bluuebunny/crossref_metadata_2025 huggingface dataset:
Relation Between the Dynamics of the Reduced Purity and Correlations
Authors: Kimura Gen , Ohno Hiromichi , Mosonyi Milán
Published: September 2010

General property of the relation between the dynamics of reduced purity and correlations in quantum mechanical systems is investigated. We show that a non-zero time-derivative of the reduced purity of a system implies the existence of non-zero correlations with its environment for any unbounded Hamiltonian with finite variance. This shows the impact of local dynamical information on the correlations, as well as the role of correlations in the mechanism of purity change.
Thermalization of Random Motion in Weakly Confining Potentials
Authors: Garbaczewski Piotr , Stephanovich Vladimir
Published: September 2010

We show that in weakly confining conservative force fields, a subclass of diffusion-type (Smoluchowski) processes, admits a family of "heavy-tailed" non-Gaussian equilibrium probability density functions (pdfs), with none or a finite number of moments. These pdfs, in the standard Gibbs-Boltzmann form, can also be inferred directly from an extremum principle, set for Shannon entropy under a constraint that the mean value of the force potential has been a priori prescribed. That enforces the corresponding Lagrange multiplier to play the role of inverse temperature. Weak confining properties of the potentials are manifested in a thermodynamical peculiarity that thermal equilibria can be approached only in a bounded temperature interval 0 ≤ T < T max = 2ϵ0/kB, where ϵ0 sets an energy scale. For T ≥ T max no equilibrium pdf exists.
A buried Palaeoproterozoic spreading ridge in the northern Nagssugtoqidian orogen, West Greenland
Authors: Garde Adam A. , Hollis Julie A.
Published: September 2010

Ophiolitic rocks on two small island groups in the northern Nagssugtoqidian orogen, West Greenland, shed new light on the eastern Laurentian Palaeoproterozoic plate-tectonic collage. The islands expose amphibolite-facies (520–550 °C, 2.6–3.0 kbar) tholeiitic pillow lava, black chloritic shale, manganiferous banded iron formation (BIF), podded chert, jasper, graded andalusite–staurolite schist with numerous sills, and terrigenous sandstone, an association that occurs today in oceanic spreading zones undergoing burial in forearc trenches. Deformation is weak, with upright folds preserving original younging. U–Pb detrital zircon ages indicate derivation from Archaean, 1890 Ma, and 1850 Ma sources. Occurring north of the Archaean Aasiaat domain that partly escaped Nagssugtoqidian deformation, the sequence pinpoints a new SSE-dipping Palaeoproterozoic subduction zone that links up in the NE with the Disko Bugt suture at the Nagssugtoqidian–Rinkian boundary. This solves an enigma of the previous plate-tectonic model, in which the Arfersiorfik magmatic arc in the central Nagssugtoqidian orogen was located within its own suture zone, and helps to explain why the Nagssugtoqidian–Rinkian system is so broad. It also explains previously recognized geochemical and Pb-isotopic compositional breaks in orthogneisses in the Kangaatsiaq region, and greatly simplifies correlation with adjacent eastern Canadian orogens in Baffin Island and Labrador.
Tectonic setting and structural evolution of the Late Cenozoic Gobi Altai orogen
Authors: Cunningham Dickson
Published: September 2010

The Gobi Altai is an intraplate, intracontinental transpressional orogen in southern Mongolia that formed in the Late Cenozoic as a distant response to the Indo-Eurasia collision. The modern range formed within crust constructed by successive terrane accretion and ocean suturing events and widespread granite plutonism throughout the Palaeozoic. Modern reactivation of the Gobi Altai crust and the kinematics of Quaternary faults are fundamentally controlled by Palaeozoic basement structural trends, the location of rigid Precambrian blocks, orientation of SH
max
and possible thermal weakening of the lower crust as a result of an extensive history of Mesozoic–Cenozoic basaltic volcanism in the region, and the presence of thermally elevated asthenosphere under the Hangay Dome to the north. Modern mountain building processes in the Gobi Altai typically involve reactivation of NW–SE-striking basement structures in thrust mode and development of linking east–west left-lateral strike-slip faults that crosscut basement structures within an overall left-lateral transpressional regime. Restraining bends, other transpressional ridges and thrust basement blocks are the main range type, but are discontinuously distributed and separated by internally drained basins filling with modern alluvial deposits. Unlike a contractional thrust belt, there is no orogenic foreland or hinterland, and thrusts are both NE and SW directed with no evidence for a basal décollement. Normal faults related to widespread Cretaceous rifting in the region appear to be unfavourably oriented for Late Cenozoic reactivation despite widespread topographic inversion of Cretaceous basin sequences. Because the Gobi Altai is an actively developing youthful mountain range in an arid region with low erosion rates, it provides an excellent opportunity to study the way in which a continental interior reactivates as a result a distant continental collision. In addition, it offers important insights into how other more advanced intracontinental transpressional orogens may have developed during earlier stages of their evolution.
Transitions among Mariana-, Japan-, Cordillera- and Alaska-type arc systems and their final juxtapositions leading to accretionary and collisional orogenesis
Authors: Xiao Wenjiao , Han Chunming , Yuan Chao , Sun Min , Zhao Guochun , Shan Yehua
Published: September 2010

