bluuebunny/crossref_metadata_2025 huggingface dataset:
Can Growth Form Classification Predict Litter Nutrient Dynamics and Decomposition Rates in Lowland Wet Forest?
Authors: Santiago Louis S.
Published: December 2009

This study investigates whether it is possible to simplify the complex influence of numerous species on leaf litter decomposition in a diverse tropical forest using functional classifications to predict litter quality, decomposition rate, and nutrient dynamics during decomposition, over a 2‐yr period. Thirty‐three lowland tropical forest plant species from contrasting growth forms (canopy trees, pioneer trees, lianas, palms, herbs) were studied. Twelve of 18 indices of litter quality varied significantly among growth forms, with canopy trees and palms showing lower litter quality than pioneer trees and herbs. Canopy leaves decomposed more slowly than understory leaves. Decomposition rate and mass loss trended greater (P<0.1) in herbs and pioneer trees compared with other growth forms. There were no significant differences between monocots and dicots, and no phylogenetic signal for decomposition was observed. Significant correlations between continuous litter quality variables and decomposition rate were observed with correlation coefficients up to 0.72. Litter lignin:Mg, P concentration, and lignin:K, were the litter quality variables most related to decomposition rate. All elements showed significant negative correlations between initial litter concentration and percent remaining, but many elements showed significant correlation between percent element remaining and initial concentrations of other elements, indicating a stoichiometric balance between these elements during decomposition. The results show that although classification by growth form and canopy position are helpful for considering the ecosystem implications of changing community composition, litter quality traits provide additional predictive power for estimating the effects of species change on decomposition.
Making Doha More Developmentally Friendly for Agriculture
Authors: Huff H. Bruce
Published: December 2009

The opportunity to achieve the substantial benefits from the “once‐in‐a‐generation” reduction in the support and protection of the agriculture sector under the Doha Development Agenda appears to be slipping away. The paper outlines a series of factors for the delay in the negotiations. The author contends that if developed countries had been more proactive on a trade and development agenda, then there could have been an agreement reached several months ago. Such a developmentally friendly agenda could involve (i) better Special and Differential Treatment on market access and more flexible market access protection for developing countries, (ii) a binding commitment to increase aid for trade assistance, (iii) more resources to provide human resource capacity building in export marketing in developing countries, (iv) an agreement for the termination of trade distorting domestic support, and (v) revisions to the SPS Agreement to accommodate the concerns of developing countries. A developmentally friendly agreement would likely still allow the majority of the Doha Round gains to be realized by developed countries. The paper also tracks the developments, describes the progress, and reviews the empirical estimates of the expected global impact of the eight‐year Doha Round negotiations.

L'occasion de profiter des avantages substantiels que pourrait procurer la réduction « unique » du soutien et du protectionnisme agricoles dans le cadre du Programme de Doha pour le développement semble s'échapper. Le présent article expose une série de facteurs responsables du retard dans les négociations. L'auteur soutient que si les pays développés avaient été davantage proactifs quant à l'élaboration d'un programme d'échanges et de développement, un accord aurait pu être conclu il y a plusieurs mois déjà. Un programme soucieux du développement pourrait inclure: i) un « Traitement spécial et différencié» amélioré sur l'accès au marché et une protection de l'accès au marché plus souple pour les pays en développement; ii) un engagement obligatoire pour accroître l'aide au commerce; iii) davantage de ressources pour accroître le renforcement des capacités des pays en développement dans le domaine de la commercialisation des exportations; iv) un accord pour mettre fin au soutien interne qui distord les échanges; v) des modifications à l'Accord MSP pour répondre aux préoccupations des pays en développement. Un accord soucieux du développement permettrait probablement aux pays développés de réaliser la majorité des gains du cycle de Doha. Le présent article fait état des développements, décrit les progrès et examine les estimations empiriques des répercussions globales de la huitième année de négociations du cycle de Doha.
The Dependence of Growth‐Model Results on Proficiency Cut Scores
Authors: Ho Andrew D. , Lewis Daniel M. , MacGregor Farris Jason L.
Published: December 2009

States participating in the Growth Model Pilot Program reference individual student growth against “proficiency” cut scores that conform with the original No Child Left Behind Act (NCLB). Although achievement results from conventional NCLB models are also cut‐score dependent, the functional relationships between cut‐score location and growth results are more complex and are not currently well described. We apply cut‐score scenarios to longitudinal data to demonstrate the dependence of state‐ and school‐level growth results on cut‐score choice. This dependence is examined along three dimensions: 1) rigor, as states set cut scores largely at their discretion, 2) across‐grade articulation, as the rigor of proficiency standards may vary across grades, and 3) the time horizon chosen for growth to proficiency. Results show that the selection of plausible alternative cut scores within a growth model can change the percentage of students “on track to proficiency” by more than 20 percentage points and reverse accountability decisions for more than 40% of schools. We contribute a framework for predicting these dependencies, and we argue that the cut‐score dependence of large‐scale growth statistics must be made transparent, particularly for comparisons of growth results across states.
Actobiotics™ as a Novel Method for Cytokine Delivery
Authors: Steidler Lothar , Rottiers Pieter , Coulie Bernard
Published: December 2009

