Linkage analysis of candidate genes as susceptibility loci for osteoarthritis-suggestive linkage of COL9A1 to female hip osteoarthritis.

PubMed

Mustafa, Z; Chapman, K; Irven, C; Carr, A J; Clipsham, K; Chitnavis, J; Sinsheimer, J S; Bloomfield, V A; McCartney, M; Cox, O; Sykes, B; Loughlin, J

2000-03-01

To examine 11 candidate genes as susceptibility loci for osteoarthritis (OA). A total of 481 families have been ascertained in which at least two siblings have had joint replacement surgery of the hip, or knee, or hip and knee for idiopathic OA. Each candidate gene was targeted using one or more intragenic or closely linked microsatellite marker. The linkage data were analysed unstratified and following stratification by sex and by joint replaced (hip or knee). The analyses revealed suggestive linkage of the type IX collagen gene COL9A1 (6q12-q13) to a subset of 132 families that contained affected females who were concordant for hip OA (female-hip) with a P-value of 0.00053 and logarithm of the odds (LOD) score of 2.33 [corrected P-value of 0. 0016, corrected LOD score of 1.85]. COL9A1 may therefore be a susceptibility locus for female hip OA. In addition, there was weak evidence of linkage to HLA/COL11A2 (6p21.3) in female hip OA with a corrected P-value of 0.016.

Apparatus to position a microelectromechanical platform

DOEpatents

Miller, Samuel Lee; Rodgers, Murray Steven

2003-09-23

The present invention comprises a microelectromechanical positioner to achieve substantially translational positioning of a platform without rotational motion, thereby maintaining a constant angular orientation of the platform during movement. A linkage mechanism of the positioner can comprise parallelogram linkages to constrain the rotational motion of the platform. Such linkages further can comprise flexural hinges or other turning joints at the linkage pivots to eliminate the need for rubbing surfaces. A plurality of the linkage mechanisms can be used to enable translational motion of the platform with two degrees of freedom. A variety of means can be used to actuate the positioner. Independent actuation of the anchor links of the linkage mechanisms with rotary electrostatic actuators can be used to provide controlled translational movement of the platform.

PRKCA: A Positional Candidate Gene for Body Mass Index and Asthma

PubMed Central

Murphy, Amy; Tantisira, Kelan G.; Soto-Quirós, Manuel E.; Avila, Lydiana; Klanderman, Barbara J.; Lake, Stephen; Weiss, Scott T.; Celedón, Juan C.

2009-01-01

Asthma incidence and prevalence are higher in obese individuals. A potential mechanistic basis for this relationship is pleiotropy. We hypothesized that significant linkage and candidate-gene association would be found for body mass index (BMI) in a population ascertained on asthma affection status. Linkage analysis for BMI was performed on 657 subjects in eight Costa Rican families enrolled in a study of asthma. Family-based association studies were conducted for BMI with SNPs within a positional candidate gene, PRKCA. SNPs within PRKCA were also tested for association with asthma. Association studies were conducted in 415 Costa Rican parent-child trios and 493 trios participating in the Childhood Asthma Management Program (CAMP). Although only modest evidence of linkage for BMI was obtained for the whole cohort, significant linkage was noted for BMI in females on chromosome 17q (peak LOD = 3.39). Four SNPs in a candidate gene in this region (PRKCA) had unadjusted association p values < 0.05 for BMI in both cohorts, with the joint p value for two SNPs remaining significant after adjustment for multiple comparisons (rs228883 and rs1005651, joint p values = 9.5 × 10−5 and 5.6 × 10−5). Similarly, eight SNPs had unadjusted association p values < 0.05 for asthma in both populations, with one SNP remaining significant after adjustment for multiple comparisons (rs11079657, joint p value = 2.6 × 10−5). PRKCA is a pleiotropic locus that is associated with both BMI and asthma and that has been identified via linkage analysis of BMI in a population ascertained on asthma. PMID:19576566

Power of a Labrador Retriever-Greyhound pedigree for linkage analysis of hip dysplasia and osteoarthritis.

PubMed

Todhunter, Rory J; Casella, George; Bliss, Stuart P; Lust, George; Williams, Alma Jo; Hamilton, Samuel; Dykes, Nathan L; Yeager, Amy E; Gilbert, Robert O; Burton-Wurster, Nancy I; Mellersh, Cathryn C; Acland, Gregory M

2003-04-01

To estimate the number of dogs required to find linkage to heritable traits of hip dysplasia in dogs from an experimental pedigree. 147 Labrador Retrievers, Greyhounds, and their crossbreed offspring. Labrador Retrievers with hip dysplasia were crossed with unaffected Greyhounds. Age at detection of femoral capital ossification, distraction index (DI), hip joint dorsolateral subluxation (DLS) score, and hip joint osteoarthritis (OA) were recorded. Power to find linkage of a single marker to a quantitative trait locus (QTL) controlling 100% of the variation in a dysplastic trait in the backcross dogs was determined. For the DI at the observed effect size, recombination fraction of 0.05, and heterozygosity of 0.75, 35 dogs in the backcross of the F1 to the Greyhound generation would yield linkage at a power of 0.8. For the DLS score, 35 dogs in the backcross to the Labrador Retriever generation would be required for linkage at the same power. For OSS, 45 dogs in the backcross to the founding Labrador Retrievers would yield linkage at the same power. Fewer dogs were projected to be necessary to find linkage to hip OA. Testing for linkage to the DLS at 4 loci simultaneously, each controlling 25% of the phenotypic variation, yielded an overall power of 0.7 CONCLUSIONS AND CLINICAL SIGNIFICANCE: Based on this conservative single-marker estimate, this pedigree has the requisite power to find microsatellites linked to susceptibility loci for hip dysplasia and hip OA by breeding a reasonable number of backcross dogs.

Nested association mapping of stem rust resistance in wheat using genotyping by sequencing

USDA-ARS?s Scientific Manuscript database

Nested association mapping is an approach to map trait loci in which families within populations are interconnected by a common parent. By implementing joint-linkage association analysis, this approach is able to map causative loci with higher power and resolution compared to biparental linkage mapp...

Joint QTL linkage mapping for multiple-cross mating design sharing one common parent

USDA-ARS?s Scientific Manuscript database

Nested association mapping (NAM) is a novel genetic mating design that combines the advantages of linkage analysis and association mapping. This design provides opportunities to study the inheritance of complex traits, but also requires more advanced statistical methods. In this paper, we present th...

Alocomotino Control Algorithm for Robotic Linkage Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dohner, Jeffrey L.

This dissertation describes the development of a control algorithm that transitions a robotic linkage system between stabilized states producing responsive locomotion. The developed algorithm is demonstrated using a simple robotic construction consisting of a few links with actuation and sensing at each joint. Numerical and experimental validation is presented.

Construction of high-quality recombination maps with low-coverage genomic sequencing for joint linkage analysis in maize

USDA-ARS?s Scientific Manuscript database

A genome-wide association study (GWAS) is the foremost strategy used for finding genes that control human diseases and agriculturally important traits, but it often reports false positives. In contrast, its complementary method, linkage analysis, provides direct genetic confirmation, but with limite...

Spacesuit mobility knee joints

NASA Technical Reports Server (NTRS)

Vykukal, H. C. (Inventor)

1979-01-01

Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

Nested association mapping for dissecting complex traits using Peanut 58K SNP array

USDA-ARS?s Scientific Manuscript database

Genome-wide association studies (GWAS) and linkage mapping have been the two most predominant strategies to dissect complex traits, but are limited by the occurrence of false positives reported for GWAS, and low resolution in the case of linkage analysis. This has led to the development of a joint a...

An instrumented spatial linkage for measuring knee joint kinematics.

PubMed

Rosvold, Joshua M; Atarod, Mohammad; Frank, Cyril B; Shrive, Nigel G

2016-01-01

In this study, the design and development of a highly accurate instrumented spatial linkage (ISL) for kinematic analysis of the ovine stifle joint is described. The ovine knee is a promising biomechanical model of the human knee joint. The ISL consists of six digital rotational encoders providing six degrees of freedom (6-DOF) to its motion. The ISL makes use of the complete and parametrically continuous (CPC) kinematic modeling method to describe the kinematic relationship between encoder readings and the relative positions and orientation of its two ends. The CPC method is useful when calibrating the ISL, because a small change in parameters corresponds to a small change in calculated positions and orientations and thus a smaller optimization error, compared to other kinematic models. The ISL is attached rigidly to the femur and the tibia for motion capture, and the CPC kinematic model is then employed to transform the angle sensor readings to relative motion of the two ends of the linkage, and thereby, the stifle joint motion. The positional accuracy for ISL after calibration and optimization was 0.3±0.2mm (mean +/- standard deviation). The ISL was also evaluated dynamically to ensure that accurate results were maintained, and achieved an accuracy of 0.1mm. Compared to the traditional motion capture methods, this system provides increased accuracy, reduced processing time, and ease of use. Future work will be on the application of the ISL to the ovine gait and determination of in vivo joint motions and tissue loads. Accurate measurement of knee joint kinematics is essential in understanding injury mechanisms and development of potential preventive or treatment strategies. Copyright © 2015 Elsevier B.V. All rights reserved.

Are all metal-on-metal hip revision operations contributing to the National Joint Registry implant survival curves? : a study comparing the London Implant Retrieval Centre and National Joint Registry datasets.

PubMed

Sabah, S A; Henckel, J; Koutsouris, S; Rajani, R; Hothi, H; Skinner, J A; Hart, A J

2016-01-01

The National Joint Registry for England, Wales and Northern Ireland (NJR) has extended its scope to report on hospital, surgeon and implant performance. Data linkage of the NJR to the London Implant Retrieval Centre (LIRC) has previously evaluated data quality for hip primary procedures, but did not assess revision records. We analysed metal-on-metal hip revision procedures performed between 2003 and 2013. A total of 69 929 revision procedures from the NJR and 929 revised pairs of components from the LIRC were included. We were able to link 716 (77.1%) revision procedures on the NJR to the LIRC. This meant that 213 (22.9%) revision procedures at the LIRC could not be identified on the NJR. We found that 349 (37.6%) explants at the LIRC completed the full linkage process to both NJR primary and revision databases. Data completion was excellent (> 99.9%) for revision procedures reported to the NJR. This study has shown that only approximately one third of retrieved components at the LIRC, contributed to survival curves on the NJR. We recommend prospective registry-retrieval linkage as a tool to feedback missing and erroneous data to the NJR and improve data quality. Prospective Registry - retrieval linkage is a simple tool to evaluate and improve data quality on the NJR. ©2016 Sabah et al.

Efficient sequential and parallel algorithms for record linkage.

PubMed

Mamun, Abdullah-Al; Mi, Tian; Aseltine, Robert; Rajasekaran, Sanguthevar

2014-01-01

Integrating data from multiple sources is a crucial and challenging problem. Even though there exist numerous algorithms for record linkage or deduplication, they suffer from either large time needs or restrictions on the number of datasets that they can integrate. In this paper we report efficient sequential and parallel algorithms for record linkage which handle any number of datasets and outperform previous algorithms. Our algorithms employ hierarchical clustering algorithms as the basis. A key idea that we use is radix sorting on certain attributes to eliminate identical records before any further processing. Another novel idea is to form a graph that links similar records and find the connected components. Our sequential and parallel algorithms have been tested on a real dataset of 1,083,878 records and synthetic datasets ranging in size from 50,000 to 9,000,000 records. Our sequential algorithm runs at least two times faster, for any dataset, than the previous best-known algorithm, the two-phase algorithm using faster computation of the edit distance (TPA (FCED)). The speedups obtained by our parallel algorithm are almost linear. For example, we get a speedup of 7.5 with 8 cores (residing in a single node), 14.1 with 16 cores (residing in two nodes), and 26.4 with 32 cores (residing in four nodes). We have compared the performance of our sequential algorithm with TPA (FCED) and found that our algorithm outperforms the previous one. The accuracy is the same as that of this previous best-known algorithm.

An equivalent viscoelastic model for rock mass with parallel joints

NASA Astrophysics Data System (ADS)

Li, Jianchun; Ma, Guowei; Zhao, Jian

2010-03-01

An equivalent viscoelastic medium model is proposed for rock mass with parallel joints. A concept of "virtual wave source (VWS)" is proposed to take into account the wave reflections between the joints. The equivalent model can be effectively applied to analyze longitudinal wave propagation through discontinuous media with parallel joints. Parameters in the equivalent viscoelastic model are derived analytically based on longitudinal wave propagation across a single rock joint. The proposed model is then verified by applying identical incident waves to the discontinuous and equivalent viscoelastic media at one end to compare the output waves at the other end. When the wavelength of the incident wave is sufficiently long compared to the joint spacing, the effect of the VWS on wave propagation in rock mass is prominent. The results from the equivalent viscoelastic medium model are very similar to those determined from the displacement discontinuity method. Frequency dependence and joint spacing effect on the equivalent viscoelastic model and the VWS method are discussed.

Solution- and solid-phase parallel synthesis of 4-alkoxy-substituted pyrimidines with high molecular diversity.

PubMed

Font, David; Heras, Montserrat; Villalgordo, José M

2003-01-01

A simple and straightforward methodology toward the synthesis of novel 2,6-disubstituted-4-alkoxypyrimidine derivatives of type 16 and 19 has been developed. This methodology, initially developed in solution, can be perfectly adapted to the solid support under analogous conditions, taking full advantage of automated parallel synthesis systems. This successful methodology benefits from the key role played by the thioether linkage placed at the 2-position in 3, 9, or 13 in a double manner: on one side, the steric effect exerted by the thioether linkage is likely to be responsible for the very high observed selectivity toward the formation of the O-alkylation products. On the other side, this sulfur linkage can serve not only as a robust point of attachment for the heterocycle, stable to a number of reaction conditions, but also as a means of introducing a new element of diversity through activation to the corresponding sulfone (safety-catch linker concept) and subsequent ipso-substitution reaction with a variety of different N-nucleophiles.

Relationship of Interfacial Compatibility to Durability of Adhesive - Bonded Joints

DTIC Science & Technology

1981-03-01

same as BR-238, but with the nitrile rubber removed. Because the phenolic matrix resin has different binding properties to the elastomer than do the...primer, which formed phase separated rubber particles having poor mechanical linkage with the matrix resin , resulted in significant loss in shear...having good mechanical linkage with the matrix resin , resulted in good shear strength retention andsignificantly increased toughness. An adhesive

Efficient sequential and parallel algorithms for record linkage

PubMed Central

Mamun, Abdullah-Al; Mi, Tian; Aseltine, Robert; Rajasekaran, Sanguthevar

2014-01-01

Background and objective Integrating data from multiple sources is a crucial and challenging problem. Even though there exist numerous algorithms for record linkage or deduplication, they suffer from either large time needs or restrictions on the number of datasets that they can integrate. In this paper we report efficient sequential and parallel algorithms for record linkage which handle any number of datasets and outperform previous algorithms. Methods Our algorithms employ hierarchical clustering algorithms as the basis. A key idea that we use is radix sorting on certain attributes to eliminate identical records before any further processing. Another novel idea is to form a graph that links similar records and find the connected components. Results Our sequential and parallel algorithms have been tested on a real dataset of 1 083 878 records and synthetic datasets ranging in size from 50 000 to 9 000 000 records. Our sequential algorithm runs at least two times faster, for any dataset, than the previous best-known algorithm, the two-phase algorithm using faster computation of the edit distance (TPA (FCED)). The speedups obtained by our parallel algorithm are almost linear. For example, we get a speedup of 7.5 with 8 cores (residing in a single node), 14.1 with 16 cores (residing in two nodes), and 26.4 with 32 cores (residing in four nodes). Conclusions We have compared the performance of our sequential algorithm with TPA (FCED) and found that our algorithm outperforms the previous one. The accuracy is the same as that of this previous best-known algorithm. PMID:24154837

Biomechanical Effects of Stiffness in Parallel With the Knee Joint During Walking.

PubMed

Shamaei, Kamran; Cenciarini, Massimo; Adams, Albert A; Gregorczyk, Karen N; Schiffman, Jeffrey M; Dollar, Aaron M

2015-10-01

The human knee behaves similarly to a linear torsional spring during the stance phase of walking with a stiffness referred to as the knee quasi-stiffness. The spring-like behavior of the knee joint led us to hypothesize that we might partially replace the knee joint contribution during stance by utilizing an external spring acting in parallel with the knee joint. We investigated the validity of this hypothesis using a pair of experimental robotic knee exoskeletons that provided an external stiffness in parallel with the knee joints in the stance phase. We conducted a series of experiments involving walking with the exoskeletons with four levels of stiffness, including 0%, 33%, 66%, and 100% of the estimated human knee quasi-stiffness, and a pair of joint-less replicas. The results indicated that the ankle and hip joints tend to retain relatively invariant moment and angle patterns under the effects of the exoskeleton mass, articulation, and stiffness. The results also showed that the knee joint responds in a way such that the moment and quasi-stiffness of the knee complex (knee joint and exoskeleton) remains mostly invariant. A careful analysis of the knee moment profile indicated that the knee moment could fully adapt to the assistive moment; whereas, the knee quasi-stiffness fully adapts to values of the assistive stiffness only up to ∼80%. Above this value, we found biarticular consequences emerge at the hip joint.

Impact of equalizing currents on losses and torque ripples in electrical machines with fractional slot concentrated windings

NASA Astrophysics Data System (ADS)

Toporkov, D. M.; Vialcev, G. B.

2017-10-01

The implementation of parallel branches is a commonly used manufacturing method of the realizing of fractional slot concentrated windings in electrical machines. If the rotor eccentricity is enabled in a machine with parallel branches, the equalizing currents can arise. The simulation approach of the equalizing currents in parallel branches of an electrical machine winding based on magnetic field calculation by using Finite Elements Method is discussed in the paper. The high accuracy of the model is provided by the dynamic improvement of the inductances in the differential equation system describing a machine. The pre-computed table flux linkage functions are used for that. The functions are the dependences of the flux linkage of parallel branches on the branches currents and rotor position angle. The functions permit to calculate self-inductances and mutual inductances by partial derivative. The calculated results obtained for the electric machine specimen are presented. The results received show that the adverse combination of design solutions and the rotor eccentricity leads to a high value of the equalizing currents and windings heating. Additional torque ripples also arise. The additional ripples harmonic content is not similar to the cogging torque or ripples caused by the rotor eccentricity.

Parallelizing Timed Petri Net simulations

NASA Technical Reports Server (NTRS)

Nicol, David M.

1993-01-01

The possibility of using parallel processing to accelerate the simulation of Timed Petri Nets (TPN's) was studied. It was recognized that complex system development tools often transform system descriptions into TPN's or TPN-like models, which are then simulated to obtain information about system behavior. Viewed this way, it was important that the parallelization of TPN's be as automatic as possible, to admit the possibility of the parallelization being embedded in the system design tool. Later years of the grant were devoted to examining the problem of joint performance and reliability analysis, to explore whether both types of analysis could be accomplished within a single framework. In this final report, the results of our studies are summarized. We believe that the problem of parallelizing TPN's automatically for MIMD architectures has been almost completely solved for a large and important class of problems. Our initial investigations into joint performance/reliability analysis are two-fold; it was shown that Monte Carlo simulation, with importance sampling, offers promise of joint analysis in the context of a single tool, and methods for the parallel simulation of general Continuous Time Markov Chains, a model framework within which joint performance/reliability models can be cast, were developed. However, very much more work is needed to determine the scope and generality of these approaches. The results obtained in our two studies, future directions for this type of work, and a list of publications are included.

A concise evidence-based physical examination for diagnosis of acromioclavicular joint pathology: a systematic review.

PubMed

Krill, Michael K; Rosas, Samuel; Kwon, KiHyun; Dakkak, Andrew; Nwachukwu, Benedict U; McCormick, Frank

2018-02-01

The clinical examination of the shoulder joint is an undervalued diagnostic tool for evaluating acromioclavicular (AC) joint pathology. Applying evidence-based clinical tests enables providers to make an accurate diagnosis and minimize costly imaging procedures and potential delays in care. The purpose of this study was to create a decision tree analysis enabling simple and accurate diagnosis of AC joint pathology. A systematic review of the Medline, Ovid and Cochrane Review databases was performed to identify level one and two diagnostic studies evaluating clinical tests for AC joint pathology. Individual test characteristics were combined in series and in parallel to improve sensitivities and specificities. A secondary analysis utilized subjective pre-test probabilities to create a clinical decision tree algorithm with post-test probabilities. The optimal special test combination to screen and confirm AC joint pathology combined Paxinos sign and O'Brien's Test, with a specificity of 95.8% when performed in series; whereas, Paxinos sign and Hawkins-Kennedy Test demonstrated a sensitivity of 93.7% when performed in parallel. Paxinos sign and O'Brien's Test demonstrated the greatest positive likelihood ratio (2.71); whereas, Paxinos sign and Hawkins-Kennedy Test reported the lowest negative likelihood ratio (0.35). No combination of special tests performed in series or in parallel creates more than a small impact on post-test probabilities to screen or confirm AC joint pathology. Paxinos sign and O'Brien's Test is the only special test combination that has a small and sometimes important impact when used both in series and in parallel. Physical examination testing is not beneficial for diagnosis of AC joint pathology when pretest probability is unequivocal. In these instances, it is of benefit to proceed with procedural tests to evaluate AC joint pathology. Ultrasound-guided corticosteroid injections are diagnostic and therapeutic. An ultrasound-guided AC joint corticosteroid injection may be an appropriate new standard for treatment and surgical decision-making. II - Systematic Review.

Changes in collagen fibril network organization and proteoglycan distribution in equine articular cartilage during maturation and growth

PubMed Central

Hyttinen, Mika M; Holopainen, Jaakko; René van Weeren, P; Firth, Elwyn C; Helminen, Heikki J; Brama, Pieter A J

2009-01-01

The aim of this study was to record growth-related changes in collagen network organization and proteoglycan distribution in intermittently peak-loaded and continuously lower-level-loaded articular cartilage. Cartilage from the proximal phalangeal bone of the equine metacarpophalangeal joint at birth, at 5, 11 and 18 months, and at 6–10 years of age was collected from two sites. Site 1, at the joint margin, is unloaded at slow gaits but is subjected to high-intensity loading during athletic activity; site 2 is a continuously but less intensively loaded site in the centre of the joint. The degree of collagen parallelism was determined with quantitative polarized light microscopy and the parallelism index for collagen fibrils was computed from the cartilage surface to the osteochondral junction. Concurrent changes in the proteoglycan distribution were quantified with digital densitometry. We found that the parallelism index increased significantly with age (up to 90%). At birth, site 2 exhibited a more organized collagen network than site 1. In adult horses this situation was reversed. The superficial and intermediate zones exhibited the greatest reorganization of collagen. Site 1 had a higher proteoglycan content than site 2 at birth but here too the situation was reversed in adult horses. We conclude that large changes in joint loading during growth and maturation in the period from birth to adulthood profoundly affect the architecture of the collagen network in equine cartilage. In addition, the distribution and content of proteoglycans are modified significantly by altered joint use. Intermittent peak-loading with shear seems to induce higher collagen parallelism and a lower proteoglycan content in cartilage than more constant weight-bearing. Therefore, we hypothesize that the formation of mature articular cartilage with a highly parallel collagen network and relatively low proteoglycan content in the peak-loaded area of a joint is needed to withstand intermittent stress and shear, whereas a constantly weight-bearing joint area benefits from lower collagen parallelism and a higher proteoglycan content. PMID:19732210

Posterior probability of linkage and maximal lod score.

PubMed

Génin, E; Martinez, M; Clerget-Darpoux, F

1995-01-01

To detect linkage between a trait and a marker, Morton (1955) proposed to calculate the lod score z(theta 1) at a given value theta 1 of the recombination fraction. If z(theta 1) reaches +3 then linkage is concluded. However, in practice, lod scores are calculated for different values of the recombination fraction between 0 and 0.5 and the test is based on the maximum value of the lod score Zmax. The impact of this deviation of the test on the probability that in fact linkage does not exist, when linkage was concluded, is documented here. This posterior probability of no linkage can be derived by using Bayes' theorem. It is less than 5% when the lod score at a predetermined theta 1 is used for the test. But, for a Zmax of +3, we showed that it can reach 16.4%. Thus, considering a composite alternative hypothesis instead of a single one decreases the reliability of the test. The reliability decreases rapidly when Zmax is less than +3. Given a Zmax of +2.5, there is a 33% chance that linkage does not exist. Moreover, the posterior probability depends not only on the value of Zmax but also jointly on the family structures and on the genetic model. For a given Zmax, the chance that linkage exists may then vary.

Horizontal slip along Alleghanian joints of the Appalachian plateau: evidence showing that mild penetrative strain does little to change the pristine appearance of early joints

NASA Astrophysics Data System (ADS)

Engelder, Terry; Haith, Benjamin F.; Younes, Amgad

2001-07-01

Some Alleghanian joints in black shales of the Geneseo and Middlesex Formations of the Catskill Delta complex, Finger Lakes district, New York, slipped horizontally up to 8 cm. Horizontal slip is measured by the offset of ENE-striking joints. Alleghanian joints striking 330-350° display a right-lateral slip with an average value of 1.9 cm, while joints striking 004-010° slip in the left-lateral sense with an average value of 1.3 cm. The maximum horizontal stress (SH) driving this slip falls between 350° and 004°, the orientation of local Alleghanian layer-parallel shortening as indicated by both disjunctive and pencil cleavage. By commonality of orientation, we infer that slip on Alleghanian joints is driven contemporaneously with layer-parallel shortening. If so, the offset ENE-striking joints predate the Alleghanian stress field. These observations mean that both pre-Alleghanian and early Alleghanian joints persist through a period of penetrative strain.

30 CFR 7.302 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... conduit box when specified. A motor assembly is comprised of one or more explosion-proof enclosures. Plane joint. A joint comprised of two adjoining surfaces in parallel planes. Step (rabbet) joint. A joint.... A step joint may be composed of a cylindrical portion and a plane portion or of two or more plane...

Discrimination of portraits using a hybrid parallel joint transform correlator system

NASA Astrophysics Data System (ADS)

Inaba, Rieko; Hashimoto, Asako; Kodate, Kashiko

1999-05-01

A hybrid parallel joint transform correlation system is demonstrated through the introduction of a five-channel binary zone plate array and is applied to the discrimination of portraits for a presumed criminal investigation. In order to improve performance, we adopt pe-processing of images with white area of 20%. Furthermore, we discuss the robustness.

Linkage of early-onset osteoarthritis and chondrocalcinosis to human chromosome 8q

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baldwin, C.T.; Farrer, L.A.; Adair, R.

Calcium pyrophosphate-deposition disease (CPDD), also called {open_quotes}chondrocalcinosis{close_quotes} or {open_quotes}pseudogout{close_quotes}, is a disorder characterized by the deposition of calcium-containing crystals in joint tissue, which leads to arthritis-like symptoms. The presence of these crystals in joint tissue is a common finding in the elderly, and, in this population, there is a poor correlation with joint pain. In contrast, early-onset CPDD has been described in several large families in which the disease progresses to severe degenerative osteoarthritis (OA). In these families, an autosomal dominant mode of inheritance is observed, with an age at onset between the 2nd and 5th decades of life. Inmore » this report, we describe a large New England family with early-onset CPDD and severe degenerative OA. We found genetic linkage between the disease in this family and chromosome 8q, with a multipoint lod score of 4.06. These results suggest that a defective gene at this location causes the disease in this family. 29 refs., 2 figs., 1 tab.« less

Internally supported flexible duct joint. [device for conducting fluids in high pressure systems

NASA Technical Reports Server (NTRS)

Kuhn, R. F., Jr. (Inventor)

1975-01-01

An internally supported, flexible duct joint for use in conducting fluids under relatively high pressures in systems where relatively large deflection angles must be accommodated is presented. The joint includes a flexible tubular bellows and an elongated base disposed within the bellows. The base is connected through radiating struts to the bellows near mid-portion and to each of the opposite end portions of the bellows through a pivotal connecting body. A motion-controlling linkage is provided for linking the connecting bodies, whereby angular displacement of the joint is controlled and uniformity in the instantaneous bend radius of the duct is achieved as deflection is imposed.

A Parallel and Distributed Processing Model of Joint Attention, Social-Cognition and Autism

PubMed Central

Mundy, Peter; Sullivan, Lisa; Mastergeorge, Ann M.

2009-01-01

Scientific Abstract The impaired development of joint attention is a cardinal feature of autism. Therefore, understanding the nature of joint attention is a central to research on this disorder. Joint attention may be best defined in terms of an information processing system that begins to develop by 4–6 months of age. This system integrates the parallel processing of internal information about one’s own visual attention with external information about the visual attention of other people. This type of joint encoding of information about self and other attention requires the activation of a distributed anterior and posterior cortical attention network. Genetic regulation, in conjunction with self-organizing behavioral activity guides the development of functional connectivity in this network. With practice in infancy the joint processing of self-other attention becomes automatically engaged as an executive function. It can be argued that this executive joint-attention is fundamental to human learning, as well as the development of symbolic thought, social-cognition and social-competence throughout the life span. One advantage of this parallel and distributed processing model of joint attention (PDPM) is that it directly connects theory on social pathology to a range of phenomenon in autism associated with neural connectivity, constructivist and connectionist models of cognitive development, early intervention, activity-dependent gene expression, and atypical ocular motor control. PMID:19358304

Motion capability analysis of a quadruped robot as a parallel manipulator

NASA Astrophysics Data System (ADS)

Yu, Jingjun; Lu, Dengfeng; Zhang, Zhongxiang; Pei, Xu

2014-12-01

This paper presents the forward and inverse displacement analysis of a quadruped robot MANA as a parallel manipulator in quadruple stance phase, which is used to obtain the workspace and control the motion of the body. The robot MANA designed on the basis of the structure of quadruped mammal is able to not only walk and turn in the uneven terrain, but also accomplish various manipulating tasks as a parallel manipulator in quadruple stance phase. The latter will be the focus of this paper, however. For this purpose, the leg kinematics is primarily analyzed, which lays the foundation on the gait planning in terms of locomotion and body kinematics analysis as a parallel manipulator. When all four feet of the robot contact on the ground, by assuming there is no slipping at the feet, each contacting point is treated as a passive spherical joint and the kinematic model of parallel manipulator is established. The method for choosing six non-redundant actuated joints for the parallel manipulator from all twelve optional joints is elaborated. The inverse and forward displacement analysis of the parallel manipulator is carried out using the method of coordinate transformation. Finally, based on the inverse and forward kinematic model, two issues on obtaining the reachable workspace of parallel manipulator and planning the motion of the body are implemented and verified by ADAMS simulation.