‘Arc system’ is used here as a collective term for a variety of arcs that occur along continental margins or in oceanic plates; it includes associated units from adjacent plates. Four major arc systems (Mariana-, Japan-, Cordillera- and Alaska-type) can be distinguished along the Circum-Pacific region. Some Japan-type arc systems in ancient orogens (e.g. the Altaids) may have been largely regarded as microcontinents because they have so-called Precambrian basement. Often the Cordillera-type arc systems can be very complicated, and if they are rifted away from the host continent they become more difficult to recognize. Commonly these arc systems interact mutually and with continental marginal sequences, leading to complicated accretionary and collisional orogens. The alternation between Western Pacific archipelagos and the Eastern Pacific active margin is the stereotype of accretionary and collisional orogenesis. More importantly, these four main types of arc systems can be juxtaposed into a final orogenic collage, which is another main expression of accretionary orogenesis. Only some parts of accretionary and collisional orogens can be terminated by attachment of a continent-size craton such as Tarim or even India, and even so the accretionary and collisional processes may continue elsewhere along strike. The significance of the interactions among these arc systems and their final juxtaposition has not been fully appreciated in ancient orogens. The Altaids together with the Circum-Pacific orogens offers a good opportunity to study such accretionary–collisional orogenesis.
The role of geochronology in understanding continental evolution
Authors: Kröner Alfred
Published: September 2010

Geochronology has become one of the most essential tools in reconstructing processes of continental growth and evolution, andin situdating of minerals has become common practice through the development of high-resolution ion microprobes and laser ablation inductively coupled plasma mass spectrometry techniques. Zircon has established itself as the most robust and reliable mineral to record magmatic and metamorphic processes. The combination of mineral ages with Sm–Nd, Lu–Hf and O isotopic systematics constrains magma sources and their evolution, and a picture is emerging that supports the beginning of modern-style plate tectonics in the early Archaean. Major fields for future research in geochronology include the search for very old crustal remnants, the establishment of Precambrian supercontinents, reconstruction of magmatic and tectonic processes in accretionary orogens, verification of ancient high-pressure rocks, and the reconstruction of detailed metamorphic histories by dating minerals in their original textural settings.
Computing Tutte Polynomials
Authors: Haggard Gary , Pearce David J. , Royle Gordon
Published: September 2010

The Tutte polynomial of a graph, also known as the partition function of the
q
-state Potts model is a 2-variable polynomial graph invariant of considerable importance in both combinatorics and statistical physics. It contains several other polynomial invariants, such as the chromatic polynomial and flow polynomial as partial evaluations, and various numerical invariants such as the number of spanning trees as complete evaluations. However despite its ubiquity, there are no widely available effective computational tools able to compute the Tutte polynomial of a general graph of reasonable size. In this article we describe the implementation of a program that exploits isomorphisms in the computation tree to extend the range of graphs for which it is feasible to compute their Tutte polynomials, and we demonstrate the utility of the program by finding counterexamples to a conjecture of Welsh on the location of the real flow roots of a graph.
A Code Based on the Two-Stage Runge-Kutta Gauss Formula for Second-Order Initial Value Problems
Authors: González-Pinto Severiano , Rojas-Bello Rogel
Published: September 2010

A code based on the two-stage Gauss formula (order four) for second-order initial value problems of a special type is developed. This code can be used to obtain a low- to medium-precision integration for a wide range of problems in the class of oscillatory type, Hamiltonian problems, and time-dependent partial differential equations discretized in space by finite differences or finite elements. The iteration process used in solving for the stage values of the Gauss formula, the selection of the initial step size, and the choice of an appropriate local error estimator for determining the step size change according to a particular tolerance specified by the user are studied. Moreover, a global error estimate and a dense output at equidistant points in the integration interval are supplied with the code. Numerical experiments and some comparisons with certain standard codes on relevant test problems are also given.
Parallel Colt
Authors: Wendykier Piotr , Nagy James G.
Published: September 2010

Major breakthroughs in chip and software design have been observed for the last nine years. In October 2001, IBM released the world’s first multicore processor: POWER4. Six years later, in February 2007, NVIDIA made a public release of CUDA SDK, a set of development tools to write algorithms for execution on Graphic Processing Units (GPUs). Although software vendors have started working on parallelizing their products, the vast majority of existing code is still sequential and does not effectively utilize modern multicore CPUs and manycore GPUs.