Interleukin‐10 (IL‐10) is central in immune downregulation, but so far its use in inflammatory diseases remains cumbersome. For treatment of inflammatory bowel disease, adequate amounts of IL‐10 must reach the intestinal lining. Systemic injection of a pharmacologically active doses of recombinant human (rh) IL‐10 results in very low mucosal levels of protein and severe toxicity and side effects. In animal models, topical and active delivery of IL‐10 by ingestion of recombinant Lactococcus lactis (L. lactis) was shown to be a valuable alternative. Starting thereof we have developed a novel pharmaceutical platform. Our expertise and TopAct™ (topical and active) delivery technology allows use of recombinant L. lactis– ActoBiotics™– in clinical practice. Here we discuss the development of recombinant L. lactis for intestinal delivery of rhIL‐10 in humans.
Heterogeneous, Longitudinally Stable Molecular Signatures in Response to Interferon‐β
Authors: Rani M. R. Sandhya , Xu Yaomin , Lee Jar‐chi , Shrock Jennifer , Josyula Anupama , Schlaak Joerg , Chakraborthy Swathi , Ja Nie , Ransohoff Richard M. , Rudick Richard A.
Published: December 2009

Interferons (IFNs) are widely used in therapy for viral, neoplastic, and inflammatory disorders, but clinical response varies among patients. The biological basis for variable clinical response is not known. We determined the primary molecular response to IFN‐beta (IFN‐β) injections in 35 treatment‐naïve multiple sclerosis (MS) patients using a customized cDNA macroarray with 186 interferon‐stimulated genes (ISGs). Our results revealed striking interindividual heterogeneity, both in the magnitude as well as the nature of the primary molecular response to IFN‐β injections. Despite marked between‐subject variability in the molecular response, responses within individual subjects were stable over a 6‐month interval. Our data suggest that clinical response to IFN‐β therapy for MS differs among patients because of qualitative rather than quantitative variability in the primary molecular response to the drug.
Cytokines as Targets for Anti‐inflammatory Agents
Authors: Moreland Larry W.
Published: December 2009

Well over a decade ago a central role of tumor necrosis factor (TNF) was first described in patients with rheumatoid arthritis (RA) when remarkable clinical benefit was demonstrated in patients with refractory disease were treated with using either a monoclonal antibody or a soluble receptor fusion protein. There are now five anti‐TNF agents approved by regulatory agencies for treating RA. Identifying which RA patients will have a meaningful clinical response (improvement in outcomes measures such as ACR 20, DAS score, remission, etc.) when used as monotherapy, or in combination with other immunosuppressive agents remains a major research effort. Also, attention has focused on the potential adverse events that can be seen with these therapies; an increase in opportunistic infections being the most clearly linked adverse event. These anti‐TNF therapies have revolutionized the clinicians’ ability to make a significant impact in RA, a disease that has significant excess morbidity and mortality.
Rilonacept—CAPS and Beyond
Authors: Stahl Neil , Radin Allen , Mellis Scott
Published: December 2009

Rilonacept is a dimeric fusion protein consisting of the extracellular domains of interleukin (IL)‐1 type 1 receptor and IL‐1 receptor accessory protein joined to the constant region (Fc) of human immunoglobulin G1. By incorporating both components of the IL‐1 binding complex, rilonacept is able to tightly bind IL‐1 with picomolar affinity. Although early clinical results in rheumatoid arthritis (RA) suggested that RA is not primarily an IL‐1‐driven disease, the discovery that the rare genetic conditions called cryopyrin‐associated periodic syndromes (CAPS) were caused by overproduction of IL‐1 led to clinical development and approval for these conditions. An assay that detects rilonacept:IL‐1 complexes in plasma is helping to identify new indications, such as gout, in which IL‐1 overproduction plays a key pathogenic role. The development of rilonacept for CAPS was achieved through collaboration between the pharmaceutical industry, academia, and government agencies, and demonstrates that knowledge gleaned in orphan indications can inform drug development for more common and heterogeneous diseases.
Blocking Interleukin‐1 in Rheumatic Diseases
Authors: Goldbach‐Mansky Raphaela
Published: December 2009

The role of the potent proinflammatory cytokine IL‐1 in disease could clinically be investigated with the development of the IL‐1 blocking agent anakinra (Kineret®), a recombinant IL‐1 receptor antagonist. It was first tested in patients with sepsis without much benefit but was later FDA approved for the treatment of patients with rheumatoid arthritis. More recently IL‐1 blocking therapies are used successfully to treat a new group of immune‐mediated inflammatory conditions, autoinflammatory diseases. These conditions include rare hereditary fever syndromes and pediatric and adult conditions of Still's disease. Recently the FDA approved two additional longer acting IL‐1 blocking agents, for the treatment of cryopyrin‐associated periodic syndromes (CAPS), an IL‐1 dependent autoinflammatory syndrome. The study of autoinflammatory diseases revealed mechanisms of IL‐1 mediated organ damage and provided concepts to a better understanding of the pathogenesis of more common diseases such as gout and Type 2 diabetes which show initial promising results with IL‐1 blocking therapy.
Pharmacologic Administration of Interleukin‐2
Authors: Chavez Antonio Romo de Vivar , Buchser William , Basse Per H. , Liang Xiaoyan , Appleman Leonard J. , Maranchie Jodi K. , Zeh Herbert , de Vera Michael E. , Lotze Michael T.
Published: December 2009