Reevaluating Musculoskeletal Linkages in Suction-Feeding Fishes with X-Ray Reconstruction of Moving Morphology (XROMM).

PubMed

Camp, Ariel L; Brainerd, Elizabeth L

2015-07-01

Suction-feeding fishes encompass a vast diversity of morphologies and ecologies, but during feeding they all rely on musculoskeletal linkages and levers to transform the shortening of muscle into 3D expansion of the mouth cavity. To relate the shape of these skeletal elements to their function in expansion of the mouth, four-bar linkage models have been developed and widely used in studies of ecology, evolution, and development. However, we have lacked the ability to test the predictions of these 2D linkage models against the actual 3D motions of fishes' skulls. A new imaging method, X-ray Reconstruction of Moving Morphology (XROMM), now makes it possible to measure 3D skeletal motions relative to other bones within the head and relative to the fish's body, and thereby to examine directly the proposed linkages. We used XROMM to examine the opercular linkage, in which shortening of the levator operculi muscle is hypothesized to retract the operculum, and thereby the interoperculum and interoperculomandibular ligament to generate depression of the lower jaw about the quadratomandibular joint. XROMM animations of suction strikes in largemouth bass revealed that the operculum is indeed retracted relative to the suspensorium as the levator operculi muscle shortens and the jaw depresses. However, the four-bar model of this linkage overestimates the depression of the jaw by nearly a factor of two. Therefore, caution should be used in interpreting and applying the predictions of this linkage model. When we measured kinematics relative to the fish's body, we found that the operculum was relatively stable, whereas the suspensorium was elevated along with the neurocranium, pushing the quadratomandibular joint forward to produce depression of the jaw. Thus, it is the epaxial muscles elevating the neurocranium that powers depression of the jaw through the opercular linkage. However, the levator operculi muscle plays a crucial role in stabilizing the operculum to allow elevation of the head to produce depression of the lower jaw. These results support the role of cranial muscles in controlling and transmitting power from the axial muscles, rather than generating substantial power themselves. We also demonstrate the utility of XROMM for assessing the function of this, and other, cranial linkages in suction-feeding fishes. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

Self-referenced processing, neurodevelopment and joint attention in autism.

PubMed

Mundy, Peter; Gwaltney, Mary; Henderson, Heather

2010-09-01

This article describes a parallel and distributed processing model (PDPM) of joint attention, self-referenced processing and autism. According to this model, autism involves early impairments in the capacity for rapid, integrated processing of self-referenced (proprioceptive and interoceptive) and other-referenced (exteroceptive) information. Measures of joint attention have proven useful in research on autism because they are sensitive to the early development of the 'parallel' and integrated processing of self- and other-referenced stimuli. Moreover, joint attention behaviors are a consequence, but also an organizer of the functional development of a distal distributed cortical system involving anterior networks including the prefrontal and insula cortices, as well as posterior neural networks including the temporal and parietal cortices. Measures of joint attention provide early behavioral indicators of atypical development in this parallel and distributed processing system in autism. In addition it is proposed that an early, chronic disturbance in the capacity for integrating self- and other-referenced information may have cascading effects on the development of self awareness in autism. The assumptions, empirical support and future research implications of this model are discussed.

Linkage of the gene that encodes the alpha 1 chain of type V collagen (COL5A1) to type II Ehlers-Danlos syndrome (EDS II).

PubMed

Loughlin, J; Irven, C; Hardwick, L J; Butcher, S; Walsh, S; Wordsworth, P; Sykes, B

1995-09-01

Ehlers-Danlos syndrome (EDS) is a group of heritable disorders of connective tissue with skin, ligaments and blood vessels being the main sites affected. The commonest variant (EDS II) exhibits an autosomal dominant mode of inheritance and is characterized by joint hypermobility, cigarette paper scars, lax skin and excessive bruising. As yet no gene has been linked to EDS II, nor has linkage been established to a specific region of the genome. However, several candidate genes encoding proteins of the extracellular matrix have been excluded. Using an intragenic simple sequence repeat polymorphism, we report linkage of the COL5A1 gene, which encodes the alpha 1(V) chain of type V collagen, to EDS II. A maximum LOD score (Zmax) for linkage of 8.3 at theta = 0.00 was generated for a single large pedigree.

Activation of preexisting transverse structures in an evolving magmatic rift in East Africa

NASA Astrophysics Data System (ADS)

Muirhead, J. D.; Kattenhorn, S. A.

2018-01-01

Inherited crustal weaknesses have long been recognized as important factors in strain localization and basin development in the East African Rift System (EARS). However, the timing and kinematics (e.g., sense of slip) of transverse (rift-oblique) faults that exploit these weaknesses are debated, and thus the roles of inherited weaknesses at different stages of rift basin evolution are often overlooked. The mechanics of transverse faulting were addressed through an analysis of the Kordjya fault of the Magadi basin (Kenya Rift). Fault kinematics were investigated from field and remote-sensing data collected on fault and joint systems. Our analysis indicates that the Kordjya fault consists of a complex system of predominantly NNE-striking, rift-parallel fault segments that collectively form a NNW-trending array of en echelon faults. The transverse Kordjya fault therefore reactivated existing rift-parallel faults in ∼1 Ma lavas as oblique-normal faults with a component of sinistral shear. In all, these fault motions accommodate dip-slip on an underlying transverse structure that exploits the Aswa basement shear zone. This study shows that transverse faults may be activated through a complex interplay among magma-assisted strain localization, preexisting structures, and local stress rotations. Rather than forming during rift initiation, transverse structures can develop after the establishment of pervasive rift-parallel fault systems, and may exhibit dip-slip kinematics when activated from local stress rotations. The Kordjya fault is shown here to form a kinematic linkage that transfers strain to a newly developing center of concentrated magmatism and normal faulting. It is concluded that recently activated transverse faults not only reveal the effects of inherited basement weaknesses on fault development, but also provide important clues regarding developing magmatic and tectonic systems as young continental rift basins evolve.

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

DOE PAGES

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton; ...

2016-11-23

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Parallel elastic elements improve energy efficiency on the STEPPR bipedal walking robot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mazumdar, Anirban; Spencer, Steven J.; Hobart, Clinton

This study describes how parallel elastic elements can be used to reduce energy consumption in the electric motor driven, fully-actuated, STEPPR bipedal walking robot without compromising or significantly limiting locomotive behaviors. A physically motivated approach is used to illustrate how selectively-engaging springs for hip adduction and ankle flexion predict benefits for three different flat ground walking gaits: human walking, human-like robot walking and crouched robot walking. Based on locomotion data, springs are designed and substantial reductions in power consumption are demonstrated using a bench dynamometer. These lessons are then applied to STEPPR (Sandia Transmission-Efficient Prototype Promoting Research), a fully actuatedmore » bipedal robot designed to explore the impact of tailored joint mechanisms on walking efficiency. Featuring high-torque brushless DC motors, efficient low-ratio transmissions, and high fidelity torque control, STEPPR provides the ability to incorporate novel joint-level mechanisms without dramatically altering high level control. Unique parallel elastic designs are incorporated into STEPPR, and walking data shows that hip adduction and ankle flexion springs significantly reduce the required actuator energy at those joints for several gaits. These results suggest that parallel joint springs offer a promising means of supporting quasi-static joint torques due to body mass during walking, relieving motors of the need to support these torques and substantially improving locomotive energy efficiency.« less

Recent progress in the joint velocity-scalar PDF method

NASA Technical Reports Server (NTRS)

Anand, M. S.

1995-01-01

This viewgraph presentation discusses joint velocity-scalar PDF method; turbulent combustion modeling issues for gas turbine combustors; PDF calculations for a recirculating flow; stochastic dissipation model; joint PDF calculations for swirling flows; spray calculations; reduced kinetics/manifold methods; parallel processing; and joint PDF focus areas.

Robot Hand Grips Cylinders Securely

NASA Technical Reports Server (NTRS)

Parma, George F.

1989-01-01

Jaws and linkage accommodate various sizes. Robot hand includes two pairs of parallel jaws that grasp rods, pipes, tubes, struts, and other long, heavy cylindrical objects. Hand features compact rotary drive and butterfly configuration simplifying approach and gripping maneuvers of robot. Parallelogram linkages maintain alignment of each jaw with other jaws. One bar of each linkage connected to one of two concentric, counterrotating shafts; rotation of shafts moves jaws in each pair toward or away from each other to grasp or release workpiece. Each jaw includes rigid gripping pad lined with rubber to give firm grip and to prevent damage to workpiece. Inner cylindrical surface (corner) of each jaw tapers off to flat sides. Enables jaw to grasp workpieces with diameters larger than or equal to twice the corner radius.

Kinematic Analysis and Performance Evaluation of Novel PRS Parallel Mechanism

NASA Astrophysics Data System (ADS)

Balaji, K.; Khan, B. Shahul Hamid

2018-02-01

In this paper, a 3 DoF (Degree of Freedom) novel PRS (Prismatic-Revolute- Spherical) type parallel mechanisms has been designed and presented. The combination of striaght and arc type linkages for 3 DOF parallel mechanism is introduced for the first time. The performances of the mechanisms are evaluated based on the indices such as Minimum Singular Value (MSV), Condition Number (CN), Local Conditioning Index (LCI), Kinematic Configuration Index (KCI) and Global Conditioning Index (GCI). The overall reachable workspace of all mechanisms are presented. The kinematic measure, dexterity measure and workspace analysis for all the mechanism have been evaluated and compared.

Modified Denavit-Hartenberg parameters for better location of joint axis systems in robot arms

NASA Technical Reports Server (NTRS)

Barker, L. K.

1986-01-01

The Denavit-Hartenberg parameters define the relative location of successive joint axis systems in a robot arm. A recent justifiable criticism is that one of these parameters becomes extremely large when two successive joints have near-parallel rotational axes. Geometrically, this parameter then locates a joint axis system at an excessive distance from the robot arm and, computationally, leads to an ill-conditioned transformation matrix. In this paper, a simple modification (which results from constraining a transverse vector between successive joint rotational axes to be normal to one of the rotational axes, instead of both) overcomes this criticism and favorably locates the joint axis system. An example is given for near-parallel rotational axes of the elbow and shoulder joints in a robot arm. The regular and modified parameters are extracted by an algebraic method with simulated measurement data. Unlike the modified parameters, extracted values of the regular parameters are very sensitive to measurement accuracy.

Investigation of deterioration of joints in concrete pavements.

DOT National Transportation Integrated Search

2016-01-01

Premature deterioration of concrete at the joints in concrete pavements and parking lots has been reported across the northern states. The distress may first appear as shadowing when microcracking near the joints traps water, or as cracks parallel to...

Anatomical landmarks of the distal femoral condyles are not always parallel to the tibial bone cut surface in flexion during total knee arthroplasty.

PubMed

Itokazu, Maki; Minoda, Yukihide; Ikebuchi, Mitsuhiko; Mizokawa, Shigekazu; Ohta, Yoichi; Nakamura, Hiroaki

2016-08-01

Soft tissue balancing is crucial to the success of total knee arthroplasty (TKA). To create a rectangular flexion joint gap, the rotation of the femoral component is important. The purpose of this study is to determine whether or not anatomical landmarks of the distal femoral condyles are parallel to the tibial bone cut surface in flexion. Forty-eight patients (three male and 45 female) with a mean age of 74years were examined. During the operation, we estimated the flexion joint gap with the following three techniques. 1) a three degree external cut to the posterior condylar line (MR1), 2) a parallel cut to the surgical transepicondylar axis (MR2), and 3) a parallel cut to the anatomical transepicondylar axis (MR3). The flexion joint gap was 1.1±3.0° (mean±standard deviation (SD)) in internal rotation in the case of MR1, 0.9±3.4° in internal rotation in the case of MR2, and 2.1±3.4° in external rotation in the case of MR3. An outlier (flexion joint gap >3.0°) was observed in 12 cases (25%) in MR1, 13 cases (27%) in MR2, and 15 cases (31%) in MR3. The anatomical landmarks of the distal femoral condyles are not always parallel to the tibial bone cut surface in flexion. To create a rectangular flexion joint gap, the rotation of the femoral component rotation is based not only on the anatomical landmarks but also on the ligament balance. Copyright © 2016 Elsevier B.V. All rights reserved.

[Environment and the "Health in All Policies" approach-an overview].

PubMed

Zeeb, Hajo; Hilderink, Henk; Forberger, Sarah

2018-06-01

One quarter of the global disease burden could be avoided with management strategies for environmental risk factors such as air and water pollution, food contamination, injuries and poor road safety. Many decisions influencing health are made outside the health sector; thus, the joint consideration and implementation of health and environmental factors in the relevant policies are becoming increasingly important. By means of a selective literature search, we identified important policy documents and selected research articles as a basis for the introduction and current discussion of the Health in All Policies (HiAP) approach. Parallels with the Environment in All Policies (EIAP) approach are debated. The consideration and reinforcement of environmental topics in HiAP and the link with health in the EiAP approach increase the chances of policies with mutually positive effects, especially with regard to the significance of social factors for health and the environment. The UN Sustainable Development Goals provide a good starting point for a joint strategy for reinforcing health and environmental aspects. Health and Environmental Impact Assessments are accepted procedures in many countries. The HiAP strategy implemented in South Australia provides a well-documented institutional approach to the integration and linkage of health and environmental issues. These examples can be used as well-established starting points for a definition of HiAP incorporating the equitable involvement of environmental issues. Barriers to this goal relate, for example, to the particular interests of the various participating sectors.

Active lower limb orthosis with one degree of freedom for people with paraplegia.

PubMed

Gloger, Michal; Obinata, Goro; Genda, Eiichi; Babjak, Jan; Pei, Yanling

2017-07-01

The main challenges of designing devices for paraplegic walking can be summarized into three groups, stability and comfort, high efficiency or low energy consumption, dimensions and weight. A new economical device for people with paraplegia which tackles all problems of the three groups is introduced in this paper. The main idea of this device is based on HALO mechanism. HALO is compact passive medial hip joint orthosis with contralateral hip and ankle linkage, which keeps the feet always parallel to the ground and assists swinging the leg. The medial hip joint is equipped with one actuator in the new design and the new orthosis is called @halo. Due to this update, we can achieve more stable and smoother walking patterns with decreased energy consumption of the users, yet maintain its compact and lightweight features. It is proven by the results from preliminary experiments with able-bodied subjects during which the same device with and without actuator was evaluated. Waddling and excessive vertical elevation of the center of gravity were decreased by 40% with significantly smaller standard deviations in case of the active orthosis. There was 52% less energy spent by the user wearing @halo which was calculated from the vertical excursion difference. There was measured 38.5% bigger impulse in crutches while using passive orthosis. The new @halo device is the first active orthosis for lower limbs with just one actuated degree of freedom for users with paraplegia.

Conclusions from the investigation of deterioration of joints in concrete pavements.

DOT National Transportation Integrated Search

2016-02-01

Premature deterioration of concrete at the joints in concrete pavements and parking lots has been reported across the northern : states. The distress may first appear as shadowing when microcracking near the joints traps water, or as cracks parallel ...

Numerical Model for the Study of the Strength and Failure Modes of Rock Containing Non-Persistent Joints

NASA Astrophysics Data System (ADS)

Vergara, Maximiliano R.; Van Sint Jan, Michel; Lorig, Loren

2016-04-01

The mechanical behavior of rock containing parallel non-persistent joint sets was studied using a numerical model. The numerical analysis was performed using the discrete element software UDEC. The use of fictitious joints allowed the inclusion of non-persistent joints in the model domain and simulating the progressive failure due to propagation of existing fractures. The material and joint mechanical parameters used in the model were obtained from experimental results. The results of the numerical model showed good agreement with the strength and failure modes observed in the laboratory. The results showed the large anisotropy in the strength resulting from variation of the joint orientation. Lower strength of the specimens was caused by the coalescence of fractures belonging to parallel joint sets. A correlation was found between geometrical parameters of the joint sets and the contribution of the joint sets strength in the global strength of the specimen. The results suggest that for the same dip angle with respect to the principal stresses; the uniaxial strength depends primarily on the joint spacing and the angle between joints tips and less on the length of the rock bridges (persistency). A relation between joint geometrical parameters was found from which the resulting failure mode can be predicted.

The influence of hand positions on biomechanical injury risk factors at the wrist joint during the round-off skills in female gymnastics.

PubMed

Farana, Roman; Jandacka, Daniel; Uchytil, Jaroslav; Zahradnik, David; Irwin, Gareth

2017-01-01

The aim of this study was to examine the biomechanical injury risk factors at the wrist, including joint kinetics, kinematics and stiffness in the first and second contact limb for parallel and T-shape round-off (RO) techniques. Seven international-level female gymnasts performed 10 trials of the RO to back handspring with parallel and T-shape hand positions. Synchronised kinematic (3D motion analysis system; 247 Hz) and kinetic (two force plates; 1235 Hz) data were collected for each trial. A two-way repeated measure analysis of variance (ANOVA) assessed differences in the kinematic and kinetic parameters between the techniques for each contact limb. The main findings highlighted that in both the RO techniques, the second contact limb wrist joint is exposed to higher mechanical loads than the first contact limb demonstrated by increased axial compression force and loading rate. In the parallel technique, the second contact limb wrist joint is exposed to higher axial compression load. Differences between wrist joint kinetics highlight that the T-shape technique may potentially lead to reducing these bio-physical loads and consequently protect the second contact limb wrist joint from overload and biological failure. Highlighting the biomechanical risk factors facilitates the process of technique selection making more objective and safe.

Conclusions from the investigation of deterioration of joints in concrete pavements : intrans project reports.

DOT National Transportation Integrated Search

2016-02-01

Premature deterioration of concrete at the joints in concrete pavements and parking lots has been reported across the northern : states. The distress may first appear as shadowing when microcracking near the joints traps water, or as cracks parallel ...

Joint linkage and association analysis with exome sequence data implicates SLC25A40 in hypertriglyceridemia.

PubMed

Rosenthal, Elisabeth A; Ranchalis, Jane; Crosslin, David R; Burt, Amber; Brunzell, John D; Motulsky, Arno G; Nickerson, Deborah A; Wijsman, Ellen M; Jarvik, Gail P

2013-12-05

Hypertriglyceridemia (HTG) is a heritable risk factor for cardiovascular disease. Investigating the genetics of HTG may identify new drug targets. There are ~35 known single-nucleotide variants (SNVs) that explain only ~10% of variation in triglyceride (TG) level. Because of the genetic heterogeneity of HTG, a family study design is optimal for identification of rare genetic variants with large effect size because the same mutation can be observed in many relatives and cosegregation with TG can be tested. We considered HTG in a five-generation family of European American descent (n = 121), ascertained for familial combined hyperlipidemia. By using Bayesian Markov chain Monte Carlo joint oligogenic linkage and association analysis, we detected linkage to chromosomes 7 and 17. Whole-exome sequence data revealed shared, highly conserved, private missense SNVs in both SLC25A40 on chr7 and PLD2 on chr17. Jointly, these SNVs explained 49% of the genetic variance in TG; however, only the SLC25A40 SNV was significantly associated with TG (p = 0.0001). This SNV, c.374A>G, causes a highly disruptive p.Tyr125Cys substitution just outside the second helical transmembrane region of the SLC25A40 inner mitochondrial membrane transport protein. Whole-gene testing in subjects from the Exome Sequencing Project confirmed the association between TG and SLC25A40 rare, highly conserved, coding variants (p = 0.03). These results suggest a previously undescribed pathway for HTG and illustrate the power of large pedigrees in the search for rare, causal variants. Copyright © 2013 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Quality control/quality assurance testing for joint density and segregation of asphalt mixtures : tech transfer summary.

DOT National Transportation Integrated Search

2013-04-01

A longitudinal joint is the interface between two adjacent and parallel hot-mix asphalt (HMA) mats. Inadequate joint construction can lead to a location where water can penetrate the pavement layers and reduce the structural support of the underlying...

Computational Methods for Structural Mechanics and Dynamics

NASA Technical Reports Server (NTRS)

Stroud, W. Jefferson (Editor); Housner, Jerrold M. (Editor); Tanner, John A. (Editor); Hayduk, Robert J. (Editor)

1989-01-01

Topics addressed include: transient dynamics; transient finite element method; transient analysis in impact and crash dynamic studies; multibody computer codes; dynamic analysis of space structures; multibody mechanics and manipulators; spatial and coplanar linkage systems; flexible body simulation; multibody dynamics; dynamical systems; and nonlinear characteristics of joints.

Programmable motion of DNA origami mechanisms.

PubMed

Marras, Alexander E; Zhou, Lifeng; Su, Hai-Jun; Castro, Carlos E

2015-01-20

DNA origami enables the precise fabrication of nanoscale geometries. We demonstrate an approach to engineer complex and reversible motion of nanoscale DNA origami machine elements. We first design, fabricate, and characterize the mechanical behavior of flexible DNA origami rotational and linear joints that integrate stiff double-stranded DNA components and flexible single-stranded DNA components to constrain motion along a single degree of freedom and demonstrate the ability to tune the flexibility and range of motion. Multiple joints with simple 1D motion were then integrated into higher order mechanisms. One mechanism is a crank-slider that couples rotational and linear motion, and the other is a Bennett linkage that moves between a compacted bundle and an expanded frame configuration with a constrained 3D motion path. Finally, we demonstrate distributed actuation of the linkage using DNA input strands to achieve reversible conformational changes of the entire structure on ∼ minute timescales. Our results demonstrate programmable motion of 2D and 3D DNA origami mechanisms constructed following a macroscopic machine design approach.

Programmable motion of DNA origami mechanisms

PubMed Central

Marras, Alexander E.; Zhou, Lifeng; Su, Hai-Jun; Castro, Carlos E.

2015-01-01

DNA origami enables the precise fabrication of nanoscale geometries. We demonstrate an approach to engineer complex and reversible motion of nanoscale DNA origami machine elements. We first design, fabricate, and characterize the mechanical behavior of flexible DNA origami rotational and linear joints that integrate stiff double-stranded DNA components and flexible single-stranded DNA components to constrain motion along a single degree of freedom and demonstrate the ability to tune the flexibility and range of motion. Multiple joints with simple 1D motion were then integrated into higher order mechanisms. One mechanism is a crank–slider that couples rotational and linear motion, and the other is a Bennett linkage that moves between a compacted bundle and an expanded frame configuration with a constrained 3D motion path. Finally, we demonstrate distributed actuation of the linkage using DNA input strands to achieve reversible conformational changes of the entire structure on ∼minute timescales. Our results demonstrate programmable motion of 2D and 3D DNA origami mechanisms constructed following a macroscopic machine design approach. PMID:25561550

Linkage design effect on the reliability of surface-micromachined microengines driving a load

NASA Astrophysics Data System (ADS)

Tanner, Danelle M.; Peterson, Kenneth A.; Irwin, Lloyd W.; Tangyunyong, Paiboon; Miller, William M.; Eaton, William P.; Smith, Norman F.; Rodgers, M. Steven

1998-09-01

The reliability of microengines is a function of the design of the mechanical linkage used to connect the electrostatic actuator to the drive. We have completed a series of reliability stress tests on surface micromachined microengines driving an inertial load. In these experiments, we used microengines that had pin mechanisms with guides connecting the drive arms to the electrostatic actuators. Comparing this data to previous results using flexure linkages revealed that the pin linkage design was less reliable. The devices were stressed to failure at eight frequencies, both above and below the measured resonance frequency of the microengine. Significant amounts of wear debris were observed both around the hub and pin joint of the drive gear. Additionally, wear tracks were observed in the area where the moving shuttle rubbed against the guides of the pin linkage. At each frequency, we analyzed the statistical data yielding a lifetime (t50) for median cycles to failure and (sigma) , the shape parameter of the distribution. A model was developed to describe the failure data based on fundamental wear mechanisms and forces exhibited in mechanical resonant systems. The comparison to the model will be discussed.

Momentum-Based Dynamics for Spacecraft with Chained Revolute Appendages

NASA Technical Reports Server (NTRS)

Queen, Steven; London, Ken; Gonzalez, Marcelo

2005-01-01

An efficient formulation is presented for a sub-class of multi-body dynamics problems that involve a six degree-of-freedom base body and a chain of N rigid linkages connected in series by single degree-of-freedom revolute joints. This general method is particularly well suited for simulations of spacecraft dynamics and control that include the modeling of an orbiting platform with or without internal degrees of freedom such as reaction wheels, dampers, and/or booms. In the present work, particular emphasis is placed on dynamic simulation of multi-linkage robotic manipulators. The differential equations of motion are explicitly given in terms of linear and angular momentum states, which can be evaluated recursively along a serial chain of linkages for an efficient real-time solution on par with the best of the O(N3) methods.

Error Modeling and Experimental Study of a Flexible Joint 6-UPUR Parallel Six-Axis Force Sensor.

PubMed

Zhao, Yanzhi; Cao, Yachao; Zhang, Caifeng; Zhang, Dan; Zhang, Jie

2017-09-29

By combining a parallel mechanism with integrated flexible joints, a large measurement range and high accuracy sensor is realized. However, the main errors of the sensor involve not only assembly errors, but also deformation errors of its flexible leg. Based on a flexible joint 6-UPUR (a kind of mechanism configuration where U-universal joint, P-prismatic joint, R-revolute joint) parallel six-axis force sensor developed during the prephase, assembly and deformation error modeling and analysis of the resulting sensors with a large measurement range and high accuracy are made in this paper. First, an assembly error model is established based on the imaginary kinematic joint method and the Denavit-Hartenberg (D-H) method. Next, a stiffness model is built to solve the stiffness matrix. The deformation error model of the sensor is obtained. Then, the first order kinematic influence coefficient matrix when the synthetic error is taken into account is solved. Finally, measurement and calibration experiments of the sensor composed of the hardware and software system are performed. Forced deformation of the force-measuring platform is detected by using laser interferometry and analyzed to verify the correctness of the synthetic error model. In addition, the first order kinematic influence coefficient matrix in actual circumstances is calculated. By comparing the condition numbers and square norms of the coefficient matrices, the conclusion is drawn theoretically that it is very important to take into account the synthetic error for design stage of the sensor and helpful to improve performance of the sensor in order to meet needs of actual working environments.

Error Modeling and Experimental Study of a Flexible Joint 6-UPUR Parallel Six-Axis Force Sensor

PubMed Central

Zhao, Yanzhi; Cao, Yachao; Zhang, Caifeng; Zhang, Dan; Zhang, Jie

2017-01-01

By combining a parallel mechanism with integrated flexible joints, a large measurement range and high accuracy sensor is realized. However, the main errors of the sensor involve not only assembly errors, but also deformation errors of its flexible leg. Based on a flexible joint 6-UPUR (a kind of mechanism configuration where U-universal joint, P-prismatic joint, R-revolute joint) parallel six-axis force sensor developed during the prephase, assembly and deformation error modeling and analysis of the resulting sensors with a large measurement range and high accuracy are made in this paper. First, an assembly error model is established based on the imaginary kinematic joint method and the Denavit-Hartenberg (D-H) method. Next, a stiffness model is built to solve the stiffness matrix. The deformation error model of the sensor is obtained. Then, the first order kinematic influence coefficient matrix when the synthetic error is taken into account is solved. Finally, measurement and calibration experiments of the sensor composed of the hardware and software system are performed. Forced deformation of the force-measuring platform is detected by using laser interferometry and analyzed to verify the correctness of the synthetic error model. In addition, the first order kinematic influence coefficient matrix in actual circumstances is calculated. By comparing the condition numbers and square norms of the coefficient matrices, the conclusion is drawn theoretically that it is very important to take into account the synthetic error for design stage of the sensor and helpful to improve performance of the sensor in order to meet needs of actual working environments. PMID:28961209

Genetic Epidemiology of Cigarette Smoke–Induced Lung Disease

PubMed Central

2012-01-01

Chronic obstructive pulmonary disease (COPD) and lung cancer represent two diseases that share a strong risk factor in smoking, and COPD increases risk of lung cancer even after adjusting for the effects of smoking. These diseases not only occur jointly within an individual but also there is evidence of shared occurrence within families. Understanding the genetic contributions to these diseases, both individually and jointly, is needed to identify the highest risk group for screening and targeted prevention, as well as aiding in the development of targeted treatments. The chromosomal regions that have been identified as being associated either jointly or independently with lung cancer, COPD, nicotine addiction, and lung function are presented. Studies jointly measuring genetic variation in lung cancer and COPD have been limited by the lack of detailed COPD diagnosis and severity data in lung cancer populations, the lack of lung cancer–specific phenotypes (histology and tumor markers) in COPD populations, and the lack of inclusion of minorities. African Americans, who smoke fewer cigarettes per day and have different linkage disequilibrium and disease patterns than whites, and Asians, also with different patterns of exposure to lung carcinogens and linkage patterns, will provide invaluable information to better understand shared and independent genetic contributions to lung cancer and COPD to more fully define the highest risk group of individuals who will most benefit from screening and to develop molecular signatures to aid in targeted treatment and prevention efforts. PMID:22550237

Modelling of lateral fold growth and fold linkage: Applications to fold-and-thrust belt tectonics

NASA Astrophysics Data System (ADS)

Grasemann, Bernhard; Schmalholz, Stefan

2013-04-01

We use a finite element model to investigate the three-dimensional fold growth and interference of two initially isolated fold segments. The most critical parameter, which controls the fold linkage mode, is the phase difference between the laterally growing fold hinge lines: 1) "Linear-linkage" yields a sub-cylindrical fold with a saddle at the location where the two initial folds linked. 2) "Oblique-linkage" produces a curved fold resembling a Type II refold structure. 3) "Oblique-no-linkage" results in two curved folds with fold axes plunging in opposite directions. 4) "Linear-no-linkage" yields a fold train of two separate sub-cylindrical folds with fold axes plunging in opposite directions. The transition from linkage to no-linkage occurs when the fold separation between the initially isolated folds is slightly larger than one half of the low-amplitude fold wavelength. The model results compare well with previously published plasticine analogue models and can be directly applied to the investigation of fold growth history in fold-and-thust belts. An excellent natural example of lateral fold linkage is described from the Zagros fold-and-thrust belt in the Kurdistan Region of Iraq. The fold growth in this region is not controlled by major thrust faults but the shortening of the Paleozoic to Cenozoic passive margin sediments of the Arabian plate occurred mainly by detachment folding. The sub-cylindrical anticlines with hinge-parallel lengths of more than 50 km have not developed from single sub-cylindrical embryonic folds but they have merged from different fold segments that joined laterally during fold amplification and lateral fold growth. Linkage points are marked by geomorphological saddle points which are structurally the lowermost points of antiforms and points of principal curvatures with opposite sign. Linkage points can significantly influence the migration of mineral-rich fluids and hydrocarbons and are therefore of great economic importance.