This article describes Parallel Colt, a multithreaded Java library for scientific computing and image processing. In addition to describing the design and functionality of Parallel Colt, a comparison to MATLAB is presented. Two ImageJ plugins for iterative image deblurring and motion correction of PET brain images are described as typical applications of this library. Performance comparisons with MATLAB, including GPU computations via AccelerEyes’ Jacket toolbox are also given.
Algorithm 904
Authors: Granat Robert , Kågström Bo
Published: September 2010

We continue our presentation of parallel ScaLAPACK-style algorithms for solving Sylvester-type matrix equations. In Part II, we present SCASY (SCAlable SYlvester solvers), a state-of-the-art HPC software library for solving 44 sign and transpose variants of eight common standard and generalized Sylvester-type matrix equations.
Algorithm 908
Authors: Zhu Yong-Kang , Hayes Wayne B.
Published: September 2010

We present a novel, online algorithm for exact summation of a stream of floating-point numbers. By “online” we mean that the algorithm needs to see only one input at a time, and can take an arbitrary length input stream of such inputs while requiring only constant memory. By “exact” we mean that the sum of the internal array of our algorithm is exactly equal to the sum of all the inputs, and the returned result is the correctly-rounded sum. The proof of correctness is valid for all inputs (including nonnormalized numbers but modulo intermediate overflow), and is independent of the number of summands or the condition number of the sum. The algorithm asymptotically needs only 5 FLOPs per summand, and due to instruction-level parallelism runs only about 2--3 times slower than the obvious, fast-but-dumb “ordinary recursive summation” loop when the number of summands is greater than 10,000. Thus, to our knowledge, it is the fastest, most accurate, and most memory efficient among known algorithms. Indeed, it is difficult to see how a faster algorithm or one requiring significantly fewer FLOPs could exist without hardware improvements. An application for a large number of summands is provided.
Adaptivity and self-organization in organic computing systems
Authors: Schmeck Hartmut , Müller-Schloer Christian , Çakar Emre , Mnif Moez , Richter Urban
Published: September 2010

Organic Computing (OC) and other research initiatives like Autonomic Computing or Proactive Computing have developed the vision of systems possessing life-like properties: they self-organize, adapt to their dynamically changing environments, and establish other so-called self-x properties, like self-healing, self-configuration, self-optimization, etc. What we are searching for in OC are methodologies and concepts for systems that allow to cope with increasingly complex networked application systems by introduction of self-x properties and at the same time guarantee a trustworthy and adaptive response to externally provided system objectives and control actions. Therefore, in OC, we talk about
controlled self-organization
.

Although the terms
self-organization
and
adaptivity
have been discussed for years, we miss a clear definition of self-organization in most publications, which have a technically motivated background.

In this article, we briefly summarize the state of the art and suggest a characterization of (controlled) self-organization and adaptivity that is motivated by the main objectives of the OC initiative. We present a system classification of robust, adaptable, and adaptive systems and define a degree of autonomy to be able to quantify how autonomously a system is working. The degree of autonomy distinguishes and measures external control that is exerted directly by the user (
no autonomy
) from internal control of a system which might be fully controlled by an observer/controller architecture that is part of the system (
full autonomy
). The quantitative degree of autonomy provides the basis for characterizing the notion of controlled self-organization. Furthermore, we discuss several alternatives for the design of organic systems.
Empowered by wireless communication
Authors: Fekete Sándor P. , Schmidt Christiane , Wegener Axel , Hellbrück Horst , Fischer Stefan
Published: September 2010

In recent years, tremendous progress has been made in understanding the dynamics of vehicle traffic flow and traffic congestion by interpreting traffic as a multiparticle system. This helps to explain the onset and persistence of many undesired phenomena, for example, traffic jams. It also reflects the apparent helplessness of drivers in traffic, who feel like passive particles that are pushed around by exterior forces; one of the crucial aspects is the inability to communicate and coordinate with other traffic participants.

We present distributed methods for solving these fundamental problems, employing modern wireless, ad-hoc, multi-hop networks. The underlying idea is to use these capabilities as the basis for self-organizing methods for coordinating data collection and processing, recognizing traffic phenomena, and changing their structure by coordinated behavior. The overall objective is a multi-level approach that reaches from protocols for local wireless communication, data dissemination, pattern recognition, over hierarchical structuring and coordinated behavior, all the way to large-scale traffic regulation.

In this article, we describe three types of results: (i) self-organizing and distributed methods for maintaining and collecting data (using our concept of
Hovering Data Clouds
); (ii) adaptive data dissemination for traffic information systems; (iii) methods for self-recognition of traffic jams. We conclude by describing higher-level aspects of our work.
Parsimonious rule generation for a nature-inspired approach to self-assembly
Authors: Grushin Alexander , Reggia James A.
Published: September 2010

Most construction of artificial, multicomponent structures is based upon an external entity that directs the assembly process, usually following a script/blueprint under centralized control. In contrast, recent research has focused increasingly on an alternative paradigm, inspired largely by the nest building behavior of social insects, in which components “self-assemble” into a given target structure. Adapting such a nature-inspired approach to precisely self-assemble artificial structures (bridge, building, etc.) presents a formidable challenge: one must create a set of local control rules to direct the behavior of the individual components/agents during the self-assembly process. In recent work, we developed a fully automated procedure that generates such rules, allowing a given structure to successfully self-assemble in a simulated environment having constrained, continuous motion; however, the resulting rule sets were typically quite large. In this article, we present a more effective methodology for automatic rule generation, which makes an attempt to parsimoniously capture both the repeating patterns that exist within a structure, and the behaviors necessary for appropriate coordination. We then empirically show that the procedure developed here generates sets of rules that are not only correct, but significantly reduced in size, relative to our earlier approach. Such rule sets allow for simpler agents that are nonetheless still capable of performing complex tasks, and therefore demonstrate the problem-solving potential of self-organized systems.
Understanding latent sector errors and how to protect against them
Authors: Schroeder Bianca , Damouras Sotirios , Gill Phillipa
Published: September 2010

Latent sector errors (LSEs) refer to the situation where particular sectors on a drive become inaccessible. LSEs are a critical factor in data reliability, since a single LSE can lead to data loss when encountered during RAID reconstruction after a disk failure or in systems without redundancy. LSEs happen at a significant rate in the field [Bairavasundaram et al. 2007], and are expected to grow more frequent with new drive technologies and increasing drive capacities. While two approaches, data scrubbing and intra-disk redundancy, have been proposed to reduce data loss due to LSEs, none of these approaches has been evaluated on real field data.

