bluuebunny/crossref_metadata_2025 huggingface dataset:
New Perspectives in Plasticity Theory: Dislocation Nucleation, Waves, and Partial Continuity of Plastic Strain Rate
Authors: Acharya Amit , Beaudoin Armand , Miller Ron
Published: April 2008

A field theory of dislocation mechanics and plasticity is illustrated through new results at the nano, meso, and macro scales. Specifically, dislocation nucleation, the occurrence of wave-type response in quasi-static plasticity, and a jump condition at material interfaces and its implications for analysis of deformation localization are discussed.
On the Elastic Interaction between a Surface Step and an Edge Dislocation
Authors: Kouris Demitris , Arai Yoshio , Yamaguchi Toru , Tsuchida Echiro
Published: April 2008

This manuscript addresses the issue of interaction between a surface step and an edge dislocation. It represents the first step in an investigation that will examine dislocation egress in the presence of surface steps. The geometric step introduces an elastic field that is altered by the presence of a dislocation in its vicinity. The complete elastic field is first determined, followed by explicit expressions for the Peach— Koehler force of the interaction. A discussion follows focusing on the possibility that an edge dislocation can be prevented from reaching the surface as a result of the field generated by the surface step. If such an outcome is possible, surface steps may be responsible for a new mechanism of strain hardening. Such a possibility has been recently suggested in the literature.
Coregulation, Dysregulation, Self-Regulation: An Integrative Analysis and Empirical Agenda for Understanding Adult Attachment, Separation, Loss, and Recovery
Authors: Sbarra David A. , Hazan Cindy
Published: April 2008

An integrative framework is proposed for understanding how multiple biological and psychological systems are regulated in the context of adult attachment relationships, dysregulated by separation and loss experiences, and, potentially, re-regulated through individual recovery efforts. Evidence is reviewed for a coregulatory model of normative attachment, defined as a pattern of interwoven physiology between romantic partners that results from the conditioning of biological reward systems and the emergence of felt security within adult pair bonds. The loss of coregulation can portend a state of biobehavioral dysregulation, ranging from diffuse psychophysiological arousal and disorganization to a full-blown (and highly organized) stress response. The major task for successful recovery is adopting a self-regulatory strategy that attenuates the dysregulating effects of the attachment disruption. Research evidence is reviewed across multiple levels of analysis, and the article concludes with a series of testable research questions on the interconnected nature of attachment, loss, and recovery processes.
`No emotion, no sympathy': The visual construction of Maxine Carr
Authors: Jones Phil J. , Wardle Claire
Published: April 2008

This article examines the visual press coverage in three centre-right British newspapers of the Soham murder trial, a very high-profile case which took place in the winter of 2003. The previous summer, two young girls had been abducted and murdered, and their school caretaker, Ian Huntley was charged with their murder. He was tried alongside his girlfriend, Maxine Carr who, significantly, was not deemed to be an accomplice but was charged with perverting the course of justice, because she provided an alibi for Huntley. Public loathing towards Carr remains intense and when she was released in May 2004 she was granted indefinite anonymity. This article focuses on the visual representation of Maxine Carr, in an attempt to understand the ways in which she was visually constructed in comparison with Ian Huntley. A content analysis and qualitative visual analysis were undertaken on the trial coverage published in The Times (broadsheet), the Daily Mail (middle market) and the Sun (tabloid). The content analysis demonstrated that images of Maxine Carr appeared more frequently than images of Ian Huntley, and were often larger and reproduced in colour. The qualitative visual analysis explored the placement and juxtaposition of the images with each other and with the headline text. We found disturbing evidence of newspaper formatting which could only encourage readers to draw misleading conclusions about Carr's role in the crime. The visual coverage in the press `told' a very different story than the one which formed the basis for her sentence. We argue that the influence of newspaper page layout and image montages is too frequently overlooked by media scholars, but that it should not be underestimated, particularly in terms of the reporting of high-profile crimes.
Seeing private security like a state
Authors: O'Connor Daniel , Lippert Randy , Spencer Dale , Smylie Lisa
Published: April 2008

Based on a systematic and detailed statutory analysis of 58 jurisdictions in Canada and the United States, this article constructs a modal typology of state regulation of contract private security. State regulation of private security has been neglected despite the fact it has grown across North American jurisdictions in the past two decades. Moving beyond rudimentary regulatory models and focusing on the contract security sector exclusively, five key dimensions of state regulation of private security are identified: governing-at-a-distance, character, identity, training, and information. Whether and how these dimensions relate to management protocols at the security agency level are then examined by combining these results with an analysis of an international survey of contract security managers within these jurisdictions. In turn, each dimension is found to relate to security agency management protocols. Implications for understanding state regulation and future research on private security governance are elaborated.
Stem-cell-abundant proteins Nanog, Nucleostemin and Musashi1 are highly expressed in malignant cervical epithelial cells
Authors: Ye Feng , Zhou Caiyun , Cheng Qi , Shen Jiajie , Chen Huaizeng
Published: April 2008

Background

Nanog, nucleostemin (NS) and musashi1 (Msi1) are proteins that are highly expressed in undifferentiated embryonic stem (ES) cells and have been shown to be essential in maintaining the pluripotency and regulating the proliferation and asymmetric division of ES cells and several nervous system tumor cells. The roles of Nanog, NS and Msi1 in development and progression of cervical carcinoma have, until now, not been well documented.

