bluuebunny/crossref_metadata_2025 huggingface dataset:
PROPERTIES OF IMPURITY BOUND MAGNETOPOLARON IN QUANTUM RODS
Authors: XIAO WEI , XIAO JING-LIN
Published: December 2010

The Hamiltonian of a quantum rod with an ellipsoidal boundary is given after a coordinate transformation, which changes the ellipsoidal boundary into a spherical one. We then study the vibrational frequency and the ground state binding energy of the weak-coupling impurity bound magnetopolaron in it. The effects of the aspect ratio of the ellipsoid, the transverse effective confinement lengths, the electron-phonon coupling strength, the magnetic field cyclotron frequency and the Coulomb bound potential are taken into consideration by using linear combination operator method. It is found that the vibrational frequency and the ground state binding energy will increase with increasing Coulomb bound potential and the cyclotron frequency. They are decreasing functions of the aspect ratio of the ellipsoid and the transverse effective confinement lengths, whereas the ground state binding energy is an increasing function of the electron-phonon coupling strength.
LOW POWER LOW-PASS FILTER WITH PROGRAMMABLE CUTOFF FREQUENCY BASED ON A TUNABLE UNITY GAIN FREQUENCY OPERATIONAL AMPLIFIER
Authors: MAHMOUD SOLIMAN A.
Published: December 2010

In this paper, a sixth-order reconfigurable low pass filter (LPF) is realized using 0.25 μm TSMC CMOS technology. The filter is based on a cascading connection of bi-quadratic active-Gm-RC cells. The active-Gm-RC cells are realized using compensated op-amps with variable transconductance gain and variable compensation capacitors (variable Gm–Cc op-amp). The tuning range of the filter's cutoff frequency is from 77.4 KHz to 37.78 MHz. The filter operates from a single supply of 1.5 V. Simulations results using PSPICE for the proposed reconfigurable LPF are presented.
FAST ALGORITHM ANALYSIS AND BIT-SERIAL ARCHITECTURE DESIGN FOR SUB-PIXEL MOTION ESTIMATION IN H.264
Authors: FATEMI MOHAMMAD REZA HOSSEINY , ATES HASAN F. , SALLEH ROSLI
Published: December 2010

The sub-pixel motion estimation (SME), together with the interpolation of reference frames, is a computationally extensive part of the H.264 encoder that increases the memory requirement 16-times for each reference frame. Due to the huge computational complexity and memory requirement of the H.264 SME, its hardware architecture design is an important issue especially in high resolution or low power applications. To solve the above difficulties, we propose several optimization techniques in both algorithm and architecture levels. In the algorithm level, we propose a parabolic based algorithm for SME with quarter-pixel accuracy which reduces the computational budget by 94.35% and the memory access requirement by 98.5% in comparison to the standard interpolate and search method. In addition, a fast version of the proposed algorithm is presented that reduces the computational budget 46.28% further while maintaining the video quality. In the architecture level, we propose a novel bit-serial architecture for our algorithm. Due to advantages of the bit-serial architecture, it has a low gate count, high speed operation frequency, low density interconnection, and a reduced number of I/O pins. Also, several optimization techniques including the sum of absolute differences truncation, source sharing exploiting and power saving techniques are applied to the proposed architecture which reduce power consumption and area. Our design can save between 57.71–90.01% of area cost and improves the macroblock (MB) processing speed between 1.7–8.44 times when compared to previous designs. Implementation results show that our design can support real time HD1080 format with 20.3 k gate counts at the operation frequency of 144.9 MHz.
LOW-VOLTAGE DOUBLE-SAMPLED HYBRID CT/DT ΣΔ MODULATOR FOR WIDEBAND APPLICATIONS
Authors: MAGHAMI MOHAMMAD HOSSEIN , YAVARI MOHAMMAD
Published: December 2010

A hybrid continuous-time (CT)/discrete-time (DT) multi-stage noise-shaping (MASH) ΣΔ modulator architecture is presented. The double-sampling technique is employed in the DT second stage modulator. A flat and a unity signal transfer functions (STFs) are used in the first and second stage modulators, respectively, to make the modulator robust to nonlinearities of the analog circuitry and well suited for low-voltage applications without influencing the inherent anti-aliasing behavior of the first stage CT modulator. Unlike the conventional MASH architecture, this structure is insensitive to the amplifier limited DC gain of CT stage and avoids the need of compensation for finite gain-bandwidth induced error in CT loop filter. Behavioral simulations confirm the effectiveness of the proposed scheme over existing cascaded topologies.
HIGH-EFFICIENCY 2-STAGE MULTIPHASE SWITCHED-CAPACITOR CONVERTER VIA VARIABLE-PHASE AND PWM CONTROL
Authors: CHANG YUEN-HAW
Published: December 2010