This article makes two contributions. We provide an extended statistical analysis of latent sector errors in the field, specifically from the view point of how to protect against LSEs. In addition to providing interesting insights into LSEs, we hope the results (including parameters for models we fit to the data) will help researchers and practitioners without access to data in driving their simulations or analysis of LSEs. Our second contribution is an evaluation of five different scrubbing policies and five different intra-disk redundancy schemes and their potential in protecting against LSEs. Our study includes schemes and policies that have been suggested before, but have never been evaluated on field data, as well as new policies that we propose based on our analysis of LSEs in the field.
Membrane
Authors: Sundararaman Swaminathan , Subramanian Sriram , Rajimwale Abhishek , Arpaci-Dusseau Andrea C. , Arpaci-Dusseau Remzi H. , Swift Michael M.
Published: September 2010

We introduce Membrane, a set of changes to the operating system to support restartable file systems. Membrane allows an operating system to tolerate a broad class of file system failures, and does so while remaining transparent to running applications; upon failure, the file system restarts, its state is restored, and pending application requests are serviced as if no failure had occurred. Membrane provides transparent recovery through a lightweight logging and checkpoint infrastructure, and includes novel techniques to improve performance and correctness of its fault-anticipation and recovery machinery. We tested Membrane with ext2, ext3, and VFAT. Through experimentation, we show that Membrane induces little performance overhead and can tolerate a wide range of file system crashes. More critically, Membrane does so with little or no change to existing file systems, thus improving robustness to crashes without mandating intrusive changes to existing file-system code.
quFiles
Authors: Veeraraghavan Kaushik , Flinn Jason , Nightingale Edmund B. , Noble Brian
Published: September 2010

A quFile is a unifying abstraction that simplifies data management by encapsulating different physical representations of the same logical data. Similar to a quBit (quantum bit), the particular representation of the logical data displayed by a quFile is not determined until the moment it is needed. The representation returned by a quFile is specified by a data-specific policy that can take context into account such as the application requesting the data, the device on which data is accessed, screen size, and battery status. We demonstrate the generality of the quFile abstraction by using it to implement six case studies: resource management, copy-on-write versioning, data redaction, resource-aware directories, application-aware adaptation, and platform-specific encoding. Most quFile policies were expressed using less than one hundred lines of code. Our experimental results show that, with caching and other performance optimizations, quFiles add less than 1% overhead to application-level file system.
An Automated Flow for Arithmetic Component Generation in Field-Programmable Gate Arrays
Authors: Smith Alastair M. , Constantinides George A. , Cheung Peter Y. K.
Published: September 2010

State-of-the-art configurable logic platforms, such as Field-Programmable Gate Arrays (FPGAs), consist of a heterogeneous mixture of different component types. Compared to traditional homogeneous configurable platforms, heterogeneity provides speed and density advantages. This is due to the replacement of inefficient programmable logic and routing with specialized logic and fixed interconnect in components such as memories, embedded processor units, and fused arithmetic units. Given the increasing complexity of these components, this article introduces a method to automatically propose and explore the benefits of different types of fused arithmetic units. The methods are based on common subgraph extraction techniques, meaning that it is possible to explore different subcircuits that occur frequently across a set of benchmarks. A quantitative analysis is performed of the various fused arithmetic circuits identified by our tool, which are then automatically synthesized to an ASIC process, providing a study of the speed and area benefits of the components. The results of this study provide bounds on the performance of heterogeneous FPGAs: by incorporating coarse-grain components which match the specific needs of a set of benchmarks we show that significant improvements in circuit speed and area can be made.
VFloat
Authors: Wang Xiaojun , Leeser Miriam
Published: September 2010

Optimal reconfigurable hardware implementations may require the use of arbitrary floating-point formats that do not necessarily conform to IEEE specified sizes. We present a variable precision floating-point library (VFloat) that supports general floating-point formats including IEEE standard formats. Most previously published floating-point formats for use with reconfigurable hardware are subsets of our format. Custom datapaths with optimal bitwidths for each operation can be built using the variable precision hardware modules in the VFloat library, enabling a higher level of parallelism. The VFloat library includes three types of hardware modules for format control, arithmetic operations, and conversions between fixed-point and floating-point formats. The format conversions allow for hybrid fixed- and floating-point operations in a single design. This gives the designer control over a large number of design possibilities including format as well as number range within the same application. In this article, we give an overview of the components in the VFloat library and demonstrate their use in an implementation of the K-means clustering algorithm applied to multispectral satellite images.
What is ECO for high-level synthesis?
Authors: Lavagno Luciano
Published: September 2010

