bluuebunny/crossref_metadata_2025 huggingface dataset:
Practice Patterns for Combined Anterior Cruciate Ligament and Meniscal Surgery in the United States
Authors: Musahl Volker , Jordan Susan S. , Colvin Alexis C. , Tranovich Michael J. , Irrgang James J. , Harner Christopher D.
Published: May 2010

Purpose

The purpose of the study was to compare frequency of meniscal repair to partial meniscectomy in patients undergoing anterior cruciate ligament reconstruction using the American Board of Orthopaedic Surgeons (ABOS) database.

Hypotheses

(1) Practice patterns are similar with respect to geographic region. (2) Surgeons with fellowship training perform more meniscal repairs compared with general orthopaedic practitioners. (3) Younger patients are more likely to be treated with meniscal repair at the time of anterior cruciate ligament reconstruction. (4) The frequency of meniscal repair in conjunction with anterior cruciate ligament reconstruction has increased over time.

Study Design

Cross-sectional study; Level of evidence, 3.

Methods

Information was extracted from the ABOS database from 2002 orthopaedic surgeons who sat for the part II examination from 2003 to 2007. The database was queried for all patients who underwent anterior cruciate ligament reconstruction (Current Procedural Terminology [CPT] code 29888) without or with meniscectomy (CPT 29881) or meniscal repair (CPT 29882). Factors affecting meniscal surgery that were investigated included patient age, geographic region of practice, fellowship training, and declared subspecialty of the surgeon.

Results

On average there were 52 000 cases per year registered in the ABOS database, approximately 1700 of whom underwent anterior cruciate ligament reconstruction. Meniscal repair was most frequently performed in the Southwest region (18.6%, P < .001) and least frequently in the Northwest region (11.3%, P < .001). Combined anterior cruciate ligament reconstruction and meniscal repair was performed significantly more often by fellowship-trained surgeons (17%) than by surgeons with other fellowship training (12%) or no fellowship training (12%, P < .001) and in patients younger than age 25 years (19%) compared with those age 40 years and older (8%, P < .001). Meniscal repair was performed in 13.9% of anterior cruciate ligament reconstructions in 2003 and in 16.4% of anterior cruciate ligament reconstructions in 2007 (P > .05).

Conclusion

Combined anterior cruciate ligament reconstruction with meniscal repair was more frequent for younger patients and by surgeons with sports fellowship training. Concomitant meniscal repair is performed by fellowship-trained surgeons in this study in only 18% of anterior cruciate ligament reconstructions.
Arthroscopic Supraspinatus Tendon Repair with Suture-Bridging Technique
Authors: Voigt Christine , Bosse Christin , Vosshenrich Rolf , Schulz Arndt P. , Lill Helmut
Published: May 2010

Background

The suture-bridging technique is a new arthroscopic technique to repair rotator cuff tears. Biomechanical advantages compared with double-row fixations have been described.

Hypothesis

The authors hypothesized that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation.

Study Design

Case series; Level of evidence, 4.

Methods

Fifty-one consecutive patients, with a median age of 62 years (range, 37-76 years), who had undergone an arthroscopic suture-bridging repair of an isolated supraspinatus tendon tear were evaluated in this prospective study 4, 12, and a median of 24 months postoperatively. Subjective and functional outcome was assessed using the simple shoulder test and Constant score. With magnetic resonance imaging 12 months postoperatively, the tendon integrity and potential predictors of failures were evaluated.

Results

The simple shoulder test scores improved significantly from 9 points (range, 1-12 points) at 4 months, to 12 points (range, 1-12 points) at 12 months, and 12 points (range, 5-12 points) at 24 months postoperatively. The Constant score increased significantly from preoperative 64% (range, 37%-92%) to 82% (range, 36%-100%) at 4 months, 96% (range, 49%-100%) at 12 months, and 96% (range, 64%-100%) at 24 months postoperatively. Magnetic resonance imaging 12 months after surgery showed retears in 28.9%. Two different types of retears could be observed: insufficiently healed and medially retorn supraspinatus tendons. The Constant score did not differ significantly between the groups with retears and intact repairs. A patient age of more than 60 years was found to influence tendon healing significantly.

Conclusion

The hypothesis, that arthroscopic suture-bridging repair of the supraspinatus tendon would result in a superior clinical outcome and lower retear rates compared with previously published results after double-row fixation, could not be confirmed. The functional outcome after the new suture-bridging technique was good and comparable with the reported results after double-row repair from the literature. A structural failure of tendon repair was not identical to clinical failure.
Can Human Rights Transcend the Commercialization of Water in South Africa? Soweto’s Legal Fight for an Equitable Water Policy
Authors: Dugard Jackie
Published: May 2010

The South African Constitution guarantees the right to water, which is reinforced by a national Free Basic Water policy. However, water delivery is a local government function, which, in the absence of a national regulator, is largely operated as a commercial service. Using the lens of the Mazibuko water rights case—the first South African test case on the right to water—this article examines the conflict between a progressive rights-based model, which views water as a social good, and the commercialized model, which treats water as a source of revenue instead of a public service. The article finds in the legal iterations of the Mazibuko applicants the potential for a new, more equitable approach to water services. This is despite the set-back occasioned by the ultimate legal defeat in the Constitutional Court in late-2009.

