bluuebunny/crossref_metadata_2025 huggingface dataset:
Selection of Medications for the International Space Station: The Space Medicine Patient Condition Database
Authors: Bacal Kira , Frey Bruce M.
Published: June 2003

Medical care available to astronauts on the International Space Station has been affected by limitations on funding, space and weight availability, and crew training. A Space Medicine Patient Condition Database (PCDB) was designed to enhance inventory control, resource selection, protocol standardization, evidence-based medicine, on-orbit diagnostic skills, and materiel management. The first step in the PCDB creation was the identification of the medical conditions anticipated among the astronaut population in the flight environment. Military databases, previous spaceflight experience, and analog populations were used to create this listing. The PCDB then linked these individual conditions with the current resources available on orbit to treat them. Other features include a resource gauge, item location information, diagnosis coding, and built-in reference capabilities. Currently in the second phase of development, specific, evidence-based treatment protocols are being developed and evaluated in comparison with the terrestrial medicine standard of care. By documenting on-orbit medical systems and their associated terrestrial standards, the PCDB enables the prioritization and allocation of limited resources. In the final phase of the project, the PCDB will make use of decision support software to enhance diagnostic determination and provide an operational tool for the crew and mission teams.
Health Consequences of Spaceflight
Authors: Paskovaty Alla , O'Rangers Eleanor A.
Published: June 2003

Although the possibility of nonastronauts making routine trips into space is an exciting prospect, many have little appreciation for the potential physiologic hazards that exposure to the space environment poses. During launch and reentry, the body is exposed to various degrees of gravitational loading, which can place strain on the cardiovascular system and its ability to maintain cerebral perfusion. In space, the body is bombarded with galactic cosmic radiation and other high-speed particle exposures, which predisposes one to chromosomal mutation, microlesions, an increased risk for cataracts, and even cancer. The possibility of spacecraft depressurization is also of concern and has been documented. The isolation of life on a spacecraft also poses psychological challenges such as loneliness, depression, and interpersonal conflict among crewmates. Finally, weightlessness itself, although undoubtedly a unique and enjoyable experience, may be the most insidious danger of all to the human body. This article will review some of the more troublesome effects—including cephalid fluid shifts, space motion sickness, bone loss, muscle atrophy, immune function, and treatment of infection—and will also provide an outline for future areas of research emphasis.
The Association of Disability, Sociodemographic Background, and Social Network Type in Later Life
Authors: Litwin Howard
Published: June 2003

Objectives: The article examines the association of disability and sociodemographic background with the type of social network in which elders are embedded and considers the implications of such associations for network continuity. Methods: Secondary analysis of data from a national probability sample of Jewish adults aged 60 and older in Israel ( N = 2,079) was used. Multinomial logistic regression analysis was employed to predict membership in different network types. Results: Higher education predicted membership in friends networks. Female gender, Asian/African origin, low income, and disability were associated with neighbors networks. Family networks were predicted by Asian/African origin, less education, younger age, and disability. Restricted networks were associated with lower income and disability, and particularly by the interaction of age and disability. Discussion: The findings suggest that network stability is most jeopardized when the oldest old become disabled. The social care needs of this latter group will continue to demand public attention.
The Working Definition of Social Work Doesn't Work Very Well in China and Malaysia
Authors: Fulcher Leon C.
Published: June 2003

Western cultural assumptions underpin the working definition of social work and contemporary social work theory. Four themes that affect the working definition of social work are highlighted from comparative research carried out in the People's Republic of China and Malaysia. Working hypotheses are offered about how each comparative theme might affect how well the working definition of social work works.
A New Working Definition of Social Work Practice: A Turtle's View
Authors: Bidgood Bruce , Holosko Michael J. , Taylor Laura E.
Published: June 2003

The authors summarize the conclusions provided by the contributors to this special issue examining the definition of social work practice. Prior definitions, including Bartlett's, have proved to be inadequate. Suggestions for developing an improved conceptualization of social work practice are provided.
Intrusion: The Central Problem for Family Health Promotion among Children and Single Mothers after Leaving an Abusive Partner
Authors: Wuest Judith , Ford-Gilboe Marilyn , Merritt-Gray Marilyn , Berman Helene
Published: June 2003

Like other single-parent families, those consisting of mothers and their children who leave abusive partners/fathers are broadly viewed as deficient, high-risk structures in which children are susceptible to multiple problems. The mechanisms of strength and vulnerability in these families are poorly understood, and, consequently, their health promotion processes remain virtually unexplored. In a feminist grounded theory study of health promotion processes of single-parent families after leaving abusive partners/fathers, the authors discovered intrusion to be the basic social problem as families strive to promote health in the aftermath of abuse. The authors discuss the complex nature of intrusion, demonstrating how health is socially determined, and the challenges of health promotion in terms of the issues and dilemmas faced by study families and consider implications for health promotion knowledge and practice.
Home Health Care Nurses' Perceptions of Physician-Nurse Relationships
Authors: Marrone Catherine
Published: June 2003

