bluuebunny/crossref_metadata_2025 huggingface dataset:
Refinement Types for Logical Frameworks and Their Interpretation as Proof Irrelevance
Authors: Lovas William , Pfenning Frank
Published: September 2011

Refinement types sharpen systems of simple and dependent types by offering
expressive means to more precisely classify well-typed terms. We present a
system of refinement types for LF in the style of recent formulations where
only canonical forms are well-typed. Both the usual LF rules and the rules for
type refinements are bidirectional, leading to a straightforward proof of
decidability of typechecking even in the presence of intersection types.
Because we insist on canonical forms, structural rules for subtyping can now be
derived rather than being assumed as primitive. We illustrate the expressive
power of our system with examples and validate its design by demonstrating a
precise correspondence with traditional presentations of subtyping. Proof
irrelevance provides a mechanism for selectively hiding the identities of terms
in type theories. We show that LF refinement types can be interpreted as
predicates using proof irrelevance, establishing a uniform relationship between
two previously studied concepts in type theory. The interpretation and its
correctness proof are surprisingly complex, lending support to the claim that
refinement types are a fundamental construct rather than just a convenient
surface syntax for certain uses of proof irrelevance.
A Logical Foundation for Environment Classifiers
Authors: Tsukada Takeshi , Igarashi Atsushi
Published: September 2011

Taha and Nielsen have developed a multi-stage calculus {\lambda}{\alpha} with
a sound type system using the notion of environment classifiers. They are
special identifiers, with which code fragments and variable declarations are
annotated, and their scoping mechanism is used to ensure statically that
certain code fragments are closed and safely runnable. In this paper, we
investigate the Curry-Howard isomorphism for environment classifiers by
developing a typed {\lambda}-calculus {\lambda}|>. It corresponds to
multi-modal logic that allows quantification by transition variables---a
counterpart of classifiers---which range over (possibly empty) sequences of
labeled transitions between possible worlds. This interpretation will reduce
the "run" construct---which has a special typing rule in
{\lambda}{\alpha}---and embedding of closed code into other code fragments of
different stages---which would be only realized by the cross-stage persistence
operator in {\lambda}{\alpha}---to merely a special case of classifier
application. {\lambda}|> enjoys not only basic properties including subject
reduction, confluence, and strong normalization but also an important property
as a multi-stage calculus: time-ordered normalization of full reduction. Then,
we develop a big-step evaluation semantics for an ML-like language based on
{\lambda}|> with its type system and prove that the evaluation of a well-typed
{\lambda}|> program is properly staged. We also identify a fragment of the
language, where erasure evaluation is possible. Finally, we show that the proof
system augmented with a classical axiom is sound and complete with respect to a
Kripke semantics of the logic.
Algebraic Notions of Termination
Authors: Jules Desharnais , Moeller Bernhard , Georg Struth
Published: September 2011

Five algebraic notions of termination are formalised, analysed and compared:
wellfoundedness or Noetherity, L\"ob's formula, absence of infinite iteration,
absence of divergence and normalisation. The study is based on modal semirings,
which are additively idempotent semirings with forward and backward modal
operators. To model infinite behaviours, idempotent semirings are extended to
divergence semirings, divergence Kleene algebras and omega algebras. The
resulting notions and techniques are used in calculational proofs of classical
theorems of rewriting theory. These applications show that modal semirings are
powerful tools for reasoning algebraically about the finite and infinite
dynamics of programs and transition systems.
Psi-calculi: a framework for mobile processes with nominal data and logic
Authors: Bengtson Jesper , Johansson Magnus , Parrow Joachim , Victor BjÃ¶rn
Published: September 2011

The framework of psi-calculi extends the pi-calculus with nominal datatypes
for data structures and for logical assertions and conditions. These can be
transmitted between processes and their names can be statically scoped as in
the standard pi-calculus. Psi-calculi can capture the same phenomena as other
proposed extensions of the pi-calculus such as the applied pi-calculus, the
spi-calculus, the fusion calculus, the concurrent constraint pi-calculus, and
calculi with polyadic communication channels or pattern matching. Psi-calculi
can be even more general, for example by allowing structured channels,
higher-order formalisms such as the lambda calculus for data structures, and
predicate logic for assertions. We provide ample comparisons to related calculi
and discuss a few significant applications. Our labelled operational semantics
and definition of bisimulation is straightforward, without a structural
congruence. We establish minimal requirements on the nominal data and logic in
order to prove general algebraic properties of psi-calculi, all of which have
been checked in the interactive theorem prover Isabelle. Expressiveness of
psi-calculi significantly exceeds that of other formalisms, while the purity of
the semantics is on par with the original pi-calculus.
Existential witness extraction in classical realizability and via a negative translation
Authors: Miquel Alexandre
Published: September 2011

