bluuebunny/crossref_metadata_2025 huggingface dataset:
The Relationship of Three Cortical Regions to an Information-Processing Model
Authors: Anderson John R. , Qin Yulin , Stenger V. Andrew , Carter Cameron S.
Published: May 2004

This research tests a model of the computational role of three cortical regions in tasks like algebra equation solving. The model assumes that there is a left parietal region-of-interest (ROI) where the problem expression is represented and transformed, a left prefrontal ROI where information for solving the task is retrieved, and a motor ROI where hand movements to produce the answer are programmed. A functional magnetic resonance imaging (fMRI) study of an abstract symbolmanipulation task was performed to articulate the roles of these three regions. Participants learned to associate words with instructions for transforming strings of letters. The study manipulated the need to retrieve these instructions, the need to transform the strings, and whether there was a delay between calculation of the answer and the output of the answer. As predicted, the left parietal ROI mainly reflected the need for a transformation and the left prefrontal ROI the need for retrieval. Homologous right ROIs showed similar but weaker responses. Neither the prefrontal nor the parietal ROIs responded to delay, but the motor ROI did respond to delay, implying motor rehearsal over the delay. Except for the motor ROI, these patterns of activity did not vary with response hand. In an ACT-R model, it was shown that the activity of an imaginal buffer predicted the blood oxygen level-dependent (BOLD) response of the parietal ROI, the activity of a retrieval buffer predicted the response of the prefrontal ROI, and the activity of a manual buffer predicted the response of the motor ROI.
The Hippocampal System Mediates Logical Reasoning about Familiar Spatial Environments
Authors: Goel Vinod , Makale Milan , Grafman Jordan
Published: May 2004

It has recently been shown that syllogistic reasoning engages two dissociable neural systems. Reasoning about familiar situations engages a frontal-temporal lobe system, whereas formally identical reasoning tasks involving unfamiliar situations recruit a frontal-parietal visuospatial network. These two systems may correspond to the “heuristic” and “formal” methods, respectively, postulated by cognitive theory. To determine if this dissociation generalizes to reasoning about transitive spatial relations, we studied 14 volunteers using event-related fMRI, as they reasoned about landmarks in familiar and unfamiliar environments. Our main finding is a task (reasoning and baseline) by spatial content (familiar and unfamiliar) interaction. Modulation of reasoning toward unfamiliar landmarks resulted in bilateral activation of superior and inferior parietal lobules (BA 7, 40), dorsal superior frontal cortex (BA 6), and right superior and middle frontal gyri (BA 8), regions widely implicated in visuospatial processing. By contrast, modulation of the reasoning task toward familiar landmarks, engaged the right inferior/orbital frontal gyrus (BA 11/47), bilateral occipital (BA 18, 19), and temporal lobes. The temporal lobe activation included the right inferior temporal gyrus (BA 37), posterior hippocampus, and parahippocampal gyrus, regions implicated in spatial memory and navigation tasks. These results provide support for the generalization of dual mechanism theory to transitive reasoning and highlight the importance of the hippocampal system in reasoning about familiar spatial environments.
Attention to 3-D Shape, 3-D Motion, and Texture in 3-D Structure from Motion Displays
Authors: Peuskens Hendrik , Claeys Kristl G. , Todd James T. , Norman J. Farley , Hecke Paul Van , Orban Guy A.
Published: May 2004

We used fMRI to directly compare the neural substrates of three-dimensional (3-D) shape and motion processing for realistic textured objects rotating in depth. Subjects made judgments about several different attributes of these objects, including 3-D shape, the 3-D motion, and the scale of surface texture. For all of these tasks, we equated visual input, motor output, and task difficulty, and we controlled for differences in spatial attention. Judgments about 3-D shape from motion involve both parietal and occipito-temporal regions. The processing of 3-D shape is associated with the analysis of 3-D motion in parietal regions and the analysis of surface texture in occipito-temporal regions, which is consistent with the different behavioral roles that are typically attributed to the dorsal and ventral processing streams.
“What” and “Where” in Visual Working Memory: A Computational Neurodynamical Perspective for Integrating fMRI and Single-Neuron Data
Authors: Deco Gustavo , Rolls Edmund T. , Horwitz Barry
Published: May 2004