Methods

In this study, expression of Nanog, NS and Msi1 was detected by immunohistochemistry analysis in 235 patients with various degrees of cervical epithelial lesions, including 49 with normal cervical epithelia, 31 with mild dysplasia (CIN I), 77 with moderate-severe dysplasia (CIN II-III) and 78 with squamous cervical carcinomas (SCCs). Associations with various clinical pathological prognostic variables were analyzed in 50 early-stage SCC patients.

Results

Nanog, NS and Msi1 expression levels were significantly higher in SCC patients compared with CIN patients, and were higher in CIN patients compared with those with normal cervical epithelia. Nanog expression levels showed significantly differences according to different tumor sizes (P < 0.05), whereas there were no differences in NS and Msi1 expression levels according to different clinical pathological parameters.

Conclusion

Our findings indicate that Nanog, NS and Msi1 may be involved in carcinogenesis of the cervix and progression of cervical carcinoma.
Comparative Analysis of the Uterine and Mammary Gland Effects of Drospirenone and Medroxyprogesterone Acetate
Authors: Otto Christiane , Fuchs Iris , Altmann Helga , Klewer Mario , Walter Alexander , Prelle Katja , Vonk Richardus , Fritzemeier Karl-Heinrich
Published: April 2008

The role of progestins in combined hormone therapy is the inhibition of uterine epithelial cell proliferation. The Women’s Health Initiative study provided evidence for an increased risk of breast cancer in women treated with conjugated equine estrogens plus the synthetic progestin medroxyprogesterone acetate (MPA), compared with conjugated equine estrogens-only treatment. These findings continue to be discussed, and it remains to be clarified whether the results obtained for MPA in the Women’s Health Initiative study are directly applicable to other progestins used in hormone therapy. In this study we compared in a mouse model the effects of the synthetic progestins, MPA, and drospirenone in two major target organs: the uterus and mammary gland. As quantitative measures of progestin activity, we analyzed maintenance of pregnancy, ductal side branching in the mammary gland, and proliferation of mammary and uterine epithelial cells as well as target gene induction in both organs. The outcome of this study is that not all synthetic progestins exhibit the same effects. MPA demonstrated uterine activity and mitogenic activity in the mammary gland at the same doses. In contrast, drospirenone behaved similarly to the natural hormone, progesterone, and exhibited uterine activity at doses lower than those leading to considerable proliferative effects in the mammary gland. We hypothesize that the safety of combined hormone therapy in postmenopausal women may be associated with a dissociation between the uterine and mammary gland activities of the progestin component.
Polychlorinated Biphenyls (Aroclor 1254) Do Not Uniformly Produce Agonist Actions on Thyroid Hormone Responses in the Developing Rat Brain
Authors: Bansal Ruby , Zoeller R. Thomas
Published: April 2008

Thyroid hormone (TH) is essential for normal brain development, and polychlorinated biphenyls (PCBs) are known to interfere with TH action in the developing brain. Thus, it is possible that the observed neurotoxic effects of PCB exposure in experimental animals and humans are mediated in part by their ability to interfere with TH signaling. PCBs may interfere with TH signaling by reducing circulating levels of TH, acting as TH receptor analogs, or both. If PCBs act primarily by reducing serum TH levels, then their effects should mimic those of low TH. In contrast, if PCBs act primarily as TH agonists in the developing brain, then they should mimic the effect of T4 in hypothyroid animals. We used a two-factor design to test these predictions. Both hypothyroidism (Htx) and/or PCB treatment reduced serum free and total T4 on postnatal d 15. However, only Htx increased pituitary TSHβ expression. RC3/neurogranin expression was decreased by Htx and increased by PCB treatment. In contrast, Purkinje cell protein-2 expression was reduced in hypothyroid animals and restored by PCB treatment. Finally, PCB treatment partially ameliorated the effect of Htx on the thickness of the external granule layer of the cerebellum. These studies demonstrate clearly that PCB exposure does not mimic the effect of low TH on several important TH-sensitive measures in the developing brain. However, neither did PCBs mimic T4 in hypothyroid animals on all end points measured. Thus, PCBs exert a complex action on TH signaling in the developing brain.
Presence of Arylsulfatase A and Sulfogalactosylglycerolipid in Mouse Ovaries: Localization to the Corpus Luteum
Authors: Anupriwan Araya , Schenk Matthias , Kongmanas Kessiri , Vanichviriyakit Rapeepun , Costa Santos Daniela , Yaghoubian Arman , Liu Fang , Wu Alexander , Berger Trish , Faull Kym F. , Saitongdee Porncharn , Sretarugsa Prapee , Tanphaichitr Nongnuj
Published: April 2008