JEL codes: I31, H41, K32, Q25
Rooting Inquiry in Tradition: The Health Baraza as a Tool for Social Research in Kenya
Authors: Naanyu Violet , Sidle John E. , Frankel Richard M. , Ayuku David , Nyandiko Winstone M. , Inui Thomas S.
Published: May 2010

The baraza is a customary form of community assembly in East Africa. We examined the use of the health baraza as a process that can improve data collection and deepen community understanding of sociocultural issues surrounding HIV/AIDS. In the evaluation of the United States Agency for International Development (USAID)—Academic Model for Prevention and Treatment of HIV/AIDS Partnership (USAID—AMPATH) in Kenya, investigators facilitated mabaraza (the plural of baraza) to gather information of relevance to program success, improvement, and community collaboration. Seven mabaraza were held at local health facilities. Mabaraza rapidly evoked essential information for the USAID—AMPATH program and facilitated vibrant discussion of themes that were of interest to local communities. Mabaraza combined individual and community outlooks, producing emic understanding of the program’s meaning to local populations. The baraza assemblage is a promising technique for applied sociology, participatory research, and program evaluation.
Weighing Public and Private Options for Reforming Long-Term Care Financing: Findings From a National Survey of Specialists
Authors: Miller Edward Alan , Mor Vincent , Clark Melissa
Published: May 2010

Deficiencies in current long-term care (LTC) financing models are substantial and must be addressed if the nation is going to meet the needs of the growing population of frail and disabled elders. Because debate over reforming LTC financing has traditionally focused on the relative roles of the public and private sectors, this article examines what characteristics predispose LTC specialists to weigh one approach— public or private—more than the other. Data are derived from a Web-based survey of 1,147 individuals with known or demonstrable experience with LTC, including consumer advocates, provider representatives, policy experts, and public officials. Results suggest that support for spurring private sector mechanisms, bolstering the government’s role, and reforming Medicare and Medicaid vary with key characteristics of the respondents, including experiential, attitudinal, and background variables. Findings also suggest consensus that reform of LTC financing should improve on the current public—private partnership in this area.
Nursing Home Organizational Change: The “Culture Change” Movement as Viewed by Long-Term Care Specialists
Authors: Miller Susan C. , Miller Edward Alan , Jung Hye-Young , Sterns Samantha , Clark Melissa , Mor Vincent
Published: May 2010

A decade-long grassroots movement aims to deinstitutionalize nursing home (NH) environments and individualize care. Coined “NH Culture Change” the movement is often described by its resident-centered/directed care focus. While empirical data of “culture change’s” costs and benefits are limited, it is broadly viewed as beneficial and widely promoted. Still, debate abounds regarding barriers to its adoption. We used data from a Web-based survey of 1,147 long-term care specialists (including NH and other providers, consumers/advocates, state and federal government officials, university/academic, researchers/consultants, and others) to better understand factors associated with perceived barriers. Long-term care specialists view the number-one barrier to adoption differently depending on their employment, familiarity with culture change, and their underlying policy views. To promote adoption, research and broad-based educational efforts are needed to influence views and perceptions. Fundamental changes in the regulatory process together with targeted regulatory changes and payment incentives may also be needed.
Motivational Processes Underlying Both Prejudice and Helping
Authors: Graziano William G. , Habashi Meara M.
Published: May 2010

Examined at the behavioral level, prejudice and helping appear as qualitatively different and perhaps mutually incompatible social behaviors. As a result, the literatures on prejudice and helping evolved largely independent of each other. When they are examined at the process level, however, underlying similarities appear. Furthermore, when anomalies are examined within each of these two separate literatures, similarities become more apparent. Finally, the personality dimension of agreeableness is systematically related to both prejudice and helping. The authors propose that many forms of prejudice and helping are expressions of underlying processes of self-regulation and social accommodation. After discussing several other social-cognitive approaches to self-correction, the authors offer a novel opponent process model of motivation that integrates the apparently exclusive processes of prejudice and helping into a single system.
Birth Order and Risk Taking in Athletics: A Meta-Analysis and Study of Major League Baseball
Authors: Sulloway Frank J. , Zweigenhaft Richard L.
Published: May 2010

According to expectations derived from evolutionary theory, younger siblings are more likely than older siblings to participate in high-risk activities. The authors test this hypothesis by conducting a meta-analysis of 24 previous studies involving birth order and participation in dangerous sports. The odds of laterborns engaging in such activities were 1.48 times greater than for firstborns ( N = 8,340). The authors also analyze performance data on 700 brothers who played major league baseball. Consistent with their greater expected propensity for risk taking, younger brothers were 10.6 times more likely to attempt the high-risk activity of base stealing and 3.2 times more likely to steal bases successfully (odds ratios). In addition, younger brothers were significantly superior to older brothers in overall batting success, including two measures associated with risk taking. As expected, significant heterogeneity among various performance measures for major league baseball players indicated that older and younger brothers excelled in different aspects of the game.
Fixing Our Focus: Training Attention to Regulate Emotion
Authors: Wadlinger Heather A. , Isaacowitz Derek M.
Published: May 2010

