 package’.
Domestic regulation, international standards, and technical barriers to trade
Authors: McDONALD JAN
Published: September 2005

There is growing concern over the use of domestic product regulations as technical barriers to trade on the one hand, and the WTO's incursion into domestic regulatory autonomy on the other. The TBTA seeks to balance competing interests – acknowledging but disciplining Members' regulatory control over traded goods. The effectiveness of these disciplines is limited by the exclusion of many modern domestic regulations from the scope of the TBTA; the surest way to prevent abuse of process-based product specifications is to subject them to the TBTA's disciplines. The WTO dispute settlement tribunals have affirmed the importance of the use or adoption of international standards. While Members are still entitled to introduce their own measures in some circumstances, the emphasis on international standards raises the status of standard-setting bodies. Despite their important new role, the composition, accountability, and decision-making procedures have so far escaped the kind of civil society scrutiny to which WTO deliberations are now subject. To achieve the TBTA's harmonization objectives, the development, and use of international standards and their legal recognition within the WTO regime should be revised to safeguard legitimate non-trade regulatory objectives.
When should new areas of rules be added to the WTO?
Authors: LLOYD PETER
Published: September 2005

When the WTO was created as an outcome of the Uruguay Round, one of the major differences from its predecessor, the GATT, was the addition of new areas of rules of trade. The General Agreement on Trade in Services (GATS), the Agreement on Trade-related Aspects of Intellectual Property (TRIPS), and to some extent also the Agreement on Trade-related Investment Measures (TRIMs) added sets of rules that were entirely new. By adding trade in services, the rules of the multilateral trade organization now encompass trade in all produced goods and services. The WTO rules, however, encompass neither the international movements of capital or labour, nor other non-trade policies, such as those relating to the environment, labour standards, and competition policy, with minor exceptions.
Susceptibility of Pseudomonas aeruginosa biofilm to UV-A illumination over photocatalytic and non-photocatalytic surfaces
Authors: Gage J. P. , Roberts T. M. , Duffy J. E.
Published: September 2005

The susceptibility of Pseudomonas aeruginosa (PA01) bacteria to ultraviolet-A (UV-A) light in photocatalytic and non-photocatalytic systems was investigated. Thin films of TiO2 were deposited on glass slides using a dip-coating method. Disinfection of both planktonic and biofilm bacterial cells was studied over both coated and uncoated slides exposed to low intensity (1.0 mW/cm2) UV-A irradiation. Photocatalytic treatment of planktonic PA01 cultures pro-vided a 4-log reduction in the number of viable cells in 3 h whereas UV light alone produced a 1-log reduction. For biofilm bacteria, photocatalytic treatment did not enhance killing relative to UV treatment alone; however, the UV illumination resulted in a 2- to 3-log reduction in viable cells as compared with non-illuminated controls. Possible explanations for the discrepancy between susceptibility of planktonic and biofilm bacteria to photocatalytic oxidation are discussed.
A modified law‐of‐the‐wall applied to oceanic bottom boundary layers
Authors: Perlin A. , Moum J. N. , Klymak J. M. , Levine M. D. , Boyd T. , Kosro P. M.
Published: September 2005

Near the bottom, the velocity profile in the bottom boundary layer over the continental shelf exhibits a characteristic law‐of‐the‐wall that is consistent with local estimates of friction velocity from near‐bottom turbulence measurements. Farther from the bottom, the velocity profile exhibits a deviation from the law‐of‐the‐wall. Here the velocity gradient continues to decrease with height but at a rate greater than that predicted by the law‐of‐the‐wall with the local friction velocity. We argue that the shape of the velocity profile is made consistent with the local friction velocity by the introduction of a new length scale that, near the boundary, asymptotes to a value that varies linearly from the bottom. Farther from the boundary, this length scale is consistent with the suppression of velocity fluctuations either by stratification in the upper part of the boundary layer or by proximity to the free surface. The resultant modified law‐of‐the‐wall provides a good representation of velocity profiles observed over the continental shelf when a local estimate of the friction velocity from coincident turbulence observations is used. The modified law‐of‐the‐wall is then tested on two very different sets of observations, from a shallow tidal channel and from the bottom of the Mediterranean outflow plume. In both cases it is argued that the observed velocity profile is consistent with the modified law‐of‐the‐wall. Implicit in the modified law‐of‐the‐wall is a new scaling for turbulent kinetic energy dissipation rate. This new scaling diverges from the law‐of‐the‐wall prediction above 0.2D(whereDis the thickness of the bottom boundary layer) and agrees with observed profiles to 0.6D.
Observations of smoke‐influenced aerosol during the Yosemite Aerosol Characterization Study: 2. Aerosol scattering and absorbing properties
Authors: McMeeking G. R. , Kreidenweis S. M. , Carrico C. M. , Collett J. L. , Day D. E. , Malm W. C.
Published: September 2005

