Showing papers by "University of North Carolina at Charlotte published in 2003"

Auditor Tenure and Perceptions of Audit Quality

Abstract: We analyze how investors and information intermediaries perceive auditor tenure. Using earnings response coefficients from returns-earnings regressions as a proxy for investor perceptions of earnings quality, we document a positive association between investor perceptions of earnings quality and tenure. Further, we find that the influence of reported earnings on stock rankings becomes larger with extended tenure, although the association between debt ratings and reported earnings does not vary with tenure. Finally, we find that the influence of past earnings on one-year-ahead earnings forecasts becomes larger as tenure increases. In general, our results are consistent with the hypothesis that investors and information intermediaries perceive auditor tenure as improving audit quality. One implication of our study is that imposing mandatory limits on the duration of the auditor-client relationship might impose unintended costs on capital market participants.

Posttraumatic growth after war: a study with former refugees and displaced people in Sarajevo.

Abstract: Research carried out with survivors of a variety of different traumata indicates that a large proportion of them perceive positive changes in themselves after the trauma. This study investigated whether posttraumatic growth also could be found among people who had been exposed to particularly severe traumata over a period of several years (1991 to 1995) during the war in the area of the former Yugoslavia. Included in the study were two representative samples of adult former refugees and displaced people who lived anywhere in former Yugoslavia before the war and were currently living in Sarajevo, Bosnia and Herzegovina, three and a half years after the war. The main instrument was a new Bosnian translation of the Posttraumatic Growth Inventory. Results indicated some differences in the factor structure as compared with the original instrument. The overall means for the scale were considerably lower than reported in most studies on other kinds of trauma. Younger people reported considerably more growth than older people.

Cultured astrocytes express toll‐like receptors for bacterial products

Abstract: It has become apparent that astrocytes may be important contributors to inflammatory immune responses within the brain in response to microbial challenges. To date, the mechanisms that underlie activation of this major glial cell type by such challenges have not been investigated. In the present study, we present evidence for members of a recently discovered family of receptors for highly conserved microbial components, the Toll-like receptors (TLRs), in isolated cultures of primary murine astrocytes. We describe the low-level constitutive expression of messenger RNA-encoding TLR2, TLR4, TLR5, and TLR9 in resting cultures of these cells. Importantly, the level of expression of messenger RNA for each of these receptors is markedly elevated following exposure to specific bacteria-derived ligands for these receptors. The functional expression of these receptor proteins is further supported by the ability of known ligands for each TLR to induce both message expression and protein secretion of the proinflammatory cytokine, interleukin-6. In addition, the recent availability of antibodies to TLR2 and TLR4 has enabled us to demonstrate directly the presence of these receptors on astrocytes by Western blot and immunofluorescence analysis, respectively. Furthermore, we have confirmed the sensitivity of such receptor expression to ligand stimulation. The present demonstration of Toll-like microbial pattern-recognition receptors on primary astrocytes provides a mechanistic link between bacterial challenge and inflammatory immune responses that may be an important component of the pathologies of bacterially induced inflammatory CNS disorders.

Relationships among Supervisors' and Subordinates' Procedural Justice Perceptions and Organizational Citizenship Behaviors

Abstract: We developed and tested a model in which supervisors' procedural justice perceptions lead to supervisors' organizational citizenship behavior (OCB), supervisors' OCB leads to subordinates' procedur

Job Satisfaction In The Public Sector: The Role of the Work Environment

Abstract: This study examines the influence of the work environment on public employee feelings of job satisfaction, linking characteristics of the work context perceived to be more prevalent in public organ...

IEEE 802.15.4 low rate - wireless personal area network coexistence issues

Abstract: IEEE 802.15.4 is a proposed standard addressing the needs of low-rate wireless personal area networks or LR-WPAN with a focus on enabling wireless sensor networks. The standard is characterized by maintaining a high level of simplicity, allowing for low cost and low power implementations. Its operational frequency band includes the 2.4 GHz industrial, scientific and medical band providing nearly worldwide availability; additionally, this band is also used by other IEEE 802 wireless standards. Coexistence among diverse collocated devices in the 2.4 GHz band is an important issue in order to ensure that each wireless service maintains its desired performance requirements. This paper presents a brief technical introduction of the IEEE 802.15.4 standard and analyzes the coexistence impact of an IEEE 802.15.4 network on the IEEE 802.11b devices.