Design of a 6-DOF upper limb rehabilitation exoskeleton with parallel actuated joints.

PubMed

Chen, Yanyan; Li, Ge; Zhu, Yanhe; Zhao, Jie; Cai, Hegao

2014-01-01

In this paper, a 6-DOF wearable upper limb exoskeleton with parallel actuated joints which perfectly mimics human motions is proposed. The upper limb exoskeleton assists the movement of physically weak people. Compared with the existing upper limb exoskeletons which are mostly designed using a serial structure with large movement space but small stiffness and poor wearable ability, a prototype for motion assistance based on human anatomy structure has been developed in our design. Moreover, the design adopts balls instead of bearings to save space, which simplifies the structure and reduces the cost of the mechanism. The proposed design also employs deceleration processes to ensure that the transmission ratio of each joint is coincident.

The plant metacaspase AtMC1 in pathogen-triggered programmed cell death and aging: functional linkage with autophagy

PubMed Central

Coll, N S; Smidler, A; Puigvert, M; Popa, C; Valls, M; Dangl, J L

2014-01-01

Autophagy is a major nutrient recycling mechanism in plants. However, its functional connection with programmed cell death (PCD) is a topic of active debate and remains not well understood. Our previous studies established the plant metacaspase AtMC1 as a positive regulator of pathogen-triggered PCD. Here, we explored the linkage between plant autophagy and AtMC1 function in the context of pathogen-triggered PCD and aging. We observed that autophagy acts as a positive regulator of pathogen-triggered PCD in a parallel pathway to AtMC1. In addition, we unveiled an additional, pro-survival homeostatic function of AtMC1 in aging plants that acts in parallel to a similar pro-survival function of autophagy. This novel pro-survival role of AtMC1 may be functionally related to its prodomain-mediated aggregate localization and potential clearance, in agreement with recent findings using the single budding yeast metacaspase YCA1. We propose a unifying model whereby autophagy and AtMC1 are part of parallel pathways, both positively regulating HR cell death in young plants, when these functions are not masked by the cumulative stresses of aging, and negatively regulating senescence in older plants. PMID:24786830

Joint multi-population analysis for genetic linkage of bipolar disorder or "wellness" to chromosome 4p.

PubMed

Visscher, P M; Haley, C S; Ewald, H; Mors, O; Egeland, J; Thiel, B; Ginns, E; Muir, W; Blackwood, D H

2005-02-05

To test the hypothesis that the same genetic loci confer susceptibility to, or protection from, disease in different populations, and that a combined analysis would improve the map resolution of a common susceptibility locus, we analyzed data from three studies that had reported linkage to bipolar disorder in a small region on chromosome 4p. Data sets comprised phenotypic information and genetic marker data on Scottish, Danish, and USA extended pedigrees. Across the three data sets, 913 individuals appeared in the pedigrees, 462 were classified, either as unaffected (323) or affected (139) with unipolar or bipolar disorder. A consensus linkage map was created from 14 microsatellite markers in a 33 cM region. Phenotypic and genetic data were analyzed using a variance component (VC) and allele sharing method. All previously reported elevated test statistics in the region were confirmed with one or both analysis methods, indicating the presence of one or more susceptibility genes to bipolar disorder in the three populations in the studied chromosome segment. When the results from both the VC and allele sharing method were considered, there was strong evidence for a susceptibility locus in the data from Scotland, some evidence in the data from Denmark and relatively less evidence in the data from the USA. The test statistics from the Scottish data set dominated the test statistics from the other studies, and no improved map resolution for a putative genetic locus underlying susceptibility in all three studies was obtained. Studies reporting linkage to the same region require careful scrutiny and preferably joint or meta analysis on the same basis in order to ensure that the results are truly comparable. (c) 2004 Wiley-Liss, Inc.

Does the cerebellum initiate movement?

PubMed

Thach, W T

2014-02-01

Opinion is divided on what the exact function of the cerebellum is. Experiments are summarized that support the following views: (1) the cerebellum is a combiner of multiple movement factors; (2) it contains anatomically fixed permanent focal representation of individual body parts (muscles and segments) and movement modes (e.g., vestibular driven vs. cognitive driven); (3) it contains flexible changing representations/memory of physical properties of the body parts including muscle strength, segment inertia, joint viscosity, and segmental interaction torques (dynamics); (4) it contains mechanisms for learning and storage of the properties in item no. 3 through trial-and-error practice; (5) it provides for linkage of body parts, motor modes, and motordynamics via the parallel fiber system; (6) it combines and integrates the many factors so as to initiate coordinated movements of the many body parts; (7) it is thus enabled to play the unique role of initiating coordinated movements; and (8) this unique causative role is evidenced by the fact that: (a) electrical stimulation of the cerebellum can initiate compound coordinated movements; (b) in naturally initiated compound movements, cerebellar discharge precedes that in downstream target structures such as motor cerebral cortex; and (c) cerebellar ablation abolishes the natural production of compound movements in the awake alert individuals.

Decentralized Adaptive Control For Robots

NASA Technical Reports Server (NTRS)

Seraji, Homayoun

1989-01-01

Precise knowledge of dynamics not required. Proposed scheme for control of multijointed robotic manipulator calls for independent control subsystem for each joint, consisting of proportional/integral/derivative feedback controller and position/velocity/acceleration feedforward controller, both with adjustable gains. Independent joint controller compensates for unpredictable effects, gravitation, and dynamic coupling between motions of joints, while forcing joints to track reference trajectories. Scheme amenable to parallel processing in distributed computing system wherein each joint controlled by relatively simple algorithm on dedicated microprocessor.

[Comparative ultrasound visualization of clinically relevant structures for evaluating the infant hip joint utilizing trapezoidal vs. parallel transducers].

PubMed

Wunsch, R; Wegener-Panzer, A; Reinehr, T; Aurisch, E; Cleaveland, B; Wunsch, C; Dudwiesus, H

2011-01-01

Sonographic evaluation of the infant hip joint according to the method of Graf has proven to be an important pediatric investigative instrument. Our goal was to investigate quantitatively whether (and in what ways) the clinically relevant infant hip joint structures visualize differently when utilizing trapezoidal as opposed to linear transducers. Our approach was both theoretical via a mathematical model and practical with in-vivo measurements in neonates. In a prospective study: 1. theoretical and computed analyses were performed for both linear and trapezoidal transducers regarding their respective accuracy for demonstrating the anatomic geometry of the infant hip, assuming not only correctly centered transducer positioning but also cases with off-centered displacement in the cranial or caudal direction; 2. both hip joints in 97 infants were examined by experienced investigators with comparison of the results for parallel vs. trapezoidal transducers. Theoretical mathematical error analysis reveals no intrinsic systemic deviations between trapezoidal vs. parallel transducers in US scanning of the infant hip and furthermore no inherent disadvantages in the trapezoidal technique. Even when off-center transducer alignments of 1.5 cm are employed in the mathematical models, there is no significant relative distortion of the required anatomic structures when comparing the characteristics of both transducers. The practical in-vivo data from our 97 neonates confirmed the theoretical considerations. No loss of accuracy or other negative factors are evident when trapezoidal transducers are used to visualize the infant hip joint in comparison with the customary parallel technique. There are no significantly measurable differences between the two approaches. © Georg Thieme Verlag KG Stuttgart · New York.

Evaluation of the impact of genetic linkage in forensic identity and relationship testing for expanded DNA marker sets.

PubMed

Tillmar, Andreas O; Phillips, Chris

2017-01-01

Advances in massively parallel sequencing technology have enabled the combination of a much-expanded number of DNA markers (notably STRs and SNPs in one or combined multiplexes), with the aim of increasing the weight of evidence in forensic casework. However, when data from multiple loci on the same chromosome are used, genetic linkage can affect the final likelihood calculation. In order to study the effect of linkage for different sets of markers we developed the biostatistical tool ILIR, (Impact of Linkage on forensic markers for Identity and Relationship tests). The ILIR tool can be used to study the overall impact of genetic linkage for an arbitrary set of markers used in forensic testing. Application of ILIR can be useful during marker selection and design of new marker panels, as well as being highly relevant for existing marker sets as a way to properly evaluate the effects of linkage on a case-by-case basis. ILIR, implemented via the open source platform R, includes variation and genomic position reference data for over 40 STRs and 140 SNPs, combined with the ability to include additional forensic markers of interest. The use of the software is demonstrated with examples from several different established marker sets (such as the expanded CODIS core loci) including a review of the interpretation of linked genetic data. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Battle Environment Assessment for Commanders: A Concept of Support for Joint and Component Strategy and Operations.

DTIC Science & Technology

1988-03-14

focused application of decision aids. These decision aids must incorporate standardized processes, computer assisted artificial intelligence, linkage...Theater Planning. A Strategic-Operational Perspective,’ by COL MIke ,or i n Olesak, John, LTC Office of the Deputy Chief of Staff, Inteligence , U S

75 FR 11189 - Bureau of Health Professions; All Advisory Committee Meeting; Notice of Meeting

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... DEPARTMENT OF HEALTH AND HUMAN SERVICES Health Resources and Services Administration Bureau of... Linkages (ACICBL), and the National Advisory Council on Nurse Education and Practice (NACNEP)] to continue their joint work on interdisciplinary education and practice, and to also discuss and identify future...

The Cyber Military Revolution and the Need for a New Framework of War

DTIC Science & Technology

2012-04-16

upon a better ability to discover and synthesize linkages and relationships between the variables and factors observed, one’s genetic heritage, social...system. The inclusion of the proposed revised framework of war in the capstone joint doctrine guidance document would provide a rubric of warfare

AIR QUALITY ASSESSMENT IN USA - TECHNICAL TOOLS AND LINKAGE TO HUMAN HEALTH

EPA Science Inventory

This is an invited presentation to the Air4EU Final Conference to held in Prague, Czech Republic, on 10 November 2006. Air4EU is a jointly-sponsored, three-year European effort to provide recommendations on air quality assessment by monitoring and modeling for regulated pollutan...

Synthesis of New Hyperbranched α-Glucans from Sucrose by Lactobacillus reuteri 180 Glucansucrase Mutants.

PubMed

Meng, Xiangfeng; Dobruchowska, Justyna M; Pijning, Tjaard; Gerwig, Gerrit J; Dijkhuizen, Lubbert

2016-01-20

α-Glucans produced by glucansucrase enzymes of lactic acid bacteria attract strong attention as novel ingredients and functional biopolymers in the food industry. In the present study, α-helix 4 amino acid residues D1085, R1088, and N1089 of glucansucrase GTF180 of Lactobacillus reuteri 180 were targeted for mutagenesis both jointly and separately. Analysis of the mutational effects on enzyme function revealed that all D1085 and R1088 mutants catalyzed the synthesis of hyperbranched α-glucans with 15-22% branching (α1→3,6) linkages, compared to 13% in the wild-type GTF180. In addition, besides native (α1→6) and (α1→3) linkages, all of the mutations introduced a small amount of (α1→4) linkages (5% at most) in the polysaccharides produced. We conclude that α-helix 4 residues, especially D1085 and R1088, constituting part of the +2 acceptor binding subsite, are important determinants for the linkage specificity. The new hyperbranched α-glucans provide very interesting structural diversities and may find applications in the food industry.

A Compliant Four-bar Linkage Mechanism that Makes the Fingers of a Prosthetic Hand More Impact Resistant

PubMed Central

Choi, Kyung Yun; Akhtar, Aadeel; Bretl, Timothy

2017-01-01

Repeated mechanical failure due to accidental impact is one of the main reasons why people with upper-limb amputations abandon commercially-available prosthetic hands. To address this problem, we present the design and evaluation of a compliant four-bar linkage mechanism that makes the fingers of a prosthetic hand more impact resistant. Our design replaces both the rigid input and coupler links with a monolithic compliant bone, and replaces the follower link with three layers of pre-stressed spring steel. This design behaves like a conventional four-bar linkage but adds lateral compliance and eliminates a pin joint, which is a main site of failure on impact. Results from free-end and fixed-end impact tests show that, compared to those made with a conventional four-bar linkage, fingers made with our design absorb up to 11% more energy on impact with no mechanical failure. We also show the integration of these fingers in a prosthetic hand that is low-cost, light-weight, and easy to assemble, and that has grasping performance comparable to commercially-available hands. PMID:29527386

Genome-wide association and linkage identify modifier loci of lung disease severity in cystic fibrosis at 11p13 and 20q13.2

PubMed Central

Wright, Fred A.; Strug, Lisa J.; Doshi, Vishal K.; Commander, Clayton W.; Blackman, Scott M.; Sun, Lei; Berthiaume, Yves; Cutler, David; Cojocaru, Andreea; Collaco, J. Michael; Corey, Mary; Dorfman, Ruslan; Goddard, Katrina; Green, Deanna; Kent, Jack W.; Lange, Ethan M.; Lee, Seunggeun; Li, Weili; Luo, Jingchun; Mayhew, Gregory M.; Naughton, Kathleen M.; Pace, Rhonda G.; Paré, Peter; Rommens, Johanna M.; Sandford, Andrew; Stonebraker, Jaclyn R.; Sun, Wei; Taylor, Chelsea; Vanscoy, Lori L.; Zou, Fei; Blangero, John; Zielenski, Julian; O’Neal, Wanda K.; Drumm, Mitchell L.; Durie, Peter R.; Knowles, Michael R.; Cutting, Garry R.

2012-01-01

A combined genome-wide association and linkage study was used to identify loci causing variation in CF lung disease severity. A significant association (P=3. 34 × 10-8) near EHF and APIP (chr11p13) was identified in F508del homozygotes (n=1,978). The association replicated in F508del homozygotes (P=0.006) from a separate family-based study (n=557), with P=1.49 × 10-9 for the three-study joint meta-analysis. Linkage analysis of 486 sibling pairs from the family-based study identified a significant QTL on chromosome 20q13.2 (LOD=5.03). Our findings provide insight into the causes of variation in lung disease severity in CF and suggest new therapeutic targets for this life-limiting disorder. PMID:21602797

A design concept of parallel elasticity extracted from biological muscles for engineered actuators.

PubMed

Chen, Jie; Jin, Hongzhe; Iida, Fumiya; Zhao, Jie

2016-08-23

Series elastic actuation that takes inspiration from biological muscle-tendon units has been extensively studied and used to address the challenges (e.g. energy efficiency, robustness) existing in purely stiff robots. However, there also exists another form of passive property in biological actuation, parallel elasticity within muscles themselves, and our knowledge of it is limited: for example, there is still no general design strategy for the elasticity profile. When we look at nature, on the other hand, there seems a universal agreement in biological systems: experimental evidence has suggested that a concave-upward elasticity behaviour is exhibited within the muscles of animals. Seeking to draw possible design clues for elasticity in parallel with actuators, we use a simplified joint model to investigate the mechanisms behind this biologically universal preference of muscles. Actuation of the model is identified from general biological joints and further reduced with a specific focus on muscle elasticity aspects, for the sake of easy implementation. By examining various elasticity scenarios, one without elasticity and three with elasticity of different profiles, we find that parallel elasticity generally exerts contradictory influences on energy efficiency and disturbance rejection, due to the mechanical impedance shift thus caused. The trade-off analysis between them also reveals that concave parallel elasticity is able to achieve a more advantageous balance than linear and convex ones. It is expected that the results could contribute to our further understanding of muscle elasticity and provide a theoretical guideline on how to properly design parallel elasticity behaviours for engineering systems such as artificial actuators and robotic joints.

A general model for likelihood computations of genetic marker data accounting for linkage, linkage disequilibrium, and mutations.

PubMed

Kling, Daniel; Tillmar, Andreas; Egeland, Thore; Mostad, Petter

2015-09-01

Several applications necessitate an unbiased determination of relatedness, be it in linkage or association studies or in a forensic setting. An appropriate model to compute the joint probability of some genetic data for a set of persons given some hypothesis about the pedigree structure is then required. The increasing number of markers available through high-density SNP microarray typing and NGS technologies intensifies the demand, where using a large number of markers may lead to biased results due to strong dependencies between closely located loci, both within pedigrees (linkage) and in the population (allelic association or linkage disequilibrium (LD)). We present a new general model, based on a Markov chain for inheritance patterns and another Markov chain for founder allele patterns, the latter allowing us to account for LD. We also demonstrate a specific implementation for X chromosomal markers that allows for computation of likelihoods based on hypotheses of alleged relationships and genetic marker data. The algorithm can simultaneously account for linkage, LD, and mutations. We demonstrate its feasibility using simulated examples. The algorithm is implemented in the software FamLinkX, providing a user-friendly GUI for Windows systems (FamLinkX, as well as further usage instructions, is freely available at www.famlink.se ). Our software provides the necessary means to solve cases where no previous implementation exists. In addition, the software has the possibility to perform simulations in order to further study the impact of linkage and LD on computed likelihoods for an arbitrary set of markers.

Joint-linkage mapping and GWAS reveal extensive genetic loci that regulate male inflorescence size in maize

USDA-ARS?s Scientific Manuscript database

Both insufficient and excessive male inflorescence size leads to a reduction in maize yield. Knowledge of the genetic architecture of male inflorescence is essential to achieve the optimum inflorescence size for maize breeding. In this study, we used approximately eight thousand inbreds, including b...

Technology Teaching or Mediated Learning, Part II, 1990s: Literacy Linkages and Intervention Contexts.

ERIC Educational Resources Information Center

Coufal, Kathy L.

2002-01-01

Themes during the 1990s included the bootstrapping effects between oral and literate language, importance of supporting emergent literacy, parallels between oral language impairment and academic failure, and challenges in facilitating language learning. This article addresses questions posed in Part I related to use of computer technology for…

Development of body weight support gait training system using antagonistic bi-articular muscle model.

PubMed

Shibata, Yoshiyuki; Imai, Shingo; Nobutomo, Tatsuya; Miyoshi, Tasuku; Yamamoto, Shin-Ichiroh

2010-01-01

The purpose of this study is to develop a body weight support gait training system for stroke and spinal cord injury. This system consists of a powered orthosis, treadmill and equipment of body weight support. Attachment of the powered orthosis is able to fit subject who has difference of body size. This powered orthosis is driven by pneumatic McKibben actuator. Actuators are arranged as pair of antagonistic bi-articular muscle model and two pairs of antagonistic mono-articular muscle model like human musculoskeletal system. Part of the equipment of body weight support suspend subject by wire harness, and body weight of subject is supported continuously by counter weight. The powered orthosis is attached equipment of body weight support by parallel linkage, and movement of the powered orthosis is limited at sagittal plane. Weight of the powered orthosis is compensated by parallel linkage with gas-spring. In this study, we developed system that has orthosis powered by pneumatic McKibben actuators and equipment of body weight support. We report detail of our developed body weight support gait training system.

IFRD1 Is a Candidate Gene for SMNA on Chromosome 7q22-q23

PubMed Central

Brkanac, Zoran; Spencer, David; Shendure, Jay; Robertson, Peggy D.; Matsushita, Mark; Vu, Tiffany; Bird, Thomas D.; Olson, Maynard V.; Raskind, Wendy H.

2009-01-01

We have established strong linkage evidence that supports mapping autosomal-dominant sensory/motor neuropathy with ataxia (SMNA) to chromosome 7q22-q32. SMNA is a rare neurological disorder whose phenotype encompasses both the central and the peripheral nervous system. In order to identify a gene responsible for SMNA, we have undertaken a comprehensive genomic evaluation of the region of linkage, including evaluation for repeat expansion and small deletions or duplications, capillary sequencing of candidate genes, and massively parallel sequencing of all coding exons. We excluded repeat expansion and small deletions or duplications as causative, and through microarray-based hybrid capture and massively parallel short-read sequencing, we identified a nonsynonymous variant in the human interferon-related developmental regulator gene 1 (IFRD1) as a disease-causing candidate. Sequence conservation, animal models, and protein structure evaluation support the involvement of IFRD1 in SMNA. Mutation analysis of IFRD1 in additional patients with similar phenotypes is needed for demonstration of causality and further evaluation of its importance in neurological diseases. PMID:19409521

Remote controlled vacuum joint closure mechanism

DOEpatents

Doll, David W.; Hager, E. Randolph

1986-01-01

A remotely operable and maintainable vacuum joint closure mechanism for a noncircular aperture is disclosed. The closure mechanism includes an extendible bellows coupled at one end to a noncircular duct and at its other end to a flange assembly having sealed grooves for establishing a high vacuum seal with the abutting surface of a facing flange which includes an aperture forming part of the system to be evacuated. A plurality of generally linear arrangements of pivotally coupled linkages and piston combinations are mounted around the outer surface of the duct and aligned along the length thereof. Each of the piston/linkage assemblies is adapted to engage the flange assembly by means of a respective piston and is further coupled to a remote controlled piston drive shaft to permit each of the linkages positioned on a respective flat outer surface of the duct to simultaneously and uniformly displace a corresponding piston and the flange assembly with which it is in contact along the length of the duct in extending the bellows to provide a high vacuum seal between the movable flange and the facing flange. A plurality of latch mechanisms are also pivotally mounted on the outside of the duct. A first end of each of the latch mechanisms is coupled to a remotely controlled latch control shaft for displacing the latch mechanism about its pivot point. In response to the pivoting displacement of the latch mechanism, a second end thereof is displaced so as to securely engage the facing flange.

Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

PubMed Central

Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

2016-01-01

Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications. PMID:27529244

Dimensional threshold for fracture linkage and hooking

NASA Astrophysics Data System (ADS)

Lamarche, Juliette; Chabani, Arezki; Gauthier, Bertrand D. M.

2018-03-01

Fracture connectivity in rocks depends on spatial properties of the pattern including length, abundance and orientation. When fractures form a single-strike set, they hardly cross-cut each other and the connectivity is limited. Linkage probability increases with increasing fracture abundance and length as small fractures connect to each other to form longer ones. A process for parallel fracture linkage is the "hooking", where two converging fracture tips mutually deviate and then converge to connect due to the interaction of their crack-tip stresses. Quantifying the processes and conditions for fracture linkage in single-strike fracture sets is crucial to better predicting fluid flow in Naturally Fractured Reservoirs. For 1734 fractures in Permian shales of the Lodève Basin, SE France, we measured geometrical parameters in 2D, characterizing three stages of the hooking process: underlapping, overlapping and linkage. We deciphered the threshold values, shape ratios and limiting conditions to switch from one stage to another one. The hook set up depends on the spacing (S) and fracture length (Lh) with the relation S ≈ 0.15 Lh. Once the hooking is initiated, with the fracture deviation length (L) L ≈ 0.4 Lh, the fractures reaches the linkage stage only when the spacing is reduced to S ≈ 0.02 Lh and the convergence (C) is < 0.1 L. These conditions apply to multi-scale fractures with a shape ratio L/S = 10 and for fracture curvature of 10°-20°.

A 17 degree of freedom anthropomorphic manipulator

NASA Technical Reports Server (NTRS)

Vold, Havard I.; Karlen, James P.; Thompson, Jack M., Jr.; Farrell, James D.; Eismann, Paul H.

1989-01-01

A 17 axis anthropomorphic manipulator, providing coordinated control of two seven degree of freedom arms mounted on a three degree of freedom torso-waist assembly, is presented. This massively redundant telerobot, designated the Robotics Research K/B-2017 Dexterous Manipulator, employs a modular mechanism design with joint-mounted actuators based on brushless motors and harmonic drive gear reducers. Direct joint torque control at the servo level causes these high-output joint drives to behave like direct-drive actuators, facilitating the implementation of an effective impedance control scheme. The redundant, but conservative motion control system models the manipulator as a spring-loaded linkage with viscous damping and rotary inertia at each joint. This approach allows for real time, sensor-driven control of manipulator pose using a hierarchy of competing rules, or objective functions, to avoid unplanned collisions with objects in the workplace, to produce energy-efficient, graceful motion, to increase leverage, to control effective impedance at the tool or to favor overloaded joints.

Dynamic coupling of underactuated manipulators

NASA Astrophysics Data System (ADS)

Bergerman, Marcel; Lee, Christopher; Xu, Yangsheng

1994-08-01

In recent years, researchers have been turning their attention to so called underactuated systems, where the term underactuated refers to the fact that the system has more joints than control actuators. Some examples of underactuated systems are robot manipulators with failed actuators; free-floating space robots, where the base can be considered as a virtual passive linkage in inertia space; legged robots with passive joints; hyper-redundant (snake-like) robots with passive joints, etc. From the examples above, it is possible to justify the importance of the study of underactuated systems. For example, if some actuators of a conventional manipulator fail, the loss of one or more degrees of freedom may compromise an entire operation. In free-floating space systems, the base (satellite) can be considered as a 6-DOF device without positioning actuators. Finally, manipulators with passive joints and hyper-redundant robots with few actuators are important from the viewpoint of energy saving, lightweight design and compactness.

Modelling Fault Zone Evolution: Implications for fluid flow.

NASA Astrophysics Data System (ADS)

Moir, H.; Lunn, R. J.; Shipton, Z. K.

2009-04-01

Flow simulation models are of major interest to many industries including hydrocarbon, nuclear waste, sequestering of carbon dioxide and mining. One of the major uncertainties in these models is in predicting the permeability of faults, principally in the detailed structure of the fault zone. Studying the detailed structure of a fault zone is difficult because of the inaccessible nature of sub-surface faults and also because of their highly complex nature; fault zones show a high degree of spatial and temporal heterogeneity i.e. the properties of the fault change as you move along the fault, they also change with time. It is well understood that faults influence fluid flow characteristics. They may act as a conduit or a barrier or even as both by blocking flow across the fault while promoting flow along it. Controls on fault hydraulic properties include cementation, stress field orientation, fault zone components and fault zone geometry. Within brittle rocks, such as granite, fracture networks are limited but provide the dominant pathway for flow within this rock type. Research at the EU's Soultz-sous-Forệt Hot Dry Rock test site [Evans et al., 2005] showed that 95% of flow into the borehole was associated with a single fault zone at 3490m depth, and that 10 open fractures account for the majority of flow within the zone. These data underline the critical role of faults in deep flow systems and the importance of achieving a predictive understanding of fault hydraulic properties. To improve estimates of fault zone permeability, it is important to understand the underlying hydro-mechanical processes of fault zone formation. In this research, we explore the spatial and temporal evolution of fault zones in brittle rock through development and application of a 2D hydro-mechanical finite element model, MOPEDZ. The authors have previously presented numerical simulations of the development of fault linkage structures from two or three pre-existing joints, the results of which compare well to features observed in mapped exposures. For these simple simulations from a small number of pre-existing joints the fault zone evolves in a predictable way: fault linkage is governed by three key factors: Stress ratio of s1 (maximum compressive stress) to s3(minimum compressive stress), original geometry of the pre-existing structures (contractional vs. dilational geometries) and the orientation of the principle stress direction (σ1) to the pre-existing structures. In this paper we present numerical simulations of the temporal and spatial evolution of fault linkage structures from many pre-existing joints. The initial location, size and orientations of these joints are based on field observations of cooling joints in granite from the Sierra Nevada. We show that the constantly evolving geometry and local stress field perturbations contribute significantly to fault zone evolution. The location and orientations of linkage structures previously predicted by the simple simulations are consistent with the predicted geometries in the more complex fault zones, however, the exact location at which individual structures form is not easily predicted. Markedly different fault zone geometries are predicted when the pre-existing joints are rotated with respect to the maximum compressive stress. In particular, fault surfaces range from evolving smooth linear structures to producing complex ‘stepped' fault zone geometries. These geometries have a significant effect on simulations of along and across-fault flow.

Numerical grid generation in computational field simulations. Volume 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soni, B.K.; Thompson, J.F.; Haeuser, J.

1996-12-31

To enhance the CFS technology to its next level of applicability (i.e., to create acceptance of CFS in an integrated product and process development involving multidisciplinary optimization) the basic requirements are: rapid turn-around time, reliable and accurate simulation, affordability and appropriate linkage to other engineering disciplines. In response to this demand, there has been a considerable growth in the grid generation related research activities involving automization, parallel processing, linkage with the CAD-CAM systems, CFS with dynamic motion and moving boundaries, strategies and algorithms associated with multi-block structured, unstructured, hybrid, hexahedral, and Cartesian grids, along with its applicability to various disciplinesmore » including biomedical, semiconductor, geophysical, ocean modeling, and multidisciplinary optimization.« less

A power study of bivariate LOD score analysis of a complex trait and fear/discomfort with strangers

PubMed Central

Ji, Fei; Lee, Dayoung; Mendell, Nancy Role

2005-01-01

Complex diseases are often reported along with disease-related traits (DRT). Sometimes investigators consider both disease and DRT phenotypes separately and sometimes they consider individuals as affected if they have either the disease or the DRT, or both. We propose instead to consider the joint distribution of the disease and the DRT and do a linkage analysis assuming a pleiotropic model. We evaluated our results through analysis of the simulated datasets provided by Genetic Analysis Workshop 14. We first conducted univariate linkage analysis of the simulated disease, Kofendrerd Personality Disorder and one of its simulated associated traits, phenotype b (fear/discomfort with strangers). Subsequently, we considered the bivariate phenotype, which combined the information on Kofendrerd Personality Disorder and fear/discomfort with strangers. We developed a program to perform bivariate linkage analysis using an extension to the Elston-Stewart peeling method of likelihood calculation. Using this program we considered the microsatellites within 30 cM of the gene pleiotropic for this simulated disease and DRT. Based on 100 simulations of 300 families we observed excellent power to detect linkage within 10 cM of the disease locus using the DRT and the bivariate trait. PMID:16451570

A power study of bivariate LOD score analysis of a complex trait and fear/discomfort with strangers.