A closed-loop scheme of 2-stage multiphase switched-capacitor (MPSC) converter is proposed by combining variable-phase control (VPC) and pulse-width-modulation (PWM) technique for low-power DC-DC step-up conversion and high-efficiency output regulation. In this MPSC, there are 2 voltage doublers in series for boosting voltage gain up to 4 at most. Here, VPC is suggested to improve power efficiency, especially for the lower output voltage. It realizes a variable multiphase operation by changing MPSC topological path for more suitable level of voltage gain (4x/3x/2x/1x) according to the desired output. Besides, PWM is adopted for better output regulation not only to compensate dynamic error, but also to reinforce robustness against source/loading variation. Further, the theoretical analysis and design include: MPSC model, steady-state analysis, power efficiency, conversion ratio, ripple percentage, capacitance selection, stability, and control design. Finally, the closed-loop MPSC is simulated, and the hardware implementation is realized and tested. All the results are illustrated to show the efficacy of the proposed scheme.
GENERALIZED ALGORITHMS FOR BINARY MODULO MULTIPLICATION AND MULTIPLICATION-DIVISION
Authors: AMIN ALAAELDIN
Published: December 2010

This paper, describes novel algorithms and circuitry for binary modulo-multiplication and combined multiplication-division. Unlike the commonly used Montgomery modular multiplier, no domain mapping is needed for the input operands or the output result. Further, the new algorithms work for both even and odd moduli. The combined multiplication-division algorithm produces the quotient as well as the remainder thus allowing the implementation of simple multiplier-dividers. The proposed algorithm uses left shift-based multiplication while maintaining the size of the intermediate running product contained by interleaving reduction and multiplication operations. Reduction is determined by examining only the two most significant bits of the running product if Carry-Propagate adders are used or the 3 most significant bits if Carry-Save Adders are used. Hardware implementations of the proposed algorithms show area and delay figures comparable to those of Montgomery.
ARTIFICIAL VISION FOR THE BLIND: A BIO-INSPIRED ALGORITHM FOR OBJECTS AND OBSTACLES DETECTION
Authors: DRAMAS FLORIAN , THORPE SIMON J. , JOUFFRAIS CHRISTOPHE
Published: December 2010

Although artificial vision systems could potentially provide very useful input to assistive devices for blind people, such devices are rarely used outside of laboratory experiments. Many current systems attempt to reproduce the visual image via an alternative sensory modality (often auditory or somatosensory), but this dominant "scoreboard" approach, is often difficult to interpret for the user. Here, we propose to offload the recognition problem onto a separate image processing system that then provides the user with just the essential information about the location of objects in the surrounding environment. Specifically, we show that a bio-inspired image processing algorithm (SpikeNet) can not only robustly, precisely, and rapidly recognize and locate key objects in the image, but also in space if the objects are in a stereoscopic field of view. In addition, the bio-inspired algorithm allows real-time calculation of optic flow. We hence propose that this system, coupled with a restitution interface allowing localization in space (i.e. three-dimensional virtual sounds synthesis) can be used to restore essential visuomotor behaviors such as grasping desired objects and navigating (finding directions, avoiding obstacles) in unknown environments.
OUTDOOR/INDOOR VISION-BASED LOCALIZATION FOR BLIND PEDESTRIAN NAVIGATION ASSISTANCE
Authors: TREUILLET SYLVIE , ROYER ERIC
Published: December 2010

The most challenging issue facing the navigation assistive systems for the visually impaired is the instantaneous and accurate spatial localization of the user. Most of the previously proposed systems are based on global positioning system (GPS) sensors. However, the accuracy of low-cost versions is insufficient for pedestrian use. Furthermore, GPS-based systems are confined to outdoor navigation and experience severe signal losts in urban areas. This paper presents a new approach for localizing a person by using a single-body-mounted camera and computer vision techniques. Instantaneous accurate localization and heading estimates of the person are computed from images as the user progresses along a memorized path. A portable prototype has been tested for outdoor as well as indoor pedestrian use. Experimental results demonstrate the effectiveness of the vision-based localization: the accuracy is sufficient for making it possible to guide and maintain the blind person within a navigation corridor less than 1 m wide along the intended path. In combination with a suitable guiding interface, such a localization system will be convenient to assist the visually impaired in their everyday movements outdoors as well as indoors.
INNOVATION AND RELIABILITY STRATEGIES IN THE DEFENSE, SPACE AND SEMICONDUCTOR INDUSTRIES: A COMPARATIVE ANALYSIS
Authors: DOS SANTOS PAULINO VICTOR , CALLOIS MICHEL
Published: December 2010

The objective of this paper is to understand why the pace of technical change has been slower in the defense and space industries than in semiconductors. To answer this question, we adopt an inductive method that exploits historical facts and patent statistics to provide empirical data. Basing our rationale on the appropriation and structural inertia arguments, we show that the constraints imposed by reliability in the defense and space industries impedes the appropriation of supra profits from innovation and thus slows the pace of technical change. The main managerial implication of this result is that technical inertia contributes to competitive success when the reliability constraint reaches high levels.
ON THE METHODOLOGY FOR QUANTIFYING INNOVATIONS
Authors: RAO BALKRISHNA C.
Published: December 2010

