bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethanol Suppression of the Hypothalamic Proopiomelanocortin Level and the Splenic NK Cell Cytolytic Activity Is Associated With a Reduction in the Expression of Proinflammatory Cytokines but Not Anti‐inflammatory Cytokines in Neuroendocrine and Immune Cells
Authors: Chen Cui Ping , Boyadjieva Nadka I. , Advis Juan P. , Sarkar Dipak K.
Published: October 2006

Background: Immune signals activate a network of cytokines in the central nervous system (CNS) that in turn causes release of neurotransmitters and hormones to modulate immune cell functions. We have recently shown that hypothalamic β‐endorphin neurons, via inhibition of the sympathetic neuronal activity, activate natural killer (NK) cell function in the spleen, and this communication is disrupted following chronic ethanol administration. β‐Endorphin neuronal function is known to be regulated by various proinflammatory and anti‐inflammatory cytokines. The effects of ethanol on the proinflammatory and anti‐inflammatory cytokines known to control β‐endorphin neuronal and NK cell functions during immune challenges have not been determined.

Methods: In the present study, we evaluated the effects of chronic ethanol consumption on the basal and lipopolysaccharide (LPS)‐activated NK cells' functions in the spleen, the β‐endorphin peptide precursor proopiomelanocortin (POMC) gene expression in the arcuate nucleus (ARC) of the hypothalamus, and mRNA levels of proinflammatory cytokines interleukin‐1β (IL‐1β), tumor necrosis factor α (TNF‐α), and anti‐inflammatory cytokines IL‐6 and IL‐10 in the spleen and in the ARC. Male rats were ad libitum fed rat chow (ad lib‐fed), pair‐fed an isocaloric liquid diet, or fed an ethanol‐containing liquid diet, and each was treated with LPS (100 μg/kg body weight). After 2 hours, splenocytes and ARC tissues were isolated and used for this study. Splenocytes were used to determine mRNA levels of IL‐1β, TNF‐α, IL‐6, IL‐10, granzyme B, and perforin using the real‐time RT‐PCR assays. Splenocytes were also used to determine the cytolytic activity using a standard 4‐hour 51Cr release assay against YAC‐1 lymphoma target cells. Arcuate nuclei were used to determine IL‐1β, TNF‐α, IL‐6, IL‐10, and POMC mRNA levels using real‐time RT‐PCR assays.

Results: The results demonstrate that ethanol feeding via a liquid diet for 2 weeks suppressed both basal and LPS‐stimulated NK cell cytolytic functions and the levels of cytotoxicity‐regulatory perforin and granzyme B mRNAs in the spleen. Ethanol feeding reduced the basal and LPS‐stimulated levels of POMC mRNA in the ARC. Ethanol also impaired LPS‐induced levels of IL‐1β and TNF‐α mRNAs both in the spleen and in the ARC. In contrast, ethanol feeding did not cause any significant changes in basal and the LPS‐stimulated expression of IL‐6 and IL‐10 mRNAs in the spleen and of IL‐6 mRNA levels in the ARC. These results indicate that ethanol suppression of hypothalamic POMC levels and splenic NK cell functions is associated with a reduced expression of proinflammatory cytokines in neuroendocrine and immune cells.
A Theory of Fraud and Overtreatment in Experts Markets
Authors: Alger Ingela , Salanié François
Published: October 2006

Consumers often rely on an expert's diagnosis to assess their needs. If the expert is also the seller of services, he may use his informational advantage to induce overtreatment, which is a pervasive phenomenon in experts markets. We offer and discuss conditions leading to equilibrium overtreatment in an otherwise purely competitive model. This market failure results from consumers' ability to turn down an expert's recommendation: experts defraud consumers to keep them uninformed, as this deters them from seeking a better price elsewhere.
Demand for Customized Products, Production Flexibility, and Price Competition
Authors: Novshek William , Thoman Lynda
Published: October 2006

We examine markets where, in addition to production of standard (core) products, mass customization is technologically feasible. We compare a setting where a monopolist provides both standard and custom goods to a setting where an entrant joins the custom market and find customers' tastes affect the social desirability of entry. The entrant is unconcerned about the impact of its custom production on the incumbent's core product market and in some cases may supply more custom products than is socially desirable. Entry enhances (reduces) social welfare if consumers' core valuations are positively (negatively) related to their value added for customization.
Melatonin inhibits maneb‐induced aggregation of α‐synuclein in rat pheochromocytoma cells
Authors: Ishido Masami
Published: October 2006