Single-neuron recordings, functional magnetic resonance imaging (fMRI) data, and the effects of lesions indicate that the prefrontal cortex (PFC) is involved in some types of working memory and related cognitive processes. Based on these data, two different models of the topographical and functional organization of the PFC have been proposed: organization-by-stimulus-domain, and organization-by-process. In this article, we utilize an integrate-and-fire network to model both single-neuron and fMRI data on short-term memory in order to understand data obtained in topologically different parts of the PFC during working memory tasks. We explicitly model the mechanisms that underlie workingmemory-related activity during the execution of delay tasks that have a “what”-then-“where” design (with both object and spatial delayed responses within the same trial). The model contains different populations of neurons (as found experimentally) in attractor networks that respond in the delay period to the stimulus object, the stimulus position, and to combinations of both object and position information. The pools are arranged hierarchically and have global inhibition through inhibitory interneurons to implement competition. It is shown that a biasing attentional input to define the current relevant information (object or location) enables the system to select the correct neuronal populations during the delay period in what is a biased competition model of attention. The processes occurring at the AMPA and NMDA synapses are dynamically modeled in the integrate-and-fire implementation to produce realistic spiking dynamics. It is shown that the fMRI data characteristic of the dorsal PFC and linked to spatial processing and manipulation of items can be reproduced in the model by a high level of inhibition, whereas the fMRI data characteristic of the ventral PFC and linked to object processing can be produced by a lower level of inhibition, even though the network is itself topographically homogeneous with no spatial topology of the neurons. This article, thus, not only presents a model for how spatial versus object short-term memory could be implemented in the PFC, but also shows that the fMRI BOLD signal measured during such tasks from different parts of the PFC could reflect a higher level of inhibition dorsally, without this dorsal region necessarily being primarily spatial and the ventral region object-related.
An fMRI Study of Syntactic Adaptation
Authors: Noppeney U. , Price C. J.
Published: May 2004

It is easier to produce and comprehend a series of sentences when they have similar syntactic structures. This “syntactic priming” effect was investigated during silent sentence reading using (i) blood oxygenation level-dependent (BOLD) response as a physiological measure in an f MRI study and (ii) reading time as a behavioral measure in a complementary selfpaced reading paradigm. We found that reading time and left anterior temporal activation were decreased when subjects read sentences with similar relative to dissimilar syntactic forms. Thus, syntactic adaptation during sentence comprehension is demonstrated in a neural area that has previously been linked to both lexical semantic and sentence processing.
Bayesian Estimation of Stimulus Responses in Poisson Spike Trains
Authors: Lehky Sidney R.
Published: May 2004

A Bayesian method is developed for estimating neural responses to stimuli, using likelihood functions incorporating the assumption that spike trains follow either pure Poisson statistics or Poisson statistics with a refractory period. The Bayesian and standard estimates of the mean and variance of responses are similar and asymptotically converge as the size of the data sample increases. However, the Bayesian estimate of the variance of the variance is much lower. This allows the Bayesian method to provide more precise interval estimates of responses. Sensitivity of the Bayesian method to the Poisson assumption was tested by conducting simulations perturbing the Poisson spike trains with noise. This did not affect Bayesian estimates of mean and variance to a significant degree, indicating that the Bayesian method is robust. The Bayesian estimates were less affected by the presence of noise than estimates provided by the standard method.
Comments on “A Parallel Mixture of SVMs for Very Large Scale Problems”
Authors: Liu Xiaomei , Hall Lawrence O. , Bowyer Kevin W.
Published: May 2004

Collobert, Bengio, and Bengio (2002) recently introduced a novel approach to using a neural network to provide a class prediction from an ensemble of support vector machines (SVMs). This approach has the advantage that the required computation scales well to very large data sets. Experiments on the Forest Cover data set show that this parallel mixture is more accurate than a single SVM, with 90.72% accuracy reported on an independent test set. Although this accuracy is impressive, their article does not consider alternative types of classifiers. We show that a simple ensemble of decision trees results in a higher accuracy, 94.75%, and is computationally efficient. This result is somewhat surprising and illustrates the general value of experimental comparisons using different types of classifiers.
Automated Algorithms for Multiscale Morphometry of Neuronal Dendrites
Authors: Weaver Christina M. , Hof Patrick R. , Wearne Susan L. , Lindquist W. Brent
Published: May 2004

We describe the synthesis of automated neuron branching morphology and spine detection algorithms to provide multiscale three-dimensional morphological analysis of neurons. The resulting software is applied to the analysis of a high-resolution (0.098 μm × 0.098 μm × 0.081 μ m) image of an entire pyramidal neuron from layer III of the superior temporal cortex in rhesus macaque monkey. The approach provides a highly automated, complete morphological analysis of the entire neuron; each dendritic branch segment is characterized by several parameters, including branch order, length, and radius as a function of distance along the branch, as well as by the locations, lengths, shape classification (e.g., mushroom, stubby, thin), and density distribution of spines on the branch. Results for this automated analysis are compared to published results obtained by other computer-assisted manual means.
Information Geometry of U-Boost and Bregman Divergence
Authors: Murata Noboru , Takenouchi Takashi , Kanamori Takafumi , Eguchi Shinto
Published: May 2004

We aim at an extension of AdaBoost to U-Boost, in the paradigm to build a stronger classification machine from a set of weak learning machines. A geometric understanding of the Bregman divergence defined by a generic convex function U leads to the U-Boost method in the framework of information geometry extended to the space of the finite measures over a label set. We propose two versions of U-Boost learning algorithms by taking account of whether the domain is restricted to the space of probability functions. In the sequential step, we observe that the two adjacent and the initial classifiers are associated with a right triangle in the scale via the Bregman divergence, called the Pythagorean relation. This leads to a mild convergence property of the U-Boost algorithm as seen in the expectation-maximization algorithm. Statistical discussions for consistency and robustness elucidate the properties of the U-Boost methods based on a stochastic assumption for training data.
A New Approach to the Extraction of ANN Rules and to Their Generalization Capacity Through GP
Authors: Rabuñal Juan R. , Dorado Julián , Pazos Alejandro , Pereira Javier , Rivero Daniel
Published: May 2004

