bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection Procedures with Frequentist Expected Opportunity Cost Bounds
Authors: Chick Stephen E. , Wu Yaozhong
Published: October 2005

Selection procedures help identify the best of a finite set of simulated alternatives. Most work has measured the quality of a selection with the probability of correct selection, P(CS), but the expected opportunity cost of a potentially incorrect decision makes more sense in business contexts. This paper analyzes the first selection procedures that guarantee an upper bound for the expected opportunity cost, in a frequentist sense, of a potentially incorrect selection. The paper therefore bridges a gap between the indifference-zone approach (with frequentist guarantees, but for the P(CS)) and the Bayesian approach to selection procedures (which has considered the opportunity cost). We also provide “unexpected” expected opportunity cost guarantees for several existing indifference-zone selection procedures that were originally designed to provide P(CS) guarantees.
Dynamic Power Control in a Wireless Static Channel Subject to a Quality-of-Service Constraint
Authors: Ata Barιş
Published: October 2005

A controller dynamically chooses a state-dependent transmission rate on a static, point-to-point wireless link by varying transmission power over time. The transmitter is modeled as a finite-buffer Markovian queue with adjustable service rates. That is, data packets arrive to the system according to a Poisson process, and packet size is exponentially distributed. The controller chooses a transmission rate from a fixed set A of available values, depending on the backlog in the system. The objective is to minimize long-run average energy consumption subject to a quality-of-service constraint, which is expressed as an upper bound on the packet drop rate. An explicit formula is developed for the optimal transmission rate as a function of the packet queue length.
A Stochastic Salvo Model for Naval Surface Combat
Authors: Armstrong Michael J.
Published: October 2005

In this paper, we propose a stochastic version of the salvo model for modern naval surface combat. We derive expressions for the mean and variance of surviving force strengths and for the probabilities of the possible salvo outcomes in forms simple enough to be implemented in spreadsheet software. Numerical comparisons of the deterministic and stochastic models indicate that while the two models tend to provide similar estimates of the average number of ships surviving a salvo, this average by itself can be highly misleading with respect to the likely outcomes of the battle. Our results also suggest that a navy’s preferences for risk (variability) and armament (offensive versus defensive) will depend on not only its mission objectives but also on whether it expects to fight from a position of strength or of weakness.
A Unified Mathematical Programming Framework for Different Statistical Disclosure Limitation Methods
Authors: Salazar-González Juan-José
Published: October 2005

This paper concerns statistical disclosure control methods to minimize information loss while keeping small the disclosure risk from different data snoopers. This issue is of primary importance in practice for statistical agencies when publishing data. It is assumed that the sensitive data have been identified by practitioners in the statistical offices, and the paper addresses the secondary problem of protecting these data with different methods, all defined in a unified mathematical framework. A common definition of protection is used in four different methodologies. Two integer linear programming models described in the literature for the cell suppression methodology are extended to work also for the controlled rounding methodology. In addition, two relaxed variants are presented using two associated linear programming models, called partial cell suppression and partial controlled rounding, respectively. A final discussion shows how to combine the four methods and how to implement a cutting-plane approach for the exact and heuristic resolution of the combinatorial problems in practice. This approach was implemented in ARGUS, a software package of disclosure limitation tools.
Bounding Distributions for the Weight of a Minimum Spanning Tree in Stochastic Networks
Authors: Hutson Kevin R. , Shier Douglas R.
Published: October 2005

This paper considers the problem of determining the distribution of the weight W of a minimum spanning tree for an undirected graph with edge weights that are independently distributed discrete random variables. Using the underlying fundamental cutsets and cycles associated with a spanning tree, we are able to obtain upper and lower bounds on the distribution of W. In turn, these are used to establish bounds on E[W]. Our general method for deriving these bounding distributions subsumes existing approximation methods in the literature. Computational results indicate that the new approximation methods provide excellent bounds for some challenging test networks.
Serial Agile Production Systems with Automation
Authors: Hopp Wallace J. , Iravani Seyed M. R. , Shou Biying
Published: October 2005

To gain insights into the design and control of manufacturing cells with automation, we study simple models of serial production systems where one flexible worker attends a set of automated stations. We (a) characterize the operational benefits of automation, (b) determine the most desirable placement of automation within a line, and (c) investigate how best to allocate labor dynamically in a line with manual and automatic equipment. We do this by first considering two-station Markov decision process models and then studying three-station simulations. Our results show that the capacity of production lines with automatic machines can be significantly lower than the rate of the bottleneck. We also show that automating a manual machine can have a dramatic effect on the average work-in-process (WIP) level, provided that labor is the system bottleneck. Once a machine becomes the bottleneck, the benefits from further automation are dramatically reduced. In general, we find that automation is more effective when placed toward the end of the line rather than toward the front. Finally, we show that automation level increases the priority workers should give to a station when selecting a work location.
A Two-Sided Optimization for Theater Ballistic Missile Defense
Authors: Brown Gerald , Carlyle Matthew , Diehl Douglas , Kline Jeffrey , Wood Kevin
Published: October 2005