The development of biologic therapies for patients with cancer has in part been impeded by the extraordinary complexity and intrinsic feedback mechanisms promoting homeostasis in tissue injury, repair, inflammation, and immunity. Recombinant interleukin 2 (IL‐2) therapy was initiated in 1984 based on its role as the prototypic T‐cell growth factor, with novel roles deduced late after its FDA approval in regulating not only effector T cells but also regulatory T cells. Complicating its application, even in the most sophisticated centers, has been the manageable but difficult toxicities attendant on its use in spite of clear evidence of complete responses in 5–10% of treated patients with melanoma and renal cell carcinoma with extraordinary durability lasting now for almost 25 years, thus tantamount to “cures.” Although efforts have been made to diminish toxicity or enhance efficacy the only substantive advance in combination therapy has been the application of tumor‐infiltrating lymphocytes and the antibody to CTLA4. A deeper understanding of the “limiting” toxicity associated with mild flu‐like symptoms and more debilitating cytokine “storm” not forthcoming. Here we propose the notion that the systemic syndrome associated with IL‐2 administration is due to global cytokine‐induced autophagy and temporally limited tissue dysfunction. The possible role of autophagy inhibitors to enhance efficacy and limit toxicity as well as possible problems with this approach are considered.
Interferon Lambda as a Potential New Therapeutic for Hepatitis C
Authors: Miller Dennis M. , Klucher Kevin M. , Freeman Jeremy A. , Hausman Diana F. , Fontana David , Williams Doug E.
Published: December 2009

Interferon lambdas (IFN‐λ) are Type III interferons with biological activity, including induction of antiviral genes, similar to Type I IFNs, but signal through a distinct receptor complex. The expression pattern for the IFN‐λ receptor is more cell specific than the widely distributed IFN‐α receptor, suggesting in vivo, IFN‐λ may have fewer side effects than IFN‐α, such as less hematologic toxicities. A PEGylated form of IFN‐λ (PEG‐rIL‐29) was well tolerated in animals and did not result in hematologic toxicity. Clinical data from initial studies of PEG‐rIL‐29 has demonstrated antiviral effects in patients with hepatitis C without producing hematologic toxicity. These preclinical and early clinical data support PEG‐rIL‐29 as a potential new therapeutic agent for treatment of patients with hepatitis C.
Transmissibility of the 1918 pandemic influenza in Montreal and Winnipeg of Canada
Authors: Zhang Shenghai , Yan Ping , Winchester Brian , Wang Jun
Published: December 2009

Background The threat of 2009 pandemic influenza A (H1N1) is still causing widespread public concern. A comprehensive understanding of the epidemiology of 1918 pandemic influenza commonly referred to as the Spanish flu may be helpful in offering insight into control strategies for the new pandemic.

Objective We explore how the preparedness for a pandemic at the community and individual level impacts the spread of the virus by comparing the transmissibility of the 1918 Spanish flu in two Canadian cities: Montreal and Winnipeg, bearing in mind that each pandemic is unique and the current one may not follow the pattern of the 1918 outbreak.

Methods The historical epidemiological data obtained for Montreal and Winnipeg in Canada is analyzed to estimate the basic reproduction number which is the most important summary measure of transmission potential of the pandemic.

Results The transmissibility of the 1918 pandemic influenza virus in Winnipeg in the fall of 1918 was found to be much lower than in Montreal based on the estimated reproduction number obtained assuming different serial intervals which are the time between onsets of symptoms in an index case and a secondary case.

Conclusion The early preparedness and public health control measures could suggest an explanation for the fact that the number of secondary cases generated by a primary case was significantly reduced in Winnipeg comparing to it in Montreal.
Combination of Super Chilling and High Carbon Dioxide Concentration Techniques Most Effectively to Preserve Freshness of Shell Eggs during Long‐Term Storage
Authors: Yanagisawa T. , Ariizumi M. , Shigematsu Y. , Kobayashi H. , Hasegawa M. , Watanabe K.
Published: December 2009

ABSTRACT:  This study was made to examine the combined effects of stored temperature and carbon dioxide atmosphere on shell egg quality. The shell eggs were packed into polyethylene terephthalate/polyethylene (PET/PE) pouches and stored at 0 °C (super chilling), 10 °C, and 20 °C, respectively for 90 d. The atmospheric carbon dioxide concentration was controlled to obtain the 3 concentration levels of high (about 2.0%), medium (about 0.5%), and low (below 0.01%). Changes in Haugh unit (HU) values, weakening of vitelline membranes, and generation of volatiles were analyzed to evaluate the freshness of shell eggs. Results showed that, compared with the other combinations, the technique of super chilling and high carbon dioxide concentration enabled shell eggs to be most effectively stored for 90 d, based on estimations of the statistical significances of differences in HU values, and on maintaining the initial HU values during storage. In addition, the storage of shell eggs using this combination technique was found to significantly prevent the weakening of the vitelline membrane based on the estimations of numbers of eggs without vitelline membrane breakage when eggs broke, and significantly lowered the incidence of hexanal in the yolk from exposure to the gas chromatographic‐mass spectrometric analyses of volatiles. Thus, these results confirmed that the combination of super chilling and high carbon dioxide concentration was the most effective technique for preserving shell eggs during a long term of 90 d compared with other combination techniques.
Review: Nanocomposites in Food Packaging
Authors: Arora Amit , Padua G.W.
Published: December 2009