Empirical studies have frequently linked negative attentional biases with attentional dysfunction and negative moods; however, far less research has focused on how attentional deployment can be an adaptive strategy that regulates emotional experience. The authors argue that attention may be an invaluable tool for promoting emotion regulation. Accordingly, they present evidence that selective attention to positive information reflects emotion regulation and that regulating attention is a critical component of the emotion regulatory process. Furthermore, attentional regulation can be successfully trained through repeated practice. The authors ultimately propose a model of attention training methodologies integrating attention-dependent emotion regulation strategies with attention networks. Although additional interdisciplinary research is needed to bolster these nascent findings, meditative practices appear to be among the most effective training methodologies in enhancing emotional well-being. Further exploration of the positive and therapeutic qualities of attention warrants the empirical attention of social and personality psychologists.
Do People Embrace Praise Even When They Feel Unworthy? A Review of Critical Tests of Self-Enhancement Versus Self-Verification
Authors: Kwang Tracy , Swann William B.
Published: May 2010

Some contemporary theorists contend that the desire for self-enhancement is prepotent and more powerful than rival motives such as self-verification. If so, then even people with negative self-views will embrace positive evaluations. The authors tested this proposition by conducting a meta-analytic review of the relevant literature. The data provided ample evidence of self-enhancement strivings but little evidence of its prepotency. Instead, the evidence suggested that both motives are influential but control different response classes. In addition, other motives may sometimes come into play. For example, when rejection risk is high, people seem to abandon self-verification strivings, apparently in an effort to gratify their desire for communion. However, when rejection risk is low, as is the case in many secure marital relationships, people prefer self-verifying evaluations. The authors conclude that future researchers should broaden the bandwidth of their explanatory frameworks to include motives other than self-enhancement.
The Local Dominance Effect in Self-Evaluation: Evidence and Explanations
Authors: Zell Ethan , Alicke Mark D.
Published: May 2010

The local dominance effect is the tendency for comparisons with a few, discrete individuals to have a greater influence on self-assessments than comparisons with larger aggregates. This review presents a series of recent studies that demonstrate the local dominance effect. The authors offer two primary explanations for the effect and consider alternatives including social categorization and the abstract versus concrete nature of local versus general comparisons. They then discuss moderators of the effect including physical proximity and self-enhancement. Finally, the theoretical and practical implications of the effect are discussed and potential future directions in this research line are proposed.
Internal Consistency, Retest Reliability, and Their Implications for Personality Scale Validity
Authors: McCrae Robert R. , Kurtz John E. , Yamagata Shinji , Terracciano Antonio
Published: May 2010

The authors examined data ( N = 34,108) on the differential reliability and validity of facet scales from the NEO Inventories. They evaluated the extent to which (a) psychometric properties of facet scales are generalizable across ages, cultures, and methods of measurement, and, (b) validity criteria are associated with different forms of reliability. Composite estimates of facet scale stability, heritability, and cross-observer validity were broadly generalizable. Two estimates of retest reliability were independent predictors of the three validity criteria; none of three estimates of internal consistency was. Available evidence suggests the same pattern of results for other personality inventories. Internal consistency of scales can be useful as a check on data quality but appears to be of limited utility for evaluating the potential validity of developed scales, and it should not be used as a substitute for retest reliability. Further research on the nature and determinants of retest reliability is needed.
Sleep and effort in adolescent athletes
Authors: Engle-Friedman Mindy , Palencar Valerie , Riela Suzanne
Published: May 2010

Adolescents’ sleep and next day effort was studied in 18 female competitive adolescent athletes. A subjective assessment of the previous night’s sleep, their perception of the difficulty of the choices offered and the difficulty of tasks selected was completed before routine lessons. Sleep amount was related to the perception of the difficulty of the task, while awakenings were related to an avoidance of the least preferred maneuvers. Individuals who experienced the greatest number of awakenings and most time awake at night were more likely to select the least difficult of these tasks. Sleep disturbance in adolescence may magnify the challenges they experience and cause them to underestimate their ability to meet those challenges.
Diffuse large B-cell lymphomas with CDKN2A deletion have a distinct gene expression signature and a poor prognosis under R-CHOP treatment: a GELA study
Authors: Jardin Fabrice , Jais Jean-Philippe , Molina Thierry-Jo , Parmentier Françoise , Picquenot Jean-Michel , Ruminy Philippe , Tilly Hervé , Bastard Christian , Salles Gilles-André , Feugier Pierre , Thieblemont Catherine , Gisselbrecht Christian , de Reynies Aurelien , Coiffier Bertrand , Haioun Corinne , Leroy Karen
Published: May 2010

