bluuebunny/crossref_metadata_2025 huggingface dataset:
A Principal-Agent Model of Contracting in Major League Baseball
Authors: Miceli Thomas J.
Published: April 2004

Traditional economic analyses of the reserve clause in major league baseball view it as having arisen from the superior bargaining of owners compared to players. This article interprets it instead as promoting efficient investment by teams in player development, given the transferability of player skills to other teams. Using a principal-agent framework, the article shows that limited player mobility emerges as part of the optimal contract between players (principals) and teams (agents).
Differences in the Success of NFL Coaches by Race, 1990-2002
Authors: Madden Janice Fanning
Published: April 2004

Although there have been numerous analyses of racial discrimination in professional sports, none have analyzed football coaching. Analyses of the regular season win records, and of making the playoffs, for National Football League (NFL) teams coached by both African Americans and Whites between 1990 and 2002 show that African American coaches were more successful. The analyses make racial comparisons for overall season records, records in the first year, and records in the year of an involuntary departure for the coach. There is evidence that teams that hire African American coaches are better than those that hire White coaches. Analyses that consider team quality effects also find significantly better performance by African Americans. African American coaches have been insignificantly less successful in the playoffs, however. Overall, the results are consistent with African American coaches being held to higher standards to get their jobs in the NFL.
Antitrust, Professional Sports, and the Public Interest
Authors: Ross Stephen F.
Published: April 2004

In a number of important cases, antitrust tribunals have intervened in ways that have significantly affected how professional sports are conducted in the United States. This article focuses on 10 important decisions where the courts ruled against sports leagues and will consider whether the public would have been better off with or without antitrust intervention. It is concluded that, in each of these cases, the private ordering challenged by antitrust litigation was not in the public interest. Although in many of the cases an optimal result would be some middle ground between the status quo and the demands of the antitrust plaintiff, in all cases, an optimal result was encouraged or facilitated by intervention.
Labor Relations in Major League Baseball
Authors: Zimbalist Andrew
Published: April 2004

This article explores some of the roots and processes of the contentiousness surrounding baseball labor relations, assesses the new collective bargaining agreement, and examines the history of negotiations that contributed to its structure. The author offers explanations why the 2002 labor agreement is not efficiently structured to achieve its professed goals and argues that the perceived tensions that afflicted the industry in 2002 are not likely to disappear by 2007, when more substantive changes will need to be made in order to avoid another confrontation between labor and management.
Challenging Five Traditional Leadership Principles
Authors: Milstead Jeri A.
Published: April 2004

Long-held principles of leadership may not be effective in today’s world. This article challenges five traditional principles and offers suggestions for the nurse leader to consider when working with colleagues, patients, and families in this new century.
Developing Passion and Excellence in Critical Care Nursing: Proposed Solutions to Current Challenges in Critical Care
Authors: Cortes Tara A.
Published: April 2004

This article addresses significant challenges in the delivery of critical care services in hospitals including the need for partnerships between service and education, the need to strengthen interdisciplinary teams, and educational challenges in preparing critical care nurses at both the specialist and generalist levels. Each of these challenges has a direct impact on the quality-of-care outcomes for critical care patients.
The Medicare Prescription Drug, Improvement, and Modernization Act of 2003
Authors: Jennings Carole P.
Published: April 2004

This article highlights the long-awaited passage of Medicare reform legislation. The new law, titled Medicare Prescription Drug, Improvement, and Modernization Act of 2003, passed by narrow votes in the House and Senate. The drug benefit is explained and the politics of congressional passage is discussed.
Employment-Related Constraints: Determinants of Primary Health Care Access?
Authors: Gleason Robyn Panther , Kneipp Shawn M.
Published: April 2004

This study examines the extent to which sick pay, job flexibility, and availability of after-hours care affect low-income workers’ ability to access primary health care services in a rural north central Florida community (n = 77). Workers with paid leave were as likely to report difficulty accessing health care as workers without paid leave; having more job flexibility, however, significantly reduced workers’ odds of experiencing difficulty accessing sick and preventive care. Reported difficulty leaving work to obtain sick care was also strongly associated with a perceived need for after-hours care. Full-time workers who were ill, did not have the flexibility of leaving work during regular working hours, and had no access to after-hours care reported the greatest difficulty accessing primary health care services.
The Nurse as Change Agent: An Approach to Environmental Health Advocacy Training
Authors: Ortner Pamela M.
Published: April 2004

In 2004, environmental health issues continue to dominate the policy agenda. Nurses, the first or only point of contact for many patients in underserved communities, are well positioned to advocate for a healthier environment. The development of excellent databases for nurses to learn about environmental health issues and develop competencies provides an opportunity for those wishing to be change agents. Nevertheless, a gap exists for nurses wishing to learn about environmental health nursing advocacy. A program, The Nurse and the Environment: Tools for Action (NETFA), was initiated in 2003 and includes information about the nurse’s advocacy role in environmental health as well as case studies about successful environmental health advocacy campaigns specific to Michigan to promote increased awareness of nurses’ need to develop a strong advocacy role. Such a role should include knowledge of policy and political practices and strategies for influencing current environmental health policy and practices.
Insights and Reflections of a Congressional Nurse Detailee
Authors: Pierce Kathleen M.
Published: April 2004