This work is a sociological analysis of the physician-nurse relationship in home health care. Data include observation, interview, and survey sources. Results confirm that, largely because of the physician's distance both physically and symbolically, home care nurses take on a more primary care role with patients than do nurses in hospitals. There are fewer instances of conflict between physician and nurse in this setting, as doctors yield more responsibility to nurses than they may in hospitals. In the end, though nurses claim higher levels of autonomy, patients appear to be the true beneficiaries of the in situ shift in nursing responsibility.
Factors Underlying Anxiety in HIV Testing: Risk Perceptions, Stigma, and the Patient-Provider Power Dynamic
Authors: Worthington Catherine , Myers Ted
Published: June 2003

Client anxiety is often associated with diagnostic testing. In this study, the authors used a grounded theory approach to examine the situational and social factors underlying anxiety associated with HIV testing, analyzing transcripts from semistructured interviews with 39 HIV test recipients in Ontario, Canada (selected based on HIV serostatus, risk experience, geographic region, gender, and number of HIV tests), then integrating emergent themes with existing research literature. Analysis revealed four themes: perceptions of risk and responsibility for health, stigma associated with HIV, the patient-provider power dynamic, and techniques used by test recipients to enhance control in their interactions with providers. Service implications include modifications to information provision during the test session, attention to privacy and anonymity, and sensitivity to patient-provider interactions.
The Bereavement Experience Following Home-Based Family Caregiving for Persons with Advanced Cancer
Authors: Koop Priscilla M. , Strang Vicki R.
Published: June 2003

The purpose of this qualitative interpretive study was to explore the experience of bereavement following home-based family caregiving for persons with advanced cancer. The research question addressed by this research was: How do family caregivers of patients with advanced cancer perceive the effects of home-based caregiving on their bereavement? Fifteen caregivers were retrospectively interviewed twice after the death of their family member. Caregivers reported both positive (e.g., feelings of accomplishment, improved family relationships) and negative (e.g., haunting images, feelings of failure) outcomes that they attributed to having cared for their family member. Overall, positive outcomes predominated and bereaved family members reported satisfaction with having provided care for their loved one who had died.
What's New on Defining Diarrhea in Tube-Feeding Studies?
Authors: Lebak Kelly J. , Bliss Donna Zimmaro , Savik Kay , Patten-Marsh Kathleen M.
Published: June 2003

Nurses who are involved in studies of tube-feeding tolerance or who review the literature on this topic are confronted with a myriad of definitions and methods of reporting diarrhea. In a 1992 study, the authors reported that these definition differences influenced results. In a review of the current literature, they determined that little progress had been made toward standardizing definitions and reports of diarrhea in studies of tube feeding. A secondary analysis of stool characteristics of hospitalized patients using various definitions of diarrhea showed there was a positive association between stool frequency and consistency. Criteria for stool consistency in the definitions of diarrhea appeared to have a greater influence on diarrhea outcomes when stool frequency was low. The authors suggest recognition of a taxonomy of definitions of diarrhea in the absence of consensus, which will help guide the design of future investigations and facilitate the evaluation and utilization of research.
Emotional Intelligence and the Career Choice Process
Authors: Emmerling Robert J. , Cherniss Cary
Published: June 2003

Once seen as something avoided in making important life decisions, recent research and theories of emotional intelligence point to the interdependence of emotion and cognition in the decision-making process. Emotional intelligence as conceptualized by Mayer and Salovey consists of four interrelated abilities: (a) perceiving emotions, (b) using emotions to facilitate thoughts, (c) understanding emotions, and (d) managing emotions to enhance personal growth. It is hypothesized that such abilities facilitate the career decision-making process and lead to decisions that more fully satisfy career-related interests, values, and aspirations. Emotions experienced during this process have implications for the perception of risk related to specific career options, amount and kind of self-exploration individuals will engage in, and how information related to career choice will be processed. Also reviewed are issues of reliability and validity of the Multifactor Emotional Intelligence Scale and the implications of emotional intelligence for the career counseling process.
Equity and Entrepreneurialism
Authors: Weber Rachel
Published: June 2003

How do the socially reproductive functions of local government fare within municipalities that adopt “entrepreneurial” economic development practices? This article examines the case of tax increment financing (TIF), a quintessentially entrepreneurial strategy whose use has significant fiscal implications for the overlapping taxing jurisdictions that provide these functions. Statistical analysis of TIF's impact on the finances of school districts in Cook County, Illinois, reveals that municipal use of TIF depletes the property tax revenues of schools during the lifespan of the TIF district but that a portion of the budget shortfalls are relieved by increases in state school aid. Entrepreneurial policies can create conflict between taxing bodies unless higher levels of government take on some of the fiscal burden of these more redistributive functions.
The Relative Importance of Income and Race in Determining Residential Outcomes in U.S. Urban Areas, 1970-2000
Authors: Fischer Mary J.
Published: June 2003

