bluuebunny/crossref_metadata_2025_split huggingface dataset:
Probing genetic algorithms for feature selection in comprehensive metabolic profiling approach
Authors: Zou Wei , Tolstikov Vladimir V. 
Published: March 2008

AbstractSix different clones of 1‐year‐old loblolly pine (Pinus taeda L.) seedlings grown under standardized conditions in a green house were used for sample preparation and further analysis. Three independent and complementary analytical techniques for metabolic profiling were applied in the present study: hydrophilic interaction chromatography (HILIC‐LC/ESI‐MS), reversed‐phase liquid chromatography (RP‐LC/ESI‐MS), and gas chromatography all coupled to mass spectrometry (GC/TOF‐MS). Unsupervised methods, such as principle component analysis (PCA) and clustering, and supervised methods, such as classification, were used for data mining. Genetic algorithms (GA), a multivariate approach, was probed for selection of the smallest subsets of potentially discriminative classifiers. From more than 2000 peaks found in total, small subsets were selected by GA as highly potential classifiers allowing discrimination among six investigated genotypes. Annotated GC/TOF‐MS data allowed the generation of a small subset of identified metabolites. LC/ESI‐MS data and small subsets require further annotation. The present study demonstrated that combination of comprehensive metabolic profiling and advanced data mining techniques provides a powerful metabolomic approach for biomarker discovery among small molecules. Utilizing GA for feature selection allowed the generation of small subsets of potent classifiers. Copyright © 2008 John Wiley & Sons, Ltd.
Robust fault estimation of uncertain systems using an LMI‐based approach
Authors: Nobrega Euripedes G. , Abdalla Musa O. , Grigoriadis Karolos M. 
Published: March 2008

AbstractGeneral recent techniques in fault detection and isolation (FDI) are based onH∞optimization methods to address the issue of robustness in the presence of disturbances, uncertainties and modeling errors. Recently developed linear matrix inequality (LMI) optimization methods are currently used to design controllers and filters, which present several advantages over the Riccati equation‐based design methods. This article presents an LMI formulation to design full‐order and reduced‐order robustH∞FDI filters to estimate the faulty input signals in the presence of uncertainty and model errors. Several cases are examined for nominal and uncertain plants, which consider a weight function for the disturbance and a reference model for the faults. The FDI LMI synthesis conditions are obtained based on the bounded real lemma for the nominal case and on a sufficient extension for the uncertain case. The conditions for the existence of a feasible solution form a convex problem for the full‐order filter, which may be solved via recently developed LMI optimization techniques. For the reduced‐order FDI filter, the inequalities include a non‐convex constraint, and an alternating projections method is presented to address this case. The examples presented in this paper compare the simulated results of a structural model for the nominal and uncertain cases and show that a degree of conservatism exists in the robust fault estimation; however, more reliable solutions are achieved than the nominal design. Copyright © 2008 John Wiley & Sons, Ltd.
Sense of place in the practice and assessment of place‐based science teaching
Authors: Semken Steven , Freeman Carol Butler 
Published: March 2008

AbstractWe teach earth, ecological, and environmental sciences in and aboutplacesimbued with meaning by human experience. Scientific understanding is but one of the many types of meanings that can accrue to a given place. People develop emotional attachments to meaningful places. Thesense of place, encompassing the meanings and attachments that places hold for people, has been well characterized in environmental psychology. Its components, place attachment and place meaning, can be measured psychometrically.Place‐basedscience teaching focuses on local and regional environments and synthesizes different ways of knowing them, leveraging the senses of place of students and teachers. Place‐based teaching has been advocated for its relevance and potential to attract underrepresented groups to science. We posit that sense of place is a measurable learning outcome of place‐based science teaching. We developed an Arizona‐based, culturally inclusive, meaning‐rich introductory geology course, and used published surveys to assess place attachment and meaning in students who took the course. We observed significant gains in student place attachment and place meaning, indicating that these instruments are generalizable and sensitive enough for use in this context. Sense of place should be engaged by teachers of place‐based science, and further explored as an assessment measure. © 2008 Wiley Periodicals, Inc.Sci Ed92:1042–1057, 2008
Nanowires Enabling Signal‐Enhanced Nanoscale Raman Spectroscopy
Authors: Becker Michael , Sivakov Vladimir , Gösele Ulrich , Stelzner Thomas , Andrä Gudrun , Reich Hans J. , Hoffmann Samuel , Michler Johannes , Christiansen Silke H. 
Published: March 2008

