bluuebunny/crossref_metadata_2025 huggingface dataset:
Study of Numerical Modeling of Moonpool as Minimization Device of Monocolumn Hull
Authors: Torres Fernando G. S. , Cueva Marcos , Malta Edgard Borges , Nishimoto Kazuo , Ferreira Marcos Donato
Published: January 2009

The steel catenary risers (SCR) have been studied to be used in ultra-deep oil fields. In Brazil, the oil field is going to deeper water. The geographical characteristics impose this type of production risers, and the necessity of these risers is real. However, in order to avoid risers fatigue problems, some premises related to low vertical motions have to be respected. To reach the necessary good seakeeping responses, new type of hull shape has been proposed, the monocolumn hull, to which some motion minimization devices have been developed. There are several conceptions of monocolumn type hull, but the concept presented in this paper is different from the existing monocolumn hull. To have good seakeeping capability, three main minimization devices were proposed: the structural skirt, the inclined wall, and the moonpool. The inclined wall, a variation of a section area near the water-plane, works together with the skirt, an enlarged bilge keel at the bottom of the platform, modifying the effect of damping, added mass and inertia. The moonpool is the old tank usually found in drilling units, properly modified to work as a motion minimization system. It works as a passive heave motion reduction system, shifting the natural period far from the wave spectrum. Some numerical analyses were made to present the effects obtained from these devices. These numerical results from WAMIT® were compared to experimental showing to be according to them.
Hindcasting VIM-Induced Mooring Fatigue for the Genesis Spar
Authors: Smith David W. , Thompson H. M. , Kokkinis T. , Greiner W. L.
Published: January 2009

A number of spars are being installed in deepwater areas in the Gulf of Mexico (GoM) which are subject to loop / eddy current conditions and require that their mooring system be designed for Vortex Induced Motion (VIM). This paper presents insights into fatigue and wear issues for mooring systems of spars subject to VIM, and illustrates the importance of reassessing industry practices for mooring strength and fatigue design for mooring systems that must resist VIM. During the GoM Millennium Eddy Current Event in April 2001, the ChevronTexaco Genesis spar platform, which is installed in Green Canyon Block 205 in the GoM, underwent VIM which was greater than anticipated during the original design of the mooring and riser systems. A key part of developing a permanent solution for ensuring integrity in future large VIM events was the assessment of fatigue and wear damage accumulated in past VIM events, for the purpose of ensuring fitness of the components of the mooring system for future service. The main elements of this assessment were: (a) The hindcast of the mooring line tensions from measured platform motions. (b) The evaluation of stress concentration on the mooring chain in the fairleads. (c) The assessment of fatigue damage for high amplitude/low cycle conditions, and (d) The assessment of accumulated wear. The results of this fatigue assessment led to a decision to replace the fairlead chain segments on 4 of the 14 mooring legs of Genesis, in order to ensure that they would have adequate fatigue endurance under the Stepped Line Tensioning (SLT) solution developed to mitigate the risk of VIM of the spar in the future. The project team’s unique understanding of mooring system response under VIM and resulting mooring component fatigue and wear issues led to the development of novel fatigue and wear hindcasting procedures that allowed the project to reliably assess the remaining life of the mooring components, and make decisions to selectively replace some of the components to ensure integrity for the remaining life of the platform under the SLT solution.
Riser Deployment and Hang-Off Analysis for a Harsh Environment, Deepwater Site
Authors: O’Sullivan Enda , Brekke James N. , Dib Michel
Published: January 2009

In planning for a deepwater well, running/retrieval of a drilling riser in advance of rapidly developing seas was identified as a critical operation. The harsh seastates required careful attention to the well-specific operating criteria, (WSOC), or the metocean conditions that limit specific operations. Certain conditions would warrant the operation being shut down so that the riser could be pulled or run before conditions became excessive. In deep water, a running/retrieval operation can take several days and the consequences of being shut down part way can be severe. Moderately high current profiles can cause the riser to bind in the diverter housing, preventing further running or retrieval. If binding occurs, a dynamically-positioned vessel can carry out “drift running” operations to increase its operability. However, if conditions prohibit further running/retrieval, the riser may need to be hung off “hard” (with no compensation) at the drill floor or “soft” on the tensioners and/or drill string compensator. In such a case, in addition to large top riser angles, vessel heave motion can cause tension variation, depending on the hang-off conditions and the length of the deployed riser. This paper discusses how riser analysis was used to support the operational understanding of the riser running/retrieval process for this deepwater well. The results were used to assist in the planning and decision-making involved in drilling this well.
Post-Collision Inspection and Data Analysis of a Passenger Rail Car
Authors: MacNeill Robert A. , Kirkpatrick Steven W.
Published: January 2009

There is an ongoing research program in the United States to investigate and improve rail equipment crashworthiness. As part of this effort, a series of full-scale rail vehicle crash tests are being performed to investigate the crash response of existing and future rail vehicle designs. The first full-scale test, an impact of a single passenger coach car into a fixed wall, was conducted at the Transportation Technology Center (TTC) in Pueblo, Colorado on November 16, 1999. The test vehicle used was a Pioneer passenger coach car. The test condition was a 35 mph impact into a fixed rigid concrete wall. Collision response data was collected in the test using accelerometers, strain gauges, string potentiometers, and high-speed photography. This paper describes the postmortem documentation and data analysis process. The objective is to develop an understanding of the vehicle collision response and to obtain a consistent correlation of the various sources to data. Specific documentation and data analysis techniques used for the study are described along with key results.
Field Testing and Monitoring of Rolling Stock Under the New Federal Track and Equipment Regulations
Authors: Lombardi Edward J. , Warner David C. , Sherrock Eric T. , Whitten Brian T. , Jamieson David W.
Published: January 2009