The author uses the unique properties of the entropy index to explore trends in segregation by race/ethnicity and income class for families from 1970 to 2000. Declines in segregation by race and increases in segregation by income class were found until the 1990s, when segregation by income declined. Segregation among certain subgroups was then examined; some groups remain more segregated, even as segregation in general has declined. In particular, the poor families experience greater segregation from others than do families in other income groups from each other. Blacks experience higher levels of segregation from other groups than those other groups do from each other. Finally, the segregation of poor, black families compared to the poor of other race/ethnic groups was examined. The author finds that poor black families are uniquely segregated and that this segregation declines only slightly with time.
The Desegregation Efficiency of Magnet Schools
Authors: Rossell Christine
Published: June 2003

Magnet schools are an attempt to introduce market incentives into school desegregation policy. The analyses presented here assess the extent to which they have improved the effectiveness of desegregation plans in a 600-school-district national sample from 1968 to 1991. I find that adding magnet schools to a voluntary plan does not seem to produce any more interracial exposure than does a voluntary plan without magnets. Moreover, there are diminishing marginal returns to magnets. The greater the percentage of magnets in a voluntary desegregation plan, the greater the white flight and the less the gain in interracial exposure. The effectiveness of magnets also varies by structure.
Setting Referral Fees in Affiliate Marketing
Authors: Libai Barak , Biyalogorsky Eyal , Gerstner Eitan
Published: June 2003

Affiliate programs offer affiliates referral fees in return for directing potential customers into a merchant's Web site. Affiliates are commonly paid based on the number of leads converted by the merchant into customers (pay-per-conversion) or based on the number of leads referred to the merchant (pay-per-lead). Given the prevalence of both, interesting questions for research are as follows: Why do both formats prevail? Under what conditions is one format preferred over the other? The authors find that pay-per-lead is more profitable when a merchant negotiates a separate deal with an affiliate. In this case, pay-per-conversion is not optimal for the affiliation alliance because it leads to suboptimal pricing by the merchant. In contrast, pay-per-lead is less profitable than pay-per-conversion for a merchant that works with a large number of affiliates all under the same terms because it is susceptible to bogus referrals that cannot be converted into customers.
An Examination of the Quality and Context-Specific Applicability of Commonly Used Customer Satisfaction Measures
Authors: Wirtz Jochen , Lee Meng Chung
Published: June 2003

The authors catalogued commonly used satisfaction measures and then examined their reliability and explained variance. Furthermore, they explored the notion that affective measures may be better in capturing satisfaction with predominantly hedonic products, whereas cognitive measures may be better for products with mostly utilitarian benefits. To do this, the authors examined all measures in a hedonic and utilitarian service context. The authors found that a six-item 7-point semantic differential scale performed best across both service contexts, followed by a four-item 7-point semantic differential scale. The third best measure was a single-item 11-point percentage scale. Furthermore, they rejected the notion that affective measures should be used for hedonic services and cognitive measures for utilitarian services. Rather, measures that were shown to be of good quality (i.e., had high satisfaction loadings, good reliability, and low error variances) were equally applicable for measuring satisfaction for both types of services. In addition, all satisfaction measures captured both affective and cognitive aspects of satisfaction, independent of their scale anchors.
Direct and Indirect Effects of Commitment to a Service Employee on the Intention to Stay
Authors: Hansen Håvard , Sandvik Kåre , Selnes Fred
Published: June 2003

The article presents a model for understanding the role of customers' commitment to service employees and their intention to stay with the firm. The model consists of two kinds of commitment—calculative and affective—to both the service employee and the service firm. The model is tested with a sample of bank customers. The findings support the direct effect of commitment to service employees on commitment to the service firm and the indirect effect on intention to stay.
Strategic Management Education Incorporating Written or Simulation Cases: An Empirical Test
Authors: Kendall K. W. , Harrington Robert J.
Published: June 2003

In the context of hospitality education, this article reports on an empirical study of student learning considering four factors: strategic management skills, team process skills, level of difficulty, and overall perceived learning. Results of the empirical study suggest that the use of management computer simulation cases facilitates greater educational development than does the use of written cases (or a combination) as perceived by hospitality students in a capstone strategic management course. Discussion and future research proposals on using computer simulation cases for team and individual strategic management development and research are noted.
Demographics of Hawaii Leisure Travel
Authors: Reece William S.
Published: June 2003

Tourist arrivals in Hawaii failed to grow during the 1990s, leading to recent strategic planning efforts to promote tourism in the state. These plans often refer to the demographics of target markets. This article measures the impacts of demographic and distance variables on household leisure travel to Hawaii. The results show that location, income, household type, and other demographic variables have large impacts on the probability that a household will travel to Hawaii. The results are based on individual household data from the 1995 American Travel Survey conducted by the U.S. Department of Transportation's Bureau of Transportation Statistics.
Community Correlates of Serious Assaults on Police
Authors: Kaminski Robert J. , Jefferis Eric , Gu Joann
Published: June 2003

