Showing papers by "Duquesne University published in 2009"

Managing product returns for remanufacturing

Abstract: Firms are often encouraged to offer environmentally friendly products as a demonstration of corporate citizenship. However, this may prove to be an unrealistic expectation since a rational firm will only engage in profitable ventures; those that increase shareholder wealth. We develop a framework for analyzing the profitability of reuse activities and show how the management of product returns influences operational requirements. We show that the acquisition of used products may be used as the control lever for the management and profitability of reuse activities. These activities, termed product acquisition management, affect several important business decisions. First, if a firm is to pursue reuse activities, these reuse activities must be value-creating. Second, if a firm is to compete by offering remanufactured products, then we show how product returns management influences the overall profitability of such activities via a trial and error EVA approach. Third, we show how operational issues are strongly affected by the approach used to manage product returns. There is a need for future research specifying the mathematical relationship between acquisition price and the nominal quality of the returned product.

Bracketing in qualitative research: Conceptual and practical matters

Abstract: Bracketing is presented as two forms of researcher engagement: with data and with evolving findings. The first form is the well-known identification and temporary setting aside of the researcher's assumptions. The second engagement is the hermeneutic revisiting of data and of one's evolving comprehension of it in light of a revised understanding of any aspect of the topic. Both of these processes are ongoing, and they include the careful development of language with which to represent findings. Extensive everyday examples of bracketing and of interviewing are presented. As a form of disclosure in qualitative research, the background from which this article was written is shared. At that point, Husserl's and Heidegger's historical introductions of bracketing are presented briefly, followed by a discussion of reflexivity and hermeneutics. The article closes with warnings of how residual positivism can work against qualitative rigor and with a suggested qualitative research study on bracketing.

Software Dependencies, Work Dependencies, and Their Impact on Failures

Abstract: Prior research has shown that customer-reported software faults are often the result of violated dependencies that are not recognized by developers implementing software. Many types of dependencies and corresponding measures have been proposed to help address this problem. The objective of this research is to compare the relative performance of several of these dependency measures as they relate to customer-reported defects. Our analysis is based on data collected from two projects from two independent companies. Combined, our data set encompasses eight years of development activity involving 154 developers. The principal contribution of this study is the examination of the relative impact that syntactic, logical, and work dependencies have on the failure proneness of a software system. While all dependencies increase the fault proneness, the logical dependencies explained most of the variance in fault proneness, while workflow dependencies had more impact than syntactic dependencies. These results suggest that practices such as rearchitecting, guided by the network structure of logical dependencies, hold promise for reducing defects.

Second-harmonic generation and crystal structure of the diamond-like semiconductors Li(2)CdGeS(4) and Li(2)CdSnS(4).

Abstract: The semiconductors Li(2)CdGeS(4) and Li(2)CdSnS(4), which are of interest for their nonlinear optical properties, were synthesized using high-temperature solid-state and polychalcogenide flux syntheses. Both compounds were found to crystallize in Pmn2(1), with R1 (for all data) = 1.93% and 1.86% for Li(2)CdGeS(4) and Li(2)CdSnS(4), respectively. The structures of both compounds are diamond-like with the tetrahedra pointing in the same direction along the c axis. The alignment of the tetrahedra results in the structure lacking an inversion center, a prerequisite for second-harmonic generation (SHG). A modified Kurtz nonlinear optical powder technique was used to determine the SHG responses of both compounds. Li(2)CdGeS(4) displayed a type I phase-matchable response of approximately 70x alpha-quartz, while Li(2)CdSnS(4) displayed a type I non-phase-matchable response of approximately 100x alpha-quartz. Diffuse-reflectance spectroscopy was used to determine band gaps of 3.10 and 3.26 eV for Li(2)CdGeS(4) and Li(2)CdSnS(4), respectively.

Understanding the health literacy of America: results of the National Assessment of Adult Literacy.