Rates of species loss from Amazonian forest fragments

Abstract: In the face of worldwide habitat fragmentation, managers need to devise a time frame for action. We ask how fast do understory bird species disappear from experimentally isolated plots in the Biological Dynamics of Forest Fragments Project, central Amazon, Brazil. Our data consist of mist-net records obtained over a period of 13 years in 11 sites of 1, 10, and 100 hectares. The numbers of captures per species per unit time, analyzed under different simplifying assumptions, reveal a set of species-loss curves. From those declining numbers, we derive a scaling rule for the time it takes to lose half the species in a fragment as a function of its area. A 10-fold decrease in the rate of species loss requires a 1,000-fold increase in area. Fragments of 100 hectares lose one half of their species in <15 years, too short a time for implementing conservation measures.

Analysis of the Reliability of the Modified Caregiver Strain Index

Abstract: Objectives The Caregiver Strain Index (CSI) is a 13-item index originally developed in the early 1980s to screen for caregiver strain after hospital discharge of an elderly family member. This study examined the reliability of a modified CSI for applications with contemporary long-term family caregivers. Methods As part of a larger family caregiver study using focus groups, telephone interviews, and mailed surveys, test-retest procedures were included to examine the reliability of the Modified CSI. The sample consisted of 158 family caregivers, with an average age of 61 years. Targeted recruitment resulted in participants from diverse racial/ethnic backgrounds. Minority caregivers represented 25% of the sample. Results The Modified CSI has slightly better internal reliability (alpha =.90) than the original Index, as reported in 1983 (alpha =.86). The two-week test-retest reliability is.88. No prior test-retest data were available for comparison. Discussion The Modified CSI can be a useful method for detecting strain levels among informal caregivers, and is easily administered and scored. The CSI continues to be a useful measure of caregiver strain for long-term care research and practice.

A meta-analytic review of the sensitivity of the Wisconsin Card Sorting Test to frontal and lateralized frontal brain damage.

Abstract: The author conducted 2 meta-analyses on the Wisconsin Card Sorting Test (WCST). The 1st compared participants with frontal lobe damage to those with posterior brain damage, whereas the 2nd compared participants with left and right frontal damage. Effect sizes based on the difference between groups were calculated for WCST variables and a composite measure. Effect sizes for these variables, except nonperseverative errors, indicated significantly poorer performance for participants with frontal damage. There were no significant differences for the left versus right comparisons. Moderator analyses using the composite measure for the frontal versus nonfrontal analyses indicated that the largest effect size was for dorsolateral damage. Though this study indicates that the WCST is sensitive to frontal lobe damage, caveats are discussed.

Right from Wrong: The Influence of Spirituality on Perceptions of Unethical Business Activities

Abstract: A network sample of 162 employees from across the US was studied to assess the relationship between individual spirituality and perceptions of unethical business activities Analyses indicate that degree of individual spirituality influences whether an individual perceives a questionable business practice as ethical or unethical Ramifications of these findings regarding the role of spirituality in enhancing workplace ethicality, as well as directions for future research, are discussed

Optimizing inventory decisions in a multi-stage multi-customer supply chain

Abstract: Most supply chain models focus on two-stage chains in which vendors supply material to one customer. In this paper, we formulate a three-stage supply chain model where a firm can supply many customers. We deal with three inventory coordination mechanisms between chain members and solve a cost minimization model for each. We show that some of the coordination mechanisms can result in a significantly lower total cost than matching production and delivery along the chain. We provide some insights into when the added complexity of the second and third coordination mechanisms lead to significant cost reductions.