This article reflects on the experiences of Navy Nurse Corps Officer, Captain Kathleen M. Pierce, who was assigned to the congressional office of Daniel K. Inouye (D-Hawaii). In this article, the author offers suggestions to nurses who want a voice in health legislation and policy.
About the Internet
Authors: Pierce Joy
Published: April 2004

This performance-based text uncovers internet knowledge/power inequalities through the use of code. The term codeis used in a very broad sense and goes beyond formal computer science language to include hardware, software, and internet terms that are used in everyday real and “virtual” dialogue. The author argues that the process of the construction of knowledge claims takes place when learning to use the internet. The researcher uses case studies to expose how these codes affect the people on the bottom half of the Digital Divide. Nearly two years of participant observation at a community-based internet program in a small midwestern city inform this work. The primary mission of the program was to provide low-income community residents with tools and access to the internet in order to help bridge the gap in the Digital Divide and to build community networks.
“Reality Goes Pop!”
Authors: Holmes Su
Published: April 2004

The reality pop programs Popstars(broadcast in 2000 in the United Kingdom) and Pop Idol (broadcast in 2001-2002 in the United Kingdom) have occupied a central place in the phenomenal rise of reality TV. More specifically, with their bid to place the entire notion of stardom at center stage, they raise important methodological and theoretical issues concerning the conceptualization of fame in reality TV. A central emphasis of the article is the importance of considering how reality TV demands a more thorough engagement with existing critical and theoretical concepts if the form is to sustain long-term academic analysis. Taking the British series of Pop Idolas the primary focus, the author explores this with respect to the concept of stardom, drawing particularly on the work of Richard Dyer and John Ellis. Pop Idol also raises crucial questions about the politics of interactivity in reality TV, a power dynamic that is ultimately configured around the program’s mediation of stardom.
“Hideously White”
Authors: Creeber Glen
Published: April 2004

This article will argue that despite gaining praise from around the world for its particular form of “public service broadcasting,” the British Broadcasting Corporation has proved to be surprisingly poor at reflecting the local, linguistic, racial, cultural, and religious differences throughout the United Kingdom. Tracing its historical development, it will argue that in the past century the British Broadcasting Corporation was responsible for simply producing a form of cultural hegemony that attempted to conceive “Britishness” within an extremely narrow set of conventions, excluding all manner of people and communities in its attempt at “making the nation as one man.” In contrast, this article will argue that new cable and satellite channels are now gradually breaking down the very notion of a “unilateral” or “unilingual” voice, eventually providing a “common culture” for those viewers who do not fit easily into any neat definition of British citizenship.
Turbulent Television
Authors: Horrocks Roger
Published: April 2004

A small country can provide particularly revealing case studies in the dynamics of media systems and the impact of new technologies. New Zealand television has been through dramatic changes, shifting from a public service to a commercial orientation, then struggling to reconstruct a minimal level of public service. New technology creates problems for a small country as well as opportunities, and investment in digitalization has helped a multinational pay television company to position itself as the powerbroker of New Zealand’s television future. This article is written from the point of view of a media activist working inside the system. He records his experience as a member of New Zealand on Air, a public funding body established by the government, as it sought to intervene creatively within the complex field of forces generated by political, economic, and technological changes.
Television, Nation, and Indigenous Media
Authors: Hartley John
Published: April 2004

Broadcast television has most often been understood as a site for the narration of unified national identity. But at the same time, it has been associated with the development of diversified cultural citizenship. This article considers some of the issues arising from situations in which cultural identities have clashed with national ones, especially the case of Indigenous issues on Australian television. The evolution of new forms of citizenship is matched by post-broadcast forms of television, in which audiences can be seen as organized around choice, affinity, and the production as well as consumption of media. These developments have powerful implications for the way nations are narrated in broadcast television and for our understanding of how television itself is evolving. The article argues that Indigeneity points the way to new notions of both nation and television.
Flame Resistant Barriers for Home Furnishings
Authors: Handermann Alan C.
Published: April 2004

