bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal mapping of joint faults into healthy joint velocity space for fault-tolerant redundant manipulators
Authors: Abdi Hamid , Nahavandi Saeid , Frayman Yakov , Maciejewski Anthony A. 
Published: August 2011

SUMMARYSelf-reconfiguration of robotic manipulators under joint failure can be achieved via fault-tolerance strategies. Fault-tolerant manipulators are required to continue their end-effector motion with a minimum velocity jump, when failures occur to their joints. Optimal fault tolerance of the manipulators requires a framework that can map the velocity jump of the end-effector to the compensating joint velocity commands. The main objective of the present paper is to propose a general framework for the fault tolerance of the manipulators, which can minimize the end-effector velocity jump. In the present paper, locked joint failures of the manipulators are modeled using matrix perturbation methodology. Then, the optimal mapping for the faults with a minimum end-effector velocity jump is presented. On the basis of this mapping, the minimum end-effector velocity jump is calculated. A generalized framework is derived from the extension of optimal mapping toward multiple locked joint failures. Two novel expressions are derived representing the generalized optimal mapping framework and the generalized minimum velocity jump. These expressions are suitable for the optimal fault tolerance of the serial link redundant manipulators. The required conditions for a zero end-effector velocity jump of the manipulators are analyzed. The generalized framework in this paper is then evaluated for different failure scenarios for a 5-DOF planar manipulator and a 5-DOF spatial manipulator. The validation includes three case studies. While the first two are instantaneous studies, the third one is for the whole trajectory of the manipulators. From the results of these case studies, it is shown that, when locked joint faults occur, the faulty manipulator is able to optimally maintain its velocity with a zero end-effector velocity jump if the conditions of a zero velocity jump are hold.
Joint stiffness identification of industrial serial robots
Authors: Dumas Claire , Caro Stéphane , Cherif Mehdi , Garnier Sébastien , Furet Benoît 
Published: August 2011

SUMMARYThis paper presents a new methodology for the joint stiffness identification of industrial serial robots and as consequence for the evaluation of both translational and rotational displacements of the robot's end-effector subject to an external wrench (force and torque). In this paper, the robot's links are supposed to be quite stiffer than the actuated joints as it is usually the case with industrial serial robots. The robustness of the identification method and the sensitivity of the results to measurement errors, and the number of experimental tests are also analyzed. The Kuka KR240-2 robot is used as an illustrative example throughout the paper.
Robust design of multiscale programs to reduce deforestation
Authors: CATTANEO ANDREA 
Published: August 2011

ABSTRACTA framework is provided for structuring programs aimed at reducing emissions from deforestation and forest degradation (REDD). Crediting reference levels and the coordination among different implementing entities at multiple geographic scales are discussed. A crediting reference level has an error component if it differs from the business-as-usual (BAU) without REDD. Both the BAU emissions and the impact of REDD actions are uncertain, implying that participating in REDD entails stakeholder risk, the distribution of which depends on REDD program design. To categorize REDD architectures we definescale-neutralitywhereby, for a given REDD design, crediting relative to the reference level at a given scale is not affected by errors in reference levels at scales below it. Sufficient conditions are derived for scale-neutrality to hold. A Brazilian Amazon example is provided, comparing potential REDD architectures, and highlighting how a cap-and-trade approach may match the environmental outcome obtainable with perfect foresight of the BAU emissions.
Political or dental power in private and public service provision: a study of municipal expenditures for child dental care
Authors: Andersen Lotte Bøgh , Bech Mickael , Lauridsen Jørgen 
Published: August 2011