Abstract:  Melatonin, a secretory product of the pineal gland, is involved in the regulation of circadian and seasonal rhythms, in oncostasis, and in inducing osteoblast differentiation. Furthermore, melatonin is a scavenger of a number of reactive oxygen and reactive nitrogen species both in vitro and in vivo. In this study, the antioxidant nature of melatonin was shown to prevent cultured neural cells from apoptosis induced by endocrine‐disrupting chemical, maneb. The neurotoxicity of the fungicide, maneb (1 μg/mL), on the PC12 cells was elicited through apoptotic cell death, concomitant with aggregation of α‐synuclein, a feature of Parkinson's disease. Activation of caspase‐3/7 was associated with this process. A fluorescence rationing technique using a mitochondrial dye revealed that maneb altered the mitochondrial membrane potential of the neural cells. However, melatonin (1 nm) largely prevented the neural cells from the neural toxicant by inhibition of both caspase‐3/7 activation and disruption of the mitochondrial transmembrane potential. Furthermore, aggregation of α‐synuclein by maneb was also inhibited by melatonin. Thus, melatonin prevents maneb‐induced neurodegeneration at a nighttime physiological blood concentration, most likely by inhibiting the aggregation of α‐synuclein as well as preventing mitochondrial dysfunction in PC 12 cells.
The Bolger Conference on PDE-5 Inhibition and HIV Risk: Implications for Health Policy and Prevention
Authors: Rosen Raymond C. , Catania Joseph A. , Ehrhardt Anke A. , Burnett Arthur L. , Lue Tom F. , McKenna Kevin , Heiman Julia R. , Schwarcz Sandy , Ostrow David G. , Hirshfield Sabina , Purcell David W. , Fisher William A. , Stall Ron , Halkitis Perry N. , Latini David M. , Elford Jonathan , Laumann Edward O. , Sonenstein Freya L. , Greenblatt David J. , Kloner Robert A. , Lee Jay , Malebranche David , Janssen Erick , Diaz Rafael , Klausner Jeffrey D. , Caplan Arthur L. , Jackson Graham , Shabsigh Ridwan , Khalsa Jag H. , Stoff David M.
Published: October 2006

Introduction

Recent reports have linked the use of phosphodiesterase type 5 (PDE-5) inhibitors with increased rates of high-risk sexual behavior and HIV transmission in some individuals.

Aim

A National Institute of Mental Health (NIMH)-funded, multidisciplinary conference was convened to evaluate scientific research, clinical and ethical considerations, and public policy implications of this topic.

Main Outcome Measures

Published and unpublished findings on effects of PDE-5 inhibitors on sexual behavior; published guidelines and management recommendations.

Methods

Leading investigators in relevant disciplines (e.g., public health, epidemiology, medical ethics, urology, psychology) participated in a 2-day meeting, including representatives of government, scientific, and regulatory agencies (the Centers for Disease Control, Food and Drug Administration, NIMH, and the National Institute on Drug Abuse). Panelists provided critical reviews of substantive areas of research, followed by question and answer sessions on each topic. On the second day, working groups were convened to identify critical gaps and priorities in three major areas: (i) research and evaluation needs; (ii) prevention strategies and clinical management issues; and (iii) policy and prevention implications.

Results

Research needs and priorities were categorized into four specific areas: (i) basic and clinical/laboratory research; (ii) epidemiology and risk factors; (iii) social-behavioral processes and interventions; and (iv) prevention/policy and educational needs. Identified gaps in the available data include populations at risk (e.g., risk among heterosexuals, risk profiles among subpopulations of men who have sex with men) and the specific role of PDE-5 inhibitors in HIV seroconversion. Specific areas of emphasis were the need for safer sex counseling, comprehensive sexually transmitted infection (STI) screening and follow-up when indicated, avoidance of potentially dangerous drug interactions, and potential benefits of testosterone replacement for HIV-positive men with decreased androgen and other symptoms of hypogonadism.

Conclusions

A conference was convened on the topic of PDE-5 inhibition and HIV risk. This “white paper” summarizes the findings of the conference and recommendations for future research.
Feasibility of the Use of Phosphodiesterase Type 5 Inhibitors in a Pharmacologic Prevention Program for Recurrent Priapism
Authors: Burnett Arthur L. , Bivalacqua Trinity J. , Champion Hunter C. , Musicki Biljana
Published: October 2006

Introduction

Recurrent ischemic priapism is an enigmatic erectile disorder in need of improved clinical interventions to avert its known, potentially serious complications.

Aim

To evaluate the use of a long-term, continuous phosphodiesterase type 5 (PDE5) inhibitor therapeutic regimen in controlling recurrent ischemic priapism and its feasibility in a clinical management program for the disorder.

Main Outcome Measures

The main outcome measure was reduction in frequency or duration of priapism episodes. A secondary outcome measure was preservation of erectile ability.

Methods

We retrospectively evaluated the clinical progress of seven patients (age 22–37 years) with sickle cell disease-associated “stuttering” priapism (N = 4) and idiopathic recurrent priapism (N = 3), who were counseled and consented to the “off-label” use of the PDE5 inhibitors sildenafil citrate and tadalafil. The medications were administered according to a specified therapeutic regimen based on scientific evidence that chronic PDE5 inhibitor administration in priapism contexts effectively reconditions PDE5 regulatory function in the penis. The duration of clinical follow-up extended through 2 years.

Results

All seven patients were confirmed to have recurrent ischemic priapism without identifiable pharmacologic, traumatic, or neoplastic disease associations based on clinical history, physical examination, laboratory testing, and penile diagnostics. PDE5 inhibitor treatment was successful in alleviating or resolving priapism recurrences in six of the seven patients. Erectile function was unchanged in six patients and improved in one patient at last follow-up compared with baseline status. All the patients reported that PDE5 inhibitor therapy was well tolerated and did not cause any adverse effects limiting their continued use of the medication.