Arylsulfatase A (AS-A) is a lysosomal enzyme, which catalyzes the desulfation of certain sulfogalactolipids, including sulfogalactosylglycerolipid (SGG), a molecule implicated in cell adhesion. In this report, immunocytochemistry revealed the selective presence of AS-A in the corpus luteum of mouse ovaries. Immunoblotting indicated that mouse corpus luteum AS-A had a molecular mass of 66 kDa, similar to AS-A of other tissues. Corpus luteum AS-A was active, capable of desulfating the artificial substrate, p-nitrocatechol sulfate, at the optimum pH of five. To understand further the role of AS-A in female reproduction, levels of AS-A were determined during corpus luteum development in pseudopregnant mice and during luteolysis after cessation of pseudopregnancy. Immunocytochemistry, immunoblotting and desulfation activity showed that AS-A expression was evident at the onset of pseudopregnancy in the newly formed corpora lutea, and its level increased steadily during gland development. The increase in the expression and activity of AS-A continued throughout luteolysis after the decrease in serum progesterone levels. We also observed the selective presence of SGG on the luteal cell surface in developed corpora lutea, as shown by immunofluorescence of mouse ovary sections as well as high-performance thin-layer chromatography of lipids isolated from mouse and pig corpora lutea. The identity of the “SGG” band on the thin layer silica plate was further validated by electrospray ionization mass spectrometry. Significantly, SGG disappeared in regressing corpora lutea. Therefore, lysosomal AS-A may be involved in cell-surface remodeling during luteolysis by desulfating SGG after its endocytosis and targeting to the lysosome.
The effects of acute temperature change on swimming performance in bluegill sunfishLepomis macrochirus
Authors: Jones Emily A. , Jong Arianne S. , Ellerby David J.
Published: April 2008

Many fish change gait within their aerobically supported range of swimming speeds. The effects of acute temperature change on this type of locomotor behavior are poorly understood. Bluegill sunfish swim in the labriform mode at low speeds and switch to undulatory swimming as their swimming speed increases. Maximum aerobic swimming speed (Umax),labriform-undulatory gait transition speed (Utrans) and the relationships between fin beat frequency and speed were measured at 14,18, 22, 26 and 30°C in bluegill acclimated to 22°C. At temperatures below the acclimation temperature (Ta), Umax, Utrans and the caudal and pectoral fin beat frequencies at these speeds were reduced relative to the acclimation level. At temperatures above Ta there was no change in these variables relative to the acclimation level. Supplementation of oxygen levels at 30°C had no effect on swimming performance. The mechanical power output of the abductor superficialis, a pectoral fin abductor muscle, was measured in vitro at the same temperatures used for the swimming experiments. At and below Ta, maximal power output was produced at a cycle frequency approximately matching the in vivo pectoral fin beat frequency. At temperatures above Ta muscle power output and cycle frequency could be increased above the in vivo levels at Utrans. Our data suggest that the factors triggering the labriform–undulatory gait transition change with temperature. Muscle mechanical performance limited labriform swimming speed at Ta and below, but other mechanical or energetic factors limited labriform swimming speed at temperatures above Ta.
Acoustic pressure and particle motion thresholds in six sciaenid fishes
Authors: Horodysky Andrij Z. , Brill Richard W. , Fine Michael L. , Musick John A. , Latour Robert J.
Published: April 2008

Sciaenid fishes are important models of fish sound production, but investigations into their auditory abilities are limited to acoustic pressure measurements on five species. In this study, we used auditory brainstem response (ABR) to assess the pressure and particle acceleration thresholds of six sciaenid fishes commonly found in Chesapeake Bay, eastern USA: weakfish(Cynoscion regalis), spotted seatrout (Cynoscion nebulosus),Atlantic croaker (Micropogonias undulatus), red drum (Sciaenops ocellatus), spot (Leiostomus xanthurus) and northern kingfish(Menticirrhus saxatilis). Experimental subjects were presented with pure 10 ms tone bursts in 100 Hz steps from 100 Hz to 1.2 kHz using an airborne speaker. Sound stimuli, monitored with a hydrophone and geophone,contained both pressure and particle motion components. Sound pressure and particle acceleration thresholds varied significantly among species and between frequencies; audiograms were notably flatter for acceleration than pressure at low frequencies. Thresholds of species with diverticulae projecting anteriorly from their swim bladders (weakfish, spotted seatrout,and Atlantic croaker) were typically but not significantly lower than those of species lacking such projections (red drum, spot, northern kingfish). Sciaenids were most sensitive at low frequencies that overlap the peak frequencies of their vocalizations. Auditory thresholds of these species were used to estimate idealized propagation distances of sciaenid vocalizations in coastal and estuarine environments.
Mechanical specialization of the obliquely striated circular mantle muscle fibres of the long-finned squidDoryteuthis pealeii
Authors: Thompson Joseph T. , Szczepanski John A. , Brody Joshua
Published: April 2008

