bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of social cognitive theory to web‐based learning through NetPorts
Authors: Wang Shu‐Ling , Lin Sunny S. J.
Published: September 2006

Although the Web allows for flexible learning, research has found that online students tend to lack focus, willingness to participate, confidence, and discipline. This study thus attempts to promote Web‐based self‐regulated learning from the social cognitive perspective, which emphasizes the interactions among personal, behavioral, and environmental influences.

This study has identified the most significant factors for personal, behavioral, and environmental influences in the social cognitive model of self‐regulated learning, and also applied this model to the development of the NetPorts web‐based learning system. NetPorts, in turn, allows us to empirically analyze the interactions between the aforementioned factors. Our Web‐based findings support the social cognitive view of self‐regulated learning: students who hold higher levels of motivation apply more effective strategies, and respond more appropriately to environmental demands, in the Web‐based learning environment. These findings also further validate the application of the social cognitive model to Web‐based learning through the NetPorts.
Providing hearing‐impaired students with learning care after classes through smart phones and the GPRS network
Authors: Liu Chen‐Chung , Hong Yi‐Ching
Published: September 2006

Although computers and network technology have been widely utilised to assist students learn, few technical supports have been developed to help hearing‐impaired students learn in Taiwan. A significant challenge for teachers is to provide after‐class learning care and assistance to hearing‐impaired students that sustain their motivation to participate in continuous learning activities. However, lacking an effective communication channel, teachers cannot easily provide after‐class learning care or instruction to sustain student motivation. This study developed a learning support system to provide after‐class learning care through smart phones and the General Packet Radio Service (GPRS) network. Student reactions identified effective strategies regarding student–teacher interaction while teachers utilised the wireless network and handheld devices to provide learning support. Questionnaire results demonstrated that most students and their parents considered student–teacher interaction and strategies through GPRS and smart phones effective in improving student learning at home.
Does Chevron Matter?
Authors: RICHARDS MARK J. , SMITH JOSEPH L. , KRITZER HERBERT M.
Published: September 2006

In this article we evaluate whether the Supreme Court's much‐discussed decision in Chevron v Natural Resources Defense Council (1984) signaled a lasting difference in how the justices decide administrative law cases, by comparing and testing the predictions of three distinct theories of Supreme Court behavior. The legal model predicts an increase in deference to administrative agencies. This prediction is shared by the jurisprudential regime model, which also predicts that the justices evaluate key case factors differently before and after Chevron. The attitudinal model predicts no change in the justices’ behavior as a result of Chevron. Although we find that attitudes matter, the fact that we also find support for the legal and jurisprudential regime models undermines the assertion of the attitudinal model that law cannot explain Supreme Court votes on the merits.
Incorporating a Built Environment Module into an Accelerated Second‐Degree Community Health Nursing Course
Authors: Hays Judith C. , Davis Jeffrey A. , Miranda Marie Lynn
Published: September 2006

ABSTRACT
Environmental quality is a leading indicator of population health. Environmental health content has been integrated into the curriculum of an Accelerated Bachelor of Science in Nursing program for second‐degree students through development of an environmental health nursing module for the final‐semester community health nursing course. The module was developed through collaboration between two professional schools at Duke University (the School of Nursing and the Nicholas School of the Environment and Earth Sciences). It focused on the role of the built environment in community health and featured a mix of teaching strategies, including five components: (1) classroom lecture with associated readings, (2) two rounds of online small‐group student discussions, (3) assessment of the built environment in local neighborhoods by student teams, (4) team presentation of the neighborhood assessments, and (5) individual student papers synthesizing the conclusions from all team presentations. The goal of the module was to provide nursing students with an organizing framework for integrating environmental health into clinical practice and an innovative tool for understanding community‐level components of public health.
Challenges and Successes of Infusing Environmental Health Content in a Nursing Program
Authors: Hewitt Jeanne Beauchamp , Candek Patricia R. , Engel Jessica M.
Published: September 2006

ABSTRACT
Environmental health has received minimal attention in nursing curricula over the past decade, despite efforts by the Institute of Medicine (1995) and others to advance the environmental health agenda in nursing education, practice, and research. This paper describes an initiative that was first funded as a part of the Environmental Health Scholars Program in 2000 to incorporate environmental health into master's and undergraduate nursing programs at one university. Evaluation of this initiative highlights the challenges and successes experienced in this academic setting. A number of recommendations based on this experience and the literature are offered. There is a perceived need to define the critical body of knowledge and skills in environmental health and to develop tools to enable educators and practitioners to apply this knowledge in public health nursing and other specialty practices. In tandem, opportunities and incentives are needed to encourage faculty development and the infusion of environmental health into existing curricula. Changes are also needed across practice settings to proactively address environmental health issues so that environmental health becomes and remains an integral part of nursing.
DY‐9760e, a Novel Calmodulin Inhibitor, Exhibits Cardioprotective Effects in the Ischemic Heart
Authors: Fukunaga Kohji , Han Feng , Shioda Norifumi , Moriguchi Shigeki , Kasahara Jiro , Shirasaki Yasufumi
Published: September 2006

