bluuebunny/crossref_metadata_2025 huggingface dataset:
Theory from Fiction: A Narrative Process Perspective on the Pedagogical Use of Feature Film
Authors: Huczynski Andrzej , Buchanan David
Published: November 2004

Analyzing film narrative to reveal embedded theory, this article suggestsa novel approach to the use of feature movies in management education. Two films are analyzed from this perspective. Contact presents a narrative of organization politics, arguing that integrity can damage an individual’s career. Elizabeth offers a leadership narrative, arguing that ruthlessness is necessary to maintain a power base. This perspective is valuable for exploring the untidy, complex, and often controversial dynamics of organizational processes, demonstrating how outcomes are shaped, not by the interaction of independent and dependent variables, but by sequences of events in particular contexts.
Reconstruction of the Environment for Sustainable Development of the Khorassan Region
Authors: Yasoori Majid
Published: November 2004

This article emphasizes the maintenance of basic production resources and reformation of economic and social structures in the Khorassan province. The region’s natural limitations and inappropriate economic and social structures (i.e., lack of necessary underlying structures, low level of literacy and skills, lack of appropriate patterns of exploitation, lack of economic institutes, and so on) have given rise to the worry that the current trend of exploitation will impose limitations on future generations. To correct the economic and social methods and to reform methods of exploiting the resources in this province, the author discusses suggestions aimed at reconstructing the region’s environmental, economical, and social structures for sustainable development, which would result in optimal use of resources, prevention of waste in both labor force and capital, and finally, a balance between man and environment.
Social Capital and National Environmental Performance: A Cross-Sectional Analysis
Authors: Grafton R. Quentin , Knowles Stephen
Published: November 2004

Using cross-country data from a sample of low-, middle-, and high-income countries, this article provides the first empirical test of the empirical relationships between national measures of social capital (civic and public), social divergence, and social capacity on various indicators of national environmental performance. Overall, the results provide little empirical support for the hypothesis that social determinants have a statistically beneficial effect on national indicators of environmental quality but do show that higher population density is associated with increases in environmental degradation. The findings suggest that the presumption that social capital is always good for the environment may be as flawed as the previously widely held view that higher incomes are always associated with increased environmental degradation. The policy implication is that improved national environmental performance may be best achieved by limiting future increases in population density and lowering emission and input intensities.
Testing Public (Un)Certainty of Science
Authors: Corbett Julia B. , Durfee Jessica L.
Published: November 2004

This exploratory study examines whether readers’assessments of the certainty of scientific findings depend on characteristics of news stories. An experimental design tested whether adding controversy and/or context to a news story about global warming influenced readers’ perceptions of its certainty. Respondents (N = 209) were randomly assigned to read one treatment and answer a questionnaire. Overall, there was a significant difference in readers’assessment of the certainty of global warming across treatments (F = 12.59, p = .00). The context treatment produced the highest level of certainty about global warming and differed significantly from the control treatment (with neither context nor controversy) and from the controversy treatment. Control and controversy treatments resulted in the lowest levels of certainty. There was an interaction effect between treatment and environmental ideology upon certainty (F = 1.64, p = .03) and a correlation between environmental ideology and prior certainty about global warming (r = .35, p = .01), suggesting that those with proenvironmental ideology were less swayed by the treatments.
Development and Preliminary Psychometric Properties of the Multidimensional Neglectful Behavior Scale-Child Report
Authors: Kantor Glenda Kaufman , Holt Melissa K. , Mebert Carolyn J. , Straus Murray A. , Drach Kerry M. , Ricci Lawrence R. , MacAllum Crystal A. , Brown Wendy
Published: November 2004

This article describes the development and psychometric properties of the Multidimensional Neglectful Behavior Scale-Child Report (MNBS-CR). The measure is broadly conceptualized to tap child neglect across four core domains: cognitive, emotional, physical and supervisory neglect, and it assesses exposure to violence, alcohol-related neglect, abandonment, and children’s appraisals of parenting. Features include pictorial items, audio computer-assisted testing, and programming by age and gender of the child and caregiver. A clinical sample of 144 children, age 6 to 15 years, and a comparison sample of 87 children were tested. Results showed that the MNBS-CR has high reliability, with higher reliability found for older children (alpha = .94) than for younger children (alpha = .66). Among older children, the MNBS-CR Supervisory scale was significantly associated with the Child Behavior Check List (CBCL), and total MNBS-CR scores were significantly associated with clinician reports of behavioral disorders. Younger and older neglected children scored significantly higher on the MNBS-CR than community children.
Increasing Readers’ Comprehension of Health Education Brochures: A Qualitative Study Into How Professional Writers Make Texts Coherent
Authors: Kools Marieke , Ruiter Robert A. C. , van de Wiel Margaretha W. J. , Kok Gerjo
Published: November 2004