PubMed

Ji, Fei; Lee, Dayoung; Mendell, Nancy Role

2005-12-30

Complex diseases are often reported along with disease-related traits (DRT). Sometimes investigators consider both disease and DRT phenotypes separately and sometimes they consider individuals as affected if they have either the disease or the DRT, or both. We propose instead to consider the joint distribution of the disease and the DRT and do a linkage analysis assuming a pleiotropic model. We evaluated our results through analysis of the simulated datasets provided by Genetic Analysis Workshop 14. We first conducted univariate linkage analysis of the simulated disease, Kofendrerd Personality Disorder and one of its simulated associated traits, phenotype b (fear/discomfort with strangers). Subsequently, we considered the bivariate phenotype, which combined the information on Kofendrerd Personality Disorder and fear/discomfort with strangers. We developed a program to perform bivariate linkage analysis using an extension to the Elston-Stewart peeling method of likelihood calculation. Using this program we considered the microsatellites within 30 cM of the gene pleiotropic for this simulated disease and DRT. Based on 100 simulations of 300 families we observed excellent power to detect linkage within 10 cM of the disease locus using the DRT and the bivariate trait.

Nonlinear conduction via solitons in a topological mechanical insulator.

PubMed

Chen, Bryan Gin-ge; Upadhyaya, Nitin; Vitelli, Vincenzo

2014-09-09

Networks of rigid bars connected by joints, termed linkages, provide a minimal framework to design robotic arms and mechanical metamaterials built of folding components. Here, we investigate a chain-like linkage that, according to linear elasticity, behaves like a topological mechanical insulator whose zero-energy modes are localized at the edge. Simple experiments we performed using prototypes of the chain vividly illustrate how the soft motion, initially localized at the edge, can in fact propagate unobstructed all of the way to the opposite end. Using real prototypes, simulations, and analytical models, we demonstrate that the chain is a mechanical conductor, whose carriers are nonlinear solitary waves, not captured within linear elasticity. Indeed, the linkage prototype can be regarded as the simplest example of a topological metamaterial whose protected mechanical excitations are solitons, moving domain walls between distinct topological mechanical phases. More practically, we have built a topologically protected mechanism that can perform basic tasks such as transporting a mechanical state from one location to another. Our work paves the way toward adopting the principle of topological robustness in the design of robots assembled from activated linkages as well as in the fabrication of complex molecular nanostructures.

Linkage analyses in Caribbean Hispanic families identify novel loci associated with familial late-onset Alzheimer's disease.

PubMed

Barral, Sandra; Cheng, Rong; Reitz, Christiane; Vardarajan, Badri; Lee, Joseph; Kunkle, Brian; Beecham, Gary; Cantwell, Laura S; Pericak-Vance, Margaret A; Farrer, Lindsay A; Haines, Jonathan L; Goate, Alison M; Foroud, Tatiana; Boerwinkle, Eric; Schellenberg, Gerard D; Mayeux, Richard

2015-12-01

We performed linkage analyses in Caribbean Hispanic families with multiple late-onset Alzheimer's disease (LOAD) cases to identify regions that may contain disease causative variants. We selected 67 LOAD families to perform genome-wide linkage scan. Analysis of the linked regions was repeated using the entire sample of 282 families. Validated chromosomal regions were analyzed using joint linkage and association. We identified 26 regions linked to LOAD (HLOD ≥3.6). We validated 13 of the regions (HLOD ≥2.5) using the entire family sample. The strongest signal was at 11q12.3 (rs2232932: HLODmax = 4.7, Pjoint = 6.6 × 10(-6)), a locus located ∼2 Mb upstream of the membrane-spanning 4A gene cluster. We additionally identified a locus at 7p14.3 (rs10255835: HLODmax = 4.9, Pjoint = 1.2 × 10(-5)), a region harboring genes associated with the nervous system (GARS, GHRHR, and NEUROD6). Future sequencing efforts should focus on these regions because they may harbor familial LOAD causative mutations. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Inspection criteria ensure quality control of parallel gap soldering

NASA Technical Reports Server (NTRS)

Burka, J. A.

1968-01-01

Investigation of parallel gap soldering of electrical leads resulted in recommendation on material preparation, equipment, process control, and visual inspection criteria to ensure reliable solder joints. The recommendations will minimize problems in heat-dwell time, amount of solder, bridging conductors, and damage of circuitry.

Comparison of linkage analysis methods for genome-wide scanning of extended pedigrees, with application to the TG/HDL-C ratio in the Framingham Heart Study

PubMed Central

Horne, Benjamin D; Malhotra, Alka; Camp, Nicola J

2003-01-01

Background High triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) jointly increase coronary disease risk. We performed linkage analysis for TG/HDL-C ratio in the Framingham Heart Study data as a quantitative trait, using methods implemented in LINKAGE, GENEHUNTER (GH), MCLINK, and SOLAR. Results were compared to each other and to those from a previous evaluation using SOLAR for TG/HDL-C ratio on this sample. We also investigated linked pedigrees in each region using by-pedigree analysis. Results Fourteen regions with at least suggestive linkage evidence were identified, including some that may increase and some that may decrease coronary risk. Ten of the 14 regions were identified by more than one analysis, and several of these regions were not previously detected. The best regions identified for each method were on chromosomes 2 (LOD = 2.29, MCLINK), 5 (LOD = 2.65, GH), 7 (LOD = 2.67, SOLAR), and 22 (LOD = 3.37, LINKAGE). By-pedigree multi-point LOD values in MCLINK showed linked pedigrees for all five regions, ranging from 3 linked pedigrees (chromosome 5) to 14 linked pedigrees (chromosome 7), and suggested localizations of between 9 cM and 27 cM in size. Conclusion Reasonable concordance was found across analysis methods. No single method identified all regions, either by full sample LOD or with by-pedigree analysis. Concordance across methods appeared better at the pedigree level, with many regions showing by-pedigree support in MCLINK when no evidence was observed in the full sample. Thus, investigating by-pedigree linkage evidence may provide a useful tool for evaluating linkage regions. PMID:14975161

Comparison of linkage analysis methods for genome-wide scanning of extended pedigrees, with application to the TG/HDL-C ratio in the Framingham Heart Study.

PubMed

Horne, Benjamin D; Malhotra, Alka; Camp, Nicola J

2003-12-31

High triglycerides (TG) and low high-density lipoprotein cholesterol (HDL-C) jointly increase coronary disease risk. We performed linkage analysis for TG/HDL-C ratio in the Framingham Heart Study data as a quantitative trait, using methods implemented in LINKAGE, GENEHUNTER (GH), MCLINK, and SOLAR. Results were compared to each other and to those from a previous evaluation using SOLAR for TG/HDL-C ratio on this sample. We also investigated linked pedigrees in each region using by-pedigree analysis. Fourteen regions with at least suggestive linkage evidence were identified, including some that may increase and some that may decrease coronary risk. Ten of the 14 regions were identified by more than one analysis, and several of these regions were not previously detected. The best regions identified for each method were on chromosomes 2 (LOD = 2.29, MCLINK), 5 (LOD = 2.65, GH), 7 (LOD = 2.67, SOLAR), and 22 (LOD = 3.37, LINKAGE). By-pedigree multi-point LOD values in MCLINK showed linked pedigrees for all five regions, ranging from 3 linked pedigrees (chromosome 5) to 14 linked pedigrees (chromosome 7), and suggested localizations of between 9 cM and 27 cM in size. Reasonable concordance was found across analysis methods. No single method identified all regions, either by full sample LOD or with by-pedigree analysis. Concordance across methods appeared better at the pedigree level, with many regions showing by-pedigree support in MCLINK when no evidence was observed in the full sample. Thus, investigating by-pedigree linkage evidence may provide a useful tool for evaluating linkage regions.

From Radio, to Satellite, to M-Learning: Interactive Distance Education in Australia

ERIC Educational Resources Information Center

Crump, Stephen

2013-01-01

This paper provides reflections on M-learning as a form of "distance education," based on a summary of the findings of the Interactive Distance e-Learning (IDL) research project in rural and remote Australia under an Australian Research Council Linkage grant. This project was a joint undertaking between 3 government agencies and an…

Air Power’s First Among Equals: Why Air Superiority Still Matters

DTIC Science & Technology

2008-04-04

School in partial satisfaction of the requirements of a Master of Science Degree in Joint Campaign Planning and Strategy . The contents of this...40  Conclusions and Linkages to Strategy .......................................................................... 44  Chapter 3...the combination of minimal commitment and footprint with maximum speed, precision and flexibility. The 2006 National Security Strategy (NSS

Framing the Dialogue: Strategies, Issues and Opportunities

DTIC Science & Technology

1993-05-01

issue is the relationship between the declining Federal financing of public works and the Federal interest in providing infrastructure services. Large...programs and projects are significant. lmprove Infrastructure Managmnt : Management improvements closely parallel the issues associated with strategic... Relationship Between Examination of the linkage between standards GKY & Standards & and the delivery of goods and services from Associates Performance

Three-Dimensional Structural and Hydrologic Evolution of Sant Corneli Anticline, a Fault-Cored Fold in the Central Spanish Pyrenees

NASA Astrophysics Data System (ADS)

Shackleton, J. R.; Cooke, M. L.

2005-12-01

The Sant Corneli Anticline is a well-exposed example of a fault-cored fold whose hydrologic evolution and structural development are directly linked. The E-W striking anticline is ~ 5 km wide with abrupt westerly plunge, and formed in response to thrusting associated with the upper Cretaceous to Miocene collision of Iberia with Europe. The fold's core of fractured carbonates contains a variety of west dipping normal faults with meter to decameter scale displacement and abundant calcite fill. This carbonate unit is capped by a marl unit with low angle, calcite filled normal faults. The marl unit is overlain by clastic syn-tectonic strata whose sedimentary architecture records limb rotation during the evolution of the fold. The syn-tectonic strata contain a variety of joint sets that record the stresses before, during, and possibly after fold growth. Faulting in the marl and calcite-filled joints in the syn-tectonic strata suggest that normal faults within the carbonate core of the fold eventually breached the overlying marl unit. This breach may have connected the joints of the syn-tectonic strata to the underlying carbonate reservoir and eliminated previous compartmentalization of fluids. Furthermore, breaching of the marl units probably enhanced joint formation in the overlying syn-tectonic strata. Future geochemical studies of calcite compositions in the three units will address this hypothesis. Preliminary mapping of joint sets in the syn-tectonic strata reveal a multistage history of jointing. Early bed-perpendicular joints healed by calcite strike NE-SW, parallel to normal faults in the underlying carbonates, and may be related to an early regional extensional event. Younger healed bed-perpendicular joints cross cut the NE-SW striking set, and are closer to N-S in strike: these joints are interpreted to represent the initial stages of folding. Decameter scale, bed perpendicular, unfilled fractures that are sub-parallel to strike probably represent small joints and faults that formed in response to outer arc extension during folding. Many filled, late stage joints strike sub-parallel to, and increase in frequency near, normal faults and transverse structures observed in the carbonate fold core. This suggests that faulting in the underlying carbonates and marls significantly affected the joint patterns in the syn-tectonic strata. Preliminary three-dimensional finite element restorations using Dynel have allowed us to test our hypotheses and constrain the timing of jointing and marl breach.

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks.

PubMed

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P; Montgomery, Claire A; McKelvey, Kevin S; Kendall, Katherine; Graves, Tabitha A; Bernstein, Richard; Schwartz, Michael K

2017-02-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities. © 2016 Society for Conservation Biology.

Trade-offs and efficiencies in optimal budget-constrained multispecies corridor networks

USGS Publications Warehouse

Dilkina, Bistra; Houtman, Rachel; Gomes, Carla P.; Montgomery, Claire A.; McKelvey, Kevin; Kendall, Katherine; Graves, Tabitha A.; Bernstein, Richard; Schwartz, Michael K.

2017-01-01

Conservation biologists recognize that a system of isolated protected areas will be necessary but insufficient to meet biodiversity objectives. Current approaches to connecting core conservation areas through corridors consider optimal corridor placement based on a single optimization goal: commonly, maximizing the movement for a target species across a network of protected areas. We show that designing corridors for single species based on purely ecological criteria leads to extremely expensive linkages that are suboptimal for multispecies connectivity objectives. Similarly, acquiring the least-expensive linkages leads to ecologically poor solutions. We developed algorithms for optimizing corridors for multispecies use given a specific budget. We applied our approach in western Montana to demonstrate how the solutions may be used to evaluate trade-offs in connectivity for 2 species with different habitat requirements, different core areas, and different conservation values under different budgets. We evaluated corridors that were optimal for each species individually and for both species jointly. Incorporating a budget constraint and jointly optimizing for both species resulted in corridors that were close to the individual species movement-potential optima but with substantial cost savings. Our approach produced corridors that were within 14% and 11% of the best possible corridor connectivity for grizzly bears (Ursus arctos) and wolverines (Gulo gulo), respectively, and saved 75% of the cost. Similarly, joint optimization under a combined budget resulted in improved connectivity for both species relative to splitting the budget in 2 to optimize for each species individually. Our results demonstrate economies of scale and complementarities conservation planners can achieve by optimizing corridor designs for financial costs and for multiple species connectivity jointly. We believe that our approach will facilitate corridor conservation by reducing acquisition costs and by allowing derived corridors to more closely reflect conservation priorities.

Comparative mapping and rapid karyotypic evolution in the genus helianthus.

PubMed Central

Burke, John M; Lai, Zhao; Salmaso, Marzia; Nakazato, Takuya; Tang, Shunxue; Heesacker, Adam; Knapp, Steven J; Rieseberg, Loren H

2004-01-01

Comparative genetic linkage maps provide a powerful tool for the study of karyotypic evolution. We constructed a joint SSR/RAPD genetic linkage map of the Helianthus petiolaris genome and used it, along with an integrated SSR genetic linkage map derived from four independent H. annuus mapping populations, to examine the evolution of genome structure between these two annual sunflower species. The results of this work indicate the presence of 27 colinear segments resulting from a minimum of eight translocations and three inversions. These 11 rearrangements are more than previously suspected on the basis of either cytological or genetic map-based analyses. Taken together, these rearrangements required a minimum of 20 chromosomal breakages/fusions. On the basis of estimates of the time since divergence of these two species (750,000-1,000,000 years), this translates into an estimated rate of 5.5-7.3 chromosomal rearrangements per million years of evolution, the highest rate reported for any taxonomic group to date. PMID:15166168

Self-Referenced Processing, Neurodevelopment and Joint Attention in Autism

ERIC Educational Resources Information Center

Mundy, Peter; Gwaltney, Mary; Henderson, Heather

2010-01-01

This article describes a parallel and distributed processing model (PDPM) of joint attention, self-referenced processing and autism. According to this model, autism involves early impairments in the capacity for rapid, integrated processing of self-referenced (proprioceptive and interoceptive) and other-referenced (exteroceptive) information.…

Binary zone-plate array for a parallel joint transform correlator applied to face recognition.

PubMed

Kodate, K; Hashimoto, A; Thapliya, R

1999-05-10

Taking advantage of small aberrations, high efficiency, and compactness, we developed a new, to our knowledge, design procedure for a binary zone-plate array (BZPA) and applied it to a parallel joint transform correlator for the recognition of the human face. Pairs of reference and unknown images of faces are displayed on a liquid-crystal spatial light modulator (SLM), Fourier transformed by the BZPA, intensity recorded on an optically addressable SLM, and inversely Fourier transformed to obtain correlation signals. Consideration of the bandwidth allows the relations among the channel number, the numerical aperture of the zone plates, and the pattern size to be determined. Experimentally a five-channel parallel correlator was implemented and tested successfully with a 100-person database. The design and the fabrication of a 20-channel BZPA for phonetic character recognition are also included.

A novel voice coil motor-driven compliant micropositioning stage based on flexure mechanism

NASA Astrophysics Data System (ADS)

Shang, Jiangkun; Tian, Yanling; Li, Zheng; Wang, Fujun; Cai, Kunhai

2015-09-01

This paper presents a 2-degrees of freedom flexure-based micropositioning stage with a flexible decoupling mechanism. The stage is composed of an upper planar stage and four vertical support links to improve the out-of-plane stiffness. The moving platform is driven by two voice coil motors, and thus it has the capability of large working stroke. The upper stage is connected with the base through six double parallel four-bar linkages mechanisms, which are orthogonally arranged to implement the motion decoupling in the x and y directions. The vertical support links with serially connected hook joints are utilized to guarantee good planar motion with heavy-loads. The static stiffness and the dynamic resonant frequencies are obtained based on the theoretical analyses. Finite element analysis is used to investigate the characteristics of the developed stage. Experiments are carried out to validate the established models and the performance of the developed stage. It is noted that the developed stage has the capability of translational motion stroke of 1.8 mm and 1.78 mm in working axes. The maximum coupling errors in the x and y directions are 0.65% and 0.82%, respectively, and the motion resolution is less than 200 nm. The experimental results show that the developed stage has good capability for trajectory tracking.

[The joint applications of DNA chips and single nucleotide polymorphisms in forensic science].

PubMed

Bai, Peng; Tian, Li; Zhou, Xue-ping

2005-05-01

DNA chip technology, being a new high-technology, shows its vigorous life and rapid growth. Single Nucleotide Polymorphisms (SNPs) is the most common diversity in the human genome. It provides suitable genetic markers which play a key role in disease linkage study, pharmacogenomics, forensic medicine, population evolution and immigration study. Their advantage such as being analyzed with DNA chips technology, is predicted to play an important role in the field of forensic medicine, especially in paternity test and individual identification. This report mainly reviews the characteristics of DNA chip and SNPs, and their joint applications in the practice of forensic medicine.

Human-modified temperatures induce species changes: Joint attribution.

PubMed

Root, Terry L; MacMynowski, Dena P; Mastrandrea, Michael D; Schneider, Stephen H

2005-05-24

Average global surface-air temperature is increasing. Contention exists over relative contributions by natural and anthropogenic forcings. Ecological studies attribute plant and animal changes to observed warming. Until now, temperature-species connections have not been statistically attributed directly to anthropogenic climatic change. Using modeled climatic variables and observed species data, which are independent of thermometer records and paleoclimatic proxies, we demonstrate statistically significant "joint attribution," a two-step linkage: human activities contribute significantly to temperature changes and human-changed temperatures are associated with discernible changes in plant and animal traits. Additionally, our analyses provide independent testing of grid-box-scale temperature projections from a general circulation model (HadCM3).

Adolescents' Use of Sexually Explicit Internet Material and Their Sexual Attitudes and Behavior: Parallel Development and Directional Effects

ERIC Educational Resources Information Center

Doornwaard, Suzan M.; Bickham, David S.; Rich, Michael; ter Bogt, Tom F. M.; van den Eijnden, Regina J. J. M.

2015-01-01

Although research has repeatedly demonstrated that adolescents' use of sexually explicit Internet material (SEIM) is related to their endorsement of permissive sexual attitudes and their experience with sexual behavior, it is not clear how linkages between these constructs unfold over time. This study combined 2 types of longitudinal modeling,…

LAVA web-based remote simulation: enhancements for education and technology innovation

NASA Astrophysics Data System (ADS)

Lee, Sang Il; Ng, Ka Chun; Orimoto, Takashi; Pittenger, Jason; Horie, Toshi; Adam, Konstantinos; Cheng, Mosong; Croffie, Ebo H.; Deng, Yunfei; Gennari, Frank E.; Pistor, Thomas V.; Robins, Garth; Williamson, Mike V.; Wu, Bo; Yuan, Lei; Neureuther, Andrew R.

2001-09-01

The Lithography Analysis using Virtual Access (LAVA) web site at http://cuervo.eecs.berkeley.edu/Volcano/ has been enhanced with new optical and deposition applets, graphical infrastructure and linkage to parallel execution on networks of workstations. More than ten new graphical user interface applets have been designed to support education, illustrate novel concepts from research, and explore usage of parallel machines. These applets have been improved through feedback and classroom use. Over the last year LAVA provided industry and other academic communities 1,300 session and 700 rigorous simulations per month among the SPLAT, SAMPLE2D, SAMPLE3D, TEMPEST, STORM, and BEBS simulators.

Development of gait training system powered by pneumatic actuator like human musculoskeletal system.

PubMed

Yamamoto, Shin-ichiroh; Shibata, Yoshiyuki; Imai, Shingo; Nobutomo, Tatsuya; Miyoshi, Tasuku

2011-01-01

The purpose of this study was to develop a body weight support gait training system for stroke and spinal cord injury (SCI) patient. This system consists of an orthosis powered by pneumatic McKibben actuators and a piece of equipment of body weight support. The attachment of powered orthosis can be fit to individual subjects with different body size. This powered orthosis is driven by pneumatic McKibben actuators arranged as a pair of agonistic and antagonistic bi-articular muscle models and two pairs of agonistic and antagonistic mono-articular muscle models like the human musculoskeletal system. The body weight support equipment suspends the subject's body in a wire harness, with the body weight is supported continuously by a counterweight. The powered orthosis is attached to the body weight support equipment by a parallel linkage, and its movement of powered orthosis is limited at the sagittal plane. The weight of the powered orthosis is compensated by a parallel linkage with a gas-spring. In this paper, we report the detailed mechanics of this body weight support gait training system and the results of several experiments for evaluating the system. © 2011 IEEE

Parallel Event Analysis Under Unix

NASA Astrophysics Data System (ADS)

Looney, S.; Nilsson, B. S.; Oest, T.; Pettersson, T.; Ranjard, F.; Thibonnier, J.-P.

The ALEPH experiment at LEP, the CERN CN division and Digital Equipment Corp. have, in a joint project, developed a parallel event analysis system. The parallel physics code is identical to ALEPH's standard analysis code, ALPHA, only the organisation of input/output is changed. The user may switch between sequential and parallel processing by simply changing one input "card". The initial implementation runs on an 8-node DEC 3000/400 farm, using the PVM software, and exhibits a near-perfect speed-up linearity, reducing the turn-around time by a factor of 8.

NIRcam-NIRSpec GTO Observations of Galaxy Evolution

NASA Astrophysics Data System (ADS)

Rieke, Marcia J.; Ferruit, Pierre; Alberts, Stacey; Bunker, Andrew; Charlot, Stephane; Chevallard, Jacopo; Dressler, Alan; Egami, Eiichi; Eisenstein, Daniel; Endsley, Ryan; Franx, Marijn; Frye, Brenda L.; Hainline, Kevin; Jakobsen, Peter; Lake, Emma Curtis; Maiolino, Roberto; Rix, Hans-Walter; Robertson, Brant; Stark, Daniel; Williams, Christina; Willmer, Christopher; Willott, Chris J.

2017-06-01

The NIRSpec and and NIRCam GTO Teams are planning a joint imaging and spectroscopic study of the high redshift universe. By virtue of planning a joint program which includes medium and deep near- and mid-infrared imaging surveys and multi-object spectroscopy (MOS) of sources in the same fields, we have learned much about planning observing programs for each of the instruments and using them in parallel mode to maximize photon collection time. The design and rationale for our joint program will be explored in this talk with an emphasis on why we have chosen particular suites of filters and spectroscopic resolutions, why we have chosen particular exposure patterns, and how we have designed the parallel observations. The actual observations that we intend on executing will serve as examples of how to layout mosaics and MOS observations to maximize observing efficiency for surveys with JWST.

A robot arm simulation with a shared memory multiprocessor machine

NASA Technical Reports Server (NTRS)

Kim, Sung-Soo; Chuang, Li-Ping

1989-01-01

A parallel processing scheme for a single chain robot arm is presented for high speed computation on a shared memory multiprocessor. A recursive formulation that is derived from a virtual work form of the d'Alembert equations of motion is utilized for robot arm dynamics. A joint drive system that consists of a motor rotor and gears is included in the arm dynamics model, in order to take into account gyroscopic effects due to the spinning of the rotor. The fine grain parallelism of mechanical and control subsystem models is exploited, based on independent computation associated with bodies, joint drive systems, and controllers. Efficiency and effectiveness of the parallel scheme are demonstrated through simulations of a telerobotic manipulator arm. Two different mechanical subsystem models, i.e., with and without gyroscopic effects, are compared, to show the trade-off between efficiency and accuracy.

Joint Book Reading and Receptive Vocabulary: A Parallel Process Model

ERIC Educational Resources Information Center

Meng, Christine

2016-01-01

The purpose of the present study was to understand the reciprocal, bidirectional longitudinal relation between joint book reading and English receptive vocabulary. To address the research goals, a nationally representative sample of Head Start children, the Head Start Family and Child Experiences Survey (2003 cohort), was used for analysis. The…

Surgical robot for single-incision laparoscopic surgery.

PubMed

Choi, Hyundo; Kwak, Ho-Seong; Lim, Yo-An; Kim, Hyung-Joo

2014-09-01

This paper introduces a novel surgical robot for single-incision laparoscopic surgeries. The robot system includes the cone-type remote center-of-motion (RCM) mechanism and two articulated instruments having a flexible linkage-driven elbow. The RCM mechanism, which has two revolute joints and one prismatic joint, is designed to maintain a stationary point at the apex of the cone shape. By placing the stationary point on the incision area, the mechanism allows a surgical instrument to explore the abdominal area through a small incision point. The instruments have six articulated joints, including an elbow pitch joint, which make the triangulation position for the surgery possible inside of the abdominal area. The presented elbow pitch structure is similar to the slider-crank mechanism but the connecting rod is composed of a flexible leaf spring for high payload and small looseness error. We verified the payload of the robot is more than 10 N and described preliminary experiments on peg transfer and suture motion by using the proposed surgical robot.

Infant Joint Attention, Neural Networks and Social Cognition

PubMed Central

Mundy, Peter; Jarrold, William

2010-01-01

Neural network models of attention can provide a unifying approach to the study of human cognitive and emotional development (Posner & Rothbart, 2007). This paper we argue that a neural networks approach to the infant development of joint attention can inform our understanding of the nature of human social learning, symbolic thought process and social cognition. At its most basic, joint attention involves the capacity to coordinate one’s own visual attention with that of another person. We propose that joint attention development involves increments in the capacity to engage in simultaneous or parallel processing of information about one’s own attention and the attention of other people. Infant practice with joint attention is both a consequence and organizer of the development of a distributed and integrated brain network involving frontal and parietal cortical systems. This executive distributed network first serves to regulate the capacity of infants to respond to and direct the overt behavior of other people in order to share experience with others through the social coordination of visual attention. In this paper we describe this parallel and distributed neural network model of joint attention development and discuss two hypotheses that stem from this model. One is that activation of this distributed network during coordinated attention enhances to depth of information processing and encoding beginning in the first year of life. We also propose that with development joint attention becomes internalized as the capacity to socially coordinate mental attention to internal representations. As this occurs the executive joint attention network makes vital contributions to the development of human symbolic thinking and social cognition. PMID:20884172

Trajectory control of an articulated robot with a parallel drive arm based on splines under tension

NASA Astrophysics Data System (ADS)

Yi, Seung-Jong

Today's industrial robots controlled by mini/micro computers are basically simple positioning devices. The positioning accuracy depends on the mathematical description of the robot configuration to place the end-effector at the desired position and orientation within the workspace and on following the specified path which requires the trajectory planner. In addition, the consideration of joint velocity, acceleration, and jerk trajectories are essential for trajectory planning of industrial robots to obtain smooth operation. The newly designed 6 DOF articulated robot with a parallel drive arm mechanism which permits the joint actuators to be placed in the same horizontal line to reduce the arm inertia and to increase load capacity and stiffness is selected. First, the forward kinematic and inverse kinematic problems are examined. The forward kinematic equations are successfully derived based on Denavit-Hartenberg notation with independent joint angle constraints. The inverse kinematic problems are solved using the arm-wrist partitioned approach with independent joint angle constraints. Three types of curve fitting methods used in trajectory planning, i.e., certain degree polynomial functions, cubic spline functions, and cubic spline functions under tension, are compared to select the best possible method to satisfy both smooth joint trajectories and positioning accuracy for a robot trajectory planner. Cubic spline functions under tension is the method selected for the new trajectory planner. This method is implemented for a 6 DOF articulated robot with a parallel drive arm mechanism to improve the smoothness of the joint trajectories and the positioning accuracy of the manipulator. Also, this approach is compared with existing trajectory planners, 4-3-4 polynomials and cubic spline functions, via circular arc motion simulations. The new trajectory planner using cubic spline functions under tension is implemented into the microprocessor based robot controller and motors to produce combined arc and straight-line motion. The simulation and experiment show interesting results by demonstrating smooth motion in both acceleration and jerk and significant improvements of positioning accuracy in trajectory planning.

Application of the surface azimuthal electrical resistivity survey method to determine patterns of regional joint orientation in glacial tills

USGS Publications Warehouse

Carlson, D.

2010-01-01

Joints within unconsolidated material such as glacial till can be primary avenues for the flow of electrical charge, water, and contaminants. To facilitate the siting and design of remediation programs, a need exists to map anisotropic distribution of such pathways within glacial tills by determining the azimuth of the dominant joint set. The azimuthal survey method uses standard resistivity equipment with a Wenner array rotated about a fixed center point at selected degree intervals that yields an apparent resistivity ellipse. From this ellipse, joint set orientation can be determined. Azimuthal surveys were conducted at 21 sites in a 500-km2 (193 mi2) area around Milwaukee, Wisconsin, and more specifically, at sites having more than 30 m (98 ft) of glacial till (to minimize the influence of underlying bedrock joints). The 26 azimuthal surveys revealed a systematic pattern to the trend of the dominant joint set within the tills, which is approximately parallel to ice flow direction during till deposition. The average orientation of the joint set parallel with the ice flow direction is N77??E and N37??E for the Oak Creek and Ozaukee tills, respectively. The mean difference between average direct observation of joint set orientations and average azimuthal resistivity results is 8??, which is one fifth of the difference of ice flow direction between the Ozaukee and Oak Creek tills. The results of this study suggest that the surface azimuthal electrical resistivity survey method used for local in situ studies can be a useful noninvasive method for delineating joint sets within shallow geologic material for regional studies. Copyright ?? 2010 The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

Changes in coronal alignment of the ankle joint after high tibial osteotomy.