Abstract: Health literacy refers to an individual's ability to understand healthcare information to make appropriate decisions. Healthcare professionals are obligated to make sure that patients understand information to maximize the benefits of healthcare. The National Assessment of Adult Literacy (NAAL) provides information on the literacy/health literacy levels of the U.S. adult population. The NAAL is the only large-scale survey of health literacy. The results of the NAAL provide information on literacy/health literacy and the relationship between background variables and literacy/health literacy. Multiple variables with potential for a relationship with literacy/health literacy were chosen for the NAAL including, but not limited to, education, language, race, gender, income, overall health, seeking health information, and health insurance.

Civic Community in Small-Town America: How Civic Welfare Is Influenced by Local Capitalism and Civic Engagement*

Abstract: The aims of this paper are twofold: first, to gain a fuller understanding of factors that foster community cohesion and contribute to the residents' social and economic well-being; and, second, to move beyond previous research that used larger spatial units such as states, counties, or aggregates of counties and to focus instead on American small towns (population 2,500–20,000). The data on small towns are drawn from public-use files and from confidential microdata from various economic censuses. From these sources we construct measures of locally oriented firms, self-employment, business establishments that serve as gathering places, and associations. The local capitalism and civic engagement variables generally perform as hypothesized; in some cases they are related quite strongly to civic welfare outcomes such as income levels, poverty rates, and nonmigration rates. We discuss the advantages and disadvantages of working with place-level data and suggest some strategies for subsequent work on small towns and other incorporated places.

The plasma zinc/serum copper ratio as a biomarker in children with autism spectrum disorders.

Abstract: The frequency of zinc deficiency, copper toxicity and low zinc/copper in children with autism spectrum disorders (ASDs) may indicate decrement in metallothionein system functioning. A retrospective review of plasma zinc, serum copper and zinc/copper was performed on data from 230 children with autistic disorder, pervasive developmental disorder-NOS and Asperger's syndrome. The entire cohort's mean zinc level was 77.2 microg dl(-1), mean copper level was 131.5 microg dl(-1), and mean Zn/Cu was 0.608, which was below the 0.7 cut-off of the lowest 2.5% of healthy children. The plasma zinc/serum copper ratio may be a biomarker of heavy metal, particularly mercury, toxicity in children with ASDs.

Capacitated remanufacturing with service level constraints

Abstract: This research examines production planning and control for a remanufacturer that can sell returned items on a graded as-is basis or remanufacture the returned items. Using a GI/G/1 queuing network, we model the firms decision to remanufacture an optimal product mix over the long run that maximizes profits while maintaining a desired service level. We further use simulation to explore dispatching heuristics that can be used at the shop-floor level to achieve the desired optimal product mix, while meeting the service level constraint. Our research is grounded in actual practice and the results provide key insights into the decision-making process required to maximize profits and minimize average flow times for remanufactured products.

Arsenic in the Evolution of Earth and Extraterrestrial Ecosystems

Abstract: If you were asked to speculate about the form extra-terrestrial life on Mars might take, which geomicrobial phenomenon might you select as a model system, assuming that life on Mars would be ‘primitive’? Give your reasons. At the end of my senior year at Rensselaer Polytechnic Institute in 1968, I took Professor Ehrlich's final for his Geomicrobiology course. The above question beckoned to me like the Sirens to Odysseus, for if I answered, it would take so much time and thought that I would never get around to the exam's other essay questions and consequently, would be “shipwrecked” by flunking the course. So, I passed it up. With this 41-year perspective in mind, this manuscript is now submitted to Professor Ehrlich for (belated) “extra-credit.” R.S. Oremland

Development of a fluorescent Pb2+ sensor.

Abstract: A real turn-on: The emission intensity of heterocycle 1 increases upon binding to Pb(2+). Thus, 1 acts as a small-molecule "turn-on" fluorescent sensor for lead. The sensor is highly selective and is functional over a wide range of pH values.

Microbial mineral weathering for nutrient acquisition releases arsenic.