Genomic alterations play a crucial role in the development and progression of diffuse large B-cell lymphomas (DLBCLs). We determined gene copy number alterations (GCNAs) of TP53, CDKN2A, CDKN1B, BCL2, MYC, REL, and RB1 with a single polymerase chain reaction (PCR) assay (quantitative multiplex PCR of short fragments [QMPSF]) in a cohort of 114 patients with DLBCL to assess their prognostic value and relationship with the gene expression profile. Losses of TP53 and CDKN2A, observed in 8% and 35% of patients, respectively, were significantly associated with a shorter survival after rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) treatment, independently of the International Prognostic Index and of the cell of origin. Analysis of the 9p21 genomic region indicated that transcripts encoding p14ARF and p16INK4A were both disrupted in most patients with CDKN2A deletion. These patients predominantly had an activated B-cell profile and showed a specific gene expression signature, characterized by dysregulation of the RB/E2F pathway, activation of cellular metabolism, and decreased immune and inflammatory responses. These features may constitute the molecular basis sustaining the unfavorable outcome and chemoresistance of this DLBCL subgroup. Detection of TP53 and CDKN2A loss by QMPSF is a powerful tool that could be used for patient stratification in future clinical trials.
Stem cell mobilization with G-CSF induces type 17 differentiation and promotes scleroderma
Authors: Hill Geoffrey R. , Olver Stuart D. , Kuns Rachel D. , Varelias Antiopi , Raffelt Neil C. , Don Alistair L. , Markey Kate A. , Wilson Yana A. , Smyth Mark J. , Iwakura Yoichiro , Tocker Joel , Clouston Andrew D. , MacDonald Kelli P. A.
Published: May 2010

The recent shift to the use of stem cells mobilized by granulocyte colony-stimulating factor (G-CSF) for hematopoietic transplantation has increased chronic graftversus-host disease (GVHD), although the mechanisms of this are unclear. We have found that G-CSF invokes potent type 17 rather than type 1 or type 2 differentiation. The amplification of interleukin-17 (IL-17) production by G-CSF occurs in both CD4 and CD8 conventional T cells and is dependent on, and downstream of, G-CSF–induced IL-21 signaling. Importantly, donor IL-17A controls the infiltration of macrophages into skin and cutaneous fibrosis, manifesting late after transplantation as scleroderma. Interestingly, donor CD8 T cells were the predominant source of IL-17A after transplantation and could mediate scleroderma independently of CD4 T cells. This study provides a logical explanation for the propensity of allogeneic stem cell transplantation to invoke sclerodermatous GVHD and suggests a therapeutic strategy for intervention.
SOCS3 regulates graft-versus-host disease
Authors: Hill Geoffrey R. , Kuns Rachel D. , Raffelt Neil C. , Don Alistair L. J. , Olver Stuart D. , Markey Kate A. , Wilson Yana A. , Tocker Joel , Alexander Warren S. , Clouston Andrew D. , Roberts Andrew W. , MacDonald Kelli P. A.
Published: May 2010

Suppressor of cytokine signaling-3 (SOCS3) is the main intracellular regulator of signaling by granulocyte colony-stimulating factor, an immune-modulatory cytokine used to mobilize stem cells for transplantation. We have therefore studied the contribution of SOCS3 to the spectrum of graft-versus-host disease (GVHD) after allogeneic stem cell transplantation (SCT). Grafts from SOCS3−/Δvav donor mice in which SOCS3 deficiency is restricted to the hematopoietic compartment had an augmented capacity to induce acute GVHD. With the use of SOCS3−/ΔLysM and SOCS3−/Δlck donors in which SOCS3 deficiency was restricted to the myeloid or T-cell lineage, respectively, we confirmed SOCS3 deficiency promoted acute GVHD mortality and histopathology within the gastrointestinal tract by effects solely within the donor T cell. SOCS3−/Δlck donor T cells underwent enhanced alloantigen-dependent proliferation and generation of interleukin-10 (IL-10), IL-17, and interferon-γ (IFNγ) after SCT. The enhanced capacity of the SOCS3−/Δlck donor T cell to induce acute GVHD was dependent on IFNγ but independent of IL-10 or IL-17. Surprisingly, SOCS3−/Δlck donor T cells also induced severe, transforming growth factor β– and IFNγ-dependent, sclerodermatous GVHD. Thus, the delivery of small molecule SOCS3 mimetics may prove to be useful for the inhibition of both acute and chronic GVHD.
Laboratory testing of individuals with severe α1-antitrypsin deficiency in three European centres
Authors: Miravitlles M. , Herr C. , Ferrarotti I. , Jardi R. , Rodriguez-Frias F. , Luisetti M. , Bals R.
Published: May 2010

α1-Antitrypsin (AT) deficiency is a hereditary disorder that may lead to early-onset emphysema, and chronic liver disease later in life. Although there are validated methods for testing, the vast majority of α1-AT-deficient individuals remain undiagnosed. Recommendations have been published for the testing and diagnosis of α1-AT deficiency; however, guidelines on best practice are not well established.

In our article, we review the developments in diagnostic techniques that have taken place in recent years, and describe the practices used in our three European centres. The determination of the level of α1-AT and genotyping are reported as the main diagnostic steps, whereas isoelectric focusing (also referred to as phenotyping) is reserved for confirmatory analysis.