We show how to extract existential witnesses from classical proofs using
Krivine's classical realizability---where classical proofs are interpreted as
lambda-terms with the call/cc control operator. We first recall the basic
framework of classical realizability (in classical second-order arithmetic) and
show how to extend it with primitive numerals for faster computations. Then we
show how to perform witness extraction in this framework, by discussing several
techniques depending on the shape of the existential formula. In particular, we
show that in the Sigma01-case, Krivine's witness extraction method reduces to
Friedman's through a well-suited negative translation to intuitionistic
second-order arithmetic. Finally we discuss the advantages of using call/cc
rather than a negative translation, especially from the point of view of an
implementation.
Symbolic and Asynchronous Semantics via Normalized Coalgebras
Authors: Bonchi Filippo , Montanari Ugo
Published: September 2011

The operational semantics of interactive systems is usually described by labeled transition systems. Abstract semantics (that is defined in terms of bisimilarity) is characterized by the final morphism in some category of coalgebras. Since the behaviour of interactive systems is for many reasons infinite, symbolic semantics were introduced as a mean to define smaller, possibly finite, transition systems, by employing symbolic actions and avoiding some sources of infiniteness. Unfortunately, symbolic bisimilarity has a different shape with respect to ordinary bisimilarity, and thus the standard coalgebraic characterization does not work. In this paper, we introduce its coalgebraic models. We will use as motivating examples two asynchronous formalisms: open Petri nets and asynchronous pi-calculus. Indeed, as we have shown in a previous paper, asynchronous bisimilarity can be seen as an instance of symbolic bisimilarity.
The Treatment of Patients with Medically Unexplained Physical Symptoms in China: A Study Comparing Expectations and Treatment Satisfaction in Psychosomatic Medicine, Biomedicine, and Traditional Chinese Medicine
Authors: Fritzsche Kurt , Xudong Zhao , Anselm Kathrin , Kern Stephanie , Wirsching Michael , Schaefert Rainer
Published: September 2011

Objective:

Little is known about treatment for patients with medically unexplained symptoms (MUS) in China. This study investigates the treatment expectations and treatment satisfaction of patients with MUS in psychosomatic medicine, biomedicine, and Traditional Chinese Medicine (TCM).

Method:

In a cross-sectional survey, n = 96 (10.3%) out of 931 participating patients were screened positive for multiple somatoform symptoms. These patients answered questionnaires concerning symptom duration, number of doctor visits, functional impairment, emotional distress, treatment expectations, treatment satisfaction, and empathy in the consultation. The physicians filled in a questionnaire about applied or recommended treatment.

Results:

Most of the patients from psychosomatic medicine wanted psychotherapy. In TCM, 55% of the patients had already received TCM treatment and most of them wanted to continue TCM treatment. Patients in biomedicine did not express clear expectations; most of them had had no previous treatment. A combination of treatment methods was most prevalent in biomedicine in comparison to psychosomatic medicine and TCM. The outcome from the patients' point of view was significantly better in TCM than in psychosomatic medicine and biomedicine. Psychosomatic medicine's strength was the empathetic physician-patient interaction.

Conclusions:

From a bio-psychosocial perspective, these results suggest that various treatment approaches with various emphases can be effective depending on the patient's complaints, his illness beliefs, and what the physician offers. The results will be verified in a larger multicenter longitudinal study.
Canada's AntiForeign Bribery Regime Requires a Balancing Act
Authors: Todgham Cherniak Cyndee D.
Published: September 2011

This article discusses Canada's unique approach to corruption in international business. Although Canada subscribes to the revulsion against corruption felt by its global partners, its anti-bribery laws aim to maintain a balance between the two extremes of putting Canadian businesses at a global disadvantage through impractical regulation and unrestricted freedom of these businesses to ignore Canada's constitutional values. The article concludes that, in spite of the uniqueness of this approach, there is need to recalibrate certain aspects of the regime in order to make it even more efficient.
Measuring Poverty: The Official U.S. Measure and Material Hardship
Authors: Nelson Gesemia
Published: September 2011

Material hardship is a concept that is crucial to our understanding of inequality. I define it as: an inadequate consumption of goods or services that the public deems minimally necessary for decent human functioning. While quantitative poverty research purports to address this concept, it in fact does so only in part. Most discussions of poverty using the official poverty line say nothing about the material situation of the poor. This study rectifies this failing by making material hardship the centerpiece of the analysis. Data from the Survey of Income and Program Participation (SIPP) are used to compare hardship figures with official poverty statistics. Comparisons of the income poor with the hardship poor find that hardship is more prevalent than official poverty figures suggest. The groups who are the worst off according to income‐poverty figures also do pretty poorly under hardship measures. But we also find that groups we generally think of as economically advantaged do suffer hardship at rates more similar to the traditionally disadvantaged groups. Non‐senior adults, married‐couple households, and workers all experience more hardship than official income rates lead us to believe. One important deviation involves seniors, who look much better off under hardship measures. Thus, the poor population that emerges under the hardship measures (younger, married, and working) looks closer to the U.S. mainstream than the official measure has led us to believe.
Provident Funds Pension Programs in English‐Speaking Sub‐Saharan Africa: A Look in the Rear Mirror and Lessons for the Future
Authors: Kpessa Michael W.
Published: September 2011