DY‐9760e (3‐[2‐[4‐(3‐chloro‐2‐methylphenyl)‐1‐piperazinyl]ethyl]‐5,6‐dimethoxy‐1‐(4‐imidazolylmethyl)‐1H‐indazole dihydrochloride‐3.5 hydrate) inhibits Ca2+/CaM‐dependent nitric oxide synthase (NOS), thereby inhibiting nitric oxide (NO) production. In cardiomyocytes from ischemic rat heart NO and superoxide levels are increased causing protein tyrosine nitration. In hearts subjected to ischemia/reperfusion DY‐9760e totally abolishes protein tyrosine nitration. Notably, DY‐9760e also inhibits calpain and cas‐pase‐3 activation that occurs prior to apoptosis in cardiomyocytes. In ischemic hearts fodrin is the substrate for calpain. DY‐9760e inhibits fodrin breakdown in the peri‐infarct area rather than in the infarct core. In the ischemic rat brain DY‐9760e inhibits caspase‐3‐induced proteolysis of calpastatin, an endogenous calpain inhibitor, suggesting that crosstalk between calpain and caspase‐3 is mediated by calpastatin breakdown. Thus, DY‐9760e rescues neurons and cardiomyocytes from ischemic injury by inhibiting crosstalk between calpain and caspase‐3 as well as protein tyrosine nitration.
Pharmacologic Profile and Therapeutic Potential of NCX 4016, a Nitric Oxide‐releasing Aspirin, for Cardiovascular Disorders
Authors: Gresele Paolo , Momi Stefania
Published: September 2006

NCX 4016, 2‐(acetyloxy)benzoic acid 3‐[(nitrooxy)methyl]phenyl ester, is a new molecule in which a nitric oxide (NO)‐releasing moiety is covalently linked to aspirin. After enzymatic metabolism, NCX 4016 releases both components.In vitroand in some animal models, these components exert their pharmacologic effects simultaneously. Nitric oxide (NO) is a small gaseous molecule that exerts several activities which may prevent atherothrombotic disorders. Moreover, it displays a protective activity on the gastric mucosa.

NCX 4016 has been shown to inhibit platelet activationin vitromore effectively than aspirin, to inhibit smooth muscle cell proliferation, to exert an endothelial cell protective activity and to suppress the function of several inflammatory cells potentially involved in atherothrombosis.

In animal models, NCX 4016 protected from platelet thromboembolism, prevented restenosis in atherosclerosis‐prone animals, protected the heart from ischemia/reperfusion injury, and induced neoangiogenesis in critically ischemic limbs. Moreover, it displayed little or no gastric toxicity and appeared to protect stomach from noxious stimuli, including aspirin.

NCX 4016 has been evaluated in healthy volunteers and found to inhibit platelet cyclo‐oxygenase‐1 (COX‐1) similarly to or slightly less than aspirin, to raise the circulating levels of NO‐degradation products, and to have little or no gastric toxicity in short term studies. In particular, in phase II studies, NCX 4016 had favorable effects on effort‐induced endothelial dysfunction in intermittent claudication and on platelet‐activation parameters elicited by short‐term hyperglycemia in type II diabetics. In patients with type II diabetes the effects of NCX 4016 on microalbuminuria and on some hemodynamic parameters were promising. The pharmacokinetics ofin vivoaspirin‐ and NO‐ released by NCX 4016, as well as the bioavailability of the two molecules, were not yet adequately studied. Also, the long‐term tolerability of NCX 4016, as well as its possible effectiveness in preventing ischemic cardiovascular events and progression of atherosclerosis, should be explored.
Cardiovascular Therapeutic Aspects of Soluble Epoxide Hydrolase Inhibitors
Authors: Imig John D.
Published: September 2006

Soluble epoxide hydrolase (sEH) is an enzyme responsible for the conversion of lipid epoxides to diols by the addition of water. Biological actions on the cardiovascular system that are attributed to epoxides include vasodilation, antiinflammatory actions and vascular smooth muscle cell antimigratory actions. Conversion of arachidonic acid epoxides to diols by sEH diminishes the beneficial cardiovascular properties of these epoxyeicosano‐ids. Cardiovascular diseases in animal models and humans have been associated with decreased epoxygenase activity or increased sEH activity and these changes are responsible for the progression of the disease state. More recently, sEH gene polymorphisms in the human population have been associated with increased risk for cardiovascular diseases. Thus the biological actions of epoxyeicosanoids and the sEH enzyme are ideal therapeutic targets for cardiovascular diseases. The rapid development of 1,3‐disubstituted urea based sEH inhibitors over the past five years has resulted in a number of studies demonstrating cardiovascular protection. sEH inhibitors have antihypertensive and antiinflammatory actions and have been demonstrated to decrease cerebral ischemic and renal injury in rat models of hypertension. These findings of beneficial actions in animal models of disease position the sEH enzyme as a promising therapeutic target for cardiovascular diseases.
Improving Recruitment into Geriatric Medicine in Canada: Findings and Recommendations from the Geriatric Recruitment Issues Study
Authors: Torrible Susan J. , Diachun Laura L. , Rolfson Darryl B. , Dumbrell Andrea C. , Hogan David B.
Published: September 2006