Human ingenuity will play an ever-important role in this century and into the foreseeable future. This is because of phenomena such as globalization and climate-change that stress the need for more innovative output from developed countries. Such a picture has made it necessary to develop reliable models for quantifying innovations. The huge momentum behind the need for quantifying innovations is brought out by the research efforts of the Organization for Economic Cooperation and Development (OECD) and the United-States (US) government, which are at the forefront of the modeling activities required for this task. This effort describes some approaches, and the resulting models, for scoring individual innovations. Most of these approaches quantify innovations by considering their ensuing societal impact. In the course of this process, numerous variables have been identified that might have a significant influence from a scoring perspective. This work is the first portion of a research effort that addresses the theoretical background needed for quantifying innovations. The empirical results will follow up in a later work.
A THEORY OF INNOVATION AND CASE STUDY
Authors: SUH NAM P.
Published: December 2010

Three laws of innovation are advanced as the necessary conditions for creating innovations hubs and innovations. The first law states that for innovation to occur, all the required steps of an innovation continuum must be present. The second law states that an innovation hub can be nucleated if the initial size of the nucleate is larger than the critical size and if the activation energy barrier for nucleation can be overcome. Once the innovation hub is nucleated, heterogeneous nucleation of innovation can occur around the innovation hub. The third law states that for innovation to occur, the nucleation rate of innovation must be faster than the rate at which innovative talent and ideas can diffuse away from the region. This theoretical framework has been proposed as a means of formulating government policies for economic growth and innovation. A case study is presented.
THE ROLE OF PATENT, CITATION AND OBJECTION STOCKS IN THE PRODUCTIVITY ANALYSIS OF R&D — USING JAPANESE COMPANY DATA
Authors: ISHII YASUYUKI
Published: December 2010

In this paper, I examine the role of patent stock, citation stock and objection stock in the analysis of R&D productivity and the exact interrelationships between those stocks by using new data on 100 large Japanese companies. I find, first, that citation and objection stock represent the knowledge stock of the company well, whereas patent stock itself is an ineffective proxy for the knowledge stock. Objection stock seems to be the best proxy for the knowledge stock. Second, citation and objection stocks are effective in playing the role of control factors for successful R&D stock, whereas patent stock is only effective if lags in R&D stock are incorporated. Third, citation and objection stocks are good proxies for controlling for the quality of patent stock. Citation stock seems to be the best variable for controlling for R&D stock and patent stock.
Coherent Control of Terahertz Wave from Coherent Longitudinal Optical Phonon in a GaAs/AlAs Multiple-Quantum-Well Structure
Authors: Mizoguchi Kohji , Kanzawa Yusuke , Oohata Goro , Saito Shingo , Sakai Kiyomi , Nakayama Masaaki
Published: December 2010

We report on the coherent control of terahertz (THz) waves emitted from coherent longitudinal optical (LO) phonons in a GaAs/AlAs multiple-quantum-well structure at room temperature using two-pulse excitation. When the time difference between the first pump pulse and second weak control pulse is increased, the intensity of THz waves from the coherent phonons is cancelled and enhanced by the control pulse, and the phase of THz waves shows periodic changes accompanied by a phase jump. The time-difference dependences of the intensity and phase of THz waves are explained in terms of the superposition of two coherent oscillations.
Energetics of Insect Diapause
Authors: Hahn Daniel A. , Denlinger David L.
Published: December 2010

Managing metabolic resources is critical for insects during diapause when food sources are limited or unavailable. Insects accumulate reserves prior to diapause, and metabolic depression during diapause promotes reserve conservation. Sufficient reserves must be sequestered to both survive the diapause period and enable postdiapause development that may involve metabolically expensive functions such as metamorphosis or long-distance flight. Nutrient utilization during diapause is a dynamic process, and insects appear capable of sensing their energy reserves and using this information to regulate whether to enter diapause and how long to remain in diapause. Overwintering insects on a tight energy budget are likely to be especially vulnerable to increased temperatures associated with climate change. Molecular mechanisms involved in diapause nutrient regulation remain poorly known, but insulin signaling is likely a major player. We also discuss other possible candidates for diapause-associated nutrient regulation including adipokinetic hormone, neuropeptide F, the cGMP-kinase For, and AMPK.
Bemisia tabaci: A Statement of Species Status
Authors: De Barro Paul J. , Liu Shu-Sheng , Boykin Laura M. , Dinsdale Adam B.
Published: December 2010

Bemisia tabaci has long been considered a complex species. It rose to global prominence in the 1980s owing to the global invasion by the commonly named B biotype. Since then, the concomitant eruption of a group of plant viruses known as begomoviruses has created considerable management problems in many countries. However, an enduring set of questions remains: Is B. tabaci a complex species or a species complex, what are Bemisia biotypes, and how did all the genetic variability arise? This review considers these issues and concludes that there is now sufficient evidence to state that B. tabaci is not made up of biotypes and that the use of biotype in this context is erroneous and misleading. Instead, B. tabaci is a complex of 11 well-defined high-level groups containing at least 24 morphologically indistinguishable species.
Arthropod-Borne Diseases Associated with Political and Social Disorder
Authors: Brouqui Philippe
Published: December 2010