Abstract: Tens of millions of people in Southeast Asia drink groundwater contaminated with naturally occurring arsenic. How arsenic is released from the sediment into the water remains poorly understood. Here, we show in laboratory experiments that phosphate-limited cells of Burkholderia fungorum mobilize ancillary arsenic from apatite. We hypothesize that arsenic mobilization is a by-product of mineral weathering for nutrient acquisition. The released arsenic does not undergo a redox transformation but appears to be solubilized from the apatite mineral lattice during weathering. Analysis of apatite from the source area in the Himalayan basin indicates the presence of elevated levels of arsenic, with an average concentration of 210 mg/kg. The rate of arsenic release is independent of the initial dissolved arsenic concentration and occurs at phosphate levels observed in Bangladesh aquifers. We also demonstrate the presence of the microbial phenotype that releases arsenic from apatite in Bangladesh aquifer sediments and groundwater. These results suggest that microbial mineral weathering for nutrient acquisition could be an important mechanism for arsenic mobilization.

Digital Storytelling: An empirical study of the impact of digital storytelling on pre-service teachers’ self-efficacy and dispositions towards educational technology

Abstract: This study examined the effects of the digital storytelling experience on pre-service teachers’ self-efficacy towards edu cational technology. Additionally, this study examined professional dispositions including openness to change towards educational technology, degree of willingness to participate in professional development and technology training, and willingness to work beyond the contractual work hours for technology infusion in classrooms. A total of 98 pre-service teachers participated in the study. After participating in a brief tutorial session, participants spent a week creating their own personal stories using Photo Story software. Results indicated that participants’ technology competency and openness to change towards educational technology improved with the experience of digital storytelling. While teaching pre-service teachers about educational technology and classroom technology integration is important, transferring the technology knowledge and skills that they already possess into the learning environment is also important.

The deterministic EPQ with partial backordering: A new approach

Abstract: Several authors have developed models for the EOQ when only a percentage of stockouts will be backordered Most of these models are complicated, with equations unlike those for the EOQ with full backordering In this paper we extend work by Pentico and Drake [The deterministic EOQ with partial backordering: a new approach European Journal of Operational Research 2008; in press] that developed equations for the EOQ with partial backordering that are more like those for the EOQ with full backordering to develop a comparable model for the EPQ with partial backordering

Enrichment and isolation of Bacillus beveridgei sp. nov., a facultative anaerobic haloalkaliphile from Mono Lake, California, that respires oxyanions of tellurium, selenium, and arsenic.

Abstract: Mono Lake sediment slurries incubated with lactate and tellurite [Te(IV)] turned progressively black with time because of the precipitation of elemental tellurium [Te(0)]. An enrichment culture was established from these slurries that demonstrated Te(IV)-dependent growth. The enrichment was purified by picking isolated black colonies from lactate/Te(IV) agar plates, followed by repeated streaking and picking. The isolate, strain MLTeJB, grew in aqueous Te(IV)-medium if provided with a small amount of sterile solid phase material (e.g., agar plug; glass beads). Strain MLTeJB grew at high concentrations of Te(IV) (~8 mM) by oxidizing lactate to acetate plus formate, while reducing Te(IV) to Te(0). Other electron acceptors that were found to sustain growth were tellurate, selenate, selenite, arsenate, nitrate, nitrite, fumarate and oxygen. Notably, growth on arsenate, nitrate, nitrite and fumarate did not result in the accumulation of formate, implying that in these cases lactate was oxidized to acetate plus CO2. Strain MLTeJB is a low G + C Gram positive motile rod with pH, sodium, and temperature growth optima at 8.5–9.0, 0.5–1.5 M, and 40°C, respectively. The epithet Bacillus beveridgei strain MLTeJBT is proposed.

