Optimal temperature profiles in tubular reactors for several catalyst decay laws

Theoretical and experimental work on tubular reactors has shown that a high temperature reaction zone can be induced to move counter to the flow of reactants by conduction and/or radiation through the solid phase. This naturally occurring phenomenon represents a transient mode of operation that can be argued to be preferable to conventional modes of operation. In order to test this hypothesis the complete time and space dependent optimal temperature policy was generated for a tubular reactor subject to several catalyst decay laws. The solutions revealed that a critical parameter is the ratio of the activation energy for the main reaction to that for the catalyst decay reaction. For values of this ratio less than one, the optimum temperature profiles represent a low temperature reaction zone that occupies the entire active bed at all times, essentially a conventional mode of operation. However, for this ratio greater than one the profiles represent a short high temperature reaction zone that propagates with time along the length of the reactor. For a catalyst decay law independent of conversion, propagation in either axial direction was optimal, but for a decay law dependent upon conversion the optimization procedure only generated reverse propagating zones.     

The North Carolina Breast Cancer Screening Program: foundations and design of a model for reaching older, minority, rural women

Breast cancer screening programs do not reach all women at the same rate. Screening mammography use varies according to sociodemographic characteristics; mammography utilization is highest among women in their fifties but then decreases with age. In North Carolina, breast cancer is a particular burden for Black and lower-income women. Black women are more likely to be diagnosed with late stage disease, and their rate of breast cancer mortality is higher than it is for White women even though the incidence in White women is greater. Older, Black, and low-income women are less likely to obtain screening by mammography and clinical breast examination. The Black-White gap is even more pronounced among rural women, in part because they are more likely to be poor. The North Carolina Breast Cancer Screening Program (NC-BCSP) was established to increase the rate of regular mammography screening by an absolute 20% in 3 years among older Black women ages 50 and older in five rural counties in the eastern part of the state. In this paper, we describe the genesis of this comprehensive community intervention model, highlighting the behavioral science constructs, health education principles, and theories of behavioral and organizational change that form its conceptual foundation. NC-BCSP's theoretical foundations include the social ecological perspective, the PRECEDE model of health promotion, the Health Belief Model of individual change, and the "stages of change" transtheoretical model. We also review the experiences and lessons learned from two previous outreach initiatives in North Carolina that provided valuable "lessons" in the development of the NC-BCSP intervention model. In the second half of the paper, we describe the actual NC-BCSP interventions, activities, and evaluation tools, citing specific examples of how the underlying theories are implemented. NC-BCSP's goal goes beyond individual behavior change to raise low mammography screening rates among Black women in rural North Carolina. Its ultimate objective is to create linkages across agencies, and between agencies and communities, that will endure after the research project ends.     

Dirty laundry: privacy issues for IT professionals

Individual online privacy, already a hot button in the political landscape, is no less important for IT professionals. In 1999, the authors distributed a survey to 500 data workers in the healthcare and financial fields. The results of the study suggest that privacy concerns are not confined to consumers, but the employees who access and collect the data are concerned as well. The survey posed 15 questions regarding the responders' attitudes about the organizational practices at their organization. The data collected from the survey reveals that healthcare workers are concerned about organizational practices causing errors in patient information, as well as unsanctioned use of patient information. Similarly, the survey research indicates that employees of financial institutions are concerned with organizational practices that allow improper access to customer information. Given the results in these two fields, IT workers and managers in all fields must be prepared to deal with this issue, for it is likely to confront them soon     

How Internet Users' Privacy Concerns Have Evolved since 2002

In 2002, the authors established a baseline for Internet users' online privacy values, finding information transfer, notice/awareness, and information storage were the top online privacy concerns. Since this survey, many privacy-related events have occurred, including changes in online trends and the creation of laws, prompting the authors to rerun the survey in 2008 to examine how these events might have affected users' online privacy concerns. In this article, they discuss the 2008 survey, which revealed that US Internet users' top three privacy concerns didn't change over the course of six years, although their level of concern did. The authors also examine differences in privacy concerns between US and international respondents. The Web extra groups the survey statements according to six dimensions of privacy concerns based on the following classifications—personalization, notice/awareness, information transfer, information collection, information storage, and access/participation.     

Examining Internet privacy policies within the context of user privacy values

Internet privacy policies describe an organization's practices on data collection, use, and disclosure. These privacy policies both protect the organization and signal integrity commitment to site visitors. Consumers use the stated website policies to guide browsing and transaction decisions. This paper compares the classes of privacy protection goals (which express desired protection of consumer privacy rights) and vulnerabilities (which potentially threaten consumer privacy) with consumer privacy values. For this study, we looked at privacy policies from nearly 50 websites and surveyed over 1000 Internet users. We examined Internet users' major expectations about website privacy and revealed a notable discrepancy between what privacy policies are currently stating and what users deem most significant. Our findings suggest several implications to privacy managers and software project managers. Results from this study can help managers determine the kinds of policies needed to both satisfy user values and ensure privacy-aware website development efforts.     