As the number of Canadians aged 65 and older continues to increase, declining recruitment into geriatric medicine (GM) raises concerns about the future viability of this medical subspecialty. To develop effective strategies to attract more GM trainees into the field, it is necessary to understand how medical students, residents, GM trainees, and specialists make career choices. The Geriatric Recruitment Issues Study (GRIST) was designed to assess specific methods that could be used to improve recruitment into geriatrics in Canada. Between November 2002 and January 2003, 530 participants were invited to complete the GRIST survey (117 Canadian geriatricians, 12 GM trainees, 96 internal medicine residents, and 305 senior medical students). Two hundred fifty‐three surveys (47.7%) were completed and returned (from 54 participating geriatricians, 9 GM trainees, 50 internal medicine residents, and 140 senior medical students). The survey asked respondents to rate factors influencing their choice of medical career, the attractiveness of GM, and the anticipated effectiveness of potential recruitment strategies. Although feedback varied across the four groups on these issues, consistencies were observed between medical students and residents and between GM trainees and geriatricians. All groups agreed that role modeling was effective and that summer student research programs were an ineffective recruitment strategy. Based on the GRIST findings, this article proposes six recommendations for improving recruitment into Canadian geriatric medicine training programs.
The Pricing of Insurer Demutualization Initial Public Offerings
Authors: Viswanathan Krupa S.
Published: September 2006

Abstract

This article examines the pricing of the initial public offerings (IPOs) that follow insurance company demutualizations. Insurers that convert from mutual to stock form typically cite the need for capital as a key motivation. Given that capital adequacy is a primary regulatory objective for insurers, one would expect that for a given number of shares to be sold, these firms would price their offerings to maximize proceeds. However, the vast literature on IPO pricing suggests various theories as to why it may be in the issuing firm's best interest to underprice its offering. By examining the initial and long‐run stock returns for these conversion IPOs, the existence and degree of underpricing, as characterized by large initial returns, can be determined. It is observed that on average demutualization insurer IPOs post significantly higher first‐day returns than nondemutualization insurer IPOs. These gains would accrue to the initial investors and to those policyholders who receive compensation in the form of shares in the newly created stock insurer. Attractive returns are sustained for both groups of insurers during the first few years after IPO.
Pareto‐Optimal Insurance Policies in the Models with a Premium Based on the Actuarial Value
Authors: Golubin A. Y.
Published: September 2006

Abstract

This article analyzes the problem of designing Pareto‐optimal insurance policies when both the insurer and the insured are risk averse and the premium is calculated as a function of the actuarial value of the insurer's risk. Two models are considered: in the first, the set of admissible policies is constrained by a given size of the premium; in the second, the premium size is not constrained so that it varies with the actuarial value of a policy chosen by the agents. For both cases a characterization of the Pareto‐optimal policies is derived. The corresponding optimality equations for the Pareto‐optimal policies are obtained and compared with the results on the classical risk exchange model.
Multi‐Event Bonus‐Malus Scales
Authors: Pitrebois Sandra , Denuit Michel , Walhin Jean‐François
Published: September 2006

Abstract

This article is devoted to the design of bonus‐malus scales involving different types of claims. Typically, claims with or without bodily injuries, or claims with full or partial liability of the insured driver, are distinguished and entail different penalties. Under mild assumptions, claim severities can also be taken into account in this way. Numerical illustrations enhance the interest of the approach.
A Voluntary Deductible in Social Health Insurance with Risk Equalization: “Community‐Rated or Risk‐Rated Premium Rebate?”
Authors: Van Kleef Richard C. , Van De Ven Wynand P. M. M. , Van Vliet René C. J. A.
Published: September 2006

Abstract

On January 1, 2006 a new mandatory basic health insurance will be introduced in the Netherlands. One aspect of the new scheme is that the insured can choose to have a deductible. This option should increase the individual responsibility and reduce moral hazard. In the new scheme, a risk equalization system is aimed at avoiding preferred risk selection and insolvency of insurance companies with a relatively high‐risk pool. A crucial issue with respect to a voluntary deductible in this type of social health insurance is whether the premium rebate should be community rated or risk rated. The Dutch government has chosen the former, which means that the premium rebate will be independent of health status and risk. Our analysis shows that, in a situation with “accurate” risk equalization, a community‐rated premium rebate could lead to an adverse selection spiral. Over time, this spiral results in none of the insured taking a deductible and thus no reduction in moral hazard.
In Search of Prudence: The Hidden Problem of Managerial Reform
Authors: Kane John , Patapan Haig
Published: September 2006

This article argues that the concept of prudence can provide valuable insights into the problems of the New Public Management. Prudence, or practical wisdom, is the ability to make sound decisions under complex, ever‐changeable conditions. Old‐style bureaucracy severely limited the discretion of most administrators but preserved a site of true prudential judgment at the peak where discreet “mandarins” policed the boundary between politics and administration. The reforms that inaugurated New Public Management dismantled this site of prudence while simultaneously attempting, in effect, to disperse prudential judgment and action throughout the service. Though raising the problem of prudence, these reforms misconceived it as the problem of how to balance new freedoms with new controls to prevent abuse or folly. This essay argues that the introduction of market mechanisms, risk‐management and cost‐benefit techniques, ethics training, performance accountability, and calls to leadership were destined to fail because they misapprehended the problem of prudence.
New Public Management à la Française: The Case of Regional Hospital Agencies
Authors: Minvielle Etienne
Published: September 2006