Pension reform has been on the social policy agenda in many countries throughout the world since the mid‐1980s. The main debate has been whether to transform existing defined benefit pay‐as‐you‐go (PAYG) social insurance programs into private pension plans based on defined contributions or maintains them. While many countries throughout the world especially those in Latin America and Central and Eastern Europe have opted for private pensions involving the partial or full replacement of pay‐as‐you‐go (PAYG) state pensions by systems of privately managed individual retirement accounts, pension reforms in English‐speaking Sub‐Saharan Africa (SSA) countries have focused on converting post‐independence defined contributions schemes known as provident funds into defined benefit PAYG social insurance schemes particularly from the 1990s. This paper analyzes the previous experience of English‐speaking SSA countries with provident funds and show that pension plans that are designed on the principles of defined contribution are evidently venerable to several socio‐economic and political factors especially in the context of developing countries. The paper provides useful lessons for countries like Ghana and Nigeria that have recently re‐introduce defined contribution pension plans.
“Stand Up and Be Counted”: The Politics of a Homeless Enumeration
Authors: Williams Jean Calterone
Published: September 2011

This study analyzes the methodological and political issues associated with homeless enumerations. While enumerations represent just one aspect of homeless politics in the United States, they incorporate many debates that are central to understanding homelessness. How to define homelessness and how to find and account for a transitory, stigmatized population are chief among the quandaries faced by counties undertaking enumerations; the extent of these difficulties calls into question the reliability of enumeration results. In studying one U.S. county's efforts to count the homeless in 2005 and 2009, this paper illuminates the obstacles faced by counties undertaking enumerations, and connects those challenges to broader debates about homelessness and homeless policy making in the United States.
Book Review of A Dream Deferred: How Social Work Education Lost Its Way and What Can Be Done
Authors: Mohan Brij
Published: September 2011

Brij Mohan, Dean Emeritus at Louisiana State University and a member of Poverty and Public Policy's editorial board, reviews this book that is centered around the state of education in the social work field.
Late Graft Loss among Pediatric Recipients of DCD Kidneys
Authors: Van Arendonk Kyle J. , James Nathan T. , Locke Jayme E. , Montgomery Robert A. , Colombani Paul M. , Segev Dorry L.
Published: September 2011

Background and objectives

Kidney transplantation from donors after cardiac death (DCD) provides similar graft survival to donors after brain death (DBD) in adult recipients. However, outcomes of DCD kidneys in pediatric recipients remain unclear, primarily because of limited sample sizes.

Design, setting, participants, & measurements

We identified 137 pediatric (<18 years old) recipients of DCD kidneys between 1994 and 2010 using Scientific Registry of Transplant Recipients data and compared outcomes with 6059 pediatric recipients of DBD kidneys during the same time period, accounting for donor, recipient, and transplant characteristics using time-varying Cox regression and matched controls. Long-term follow-up (4 years or beyond) was available for 31 DCD recipients.

Results

Pediatric recipients of DCD kidneys experienced a significantly higher rate of delayed graft function (22.0% versus 12.3%; P = 0.001), although lower than reported delayed graft function rates of DCD grafts in adults. Although DCD and DBD graft survival was equal in the early postoperative period, graft loss among pediatric recipients of DCD kidneys exceeded their DBD counterparts starting 4 years after transplantation. This effect was statistically significant in a multivariate Cox model (hazard ratio = 2.03; 95% confidence interval, 1.21 to 3.39; P = 0.007) and matched-controls analysis (hazard ratio = 2.36; 95% confidence interval, 1.11 to 5.03; P = 0.03).

Conclusions

A significant increase in DCD graft loss starting 4 years after transplantation motivates a cautious approach to the use of DCD kidneys in children, in whom long-term graft survival is of utmost importance.
Pregnancy Outcomes in Women with Chronic Kidney Disease
Authors: Nevis Immaculate F. , Reitsma Angela , Dominic Arunmozhi , McDonald Sarah , Thabane Lehana , Akl Elie A. , Hladunewich Michelle , Akbari Ayub , Joseph Geena , Sia Winnie , Iansavichus Arthur V. , Garg Amit X.
Published: September 2011

Background and objectives

Pregnant women with chronic kidney disease (CKD) are at risk of adverse maternal and fetal outcomes. We conducted a systematic review of observational studies that described this risk.

Design, setting, participants, & measurements

We searched several databases from their date of inception through June 2010 for eligible articles published in any language. We included any study that reported maternal or fetal outcomes in at least five pregnant women in each group with or without CKD. We excluded pregnant women with a history of transplantation or maintenance dialysis.

Results

We identified 13 studies. Adverse maternal events including gestational hypertension, pre-eclampsia, eclampsia, and maternal mortality were reported in 12 studies. There were 312 adverse maternal events among 2682 pregnancies in women with CKD (weighted average of 11.5%) compared with 500 events in 26,149 pregnancies in normal healthy women (weighted average of 2%). One or more adverse fetal outcomes such as premature births, intrauterine growth restriction, small for gestational age, neonatal mortality, stillbirths, and low birth weight were reported in nine of the included studies. Overall, the risk of developing an adverse fetal outcome was at least two times higher among women with CKD compared with those without.