AbstractSilicon nanowires grown by the vapor–liquid–solid (VLS) mechanism catalyzed by gold show gold caps (droplets) ≈20–500 nm in diameter with a half spherical towards almost spherical shape. These gold droplets are well suited to exploit the surface‐enhanced Raman scattering (SERS) effect and could be used for tip‐enhanced Raman spectroscopy (TERS). The gold droplet of a nanowire attached to an atomic force microscopy (AFM) tip could locally enhance the Raman signal and increase the spatial resolution. Used as a SERS template, an ensemble of self‐organizing nanowires grown bottom up on a silicon substrate could allow highly sensitive signal‐enhanced Raman spectroscopy of materials that show a characteristic Raman signature. A combination of a nanowire‐based TERS probe and a nanowire‐based SERS substrate promises optimized signal enhancement so that the detection of highly dilute species, even single molecules or single bacteria or DNA strands, and other soft matter is within reach. Potential applications of this novel nanowire‐based SERS and TERS solution lie in the fields of biomedical and life sciences, as well as security and solid‐state research such as silicon technology.
Adaptive wireless thin‐client model for mobile computing
Authors: Al‐Turkistany Mohammad , (Sumi) Helal Abdelsalam , Schmalz Mark 
Published: March 2008

AbstractThe thin‐client computing model has the potential to significantly increase the performance of mobile computing environments. By delivering any application through a single, small‐footprint client (called a thin client) implemented on a mobile device, it is possible to optimize application performance without the need for building wireless application gateways. We thus present two significant contributions in the area of wireless thin‐client computing. Firstly, a mathematical performance model is derived for wireless thin‐client system. This model identifies factors that affect the performance of the system and supports derivation and analysis of adaptation strategies to maintain a user‐specified quality of service (QoS). Secondly, a proxy‐based adaptation framework is developed for wireless thin‐client systems, which dynamically optimizes performance of a wireless thin client via dynamically discovered context. This is implemented with rule‐based fuzzy logic that responds to variations in wireless link bandwidth and client processing power. Our fuzzy inference engine uses contextual data to dynamically optimize tradeoffs among different quality of service parameters offered to the end users. Additionally, our adaptation framework uses highly scalable wavelet‐based image coding to provide scalable QoS that can degrade gracefully. Our thin‐client adaptation framework shields the user from ill effects of highly variable wireless network quality and mobile device resources. This improves performance of active applications, in which the display changes frequently. Further, active application behaviour may produce high transmission latency for screen updates, which can adversely affect user perception of QoS, resulting in poor interactivity. We report measured adaptive performance under realistic mobile device and network conditions for several different clients and servers. Copyright © 2008 John Wiley & Sons, Ltd.
Effects of High Frequency Exercise in Patients before and after Elective Percutaneous Coronary Intervention
Authors: Bäck Maria , Wennerblom Bertil , Wittboldt Susanna , Cider Åsa 
Published: March 2008

Background: The aim of this study was to evaluate the effects of high frequency exercise for patients before and after an elective percutaneous coronary intervention (PCI), with special reference to maximal aerobic capacity, muscle function, health related quality of life (HRQoL), waist–hip ratio (WHR) and restenosis. Methods: A randomised, controlled study was performed in Sweden between 2004 and 2006 in thirty-seven patients (five women) with stable coronary artery disease (CAD), age 63.6 ± 6.9 years, randomised to either high frequency exercise or control group. The patients in the training group performed three endurance resistance exercises and trained on a cycle ergometer 30 min, 5 times a week for 8 months at 70% of VO2max. Results: Patients in the training group significantly improved their maximal aerobic capacity (15 (9–46) vs. 8 (0–18)% p ≤ 0.05), shoulder flexion ( p ≤ 0.01), shoulder abduction ( p ≤ 0.01) and heel-lift ( p ≤ 0.05) compared to the control group. There were no significant differences between the groups in HRQoL, WHR and restenosis. Conclusion: High frequency exercise in patients treated with PCI seems to improve maximal aerobic capacity and muscle function, which may reduce the risks of further progression of atherosclerosis. However, further larger studies are needed to fully investigate the effects of exercise in patients with PCI.
Amitriptyline: sex‐dependent effect on sympathetic response and anxiety in rats submitted to early maternal separation and variable chronic stress in adulthood
Authors: Díaz Luján V.E. , Castellanos M.M. , Levin G. , Suárez M.M. 
Published: March 2008