The aim of this study was to gain insight into the extent to which health education text writers apply writing principles derived from cognitive psychological theory. Seventeen professional text writers of health education materials participated in a qualitative study, consisting of a rewriting task combined with a think-aloud procedure and a semistructured interview. The verbal data were explored carefully in light of seven text coherence principles that have proven effective in cognitive psychological research to increase text comprehension. Findings indicate text writers vary in their ideas and use of coherence principles to make a text comprehensible. It is argued that the health education profession can benefit greatly from knowledge about cognitive text processing and cognitive coherence principles for realizing effective comprehension of written health education messages.
Assessing Interorganizational Networks as a Dimension of Community Capacity: Illustrations From a Community Intervention to Prevent Lead Poisoning
Authors: Singer Helen Harber , Kegler Michelle Crozier
Published: November 2004

Network analysis is often cited as a method for assessing collaboration among organizations as an indicator of community capacity. The purpose of this study was to (1) document patterns of collaboration in organizational networks related to lead poisoning prevention in a Native American community and (2) examine measurement issues in using organizational network analysis to assess community capacity. Interviews were conducted with representatives from 22 tribes, government agencies, schools, and community-based organizations in northeastern Oklahoma. Intensity, density, and reliability were assessed for several stages of collaboration. Intensity and density were greater for similar types of organizations than for the network as a whole and decreased as stage of collaboration increased. Network data were more reliable when responses were dichotomized than when intensities were compared. Mean reliability scores across two respondents from the same organization ranged from 60% to 90%. Results from network studies may help communities learn how to strengthen organizational networks to enhance community capacity.
Toward a Unified System of Accreditation for Professional Preparation in Health Education: Final Report of the National Task Force on Accreditation in Health Education
Authors: Allegrante John P. , Airhihenbuwa Collins O. , Auld M. Elaine , Birch David A. , Roe Kathleen M. , Smith Becky J. ,   National Task Force on Accreditation in Health Education
Published: November 2004

During the past 40 years, health education has taken significant steps toward improving quality assurance in professional preparation through individual certification and program approval and accreditation. Although the profession has begun to embrace individual certification, program accreditation in health education has been neither uniformly available nor universally accepted by institutions of higher education. To further strengthen professional preparation in health education, the Society for Public Health Education (SOPHE) and the American Association for Health Education (AAHE) established the National Task Force on Accreditation in Health Education in 2001. The 3-year Task Force was charged with developing a detailed plan for a coordinated accreditation system for undergraduate and graduate programs in health education. This article summarizes the Task Force’s findings and recommendations, which have been approved by the SOPHE and AAHE boards, and, if implemented, promise to lay the foundation for the highest quality professional preparation and practice in health education.
A survey of individual preference for colorectal cancer screening technique
Authors: Nelson Richard L , Schwartz Alan
Published: November 2004

Background

Due to the low participation in colorectal cancer screening, public preference for colorectal cancer screening modality was determined.

Methods

A cross-sectional survey was performed of healthy ambulatory adults in a pediatrics primary care office and neighboring church. Overall preference was ranked for each of four colorectal cancer screening modalities: Faecal Occult Blood, Fiberoptic Sigmoidoscopy, Barium Enema and Colonoscopy. Four additional domains of preference also were ranked: suspected discomfort, embarrassment, inconvenience and danger of each exam.

Results

80 surveys were analyzed, 57 of which were received from participants who had experienced none of the screening tests. Fecal Occult Blood Testing is significantly preferred over each other screening modality in overall preference and every domain of preference, among all subjects and those who had experienced none of the tests.

Conclusions

Efforts to increase public participation in colorectal cancer screening may be more effective if undertaken in the context of public perceptions of screening choices.
Overweight, obesity, and colorectal cancer screening: Disparity between men and women
Authors: Heo Moonseong , Allison David B , Fontaine Kevin R
Published: November 2004

Background

To estimate the association between body-mass index (BMI: kg/m2) and colorectal cancer (CRC) screening among US adults aged ≥ 50 years.

Methods

Population-based data from the 2001 Behavioral Risk Factor Surveillance Survey. Adults (N = 84,284) aged ≥ 50 years were classified by BMI as normal weight (18.5–<25), overweight (25–<30), obesity class I (30–<35), obesity class II (35–<40), and obesity class III (≥ 40). Interval since most recent screening fecal occult blood test (FOBT): (0 = >1 year since last screening vs. 1 = screened within the past year), and screening sigmoidoscopy (SIG): (0 = > 5 years since last screening vs. 1 = within the past 5 years) were the outcomes.

Results

Results differed between men and women. After adjusting for age, health insurance, race, and smoking, we found that, compared to normal weight men, men in the overweight (odds ratio [OR] 1.25, 95% CI = 1.05–1.51) and obesity class I (OR = 1.21, 95% CI = 1.03–1.75) categories were more likely to have obtained a screening SIG within the previous 5 years, while women in the obesity class I (OR = 0.86, 95%CI = 0.78–0.94) and II (OR = 0.88, 95%CI = 0.79–0.99) categories were less likely to have obtained a screening SIG compared to normal weight women. BMI was not associated with FOBT.

Conclusion

Weight may be a correlate of CRC screening behavior but in a different way between men and women.
Clinical education of ethicists: the role of a clinical ethics fellowship
Authors: Chidwick Paula , Faith Karen , Godkin Dianne , Hardingham Laurie
Published: November 2004

Background

Although clinical ethicists are becoming more prevalent in healthcare settings, their required training and education have not been clearly delineated. Most agree that training and education are important, but their nature and delivery remain topics of debate. One option is through completion of a clinical ethics fellowship.