Violence against police officers is a widely held concern for the law enforcement profession. Prior research into this problem has focused almost exclusively on individual, situational, or ecological correlates at the city or higher levels of aggregation rather than at the neighborhood level, potentially masking important local variation. This study examines block-group-level risk factors for serious assaults on police from a criminal opportunity perspective. Data for the study included 603 aggravated assaults on police in Boston, arrestee location data, violent crimes known to the police for the years 1993 to 1999, and 1990 census data. Findings indicate strong associations between serious assaults on police and block groups characterized by high arrestee density, criminogenic conditions, and propensity for violence.
Toward an Understanding of the Physical Hazards of Police Work
Authors: Brandl Steven G. , Stroshine Meghan S.
Published: June 2003

Most of the existing research on the hazards of police work concludes that policing is a dangerous occupation. The operationalization of dangerousness used by most researchers, however, fails to account for injuries and deaths that occur as a result of accidents, relying instead on the analysis of assaults and homicides. Defining dangerousness in this manner not only provides an incomplete picture of the dangers associated with the job but also precludes the comparison of policing to other occupations. Using injury report data from a police department and fire department in a large Midwestern city, this study contributes to knowledge in this area by (a) expanding the conceptualization of dangerousness to include injuries that occur as a result of accidents, (b) comparing accidental injuries to those that result from felonious acts, and (c) comparing injury incidents of varying natures and causes across occupations.
Adaptation of the Weighed Food Record Method to Households in the Peruvian Andes and Ethnographic Insights on Hunger
Authors: Graham Margaret A.
Published: June 2003

This article is a methodological analysis of anthropological research on child nutrition carried out during fifteen months in a small farming community in the southern Peruvian highlands. Based on the measurement of food intake of seventy-five people during three seasons for a total of more than six hundred meals, the author explains the various ways in which she adapted the weighed food record technique for measuring dietary intake to make it acceptable in this cultural context. She also shows how this method yielded ethnographic data on nonbiological dimensions of hunger in rural households that are concealed from sight of other community members. This analysis shows that the process of collecting quantitative data is itself a sociocultural process that illuminates the realities of people's lives. This article is intended to be useful for researchers, both seasoned and neophytes, who seek a detailed discussion of doing dietary assessment in the field.
Case Study of Organizational and Community Health Changes Under New Jersey State Welfare Reform
Authors: Burger Susan
Published: June 2003

Nursing research has predominantly examined the environment at the micro level; however, nurse scholars are increasingly calling for studies that examine macro-level environmental factors on population health. This comparative case study examined changes made by health-related organizations and in community health during the 1st years of New Jersey welfare reform policy implementation (1992-1998). The boundaries of these case descriptions were directed by Milio's ecological framework for policy studies. Throughout these years, county welfare agencies made organizational changes that shifted their focus from supporting family well-being to encouraging work as a means to achieving independence from welfare. Health care provider organizations are just now beginning to make organizational changes in response to the ripple effects of welfare reform. Beyond providing insight into the possible health consequences of welfare reform policy, this study may prove useful as a methodological guide for nurse researchers confronting the challenges inherent in process-oriented policy research.
The Performance of White Masculinity in Boys Don't Cry: Identity, Desire, (Mis)Recognition
Authors: Esposito Jennifer
Published: June 2003

Using a theoretical discussion of gender performance and border patrol/inspection to situate the analysis, this article examines the film Boys Don't Cry to investigate the performances of White masculinity and how Brandon Teena's body becomes constructed as a “contested site.” The author argues that the film reinscribes the normative nature of White masculinity by showcasing Brandon Teena's “failed” performance as a performance while allowing the “biological men” to just “be” men. The film was not able to allow Brandon to exist in the “borderlands,” a space where he did not have to be labeled outside of his own desires. The film contains Brandon, categorizes him as “lesbian.” We, as viewers of the film, are interpellated as border patrols and aid in the lesbianizing of Brandon.
Differential expression and regulation of protease-activated receptors in human peripheral monocytes and monocyte-derived antigen-presenting cells
Authors: Colognato Renato , Slupsky Joseph R. , Jendrach Marina , Burysek Ladislav , Syrovets Tatiana , Simmet Thomas
Published: June 2003