In the past three years, the Federal Railroad Administration (FRA) has issued two significant new regulations covering the qualification and operation of passenger railroad equipment. The 1998 Track Safety Standards and 1999 Passenger Equipment Safety Standards provide comprehensive requirements for the qualification and operation of passenger equipment. Among many safety issues, these standards address the response of rolling stock at speed to track deviations, and the potential for derailment and/or injury to passengers. The principles contained in the Safety Standards are also used by FRA to evaluate safety performance of vehicles for operation at high cant deficiency for speeds less than 90 mph as part of FRA’s waiver process. This paper describes the types of static and dynamic tests and equipment that are required with respect to vehicle-track interaction to demonstrate compliance of new equipment with the Standards, and the technical fundamentals behind the requirements. Examples include the National Railroad Passenger Corporation’s (Amtrak’s) experiences in applying for waivers and qualifying new equipment under these regulations, particularly the high cant deficiency testing of the Talgo train in the Pacific Northwest, and the high-speed and high cant deficiency testing of Maryland Rail Commuter’s (MARC’s) MARC-III bi-level cars, Acela Express trainsets and Amtrak’s high-horsepower electric locomotives in the Northeast Corridor. In addition, technical data and procedures necessary to have existing equipment approved for operation at higher speed or cant deficiency are also described. This paper highlights nuances of the new regulations and common misinterpretations.
Solar Powered Module for Portable Computers
Authors: Serrano David
Published: January 2009

A laptop by its virtue is a mobile apparatus therefore a power outlet may not necessarily be available to charge its batteries. Typical laptops have a range of up to two and a half hours of battery life under normal operation and some have as little as one and a half hours. Therefore for the computer user on the move it is important to have enough power available for more extended periods of time. Today’s technology provides a large number of other mobile appliances, instruments and tools that will also greatly benefit from extended power. Existing solar panels operate under direct sunlight conditions and are deployed only when the equipment is in use or stationary. The solar powered module developed at the Department of Mechanical Engineering, University of Puerto Rico – Mayaguez has the advantage that it recharges the laptop in transit even when it is not in operation. By charging the battery when it is stored it allows the battery to be recharged during a larger period of time therefore increasing the amount of energy stored. Different types of solar cells were tested under “real world” lighting situations in order to assess their potential for the intended application. The solar array was optimized for use under a larger range of illumination conditions such that it may operate when direct sunlight is not available. The ergonomic design is integrated into the laptop’s carrying case but it may also be detached and/or repositioned if desired. The solar panel is based on the latest technology of triple junction spectrum-splitting amorphous silicon solar cells. The equipment allows the use of a laptop or other portable equipment in situations when power is not available, therefore providing a needed service in remote locations to professionals in the field and provides a backup power source in the event of an emergency or lack of adequate infrastructure. The paper describes the design process in the selection of the solar cell technology used in the module.
Microstructural Characterization of Ti-6Al-4V Subjected to Fretting
Authors: Swalla Dana R. , Neu Richard W. , McDowell David L.
Published: January 2009

This study is focused on characterization of microstructural changes linked to deformation and crack formation mechanisms in duplex Ti-6Al-4V specimens used in displacement controlled fretting only experiments. In particular, the effect of slip displacement amplitude and number of fretting cycles on the evolution of grain morphology, grain orientation, misorientation distribution, composition, and microhardness is investigated using electron backscatter diffraction (EBSD), energy dispersive X-ray analysis (EDX) and nanoindentation. A strong basal microtexture and significant oxygen diffusion were observed in the Ti-6Al-4V specimen that exhibited the most significant cracking. A critical slip amplitude threshold may exist for which a combination of mechanisms such as plastic deformation, grain reorientation, and oxygen diffusion occur during fretting that make conditions ideal for crack formation. The results provide insights for development and validation of computational crystal plasticity models with application to fretting and sliding contact problems. New fretting damage assessment measures have also been identified and have application for components that suffer from fretting wear and/or fatigue related failures.
Tribological Study of Micro Bearings for MEMS Applications
Authors: Kim Daejong , Cao Dongmei , Bryant Michael D. , Meng Wenjin
Published: January 2009