Direct observations and size‐distribution‐based estimates of light‐scattering coefficients (bsp) are presented for the Yosemite Aerosol Characterization Study (YACS), which took place during the summer of 2002, an active fire year. Uncertainty in the estimates of bsp were found to be sensitive to the choice of the aerosol refractive indices, which were retrieved by aligning optical particle counter measurements to differential mobility analyzer observations and, in addition, were calculated from composition measurements. Aerosol composition during the study was dominated by organic carbon, with highest levels observed during periods impacted by biomass burning smoke influenced hazes. As a result, estimates of the aerosol refractive index from composition measurements were highly sensitive to the assumed properties of organic carbon. Retrieved and calculated refractive indices were in agreement for reasonable assumptions for properties of organic carbon. Excellent agreement (within 6%) was found between measured bsp and size‐distribution derived bsp if the imaginary component of the refractive index, determined from composition measurements and assuming all species were internally mixed, was included in the Mie calculation. Under the internally mixed assumption, aerosols sampled during the study were modeled as weakly absorbing, with computed dry single scattering albedo ranging from 0.86 to 0.94. Calculated light absorption coefficients yielded a study‐averaged dry aerosol mass absorption efficiency of 0.37 ± 0.05 m2g−1.
Influence of water‐soluble organic carbon on cloud drop number concentration
Authors: Ervens Barbara , Feingold Graham , Kreidenweis Sonia M.
Published: September 2005

Studies published to date produce ambiguous results regarding the magnitude and even the sign of the effect of water‐soluble organic carbon (WSOC) on cloud drop concentration compared to well‐characterized inorganics. We present a systematic investigation of the reasons for these discrepancies by examining the ranges of physico‐chemical properties of water soluble organics that most influence drop formation. We show that when considered individually, composition parameters such as low solubility, increased molecular weight, and surface tension suppression can lead to significant effects on droplet concentration, compared to the equivalent aerosol size distribution assuming properties of ammonium sulfate solutions. When considered together, these effects tend to counteract one another and produce much smaller changes. In addition, an assessment of the published literature suggests that estimates of composition effects on drop concentration based on equilibrium assumptions can be much larger than similar estimates under nonequilibrium conditions.
Statistical distributions of dissipated power in electronic circuits immersed in a random electromagnetic field
Authors: Arnaut L. R.
Published: September 2005

Statistical distributions are derived for power dissipation inside linear or nonlinear circuit elements driven by a circuit source and illuminated by an external random electromagnetic field. The probability density functions of the normalized power dissipated inside rectilinear, planar, and volumetric resistive elements are derived by splitting the total internal field in components with appropriate bias fields. These results are extended and generalized to several canonical configurations, for the combined internal and external deterministic or random excitation of single or multiple circuit elements. The results are fundamental to the analysis of the operation and malfunction of electronic circuits and their elements when placed inside complex electromagnetic environments, such as reverberation chambers, or on printed circuit board, as well as to their electromagnetic compatibility, emissions, and susceptibility.
A Markov switching model for annual hydrologic time series
Authors: Akintug B. , Rasmussen P. F.
Published: September 2005