Various techniques for the extraction of ANN rules have been used, but most of them have focused on certain types of networks and their training. There are very few methods that deal with ANN rule extraction as systems that are independent of their architecture, training, and internal distribution of weights, connections, and activation functions. This article proposes a methodology for the extraction of ANN rules, regardless of their architecture, and based on genetic programming. The strategy is based on the previous algorithm and aims at achieving the generalization capacity that is characteristic of ANNs by means of symbolic rules that are understandable to human beings.
A Classification Paradigm for Distributed Vertically Partitioned Data
Authors: Basak Jayanta , Kothari Ravi
Published: May 2004

In general, pattern classification algorithms assume that all the features are available during the construction of a classifier and its subsequent use. In many practical situations, data are recorded in different servers that are geographically apart, and each server observes features of local interest. The underlying infrastructure and other logistics (such as access control) in many cases do not permit continual synchronization. Each server thus has a partial view of the data in the sense that feature subsets (not necessarily disjoint) are available at each server. In this article, we present a classification algorithm for this distributed vertically partitioned data.

We assume that local classifiers can be constructed based on the local partial views of the data available at each server. These local classifiers can be any one of the many standard classifiers (e.g., neuralnetworks, decision tree, k nearest neighbor). Often these local classifiers are constructed to support decision making at each location, and our focus is not on these individual local classifiers. Rather, our focus is constructing a classifier that can use these local classifiers to achieve an error rate that is as close as possible to that of a classifier having access to the entire feature set. We empirically demonstrate the efficacy of the proposed algorithm and also provide theoretical results quantifying the loss that results as compared to the situation where the entire feature set is available to any single classifier.
“Where's My Parade?”: Margaret Cho and the Asian American Body in Space
Authors: Lee Rachel C.
Published: May 2004

Margaret Cho rose to fame as the star of the first television sitcom to feature an all Asian American cast. Her one-woman show, I'm the One That I Want, recounts that disastrous experience, as it also maps American culture as a series of segregated spaces. Lee's article explores Cho's construction of her bodily excesses—her dirty vagina, collapsed bladder, inability to be decidable as either gay or straight—and theorizes these bodily tactics in terms of a spatial rather than temporal dialectic.
Display of Holistic Haptic Sensations by Combined Tactile and Kinesthetic Feedback
Authors: Kammermeier Peter , Kron Alexander , Hoogen Jens , Schmidt Günther
Published: May 2004

This article presents conceptual as well as experimental work toward the display of holistic haptic sensations in telepresence and virtual environment applications. (In this context holistic is understood in the sense of “not neglecting an essential component.”) In contrast to most existing developments, the presented haptic humansystem interface is a combination of dedicated subsystems for both kinesthetic and tactile display. With respect to the mechanical coupling of both subsystems, we propose two basic approaches. One is based on a parallel kinematic system setup and forms the conceptual basis of a multifingered experimental feedback device generating vibrotactile, thermal, and wrist/finger kinesthetic stimuli. Another is to demonstrate the potential to reduce the design complexity of tactile display subsystems in haptic human-system interfaces with a serial kinematic structure. For verification purposes, a tactile actuator array providing spatially distributed tactile shape display on a single fingertip has been combined with a single-fingered kinesthetic display. Each of the investigated combined haptic systems features significant functional advances compared to existing developments. The usability of our systems has been demonstrated in haptic exploration and object identification experiments in virtual environments.
A Study on Visual, Auditory, and Haptic Feedback for Assembly Tasks
Authors: Petzold Bernd , Zaeh Michael F. , Faerber Berthold , Deml Barbara , Egermeier Hans , Schilp Johannes , Clarke Stella
Published: May 2004

Telepresent tasks involve removal of the human operator from an immediate working area and relocation to a remote environment that offers the operator all necessary control features. In this remote location, the operator must be provided with adequate feedback information such that the task at hand can be effectively executed. This research explores the effectiveness of various feedback methods. More specifically, graphical feedback in the form of video streamed images is compared against rendered 3D models, the overall effectiveness of haptic feedback is analyzed, and the influences of sensory augmentation and sensory substitution are examined. This study involved 48 participants, each of whom executed a simple clockwork assembly task under various feedback mechanisms. The results support the use of 3D models as opposed to live video streams for graphical presentation, utilization of haptic feedback (which was found to significantly enhance operation effectiveness), and the use of sensory augmentation and substitution under specific circumstances.
A Photorealistic Predictive Display
Authors: Burkert Tim , Leupold Jan , Passig Georg
Published: May 2004

The quality of a teleoperation system is decreased by time delays in the communication channel. Delays as low as a few hundred milliseconds between commanding an action and getting the visual feedback reduce the operator's performance. Predictive displays have proven their suitability to compensate for these delays, but at the expense of image quality when using computer-generated images. A photorealistic predictive display is presented that closes the feedback loop locally at the operator's side of a telepresence system. Photorealism is achieved using delayed camera images for texturing the predicted scene. Consumer graphics hardware is not only used for rendering but also for hardware-accelerated texture extraction. To allow concurrent access to model data, a multibuffer model structure is presented. A model of the teleoperator's environment is automatically acquired and updated by image processing techniques using a stereo camera as the only sensor.
Motion Compression for Telepresent Walking in Large Target Environments
Authors: Nitzsche Norbert , Hanebeck Uwe D. , Schmidt Günther
Published: May 2004