Conclusions

This review summarizes current available evidence to guide physicians in their decision-making, advice, and care for pregnant women with CKD. Additional studies are needed to better characterize the risks.
Academic Decision Making and Prospect Theory
Authors: Mowrer Robert R. , Davidson William B.
Published: September 2011

Two studies are reported that investigate the applicability of prospect theory to college students' academic decision making. Exp. 1 failed to provide support for the risk-seeking portion of the fourfold pattern predicted by prospect theory but did find the greater weighting of losses over gains. Using a more sensitive dependent measure, in Exp. 2 the results of the first experiment were replicated in terms of the gain-loss effect and also found some support for the fourfold pattern in the interaction between probabilities and gain versus loss. The greatest risk-seeking was found in the high probability loss condition.
Characteristics of the Work Environment Related to Older Employees' Willingness to Continue Working: Intrinsic Motivation as a Mediator
Authors: van Den Berg Peter T.
Published: September 2011

The relationships between older employees' willingness to continue working and characteristics of the work environment for older workers were investigated, as well as a possible mediation by intrinsic motivation. 103 employees ages 50 to 65 years, from various sectors of the Dutch labor market, completed questionnaires that measured willingness to continue working, intrinsic motivation, organizational stimulation, work variety, work challenge, and job autonomy. Hierarchical regression analyses showed organizational stimulation, as well as the various job characteristics, were positively related to employees' willingness to continue working. Moreover, intrinsic motivation fully mediated the relationship of work variety with willingness to continue working and partially mediated the relationships of organizational stimulation, work challenge, and job autonomy with willingness to continue working. It was concluded that organizations can encourage older workers to work until age 65 and beyond by shifting their focus from extrinsic to intrinsic rewards.
Higher Rates of Victimization to Physical Abuse by Adults Found among Victims of School Bullying
Authors: Björkqvist Kaj , Österman Karin , Berg Petra
Published: September 2011

Retrospective reports of exposure to physical abuse by an adult during childhood was assessed in 874 adolescents (426 boys, 448 girls; M age = 11.5 yr., SD = 0.8) who also reported whether they had been victimized by school bullying. Having been hit by an adult was significantly more common among victims of school bullying (39.5%) than among adolescents not victimized by school bullying (16.8%). No sex difference was found. The finding raises questions about whether victimization by physical abuse puts a child at greater risk for developing a “victim personality.”
Distress after a Single Violent Crime: How Shame-Proneness and Event-Related Shame Work Together as Risk Factors for Post-Victimization Symptoms
Authors: Semb Olof , Strömsten Lotta M.J. , Sundbom Elisabet , Fransson Per , Henningsson Mikael
Published: September 2011

To increase understanding of post-victimization symptom development, the present study investigated the role of shame- and guilt-proneness and event-related shame and guilt as potential risk factors. 35 individuals ( M age = 31.7 yr.; 48.5% women), recently victimized by a single event of severe violent crime, were assessed regarding shame- and guilt-proneness, event-related shame and guilt, and post-victimization symptoms. The mediating role of event-related shame was investigated with structural equation modeling (SEM), using bootstrapping. The guilt measures were unrelated to each other and to post-victimization symptoms. The shame measures were highly intercorrelated and were both positively correlated to more severe post-victimization symptom levels. Event-related shame as mediator between shame-proneness and post-victimization symptoms was demonstrated by prevalent significant indirect effects. Both shame measures are potent risk factors for distress after victimization, whereby part of the effect of shame-proneness on post-victimization symptoms is explained by event-related shame.
Chilean Validation of the Posttraumatic Stress Disorder Checklist–Civilian Version (PCL–C) after the Earthquake on February 27, 2010
Authors: Vera-Villarroel Pablo , Celis-Atenas Karem , Córdova-Rubio Natalia , Zych Izabela , Buela-Casal Gualberto
Published: September 2011

Posttraumatic stress disorder (PTSD) is an anxiety disorder in which an individual re-experiences a traumatic event, avoids situations related to it, and shows excessive arousal. The disorder appears after experiencing a life-threatening event, such as a war or a natural disaster. Thus, the validation of tests which assess the disorder after the earthquake on February 27, 2010, in Chile is crucial for its evaluation and subsequent intervention. The present study includes psychometric data for the Posttraumatic Stress Disorder Checklist–Civilian version (PCL–C) on a sample of 509 survivors of the disaster. Values indicate good psychometric properties of the questionnaire.
Cross-National Measure of Fear-Based Xenophobia: Development of a Cumulative Scale
Authors: van der Veer Kees , Yakushko Oksana , Ommundsen Reidar , Higler Laurens
Published: September 2011

To apply a Mokken Scale Procedure in developing a hierarchical cross-national scale to measure xenophobia, a pool of 30 xenophobia-related items was collected from several sources and modified using established unidimensional criteria. The survey was administered to 608 undergraduate students in the USA, 193 undergraduate students in The Netherlands, and 303 undergraduate students in Norway. 14 items measuring perceived threat or fear and meeting the criteria of the Stereotype Content Model were selected for further analysis. A separate item analysis and, subsequently, Mokken Scale Procedure yielded a cumulative scale with the same five items for each of the three samples. The items and the total scale met criteria for homogeneity in all samples with H >….40.
Relationship between Learning Environment Characteristics and Academic Engagement
Authors: Opdenakker Marie-Christine , Minnaert Alexander
Published: September 2011