Protease-activated receptors (PARs) are stimulated by proteolytic cleavage of their extracellular domain, unmasking a new N-terminus acting as tethered ligand. Whereas the role of PARs in platelets is well known, their presence and function in human monocytes and other antigen-presenting cells has not been characterized. Here it is demonstrated that human peripheral monocytes and monocyte-derived macrophages and dendritic cells differentially express PARs. Human monocytes express mainly PAR1 and less PAR3. Differentiation of monocytes into macrophages by either macrophage colony-stimulating factor (M-CSF) or granulocyte-macrophage colony-stimulating factor (GM-CSF) elicits enhanced expression of PAR1, PAR2, and PAR3. In contrast, dendritic cells differentiated from monocytes by GM-CSF and interleukin-4 (IL-4) strongly down-regulated PAR1, PAR2, and PAR3, both at the mRNA and the protein level. Down-regulation of the PAR expression was apparently due to IL-4, because treatment of macrophages with IL-4 caused down-regulation of PAR1, PAR2, and PAR3. PAR4 mRNA expression remained undetectable in any of the cell types investigated. Stimulation of PAR1, PAR2, and PAR3 with thrombin, trypsin, or established receptor-activating peptides (PAR-APs) triggered cytosolic Ca2+ responses, indicating functionally active PARs. Further, stimulation of monocytes or macrophages with thrombin or PAR1-AP, but not with PAR2-or PAR4-AP, triggers expression of monocyte chemoattractant protein-1 (MCP-1) both at the mRNA and the protein level. These data demonstrate that differentiation of human monocytes is associated with differential expression of functionally active PARs that mediate distinct regulatory functions in inflammation and atherogenesis. (Blood. 2003;102:2645-2652)
Sickle blood contains tissue factor–positive microparticles derived from endothelial cells and monocytes
Authors: Shet Arun S. , Aras Omer , Gupta Kalpna , Hass Mathew J. , Rausch Douglas J. , Saba Nabil , Koopmeiners Louann , Key Nigel S. , Hebbel Robert P.
Published: June 2003

Blood microparticles (MPs) in sickle cell disease (SCD) are reportedly derived only from erythrocytes and platelets. Yet in SCD, endothelial cells and monocytes are activated and abnormally express tissue factor (TF). Thus, sickle blood might contain TF-positive MPs derived from these cells. With the use of flow cytometry to enumerate and characterize MPs, we found total MPs to be elevated in crisis (P = .0001) and steady state (P = .02) in subjects with sickle cell disease versus control subjects. These MPs were derived from erythrocytes, platelets, monocytes, and endothelial cells. Erythrocyte-derived MPs were elevated in sickle crisis (P = .0001) and steady state (P = .02) versus control subjects, as were monocyte-derived MPs (P = .0004 and P = .009, respectively). Endothelial and platelet-derived MPs were elevated in sickle crisis versus control subjects. Total TF-positive MPs were elevated in sickle crisis versus steady state (P = .004) and control subjects (P < .0001) and were derived from both monocytes and endothelial cells. Sickle MPs shortened plasma-clotting time compared with control MPs, and a TF antibody partially inhibited this procoagulant activity. Markers of coagulation were elevated in patients with sickle cell disease versus control subjects and correlated with total MPs and TF-positive MPs (P < .01 for both). These data support the concept that SCD is an inflammatory state with monocyte and endothelial activation and abnormal TF activity. (Blood. 2003;102:2678-2683)
Intracerebroventricular Galanin-Like Peptide Induces Different Brain Activation Compared with Galanin
Authors: Lawrence Catherine B. , Williams Torrie , Luckman Simon M.
Published: June 2003

Like galanin, the 60-amino-acid peptide, galanin-like peptide (GALP), has orexigenic actions, demonstrated by an acute increase in feeding after central injection in rodents. However, in contrast to galanin, GALP causes a prolonged rise in core body temperature and a reduction in body weight over 24 h. In an attempt to identify potential explanations for the observed differences between GALP and galanin, this study examined which brain areas were activated by these peptides. Intracerebroventricular injection of GALP into conscious rats significantly stimulated feeding over 0–1 h, increased core body temperature, but reduced body weight gain over 24 h. Immunohistochemistry to detect c-fos demonstrated that intracerebroventricular injection of GALP or galanin activated several brain regions in common, including the dorsomedial nucleus of the hypothalamus, lateral hypothalamus, and nucleus tractus solitarius of the brainstem. However, GALP also induced c-fos expression in the periventricular hypothalamic region and supraoptic hypothalamic nucleus. Cell activation induced by GALP in the supraoptic hypothalamic nucleus and nucleus tractus solitarius was dependent on food intake but independent of food consumption in all other brain regions. Double immunohistochemistry indicated that small cells expressing c-fos in the periventricular hypothalamic region after GALP were astrocytes and not microglia.
Stimulation of MMP-7 (matrilysin) byHelicobacter pyloriin human gastric epithelial cells: role in epithelial cell migration
Authors: Wroblewski Lydia E. , Noble P.-J. M. , Pagliocca Adelina , Pritchard D. Mark , Hart C. Anthony , Campbell Fiona , Dodson Andrew R. , Dockray Graham J. , Varro Andrea
Published: June 2003

Epithelial cell responses to bacterial infection include induction of matrix metalloproteinase 7 (MMP-7). Here, we identify increased MMP-7 expression in the gastric epithelium in response to the oncogenic bacterium Helicobacter pylori, and report on the mechanisms and consequences for gastric epithelial cell migration. In patients infected with H. pylori, there was increased MMP-7 in gastric biopsies detected by western blot. MMP-7 was localized to the advancing edge of migrating gastric epithelial cell colonies, including lamellipodia. Rates of spreading of gastric gland cells were higher in H. pylori-infected cultures compared with control, and this was inhibited by antisense oligonucleotides to MMP-7. Complementary data were obtained in a gastric cancer cell line (AGS cells). In the latter, H. pylori induced expression of an MMP-7-luciferase promoter/reporter vector through mechanisms that involved activation of Rho and Rac. RhoA acted through activation of both NF-κB and AP-1, whereas Rac activated NF-κB but not AP-1. MMP-7 is commonly upregulated in gastric cancer; since H. pylori is a recognized gastric carcinogen, the data suggest a new mechanism by which the bacterium might predispose towards gastric neoplasia.
Thrombospondin signaling through the calreticulin/LDL receptor-related protein co-complex stimulates random and directed cell migration
Authors: Orr A. Wayne , Elzie Carrie A. , Kucik Dennis F. , Murphy-Ullrich Joanne E.
Published: June 2003