PubMed

Choi, Gi Won; Yang, Jae Hyuk; Park, Jung Ho; Yun, Ho Hyun; Lee, Yong In; Chae, Jin Eon; Yoon, Jung Ro

2017-03-01

The purpose of this study was to investigate changes in coronal alignment of the ankle joint after HTO. Our hypothesis was that ankle joint orientation may become more parallel or less parallel to the ground after HTO, and this change may affect ankle symptoms. Eighty-six knees were retrospectively analysed after HTO for varus osteoarthritis. Preoperative and follow-up whole-leg radiographs were taken. The hip-knee-ankle (HKA) angle and medial proximal tibial angle (MPTA) were measured to evaluate coronal alignment of the knee. Tibial plafond inclination (TPI), talar inclination (TI), talar tilt (TT), and lateral distal tibial angle (LDTA) were measured to evaluate coronal alignment of the ankle. Patients were divided into two groups: those who exhibited a decrease in the absolute value of TPI and TI after HTO (group A) and those who exhibited an increase in the absolute value of TPI or TI after HTO (group B). Clinical outcomes of the knee and ankle were evaluated pre- and postoperatively. Mean TPI and TI changed from 6.9° ± 3.6° and 8.0° ± 3.8° to 2.8° ± 3.1° and 3.9° ± 3.0° in group A (P < 0.001 for both) and from -1.3° ± 3.7° and 0.6° ± 4.5° to -6.0° ± 4.2° and -4.6° ± 5.9° in group B (P = 0.018 for both). VAS for ankle pain did not change significantly after HTO (n.s.) in group A, whereas those of group B increased significantly after HTO (P = 0.014). Ankle joint orientation becomes more parallel or less parallel to the ground after HTO. Smaller preoperative HKA and LDTA result in a more valgus ankle joint orientation after HTO. Ankle symptoms were affected by coronal alignment changes of the ankle after HTO. III.

Joint source based morphometry identifies linked gray and white matter group differences.

PubMed

Xu, Lai; Pearlson, Godfrey; Calhoun, Vince D

2009-02-01

We present a multivariate approach called joint source based morphometry (jSBM), to identify linked gray and white matter regions which differ between groups. In jSBM, joint independent component analysis (jICA) is used to decompose preprocessed gray and white matter images into joint sources and statistical analysis is used to determine the significant joint sources showing group differences and their relationship to other variables of interest (e.g. age or sex). The identified joint sources are groupings of linked gray and white matter regions with common covariation among subjects. In this study, we first provide a simulation to validate the jSBM approach. To illustrate our method on real data, jSBM is then applied to structural magnetic resonance imaging (sMRI) data obtained from 120 chronic schizophrenia patients and 120 healthy controls to identify group differences. JSBM identified four joint sources as significantly associated with schizophrenia. Linked gray-white matter regions identified in each of the joint sources included: 1) temporal--corpus callosum, 2) occipital/frontal--inferior fronto-occipital fasciculus, 3) frontal/parietal/occipital/temporal--superior longitudinal fasciculus and 4) parietal/frontal--thalamus. Age effects on all four joint sources were significant, but sex effects were significant only for the third joint source. Our findings demonstrate that jSBM can exploit the natural linkage between gray and white matter by incorporating them into a unified framework. This approach is applicable to a wide variety of problems to study linked gray and white matter group differences.

Effect of Gold on the Microstructural Evolution and Integrity of a Sintered Silver Joint

NASA Astrophysics Data System (ADS)

Muralidharan, Govindarajan; Leonard, Donovan N.; Meyer, Harry M.

2017-07-01

There is a need for next-generation, high-performance power electronic packages and systems employing wide-bandgap devices to operate at high temperatures in automotive and electric grid applications. Sintered silver joints are currently being evaluated as an alternative to Pb-free solder joints. Of particular interest is the development of joints based on silver paste consisting of nano- or micron-scale particles that can be processed without application of external pressure. The microstructural evolution at the interface of a pressureless-sintered silver joint formed between a SiC die with Ti/Ni/Au metallization and an active metal brazed (AMB) substrate with Ag metallization at 250°C has been evaluated using scanning electron microscopy (SEM), x-ray microanalysis, and x-ray photoelectron spectroscopy (XPS). Results from focused ion beam (FIB) cross-sections show that, during sintering, pores in the sintered region near to the Au layer tend to be narrow and elongated with long axis oriented parallel to the interface. Further densification results in formation of many small, relatively equiaxed pores aligned parallel to the interface, creating a path for easy crack propagation. X-ray microanalysis results confirm interdiffusion between Au and Ag and that a region with poor mechanical strength is formed at the edge of this region of interdiffusion.

Design of a biologically inspired lower limb exoskeleton for human gait rehabilitation.

PubMed

Lyu, Mingxing; Chen, Weihai; Ding, Xilun; Wang, Jianhua; Bai, Shaoping; Ren, Huichao

2016-10-01

This paper proposes a novel bionic model of the human leg according to the theory of physiology. Based on this model, we present a biologically inspired 3-degree of freedom (DOF) lower limb exoskeleton for human gait rehabilitation, showing that the lower limb exoskeleton is fully compatible with the human knee joint. The exoskeleton has a hybrid serial-parallel kinematic structure consisting of a 1-DOF hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism is introduced in the design to fully accommodate the motion of the human knee joint, which features not only rotation but also relative sliding. Therefore, the design is consistent with the requirements of bionics. The forward and inverse kinematic analysis is studied and the workspace of the exoskeleton is analyzed. The structural parameters are optimized to obtain a larger workspace. The results using MATLAB-ADAMS co-simulation are shown in this paper to demonstrate the feasibility of our design. A prototype of the exoskeleton is also developed and an experiment performed to verify the kinematic analysis. Compared with existing lower limb exoskeletons, the designed mechanism has a large workspace, while allowing knee joint rotation and small amount of sliding.

Design of a biologically inspired lower limb exoskeleton for human gait rehabilitation

NASA Astrophysics Data System (ADS)

Lyu, Mingxing; Chen, Weihai; Ding, Xilun; Wang, Jianhua; Bai, Shaoping; Ren, Huichao

2016-10-01

This paper proposes a novel bionic model of the human leg according to the theory of physiology. Based on this model, we present a biologically inspired 3-degree of freedom (DOF) lower limb exoskeleton for human gait rehabilitation, showing that the lower limb exoskeleton is fully compatible with the human knee joint. The exoskeleton has a hybrid serial-parallel kinematic structure consisting of a 1-DOF hip joint module and a 2-DOF knee joint module in the sagittal plane. A planar 2-DOF parallel mechanism is introduced in the design to fully accommodate the motion of the human knee joint, which features not only rotation but also relative sliding. Therefore, the design is consistent with the requirements of bionics. The forward and inverse kinematic analysis is studied and the workspace of the exoskeleton is analyzed. The structural parameters are optimized to obtain a larger workspace. The results using MATLAB-ADAMS co-simulation are shown in this paper to demonstrate the feasibility of our design. A prototype of the exoskeleton is also developed and an experiment performed to verify the kinematic analysis. Compared with existing lower limb exoskeletons, the designed mechanism has a large workspace, while allowing knee joint rotation and small amount of sliding.

Knowledge representation into Ada parallel processing

NASA Technical Reports Server (NTRS)

Masotto, Tom; Babikyan, Carol; Harper, Richard

1990-01-01

The Knowledge Representation into Ada Parallel Processing project is a joint NASA and Air Force funded project to demonstrate the execution of intelligent systems in Ada on the Charles Stark Draper Laboratory fault-tolerant parallel processor (FTPP). Two applications were demonstrated - a portion of the adaptive tactical navigator and a real time controller. Both systems are implemented as Activation Framework Objects on the Activation Framework intelligent scheduling mechanism developed by Worcester Polytechnic Institute. The implementations, results of performance analyses showing speedup due to parallelism and initial efficiency improvements are detailed and further areas for performance improvements are suggested.

Remote controlled vacuum joint closure mechanism

DOEpatents

Doll, D.W.; Hager, E.R.

1984-02-22

A remotely operable and maintainable vacuum joint closure mechanism for a noncircular aperture is disclosed. The closure mechanism includes an extendible bellows coupled at one end to a noncircular duct and at its other end to a flange assembly having sealed grooves for establishing a high vacuum seal with the abutting surface of a facing flange which includes an aperture forming part of the system to be evacuated. A plurality of generally linear arrangements of pivotally coupled linkages and piston combinations are mounted around the outer surface of the duct and aligned along the length thereof. Each of the piston/linkage assemblies is adapted to engage the flange assembly by means of a respective piston and is further coupled to a remote controlled piston drive shaft to permit each of the linkages positioned on a respective flat outer surface of the duct to simultaneously and uniformly displace a corresponding piston and the flange assembly with which it is in contact along the length of the duct in extending the bellows to provide a high vacuum seal between the movable flange and the facing flange. A plurality of latch mechanisms are also pivotally mounted on the outside of the duct. A first end of each of the latch mechanisms is coupled to a remotely controlled latch control shaft for displacing the latch mechanism about its pivot point. In response to the pivoting displacement of the latch mechanism, a second end thereof is displaced so as to securely engage the facing flange and maintain the high vacuum seal established by the displacement of the flange assembly and extension of the bellows without displacing the entire duct.

Quantitative genetics of secondary hip joint osteoarthritis in a Labrador Retriever-Greyhound pedigree.

PubMed

Hays, Laurel; Zhang, Zhiwu; Mateescu, Raluca G; Lust, George; Burton-Wurster, Nancy I; Todhunter, Rory J

2007-01-01

To evaluate the quantitative inheritance of secondary hip joint osteoarthritis in a canine pedigree. 137 Labrador Retrievers, Greyhounds, and mixed-breed dogs. Necropsy scores ranging from 0 to 4 were obtained for each hip joint. Seven unaffected Greyhounds with normal hip joint conformation were also used for genetic modeling, but were not euthanized. Sixty-six male and 71 female dogs were allocated to 2 groups (< or = 12 months of age and > 12 months of age). Statistical models were developed to establish the inheritance pattern of hip joint osteoarthritis that developed secondary to hip dysplasia. 62 dogs had evidence of osteoarthritis in a hip joint, and 75 had no evidence of osteoarthritis. After sex was adjusted for, the necropsy score was found to be inherited additively but without dominance. Each Labrador Retriever allele increased the necropsy score by 0.7 to 0.9 points, compared with the Greyhound allele, and male sex increased the necropsy score 0.74 over female sex. Approximately 10% of the variation in necropsy score was attributable to the litter of puppies' origin. Because secondary hip joint osteoarthritis is inherited additively, selection pressure could be applied to reduce its incidence. Similar statistical models can be used in linkage and association mapping to detect the genes in the underlying quantitative trait loci that contribute to hip joint osteoarthritis.

Parallel Attack and the Enemy’s Decision Making Process

DTIC Science & Technology

1998-04-01

Theory Coursebook , Vol 2, Sept 1997, p 365 8 Joint Publication 3-0, Doctrine for Joint Operations, 1 Feb 1995, p III-11 9 Gorrell, LtCol Edgar S., “The...Behavioral Strategies,” Journal of the American Statistical Association, Vol 90, Issue 432, December, 1995, p1137 3 Joint Publication 5-0, Doctrine for...Strategies,” Journal of the American Statistical Association, Vol 90, Issue 432, December, 1995, p1137 Allison, Graham T., “Conceptual Models and the Cuban

Cognitive science speaks to the "common-sense" of chronic illness management.

PubMed

Leventhal, Howard; Leventhal, Elaine A; Breland, Jessica Y

2011-04-01

We describe the parallels between findings from cognitive science and neuroscience and Common-Sense Models in four areas: (1) Activation of illness representations by the automatic linkage of symptoms and functional changes with concepts (an integration of declarative and perceptual and procedural knowledge); (2) Action plans for the management of symptoms and disease; (3) Cognitive and behavioral heuristics (executive functions parallel to recent findings in cognitive science) involved in monitoring and modifying automatic control processes; (4) Perceiving and communicating to "other minds" during medical visits to address the declarative and non-declarative (perceptual and procedural) knowledge that comprise a patient's representations of illness and treatment (the transparency of other minds).

Joint Inference of Population Assignment and Demographic History

PubMed Central

Choi, Sang Chul; Hey, Jody

2011-01-01

A new approach to assigning individuals to populations using genetic data is described. Most existing methods work by maximizing Hardy–Weinberg and linkage equilibrium within populations, neither of which will apply for many demographic histories. By including a demographic model, within a likelihood framework based on coalescent theory, we can jointly study demographic history and population assignment. Genealogies and population assignments are sampled from a posterior distribution using a general isolation-with-migration model for multiple populations. A measure of partition distance between assignments facilitates not only the summary of a posterior sample of assignments, but also the estimation of the posterior density for the demographic history. It is shown that joint estimates of assignment and demographic history are possible, including estimation of population phylogeny for samples from three populations. The new method is compared to results of a widely used assignment method, using simulated and published empirical data sets. PMID:21775468

Progressive failure of sheeted rock slopes: the 2009–2010 Rhombus Wall rock falls in Yosemite Valley, California, USA

USGS Publications Warehouse

Stock, Greg M.; Martel, Stephen J.; Collins, Brian D.; Harp, Edwin L.

2012-01-01

Progressive rock-fall failures in natural rock slopes are common in many environments, but often elude detailed quantitative documentation and analysis. Here we present high-resolution photography, video, and laser scanning data that document spatial and temporal patterns of a 15-month-long sequence of at least 14 rock falls from the Rhombus Wall, a sheeted granitic cliff in Yosemite Valley, California. The rock-fall sequence began on 26 August 2009 with a small failure at the tip of an overhanging rock slab. Several hours later, a series of five rock falls totaling 736 m3progressed upward along a sheeting joint behind the overhanging slab. Over the next 3 weeks, audible cracking occurred on the Rhombus Wall, suggesting crack propagation, while visual monitoring revealed opening of a sheeting joint adjacent to the previous failure surface. On 14 September 2009 a 110 m3 slab detached along this sheeting joint. Additional rock falls between 30 August and 20 November 2010, totaling 187 m3, radiated outward from the initial failure area along cliff (sub)parallel sheeting joints. We suggest that these progressive failures might have been related to stress redistributions accompanying propagation of sheeting joints behind the cliff face. Mechanical analyses indicate that tensile stresses should occur perpendicular to the cliff face and open sheeting joints, and that sheeting joints should propagate parallel to a cliff face from areas of stress concentrations. The analyses also account for how sheeting joints can propagate to lengths many times greater than their depths behind cliff faces. We posit that as a region of failure spreads across a cliff face, stress concentrations along its margin will spread with it, promoting further crack propagation and rock falls.

Infant joint attention, neural networks and social cognition.

PubMed

Mundy, Peter; Jarrold, William

2010-01-01

Neural network models of attention can provide a unifying approach to the study of human cognitive and emotional development (Posner & Rothbart, 2007). In this paper we argue that a neural network approach to the infant development of joint attention can inform our understanding of the nature of human social learning, symbolic thought process and social cognition. At its most basic, joint attention involves the capacity to coordinate one's own visual attention with that of another person. We propose that joint attention development involves increments in the capacity to engage in simultaneous or parallel processing of information about one's own attention and the attention of other people. Infant practice with joint attention is both a consequence and an organizer of the development of a distributed and integrated brain network involving frontal and parietal cortical systems. This executive distributed network first serves to regulate the capacity of infants to respond to and direct the overt behavior of other people in order to share experience with others through the social coordination of visual attention. In this paper we describe this parallel and distributed neural network model of joint attention development and discuss two hypotheses that stem from this model. One is that activation of this distributed network during coordinated attention enhances the depth of information processing and encoding beginning in the first year of life. We also propose that with development, joint attention becomes internalized as the capacity to socially coordinate mental attention to internal representations. As this occurs the executive joint attention network makes vital contributions to the development of human symbolic thinking and social cognition. Copyright © 2010 Elsevier Ltd. All rights reserved.

Biomimetic shoulder complex based on 3-PSS/S spherical parallel mechanism

NASA Astrophysics Data System (ADS)

Hou, Yulei; Hu, Xinzhe; Zeng, Daxing; Zhou, Yulin

2015-01-01

The application of the parallel mechanism is still limited in the humanoid robot fields, and the existing parallel humanoid robot joint has not yet been reflected the characteristics of the parallel mechanism completely, also failed to solve the problem, such as small workspace, effectively. From the structural and functional bionic point of view, a three degrees of freedom(DOFs) spherical parallel mechanism for the shoulder complex of the humanoid robot is presented. According to the structure and kinetic characteristics analysis of the human shoulder complex, 3-PSS/S(P for prismatic pair, S for spherical pair) is chosen as the original configuration for the shouder complex. Using genetic algorithm, the optimization of the 3-PSS/S spherical parallel mechanism is performed, and the orientation workspace of the prototype mechanism is enlarged obviously. Combining the practical structure characteristics of the human shouder complex, an offset output mode, which means the output rod of the mechanism turn to any direction at the point a certain distance from the rotation center of the mechanism, is put forward, which provide possibility for the consistent of the workspace of the mechanism and the actual motion space of the human body shoulder joint. The relationship of the attitude angles between different coordinate system is derived, which establishs the foundation for the motion descriptions under different conditions and control development. The 3-PSS/S spherical parallel mechanism is proposed for the shoulder complex, and the consistence of the workspace of the mechanism and the human shoulder complex is realized by the stuctural parameter optimization and the offset output design.

An Analysis of the Joint Modular Intermodal Distribution System

DTIC Science & Technology

2007-06-01

the differing airframes. “Two methods are available to move a CROP-load of ammunition: 1. Reconfigure the load from the CROP onto multiple 463L...used among the services lack: • Transportability across different modes without re-handling/packaging • Quick reconfiguration for onward movement...numerous linkages among different channels of distribution. In the world of integrated logistics, that means that ground, rail, air, and sea modes of

A decision support tool for setting population objectives for priority landbirds in the Central Hardwoods and West Gulf Coastal Plain/Quachitas Bird Conservation Regions

Treesearch

D. Todd Jones-Farrand; John M. Tirpak; Frank R. Thompson; Daniel J. Twedt; Charles K. Baxter; Jane A. Fitzgerald; William B. Uihlein

2009-01-01

Setting and achieving population objectives for priority landbirds must be informed by, 1) the quantity, quality, and spatial confi guration of available habitat, 2) an explicit linkage between habitat condition and population response, and 3) expected future habitat conditions. Based on this philosophy, the Central Hardwoods and Lower Mississippi Valley Joint Ventures...

Military Review. Volume 73. June 1993, Number 6

DTIC Science & Technology

1993-06-01

1993 * MILITARY REVIEW JOINT OPERATIONS allied landing forces to Field Marshal Erwin battle and smooth linkages between the dib- Rommel’s ability to...to understand its risks and effecting synchronization. Differences in strengths. Almost every nation’s military language, technology , doctrine and... military lessons learned from the Gulf War. The perforancsie following Operation Desert future role of the RC is certainly receiving a Not sfaane ede

Genome-Wide Association Mapping for Intelligence in Military Working Dogs: Canine Cohort, Canine Intelligence Assessment Regimen, Genome-Wide Single Nucleotide Polymorphism (SNP) Typing, and Unsupervised Classification Algorithm for Genome-Wide Association Data Analysis

DTIC Science & Technology

2011-09-01

Almasy, L, Blangero, J. (2009) Human QTL linkage mapping. Genetica 136:333-340. Amos, CI. (2007) Successful design and conduct of genome-wide...quantitative trait loci. Genetica 136:237-243. Skol AD, Scott LJ, Abecasis GR, Boehnke M. (2006) Joint analysis is more efficient than replication

The Role of Coseismic Coulomb Stress Changes in Shaping the Hard Link Between Normal Fault Segments

NASA Astrophysics Data System (ADS)

Hodge, M.; Fagereng, Å.; Biggs, J.

2018-01-01

The mechanism and evolution of fault linkage is important in the growth and development of large faults. Here we investigate the role of coseismic stress changes in shaping the hard links between parallel normal fault segments (or faults), by comparing numerical models of the Coulomb stress change from simulated earthquakes on two en echelon fault segments to natural observations of hard-linked fault geometry. We consider three simplified linking fault geometries: (1) fault bend, (2) breached relay ramp, and (3) strike-slip transform fault. We consider scenarios where either one or both segments rupture and vary the distance between segment tips. Fault bends and breached relay ramps are favored where segments underlap or when the strike-perpendicular distance between overlapping segments is less than 20% of their total length, matching all 14 documented examples. Transform fault linkage geometries are preferred when overlapping segments are laterally offset at larger distances. Few transform faults exist in continental extensional settings, and our model suggests that propagating faults or fault segments may first link through fault bends or breached ramps before reaching sufficient overlap for a transform fault to develop. Our results suggest that Coulomb stresses arising from multisegment ruptures or repeated earthquakes are consistent with natural observations of the geometry of hard links between parallel normal fault segments.

A broader classification of damage zones

NASA Astrophysics Data System (ADS)

Peacock, D. C. P.; Dimmen, V.; Rotevatn, A.; Sanderson, D. J.

2017-09-01

Damage zones have previously been classified in terms of their positions at fault tips, walls or areas of linkage, with the latter being described in terms of sub-parallel and synchronously active faults. We broaden the idea of linkage to include structures around the intersections of non-parallel and/or non-synchronous faults. These interaction damage zones can be divided into approaching damage zones, where the faults kinematically interact but are not physically connected, and intersection damage zones, where the faults either abut or cross-cut. The damage zone concept is applied to other settings in which strain or displacement variations are taken up by a range of structures, such as at fault bends. It is recommended that a prefix can be added to a wide range of damage zones, to describe the locations in which they formed, e.g., approaching, intersection and fault bend damage zone. Such interpretations are commonly based on limited knowledge of the 3D geometries of the structures, such as from exposure surfaces, and there may be spatial variations. For example, approaching faults and related damage seen in outcrop may be intersecting elsewhere on the fault planes. Dilation in intersection damage zones can represent narrow and localised channels for fluid flow, and such dilation can be influenced by post-faulting stress patterns.

Improving estimates of genetic maps: a meta-analysis-based approach.

PubMed

Stewart, William C L

2007-07-01

Inaccurate genetic (or linkage) maps can reduce the power to detect linkage, increase type I error, and distort haplotype and relationship inference. To improve the accuracy of existing maps, I propose a meta-analysis-based method that combines independent map estimates into a single estimate of the linkage map. The method uses the variance of each independent map estimate to combine them efficiently, whether the map estimates use the same set of markers or not. As compared with a joint analysis of the pooled genotype data, the proposed method is attractive for three reasons: (1) it has comparable efficiency to the maximum likelihood map estimate when the pooled data are homogeneous; (2) relative to existing map estimation methods, it can have increased efficiency when the pooled data are heterogeneous; and (3) it avoids the practical difficulties of pooling human subjects data. On the basis of simulated data modeled after two real data sets, the proposed method can reduce the sampling variation of linkage maps commonly used in whole-genome linkage scans. Furthermore, when the independent map estimates are also maximum likelihood estimates, the proposed method performs as well as or better than when they are estimated by the program CRIMAP. Since variance estimates of maps may not always be available, I demonstrate the feasibility of three different variance estimators. Overall, the method should prove useful to investigators who need map positions for markers not contained in publicly available maps, and to those who wish to minimize the negative effects of inaccurate maps. Copyright 2007 Wiley-Liss, Inc.

A hybrid genetic linkage map of two ecologically and morphologically divergent Midas cichlid fishes (Amphilophus spp.) obtained by massively parallel DNA sequencing (ddRADSeq).

PubMed

Recknagel, Hans; Elmer, Kathryn R; Meyer, Axel

2013-01-01

Cichlid fishes are an excellent model system for studying speciation and the formation of adaptive radiations because of their tremendous species richness and astonishing phenotypic diversity. Most research has focused on African rift lake fishes, although Neotropical cichlid species display much variability as well. Almost one dozen species of the Midas cichlid species complex (Amphilophus spp.) have been described so far and have formed repeated adaptive radiations in several Nicaraguan crater lakes. Here we apply double-digest restriction-site associated DNA sequencing to obtain a high-density linkage map of an interspecific cross between the benthic Amphilophus astorquii and the limnetic Amphilophus zaliosus, which are sympatric species endemic to Crater Lake Apoyo, Nicaragua. A total of 755 RAD markers were genotyped in 343 F(2) hybrids. The map resolved 25 linkage groups and spans a total distance of 1427 cM with an average marker spacing distance of 1.95 cM, almost matching the total number of chromosomes (n = 24) in these species. Regions of segregation distortion were identified in five linkage groups. Based on the pedigree of parents to F(2) offspring, we calculated a genome-wide mutation rate of 6.6 × 10(-8) mutations per nucleotide per generation. This genetic map will facilitate the mapping of ecomorphologically relevant adaptive traits in the repeated phenotypes that evolved within the Midas cichlid lineage and, as the first linkage map of a Neotropical cichlid, facilitate comparative genomic analyses between African cichlids, Neotropical cichlids and other teleost fishes.

A Hybrid Genetic Linkage Map of Two Ecologically and Morphologically Divergent Midas Cichlid Fishes (Amphilophus spp.) Obtained by Massively Parallel DNA Sequencing (ddRADSeq)

PubMed Central

Recknagel, Hans; Elmer, Kathryn R.; Meyer, Axel

2013-01-01

Cichlid fishes are an excellent model system for studying speciation and the formation of adaptive radiations because of their tremendous species richness and astonishing phenotypic diversity. Most research has focused on African rift lake fishes, although Neotropical cichlid species display much variability as well. Almost one dozen species of the Midas cichlid species complex (Amphilophus spp.) have been described so far and have formed repeated adaptive radiations in several Nicaraguan crater lakes. Here we apply double-digest restriction-site associated DNA sequencing to obtain a high-density linkage map of an interspecific cross between the benthic Amphilophus astorquii and the limnetic Amphilophus zaliosus, which are sympatric species endemic to Crater Lake Apoyo, Nicaragua. A total of 755 RAD markers were genotyped in 343 F2 hybrids. The map resolved 25 linkage groups and spans a total distance of 1427 cM with an average marker spacing distance of 1.95 cM, almost matching the total number of chromosomes (n = 24) in these species. Regions of segregation distortion were identified in five linkage groups. Based on the pedigree of parents to F2 offspring, we calculated a genome-wide mutation rate of 6.6 × 10−8 mutations per nucleotide per generation. This genetic map will facilitate the mapping of ecomorphologically relevant adaptive traits in the repeated phenotypes that evolved within the Midas cichlid lineage and, as the first linkage map of a Neotropical cichlid, facilitate comparative genomic analyses between African cichlids, Neotropical cichlids and other teleost fishes. PMID:23316439

Design and energetic evaluation of a prosthetic knee joint actuator with a lockable parallel spring.

PubMed

Geeroms, J; Flynn, L; Jimenez-Fabian, R; Vanderborght, B; Lefeber, D

2017-02-03

There are disadvantages to existing damping knee prostheses which cause an asymmetric gait and higher metabolic cost during level walking compared to non-amputees. Most existing active knee prostheses which could benefit the amputees use a significant amount of energy and require a considerable motor. In this work, a novel semi-active actuator with a lockable parallel spring for a prosthetic knee joint has been developed and tested. This actuator is able to provide an approximation of the behavior of a healthy knee during most of the gait cycle of level walking. This actuator is expanded with a series-elastic actuator to mimic the full gait cycle and enable its use in other functional tasks like stair climbing and sit-to-stance. The proposed novel actuator reduces the energy consumption for the same trajectory with respect to a compliant or directly-driven prosthetic active knee joint and improves the approximation of healthy knee behavior during level walking compared to passive or variable damping knee prostheses.

Improvement of psoriatic arthritis in a patient treated with bromocriptine for hyperprolactinemia.

PubMed

Buskila, D; Sukenik, S; Holcberg, G; Horowitz, J

1991-04-01

We describe a woman with psoriatic arthritis who experienced a remarkable improvement of her skin and joint disease while only taking bromocriptine therapy. She was treated with bromocriptine for primary infertility due to hyperprolactinemia. The improvement in joint symptoms appeared to parallel that of the skin. More studies are required to determine the reproducibility of this observation.

Joint carrier phase and frequency-offset estimation with parallel implementation for dual-polarization coherent receiver.

PubMed

Lu, Jianing; Li, Xiang; Fu, Songnian; Luo, Ming; Xiang, Meng; Zhou, Huibin; Tang, Ming; Liu, Deming

2017-03-06

We present dual-polarization complex-weighted, decision-aided, maximum-likelihood algorithm with superscalar parallelization (SSP-DP-CW-DA-ML) for joint carrier phase and frequency-offset estimation (FOE) in coherent optical receivers. By pre-compensation of the phase offset between signals in dual polarizations, the performance can be substantially improved. Meanwhile, with the help of modified SSP-based parallel implementation, the acquisition time of FO and the required number of training symbols are reduced by transferring the complex weights of the filters between adjacent buffers, where differential coding/decoding is not required. Simulation results show that the laser linewidth tolerance of our proposed algorithm is comparable to traditional blind phase search (BPS), while a complete FOE range of ± symbol rate/2 can be achieved. Finally, performance of our proposed algorithm is experimentally verified under the scenario of back-to-back (B2B) transmission using 10 Gbaud DP-16/32-QAM formats.

