Showing papers by "University at Buffalo published in 2008"

The CMS experiment at the CERN LHC

Abstract: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.

Revised Definitions of Invasive Fungal Disease from the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group

Abstract: BACKGROUND: Invasive fungal diseases are important causes of morbidity and mortality. Clarity and uniformity in defining these infections are important factors in improving the quality of clinical studies. A standard set of definitions strengthens the consistency and reproducibility of such studies. METHODS: After the introduction of the original European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) Consensus Group definitions, advances in diagnostic technology and the recognition of areas in need of improvement led to a revision of this document. The revision process started with a meeting of participants in 2003, to decide on the process and to draft the proposal. This was followed by several rounds of consultation until a final draft was approved in 2005. This was made available for 6 months to allow public comment, and then the manuscript was prepared and approved. RESULTS: The revised definitions retain the original classifications of "proven," "probable," and "possible" invasive fungal disease, but the definition of "probable" has been expanded, whereas the scope of the category "possible" has been diminished. The category of proven invasive fungal disease can apply to any patient, regardless of whether the patient is immunocompromised, whereas the probable and possible categories are proposed for immunocompromised patients only. CONCLUSIONS: These revised definitions of invasive fungal disease are intended to advance clinical and epidemiological research and may serve as a useful model for defining other infections in high-risk patients.

A trust-based consumer decision-making model in electronic commerce: The role of trust, perceived risk, and their antecedents

Abstract: Are trust and risk important in consumers' electronic commerce purchasing decisions? What are the antecedents of trust and risk in this context? How do trust and risk affect an Internet consumer's purchasing decision? To answer these questions, we i) develop a theoretical framework describing the trust-based decision-making process a consumer uses when making a purchase from a given site, ii) test the proposed model using a Structural Equation Modeling technique on Internet consumer purchasing behavior data collected via a Web survey, and iii) consider the implications of the model. The results of the study show that Internet consumers' trust and perceived risk have strong impacts on their purchasing decisions. Consumer disposition to trust, reputation, privacy concerns, security concerns, the information quality of the Website, and the company's reputation, have strong effects on Internet consumers' trust in the Website. Interestingly, the presence of a third-party seal did not strongly influence consumers' trust.

Multiphoton Absorbing Materials : Molecular Designs, Characterizations, and Applications

Abstract: 4. Survey of Novel Multiphoton Active Materials 1257 4.1. Multiphoton Absorbing Systems 1257 4.2. Organic Molecules 1257 4.3. Organic Liquids and Liquid Crystals 1259 4.4. Conjugated Polymers 1259 4.4.1. Polydiacetylenes 1261 4.4.2. Polyphenylenevinylenes (PPVs) 1261 4.4.3. Polythiophenes 1263 4.4.4. Other Conjugated Polymers 1265 4.4.5. Dendrimers 1265 4.4.6. Hyperbranched Polymers 1267 4.5. Fullerenes 1267 4.6. Coordination and Organometallic Compounds 1271 4.6.1. Metal Dithiolenes 1271 4.6.2. Pyridine-Based Multidentate Ligands 1272 4.6.3. Other Transition-Metal Complexes 1273 4.6.4. Lanthanide Complexes 1275 4.6.5. Ferrocene Derivatives 1275 4.6.6. Alkynylruthenium Complexes 1279 4.6.7. Platinum Acetylides 1279 4.7. Porphyrins and Metallophophyrins 1279 4.8. Nanoparticles 1281 4.9. Biomolecules and Derivatives 1282 5. Nonlinear Optical Characterizations of Multiphoton Active Materials 1282

Optimal Medical Therapy With or Without Percutaneous Coronary Intervention to Reduce Ischemic Burden Results From the Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) Trial Nuclear Substudy

Abstract: Background— Extent and severity of myocardial ischemia are determinants of risk for patients with coronary artery disease, and ischemia reduction is an important therapeutic goal. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) nuclear substudy compared the effectiveness of percutaneous coronary intervention (PCI) for ischemia reduction added to optimal medical therapy (OMT) with the use of myocardial perfusion single photon emission computed tomography (MPS). Methods and Results— Of the 2287 COURAGE patients, 314 were enrolled in this substudy of serial rest/stress MPS performed before treatment and 6 to 18 months (mean=374±50 days) after randomization using paired exercise (n=84) or vasodilator stress (n=230). A blinded core laboratory analyzed quantitative MPS measures of percent ischemic myocardium. Moderate to severe ischemia encumbered ≥10% myocardium. The primary end point was ≥5% reduction in ischemic myocardium at follow-up. Treatment groups had similar ...