We describe JOINT DEFENDER, a new two-sided optimization model for planning the pre-positioning of defensive missile interceptors to counter an attack threat. In our basic model, a defender pre-positions ballistic missile defense platforms to minimize the worst-case damage an attacker can achieve; we assume that the attacker will be aware of defensive pre-positioning decisions, and that both sides have complete information as to target values, attacking-missile launch sites, weapon system capabilities, etc. Other model variants investigate the value of secrecy by restricting the attacker’s and/or defender’s access to information. For a realistic scenario, we can evaluate a completely transparent exchange in a few minutes on a laptop computer, and can plan near-optimal secret defenses in seconds. JOINT DEFENDER’s mathematical foundation and its computational efficiency complement current missile-defense planning tools that use heuristics or supercomputing. The model can also provide unique insight into the value of secrecy and deception to either side. We demonstrate with two hypothetical North Korean scenarios.
A 12‐month follow‐up study of self‐management training for people with chronic disease: Are changes maintained over time?
Authors: Barlow J. H. , Wright C. C. , Turner A. P. , Bancroft G. V.
Published: October 2005

Objective. A previous study reported some improved outcomes at 4‐month follow‐up after attendance on a lay‐led, chronic disease self‐management course (CDSMC). The purpose of this study was to determine whether changes were maintained over time (i.e. at 12 months) and to describe participants' current use of self‐management techniques.

Design. The study was a 12‐month follow‐up of a sample of 171 participants who attended a CDSMC in the UK.

Method. Data were collected by self‐administered questionnaires mailed to participants 12 months after they commenced a CDSMC and via telephone interviews with a sub‐sample.

Results. The sample had a mean age of 54 years, mean disease duration of 16 years, 73% were women, and chronic diseases included endometriosis, depression, diabetes, myalgic encephalomyelitis, osteoporosis and polio. The significant improvements in outcomes identified at 4 months (i.e. cognitive symptom management, self‐efficacy, communication with physician, fatigue, anxious and depressed moods and health distress) were sustained at 12 months. No significant changes between 4‐ and 12‐month assessments were found on any study variables. Interview data confirmed that participants continued to use some of the self‐management techniques learned on the course.

Conclusion. Attendance on the CDSMC may lead to longer‐term changes in key outcomes such as self‐efficacy, use of some self‐management behaviours and some aspects of health status (e.g. fatigue, depressed mood).
Early treatment response as a predictor of ongoing weight loss in obesity treatment
Authors: Stotland S. C. , Larocque M.
Published: October 2005

Objectives. This study examined early treatment response in obesity treatment, defined as early change in body mass index (BMI) and early change in eating behaviour, as a predictor of ongoing weight loss in obese patients.

Methods.  We conducted a repeated measures analysis of eating behaviour, emotional factors (depression, stress, perfectionism) and BMI, over a 9 month period. Subjects were 344 females, aged 18–65 (mean = 41.8), with a BMI of at least 25 (mean BMI = 33.7), engaged in very‐low calorie (VLCD) or low‐calorie (LCD) diets.

Results. Multi‐level modelling identified four significant predictors of ongoing weight loss (weight loss occurring between 5 weeks and 9 months after the start of treatment). These included: type of diet, early BMI change (start to 5 weeks), number of weigh‐ins and the early change in uncontrolled eating (start to 5 weeks). Estimates based on multi‐level modelling indicate that patients with strong versus weak early treatment responses would be expected to show large differences in ongoing weight loss.

Conclusions. Early improvements in eating behaviour and weight appear to have additive effects in the prediction of ongoing weight change. Future research is required to identify the optimal rate of weight loss, whether there are critical periods for behaviour change, and factors which influence the likelihood of early behaviour change.
Health of people with intellectual disabilities: A review of factors influencing access to health care
Authors: Ruddick Loraine
Published: October 2005

The rights and needs of people with intellectual disabilities are being acknowledged within Department of Health policies. In spite of this, however, it is frequently cited that people with intellectual disabilities are vulnerable to many health problems but have poor access to health‐related services. There are many factors that can act as barriers to people with intellectual disabilities enjoying good health and accessing services. These include: (a) a lack of clarity regarding responsibilities for ensuring that health policies are operationalized; (b) social and residential aspects of life being emphasized within the quality of life framework for evaluating services for people with intellectual disabilities, with health as an under‐represented domain; (c) a lack of reliable and valid measures that can be used with carers and people with intellectual disabilities to explore health, particularly in comparison to literature on the general population; (d) potential communication difficulties (between the person with intellectual disabilities, their carers and health staff) that can impact on decision‐making processes from early identification of health problems through to the stage of gaining appropriate treatment. These areas are discussed giving rise to questions and challenges for policy makers, researchers and clinicians.
Goal disturbance predicts health‐related quality of life and depression 4 months after myocardial infarction
Authors: Boersma Sandra N. , Maes Stan , van Elderen Thérèse
Published: October 2005

Objectives.The aim of this longitudinal study was to determine whether the event of a myocardial infarction (MI) would lead to a disturbance in important higher‐order goals, and whether goal disturbance could predict health‐related quality of life (HRQL) and depression 4 months later, in addition to baseline scores, demographic characteristics, presence of anginal complaints (AP) or chest pain, coping strategies and social support.