California’s Assembly Bill 603 (AB603), requiring all bed sets manufactured for sale in the State of California comply with new open-flame resistant (FR) standards, was passed on August 10, 2001. A revised test method, California Test Bulletin 603 (TB603) and pass/fail criteria were announced in July 2003. The California’s bureau of home furnishings and thermal insulation (CBHFTI) is in the process of finalizing its ruling for mandatory compliance with this standard by January 2005. Although the timing of a national FR standard for bed sets with the Consumer Product Safety Commission (CPSC) has not been set, an Advanced Notice for Proposed Rulemaking (ANPR) was announced in October 2001. In July 2003, CPSC staff recommended that another ANPR be issued for a FR standard for upholstered furniture. FR barrier technologies, which utilize no FR chemicals or coatings, have been developed to comply with TB603 and have also been tested in upholstered furniture applications. This paper details some of the statistics behind the effort to develop safe and effective open-flame resistant home furnishings and summarizes the latest developments in FR barrier technology utilizing Basofil® fiber. Test results in both bedding and upholstered furniture applications are also presented.
What’s in a Name? A Literature-Based Approach to Understanding Mentoring, Coaching, and Other Constructs That Describe Developmental Interactions
Authors: D’Abate Caroline P. , Eddy Erik R. , Tannenbaum Scott I.
Published: April 2004

Employee development can take a variety of forms including “developmental interactions” such as coaching, mentoring, apprenticeship, and action learning. The broad literature on approaches to development lacks agreement on what these constructs represent. Rather than impose new construct definitions on the field, the current research addressed the need for construct clarification using existing descriptions of common developmental interactions to create a snapshot of the developmental interaction literature. A qualitative, literature-based approach developed a nomological network of 13 common developmental interaction constructs. A total of 227 construct descriptions were extracted from 182 sources. These were systematically analyzed for the characteristics that help explain construct meanings. A model (i.e., nomological network) was developed to summarize the current understanding of developmental interaction constructs. Analysis of this model provides better understanding of the current state of the literature, identifies gaps in the literature, and informs and directs future research on developmental interaction constructs.
The Duality of Race and Gender for Managerial African American Women: Implications of Informal Social Networks on Career Advancement
Authors: Combs Gwendolyn M.
Published: April 2004

Research suggests that women have progressed in equalizing their representation,status,and earning power as managers in organizations. These improvements may not reflect the career advancement of managerial African American women. African American women contend with the convergence of race and gender in improving their organizational standing and career advancement opportunities. The literature on workplace social networks indicates that informal more than formal socialization systems are salient in advancing careers. Due to the duality of race and gender, African American women in managerial and executive positions may be forced into out-group status in terms of informal social networks. Informal social networks for managerial African American women may be less accessible and may operate under different dimensions than for their African American male and White female and male counterparts. Critical examination of the effect of the interaction of race and gender on informal networks of managerial African American women in organizations is needed.
On the Two-Way Customer Service Model in HRD Practice
Authors: Wang Greg G.
Published: April 2004

Through a discussion on “customer services” in the higher education setting, this article argues that human resource development (HRD)pr actice should follow a similar two-way customer service model. That is, while serving client organizations to improve human performance, HRD professionals should “serve” and adhere to a standard of practice that is based on sound theoretical foundations and professional integrity and educate the clients subsequently. Neglecting the second “customer” may not only jeopardize HRD as a profession but cause additional problems in practice, such as outcome evaluation and measurement. The article also raises the issue of two-way customer services in current for-profit higher education practice.
An Impressionistic Framework for Theorizing About Human Resource Development
Authors: Callahan Jamie L. , De Dávila Tiffany Dunne
Published: April 2004

Human resource development (HRD) can be seen as both a professional field and an organizational function; the I-A framework introduced in this article is a heuristic that enables us to understand HRD from both of these perspectives. Although scholars have presented frameworks for under-standing the underlying theories, philosophies, and meanings of HRD, no framework has been presented to help researchers and practitioners understand the actions they take in the name of HRD. The framework introduced here is an action-oriented conceptual approach to social systems that answers the call for a different means for understanding HRD.
Folie à Deux in Children
Authors: Tishler Carl L. , Meltzer Janet
Published: April 2004

The factors that predispose to suicide pacts strongly parallel those factors that predispose to folie à deux, a phenomenon in which psychoses transfer from a mentally ill person to a mentally healthier one. Review of recent literature reveals scant coverage of the joint occurrence of these phenomena, especially between children. This article presents a case study of two brothers who possibly represent a rare instance of folie à deux and subsequent suicide pact between children. Discussion following the case study targets the role of separation in the treatment of folie à deux and uncertainties in diagnosing suicide pacts among children.
Mathematical Methods Relevant to the Study of Wound Healing
Authors: Schley David
Published: April 2004

Over recent years there has been a growing interest in the application of mathematical techniques and methods to improve understanding of clinical problems. Mathematical methods permit accurate description and quantification of observations and processes. Wound healing is a clinical problem that needs support in order to improve management and understanding of the mechanisms that may disarrange healing processes. This article attempts to provide an overview of currently available methods that have a direct relevance to the management of lower extremity wounds. Mathematics can provide valuable assistance and insight to clinical understanding, but only if applied correctly. It is hoped that examples of good practice will promote the utilization of this versatile tool.
Skin Grafting of Venous Ulcers: A Review of its Current Role
Authors: Becker Horst-Dieter , Beckert Stefan , Coerper Stephan
Published: April 2004