Evidence-Based Psychosocial Treatments for Attention-Deficit/Hyperactivity Disorder

Abstract: Pelham, Wheeler, and Chronis (1998) reviewed the treatment literature on attention-deficit/hyperactivity disorder (ADHD) and concluded behavioral parent training (BPT) and behavioral classroom management (BCM) were well-established treatments for children with ADHD. This review updates and extends the finding of the prior review. Studies conducted since the 1998 review were identified and coded based on standard criteria, and effect sizes were calculated where appropriate. The review reinforces the conclusions of Pelham, Wheeler, and Chronis regarding BPT and BCM. Further, the review shows that intensive peer-focused behavioral interventions implemented in recreational settings (e.g., summer programs) are also well-established. The results of this update are discussed in the context of the existing treatment literature on ADHD. Implications for practice guidelines are suggested, as are directions for future research.

Consistent blind protein structure generation from NMR chemical shift data

Abstract: Protein NMR chemical shifts are highly sensitive to local structure. A robust protocol is described that exploits this relation for de novo protein structure generation, using as input experimental parameters the (13)C(alpha), (13)C(beta), (13)C', (15)N, (1)H(alpha) and (1)H(N) NMR chemical shifts. These shifts are generally available at the early stage of the traditional NMR structure determination process, before the collection and analysis of structural restraints. The chemical shift based structure determination protocol uses an empirically optimized procedure to select protein fragments from the Protein Data Bank, in conjunction with the standard ROSETTA Monte Carlo assembly and relaxation methods. Evaluation of 16 proteins, varying in size from 56 to 129 residues, yielded full-atom models that have 0.7-1.8 A root mean square deviations for the backbone atoms relative to the experimentally determined x-ray or NMR structures. The strategy also has been successfully applied in a blind manner to nine protein targets with molecular masses up to 15.4 kDa, whose conventional NMR structure determination was conducted in parallel by the Northeast Structural Genomics Consortium. This protocol potentially provides a new direction for high-throughput NMR structure determination.

Biocompatible luminescent silicon quantum dots for imaging of cancer cells.

Abstract: Luminescent silicon quantum dots (Si QDs) have great potential for use in biological imaging and diagnostic applications. To exploit this potential, they must remain luminescent and stably dispersed in water and biological fluids over a wide range of pH and salt concentration. There have been many challenges in creating such stable water-dispersible Si QDs, including instability of photoluminescence due their fast oxidation in aqueous environments and the difficulty of attaching hydrophilic molecules to Si QD surfaces. In this paper, we report the preparation of highly stable aqueous suspensions of Si QDs using phospholipid micelles, in which the optical properties of Si nanocrystals are retained. These luminescent micelle-encapsulated Si QDs were used as luminescent labels for pancreatic cancer cells. This paves the way for silicon quantum dots to be a valuable optical probe in biomedical diagnostics.

The Financial and Market Effects of the SEC's Accounting and Auditing Enforcement Releases