Micro sleeve bearings intended for micro rotational machinery were fabricated by X-ray lithography and Ni electroplating. Coated to the working surfaces of the bearings was a 900nm thick uniform tungsten hydrocarbon (W-C:H) coating using an inductively coupled plasma (ICP) assisted, hybrid chemical vapor deposition (CVD)/physical vapor deposition (PVD) tool. Tribological characteristics and mechanical properties of as-electrodeposited Ni micro bearings, annealed Ni micro bearings at 800°C, and W-C:H coated micro bearings were investigated. Potential applications of the micro bearings may involve very light contact pressure (5∼30MPa) and high sliding speed, such as micro motors and micro turbines. Conventional pin-on disc test methods on top flat surfaces, (001) planes, cannot effectively predict tribological characteristics because these micro bearings use the sidewall (110 plane) as a working surface. A special micro wear tester and friction tester were developed. Surface morphologies of new and worn bearing surfaces were studied using SEM. Raman Spectroscopy and X-ray Photoelectron Spectroscopy (XPS) characterized the W-C:H coated micro bearings. Test results of the W-C:H coated micro bearings (wear characteristics and friction) are also presented. W-C:H coated micro bearings had much lower wear rate than uncoated bearings. During the wear test, a transfer layer formed on the counter steel shaft even under very small contact pressure, leading to low steady state friction and high wear resistance.
On the Vibration in Wet Friction Systems With Paper-Based Materials: Effects of Driving Conditions and Design Factors
Authors: Shibuya Takao , Sambongi Yuzuru , Morishita Shin
Published: January 2009

The vibration caused by friction force is a wet friction system was studied in the present paper. In these systems, unexpected vibration or noise occasionally occurs during the engagement process of the input shaft to the output one. Such a vibration has been explained as self-excited vibration caused by friction force. When friction force increases with decreasing relative sliding speed, this friction characteristic is generally expressed as negative damping. In this study, a testing machine was developed to evaluate the vibration characteristics of wet friction systems with paper-based materials. The acceleration of the input shaft and the separator plate were directly measured in the engagement process together with the variation of transmitted torque. The effects of the driving conditions and design factors of wet friction systems with paper-based friction materials on the vibration and their characteristics were discussed. It is shown that the in-plane and out-of-plane vibration of the separator plate were induced by the torsional vibration of the input shaft during the engagement process of the friction plate and separator plate. While the torsional vibration of the input shaft was observed, the Torque-V slope was estimated to be negative, and its magnitude grew faster as the number of friction plates increased even under the same applied normal load condition.
An Experimental Study of Bearing and Thread Friction in Fasteners
Authors: Nassar S. A. , El-Khiamy H. , Barber G. C. , Zou Q. , Sun T. S.
Published: January 2009

An experimental procedure is proposed for studying the underhead and thread friction in fasteners. The effective bearing friction radius, the underhead friction coefficient, and the thread friction coefficient are experimentally determined for fasteners with standard hexagonal heads and for flanged head fasteners. Hence, greater accuracy has been achieved in determining the value of the torque components that are consumed in overcoming friction in threaded fasteners. This would lead to a more reliable torque-tension correlation and would enhance the safety and quality of bolted assemblies. A Design of Experiment (DOE) procedure is presented in order to investigate the effect of fastener material class, the thread pitch, and the fastener size on thread friction coefficient. For the underhead bearing friction, an experimental model is presented in order to determine the effect of the contact area radii ratio on the bearing friction radius.
The Degradation of Electrical Contact Resistance of Metal Films at Low Contact Force
Authors: Dickrell Daniel J. , Dugger Michael T.
Published: January 2009

The quality of electrical contact resistance is important to the performance and reliability of metal-contact microelectromechanical system (MEMS) relays and switches. The cyclic degradation of contact resistance was examined for a metal multilayer sphere-on-flat contact at low contact force. The relationships between the degradation and underlying mechanisms, particularly surface contamination effects, were investigated through experimentation and analysis. Results indicated that the degradation severity could be significantly decreased with environmental control and contact current reduction. Micro-arcs at very small surface gaps, which can decompose adsorbed contaminants and leave an insulating surface film, were proposed as a cause of the resistance degradation.
Molecular Dynamics Simulation of Single Asperity Contact
Authors: Cha Pil-Ryung , Song Jun , Vanderlick T. Kyle , Srolovitz David J.
Published: January 2009

Many state-of-art microelectronic, photonic and MEMS devices are based upon or created using small-scale contacts. These include, for example, high frequency, microscale electromechanical switches and nanopatterning of organic optoelectronic materials by contact adhesion, cold welding, and lift-off. The initial stages of contact occur between asperities of micro- and/or nano-scopic dimensions. As a consequence, understanding the processes that occur at the atomic level when two rough surfaces are bought into contact is fundamentally important for a wide range of problems including adhesion, contact formation, contact resistance, materials hardness, friction, wear, and fracture. The centrality of single asperities in the fundamental micromechanical response of contact between two rough surfaces has long been recognized. A wide range of experiments has shown that the conductance of small contacts changes abruptly as a function of contact size. In some cases, the conductance through individual asperities increases in a stepwise manner as the two surfaces are pressed into contact. These jumps conductance appear to be correlated with jumps in the force. The observed force-displacement relation appears to be poorly described by JKR theory during loading, while JKR provides a reasonable description of the behavior in unloading. In this presentation (see Acta Materialia 52, 3983 (2004) for more details), we report the results of molecular dynamics simulations of single asperity contact during multiple cycles of loading and unloading at room temperature. We focus on the mechanisms by which contact deformation occurs and the relationship between contact conductance (and contact area) and the deformation. These simulations account for adhesion, elastic deformation, dislocation generation and migration, the formation of other types of defects and morphology evolution. In order to study the elastic and plastic deformation of the asperities on a rough surface, we set up a model system, as shown in Fig. 1. For simplificity, we consider a single deformable asperity on a deformable substrate that interacts with a flat, rigid plate. We calculate the conductance of the contact during loading and unloading through the modified Sharvin model [12]. To our knowledge, this study represents the first dynamic, atomistic simulation of the elastic and plastic deformation behavior of a single asperity and the corresponding evolution of the contact area and contact conductance. The present simulation results reproduce a large body of existing nano-contact experimental results, including the stepwise variation of contact area and conductance with displacement and the hysteresis in the contact radius and contact resistance versus force curves.
New Investigations of Finite Length Line Contact
Authors: Glovnea Marilena , Diaconescu Emanuel
Published: January 2009