Conclusions

Because of their efficacy, safety, and tolerability as shown in this case series, PDE5 inhibitors would appear to have a possible role in a rigorously implemented clinical management program to control recurrent priapism. However, completion of a controlled clinical trial is necessary to confirm the utility of this treatment.
Wide Variability in Laboratory Reference Values for Serum Testosterone
Authors: Lazarou Stephen , Reyes-Vallejo Luis , Morgentaler Abraham
Published: October 2006

Introduction

The laboratory determination of testosterone levels consistent with a diagnosis of hypogonadism is complicated by the availability of multiple testosterone assays and varying reference ranges.

Aim

To assess current laboratory practices regarding availability of testosterone assays and use of reference values.

Methods

A telephone survey of 12 academic, 12 community medical laboratories, and one national laboratory.

Main Outcome Measures

Types of androgen assays offered and determination of reference values.

Results

All of the academic and eight of the community centers performed total testosterone testing. Free testosterone was performed in-house by six of the 12 academic and one community center. Testing for bioavailable testosterone, free androgen index, and percent free testosterone was performed in-house by no more than two centers. There were eight and four different assays used for total and free testosterone, respectively. One national laboratory offered equilibrium dialysis measurement of free testosterone. Of the 25 labs, there were 17 and 13 different sets of reference values for total and free testosterone, respectively. The low reference value for total testosterone ranged from 130 to 450 ng/dL (350% difference), and the upper value ranged from 486 to 1,593 ng/dL (325% difference). Age-adjusted reference values were applied in four centers for total testosterone and in seven labs for free testosterone. All reference values were based on a standard statistical model without regard for clinical aspects of hypogonadism. Twenty-three of the 25 lab directors responded that clinically relevant testosterone reference ranges would be preferable to current standards.

Conclusions

Laboratory reference values for testosterone vary widely, and are established without clinical considerations.
Nurse practitioner’s characteristics and job satisfaction
Authors: Wild Priscilla , Parsons Virgil , Dietz Elizabeth
Published: October 2006

Purpose: To identify the demographics and job satisfaction levels of currently working nurse practitioners (NPs) in California.

Data sources: The Mueller McCloskey Satisfaction Scale (MMSS) was mailed to a random sample of 200 California NPs with active licensure. Descriptive analysis was employed.

Conclusions: The NPs reported high levels of job satisfaction according to the MMSS. Aspects of the job that showed significant levels of satisfaction were schedules, flexibility of hours, and interprofessional relationships. NPs were least satisfied with not having professional opportunities such as participation in nursing research, writing/publishing, and belonging to a department/nursing committee.

Implications for practice: The findings may be used to guide NP recruitment and retention strategies, influence practice issues, and facilitate job satisfaction for NPs by employing agencies.
Association of spinal cord compression seen on magnetic resonance imaging with clinical outcome in 67 dogs with thoracolumbar intervertebral disc extrusion
Authors: Penning V. , Platt S. R. , Dennis R. , Cappello R. , Adams V
Published: October 2006

Objectives:To determine whether there is an association between the degree of transverse spinal cord compression detected by magnetic resonance imaging following thoracolumbar Hansen type 1 intervertebral disc disease in dogs and their presenting and postsurgical neurological status.

Methods:Medical records of 67 dogs with surgically confirmed Hansen type 1 intervertebral disc disease (2000 to 2004) were reviewed to obtain the rate of onset of disease, duration of clinical signs and presurgical and postsurgical neurological grade. Percentage of spinal cord compression was determined on transverse T2‐weighted magnetic resonance images. Linear regression was used to examine the association between spinal cord compression and each of the above variables. Chi‐squared tests were used to examine associations among postsurgical outcome and presurgical variables.

Results:Eighty‐five per cent (57 of 67) of dogs were chondrodystrophoid. Mean spinal cord compression was 53 per cent (sd=219·7, range 14·3 to 84·9 per cent). There was no association between the degree of spinal cord compression and the neurological grade at presentation, rate of onset of disease, duration of clinical signs or postsurgical outcome, with no difference between chondrodystrophoid and non‐chondrodystrophoid dogs.

ClinicalSignificance:The degree of spinal cord compression documented with magnetic resonance imaging in dogs with thoracolumbar Hansen type 1 intervertebral disc disease was not associated with the severity of neurological signs and was not a prognostic indicator in this study.
New clinical practice guidelines for venous thromboembolism prevention: orthopedic surgery as a paradigm
Authors: SAMAMA CHARLES‐MARC , ALBALADEJO PIERRE , LAVERSIN SABINE , MARRET EMMANUEL , MISMETTI PATRICK
Published: October 2006