The following recommendations for best practice are put forward: detection of all PiZZ and other severe deficiency individuals; automated genotyping; preparation of reference standards; quality control programmes; development of standard operating procedure documents; and standardised methods for the collection of dried blood samples. Closer cooperation between laboratories and the sharing of knowledge are recommended, with the objectives of improving the efficiency of the diagnosis of severe α1-AT deficiency, increasing the numbers of individuals who are detected with the disorder, and assisting the establishment of new patient identification programmes.
Influence of mutation rate on estimators of genetic differentiation - lessons from Arabidopsis thaliana
Authors: Kronholm Ilkka , Loudet Olivier , de Meaux Juliette
Published: May 2010

Background

The analysis of molecular variation within and between populations is crucial to establish strategies for conservation as well as to detect the footprint of spatially heterogeneous selection. The traditional estimator of genetic differentiation (F

ST
) has been shown to be misleading if genetic diversity is high. Alternative estimators of F

ST
have been proposed, but their robustness to variation in mutation rate is not clearly established. We first investigated the effect of mutation and migration rate using computer simulations and examined their joint influence on Q

ST
, a measure of genetic differentiation for quantitative traits. We further used experimental data in natural populations of Arabidopsis thaliana to characterize the effect of mutation rate on various estimates of population differentiation. Since natural species exhibit various degrees of self-fertilisation, we also investigated the effect of mating system on the different estimators.

Results

If mutation rate is high and migration rate low, classical measures of genetic differentiation are misleading. Only Φ
ST
, an estimator that takes the mutational distances between alleles into account, is independent of mutation rate, for all migration rates. However, the performance of Φ
ST
depends on the underlying mutation model and departures from this model cause its performance to degrade. We further show that Q

ST
has the same bias. We provide evidence that, in A. thaliana, microsatellite variation correlates with mutation rate. We thereby demonstrate that our results on estimators of genetic differentiation have important implications, even for species that are well established models in population genetics and molecular biology.

Conclusions

We find that alternative measures of differentiation like F'

ST
and D are not suitable for estimating effective migration rate and should not be used in studies of local adaptation. Genetic differentiation should instead be measured using an estimator that takes mutation rate into account, such as Φ
ST
. Furthermore, in systems where migration between populations is low, such as A. thaliana, Q

ST
< F

ST
cannot be taken as evidence for homogenising selection as has been traditionally thought.
Torsional stability of interference screws derived from bovine bone - a biomechanical study
Authors: Bauer Joscha , Efe Turgay , Herdrich Silke , Gotzen Leo , El-Zayat Bilal Farouk , Schmitt Jan , Timmesfeld Nina , Schofer Markus Dietmar
Published: May 2010

Background

In the present biomechanical study, the torsional stability of different interference screws, made of bovine bone, was tested. Interference screws derived from bovine bone are a possible biological alternative to conventional metallic or bioabsorbable polymer interference screws.

Methods

In the first part of the study we compared the torsional stability of self-made 8 mm Interference screws (BC) and a commercial 8 mm interference screw (Tutofix®). Furthermore, we compared the torsional strength of BC screws with different diameters. For screwing in, a hexagon head and an octagon head were tested. Maximum breaking torques in polymethyl methacrylate resin were recorded by means of an electronic torque screw driver. In the second part of the study the tibial part of a bone-patellar tendon-bone graft was fixed in porcine test specimens using an 8 mm BC screw and the maximum insertion torques were recorded. Each interference screw type was tested 5 times.

Results

There was no statistically significant difference between the different 8 mm interference screws (p = 0.121). Pairwise comparisons did not reveal statistically significant differences, either. It was demonstrated for the BC screws, that a larger screw diameter significantly leads to higher torsional stability (p = 9.779 × 10-5). Pairwise comparisons showed a significantly lower torsional stability for the 7 mm BC screw than for the 8 mm BC screw (p = 0.0079) and the 9 mm BC screw (p = 0.0079). Statistically significant differences between the 8 mm and the 9 mm BC screw could not be found (p = 0.15). During screwing into the tibial graft channel of the porcine specimens, insertion torques between 0.5 Nm and 3.2 Nm were recorded. In one case the hexagon head of a BC screw broke off during the last turn.

Conclusions

The BC screws show comparable torsional stability to Tutofix® interference screws. As expected the torsional strength of the screws increases significantly with the diameter. The safety and in vivo performance of products derived from xenogeneic bone should be the focus of further investigations.
Prostate apoptosis response protein 4 sensitizes human colon cancer cells to chemotherapeutic 5-FU through mediation of an NFκB and microRNA network
Authors: Wang Bi-Dar , Kline Christina Leah B. , Pastor Danielle M. , Olson Thomas L. , Frank Bryan , Luu Truong , Sharma Arun K. , Robertson Gavin , Weirauch Matthew T. , Patierno Steven R. , Stuart Joshua M. , Irby Rosalyn B. , Lee Norman H.
Published: May 2010

Background

Diminished expression or activity of prostate apoptosis response protein 4 (Par-4) has been demonstrated in a number of cancers, although reports on Par-4 expression during colon cancer progression are lacking. An understanding of the molecular events in conjunction with the genetic networks affected by Par-4 is warranted.