Telepresent walking allows visits to remote places such as museums, exhibitions, architecture, or industrial sites with a high degree of realism. While walking freely around in the user environment, the user sees the remote environment through the “eyes” of a remote mobile teleoperator. For that purpose, the user's motion is tracked and transferred to the teleoperator. Without additional processing of the motion data, the size of the remote environment to be explored is limited to the size of the user environment. This paper proposes an extension of telepresent walking to arbitrarily large remote or virtual spaces based on compressing wide-area motion into the available user space. Motion compression is a novel approach and does not make use of scaling or walking-in-place metaphors. Rather, motion compression introduces some deviation of curvature between user motion and teleoperator motion. An optimization approach is used to find the user path of minimum curvature deviation with respect to a given predicted teleoperator path that fits inside the boundaries of the user environment. Turning angles and travel distan ces are mapped with a 1:1 ratio to provide the desired impression of realistic selflocomotion in the teleoperator's environment. The effects of the curvature deviation on inconsistent perception of locomotion are studied in two experiments.
A Product‐Nonspecific Framework for Evaluating the Potential of Biomass‐Based Products to Displace Fossil Fuels
Authors: Lynd Lee R. , Wang Michael Q.
Published: May 2004

The use of biomass as a raw material for production of fuels and commodity chemicals is attracting increasing attention motivated by the possibility of positive contributions to a sustainable resource supply, enhanced national security, and macroeconomic benefits for rural communities and society at large. Fossil fuel displacement exclusive of product recovery can be estimated for biological processing of biomass in the absence of product‐specific information other than the product yield and whether fermentation is aerobic or anaerobic. Based on this observation, a framework is proposed for estimating fossil fuel displacement on a per‐unit‐product or per‐unit‐biomass basis. Use of a per‐unit‐biomass basis offers somewhat different insights as compared to a per‐unit‐product basis and appears particularly appropriate for consideration of the efficacy of resource or land use. Using the proposed framework, the following feedstock and process factors are shown to be particularly important in determining the extent of fossil fuel displacement via biological processes: feedstock (corn or cellulosic) and, for corn, harvest mode (e.g., with or without stover recovery); biological conversion (aerobic or anaerobic); product yield; and the energy requirements for product recovery. When all of these factors are favorable, as in the case of the cellulosic ethanol scenario examined, significant fossil fuel displacement can be achieved. When all of these factors are unfavorable, as in the case of a scenario involving polyhydroxyalkanoate (PHA) production from corn without stover recovery, no net displacement is achieved. The proposed framework provides a means to screen processes with respect to potential for fossil fuel displacement in the absence of product‐specific information, to gain general insights into feedstock and process features important in determining the extent to which fossil displacement is realized, and to rapidly incorporate product‐specific information into a preexisting evaluative rubric.
Surfactants Based on Renewable Raw Materials
Authors: Patel Martin
Published: May 2004

Under the European Commission's European Climate Change Programme, a group of experts studied the possibilities of using more renewable raw materials as chemical feedstock and assessed the related potential for greenhouse gas (GHG) emission reduction. Surfactants were among the products studied. Surfactants are currently produced from both petro‐chemical feedstocks and renewable resources (oleochemical surfactants). Assuming, in a first step, that total surfactant production in the European Union remains constant until 2010, it was estimated that the amount of oleochemical surfactants could be increased from about 880 kilotons (kt) in 1998 to approximately 1, 100 kt in 2010 (an increase of 24%). This substitution reduces the life‐cycle CO2emissions from surfactants by 8%; the theoretical maximum potential for total substitution is 37%. Because the surfactant market is expected to grow, the avoided emissions will probably exceed 8% of the current life‐cycle CO2emissions from surfactants. If compared to the CO2emissions from the total industrial sector and, even more so, if compared to the total economy, the relative savings are much lower (0.02% to 0.09%). This leads to the conclusion that the increased production and use of biobased surfactants should be part of an overall GHG emission reduction strategy consisting of a whole range of measures addressing both energy demand and supply. This article also discusses policies and measures designed to increase the use of biobased surfactants.
Making Plastics from Garbage
Authors: Sakai Kenji , Taniguchi Masayuki , Miura Shigenobu , Ohara Hitomi , Matsumoto Toru , Shirai Yoshihito
Published: May 2004

We propose a novel recycling system for municipal food waste that combines fermentation and chemical processes to produce high‐quality poly‐L‐lactate (PLLA) biodegradable plastics. The process consists of removal of endogenous D, L‐lactic acid from minced food waste by a propionibacterium, L‐lactic acid fermentation under semisolid conditions, L‐lactic acid purification via butyl esterification, and L‐lactic acid polymerization via LL‐lactide. The total design of the process enables a high yield of PLLA with high optical activity (i.e., a high proportion of optical isomers) and novel recycling of all materials produced at each step, with energy savings and minimal emissions. Approximately 50% of the total carbon was removed, mostly as L‐lactic acid, and 100 kg of collected food waste yielded 7.0 kg PLLA (about 34% of the total carbon). The physical properties of the PLLA yielded in this manner were comparable to those of PLLA generated from commercially available. L‐lactic acid. Evaluation of the process is also discussed from the viewpoints of material and energy balances and environmental impact.
Using Life‐Cycle Assessment in Process Design
Authors: Gasafi Edgar , Meyer Lutz , Schebek Liselotte
Published: May 2004