Important end effects occur in Hertz-like finite length line contacts. If the length of shorter contacting cylinder is bounded by flat surfaces, the pressure tends to infinity at both ends. Many design measures were advanced to reduce or attenuate these pressure riser effects. These imply modification of contact geometry and, in most cases, numerical investigations. Few experiments were performed to check the actual contact between modified surfaces. Applying a previous proposal, contact area between a modified steel roller and a sapphire window is measured by scanning the reflectivity of metallic surface. A typical “dog bone” shape for this area is found. Lateral extensions of contact area, measured experimentally for a roller with rounded edges, agree well with numerical results obtained by a new, refined numerical procedure.
Dynamic Contact Between a Rigid Indenter and a Zener Half-Space
Authors: Ciornei Florina Carmen , Diaconescu Emanuel N.
Published: January 2009

This paper investigates the dynamic contact between an axi-symmetric rigid paraboloid and a standard solid (Zener) viscoelastic half-space. The load consists of a pulse cosine applied over a step function. Following the theory developed by Ting, analytical expression of contact radius for an advancing contact is derived. For receding contact, contact radius is numerically obtained. Contact pressures for increasing and decreasing contacts are derived. The influence of load frequency is evidenced. At low frequencies, contact pressure has an initial Hertz shape and then, as the contact increases, a relaxed one. As the contact reaches its maximum, the pressure tends again to an elastic pattern. Experimental tests were carried out on a contact between a polymeric sphere and a glass plate. A good agreement is found with theoretical results by measuring contact radius.
CFD Analysis of a Low Friction Pocketed Pad Bearing
Authors: Brajdic-Mitidieri Petra , Gosman A. David , Ioannides Stathis , Spikes Hugh A.
Published: January 2009

A commercial CFD code has been applied to model lubricant flow behaviour within 2D and 3D linear pad bearings having closed pockets or recesses. The study indicates that the presence of closed pockets can result in a significant reduction in bearing friction coefficient. At high convergence ratios, no cavitation is predicted within the pockets. This means that suitably-positioned pockets in the high-pressure region of the bearing result in a much greater reduction in local shear stress than in local pressure, so that there is an overall reduction in friction coefficient. At low convergence ratios, cavitation occurs in the inlet to the pockets so that each pocket acts an effectively-independent step bearing. This results in the overall bearing supporting a higher load and thus having lower friction coefficient than is the case without pockets.
FRACTIONAL LANDAU–GINZBURG EQUATIONS ON A SEGMENT
Authors: KAIKINA ELENA I.
Published: January 2009

We study the initial-boundary value problem for the fractional Landau–Ginzburg equations on a segment. The aim of this paper is to prove the global existence of solutions to the inital-boundary value problem and to find the main term of the asymptotic representation of solutions.
KATO'S INEQUALITY UP TO THE BOUNDARY
Authors: BREZIS HAÏM , PONCE AUGUSTO C.
Published: January 2009

We show that if Δu is a finite measure in Ω then, under suitable assumptions on u near ∂Ω, Δu+is also a finite measure in Ω. We also study properties of the normal derivatives [Formula: see text] and [Formula: see text] on ∂Ω.
Physical Activity and Risk of Recurrence and Mortality in Breast Cancer Survivors: Findings from the LACE Study
Authors: Sternfeld Barbara , Weltzien Erin , Quesenberry Charles P. , Castillo Adrienne L. , Kwan Marilyn , Slattery Martha L. , Caan Bette J.
Published: January 2009

Introduction: Identifying modifiable factors that reduce the risk of recurrence and improve survival in breast cancer survivors is a pressing concern. The purpose of this study was to examine the association of physical activity following diagnosis and treatment with the risk of breast cancer recurrence and mortality and all-cause mortality in women with early-stage breast cancer.

Materials and Methods: The sample consisted of 1,970 women from the Life After Cancer Epidemiology study, a prospective investigation of behavioral risk factors and health outcomes. Self-reported frequency and duration of work-related, household and caregiving, recreational, and transportation-related activities during the six months prior to enrollment were assessed. Outcomes were ascertained from electronic or paper medical charts. Hazard ratios and 95% confidence intervals were estimated from delayed entry Cox proportional hazards models.

Results: Although age-adjusted results suggested that higher levels of physical activity were associated with reduced risk of recurrence and breast cancer mortality (P for trend = 0.05 and 0.07, respectively for highest versus lowest level of hours per week of moderate physical activity), these associations were attenuated after adjustment for prognostic factors and other confounding variables (P for trend = 0.36 and 0.26). In contrast, a statistically significant protective association between physical activity and all-cause mortality remained in multivariable analyses (hazard ratio, 0.66; 95% confidence interval, 0.42-1.03; P for trend = 0.04).