Measuring battering: development of the Women's Experience with Battering (WEB) Scale

Measuring only the physical markers of violence (e.g., slapping, beating) fails to capture the chronic vulnerability and gendered nature of battered women's experiences. Instruments that measure only observable discrete events may mask the continuous nature of battering and the relation between events and experience. Our approach to measuring battering operationalizes the experiences of battered women rather than the abusive behaviors they encounter. This alternative approach emphasizes the meanings battered women attach to the violence and to battering as an enduring presence in their lives. Focus groups with 22 battered women generated qualitative data for developing scale items (Smith, Tessaro, & Earp, 1995) and a known-groups survey with 185 battered and 204 nonbattered women determined the final scale items. Factor analysis of 40 initial items revealed a strong single-factor solution. The resulting 10-item Women's Experiences with Battering (WEB) Scale demonstrated high internal consistency reliability, was significantly correlated with known-group status, exhibited good construct validity, and was not significantly correlated with a measure of social desirability. The WEB Scale provides researchers with a valid and concise measure for studying relations between battering and health or health behavior, as well as evaluating the impact of interventions on battered women or prevalence.     

The development of an instrument for assessing the quality of life of people with diabetes. Diabetes-39

OBJECTIVES: The aim of this 2-year research project was to develop an instrument specifically designed to assess the quality of life of people with diabetes. METHODS: The project was divided into two phases. In the first phase, information from a detailed literature review, from existing quality-of-life instruments, and from interviews with health professionals and people with diabetes was used to develop an initial instrument of 92 items considered to address important aspects of patients' lives. This questionnaire was mailed to 1,000 people with diabetes, and data from the 516 respondents were used to select the most important and useful items. Fifty items were excluded, leaving 42 items that constituted the pilot instrument. During phase 2, the pilot instrument was used to assess the quality of life of 427 diabetic patients who completed the revised questionnaire. After analyzing this data, three additional items were dropped. The final instrument consists of 39 items and covers five dimensions of patients' lives: Energy and Mobility, Diabetes Control, Anxiety and Worry, Social Burden, and Sexual Functioning. RESULTS: The results of validity and reliability tests conducted to date testify to the relevance of the 39-item questionnaire (Diabetes-39) as a valid discriminative instrument, one which shows significant correlations with an overall quality-of-life assessment, the pattern of diabetes severity, and comorbidity. Further, the results from Diabetes-39 correlate well with the results from the established generic quality-of-life instrument, the Medical Outcomes Study 36-Item Short-Form Health Survey. CONCLUSIONS: Validation of a quality-of-life instrument, however, is an ongoing process. Further research is required to corroborate these early findings and to ensure that this is an instrument that can capture data of greatest relevance to the diabetic patient and that is responsive to change in quality of life.     

Maximising the light output of a Luminescent Solar Concentrator

Luminescent Solar Concentrators (LSC's) are currently being developed so that sunlight may be more fully utilised in place of conventional lighting sources. In order to optimise the light output of an LSC, various collector properties including fluorescent dye concentration, collector dimensions and matrix quality have been investigated. This study, involving measurement and computer modelling of the light transport in a single colour LSC, shows that luminous output is highly sensitive to weak extinction processes in the emission spectral band. These fine details in the loss spectrum play a key role in determining the output and efficiency of an LSC system. The separation of dye and matrix losses enables a quantitative study of the effect of matrix optical quality on performance.     

The Epstein-Barr virus latent membrane protein 1 induces expression of the epidermal growth factor receptor

The Epstein-Barr virus (EBV)-encoded LMP1 protein is an important component of the process of transformation by EBV. LMP1 is essential for transformation of B lymphocytes, most likely because of its profound effects on cellular gene expression. Although LMP1 is expressed in the majority of nasopharyngeal carcinoma (NPC) tumors, the effect of LMP1 on cellular gene expression and its contribution to the development of malignancy in epithelial cells is largely unknown. In this study the effects of LMP1 on the expression and tyrosine kinase activity of the epidermal growth factor receptor (EGFR) were investigated in C33A human epithelial cells. Stable or transient expression of LMP1 in C33A cells increased expression of the EGFR at both the protein and mRNA levels. In contrast, expression of the EGFR was not induced by LMP1 in EBV-infected B lymphocytes. Stimulation of LMP1-expressing C33A cells with epidermal growth factor (EGF) caused rapid tyrosine phosphorylation of the EGFR (pp170) as well as several other proteins, including pp120, pp85, pp75, and pp55, indicating that the EGFR induced by LMP1 is functional. LMP1 also induced expression of the A20 gene in C33A epithelial cells. In C33A cells, LMP1 expression increased the proliferative response to EGF, as LMP1-expressing C33A cells continued to increase in number when plated in serum-free media supplemented with EGF, while the neo control cells exhibited very low levels of viability and did not proliferate. Immunoblot analysis of protein extracts from nude mouse-passaged NPC tumors also demonstrated that the EGFR is overexpressed in primary NPC tumors as well as those passaged in nude mice. This study suggests that the alteration in the growth patterns of C33A cells expressing LMP1 is a result of increased proliferative signals due to enhanced EGFR expression, as well as protection from cell death due to LMP1-induced A20 expression. The induction of EGFR and A20 by LMP1 may be an important component of EBV infection in epithelial cells and could contribute to the development of epithelial malignancies such as NPC.     

Facilitating educators’ knowledge sharing with dedicated Information Systems

The process of knowledge sharing can be seen as the lifeblood for the establishment of a true Knowledge Society. Such a society must be grounded on an iterative process whereby existing knowledge is constantly shared, consolidated and – crucially – enriched with new knowledge. And knowledge sharing is the means by which that enrichment can take place. Without doubt, these processes play a vital role in the context of education, which ultimately has a strong bearing on the formation of the Knowledge Society. In this paper, knowledge sharing among educators is discussed within the context of long-term research work that the authors have carried out in the field. The paper reports on the design and development of a series of Information Systems conceived for the sharing of practices among educational practitioners. It discusses the thinking behind these different but related systems and examines how this is borne out in the implementation of key system features.