AbstractThe aim of the present study was to determine the effects of chronic treatment with the antidepressant amitriptyline on sympathetic nervous system activity and anxiety in male and female rats submitted to maternal separation (MS) and variable chronic stress (VCS). We observed that the treatment with amitriptyline produced a significant increase in norepinephrine (NE) plasma levels in non‐maternally separated (NMS), non‐stressed (NVCS) males in relation to vehicle‐treated males, whereas in females the antidepressant produced a significant decrease in epinephrine (E) and NE when compared to the vehicle‐treated group. In NMS/VCS males, amitriptyline produced a significant increase in the time spent on the open arms (TIME) in relation to the vehicle‐treated group. In NMS/VCS females, amitriptyline produced a significant increase in TIME when compared to males. MS/VCS females showed a significant increase in the number of entries into the open arms (ENTRIES) in relation to males with the same treatment. This result suggests that there is a dimorphic response in coping with physical or emotional stressful situations and that amitriptyline acts in a differential way, being more effective in females.
Chronic developmental exposure to phenytoin has long‐term behavioral consequences
Authors: Mowery Todd M. , McDowell Angela L. , Garraghty Preston E. 
Published: March 2008

AbstractAnti‐epileptic compounds have been linked to several developmental disorders. Specifically, fetal exposure to phenytoin is linked to fetal hydantoin syndrome in humans. We have developed a rat model of fetal hydantoin syndrome in an effort to explore the relationship between drug exposure, development, and learning and memory. Previous studies of this animal model have used various embryological periods of exposure; however, the human syndrome is reported in the offspring of mothers that maintain drug regimens throughout gestation and nursing. To that end, the present study investigated associative learning in rats exposed to therapeutic levels of phenytoin throughout prenatal development and the postnatal pre‐weaning period. We used an instrumental appetitive‐to‐aversive transfer paradigm, which has hippocampal‐dependent components, and an avoidance‐conditioning paradigm to test simple associative learning and higher‐order learning and memory. Compared to controls, we report increased rates of acquisition and performance by the phenytoin group in both the appetitive and the avoidance learning paradigm, and a substantial impairment in avoidance learning following the transfer from appetitive to aversive conditioning. The positive deficit observed with simple associative learning and the negative transfer effect associated with higher order learning suggests that chronic exposure to phenytoin throughout gestation disrupts hippocampal development, which subsequently leads to impaired function in adulthood.
Current crustal deformation in the northern Tien Shan: GPS and seismological data
Authors: Tychkov S.A. , Kuchai O.A. , Bushenkova N.A. , Bragin V.D. , Kalmetieva Z.A. 
Published: March 2008

AbstractWe study crustal deformation in the northern Tien Shan as recorded in strain rates derived from earthquake and GPS data. Geodetic strain rates indicate general shortening along the N-S component and agree with Quaternary fault slip rates and with the strain field obtained from earthquake mechanisms, all being signature of overall north-south contraction in the region.The GPS strain field changes quickly in time, especially in the W-E direction, and is produced by a joint effect of elastic, plastic, and quasi-plastic deformation. The seismological strain field reflects the effect of external tectonic forces applied to seismogenic crust and the stress change due to crustal heterogeneity and geometry of the study area. Seismological and GPS strain rates carry information of different kinds. The former reflect formation of local structures mainly in the brittle crust, such as a local pull-apart in the center of the Lake Issyk Kul area, whereas the latter provide clues to mechanisms that drive the geological evolution of the mountain terrain as a whole. The current evolution may involve the effect of density instability at the lithosphere-asthenosphere boundary.
The genetic relationship of the deformed peridotites and garnet megacrysts from kimberlites with asthenospheric melts
Authors: Solov’eva L.V. , Lavrent’ev Yu.G. , Egorov K.N. , Kostrovitskii S.I. , Korolyuk V.N. , Suvorova L.F. 
Published: March 2008