Listening beneath the Words: Parallel Processes in Music and Psychotherapy

ERIC Educational Resources Information Center

Shapiro, Yakov; Marks-Tarlow,Terry; Fridman, Joseph

2017-01-01

The authors investigate the parallels between musical performance and psychoanalytical therapy, using the former as a metaphor for the way therapist and patient jointly compose the therapeutic experience and better the treatment it offers. [Note: The volume and issue number (v9 n1) shown on this PDF is incorrect. The correct citation is v9 n2.

Output Error Analysis of Planar 2-DOF Five-bar Mechanism

NASA Astrophysics Data System (ADS)

Niu, Kejia; Wang, Jun; Ting, Kwun-Lon; Tao, Fen; Cheng, Qunchao; Wang, Quan; Zhang, Kaiyang

2018-03-01

Aiming at the mechanism error caused by clearance of planar 2-DOF Five-bar motion pair, the method of equivalent joint clearance of kinematic pair to virtual link is applied. The structural error model of revolute joint clearance is established based on the N-bar rotation laws and the concept of joint rotation space, The influence of the clearance of the moving pair is studied on the output error of the mechanis. and the calculation method and basis of the maximum error are given. The error rotation space of the mechanism under the influence of joint clearance is obtained. The results show that this method can accurately calculate the joint space error rotation space, which provides a new way to analyze the planar parallel mechanism error caused by joint space.

An assessment of the realism of digital human manikins used for simulation in ergonomics.

PubMed

Nérot, Agathe; Skalli, Wafa; Wang, Xuguang

2015-01-01

In this study, the accuracy of the joint centres of the manikins generated by RAMSIS and Human Builder (HB), two digital human modelling (DHM) systems widely used in industry for virtual ergonomics simulation, was investigated. Eighteen variously sized females and males were generated from external anthropometric dimensions and six joint centres (knee, hip and four spine joints) were compared with their anatomic locations obtained from the three-dimensional reconstructed bones from a low-dose X-ray system. Both RAMSIS and HB could correctly reproduce external anthropometric dimensions, while the estimation of internal joint centres location presented an average error of 27.6 mm for HB and 38.3 mm for RAMSIS. Differences between both manikins showed that a more realistic kinematic linkage led to better accuracy in joint location. This study opens the way to further research on the relationship between the external body geometry and internal skeleton in order to improve the realism of the internal skeleton of DHMs, especially for a biomechanical analysis requiring information of joint load and muscle force estimation. This study assessed two digital human modelling (DHM) systems widely used in industry for virtual ergonomics. Results support the need of a more realistic human modelling, especially for a biomechanical analysis and a standardisation of DHMs.

Efficient strategy for detecting gene × gene joint action and its application in schizophrenia.

PubMed

Won, Sungho; Kwon, Min-Seok; Mattheisen, Manuel; Park, Suyeon; Park, Changsoon; Kihara, Daisuke; Cichon, Sven; Ophoff, Roel; Nöthen, Markus M; Rietschel, Marcella; Baur, Max; Uitterlinden, Andre G; Hofmann, A; Lange, Christoph

2014-01-01

We propose a new approach to detect gene × gene joint action in genome-wide association studies (GWASs) for case-control designs. This approach offers an exhaustive search for all two-way joint action (including, as a special case, single gene action) that is computationally feasible at the genome-wide level and has reasonable statistical power under most genetic models. We found that the presence of any gene × gene joint action may imply differences in three types of genetic components: the minor allele frequencies and the amounts of Hardy-Weinberg disequilibrium may differ between cases and controls, and between the two genetic loci the degree of linkage disequilibrium may differ between cases and controls. Using Fisher's method, it is possible to combine the different sources of genetic information in an overall test for detecting gene × gene joint action. The proposed statistical analysis is efficient and its simplicity makes it applicable to GWASs. In the current study, we applied the proposed approach to a GWAS on schizophrenia and found several potential gene × gene interactions. Our application illustrates the practical advantage of the proposed method. © 2013 WILEY PERIODICALS, INC.

Assignment of a gene for autosomal recessive retinitis pigmentosa (RP12) to chromosome 1q31-q32.1 in an inbred and genetically heterogeneous disease population

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Soest, S.; Ingeborgh Van Den Born, L.; Bergen, A.A.B.

1994-08-01

Linkage analysis was carried out in a large family segregating for autosomal recessive retinitis pigmentosa (arRP), originating from a genetically isolated population in The Netherlands. Within the family, clinical heterogeneity was observed, with a major section of the family segregating arRP with characteristic para-arteriolar preservation of the retinal pigment epithelium (PPRPE). In the remainder of the arRP patients no PPRPE was found. Initially, all branches of the family were analyzed jointly, and linkage was found between the marker F13B, located at 1q31-q32.1, and RP12 ({Zeta}{sub max} = 4.99 at 8% recombination). Analysis of linkage heterogeneity between five branches of themore » family yielded significant evidence for nonallelic genetic heterogeneity within this family, coinciding with the observed clinical differences. Multipoint analysis, carried out in the branches that showed linkage, favored the locus order 1cen-D1S158-(F13B, RP12)-D1S53-1qter ({Zeta}{sub max} = 9.17). The finding of a single founder allele associated with the disease phenotype supports this localization. This study reveals that even in a large family, apparently segregating for a single disease entity, genetic heterogeneity can be detected and resolved successfully. 35 refs., 5 figs.« less

The joint in psoriatic arthritis.

PubMed

Mortezavi, Mahta; Thiele, Ralph; Ritchlin, Christopher

2015-01-01

Psoriatic arthritis (PsA), a chronic inflammatory joint disease associated with psoriasis, is notable for diversity in disease presentation, course and response to treatment. Equally varied are the types of musculoskeletal involvement which include peripheral and axial joint disease, dactylitis and enthesitis. In this review, we focus on the psoriatic joint and discuss pathways that underlie synovial, cartilage and bone inflammation and highlight key histopathologic features. The pivotal inflammatory mechanisms and pathobiology of PsA parallel findings in other forms of spondyloarthritis but are distinct from disease pathways described in rheumatoid synovitis and bone disease. The diagnosis of PsA from both a clinical and imaging perspective is also discussed.

Joint source based morphometry identifies linked gray and white matter group differences

PubMed Central

Xu, Lai; Pearlson, Godfrey; Calhoun, Vince D.

2009-01-01

We present a multivariate approach called joint source based morphometry (jSBM), to identify linked gray and white matter regions which differ between groups. In jSBM, joint independent component analysis (jICA) is used to decompose preprocessed gray and white matter images into joint sources and statistical analysis is used to determine the significant joint sources showing group differences and their relationship to other variables of interest (e.g. age or sex). The identified joint sources are groupings of linked gray and white matter regions with common covariation among subjects. In this study, we first provide a simulation to validate the jSBM approach. To illustrate our method on real data, jSBM is then applied to structural magnetic resonance imaging (sMRI) data obtained from 120 chronic schizophrenia patients and 120 healthy controls to identify group differences. JSBM identified four joint sources as significantly associated with schizophrenia. Linked gray–white matter regions identified in each of the joint sources included: 1) temporal — corpus callosum, 2) occipital/frontal — inferior fronto-occipital fasciculus, 3) frontal/parietal/occipital/temporal —superior longitudinal fasciculus and 4) parietal/frontal — thalamus. Age effects on all four joint sources were significant, but sex effects were significant only for the third joint source. Our findings demonstrate that jSBM can exploit the natural linkage between gray and white matter by incorporating them into a unified framework. This approach is applicable to a wide variety of problems to study linked gray and white matter group differences. PMID:18992825

A kinematic analysis of the modified flight telerobotic servicer manipulator system

NASA Technical Reports Server (NTRS)

Crane, Carl; Carnahan, Tim; Duffy, Joseph

1992-01-01

A reverse kinematic analysis is presented of a six-DOF subchain of a modified seven-DOF flight telerobotic servicer manipulator system. The six-DOF subchain is designated as a TR-RT chain, which describes the sequence of manipulator joints beginning with the first grounded hook joint (universal joint) T, where the sequence R-R designates a pair of revolute joints with parallel axes. At the outset, it had been thought that the reverse kinematic analysis would be similar to a TTT manipulator previously analyzed, in which the third and fourth joints intersected at a finite point. However, this is shown not the case, and a 16th-degree tan-half-angle polynomial is derived for the TR-RT manipulator.

Development of an Underactuated 2-DOF Wrist Joint using McKibben PAMs

NASA Astrophysics Data System (ADS)

Rajagopal, S. P.; Jain, S.; Ramasubramanian, S. N.; Johnson, B. V.; Dwivedy, S. K.

2014-10-01

In this work, model of an underactuated 2-DOF wrist joint with pneumatically actuated muscles is proposed. For the joint, McKibben-type artificial muscles are used in parallel configuration for the actuation. For each Degree of Freedom (DOF) one agonist-antagonist pair arrangement is usually used with a pulley mechanism. A mathematical model of wrist joint is derived using conventional forward kinematic analysis. The static model relating pressure in the muscle with the orientation of the wrist joint is obtained by combining the experimental data and mathematical model. Regulation of pressure can be achieved by pulse width modulation control of on/off solenoid valves. A set of free vibration experiments are done for the dynamic identification of the muscle characteristics.

Effect of Gold on the Microstructural Evolution and Integrity of a Sintered Silver Joint

DOE PAGES

Muralidharan, Govindarajan; Leonard, Donovan N.; Meyer, Harry M.

2017-01-05

There is a need for next-generation, high-performance power electronic packages and systems employing wide band gap devices to operate at high temperatures in automotive and electric grid applications. Sintered silver joints are currently being evaluated as an alternative to Pb-free solder joints. Of particular interest is the development of joints based on silver paste consisting of nanoscale or micron scale particles that can be processed without the application of an external pressure. Microstructural evolution at the interface of a pressureless sintered silver joint formed between a SiC die with a Ti/Ni/Au metallization and an Active Metal Brazed substrate with Agmore » metallization at 250 °C was evaluated using Scanning Electron Microscopy, X-ray microanalysis, and X-ray Photo Electron Spectroscopy. Results from Focused Ion Beam cross-sections show that during sintering, the pores in the sintered region close to the Au layer tend to be smaller and are oriented predominantly with their longer dimension oriented parallel to the interface. With further densification, this results in the alignment of small pores parallel to the interface, creating a path for easy crack propagation. Lastly, X-ray microchemical analyses results confirm interdiffusion between Au and Ag and that a region with poor mechanical strength is formed at the edge of this region of interdiffusion.« less

Calibrationless parallel magnetic resonance imaging: a joint sparsity model.

PubMed

Majumdar, Angshul; Chaudhury, Kunal Narayan; Ward, Rabab

2013-12-05

State-of-the-art parallel MRI techniques either explicitly or implicitly require certain parameters to be estimated, e.g., the sensitivity map for SENSE, SMASH and interpolation weights for GRAPPA, SPIRiT. Thus all these techniques are sensitive to the calibration (parameter estimation) stage. In this work, we have proposed a parallel MRI technique that does not require any calibration but yields reconstruction results that are at par with (or even better than) state-of-the-art methods in parallel MRI. Our proposed method required solving non-convex analysis and synthesis prior joint-sparsity problems. This work also derives the algorithms for solving them. Experimental validation was carried out on two datasets-eight channel brain and eight channel Shepp-Logan phantom. Two sampling methods were used-Variable Density Random sampling and non-Cartesian Radial sampling. For the brain data, acceleration factor of 4 was used and for the other an acceleration factor of 6 was used. The reconstruction results were quantitatively evaluated based on the Normalised Mean Squared Error between the reconstructed image and the originals. The qualitative evaluation was based on the actual reconstructed images. We compared our work with four state-of-the-art parallel imaging techniques; two calibrated methods-CS SENSE and l1SPIRiT and two calibration free techniques-Distributed CS and SAKE. Our method yields better reconstruction results than all of them.

Adaptive independent joint control of manipulators - Theory and experiment

NASA Technical Reports Server (NTRS)

Seraji, H.

1988-01-01

The author presents a simple decentralized adaptive control scheme for multijoint robot manipulators based on the independent joint control concept. The proposed control scheme for each joint consists of a PID (proportional integral and differential) feedback controller and a position-velocity-acceleration feedforward controller, both with adjustable gains. The static and dynamic couplings that exist between the joint motions are compensated by the adaptive independent joint controllers while ensuring trajectory tracking. The proposed scheme is implemented on a MicroVAX II computer for motion control of the first three joints of a PUMA 560 arm. Experimental results are presented to demonstrate that trajectory tracking is achieved despite strongly coupled, highly nonlinear joint dynamics. The results confirm that the proposed decentralized adaptive control of manipulators is feasible, in spite of strong interactions between joint motions. The control scheme presented is computationally very fast and is amenable to parallel processing implementation within a distributed computing architecture, where each joint is controlled independently by a simple algorithm on a dedicated microprocessor.

Joint Experimentation on Scalable Parallel Processors (JESPP)

DTIC Science & Technology

2006-04-01

made use of local embedded relational databases, implemented using sqlite on each node of an SPP to execute queries and return results via an ad hoc ...rl.af.mil 12a. DISTRIBUTION / AVAILABILITY STATEENT APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. 12b. DISTRIBUTION CODE 13. ABSTRACT...Experimentation Directorate (J9) required expansion of its joint semi-automated forces (JSAF) code capabilities; including number of entities, behavior complexity

Conceptual Framework and Guidelines for Establishing Geographic Information Systems Capable of Integrating Natural Resources Data and Socio-Economic Data for Development-Oriented Planning, Monitoring and Research. (Preliminary Version).

ERIC Educational Resources Information Center

de Man, W. H. Erik, Ed.

This preliminary conceptual framework and the 23 related guidelines have been prepared by specialists drawn from both developed and developing nations as a joint project of the International Institute for Aerial Survey and Earth Sciences (ITC). The project was designed to analyze linkages between natural resource based data and certain types of…

A novel four-bar linkage prosthetic knee based on magnetorheological effect: principle, structure, simulation and control

NASA Astrophysics Data System (ADS)

Xu, Lei; Wang, Dai-Hua; Fu, Qiang; Yuan, Gang; Hu, Lei-Zi

2016-11-01

In this paper, the principle and structure of the four-bar linkage prosthetic knee based on the magnetorheological effect (FLPKME) are proposed and realized by individually integrating the upper and lower link rods of the four-bar linkage with the piston rod and the outer cylinder of the magnetorheological (MR) damper. The integrated MR damper, in which the MR fluid is operated in the shear mode, has a double-ended structure. The prototype of the FLPKME is designed and fabricated. Utilizing the developed FLPKME, the lower limb prosthesis is developed, modeled, and simulated. On these bases, the control algorithm for the FLPKME is developed. A test platform for the FLPKME is developed and the performance of the FLPKME with seven constant currents and controlled currents by the control algorithm developed in this paper are experimentally tested. The results show that the FLPKME with a constant current of 1.6 A possesses the basic stable gait, and the FLPKME with the controlled currents by the control algorithm developed in this paper is able to track the motions well and to imitate the natural motions of a healthy human knee joint.

Can generic knee joint models improve the measurement of osteoarthritic knee kinematics during squatting activity?

PubMed

Clément, Julien; Dumas, Raphaël; Hagemeister, Nicola; de Guise, Jaques A

2017-01-01

Knee joint kinematics derived from multi-body optimisation (MBO) still requires evaluation. The objective of this study was to corroborate model-derived kinematics of osteoarthritic knees obtained using four generic knee joint models used in musculoskeletal modelling - spherical, hinge, degree-of-freedom coupling curves and parallel mechanism - against reference knee kinematics measured by stereo-radiography. Root mean square errors ranged from 0.7° to 23.4° for knee rotations and from 0.6 to 9.0 mm for knee displacements. Model-derived knee kinematics computed from generic knee joint models was inaccurate. Future developments and experiments should improve the reliability of osteoarthritic knee models in MBO and musculoskeletal modelling.

Development of a Big Data Application Architecture for Navy Manpower, Personnel, Training, and Education

DTIC Science & Technology

2016-03-01

science IT information technology JBOD just a bunch of disks JDBC java database connectivity xviii JPME Joint Professional Military Education JSO...Joint Service Officer JVM java virtual machine MPP massively parallel processing MPTE Manpower, Personnel, Training, and Education NAVMAC Navy...27 external database, whether it is MySQL , Oracle, DB2, or SQL Server (Teller, 2015). Connectors optimize the data transfer by obtaining metadata

Expansion joint for guideway for magnetic levitation transportation system

DOEpatents

Rossing, Thomas D.

1993-01-01

An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.

Expansion joint for guideway for magnetic levitation transportation system

DOEpatents

Rossing, T.D.

1993-02-09

An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.

Compliant Robot Wrist

NASA Technical Reports Server (NTRS)

Voellmer, George

1992-01-01

Compliant element for robot wrist accepts small displacements in one direction only (to first approximation). Three such elements combined to obtain translational compliance along three orthogonal directions, without rotational compliance along any of them. Element is double-blade flexure joint in which two sheets of spring steel attached between opposing blocks, forming rectangle. Blocks moved parallel to each other in one direction only. Sheets act as double cantilever beams deforming in S-shape, keeping blocks parallel.

Connectionist Models and Parallelism in High Level Vision.

DTIC Science & Technology

1985-01-01

GRANT NUMBER(s) Jerome A. Feldman N00014-82-K-0193 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENt. PROJECT, TASK Computer Science...Connectionist Models 2.1 Background and Overviev % Computer science is just beginning to look seriously at parallel computation : it may turn out that...the chair. The program includes intermediate level networks that compute more complex joints and ones that compute parallelograms in the image. These

Joint Experiment on Scalable Parallel Processors (JESPP) Parallel Data Management

DTIC Science & Technology

2006-05-01

management and analysis tool, called Simulation Data Grid ( SDG ). The design principles driving the design of SDG are: 1) minimize network communication...or SDG . In this report, an initial prototype implementation of this system is described. This project follows on earlier research, primarily...distributed logging system had some 2 limitations. These limitations will be described in this report, and how the SDG addresses these limitations. 3.0

Issue bricolage: explaining the configuration of the social movement sector, 1960-1995.

PubMed

Jung, Wooseok; King, Brayden G; Soule, Sarah A

2014-07-01

Social movements occupy a shared ideational and resource space, which is often referred to as the social movement sector. This article contributes to the understanding of the relational dynamics of the social movement sector by demonstrating how ideational linkages are formed through protest events. Using a data set of protest events occurring in the United States from 1960 to 1995, the authors model the mechanisms shaping why certain movement issues (e.g., women's and peace or environmental and gay rights) appear together at protest events. They argue that both cultural similarity and status differences between two social movement issues are the underlying mechanisms that shape joint protest and the resultant ideational linkages between issues. Finally, they show that the linking of issues at protest events results in changes in the prominence of a given issue in the social movement sector.

Report of the 2016-17 Academic Affairs Standing Committee: Entrustable Professional Activities Implementation Roadmap.

PubMed

Pittenger, Amy L; Copeland, Debra A; Lacroix, Matthew M; Masuda, Quamrun N; Mbi, Peter; Medina, Melissa S; Miller, Susan M; Stolte, Scott K; Plaza, Cecilia M

2017-06-01

The purpose of this report is to: 1) Identify linkages across the EPA statements, Center for the Advancement of Pharmacy Education 2013 Educational Outcomes (CAPE 2013) and the Joint Commission of Pharmacy Practitioners' Pharmacist Patient Care Process (PPCP); 2) Provide ways EPA statements can be used to communicate core skills that are part of the entry-level pharmacist identity; 3) Suggest a potential roadmap for AACP members on how to implement EPA statements.

A Versatile Omnibus Test for Detecting Mean and Variance Heterogeneity

PubMed Central

Bailey, Matthew; Kauwe, John S. K.; Maxwell, Taylor J.

2014-01-01

Recent research has revealed loci that display variance heterogeneity through various means such as biological disruption, linkage disequilibrium (LD), gene-by-gene (GxG), or gene-by-environment (GxE) interaction. We propose a versatile likelihood ratio test that allows joint testing for mean and variance heterogeneity (LRTMV) or either effect alone (LRTM or LRTV) in the presence of covariates. Using extensive simulations for our method and others we found that all parametric tests were sensitive to non-normality regardless of any trait transformations. Coupling our test with the parametric bootstrap solves this issue. Using simulations and empirical data from a known mean-only functional variant we demonstrate how linkage disequilibrium (LD) can produce variance-heterogeneity loci (vQTL) in a predictable fashion based on differential allele frequencies, high D’ and relatively low r2 values. We propose that a joint test for mean and variance heterogeneity is more powerful than a variance only test for detecting vQTL. This takes advantage of loci that also have mean effects without sacrificing much power to detect variance only effects. We discuss using vQTL as an approach to detect gene-by-gene interactions and also how vQTL are related to relationship loci (rQTL) and how both can create prior hypothesis for each other and reveal the relationships between traits and possibly between components of a composite trait. PMID:24482837

Use of two-dimensional transmission photoelastic models to study stresses in double-lap bolted joints

NASA Technical Reports Server (NTRS)

Hyer, M. W.; Liu, D. H.

1981-01-01

The stress distribution in two hole connectors in a double lap joint configuration was studied. The following steps are described: (1) fabrication of photoelastic models of double lap double hole joints designed to determine the stresses in the inner lap; (2) assessment of the effects of joint geometry on the stresses in the inner lap; and (3) quantification of differences in the stresses near the two holes. The two holes were on the centerline of the joint and the joints were loaded in tension, parallel to the centerline. Acrylic slip fit pins through the holes served as fasteners. Two dimensional transmission photoelastic models were fabricated by using transparent acrylic outer laps and a photoelastic model material for the inner laps. It is concluded that the photoelastic fringe patterns which are visible when the models are loaded are due almost entirely to stresses in the inner lap.

THE KINEMATICS OF PRIMATE MIDFOOT FLEXIBILITY

PubMed Central

Greiner, Thomas M.; Ball, Kevin A.

2015-01-01

This study describes a unique assessment of primate intrinsic foot joint kinematics based upon bone pin rigid cluster tracking. It challenges the assumption that human evolution resulted in a reduction of midfoot flexibility, which has been identified in other primates as the “midtarsal break.” Rigid cluster pins were inserted into the foot bones of human, chimpanzee, baboon and macaque cadavers. The positions of these bone pins were monitored during a plantarflexion-dorsiflexion movement cycle. Analysis resolved flexion-extension movement patterns and the associated orientation of rotational axes for the talonavicular, calcaneocuboid and lateral cubometatarsal joints. Results show that midfoot flexibility occurs primarily at the talonavicular and cubometatarsal joints. The rotational magnitudes are roughly similar between humans and chimps. There is also a similarity among evaluated primates in the observed rotations of the lateral cubometatarsal joint, but there was much greater rotation observed for the talonavicular joint, which may serve to differentiate monkeys from the hominines. It appears that the capability for a midtarsal break is present within the human foot. A consideration of the joint axes shows that the medial and lateral joints have opposing orientations, which has been associated with a rigid locking mechanism in the human foot. However, the potential for this same mechanism also appears in the chimpanzee foot. These findings demonstrate a functional similarity within the midfoot of the hominines. Therefore, the kinematic capabilities and restrictions for the skeletal linkages of the human foot may not be as unique as has been previously suggested. PMID:25234343

Evaluation of aural manifestations in temporo-mandibular joint dysfunction.

PubMed

Sobhy, O A; Koutb, A R; Abdel-Baki, F A; Ali, T M; El Raffa, I Z; Khater, A H

2004-08-01

Thirty patients with temporo-mandibular joint dysfunction were selected to investigate the changes in otoacoustic emissions before and after conservative treatment of their temporo-mandibular joints. Pure tone audiometry, transient-evoked otoacoustic emissions (TEOAE), distortion-product otoacoustic emissions (DPOAE) as well as a tinnitus questionnaire were administered to all patients before and after therapy. Therapy was conservative in the form of counselling, physiotherapy, anti-inflammatory agents, muscle relaxants, and occlusal splints. Results indicated insignificant changes in the TEOAEs, whereas there were significant increases in distortion product levels at most of the frequency bands. These results were paralleled to subjective improvement of tinnitus.

Interfacing Computer Aided Parallelization and Performance Analysis

NASA Technical Reports Server (NTRS)

Jost, Gabriele; Jin, Haoqiang; Labarta, Jesus; Gimenez, Judit; Biegel, Bryan A. (Technical Monitor)

2003-01-01

When porting sequential applications to parallel computer architectures, the program developer will typically go through several cycles of source code optimization and performance analysis. We have started a project to develop an environment where the user can jointly navigate through program structure and performance data information in order to make efficient optimization decisions. In a prototype implementation we have interfaced the CAPO computer aided parallelization tool with the Paraver performance analysis tool. We describe both tools and their interface and give an example for how the interface helps within the program development cycle of a benchmark code.

A Subspace Approach to the Structural Decomposition and Identification of Ankle Joint Dynamic Stiffness.

PubMed

Jalaleddini, Kian; Tehrani, Ehsan Sobhani; Kearney, Robert E

2017-06-01

The purpose of this paper is to present a structural decomposition subspace (SDSS) method for decomposition of the joint torque to intrinsic, reflexive, and voluntary torques and identification of joint dynamic stiffness. First, it formulates a novel state-space representation for the joint dynamic stiffness modeled by a parallel-cascade structure with a concise parameter set that provides a direct link between the state-space representation matrices and the parallel-cascade parameters. Second, it presents a subspace method for the identification of the new state-space model that involves two steps: 1) the decomposition of the intrinsic and reflex pathways and 2) the identification of an impulse response model of the intrinsic pathway and a Hammerstein model of the reflex pathway. Extensive simulation studies demonstrate that SDSS has significant performance advantages over some other methods. Thus, SDSS was more robust under high noise conditions, converging where others failed; it was more accurate, giving estimates with lower bias and random errors. The method also worked well in practice and yielded high-quality estimates of intrinsic and reflex stiffnesses when applied to experimental data at three muscle activation levels. The simulation and experimental results demonstrate that SDSS accurately decomposes the intrinsic and reflex torques and provides accurate estimates of physiologically meaningful parameters. SDSS will be a valuable tool for studying joint stiffness under functionally important conditions. It has important clinical implications for the diagnosis, assessment, objective quantification, and monitoring of neuromuscular diseases that change the muscle tone.

Design and implementation of a novel modal space active force control concept for spatial multi-DOF parallel robotic manipulators actuated by electrical actuators.

PubMed

Yang, Chifu; Zhao, Jinsong; Li, Liyi; Agrawal, Sunil K

2018-01-01

Robotic spine brace based on parallel-actuated robotic system is a new device for treatment and sensing of scoliosis, however, the strong dynamic coupling and anisotropy problem of parallel manipulators result in accuracy loss of rehabilitation force control, including big error in direction and value of force. A novel active force control strategy named modal space force control is proposed to solve these problems. Considering the electrical driven system and contact environment, the mathematical model of spatial parallel manipulator is built. The strong dynamic coupling problem in force field is described via experiments as well as the anisotropy problem of work space of parallel manipulators. The effects of dynamic coupling on control design and performances are discussed, and the influences of anisotropy on accuracy are also addressed. With mass/inertia matrix and stiffness matrix of parallel manipulators, a modal matrix can be calculated by using eigenvalue decomposition. Making use of the orthogonality of modal matrix with mass matrix of parallel manipulators, the strong coupled dynamic equations expressed in work space or joint space of parallel manipulator may be transformed into decoupled equations formulated in modal space. According to this property, each force control channel is independent of others in the modal space, thus we proposed modal space force control concept which means the force controller is designed in modal space. A modal space active force control is designed and implemented with only a simple PID controller employed as exampled control method to show the differences, uniqueness, and benefits of modal space force control. Simulation and experimental results show that the proposed modal space force control concept can effectively overcome the effects of the strong dynamic coupling and anisotropy problem in the physical space, and modal space force control is thus a very useful control framework, which is better than the current joint space control and work space control. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Simulation of ground-water flow to assess geohydrologic factors and their effect on source-water areas for bedrock wells in Connecticut

USGS Publications Warehouse

Starn, J. Jeffrey; Stone, Janet Radway

2005-01-01

Generic ground-water-flow simulation models show that geohydrologic factors?fracture types, fracture geometry, and surficial materials?affect the size, shape, and location of source-water areas for bedrock wells. In this study, conducted by the U.S. Geological Survey in cooperation with the Connecticut Department of Public Health, ground-water flow was simulated to bedrock wells in three settings?on hilltops and hillsides with no surficial aquifer, in a narrow valley with a surficial aquifer, and in a broad valley with a surficial aquifer?to show how different combinations of geohydrologic factors in different topographic settings affect the dimensions and locations of source-water areas in Connecticut. Three principal types of fractures are present in bedrock in Connecticut?(1) Layer-parallel fractures, which developed as partings along bedding in sedimentary rock and compositional layering or foliation in metamorphic rock (dips of these fractures can be gentle or steep); (2) unroofing joints, which developed as strain-release fractures parallel to the land surface as overlying rock was removed by erosion through geologic time; and (3) cross fractures and joints, which developed as a result of tectonically generated stresses that produced typically near-vertical or steeply dipping fractures. Fracture geometry is defined primarily by the presence or absence of layering in the rock unit, and, if layered, by the angle of dip in the layering. Where layered rocks dip steeply, layer-parallel fracturing generally is dominant; unroofing joints also are typically well developed. Where layered rocks dip gently, layer-parallel fracturing also is dominant, and connections among these fractures are provided only by the cross fractures. In gently dipping rocks, unroofing joints generally do not form as a separate fracture set; instead, strain release from unroofing has occurred along gently dipping layer-parallel fractures, enhancing their aperture. In nonlayered and variably layered rocks, layer-parallel fracturing is absent or poorly developed; fracturing is dominated by well-developed subhorizontal unroofing joints and steeply dipping, tectonically generated fractures and (or) cooling joints. Cross fractures (or cooling joints) in nonlayered and variably layered rocks have more random orientations than in layered rocks. Overall, nonlayered or variably layered rocks do not have a strongly developed fracture direction. Generic ground-water-flow simulation models showed that fracture geometry and other geohydrologic factors affect the dimensions and locations of source-water areas for bedrock wells. In general, source-water areas to wells reflect the direction of ground-water flow, which mimics the land-surface topography. Source-water areas to wells in a hilltop setting were not affected greatly by simulated fracture zones, except for an extensive vertical fracture zone. Source-water areas to wells in a hillside setting were not affected greatly by simulated fracture zones, except for the combination of a subhorizontal fracture zone and low bedrock vertical hydraulic conductivity, as might be the case where an extensive subhorizontal fracture zone is not connected or is poorly connected to the surface through vertical fractures. Source-water areas to wells in a narrow valley setting reflect complex ground-water-flow paths. The typical flow path originates in the uplands and passes through either till or bedrock into the surficial aquifer, although only a small area of the surficial aquifer actually contributes water to the well. Source-water areas in uplands can include substantial areas on both sides of a river. Source-water areas for wells in this setting are affected mainly by the rate of ground-water recharge and by the degree of anisotropy. Source-water areas to wells in a broad valley setting (bedrock with a low angle of dip) are affected greatly by fracture properties. The effect of a given fracture is to channel the

Active Metal Brazing and Characterization of Brazed Joints in Titanium to Carbon-Carbon Composites

NASA Technical Reports Server (NTRS)

Singh, M.; Shpargel, T. P.; Morscher, G. N.; Asthana, R.