Abstract: ed in the Journal of Economic Literature, September 1992, this paper explores three questions related to the SEC's accounting enforcement program: (1) what types of accounting and auditing problems motivate enforcement actions, (2) what are the consequences of investigations on targets' financial statements, managers, and auditors, and (3) how do investors and other market agents view the SEC's actions? The SEC enforcement program, which consists of investigations and subsequent injunctive actions or administrative proceedings against offending registrants and auditors, is designed "to concentrate on particular problem areas and to anticipate emerging problems" (SEC,1989,p.1). The potential for SEC enforcement action provides incentives for corporate officers and independent CPAs to avoid unacceptable practices whose "effective prosecution is essential to preserving the integrity of the disclosure system" (SEC, 1989,p.81). The SEC summarizes its accounting-based enforcement actions in the Accounting and Auditing Enforcement Releases (AAERs). We examined 224 AAERs, issued between April 1982 and April 1989, describing the results of investigations against 188 firms. In the sample period, the SEC most often pursued overstatements of accounts receivable and inventories resulting from premature revenue recognition and delayed write-off, respectively. These two accounts make up 70% of the investigations. The income effects of these financial disclosure violations average more than 50% of reported income. We find that the disclosure of these reporting violations changed expectations of targets' future earnings as reflected in financial analysts' reduced earnings estimated after the disclosures.Disclosures and investigations of reporting violations have other consequences. Typically, targets' managers settle enforcement actions by consenting to an injunction that prohibits future violations of securities laws. Subsequently, more than 72% of the enforcement targets fired or forced the resignations of top managers and 81% were sued by their shareholders. In 42% of our sample, the SEC also censured the target's auditor; criticisms and penalties were more likely for smaller audit firms. In exploring how market agents react to the enforcement process, we focus on market returns around disclosures of alleged reporting violations, investigations, and final settlements. Disclosures of reporting violations are associated with average two-day abnormal returns of -13%; the magnitude of these returns is highly correlated with the earnings impact of the disputed accounting. We also observe abnormal returns of -6% at disclosures of investigations, even when the accounting errors were announced earlier. These negative returns imply substantial incentives for managers to avoid these investigation. We do not observe any changes in targets, share values at the investigations' final settlement. Section 2 describes the SEC enforcement process. Section 3 documents the effects of the SEC investigations and settlements on firms' financial statement, managers, and auditors. Section 4 addresses the stock market's reactions to the disclosure of reporting violations, investigations, and settlements. Section 5 provides conclusions and policy implications.

A Randomized Trial of the Effects of Reducing Television Viewing and Computer Use on Body Mass Index in Young Children

Abstract: The design of this study was a randomized controlled clinical trial. Seventy children aged between 4 and 7 whose BMI was at or above the 75th BMI percentile for age and sex participated. Children were randomized to an intervention to reduce their television viewing and computer use by 50% versus a monitoring control group that did not reduce television viewing or computer use. Age- and sex-standardized BMI (zBMI), television viewing, energy intake, and physical activity were monitored every 6 months during 2 years. Children randomized to the intervention group showed greater reductions in targeted sedentary behavior and energy intake compared with the monitoring control group. Socioeconomic status moderated zBMI change, with the experimental intervention working better among families of low socioeconomic status. Changes in targeted sedentary behavior mediated changes in zBMI. The change in television viewing was related to the change in energy intake but not to the change in physical activity. The researchers concluded that reducing television viewing and computer use may have an important role in preventing obesity and in lowering BMI in young children, and these changes may be related more to changes in energy intake than to changes in physical activity.

Promoting coherent minimum reporting guidelines for biological and biomedical investigations: the MIBBI project

Abstract: The Minimum Information for Biological and Biomedical Investigations (MIBBI) project aims to foster the coordinated development of minimum-information checklists and provide a resource for those exploring the range of extant checklists.