Abstract
New data on geochemistry of incompatible trace elements (Nb, Zr, Hf, Ti, Y, REE) in garnets (Ga) and clinopyroxenes (Cpx) from deformed high-temperature garnet lherzolites, harzburgites, and garnet megacrysts from the Udachnaya pipe are presented. According to textures and petrographic composition, the deformed Ga-bearing peridotites are subdivided into coarse- and fine-porphyroclastic. Rocks of the first type (Ga-lherzolites) are enriched in Ga and Cpx (up to 30% each); among them, there are xenoliths with deformed Ga, Cpx, and Ol megacrysts. Deformed fine-porphyroclastic peridotites (Ga-lherzolites and Ga-harzburgites) are depleted in Ga (≤10%) and Cpx (≤3–5%). Four Ga megacrysts are typical of a Cr-poor association (0.33–1.63% Cr2O3; 0.56–1.05% TiO2; Mg# = 0.67–0.86). Garnets from deformed high-temperature coarse-porphyroclastic Ga-lherzolites are similar in geochemistry to Ga megacrysts: Their chondrite-normalized REE curves rise smoothly from La to Yb, and their spidergrams show peaks of Nb, Zr + Hf, and Ti. The narrow marginal zones of Ga grains from Ga-lherzolites are enriched in LREE. The peaks of HFSE in the Ga curves are smoothed out. The element patterns of garnet from fine-porphyroclastic Ga-lherzolites and Ga-harzburgites show a sinusoidal distribution of REE and Zr + Hf and Ti minima on the spidergrams. The element patterns of Cpx from both types of rocks are nearly the same: The curves are convex in the field of LREE, drastically drop from Nd to Yb, and have minima of Nb, Zr + Hf, and Ti. The curves of melts (L) equilibrated with Ga (calculated from partition coefficients) show a drastic enrichment in LREE and peaks of Nb, Zr + Hf, and Ti for garnet from deformed coarse-porphyroclastic lherzolites and megacrysts. The L curves of fine-porphyroclastic lherzolites and harzburgites have distinct minima of Zr + Hf and more sharply slope from Nd to Yb. The L curves of Cpx have minima of Nb, Zr + Hf, and Ti and lie near the field of basaltoid kimberlites from the Udachnaya pipe. All these data are consistent with the model of percolative fractional crystallization. The matter of mantle plume arrived from the mantle transition zone might have been the source of asthenospheric liquids inducing specific magmatic metasomatism at the continental lithosphere–asthenosphere boundary. The source material was enriched in majorite and silicate-perovskite or in ancient oceanic crustal matter.
HIV-1/parasite co-infection and the emergence of new parasite strains
Authors: LLOYD-SMITH JAMES O. , POSS MARY , GRENFELL BRYAN T. 
Published: March 2008

SUMMARYHIV-1 and parasitic infections co-circulate in many populations, and in a few well-studied examples HIV-1 co-infection is known to amplify parasite transmission. There are indications that HIV-1 interacts significantly with many other parasitic infections within individual hosts, but the population-level impacts of co-infection are not well-characterized. Here we consider how alteration of host immune status due to HIV-1 infection may influence the emergence of novel parasite strains. We review clinical and epidemiological evidence from five parasitic diseases (malaria, leishmaniasis, schistosomiasis, trypanosomiasis and strongyloidiasis) with emphasis on how HIV-1 co-infection alters individual susceptibility and infectiousness for the parasites. We then introduce a simple modelling framework that allows us to project how these individual-level properties might influence population-level dynamics. We find that HIV-1 can facilitate invasion by parasite strains in many circumstances and we identify threshold values of HIV-1 prevalence that allow otherwise unsustainable parasite strains to invade successfully. Definitive evidence to test these predicted effects is largely lacking, and we conclude by discussing challenges in interpreting available data and priorities for future studies.
Measuring immune system variation to help understand host-pathogen community dynamics
Authors: BRADLEY J. E. , JACKSON J. A. 
Published: March 2008