The matricellular extracellular matrix protein thrombospondin-1 (TSP1)stimulates focal adhesion disassembly through a sequence (known as the hep I peptide) in its heparin-binding domain. This mediates signaling through a receptor co-complex involving calreticulin and low-density lipoprotein (LDL)receptor-related protein (LRP). We postulate that this transition to an intermediate adhesive state enhances cellular responses to dynamic environmental conditions. Since cell adhesion dynamics affect cell motility,we asked whether TSP1/hep I-induced intermediate adhesion alters cell migration. Using both transwell and Dunn chamber assays, we demonstrate that TSP1 and hep I gradients stimulate endothelial cell chemotaxis. Treatment with focal adhesion-labilizing concentrations of TSP1/hep I in the absence of a gradient enhances endothelial cell random migration, or chemokinesis,associated with an increase in cells migrating, migration speed, and total cellular displacement. Calreticulin-null and LRP-null fibroblasts do not migrate in response to TSP1/hep I, nor do endothelial cells treated with the LRP inhibitor receptor-associated protein (RAP). Furthermore, TSP1/hep I-induced focal adhesion disassembly is associated with reduced chemotaxis to basic fibroblast growth factor (bFGF) but enhanced chemotaxis to acidic(a)FGF, suggesting differential modulation of growth factor-induced migration. Thus, TSP1/hep I stimulation of intermediate adhesion regulates the migratory phenotype of endothelial cells and fibroblasts, suggesting a role for TSP1 in remodeling responses.
LFA-1-induced T cell migration on ICAM-1 involves regulation of MLCK-mediated attachment and ROCK-dependent detachment
Authors: Smith Andrew , Bracke Madelon , Leitinger Birgit , Porter Joanna C. , Hogg Nancy
Published: June 2003

This study analyzes signaling events initiated through binding of the leukocyte integrin LFA-1 to ICAM-1, which leads to T cell attachment,polarization and random migration. These events are critically dependent on dynamic changes in the acto-myosin cytoskeleton under the regulation of myosin light chain kinase and ROCK (Rho kinase). A key finding is that the activity of these two kinases is spatially segregated. Myosin light chain kinase (MLCK)must operate at the leading edge of the T cell because blocking its activity causes the polarized T cell to retract from the front of the cell. These activities are mirrored by inhibiting calmodulin, the activator of MLCK. In contrast inhibition of ROCK (and RhoA) has the effect of preventing detachment of the T cell trailing edge, showing that this kinase operates at the rear of the cell. This compartmentalized activity of the two kinases is reflected in their localization within the T cell. Myosin light chain kinase is concentrated at the leading edge, overlapping F-actin, whereas ROCK is more widely distributed in the trailing edge of the T cell. Thus these two kinases perform two different functions in the migrating T cell, with myosin light chain kinase activity important for attachment and movement at the leading edge and ROCK activity required for the detachment of the trailing edge. These two actomyosin-dependent processes operate coordinately to cause forward migration of a T cell.
DYRK1A accumulates in splicing speckles through a novel targeting signal and induces speckle disassembly
Authors: Álvarez Mónica , Estivill Xavier , de la Luna Susana
Published: June 2003

The protein kinase DYRK1A is distributed throughout the nucleoplasm,accumulating in speckle-like regions. We have found that this punctuated nuclear distribution is determined by the contribution of several elements. Although the nuclear import is mediated by two distinct nuclear localization signals, one at the N-terminus and the other located in the linker region,between subdomains X and XI of the catalytic domain, the accumulation in speckles that are SC35 positive depends on a sequence motif that is located C-terminal to the kinase domain and comprises a histidine tail. A similar sequence is also responsible for the targeting of cyclin T1. Therefore the histidine-rich region represents a novel splicing speckle targeting signal. Moreover, overexpression of DYRK1A induces speckle disassembly. Such disassembly is DYRK1A activity specific, since the overexpression of a DYRK1A kinase inactive mutant, the paralogous DYRK1B or a chimeric protein DYRK1B that has been directed to the speckles via the DYRK1A targeting signal, leaves the SC35 speckle pattern untouched. Thus DYRK1A protein kinase may play a role in regulating the biogenesis of the splicing speckle compartment.
The ectodomain shedding of angiotensin-converting enzyme is independent of its localisation in lipid rafts
Authors: Parkin Edward T. , Tan Fulong , Skidgel Randal A. , Turner Anthony J. , Hooper Nigel M.
Published: June 2003