This article presents the application of life‐cycle assessment in early phases of process design in the context of technology that employs a bio‐based material. The goal is to identify hot spots in the process chains with regard to environmental impacts by performing a dominance analysis. By focusing his activities on the hot spots identified, the designer is given the opportunity to efficiently improve environmental performance. This approach is illustrated for the case of supercritical water gasification, a novel technology for the treatment of organic feedstock with high moisture content. In the reactor under supercritical conditions, organic components are converted into a high‐caloric synthesis gas, with hydrogen, methane, and carbon dioxide as the main products. The data used for the assessment are obtained from laboratory tests and the literature, completed by assumptions for missing data. The scope of assessment ranges from the extraction of raw materials to the product, that is, hydrogen (cradle to gate) with sewage sludge of a municipal wastewater treatment plant used as feedstock. The assessment identifies the main sources of environmental impacts. The predominant process step in terms of global warming potential is the supply of the gasification process with additional heat. The production of a blending agent in the dewatering step is the main source of the impact category of acidification, whereas the wastewater treatment plant is the origin of emissions that lead to eutrophication. The revealed sources are analyzed further and options for reducing the environmental impacts are discussed.
Energy and Environmental Aspects of Using Corn Stover for Fuel Ethanol
Authors: Sheehan John , Aden Andy , Paustian Keith , Killian Kendrick , Brenner John , Walsh Marie , Nelson Richard
Published: May 2004

Corn stover is the residue that is left behind after corn grain harvest. We have constructed a life‐cycle model that describes collecting corn stover in the state of Iowa, in the Midwest of the United States, for the production and use of a fuel mixture consisting of 85% ethanol/15% gasoline (known as “E85”) in a flexible‐fuel light‐duty vehicle. The model incorporates results from individual models for soil carbon dynamics, soil erosion, agronomics of stover collection and transport, and biocon‐version of stover to ethanol.

Limitations in available data forced us to focus on a scenario that assumes all farmers in the state of Iowa switch from their current cropping and tilling practices to continuous production of corn and “no‐till” practices. Under these conditions, which maximize the amount of collectible stover, Iowa alone could produce almost 8 billion liters per year of pure stover‐derived ethanol (E100) at prices competitive with today's corn‐starch‐derived fuel ethanol. Soil organic matter, an important indicator of soil health, drops slightly in the early years of stover collection but remains stable over the 90‐year time frame studied. Soil erosion is controlled at levels within tolerable soil‐loss limits established for each county in Iowa by the U.S. Department of Agriculture.

We find that, for each kilometer fueled by the ethanol portion of E85, the vehicle uses 95% less petroleum compared to a kilometer driven in the same vehicle on gasoline. Total fossil energy use (coal, oil, and natural gas) and greenhouse gas emissions (fossil CO2, N2O, and CH4) on a life‐cycle basis are 102% and 113% lower, respectively. Air quality impacts are mixed, with emissions of CO, NOx, and SOx increasing, whereas hydrocarbon ozone precursors are reduced.

This model can serve as a platform for future discussion and analysis of possible scenarios for the sustainable production of transportation fuels from corn stover and other agricultural residues.
Cumulative Energy and Global Warming Impact from the Production of Biomass for Biobased Products
Authors: Kim Seungdo , Dale Bruce E.
Published: May 2004

The cumulative energy and global warming impacts associated with producing corn, soybeans, alfalfa, and switchgrass and transporting these crops to a central crop processing facility (called a “biorefinery”) are estimated. The agricultural inputs for each crop are collected from seven states in the United States: Illinois, Indiana, Iowa, Michigan, Minnesota, Ohio, and Wisconsin. The cumulative energy requirement for producing and transporting these crops is 1.99 to 2.66 megajoules/kilo‐gram (MJ/kg) for corn, 1.98 to 2.04 MJ/kg for soybeans, 1.24 MJ/kg for alfalfa, and 0.97 to 1.34 MJ/kg for switchgrass. The global warming impact associated with producing biomass is 246 to 286 grams (g) CO2 equivalent/kg for corn, 159 to 163gCO2 equivalent/kg for soybeans, 89 g CO2 equivalent/ kg for alfalfa, and 124 to 147 g CO2 equivalent/kg for switch‐grass. The detailed agricultural data are used to assess previous controversies over the energy balance of bioethanol and, in light of the ongoing debates on this topic, provide a needed foundation for future life‐cycle assessments.
U.S. Federal Initiatives to Support Biomass Research and Development
Authors: Duncan Marvin
Published: May 2004