To produce up‐to‐date clinical practice guidelines on the prevention of venous thromboembolism (VTE) in orthopedic surgery. A Steering Committee defined the scope of the topic, the questions to be answered, and the assessment criteria. A multidisciplinary working group performed a critical appraisal of the literature. The resultant reports and guidelines were submitted for comment and completion of the AGREE questionnaire to peer reviewers, before producing definite guidelines. The report answers the following questions: (i) What is the VTE incidence according to clinical and/or paraclinical criteria in the absence of prophylaxis? (with stratification of VTE risk into low, moderate and high categories); (ii) What is the efficacy and safety of the prophylactic measures used? (iii) When should prophylaxis be introduced and how long should it last? (iv) Does ambulatory surgery affect efficacy and safety of prophylaxis? Apart from answering the above questions, the guidelines provide a summary table. This table stratifies types of surgery into the three risk categories, specifies the recommended prophylaxis for VTE (pharmacological and/or mechanical) and grades each recommendation. In addition, whenever appropriate, the recommended prophylaxis is adjusted to low‐ and high‐risk patients.
Course of D‐dimer concentrations after total knee replacement surgery: effect of allogeneic and unwashed drainage blood transfusion
Authors: MUÑOZ MANUEL , GARCÍA‐ERCE JOSE A. , CUENCA JORGE , SOLANO VICTOR M.
Published: October 2006

Salvage and return of unwashed filtered shed blood (USB) after unilateral total knee replacement (TKR) is a blood‐saving method frequently used to avoid allogeneic blood transfusion (ABT). However, the use of USB is controversial, as it may impair hemostasis when retransfused. We report on 1‐month follow‐up of fibrinolytic activity in TKR patients who received either ABT, USB or no transfusion. One hundred and six consecutive TKR patients entered the study: 88 received no transfusion (group 1), five received ABT (group 2), and 13 received USB (group 3). Blood samples were obtained on day of surgery and postoperative days 1, 7 and 30, and assayed for blood counts, C‐reactive protein (CRP), and D‐dimers. Demographic and clinical data were also collected. There were no differences in demographic data or postoperative infection rate between groups, but length of hospital stay was longer in group 2 (P < 0.05). Postoperative levels of D‐dimers increased on day 1, and remained elevated on day 30 in all groups, but on day 1 they were higher in group 3 (P < 0.05). There were no differences in perioperative levels of CRP between groups, and they correlated with D‐dimers both preoperatively and on day 30. Taken together, these data suggest that surgery for TKR induced an activation of coagulation and fibrinolysis. This situation lasts at least as late as 30 days after surgery, and is not modified by transfusion, except for a transitory induction of fibrinolysis by USB return in the early postoperative period.
The Economics of Information Security
Authors: Anderson Ross , Moore Tyler
Published: October 2006

The economics of information security has recently become a thriving and fast-moving discipline. As distributed systems are assembled from machines belonging to principals with divergent interests, we find that incentives are becoming as important as technical design in achieving dependability. The new field provides valuable insights not just into “security” topics (such as bugs, spam, phishing, and law enforcement strategy) but into more general areas such as the design of peer-to-peer systems, the optimal balance of effort by programmers and testers, why privacy gets eroded, and the politics of digital rights management.
Role of computed tomography in risk assessment for coronary heart disease
Authors: Mittal Tarun K , Barbir Mahmoud , Rubens Michael
Published: October 2006

Coronary heart disease is the most common cause of death in Western countries, with a rising incidence in developing countries. It is part of the spectrum of cardiovascular diseases that have common end points of myocardial infarction, stroke and death. As these end points often occur suddenly and often in those with no known disease, identification of those people at high risk is important. Besides the known traditional risk factors, direct imaging of the calcified plaque as a marker for atherosclerotic disease has been extensively studied with electron beam computed tomography and now with multislice computed tomography. This review discusses the role of computed tomography in assessment of cardiovascular risk in both people with or without symptoms.
Digital photography
Authors: Windsor J S , Rodway G W , Middleton P M , McCarthy S
Published: October 2006

Objective

The emergence of a new generation of “point-and-shoot” digital cameras offers doctors a compact, portable and user-friendly solution to the recording of highly detailed digital photographs and video images. This work highlights the use of such technology, and provides information for those who wish to record, store and display their own medical images.

Methods

Over a 3-month period, a digital camera was carried by a doctor in a busy, adult emergency department and used to record a range of clinical images that were subsequently transferred to a computer database.

Results

In total, 493 digital images were recorded, of which 428 were photographs and 65 were video clips. These were successfully used for teaching purposes, publications and patient records.

Conclusions

This study highlights the importance of informed consent, the selection of a suitable package of digital technology and the role of basic photographic technique in developing a successful digital database in a busy clinical environment.
Modernising Medical Careers foundation programme curriculum competencies: will all rotations allow the necessary skills to be acquired? The consultants' predictions
Authors: Higgins R , Cavendish S
Published: October 2006

The new UK Foundation Programme is competency based, with a trainee's progression dependent on achieving and demonstrating a range of competencies. However, we do not know whether all rotations, comprising different combinations of specialties, will enable the foundation programme trainees to acquire these competencies. Questionnaires were sent to 100 consultants from a range of specialties asking them to predict if a foundation year 1 or foundation year 2 doctor could acquire each competency when working in the consultant's specialty. Views on the competency framework as a whole were also sought. Results suggest that the competencies trainees may acquire depend on the specialties they experience in their rotation. Moreover, a range of competencies may prove difficult to acquire across most of the specialties. This has implications for the composition of foundation programme rotations, for educational and clinical supervision, and for the content and mode of curriculum delivery.
POWER-CONSTRAINED SYSTEM-ON-A-CHIP TEST SCHEDULING USING A GENETIC ALGORITHM
Authors: HARMANANI HAIDAR M. , SALAMY HASSAN A.
Published: October 2006