The Medical Home: Growing Evidence to Support a New Approach to Primary Care

Abstract: Introduction: A medical home is a patient-centered, multifaceted source of personal primary health care. It is based on a relationship between the patient and physician, formed to improve the patient’s health across a continuum of referrals and services. Primary care organizations, including the American Board of Family Medicine, have promoted the concept as an answer to government agencies seeking political solutions that make quality health care affordable and accessible to all Americans. Methods: Standard literature databases, including PubMed, and Internet sites of numerous professional associations, government agencies, business groups, and private health organizations identified over 200 references, reports, and books evaluating the medical home and patient-centered primary care. Findings: Evaluations of several patient-centered medical home models corroborate earlier findings of improved outcomes and satisfaction. The peer-reviewed literature documents improved quality, reduced errors, and increased satisfaction when patients identify with a primary care medical home. Patient autonomy and choice also contributes to satisfaction. Although industry has funded case management models demonstrating value superior to traditional fee-for-service reimbursement adoption of the medical home as a basis for medical care in the United States, delivery will require effort on the part of providers and incentives to support activities outside of the traditional face-to-face office visit. Conclusions: Evidence from multiple settings and several countries supports the ability of medical homes to advance societal health. A combination of fee-for-service, case management fees, and quality outcome incentives effectively drive higher standards in patient experience and outcomes. Community/ provider boards may be required to safeguard the public interest. (J Am Board Fam Med 2008;21: 427– 440.)

Security Analyst Superiority Relative to Univariate Time-Series Models in Forecasting Quarterly Earnings

Abstract: Evidence is provided of security analyst (SA) superiority relative to univariate time-series (TS) models in predicting firms' quarterly earnings numbers. It is demonstrated that SA forecast superiority in the sample is attributable to: 1. better use of information that exists on the date that TS model forecasts can be initiated, a contemporaneous advantage, and 2. use of information acquired between the date of initiation of TS model forecasts and the date when SA forecasts are published, a timing advantage.

Comparative Genome Sequence Analysis of Multidrug-Resistant Acinetobacter baumannii

Abstract: The recent emergence of multidrug resistance (MDR) in Acinetobacter baumannii has raised concern in health care settings worldwide. In order to understand the repertoire of resistance determinants and their organization and origins, we compared the genome sequences of three MDR and three drug-susceptible A. baumannii isolates. The entire MDR phenotype can be explained by the acquisition of discrete resistance determinants distributed throughout the genome. A comparison of closely related MDR and drug-susceptible isolates suggests that drug efflux may be a less significant contributor to resistance to certain classes of antibiotics than inactivation enzymes are. A resistance island with a variable composition of resistance determinants interspersed with transposons, integrons, and other mobile genetic elements is a significant but not universal contributor to the MDR phenotype. Four hundred seventy-five genes are shared among all six clinical isolates but absent from the related environmental species Acinetobacter baylyi ADP1. These genes are enriched for transcription factors and transporters and suggest physiological features of A. baumannii that are related to adaptation for growth in association with humans.

Effect of obesity on intensive care morbidity and mortality: a meta-analysis.

Abstract: not associated with an increased risk of intensive care unit mortality (relative risk, 1.00; 95% confidence interval, 0.86‐1.16; p .97). However, duration of mechanical ventilation and intensive care unit length of stay were significantly longer in the obese group by 1.48 days (95% confidence interval, 0.07‐2.89; p .04) and 1.08 days (95% confidence interval, 0.27‐1.88; p .009), respectively, compared with the nonobese group. In a subgroup analysis, an improved survival was observed in obese patients with body mass index ranging between 30 and 39.9 kg/m 2 compared with nonobese patients (relative risk, 0.86; 95% confidence interval, 0.81‐0.91; p < .001). Conclusion: Obesity in critically ill patients is not associated with excess mortality but is significantly related to prolonged duration of mechanical ventilation and intensive care unit length of stay. Future studies should target this population for intervention studies to reduce their greater resource utilization. (Crit Care Med 2008; 36:151‐158)

Efficient Multilevel Brain Tumor Segmentation With Integrated Bayesian Model Classification

Abstract: We present a new method for automatic segmentation of heterogeneous image data that takes a step toward bridging the gap between bottom-up affinity-based segmentation methods and top-down generative model based approaches. The main contribution of the paper is a Bayesian formulation for incorporating soft model assignments into the calculation of affinities, which are conventionally model free. We integrate the resulting model-aware affinities into the multilevel segmentation by weighted aggregation algorithm, and apply the technique to the task of detecting and segmenting brain tumor and edema in multichannel magnetic resonance (MR) volumes. The computationally efficient method runs orders of magnitude faster than current state-of-the-art techniques giving comparable or improved results. Our quantitative results indicate the benefit of incorporating model-aware affinities into the segmentation process for the difficult case of glioblastoma multiforme brain tumor.