The living conditions and the crowded situations of the homeless, war refugees, or victims of a natural disaster provide ideal conditions for the spread of lice, fleas, ticks, flies and mites. The consequence of arthropod infestation in these situations is underestimated. Along with louse-borne infections such as typhus, trench fever, and relapsing fever, the relationship between Acinetobacter spp.–infected lice and bacteremia in the homeless is not clear. Murine typhus, tungiasis, and myiasis are likely underestimated, and there has been a reemergence of bed bugs. Attempted eradication of the body louse, despite specific measures, has been disappointing, and infections with Bartonella quintana continue to be reported. The efficacy of ivermectin in eradicating the human body louse, although the effect is not sustained, might provide new therapeutic approaches. Arthropod-borne diseases continue to emerge within the deprived population. Public health programs should be engaged rapidly to control these pests and reduce the incidence of these transmissible diseases.
Arthropods of Medicoveterinary Importance in Zoos
Authors: Adler Peter H. , Tuten Holly C. , Nelder Mark P.
Published: December 2010

Zoos present a unique assemblage of arthropods, captive vertebrates, free-roaming wildlife, humans, and plants, each with its own biota of symbiotic organisms. Arthropods of medicoveterinary importance are well represented in zoos, and an ample literature documents their influence in these animal-rich environments. Mosquitoes are of greatest significance because of the animal and human pathogens they transmit, followed by ectoparasites, many of which are exotic and present health risks to captive and native animals. Biting flies, cockroaches, filth flies, and triatomid bugs represent additional concerns. Integrated management programs for arthropods in zoos are commonplace. Zoos can play a role in biosurveillance, serving as an advanced guard for detecting exotic arthropods and vector-borne diseases. We provide the first review of arthropods of medicoveterinary importance in zoos. A case is made for the value of collaborations between entomologists and zoo personnel as a means of enhancing research and public education while safeguarding the health of captive animals and the public.
Climate Change and Evolutionary Adaptations at Species' Range Margins
Authors: Hill Jane K. , Griffiths Hannah M. , Thomas Chris D.
Published: December 2010

During recent climate warming, many insect species have shifted their ranges to higher latitudes and altitudes. These expansions mirror those that occurred after the Last Glacial Maximum when species expanded from their ice age refugia. Postglacial range expansions have resulted in clines in genetic diversity across present-day distributions, with a reduction in genetic diversity observed in a wide range of insect taxa as one moves from the historical distribution core to the current range margin. Evolutionary increases in dispersal at expanding range boundaries are commonly observed in virtually all insects that have been studied, suggesting a positive feedback between range expansion and the evolution of traits that accelerate range expansion. The ubiquity of this phenomenon suggests that it is likely to be an important determinant of range changes. A better understanding of the extent and speed of adaptation will be crucial to the responses of biodiversity and ecosystems to climate change.
Insect-Resistant Genetically Modified Rice in China: From Research to Commercialization
Authors: Chen Mao , Shelton Anthony , Ye Gong-yin
Published: December 2010

From the first insect-resistant genetically modified (IRGM) rice transformation in 1989 in China to October 2009 when the Chinese Ministry of Agriculture issued biosafety certificates for commercial production of two cry1Ab/Ac Bacillus thuringiensis (Bt) lines, China made a great leap forward from IRGM rice basic research to potential commercialization of the world's first IRGM rice. Research has been conducted on developing IRGM rice, assessing its environmental and food safety impacts, and evaluating its socioeconomic consequences. Laboratory and field tests have confirmed that these two Bt rice lines can provide effective and economic control of the lepidopteran complex on rice with less risk to the environment than present practices. Commercializing these Bt plants, while developing other GM plants that address the broader complex of insects and other pests, will need to be done within a comprehensive integrated pest management program to ensure the food security of China and the world.
Insect Seminal Fluid Proteins: Identification and Function
Authors: Avila Frank W. , Sirot Laura K. , LaFlamme Brooke A. , Rubinstein C. Dustin , Wolfner Mariana F.
Published: December 2010

Seminal fluid proteins (SFPs) produced in reproductive tract tissues of male insects and transferred to females during mating induce numerous physiological and behavioral postmating changes in females. These changes include decreasing receptivity to remating; affecting sperm storage parameters; increasing egg production; and modulating sperm competition, feeding behaviors, and mating plug formation. In addition, SFPs also have antimicrobial functions and induce expression of antimicrobial peptides in at least some insects. Here, we review recent identification of insect SFPs and discuss the multiple roles these proteins play in the postmating processes of female insects.
Robert F. Denno (1945–2008): Insect Ecologist Extraordinaire
Authors: Eubanks Micky D. , Raupp Michael J. , Finke Deborah L.
Published: December 2010