On the origin, homologies and evolution of primate facial muscles, with a particular focus on hominoids and a suggested unifying nomenclature for the facial muscles of the Mammalia

Abstract: The mammalian facial muscles are a subgroup of hyoid muscles (i.e. muscles innervated by cranial nerve VII). They are usually attached to freely movable skin and are responsible for facial expressions. In this study we provide an account of the origin, homologies and evolution of the primate facial muscles, based on dissections of various primate and non-primate taxa and a review of the literature. We provide data not previously reported, including photographs showing in detail the facial muscles of primates such as gibbons and orangutans. We show that the facial muscles usually present in strepsirhines are basically the same muscles that are present in non-primate mammals such as tree-shrews. The exceptions are that strepsirhines often have a muscle that is usually not differentiated in tree-shrews, the depressor supercilii, and lack two muscles that are usually differentiated in these mammals, the zygomatico-orbicularis and sphincter colli superficialis. Monkeys such as macaques usually lack two muscles that are often present in strepsirhines, the sphincter colli profundus and mandibulo-auricularis, but have some muscles that are usually absent as distinct structures in non-anthropoid primates, e.g. the levator labii superioris alaeque nasi, levator labii superioris, nasalis, depressor septi nasi, depressor anguli oris and depressor labii inferioris. In turn, macaques typically lack a risorius, auricularis anterior and temporoparietalis, which are found in hominoids such as humans, but have muscles that are usually not differentiated in members of some hominoid taxa, e.g. the platysma cervicale (usually not differentiated in orangutans, panins and humans) and auricularis posterior (usually not differentiated in orangutans). Based on our observations, comparisons and review of the literature, we propose a unifying, coherent nomenclature for the facial muscles of the Mammalia as a whole and provide a list of more than 300 synonyms that have been used in the literature to designate the facial muscles of primates and other mammals. A main advantage of this nomenclature is that it combines, and thus creates a bridge between, those names used by human anatomists and the names often employed in the literature dealing with non-human primates and non-primate mammals.

Simultaneous Extraction of Arsenic and Selenium Species From Rice Products by Microwave-Assisted Enzymatic Extraction and Analysis by Ion Chromatography-Inductively Coupled Plasma-Mass Spectrometry

Abstract: A microwave-assisted enzymatic extraction (MAEE) method was developed for the simultaneous extraction of arsenic (As) and selenium (Se) species in rice products. The total arsenic and selenium content in the enzymatic extracts were determined by inductively coupled plasma mass spectrometry (ICP-MS), while the speciation analysis was performed by ion chromatography coupled to inductively coupled plasma-mass spectrometry (IC-ICP-MS). The main factors affecting the enzymatic extraction process were evaluated in NIST SRM-1568a rice flour. The optimum extraction conditions were 500 mg of sample, 50 mg of protease XIV, and 25 mg of α-amylase in aqueous medium during 40 min at 37 °C. The extraction recoveries of total As and Se reached 100 ± 3 and 80 ± 4%, respectively. The species stability study during the MAEE process did not show transformation of the target species in rice products. The results of As speciation obtained for SRM-1568a were in agreement with previous studies of As speciation performed on the ...

Periodic trends and index of boron LEwis acidity.

Abstract: Lewis acidity is customarily gauged by comparing the relative magnitude of coordinate covalent bonding energies, where the Lewis acid moiety is varied and the Lewis base is kept constant. However, the prediction of Lewis acidity from first principles is sometimes contrary to that suggested by experimental bond energies. Specifically, the order of boron trihalide Lewis acidities predicted from substituent electronegativity arguments is opposite to that inferred by experiment. Contemporary explanations for the divergence between theory, computation, and experiment have led to further consternation. Due to the fundamental importance of understanding the origin of Lewis acidity, we report periodic trends for 21 boron Lewis acids, as well as their coordinate covalent bond strengths with NH3, utilizing ab initio, density functional theory, and natural bond orbital analysis. Coordinate covalent bond dissociation energy has been determined to be an inadequate index of Lewis acid strength. Instead, acidity is meas...

Prevalence of eating disturbance and body image dissatisfaction in young girls: an examination of the variance across racial and socioeconomic groups.