As a therapeutic option, grafting of venous ulcers has not been very successfully received despite the different types of grafting methods. Currently, there are only a few controlled randomized trials offering clear guidance to clinicians. The development of artificially bioengineered skin constructs has led to a renewed interest in wound bed preparation, and preliminary successes suggest that the role of skin grafting could be studied in the current context.
Contact Sensitization in Patients with Leg Ulcers and/or Leg Eczema: Comparison between Centers
Authors: Renner Regine , Wollina Uwe
Published: April 2004

Patients with leg ulcers and/or eczema of the legs are at risk of contact sensitization. The aim of this retrospective study was to investigate the impact of some aspects of practice of leg ulcer treatment and availability of drugs and dressings in a university-based wound care center. These data were compared with those from the Information Network of Departments of Dermatology (IVDK), where patch test reactions of 3529 patients with leg ulcers and/or eczema of the lower legs were documented. Data analyses showed frequencies of sensitization for single and multiple allergens. The change of treatment modalities may have a positive impact on lowering sensitization rates, but the ongoing use of topical drugs outside wound care centers may be expected to limit the effects of modern wound treatment.
Acute Compartment Syndrome of the Lower Leg: Changing Concepts
Authors: Bhattacharya Kaushik , Catherine A. Neela
Published: April 2004

The acute limb compartment syndrome is caused by bleeding or edema in a closed muscle compartment surrounded by fascia and bone, leading to muscle and nerve ischemia. The value offasciotomy has been demonstrated in the management of acute compartment syndrome, but ifperformed after a delay of8 to 10 hours, it can prove to be a double-edged weapon, as necrotic muscle would get exposed leading to muscle infections and massive bleeding.
Ingrowing Toenails: Management Practices and Research Outcomes
Authors: Weaver Terry D. , Vy Ton Minh , Pham Thuan V.
Published: April 2004

The ingrowing toenail, often seen as a trivial condition, can be a substantial source of pain and potential morbidity in high-risk patients. Furthermore, this malady is commonly seen by the general practitioner who possesses little training in the management of the condition. Compounding the problem is the myriad of reported nonsurgical and surgical treatments. This article reviews the topic of ingrowing toenails and offers treatment options based on a review of the literature.
Oncology Nursing and Integrative Care: ANewWay of Being
Authors: Johnson Mary B.
Published: April 2004

Oncology nursing is a long-established specialty in the practice of professional nursing. The paradigm shift to a more holistic perspective in health care is affecting not only the delivery of care but also the beliefs and value of nurses who work with people experiencing cancer. This article will examine the role of holistic theory and complementary therapies as innovations in nursing education and nursing practice. Suggestions for assessing and planning for an integrative approach to intervention will be discussed. Outcomes from a senior nursing student survey concerning the integration of holistic nursing and complementary therapies will be described. The future offers many challenges for professional nursing as a major player in today’s health care system.
Ganoderma Lucidum(Reishi) in Cancer Treatment
Authors: Sliva Daniel
Published: April 2004

The popular edible mushroom Ganoderma lucidum(Reishi) has been widely used for the general promotion of health and longevity in Asian countries. The dried powder of Ganoderma lucidumwas popular as a cancer chemotherapy agent in ancient China. The authors recently demonstrated that Ganoderma luciduminhibits constitutively active transcription factors nuclear factor kappa B (NF-.B) and AP-1, which resulted in the inhibition of expression of urokinasetype plasminogen activator (uPA) and its receptor uPAR. Ganoderma lucidumalso suppressed cell adhesion and cell migration of highly invasive breast and prostate cancer cells, suggesting its potency to reduce tumor invasiveness. Thus, Ganoderma lucidumclearly demonstrates anticancer activity in experiments with cancer cells and has possible therapeutic potential as a dietary supplement for an alternative therapy for breast and prostate cancer. However, because of the availability of Ganoderma lucidum from different sources, it is advisable to test its biologic activity.
Insulin and Cancer
Authors: Boyd D. Barry
Published: April 2004

Obesity has recently been linked to mortality from the majority of cancers. The insulin/insulin-like growth factor (IGF) system may partly explain this effect. The metabolic syndrome, associated with hyperinsulinemia, may modulate this effect. Recent evidence supports the role of insulin and IGF-1 as important growth factors, acting through the tyrosine kinase growth factor cascade in enhancing tumor cell proliferation. In addition, the metabolic syndrome associated with a chronic inflammatory state and accompanying cytokine abnormalities may also contribute to tumor progression. Growing links between insulin and the etiology as well as prognosis in colon, prostate, pancreatic, and, particularly, breast cancer are reviewed. Of particular concern is the evidence that elevated IGF-1 may interfere with cancer therapy, adversely affecting prognosis. The role of insulin is of concern because of the increasing levels of obesity and the associated metabolic syndrome. Weight gain, through typical Western diet; limited levels of activity; and, more recently, stress-related changes in neuroendocrine function may lead to insulin resistance and hyperinsulinemia. The opportunity for a multidisciplinary approach involving nutrition, exercise, and stress reduction in an integrative setting may be crucial to limiting the insulin-resistant state and improving cancer outcomes.
Cruciferous Vegetables: Cancer Protective Mechanisms of Glucosinolate Hydrolysis Products and Selenium
Authors: Keck Anna-Sigrid , Finley John W.
Published: April 2004