This paper presents an efficient approach for the test scheduling problem of core-based systems based on a genetic algorithm. The method minimizes the overall test application time of a system-on-a-chip through efficient and compact test schedules. The problem is solved using a "sessionless" scheme that minimizes the number of idle test slots. The method can handle SOC test scheduling with and without power constraints. We present experimental results for various SOC examples that demonstrate the effectiveness of our method. The method achieved optimal test schedules in all attempted cases in a short CPU time.
SIZING CMOS INVERTERS WITH MILLER EFFECT AND THRESHOLD VOLTAGE VARIATIONS
Authors: ANDREEV BORIS , TITLEBAUM EDWARD L. , FRIEDMAN EBY G.
Published: October 2006

The maximum speed of synchronous circuits is generally constrained by the worst case propagation delay, which limits the system clock frequency. Various techniques exist to manage the circuit delay, trading off speed for other system resources. One such approach is to equalize the rise and fall delay times. The primary design parameter for equalizing these delay times is the ratio between the width of the PMOS and NMOS transistors, which determines the relationship between the currents passed along the pull-up and pull-down paths. The variation of the pull-up to pull-down ratio for different circuit parameters is discussed in this paper under the constraint of equal rise and fall delay times. It is shown that the short-circuit current and the Miller capacitance affect the ideal linear relationship between the CMOS inverter delay times and the load capacitance, requiring the pull-up to pull-down ratio to be adjusted as circuit parameters are varied. These effects are more pronounced in deep submicrometer technologies with significant parasitic MOSFET capacitances and threshold voltage variations. Based on analytic and experimental observations, circuit design guidelines are proposed to minimize the Miller effect.
PERFORMANCE ANALYSIS OF A NOVEL M-ARY CODE SELECTED DS-BPAM UWB COMMUNICATION SYSTEM
Authors: BAI ZHIQUAN , XU SHAOYI , ZHANG WEIHUA , KWAK KYUNGSUP
Published: October 2006

A novel M-ary direct sequence ultra wideband (UWB) communication system based on the selection of the direct sequence code is studied in this paper. The proposed M-ary code selected direct sequence bipolar pulse amplitude modulation scheme can achieve high bit rate without increasing the system bandwidth or changing the pulse shape. With the increase of the modulation level M, the system bit error rate will be improved even at lower signal to noise ratio per bit. The exact bit error probability is derived over the AWGN channel and correlation receivers. Both Monte-Carlo simulation and the theoretical analysis prove the efficiency of this M-ary UWB system.
CONJUGACY IN ARTIN GROUPS AND APPLICATION TO THE CLASSIFICATION OF SURFACES
Authors: EDDY GODELLE , SHMUEL KAPLAN , MINA TEICHER
Published: October 2006

We show that the double reversing algorithm proposed by Dehornoy in [3] for solving the word problem in the braid group can also be used to recognize the conjugates of powers of the generators in an Artin group of spherical type. The proof uses a characterization of these powers in terms of their fractional decomposition. This algorithm could have potential applications to braid-based cryptography; it also provides a fast method for testing a necessary condition in the classification of surfaces in algebraic geometry.
Sodium depletion activates the aldosterone-sensitive neurons in the NTS independently of thirst
Authors: Geerling Joel C. , Loewy Arthur D.
Published: October 2006

Thirst and sodium appetite are both critical for restoring blood volume. Because these two behavioral drives can arise under similar physiological conditions, some of the brain sensory sites that stimulate thirst may also drive sodium appetite. However, the physiological and temporal dynamics of these two appetites exhibit clear differences, suggesting that they involve separate brain circuits. Unlike thirst-associated sensory neurons in the hypothalamus, the 11-β-hydroxysteroid dehydrogenase type 2 (HSD2) neurons in the rat nucleus tractus solitarius (NTS) are activated in close association with sodium appetite ( 16 ). Here, we tested whether the HSD2 neurons are also activated in response to either of the two physiological stimuli for thirst: hyperosmolarity and hypovolemia. Hyperosmolarity, produced by intraperitoneal injection of hypertonic saline, stimulated a large increase in water intake and a substantial increase in immunoreactivity for the neuronal activity marker c-Fos within the medial NTS, but not in the HSD2 neurons. Hypovolemia, produced by subcutaneous injection of hyperoncotic polyethylene glycol (PEG), stimulated an increase in water intake within 1–4 h without elevating c-Fos expression in the HSD2 neurons. The HSD2 neurons were, however, activated by prolonged hypovolemia, which also stimulated sodium appetite. Twelve hours after PEG was injected in rats that had been sodium deprived for 4 days, the HSD2 neurons showed a consistent increase in c-Fos immunoreactivity. In summary, the HSD2 neurons are activated specifically in association with sodium appetite and appear not to function in thirst.
fMRI Adaptation Reveals Separate Mechanisms for First-Order and Second-Order Motion
Authors: Ashida Hiroshi , Lingnau Angelika , Wall Matthew B. , Smith Andrew T.
Published: October 2006