Method.A total of 113 MI patients completed questionnaires shortly after hospitalization (T1) and 4 months later (T2), assessing (an impact of the event on) important higher‐order goals (T1), disease‐related coping strategies (T1), perceived adequacy of social support (T2), AP (T2), HRQL, and depression (T2). Two separate hierarchical regression analyses were performed with HRQL and depression at T2 as dependent variables.

Results.The results suggest that the experience of an MI has an impact on the attainment of higher‐order goals. Goal disturbance is an independent predictor of both HRQL and depression after MI.

Conclusion.A goal theory perspective can provide additional insights into HRQL outcomes after an MI.
Where Is Guantanamo?
Authors: Kaplan Amy
Published: October 2005

This essay argues that Guantánamo lies at the heart of the American Empire. The legal status of the prisoners there must be understood in the context of an imperial history that dates back to the U.S. occupation of Cuba in 1898. This history explains how the U.S. Naval Station, Guantánamo Bay, Cuba, has become an ambiguous space, both inside and outside national and juridical borders and how this ambiguity reinforces the harsh penal regime. The essay argues that the legacies of U.S. imperialism inform key contemporary debates about Guantánamo: the question of national sovereignty, the codification of the prisoners as "enemy combatants," and the uncertainty about whether the U.S. Constitution holds sway there. Turning to the 2004 Supreme Court decision, Rasul v. Bush, the essay argues that the justices are not only interested in restraining executive power to bring Guantánamo within the rule of domestic law; they also show concern with the scope of U.S. power in the world and the extent to which the judiciary should accompany or limit U.S. military rule abroad. A close reading of the Supreme Court's decision and dissent shows that the logic and rhetoric of Rasul v. Bush rely on and perpetuate the imperial history the decision also elides. In concert other recent decisions about civil liberties and national security, Rasul v. Bush contributes to the global expansion of U.S. power by reworking the earlier history of imperial rule. The Court's legal decisions respond to the changing demands of empire today by creating new categories of persons before the law that extend far beyond Guantánamo Bay, Cuba.
Liberation under Siege: U.S. Military Occupation and Japanese Women's Enfranchisement
Authors: Yoneyama Lisa
Published: October 2005

"Liberation under Siege" analyzes knowledge produced about Japanese womenÕs enfranchisement under U.S. military occupation, 1945-52. American popular memory remembers that Douglas MacArthur "liberated" Japanese women but forgets that the space in which Japanese womenÕs civil rights was realized was one of un-freedom and non-rights. The article reveals the ways in which mainstream and other U.S. media representations over the transwar decade (from 1940 through 1955) contributed to the initial knowledge formation regarding how Japanese women obtained legal and other rights while under occupation. Relying on the critiques of liberal and radical feminisms by Third World and other feminists of color, the article demonstrates that the knowledge that uni-dimensionally celebrates the U.S. liberation of Japanese women while obscuring the reality of military occupation was in large part facilitated by what might best be termed a cold war feminism. Prescribing equal opportunity for women while insisting on a pure notion of gender and the disavowal of race, class, colonial, and other social relations, this feminism ultimately allowed the United States to assert itself as the liberator and rehabilitator of the defeated enemy while masking the paradox of the simultaneity of violence and benevolence. Moreover, cold war feminismÕs representation of Japanese womenÕs liberation was intimately tied to the American audienceÕs subjecthood: the presence of "Japanese women" helped contain "American women" domestically while centering them securely within cold war global politics. Finally, the article demonstrates that the knowledge concerning Japanese womenÕs enfranchisement has enduring ideological effects as it continues to be mobilized in the current post-9/11 milieu. Popular memories of Japanese womenÕs enfranchisement reinforces the belief that U.S. military operations serve the purpose of rescue and rehabilitation, so much so that they remain vital to the production of U.S. "just war" narratives. In order to undo this myth that propels us into wars and military occupations, it is crucial to remember that the celebrated space of womenÕs liberation was simultaneously one of liminality, a legal borderland in which U.S. sovereignty asserted itself by both suspending and granting the rights of people under siege.
From Hierarchy to Network: a richer view of evidence for evidence-based medicine
Authors: Bluhm Robyn
Published: October 2005

Evidence-based medicine (EBM) advocates the improvement of patient care through the use of current best research evidence in medical decision making. In practice, "best evidence" generally refers to where a study fits on a hierarchy of evidence, which places randomized controlled trials (RCTs) and other population-level research above laboratory research. Because population research is concerned primarily with average results obtained from large groups of people, ranking evidence on the basis of its place in the hierarchy is shortsighted and ultimately limits the ability of research results to inform the care of individual patients. The history and methodology of epidemiology reveals a close relationship between population-level and laboratory research; both types of research are necessary if we are to understand the causes of a disease. What EBM does not take into account in its hierarchy of evidence is that the same thing is true for research on the safety and efficacy of medical interventions. To maximize the information that clinical research can provide for clinical care, RCTs should be designed to elucidate within-group variability. This can only be done if the hierarchy of evidence is replaced by a network that takes into account the relationship between epidemiological and laboratory research.
The Randomized Controlled Trial: gold standard, or merely standard?
Authors: Grossman Jason , Mackenzie Fiona J
Published: October 2005