Dietetic professionals urge Americans to increase fruit and vegetable intakes. The American Institute of Cancer Research estimates that if the only dietary change made was to increase the daily intake of fruits and vegetables to 5 servings per day, cancer rates could decline by as much as 20%. Among the reasons cited for this health benefit are that fruits and vegetables are excellent sources of fiber, vitamins, and minerals. They also contain nonnutritive components that may provide substantial health benefits beyond basic nutrition. Examples of the latter are the glucosinolate hydrolysis products, sulforaphane, and indole-3-carbinol. Epidemiological studies provide evidence that the consumption of cruciferous vegetables protects against cancer more effectively than the total intake of fruits and vegetables. This review describes the anticarcinogenic bioactivities of glucosinolate hydrolysis products, the mineral selenium derived from crucifers, and the mechanisms by which they protect against cancer. These mechanisms include altered estrogen metabolism, protection against reactive oxygen species, altered detoxification by induction of phase II enzymes, decreased carcinogen activation by inhibition of phase I enzymes, and slowed tumor growth and induction of apoptosis.
The Experience of Indigenous Traditional Healing and Cancer
Authors: Struthers Roxanne , Eschiti Valerie S.
Published: April 2004

Indigenous traditional healing is an ancient, deeply rooted, complex holistic health care system practiced by indigenous people worldwide. However, scant information exists to explain the phenomenon of indigenous medicine and indigenous health. Even less is known about how indigenous healing takes place. The purpose of this study is to describe the meaning and essence of the lived experience of 4 indigenous people who have been diagnosed with cancer and have used indigenous traditional healing during their healing journey. The researcher used a qualitative phenomenological methodology to collect and analyze interview data. Interviews were conducted with 4 self-identified indigenous people, ages 49 to 61, from diverse tribes. Time since cancer diagnosis varied from 2 to 20 years; types of cancer included lung, prostate, sarcoma of the leg, and breast. Four themes and 2 subthemes emerged (1) receiving the cancer diagnosis (with subthemes of knowing something was wrong and hearing something was wrong), (2) seeking healing, (3) connecting to indigenous culture, and (4) contemplating life’s future. This study demonstrates that 4 individuals with cancer integrated Western medicine and traditional healing to treat their cancer. This knowledge provides necessary data about the phenomena of being healed by indigenous healers. Such data may serve as an initial guide for health care professionals while interacting with indigenous people diagnosed with cancer. Accordingly, traditional healing may be used to decrease health disparities.
The Present State of Antineoplaston Research (1)
Authors: Burzynski Stanislaw R.
Published: April 2004

Antineoplastons work as molecular switches, which regulate expression of genes p53 and p21 through demethylation of promoter sequences and acetylation of histones. They also inhibit the uptake of growth-critical amino acids, such as 1- glutamine and 1-leucine in neoplastic cells. Phase II trials indicate efficacy of antineoplastons in low-grade glioma, brain stem glioma, high-grade glioma, adenocarcinoma of the colon, and hepatocellular carcinoma. The best results were observed in children with low-grade glioma, where 74% of patients obtained objective response, and in patients with adenocarcinoma of the colon with liver metastases whose survival rate of more than 5 years is 91% versus 39% in controls on chemotherapy. Gene array studies will explain antineoplaston-induced changes in gene expression.
Mentoring the Parentified Child: The Professional Development of the Latina(O) Psychologist
Authors: Chamorro Rebeca
Published: April 2004

Psychology graduate programs actively recruit Latino students. Nonetheless, Latino students remain a minority in their classes, clinical training programs, and professions. Given the paucity of Latino faculty, Latino students are often asked early in their training to instruct others about their culture. Thus, Latino students’ professional development can include premature responsibility, role reversal, and isolation. This process reenacts the syndrome of the parentified child, a situation possibly familiar to the graduate Latina(o) student’s personal experience. Recommendations are proposed to attend to this process.
Critical Sociology in K-16 Early Intervention: Remaking Latino Pathways to Higher Education
Authors: Collatos Anthony , Morrell Ernest , Nuno Alejandro , Lara Roger
Published: April 2004

This article examines the pathways to higher education of two working-class Latino students participating in an intervention program at a diverse, metropolitan high school. Using critical narratives from 2 of the 30 student participants, this article exposes several reasons disproportionately low numbers of Latino students gain access to higher education. Furthermore, their narratives identify several strategies to empower and guide first-generation Latino students toward college access.
Planned Industrial Districts in Chicago: Firms, Networks, and Boundaries
Authors: Lewis Robert
Published: April 2004