In 1996, French authorities—committed to developing an innovative, decentralized style of public intervention in a country with a reputation for administrative conservatism and a historical bias toward centralization—created the Regional Hospital Agencies. The author asks whether these agencies exemplify the modernization of French public administration. A survey of all 26 such agencies indicates that they did introduce novel management practices and do, in fact, illustrate New Public Management “ à la française.”
Transforming the FBI: A Challenge of Culture, Resources, and Mission
Authors: Vizzard William
Published: September 2006

A recent review of restructuring efforts at the Federal Bureau of Investigation published by the National Academy of Public Administration examines several studies that precipitated the reorganization and discusses the current state of counterterrorism, intelligence, and internal security functions within the agency. However, the report fails to seriously engage the benefits of restructuring federal agencies to separate criminal investigation from antiterrorism or to address the financial implications of the current reorganization. Although it provides a useful overview of current changes within the FBI, it lacks theoretical linkages.
How Religiosity Helps Couples Prevent, Resolve, and Overcome Marital Conflict*
Authors: Lambert Nathaniel M. , Dollahite David C.
Published: September 2006

Abstract: This study reports on in‐depth interviews with 57 highly religious, middle‐aged married couples representing the major Abrahamic faiths (Christianity, Judaism, Islam) residing in New England and Northern California. The study uses grounded theory methods to create themes and a model describing the ways that religiosity influences marital conflict. Couples reported that religiosity affects the conflict in their marriage at three phases of the conflict process: (a) problem prevention, (b) conflict resolution, and (c) relationship reconciliation. Practitioners may assist religious couples that are struggling with marital conflict by encouraging them to look to religious beliefs and practices.
Design issues with clinical experimental platelet transfusion studies
Authors: HEDDLE NANCY M. , COOK RICHARD J.
Published: September 2006

Evidence‐based platelet transfusion therapy has been facilitated by a recent number of clinical trials addressing issues of optimal trigger, dose, product efficacy and adverse events. Valid results depend upon carefully planning the study including: developing a well‐defined research question and hypothesis; selecting the most appropriate study design; identifying all aspects of the optimal intervention to be studied; selecting a clinically relevant outcome measure; determining the sample size requirements; and planning the analysis a priori. Safety issues also need to be considered during the planning stage and often includes the implementation of a data safety monitoring board. Websites that provide useful information and checklists to facilitate researchers when designing clinical studies include: CONSORT (http://www.consort‐statement.org/index.html) and the ICH (International Conference on Harmonization) of Technical Requirements for Registration of Pharmaceutical for Human use (http://www.ich.org).
A strategy for platelet transfusion in patients with alloantibodies to platelets
Authors: SKOGEN BJØRN , HUSEBEKK ANNE
Published: September 2006

Although antibody‐dependent platelet transfusion refractoriness has become less frequent with the introduction of leukocyte filtration of platelet concentrates, it remains a challenge in transfusion medicine. Small transfusion centers do not have easy access to an inventory of human leukocyte antigen (HLA)‐typed platelet donors. As flow cytometry has become more common, this technology can easily be introduced in platelet crossmatching, with sensitivity and predictive values comparable to those of other techniques, and with the advantage of automation. An algorithm is presented for use of flow cytometry in the selection of compatible platelets for alloimmunized patients.
Cold-Seep Mollusks Are Older Than the General Marine Mollusk Fauna
Authors: Kiel Steffen , Little Crispin T. S.
Published: September 2006

The origin and possible antiquity of faunas at deep-sea hydrothermal vents and seeps have been debated since their discovery. We used the fossil record of seep mollusks to show that the living seep genera have significantly longer geologic ranges than the marine mollusks in general, but have ranges similar to those of deep-sea taxa, suggesting that seep faunas may be shaped by the factors that drive the evolution of life in the deep sea in general. Our data indicate that deep-sea anoxic/dysoxic events did not affect seep faunas, casting doubt on the suggested anoxic nature and/or global extent of these events.
Response to Comment on "Transitions to Asexuality Result in Excess Amino Acid Substitutions"
Authors: Paland Susanne , Lynch Michael
Published: September 2006

Asexual populations experience a reduction in the efficiency of selection when compared with sexual populations. Because asexual lineages of
Daphnia pulex
exhibit no consistent change in mitochondrial base-composition bias, Butlin suggests that this bias is not maintained by selection. On the basis of frequencies of polymorphic directional base changes, we suggest that it predominantly reflects mutation bias.
Exotic Earths: Forming Habitable Worlds with Giant Planet Migration
Authors: Raymond Sean N. , Mandell Avi M. , Sigurdsson Steinn
Published: September 2006

Close-in giant planets (e.g., “hot Jupiters”) are thought to form far from their host stars and migrate inward, through the terrestrial planet zone, via torques with a massive gaseous disk. Here we simulate terrestrial planet growth during and after giant planet migration. Several-Earth-mass planets also form interior to the migrating jovian planet, analogous to recently discovered “hot Earths.” Very-water-rich, Earth-mass planets form from surviving material outside the giant planet's orbit, often in the habitable zone and with low orbital eccentricities. More than a third of the known systems of giant planets may harbor Earth-like planets.
Washing Away Your Sins: Threatened Morality and Physical Cleansing
Authors: Zhong Chen-Bo , Liljenquist Katie
Published: September 2006