The randomized controlled trial (RCT) is not a gold standard: it is a good experimental design in some circumstances, but that's all. Potential shortcomings in the design and implementation of RCTs are often mentioned in passing, yet most researchers consider that RCTs are always superior to all other types of evidence. This paper examines the limitations of RCTs and shows that some types of evidence commonly supposed to be inferior to all RCTs are actually superior to many. This has important consequences for research methodology, for quality of care in clinical medicine, and—especially—for research funding policy. Because every study design may have problems in particular applications, studies should be evaluated by appropriate criteria, and not primarily according to the simplistic RCT/non-RCT dichotomy promoted by some prominent advocates of the evidence-based medicine movement and by the research evaluation guidelines based on its principles.
Independent Validation of Candidate Breast Cancer Serum Biomarkers Identified by Mass Spectrometry
Authors: Li Jinong , Orlandi Rosaria , White C Nicole , Rosenzweig Jason , Zhao Jing , Seregni Ettore , Morelli Daniele , Yu Yinhua , Meng Xiao-Ying , Zhang Zhen , Davidson Nancy E , Fung Eric T , Chan Daniel W
Published: October 2005

Background: We previously selected a panel of 3 breast cancer biomarkers (BC1, BC2, and BC3) from serum samples collected at a single hospital based on their collective contribution to the optimal separation of breast cancer patients and noncancer controls by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The identities and general applicability of these markers, however, were unknown. In this study, we performed protein expression profiling on samples obtained from a second hospital, included a greater number of ductal carcinoma in situ (DCIS) cases, and performed purification and identification of the 2 confirmed markers.

Methods: Using a case–control study design, we performed protein expression profiling on serum samples from the National Cancer Institute (Milan, Italy). The validation sample cohort consisted of 61 women with locally invasive breast cancer, 32 with DCIS, 37 with various benign breast diseases (including 13 atypical), and 46 age-matched apparently healthy women (age range, 44–68 years). Validated biomarkers were purified and identified with serial chromatography, 1-dimensional gel electrophoresis, in-gel ASP-N digestion, peptide mass fingerprinting, and tandem mass peptide sequencing.

Results: The BC3 and BC2 expression patterns in this sample set were consistent with the first study sample set. BC3 and BC2 were identified to be complement component C3adesArg and a C-terminal–truncated form of C3adesArg, respectively.

Conclusions: Evaluation of biomarkers in independent sample sets can help determine the broader utility of candidate markers, and protein identification permits understanding of their molecular basis. C3adesArg appears to lack specificity among patients with benign diseases, limiting its utility as a stand-alone tumor marker, but it may still be useful in a multimarker panel for early detection of breast cancer.
Estimating the Time of Last Cannabis Use from Plasma Δ9-Tetrahydrocannabinol and 11-nor-9-Carboxy-Δ9-Tetrahydrocannabinol Concentrations
Authors: Huestis Marilyn A , Barnes Allan , Smith Michael L
Published: October 2005

Background: Knowing the time cannabis was last used is important for determining impairment in accident investigations and clinical evaluations. Two models for predicting time of last cannabis use from single plasma cannabinoid concentrations—model I, using Δ9-tetrahydrocannabinol (THC), and model II, using the concentration ratio of 11-nor-9-carboxy-THC (THCCOOH) to THC—were developed and validated from controlled drug administration studies. Objectives of the current study were to extend the validation by use of a large number of plasma samples collected after administration of single and multiple doses of THC and to examine the effectiveness of the models at low plasma cannabinoid concentrations.

Methods: Thirty-eight cannabis users each smoked a 2.64% THC cigarette in the morning, and 30 also smoked a second cigarette in the afternoon. Blood samples (n = 717) were collected at intervals after smoking, and plasma THC and THCCOOH concentrations measured by gas chromatography–mass spectrometry. Predicted times of cannabis smoking, based on each model, were compared with actual smoking times.

Results: The most accurate approach applied a combination of models I and II. For all 717 plasma samples, 99% of predicted times of last use were within the 95% confidence interval, 0.9% were overestimated, and none were underestimated. For 289 plasma samples collected after multiple doses, 97% were correct with no underestimates. All time estimates were correct for 76 plasma samples with THC concentrations between 0.5 and 2 μg/L, a concentration range not previously examined.

Conclusions: This study extends the validation of the predictive models of time of last cannabis use to include multiple exposures and low THC concentrations. The models provide an objective and validated method for assessing the contribution of cannabis to accidents or clinical symptoms.
Lipoprotein-Associated Phospholipase A2 Activity Is a Marker of Small, Dense LDL Particles in Human Plasma
Authors: Gazi Irene , Lourida Evangelia S , Filippatos Theodosios , Tsimihodimos Vasilis , Elisaf Moses , Tselepis Alexandros D
Published: October 2005

Background: Recent clinical studies showed that lipoprotein-associated phospholipase A2 (Lp-PLA2) is a predictor for incident atherosclerotic disease. We have previously shown that among the LDL subfractions, Lp-PLA2 activity is preferentially associated with the atherogenic small, dense (sdLDL) particles in vitro. We investigated whether Lp-PLA2 could be a marker of sdLDL in human plasma.