Functional verification at the Register Transfer Level is quite often the most time and resource consuming step of the entire design flow of a digital integrated circuit. For this reason, designers are moving towards high-level design methods in which they explore different algorithmic approaches, change memory organization, and modify area, power and performance constraints, in order to delimit the trade-off space and select points worthy of deeper investigation. During these phases, functional verifications are carried out continuously using fast simulation models in C, C++ or SystemC, in order to ensure that the design is correct with respect to its specifications. The result is a "golden" RTL specification that becomes very expensive to modify once the following logical and physical design steps have started, because executing functional verification is very time consuming. Moreover, any significant changes to the logic circuit are extremely risky, since the physical design steps may no longer satisfy performance constraints, and lengthy iterations are required to properly re-constrain the implementation.
What is graphene?
Authors: Murali Raghunath , Meindl James D.
Published: September 2010

Graphene is a 2D material with a honeycomb lattice structure made of sp2 bonded carbon atoms. Graphene is essentially the mother of all graphitic materials - it can be formed into buckyballs and nanotubes, etched into nanoribbons, or stacked into bulk graphite. The properties of graphene that have researchers excited [1-2] include its excellent mobility[4-5,8], long mean free path, high thermal conductivity [9], high mechanical strength, high surface area to volume ratio, width-dependent bandgap [3,6], and high current carrying capacity [17]. Most of these properties are also true for carbon nanotubes (CNTs); however, graphene also has the advantage over CNTs . if graphene can be produced as a single two-dimensional sheet, it allows for easy patterning and can be integrated into the processes used in silicon integrated circuit manufacturing. As a truly 2D material, graphene has been of theoretical significance for more than 60 years. The discovery of graphene isolated from graphite in 2004 [1] proved that a 2D material such as graphene can exist in a flat state on a substrate rather than curl up as previously thought.
What are corners?
Authors: Nassif Sani
Published: September 2010

Corners. No, not those places under your desk that collect all that dust. "Process Corners"... Those mythical parameter settings that are supposed to define some unknown measure of variability in a semiconductor manufacturing process. What are those corners? What does "Fast/Fast" really mean? How can one interpret the results of simulation using those corner parameters?
Nutritional Labeling and Consumer Choices
Authors: Kiesel Kristin , McCluskey Jill J. , Villas-Boas Sofia B.
Published: September 2010

In 1994, nutritional facts panels became mandatory for processed foods to improve consumer access to nutritional information and to promote healthy food choices. Recent applied work is reviewed here in terms of how consumers value and respond to nutritional labels. We first summarize the health and nutritional links found in the literature and frame this discussion in terms of the obesity policy debate. Second, we discuss several approaches that have been used to empirically investigate consumer responses to nutritional labels: (a) surveys, (b) nonexperimental approaches utilizing revealed preferences, and (c) experiment-based approaches. We conclude with a discussion and suggest avenues of future research.
Commodity Booms and Busts
Authors: Carter Colin A. , Rausser Gordon C. , Smith Aaron
Published: September 2010

Periodically, the global economy experiences great commodity booms and busts, characterized by a broad and sharp comovement of commodity prices. There have been two such episodes since the Korean War. The first event peaked in 1974 and the second in 2008, 34 years apart. Both created major economic and political shocks, including fallen governments and human suffering due to high food prices. Each occurrence raised serious concerns over food and energy security and led to more government intervention in the commodity markets. Although there is no simple explanation for what causes such complex events, they do share similar characteristics. We find at the core of these cycles a set of contemporaneous supply and demand surprises that coincided with low inventories and that were magnified by macroeconomic shocks and policy responses. In the next few decades, the world faces the prospect of continued increases in the demand for commodities and greater uncertainty about supply. However, because market participants are likely to respond by increasing inventory holdings and investing in new technologies, we see no reason to expect an increase in the frequency of dramatic commodity booms and busts.
The Economics of the Food System Revolution
Authors: Reardon Thomas , Timmer C. Peter
Published: September 2010

A revolution in food systems—food supply chains upstream from farms, to the food industry in the midstream segments of processing and wholesale and in the downstream segment of retail, then on to consumers—has been under way in the United States for more than a century and in developing countries for more than three decades. The transformation includes extensive consolidation, very rapid institutional and organizational change, and progressive modernization of the procurement system. In this article we examine the economics of these system-wide changes. We argue that the steps of conceptualizing and empirically researching this transformation—its patterns and trends, determinants, and impacts on farms and processing small and micro enterprises—are still in their infancy because of (a) remaining limitations on data suitable for formal modeling and hypothesis testing and (b) the sheer complexity of food system–related decisions that need to be modeled and understood. With the rapid accumulation of high-quality data now under way, conceptual and theoretical progress is also likely to be rapid.
A critical appraisal of the prevalence and metabolic significance of brown adipose tissue in adult humans
Authors: Lee Paul , Greenfield Jerry R. , Ho Ken K. Y. , Fulham Michael J.
Published: September 2010