Method

In this paper, the first four fellows to complete a newly developed fellowship program discuss their experiences. They describe the goals, structure, participants and activities of the fellowship. They identify key elements for succeeding as a clinical ethicist and sustaining a clinical ethics program. They critically reflect upon the challenges faced in the program.

Results

The one-year fellowship provided real-time clinical opportunities that helped them to develop the necessary knowledge and skills, gain insight into the role and scope of practice of clinical ethicists and hone valuable character traits.

Conclusion

The fellowship enabled each of the fellows to assume confidently and competently a position as a clinical ethicist upon completion.
Case-based medical informatics
Authors: Pantazi Stefan V , Arocha José F , Moehr Jochen R
Published: November 2004

Background

The "applied" nature distinguishes applied sciences from theoretical sciences. To emphasize this distinction, we begin with a general, meta-level overview of the scientific endeavor. We introduce the knowledge spectrum and four interconnected modalities of knowledge. In addition to the traditional differentiation between implicit and explicit knowledge we outline the concepts of general and individual knowledge. We connect general knowledge with the "frame problem," a fundamental issue of artificial intelligence, and individual knowledge with another important paradigm of artificial intelligence, case-based reasoning, a method of individual knowledge processing that aims at solving new problems based on the solutions to similar past problems.

We outline the fundamental differences between Medical Informatics and theoretical sciences and propose that Medical Informatics research should advance individual knowledge processing (case-based reasoning) and that natural language processing research is an important step towards this goal that may have ethical implications for patient-centered health medicine.

Discussion

We focus on fundamental aspects of decision-making, which connect human expertise with individual knowledge processing. We continue with a knowledge spectrum perspective on biomedical knowledge and conclude that case-based reasoning is the paradigm that can advance towards personalized healthcare and that can enable the education of patients and providers.

We center the discussion on formal methods of knowledge representation around the frame problem. We propose a context-dependent view on the notion of "meaning" and advocate the need for case-based reasoning research and natural language processing. In the context of memory based knowledge processing, pattern recognition, comparison and analogy-making, we conclude that while humans seem to naturally support the case-based reasoning paradigm (memory of past experiences of problem-solving and powerful case matching mechanisms), technical solutions are challenging.

Finally, we discuss the major challenges for a technical solution: case record comprehensiveness, organization of information on similarity principles, development of pattern recognition and solving ethical issues.

Medical Informatics is an applied science that should be committed to advancing patient-centered medicine through individual knowledge processing. Case-based reasoning is the technical solution that enables a continuous individual knowledge processing and could be applied providing that challenges and ethical issues arising are addressed appropriately.
The Chernobyl childhood leukemia study: background & lessons learned
Authors: Mahoney Martin C , Moysich Kirsten B , McCarthy Philip L , McDonald Richard C , Stepanenko Valery F , Day Robert W , Michalek Arthur M
Published: November 2004

Many challenges emerged during completion of a study to examine radiation dose and acute leukemia among children in areas of the former Soviet Union. In an era of globalization, our experiences might benefit others involved in multinational investigations.
Elevated matrix metalloproteinase-9 in patients with systemic sclerosis
Authors: Kim Wan-Uk , Min So-Youn , Cho Mi-La , Hong Kyung-Hee , Shin Yong-Joo , Park Sung-Hwan , Cho Chul-Soo
Published: November 2004

Matrix metalloproteinase-9 (MMP-9) has been implicated in the pathogenesis of cancer, autoimmune disease, and various pathologic conditions characterized by excessive fibrosis. In this study, we investigated the expression of MMP-9 and its clinical significance in systemic sclerosis (SSc). The patients (n = 42) with SSc had higher concentrations of MMP-9 and of tissue inhibitor of metalloproteinase-1 (TIMP-1) and a higher ratio of MMP-9 to TIMP-1 in sera than healthy controls (n = 32). Serum MMP-9 concentrations were significantly higher in the diffuse type (n = 23) than the limited type of SSc (n = 19). Serum concentrations of MMP-9 correlated well with the degree of skin involvement, as determined by the Rodnan score and with serum concentrations of transforming growth factor β. Moreover, dermal fibroblasts from patients with SSc produced more MMP-9 than those from healthy controls when they were stimulated with IL-1β, tumor necrosis factor α, or transforming growth factor β. Such an increase in MMP-9 production was partially blocked by treatment with cyclosporin A. In summary, the serum MMP-9 concentrations were elevated in SSc patients and correlated well with skin scores. The increased MMP-9 concentrations may be attributable to overproduction by dermal fibroblasts in SSc. These findings suggest that the enhanced production of MMP-9 may contribute to fibrogenic remodeling during the progression of skin sclerosis in SSc.
Hepatotoxicity induced by antifungal drugs itraconazole and fluconazole in rats: a comparative in vivo study
Authors: Somchit N , Norshahida A R , Hasiah A H , Zuraini A , Sulaiman M R , Noordin M M
Published: November 2004