Conclusions: These findings do not support a protective effect of physical activity on breast cancer recurrence or mortality but do suggest that regular physical activity is beneficial for breast cancer survivors in terms of total mortality. (Cancer Epidemiol Biomarkers Prev 2009;18(1):87–95)
Urinary Isothiocyanates; Glutathione S-Transferase M1, T1, and P1 Polymorphisms; and Risk of Colorectal Cancer: The Multiethnic Cohort Study
Authors: Epplein Meira , Wilkens Lynne R. , Tiirikainen Maarit , Dyba Marcin , Chung Fung-Lung , Goodman Marc T. , Murphy Suzanne P. , Henderson Brian E. , Kolonel Laurence N. , Le Marchand Loïc
Published: January 2009

Although an association between diet, especially cruciferous vegetables, and colorectal cancer has been hypothesized, recent studies have been inconsistent with their findings. One possibility for the discrepant results is that the interaction with related genes has not generally been considered. The present study examined the associations among urinary isothiocyanates, glutathione S-transferase (GST) polymorphisms, and colorectal cancer risk in a case-control study nested within the Multiethnic Cohort Study, based in Hawaii and Los Angeles, California. We measured prediagnositic urinary isothiocyanate levels adjusted for creatinine and analyzed GSTM1, GSTT1, and GSTP1 polymorphisms in 173 cases and 313 matched controls, with biospecimens collected between 2001 and 2006. Conditional logistic regression was used to compute odds ratios and 95% confidence intervals (95% CI). A detectable amount of urinary isothiocyanates was associated with a 41% decrease in colorectal cancer risk (95% CI, 0.36-0.98). No significant, main-effect associations were seen with a homozygous deletion of the GSTM1 or GSTT1 polymorphism, or with the AG or GG genotypes for GSTP1 rs1695. There was a weak suggestion that for individuals with the GSTP1 AG or GG genotype, a detectable amount of isothiocyanates further decreases one's risk of colorectal cancer compared with those with the GSTP1 AA genotype, but the interaction term was not statistically significant (P = 0.09). This is only the second study published on the association between urinary isothiocyanates and colorectal cancer risk. The results suggest that further studies, with larger numbers, examining a possible interaction with the GSTP1 polymorphisms are warranted. (Cancer Epidemiol Biomarkers Prev 2009;18(1):314–20)
Urinary Melatonin Levels and Postmenopausal Breast Cancer Risk in the Nurses' Health Study Cohort
Authors: Schernhammer Eva S. , Hankinson Susan E.
Published: January 2009

Background: Melatonin seems to play a role in breast cancer etiology, but data addressing the association between melatonin levels and breast cancer risk in postmenopausal women is sparse.

Methods: We conducted a nested case-control study in the Nurses' Health Study cohort. First spot morning urine was collected from 18,643 cancer-free women from March 2000 through December 2002. The concentration of the major metabolite of melatonin, 6-sulfatoxymelatonin (aMT6s), was available for 357 postmenopausal women who developed incident breast cancer through May 31, 2006, along with 533 matched control subjects. We used multivariable conditional logistic regression models to investigate associations. All statistical tests were two sided.

Results: An increased concentration of urinary aMT6s was statistically significantly associated with a lower risk of breast cancer (odds ratio for the highest versus lowest quartile of morning urinary aMT6s, 0.62; 95% confidence interval, 0.41-0.95; Ptrend = 0.004). There was no apparent modification of risk by hormone receptor status of breast tumors, age, body mass index, or smoking status.

Conclusion: Results from this prospective study add substantially to the growing literature that supports an inverse association between melatonin levels and breast cancer risk. (Cancer Epidemiol Biomarkers Prev 2009;18(1):74–9)
Two Estrogen-Related Variants in CYP19A1 and Endometrial Cancer Risk: A Pooled Analysis in the Epidemiology of Endometrial Cancer Consortium
Authors: Setiawan Veronica Wendy , Doherty Jennifer A. , Shu Xiao-ou , Akbari Mohammad R. , Chen Chu , De Vivo Immaculata , DeMichele Angela , Garcia-Closas Montserrat , Goodman Marc T. , Haiman Christopher A. , Hankinson Susan E. , Henderson Brian E. , Horn-Ross Pamela L. , Lacey James V. , Le Marchand Loic , Levine Douglas A. , Liang Xiaolin , Lissowska Jolanta , Lurie Galina , McGrath Monica , Narod Steven A. , Rebbeck Timothy R. , Ursin Giske , Weiss Noel S. , Xiang Yong-Bing , Yang Hannah P. , Zheng Wei , Olson Sara H.
Published: January 2009