The planned industrial district contributed to the planning of the twentieth-century metropolitan landscape. Using Chicago as a case study, this article examines the early history of the planned district. Two aspects are emphasized. First, the article outlines the manner in which a coalition of business and political actors planned and created a new industrial landscape. Second, the article looks at the interaction between firm boundaries, industrial networks, and urban space. This interaction is illustrated through an examination of three aspects of the planned district: incubators, clubhouses, and factories. The article combines recent research on the dynamics of industrial activity with historical evidence on Chicago’s industrial districts.
The Planner in the Garden: A Historical View into the Relationship between Planning and Community Gardens
Authors: Lawson Laura
Published: April 2004

A historical review of community garden programs in the United States since the 1890s reveals an ambivalent relationship between community gardens and the planning profession. On one hand, garden programs are praised and supported as local action to serve environmental, social, and individual objectives. On the other hand, because they are perceived as opportunistic and temporary, community gardens are largely ignored in long-range planning. Socially constructed as public catalyst and private resource, community gardens illustrate unresolved tensions between planning as a profession and as a civic concern and between comprehensive planning and interim, local interventions.
Development of a Food Packaging Coating Material with Antimicrobial Properties
Authors: Limjaroen Paweena , Ryser Elliot , Lockhart Hugh , Harte Bruce
Published: April 2004

Antimicrobial films may provide an effective way to control food-borne pathogens and spoilage microorganisms to thus enhance food safety and decrease product spoilage. Antimicrobial films can be produced by incorporation of chemical preservatives or antimicrobial agents into a plastic film. The agents can then diffuse into the food to control target microorganisms.

In this work, antimicrobial coatings were developed by incorporation of nisin, lactoferrin (an antimicrobial peptide derived from bovine lactoferrin in cow’s milk), sodium diacetate, sorbic acid, and potassium sorbate into a coating material. Saran® F-310 resin, a copolymer of vinylidene chloride, was used to produce the base coating using a solvent casting method. The antimicrobial activity of these films was verified on laboratory media against the food-borne pathogen Listeria monocytogenes. Films containing nisin, sorbic acid, and potassium sorbate inhibited L. monocytogenes strain CWD 95. The lowest level of nisin, sorbic acid, and potassium sorbate that had antimicrobial activity was 1, 1.5, and 2% w/v respectively. Films containing sorbic acid were the most compatible with the resin solution and had the best physical appearance. The water vapor barrier of films containing sorbic acid was almost unchanged compared to the control film (no antimicrobial agent). The three-dimensional structure of the films was observed using Scanning Electron Microscope (SEM). The results show that films containing sorbic acid were the most homogenous of the sample films.
Viscous and Elastic Effects in Polymer Coextrusion
Authors: Dooley Joseph , Rudolph Luciana
Published: April 2004

Multilayer coextrusion is a process in which two or more polymers are extruded and joined together in a feed block or die to form a single structure with multiple layers. These layers should be uniform in thickness across the structure for best performance. However, layer thickness nonuniformities have been observed in many coextruded products. Previous work has shown that these layer thickness variations can occur due to viscosity differences between the polymers in the layers and/or elastic effects that introduce secondary flows. The objective of this work is to examine the effect of viscous and elastic forces present in polyethylene coextrusion processes.
Mechanical, Physical, and Barrier Properties of Poly(Lactide) Films
Authors: Auras Rafael A. , Harte Bruce , Selke Susan , Hernandez Ruben
Published: April 2004

High molecular mass poly(lactide), (PLA), is an attractive polymer family because in addition to being thermoplastic, biodegradable, compostable, and produced from annually renewable resources, it shows mechanical and barrier behavior comparable to synthetic polymers like polystyrene (PS) and polyethylene terephthalate (PET). Furthermore, technology for large-scale fabrication of PLA has been fully developed. However, there is still a need to better understand the properties of PLA as this polymer is adapted to packaging applications, especially for food packaging. In this work, films from two PLA resins were studied by tensile testing; differential scanning calorimetry (DSC); and permeation of carbon dioxide, oxygen, and water vapor. The data from these two PLA film samples are compared to those of PS and PET.
Nylon-6 and Montmorillonite-Layered Silicate (MLS) Nanocomposites
Authors: Ranade Ajit , D’Souza Nandika Anne , Gnade Bruce , Dharia Amit
Published: April 2004