Calcium Plus Vitamin D Supplementation and the Risk of Breast Cancer

Abstract: Results Invasive breast cancer incidence was similar in the two groups (528 supplement vs 546 placebo; hazard ratio = 0.96; 95% confidence interval = 0.85 to 1.09). In the nested case – control study, no effect of supplement group assignment on breast cancer risk was seen. Baseline 25-hydroxyvitamin D levels were modestly correlated with total vitamin D intake (diet and supplements) ( r = 0.19, P < .001) and were higher among women with lower BMI and higher recreational physical activity (both P < .001). Baseline 25-hydroxyvitamin D levels were not associated with breast cancer risk in analyses that were adjusted for BMI and physical activity ( P trend = .20).

Self-Compassion and Self-Construal in the United States, Thailand, and Taiwan

Abstract: Self-compassion is a self-attitude construct derived from Buddhist psychology (Neff, 2003a). It entails being kind rather than harshly critical toward oneself, perceiving one's experiences as part of the larger human experience, and holding painful feelings in mindful awareness. Given that self-compassion is an Asian construct, this study compares self-compassion levels in the United States, Thailand, and Taiwan. Results indicate that self-compassion is highest in Thailand and lowest in Taiwan, with the United States falling in between. Interdependence is linked to self-compassion in Thailand only, whereas independence is linked to self-compassion in Taiwan and the United States. Results suggest that self-compassion levels in these societies are linked to specific cultural features rather than general East—West differences. However, self-compassion is significantly associated with well-being in all three cultures.

Corporate Governance and Liquidity

Abstract: We investigate the empirical relation between corporate governance and stock market liquidity. We find that firms with better corporate governance have narrower spreads, higher market quality index, smaller price impact of trades, and lower probability of information-based trading. In addition, we show that changes in our liquidity measures are significantly related to changes in the governance index over time. These results suggest that firms may alleviate information-based trading and improve stock market liquidity by adopting corporate governance standards that mitigate informational asymmetries. Our results are remarkably robust to alternative model specifications, across exchanges, and different measures of liquidity.

Differential gene expression during thermal stress and bleaching in the Caribbean coral Montastraea faveolata.

Abstract: The declining health of coral reefs worldwide is likely to intensify in response to continued anthropogenic disturbance from coastal development, pollution, and climate change. In response to these stresses, reef-building corals may exhibit bleaching, which marks the breakdown in symbiosis between coral and zooxanthellae. Mass coral bleaching due to elevated water temperature can devastate coral reefs on a large geographical scale. In order to understand the molecular and cellular basis of bleaching in corals, we have measured gene expression changes associated with thermal stress and bleaching using a complementary DNA microarray containing 1310 genes of the Caribbean coral Montastraea faveolata. In a first experiment, we identified differentially expressed genes by comparing experimentally bleached M. faveolata fragments to control non-heat-stressed fragments. In a second experiment, we identified differentially expressed genes during a time course experiment with four time points across 9 days. Results suggest that thermal stress and bleaching in M. faveolata affect the following processes: oxidative stress, Ca2+ homeostasis, cytoskeletal organization, cell death, calcification, metabolism, protein synthesis, heat shock protein activity, and transposon activity. These results represent the first medium-scale transcriptomic study focused on revealing the cellular foundation of thermal stress-induced coral bleaching. We postulate that oxidative stress in thermal-stressed corals causes a disruption of Ca2+ homeostasis, which in turn leads to cytoskeletal and cell adhesion changes,