Robert F. Denno was widely recognized as one of the leading insect ecologists in the world. He made major contributions to the study of plant-insect interactions, dispersal, interspecific competition, predator-prey interactions, and food web dynamics. He was especially well known for his detailed and comprehensive study of the arthropods that inhabit salt marshes. Denno promoted a research approach that included detailed knowledge of the natural history of the study system, meticulous experiments that often pushed logistical possibilities, and a focus on important ecological questions of the day. He was an enthusiastic collaborator and excellent mentor who invested incredible amounts of time and energy in the training and placement of graduate students and postdoctoral associates. As a result, Denno's legacy will continue to shape the field of insect ecology for generations to come.
The Alfalfa Leafcutting Bee,Megachile rotundata: The World's Most Intensively Managed Solitary Bee
Authors: Pitts-Singer Theresa L. , Cane James H.
Published: December 2010

The alfalfa leafcutting bee (ALCB), Megachile rotundata F. (Megachildae), was accidentally introduced into the United States by the 1940s. Nest management of this Eurasian nonsocial pollinator transformed the alfalfa seed industry in North America, tripling seed production. The most common ALCB management practice is the loose cell system, in which cocooned bees are removed from nesting cavities for cleaning and storage. Traits of ALCBs that favored their commercialization include gregarious nesting; use of leaves for lining nests; ready acceptance of affordable, mass-produced nesting materials; alfalfa pollination efficacy; and emergence synchrony with alfalfa bloom. The ALCB became a commercial success because much of its natural history was understood, targeted research was pursued, and producer ingenuity was encouraged. The ALCB presents a model system for commercializing other solitary bees and for advancing new testable hypotheses in diverse biological disciplines.
Salivary Gland Hypertrophy Viruses: A Novel Group of Insect Pathogenic Viruses
Authors: Lietze Verena-Ulrike , Abd-Alla Adly M.M. , Vreysen Marc J.B. , Geden Christopher J. , Boucias Drion G.
Published: December 2010

Salivary gland hypertrophy viruses (SGHVs) are a unique, unclassified group of entomopathogenic, double-stranded DNA viruses that have been reported from three genera of Diptera. These viruses replicate in nuclei of salivary gland cells in adult flies, inducing gland enlargement with little obvious external disease symptoms. Viral infection inhibits reproduction by suppressing vitellogenesis, causing testicular aberrations, and/or disrupting mating behavior. Historical and present research findings support a recent proposal of a new virus family, the Hytrosaviridae. This review describes the discovery and prevalence of different SGHVs, summarizes their biochemical characterization and taxonomy, compares morphological and histopathological properties, and details transmission routes and the influence of infection on host biology and reproduction. In addition, the potential use of SGHVs as sterilizing agents for house fly control and the deleterious impact of SGHVs on colonized tsetse flies reared for sterile insect technique are discussed.
Urticating Hairs in Arthropods: Their Nature and Medical Significance
Authors: Battisti Andrea , Holm Göran , Fagrell Bengt , Larsson Stig
Published: December 2010

The ecological phenomenon of arthropods with defensive hairs is widespread. These urticating hairs can be divided into three categories: true setae, which are detachable hairs in Lepidoptera and in New World tarantula spiders; modified setae, which are stiff hairs in lepidopteran larvae; and spines, which are complex and secretion-filled structures in lepidopteran larvae. This review focuses on the true setae because their high density on a large number of common arthropod species has great implications for human and animal health. Morphology and function, interactions with human tissues, epidemiology, and medical impact, including inflammation and allergy in relation to true setae, are addressed. Because data from epidemiological and other clinical studies are ambiguous with regard to frequencies of setae-caused allergic reactions, other mechanisms for setae-mediated disease are suggested. Finally, we briefly discuss current evidence for the adaptive and ecological significance of true setae.
Visual Cognition in Social Insects
Authors: Avarguès-Weber Aurore , Deisig Nina , Giurfa Martin
Published: December 2010

Visual learning admits different levels of complexity, from the formation of a simple associative link between a visual stimulus and its outcome, to more sophisticated performances, such as object categorization or rules learning, that allow flexible responses beyond simple forms of learning. Not surprisingly, higher-order forms of visual learning have been studied primarily in vertebrates with larger brains, while simple visual learning has been the focus in animals with small brains such as insects. This dichotomy has recently changed as studies on visual learning in social insects have shown that these animals can master extremely sophisticated tasks. Here we review a spectrum of visual learning forms in social insects, from color and pattern learning, visual attention, and top-down image recognition, to interindividual recognition, conditional discrimination, category learning, and rule extraction. We analyze the necessity and sufficiency of simple associations to account for complex visual learning in Hymenoptera and discuss possible neural mechanisms underlying these visual performances.
Spiked Dirichlet Process Priors for Gaussian Process Models
Authors: Savitsky Terrance , Vannucci Marina
Published: December 2010