The relationship between learning environment characteristics and academic engagement of 777 Grade 6 children located in 41 learning environments was explored. Questionnaires were used to tap learning environment perceptions of children, their academic engagement, and their ethnic-cultural background. The basis of the learning environment questionnaire was the International System for Teacher Observation and Feedback (ISTOF). Factor analysis indicated three factors: the teacher as a helpful and good instructor (having good instructional skills, clear instruction), the teacher as promoter of active learning and differentiation, and the teacher as manager and organizer of classroom activities. Multilevel analysis indicated that about 12% of the differences in engagement between children was related to the learning environment. All the mentioned learning environment characteristics mattered, but the teacher as a helpful, good instructor was most important followed by the teacher as promoter of active learning and differentiation.
Fault monitoring and fault recovery control for position-moored vessels
Authors: Fang Shaoji , Blanke Mogens
Published: September 2011

Fault monitoring and fault recovery control for position-moored vessels

This paper addresses fault-tolerant control for position mooring of a shuttle or floating production storage and offloading vessels. A complete framework for fault diagnosis is presented. A loss of a sub-sea mooring line buoyancy element and line breakage are given particular attention, since such failures might cause high-risk abortion of an oil-loading operation. With significant drift forces from waves, non-Gaussian elements dominate forces and the residuals designed for fault diagnosis. Hypothesis testing is designed using dedicated change detection for the type of distribution encountered. A new position recovery algorithm is proposed as a means of fault accommodation in order to keep the mooring system in a safe state, despite faults. The position control is shown to be capable of accommodating serious failures and preventing breakage of a mooring line, or a loss of a buoyancy element, from causing subsequent failures. Properties of the detection and fault-tolerant control algorithms are demonstrated by high fidelity simulations.
Regional control problem for distributed bilinear systems: Approach and simulations
Authors: Ztot Karima , Zerrik El , Bourray Hamid
Published: September 2011

Regional control problem for distributed bilinear systems: Approach and simulations

This paper investigates the regional control problem for infinite dimensional bilinear systems. We develop an approach that characterizes the optimal control and leads to a numerical algorithm. The obtained results are successfully illustrated by simulations.
National Evaluation of Mileage-Based Charges for Drivers
Authors: Hanley Paul F. , Kuhl Jon G.
Published: September 2011

This paper presents initial results and conclusions from the National Evaluation of a Mileage-Based Road User Charge, a 2-year field study conducted by the University of Iowa Public Policy Center. The study, which evaluates technical feasibility and user acceptance of mileage-based charging as a potential replacement for the current motor fuel tax, was authorized by the 2005 Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users, which reauthorized federal transportation funding. This study is the first to examine road user charges on a national and multijurisdictional scale. Approximately 2,650 volunteers from 12 areas throughout the country participated in the study, which concluded in July 2010. The system mileage charges were totaled and apportioned to the federal, state, and local levels with the use of onboard computers installed in participants' vehicles. The onboard computers contained Global Positioning System (GPS) receivers with an associated geographic database to identify the taxing jurisdictions in which the vehicles traveled. The average participant drove approximately 9,000 mi during the study (the study totaled more than 21 million miles). Approximately 92.5% of all driven miles were successfully measured by both the GPS and the onboard diagnostics system (OBD-II). Of the miles driven without GPS, 6.9% could be reliably assigned to jurisdictions by using straightforward interpolation techniques. Approximately 0.6% of total miles driven could not be reliably assigned to a state or local jurisdiction. Participant attitudes regarding the system and the overall concept of mileage-based charging were assessed. At the end of the study, 71% had a highly or somewhat positive view, and 17% held a highly or somewhat negative view. Participants consistently (but to varying degrees) preferred audit ability, which consisted of receiving detailed monthly invoices, over maximum privacy protection.
Cost Estimates for Collecting Fees for Vehicle Miles Traveled
Authors: Rufolo Anthony M.
Published: September 2011

Interest in collecting mileage fees for road usage is growing. However, the cost of collecting fuel taxes is relatively low, while the cost of collecting mileage fees appears to be quite high. There is relatively little actual experience with mileage systems, but information related to the cost of systems for heavy vehicles, experimental systems, and a proposed Dutch system provides a starting point for identifying the key cost components. This paper summarizes cost information from a variety of sources and identifies key areas for cost comparison.
Urban Network Privatization
Authors: Rouhani Omid M. , Niemeier Debbie
Published: September 2011

The majority of recent private facilities are rural highways (outside city boundaries), but privatization of other types of roads could be more beneficial to society. Increasing congestion problems and the existence of transportation modes other than private cars suggest the privatization of urban roads. This study examines the effects of privatization strategies on a simple network with two modes of transportation, such as private cars and buses. With refinement of the general costs of travel, the choice of the links to be privatized, and the enabling policies, a more efficient roadway usage can be achieved. The results from this test network show that (a) in some cases a monopoly ownership performs better than an oligopoly one and (b) privatizing arterials (secondary roads) as well as freeways (primary roads) can lead to lower total costs than privatizing only freeways. This study helps to provide the foundation for more large-scale exploration.
Glioblastoma therapy in the elderly and the importance of the extent of resection regardless of age
Authors: Oszvald Ági , Güresir Erdem , Setzer Matthias , Vatter Hartmut , Senft Christian , Seifert Volker , Franz Kea
Published: September 2011

Object

The objective of this study was to analyze whether age influences the outcome of patients with glioblastoma and whether elderly patients with glioblastoma can tolerate the same aggressive treatment as younger patients.