ABSTRACT:  The development of nanocomposites is a new strategy to improve physical properties of polymers, including mechanical strength, thermal stability, and gas barrier properties. The most promising nanoscale size fillers are montmorillonite and kaolinite clays. Graphite nanoplates are currently under study. In food packaging, a major emphasis is on the development of high barrier properties against the migration of oxygen, carbon dioxide, flavor compounds, and water vapor. Decreasing water vapor permeability is a critical issue in the development of biopolymers as sustainable packaging materials. The nanoscale plate morphology of clays and other fillers promotes the development of gas barrier properties. Several examples are cited. Challenges remain in increasing the compatibility between clays and polymers and reaching complete dispersion of nanoplates. Nanocomposites may advance the utilization of biopolymers in food packaging.
Fostering Solutions: Bringing Brief‐Therapy Principles and Practices to the Child Welfare System
Authors: Flemons Douglas , Liscio Michele , Gordon Arlene Brett , Hibel James , Gutierrez‐Hersh Annette , Rebholz Cynthia L.
Published: December 2009

This article describes a 15‐month university‐community collaboration that was designed to fast‐track children out of foster care. The developers of the project initiated resource‐oriented “systems facilitations,” allowing wraparound professionals and families to come together in large meetings to solve problems and find solutions. Families also participated in strength‐based brief‐therapy sessions. The authors describe the history, structure, and process of the project, and they provide a case study to illustrate the approach and exemplify the kinds of changes that occurred throughout the system. In the final section of the article, the authors reflect on what they learned about their university‐community partnership, what they would do differently the next time, and the implications of such larger‐system involvements for American Association for Marriage and Family Therapy’s Core Competencies.
pedagog: software for simulating eco‐evolutionary population dynamics
Authors: COOMBS JASON A. , LETCHER B. H. , NISLOW K. H.
Published: December 2009

pedagogis a Windows program that can be used to determine power for, and validate inferences drawn from, eco‐evolutionary studies. It models dynamics of multiple populations and their interactions through individual‐based simulations while simultaneously recording genotype, pedigree and trait information at the individual level.pedagogalso allows for specification of heritable traits, natural and sexual selection acting upon those traits, population sampling schemes and incorporation of genetic and demographic errors into the output. Overall, parameters can be specified for genetic diversity, demographics, mating design, genetic and demographic errors, individual growth models, trait heritability and selection, and output formatting. Demographic parameters can be either age or function based, and all parameters can be drawn from 12 statistical distributions where appropriate. Simulation results can be automatically formatted for 57 existing software programs to facilitate postsimulation analyses.pedagogis freely available for download athttps://bcrc.bio.umass.edu/pedigreesoftware/.
Catching the baby: accounting for biodiversity and the ecosystem sector in emissions trading
Authors: Van Oosterzee Penny , Preece Noel , Dale Allan
Published: December 2009

The agriculture, forestry, and other land‐use sector is a crucial sector, second only to the energy sector, in fighting climate change, and provides an important greenhouse gas abatement opportunity for the world. Recently, released figures for Australia, for example, suggest that agriculture, forestry, and other land‐uses, which depend on healthy functioning ecosystems, could abate as much as three quarters of the country's emissions. The United Nations Framework Convention on Climate Change was concerned primarily with ecosystems and humankind, but the Kyoto Protocol of the Convention forfeited the potential of using agriculture, forestry, and other land‐uses for global climate mitigation. This had the effect of decoupling biodiversity and ecosystems from carbon pollution reduction and climate change considerations. The Australian Carbon Pollution Reduction Scheme, one of the first emission trading schemes in the world to follow Kyoto “rules,” excludes the agriculture, forestry, and other land‐use sector, apart from plantation reforestation, potentially creating perverse incentives that themselves can turn into threatening ecological processes. We use Australia and its emerging emissions trading scheme as a case study of the potential effects of this decoupling, and demonstrate the potential impacts on a landscape‐scale regional greenhouse gas abatement and carbon sequestration project.
Assessing Cognitively Complex Strategy Use in an Untrained Domain
Authors: Jackson George T. , Guess Rebekah H. , McNamara Danielle S.
Published: December 2009

Researchers of advanced technologies are constantly seeking new ways of measuring and adapting to user performance. Appropriately adapting system feedback requires accurate assessments of user performance. Unfortunately, many assessment algorithms must be trained on and use pre‐prepared data sets or corpora to provide a sufficiently accurate portrayal of user knowledge and behavior. However, if the targeted content of the tutoring system changes depending on the situation, the assessment algorithms must be sufficiently independent to apply to untrained content. Such is the case for Interactive Strategy Training for Active Reading and Thinking (iSTART), an intelligent tutoring system that assesses the cognitive complexity of strategy use while a reader self‐explains a text. iSTART is designed so that teachers and researchers may add their own (new) texts into the system. The current paper explores student self‐explanations from newly added texts (which iSTART had not been trained on) and focuses on evaluating the iSTART assessment algorithm by comparing it to human ratings of the students’ self‐explanations.
A Model for Lubrication by Oil-in-Water Emulsions
Authors: Lo Sy-Wei , Yang Tzu-Chun , Cian Yong-An , Huang Kuo-Cheng
Published: December 2009