Results

Colon cancer specimens derived from patients have significantly diminished expression of Par-4 mRNA relative to paired normal colon. Hence, the functional consequences of reintroducing Par-4 into HT29 colon cancer cells were assessed. Overexpression augmented the interaction of Par-4 with NFκB in the cytosol but not nucleus, and facilitated apoptosis in the presence of 5-fluorouracil (5-FU). Analogous findings were obtained when AKT1 pro-survival signaling was inhibited. Transcriptome profiling identified ~700 genes differentially regulated by Par-4 overexpression in HT29 cells. Nearly all Par-4-regulated genes were shown by promoter analysis to containcis-binding sequences for NFκB, and meta-analysis of patient expression data revealed that one-third of these genes exist as a recurrent co-regulated network in colon cancer specimens. Sets of genes involved in programmed cell death, cell cycle regulation and interestingly the microRNA pathway were found overrepresented in the network. Noteworthy, Par-4 overexpression decreased NFκB occupancy at the promoter of one particular network geneDROSHA, encoding a microRNA processing enzyme. The resulting down-regulation ofDROSHAwas associated with expression changes in a cohort of microRNAs. Many of these microRNAs are predicted to target mRNAs encoding proteins with apoptosis-related functions. Western and functional analyses were employed to validate several predictions. For instance, miR-34a up-regulation corresponded with a down-regulation of BCL2 protein. Treating Par-4-overexpressing HT29 cells with a miR-34a antagomir functionally reversed both BCL2 down-regulation and apoptosis by 5-FU. Conversely, bypassing Par-4 overexpression by direct knockdown ofDROSHAexpression in native HT29 cells increased miR-34a expression and 5-FU sensitivity.

Conclusion

Our findings suggest that the initiation of apoptotic sensitivity in colon cancer cells can be mediated by Par-4 binding to NFκB in the cytoplasm with consequential changes in the expression of microRNA pathway components.
A multiplex reverse transcription-nested polymerase chain reaction for detection and differentiation of wild-type and vaccine strains of canine distemper virus
Authors: Si Wei , Zhou Shun , Wang Zhao , Cui Shang-jin
Published: May 2010

A multiplex reverse transcription-nested polymerase chain reaction (RT-nPCR) method was developed for the detection and differentiation of wild-type and vaccine strains of canine distemper virus (CDV). A pair of primers (P1 and P4) specific for CDV corresponding to the highly conserved region of the CDV genome were used as a common primer pair in the first-round PCR of the nested PCR. Primers P2 specific for CDV wild-type strains, were used as the forward primer together with the common reverse primer P4 in the second round of nested PCR. Primers P3, P5 specific for CDV wild-type strain or vaccine strain, were used as the forward primer together with the common reverse primer P4+P6 in the second round of nested PCR. A fragment of 177 bp was amplified from vaccine strain genomic RNA, and a fragment of 247 bp from wild-type strain genomic RNA in the RT-nPCR, and two fragments of 247 bp and 177 bp were amplified from the mixed samples of vaccine and wild-type strains. No amplification was achieved for uninfected cells, or cells infected with Newcastle disease virus (NDV), canine parvovirus (CPV), canine coronavirus (CCV), rabies virus (RV), or canine adenovirus (CAV). The RT-nPCR method was used to detect 30 field samples suspected of canine distemper from Heilongjiang and Jilin Provinces, and 51 samples in Shandong province. As a result of 30 samples, were found to be wild-type-like, and 5 to be vaccine-strain-like. The RT-nPCR method can be used to effectively detect and differentiate wild-type CDV-infected dogs from dogs vaccinated with CDV vaccine, and thus can be used in clinical detection and epidemiological surveillance.
Human neutrophil integrin α9β1: up-regulation by cell activation and synergy with β2 integrins during adhesion to endothelium under flow
Authors: Mambole Agnès , Bigot Sylvain , Baruch Dominique , Lesavre Philippe , Halbwachs-Mecarelli Lise
Published: May 2010

α9β1 is the main β1 integrin of human activated neutrophils; and α9β1/VCAM-1 interactions participate to neutrophilrolling on endothelial cells.

Neutrophil β1 integrin expression and contribution to cell adhesion were revisited in this study. α9β1 and α5β1 appeared here as the main β1 integrins expressed on the membrane of resting platelet-depleted neutrophils—α6β1 representing <15% and α2β1 undetectable. Neutrophil activation slightly enhanced α5 expression, did not change α6, but resulted in a two- to threefold increase of α9β1, which then became the major β1 integrin of the neutrophil membrane. α9β1 was the only β1 integrin to be up-regulated after transendothelial migration across TNF-α-activated HUVECs. As α9β1 binds VCAM-1, we analyzed its participation to neutrophil adhesion to TNF-α-activated endothelial cells. Blocking anti-α9 mAb had little effect on neutrophil static adhesion, contrasting with the strong inhibition by anti-β2 mAb. Under flow conditions, the anti-α9 mAb had no effect by itself on neutrophil adhesion to activated HUVECs but enhanced the blocking effect of anti-β2 antibodies significantly and further enhanced the velocity of β2–blocked rolling neutrophils. In conclusion, we describe here for the first time a nearly exclusive up-regulation of α9β1 expression among all β1 integrins during neutrophil activation and transendothelial migration and a possibly important synergy between α9β1 and β2 integrins in stabilizing neutrophil adhesion to endothelium under flow conditions.
A Tale of Two Cities
Authors: Mehrling Perry
Published: May 2010