Methods

Data from 361 consecutive patients with newly diagnosed cerebral glioblastoma (2000–2006) who underwent regular follow-up evaluation from initial diagnosis until death were prospectively entered into a database. Patients underwent resection (complete, subtotal, or partial) or biopsy, depending on tumor size, location, and Karnofsky Performance Scale score. Following surgery, all patients underwent adjuvant treatment consisting of radiotherapy, chemotherapy, or combined treatment. Patients older than 65 years of age were defined as elderly (146 total).

Results

Two hundred thirty-four patients underwent tumor resection (complete 26%, subtotal 29%, and partial 45%). One hundred twenty-seven underwent biopsy. Mean patient age was 61 years, and overall survival was 11.6 ± 12.1 months. The overall survival of elderly patients (9.1 ± 11.6 months) was significantly lower than that of younger patients (14.9 ± 16.7 months; p = 0.0001). Stratifying between resection or biopsy, age was a negative prognostic factor in patients undergoing biopsy (4.0 ± 7.1 vs 7.9 ± 8.7 months; p = 0.007), but not in patients undergoing tumor resection (13.0 ± 8.5 vs 13.3 ± 14.5 months; p = 0.86). Survival of elderly patients undergoing complete tumor resection was 17.7 ± 8.1 months.

Conclusions

In this series of patients with glioblastoma, age was a prognostic factor in patients undergoing biopsy, but not in patients undergoing resection. Tumor location and patient clinical status may prohibit extensive resection, but resection should not be withheld from patients only on the basis of age. In elderly patients with glioblastoma, undergoing resection to the extent feasible, followed by adjuvant therapies, is warranted.
Multicenter validation of a formula predicting postoperative spinopelvic alignment
Authors: Lafage Virginie , Bharucha Neil J. , Schwab Frank , Hart Robert A. , Burton Douglas , Boachie-Adjei Oheneba , Smith Justin S. , Hostin Richard , Shaffrey Christopher , Gupta Munish , Akbarnia Behrooz A. , Bess Shay
Published: September 2011

Object

Sagittal spinopelvic imbalance is a major contributor to pain and disability for patients with adult spinal deformity (ASD). Preoperative planning is essential for pedicle subtraction osteotomy (PSO) candidates; however, current methods are often inaccurate because no formula to date predicts both postoperative sagittal balance and pelvic alignment. The authors of this study aimed to evaluate the accuracy of 2 novel formulas in predicting postoperative spinopelvic alignment after PSO.

Methods

This study is a multicenter retrospective consecutive PSO case series. Adults with spinal deformity (> 21 years old) who were treated with a single-level lumbar PSO for sagittal imbalance were evaluated. All patients underwent preoperative and a minimum of 6-month postoperative radiography. Two novel formulas were used to predict the postoperative spinopelvic alignment. The results predicted by the formulas were then compared with the actual postoperative radiographic values, and the formulas' ability to identify successful (sagittal vertical axis [SVA] ≤ 50 mm and pelvic tilt [PT] ≤ 25°) and unsuccessful (SVA > 50 mm or PT > 25°) outcomes was evaluated.

Results

Ninety-nine patients met inclusion criteria. The median absolute error between the predicted and actual PT was 4.1° (interquartile range 2.0°–6.4°). The median absolute error between the predicted and actual SVA was 27 mm (interquartile range 11–47 mm). Forty-one of 54 patients with a formula that predicted a successful outcome had a successful outcome as shown by radiography (positive predictive value = 0.76). Forty-four of 45 patients with a formula that predicted an unsuccessful outcome had an unsuccessful outcome as shown by radiography (negative predictive value = 0.98).

Conclusions

The spinopelvic alignment formulas were accurate when predicting unsuccessful outcomes but less reliable when predicting successful outcomes. The preoperative surgical plan should be altered if an unsuccessful result is predicted. However, even after obtaining a predicted successful outcome, surgeons should ensure that the predicted values are not too close to unsuccessful values and should identify other variables that may affect alignment. In the near future, it is anticipated that the use of these formulas will lead to better surgical planning and improved outcomes for patients with complex ASD.
Alcohol Policy, Social Context, and Infant Health: The Impact of Minimum Legal Drinking Age
Authors: Zhang Ning , Caine Eric
Published: September 2011