Itraconazole and fluconazole are oral antifungal drugs, which have a wide spectrum antifungal activity and better efficacy than the older drugs. However, both drugs have been associated with hepatotoxicity in susceptible patients. The mechanism of antifungal drug-induced hepatotoxicity is largely unknown. Therefore, the aim of this present study was to investigate and compare the hepatotoxicity induced by these drugs in vivo. Rats were treated intraperitoneally with itraconazole or fluconazole either single (0, 10, l00 and 200 mg/kg) or subchronic (0, 10, 50 and loo mg/kg per day for 14 days) doses. Plasma and liver samples were taken at the end of the study. A statistically significant and dose dependent increase of plasma alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities were detected in the subchronic itraconazole-treated group. In addition, dose-dependent hepatocellular necrosis, degeneration of periacinar and mizonal hepatocytes, bile duct hyperplasia and biliary cirrhosis and giant cell granuloma were observed histologically in the same group. Interestingly, fluconazole treated rats had no significant increase in transaminases for both single and subchronic groups. In the subchronic fluconazole treated rats, only mild degenerative changes of centrilobular hepatocytes were observed. These results demonstrated that itraconazole was a more potent hepatotoxicant than fluconazole in vivo in rats.
Evaluating the cytotoxicity of ionic liquids using human cell line HeLa
Authors: Stepnowski P , Skladanowski A C , Ludwiczak A , Laczyńska E
Published: November 2004

This paper presents cytotoxicity data of selected imidazolium ionic liquids evaluated in vitro on the human tumor cell line HeLa. It was found that for 1-n-butyl-3-methylimidazolium entities the toxicity depends strongly on the associated anion; EC50 values are lowest for tetrafluoroborate. No direct dependence of the reduced effect concentration was found on elongating the short, methyl chain to ethyl or n-hexyl. Only for the ionic liquid with an n-decyl chain, the longest one studied, did higher hydrophobicity result in a EC50 one order of magnitude lower than that obtained with the n-butyl entity. The effect concentrations of imidazolium ionic liquids in the HeLa system used are lower than the values obtained for conventional organic solvents such as dichloromethane, toluene or xylene.
Effects of mono-2-ethylhexyl phthalate on the respiratory tract in BALB/c mice
Authors: Larsen S Thor , Hansen J Stilund , Hammer M , Alarie Y , Nielsen G Damgård
Published: November 2004

Airborne mono-2-ethylhexyl phthalate (MEHP) was studied for acute airway effects using a bioassay with BALB/c mice. Concentration-and time-dependent effects were obtained by continuous monitoring of the breathing pattern during exposure to 0.3-43.6 mg/m3 MEHP for 60 min. Additionally, inflammatory effects of MEHP were studied from bronchoalveolar lavage (BAL) fluid. MEHP showed no upper airway irritating effect. Lower airway irritation was apparent from a concentration-dependent decrease in tidal volume (shallow respiration) with a no-observed effect level (NOEL) of 0.3 mg/m3. The respiratory rate reached a maximum at about 8 mg/m3, demonstrating a rapid shallow breathing pattern. At concentrations above 4.9 mg/m3, the time of pause, another marker of lung irritation, increased concentration-dependently, resulting in a decrease in respiratory rate at high exposure levels. BAL fluid obtained from 0 to 72 hours after a 60 min exposure to 30 mg/m3 MEHP showed that the number of macrophage reached maximum about 16 hours after exposure. The NOEL was 1.7 mg/m3. BAL content of neutrophils, lymphocytes, eosinophils and epithelial cells was normal after exposure to 30 or 1.7 mg/m3 MEHP. Based on worst case inhalation scenario in the general population, no airway irritation is expected from non-occupational levels of MEHP originating from DEHP.
Change in profile of acute self drug-poisonings over a 10–year period
Authors: Staikowsky Frédérik , Theil Florence , Mercadier Paule , Candella Séebastien , Benais Jean Pierre
Published: November 2004

All acute, deliberate, drug-poisoning-related emergency department visits over two periods of one year, 1992-1993 (P1) and 2001-2002 (P2), were reviewed to investigate trends in substances used for acute self drug-poisonings over a 10-year period. For P1 and P2 respectively, 804 and 830 episodes of acute self drug-poisonings were compared. For the two studied periods, psycholeptic drugs predominated (78 and 77%); however, benzodiazepines declined (67 to 55%; P <0.01) and antidepressants in-creased (9.5 to 15%; P <0.01). Moreover, the type of antidepressant changed markedly with a decrease of the imipraminic antidepressants (48.4 to 10.7%) and an increase of selective serotonin reuptake inhibitors (31.2 to 74%). The proportion of benzodiazepine-related drugs increased with time (7.9 to 14.1%). The proportion of analgesics was 5.4% for P1 and 7.3% for P2; paracetamol, alone or associated to other compounds, remained the most incriminated. Nevertheless, opioids were more often mentioned during the later period (11.6 to 24.5%). The trend of the different pharmacological families used in acute self drug-poisonings is not fundamentally different over a 10-year period. However, there are some qualitative modifications, which are important for readjusting the emergency physician's toxicological knowledge and public health actions.
mau-2acts cell-autonomously to guide axonal migrations inCaenorhabditis elegans
Authors: Bénard Claire Y. , Kébir Hania , Takagi Shin , Hekimi Siegfried
Published: November 2004