A model for oil-in-water emulsion has been developed in this paper. A group of viscosity coefficients transiting smoothly and incessantly from the thick film region to the thin film region is defined. The contributions from disperse and continuous phases to the total lubricant pressure and pressure gradient are functions of the oil concentration and the film thickness. The parameters used in these functions are determined by a series of computational fluid dynamics simulations. The onset of inversion and the viscosity after inversion are also investigated. It is found that the critical volume fraction of oil in the inception of inversion is dependent on the oil viscosity and a factor regarding the combined effects from the emulsifier, pH value, droplet size, and the shear rate. A series of simulations using the proposed model has been carried out and compared with the experimental results, such as the film thickness and the extension of oil pool for various rolling speeds and supply oil concentrations. The numerical outputs are basically in agreement with the experiments.
Lubrication of the Human Ankle Joint in Walking
Authors: Hlaváček Miroslav
Published: December 2009

Human ankle joint lubrication in walking is analyzed. A biphasic mixture model is considered for articular cartilage (ideal interstitial fluid and elastic porous matrix that is transversely isotropic and inhomogeneous throughout its thickness). Synovial fluid is considered Newtonian. Its viscosity is due to the macromolecules of hyaluronic acid that are too large to enter the matrix pores. Due to the fluid pressure gradient water and small solutes pass through the matrix pores and across the articular surface in both directions. The effect of the time varying concentration of hyaluronic acid or of the synovial fluid viscosity on the synovial film thickness distribution is small and neglected in the model. Periodic sliding motion of the articular surfaces and periodic loading of the joint as encountered in walking are included in the analysis. Synovial fluid serves as a fluid lubricant. The model shows that soon after the onset of walking the normal human ankle joint works in a mixed lubrication mode (a combination of boundary and fluid-film lubrications). A protective gel layer formed in the gap due to the synovial fluid filtration by cartilage may serve as a boundary lubricant. The synovial gel layer is not guaranteed in the osteoarthritic case, and the rough sliding surfaces may get repeatedly into an intimate contact and wear off due to the reciprocating sliding motion.
Thermohydrodynamic Model Predictions and Performance Measurements of Bump-Type Foil Bearing for Oil-Free Turboshaft Engines in Rotorcraft Propulsion Systems
Authors: Kim Tae Ho , San Andrés Luis
Published: December 2009

An engineered thermal management is fundamental to the application of gas foil bearings (GFBs) as turboshaft supports in rotorcraft propulsion systems. The paper presents a model for the thermal energy transport in a rotor-GFB system operating at high temperature with typical inner and/or outer cooling flows. Predicted film temperatures agree with published test data, demonstrating the effectiveness of an outer cooling stream to remove heat and to control the operating temperature. The inner flow stream is not as efficient. The analysis shows paths of thermal energy by conduction and convection to assist in the design and troubleshooting of rotor-GFB systems operating hot. Bearing temperatures and shaft motions measurements are obtained in a test rotor electrically heated to 132°C. In speed-up tests to 26 krpm, the rotor motion amplitude drops suddenly just above the critical speed, thus, evidencing the typical hardening of compliant bearings. At the hottest test condition, since air is more viscous, the rotor peak motion amplitude decreases, not showing a jump. The coastdown tests show the critical speed increases slightly as the temperature increases.
On the Behavior of Friction in Lubricated Point Contact With Provision for Surface Roughness
Authors: Sojoudi H. , Khonsari M. M.
Published: December 2009

This paper presents a simple approach to predict the behavior of friction coefficient in the sliding lubricated point contact. Based on the load-sharing concept, the total applied load is supported by the combination of hydrodynamic film and asperity contact. The asperity contact load is determined in terms of maximum Hertzian pressure in the point contact while the fluid hydrodynamic pressure is calculated through adapting the available numerical solutions of elastohydrodynamic lubrication (EHL) film thickness formula for smooth surfaces. The simulations presented cover the entire lubrication regime including full-film EHL, mixed-lubrication, and boundary-lubrication. The results of friction, when plotted as a function of the sum velocity, result in the familiar Stribeck-type curve. The simulations are verified by comparing the results with published experimental data. A parametric study is conducted to investigate the influence of operating condition on the behavior of friction coefficient. A series of simulations is performed under various operating conditions to explore the behavior of lift-off speed. An equation is proposed to predict the lift-off speed in sliding lubricated point contact, which takes into account the surface roughness.
Numerical Investigation of Bouncing Vibrations of an Air Bearing Slider in Near or Partial Contact
Authors: Chen Du , Bogy David B.
Published: December 2009