Abstract: Eating disorder research has predominantly focused on White adolescent females. More recent research suggests that eating disorders occur in various racial and age groups. The current study examines prevalence and stability of body image dissatisfaction and eating disturbance in 9- and 10-year-old girls and whether there is variability by racial group or socioeconomic status (SES). Five hundred eighty-one girls completed the Children's Eating Attitude Test (ChEAT) and the Body Image Measure (BIM). Results showed that 11% of the sample scored in the Anorexic range at age 9 and about 7% at age 10. When examining body image, 35% of the sample at age 9 and 38% at age 10 selected Ideal Figures that were smaller than their Real Figures on the BIM. There was a significant difference between the racial groups in their reports of eating disturbance, but not body image dissatisfaction. Specifically, the Minority group had higher eating disturbance scores on average at ages 9 and 10 when compared to the White group. SES did not account for eating disturbance or body image dissatisfaction. These results challenge the maxim that eating disturbance and body image dissatisfaction occur primarily in White females from middle and upper SES populations.

Lifestyle predicts falls independent of physical risk factors.

Abstract: Summary Many falls occur among older adults with no traditional risk factors. We examined potential independent effects of lifestyle on fall risk. Not smoking and going outdoors frequently or infrequently were independently associated with more falls, indicating lifestyle-related behavioral and environmental risk factors are important causes of falls in older women.

Designing Blended Inquiry Learning in a Laboratory Context: A Study of Incorporating Hands-On and Virtual Laboratories

Abstract: This article reports on the development of a methodology that integrates virtual and hands-on inquiry in a freshman introductory biology course. Using a two time × two order-condition design, an effective combination (blend) of the two environments was evaluated with 39 freshman biology participants. The quantitative results documented no significant effect of presentation order but demonstrated a significant effect of the combined learning experience. The qualitative results showed a strong preference by students for the virtual work preceding the hands-on laboratory. The study provides practitioners an effective alternative to traditional instructional practices by combining virtual and hands-on inquiry learning.

Human development and the optimal size of government

Abstract: Previous studies have found evidence for an optimal size of government with respect to GDP growth. In this paper, I look at the impact of the size of government consumption expenditures on social welfare as measured by the Human Development Index. Utilizing dynamic GMM estimation in a panel data framework, I find that evidence for an optimal size of government with respect to social welfare.

Cliques, Rumors, and Gossip by the Water Cooler: Female Bullying in the Workplace

Abstract: Aggression in the workplace has developed as a topic of interest to many in the past decade. Although aggression has been traditionally distinguished in the theoretical and empirical literature as sexual aggression (harassment) and nonsexual aggression, in this manuscript the authors will argue that there are also unique characteristics as well as effects upon recipients of a particular kind of nonsexual aggression: workplace bullying. In particular, a specific type of bullying primarily used by women, relational aggression, will be reviewed and recommendations for managers in addressing relational aggression and bullying in the workplace will be offered.

Effects of the Use of the Availability Heuristic on Ethical Decision-Making in Organizations

Abstract: Recent corporate scandals across various industries have led to an increased focus on research in business ethics, particularly on understanding ethical decision-making. This increased interest is due largely to managers’ desire to reduce the incidence of unwanted behaviors in the workplace. This article examines one major moderator of the ethical decision-making process – moral intensity. In particular, we explore the potential influence of a particular cognitive heuristic – the availability heuristic – on perceptions of moral intensity. It is our contention that moral intensity is a perceptual construct, and that individuals’ use of the availability heuristic will influence perceptions of moral intensity which, in turn, will affect how moral issues are viewed and ultimately resolved. In this article, we present propositions concerning possible relationships between the availabilities of various phenomena and the components that moral intensity comprises, and report on two studies examining the effects of availabilities on two␣of these components: magnitude of consequences and social consensus. Our findings indicated that the availability of consequences associated with an act was positively related to perceptions of the magnitude of consequences of that act. We also found that the availability of others who believe that a particular act is morally acceptable is positively related to perceptions of social consensus that that act is morally acceptable. We posit that our results suggest the possibility that perceptions of moral intensity can be actively influenced to reduce unethical behavior in organizations.