This article provides a brief overview of federal initiatives in the United States to support biomass research, demonstration, and development. The interest in the biomass industry and U.S. federal efforts to spur development of, increased production of, and use of biopower, biofuels, and biobased products, collectively known as the “biomass industry”, are discussed. A growing level of leadership from the executive branch of the federal government and support by the U.S. Congress are documented. Five important policy drivers that support this heightened emphasis on biomass for power, fuels, and products are identified and discussed. The current status of U.S. dependence on these renewable energy sources is briefly outlined. Federal biomass funding activity for the current fiscal year by the U.S. Department of Agriculture and the U.S. Department of Energy, two major federal participants in research, demonstration, and development for this industry, is briefly outlined. This funding commitment is placed into an overall context of total federal support for all research and development. Finally, the article suggests future market penetration targets for this industry, emphasizes the importance of infrastructure development necessary to support the industry's growth, and notes the payoff from such development for farmers, foresters, rural communities, and the environment.
Reviews
Authors: Richard Tom
Published: May 2004

Book reviewed in this article:

Feeding the World: A Challenge for the Twenty‐First Century, by Vaclav Smil

Quantifying Sustainable Development: The Future of Tropical Economies, edited by Charles A. S. Hall
No major association of A poE genotype with disease characteristics and MRI findings in multiple sclerosis
Authors: Zwemmer J NP , van Veen T , van Winsen L , van Kamp G J , Barkhof F , Polman C H , Uitdehaag B MJ
Published: May 2004

Background: Whereas a number of studies suggest that the A poE polymorphism is not associated with disease susceptibility in multiple sclerosis (MS), results with regard to disease severity, however, are conflicting. Some studies suggest an unfavourable role of the 4 allele. This study was performed to assess the association of the A poE polymorphism with both disease susceptibility and disease course in a large group of MS patients using clinical and MRI measures. In addition the data were combined with available data from the literature. Methods: In a group of 408 patients with clinically definite MS, genotype distribution was compared with that of 144 healthy controls. C ombined analysis of published data on the association of A poE polymorphism with MS was performed. Demographic and clinical findings were recorded and related to the A poE genotype. In a subgroup, longitudinal MRI findings were available and related to the A poE genotype. Results: No significant differences were found in the distribution of genotypes between MS patients and controls. C ombined analysis of published data showed a slightly increased susceptibility for MS in 2-carriers. Disease character istics (including age at onset and onset type), disease severity (progression index, time to reach EDSS 6) and MRI findings (lesion volumes and atrophy measures) were not associated with carriership o 2 or 4. Conclusions: In this cohort no association of the A poE genotype with disease susceptibility nor clinical and MRI measures could be identified. However, combined analysis of published data could not definitely exclude the possibility of a minor role for 2-carriership in MS.
Association of apolipoprotein E and myeloperoxidase genotypes to clinical course of familial and sporadic multiple sclerosis
Authors: Zakrzewska-Pniewska B , Styczynska M , Podlecka A , Samocka R , Peplonska B , Barcikowska M , Kwiecinski H
Published: May 2004

The importance of apolipoprotein E (ApoE) and myeloperoxidase (MPO) genotypes in the clinical characteristics of multiple sclerosis (MS) has been recently emphasized. In a large group of Polish patients we have tested the hypothesis that polymorphism in ApoE and MPO genes may influence the course of the disease. G enotypes were determined in 117 MS patients (74 females and 43 males; 99 sporadic and 18 familial cases) with mean EDSS of 3.6, mean age of 44.1 years, mean duration of the disease 12.8 years and mean onset of MS at 31.2 years, and in 100 healthy controls. The relationship between ApoE and MPO genes’ polymorphism and the MS activity as well as the defect of remyelination (diffuse demyelination) and brain atrophy on MRI were analysed. The ApoE o4 allele was not related to the disease course or the ApoE o2 to the intensity of demyelination on MRI. The genotype MPO G/G was found in all familial MS and in 57% (56/99) of sporadic cases. This genotype was also related to more pronounced brain atrophy on MRI. The MPO G/G subpopulation was characterized by a significantly higher proportion of patients with secondary progressive MS (PB- 0.05) and by a higher value of EDSS. A ccording to our results the MPO G allele is frequently found (in 96% of cases) among Polish patients with MS. More severe nervous tissue damage in the MPO G/G form can be explained by the mechanism of accelerated oxidative stress. It seems that MPO G/G genotype may be one of the genetic factors influencing the progression rate of disability in MS patients.
Interferon-beta inhibits the expression of metalloproteinases in rat glial cell cultures: implications for multiple sclerosis pathogenesis and treatment
Authors: Liuzzi Grazia Maria , Latronico Tiziana , Fasano Anna , Carlone Giulia , Riccio Paolo
Published: May 2004