Physical cleansing has been a focal element in religious ceremonies for thousands of years. The prevalence of this practice suggests a psychological association between bodily purity and moral purity. In three studies, we explored what we call the “Macbeth effect”—that is, a threat to one's moral purity induces the need to cleanse oneself. This effect revealed itself through an increased mental accessibility of cleansing-related concepts, a greater desire for cleansing products, and a greater likelihood of taking antiseptic wipes. Furthermore, we showed that physical cleansing alleviates the upsetting consequences of unethical behavior and reduces threats to one's moral self-image. Daily hygiene routines such as washing hands, as simple and benign as they might seem, can deliver a powerful antidote to threatened morality, enabling people to truly wash away their sins.
Two Years at Meridiani Planum: Results from the Opportunity Rover
Authors: Squyres S. W. , Knoll A. H. , Arvidson R. E. , Clark B. C. , Grotzinger J. P. , Jolliff B. L. , McLennan S. M. , Tosca N. , Bell J. F. , Calvin W. M. , Farrand W. H. , Glotch T. D. , Golombek M. P. , Herkenhoff K. E. , Johnson J. R. , Klingelhöfer G. , McSween H. Y. , Yen A. S.
Published: September 2006

The Mars Exploration Rover Opportunity has spent more than 2 years exploring Meridiani Planum, traveling ∼8 kilometers and detecting features that reveal ancient environmental conditions. These include well-developed festoon (trough) cross-lamination formed in flowing liquid water, strata with smaller and more abundant hematite-rich concretions than those seen previously, possible relict “hopper crystals” that might reflect the formation of halite, thick weathering rinds on rock surfaces, resistant fracture fills, and networks of polygonal fractures likely caused by dehydration of sulfate salts. Chemical variations with depth show that the siliciclastic fraction of outcrop rock has undergone substantial chemical alteration from a precursor basaltic composition. Observations from microscopic to orbital scales indicate that ancient Meridiani once had abundant acidic groundwater, arid and oxidizing surface conditions, and occasional liquid flow on the surface.
How Do Scientists Think?
Authors: Lagnado David
Published: September 2006

The Psychology of Science and the Origins of the Scientific Mind
.
By Gregory J. Feist
. Yale University Press, New Haven, CT, 2006. 336 pp. $38, £25. ISBN 0-300-11074-X.

Discussing the evolutionary origins of the human mind and the role of psychological forces in shaping individuals' scientific interests and talents, Feist argues for a discipline of the psychology of science.
Altered Enzyme-Linked Immunosorbent Assay Immunoglobulin M (IgM)/IgG Optical Density Ratios Can Correctly Classify All Primary or Secondary Dengue Virus Infections 1 Day after the Onset of Symptoms, when All of the Viruses Can Be Isolated
Authors: Falconar Andrew K. I. , de Plata Elsa , Romero-Vivas Claudia M. E.
Published: September 2006

We compared dengue virus (DV) isolation rates and tested whether acute primary (P) and acute/probable acute secondary (S/PS) DV infections could be correctly classified serologically when the patients' first serum (S1) samples were obtained 1 to 3 days after the onset of symptoms (AOS). DV envelope/membrane protein-specific immunoglobulin M (IgM) capture and IgG capture enzyme-linked immunosorbent assay (ELISA) titrations (1/log
10
1.7 to 1 log
10
6.6 dilutions) were performed on 100 paired S1 and S2 samples from suspected DV infections. The serologically confirmed S/PS infections were divided into six subgroups based on their different IgM and IgG responses. Because of their much greater dynamic ranges, IgG/IgM ELISA titer ratios were more accurate and reliable than IgM/IgG optical density (OD) ratios recorded at a single cutoff dilution for discriminating between P and S/PS infections. However, 62% of these patients' S1 samples were DV IgM and IgG titer negative (<OD
max
/2 titer threshold), and in 35% of the S/PS infections, the patients' S1 and S2 samples were IgM titer negative. The IgM OD values were, however, much higher than those of IgG in the S1 samples of many of these, and the other, S/PS infections. This necessitated using higher (≥2.60 and <2.60) discriminatory IgM/IgG OD (DOD) ratios on these S1 samples than those published previously to correctly classify the highest percentage of these P and S/PS infections. The DV isolation rate was highest (12/12; 100%) using IgG and IgM titer-negative S1 samples collected 1 day AOS, when 100% of them were correctly classified as P or S/PS infections using these higher DOD ratios.
Cattle Husbandry in Ethiopia Is a Predominant Factor Affecting the Pathology of Bovine Tuberculosis and Gamma Interferon Responses to Mycobacterial Antigens
Authors: Ameni Gobena , Aseffa Abraham , Engers Howard , Young Douglas , Hewinson Glyn , Vordermeier Martin
Published: September 2006