Once upon a time, macroeconomics was a field organized around money and the equation of exchange, as in Fisher 1911. Today, the field is organized instead around finance and the intertemporal Euler equation. This article tells the story of how we moved from then to now, a story that revolves around the key role played by Jacob Marschak and the rise of monetary Walrasianism.
Stackelberg Routing in Arbitrary Networks
Authors: Bonifaci Vincenzo , Harks Tobias , Schäfer Guido
Published: May 2010

We investigate the impact of Stackelberg routing to reduce the price of anarchy in network routing games. In this setting, an α fraction of the entire demand is first routed centrally according to a predefined Stackelberg strategy and the remaining demand is then routed selfishly by (nonatomic) players. Although several advances have been made recently in proving that Stackelberg routing can, in fact, significantly reduce the price of anarchy for certain network topologies, the central question of whether this holds true in general is still open. We answer this question negatively by constructing a family of single-commodity instances such that every Stackelberg strategy induces a price of anarchy that grows linearly with the size of the network. Moreover, we prove upper bounds on the price of anarchy of the largest-latency-first (LLF) strategy that only depend on the size of the network. Besides other implications, this rules out the possibility to construct constant-size networks to prove an unbounded price of anarchy. In light of this negative result, we consider bicriteria bounds. We develop an efficiently computable Stackelberg strategy that induces a flow whose cost is at most the cost of an optimal flow with respect to demands scaled by a factor of 1 + √1−α. Finally, we analyze the effectiveness of an easy-to-implement Stackelberg strategy, called SCALE. We prove bounds for a general class of latency functions that includes polynomial latency functions as a special case. Our analysis is based on an approach that is simple yet powerful enough to obtain (almost) tight bounds for SCALE in general networks.
Customer Abandonment in Many-Server Queues
Authors: Dai J. G. , He Shuangchi
Published: May 2010

We study G/G/n + GI queues in which customer patience times are independent, identically distributed following a general distribution. When a customer's waiting time in queue exceeds his patience time, the customer abandons the system without service. For the performance of such a system, we focus on the abandonment process and the queue length process. We prove that under some conditions, a deterministic relationship between the two stochastic processes holds asymptotically under the diffusion scaling when the number of servers n goes to infinity. These conditions include a minor assumption on the arrival processes that can be time-nonhomogeneous and a key assumption that the sequence of diffusion-scaled queue length processes, indexed by n, is stochastically bounded. We also establish a comparison result that allows one to verify the stochastic boundedness by studying a corresponding sequence of systems without customer abandonment.
Models for Minimax Stochastic Linear Optimization Problems with Risk Aversion
Authors: Bertsimas Dimitris , Doan Xuan Vinh , Natarajan Karthik , Teo Chung-Piaw
Published: May 2010

We propose a semidefinite optimization (SDP) model for the class of minimax two-stage stochastic linear optimization problems with risk aversion. The distribution of second-stage random variables belongs to a set of multivariate distributions with known first and second moments. For the minimax stochastic problem with random objective, we provide a tight SDP formulation. The problem with random right-hand side is NP-hard in general. In a special case, the problem can be solved in polynomial time. Explicit constructions of the worst-case distributions are provided. Applications in a production-transportation problem and a single facility minimax distance problem are provided to demonstrate our approach. In our experiments, the performance of minimax solutions is close to that of data-driven solutions under the multivariate normal distribution and better under extremal distributions. The minimax solutions thus guarantee to hedge against these worst possible distributions and provide a natural distribution to stress test stochastic optimization problems under distributional ambiguity.
Linearly Parameterized Bandits
Authors: Rusmevichientong Paat , Tsitsiklis John N.
Published: May 2010

We consider bandit problems involving a large (possibly infinite) collection of arms, in which the expected reward of each arm is a linear function of an r-dimensional random vector Z ∈ ℝr, where r ≥ 2. The objective is to minimize the cumulative regret and Bayes risk. When the set of arms corresponds to the unit sphere, we prove that the regret and Bayes risk is of order Θ(r √T), by establishing a lower bound for an arbitrary policy, and showing that a matching upper bound is obtained through a policy that alternates between exploration and exploitation phases. The phase-based policy is also shown to be effective if the set of arms satisfies a strong convexity condition. For the case of a general set of arms, we describe a near-optimal policy whose regret and Bayes risk admit upper bounds of the form O(r √T log3/2T).
Occupation Times of Jump-Diffusion Processes with Double Exponential Jumps and the Pricing of Options
Authors: Cai Ning , Chen Nan , Wan Xiangwei
Published: May 2010