The centrally located, mitochondria-poor (CMP) and superficially located,mitochondria-rich (SMR) circular muscle fibres in the mantles of some squids provide one of the few known examples of specialization in an obliquely striated muscle. Little is known of the mechanical properties or of the mechanisms and performance consequences of specialization in these fibres. We combined morphological and physiological approaches to study specialization in the SMR and CMP fibres of the long-finned squid Doryteuthis pealeii. The mean thick filament length was 3.12±0.56 μm and 1.78±0.27μm for the SMR and CMP fibres, respectively. The cross-sectional areas of the whole fibre and the core of mitochondria were significantly higher in the SMR fibres, but the area occupied by the myofilaments did not differ between the two fibre types. The area of sarcoplasmic reticulum visible in cross sections was significantly higher in CMP fibres than in SMR fibres. In live bundles of muscle fibres partially isolated from the mantle, mean peak isometric stress during tetanus was significantly greater in SMR [335 mN mm–2 physiological cross section (pcs)] than in CMP (216 mN mm–2 pcs) fibres. SMR fibres had a lower average twitch:tetanus ratio (SMR=0.073; CMP=0.18) and a twofold lower unloaded maximum shortening velocity at 20°C (SMR=2.4 L0s–1; CMP=5.1 L0 s–1),where L0 was the preparation length that yielded the highest tetanic force. The structural differences in the two muscle fibre types play a primary role in determining their mechanical properties, and the significant differences in mechanical properties indicate that squid have two muscle gears. A simple model of the mantle shows that a gradient of strain and strain rate exists across the mantle wall, with fibres adjacent to the outer edge of the mantle experiencing 1.3- to 1.4-fold lower strain and strain rate than fibres adjacent to the inner edge of the mantle. The model also predicts that the CMP fibres generate virtually no power for slow jetting while the SMR fibres are too slow to generate power for the escape jets. The transmural differences in strain and strain rate predicted by the model apply to any cylindrical animal that has circumferentially oriented muscle fibres and an internal body cavity.
How Capability Differences, Transaction Costs, and Learning Curves Interact to Shape Vertical Scope
Authors: Jacobides Michael G.
Published: April 2008

This paper provides an integrative analysis of the drivers of vertical scope, using analytical and computational methods. I propose a model with two vertical segments (upstream and downstream), firm populations with heterogeneous capabilities, and an intermediate market subject to transaction costs in which firms can choose whether to be integrated or vertically specialized. By varying the level of transaction costs and changing the structure of the correlation between upstream and downstream capabilities in the industry, learning curves, and the way in which profitability leads to capability improvement in the upstream and downstream segments, I generate numerical results to explain how vertical integration evolves over time. The results suggest that (a) with no capability differences, even if transaction costs are nil, firms remain integrated; (b) transaction costs catalyze the underlying capability differences to drive scope; (c) dynamic factors, such as learning curves, returns to investment in capabilities, or limits to expansion, exacerbate small, random capability differences and as such promote specialization. These dynamic factors can by themselves lead to substantial specialization when they differ between the upstream and downstream segments. The model also provides a rationale for mixed governance (i.e., concurrent use of both the market and integration), as well as for the initial period of vertical integration, followed by specialization.
Exposure of Violent Video Games to Children and Public Policy Implications
Authors: Collier Joel E. , Liddell Pearson , Liddell Gloria J.
Published: April 2008

As the popularity of violent video games increases, many concerned parents and legislators are trying to legally restrict the purchase or rental of these adult-oriented games from minors. Numerous states have tried to enact violent video game legislation, but all such laws have been overturned by the courts as a violation of First Amendment rights. This essay discusses why both state and local governments have been wholly unsuccessful in restricting minors’ access to violent video games and the strict scrutiny requirements that must be met to limit a person's First Amendment rights. Finally, this essay provides recommendations for areas that must be specifically addressed to legally restrict minors’ access to these adult-oriented games.
Stakeholder Marketing: Beyond the Four Ps and the Customer
Authors: Bhattacharya C.B. , Korschun Daniel
Published: April 2008

To better understand the full impact of marketing on society, there is an urgent need for new research that looks beyond customers as the target of marketing activities and firms as the primary intended beneficiary. A consortium of leading scholars and practitioners was convened to discuss how adopting a stakeholder perspective gives birth to a host of research questions that are relevant to the broader academic community.
Online Privacy and the Disclosure of Cookie Use: Effects on Consumer Trust and Anticipated Patronage
Authors: Miyazaki Anthony D.
Published: April 2008

The use of Internet cookies by visited Web sites and third-party firms has been criticized by consumer advocates, policy makers, and even marketers themselves as a potential threat to consumer privacy. However, surprisingly little research has examined how the interactive effects of the disclosure and practice of cookie use as a method of nonconsensual identification might influence online users’ affect or behavior. The current research addresses this lack of research by presenting the results of three studies. Study 1, a longitudinal examination of the online environment from 2000 to 2007, finds that both cookie use and disclosure have increased, but the covert use of cookies is still a concern. Study 2 finds that consumers’ negative reactions to cookie use are significantly reduced by a priori cookie disclosure by the visited Web site. Study 3 shows that consumers’ online experience and desire for privacy act as additional moderators of reactions to cookie use. The author examines the implications of the three studies from the perspectives of research, management, and public policy.
Stained by the Label? Stigma and the Case of Genetically Modified Foods
Authors: Ellen Pam Scholder , Bone Paula Fitzgerald
Published: April 2008