Reducing the high gas permeability of plastic packaging is of serious concern for a variety of applications in food packaging and microelectronics arena. In the development of high altitude scientific balloons, the potential for unmanned mission success is critically related to the improvement in helium barrier capability. Separately, the introduction of expandable smectite clays, such as montmorillonites, into polymers has resulted in improved barrier properties. Here we investigate the mechanical properties and helium permeability of dispersed montmorillonite-layered silicates (MLS) in nylon-6 nanocomposite films. A 20 wt% MLS in nylon-6 master batch was prepared in a twin-screw extruder and then mixed with nylon to produce nylon MLS nanocomposites with MLS content ranging from 1 to 5% for testing. The nylon nanocomposites were extruded into films. A highly exfoliated dispersion in different films was determined using X-ray diffraction. Nylon-6 nanocomposites showed formation of -crystalline form, which was absent in neat nylon-6. Differential Scanning Calorimetry (DSC) confirmed the crystallinity change and the role of MLS as an additional nucleation contributor. The glass transition and mechanical properties were related to the nucleation capabilities of MLS. Increase in the degree and type of crystallinity together with tortuous path development due to exfoliated dispersion were the primary reasons behind the improvement in gas barrier properties of exfoliated nylon-6 nanocomposites.
Post—Myocardial Infarction Ventricular Septal Defect
Authors: Greer Jonathan , Loussararian Arthur
Published: April 2004

The case presented is that of a man in his late 60s who experienced an acute anterior myocardial infarction. A complete 2D echocardiogram with color flow and Doppler imaging had been performed on the patient's first hospital day. On day 2 of his hospitalization, a follow-up limited study was performed to reevaluate left ventricular function. Cardiac function was essentially unchanged from the prior day's study. However, color flow Doppler was performed, and a distal septal ventricular septal defect was detected incidentally, only in the final apical view while using the full-height color sector box. This study demonstrates the value of using the full-size color sector box as a screening tool when performing color flow Doppler. Current high-capacity (256 channel and above) equipment assists the sonographer with image optimization and decreases the need to use the truncated color flow box.
Serial Evaluations of Perinatal Uterine Synechiae Versus Amniotic Bands
Authors: Burton Elizabeth
Published: April 2004

The author describes two cases in which the presence of thick amniotic bands is identified and followed throughout the course of each pregnancy. The etiology of these bands is preexisting uterine synechiae, which is substantiated in the first case by a pathology report indicating the presence of smooth myometrial muscle tissue within the band. The identification of thick bands in pregnancy should not be confused with the more serious sequelae of amniotic band syndrome, which is a phenomenon directly related to embryogenesis and gestational sac development.
Prenatal Diagnosis of Neuroblastoma
Authors: Baun Jim , Garcia Katie
Published: April 2004

Reports of the prenatal detection of fetalneuroblastoma have increased over the pastseveral years. Sonography has played a significantrole in the early detection of these masses andhas helped in preparing for the postnatalmanagement of these neonates. In fact, earlysonographic detection of adrenal neuroblastoma, inconjunction with early postnatal surgicalintervention, has helped improve the prognosis ofinfants born with these suprarenal masses.Reported here is a case of fetal adrenalneuroblastoma diagnosed prenatally withconventional gray-scale and color Doppler imaging.
Sonographic Characteristics of a Dilated Cardiomyopathy Pre- and Post-Cardiac Resynchronization Therapy
Authors: Heaton Angela K.
Published: April 2004

Cardiac resynchronization therapy (CRT) is achieved by implanting a biventricular pacemaker (BiV) into patients suffering from congestive heart failure secondary to a dilated cardiomyopathy. Congestive heart failure patients are first treated with standard heart failure drug therapy; however, if this therapy is not sufficient and the patients meet specific criteria, they can be selected for CRT. This therapy can create vast cardiac and symptomatic improvements in a relatively short time. This case report discusses the characteristics of a dilated cardiomyopathy before and after CRT and the associated cardiac improvements. Sonography continues to play an important role in diagnosing dilated cardiomyopathies, as well as congestive heart failure, and monitoring the progression after treatment.
Microstructure and creep strength of welds in advanced ferritic power plant steels
Authors: Abe F. , Tabuchi M.
Published: April 2004

The microstructure and creep strength of simulated heat affected zone (HAZ) specimens and welded joints have been investigated for advanced 9-12%Cr steels in order to understand the mechanisms responsible for Type IV cracks and to improve the creep strength of welded joints at high temperature. The creep and creep rupture tests were carried out at 650° C (923 K) for up to about 104 h. The creep crack growth tests were also carried out for welded joints, base metal and simulated HAZ specimens using the CT specimens. The creep rupture time of simulated HAZ specimens has its minimum after heating to AC3 temperature, which produces fine-grained martensitic microstructure. Decreasing the width of HAZ by means of electron beam (EB) welding is effective for the extension of creep life but the brittle Type IV fracture appears even in the EB welded joints at low stress and long time conditions. Most of the welded joint specimens were fractured in fine-grained HAZ and resulted in shorter creep life than those of base metals as a result of the formation of creep voids and cracks. It should also be noted that in the fine-grained zone, the recovery of martensitic microstructure during creep is inhomogeneous as shown by the formation of coarse subgrains in the region of fine subgrains. Using a specially designed FEM code for Type IV crack growth behaviour, the vacancy diffusion under multi-axial stress conditions of welded joints in HAZ is analysed. The effect of creep ductility and void formation ahead of the crack tip on creep crack growth rate is successfully simulated.
Friction welding of Al–Mg–Si alloy to Ni–Cr–Mo low alloy steel
Authors: Fuji A.
Published: April 2004