Methods: One hundred and seventy-six individuals participated in the study. LDL subclass analysis was performed by polyacrylamide gel electrophoresis. Lp-PLA2 activity and mass were determined in total plasma and in apolipoprotein B-depleted plasma (HDL-Lp-PLA2). Non–HDL-Lp-PLA2 activity and mass were calculated by subtracting the HDL-Lp-PLA2 from total plasma Lp-PLA2.

Results: On the basis of the LDL subclass analysis, participants were categorized into phenotype A and non-A (total cholesterol mass of the sdLDL subfractions ≤0.155 and >0.155 mmol/L, respectively). Unlike total plasma Lp-PLA2 mass, total plasma Lp-PLA2 activity and non–HDL-Lp-PLA2 activity and mass were significantly higher in persons with phenotype non-A compared with persons with phenotype A, whereas HDL-Lp-PLA2 activity and mass were lower in persons with phenotype non-A compared with phenotype A. Total plasma activity and non–HDL-Lp-PLA2 activity and mass, but not Lp-PLA2 mass, were correlated with sdLDL-cholesterol mass, proportion, and mean LDL particle size. In multiple regression analysis, total plasma and non–HDL-Lp-PLA2 activities were the second best predictors of the presence of sdLDL particles in human plasma after serum triglyceride concentrations. At serum triglyceride concentrations >1.356 mmol/L, total plasma and non–HDL-Lp-PLA2 activity added significantly to the prediction of the presence of sdLDL in plasma.

Conclusions: Lp-PLA2 activity, but not the enzyme mass, is a marker of sdLDL in human plasma.
Petroleum, Enhanced Oil Recovery
Authors: Borchardt John K.
Published: October 2005

The petroleum industry is becoming ever more dependent on increasing oil production from existing oil fields beyond the recovery in primary production and water flooding. Enhanced oil recovery employs various chemicals to increase the reservoir volume contracted by oil well injected fluids, ie, to increase the volumetric sweep efficiency, and thus increase production. Increases in the oil displacement efficiency can be brought about by a variety of mechanisms. The primary processes used to increase oil displacement efficiency are miscible gas flooding and steam flooding. Micellar polymer flooding and alkaline flooding may also be used. Miscible gas flooding most often employs carbon dioxide and/or hydrocarbon gases. Polymer flooding increases the volumetric sweep efficiency of waterflooding. The two most commonly used polymers used are partially hydrolyzed polyacrylamides and xanthan gum. Polymer injection followed byin situcross‐linking reduces the permeability of fractures and rock thief zones increasing volumetric sweep efficiency. Injection of surfactants and noncondensible gases to generate foamin situalso increases volumetric sweep efficiency.
Mass Spectrometry
Authors: de Hoffmann Edmond
Published: October 2005

Mass spectrometry is a technique which involves measurements of mass‐to‐charge ratios of the ions formed when a sample is ionized. The types of spectrometers are discussed, as are the ionization techniques and types of mass spectrometers used to solve analytical problems in biotechnology, environmental studies, polymer chemistry, forensics and inorganic applications. Detailed descriptions of instrumental components, the various ion paths, and data analyses are presented. Mass spectrometers for tandem mass spectrometry are discussed. The methodologies used to interface hplc and other separations systems to mass spectrometers are described.
Titanium Compounds, Organic
Authors: Putzig Donald E. , Moncarz Jillian R.
Published: October 2005

Organic titanium compounds are materials having a covalent bond between titanium and another atom that is also bonded to a carbon‐based group. Titanium tetrachloride, the basic raw material from which organic titanate compounds are made, is readily converted to tetraisopropyl titanate, TYZOR TPT, by the Nelles process. This ester can be converted by alkoxy exchange (transesterification) to a wide variety of tetraalkyl titanates, which in turn react with other ligands and chelating agents to give complexes having properties significantly different from the starting materials. This article covers all aspects of the organic titanium compound, from properties, reactions, and synthesis, to uses and health and safety factors.
Polyester Fibers
Authors: Hansen Steven , Atwood Kenneth B.
Published: October 2005

Polyester fiber is the largest volume, most versatile synthetic fiber in the world. Useful textile fibers of poly(ethylene terephthalate) (PET) were invented in the 1940s and commercially introduced by Du Pont and ICI in the 1950s. A broad range of PET processing options allows the fiber to be engineered for a variety of uses by modifying the filament size, cross‐sectional shape, polymer molecular weight, tensile strength, composition, dyeability, luster, and color, as well as other fiber properties. Poly(ethylene terephthalate) is produced by ester interchange of dimethyl terephthalate and ethylene glycol to form a monomer, or by direct esterification of terephthalic acid with ethylene glycol to form an oligomer. The low molecular weight monomer or oligomer is polycondensed at high temperature and reduced pressure to form a PET polymer.