Stigma is a concept that marketers frequently and casually use, but it is underexplored as a theoretical construct. The authors propose a theory of stigma that identifies it as a formative construct associated with perceptions of deviance and undesirability along with inflated risk perceptions. This research also goes beyond the social stigma typically studied in marketing and related fields to examine product stigma. Specifically, this research explores the stigmatizing effects of labeling on genetically modified foods, a domain of economic and political importance. Using different labels proposed in international debates, the experiment reveals that such labels can create stigma and that, to some degree, marketers can attenuate stigma through certain qualified labeling.
How Modification of the Nutrition Facts Panel Influences Consumers at Risk for Heart Disease: The Case of Trans Fat
Authors: Howlett Elizabeth , Burton Scot , Kozup John
Published: April 2008

Making well-informed, healthful food choices helps people maintain a high quality of life. This is especially true for consumers suffering from serious diseases and conditions, such as coronary heart disease and diabetes. Two studies examine how the provision of information on trans fat, a nutrient that provides no known beneficial health benefits, in the Nutrition Facts panel influences consumers’ product perceptions and purchase intentions. Using a sample of consumers suffering from diabetes, the authors show that trans fat knowledge and level (disclosed in a Nutrition Facts panel) interact to influence risk perceptions of cardiovascular disease. The results also indicate that responses of consumers who are at risk for heart disease are influenced by the interplay among consumer knowledge, trans fat level, and motivation to process nutrition information. Specifically, the authors find that motivation in the absence of knowledge can lead to a misinterpretation of the nutrient information. Overall, the results indicate that without appropriate consumer education programs, the addition of trans fat levels to the Nutrition Facts panel may have limited or even unintended consequences. The article concludes with a discussion of the implications of these results for public policy.
Material Aging and Reliability of Engineered Systems
Authors: Wei RP
Published: April 2008

Material aging is a principal cause for the aging of engineered systems that can lead to reductions in their reliability and continued safety, and increases in the costs of operation and sustainment. To meet the challenges of designing systems for a competitive global market and of ensuring their reliability and continued safety, a new paradigm for design is needed to quantitatively integrate materials aging into the processes of design, reliability assessment and life-cycle management planning. In this paper, a multidisciplinary, mechanistically based probability approach is reviewed as a framework for this new design paradigm. The efficacy and value of this approach is demonstrated through an example on the aging of aluminum alloys used in aircraft construction that showed the feasibility of using a simplified model to predict the distribution in damage in transport aircraft that had been in long-term commercial service. The need and directions for further research are discussed.
Standardization of Rising Load/Rising Displacement SCC Testing
Authors: Dietzel W
Published: April 2008

Two new draft standards for fracture mechanics based stress corrosion cracking (SCC) tests have recently been issued by ASTM and ISO committees. Both concern the determination of the threshold stress intensity factor, KISCC, and the crack growth velocity, da/dt = f(KI) from rising load or rising displacement tests. One of these drafts, prepared by ASTM Committee G-l on Corrosion of Metals, is an extension of an existing ASTM standard on slow strain rate testing. The second one was elaborated by ISO TC 156 and is based on a procedure proposed by the European Structural Integrity Society, ESIS. This procedure has been validated in an interlaboratory test program. Results of this research project and issues of both drafts are discussed in the paper.
Embryotoxicity of Arsenic Trioxide and Atrazine to Japanese Medaka (Oryzias latipes), and Cytotoxicity to Human Liver Carcinoma Cells (HepG2)
Authors: Tchounwou PB , Wilson BA , Ishaque1 AB
Published: April 2008

We investigated the acute toxicity of arsenic trioxide and atrazine, singly and in combination, to Japanese medaka embryos, and the cytotoxicity of these chemicals to human liver carcinoma cell lines (HepG2). Two day-old embryos were exposed to serial concentrations of arsenic, atrazine, and a mixture of the two, following a 96-hrs static renewal test protocol. The in vitro bioassay was performed by exposing HepG2 cells to arsenic and atrazine, and measuring the activity of lactate dehydrogenase using a spectrophotometer at 340 nm, after 48 hrs of incubation at 37°C and 5% CO2. Results of the embryo bioassay indicated a concentration-response relationship with respect to chemical toxicity. Upon 96 hrs of exposure, the NOAEL, LOAEL, LC50 and LC95 of arsenic were 0.07 (0.04–0.09), 0.15 (0.10–0.18), 0.23 (0.21–0.26), and 0.32 (0.28–0.41) mg/L, respectively. No significant differences (p > 0.05) in LC50 values were found between 24 and 96 hrs of exposure, indicating that arsenic is a fast acting chemical, with most acute poisoning occurring within 24 hrs of exposure. Within the range of concentrations tested, atrazine was found to be non-toxic to embryos, even at its maximum solubility of 200 mg/L in 2% DMSO. The mixture of arsenic with 100 mg/L atrazine resulted in a 96hrs-LC50 of 0.28 (0.26–0.31) mg/L, indicating a combined toxic effect that is simply additive or slightly antagonistic. The cytotoxicity assay yielded a LC50 value of 11.94 (8.8–15.1) mg/L for arsenic. Under the test conditions, the LC50 of atrazine was greater than 100 mg/L, and could not be computed with certainty due to its poor solubility in the test medium.
Statistical Evaluation of the UTAB Database for Use in Terrestrial Nontarget Organism Probabilistic Risk Assessments
Authors: Baehr CH , Habig C
Published: April 2008