This paper investigates the properties of Markov switching (MS) models (also known as hidden Markov models) for generating annual time series. This type of model has been used in a number of recent studies in the water resources literature. The model considered here assumes that climate is switching between M states and that the state sequence can be described by a Markov chain. Observations are assumed to be drawn from a normal distribution whose parameters depend on the state variable. We present the stochastic properties of this class of models along with procedures for model identification and parameter estimation. Although, at a first glance, MS models appear to be quite different from ARMA models, we show that it is possible to find an ARMA model that has the same autocorrelation function and the same marginal distribution as any given MS model. Hence, despite the difference in model structure, there are strong similarities between MS and ARMA models. MS and ARMA models are applied to the time series of mean annual discharge of the Niagara River. Although it is difficult to draw any general conclusion from a single case study, it appears that MS models (and ARMA models derived from MS models) generally have stronger autocorrelation at higher lags than ARMA models estimated by conventional maximum likelihood. This may be an important property if the purpose of the study is the analysis of multiyear droughts.
A two‐layer model to simulate variations in surface water chemistry draining a northern forest watershed
Authors: Chen Limin , Driscoll Charles T.
Published: September 2005

Seasonal patterns are evident in surface water chemistry draining forested headwaters in the northeastern United States. This variation in surface water chemistry is largely driven by seasonal fluctuations in hydrologic flow paths and biological activity. Especially during spring snowmelt, high‐flow conditions are characterized by high concentrations of NO3‒, naturally occurring organic anions and aluminum species, and depression in surface water pH and acid neutralizing capacity (ANC). Under extreme conditions, decreases in pH and ANC and increases in aluminum can have adverse effects on aquatic biota. As a result, there is a critical need to be able to simulate seasonal variations in surface water acid‐base chemistry. Previously, a single soil layer biogeochemical model (PnET‐BGC) was found to be inadequate to simulate seasonal variations in stream chemistry draining acid‐sensitive forest watersheds. In order to better simulate the seasonal variations in the acid‐base chemistry of surface waters, a two‐layer model (PnET‐BGC2) was formulated and applied to a northern forest ecosystem. End‐member mixing analysis was used to better understand hydrologic flow paths contributing to temporal patterns in stream chemistry and to parameterize the model. The resulting two‐layer model is generally able to reproduce the seasonal variations in surface water runoff, concentrations of base cations, SO42‒, NO3‒, pH, and ANC.
A simulation of the effect of climate change–induced desertification on mineral dust aerosol
Authors: Woodward S. , Roberts D. L. , Betts R. A.
Published: September 2005

Vegetation and climate fields from a coupled carbon‐cycle – climate model integration, which included the feedback of vegetation on climate, have been used to drive the HadAM3 AGCM incorporating the Hadley Centre mineral dust scheme in experiments to investigate future dust concentration and forcing. Comparison of 2000 with 2100 simulations shows the global annual mean atmospheric dust load increases from 4 × 104 to 1.3 × 105 mg m−2, due to the combination of desertification and climate change. The global mean radiative forcing due to dust increases from 0.04 to 0.21 Wm−2 at the top of the atmosphere and from −0.74 to −1.82 Wm−2 at the surface.
On the recent changes in surface temperature trends over India
Authors: Kothawale D. R. , Rupa Kumar K.
Published: September 2005

Marked differences from global trends in terms of diurnal asymmetry of temperature trends were reported earlier for India, indicating that the warming over India was solely contributed by maximum temperatures. We report substantial recent changes in the nature of trends, using updated data sets up to 2003, with special focus on the last three decades. While all‐India mean annual temperature has shown significant warming trend of 0.05°C/10yr during the period 1901–2003, the recent period 1971–2003 has seen a relatively accelerated warming of 0.22°C/10yr, which is largely due to unprecedented warming during the last decade. Further, in a major shift, the recent period is marked by rising temperatures during the monsoon season, resulting in a weakened seasonal asymmetry of temperature trends reported earlier. The recent accelerated warming over India is manifest equally in daytime and nighttime temperatures.
Improving the spatial distribution of modeled Arctic sea ice thickness
Authors: Miller Paul A. , Laxon Seymour W. , Feltham Daniel L.
Published: September 2005

The spatial distribution of ice thickness/draft in the Arctic Ocean is examined using a sea ice model. A comparison of model predictions with submarine observations of sea ice draft made during cruises between 1987 and 1997 reveals that the model has the same deficiencies found in previous studies, namely ice that is too thick in the Beaufort Sea and too thin near the North Pole. We find that increasing the large scale shear strength of the sea ice leads to substantial improvements in the model's spatial distribution of sea ice thickness, and simultaneously improves the agreement between modeled and ERS‐derived 1993–2001 mean winter ice thickness.
Hydrological cycle in the upper Mississippi River basin: 20th century simulations by multiple GCMs
Authors: Takle Eugene S. , Jha Manoj , Anderson Christopher J.
Published: September 2005