Common variants in CYP19A1 (the A alleles of rs749292 and rs727479) have been associated with a 10% to 20% increase in circulating estrogen levels in postmenopausal women. We hypothesized that the presence of one or both A alleles in these single nucleotide polymorphisms (SNP) is associated with increased endometrial cancer risk. We tested this hypothesis in a large pooled analysis of 4,998 endometrial cancer cases and 8,285 controls from 10 studies in the Epidemiology of Endometrial Cancer Consortium. The majority of women (>66%) were whites, with smaller proportions of other races and ethnic groups (blacks, Asians, and Latinas) also included in this pooled analysis. Unconditional logistic regression was used to model the association between SNPs/haplotypes and endometrial cancer risk. Carrying the A allele of either of these SNPs was associated with an increased risk of endometrial cancer, with pooled odds ratios per allele of 1.14, 95% confidence interval of 1.09-1.21, and P = 7.1 × 10-7 for rs749292, and odds ratio per allele of 1.08, 95% confidence interval of 1.02-1.14, and P = 0.009 for rs727479. For rs749292, these associations were generally stronger among women age ≥55 years. For both SNPs, risk increased with increasing body mass index, and for rs727479, this pattern seemed stronger among women age ≥55 years (P interaction = 0.007). The combination of A alleles in the two SNPs, either by direct count or by haplotype analysis, did not increase risk above that observed for the individual SNPs. Our study provides evidence that CYP19A1 genetic variation influences susceptibility to endometrial cancer, particularly among older and obese women. (Cancer Epidemiol Biomarkers Prev 2009;18(1):242–7)
Serum Concentrations of Cytokines and Lung Cancer Survival in African Americans and Caucasians
Authors: Enewold Lindsey , Mechanic Leah E. , Bowman Elise D. , Zheng Yun-Ling , Yu Zhipeng , Trivers Glenwood , Alberg Anthony J. , Harris Curtis C.
Published: January 2009

Accumulating evidence suggests a role for inflammation in the development and progression of cancer. Our group recently identified a cytokine gene signature in lung tissue associated with lung cancer prognosis. Therefore, we hypothesized that concentrations of circulating cytokines in serum may be associated with lung cancer survival. Ten serum cytokines, namely, interleukin (IL)-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, granulocyte macrophage colony-stimulating factor, interferon (IFN)-γ, and tumor necrosis factor-α, were assessed in 353 non–small cell lung cancer cases from a case-control study of lung cancer in the greater Baltimore, Maryland area. Cytokines were measured using an ultrasensitive electrochemiluminescence immunoassay. IL-6 serum concentrations (≥4.0 pg/mL) were associated with significantly poorer survival in both African Americans [hazard ratio (HR), 2.71; 95% confidence interval (CI), 1.26-5.80] and Caucasians (HR, 1.71; 95% CI, 1.22-2.40). IL-10 (HR, 2.62; 95% CI, 1.33-5.15) and IL-12 (HR, 1.98; 95% CI, 1.14-3.44) were associated with lung cancer survival only in African Americans. Some evidence for an association of tumor necrosis factor-α levels with survival in Caucasians was observed, although these results were not significant. These hypothesis-generating findings indicate that selected serum cytokine concentrations are associated with lung cancer survival, and indicate that further research is warranted to better understand the mechanistic underpinnings of these associations. (Cancer Epidemiol Biomarkers Prev 2009;18(1):215–22)
Estrogen Receptor-β as a Potential Target for Colon Cancer Prevention: Chemoprevention of Azoxymethane-Induced Colon Carcinogenesis by Raloxifene in F344 Rats
Authors: Janakiram Naveena B. , Steele Vernon E. , Rao Chinthalapally V.
Published: January 2009

Raloxifene, selective estrogen receptor (ER) modulator, is not fully explored in colorectal cancer. In the present study we, (a) investigated the effect of raloxifene on ER-positive colon cancer HCT-116 cell growth, (b) assessed the relevance of ER-β in colon tumorigenesis, and (c) assessed the chemopreventive efficacy of raloxifene against azoxymethane (AOM)-induced colon carcinogenesis using aberrant crypt foci (ACF) as surrogate end point marker. HCT-116 cells treated with raloxifene showed a significant decrease in cell growth associated with a decrease in ER-β expression levels. AOM-induced colon adenocarcinoma showed significant up-regulation of ER-β expression at both the protein and mRNA levels compared with normal mucosa, suggesting that ER-β is positively associated with colon cancer. An assay using five different dietary dose levels (0.31, 0.62, 1.25, 2.5, or 5 ppm) of raloxifene for 6 weeks in male F344 rats found the maximum tolerated dose to be 5 ppm. To evaluate inhibitory properties of raloxifene on colonic ACF, 7-week-old rats were fed experimental diets containing 0, 0.625, 1.25, and 2.5 ppm of raloxifene. After 1 week, rats received s.c. injections of AOM, 15 mg/kg body weight, once weekly for 2 weeks. Rats continued to receive respective experimental diets and sacrificed 8 weeks after the last AOM treatment. Raloxifene given in the diet significantly inhibited AOM-induced total colonic ACF (31-40%; P < 0.001-0.0005) and multicrypt (four or more) aberrant foci (23-50%; P < 0.05-0.005) in F344 rats. Our findings suggest that ER-β acts as a colon tumor promoter and raloxifene as an antagonist to ER-β, providing protection against colon carcinogenesis.
Anthocyanins in Black Raspberries Prevent Esophageal Tumors in Rats
Authors: Wang Li-Shu , Hecht Stephen S. , Carmella Steven G. , Yu Nanxiong , Larue Bethany , Henry Cassandra , McIntyre Colleen , Rocha Claudio , Lechner John F. , Stoner Gary D.
Published: January 2009