2006-01-01

The Ti-metal/C-C composite joints were formed by reactive brazing with three commercial brazes, namely, Cu-ABA, TiCuNi, and TiCuSiI. The joint microstructures were examined using optical microscopy and scanning electron microscopy (SEM) coupled with energy dispersive spectrometry (EDS). The results of the microstructure analysis indicate solute redistribution across the joint and possible metallurgical bond formation via interdiffusion, which led to good wetting and spreading. A tube-on-plate tensile test was used to evaluate joint strength of Ti-tube/ C-C composite joints. The load-carrying ability was greatest for the Cu-ABA braze joint structures. This system appeared to have the best braze spreading which resulted in a larger braze/C-C composite bonded area compared to the other two braze materials. Also, joint loadcarrying ability was found to be higher for joint structures where the fiber tows in the outer ply of the C-C composite were aligned perpendicular to the tube axis when compared to the case where fiber tows were aligned parallel to the tube axis.

Building effective service linkages in primary mental health care: a narrative review part 2

PubMed Central

2011-01-01

Background Primary care services have not generally been effective in meeting mental health care needs. There is evidence that collaboration between primary care and specialist mental health services can improve clinical and organisational outcomes. It is not clear however what factors enable or hinder effective collaboration. The objective of this study was to examine the factors that enable effective collaboration between specialist mental health services and primary mental health care. Methods A narrative and thematic review of English language papers published between 1998 and 2009. An expert reference group helped formulate strategies for policy makers. Studies of descriptive and qualitative design from Australia, New Zealand, UK, Europe, USA and Canada were included. Data were extracted on factors reported as enablers or barriers to development of service linkages. These were tabulated by theme at clinical and organisational levels and the inter-relationship between themes was explored. Results A thematic analysis of 30 papers found the most frequently cited group of factors was "partnership formation", specifically role clarity between health care workers. Other factor groups supporting clinical partnership formation were staff support, clinician attributes, clinic physical features and evaluation and feedback. At the organisational level a supportive institutional environment of leadership and change management was important. The expert reference group then proposed strategies for collaboration that would be seen as important, acceptable and feasible. Because of the variability of study types we did not exclude on quality and findings are weighted by the number of studies. Variability in local service contexts limits the generalisation of findings. Conclusion The findings provide a framework for health planners to develop effective service linkages in primary mental health care. Our expert reference group proposed five areas of strategy for policy makers that address organisational level support, joint clinical problem solving, local joint care guidelines, staff training and supervision and feedback. PMID:21435273

Seismic Strengthening of Carpentry Joints in Traditional Timber Structures

NASA Astrophysics Data System (ADS)

Parisi, Maria A.; Cordié, Cinzia; Piazza, Maurizio

2008-07-01

The static and dynamic behavior of timber structures largely depends on their connections. In traditional timber construction, elements are usually connected with carpentry joints based on contact pressure and friction, often with only minor reinforcement generically intended to avoid disassembling. In current practice, interventions for the upgrading of carpentry joints are mainly based on empirical knowledge according to tradition. Often they produce a general strengthening of the connection, but are not specific for the case of seismic action. Strengthening on heuristic bases may be only partially effective or possibly disproportioned. The behavior of the carpentry joints most used in roof structures is examined. The birdsmouth joint, connecting rafters to the tie beam, has been studied first, characterizing its behavior numerically and experimentally in monotonic and cyclic conditions. Other forms of the rafter-to-tie connection, the double notch joint and the case of parallel rafters, are discussed. Some general criteria for the seismic strengthening of these joints are presented.

An algorithm for continuum modeling of rocks with multiple embedded nonlinearly-compliant joints [Continuum modeling of elasto-plastic media with multiple embedded nonlinearly-compliant joints

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hurley, R. C.; Vorobiev, O. Y.; Ezzedine, S. M.

Here, we present a numerical method for modeling the mechanical effects of nonlinearly-compliant joints in elasto-plastic media. The method uses a series of strain-rate and stress update algorithms to determine joint closure, slip, and solid stress within computational cells containing multiple “embedded” joints. This work facilitates efficient modeling of nonlinear wave propagation in large spatial domains containing a large number of joints that affect bulk mechanical properties. We implement the method within the massively parallel Lagrangian code GEODYN-L and provide verification and examples. We highlight the ability of our algorithms to capture joint interactions and multiple weakness planes within individualmore » computational cells, as well as its computational efficiency. We also discuss the motivation for developing the proposed technique: to simulate large-scale wave propagation during the Source Physics Experiments (SPE), a series of underground explosions conducted at the Nevada National Security Site (NNSS).« less

An algorithm for continuum modeling of rocks with multiple embedded nonlinearly-compliant joints [Continuum modeling of elasto-plastic media with multiple embedded nonlinearly-compliant joints

DOE PAGES

Hurley, R. C.; Vorobiev, O. Y.; Ezzedine, S. M.

2017-04-06

Here, we present a numerical method for modeling the mechanical effects of nonlinearly-compliant joints in elasto-plastic media. The method uses a series of strain-rate and stress update algorithms to determine joint closure, slip, and solid stress within computational cells containing multiple “embedded” joints. This work facilitates efficient modeling of nonlinear wave propagation in large spatial domains containing a large number of joints that affect bulk mechanical properties. We implement the method within the massively parallel Lagrangian code GEODYN-L and provide verification and examples. We highlight the ability of our algorithms to capture joint interactions and multiple weakness planes within individualmore » computational cells, as well as its computational efficiency. We also discuss the motivation for developing the proposed technique: to simulate large-scale wave propagation during the Source Physics Experiments (SPE), a series of underground explosions conducted at the Nevada National Security Site (NNSS).« less

Development of a Scientific Basis for Analysis of Aircraft Seating Systems

DTIC Science & Technology

1975-01-01

JOINT MOVEMENTS IN NORMAL MALE HUMAN ADULTS, Human Biology , Vol. 9, pp. 197-211, 1937. 10. Brinkley, J. W., DEVELOPMENT OF AEROSPACE ESCAPE SYSTEMS...Resisting Torque 21 8 Human Joint Resisting Torques: (a) Displacement- Limiting Moment; (b) Muscular Resistance 22 9 Fxternal Forces of Cushions, Floor...head strike on rigid cockpit structure. Also, the relatively low tolerance of the human b.ody to accelerations in a direction parallel to the spine

Cross-bedding Related Anisotropy and its Role in the Orientation of Joints in an Aeolian Sandstone

NASA Astrophysics Data System (ADS)

Deng, S.; Cilona, A.; Mapeli, C.; Panfilau, A.; Aydin, A.; Prasad, M.

2014-12-01

Previous research revealed that the cross-bedding related anisotropy in aeolian sandstones affects the orientation of compaction bands, also known as anticracks. We hypothesize that cross-bedding should a have similar influence on the orientation of the joints within the same rock at the same location. To test this hypothesis, we investigated the relationship between the cross-beds and the cross-bed package confined joints in the Jurassic aeolian Aztec Sandstone cropping out in the Valley of Fire State Park, Nevada. The field data demonstrates that the cross-bed package confined joints occur at high-angle to bedding and trend roughly parallel to the dip direction of the cross-beds. This shows that the cross-bed orientation and the associated anisotropy also exert a strong control on the formation and orientation of the joints. In order to characterize the anisotropy due to cross-bedding in the Aztec Sandstone, we measured the P-wave velocities parallel and perpendicular to bedding from 11 samples in the laboratory using a bench-top ultrasonic assembly. The measured P-wave anisotropy is about 13% on average. Based on these results, a numerical model based on the generalized Hooke's law for anisotropic materials is analyzed assuming the cross-bedded sandstone to be transversely isotropic. Using this model, we tested various cross-bed orientations as well as different strain boundary conditions (uniaxial, axisymmetric and triaxial). It is possible to define a boundary condition under which the modeled results roughly match with the observed relationship between cross-bed package confined joints and cross-beds. These results have important implications for fluid flow through aeolian sandstones in reservoirs and aquifers.

Coherence between harvest and habitat management -- Joint venture perspectives

USGS Publications Warehouse

Baxter, C.K.; Nelson, J.W.; Reinecke, K.J.; Stephens, S.E.

2006-01-01

Introduction: In recent months, an ad hoc group of waterfowl scientists, representing the International Association of Fish and Wildlife Agencies (IAFWA) Adaptive Harvest Management (ARM) Task Force and the North American Waterfowl Management Plan (NAWMP) Committee, have collaborated as a Joint Task Group (JTG) to assess options for unifying the population goals guiding waterfowl harvest management and habitat management. The JTG has been charged with bringing coherence to the population goals of the two programs. Characterizing the problem as one of coherence indicates value judgments exist regarding its significance or perhaps existence. For purposes of this paper, we characterize the lack of coherence as the absence of consistent population goals in the two related components of waterfowl conservation habitat and harvest management. Our purpose is to support continued dialogue on the respective goals of these programs and the possible implications of discordant goals to habitat joint ventures. Our objectives are two-fold: (1) illustrate how NAWMP habitat management goals and strategies have been interpreted and pursued in both breeding and wintering areas, and (2) provide perspectives on the linkages between regional habitat management programs and harvest management. The Lower Mississippi Valley and the Prairie Pothole joint ventures (LMVJV and PPJV, respectively) will be used as examples.

Kinematics and dynamics of robotic systems with multiple closed loops

NASA Astrophysics Data System (ADS)

Zhang, Chang-De

The kinematics and dynamics of robotic systems with multiple closed loops, such as Stewart platforms, walking machines, and hybrid manipulators, are studied. In the study of kinematics, focus is on the closed-form solutions of the forward position analysis of different parallel systems. A closed-form solution means that the solution is expressed as a polynomial in one variable. If the order of the polynomial is less than or equal to four, the solution has analytical closed-form. First, the conditions of obtaining analytical closed-form solutions are studied. For a Stewart platform, the condition is found to be that one rotational degree of freedom of the output link is decoupled from the other five. Based on this condition, a class of Stewart platforms which has analytical closed-form solution is formulated. Conditions of analytical closed-form solution for other parallel systems are also studied. Closed-form solutions of forward kinematics for walking machines and multi-fingered grippers are then studied. For a parallel system with three three-degree-of-freedom subchains, there are 84 possible ways to select six independent joints among nine joints. These 84 ways can be classified into three categories: Category 3:3:0, Category 3:2:1, and Category 2:2:2. It is shown that the first category has no solutions; the solutions of the second category have analytical closed-form; and the solutions of the last category are higher order polynomials. The study is then extended to a nearly general Stewart platform. The solution is a 20th order polynomial and the Stewart platform has a maximum of 40 possible configurations. Also, the study is extended to a new class of hybrid manipulators which consists of two serially connected parallel mechanisms. In the study of dynamics, a computationally efficient method for inverse dynamics of manipulators based on the virtual work principle is developed. Although this method is comparable with the recursive Newton-Euler method for serial manipulators, its advantage is more noteworthy when applied to parallel systems. An approach of inverse dynamics of a walking machine is also developed, which includes inverse dynamic modeling, foot force distribution, and joint force/torque allocation.

An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

PubMed

Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

2010-01-01

To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at P<.05. Mean yield load, yield stiffness, and failure load under axial compression and torsion, single cycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

Iterative nonlinear joint transform correlation for the detection of objects in cluttered scenes

NASA Astrophysics Data System (ADS)

Haist, Tobias; Tiziani, Hans J.

1999-03-01

An iterative correlation technique with digital image processing in the feedback loop for the detection of small objects in cluttered scenes is proposed. A scanning aperture is combined with the method in order to improve the immunity against noise and clutter. Multiple reference objects or different views of one object are processed in parallel. We demonstrate the method by detecting a noisy and distorted face in a crowd with a nonlinear joint transform correlator.

[Subtalar arthrodesis].

PubMed

Fuhrmann, R A; Pillukat, T

2016-06-01

Realignment and stabilization of the hindfoot by subtalar joint arthrodesis. Idiopathic/posttraumatic arthritis, inflammatory arthritis of the subtalar joint with/without hindfoot malalignment. Optional flatfoot/cavovarus foot reconstruction. Inflammation, vascular disturbances, nicotine abuse. Approach dependent on assessment. Lateral approach: Supine position. Incision above the sinus tarsi. Exposure of subtalar joint. Removal of cartilage and breakage of the subchondral sclerosis. In valgus malalignment, interposition of corticocancellous bone segment; in varus malalignment resection of bone segment from the calcaneus. Reposition and temporarily stabilization with Kirschner wires. Imaging of hindfoot alignment. Stabilization with cannulated screws. Posterolateral approach: Prone position. Incision parallel to the lateral Achilles tendon border. Removal of cartilage and breakage of subchondral sclerosis. Medial approach: Supine position. Incision just above and parallel to the posterior tibial tendon. Removal of cartilage and breakage of subchondral sclerosis. Stabilization with screws. Lower leg walker with partial weightbearing. Active exercises of the ankle. After a 6‑week X‑ray, increase of weightbearing. Full weightbearing not before 8 weeks; with interpositioning bone grafts not before 10-12 weeks. Stable walking shoes. Active mobilization of the ankle. Of 43 isolated subtalar arthrodesis procedures, 5 wound healing disorders and no infections developed. Significantly improved AOFAS hindfood score. Well-aligned heel observed in 34 patients; 5 varus and 2 valgus malalignments. Sensory disturbances in 8 patients; minor ankle flexion limitations. Full bone healing in 36 subtalar joints, pseudarthrosis in 4 patients.

Nucleation and growth of strike slip faults in granite.

USGS Publications Warehouse

Segall, P.; Pollard, D.P.

1983-01-01

Fractures within granodiorite of the central Sierra Nevada, California, were studied to elucidate the mechanics of faulting in crystalline rocks, with emphasis on the nucleation of new fault surfaces and their subsequent propagation and growth. Within the study area the fractures form a single, subparallel array which strikes N50o-70oE and dips steeply to the S. Some of these fractures are identified as joints because displacements across the fracture surfaces exhibit dilation but no slip. The joints are filled with undeformed minerals, including epidote and chlorite. Other fractures are identified as small faults because they display left-lateral strike slip separations of up to 2m. Slickensides, developed on fault surfaces, plunge 0o-20o to the E. The faults occur parallel to, and in the same outcrop with, the joints. The faults are filled with epidote, chlorite, and quartz, which exhibit textural evidence of shear deformation. These observations indicate that the strike slip faults nucleated on earlier formed, mineral filled joints. Secondary, dilational fractures propagated from near the ends of some small faults contemporaneously with the left-lateral slip on the faults. These fractures trend 25o+ or -10o from the fault planes, parallel to the direction of inferred local maximum compressive stress. The faults did not propagate into intact rock in their own planes as shear fractures. -from Authors

Grasp cueing and joint attention.

PubMed

Tschentscher, Nadja; Fischer, Martin H

2008-10-01

We studied how two different hand posture cues affect joint attention in normal observers. Visual targets appeared over lateralized objects, with different delays after centrally presented hand postures. Attention was cued by either hand direction or the congruency between hand aperture and object size. Participants pressed a button when they detected a target. Direction cues alone facilitated target detection following short delays but aperture cues alone were ineffective. In contrast, when hand postures combined direction and aperture cues, aperture congruency effects without directional congruency effects emerged and persisted, but only for power grips. These results suggest that parallel parameter specification makes joint attention mechanisms exquisitely sensitive to the timing and content of contextual cues.

[Possibilities of magnetic resonance tomography in diagnostic imaging of the shoulder joint].

PubMed

Reiser, M; Erlemann, R; Bongartz, G; Pauly, T; Kunze, V; Mathiass, H H; Peters, P E

1988-02-01

By virtue of its multiplanar representation, magnetic resonance imaging (MRI) allows clear visualization of the complex anatomical relationships of the shoulder joint. In addition to axial planes, slices perpendicular and parallel to the glenoid cavity are used to good advantage. In tears of the rotator cuff an increase in signal intensity within the cuff is recognized in T2- and proton-density-weighted images. Lesions of the glenoid labrum following luxations of the glenohumeral joint can be detected and classified using MRI. The diagnostic value of MRI as compared with other imaging modalities will have to be evaluated in larger series with operative verification.

Designs of Optoelectronic Trinary Signed-Digit Multiplication by use of Joint Spatial Encodings and Optical Correlation

NASA Astrophysics Data System (ADS)

Cherri, Abdallah K.

1999-02-01

Trinary signed-digit (TSD) symbolic-substitution-based (SS-based) optical adders, which were recently proposed, are used as the basic modules for designing highly parallel optical multiplications by use of cascaded optical correlators. The proposed multiplications perform carry-free generation of the multiplication partial products of two words in constant time. Also, three different multiplication designs are presented, and new joint spatial encodings for the TSD numbers are introduced. The proposed joint spatial encodings allow one to reduce the SS computation rules involved in optical multiplication. In addition, the proposed joint spatial encodings increase the space bandwidth product of the spatial light modulators of the optical system. This increase is achieved by reduction of the numbers of pixels in the joint spatial encodings for the input TSD operands as well as reduction of the number of pixels used in the proposed matched spatial filters for the optical multipliers.

Designs of optoelectronic trinary signed-digit multiplication by use of joint spatial encodings and optical correlation.

PubMed

Cherri, A K

1999-02-10

Trinary signed-digit (TSD) symbolic-substitution-based (SS-based) optical adders, which were recently proposed, are used as the basic modules for designing highly parallel optical multiplications by use of cascaded optical correlators. The proposed multiplications perform carry-free generation of the multiplication partial products of two words in constant time. Also, three different multiplication designs are presented, and new joint spatial encodings for the TSD numbers are introduced. The proposed joint spatial encodings allow one to reduce the SS computation rules involved in optical multiplication. In addition, the proposed joint spatial encodings increase the space-bandwidth product of the spatial light modulators of the optical system. This increase is achieved by reduction of the numbers of pixels in the joint spatial encodings for the input TSD operands as well as reduction of the number of pixels used in the proposed matched spatial filters for the optical multipliers.

Experiments and kinematics analysis of a hand rehabilitation exoskeleton with circuitous joints.

PubMed

Zhang, Fuhai; Fu, Yili; Zhang, Qinchao; Wang, Shuguo

2015-01-01

Aiming at the hand rehabilitation of stroke patients, a wearable hand exoskeleton with circuitous joint is proposed. The circuitous joint adopts the symmetric pinion and rack mechanism (SPRM) with the parallel mechanism. The exoskeleton finger is a serial mechanism composed of three closed-chain SPRM joints in series. The kinematic equations of the open chain of the finger and the closed chains of the SPRM joints were built to analyze the kinematics of the hand rehabilitation exoskeleton. The experimental setup of the hand rehabilitation exoskeleton was built and the continuous passive motion (CPM) rehabilitation experiment and the test of human-robot interaction force measurement were conducted. Experiment results show that the mechanical design of the hand rehabilitation robot is reasonable and that the kinematic analysis is correct, thus the exoskeleton can be used for the hand rehabilitation of stroke patients.

Parallel implementation of all-digital timing recovery for high-speed and real-time optical coherent receivers.

PubMed

Zhou, Xian; Chen, Xue

2011-05-09

The digital coherent receivers combine coherent detection with digital signal processing (DSP) to compensate for transmission impairments, and therefore are a promising candidate for future high-speed optical transmission system. However, the maximum symbol rate supported by such real-time receivers is limited by the processing rate of hardware. In order to cope with this difficulty, the parallel processing algorithms is imperative. In this paper, we propose a novel parallel digital timing recovery loop (PDTRL) based on our previous work. Furthermore, for increasing the dynamic dispersion tolerance range of receivers, we embed a parallel adaptive equalizer in the PDTRL. This parallel joint scheme (PJS) can be used to complete synchronization, equalization and polarization de-multiplexing simultaneously. Finally, we demonstrate that PDTRL and PJS allow the hardware to process 112 Gbit/s POLMUX-DQPSK signal at the hundreds MHz range. © 2011 Optical Society of America

Ascertainment correction for Markov chain Monte Carlo segregation and linkage analysis of a quantitative trait.

PubMed

Ma, Jianzhong; Amos, Christopher I; Warwick Daw, E

2007-09-01

Although extended pedigrees are often sampled through probands with extreme levels of a quantitative trait, Markov chain Monte Carlo (MCMC) methods for segregation and linkage analysis have not been able to perform ascertainment corrections. Further, the extent to which ascertainment of pedigrees leads to biases in the estimation of segregation and linkage parameters has not been previously studied for MCMC procedures. In this paper, we studied these issues with a Bayesian MCMC approach for joint segregation and linkage analysis, as implemented in the package Loki. We first simulated pedigrees ascertained through individuals with extreme values of a quantitative trait in spirit of the sequential sampling theory of Cannings and Thompson [Cannings and Thompson [1977] Clin. Genet. 12:208-212]. Using our simulated data, we detected no bias in estimates of the trait locus location. However, in addition to allele frequencies, when the ascertainment threshold was higher than or close to the true value of the highest genotypic mean, bias was also found in the estimation of this parameter. When there were multiple trait loci, this bias destroyed the additivity of the effects of the trait loci, and caused biases in the estimation all genotypic means when a purely additive model was used for analyzing the data. To account for pedigree ascertainment with sequential sampling, we developed a Bayesian ascertainment approach and implemented Metropolis-Hastings updates in the MCMC samplers used in Loki. Ascertainment correction greatly reduced biases in parameter estimates. Our method is designed for multiple, but a fixed number of trait loci. Copyright (c) 2007 Wiley-Liss, Inc.

Linkage Analysis of Urine Arsenic Species Patterns in the Strong Heart Family Study

PubMed Central

Gribble, Matthew O.; Voruganti, Venkata Saroja; Cole, Shelley A.; Haack, Karin; Balakrishnan, Poojitha; Laston, Sandra L.; Tellez-Plaza, Maria; Francesconi, Kevin A.; Goessler, Walter; Umans, Jason G.; Thomas, Duncan C.; Gilliland, Frank; North, Kari E.; Franceschini, Nora; Navas-Acien, Ana

2015-01-01

Arsenic toxicokinetics are important for disease risks in exposed populations, but genetic determinants are not fully understood. We examined urine arsenic species patterns measured by HPLC-ICPMS among 2189 Strong Heart Study participants 18 years of age and older with data on ∼400 genome-wide microsatellite markers spaced ∼10 cM and arsenic speciation (683 participants from Arizona, 684 from Oklahoma, and 822 from North and South Dakota). We logit-transformed % arsenic species (% inorganic arsenic, %MMA, and %DMA) and also conducted principal component analyses of the logit % arsenic species. We used inverse-normalized residuals from multivariable-adjusted polygenic heritability analysis for multipoint variance components linkage analysis. We also examined the contribution of polymorphisms in the arsenic metabolism gene AS3MT via conditional linkage analysis. We localized a quantitative trait locus (QTL) on chromosome 10 (LOD 4.12 for %MMA, 4.65 for %DMA, and 4.84 for the first principal component of logit % arsenic species). This peak was partially but not fully explained by measured AS3MT variants. We also localized a QTL for the second principal component of logit % arsenic species on chromosome 5 (LOD 4.21) that was not evident from considering % arsenic species individually. Some other loci were suggestive or significant for 1 geographical area but not overall across all areas, indicating possible locus heterogeneity. This genome-wide linkage scan suggests genetic determinants of arsenic toxicokinetics to be identified by future fine-mapping, and illustrates the utility of principal component analysis as a novel approach that considers % arsenic species jointly. PMID:26209557

Classified one-step high-radix signed-digit arithmetic units

NASA Astrophysics Data System (ADS)

Cherri, Abdallah K.

1998-08-01

High-radix number systems enable higher information storage density, less complexity, fewer system components, and fewer cascaded gates and operations. A simple one-step fully parallel high-radix signed-digit arithmetic is proposed for parallel optical computing based on new joint spatial encodings. This reduces hardware requirements and improves throughput by reducing the space-bandwidth produce needed. The high-radix signed-digit arithmetic operations are based on classifying the neighboring input digit pairs into various groups to reduce the computation rules. A new joint spatial encoding technique is developed to present both the operands and the computation rules. This technique increases the spatial bandwidth product of the spatial light modulators of the system. An optical implementation of the proposed high-radix signed-digit arithmetic operations is also presented. It is shown that our one-step trinary signed-digit and quaternary signed-digit arithmetic units are much simpler and better than all previously reported high-radix signed-digit techniques.

A feasibility study of hand kinematics for EVA analysis using magnetic resonance imaging

NASA Technical Reports Server (NTRS)

Dickenson, Rueben D.; Lorenz, Christine H.; Peterson, Steven W.; Strauss, Alvin M.; Main, John A.

1992-01-01

A new method of analyzing the kinematics of joint motion is developed. Magnetic Resonance Imaging (MRI) offers several distinct advantages. Past methods of studying anatomic joint motion have usually centered on four approaches. These methods are x-ray projection, goniometric linkage analysis, sonic digitization, and landmark measurement of photogrammetry. Of these four, only x-ray is applicable for in vivo studies. The remaining three methods utilize other types of projections of inter-joint measurements, which can cause various types of error. MRI offers accuracy in measurement due to its tomographic nature (as opposed to projection) without the problems associated with x-ray dosage. Once the data acquisition of MR images was complete, the images were processed using a 3D volume rendering workstation. The metacarpalphalangeal (MCP) joint of the left index finger was selected and reconstructed into a three-dimensional graphic display. From the reconstructed volumetric images, measurements of the angles of movement of the applicable bones were obtained and processed by analyzing the screw motion of the MCP joint. Landmark positions were chosen at distinctive locations of the joint at fixed image threshold intensity levels to ensure repeatability. The primarily two dimensional planar motion of this joint was then studied using a method of constructing coordinate systems using three (or more) points. A transformation matrix based on a world coordinate system described the location and orientation of a local target coordinate system. Future research involving volume rendering of MRI data focusing on the internal kinematics of the hand's individual ligaments, cartilage, tendons, etc. will follow. Its findings will show the applicability of MRI to joint kinematics for gaining further knowledge of the hand-glove (power assisted) design for extravehicular activity (EVA).

Why Does Joint Attention Look Atypical in Autism?

PubMed Central

Gernsbacher, Morton Ann; Stevenson, Jennifer L.; Khandakar, Suraiya; Goldsmith, H. Hill

2014-01-01

This essay answers the question of why autistic children are less likely to initiate joint attention (e.g., use their index finger to point to indicate interest in something) and why they are less likely to respond to bids for their joint attention (e.g., turn their heads to look at something to which another person points). It reviews empirical evidence that autistic toddlers, children, adolescents, and adults can attend covertly, even to social stimuli, such as the direction in which another person’s eyes are gazing. It also reviews empirical evidence that autistics of various ages understand the intentionality of other persons’ actions. The essay suggests that autistics’ atypical resistance to distraction, atypical skill at parallel perception, and atypical execution of volitional actions underlie their atypical manifestations of joint attention. PMID:25520747

Joint torques in a freely walking insect reveal distinct functions of leg joints in propulsion and posture control

PubMed Central

2016-01-01

Determining the mechanical output of limb joints is critical for understanding the control of complex motor behaviours such as walking. In the case of insect walking, the neural infrastructure for single-joint control is well described. However, a detailed description of the motor output in form of time-varying joint torques is lacking. Here, we determine joint torques in the stick insect to identify leg joint function in the control of body height and propulsion. Torques were determined by measuring whole-body kinematics and ground reaction forces in freely walking animals. We demonstrate that despite strong differences in morphology and posture, stick insects show a functional division of joints similar to other insect model systems. Propulsion was generated by strong depression torques about the coxa–trochanter joint, not by retraction or flexion/extension torques. Torques about the respective thorax–coxa and femur–tibia joints were often directed opposite to fore–aft forces and joint movements. This suggests a posture-dependent mechanism that counteracts collapse of the leg under body load and directs the resultant force vector such that strong depression torques can control both body height and propulsion. Our findings parallel propulsive mechanisms described in other walking, jumping and flying insects, and challenge current control models of insect walking. PMID:26791608

A Scalable Approach for Discovering Conserved Active Subnetworks across Species

PubMed Central

Verfaillie, Catherine M.; Hu, Wei-Shou; Myers, Chad L.