Near or partial contact sliders are designed for the areal recording density of 1 Tbit/in.2 or even higher in hard disk drives. The bouncing vibration of an air bearing-slider in near or partial contact with the disk is numerically analyzed using three different nonlinear slider dynamics models. In these three models, the air bearing with contact is modeled either by using the generalized Reynolds equation modified with the Fukui–Kaneko slip correction and a recent second order slip correction for the contact situation, or using nonlinear springs to represent the air bearing. The contact and adhesion between the slider and the disk are considered either through an elastic contact model and an improved intermolecular adhesion model, respectively, or using an Ono–Yamane multi-asperity contact and adhesion model (2007, “Improved Analysis of Unstable Bouncing Vibration and Stabilizing Design of Flying Head Slider in Near-Contact Region,” ASME J. Tribol., 129, pp. 65–74.). The contact friction is calculated by using Coulomb’s law and the contact force. The simulation results from all of these models show that the slider’s bouncing vibration occurs as a forced vibration caused by the moving microwaviness and roughness on the disk surface. The disk surface microwaviness and roughness, which move into the head disk interface as the disk rotates, excite the bouncing vibration of the partial contact slider. The contact, adhesion, and friction between the slider and the disk do not directly cause a bouncing vibration in the absence of disk microwaviness or roughness.
Thermohydrodynamic Lubrication Analysis of Misaligned Plain Journal Bearing With Rough Surface
Authors: Sun Jun , Deng Mei , Fu Yonghong , Gui Changlin
Published: December 2009

Journal misalignment exists generally in journal bearings. When severe journal misalignment takes place, the minimum film thickness of journal bearings reduces greatly. In this condition, the surface roughness, the oil viscosity-pressure relationship (VPR), and the thermal effect have obvious effects on hydrodynamic lubrication performance of misaligned bearings. In this paper, the oil film pressure, oil film temperature, load-carrying capacity, end leakage flow rate, frictional coefficient, and misalignment moment of a journal bearing with different angles of journal misalignment and surface roughness, and considering oil VPR and thermal effect, were calculated based on the generalized Reynolds equation, energy equation, and solid heat conduction equation. The results show that the oil VPR and surface roughness have a significant effect on the lubrication of misaligned journal bearings under large eccentricity ratio. The thermal effect will affect obviously the lubrication of misaligned journal bearings when eccentricity ratio and angle of journal misalignment are all large. In the present design, the size of the journal bearing is compact more and more, and the eccentricity ratio and angle of journal misalignment are usually large in operating conditions. Therefore, it is necessary to take the effects of journal misalignment, surface roughness, oil VPR, and thermal effect into account in the design and analyses of journal bearings.
Contrast enhancement behavior of hydrogen silsesquioxane in a salty developer
Authors: Nam Sung-Wook , Rooks Michael J. , Yang Joel K. W. , Berggren Karl K. , Kim Hyun-Mi , Lee Min-Hyun , Kim Ki-Bum , Sim Jae Hwan , Yoon Do Yeung
Published: December 2009

The authors investigated a contrast enhancement behavior of hydrogen silsesquioxane (HSQ) in a salty development system (NaOH∕NaCl). Time-resolved analysis of contrast curves and line-grating patterns were carried out to investigate the unique properties of a salty development process. In NaOH developer without salt, the development process was saturated beyond a certain development time. On the other hand, the addition of salt enabled a continuous development, which was not observed in the pure NaOH development. The continuous thinning process enhances the contrast of HSQ in the salty developer, which allows a fast collapsing behavior in HSQ line-grating patterns. During development process, salt seems to have the role of modifying HSQ by breaking network bonds preferentially, leading to a continuous development rate.
Ultradense gold nanostructures fabricated using hydrogen silsesquioxane resist and applications for surface-enhanced Raman spectroscopy
Authors: Choi Sookyung , Yan Minjun , Adesida Ilesanmi , Hsu Keng H. , Fang Nicholas X.
Published: December 2009

Metal nanostructures have been routinely fabricated by lift-off process using electron-beam lithography. However, for ultradense structures, this method has been limited by metal film thickness with resulting poor pattern quality. The authors report an alternative approach for the fabrication of ultradense gold (Au) nanostructures using hydrogen silsesquioxane (HSQ). Due to the high resolution and excellent etch durability of HSQ resists, ultradense Au gratings with high quality were fabricated. As a promising application, they demonstrate that these structures can be applied to surface-enhanced Raman scattering (SERS) for bioanalysis. Ultradense Au structures fabricated using HSQ resists have proven to be a robust and effective SERS-active substrate.
Lumpers and Splitters: Darwin, Hooker, and the Search for Order
Authors: Endersby Jim
Published: December 2009

An Odd Sort of Revolution

Joseph Hooker was the director of the Royal Botanic Gardens at Kew, London, when Charles Darwin and Alfred Wallace were presenting their ideas about evolution by natural selection. Hooker was a good friend of Darwin's and an ardent ally of evolutionary thinking, who came to realize that natural selection would have little impact on the taxonomist's endeavor.
Endersby
(p.
1496
) reviews taxonomic practice in the 19th century, arguing that the concept of evolution was almost a sideshow in the energetic debate about whether to group varieties into single species or whether to divide species into endless varieties. On the one hand, Hooker was a “lumper,” who found it hard to tolerate the thought of species constantly emerging, because it hindered his analysis of global patterns of species richness. On the other hand, Darwin's vision reconciled both modes of classification in revealing the genealogy of life on Earth.
Cell-Specific Information Processing in Segregating Populations of Eph Receptor Ephrin–Expressing Cells
Authors: Jørgensen Claus , Sherman Andrew , Chen Ginny I. , Pasculescu Adrian , Poliakov Alexei , Hsiung Marilyn , Larsen Brett , Wilkinson David G. , Linding Rune , Pawson Tony
Published: December 2009

Dissecting Ephrin-Receptor Interaction

Ephrins are transmembrane proteins that bind ephrin receptors on adjacent cells, leading to propagation of biochemical signals within both cells.