Bovine tuberculosis is a major economic problem and a potential public health risk. Improved diagnostics like the gamma interferon (IFN-γ) test with ESAT6 and/or CFP10 could contribute to the control program. We assessed IFN-γ responses in zebu (Ethiopian Arsi breed) and Holstein cattle kept indoors or in a pasture to tuberculin purified protein derivative (PPD) and an ESAT6-CFP10 protein cocktail. Furthermore, the intensity and distribution of pathology of bovine tuberculosis were compared between the two breeds. Our data demonstrated significantly (all
P
< 0.02) higher IFN-γ responses to avian PPD, bovine PPD, and the ESAT6-CFP10 protein cocktail in Holstein than in zebu cattle, while lesion severities in infected animals and tuberculin skin test responses did not differ significantly (
P
> 0.05) between the two breeds. Holstein cattle that were kept indoors produced significantly (all
P
< 0.01) higher IFN-γ levels in response to avian PPD, bovine PPD, and the ESAT6-CFP10 protein cocktail than did Holstein cattle kept in a pasture. Moreover, lesion severity was significantly higher in Holstein cattle kept indoors (
P
= 0.001) than in those kept in the pasture. Lesions were localized predominantly in the digestive tract in cattle kept in a pasture, while they were localized in the respiratory tract in cattle kept indoors. In conclusion, in Holstein cattle, husbandry was a dominant factor influencing the severity of tuberculosis lesions and IFN-γ responses to mycobacterial antigens compared to breed. A difference in the cellular immune response between zebu and Holstein cattle was observed, while tuberculosis lesion severities were identical in the two breeds, when both were kept in a pasture.
Distinct Contributions of Vaccine-Induced Immunoglobulin G1 (IgG1) and IgG2a Antibodies to Protective Immunity against Influenza
Authors: Huber Victor C. , McKeon Raelene M. , Brackin Martha N. , Miller Laura A. , Keating Rachael , Brown Scott A. , Makarova Natalia , Perez Daniel R. , MacDonald Gene H. , McCullers Jonathan A.
Published: September 2006

Vaccination represents the most effective form of protection against influenza infection. While neutralizing antibodies are typically measured as a correlate of vaccine-induced protective immunity against influenza, nonneutralizing antibodies may contribute to protection or amelioration of disease. The goal of this study was to dissect the individual contributions of the immunoglobulin G1 (IgG1) and IgG2a antibody isotypes to vaccine-induced immunity against influenza virus. To accomplish this, we utilized an influenza vaccine regimen that selectively enhanced IgG1 or IgG2a antibodies by using either DNA or viral replicon particle (VRP) vectors expressing influenza virus hemagglutinin (HA) (HA-DNA or HA-VRP, respectively). After HA-DNA vaccination, neutralizing antibodies were detected by both in vitro (microneutralization) and in vivo (lung viral titer) methods and were associated with increased IgG1 expression by enzyme-linked immunosorbent assay (ELISA). Vaccination with HA-VRP did not strongly stimulate either neutralizing or IgG1 antibodies but did induce IgG2a antibodies. Expression of IgG2a antibodies in this context correlated with clearance of virus and increased protection against lethal influenza challenge. Increased induction of both antibody isotypes as measured by ELISA was a better correlate for vaccine efficacy than neutralization alone. This study details separate but important roles for both IgG1 and IgG2a expression in vaccination against influenza and argues for the development of vaccine regimens that stimulate and measure expression of both antibody isotypes.
Probiotics Stimulate Production of Natural Antibodies in Chickens
Authors: Haghighi Hamid R. , Gong Jianhua , Gyles Carlton L. , Hayes M. Anthony , Zhou Huaijun , Sanei Babak , Chambers James R. , Sharif Shayan
Published: September 2006

Commensal bacteria in the intestine play an important role in the development of immune response. These bacteria interact with cells of the gut-associated lymphoid tissues (GALT). Among cells of the GALT, B-1 cells are of note. These cells are involved in the production of natural antibodies. In the present study, we determined whether manipulation of the intestinal microbiota by administration of probiotics, which we had previously shown to enhance specific systemic antibody response, could affect the development of natural antibodies in the intestines and sera of chickens. Our findings demonstrate that when 1-day-old chicks were treated with probiotics, serum and intestinal antibodies reactive to tetanus toxoid (TT) andClostridium perfringensalpha-toxin in addition to intestinal immunoglobulin A (IgA) reactive to bovine serum albumin (BSA) were increased in unimmunized chickens. Moreover, IgG antibodies reactive to TT were increased in the intestines of probiotic-treated chickens compared to those of untreated controls. In serum, IgG and IgM reactive to TT and alpha-toxin were increased in probiotic-treated, unimmunized chickens compared to levels in untreated controls. However, no significant difference in serum levels of IgM or IgG response to BSA was observed. These results are suggestive of the induction of natural antibodies in probiotic-treated, unimmunized chickens. Elucidating the role of these antibodies in maintenance of the chicken immune system homeostasis and immune response to pathogens requires further investigation.
Characterization of a Phenotypically Unique Population of CD13+Dendritic Cells Resident in the Spleen
Authors: Zhuang Yan , Mwangi Waithaka , Brown Wendy C. , Davis William C. , Hope Jayne C. , Palmer Guy H.
Published: September 2006