Posttraumatic stress symptoms in adolescent survivors of childhood cancer and their mothers

Abstract: We examined symptoms of posttraumatic stress disorder (PTSD) in adolescent survivors of childhood cancer and their mothers and the contribution of family functioning, including perceived emotional support and familial conflict, and individual factors including life stress and severity of disease to PTSD symptoms Participants were 52 adolescent cancer survivors and their mothers and 42 healthy adolescent counterparts and their mothers Findings revealed that mothers of cancer survivors endorsed more PTSD symptoms than did their healthy counterparts and that survivors and mothers also reported greater recent and past stressful life events Although no survivors met clinical criteria for a PTSD diagnosis, over 36% endorsed mild subthreshold symptomatology Findings are discussed in the context of understanding PTSD symptoms within a family systems framework

The Effects Of Collaborative Action Research On Preservice And Experienced Teacher Partners In Professional Development Schools

Abstract: This study describes the perspectives of five pairs of preservice teachers and their experienced mentor teachers who engaged collaboratively in planning, implementing, and evaluating action research projects during a semester-long internship experience in their professional development school sites. The views of novice and experienced teachers about the costs and benefits of doing collaborative action research are presented, and the authors elaborate on the development of the mentor/mentee relationship between the preservice and experienced teacher pairs. The authors also offer guidelines for successfully engaging preservice and experienced teachers in collaborative action research.

After the fall: Layoff victims' trust and cynicism in re‐employment

Abstract: The relationship between an individual's psychological contract violation by a former employer and his or her attitudes toward a new employer was examined in a sample of lay off victims (N =141) Violation was negatively related to trust in the new employer, and positively related to employee cynicism The degree that participants worried about being similarly mistreated by their new employer mediated the relationship between violation and both trust and cynicism

A rule-based framework for role-based delegation and revocation

Abstract: Delegation is the process whereby an active entity in a distributed environment authorizes another entity to access resources. In today's distributed systems, a user often needs to act on another user's behalf with some subset of his/her rights. Most systems have attempted to resolve such delegation requirements with ad-hoc mechanisms by compromising existing disorganized policies or simply attaching additional components to their applications. Still, there is a strong need in the large, distributed systems for a mechanism that provides effective privilege delegation and revocation management. This paper describes a rule-based framework for role-based delegation and revocation. The basic idea behind a role-based delegation is that users themselves may delegate role authorities to others to carry out some functions authorized to the former. We present a role-based delegation model called RDM2000 (role-based delegation model 2000) supporting hierarchical roles and multistep delegation. Different approaches for delegation and revocation are explored. A rule-based language for specifying and enforcing policies on RDM2000 is proposed. We describe a proof-of-concept prototype implementation of RDM2000 to demonstrate the feasibility of the proposed framework and provide secure protocols for managing delegations. The prototype is a web-based application for law enforcement agencies allowing reliable delegation and revocation. The future directions are also discussed.

Critical Incidents in Student Counselor Development.

Abstract: Students in a master's degree program in counseling were asked to report critical incidents that had influenced their development as counselors. Participants most frequently cited courses based on experiential learning and field experiences as being influential in their development. Events external to the graduate program also were frequently reported as influencing their professional development.

Adaptive varying-coefficient linear models

Abstract: Varying-coefficient linear models arise from multivariate nonparametric regression, nonlinear time series modelling and forecasting, functional data analysis, longitudinal data analysis, and others. It has been a common practice to assume that the vary-coefficients are functions of a given variable which is often called an index. A frequently asked question is which variable should be used as the index. In this paper, we explore the class of the varying-coefficient linear models in which the index is unknown and is estimated as a linear combination of regression and/or other variables. This will enlarge the modelling capacity substantially. We search for the index such that the derived varying-coefficient model provides the best approximation to the underlying unknown multi-dimensional regression function in the least square sense. The search is implemented through the newly proposed hybrid backfitting algorithm. The core of the algorithm is the alternative iteration between estimating the index through a one-step scheme and estimating coefficient functions through a one-dimensional local linear smoothing. The generalised cross-validation method for choosing bandwidth is efficiently incorporated into the algorithm. The locally significant variables are selected in terms of the combined use of t-statistic and Akaike information criterion. We further extend the algorithm for the models with two indices. Simulation shows that the proposed methodology has appreciable flexibility to model complex multivariate nonlinear structure and is practically feasible with average modern computers. The methods are further illustrated through the Canadian mink-muskrat data in 1925-1994 and the pound/dollar exchange rates in 1974-1983.

Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina.

Abstract: While several studies on the ecology of Vibrio vulnificus in Gulf Coast environments have been reported, there is little information on the distribution of this pathogen in East Coast waters. Thus, we conducted a multiyear study on the ecology of V. vulnificus in estuarine waters of the eastern United States, employing extensive multiple regression analyses to reveal the major environmental factors controlling the presence of this pathogen, and of Vibrio spp., in these environments. Monthly field samplings were conducted between July 2000 and April 2002 at six different estuarine sites along the eastern coast of North Carolina. At each site, water samples were taken and nine physicochemical parameters were measured. V. vulnificus isolates, along with estuarine bacteria, Vibrio spp., Escherichia coli organisms, and total coliforms, were enumerated in samples from each site by using selective media. During the last 6 months of the study, sediment samples were also analyzed for the presence of vibrios, including V. vulnificus. Isolates were confirmed as V. vulnificus by using hemolysin gene PCR or colony hybridization. V. vulnificus was isolated only when water temperatures were between 15 and 27°C, and its presence correlated with water temperature and dissolved oxygen and vibrio levels. Levels of V. vulnificus in sediments were low, and no evidence for an overwintering in this environment was found. Multiple regression analysis indicated that vibrio levels were controlled primarily by temperature, turbidity, and levels of dissolved oxygen, estuarine bacteria, and coliforms. Water temperature accounted for most of the variability in the concentrations of both V. vulnificus (47%) and Vibrio spp. (48%).

Identity-Based Threshold Decryption.

Abstract: In this paper, we examine issues related to the construction of identity-based threshold decryption schemes and argue that it is important in practice to design an identity-based threshold decryption scheme in which a private key associated with an identity is shared. A major contribution of this paper is to construct the first identity-based threshold decryption scheme secure against chosen-ciphertext attack. A formal proof of security of the scheme is provided in the random oracle model, assuming the Bilinear Diffie-Hellman problem is computationally hard. Another contribution of this paper is, by extending the proposed identity-based threshold decryption scheme, to construct a mediated identity-based encryption scheme secure against more powerful attacks than those considered previously.

Local Linear Estimation for Time-Dependent Coefficients in Cox's Regression Models

Abstract: This article develops a local partial likelihood technique to estimate the time-dependent coefficients in Cox's regression model. The basic idea is a simple extension of the local linear fitting technique used in the scatterplot smoothing. The coefficients are estimated locally based on the partial likelihood in a window around each time point. Multiple time-dependent covariates are incorporated in the local partial likelihood procedure. The procedure is useful as a diagnostic tool and can be used in uncovering time-dependencies or departure from the proportional hazards model. The programming involved in the local partial likelihood estimation is relatively simple and it can be modified with few efforts from the existing programs for the proportional hazards model. The asymptotic properties of the resulting estimator are established and compared with those from the local constant fitting. A consistent estimator of the asymptotic variance is also proposed. The approach is illustrated by a real data set from the study of gastric cancer patients and a simulation study is also presented.

Survival of Helicobacter pylori in a natural freshwater environment.

Abstract: The mode by which Helicobacter pylori, the causative agent of most gastric ulcers, is transmitted remains undetermined. Epidemiological evidence suggests these organisms are waterborne; however, H. pylori has rarely been grown from potential water sources. This may be due to the ability of this organism to rapidly enter the viable but nonculturable (VBNC) state. Our investigation examines the entrance of H. pylori into this state in laboratory cultures and a natural freshwater environment as well as the relationship between morphology and culturability. To this end, membrane diffusion chambers were utilized to expose the cells to the natural fluctuations of a freshwater stream. In both the laboratory and environment, samples were assayed for culturability using plate counts and stained using a LIVE/DEAD BacLight assay for viability and morphological determinations. Additionally, water samples were collected, six environmental parameters were measured, and resuscitation conditions were examined. H. pylori was observed to lose culturability in the laboratory and stream, although viability was maintained. While the results of our study agree with those of previous studies which suggested that there is a transition in morphology from rods to cocci as culturability is lost, the morphological distribution of cells did not change as culturability was lost in the environment. The majority of cells in the VBNC state in the laboratory are cocci; however, all morphological forms were present in the environment. The results of these studies suggest that H. pylori persists in laboratory cultures and the environment in the VBNC state and that cells in this state represent a public health hazard.