Jørgensen
et al.

(p.
1502
) devised a way to use differential isotopic labeling to distinguish cells engineered to express either the receptor or the ligand and to monitor bidirectional signaling events by mass spectrometry of the labeled peptides when the cells were mixed together. Signaling networks were constructed, and the information processing by the two interacting cell types was modeled. Changes in signaling within cells expressing just the ligand (ephrin) caused changes in the signal processing during the adjacent cell's response to binding of the ephrin receptor.
A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs
Authors: Nesbitt Sterling J. , Smith Nathan D. , Irmis Randall B. , Turner Alan H. , Downs Alex , Norell Mark A.
Published: December 2009

Early Dinosaur Discovery

Our understanding of the evolution of early dinosaurs is hampered by limited material, especially compared to the many Jurassic and Cretaceous samples.

Nesbitt
et al.

(p.
1530
) provide a complete view of a Late Triassic theropod based on several nearly complete skeletons from New Mexico. The dinosaur elucidates the likely relationships between early theropods and shows that some prominent features were already derived by this time. Comparison among Triassic dinosaur fauna and other early species suggests that Triassic North American fauna were diverse but not endemic, perhaps arising from earlier migrants from South America.
MicroRNA-206 Delays ALS Progression and Promotes Regeneration of Neuromuscular Synapses in Mice
Authors: Williams Andrew H. , Valdez Gregorio , Moresi Viviana , Qi Xiaoxia , McAnally John , Elliott Jeffrey L. , Bassel-Duby Rhonda , Sanes Joshua R. , Olson Eric N.
Published: December 2009

An Innervative Small RNA

Amyotrophic lateral sclerosis (ALS) is a relentless disease characterized by progressive degeneration of motor neurons that control muscle movement, leading to muscle atrophy and paralysis.

Williams
et al.

(p.
1549
; see the Perspective by

Brown

) show that a small noncoding RNA that is selectively expressed in skeletal muscle, miR-206, senses motor neuron injury or loss and helps ameliorate resultant muscle damage by promoting regeneration of neuromuscular synapses. Expression of miR-206 was dramatically induced in a mouse model of ALS, and when this RNA was removed from mice by genetic manipulation, the disease progressed at a faster rate. The salutary effects of miR-206 appear to be mediated through a signaling pathway in muscle cells involving histone deacetylase 4 and a fibro-blast growth factor modulator, activation of which leads to release of factors that promote nerve-muscle interactions.
DNA Binding Made Easy
Authors: Voytas Daniel F. , Joung J. Keith
Published: December 2009

A mechanism by which proteins of bacterial plant pathogens recognize and control the expression of host plant genes to promote infection is identified.
A Strongly Driven Spin
Authors: Gerardot Brian D. , Öhberg Patrik
Published: December 2009

Extremely fast manipulation of an electron spin at a defect site in diamond may enable advances in quantum information science.
Harmonizing Global Science
Authors: Leshner Alan I. , Turekian Vaughan
Published: December 2009

Every major problem facing modern society now has a science and technology component—either as a cause or cure—whether it's energy and the environment, access to water and fertile land, the spread of infectious diseases, or sustaining a viable economy. Although every societal problem has unique regional characteristics that require attention, there are sufficient implications across regions for which only globally coordinated efforts will be successful. The recent assessments of the Intergovernmental Panel on Climate Change and their impacts on public and policy-maker perceptions provide one example of successful cooperation on a near-global scale. The betterment of humankind depends on a deliberate move from being an international community of scientists to being a truly global community.
Chagnon Critics Overstepped Bounds, Historian Says
Authors: Mann Charles C.
Published: December 2009

Nine years ago, much of the American Anthropological Association's (AAA's) annual meeting echoed journalist Patrick Tierney in attacking Napoleon A. Chagnon, an anthropologist who studied the Yanamamö Indians of southern Venezuela and northern Brazil. At this year's meeting, most of the criticism was leveled at Chagnon's accusers and the AAA itself.
NIH Approves First New Lines; Many More on the Way
Authors: Holden Constance
Published: December 2009

Last week, the National Institutes of Health (NIH) named the first 13 human embryonic stem cell lines approved for federal funding under President Barack Obama's revised policy.
Plans for London 'Cathedral Of Science' Unveiled
Authors: Travis John
Published: December 2009

At a media briefing this week, backers of the proposed £500 million–plus United Kingdom Centre for Medical Research and Innovation affirmed their financial commitments to the project and unveiled architects' drawings and a "scientific vision" for the facility.
β-Thalassemia Treatment Succeeds, With a Caveat
Authors: Kaiser Jocelyn
Published: December 2009

Gene therapy researchers are approaching a key milestone: They appear to have controlled an inherited blood disorder called β-thalassemia that's more common than any disease treated so far with gene therapy.
What's for Dinner? Researchers Seek Our Ancestors' Answers
Authors: Gibbons Ann
Published: December 2009