A key unresolved debate in human vision concerns whether we have two different low-level mechanisms for encoding image motion. Separate neural mechanisms have been suggested for first-order (luminance modulation) and second-order (e.g., contrast modulation) motion in the retinal image but a single mechanism could handle both. Human functional magnetic resonance imaging (fMRI) has not so far convincingly revealed separate anatomical substrates. To examine whether two separate but co-localized mechanisms might exist, we used the technique of fast fMRI adaptation. We found direction-selective adaptation independently for each type of motion in the motion area V5/MT+ of the human brain. However, there was a total absence of cross-adaptation between first-order and second-order motion stimuli. This was true in both of the two subcomponents of MT+ (MT and MST) and similar results were found in V3A. This pattern of adaptation was consistent with psychophysical measurements of detection thresholds in similar stimulus sequences. The results provide strong evidence for separate neural populations that are responsible for detecting first- and second-order motion.
Broaden Your Views: Implicatures of Domain Widening and the “Logicality” of Language
Authors: Chierchia Gennaro
Published: October 2006

This article presents a unified theory of polarity-sensitive items (PSIs) based on the notion of domain widening. PSIs include negative polarity items (like Italian mai ‘ever’), universal free choice items (like Italian qualunque ‘any/whatever’), and existential free choice items (like Italian uno qualunque ‘a whatever’). The proposal is based on a ‘‘recursive,’’ grammatically driven approach to scalar implicatures that breaks with the traditional view that scalar implicatures arise via post- grammatical pragmatic processes. The main claim is that scalar items optionally activate scalar alternatives that, when activated, are then recursively factored into meaning via an alternative sensitive operator similar to only. PSIs obligatorily activate domain alternatives that are factored into meaning in much the same way.
How Fast Do Students Forget What They Learn in Consumer Behavior? A Longitudinal Study
Authors: Bacon Donald R. , Stewart Kim A.
Published: October 2006

The retention curve for knowledge acquired in a consumer behavior course is explored in a longitudinal study, tracking individual students from 8 to 101 weeks following course completion. Rasch measurement is used to link tests and to achieve intervally scaled measures of knowledge. The findings indicate that most of the knowledge gained in the course is lost within 2 years. Evidence is provided that knowledge acquired at a deep level of understanding is more likely to be retained than knowledge acquired at a surface level of understanding, and knowledge tested more than once during a course is more likely to be retained than knowledge tested only once. No significant differences in retention were observed related to material covered in a project. Implications are discussed.
Looking for Evidence of Public Employee Opposition to Privatization
Authors: Fernandez Sergio , Smith Craig R.
Published: October 2006

Contemporary public administration encompasses a wide variety of service delivery options. During the past two decades, privatization has become an increasingly utilized and legitimized approach. The perception that privatization poses a threat to public employment is seemingly widespread. Indeed, public sector unions often challenge the adoption of privatization programs. There is little evidence that individual rank-and-file public employees oppose privatization, however. In this study, the authors develop a multivariate model of support for privatization. Using a large-size public opinion data set from Georgia, the authors test the model and find that an individual’s employment in the public sector is a predictor of opposition to privatization. The authors then discuss the practical implications of public employee opposition to privatization. The authors conclude with a discussion of ways for reducing such opposition.
A Process for Development and Validation of a Customized Scale to Assess Work Environment in Government Organizations
Authors: Ritchie William J. , Kirche Elias , Rubens Arthur J.
Published: October 2006

This study developed and tested a survey instrument to evaluate work environment in a government organization. A three-phase process, using both qualitative and quantitative methods, is presented for questionnaire development. The instrument measures the workplace domains of satisfaction with workload, communication with coworkers, satisfaction with manager, satisfaction with top management, esprit de corps, and satisfaction with job training.
The Impact of Discipline on the Use and Rapidity of Dismissal in State Governments
Authors: Selden Sally Coleman
Published: October 2006

Although several studies have looked at voluntary turnover in public organizations, little research has examined involuntary turnover and average time to terminate employees in public organizations. This study focuses on the impact of a state’s discipline system on its use and rapidity of discharge of state employees. Results show that factors associated with utilization of dismissal of state employees differ from factors associated with how quickly states terminate employees. This study shows that states adopting at-will employment are no more likely to fire employees than states with civil service employment systems are, but they do terminate employment relationships more quickly.
Symbolic Mobilization?
Authors: Dolan Kathleen
Published: October 2006

The increase in the number of women candidates in American politics has raised questions about whether the presence of these women has an impact on the public by mobilizing attitudes and behaviors. Employing National Election Study data from 1990 to 2004, this work examines whether women candidates influence levels of voter attitudes and behaviors and considers the role of political party and electoral competitiveness in this symbolic mobilization. The results indicate that there is little empirical analysis to support the assumption that the presence of women candidates translates into any widespread increase in political attitudes and behaviors.
A Comparison of Conventional and Internet Political Mobilization
Authors: Krueger Brian S.
Published: October 2006