This paper provides a statistical analysis of the UTAB database (uptake/ accumulation, translocation, adhesion, and biotransformation). This database contains extensive data on organic chemicals and heavy metals in vascular plants. Data from the UTAB database are currently used by the U.S. Environmental Protection Agency (EPA) and pesticide registrants for conducting deterministic risk assessments of pesticide residues in the food chain of wildlife for pesticide registration. The primary purpose for this detailed analysis of UTAB data was to develop models for the distribution of pesticide residues in plant feed items so that these residue distributions can be used in probabilistic risk assessments for wildlife. Relevant data were grouped into the four feed item categories used by EPA for wildlife risk assessment. The data were analyzed statistically and percentiles were calculated. Results were compared to the currently used deterministic maximum and typical residue predictions of the U.S. EPA residue nomogram. More importantly, log normal and exponential distribution models were developed from the analysis, allowing simulation of typical and extreme dietary exposure scenarios in a probabilistic manner. These models can be used in Monte Carlo simulations to generate joint probability functions for a more probabilistic approach to wildlife risk assessment.
Examination of EROD Activity and Fibronectin Levels in Lake Whitefish as Biomarkers of Neoplasia
Authors: Lee LEJ , Mann T , Pagniello K , Mikaelian I , de Lafontaine Y
Published: April 2008

The study of tumors in fish has been hampered by the lack of suitable bioindicators especially because the ultimate diagnosis is not achieved until the fish are dead or killed. The present study was undertaken to develop simple, reliable and minimally invasive procedures to detect neoplasms in lake whitefish (Coregonus clupeaformis) and investigate their applicability as fish tumor biomarkers. Ethoxyresorufin-o-deethylase (EROD) assays have been widely used as an indicator of the activity of cytochrome P450-1A1, an isozyme located in a variety of tissues and in measurable amounts in the liver of many vertebrates. A fluorometric protocol using very small sized samples such as those from biopsies was used to measure EROD activity. Although no direct correlation could be made between EROD activity and liver tumor occurrence, EROD activity was significantly higher in livers with high melanomacrophage aggregates (P<0.001). Fibronectin (Fn) is a plasma and cellular protein that can be conveniently measured from biological fluids and has been used as tumor biomonitor in humans. Changes in Fn within serum and tissue samples of whitefish were monitored. Mean Fn levels in serum samples (n=65) was 2.03% of total serum proteins. Among the serologically evaluated fish, three had hepatic neoplasia as diagnosed by histological means. Fn levels in two of these were reduced at 1.89 and 1.22% of total serum proteins, however, no statistical correlations could be made with such small sample size, and further analysis is in progress.
Combining Remediation Techniques Increases Kinetics for Removal of Persistent Organic Contaminants from Soil
Authors: Huang XD , Glick BR , Greenberg BM
Published: April 2008

A number of techniques, both mechanical and biological, have been investigated for the remediation of persistent organic contaminants from soils. However, most of these techniques have been applied independently. As a consequence of using only one process, remediation usually is slow for persistent organic contaminants. To improve remediation, multiple techniques that complement different aspects of contaminant removal have been applied to soils in combination. This resulted in an enhanced multi-process phytoremediation system that improved and accelerated the overall remediation resulting in removal of 95% of total PAHs. The remediation system includes physical (volatilization), photochemical (photooxidation), microbial degradation and plant growth (phytoremediation) processes. The techniques applied to realize these processes are land fanning (aeration and light exposure), microbial remediation (introduction of contaminant degrading bacteria) and phytoremediation (plant growth with plant growth promoting rhizobacteria). This system was very effective at removal of persistent, strongly bound contaminants from soil. It appears that the combination of these components may be a viable solution for remediating persistent organic contaminants from soils.
Effects of Oil-Spill Bioremediation Strategies on the Survival, Growth and Reproductive Success of the Mystery Snail, Viviparus georgianus
Authors: Lee LEJ , McDonald A , Stassen J , Lee K
Published: April 2008

In situ bioremediation is now being considered as an operational oil-spill countermeasure technology. While the effects of treatment strategies on microbial populations have been studied extensively, information on bioconcentration and effects on survival, growth and reproduction of higher level macrobiota are limited. Mystery snails, Viviparus georgianus, are attractive wetland biomonitors because they are abundant, short-lived, dioecious, ovoviviparous, easy to collect and grow rapidly during summer months feeding on sediment debris. V. georgianus was used as biomonitors in a controlled oil spill experiment at a wetland site along the St. Lawrence River (Ste. Croix, QC) to assess the impact of crude oil and efficacy of bioremediation treatments. Snails were placed at various time intervals in special enclosures deployed within five treatments and control background plots (n=50/treatment/collection time). Treatments consisted of A: oiled control (natural attenuation), B: as A + ammonium nitrate + triple superphosphate + culling of plants, C: as B but plants left intact, D: as C but sodium nitrate instead of ammonium nitrate, and E: as C with no oil treatment. Although snails could survive in the presence of oil for up to two months, fertilizer treatments brought about increased mortality. Generalized tissue damage with edema and hemocytic infiltration was seen consistently in snails from treatment D and reproduction was impaired in all treatments with or without oil. These findings disclose the need to further evaluate bioremediants in oil-spill response operations for appropriate recovery.
Implementation of the Food Quality Protection Act (FQPA): An Analysis
Authors: Stickle WE
Published: April 2008