Matrix metalloproteinases (MMPs) have been identified as mediators of brain injury in multiple sclerosis (MS) and it has recently been reported that treatment of MS patients with interferon-beta (IFN-b) reduces MMP-9 serum levels and in vitro release from monocytes. We investigated whether IFN-b is able to modulate the expression of MMPs in glial cell cultures. Rat microglial and astrocyte cultures were treated with different doses of IFN-b, then activated by exposure to LPS. In another set of experiments cells were simultaneously activated with LPS and treated with IFN-b. C ulture supernatants collected from astrocytes and microglia were subjected to zymography for the assessment of MMP-2 and MMP-9. Increased amounts of MMP-9 and MMP-2 were observed in supernatants from LPS-treated astrocytes in comparison with supernatants from nontreated control cells. MMP-9 also increased in LPS-treated microglia. The treatment of astrocytes and microglia with IFN-b inhibited dose-dependently the expression of both MMP-2 and MMP-9 in LPS-treated astrocytes and of MMP-9 in LPS-treated microglia. These results demonstrate a modulating effect of IFN-b on the release of MMPs from C NS cells. This effect represents an additional mechanism by which IFN-b may decrease the development of new C NS lesions in the course of MS.
Cerebrospinal fluid levels of brain specific proteins in optic neuritis
Authors: Lim E T , Grant D , Pashenkov M , Keir G , Thompson E J , Söderström M , Giovannoni G
Published: May 2004

This study evaluates levels of cerebrospinal fluid (C SF) brain-specific proteins (BSP) in subjects with optic neuritis (O N) who are at high risk of progression to multiple sclerosis (MS). Forty-one subjects had acute O N and 17 subjects with other neurological diseases (OND) served as controls. Twenty-o ne subjects with O N had white matter lesions on magnetic resonance imaging (MRI) and intrathecal synthesis of oligoclonal IgG bands (OB) consistent with being at high risk of progression to MS; eight of whom later were diagnosed with clinically definite MS (C DMS). Levels of S100B, ferritin and two neurofilament heavy chain phosphoforms (NfHSMI34 and NfHSMI35) were analysed using ELISA technique. A putative index of ‘axonal health’ was expressed as a ratio of NfHSMI34 to NfHSMI35. NfHSMI34 and the NfHSMI34:SMI35 were significantly elevated in subjects with O N compared to controls. No significant differences in levels of C SF BSP were seen between O N subjects with C DMS plus those at high risk of progression to MS and O N subjects with normal MRI and negative C SF analysis. In conclusion, there is evidence of axonal damage in subjects who present with O N, which is independent of the diagnosis of C DMS.
Treatment response in relation to inflammatory and axonal surrogate marker in multiple sclerosis
Authors: Petzold A , Brassat D , Mas P , Rejdak K , Keir G , Giovannoni G , Thompson E J , Clanet M.
Published: May 2004

Background: This study aimed to investigate if treatment response could retrospectively be related to inflammatory or axonal patho logy as measured by plasma surrogate markers. Methods: In this 1-year observational study 30 multiple sclerosis (MS) patients with relapsing-remitting disease were treated with intramuscular IFNb-1a or subcutaneous IFNb-1b. Responders and nonresponders were defined according to clinical and magnetic resonance imaging criteria. The control group consisted of 14 healthy subjects. Plasma levels of surrogate markers for inflammation (nitric oxide metabolites (NO x)), astrocytic activation (S100B) and axonal damage (NfHSMI35) were measured using standard assays. Results: There were 11 nonresponders and 19 responders to IFNb treatment. Median S100B levels were elevated in a higher proportion of treatment responders (63%, 42.9 pg/mL) compared to nonresponders (18%, 11.7 pg/mL, PB- 0.05, Fisher’s exact test) and controls (0%, 2 pg/mL, PB- 0.001). Levels of NO x were found to be more frequently elevated in nonresponders (72%, 39 mM) compared to healthy controls (0%, 37 mM, PB- 0.05). Levels of NfHSMI35 were more frequently elevated in responders (58%, 300 pg/mL, PB- 0.001) and nonresponders (72%, 500 pg/mL, PB- 0.001) compared to controls (0%, 4.5 pg/mL). Conclusion: Patients with relapsing-remitting MS who had surrogate marker supported evidence for astrocytic activation responded more frequently to treatment with IFNb.
Discordant functional and inflammatory parameters in multiple sclerosis patients after autologous haematopoietic stem cell transplantation
Authors: Healey Kathleen M , Pavletic Steven Z , Al-Omaishi Jinan , Leuschen M Patricia , Pirruccello Samuel J , Filipi Mary L , Enke Charles , Ursick Mary Margaret , Hahn Francis , Bowen J D , Nash Richard A
Published: May 2004

This article describes outcomes in four patients with advanced multiple sclerosis up to two years after autologous haematopoietic stem cell transplantation using a total-body irradiation-based preparative regimen. MRI and C SF analyses demonstrated clear suppression of the inflammatory processes. The results demonstrate however, a dissociation of inflammation parameters and functional disability findings raising questions about optimal future stem cell transplantatio n strategies for this disease.
Proteomic analysis of multiple sclerosis cerebrospinal fluid
Authors: Hammack B N , Fung K YC , Hunsucker S W , Duncan M W , Burgoon M P , Owens G P , Gilden D H
Published: May 2004