The gene mau-2 has been found to be required for the guidance of cellular and axonal migrations along both the anteroposterior and the dorsoventral body axes during the development of the nematode C. elegans. We show that mau-2 encodes a novel, previously uncharacterized protein that is highly conserved among animals. Maternal mau-2 gene expression is sufficient for normal development until the fourth larval stage, and a MAU-2::GFP fusion protein localizes to the cytoplasm of neurones. mau-2 is ubiquitously expressed in embryos by late gastrulation and becomes predominantly expressed in the nervous system as morphogenesis progresses. Expression of mau-2 within individual neurones rescues the guidance defects of mau-2 mutants, indicating that mau-2 functions cell-autonomously. Altering the activity of both the dorsal repellent slt-1 and mau-2 leads to the abnormal dorsal projection of the AVM axon, a phenotype that is novel and specific to the interaction of these two genes, indicating that mau-2participates in the guidance of AVM by a slt-1-independent mechanism. Taken together, mau-2 defines a novel guidance factor that might be involved in the intracellular processing of guidance cues encountered by migrating cells and axons during development.
A role forextra macrochaetaedownstream of Notch in follicle cell differentiation
Authors: Adam Jennifer C. , Montell Denise J.
Published: November 2004

The Drosophila ovary provides a model system for studying the mechanisms that regulate the differentiation of somatic stem cells into specific cell types. Ovarian somatic stem cells produce follicle cells, which undergo a binary choice during early differentiation. They can become either epithelial cells that surround the germline to form an egg chamber (`main body cells') or a specialized cell lineage found at the poles of egg chambers. This lineage goes on to make two cell types: polar cells and stalk cells. To better understand how this choice is made, we carried out a screen for genes that affect follicle cell fate specification or differentiation. We identified extra macrochaetae (emc), which encodes a helix-loop-helix protein, as a downstream effector of Notch signaling in the ovary. EMC is expressed in proliferating cells in the germarium, as well as in the main body follicle cells. EMC expression in the main body cells is Notch dependent, and emc mutant cells located on the main body failed to differentiate. EMC expression is reduced in the precursors of the polar and stalk cells, and overexpression of EMC caused dramatic egg chamber fusions,indicating that EMC is a negative regulator of polar and/or stalk cells. EMC and Notch were both required in the main body cells for expression of Eyes Absent (EYA), a negative regulator of polar and stalk cell fate. We propose that EMC functions downstream of Notch and upstream of EYA to regulate main body cell fate specification and differentiation.
A conserved metalloprotease mediates ecdysis inCaenorhabditis elegans
Authors: Davis M. Wayne , Birnie Andrew J. , Chan Aubrey C. , Page Antony P. , Jorgensen Erik M.
Published: November 2004

Molting is required for progression between larval stages in the life cycle of nematodes. We have identified four mutant alleles of a Caenorhabditis elegans metalloprotease gene, nas-37, that cause incomplete ecdysis. At each molt the cuticle fails to open sufficiently at the anterior end and the partially shed cuticle is dragged behind the animal. The gene is expressed in hypodermal cells 4 hours before ecdysis during all larval stages. The NAS-37 protein accumulates in the anterior cuticle and is shed in the cuticle after ecdysis. This pattern of protein accumulation places NAS-37 in the right place and at the right time to degrade the cuticle to facilitate ecdysis. The nas-37 gene has orthologs in other nematode species,including parasitic nematodes, and they undergo a similar shedding process. For example, Haemonchus contortus molts by digesting a ring of cuticle at the tip of the nose. Incubating Haemonchus larvae in extracted exsheathing fluids causes a refractile ring of digested cuticle to form at the tip of the nose. When Haemonchus cuticles are incubated with purified NAS-37, a similar refractile ring forms. NAS-37 degradation of the Haemonchus cuticle suggests that the metalloproteases and the cuticle substrates involved in exsheathment of parasitic nematodes are conserved in free-living nematodes.
The conserved kinase UNC-51 acts with VAB-8 and UNC-14 to regulate axon outgrowth in C. elegans
Authors: Lai Tina , Garriga Gian
Published: November 2004

Directional cues guide growth cones. While molecules like UNC-6/netrin direct migrations along the dorsoventral axis of many organisms, it is unclear how anteroposterior guidance is achieved. We describe a physical interaction between VAB-8, a protein both necessary and sufficient for posteriorly directed migrations in C. elegans, and UNC-51, a conserved serine/threonine kinase that functions generally in axon outgrowth. We show that both proteins function in the CAN neurons to direct their axons posteriorly. Expression in the CANs of peptides predicted to interfere with interactions between UNC-51 and both VAB-8 and UNC-14, a second protein that interacts physically with UNC-51, disrupts CAN axon outgrowth. We provide genetic evidence that VAB-8 functions in an UNC-51 pathway for posteriorly directed CAN axon guidance and show that VAB-8 and UNC-14 can be targets of UNC-51 kinase activity. Taken together, our results suggest that VAB-8 and UNC-14 are substrates that mediate the function of UNC-51 in axon outgrowth.
Altered endochondral bone development in matrix metalloproteinase 13-deficient mice
Authors: Stickens Dominique , Behonick Danielle J. , Ortega Nathalie , Heyer Babette , Hartenstein Bettina , Yu Ying , Fosang Amanda J. , Schorpp-Kistner Marina , Angel Peter , Werb Zena
Published: November 2004