Objective: The minimum legal drinking age (MLDA) was increased in the U.S. in the late 1980s in an effort to reduce intoxication-associated injuries, especially those related to motor vehicle accidents. This paper explores distal (secondary) effects of changing MLDA on indices of infant health, and whether changes in drinking behaviors or birth composition contributed to these effects. Methods: State- and year-fixed-effects models are used to analyze the relationship between MLDA, drinking behaviors, and birth outcomes. We studied the effects of different MLDA (age 18, 19, 20, or 21 years) when potential mothers were 14 years old by merging two population-based datasets, the Natality Detailed Files and the Behavioral Risk Factor Surveillance System between 1985 and 2002. Results: A MLDA of 18 years old (when potential mothers were 14 years old) increased the prevalence of low birth weight, low Apgar scores, and premature births. Effects were stronger among children born to black women compared with white women. Moreover, a younger MLDA was associated with an increasing proportion of very young and high school dropouts for black women. Furthermore, older MLDA laws at age 14 years decreased the prevalence of binge drinking among black women. Conclusions: Increasing the MLDA had longer term, distal impacts beyond the initially intended outcomes, specifically on birth outcomes (particularly among infants born to black women) as well as school drop-outs and binge drinking patterns among black young females. The older MLDA, intended initially to reduce problematic drinking behaviors, appeared to alter broader social contexts that influenced young women during their early childbearing years.
Convergent Validity of the Arab Teens Lifestyle Study (ATLS) Physical Activity Questionnaire
Authors: Al-Hazzaa Hazzaa M. , Al-Sobayel Hana I. , Musaiger Abdulrahman O.
Published: September 2011

The Arab Teens Lifestyle Study (ATLS) is a multicenter project for assessing the lifestyle habits of Arab adolescents. This study reports on the convergent validity of the physical activity questionnaire used in ATLS against an electronic pedometer. Participants were 39 males and 36 females randomly selected from secondary schools, with a mean age of 16.1 ± 1.1 years. ATLS self-reported questionnaire was validated against the electronic pedometer for three consecutive weekdays. Mean steps counts were 6,866 ± 3,854 steps/day with no significant gender difference observed. Questionnaire results showed no significant gender differences in time spent on total or moderate-intensity activities. However, males spent significantly more time than females on vigorous-intensity activity. The correlation of steps counts with total time spent on all activities by the questionnaire was 0.369. Relationship of steps counts was higher with vigorous-intensity (r = 0.338) than with moderate-intensity activity (r = 0.265). Pedometer steps counts showed higher correlations with time spent on walking (r = 0.350) and jogging (r = 0.383) than with the time spent on other activities. Active participants, based on pedometer assessment, were also most active by the questionnaire. It appears that ATLS questionnaire is a valid instrument for assessing habitual physical activity among Arab adolescents.
Probing Structural Features and Binding Mode of 3-Arylpyrimidin-2,4-diones within Housefly γ-Aminobutyric Acid (GABA) Receptor
Authors: Li Qinfan , Zhang Lihui , Ma Zhi , Kong Xiangya , Wang Fangfang , Zhang Hong , Wang Yonghua
Published: September 2011

In order to obtain structural features of 3-arylpyrimidin-2,4-diones emerged as promising inhibitors of insect γ-aminobutyric acid (GABA) receptor, a set of ligand-/receptor-based 3D-QSAR models for 60 derivatives are generated using Comparative Molecular Field Analysis (CoMFA) and Comparative Molecular Similarity Index Analysis (CoMSIA). The statistically optimal CoMSIA model is produced with highest q2 of 0.62, r2ncv of 0.97, and r2pred of 0.95. A minor/bulky electronegative hydrophilic polar substituent at the 1-/6-postion of the uracil ring, and bulky substituents at the 3'-, 4'- and 5'-positions of the benzene ring are beneficial for the enhanced potency of the inhibitors as revealed by the obtained 3D-contour maps. Furthermore, homology modeling, molecular dynamics (MD) simulation and molecular docking are also carried out to gain a better understanding of the probable binding modes of these inhibitors, and the results show that residues Ala-183(C), Thr-187(B), Thr-187(D) and Thr-187(E) in the second transmembrane domains of GABA receptor are responsible for the H-bonding interactions with the inhibitor. The good correlation between docking observations and 3D-QSAR analyses further proves the model reasonability in probing the structural features and the binding mode of 3-arylpyrimidin-2,4-dione derivatives within the housefly GABA receptor.
Effect of Low Concentration Sn Doping on Optical Properties of CdS Films Grown by CBD Technique
Authors: Jafari Atefeh , Zakaria Azmi , Rizwan Zahid , Ghazali Mohd Sabri Mohd
Published: September 2011

Thin and transparent films of doped cadmium sulfide (CdS) were obtained on commercial glass substrates by Chemical Bath Deposition (CBD) technique. The films were doped with low concentration of Sn, and annealed in air at 300 °C for 45 min. The morphological characterization of the films with different amounts of dopant was made using SEM and EDAX analysis. Optical properties of the films were evaluated by measuring transmittance using the UV-vis spectrophotometer. A comparison of the results revealed that lower concentration of Sn doping improves transmittance of CdS films and makes them suitable for application as window layer of CdTe/CIGS solar cells.
Recognition-Mediated Assembly of Quantum Dot Polymer Conjugates with Controlled Morphology
Authors: Nandwana Vikas , Subramani Chandramouleeswaran , Eymur Serkan , Yeh Yi-Cheun , Tonga Gulen Yesilbag , Tonga Murat , Jeong Youngdo , Yang Boqian , Barnes Michael D. , Cooke Graeme , Rotello Vincent M.
Published: September 2011