We expand a framework for Bayesian variable selection for
Gaussian process (GP) models by employing spiked Dirichlet process (DP)
prior constructions over set partitions containing covariates. Our approach
results in a nonparametric treatment of the distribution of the covariance parameters of the GP covariance matrix that in turn induces a clustering of the
covariates. We evaluate two prior constructions: the first one employs a mixture of a point‐mass and a continuous distribution as the centering distribution
for the DP prior, therefore, clustering all covariates. The second one employs a
mixture of a spike and a DP prior with a continuous distribution as the centering distribution, which induces clustering of the selected covariates only. DP
models borrow information across covariates through model‐based clustering.
Our simulation results, in particular, show a reduction in posterior sampling
variability and, in turn, enhanced prediction performances. In our model formulations, we accomplish posterior inference by employing novel combinations and extensions of existing algorithms for inference with DP prior models and
compare performances under the two prior constructions.
Complete Mitochondrial Genome Sequence ofAcrida cinerea(Acrididae: Orthoptera) and Comparative Analysis of Mitochondrial Genomes in Orthoptera
Authors: Liu Nian , Huang Yuan
Published: December 2010

The complete 15,599-bp mitogenome ofAcrida cinereawas determined and compared with that of the other 20 orthopterans. It displays characteristic gene content, genome organization, nucleotide composition, and codon usage found in other Caelifera mitogenomes. Comparison of 21 orthopteran sequences revealed that the tRNAs encoded by the H-strand appear more conserved than those by the L-stand. All tRNAs form the typical clover-leaf structure excepttrnS(agn), and most of the size variation among tRNAs stemmed from the length variation in the arm and loop of TΨC and the loop of DHU. The derived secondary structure models of therrnSandrrnLfrom 21 orthoptera species closely resemble those from other insects on CRW except a considerably enlarged loop of helix 1399 ofrrnSin Caelifera, which is a potentially autapomorphy of Caelifera. In the A+T-rich region, tandem repeats are not only conserved in the closely related mitogenome but also share some conserved motifs in the same subfamily. A stem-loop structure, 16 bp or longer, is likely to be involved in replication initiation in Caelifera and Grylloidea. A long T-stretch (>17 bp) with conserved stem-loop structure next torrnSon the H-strand, bounded by a purine at either end, exists in the three species from Tettigoniidae.
Lymphadenitis as a Rare Side Effect of H1N1 Vaccine in a Child
Authors: Gundogdu Zuhal , Seyhogullari Mualla
Published: December 2010

We present a 5-year-old boy who had the complaint of swelling and pain on the right vaccine shot and right axillary areas. The right axillary area was diagnosed as reactive lymphadenitis, which we believe is a rare local side effect of the swine flu vaccine. The key message to take away from this case is that the patient had lymphadenitis as a local side effect of the swine flu vaccine. Lymphadenitis should be reported as a possible local side effect of the swine flu vaccine.
Positive Solutions to Nonlinear Higher‐Order Nonlocal Boundary Value Problems for Fractional Differential Equations
Authors: Rehman Mujeeb Ur , Ali Khan Rahmat
Published: December 2010

We study existence of positive solutions to nonlinear higher‐order nonlocal
boundary value problems corresponding to fractional differential equation of the type , t ∈ (0, 1), 0 < t < 1. u(1) = βu(η) + λ2, u′(0) = αu′(η) − λ1, u′′(0) = 0, u′′′(0) = 0 ⋯ u(n−1)(0) = 0, where, n − 1 < δ < n, n(≥3) ∈ ℕ, 0 < η, α, β < 1, the boundary parameters λ1, λ2 ∈ ℝ+  and is the Caputo fractional derivative. We use the classical tools from functional analysis to obtain
sufficient conditions for the existence and uniqueness of positive solutions to the boundary value
problems. We also obtain conditions for the nonexistence of positive solutions to the problem. We
include examples to show the applicability of our results.
Resilience Significantly Contributes to Exceptional Longevity
Authors: Zeng Yi , Shen Ke
Published: December 2010

Objective. We aim to investigate whether centenarians are significantly more resilient than younger elders and whether resilience significantly contributes to exceptional longevity.Data. We use a unique dataset from the Chinese Longitudinal Healthy Longevity Survey with the largest sample to date of centenarians, nonagenarians, octogenarians, and a compatible group of young old aged 65–79.Methods and Results. Logistic regressions based on the cross-sectional sample show that after controlling for various confounders, including physical health and cognitive status, centenarians are significantly more resilient than any other old-age group. Logistic regression analyses based on the longitudinal data show that nonagenarians aged 94–98 with better resilience have a 43.1% higher likelihood of becoming a centenarian compared to nonagenarians with lower resilience.Conclusions. Resilience significantly contributes to longevity at all ages, and it becomes even more profound at very advanced ages. These findings indicate that policies and programs to promote resilience would have long-term and positive effects on the well-being and longevity for senior citizens and their families.
Transition Frequencies and Negative Resistance of Inductively Terminated CMOS Buffer Cell and Application in MMW LC VCO
Authors: Hasan S. M. Rezaul
Published: December 2010