Polyester is melt‐spun over a wide range of spinning speeds depending on the desired use. The mechanical and thermal properties of PET fiber are affected by the degree of molecular orientation and crystallinity, which depend on the fiber formation process used. At low spinning speeds, fibers are usually further drawn to obtain useful tensile properties. At high spinning speeds, useful PET yarns can be obtained directly. Additional processing steps, including drawing, thermal treatment, texturing, and others, significantly influence the fiber physical properties and applications.
Particle Size Measurement
Authors: Trottier Remi , Wood Stewart
Published: October 2005

The size distribution of particles is of importance to a wide variety of particulate systems in the chemical process industries. The compacting and sintering behavior of metallurgical powders, flow characteristics of granular materials, hiding power of paint pigments, and the combustion efficiency of coal and sprayed liquids all depend on particle size. The various means of data representation in particle size measurements are defined and sampling procedures are presented. Methods of size measurement ranging from the historical yet still useful sieving, through the use of modern instrumentation such as laser diffraction equipment and optical counters, are discussed.
Entropy maximization as a holistic design principle for complex optimal networks
Authors: Venkatasubramanian Venkat , Politis Dimitris N. , Patkar Priyan R.
Published: October 2005

A general holistic theory is presented for the organization of complex networks. The theory proposes that complex networks, both human‐engineered and naturally evolved, are organized to meet certain design or survival objective(s) for a wide variety of operating or environmental conditions. Using the concepts of “value ” of interactions and “satisfaction ” in a network as generic performance measures, we show that the underlying organizing principle is to meet an overall performance target for a wide variety of operating environments as the design objective. This design requirement for reliable performance under maximum uncertainty leads to the emergence of power laws as a consequence of the Maximum Entropy Principle. The theory also predicts the emergence of exponential and Poisson distribution regimes as a function of the redundancy of the network, thus explaining all three regimes as different manifestations of the same underlying phenomenon within a unified theoretical framework. © 2005 American Institute of Chemical Engineers AIChE J, 2006
Mass transfer during drop formation on the nozzle: New flow expansion model
Authors: Javadi A. , Bastani D. , Taeibi‐Rahni M.
Published: October 2005

An attempt was made to introduce a new approach for evaluating mass transfer during drop formation via definition of a parameter related to the extent of the convective mixing within the growing drop. For this purpose it was assumed that the entrance of the dispersed flow into the growing drop from the nozzle is analogous to the entrance of the flow from a smaller channel to a larger one. This transfer mechanism has been dubbed the “flow expansion.” A global time‐dependent Reynolds number of growing drop (Regd) was defined based on the equivalent diameter of growing drop as a length scale and also on a velocity scale, which is obtained using this flow expansion assumption. The results show that (Regd) has an important role on the mass transfer coefficient. The results of the model for prediction of instantaneous mass transfer coefficients and total cumulative mass transfer demonstrated relatively good agreements with experimental data. In some cases, however, for large nozzle diameter and relatively low nozzle velocity, i.e. in cases with large nozzle time scale (TN = RN / UN), the flow expansion model showed some shortcomings. Subsequently, a modification called the transient flow expansion model was introduced which could improve the results of the previous model for large TN cases. Comparison of the results of the transient flow expansion model with experimental data reported in the literature showed relatively good agreement for a wide range of operational conditions: nozzle diameter, nozzle velocity, final formation time and various liquid‐liquid systems. The capabilities of the model were also evaluated in comparison with other well‐known analytical (surface stretch and the fresh surface elements) and semi‐empirical models, along with available experimental data. The comparison of the model with the previous incorporated convection/circulating models demonstrated a high potential for this new approach. © 2005 American Institute of Chemical Engineers AIChE J, 2006
The effect of oxygen on chemotaxis to naphthalene by Pseudomonas putida G7
Authors: Law Aaron M.J. , Aitken Michael D.
Published: October 2005

Chemotactic bacteria can be attracted to electron donors they consume. In systems where donor is heterogeneously distributed, chemotaxis can lead to enhanced removal of donor relative to that achieved in the absence of chemotaxis. However, simultaneous consumption of an electron acceptor may result in the formation of an acceptor gradient to which the bacteria also respond, thus diminishing the positive effect of chemotaxis. Depletion of an electron acceptor can also reduce the rate of electron donor consumption in addition to its effect on chemotaxis. In this study, we examined the effect of oxygen on chemotaxis to naphthalene and on naphthalene consumption by Pseudomonas putida G7. The organism was able to move up an oxygen gradient when there was a naphthalene gradient in the opposite direction. In the absence of an oxygen gradient, low levels of oxygen attenuated chemotaxis to naphthalene but did not affect random motility. The rate of naphthalene consumption decreased at dissolved oxygen concentrations similar to those at which chemotaxis was attenuated. These results suggest that low dissolved oxygen concentrations can reduce naphthalene removal by P. putida G7 in systems where naphthalene is heterogeneously distributed by simultaneously attenuating chemotactic motion toward naphthalene and decreasing the rate of naphthalene degradation. © 2005 Wiley Periodicals, Inc.
Surface‐Functionalized Latex Particles as Controlling Agents for the Mineralization of Zinc Oxide in Aqueous Medium
Authors: Muñoz‐Espí Rafael , Qi Yun , Lieberwirth Ingo , Gómez Clara M. , Wegner Gerhard
Published: October 2005