Diets containing freeze-dried black raspberries (BRB) suppress the development of N-nitrosomethylbenzylamine (NMBA)–induced tumors in the rat esophagus. Using bioassay-directed fractionation, the anthocyanins in BRB were found to be the most active constituents for down-regulation of carcinogen-induced nuclear factor-κB and activator protein-1 expression in mouse epidermal cells in vitro. The present study was undertaken, therefore, to determine if the anthocyanins contribute to the chemopreventive activity of BRB in vivo. F344 rats consumed diets containing either (a) 5% whole BRB powder, (b) an anthocyanin-rich fraction, (c) an organic solvent-soluble extract (a–c each contained ∼3.8 μmol anthocyanins/g diet), (d) an organic-insoluble (residue) fraction (containing 0.02 μmol anthocyanins/g diet), (e) a hexane extract, and (f) a sugar fraction (e and f had only trace quantities of anthocyanins), all derived from BRB. Animals were fed diets 2 weeks before treatment with NMBA and throughout the bioassay. Control rats were treated with NMBA only. Animals were killed at week 30, and esophageal tumors were enumerated. The anthocyanin treatments (diet groups a–c) were about equally effective in reducing NMBA tumorigenesis in the esophagus, indicating that the anthocyanins in BRB have chemopreventive potential. The organic-insoluble (residue) fraction (d) was also effective, suggesting that components other than berry anthocyanins may be chemopreventive. The hexane and sugar diets were inactive. Diet groups a, b, and d all inhibited cell proliferation, inflammation, and angiogenesis and induced apoptosis in both preneoplastic and papillomatous esophageal tissues, suggesting similar mechanisms of action by the different berry components.
Real-time Bounded-error State Estimation for Vehicle Tracking
Authors: Seignez E. , Kieffer M. , Lambert A. , Walter E. , Maurin T.
Published: January 2009

Estimating the configuration of a vehicle is crucial for its navigation. Most approaches are based on (extended) Kalman filtering or particle filtering. An attractive alternative is considered here, which relies on interval analysis. Contrary to classical extended Kalman filtering it allows global localization, and contrary to particle filtering it provides guaranteed results in the sense that a set is computed that contains all of the configurations that are consistent with the data and hypotheses. This paper presents a real-time implementation of the process including a description of the platform and its modeling, the integration of the errors on the model and the localization method itself.
Minimum Wheel-Rotation Paths for Differential-Drive Mobile Robots
Authors: Chitsaz Hamidreza , LaValle Steven M. , Balkcom Devin J. , Mason Matthew T.
Published: January 2009

The shortest paths for a mobile robot are a fundamental property of the mechanism, and may also be used as a family of primitives for motion planning in the presence of obstacles. This paper characterizes shortest paths for differential-drive mobile robots, with the goal of classifying solutions in the spirit of Dubins curves and Reeds—Shepp curves for car-like robots. To obtain a well-defined notion of shortest , the total amount of wheel-rotation is optimized. Using the Pontryagin Maximum Principle and other tools, we derive the set of optimal paths, and we give a representation of the extremals in the form of finite automata. It turns out that minimum time for the Reeds—Shepp car is equal to minimum wheel-rotation for the differential-drive, and minimum time curves for the convexified Reeds—Shepp car are exactly the same as minimum wheel-rotation paths for the differential-drive. It is currently unknown whether there is a simpler proof for this fact.
A Hybrid Approach to Intricate Motion, Manipulation and Task Planning
Authors: Cambon Stéphane , Alami Rachid , Gravot Fabien
Published: January 2009

We propose a representation and a planning algorithm able to deal with problems integrating task planning as well as motion and manipulation planning knowledge involving several robots and objects. Robot plans often include actions where the robot has to place itself in some position in order to perform some other action or to “modify” the configuration of its environment by displacing objects. Our approach aims at establishing a bridge between task planning and manipulation planning that allows a rigorous treatment of geometric preconditions and effects of robot actions in realistic environments. We show how links can be established between a symbolic description and its geometric counterpart and how they can be used in an integrated planning process that is able to deal with intricate symbolic and geometric constraints. Finally, we describe the main features of an implemented planner and discuss several examples of its use.
“In Case You Didn't Hear Me the First Time”
Authors: Kassing Jeffrey W.
Published: January 2009

This study explores how employees express dissent to management about the same issue on multiple occasions across time (i.e., how they practice repetition). Employees completed a survey instrument reporting how often they used varying upward dissent tactics, how often and for how long they raised the same issue, and how they perceived their supervisors responded to their concerns. Results indicate that employees relied predominantly on competent upward dissent tactics but that they adopted less competent and more face-threatening tactics as repetition progressed. In addition, employees' perceptions of their supervisors' responses to repetition related to the overall duration of repetition but not to the frequency with which employees raised issues or the amount of time that elapsed between dissent episodes.
Experiences of Childlessness in an Indian Context
Authors: Mehta Bhamini , Kapadia Shagufa
Published: January 2009