AbstractBoth professionals and politicians may affect expenditures for highly professional services provided in the public and private sector. We investigated Danish publicly financed child dental care with a special focus on the influence of politicians and dentists on the expenditure level. By studying spatial patterns in expenditure levels across municipalities, we are able to test the influences of these two main actors and the networks through which learning is achieved. Four hypotheses on the existence of different spatial spillover effects are tested. The empirical analysis is based on annual data from 1996 to 2001 for 226 Danish municipalities, thus allowing for the control for heterogeneity between municipalities and for intra-municipal correlations across time. The results point to differences in expenditures between municipalities with privately and publicly produced dental care. Furthermore, dentists appear to be the most important actors for the spatial spillover effects, and these effects are especially strong for municipalities situated in the same county that use private dental clinics. There is no evidence of political spatial spillover effects between municipalities.
Environmental Pursuits In Nanomaterial Systems Science With Indian Exemplars
Authors: Sen Ranen , Seth Dipankar , Roy Indrani , Dasgupta Debmalya , Goswami Arunava 
Published: August 2011

AbstractThe behavior and pattern of NPs of minerals in the evolutionary history of the earth vis – a –vis the environmental context are inquired into, with a riverine system as a model. The study of fractal dimensions of NPs of interest serves as an aid to obtain a comprehensive view of natural NPs in the model system. The present study combines inputs from work done on nanoparticles, derived from the Subanarekha River System and products of base metal mine effluents that are rich in NPs of minerals. The authors believe this study would help to establish certain universalities about NPs and provide an updated framework for understanding the current state of nanomineral science.
Soil Disturbance Increases Soil Microbial Enzymatic Activity in Arid Ecoregions
Authors: Schwab-Uchanski Lori Kae , Unc Adrian , Lucero Mary 
Published: August 2011

AbstractFunctional diversity of the soil microbial community is commonly used in the assessment of soil health as it relates to the activity of soil microflora involved in carbon cycling. Soil microbes in different microenvironments will have varying responses to different substrates, thus catabolic fingerprint information of each location-specific community can be obtained. The purpose of this study was to evaluate total-soil enzymatic activity profiles across three disturbance regimes in an arid desert grassland in the Southwestern United States. Microbial enzymatic activity was measured using the MicroResp™ system, which measures respiration of microbes within whole soil samples supplemented with various carbon sources (simple and polymeric sugars, amino acids, carboxylic acids, and fatty acids - tests run in the absence of light). Total bacterial diversity was assessed by 16s DNA pyrosequencing. Microbial activity was greatest and most variable in sites exposed to disturbance (grazing, natural gas extraction). Decoupling the C cycle from the C-fixing cyanobacteria may induce more diverse C uptake pathways associated with a more diverse microbial population. Similarities in taxonomic diversity and C substrate utilization patterns show that, for arid lands, any degradation-enhanced heterogeneity in soil’s biotic and abiotic parameters may drive changes in soils towards higher functional diversity to adapt to the disturbance.
Rapid bioassay for evaluating enzyme production in fungal isolates from environmental sources
Authors: Bordo Eleonora , Luziatellie Francesca , Crognale Silvia , Marinari Sara , Grego Stefano , Ruzzi Maurizio 
Published: August 2011

AbstractFungal hydrolytic enzymes have a great potential due to the rapid development of enzyme technology and their industrial applications. A fluorimetric microplate assay has been developed for measuring activity of β-D-exoglucanase, β-D-glucosidase, α-D-glucosidase, β-N-acetyl-hexosaminidase, β-D-xylosidase in diluted culture broth samples. The substrates used are conjugates of the highly fluorescent compounds 4-methylumbelliferone (MUB) and thus product formation can be measured directly in the microplate without previous extraction and purification of the product. The developed system was evaluated on eight fungal strains isolated from shrub species (Tamarix) that can be used in phytoremediation. Depending upon the enzyme, each species exhibited different levels of enzymatic activities as well as different production profiles. The fluorimetric method could constitute an effective alternative to the pectrophotometric method to screen hydrolase-producing microbial strains.
Peripheral insertion modulates the editing activity of the isolated CP1 domain of leucyl-tRNA synthetase
Authors: Liu Ru-Juan , Tan Min , Du Dao-Hai , Xu Bei-Si , Eriani Gilbert , Wang En-Duo 
Published: August 2011