Angiotensin-converting enzyme (ACE), a type I integral membrane protein that plays a major role in vasoactive peptide metabolism, is shed from the plasma membrane by proteolytic cleavage within the juxtamembrane stalk. To investigate whether this shedding is regulated by lateral segregation in cholesterol-rich lipid rafts, Chinese hamster ovary cells and human neuroblastoma SH-SY5Y cells were transfected with either wild-type ACE(WT-ACE) or a construct with a glycosylphosphatidylinositol (GPI) anchor attachment signal replacing the transmembrane and cytosolic domains (GPI-ACE). In both cell types, GPI-ACE, but not WT-ACE, was sequestered in caveolin or flotillin-enriched lipid rafts and was released from the cell surface by treatment with phosphatidylinositol-specific phospholipase C. When cells were treated with activators of the protein kinase C signalling cascade (phorbol myristate acetate or carbachol) the shedding of GPI-ACE was stimulated to a similar extent to that of WT-ACE. The release of WT-ACE and GPI-ACE from the cells was inhibited in an identical manner by a range of hydroxamate-based zinc metalloprotease inhibitors. Disruption of lipid rafts by filipin treatment did not alter the shedding of GPI-ACE, and phorbol ester treatment did not alter the distribution of WT-ACE or GPI-ACE between raft and non-raft membrane compartments. These data clearly show that the protein kinase C-stimulated shedding of ACE does not require the transmembrane or cytosolic regions of the protein, and that sequestration in lipid rafts does not regulate the shedding of the protein.
Preparation of Colloidal Au by a Femtosecond Laser
Authors: Zhao Chongjun , Qu Shiliang , Qiu Jianrong , Zhu Congshan , Hirao Kazuyuki
Published: June 2003

Au colloid was photoinduced by a focused infrared femtosecond laser at 800 nm. The Au colloid was characterized by absorption spectra, X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). A mechanism for the formation of Au nanoparticles was proposed.
Amino Acid Precursors from Carbon Monoxide in Simulated Interstellar Dust Ice Mantle by UV Irradiation at 10 K
Authors: Takano Yoshinori , Ushio Kentaro , Kaneko Takeo , Kobayashi Kensei , Hashimoto Hirofumi
Published: June 2003

An ice mantle mixture of carbon monoxide, ammonia (or dinitrogen), and water was irradiated in a highly vacuumed cryostat with ultraviolet light at 10 K. The primary products were identified as amino acid precursors when ammonia was used as a nitrogen source, which strongly suggested abiotic formation of bioorganic compounds in ice mantle of interstellar dusts in molecular clouds. The present results have significant implication for organic formation in interstellar dust ice mantles and the energetics of nitrogen fixation.
The Fall of Enron
Authors: Healy Paul M , Palepu Krishna G
Published: June 2003

The financial reporting and disclosure problems at Enron, as well as the high market valuations for its stock raise troubling questions about the functioning of capital market intermediaries, regulators and governance experts whose are supposed to ensure the effective functioning of the stock market. This paper examines the functions of key capital market intermediaries and analyzes how their own governance and incentive problems may have contributed to Enron's rise and fall. We conclude by proposing system modifications to resolve the observed problems.
Corporate Conflicts of Interest
Authors: Demski Joel S
Published: June 2003

This paper surveys conflicts of interest in the corporate governance arena, with emphasis on auditors, boards of directors, analysts and investment bankers, regulators, management, attorneys and investors. Enron provides a host of examples as well. I stress the multifaceted nature of these conflicts, and the fact most research looks at some conflicts, such as auditor independence, absent the larger setting and potential interactions among various players. I further speculate herding behavior is an important explanatory device in understanding periodic failures.
Contracts Between Art and Commerce
Authors: Caves Richard E
Published: June 2003

Contract structures used in the arts and entertainment industries are central to understanding their economic organization. The structures spring from common bedrock traits of these industries—pervasive product differentiation, all costs sunk, consumers' valuations unpredictable, artists having tastes for how creative work is done. Joint-venture structures are commen, with revenue (not profit) shared. Advances to artists help bring incentive and distributive goals into consistency, as do long-term contracts covering successive cycles of the artist's output. Real option contracts allow the efficient allocation of decision rights in a project on which collaborators work successively.
Policy Watch: The Expanding Reach of the Individual Alternative Minimum Tax
Authors: Burman Leonard E , Gale William G , Rohaly Jeffrey
Published: June 2003

The individual alternative minimum tax (AMT) was designed in 1970 to apply reduce aggressive tax sheltering, but under current law will grow to cover tens of millions of households in the next decade. The growth occurs because the AMT is not indexed for inflation and the 2001 tax cut reduced regular income taxes but not the AMT. AMT growth is troubling because the tax has questionable effects on equity and efficiency and is inordinately complex. This paper describes the AMT, discusses economic issues related to the alternative minimum tax, and examines options for reform.
Achieving a Superplastic Forming Capability through Severe Plastic Deformation
Authors: Xu C. , Furukawa M. , Horita Z. , Langdon T.G.
Published: June 2003