Brown adipose tissue (BAT) plays a major role in energy homeostasis in animals. Detection of BAT using positron emission tomography (PET)-CT in humans has challenged the view that BAT disappears after infancy. Several recent studies, based on analysis of single scans, have reported a low prevalence of only 5–10% in humans, casting doubt on its significance. We undertook a critical analysis of the sensitivity, reproducibility, and accuracy of PET-CT to deduce the prevalence of BAT and factors associated with its detection in adult humans. In a retrospective evaluation of PET-CT, using [18F]fluorodeoxyglucose, performed in 2,934 patients, BAT was identified in 250 patients, yielding an apparent prevalence of 8.5%. Among those patients with BAT, 145 were scanned more than once. The frequency of another scan being positive increased from 8 to 65% for one to more than four additional studies. The average probability of obtaining another positive scan among patients with BAT is 13%, from which the prevalence of BAT is estimated at 64%. BAT was more commonly detected in women, in younger (36 ± 1 vs. 52 ± 1 years, P < 0.001) and leaner (20.1 ± 0.9 vs. 24.9 ± 0.9 kg/m2, P < 0.01) individuals. Fasting glucose was lower in those with BAT than those without (4.9 ± 0.1 vs. 5.5 ± 0.1 mmol/l, P < 0.01). Among patients scanned more than once, BAT was detected when body weight and fasting glucose were lower (54.9 ± 0.5 vs. 58.2 ± 0.8 kg, P < 0.001 and 4.9 ± 0.3 vs. 5.5 ± 0.3 mmol/l, P = 0.03). We conclude that BAT is present in the majority of adult humans. Presence of BAT correlates negatively with body mass index and glucose concentration. BAT may play an important role in energy homeostasis in adults.
Artificial Neural Network‐Based System for PET Volume Segmentation
Authors: Sharif Mhd Saeed , Abbod Maysam , Amira Abbes , Zaidi Habib
Published: September 2010

Tumour detection, classification, and quantification in positron emission tomography (PET) imaging at early stage of disease are important issues for clinical diagnosis, assessment of response to treatment, and radiotherapy planning. Many techniques have been proposed for segmenting medical imaging data; however, some of the approaches have poor performance, large inaccuracy, and require substantial computation time for analysing large medical volumes. Artificial intelligence (AI) approaches can provide improved accuracy and save decent amount of time. Artificial neural networks (ANNs), as one of the best AI techniques, have the capability to classify and quantify precisely lesions and model the clinical evaluation for a specific problem. This paper presents a novel application of ANNs in the wavelet domain for PET volume segmentation. ANN performance evaluation using different training algorithms in both spatial and wavelet domains with a different number of neurons in the hidden layer is also presented. The best number of neurons in the hidden layer is determined according to the experimental results, which is also stated Levenberg‐Marquardt backpropagation training algorithm as the best training approach for the proposed application. The proposed intelligent system results are compared with those obtained using conventional techniques including thresholding and clustering based approaches. Experimental and Monte Carlo simulated PET phantom data sets and clinical PET volumes of nonsmall cell lung cancer patients were utilised to validate the proposed algorithm which has demonstrated promising results.
Transport Phenomena of Solid Particles in Pulsatile Pipe Flow
Authors: Fujimoto Hitoshi , Kubo Masahiro , Hama Takayuki , Takuda Hirohiko
Published: September 2010

The transportation mechanism of single solid particles in pulsating water flow in a vertical pipe was investigated by means of videography and numerical simulations. The trajectories of alumina particles were observed experimentally by stereo videography. The particle diameter was 3 mm or 5 mm, and the pipe diameter was 18 mm or 22 mm. The frequency of flow pulsation was less than or equal to 6.67 Hz. It was found that the critical minimum water flux at which the particle can be transported upward depended on the pulsating pattern. Two types of numerical simulations were conducted, namely, one-dimensional simulations for tracking the vertical motion of the solid particles and two-dimensional simulations of the pulsating pipe flows in an axisymmetric coordinate system. The computer simulations of axisymmetric pipe flows revealed that the time-averaged radial velocity profile of water in the pulsating flows was very different from that in steady pipe flows. The motion of the particles is discussed in detail for a better understanding of the physics of the transport phenomena.
Nanoporous Calcium Silicate and PLGA Biocomposite for Bone Repair
Authors: Su Jiacan , Wang Zhiwei , Yan Yonggang , Wu Yongfa , Cao Liehu , Ma Yuhai , Yu Baoqing , Li Ming
Published: September 2010