The assembly and degradation of extracellular matrix (ECM) molecules are crucial processes during bone development. In this study, we show that ECM remodeling is a critical rate-limiting step in endochondral bone formation. Matrix metalloproteinase (MMP) 13 (collagenase 3) is poised to play a crucial role in bone formation and remodeling because of its expression both in terminal hypertrophic chondrocytes in the growth plate and in osteoblasts. Moreover, a mutation in the human MMP13 gene causes the Missouri variant of spondyloepimetaphyseal dysplasia. Inactivation of Mmp13 in mice through homologous recombination led to abnormal skeletal growth plate development. Chondrocytes differentiated normally but their exit from the growth plate was delayed. The severity of the Mmp13- null growth plate phenotype increased until about 5 weeks and completely resolved by 12 weeks of age. Mmp13-null mice had increased trabecular bone, which persisted for months. Conditional inactivation of Mmp13 in chondrocytes and osteoblasts showed that increases in trabecular bone occur independently of the improper cartilage ECM degradation caused by Mmp13 deficiency in late hypertrophic chondrocytes. Our studies identified the two major components of the cartilage ECM, collagen type II and aggrecan, as in vivo substrates for MMP13. We found that degradation of cartilage collagen and aggrecan is a coordinated process in which MMP13 works synergistically with MMP9. Mice lacking both MMP13 and MMP9 had severely impaired endochondral bone, characterized by diminished ECM remodeling,prolonged chondrocyte survival, delayed vascular recruitment and defective trabecular bone formation (resulting in drastically shortened bones). These data support the hypothesis that proper ECM remodeling is the dominant rate-limiting process for programmed cell death, angiogenesis and osteoblast recruitment during normal skeletal morphogenesis.
Par-1 regulatesbicoidmRNA localisation by phosphorylating Exuperantia
Authors: Riechmann Veit , Ephrussi Anne
Published: November 2004

The Ser/Thr kinase Par-1 is required for cell polarisation in diverse organisms such as yeast, worms, flies and mammals. During Drosophilaoogenesis, Par-1 is required for several polarisation events, including localisation of the anterior determinant bicoid. To elucidate the molecular pathways triggered by Par-1, we have performed a genome-wide,high-throughput screen for Par-1 targets. Among the targets identified in this screen was Exuperantia (Exu), a mediator of bicoid mRNA localisation. We show that Exu is a phosphoprotein whose phosphorylation is dependent on Par-1 in vitro and in vivo. We identify two motifs in Exu that are phosphorylated by Par-1, and show that their mutation abolishes bicoid mRNA localisation during mid-oogenesis. Interestingly, exu mutants in which Exu phosphorylation is specifically affected can to some extent recover from these bicoid mRNA localisation defects during late oogenesis. These results demonstrate that Par-1 establishes polarity in the oocyte by activating a mediator of bicoid mRNA localisation. Furthermore, our analysis reveals two phases of Exu-dependent bicoid mRNA localisation: an early phase that is strictly dependent on Exu phosphorylation and a late phase that is less phosphorylation dependent.
Coordinated development of muscles and tendons of theDrosophilaleg
Authors: Soler Cédric , Daczewska Malgorzata , Da Ponte Jean Philippe , Dastugue Bernard , Jagla Krzysztof
Published: November 2004

Since Miller's morphological description, the Drosophila leg musculature and its formation has not been revisited. Here, using a set of GFP markers and confocal microscopy, we analyse Drosophila leg muscle development, and describe all the muscles and tendons present in the adult leg. Importantly, we provide for the first time evidence for tendons located internally within leg segments. By visualising muscle and tendon precursors,we demonstrate that leg muscle development is closely associated with the formation of internal tendons. In the third instars discs, in the vicinity of tendon progenitors, some Twist-positive myoblasts start to express the muscle founder cell marker dumbfounded (duf). Slightly later, in the early pupa, epithelial tendon precursors invaginate inside the developing leg segments, giving rise to the internal string-like tendons. The tendon-associated duf-lacZ-expressing muscle founders are distributed along the invaginating tendon precursors and then fuse with surrounding myoblasts to form syncytial myotubes. At mid-pupation, these myotubes grow towards their epithelial insertion sites, apodemes, and form links between internally located tendons and the leg epithelium. This leads to a stereotyped pattern of multifibre muscles that ensures movement of the adult leg.
Dopants for a Perfluorinated Graded Index Polymer Optical Fiber
Authors: Naritomi Masaki , Murofushi Hidenobu , Nakashima Naotoshi
Published: November 2004

A perfluorinated graded index polymer optical fiber (PFGI-POF) has been developed and manufactured for data communication to provide a high bandwidth with easy termination and cabling. In the PFGI-POF technology, the graded refractive index profile using dopants is a key technology to obtain a high bandwidth, excellent transparency and thermal durability. This study of the dopant selection for the PFGI-POF is reported for the first time.
How Effective Are Electronic Reputation Mechanisms? An Experimental Investigation
Authors: Bolton Gary E. , Katok Elena , Ockenfels Axel
Published: November 2004