Polystyrene latex particles modified at the surface with different hydrophilic functional groups were prepared by miniemulsion polymerization and used as controlling agents in the crystallization of zinc oxide from aqueous medium. The effects of the chemical nature of the surface functionalization and the latex concentration on the crystal growth, morphology, and crystalline structure of the resulting zinc oxide were analyzed. Micro‐ and submicrosized crystals with a broad variety of morphologies depending on the functionalization were obtained. Among the different latexes studied, the acrylic‐acid‐derived particles were shown to be a convenient system for further quantitative investigations. In this case, as the additive concentration increases, the length‐to‐width ratio (aspect ratio) of the crystals decreases systematically. Preferential adsorption of the latex particles onto the fast‐growing faces {001} of ZnO is assumed to follow a Langmuir‐type isotherm, and interaction of the adsorbed particles with the growth centers will reduce the growth rate in [001]. This leads to a quantitative relationship linking the aspect ratio to the latex concentration at constant diameter and surface chemistry of the latex. The dependence of the aspect ratio on charge density of the latex can also be modeled by an algorithm in which attractive forces between the latex particle and the ZnO surface are balanced against repulsive forces of an osmotic nature. The latter are associated with the confined volume between the crystal and latex particle surfaces.
Synthesis of Unsymmetrical Tweezer Receptor Libraries and Identification of Receptors for Lys‐D‐Ala‐D‐Ala in Aqueous Solution
Authors: Shepherd Jon , Gale Tom , Jensen Kim B. , Kilburn Jeremy D.
Published: October 2005

Libraries of “unsymmetrical” tweezer receptors, featuring a guanidinium head group as a carboxylate binding site and two independently synthesized peptidic arms, have been prepared and screened to identify receptors for the N‐Ac‐Lys‐D‐Ala‐D‐Ala tripeptide sequence. The binding properties of one such receptor structure, with dye‐labeled N‐Ac‐Lys‐D‐Ala‐D‐Ala, were investigated. These studies demonstrated that when attached to the solid‐phase, the receptor binds dye‐labeled N‐Ac‐Lys‐D‐Ala‐D‐Ala, in buffered aqueous media, with mM binding affinity.
Human embryonic stem cell genes OCT4, NANOG, STELLAR, and GDF3 are expressed in both seminoma and breast carcinoma
Authors: Ezeh Uche I. , Turek Paul J. , Reijo Renee A. , Clark Amander T.
Published: October 2005

BACKGROUND

The seminoma class of testicular germ cell tumor (TGCT) are characterized by a morphological resemblance to primordial germ cells (PGCs) or gonocytes, and chromosome duplications at 12p. Recently, it was determined that human embryonic stem cells (hESCs) express genes in common with PGCs, and that three of these genes, GDF3, STELLAR, and NANOG, are located on 12p. The current study was designed to identify whether expression of these 12p genes were elevated in seminoma relative to normal testis, and to determine whether elevated expression was unique to seminoma.

METHODS

Real‐time polymerase chain reaction (PCR) and immunohistochemistry were used to assess gene expression in seminoma samples relative to normal testis and endpoint PCR was used to identify the presence or absence of these genes in breast carcinoma.

RESULTS

GDF3 expression was increased in eight of nine seminomas compared with normal testis, whereas NANOG, OCT4, or both were expressed at the highest levels in seminoma compared with all other markers analyzed. In addition, the NANOG protein was expressed in the majority of seminoma cells. The adult meiotic germ cell markers BOULE and TEKT1 were undetectable in seminoma, whereas the embryonic and adult germ cell markers DAZL and VASA were significantly reduced. Analysis of these markers in breast carcinoma and the MCF7 breast carcinoma cell line revealed that a core hESC‐transcriptional profile could be identified consisting of OCT4, NANOG, STELLAR, and GDF3 and that NANOG protein could be detected in breast carcinoma.

CONCLUSIONS

These observations suggest that seminoma and breast carcinoma express a common stem cell profile and that the expression of DAZL and VASA in seminoma mark the germ cell origin of seminoma that is absent in breast carcinoma. Our findings suggest that stem cell genes may either play a direct role in different types of carcinoma progression or serve as valuable markers of tumorigenesis. Cancer 2005. © 2005 American Cancer Society.
The anxiogenic drug yohimbine activates central viscerosensory circuits in rats
Authors: Myers Elizabeth A. , Banihashemi Layla , Rinaman Linda
Published: October 2005