Electronic window dressing: impression management with websites

Abstract: Businesses have embraced the Internet to reap economic advantages through the use of Websites Most Website design guidelines fail to address issues of branding and identity formation, focusing instead on concerns adapted from previous technologies However, many firms are not getting their desired results from the Website investments they have made following design guidelines reflecting graphic layout and system usability issues We suggest that Websites should be considered 'electronic storefronts' or public work areas providing frames of symbolic representations that create impressions of their sponsoring firms Our exploratory study shows that Websites influence potential customers' impressions of firms' legitimacy, innovation and caring, and that these impressions vary significantly across firms and industries Website visitors encounter symbols that are compared to mental models stored in memory and used to form impressions of the site and to draw inferences about the firm These inferences have previously been found to influence purchasing behavior Designers should be cognizant of these aspects of e-Business and executives should recognize the power of Web-based impression management Identity management must take center stage in creating a Web presence

Evidence-Based Practices for Students with Severe Disabilities and the Requirement for Accountability in “No Child Left Behind”

Abstract: To define what is special about the education of students with severe disabilities, this article provides a snapshot of research-based practices that are relevant to the “No Child Left Behind” (NCLB) focus on accountability. The NCLB requirement to assess all students in reading, math, and science is contrasted to the functional approach typical of skill acquisition research for this population. The concept of adequate yearly progress is addressed by reviewing the types of instructional strategies that would most likely yield progress. Information is also provided on the extent to which teachers use research-based strategies. We conclude that prior research provides guidance for how to select and teach skills even though new applications for academics are needed.

Systems and methods for enhanced network security

Abstract: Systems and methods for an information system security infrastructure are described. One embodiment of the present invention comprises global Internet-scale defense infrastructure, referred to as the Intrusion Detection Force (IDF). The IDF comprises a virtual infrastructure implemented on top of an existing network, such as the Internet. The IDF enables secure information sharing and intelligent data analysis and response. The node (e.g. 102 of FIG. 1) is the most primitive entity in the IDF architecture, and may be a switch, router, server, or workstation. The IDF may be implemented in small networks of computers or may be utilized by millions of hosts throughout the Internet, spanning different organizations, countries, and continents.

Intracellular Staphylococcus aureus. A mechanism for the indolence of osteomyelitis.

Abstract: Staphylococcus aureus is the bacterial pathogen which is responsible for approximately 80% of all cases of human osteomyelitis. It can invade and remain within osteoblasts. The fate of intracellular Staph. aureus after the death of the osteoblast has not been documented. We exposed human osteoblasts to Staph. aureus. After infection, the osteoblasts were either lysed with Triton X-100 or trypsinised. The bacteria released from both the trypsinised and lysed osteoblasts were cultured and counted. Colonies of the recovered bacteria were then introduced to additional cultures of human osteoblasts. The number of intracellular Staph. aureus recovered from the two techniques was equivalent. Staph. aureus recovered from time zero and 24 hours after infection, followed by lysis/trypsinisation, were capable of invading a second culture of human osteoblasts. Our findings indicate that dead or dying osteoblasts are capable of releasing viable Staph. aureus and that Staph. aureus released from dying or dead osteoblasts is capable of reinfecting human osteoblasts in culture.

Acknowledging sexual victimization as rape: Results from a national-level study

Abstract: There has been ongoing debate on how women are counted when they do not acknowledge as rapes experiences that are characterized by the key components of rape. This article explores this methodological issue by using a two-stage measurement strategy with behaviorally specific screen questions to gather information on incidents of sexual victimization from 4,446 randomly selected female college students. Our results revealed that almost half of the completed rape victims considered the incidents rapes, yet few of the attempted rape or nonrape victims considered the incidents rapes. The results of a multivariate analysis highlighted the characteristics of incidents that are likely to be considered rapes. The findings buttress the assertion that women who are counted as rape victims have experienced such victimization.