This paper investigates the transition frequencies () of an inductively terminated CMOS source follower buffer for negative resistance behavior at which the effective shunt resistance looking into the source of the buffer cell changes sign. Possible limiting frequencies of oscillation are determined based on resonators formed by a grounded gate inductor and a parasitic capacitance at the gate of the negative resistance buffer cell. The range of frequencies of oscillation of this negative resistance buffer cell for variations in the different circuit parameters/elements is explored. Following this, a millimeter wave (MMW) oscillator is simulated using the IBM 130 nm CMOS process technology which can operate at 70 GHz. High-frequency MOSFET model was used for these simulations. The cell had an extremely low power dissipation of under 3 mW. Extensive Monte Carlo simulations were carried out for manufacturability analysis considering up to 50% variation in process and geometrical parameters, supply voltage, and ambient temperature. Noise analysis and a simulated estimate of the phase noise in an MMW LC VCO application is also reported.
Primary Retroperitoneal Paraganglioma Simulating a Pancreatic Mass: A Case Report and Review of the Literature
Authors: Sangster Guillermo , Do Daniel , Previgliano Carlos , Li Benjamin , LaFrance Delecia , Heldmann Maureen
Published: December 2010

Paragangliomas are extra-adrenal tumors of the autonomic nervous system and may be found within the skull base, neck, chest, and abdomen. When presenting within the abdominal cavity, they may arise as a primary retroperitoneal neoplasm and can mimic vascular malformations or other conditions related to specific retroperitoneal organs such as the pancreas, kidneys, or adrenals. Retroperitoneal paragangliomas are mostly benign with good prognosis; however, they can present with abdominal pain, palpable mass, or hypertensive episodes. Patients should be initially evaluated with catecholamine levels, followed by computed tomography or magnetic resonance imaging to locate the primary lesion. Surgical excision remains the mainstay of treatment, although advanced disease and proximity to vital organs can make excision difficult or impossible. This case report describes a patient who initially underwent work up for a suspected pancreatic head mass which was discovered to be a retroperitoneal paraganglioma by frozen section.
Hepatitis C Virus Induces Regulatory T Cells by Naturally Occurring Viral Variants to Suppress T Cell Responses
Authors: Cusick Matthew F. , Schiller Jennifer J. , Gill Joan C. , Eckels David D.
Published: December 2010

Regulatory T cell markers are increased in chronically infected individuals with the hepatitis C virus (HCV), but to date, the induction and maintenance of Tregs in HCV infection has not been clearly defined. In this paper, we demonstrate that naturally occurring viral variants suppress T cell responses to cognate NS3358-375in an antigen-specific manner. Of four archetypal variants, S370P induced regulatory T cell markers in comparison to NS3358-375-stimulated CD4 T cells. Further, the addition of variant-specific CD4 T cells back into a polyclonal culture in a dose-dependent manner inhibited the T cell response. These results suggest that HCV is able to induce antigen-specific regulatory T cells to suppress the antiviral T cell response in an antigen-specific manner, thus contributing to a niche within the host that could be conducive to HCV persistence.
Abstract A104: Involvement of FOXO1 in E2/ER pathway and tamoxifen resistance in MCF-7 cells
Authors: Washington Eleby R. , Sarkissyan Marianna , Sarkissyan Suren , Wu Yanyuan , Vadgama Jay V.
Published: December 2010

Introduction: Estrogen receptor positive breast tumors frequently become resistant to Tamoxifen therapy. Elucidating mechanisms that contribute to resistance are critical for developing therapeutic targets. Previously, we have shown in our lab that FOXO1, a pro-apoptotic transcription factor, plays a role in Trastuzumab resistance, and is inactivated in Her2-overexpressing tumors associated with increased AKT activation. Restoration of FOXO1, both by inhibiting the AKT pathway and by FOXO1 transfection, restored cell-sensitivity to Trastuzumab. Currently, we are exploring whether FOXO1 may play a similar role in resistance to Tamoxifen in ER positive breast cancer cells. We hypothesize that loss of function of FOXO1 may contribute to Tamoxifen resistance and reactivation may restore sensitivity to tamoxifen.

Methods: We have generated two tamoxifen resistant clones and in addition have studied a Tamoxifen resistant clone called MCF-7 TAMR/HER2 (HER2-transfected). tamoxifen resistant clones were generated by passaging wildtype MCF-7 (WT) cells through sphere cultures in the presence of tamoxifen. These clones are termed MCF-7 TAMR7 and MCF-7 TAMR26, representing 7 and 26 passages in sphere culture respectively. Cell line characteristics were assayed by immunohistochemistry (IHC) and RT-Q-PCR. Furthermore, MTT assays were used to test for E2 response in WT and TAMR cells.

Results: Tamoxifen resistance was acquired by utilizing the sphere assay in the presence of Tamoxifen. IHC results revealed a significant loss of ER receptor in TAMR7 and TAMR26 clones. RT-Q-PCR demonstrated 85% loss of ER receptor mRNA in the TAMR7 and TAMR26 compared to WT cells. There was no difference in ER expression in WT and TAMR/HER2 cells. KI67 and CyclinD1 expression were lower in TAMR (TAMR7 and TAMR26) cells compared to WT and TAMR/HER2 cells. TAMR26 cells had lower proliferative response to E2 compared to WT cells. There was increased expression of CK5 in TAMR26 cells. FOXO1 was phosphorylated and located in the cytoplasm of the TAMR cells (TAMR7 and TAMR26) compared to WT and TAMR/HER2 cells.