Electronic reputation or “feedback” mechanisms aim to mitigate the moral hazard problems associated with exchange among strangers by providing the type of information available in more traditional close-knit groups, where members are frequently involved in one another's dealings. In this paper, we compare trading in a market with online feedback (as implemented by many Internet markets) to a market without feedback, as well as to a market in which the same people interact with one another repeatedly (partners market). We find that while the feedback mechanism induces quite a substantial improvement in transaction efficiency, it also exhibits a kind of public goods problem in that, unlike in the partners market, the benefits of trust and trustworthy behavior go to the whole community and are not completely internalized. We discuss the implications of this perspective for improving feedback systems.
Effects of Adaptive Behaviors and Shared Mental Models on Control Crew Performance
Authors: Waller Mary J. , Gupta Naina , Giambatista Robert C.
Published: November 2004

Control crews are highly trained teams responsible for monitoring complex systems, performing routine procedures, and quickly responding to nonroutine situations. Previous literature suggests that higher-performing control crews engage in adaptive behavior during high-workload or crisis situations. Other work suggests that higher-performing crews use periods of lower workloads to prepare for future problems. To understand which behaviors performed during which situations better differentiate lower- from higher-performing crews, we conducted a study of 14 nuclear power plant control room crews and examined adaptive behaviors and shared mental model development in the crews as they faced monitoring, routine, and nonroutine situations. Our results suggest that few differences in adaptive behaviors exist between higher- and lower-performing crews during monitoring or routine situations, but that information collection and shared mental model development activities, and intracrew processes used during model development, differ significantly between lower- and higher-performing control crews during nonroutine situations.
Focusing Firm Evolution: The Impact of Information Infrastructure on Market Entry by U.S. Telecommunications Companies, 1984–1998
Authors: Williams Charles , Mitchell Will
Published: November 2004

Organization structure acts as a lens on the environment, gathering information and shaping its flow through a firm to inform managers' choices. This shaping of information flow happens through an organization's operating units, which selectively process information from the environment, and through the links between them, which pass information between units. We explore the relationship between this “information infrastructure” and firm strategy using structure and service information from the eight largest telephone service providers in the United States from 1984 to 1998. We find that firms with more units that scan areas of opportunity are more likely to enter a market, while firms with more units that scan nonfocal areas are less likely to enter the market. We also find that personnel links between units and the corporate level of the firm often constrain entry to new markets by dampening a unit's appetite for risk. Personnel links between operating units, on the other hand, can make a firm more likely to enter new markets, particularly when the cooperating units combine different sets of information. Thus, a firm's information infrastructure plays a dual role in shaping firm evolution, leading toward some paths and away from others.
Managing Knowledge in the Dark: An Empirical Study of the Reliability of Capability Evaluations
Authors: Denrell Jerker , Arvidsson Niklas , Zander Udo
Published: November 2004

If knowledge is to be managed and transferred, it is essential that members of organizations know and agree on where capabilities reside. Few studies, however, have examined the difficulties of evaluating capabilities in large firms. This paper reports an in-depth empirical study of capabilities central to knowledge management efforts in large leading multinational companies. The results show that evaluation of these capabilities is a complex task. The median interrater correlation for capabilities designated as strategic by top management is only 0.28. Analysis of the determinants of reliability show that the difference in evaluations is largest for subsidiaries managers know less about, for younger subsidiaries, and for subsidiaries in less important markets. The results of our empirical study have important implications for creating, retaining, and transferring knowledge in organizations.
Remembrance of Things Past? The Dynamics of Organizational Forgetting
Authors: Holan Pablo Martin de , Phillips Nelson
Published: November 2004

How organizations create, transfer, and retain knowledge has been the focus of intensive investigation by management researchers. However, one aspect of the dynamics of knowledge—organizational forgetting—has received comparatively little attention. In this paper, we draw on an exploratory, multiple-case study of learning in international strategic alliances to explore how and why organizations forget. Based on our case study, we develop a theory of organizational forgetting, discuss the role of forgetting in the dynamics of organizational knowledge, and present a typology of types of organizational forgetting.
Convergence in Probability of Compressed Annealing
Authors: Ohlmann Jeffrey W. , Bean James C. , Henderson Shane G.
Published: November 2004

We consider combinatorial optimization problems for which the formation of a neighborhood structure of feasible solutions is impeded by a set of constraints. Neighborhoods are recovered by relaxing the complicating constraints into the objective function within a penalty term. We examine a heuristic called compressed annealing that integrates a variable penalty multiplier approach within the framework of simulated annealing. We refer to the value of the penalty multiplier as “pressure.” We analyze the behavior of compressed annealing by exploring the interaction between temperature (which controls the ability of compressed annealing to climb hills) and pressure (which controls the height of the hills). We develop a necessary and sufficient condition on the joint cooling and compression schedules for compressed annealing to converge in probability to the set of global minima. Our work generalizes the results of Hajek (1988) in the sense that when there are no relaxed constraints, our results reduce to his.
Learning Algorithms for Separable Approximations of Discrete Stochastic Optimization Problems
Authors: Powell Warren , Ruszczyński Andrzej , Topaloglu Huseyin
Published: November 2004