A large insertion domain called CP1 (connective peptide 1) present in class Ia aminoacyl-tRNA synthetases is responsible for post-transfer editing. LeuRS (leucyl-tRNA synthetase) from Aquifex aeolicus and Giardia lamblia possess unique 20 and 59 amino acid insertions respectively within the CP1 that are crucial for editing activity. Crystal structures of AaLeuRS-CP1 [2.4 Å (1 Å=0.1 nm)], GlLeuRS-CP1 (2.6 Å) and the insertion deletion mutant AaLeuRS-CP1Δ20 (2.5 Å) were solved to understand the role of these insertions in editing. Both insertions are folded as peripheral motifs located on the opposite side of the proteins from the active-site entrance in the CP1 domain. Docking modelling and site-directed mutagenesis showed that the insertions do not interact with the substrates. Results of molecular dynamics simulations show that the intact CP1 is more dynamic than its mutant devoid of the insertion motif. Taken together, the data show that a peripheral insertion without a substrate-binding site or major structural role in the active site may modulate catalytic function of a protein, probably from protein dynamics regulation in two respective LeuRS CP1s. Further results from proline and glycine mutational analyses intended to reduce or increase protein flexibility are consistent with this hypothesis.
Biologically induced initiation of Neoproterozoic snowball-Earth events
Authors: Tziperman Eli , Halevy Itay , Johnston David T. , Knoll Andrew H. , Schrag Daniel P. 
Published: August 2011

The glaciations of the Neoproterozoic Era (1,000 to 542 MyBP) were preceded by dramatically light C isotopic excursions preserved in preglacial deposits. Standard explanations of these excursions involve remineralization of isotopically light organic matter and imply strong enhancement of atmospheric CO
2
greenhouse gas concentration, apparently inconsistent with the glaciations that followed. We examine a scenario in which the isotopic signal, as well as the global glaciation, result from enhanced export of organic matter from the upper ocean into anoxic subsurface waters and sediments. The organic matter undergoes anoxic remineralization at depth via either sulfate- or iron-reducing bacteria. In both cases, this can lead to changes in carbonate alkalinity and dissolved inorganic pool that efficiently lower the atmospheric CO
2
concentration, possibly plunging Earth into an ice age. This scenario predicts enhanced deposition of calcium carbonate, the formation of siderite, and an increase in ocean pH, all of which are consistent with recent observations. Late Neoproterozoic diversification of marine eukaryotes may have facilitated the episodic enhancement of export of organic matter from the upper ocean, by causing a greater proportion of organic matter to be partitioned as particulate aggregates that can sink more efficiently, via increased cell size, biomineralization or increased C∶N of eukaryotic phytoplankton. The scenario explains isotopic excursions that are correlated or uncorrelated with snowball initiation, and suggests that increasing atmospheric oxygen concentrations and a progressive oxygenation of the subsurface ocean helped to prevent snowball glaciation on the Phanerozoic Earth.
Fast-folding α-helices as reversible strain absorbers in the muscle protein myomesin
Authors: Berkemeier Felix , Bertz Morten , Xiao Senbo , Pinotsis Nikos , Wilmanns Matthias , Gräter Frauke , Rief Matthias 
Published: August 2011

The highly oriented filamentous protein network of muscle constantly experiences significant mechanical load during muscle operation. The dimeric protein myomesin has been identified as an important M-band component supporting the mechanical integrity of the entire sarcomere. Recent structural studies have revealed a long α-helical linker between the C-terminal immunoglobulin (Ig) domains My12 and My13 of myomesin. In this paper, we have used single-molecule force spectroscopy in combination with molecular dynamics simulations to characterize the mechanics of the myomesin dimer comprising immunoglobulin domains My12–My13. We find that at forces of approximately 30 pN the α-helical linker reversibly elongates allowing the molecule to extend by more than the folded extension of a full domain. High-resolution measurements directly reveal the equilibrium folding/unfolding kinetics of the individual helix. We show that α-helix unfolding mechanically protects the molecule homodimerization from dissociation at physiologically relevant forces. As fast and reversible molecular springs the myomesin α-helical linkers are an essential component for the structural integrity of the M band.
Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards
Authors: Hinckley Eve-Lyn S. , Matson Pamela A. 
Published: August 2011

Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S
0
) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S
0
in soils, vegetation, and hydrologic export pathways of Napa Valley, CA vineyards, documenting that all applied S is lost from the vineyard ecosystem on an annual basis. We found that S
0
oxidizes rapidly to sulfate (

) on the soil surface where it then accumulates over the course of the growing season. Leaf and grape tissues accounted for only 7–13% of applied S whereas dormant season cover crops accounted for 4–10% of applications. Soil S inventories were largely

and ester-bonded sulfates; they decreased from 1,623 ± 354 kg ha
-1
during the dry growing season to 981 ± 526 kg ha
-1
(0–0.5 m) during the dormant wet season. Nearly all S applied to the vineyard soils is transported offsite in dissolved oxidized forms during dormant season rainstorms. Thus, the residence time of reactive S is brief in these systems, and largely driven by hydrology. Our results provide new insight into how S use in vineyards constitutes a substantial perturbation of the S cycle in Northern California winegrowing regions and points to the unintended consequences that agricultural S use may have at larger scales.
Outcomes and Genetic Relatedness of Carbapenem-Resistant Enterobacteriaceae at Detroit Medical Center
Authors: Marchaim Dror , Chopra Teena , Perez Federico , Hayakawa Kayoko , Lephart Paul R. , Bheemreddy Suchitha , Blunden Christopher , Hujer Andrea M. , Rudin Susan , Shango Maryann , Campbell Michelle , Varkey Jastin , Slim Jessica , Ahmad Farah , Patel Diixa , Chen Ting-Yi , Pogue Jason M. , Salimnia Hossein , Dhar Sorabh , Bonomo Robert A. , Kaye Keith S. 
Published: August 2011

Background.Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging in hospitals in the United States and are posing a significant threat. To better understand the transmission dynamics and the acquisition of resistant strains, a thorough analysis of epidemiologic and molecular characteristics was performed.Methods.CRE isolated at Detroit Medical Center were analyzed from September 2008 to September 2009. blaKPC genes were investigated by polymerase chain reaction (PCR), and repetitive extragenic palindromic PCR (rep-PCR) was used to determine genetic similarity among strains. Epidemiologic and outcomes analyses were performed.Results.Ninety-two unique patient CRE isolates were recovered. Sixty-eight strains (74%) were Klebsiella pneumoniae, 7 were Klebsiella oxytoca, 15 were Enterobacter species, and 2 were Escherichia coli. Fifteen isolates (16%) were resistant to Colistin, 14 (16%) were resistant to tigecycline, and 2 were resistant to all antimicrobials tested. The mean ± standard deviation age of patients was 63 ± 2 years. Sixty patients (68%) were admitted to the hospital from long-term care facilities. Only 70% of patients received effective antimicrobial therapy when infection was suspected, with a mean time to appropriate therapy of 120 ± 23 hours following sample culturing. The mean length of hospitalization after sample culturing was 18.6 ± 2.5 days. Of 57 inpatients, 18 (32%) died in the hospital. Independent predictors for mortality were intensive care unit stay (odds ratio [OR], 15.8; P = .003) and co-colonization with CRE and either Acinetobacter baumannii or Pseudomonas aeruginosa (OR, 17.2; P = .006). Among K. pneumoniae CRE, rep-PCR revealed 2 genetically related strains that comprised 70% and 20% of isolates, respectively.Conclusions.In this large U.S. cohort of patients with CRE infection, which reflects the modern continuum of medical care, co-colonization with CRE and A. baumannii or P. aeruginosa was associated with increased mortality. Two predominant clones of K. pneumoniae accounted for the majority of cases of CRE infection.
Inferring disease and gene set associations with rank coherence in networks
Authors: Hwang TaeHyun , Zhang Wei , Xie Maoqiang , Liu Jinfeng , Kuang Rui 
Published: August 2011