A new class of homoserine lactone quorum-sensing signals

Abstract: Quorum sensing is a term used to describe cell-to-cell communication that allows cell-density-dependent gene expression. Many bacteria use acyl-homoserine lactone (acyl-HSL) synthases to generate fatty acyl-HSL quorum-sensing signals, which function with signal receptors to control expression of specific genes. The fatty acyl group is derived from fatty acid biosynthesis and provides signal specificity, but the variety of signals is limited. Here we show that the photosynthetic bacterium Rhodopseudomonas palustris uses an acyl-HSL synthase to produce p-coumaroyl-HSL by using environmental p-coumaric acid rather than fatty acids from cellular pools. The bacterium has a signal receptor with homology to fatty acyl-HSL receptors that responds to p-coumaroyl-HSL to regulate global gene expression. We also found that p-coumaroyl-HSL is made by other bacteria including Bradyrhizobium sp. and Silicibacter pomeroyi. This discovery extends the range of possibilities for acyl-HSL quorum sensing and raises fundamental questions about quorum sensing within the context of environmental signalling.

Experimental Evaluation of the Effects of a Research-Based Preschool Mathematics Curriculum:

Abstract: A randomized-trials design was used to evaluate the effectiveness of a preschool mathematics program based on a comprehensive model of researchbased curricula development. Thirty-six preschool classrooms were assigned to experimental (Building Blocks), comparison (a different preschool mathematics curriculum), or control conditions. Children were individually pre- and posttested, participating in 26 weeks of instruction in between. Observational measures indicated that the curricula were implemented with fidelity, and the experimental condition had significant positive effects on classrooms’ mathematics environment and teaching. The experimental group score increased significantly more than the comparison group score (effect size = 0.47) and the control group score (effect size = 1.07). Early interventions can increase the quality of the mathematics environment and help preschoolers develop a foundation of mathematics knowledge.

Behavioural biometrics: a survey and classification

Abstract: This study is a survey and classification of the state-of-the-art in behavioural biometrics which is based on skills, style, preference, knowledge, motor-skills or strategy used by people while accomplishing different everyday tasks such as driving an automobile, talking on the phone or using a computer. The authors examine current research in the field and analyse the types of features used to describe different types of behaviour. After comparing accuracy rates for verification of users using different behavioural biometric approaches, researchers address privacy issues which arise or might arise in the future with the use of behavioural biometrics.

Syntheses, Properties, and Potential Applications of Multicomponent Magnetic Nanoparticles†

Abstract: Multicomponent hybrid nanostructures that contain two or more nanometer-scale components have attracted much attention recently owing to the synergistic properties induced by interactions between these different nanometer-scale objects. Herein, we give an overview of the efforts to synthesize multicomponent nanoparticles with at least one component being magnetic, and focus on our recent developments. The syntheses are based on heterogeneous nucleation and growth of a second and third component onto seed nanoparticles. These multicomponent nanoparticles show interesting magnetic, magneto-optical, plasmonic, and semiconducting properties that can be modulated by interfacial interactions between different nanocomponents. This opens up a new avenue to advanced multifunctional nanomaterials for device concepts and applications.

Interpretation of treatment changes in 6-minute walk distance in patients with COPD.

Abstract: There is uncertainty about the interpretation of changes in the 6-min walk distance (6MWD) in chronic obstructive pulmonary disease (COPD) patients and whether the minimal important difference (MID) for this useful outcome measure exists. Data were used from nine trials enrolling a wide spectrum of COPD patients with 6MWD at baseline and follow-up and used to determine threshold values for important changes in 6MWD using three distribution-based methods. Anchor-based methods to determine a MID were also evaluated. Data were included of 460 COPD patients with a mean+/-sd forced expiratory volume in one second (FEV(1)) of 39.2+/-14.1% predicted and 6MWD of 361+/-112 m at baseline. Threshold values for important effects in 6MWD were between 29 and 42 m, respectively, using the empirical rule effect size and the standardised response mean. The threshold value was 35 m (95% confidence interval 30-42 m) based on the standard error of measurement. Correlations of 6MWD with patient-reported anchors were too low to provide meaningful MID estimates. 6-min walk distance should change by approximately 35 m for patients with moderate to severe chronic obstructive pulmonary disease in order to represent an important effect. This corresponds to a 10% change of baseline 6-min walk distance. The low correlations of 6-min walk distance with patient-reported anchors question whether a minimal important difference exists for the 6-min walk distance.