Nanoporous calcium silicate (n‐CS) with high surface area was synthesized using the mixed surfactants of EO20PO70EO20 (polyethylene oxide) 20(polypropylene oxide) 70(polyethylene oxide) 20, P123) and hexadecyltrimethyl ammonium bromide (CTAB) as templates, and its composite with poly(lactic acid‐co‐glycolic acid) (PLGA) were fabricated. The results showed that the n‐CS/PLGA composite (n‐CPC) with 20 wt% n‐CS could induce a dense and continuous layer of apatite on its surface after soaking in simulated body fluid (SBF) for 1 week, suggesting the excellent in vitro bioactivity. The n‐CPC could promote cell attachment on its surfaces. In addition, the proliferation ratio of MG63 cells on n‐CPC was significantly higher than PLGA; the results demonstrated that n‐CPC had excellent cytocompatibility. We prepared n‐CPC scaffolds that contained open and interconnected macropores ranging in size from 200 to 500 μm. The n‐CPC scaffolds were implanted in femur bone defect of rabbits, and the in vivo biocompatibility and osteogenicity of the scaffolds were investigated. The results indicated that n‐CPC scaffolds exhibited good biocompatibility, degradability, and osteogenesis in vivo. Collectively, these results suggested that the incorporation of n‐CS in PLGA produced biocomposites with improved bioactivity and biocompatibility.
Self-Reported Low Vitality, Poor Mental Health, and Low Dietary Restraint Are Associated with Overperception of Physical Exertion
Authors: Chandler-Laney Paula C. , Brock David W. , Gower Barbara A. , Alvarez Jessica A. , Bush Nikki C. , Hunter Gary R.
Published: September 2010

Objective. We investigated whether perceived exertion, in comparison to the physiological response to exercise, was associated with self-reported vitality, mental health, and physical function during daily activities, or weight control behaviors.Design. Weight-reduced, formerly overweight women (n=126, aged 22–46 years), completed health and dietary control questionnaires, and underwent a treadmill-walking task while heart rate, ventilation, respiratory exchange ratio, and ratings of perceived exertion were recorded.Results. Overperception of exertion (perceived exertion physiological exertion) was inversely associated with vitality (r=−0.190,P<.05), mental health (r=−0.188,P<.05), and dietary control (rvalues range−0.231to−0.317,P<.05). In linear regression modeling, vitality or mental health, and cognitive dietary restraint were independently associated with accuracy of perceived exertion, independent of age, ethnicity, and engagement in exercise during weight loss. Each model explained 7%-8% of the variance in accuracy of perceived exertion.Conclusion. Women with low vitality or poor mental health, and poor dietary control may overperceive exertion. Such overperception may be a barrier to engage in physical activity and thus increase susceptibility to weight gain.
Electromagnetic Topology Analysis to Coupling Wires Enclosed in Cavities with Apertures
Authors: Li Ying , Luo Jianshu , Ni Guyan , Shi Jiyuan
Published: September 2010

We use both electromagnetic topology (EMT) and the Baum‐Liu‐Tesche (BLT) equation to analyze a cavity model with an aperture. More precisely, we combine the aperture coupling theory and EMT to study the issues of the electromagnetic field penetration
through apertures into a cavity and the coupling to a two‐wire transmission line in it. We employ the equivalence principle to establish the equivalent source on the aperture. Then, we obtain the semi analytic solutions of the load response of the two‐wire line in the cavity based on the Baum‐Liu‐Tesche (BLT) equation. In addition, based on the Agrawal model, we give the coupling current distribution at two loads for a two‐wire line in the cavity. Finally, we present some numerical results to demonstrate the semi‐analytic approach of this paper. In fact, these numerical results on the electric field shielding (EFS) of a rectangular cavity with an aperture agree well with the experimental results in the literature. Furthermore, for a two‐wire line in the cavity with an aperture the induced current peaks at loads are observed in the frequency range, some of which are associated with the resonance of the aperture, and others
correspond to the resonant frequencies of the cavity.
Glucocorticoid‐Induced TNFR‐Related (GITR) Protein and Its Ligand in Antitumor Immunity: Functional Role and Therapeutic Modulation
Authors: Placke Theresa , Kopp Hans-Georg , Salih Helmut Rainer
Published: September 2010

The ability of the tumor necrosis factor receptor (TNFR) family member GITR to modulate immune responses has been the subject of multiple studies. Initially thought to be critically involved in governing functions of regulatory T cells, GITR and its ligand GITRL have meanwhile been found to modulate the reactivity of various different cell types and to influence a broad variety of immunological conditions including the immune response against tumors. Not only GITR, but also GITRL is capable of transducing signals, and the consequences of GITR‐GITRL interaction may vary among different effector cell types, differ upon signal transduction via the receptor, the ligand, or both, depend on the level of an ongoing immune response, and even differ among mice and men. In this paper, we address available data on GITR and its ligand in immune responses and discuss the role and potential therapeutic modulation of this molecule system in antitumor immunity.
𝒩‐Subalgebras in BCK/BCI‐Algebras Based on Point 𝒩‐Structures
Authors: Jun Young Bae , Kang Min Su , Park Chul Hwan
Published: September 2010

The notion of 𝒩‐subalgebras of several types is introduced, and related properties
are investigated. Conditions for an 𝒩‐structure to be an 𝒩‐subalgebra of type (q, ∈⋁ q) are provided, and a characterization of an 𝒩‐subalgebra of type (∈, ∈⋁ q) is considered.
‘‘Two-Week Waits’’—Are They Leading to Earlier Diagnosis of Soft-Tissue Sarcomas?
Authors: Taylor W. St. J. , Grimer R. J. , Carter S. R. , Tillman R. M. , Abudu A. , Jeys L.
Published: September 2010