Two-dimensional gel electrophoresis and peptide mass fingerprinting were used to identify proteins in cerebrospinal fluid (C SF) pooled from three patients with multiple sclerosis (MS) and in C SF pooled from three patients with non-MS inflammatory central nervous system (C NS) disorders. Resolution of C SF proteins on three pH gradients (3-10, 4-7 and 6-11) enabled identification of a total of 430 spots in the MS C SF proteome that represented 61 distinct proteins. The gels containing MS C SF revealed 103 protein spots that were not seen on control gels. A ll but four of these 103 spots were proteins known to be present in normal human C SF. The four exceptio ns were: C RTAC -1B (cartilage acidic protein), tetranectin (a plasminogen-binding protein), SPARC -like protein (a calcium binding cell signalling glycoprotein), and autotaxin t (a phosphodiesterase). It remains unknown whether these four proteins are related to the cause and patho genesis of MS.
A central demyelinating disease with atypical features
Authors: Pradhan S , Mishra V N
Published: May 2004

There are clinical, laboratory and imaging criteria to distinguish multiple sclerosis (MS) from neuromyelitis optica (NMO) and acute disseminated encephalo myelitis (ADEM). While MS has unknown aetiology, NMO is commonly associated with vasculitis and A DEM is supposed to be parainfectious in origin. In the present study, six patients are described from a group of 67 with a central demyelinating disorder, whose clinical presentation did not conform to existing diagnostic criteria for A DEM, NMO or MS. Their clinical, laboratory and imaging character istics were studied and analysed. Some features suggested a particular diagnosis but some other features favoured another diagnosis. The features included spinal cord involvement in a large vertical segment with cord swelling, optic neuritis, no lesions in the cerebral cortex, paraplegia with urinary retentio n during the acute phase, no oligoclonal band in cerebrospinal fluid, absence of any evidence of vasculitis, wide time-gap between spinal cord and optic nerve involvement, good recovery from acute phase of disease and a relatively benign course. We conclude that there exists a subpopulation of patients with central demyelinating disease in this region with mixed clinical features. O verall features suggested either a widened clinical spectrum of MS, NMO or A DEM or a possible overlap between them.
Vestibular evoked myogenic potentials in multiple sclerosis: clinical and imaging correlations
Authors: Alpini D , Pugnetti L , Caputo D , Cornelio F , Capobianco S , Cesarani A
Published: May 2004

Patients with multiple sclerosis (MS) frequently report symptoms related to vestibular disorders in the course of their disease. At present, the fundamental tests assessing vestibulospinal involvement are posturography and vestibular evoked myogenic potentials (VEMPs). While posturography cannot be performed in every subject requiring minimal stance control, VEMPs do not require any specific skill on the part of the subjects and they may be investigated in all patients able to sit. VEMPs were recorded for 40 patients (17 men, 23 women; mean age 38 years, range 17-71 years) fulfilling diagnostic criteria of clinically defined MS, by means of rarefaction clicks, recording modulation of sterno-cleido-mastoideus tonic contraction saccule-mediated modulation. VEMPs were found to be abnormal in 28 of 40 patients. In 18 of the cases the VEMPs were asymmetric, i.e., had a prolonged latency on one side. In six cases latency was increased on both sides (mean delay 4.1 ms). In four subjects VEMPs were absent on one side. C oncordance with clinical findings of presence/absence of brainstem involvement was found in 55% and with MRI findings in 65% of the cases. A bnormal VEMPs indicated brainstem dysfunction in four patients (10%) with normal MRI and no specific clinical signs.
Serum uric acid levels in optic neuritis
Authors: Knapp C M , Constantinescu C S , Tan J HY , McLean R , Cherryman G R , Gottlob I
Published: May 2004

Uric acid, an antioxidant, is reduced in multiple sclerosis (MS). Patients with gout have a reduced incidence of MS. O ptic neuritis (O N), often the first manifestation of MS, is not known to be associated with reduced uric acid. Patients with recent onset of O N were investigated to determine whether uric acid levels were reduced at presentatio n. Twenty-o ne patients with O N were included, 17 females and 4 males. The mean (SD) serum uric acid in the O N female group was 184.4 (±55.1) mmol/L (range, 116- 309 mmol/L), whilst in the control group it was 235.2 (±50.2) mmol/L (range, 172- 381 mmol/L). The difference was statistically significant (x2 = 8.93, P = 0.003). In the small male cohort, mean (SD) serum uric acid was 305 (±52.1) mmol/L, whilst in the control group it was 328 (±80.4) mmol/L. These differences were not statistically significant. Reduced antioxidant reserve is possibly an early patho genic mechanism in inflammatory demyelination, and raises the possibility that low uric acid levels could be an indicator of disease activity. Since optic neuropathies of other causes were not investigated, future research needs to determine whether low uric acid represents a unique feature of optic neuritis or is seen in other optic neuropathies.
Multiple sclerosis following treatment with a cannabinoid receptor-1 antagonist
Authors: van Oosten B W , Killestein J , Mathus-Vliegen E MH , Polman C H
Published: May 2004

Laboratory research including animal models of human disease suggests that cannabinoids might have therapeutic potential in multiple sclerosis (MS). We have recently seen a 46-year-old woman who developed MS after starting treatment with a cannabino id recepto r antagonist for obesity. The occurrence of MS several months after starting a cannabinoid receptor antagonist suggests that the cannabino id system might indeed be relevant to disease pathogenesis in MS.