The high cost of contacting individuals encourages mobilizing institutions to maximize resources by targeting those most likely to effectively respond, resulting in stimulation of the politically engaged, civically skilled, and socioeconomically advantaged. By dramatically reducing communication costs, the Internet should eliminate the underpinning of this “rational prospecting.” However, because most e-mail addresses are not available in public directories and cultural norms make sending unsolicited e-mail politically risky, individuals generally must provide their e-mail address before receiving e-mail messages from political organizations. Online mobilization campaigns should disproportionately contact those with the political motivation and technical ability to submit their e-mail. The author tests these expectations about online political mobilization using a probability sample survey. Although most of the long-standing determinants of offline political mobilization fail to predict online mobilization, political interest and Internet skills powerfully determine online mobilization. However, because socioeconomic status, civic skills, and political interest directly predict online skills, these factors indirectly influence the likelihood of online mobilization.
Using the nucleotide substitution rate matrix to detect horizontal gene transfer
Authors: Hamady Micah , Betterton M D , Knight Rob
Published: October 2006

Background

Horizontal gene transfer (HGT) has allowed bacteria to evolve many new capabilities. Because transferred genes perform many medically important functions, such as conferring antibiotic resistance, improved detection of horizontally transferred genes from sequence data would be an important advance. Existing sequence-based methods for detecting HGT focus on changes in nucleotide composition or on differences between gene and genome phylogenies; these methods have high error rates.

Results

First, we introduce a new class of methods for detecting HGT based on the changes in nucleotide substitution rates that occur when a gene is transferred to a new organism. Our new methods discriminate simulated HGT events with an error rate up to 10 times lower than does GC content. Use of models that are not time-reversible is crucial for detecting HGT. Second, we show that using combinations of multiple predictors of HGT offers substantial improvements over using any single predictor, yielding as much as a factor of 18 improvement in performance (a maximum reduction in error rate from 38% to about 3%). Multiple predictors were combined by using the random forests machine learning algorithm to identify optimal classifiers that separate HGT from non-HGT trees.

Conclusion

The new class of HGT-detection methods introduced here combines advantages of phylogenetic and compositional HGT-detection techniques. These new techniques offer order-of-magnitude improvements over compositional methods because they are better able to discriminate HGT from non-HGT trees under a wide range of simulated conditions. We also found that combining multiple measures of HGT is essential for detecting a wide range of HGT events. These novel indicators of horizontal transfer will be widely useful in detecting HGT events linked to the evolution of important bacterial traits, such as antibiotic resistance and pathogenicity.
High Smac/DIABLO expression is associated with early local recurrence of cervical cancer
Authors: Arellano-Llamas Abril , Garcia Francisco J , Perez Delia , Cantu David , Espinosa Magali , De la Garza Jaime G , Maldonado Vilma , Melendez-Zajgla Jorge
Published: October 2006

Background

In a recent pilot report, we showed that Smac/DIABLO mRNA is expressed de novo in a subset of cervical cancer patients. We have now expanded this study and analyzed Smac/DIABLO expression in the primary lesions in 109 cervical cancer patients.

Methods

We used immunohistochemistry of formalin-fixed, paraffin-embedded tissue sections to analyze Smac/DIABLO expression in the 109 primary lesions. Seventy-eight samples corresponded to epidermoid cervical cancer and 31 to cervical adenocarcinoma. The median follow up was 46.86 months (range 10–186).

Results

Smac/DIABLO was expressed in more adenocarcinoma samples than squamous tumours (71% vs 50%; p = 0.037). Among the pathological variables, a positive correlation was found between Smac/DIABLO immunoreactivity and microvascular density, a marker for angiogenesis (p = 0.04). Most importantly, Smac/DIABLO immunoreactivity was associated with a higher rate of local recurrence in squamous cell carcinoma (p = 0.002, log rank test). No association was found between Smac/DIABLO and survival rates.

Conclusion

Smac/DIABLO expression is a potential marker for local recurrence in cervical squamous cell carcinoma patients.
MR thermometry characterization of a hyperthermia ultrasound array designed using the k-space computational method
Authors: Al-Bataineh Osama M , Collins Christopher M , Park Eun-Joo , Lee Hotaik , Smith Nadine Barrie
Published: October 2006

Background

Ultrasound induced hyperthermia is a useful adjuvant to radiation therapy in the treatment of prostate cancer. A uniform thermal dose (43°C for 30 minutes) is required within the targeted cancerous volume for effective therapy. This requires specific ultrasound phased array design and appropriate thermometry method. Inhomogeneous, acoustical, three-dimensional (3D) prostate models and economical computational methods provide necessary tools to predict the appropriate shape of hyperthermia phased arrays for better focusing. This research utilizes the k-space computational method and a 3D human prostate model to design an intracavitary ultrasound probe for hyperthermia treatment of prostate cancer. Evaluation of the probe includes ex vivo and in vivo controlled hyperthermia experiments using the noninvasive magnetic resonance imaging (MRI) thermometry.