Immature dendritic cells (DCs) resident in bovine spleens represent a distinct CD11a+CD11c+CD13+CD172+CD205+population compared to those circulating in peripheral blood or trafficking via afferent lymph. Upon cytokine-induced maturation, splenic DCs both efficiently present antigen in the stimulation of allogeneic lymphocyte proliferation and recall antigen-specific responses.
Genetic Analysis ofMycobacterium aviumComplex Strains Used for Producing Purified Protein Derivatives
Authors: Semret Makeda , Bakker Douwe , Smart Nonie , Olsen Ingrid , Haslov Kaare , Behr Marcel A.
Published: September 2006

For over a century, purified protein derivatives (PPD) have been used to detect mycobacterial infections in humans and livestock. Among these, reagents to detect infections byMycobacterium aviumcomplex organisms have been produced, but the utility of these reagents has not been clearly established due in part to limited biologic and immunologic standardization. Because there is little information about the strains used to produce these reagents (avian PPD, intracellulare PPD, scrofulaceum PPD, and Johnin), we have performed genetic characterizations of strains used to produce these products. Sequence analysis of 16S rRNA and thehsp65gene provided results concordant with species designations provided forM. avium,Mycobacterium intracellulare, andMycobacterium scrofulaceumorganisms. ForM. aviumstrains, comparative genomic hybridization was performed on a whole-genome DNA microarray, revealing one novel 7.9-kilobase genomic deletion in certain Johnin-producing strains, in addition to genomic variability inherent to the particularM. aviumsubspecies. Our findings indicate that considerable genomic differences exist between organisms used for reagents and the infecting organism being studied. These results serve as a baseline for potency studies of different preparations and should aid in comparative studies of newly discovered antigens for the diagnosis of infection and disease byM. aviumcomplex organisms.
The Yin and Yang of P-TEFb Regulation: Implications for Human Immunodeficiency Virus Gene Expression and Global Control of Cell Growth and Differentiation
Authors: Zhou Qiang , Yik Jasper H. N.
Published: September 2006

The positive transcription elongation factor b (P-TEFb) stimulates transcriptional elongation by phosphorylating the carboxy-terminal domain of RNA polymerase II and antagonizing the effects of negative elongation factors. Not only is P-TEFb essential for transcription of the vast majority of cellular genes, but it is also a critical host cellular cofactor for the expression of the human immunodeficiency virus (HIV) type 1 genome. Given its important role in globally affecting transcription, P-TEFb's activity is dynamically controlled by both positive and negative regulators in order to achieve a functional equilibrium in sync with the overall transcriptional demand as well as the proliferative state of cells. Notably, this equilibrium can be shifted toward either the active or inactive state in response to diverse physiological stimuli that can ultimately affect the cellular decision between growth and differentiation. In this review, we examine the mechanisms by which the recently identified positive (the bromodomain protein Brd4) and negative (the noncoding 7SK small nuclear RNA and the HEXIM1 protein) regulators of P-TEFb affect the P-TEFb-dependent transcriptional elongation. We also discuss the consequences of perturbations of the dynamic associations of these regulators with P-TEFb in relation to the pathogenesis and progression of several major human diseases, such as cardiac hypertrophy, breast cancer, and HIV infection.
The Yeast Actin Cytoskeleton: from Cellular Function to Biochemical Mechanism
Authors: Moseley James B. , Goode Bruce L.
Published: September 2006

All cells undergo rapid remodeling of their actin networks to regulate such critical processes as endocytosis, cytokinesis, cell polarity, and cell morphogenesis. These events are driven by the coordinated activities of a set of 20 to 30 highly conserved actin-associated proteins, in addition to many cell-specific actin-associated proteins and numerous upstream signaling molecules. The combined activities of these factors control with exquisite precision the spatial and temporal assembly of actin structures and ensure dynamic turnover of actin structures such that cells can rapidly alter their cytoskeletons in response to internal and external cues. One of the most exciting principles to emerge from the last decade of research on actin is that the assembly of architecturally diverse actin structures is governed by highly conserved machinery and mechanisms. With this realization, it has become apparent that pioneering efforts in budding yeast have contributed substantially to defining the universal mechanisms regulating actin dynamics in eukaryotes. In this review, we first describe the filamentous actin structures found inSaccharomyces cerevisiae(patches, cables, and rings) and their physiological functions, and then we discuss in detail the specific roles of actin-associated proteins and their biochemical mechanisms of action.
Nuclear ADP-Ribosylation Reactions in Mammalian Cells: Where Are We Today and Where Are We Going?
Authors: Hassa Paul O. , Haenni Sandra S. , Elser Michael , Hottiger Michael O.
Published: September 2006