It is difficult to weld the dissimilar material combination of aluminium alloys and low alloy steels using fusion welding processes, on account of the formation of a brittle interlayer composed of intermetallic compound phases and the significant difference in physical and mechanical properties. In the present work an attempt has been made to join these materials via the friction welding method, i.e. one of the solid phase joining processes. In particular, the present paper describes the optimisation of friction welding parameters so that the intermetallic layer is narrow and joints of acceptable quality can be produced for a dissimilar joint between Al-Mg-Si alloy (AA6061) and Ni-Cr-Mo low alloy steel, using a design of experiment method. The effect of post-weld heat treatment on the tensile strength of the joints was then clarified. It was concluded that the friction time strongly affected the joint tensile strength, the latter decreasing rapidly with increasing friction time. The highest strength was achieved using the shortest friction time. The highest joint strength was greater than that of the AA6061 substrate in the as welded condition. This is due to the narrow width of the brittle intermetallic layer generated, which progressed from the peripheral (outer surface) region to the centreline region of the joint with increasing friction time. The joints in the as welded condition could be bent without cracking in a bend test. The joint tensile strength in the as welded condition was increased by heat treatment at 423 K (150° C), and then it decreased when the heat treatment temperature exceeded 423 K. All joints fractured in the AA6061 substrate adjacent to the interface except for the joints heated at 773 K (500° C). The joints fractured at the interface because of the occurrence of a brittle intermetallic compound phase.
Investigation into micro-tungsten inert gas arc behaviour and weld formation
Authors: Wang J. , Kusumoto K. , Nezu K.
Published: April 2004

Current pulsing patterns are defined for the micro-tungsten inert gas welding apparatus developed and are described as: no pulsation (NP), high frequency pulsation (HFP), slightly hybrid pulsation (SHP), and heavily hybrid pulsation (HHP). The characteristics of the microarc behaviour and weld formation are then investigated in detail for these patterns. The parameters and pattern of the pulsating current dominate arcing power and arc stiffness at a given average current, thus affecting arc state and bead formation. The arc image analysis shows that the HFP and HHP arcs can burn more steadily even at an average current of 2 A because of the arc stabilising effect from the superimposed high frequency components. During the on time of the pulse, the state of the hybrid pulsating (HP) arc varies successively from an apple like shape to a cone with an increased taper. Furthermore, this HP arc shrinks owing to the decreases in the peak current and arcing power with increasing frequency of the base pulse, but is still much greater in size than the NP and HFP arcs. Finally, welding experimental results demonstrate that the HP welds are the widest and become narrow with an increase in the pulse frequency, and the NP and HHP beads are somewhat wider than the HFP and SHP beads respectively.
Otx2 regulates the extent, identity and fate of neuronal progenitor domains in the ventral midbrain
Authors: Puelles Eduardo , Annino Alessandro , Tuorto Francesca , Usiello Alessandro , Acampora Dario , Czerny Thomas , Brodski Claude , Ang Siew-Lan , Wurst Wolfgang , Simeone Antonio
Published: April 2004

The specification of distinct neuronal cell-types is controlled by inducing signals whose interpretation in distinct areas along the central nervous system provides neuronal progenitors with a precise and typical expression code of transcription factors.

To gain insights into this process, we investigated the role of Otx2 in the specification of identity and fate of neuronal progenitors in the ventral midbrain. To achieve this, Otx2 was inactivated by Cre recombinase under the transcriptional control of En1. Lack of Otx2 in the ventrolateral and posterior midbrain results in a dorsal expansion of Shh expression and in a dorsal and anterior rotation of the midbrain-hindbrain boundary and Fgf8 expression. Indeed, in this mutant correct positioning of the ventral site of midbrain-hindbrain boundary and Fgf8 expression are efficiently controlled by Otx1 function, thus allowing the study of the identity and fate of neuronal progenitors of the ventral midbrain in the absence of Otx2. Our results suggest that Otx2 acts in two ways: by repressing Nkx2.2 in the ventral midbrain and maintaining the Nkx6.1-expressing domain through dorsal antagonism on Shh. Failure of this control affects the identity code and fate of midbrain progenitors, which exhibit features in common with neuronal precursors of the rostral hindbrain even though the midbrain retains its regional identity and these neuronal precursors are rostral to Fgf8 expression. Dopaminergic neurons are greatly reduced in number, red nucleus precursors disappear from the ventral midbrain where a relevant number of serotonergic neurons are generated. These results indicate that Otx2 is an essential regulator of the identity, extent and fate of neuronal progenitor domains in the ventral midbrain and provide novel insights into the mechanisms by which neuronal diversity is generated in the central nervous system.