This article focuses on the gendered experiences of involuntary childlessness and the societal perceptions of the state of being childless. It is based on research aimed at understanding the experience of involuntary childlessness among women and men in the urban middle class of a cosmopolitan city (Vadodara) in India. The study involved a gendered analysis of individuals’ experiences, with specific reference to ideas about parenthood, the importance of children, and the psychosocial implications on self and marital relationships within the context of family and society. The results revealed substantial gender differences. The euphoria surrounding the event of parent-hood, the importance of a child in fostering cohesiveness among family members, and strengthening the marital bond were also examined. The implications of childlessness on self and on marital relations were manifested as feelings of loss, especially during the initial years. Based on the findings, interrelationships are drawn between larger ideologies of Indian culture.
Review: Current status of therapy in nonalcoholic fatty liver disease
Authors: McNear Scott , Harrison Stephen A.
Published: January 2009

The obesity epidemic has now spread worldwide. With increase in weight, there is an increase in dysregulated energy metabolism ultimately leading to dysfunction of multiple organ systems recognized as the metabolic syndrome. Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease worldwide, and is thought to be the hepatic manifestation of metabolic syndrome. It is a nondiscriminating disease affecting both children and adults and no socioeconomic class is spared. There is a well-defined increase in both liver-related and all-cause mortality. Current projections foresee a continued worsening in prevalence, especially with the increased rate of childhood obesity. Prevention would be the ultimate goal, but with continued trends in obesity, therapeutic options are needed to manage this chronic liver disease and prevent its complications of cirrhosis and even hepatocellular carcinoma. Therapies will need to be affordable, tolerable, and safe to be useful on such a large scale. This article will discuss some of the basic understanding of NAFLD, as well as review the currently tested therapies, some novel therapies, and potential future therapeutic options.
A Facile Fabrication of Superhydrophobic Films by Electrophoretic Deposition of Hydrophobic Particles
Authors: Ogihara Hitoshi , Okagaki Jun , Saji Tetsuo
Published: January 2009

We demonstrated a fabrication of superhydrophobic colored films by the electrophoretic deposition (EPD) of hydrophobic pigment particles on substrates. The superhydrophobic films showed various colors such as black, white, blue, and green.
Heat Transfer During Quenching and Assessment of Quench Severity—A Review
Authors: Prabhu K. Narayan , Fernandes Peter
Published: January 2009

In the heat treatment of steel, quenching is done to prevent ferrite or pearlite formation and allows formation of bainite and martensite. For a particular grade of steel, the effectiveness of quenching depends on the cooling characteristics of the quenching medium. The cooling rate is not a constant throughout the quenching process; instead it varies depending upon the various stages that occur during the quenching process. Knowledge of heat transfer during various stages of quenching and kinetics of wetting of the quench medium is fundamental to the understanding of the relationship between material, quench medium, microstructure, and properties. In this paper the characteristics of various quench media, the effect of process parameters on quenching, mechanisms of thermal transport, methods of assessing severity of quenching, and techniques of estimation of heat transfer coefficients are reviewed. An attempt is also made to highlight the importance of wetting kinetics of liquid media on quenching.
Some Notes on Kamala??la’s Understanding of Insight Considered as the Discernment of Reality (bh?ta-pratyavek??).
Authors: Adam Dr Martin T.
Published: January 2009

The present article aims to explain Kamala??la’s understanding of the nature of insight, specifically considering it as the ‘discernment of reality’ (bh?ta-pratyavek??) -- a technical term identified with insight (vipa?yan?) in the author’s well known Bh?van?krama? texts. I approach my analysis of bh?ta-pratyavek?? from three different angles. I begin by providing a rationale for its translation. This is followed by an account of Kamala??la’s reading of key passages in the La?k?vat?ra S?tra describing the process to which the term refers. Here the aim is to illustrate Kamala??la’s understanding of bh?ta-pratyavek?? as it is actually experienced in meditation. The final section examines bh?ta-pratyavek?? in relation to other important technical terminology employed in the course of making arguments against his historical rival in debate, the Ch’an monk Mo ho yen. By providing these three different perspectives on the same process it is my hope that both scholars and practitioners will be able to more fully comprehend and benefit from the instructions provided by the ancient master Kamala??la.
Yellow Nutsedge (Cyperus esculentus) Growth and Reproduction in Response to Nitrogen and Irrigation
Authors: Ransom Corey V. , Rice Charles A. , Shock Clinton C.
Published: January 2009

Growth and reproductive potential of individual yellow nutsedge plants were examined under two nitrogen levels and three soil moisture regimes. Irrigation levels were selected on the basis of irrigating at soil water potentials of −20, −50, and −80 kPa. Yellow nutsedge patch expansion was measured using digital images to determine ground cover, while plots were subsampled to estimate total shoot and tuber production. High nitrogen increased shoot production in 2004. When plots were irrigated at a soil water potential of −20 kPa, a single yellow nutsedge plant produced 3,000 and 1,700 shoots and 19,000 and 20,000 tubers in 2003 and 2004, respectively. Patch expansion at −20 kPa was exponential, with the greatest expansion occurring between the middle of July and mid to late August. This research demonstrates that the vegetative and reproductive potential of yellow nutsedge is greatly influenced by irrigation level. With such extensive growth and reproductive potential, management strategies for yellow nutsedge should focus on prevention, early detection and containment, early treatment, and integration of control strategies to reduce its competitiveness and spread.