We propose the use of sequences of separable, piecewise linear approximations for solving nondifferentiable stochastic optimization problems. The approximations are constructed adaptively using a combination of stochastic subgradient information and possibly sample information on the objective function itself. We prove the convergence of several versions of such methods when the objective function is separable and has integer break points, and we illustrate their behavior on numerical examples. We then demonstrate the performance on nonseparable problems that arise in the context of two-stage stochastic programming problems, and demonstrate that these techniques provide near-optimal solutions with a very fast rate of convergence compared with other solution techniques.
A Two-Stage Hybrid Local Search for the Vehicle Routing Problem with Time Windows
Authors: Bent Russell , Van Hentenryck Pascal
Published: November 2004

The vehicle routing problem with time windows is a hard combinatorial optimization problem that has received considerable attention in the last decades. This paper proposes a two-stage hybrid algorithm for this transportation problem. The algorithm first minimizes the number of vehicles, using simulated annealing. It then minimizes travel cost by using a large neighborhood search that may relocate a large number of customers. Experimental results demonstrate the effectiveness of the algorithm, which has improved 10 (17%) of the 56 best published solutions to the Solomon benchmarks, while matching or improving the best solutions in 46 problems (82%). More important perhaps, the algorithm is shown to be very robust. With a fixed configuration of its parameters, it returns either the best published solutions (or improvements thereof) or solutions very close in quality on all Solomon benchmarks. Very preliminary results on the extended Solomon benchmarks are also given.
Anticipatory Route Selection
Authors: Thomas Barrett W. , White Chelsea C.
Published: November 2004

Mobile communication technologies enable communication between dispatchers and drivers and hence can enable fleet management based on real-time information. We assume that such communication capability exists for a single pickup and delivery vehicle and that we know the likelihood, as a function of time, that each of the vehicle's potential customers will make a pickup request. We then model and analyze the problem of constructing a minimum expected total cost route from an origin to a destination that anticipates and then responds to service requests, if they occur, while the vehicle is en route. We model this problem as a Markov decision process and present several structured results associated with the optimal expected cost-to-go function and an optimal policy for route construction. We illustrate the behavior of an optimal policy with several numerical examples and demonstrate the superiority of an optimal anticipatory policy, relative to a route design approach that reflects the reactive nature of current routing procedures for less-than-truckload pickup and delivery.
Global existence and boundedness of solutions to a second order nonlinear differential system
Authors: Yin Z.
Published: November 2004

We investigate the global existence and the boundedness of solutions of a second order nonlinear differential system.
On the Riesz-Fischer theorem
Authors: Horváth J.
Published: November 2004

Are the two forms in which the theorem of the title is usually stated equivalent? We first summarize the three Comptes Rendus notes in which Frédéric Riesz published his results concerning L2, and then, in somewhat more detail, an article from 1910 which has been published only in Hungarian. Riesz deduces the two forms not from each other but both from the Fréchet—Riesz representation theorem. A theorem states that some of Riesz's results hold in the case of an abstract inner product space, and leads to maximal orthonormal systems which are not total. We conclude with a proof due to Ákos Császár which shows that a variant of Riesz's condition implies the Fischer form (i.e., completeness).
Cesàro summability of lagrange interpolation on Jacobi roots
Authors: Szili L.
Published: November 2004

The aim of this paper is to give such weighted function spaces in which the sequence of Cesàro means of Lagrange interpolatory polynomials on Jacobi roots are uniformly convergent.
Ejection of Clusters from Liquid Beam Surface by IR Laser Irradiation
Authors: Kohno Jun‐Ya , Toyama Namiki , Mafuné Fumitaka , Kondow Tamotsu
Published: November 2004

A continuous liquid flow of an aqueous solution of phenol (Phe) in a vacuum (a liquid beam) was irradiated with an IR laser at 2.85 μm, which is resonant to the vibrational absorption band of the liquid water. The Phe (H2O)N, ejected from the liquid beam surface into the gas phase, was ionized by a UV laser at 270 nm into hydrated phenol cluster ions, Phe+ (H2O)n (n = 0 − 30), and analyzed by a time‐of‐flight mass spectrometer. The velocity distributions of the product cluster ions were derived from the spatial distributions measured at different elapsed times after the IR laser irradiation. The results and the analysis show that dense neutral clusters are ejected from surface regions locally heated by the intense IR laser.
Conformations of Unfolded S. cerevisiae Cytochrome c Probed by Fluorescence Energy Transfer Kinetics
Authors: Lyubovitsky Julia G. , Gray Harry B. , Winkler Jay R.
Published: November 2004

Employing fluorescence energy transfer kinetics, we have shown that substantial populations of compact molecules are present in GuHCl‐denatured CX‐dansyl‐labeled (X = 39, 85, 102) S. cerevisiae iso‐1 cytochrome c. Fully 40% of unfolded molecules are in compact conformations in the C39 protein.