The Food Quality Protection Act of 1996 (FQPA), enacted on August 3,1996, brought about significant changes in the way in which pesticides are registered by the U.S. Environmental Protection Agency (EPA). If not implemented properly, the new requirements of FQPA could lead to the removal from the market of a number of beneficial pesticide products and cause substantial disruptions for agriculture in the United States. For many of these products, there is no suitable alternative pest control tool or the substitute pesticide may not be as efficacious or it may be more costly. Ultimately, the potential loss of many existing products could place American farmers at a disadvantage with foreign growers in competing nations who will continue to enjoy access to a variety of effective pesticides in use today. EPA must rely upon the principles of sound science and base its decisions on actual data when making these important FQPA decisions.
Analyses of Equipment, Meteorology and Other Factors Affecting Drift from Applications of Sprays by Ground Rig Sprayers
Authors: Hewitt AJ , Valcore DL , Barry T
Published: April 2008

Studies were conducted in the field to measure off-target spray deposition rates from applications of sprays under different application (nozzle/droplet size and boom height) and meteorological conditions. The results were analyzed to investigate the effects of spray quality, boom height and wind speed on spray deposition rates. Curves are presented showing that deposition rates were greater for fine sprays than medium to extra coarse sprays, and for greater boom heights. There was not a strong correlation between deposition rates and wind speed. This was probably due mainly to the relatively far distance of the first sampling location at 25 ft (7.5 m) from the edge of the application area, and to the fact that most of the wind speeds in the studies were greater than the <10 mph (<16 km/hr) where wind speed effects would be most likely to be most evident.
Performance Advantages of Turbine Oils Formulated with Group II and Group III Basestocks
Authors: Irvine DJ
Published: April 2008

High temperature gas turbine applications, such as GE Frame 7 turbines, place high demands on the thermal and oxidative stability of turbine oils. Successful products not only start with a superior quality basestock, but must also employ a carefully balanced, low volatility, thermally stable additive system. The excellent properties of Group II and Group III basestocks such as high viscosity index, low volatility, superior oxidative resistance, and high thermal stability make them ideal choices for this service. Turbine oils formulated with severely hydrocracked Group II and Group III basestocks offer performance on par with those formulated with synthetic hydrocarbons.

A brief review of the role and requirements of modern turbine oils is given together with a more extensive look at current basestock technology versus traditional solvent refined basestocks. Additive selection for high temperature turbine oils is also discussed.

In addition, data presenting the impact of poly-cycloparaffin content on the stability of highly saturated Group II and Group III basestocks is presented. The oxidative stability of additized basestocks increases as poly-cycloparaffin content decreases.
The Luleå Ball and Disc Apparatus
Authors: Lord J , Jonsson U , Larsson R , Marklund O , Eriksson E , Uusitalo Ö
Published: April 2008

The ability to measure lubricant film thickness in elastohydrodynamic point contacts was greatly improved when the method of interferometry was introduced in the late 1960s. Constant refinements of the technique have made it possible to measure the thickness of thin films with an accuracy of a few nanometers. In order to further develop the technique and provide a tool for advanced lubricant experiments, a Ball and Disc Apparatus was developed. The aim was to accomplish an apparatus with an “open architecture” for easy expansion and the ability to use several sub-methods for film thickness determination.

The combination of suitable computer programming, electronics, mechanics, optics and fluid dynamics made it a complex task since several individuals had to merge their ideas into one design where the result had to be satisfying in all aspects. Even though the apparatus is under constant development, the basics are the same: a mainly computer controlled apparatus able to measure film thicknesses with high accuracy down to zero, friction force from zero to 120 N, contact loads from zero to 140 N (solely dependent on the disc used), running speeds, apart from static, from at least 1×10-3 to 4 m/s and producing detailed digital interferograms directly onto the computer's hard drive for analysis.

Analyzing images is itself a tedious and sometimes difficult task if the appropriate tools are not available. However, a multi-channel method was also developed concurrently which does not depend on the usual colorimetric calibration problems, but rather on a trichromatic light source. This method of determining film thicknesses reduces the time spent to a few seconds per image captured during operation.
A Spiral Orbit Rolling Contact Tribometer
Authors: Kingsbury E , Pepper S
Published: April 2008

We describe a rolling contact tribometer exhibiting realistic, reproducible, quantifiable performance over a wide range of contact conditions. These conditions are variable to match a calculated severity integral for real ball bearing contacts. First-order kinematics in the tribometer are described by published ball bearing equations. The tribometer exhibits second-order mechanical contact effects found in real rolling contacts. It has elevated temperature, purged atmosphere, and vacuum capabilities. Results from the tribometer are shown to be directly applicable to a variety of situations in the real world.
A New Device for Traction Measurement on Ice
Authors: Xiao J , Liang H , Crisenberry R , Cook M
Published: April 2008