SUMMARYCarefully chosen immunological measurements, informed by recent advances in our understanding of the diversity and control of immune mechanisms, can add great interpretative value to ecological studies of infection. This is especially so for co-infection studies, where interactions between species are often mediated via the host's immune response. Here we consider how immunological measurements can strengthen inference in different types of co-infection analysis. In particular, we identify how measuring immune response variables in field studies can help reveal inter-species interactions otherwise obscured by confounding processes operating on count or prevalence data. Furthermore, we suggest that, due to the difficulty of quantifying microbial pathogen communities in field studies, innate responses against broad pathogen types (mediated by pattern response receptors) may be useful quantitative markers of exposure to bacteria and viruses. An ultimate goal of ecological co-infection studies may also be to understand how dynamics within host-parasite assemblages emerge from trade-offs involving different arms of the immune system. We reflect on the phenotypic measures that might best represent levels of responsiveness and bias in immune function. These include mediators associated with different T-helper cell subsets and innate responses controlled by pattern response receptors, such as the Toll-like receptors (TLRs).
Infection with acanthocephalans increases the vulnerability ofGammarus pulex(Crustacea, Amphipoda) to non-host invertebrate predators
Authors: KALDONSKI N. , PERROT-MINNOT M.-J. , MOTREUIL S. , CÉZILLY F. 
Published: March 2008

SUMMARYPhenotypic alterations induced by parasites in their intermediate hosts often result in enhanced trophic transmission to appropriate final hosts. However, such alterations may also increase the vulnerability of intermediate hosts to predation by non-host species. We studied the influence of both infection with 3 different acanthocephalan parasites (Pomphorhynchus laevis,P. tereticollis, andPolymorphus minutus) and the availability of refuges on the susceptibility of the amphipodGammarus pulexto predation by 2 non-host predators in microcosms. Only infection withP. laevisincreased the vulnerability of amphipods to predation by crayfish,Orconectes limosus. In contrast, in the absence of refuges, the selectivity of water scorpions,Nepa cinerea, for infected prey was significant and did not differ according to parasite species. When a refuge was available for infected prey, however, water scorpion selectivity for infected prey differed between parasite species. BothP. tereticollis- andP. laevis-infected gammarids were more vulnerable than uninfected ones, whereas the reverse was true ofP. minutus-infected gammarids. These results suggest that the true consequences of phenotypic changes associated with parasitic infection in terms of increased trophic transmission of parasites deserve further assessment.
Incomplete stimulus representations and the loss of cognitive access in cerebral achromatopsia
Authors: Kentridge Robert William 
Published: March 2008

AbstractWhen processing of stimuli occurs without attention, phenomenal experience, as well as cognitive access, may be lost. Sensory representations are, however, constructed by neural machinery extending far beyond sensory receptors. In conditions such as cerebral achromatopsia incomplete sensory representations may still elicit phenomenal experience but these representations might be too aberrant to be integrated into the wider cognitive workspace.
Phenomenology without conscious access is a form of consciousness without top-down attention
Authors: Koch Christof , Tsuchiya Naotsugu 
Published: March 2008

AbstractWe agree with Block's basic hypothesis postulating the existence of phenomenal consciousness without cognitive access. We explain such states in terms of consciousness without top-down, endogenous attention and speculate that their correlates may be a coalition of neurons that are consigned to the back of cortex, without access to working memory and planning in frontal cortex.
Partial awareness and the illusion of phenomenal consciousness
Authors: Kouider Sid , de Gardelle Vincent , Dupoux Emmanuel 
Published: March 2008

AbstractThe dissociation Block provides between phenomenal and access consciousness (P-consciousness and A-consciousness) captures much of our intuition about conscious experience. However, it raises a major methodological puzzle, and is not uniquely supported by the empirical evidence. We provide an alternative interpretation based on the notion of levels of representation and partial awareness.
Dodging the explanatory gap – or bridging it
Authors: McDermott Drew 
Published: March 2008

AbstractAssuming our understanding of the brain continues to advance, we will at some point have a computational theory of how access consciousness works. Block's supposed additional kind of consciousness will not appear in this theory, and continued belief in it will be difficult to sustain. Appeals to “what it's like” to experience such-and-such will carry little weight when we cannot locate a subject for whom it might be like something.