Since poly-ADP ribose was discovered over 40 years ago, there has been significant progress in research into the biology of mono- and poly-ADP-ribosylation reactions. During the last decade, it became clear that ADP-ribosylation reactions play important roles in a wide range of physiological and pathophysiological processes, including inter- and intracellular signaling, transcriptional regulation, DNA repair pathways and maintenance of genomic stability, telomere dynamics, cell differentiation and proliferation, and necrosis and apoptosis. ADP-ribosylation reactions are phylogenetically ancient and can be classified into four major groups: mono-ADP-ribosylation, poly-ADP-ribosylation, ADP-ribose cyclization, and formation ofO-acetyl-ADP-ribose. In the human genome, more than 30 different genes coding for enzymes associated with distinct ADP-ribosylation activities have been identified. This review highlights the recent advances in the rapidly growing field of nuclear mono-ADP-ribosylation and poly-ADP-ribosylation reactions and the distinct ADP-ribosylating enzyme families involved in these processes, including the proposed family of novel poly-ADP-ribose polymerase-like mono-ADP-ribose transferases and the potential mono-ADP-ribosylation activities of the sirtuin family of NAD+-dependent histone deacetylases. A special focus is placed on the known roles of distinct mono- and poly-ADP-ribosylation reactions in physiological processes, such as mitosis, cellular differentiation and proliferation, telomere dynamics, and aging, as well as “programmed necrosis” (i.e., high-mobility-group protein B1 release) and apoptosis (i.e., apoptosis-inducing factor shuttling). The proposed molecular mechanisms involved in these processes, such as signaling, chromatin modification (i.e., “histone code”), and remodeling of chromatin structure (i.e., DNA damage response, transcriptional regulation, and insulator function), are described. A potential cross talk between nuclear ADP-ribosylation processes and other NAD+-dependent pathways is discussed.
QUANTUM EFFECTS IN THE THREE-DIMENSIONAL DILUTE BOSE SYSTEM AT FINITE TEMPERATURE: RENORMALIZATION GROUP APPROACH
Authors: CRISAN M. , TRIF M. , GROSU I.
Published: September 2006

We consider the influence of temperature on the critical behavior of the weakly interacting three-dimensional Bose system. Using the flow equations of the Renormalization group and a Φ4 model with dynamical critical exponent z = 2, we calculated the critical exponent ν, and the thermodynamic parameters near the critical temperature, taking into consideration the quantum effects. The quantum effects considered in this method gives ν the value 0.75, which is close to the value 0.73 obtained by the polynomial method. The critical temperature shift ΔTc was obtained, in the lowest order approximation, proportional to the scattering length.
MARKOV CHAIN PERTURBATIONS OF A CLASS OF PARTIALLY EXPANDING ATTRACTORS
Authors: LIU PEIDONG , ZHENG YAN
Published: September 2006

In this paper Markov chain perturbations of a class of partially expanding attractors of a diffeomorphism are considered. We show that, under some regularity conditions on the transition probabilities, the zero-noise limits of stationary measures of the Markov chains are Sinai–Ruelle–Bowen measures of the diffeomorphism on the attractors.
RANDOM DYNAMICAL SYSTEMS ON ORDERED TOPOLOGICAL SPACES
Authors: KELLERER HANS G. , WINKLER G.
Published: September 2006

Let (Xn, n ≥ 0) be a random dynamical system and its state space be endowed with a reasonable topology. Instead of completing the structure as common by some linearity, this study stresses — motivated in particular by economic applications — order aspects. If the underlying random transformations are supposed to be order-preserving, this results in a fairly complete theory. First of all, the classical notions of and familiar criteria for recurrence and transience can be extended from discrete Markov chain theory. The most important fact is provided by the existence and uniqueness of a locally finite-invariant measure for recurrent systems. It allows to derive ergodic theorems as well as to introduce an attract or in a natural way. The classification is completed by distinguishing positive and null recurrence corresponding, respectively, to the case of a finite or infinite invariant measure; equivalently, this amounts to finite or infinite mean passage times. For positive recurrent systems, moreover, strengthened versions of weak convergence as well as generalized laws of large numbers are available.
STABILIZATION OF CONTROLLED DIFFUSIONS AND ZUBOV'S METHOD
Authors: CAMILLI FABIO , CESARONI ANNALISA , GRÜNE LARS , WIRTH FABIAN
Published: September 2006

We consider a controlled stochastic system which is exponentially stabilizable in probability near an attractor. Our aim is to characterize the set of points which can be driven by a suitable control to the attractor with either positive probability or with probability one. This will be done by associating to the stochastic system a suitable control problem and the corresponding Zubov equation. We then show that this approach can be used as a basis for numerical computations of these sets.
SIMILARITIES OF ORDERED GENE LISTS
Authors: YANG XINAN , BENTINK STEFAN , SCHEID STEFANIE , SPANG RAINER
Published: September 2006

Motivation: Many applications of microarray technology in clinical cancer studies aim at detecting molecular features for refined diagnosis. In this paper, we follow an opposite rationale: we try to identify common molecular features shared by phenotypically distinct types of cancer using a meta-analysis of several microarray studies. We present a novel algorithm to uncover that two lists of differentially expressed genes are similar, even if these similarities are not apparent to the eye. The method is based on the ordering in the lists.

Results: In a meta-analysis of five clinical microarray studies we were able to detect significant similarities in five of the ten possible comparisons of ordered gene lists. We included studies, where not a single gene can be significantly associated to outcome. The detection of significant similarities of gene lists from different microarray studies is a novel and promising approach. It has the potential to improve upon specialized cancer studies by exploring the power of several studies in one single analysis. Our method is complementary to previous methods in that it does not rely on strong effects of differential gene expression in a single study but on consistent ones across multiple studies.