We have demonstrated a polymer mediated “bricks and mortar” method for the self-assembly of quantum dots (QDs). This strategy allows QDs to self-assemble into structured aggregates using complementary three-point hydrogen bonding. The resulting nanocomposites have distinct morphologies and inter-particle distances based on the ratio between QDs and polymer. Time resolved photoluminescence measurements showed that the optical properties of the QDs were retained after self-assembly.
Coating of Carbon Fiber with Polyhedral Oligomeric Silsesquioxane (POSS) to Enhance Mechanical Properties and Durability of Carbon/Vinyl Ester Composites
Authors: Mahfuz Hassan , Powell Felicia , Granata Richard , Hosur Mahesh , Khan Mujib
Published: September 2011

Our continuing quest to improve the performance of polymer composites under moist and saltwater environments has gained momentum in recent years with the reinforcement of inorganic nanoparticles into the polymer. The key to mitigate degradation of composites under such environments is to maintain the integrity of the fiber/matrix (F/M) interface. In this study, the F/M interface of carbon/vinyl ester composites has been modified by coating the carbon fiber with polyhedral oligomeric silsesquioxane (POSS). POSS is a nanostructured inorganic-organic hybrid particle with a cubic structure having silicon atoms at the core and linked to oxygen atoms. The advantage of using POSS is that the silicon atoms can be linked to a substituent that can be almost any chemical group known in organic chemistry. Cubic silica cores are ‘hard particles’ and are about 0.53 nm in diameter. The peripheral organic unit is a sphere of about 1–3 nm in diameter. Further, cubic structure of POSS remains intact during the polymerization process and therefore with appropriate functional groups, if installed on the fiber surface, would provide a stable and strong F/M interface. Two POSS systems with two different functional groups; namely, octaisobutyl and trisilanolphenyl have been investigated. A set of chemical and mechanical procedures has been developed to coat carbon fibers with POSS, and to fabricate layered composites with vinyl ester resin. Interlaminar shear and low velocity impact tests have indicated around 17–38% improvement in mechanical properties with respect to control samples made without the POSS coating. Saltwater and hygrothermal tests at various environmental conditions have revealed that coating with POSS reduces water absorption by 20–30% and retains the composite properties.
Integration of OHS into Risk Management in an Open-Pit Mining Project in Quebec (Canada)
Authors: Badri Adel , Nadeau Sylvie , Gbodossou André
Published: September 2011

Despite undeniable progress, the mining industry remains the scene of serious accidents revealing disregard for occupational health and safety (OHS) and leaving open the debate regarding the safety of its employees. The San José mine last collapse near Copiapó, Chile on 5 August 2010 and the 69-day rescue operation that followed in order to save 33 miners trapped underground show the serious consequences of neglecting worker health and safety. The aim of this study was to validate a new approach to integrating OHS into risk management in the context of a new open-pit mining project in Quebec, based on analysis of incident and accident reports, semi-structured interviews, questionnaires and collaborative field observations. We propose a new concept, called hazard concentration, based on the number of hazards and their influence. This concept represents the weighted fraction of each category of hazards related to an undesirable event. The weight of each category of hazards is calculated by AHP, a multicriteria method. The proposed approach included the creation of an OHS database for facilitating expert risk management. Reinforcing effects between hazard categories were identified and all potential risks were prioritized. The results provided the company with a rational basis for choosing a suitable accident prevention strategy for its operational activities.
Evaluation of the Content Coverage of SNOMED CT Representing ICNP Seven-axis Version 1 Concepts
Authors: Lundberg C. , Coenen A. , Konicek D. , Park H. A.
Published: September 2011

Objectives: The purpose of this study is to evaluate the ability of SNOMED CT (Systematized Nomenclature of Medicine Clinical Terms) to represent the concepts of the ICNP version 1 – the seven-axis model.

Methods: The first author mapped 1658 concepts of the ICNP version 1 to SNOMED CT using CLUE browser 5.0. The second author from SNOMED Terminology Solutions – with a team of SNOMED CT experts – and the third author from the ICN with a team of ICNP experts validated the mapping result. If there was any disagreement during the validation process, the three of us convened online meetings to reach a consensus.

Results: In total, SNOMED CT covered 1331 out of 1658 (80%) ICNP seven-axis model concepts ranging from a 61% coverage rate of the Actions Axis concepts to a 94% coverage rate of the Judgment axis concepts.

Conclusions: SNOMED CT can represent most (80%) of the ICNP version 1 concepts. However, improvements in the ICNP version 1 in terms of concept naming and definition, and the addition of missing concepts to SNOMED CT, would lead to a greater harmonization of the ICNP seven-axis model version 1 concepts with SNOMED CT.