Processing by severe plastic deformation (SPD) leads to very significant grain refinement in metallic alloys. Furthermore, if these ultrafine grains are reasonably stable at elevated temperatures, there is a potential for achieving high tensile ductilities, and superplastic elongations, in alloys that are generally not superplastic. In addition, the production of ultrafine grains leads to the occurrence of superplastic flow at strain rates that are significantly faster than in conventional alloys so that processing by SPD introduces the possibility of using these alloys for the rapid fabrication of complex parts through superplastic forming operations. This paper examines the development of superplasticity in various aluminum alloys processed by equal‐channel angular pressing (ECAP).
Commercialization of Nanostructured Metals Produced by Severe Plastic Deformation Processing
Authors: Lowe T.C. , Zhu Y.T.
Published: June 2003

The promise of nanotechnology is increasingly being realized as governments, universities, public and private research laboratories, and the various industrial sectors devote resources to this emerging area. Estimates for the economic impact of nanotechnology on existing global markets exceed 700 billion by the year 2008. Nanomaterials are projected to be one of the earliest components of nanotechnology to appear in commercial applications. Amongst the emerging new nanomaterials, bulk nanostructured metals produced by severe plastic deformation (SPD) have shown promise in a wide range of application areas. In this paper, we overview developments in severe plastic deformation technology, emphasizing progress since the international workshop “Investigations and Applications of Severe Plastic Deformation” held 2–8 August 1999 in Moscow, Russia. Then, we overview some of principal areas of application for SPD metals and alloys.
Diffusion in Nanocrystalline Metals and Alloys—A Status Report
Authors: Würschum R. , Herth S. , Brossmann U.
Published: June 2003

Diffusion is a key property determining the suitability of nanocrystalline materials for use in numerous applications, and it is crucial to the assessment of the extent to which the interfaces in nanocrystalline samples differ from conventional grain boundaries. The present article offers an overview of diffusion in nanocrystalline metals and alloys. Emphasis is placed on the interfacial characteristics that affect diffusion in nanocrystalline materials, such as structural relaxation, grain growth, porosity, and the specific type of interface. In addition, the influence of intergranular amorphous phases and intergranular melting on diffusion is addressed, and the atomistic simulation of GB structures and diffusion is briefly summarized. On the basis of the available diffusion data, the diffusion‐mediated processes of deformation and induced magnetic anisotropy are discussed.
Atomistic Modeling of Strength of Nanocrystalline Metals
Authors: Van Swygenhoven H. , Derlet P.M. , Hasnaoui A.
Published: June 2003

Large scale atomistic simulations of model nanocrystalline materials are used to investigate the plastic deformation mechnisms active in interface dominated materials, with the view to understanding the origin of the related high strength seen in experiment. Results are presented detailing both inter‐ and intra‐granular deformation processes under uniaxial tensile and nano‐indentation loading conditions.
Properties, Benefits, and Application of Nanocrystalline Structures in Magnetic Materials
Authors: Grössinger R. , Sato R. , Holzer D. , Dahlgren M.
Published: June 2003

The magnetic properties of nanocrystalline hard magnetic and soft magnetic are summarized. When the grain size becomes of the order f the magnetic exchange length exchange coupling occurs. The different concepts of exchange coupling in these materials are discussed. Exchange coupling leads in isotropic hard magnetic materials to a remanence enhancement. Soft magnetic materials exhibit due to exchange coupling a lower coercivity, lower losses and consequently also improved properties.
Texture Evolution in Severe Plastic Deformation by Equal Channel Angular Extrusion
Authors: Tóth L.S.
Published: June 2003

The majority of the techniques of severe plastic deformation calls for simple shear deformation mode. This is why a special interest is given in this paper to textures that develop in simple shear. The evolution of texture in Equal Channel Angular Extrusion (ECAE) is also discussed in detail. The classical “simple shear model” of ECAE is examined as well as a new, more precise flow field which uses an analytical flow function. The proposed function is inspired from finite element calculations. The velocity gradient that follows from the analysis is incorporated into the self consistent viscoplastic polycrystal code. The evolution of deformation texture is predicted up to two passes in the A‐route ECAE deformation of copper polycrystal when the extrusion angle is 90°.
The Meaning of Size Obtained from Broadened X‐ray Diffraction Peaks
Authors: Ungár T.
Published: June 2003

X‐ray diffraction peak profile analysis (DPPA) is a powerful tool for the characterisation of microstructures either in the bulk or in loose powder materials. The evaluation and modelling procedures have been developed together with the experimental techniques. The dislocation density and structure, as obtained from peak profile analysis, is in good correlation with TEM observations. As for the crystallite size, in some cases a good correlation, however, in other cases definite discrepancies with TEM results can be observed. In the present work those literature data are critically reviewed where crystallite size or grain size have been determined by DPPA and TEM simultaneously. The correlation and discrepancies between DPPA and TEM results are discussed in terms of the microstructures in different types of specimens.