To help prevent diseases like diabetes and heart disease today, evolutionary biologists are seeking to understand the tastes of our diverse ancestors.
Immune Responses in Cattle Inoculated with
Mycobacterium bovis
,
Mycobacterium tuberculosis
, or
Mycobacterium kansasii
Authors: Waters W. R. , Whelan A. O. , Lyashchenko K. P. , Greenwald R. , Palmer M. V. , Harris B. N. , Hewinson R. G. , Vordermeier H. M.
Published: December 2009

Cattle were inoculated with
Mycobacterium bovis
,
Mycobacterium tuberculosis
, or
Mycobacterium kansasii
to compare the antigen-specific immune responses to various patterns of mycobacterial disease. Disease expression ranged from colonization with associated pathology (
M. bovis
infection) and colonization without pathology (
M. tuberculosis
infection) to no colonization or pathology (
M. kansasii
infection). Delayed-type hypersensitivity and gamma interferon responses were elicited by each mycobacterial inoculation; however, the responses by the
M. bovis
- and
M. tuberculosis
-inoculated animals exceeded those of the
M. kansasii
-inoculated animals. Specific antibody responses were detected in all
M. tuberculosis
- and
M. bovis
-inoculated cattle 3 weeks after inoculation. From 6 to 16 weeks after
M. tuberculosis
inoculation, the antibody responses waned, whereas the responses persisted with
M. bovis
infection. With
M. kansasii
inoculation, initial early antibody responses waned by 10 weeks after inoculation and then increased 2 weeks after the injection of purified protein derivative for the skin test at 18 weeks after challenge. These findings indicate that antibody responses are associated with the antigen burden rather than the pathology, cellular immune responses to tuberculin correlate with infection but not necessarily with the pathology or bacterial burden, and exposure to mycobacterial antigens may elicit an antibody response in a presensitized animal.
Integrated Detection of Extended-Spectrum-Beta-Lactam Resistance by DNA Microarray-Based Genotyping of TEM, SHV, and CTX-M Genes
Authors: Leinberger Dirk M. , Grimm Verena , Rubtsova Maya , Weile Jan , Schröppel Klaus , Wichelhaus Thomas A. , Knabbe Cornelius , Schmid Rolf D. , Bachmann Till T.
Published: December 2009

Extended-spectrum beta-lactamases (ESBL) of the TEM, SHV, or CTX-M type confer resistance to beta-lactam antibiotics in Gram-negative bacteria. The activity of these enzymes against beta-lactam antibiotics and their resistance against inhibitors can be influenced by genetic variation at the single-nucleotide level. Here, we describe the development and validation of an oligonucleotide microarray for the rapid identification of ESBLs in Gram-negative bacteria by simultaneously genotypingblaTEM,blaSHV, andblaCTX-M. The array consists of 618 probes that cover mutations responsible for 156 amino acid substitutions. As this comprises unprecedented genotyping coverage, the ESBL array has a high potential for epidemiological studies and infection control. With an assay time of 5 h, the ESBL microarray also could be an attractive option for the development of rapid antimicrobial resistance tests in the future. The validity of the DNA microarray was demonstrated with 60 blinded clinical isolates, which were collected during clinical routines. Fifty-eight of them were characterized phenotypically as ESBL producers. The chip was characterized with regard to its resolution, phenotype-genotype correlation, and ability to resolve mixed genotypes. ESBL phenotypes could be correctly ascribed to ESBL variants ofblaCTX-M(76%),blaSHV(22%), or both (2%), whereas no ESBL variant ofblaTEMwas found. The most prevalent ESBLs identified were CTX-M-15 (57%) and SHV-12 (18%).
Caspofungin Etest Endpoint for
Aspergillus
Isolates Shows Poor Agreement with the Reference Minimum Effective Concentration
Authors: Fuller Jeff , Schofield Adam , Jiwa Safeer , Sand Crystal , Jansen Brad , Rennie Robert
Published: December 2009

The Clinical and Laboratory Standards Institute (CLSI) M38-A2 reference broth microdilution (BMD) method for the antifungal susceptibility testing of filamentous fungi now includes guidelines for testing echinocandin activity using the minimum effective concentration (MEC) as the endpoint measurement. In this study, we compared the caspofungin Etest MIC on RPMI agar and Mueller-Hinton agar (supplemented with glucose and methylene blue [MGM]) to the BMD MEC for 345 clinical
Aspergillus
isolates, including
A. flavus
,
A. fumigatus
,
A. nidulans
,
A. niger
, and
A. terreus
. The essential agreement (±1 log
2
dilution) of the Etest on MGM and RPMI agar with the reference BMD MEC was 18 and 26%, respectively. The geometric mean values for BMD MEC and MGM Etest were 0.137 and 0.024 μg/ml, respectively, and the geometric mean values for BMD and RPMI agar were 0.128 and 0.031 μg/ml, respectively. Comparatively, 91% of paired MGM and RPMI Etest results were within 2 log
2
dilutions of each other and consistently produced clearly defined endpoints. In conclusion, the caspofungin Etest MIC, like the BMD MEC, is a reproducible endpoint but is markedly lower than the reference BMD. In anticipation of susceptibility breakpoint assignments, optimization studies will be required to improve the concordance of these two assays so that the potential for underreporting echinocandin resistance in
Aspergillus
is mitigated.