AbstractMotivation: To validate the candidate disease genes identified from high-throughput genomic studies, a necessary step is to elucidate the associations between the set of candidate genes and disease phenotypes. The conventional gene set enrichment analysis often fails to reveal associations between disease phenotypes and the gene sets with a short list of poorly annotated genes, because the existing annotations of disease-causative genes are incomplete. This article introduces a network-based computational approach called rcNet to discover the associations between gene sets and disease phenotypes. A learning framework is proposed to maximize the coherence between the predicted phenotype–gene set relations and the known disease phenotype-gene associations. An efficient algorithm coupling ridge regression with label propagation and two variants are designed to find the optimal solution to the objective functions of the learning framework.Results: We evaluated the rcNet algorithms with leave-one-out cross-validation on Online Mendelian Inheritance in Man (OMIM) data and an independent test set of recently discovered disease–gene associations. In the experiments, the rcNet algorithms achieved best overall rankings compared with the baselines. To further validate the reproducibility of the performance, we applied the algorithms to identify the target diseases of novel candidate disease genes obtained from recent studies of Genome-Wide Association Study (GWAS), DNA copy number variation analysis and gene expression profiling. The algorithms ranked the target disease of the candidate genes at the top of the rank list in many cases across all the three case studies.Availability: http://compbio.cs.umn.edu/dgsa_rcNetContact: kuang@cs.umn.edu
Delineating the habitat of demersal fish assemblages with acoustic seabed technologies
Authors: van der Kooij Jeroen , Kupschus Sven , Scott Beth E. 
Published: August 2011

Abstract
van der Kooij, J., Kupschus, S., and Scott, B. E. 2011. Delineating the habitat of demersal fish assemblages with acoustic seabed technologies. – ICES Journal of Marine Science, 68: 1973–1985. Habitats influence species distribution and, although the seabed is an important habitat factor for demersal species, traditional sampling methods often provide no practical solution to investigating the seabed over large areas. The ability of a multivariate method that utilizes single-beam acoustic seabed data combined with species composition data to define demersal fish habitats was tested. The best model explained 19.4% of the variance observed in the species data and was robust between years. Ten biotopes were identified, each containing species that, either alone or in combination with others, were indicative of that biotope. Using unclassified acoustic seabed data as explanatory variables, discrepancies between the numbers of acoustically distinct classes and species assemblages, as previously reported in the literature, were avoided, while utilizing their relationship with community structure. The study focused on the relationship between simultaneously recorded species composition and seabed data from fishing stations, but because continuous acoustic data along the survey tracks were available between stations, the model could be used to predict the spatial extent of the biotopes. Although the method was developed with the eventual aim of providing a meaningful foundation to the spatial management of mixed fisheries, it could also contribute to applications in spatial planning.
The structure of demersal fish assemblages in a cold, highly stratified environment
Authors: Chouinard P-M. , Dutil J-D. 
Published: August 2011

Abstract
Chouinard, P-M., and Dutil, J-D. 2011. The structure of demersal fish assemblages in a cold, highly stratified environment. – ICES Journal of Marine Science, 68: 1896–1908. Fish are a major component of marine ecosystems, with many species co-occuring in the same habitats. Potential interactions among species and with the environment can be studied through the identification of species assemblages. Data from bottom trawl surveys (2004–2008) conducted in the estuary and northern Gulf of St Lawrence were analysed using multivariate methods (cluster, multidimensional scaling, and detrended canonical correspondence analysis) to describe the structure and composition of demersal fish assemblages, including rare and smaller non-commercial species. The spatial variability in environmental conditions that characterizes the study area has a significant impact on the composition of fish assemblages in the region. In all, 35 taxa were classified as key, and 6 main fish assemblages were described, based on catch in numbers. These assemblages had a coherent spatial distribution in the study area, associated with either depth, salinity and temperature, or dissolved oxygen. The analyses showed overall strong correlations between species abundance and prevalent environmental conditions and explained 18.4% of the variance in species abundance data and 79.2% of the variance in the species–environment relationship.