In this paper, we provide Laplace transform-based analytical solutions to pricing problems of various occupation-time-related derivatives such as step options, corridor options, and quantile options under Kou's double exponential jump diffusion model. These transforms can be inverted numerically via the Euler Laplace inversion algorithm, and the numerical results illustrate that our pricing methods are accurate and efficient. The analytical solutions can be obtained primarily because we derive the closed-form Laplace transform of the joint distribution of the occupation time and the terminal value of the double exponential jump diffusion process. Beyond financial applications, the mathematical results about occupation times of a jump diffusion process are of more general interest in applied probability.
Proximal Alternating Minimization and Projection Methods for Nonconvex Problems: An Approach Based on the Kurdyka-Łojasiewicz Inequality
Authors: Attouch Hédy , Bolte Jérôme , Redont Patrick , Soubeyran Antoine
Published: May 2010

We study the convergence properties of an alternating proximal minimization algorithm for nonconvex structured functions of the type: L(x,y)=f(x)+Q(x,y)+g(y), where f and g are proper lower semicontinuous functions, defined on Euclidean spaces, and Q is a smooth function that couples the variables x and y. The algorithm can be viewed as a proximal regularization of the usual Gauss-Seidel method to minimize L.

We work in a nonconvex setting, just assuming that the function L satisfies the Kurdyka-Łojasiewicz inequality. An entire section illustrates the relevancy of such an assumption by giving examples ranging from semialgebraic geometry to “metrically regular” problems.

Our main result can be stated as follows: If L has the Kurdyka-Łojasiewicz property, then each bounded sequence generated by the algorithm converges to a critical point of L. This result is completed by the study of the convergence rate of the algorithm, which depends on the geometrical properties of the function L around its critical points. When specialized to [Formula: see text] and to f, g indicator functions, the algorithm is an alternating projection mehod (a variant of von Neumann's) that converges for a wide class of sets including semialgebraic and tame sets, transverse smooth manifolds or sets with “regular” intersection. To illustrate our results with concrete problems, we provide a convergent proximal reweighted ℓ1 algorithm for compressive sensing and an application to rank reduction problems.
Spending Constraint Utilities with Applications to the Adwords Market
Authors: Vazirani Vijay V.
Published: May 2010

The notion of a “market” has undergone a paradigm shift with the Internet. Totally new and highly successful markets have been defined and launched by Internet companies, which already form an important part of today's economy and are projected to grow considerably in the future. Another major change is the availability of massive computational power for running these markets in a centralized or distributed manner.

In view of these new realities, the study of market equilibria, an important, though essentially nonalgorithmic, theory within mathematical economics, needs to be revived and rejuvenated via an inherently algorithmic approach. Such a theory should not only address traditional market models, but also define new models for some of the new markets.

We present a new, natural class of utility functions that allow buyers to explicitly provide information on their relative preferences as a function of the amount of money spent on each good. These utility functions offer considerable expressivity, especially in Google's Adwords market. In addition, they lend themselves to efficient computation, while retaining some of the nice properties of traditional models. The latter include weak gross substitutability, and the uniqueness and continuity of equilibrium prices and utilities.
Repeated colonoscopic screening of patients with acromegaly: 15-year experience identifies those at risk of new colonic neoplasia and allows for effective screening guidelines
Authors: Dworakowska D , Gueorguiev M , Kelly P , Monson J P , Besser G M , Chew S L , Akker S A , Drake W M , Fairclough P D , Grossman A B , Jenkins P J
Published: May 2010

Objective

It is suggested that patients with acromegaly have an increased risk of colorectal cancer and pre-malignant adenomatous polyps. However, the optimum frequency with which colonoscopic screening should be offered remains unclear.

Design

To determine the optimum frequency for repeated colonoscopic surveillance of acromegalic patients.

Methods

We retrospectively reviewed the case records of all patients with acromegaly seen in our centre since 1992: 254 patients had at least one surveillance colonoscopy, 156 patients had a second surveillance colonoscopy, 60 patients had a third surveillance colonoscopy and 15 patients had a fourth surveillance colonoscopy.

Results

The presence of hyperplastic or adenomatous polyps was assessed in all patients, while one cancer was detected at the second surveillance. At the third surveillance, mean (±s.d.) serum IGF1 levels (ng/ml) in patients with hyperplastic polyps were significantly higher than those with normal colons (P<0.05). The presence of an adenoma rather than a normal colon at the first colonoscopy was associated with a significantly increased risk of adenoma at the second (odds ratio (OR) 4.4, 95% confidence interval (CI) 1.9–10.4) and at the third (OR 8.8, 95% CI 2.9–26.5) screens. Conversely, a normal colon at the first surveillance gave a high chance of normal findings at the second (78%) or third surveillance (78%), and a normal colon at the second colonoscopy was associated with normality at the third colonoscopy (81%).

Conclusions

Repeated colonoscopic screening of patients with acromegaly demonstrated a high prevalence of new adenomatous and hyperplastic colonic polyps, dependent on both the occurrence of previous polyps and elevated IGF1 levels.