Methods

A 3D acoustical prostate model was created using photographic data from the Visible Human Project®. The k-space computational method was used on this coarse grid and inhomogeneous tissue model to simulate the steady state pressure wavefield of the designed phased array using the linear acoustic wave equation. To ensure the uniformity and spread of the pressure in the length of the array, and the focusing capability in the width of the array, the equally-sized elements of the 4 × 20 elements phased array were 1 × 14 mm. A probe was constructed according to the design in simulation using lead zerconate titanate (PZT-8) ceramic and a Delrin® plastic housing. Noninvasive MRI thermometry and a switching feedback controller were used to accomplish ex vivo and in vivo hyperthermia evaluations of the probe.

Results

Both exposimetry and k-space simulation results demonstrated acceptable agreement within 9%. With a desired temperature plateau of 43.0°C, ex vivo and in vivo controlled hyperthermia experiments showed that the MRI temperature at the steady state was 42.9 ± 0.38°C and 43.1 ± 0.80°C, respectively, for 20 minutes of heating.

Conclusion

Unlike conventional computational methods, the k-space method provides a powerful tool to predict pressure wavefield in large scale, 3D, inhomogeneous and coarse grid tissue models. Noninvasive MRI thermometry supports the efficacy of this probe and the feedback controller in an in vivo hyperthermia treatment of canine prostate.
Factors contributing to intervention fidelity in a multi-site chronic disease self-management program
Authors: Perrin Karen M , Burke Somer Goad , O'Connor Danielle , Walby Gary , Shippey Claire , Pitt Seraphine , McDermott Robert J , Forthofer Melinda S
Published: October 2006

Background and objectives

Disease self-management programs have been a popular approach to reducing morbidity and mortality from chronic disease. Replicating an evidence-based disease management program successfully requires practitioners to ensure fidelity to the original program design.

Methods

The Florida Health Literacy Study (FHLS) was conducted to investigate the implementation impact of the Pfizer, Inc. Diabetes Mellitus and Hypertension Disease Self-Management Program based on health literacy principles in 14 community health centers in Florida. The intervention components discussed include health educator recruitment and training, patient recruitment, class sessions, utilization of program materials, translation of program manuals, patient retention and follow-up, and technical assistance.

Results

This report describes challenges associated with achieving a balance between adaptation for cultural relevance and fidelity when implementing the health education program across clinic sites. This balance was necessary to achieve effectiveness of the disease self-management program. The FHLS program was implemented with a high degree of fidelity to the original design and used original program materials. Adaptations identified as advantageous to program participation are discussed, such as implementing alternate methods for recruiting patients and developing staff incentives for participation.

Conclusion

Effective program implementation depends on the talent, skill and willing participation of clinic staff. Program adaptations that conserve staff time and resources and recognize their contribution can increase program effectiveness without jeopardizing its fidelity.
Themir-84andlet-7paralogous microRNA genes ofCaenorhabditis elegansdirect the cessation of molting via the conserved nuclear hormone receptors NHR-23 and NHR-25
Authors: Hayes Gabriel D. , Frand Alison R. , Ruvkun Gary
Published: October 2006

The let-7 microRNA (miRNA) gene of Caenorhabditis eleganscontrols the timing of developmental events. let-7 is conserved throughout bilaterian phylogeny and has multiple paralogs. Here, we show that the paralog mir-84 acts synergistically with let-7 to promote terminal differentiation of the hypodermis and the cessation of molting in C. elegans. Loss of mir-84 exacerbates phenotypes caused by mutations in let-7, whereas increased expression of mir-84 suppresses a let-7 null allele. Adults with reduced levels of mir-84 and let-7 express genes characteristic of larval molting as they initiate a supernumerary molt. mir-84 and let-7 promote exit from the molting cycle by regulating targets in the heterochronic pathway and also nhr-23 and nhr-25, genes encoding conserved nuclear hormone receptors essential for larval molting. The synergistic action of miRNA paralogs in development may be a general feature of the diversified miRNA gene family.
A direct role for Sox10 in specification of neural crest-derived sensory neurons
Authors: Carney Thomas J. , Dutton Kirsten A. , Greenhill Emma , Delfino-Machín Mariana , Dufourcq Pascale , Blader Patrick , Kelsh Robert N.
Published: October 2006

sox10 is necessary for development of neural and pigment cell derivatives of the neural crest (NC). However, whereas a direct role for Sox10 activity has been established in pigment and glial lineages, this is more controversial in NC-derived sensory neurons of the dorsal root ganglia (DRGs). We proposed that sox10 functioned in specification of sensory neurons, whereas others suggested that sensory neuronal defects were merely secondary to absence of glia. Here we provide evidence that in zebrafish,early DRG sensory neuron survival is independent of differentiated glia. Critically, we demonstrate that Sox10 is expressed transiently in the sensory neuron lineage, and specifies sensory neuron precursors by regulating the proneural gene neurogenin1. Consistent with this, we have isolated a novel sox10 mutant that lacks glia and yet displays a neurogenic DRG phenotype. In conjunction with previous findings, these data establish the generality of our model of Sox10 function in NC fate specification.