We used 20th century simulations by nine global climate models (GCMs) to provide input for a streamflow model to simulate baseline hydrologic conditions in the Upper Mississippi River Basin (UMRB). Statistical tests revealed that streamflow data produced by members of the GCM multi‐model ensemble were serially uncorrelated at all lags and formed unimodal distributions and that GCM multi‐model results may be used to assess annual streamflow in the UMRB. Although all low‐resolution GCMs produced large differences from observations of streamflow and hydrological components simulated by the streamflow model, the nine‐member ensemble performed quite well. Results of statistical tests indicate that, of all models used, the high‐resolution GCM – the only high‐resolution model tested – gives simulated streamflows much closer to observed values, despite the fact that its low‐resolution sister model has no advantage over the other seven low‐resolution models.
Estimated solar contribution to the global surface warming using the ACRIM TSI satellite composite
Authors: Scafetta N. , West B. J.
Published: September 2005

We study, by using a wavelet decomposition methodology, the solar signature on global surface temperature data using the ACRIM total solar irradiance satellite composite by Willson and Mordvinov. These data present a +0.047%/decade trend between minima during solar cycles 21–23 (1980–2002). We estimate that the ACRIM upward trend might have minimally contributed ∼10–30% of the global surface temperature warming over the period 1980–2002.
DCXNET: E-Transformation at DaimlerChrysler
Authors: Klein Arnd , Krcmar Helmut
Published: September 2005

In 1999, the automotive industry was in a difficult situation: overcapacity and customer demand for faster delivery and better service drove executives to explore the potential business value of the internet. The authors provide a teaching case, which is based on an analysis of the DCXNET initiative which bundled all e-business actions taken by DaimlerChrysler to exploit the opportunities of this then new technology. The teaching case describes the strategic planning process for e-business at DaimlerChrysler, resulting organizational structures and an outline of the components of DCXNET. Furthermore, the authors provide results of the initiative, success factors and lessons learned.
A study of molecular vibrational relaxation mechanism in condensed phase based upon mixed quantum-classical molecular dynamics. I. A test of IBC model for the relaxation of a nonpolar solute in nonpolar solvent at high density
Authors: Sato Masahiro , Okazaki Susumu
Published: September 2005

In order to investigate vibrational relaxation mechanism in condensed phase, a series of mixed quantum-classical molecular dynamics calculations have been executed for nonpolar solute in nonpolar solvent and polar solute in polar solvent. In the first paper (Paper I), relaxation mechanism of I2 in Ar, where Lennard-Jones force is predominant in the interaction, is investigated as a function of density and temperature, focusing our attention on the isolated binary collision (IBC) model. The model was originally established for the relaxation in gas phase. A key question, here, is “can we apply the IBC model to the relaxation in the high-density fluid?” Analyzing the trajectory of solvent molecule as well as its interaction with the solute, we found that collisions between them may be defined clearly even in the high-density fluid. Change of the survival probability of the vibrationally first excited state on collision was traced. The change caused by collisions with a particular solvent molecule was also traced together with the interaction between them. Each collision makes a contribution to the relaxation by a stepwise change in the probability. The analysis clearly shows that the relaxation is caused by collisions even in the high-density fluid. The difference between stepwise relaxation and the continuous one found for the total relaxation in the low-density fluid and in the high-density one, respectively, was clarified to come from just the difference in frequency of the collision. The stronger the intensity of the collision is, the greater the relaxation caused by the collision is. Further, the shorter the collision time is, the greater the resultant relaxation is. The discussion is followed by the succeeding paper (Paper II), where we report that molecular mechanism of the relaxation of a polar molecule in supercritical water is significantly different from that assumed in the IBC model despite that the density dependence of the relaxation rate showed a linear correlation with the local density of water around the solute, the linear correlation being apparently in good accordance with the IBC model. The puzzle will be solved in Paper II.