Systemic administration of the α2‐adrenoceptor antagonist yohimbine (YO) activates the HPA stress axis and promotes anxiety in humans and experimental animals. We propose that visceral malaise contributes to the stressful and anxiogenic effects of systemic YO and that YO recruits brainstem noradrenergic (NA) and peptidergic neurons that relay viscerosensory signals to the hypothalamus and limbic forebrain. To begin testing these hypotheses, the present study explored dose‐related effects of YO on food intake, conditioned flavor avoidance (CFA), and Fos immunolabeling in rats. Systemic YO (5.0 mg/kg BW, i.p.) inhibited food intake, supported CFA, and increased Fos immunolabeling in identified NA neurons in the ventrolateral medulla, nucleus of the solitary tract, and locus coeruleus. YO also increased Fos in the majority of corticotropin releasing hormone‐positive neurons in the paraventricular nucleus of the hypothalamus. YO administered at 1.0 mg/kg BW did not inhibit food intake, did not support CFA, and did not increase Fos immunolabeling. Retrograde neural tracing demonstrated that neurons activated by YO at 5.0 mg/kg BW included medullary and pontine neurons that project to the central nucleus of the amygdala and to the lateral bed nucleus of the stria terminalis, the latter region receiving comparatively greater input by Fos‐positive neurons. We conclude that YO produces anorexigenic and aversive effects that correlate with activation of brainstem viscerosensory inputs to the limbic forebrain. These findings invite continued investigation of how central viscerosensory signaling pathways interact with hypothalamic and limbic regions to influence interrelated physiological and behavioral components of anxiety, stress, and visceral malaise. J. Comp. Neurol. 492:426–441, 2005. © 2005 Wiley‐Liss, Inc.
Epidermal growth factor‐dependent enhancement of axonal regeneration in the pond snail Lymnaea stagnalis: Role of phagocyte survival
Authors: Hermann Petra M. , Nicol Jennifer J. , Nagle Gregg T. , Bulloch Andrew G.M. , Wildering Willem C.
Published: October 2005

Peripheral nerve injury triggers complex responses from neuronal as well as from multiple nonneuronal cell types. These responses are coordinated by a wide spectrum of secreted and nonsecreted factors, including growth factors, cytokines, and cell adhesion molecules. These molecules originate from different sources and act both locally at the site of injury as well as centrally at the location of the neuronal cell bodies. One of the signal systems frequently implicated in this process is the epidermal growth factor (EGF) family and its receptors. Expression of members of this family as well as that of EGF‐receptors is upregulated in different cell types after peripheral nerve injury. However, the functional significance of this response is unclear. Using a simple invertebrate model system (Lymnaea stagnalis), the present study implicates the EGF/EGF‐receptor system in the survival of ionized calcium‐binding adaptor molecule 1 (Iba1)‐positive phagocytes that reside in the nervous system. We show that inhibiting the EGF‐signaling pathway enhances cell death in this type of cell, an effect paralleled by a substantial reduction in axonal regeneration. Therefore, complementing our previous observation that Lymnaea EGF provides trophic support to axotomized neurons, the present results emphasize the significance of nonneuronal actions of EGF receptor ligands in axonal regeneration. Thus, we add a novel perspective to the ongoing discussion on the functional significance of the EGF signaling system in the injury responses of the nervous system. J. Comp. Neurol. 492:383–400, 2005. © 2005 Wiley‐Liss, Inc.
Coexpression of vesicular glutamate transporter‐3 and γ‐aminobutyric acidergic markers in rat rostral medullary raphe and intermediolateral cell column
Authors: Stornetta Ruth L. , Rosin Diane L. , Simmons Johnny R. , McQuiston Travis J. , Vujovic Nina , Weston Matthew C. , Guyenet Patrice G.
Published: October 2005

Markers of serotonergic, γ‐aminobutyric acid (GABA)‐ergic (glutamic acid decarboxylase, 67 kDa isoform; GAD‐67), and glutamatergic transmission (vesicular glutamate transporter 3; VGLUT3) have been detected in presumed sympathetic premotor neurons of the medullary raphe, a region that controls sympathetic tone to brown fat, skin blood vessels, and heart. In this study, the degree of coexpression of these markers was examined in raphe neurons by simultaneous histological detection of tryptophan hydroxylase (TrpOH) immunoreactivity with GAD‐67 mRNA and VGLUT3 mRNA. Over half (52%) of the VGLUT3 mRNA‐positive neurons expressed one or both of the other markers. The proportion of VGLUT3 neurons containing at least one of the other two markers was even higher (89%) for VGLUT3 spinally projecting neurons. VGLUT3 neurons containing markers for both serotonin and GABA were especially numerous (50–72%, depending on rostrocaudal level) within the marginal layer of raphe pallidus and the parapyramidal region. The dual GABAergic and glutamatergic nature of some bulbospinal raphe neurons was suggested by the presence of nerve terminals immunoreactive (ir) for both VGLUT3 and GABA in the intermediolateral cell column (IML) as detected by electron microscopy. VGLUT3‐ir terminals formed approximately equal numbers of symmetric and asymmetric synapses onto presumed preganglionic neurons (nitric oxide synthase‐ir profiles) or GABA‐ir dendrites in IML, and terminals immunoreactive for both VGLUT3 and GABA always formed symmetric synapses. These data suggest that medullary raphe VGLUT3 neurons could inhibit sympathetic outflow and that their spinal targets include both preganglionic neurons and GABAergic interneurons. J. Comp. Neurol. 492:477–494, 2005. © 2005 Wiley‐Liss, Inc.