Friction on ice in driving, running, and walking situations is important for winter activities in Alaska. In order to simulate the friction, we designed a traction-measuring device fitting to low-temperature applications. By using a hydraulic system we apply a load ranging from less than one pound to as high as five hundred pounds. The static friction can be measured by moving the ice block against any materials desired. Results showed that the ice surface changes according to applied load, sliding speed, and temperature. This device is capable of providing insight of tribological behavior of ice and snow against materials such as automobile tires and shoe materials, etc.
Evaluation of Fretting Wear Under Oscillating Normal Force
Authors: Huq MZ , Celis J-P
Published: April 2008

In this paper a novel fretting mode II wear test is presented. This test consists of an oscillating normal force superimposed on a constant force. The oscillating force can be applied over a range of frequencies. The principles of this fretting mode II test and the type of damage induced in this particular test and contact motion are discussed. The influence of the main fretting mode II parameters (force amplitude, test duration, etc.) on the materials degradation in the contact has been analyzed. Experimental data were obtained for different materials combinations, e.g., bulk WC-Co oscillating against alumina, hard coatings such as physical vapor deposited (PVD) (Ti,Al)N and PVD TiN oscillating against alumina and silicon nitride counterbodies, and a soft tin coating oscillating against a self mated one. The mode II fretting test results indicate that wear takes place in the slip region. Cracking and spalling out in the slip region are both observed in some instances. The critical normal force at which fatigue failure occurs, was determined for bulk ceramics and ceramic coatings. The evolution of the electrical contact resistance in the case of self-mated soft tin coatings tested under fretting mode II conditions is also reported.
The Use of Tribological Aspect Numbers in Bench Test Selection — A Review Update
Authors: Anderson M
Published: April 2008

This paper will review the use of tribological aspect numbers when selecting a bench test to simulate a field application. “Realizing Bench Test Solutions to Field Tribology Problems by Utilizing Tribological Aspect Numbers” [1] first published in 1993 is an analytical method for selecting bench tests that best simulate field conditions or wear problems. Scientists, product developers, lubrication formulators, and material engineers and scientists can use this approach to select the most applicable bench test. The bench test selected can then be used to evaluate materials under laboratory conditions that can simulate field conditions and environments.

Bench testing is the simplest form of testing, isolating one particular set of tribological conditions. It is generally the first step in the testing program, preceding more complex, multi-variable, component tests. The tribological aspect number (TAN) was developed to identify and code a particular tribological condition. This identification or coding simplifies the process of matching the field condition to a bench test. Today, more individual bench tests are available to the tribologist. This review paper will describe the TAN approach, update the list of bench tests and their corresponding TAN and give several specific situations. This paper will also investigate the test parameter options and acceleration of test procedures required to produce test results in a reasonable time period.
Review of Current Recommendations from the Recent IAEA Specialists Meeting on Irradiation Effects on Pressure Vessel Steels and its Mitigation
Authors: Davies LM , Server WL , Lyssakov V , Rosinski ST
Published: April 2008

Under the auspices of the International Atomic Energy Agency (IAEA), the International Working Group on Life Management of Nuclear Power Plants sponsors specialists meetings on radiation embrittlement and mitigation. The purpose of these international meetings is to present state-of-the-art research results in the area of radiation embrittlement, identify critical technical issues that require resolution in the international community, and officially to recommend research activities for IAEA member states in order to resolve these issues. The most recent of these international meetings was held April 1999 in Madrid. This paper discusses the specific conclusions and recommendations drawn at this most recent specialists meeting. Critical technical issues in the area of radiation embrittlement and mitigation, as identified through these specialists meetings, are discussed and summarised.
Swelling and Microstructural Evolution in 316 Stainless Steel Hexagonal Ducts Following Long-Term Irradiation in EBR-II
Authors: Cole JI , Allen TR , Tsai H , Ukai S , Mizuta S , Akasaka N , Donomae T , Yoshitake T
Published: April 2008

Swelling behavior and microstructural evolution of 12% cold-worked 316 SS hexagonal ducts following irradiation in the outer rows of EBR-II is described. Immersion density measurements and transmission electron microscopy (TEM) examination were performed on a total of seven irradiation conditions. The samples were irradiated to temperatures between 375 and 430°C to doses between 23 and 51 dpa and at dose-rates ranging from 1.3 × 10-7 to 5.8 × 10-7 dpa/s. Dose-rates and temperatures approach conditions experienced by a variety of components in pressurized water reactors (PWR's) and those which may be present in future advanced reactors designs. TEM analysis was employed to elucidate the effect of radiation on the dislocation, void and precipitate structures as a function of irradiation conditions. A moderate dose-rate effect was observed for samples which were irradiated at dose-rates differing by a factor of two. Lower dose-rate samples contained voids of larger diameter and typically swelled more in the bulk. The dislocation and precipitate structure was not visibly influenced by a dose-rate decrease.