Conclusions: This study demonstrates that one mechanism of Tamoxifen resistance may be through the loss of the Tamoxifen target, the estrogen receptor (ER). TAMR clones isolated from mammosphere cultures with long term Tamoxifen treatment acquire an ER negative phenotype. These cells demonstrate loss of function of FOXO1. In addition, TAMR cells with high HER2 and normal ER, also acquire Tamoxifen resistance, by mechanisms not clearly understood. Further studies are currently underway in our lab to explore these mechanisms.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A104.
Abstract A13: How do breast imaging centers communicate results: A national survey
Authors: Marcus Erin N. , Koru-Sengul Tulay
Published: December 2010

Background: Effective communication of mammogram results is important as a step toward reducing patient anxiety and diagnostic delay. Research suggests, however, that many women do not correctly understand their results. The purpose of this study is to describe current communication practices among a nationally representative sample of mammography centers.

Methods: A 35-question anonymous online survey was sent to members of the National Consortium of Breast Centers (NCBC), an association of more than 2000 physicians, nurses, administrators, radiology technicians, and others involved in breast care. Those involved in mammography were invited to participate. The survey was also distributed at the NCBC's annual meeting. It asked about centers’ verbal, written, and telephone communication with patients, whether they employ patient navigators and staff with fluency in languages other than English, and whether and how they contact patients who do not follow up. Descriptive statistics were calculated for all responses. Additional analysis to assess the association of demographic variables with responses is ongoing.

Results: 221 centers completed the questionnaire. 34% were affiliated with a private radiology practice, 26% were academically affiliated, and 16% were free-standing centers. Nearly half of the centers indicated that more than a quarter of their patients lacked insurance and/or relied on government programs such as Medicaid. Ten percent of the centers indicated that more than a quarter of their patients lacked English proficiency.

Ten percent of the respondents indicated that they rarely inform patients of their results at the time of their mammogram; 17% indicated that they inform patients all or most of the time; 35% indicated that the result letters they send are English only; and 12% indicated that they do not have multilingual staff or translators available to answer questions. 22% of the centers indicated that they use patient navigators. 16% of respondents indicated that they do not routinely telephone any patients about results. Chi-square analysis to detect associations between variables is ongoing.

Conclusions and Implications: Our sample included a diverse cross-section of mammogram centers, many of which serve low-income patients. More than one in three centers indicated that they do not send result letters in languages other than English, which is concerning given the increasing number of patients with limited English proficiency in the U.S. and past research indicating many women do not understand their result. One in five centers use patient navigators, however, which may help ensure appropriate follow up among patients who lack easy access to healthcare. Informing patients of their results at the time of their test may also be a step more centers could take to enhance patient understanding and reduce anxiety.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A13.
Abstract A14: Qualitative study of African American smokers regarding lung cancer
Authors: Lathan Christopher , Browning Emily , Gagne Joshua
Published: December 2010

Background: The differences in mortality and incidence for lung cancer in African Americans are well-documented; however, the underlying reasons for these disparities are not well-delineated. The role that patient preferences and knowledge play in exploring these patterns among African American patients is unclear. This qualitative study was designed to explore potential themes involving treatment, and assess the level of general knowledge about lung cancer in African Americans.

Methods: 32 African American smokers with ages ranging from 26 to 70 years of age, (mean, 47.5 years), who did not have a cancer diagnosis were recruited to a series of focus groups held in a Boston housing complex. Four focus groups were held over an 8-week period. The groups were evenly divided between men and women. Focus groups were facilitated by a trained qualitative researcher and the sessions were audio taped. The data was transcribed and analyzed using standard anthropology coding and thematic formulation processes.

Results: Participants understood the link between smoking and lung cancer, as well as the common signs and symptoms of the disease. Regarding prevention, participants wanted the information to be in-depth, and tailored to their situation. They were familiar with the lethality of lung cancer, and had a good working knowledge of the treatment modalities. The impact of patient preferences and mistrust on treatment choice was minimal. When asked specifically about the role of race in getting appropriate treatment for lung cancer; most participants felt that insurance and socioeconomic factors were more important than race.

Conclusions: This study suggests that African American smokers are informed about the link between smoking and lung cancer, and have a good working knowledge of the disease. Participants did not feel that their race prevented them from accessing high-quality cancer care, but were concerned about the effect of socioeconomic status and insurance on this process. Our study suggests that African Americans are interested in access to quality cancer treatment and information, and that patient preferences and mistrust of clinicians may not be major factors in lung cancer treatment disparities.

Citation Information: Cancer Epidemiol Biomarkers Prev 2010;19(10 Suppl):A14.