Introduction. The ‘‘two-week wait’’ was established as a potential means of diagnosing malignant tumours earlier. This paper investigated whether these clinics are leading to earlier diagnosis of malignant soft-tissue lumps.Method. We identified all referrals to our centre from a database over a 4-year period.Results. 2225 patients were referred to our unit for investigation of a soft-tissue mass. 576 (26%) were referred under the ‘‘two-week wait’’ criteria. 153 (27%) of which were found to have a malignant or borderline malignant diagnosis. 1649 patients were referred nonurgently. 855 (52%) of which were diagnosed with a malignant or borderline lesion. The average size at diagnosis was 9.4 cm with no difference in size between the different referral routes.Conclusion. There is little evidence that the two-week wait clinic is leading to earlier diagnosis of soft-tissue sarcomas with the majority still being referred nonurgently.
Eye Movement Impairment Recovery in a Gaucher Patient Treated with Miglustat
Authors: Accardo Agostino , Pensiero Stefano , Ciana Giovanni , Parentin Fulvio , Bembi Bruno
Published: September 2010

In Gaucher Disease (GD) the enzyme (imiglucerase) replacement therapy (ERT) is not able to stop the progression of the neurological involvement, while the substrate reduction therapy (SRT), performed by N-Butyldeoxynojirimycin (miglustat), is an alternative that should be evaluated. Two sisters, presenting the same genotype (R353G/R353G), were diagnosed as suffering from GD; one of them later developed neurological alterations identified by quantitative saccadic eye movements analysis. The aim of the study was to quantitatively measure the miglustat effects in this GD neurological patient. Eye movement analysis during subsequent controls was performed by estimating the characteristic parameters of saccadic main sequence. The study demonstrates that the SRT alone can be effective in GD3. Moreover, it confirms that quantitative eye movement analysis is able to precociously identify also slight neurological alterations, permitting more accurate GD classification.
Soil Test Phosphorus Recovery from Livestock Manures Compared with Inorganic Fertilizer in Soil Incubations
Authors: Miller J. Craig , Astatkie T. , Madani Ali
Published: September 2010

This paper compared dairy and hen manure P recovery relative to fertilizer P recovery for two Nova Scotia soils with different antecedent soil test P (STP), incubated for 5, 15, 30, 60, and 110 days. Fertilizer equivalence of manure P was expressed as P recovery ratio in percentage points (%PRR). Repeated measures analysis with soil pH covariate revealed: (1) manure %PRR averaged 72% (low-STP soil) and 80% (medium-STP soil), (2) there were no significant differences in %PRR between dairy and hen manure, and (3) manure %PRR decreased with incubation time for the low-STP soil but not for the medium-STP soil. The soil pH covariate was significant for both low- and medium-STP soils, and the relationship with %PRR was positive for low- but not for the medium-STP soil.
Viscosity Approximation to Common Fixed Points of Families of Nonexpansive Mappings with Weakly Contractive Mappings
Authors: Razani A , Homaeipour S
Published: September 2010

Let X be a reflexive Banach space which has a weakly sequentially continuous duality mapping. In this paper, we consider the following viscosity approximation sequence "Equation missing", where "Equation missing""Equation missing" (0, 1), "Equation missing" is a uniformly asymptotically regular sequence, and f is a weakly contractive mapping. Strong convergence of the sequence "Equation missing" is proved.
Yeasts Occurring in Surface and Mouth Cavity of Two Chelonian Species,Podocnemis expansaSchweigger andP. unifilisTroschel (Reptilia: Chelonia: Pelomedusidae), in the Javaés River Border of Araguaia National Park in Brazil
Authors: Morais Paula Benevides de , Pimenta Raphael Sanzio , Tavares Inara Brito , de Garcia Virginia , Rosa Carlos Augusto
Published: September 2010

Thirty-eight specimens of free-rangingPodocnemis expansa(Amazon turtle) and 22 ofP. unifilis(Tracajá) were screened for yeast isolation from surface (plastron, skin, and nails), eye, and mouth cavity. A hundred and eighteen yeast isolates belonging to 39 species were obtained.Debaryomyces hansenii,Candida galli,C. sake, andRhodotorula mucilaginosawere the most frequent species isolated from these chelonians. Species diversity measured by Shannon's index was shown to be low and a degree of dominance could be detected as species known as potential pathogens were commonly isolated. The effective number of species in plastron ofP. expansawas higher than in mouth samples, but not inP. unifilisprobably due to dietary factors.P. expansaanimals were captured on the beaches, and the superficial yeast populations may include terrestrial species.P. unifilisanimals were captured in the water and the yeasts from superficial sites may represent species from river water.
Mean Square Exponential Stability of Stochastic Cohen‐Grossberg Neural Networks with Unbounded Distributed Delays
Authors: Huang Chuangxia , Huang Lehua , He Yigang
Published: September 2010

This paper addresses the issue of mean square
exponential stability of stochastic Cohen‐Grossberg neural
networks (SCGNN), whose state variables are described by
stochastic nonlinear integrodifferential equations. With the
help of Lyapunov function, stochastic analysis technique, and
inequality techniques, some novel sufficient conditions on mean
square exponential stability for SCGNN are given. Furthermore,
we also establish some sufficient conditions for checking
exponential stability for Cohen‐Grossberg neural networks with
unbounded distributed delays.