2010-01-01

Overlaying differential changes in gene expression on protein interaction networks has proven to be a useful approach to interpreting the cell's dynamic response to a changing environment. Despite successes in finding active subnetworks in the context of a single species, the idea of overlaying lists of differentially expressed genes on networks has not yet been extended to support the analysis of multiple species' interaction networks. To address this problem, we designed a scalable, cross-species network search algorithm, neXus (Network - cross(X)-species - Search), that discovers conserved, active subnetworks based on parallel differential expression studies in multiple species. Our approach leverages functional linkage networks, which provide more comprehensive coverage of functional relationships than physical interaction networks by combining heterogeneous types of genomic data. We applied our cross-species approach to identify conserved modules that are differentially active in stem cells relative to differentiated cells based on parallel gene expression studies and functional linkage networks from mouse and human. We find hundreds of conserved active subnetworks enriched for stem cell-associated functions such as cell cycle, DNA repair, and chromatin modification processes. Using a variation of this approach, we also find a number of species-specific networks, which likely reflect mechanisms of stem cell function that have diverged between mouse and human. We assess the statistical significance of the subnetworks by comparing them with subnetworks discovered on random permutations of the differential expression data. We also describe several case examples that illustrate the utility of comparative analysis of active subnetworks. PMID:21170309

Genome-wide distribution of genetic diversity and linkage disequilibrium in a mass-selected population of maritime pine

PubMed Central

2014-01-01

Background The accessibility of high-throughput genotyping technologies has contributed greatly to the development of genomic resources in non-model organisms. High-density genotyping arrays have only recently been developed for some economically important species such as conifers. The potential for using genomic technologies in association mapping and breeding depends largely on the genome wide patterns of diversity and linkage disequilibrium in current breeding populations. This study aims to deepen our knowledge regarding these issues in maritime pine, the first species used for reforestation in south western Europe. Results Using a new map merging algorithm, we first established a 1,712 cM composite linkage map (comprising 1,838 SNP markers in 12 linkage groups) by bringing together three already available genetic maps. Using rigorous statistical testing based on kernel density estimation and resampling we identified cold and hot spots of recombination. In parallel, 186 unrelated trees of a mass-selected population were genotyped using a 12k-SNP array. A total of 2,600 informative SNPs allowed to describe historical recombination, genetic diversity and genetic structure of this recently domesticated breeding pool that forms the basis of much of the current and future breeding of this species. We observe very low levels of population genetic structure and find no evidence that artificial selection has caused a reduction in genetic diversity. By combining these two pieces of information, we provided the map position of 1,671 SNPs corresponding to 1,192 different loci. This made it possible to analyze the spatial pattern of genetic diversity (H e ) and long distance linkage disequilibrium (LD) along the chromosomes. We found no particular pattern in the empirical variogram of H e across the 12 linkage groups and, as expected for an outcrossing species with large effective population size, we observed an almost complete lack of long distance LD. Conclusions These results are a stepping stone for the development of strategies for studies in population genomics, association mapping and genomic prediction in this economical and ecologically important forest tree species. PMID:24581176

Waveguide Photonic Choke Joint with Wide Out-of-Band Rejection

NASA Technical Reports Server (NTRS)

U-yen, Kongpop; Wollack, Edward J.

2015-01-01

A photonic choke joint structure with a wide-stop-band is proposed for use as a waveguide flange interface. The structure consists of arrays of square metal pillars arranged in a periodic pattern to suppress the dominant-mode wave propagation in parallel-plate waveguide over a wide frequency bandwidth. The measurement results at microwave frequencies confirm that the structure can provide broadband suppression of more than 56dB over 6.25 times its operating frequency. Applications at millimeter wavelength are discussed.

Waveguide Photonic Choke Joint with Wide Out-of-Band Rejection

NASA Technical Reports Server (NTRS)

U-yen, Kongpop; Wollack, Edward J.

2015-01-01

A photonic choke joint structure with a wide- stop-band is proposed for use as a waveguide flange interface. The structure consists of arrays of square metal pillars arranged in a periodic pattern to suppress the dominant-mode wave propagation in parallel-plate waveguide over a wide frequency bandwidth. The measurement results at microwave frequencies confirm the structure can provide broadband suppression, more than 56 dB over 6.25 times its operating frequency. Applications at millimeter wavelength are discussed.

Computational structures for robotic computations

NASA Technical Reports Server (NTRS)

Lee, C. S. G.; Chang, P. R.

1987-01-01

The computational problem of inverse kinematics and inverse dynamics of robot manipulators by taking advantage of parallelism and pipelining architectures is discussed. For the computation of inverse kinematic position solution, a maximum pipelined CORDIC architecture has been designed based on a functional decomposition of the closed-form joint equations. For the inverse dynamics computation, an efficient p-fold parallel algorithm to overcome the recurrence problem of the Newton-Euler equations of motion to achieve the time lower bound of O(log sub 2 n) has also been developed.

Cross-bedding related anisotropy and its interplay with various boundary conditions in the formation and orientation of joints in an aeolian sandstone

NASA Astrophysics Data System (ADS)

Deng, Shang; Cilona, Antonino; Morrow, Carolyn; Mapeli, Cesar; Liu, Chun; Lockner, David; Prasad, Manika; Aydin, Atilla

2015-08-01

Previous research revealed that the cross-bedding related anisotropy in Jurassic aeolian Aztec Sandstone cropping out in the Valley of Fire State Park, Nevada, affects the orientation of compaction bands, also known as anti-cracks or closing mode structures. We hypothesize that cross-bedding should have a similar influence on the orientation of the opening mode joints within the same rock at the same location. To test this hypothesis, we investigated the relationship between the orientation of cross-beds and the orientation of different categories of joint sets including cross-bed package confined joints and joint zones in the Aztec Sandstone. The field data show that the cross-bed package confined joints occur at high-angle to bedding and trend roughly parallel to the dip direction of the cross-beds. In comparison, the roughly N-S trending joint zones appear not to be influenced by the cross-beds in any significant way but frequently truncate against the dune boundaries. To characterize the anisotropy due to cross-bedding in the Aztec Sandstone, we measured the P-wave velocities parallel and perpendicular to bedding from 11 samples and determined an average P-wave anisotropy to be slightly larger than 13%. From these results, a model based on the generalized Hooke's law for anisotropic materials is used to analyze deformation of cross-bedded sandstone as a transversely isotropic material. In the analysis, the dip angle of cross-beds is assumed to be constant and the strike orientation varying from 0° to 359° in the east (x), north (y), and up (z) coordinate system. We find qualitative agreement between most of the model results and the observed field relations between cross-beds and the corresponding joint sets. The results also suggest that uniaxial extension (εzz > εxx = εyy = 0) and axisymmetric extension (εxx = εyy < εzz and εxx = εyy > εzz) would amplify the influence of cross-bedding associated anisotropy on the joint orientation whereas a triaxial extension (εxx > εyy > εzz) would mitigate this influence. We suggest that the potential implication of different categories of joint sets (i.e., cross-bed package confined joints and joint zones) forming in response to the variation of the boundary conditions (axisymmetric extension and triaxial extension, respectively) and the interplay with the rock anisotropy is significant. These results have important implications for fluid flow through aeolian sandstones in reservoirs and aquifers.

Seed colour loci, homoeology and linkage groups of the C genome chromosomes revealed in Brassica rapa–B. oleracea monosomic alien addition lines

PubMed Central

Heneen, Waheeb K.; Geleta, Mulatu; Brismar, Kerstin; Xiong, Zhiyong; Pires, J. Chris; Hasterok, Robert; Stoute, Andrew I.; Scott, Roderick J.; King, Graham J.; Kurup, Smita

2012-01-01

Background and Aims Brassica rapa and B. oleracea are the progenitors of oilseed rape B. napus. The addition of each chromosome of B. oleracea to the chromosome complement of B. rapa results in a series of monosomic alien addition lines (MAALs). Analysis of MAALs determines which B. oleracea chromosomes carry genes controlling specific phenotypic traits, such as seed colour. Yellow-seeded oilseed rape is a desirable breeding goal both for food and livestock feed end-uses that relate to oil, protein and fibre contents. The aims of this study included developing a missing MAAL to complement an available series, for studies on seed colour control, chromosome homoeology and assignment of linkage groups to B. oleracea chromosomes. Methods A new batch of B. rapa–B. oleracea aneuploids was produced to generate the missing MAAL. Seed colour and other plant morphological features relevant to differentiation of MAALs were recorded. For chromosome characterization, Snow's carmine, fluorescence in situ hybridization (FISH) and genomic in situ hybridization (GISH) were used. Key Results The final MAAL was developed. Morphological traits that differentiated the MAALs comprised cotyledon number, leaf morphology, flower colour and seed colour. Seed colour was controlled by major genes on two B. oleracea chromosomes and minor genes on five other chromosomes of this species. Homoeologous pairing was largely between chromosomes with similar centromeric positions. FISH, GISH and a parallel microsatellite marker analysis defined the chromosomes in terms of their linkage groups. Conclusions A complete set of MAALs is now available for genetic, genomic, evolutionary and breeding perspectives. Defining chromosomes that carry specific genes, physical localization of DNA markers and access to established genetic linkage maps contribute to the integration of these approaches, manifested in the confirmed correspondence of linkage groups with specific chromosomes. Applications include marker-assisted selection and breeding for yellow seeds. PMID:22628364

A linkage analysis toolkit for studying allosteric networks in ion channels

PubMed Central

2013-01-01

A thermodynamic approach to studying allosterically regulated ion channels such as the large-conductance voltage- and Ca2+-dependent (BK) channel is presented, drawing from principles originally introduced to describe linkage phenomena in hemoglobin. In this paper, linkage between a principal channel component and secondary elements is derived from a four-state thermodynamic cycle. One set of parallel legs in the cycle describes the “work function,” or the free energy required to activate the principal component. The second are “lever operations” activating linked elements. The experimental embodiment of this linkage cycle is a plot of work function versus secondary force, whose asymptotes are a function of the parameters (displacements and interaction energies) of an allosteric network. Two essential work functions play a role in evaluating data from voltage-clamp experiments. The first is the conductance Hill energy WH[g], which is a “local” work function for pore activation, and is defined as kT times the Hill transform of the conductance (G-V) curve. The second is the electrical capacitance energy WC[q], representing “global” gating charge displacement, and is equal to the product of total gating charge per channel times the first moment (VM) of normalized capacitance (slope of Q-V curve). Plots of WH[g] and WC[q] versus voltage and Ca2+ potential can be used to measure thermodynamic parameters in a model-independent fashion of the core gating constituents (pore, voltage-sensor, and Ca2+-binding domain) of BK channel. The method is easily generalized for use in studying other allosterically regulated ion channels. The feasibility of performing linkage analysis from patch-clamp data were explored by simulating gating and ionic currents of a 17-particle model BK channel in response to a slow voltage ramp, which yielded interaction energies deviating from their given values in the range of 1.3 to 7.2%. PMID:23250867

Inferring the Joint Demographic History of Multiple Populations from Multidimensional SNP Frequency Data

PubMed Central

Gutenkunst, Ryan N.; Hernandez, Ryan D.; Williamson, Scott H.; Bustamante, Carlos D.

2009-01-01

Demographic models built from genetic data play important roles in illuminating prehistorical events and serving as null models in genome scans for selection. We introduce an inference method based on the joint frequency spectrum of genetic variants within and between populations. For candidate models we numerically compute the expected spectrum using a diffusion approximation to the one-locus, two-allele Wright-Fisher process, involving up to three simultaneous populations. Our approach is a composite likelihood scheme, since linkage between neutral loci alters the variance but not the expectation of the frequency spectrum. We thus use bootstraps incorporating linkage to estimate uncertainties for parameters and significance values for hypothesis tests. Our method can also incorporate selection on single sites, predicting the joint distribution of selected alleles among populations experiencing a bevy of evolutionary forces, including expansions, contractions, migrations, and admixture. We model human expansion out of Africa and the settlement of the New World, using 5 Mb of noncoding DNA resequenced in 68 individuals from 4 populations (YRI, CHB, CEU, and MXL) by the Environmental Genome Project. We infer divergence between West African and Eurasian populations 140 thousand years ago (95% confidence interval: 40–270 kya). This is earlier than other genetic studies, in part because we incorporate migration. We estimate the European (CEU) and East Asian (CHB) divergence time to be 23 kya (95% c.i.: 17–43 kya), long after archeological evidence places modern humans in Europe. Finally, we estimate divergence between East Asians (CHB) and Mexican-Americans (MXL) of 22 kya (95% c.i.: 16.3–26.9 kya), and our analysis yields no evidence for subsequent migration. Furthermore, combining our demographic model with a previously estimated distribution of selective effects among newly arising amino acid mutations accurately predicts the frequency spectrum of nonsynonymous variants across three continental populations (YRI, CHB, CEU). PMID:19851460

A high-resolution genetic map of yellow monkeyflower identifies chemical defense QTLs and recombination rate variation.

PubMed

Holeski, Liza M; Monnahan, Patrick; Koseva, Boryana; McCool, Nick; Lindroth, Richard L; Kelly, John K

2014-03-13

Genotyping-by-sequencing methods have vastly improved the resolution and accuracy of genetic linkage maps by increasing both the number of marker loci as well as the number of individuals genotyped at these loci. Using restriction-associated DNA sequencing, we construct a dense linkage map for a panel of recombinant inbred lines derived from a cross between divergent ecotypes of Mimulus guttatus. We used this map to estimate recombination rate across the genome and to identify quantitative trait loci for the production of several secondary compounds (PPGs) of the phenylpropanoid pathway implicated in defense against herbivores. Levels of different PPGs are correlated across recombinant inbred lines suggesting joint regulation of the phenylpropanoid pathway. However, the three quantitative trait loci identified in this study each act on a distinct PPG. Finally, we map three putative genomic inversions differentiating the two parental populations, including a previously characterized inversion that contributes to life-history differences between the annual/perennial ecotypes. Copyright © 2014 Holeski et al.

Pleiotropic QTL on chromosome 19q13 for triglycerides and adiposity: the HERITAGE Family Study.

PubMed

Feitosa, Mary F; Rice, Treva; North, Kari E; Kraja, Aldi; Rankinen, Tuomo; Leon, Arthur S; Skinner, James S; Blangero, John; Bouchard, Claude; Rao, D C

2006-04-01

Motivated by strong correlations between plasma levels of triglycerides (TG) and adiposity traits, we conducted a series of bivariate genome-wide linkage analyses of TG with body mass index (BMI), total fat mass (FAT), percentage of body fat (FATPC), and abdominal subcutaneous fat (ASF). Maximum lod scores of 3.3, 3.0, 2.2 and 2.4, respectively, were found on chromosome 19q13. This linkage region includes the APOE gene, a predictor of variation in lipid-lipoprotein levels, and the hormone-sensitive lipase (LIPE) gene, a key enzyme in the mobilization of fatty acids from triglyceride stores. In addition, the adiposity measures together with the APOE marker showed significant association with TG levels (p = 0.02 to p = 0.03). In summary, these results suggest that one or more QTLs in the 19q13 region jointly influence TG levels and adiposity. Polymorphisms in the APOE gene, and possibly LIPE gene, appear to be strong candidates for the source of this pleiotropic QTL.

Opportunities and challenges for real-world studies on chronic inflammatory joint diseases through data enrichment and collaboration between national registers: the Nordic example

PubMed Central

Chatzidionysiou, Katerina; Hetland, Merete Lund; Frisell, Thomas; Di Giuseppe, Daniela; Hellgren, Karin; Glintborg, Bente; Nordström, Dan; Aaltonen, Kalle; Törmänen, Minna RK; Klami Kristianslund, Eirik; Kvien, Tore K; Provan, Sella A; Guðbjörnsson, Bjorn; Dreyer, Lene; Kristensen, Lars Erik; Jørgensen, Tanja Schjødt; Jacobsson, Lennart; Askling, Johan

2018-01-01

There are increasing needs for detailed real-world data on rheumatic diseases and their treatments. Clinical register data are essential sources of information that can be enriched through linkage to additional data sources such as national health data registers. Detailed analyses call for international collaborative observational research to increase the number of patients and the statistical power. Such linkages and collaborations come with legal, logistic and methodological challenges. In collaboration between registers of inflammatory arthritides in Sweden, Denmark, Norway, Finland and Iceland, we plan to enrich, harmonise and standardise individual data repositories to investigate analytical approaches to multisource data, to assess the viability of different logistical approaches to data protection and sharing and to perform collaborative studies on treatment effectiveness, safety and health-economic outcomes. This narrative review summarises the needs and potentials and the challenges that remain to be overcome in order to enable large-scale international collaborative research based on clinical and other types of data. PMID:29682328

Sequential bearings-only-tracking initiation with particle filtering method.

PubMed

Liu, Bin; Hao, Chengpeng

2013-01-01

The tracking initiation problem is examined in the context of autonomous bearings-only-tracking (BOT) of a single appearing/disappearing target in the presence of clutter measurements. In general, this problem suffers from a combinatorial explosion in the number of potential tracks resulted from the uncertainty in the linkage between the target and the measurement (a.k.a the data association problem). In addition, the nonlinear measurements lead to a non-Gaussian posterior probability density function (pdf) in the optimal Bayesian sequential estimation framework. The consequence of this nonlinear/non-Gaussian context is the absence of a closed-form solution. This paper models the linkage uncertainty and the nonlinear/non-Gaussian estimation problem jointly with solid Bayesian formalism. A particle filtering (PF) algorithm is derived for estimating the model's parameters in a sequential manner. Numerical results show that the proposed solution provides a significant benefit over the most commonly used methods, IPDA and IMMPDA. The posterior Cramér-Rao bounds are also involved for performance evaluation.

Design and Calibration of a New 6 DOF Haptic Device

PubMed Central

Qin, Huanhuan; Song, Aiguo; Liu, Yuqing; Jiang, Guohua; Zhou, Bohe

2015-01-01

For many applications such as tele-operational robots and interactions with virtual environments, it is better to have performance with force feedback than without. Haptic devices are force reflecting interfaces. They can also track human hand positions simultaneously. A new 6 DOF (degree-of-freedom) haptic device was designed and calibrated in this study. It mainly contains a double parallel linkage, a rhombus linkage, a rotating mechanical structure and a grasping interface. Benefited from the unique design, it is a hybrid structure device with a large workspace and high output capability. Therefore, it is capable of multi-finger interactions. Moreover, with an adjustable base, operators can change different postures without interrupting haptic tasks. To investigate the performance regarding position tracking accuracy and static output forces, we conducted experiments on a three-dimensional electric sliding platform and a digital force gauge, respectively. Displacement errors and force errors are calculated and analyzed. To identify the capability and potential of the device, four application examples were programmed. PMID:26690449

Analysis of borehole expansion and gallery tests in anisotropic rock masses

USGS Publications Warehouse

Amadei, B.; Savage, W.Z.

1991-01-01

Closed-form solutions are used to show how rock anisotropy affects the variation of the modulus of deformation around the walls of a hole in which expansion tests are conducted. These tests include dilatometer and NX-jack tests in boreholes and gallery tests in tunnels. The effects of rock anisotropy on the modulus of deformation are shown for transversely isotropic and regularly jointed rock masses with planes of transverse isotropy or joint planes parallel or normal to the hole longitudinal axis for plane strain or plane stress condition. The closed-form solutions can also be used when determining the elastic properties of anisotropic rock masses (intact or regularly jointed) in situ. ?? 1991.

Experimental characterization of a binary actuated parallel manipulator

NASA Astrophysics Data System (ADS)

Giuseppe, Carbone

2016-05-01

This paper describes the BAPAMAN (Binary Actuated Parallel MANipulator) series of parallel manipulators that has been conceived at Laboratory of Robotics and Mechatronics (LARM). Basic common characteristics of BAPAMAN series are described. In particular, it is outlined the use of a reduced number of active degrees of freedom, the use of design solutions with flexural joints and Shape Memory Alloy (SMA) actuators for achieving miniaturization, cost reduction and easy operation features. Given the peculiarities of BAPAMAN architecture, specific experimental tests have been proposed and carried out with the aim to validate the proposed design and to evaluate the practical operation performance and the characteristics of a built prototype, in particular, in terms of operation and workspace characteristics.

Modeling Anisotropic Elastic Wave Propagation in Jointed Rock Masses

NASA Astrophysics Data System (ADS)

Hurley, R.; Vorobiev, O.; Ezzedine, S. M.; Antoun, T.

2016-12-01

We present a numerical approach for determining the anisotropic stiffness of materials with nonlinearly-compliant joints capable of sliding. The proposed method extends existing ones for upscaling the behavior of a medium with open cracks and inclusions to cases relevant to natural fractured and jointed rocks, where nonlinearly-compliant joints can undergo plastic slip. The method deviates from existing techniques by incorporating the friction and closure states of the joints, and recovers an anisotropic elastic form in the small-strain limit when joints are not sliding. We present the mathematical formulation of our method and use Representative Volume Element (RVE) simulations to evaluate its accuracy for joint sets with varying complexity. We then apply the formulation to determine anisotropic elastic constants of jointed granite found at the Nevada Nuclear Security Site (NNSS) where the Source Physics Experiments (SPE), a campaign of underground chemical explosions, are performed. Finally, we discuss the implementation of our numerical approach in a massively parallel Lagrangian code Geodyn-L and its use for studying wave propagation from underground explosions. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

High temperature turbine engine structure

DOEpatents

Boyd, Gary L.

1991-01-01

A high temperature turbine engine includes a rotor portion having axially stacked adjacent ceramic rotor parts. A ceramic/ceramic joint structure transmits torque between the rotor parts while maintaining coaxial alignment and axially spaced mutually parallel relation thereof despite thermal and centrifugal cycling.

Modular, security enclosure and method of assembly

DOEpatents

Linker, Kevin L.; Moyer, John W.

1995-01-01

A transportable, reusable rapidly assembled and disassembled, resizable modular, security enclosure utilizes a stepped panel construction. Each panel has an inner portion and an outer portion which form joints. A plurality of channels can be affixed to selected joints of the panels. Panels can be affixed to a base member and then affixed to one another by the use of elongated pins extending through the channel joints. Alternatively, the base member can be omitted and the panels themselves can be used as the floor of the enclosure. The pins will extend generally parallel to the joint in which they are located. These elongated pins are readily inserted into and removable from the channels in a predetermined sequence to allow assembly and disassembly of the enclosure. A door constructed from panels is used to close the opening to the enclosure.

Carbohydrate Nanotechnology: Hierarchical Assemblies and Information Processing with Oligosaccharide-Synthetic Lectin Host-Guest Systems

DTIC Science & Technology

2013-08-05

pyrrole Hk protons of the receptor. Additionally, a C–H…π interaction between the phenyl ring and H4 and two more H- bonds between the hydroxyl group of...C3 and an amino He and pyrrole Hk proton of the receptor were observed. Side views b) parallel and c) perpendicular to the biphenyl linkage of the...located on the biphenyl base and pyrroles , suggesting a geometry where one molecule of β-Man is encaged by two molecules of 1, and the two molecules of

Kinematically aligned TKA can align knee joint line to horizontal.

PubMed

Ji, Hyung-Min; Han, Jun; Jin, Dong San; Seo, Hyunseok; Won, Ye-Yeon

2016-08-01

The joint line of the native knee is horizontal to the floor and perpendicular to the vertical weight-bearing axis of the patient in a bipedal stance. The purposes of this study were as follows: (1) to find out the distribution of the native joint line in a population of normal patients with normal knees; (2) to compare the native joint line orientation between patients receiving conventional mechanically aligned total knee arthroplasty (TKA), navigated mechanically aligned TKA, and kinematically aligned TKA; and (3) to determine which of the three TKA methods aligns the postoperative knee joint perpendicular to the weight-bearing axis of the limb in bipedal stance. To determine the joint line orientation of a native knee, 50 full-length standing hip-to-ankle digital radiographs were obtained in 50 young, healthy individuals. The angle between knee joint line and the line parallel to the floor was measured and defined as joint line orientation angle (JLOA). JLOA was also measured prior to and after conventional mechanically aligned TKA (65 knees), mechanically aligned TKA using imageless navigation (65 knees), and kinematically aligned TKA (65 knees). The proportion of the knees similar to the native joint line was calculated for each group. The mean JLOA in healthy individuals was parallel to the floor (0.2° ± 1.1°). The pre-operative JLOA of all treatment groups slanted down to the lateral side. Postoperative JLOA slanted down to the lateral side in conventional mechanically aligned TKA (-3.3° ± 2.2°) and in navigation mechanically aligned TKA (-2.6° ± 1.8°), while it was horizontal to the floor in kinematically aligned TKA (0.6° ± 1.7°). Only 6.9 % of the conventional mechanically aligned TKA and 16.9 % of the navigation mechanically aligned TKA were within one SD of the mean JLOA of the native knee, while the proportion was significantly higher (50.8 %) in kinematically aligned TKA. The portion was statistically greater in mechanically aligned TKA group than the other two. Postoperative joint line orientation after kinematically aligned TKA was more similar to that of native knees than that of mechanically aligned TKA and horizontal to the floor. Kinematically aligned TKA can restore pre-arthritic knee joint line orientation, while mechanically aligned TKA is inefficient in achieving the purpose even if navigation TKA is employed. III.

Influence of geologic setting on ground-water availability in the Lawrenceville area, Gwinnett County, Georgia

USGS Publications Warehouse

Williams, Lester J.; Kath, Randy L.; Crawford, Thomas J.; Chapman, Melinda J.

2005-01-01

Obtaining large quantities of ground water needed for municipal and industrial supply in the Piedmont and Blue Ridge physiographic provinces can be challenging because of the complex geology and the typically low primary permeability of igneous and metamorphic rocks. Areas of enhanced secondary permeability in the bedrock do occur, however, and 'high-yield' wells are not uncommon, particularly where careful site-selection techniques are used prior to test drilling. The U.S. Geological Survey - in cooperation with the City of Lawrenceville, Georgia - conducted this study from 2000 to 2002 to learn more about how different geologic settings influence the availability of ground water in igneous and metamorphic bedrock with the expectation that this knowledge could be used to help identify additional water resources in the area. In compositionally layered-rock settings, wells derive water almost exclusively from lithologically and structurally controlled water-bearing zones formed parallel to foliation and compositional layering. These high-permeability, water-bearing zones - termed foliation-parallel parting systems -combined with high-angle joint systems, are the primary control for the high-yield wells drilled in the Lawrenceville area; yields range from 100 to several hundred gallons per minute (gal/min). Near Lawrenceville, areas with high ground-water yield are present in sequences of amphibolite, biotite gneiss, and button schist where the structural attitude of the rocks is gently dipping, in areas characterized by abundant jointing, and in topographic settings with a continuous source of recharge along these structures. In massive-rock settings, wells derive water mostly from joint systems, although foliation-parallel parting systems also may be important. Wells deriving water primarily from steeply-dipping joint systems typically have low yields ranging from 1 to 5 gal/min. Joint systems in massive-rock settings can be identified and characterized by using many of the methods described in this report. Geologic mapping was the primary method used to determine the distribution, variability, and relative concentrations (intensity) of joint systems. In the subsurface, joints were characterized by taking orientation measurements in the open boreholes of wells using acoustic and/or optical televiewers. In this investigation, the only practical approach found for locating areas of high ground-water potential was first through detailed geologic mapping followed by test drilling, borehole geophysical logging, and aquifer testing. Geologic methods help characterize both large- and small-scale structures and other lithologic and stratigraphic features that influence development of increased secondary permeability in the bedrock. The rock types, discontinuities, depth of weathering, topographic position, and recharge potential - which were the principal factors assessed through detailed geologic mapping - must be evaluated carefully, in relation to one another, to assess the ground-water potential in a given area.

Can Exceptional, Visually Impaired Graduate Students, Educationally Funded by their use of Initially Profit-free Franchised Naturoptics, be Recruited to Proposed Native American Universities, and their Mentor Partners with Joint-degree Agreements?

NASA Astrophysics Data System (ADS)

Ferreira, Nadja; McLeod, David; McLeod, Roger

2006-10-01

Naturoptic Vision Improvement Methods developed and first propagated in the Americas can be transferred to other locales, particularly to Germany, Austria, and German-speaking areas of Switzerland, and to British (or former) Commonwealth areas, France, Greece, Russia, and diverse areas of Africa and Asia, particularly Japan. The method will attempt to mimic any successful transplants already in progress, or in the planning stages. It will consist primarily in recruiting visually impaired students who have finished their undergraduate work, and who are outstanding enough to be admitted into an appropriate university of their choice. Joint-degree linkages with universities in mentoring agreements with any potential universities, naturopathic or otherwise, are among our favorites. Potential faculty for proposed universities will have longer term use of an appropriate franchise in some profit- free franchisor agreements.

A Generalized Method for Automatic Downhand and Wirefeed Control of a Welding Robot and Positioner

NASA Technical Reports Server (NTRS)

Fernandez, Ken; Cook, George E.

1988-01-01

A generalized method for controlling a six degree-of-freedom (DOF) robot and a two DOF positioner used for arc welding operations is described. The welding path is defined in the part reference frame, and robot/positioner joint angles of the equivalent eight DOF serial linkage are determined via an iterative solution. Three algorithms are presented: the first solution controls motion of the eight DOF mechanism such that proper torch motion is achieved while minimizing the sum-of-squares of joint displacements; the second algorithm adds two constraint equations to achieve torch control while maintaining part orientation so that welding occurs in the downhand position; and the third algorithm adds the ability to control the proper orientation of a wire feed mechanism used in gas tungsten arc (GTA) welding operations. A verification of these algorithms is given using ROBOSIM, a NASA developed computer graphic simulation software package design for robot systems development.

Normal radiological unossified hip joint space and femoral head size development during growth in 675 children and adolescents.

PubMed

Wegener, Veronika; Jorysz, Gabriele; Arnoldi, Andreas; Utzschneider, Sandra; Wegener, Bernd; Jansson, Volkmar; Heimkes, Bernhard

2017-03-01

Evaluation of hip joint space width during child growth is important to aid in the early diagnosis of hip pathology in children. We established reference values for hip joint space and femoral head size for each age. Hip joint space development during growth was retrospectively investigated medial and cranial in 1350 hip joints of children using standard anteroposterior supine plain pelvic radiographs. Maximum capital femoral epiphysis diameter and femoral radii were further more investigated. Hip joint space values show a slow decline during growth. Joint space was statistically significantly (p < 0.006) larger in boys than girls. Our hip joint space measurements on supine subjects seem slightly larger than those reported by Hughes on standing subjects. Evaluation of the femoral head diameter and the radii showed a size curve quite parallel to the known body growth charts. Radii medial and perpendicular to the physis are not statistically significantly different. We recommend to compare measurements of hip joint space at two locations to age dependent charts using the same imaging technique. During growth, a divergence in femoral head size from the expected values or loss of the spherical shape should raise the question of hip disorder. Clin. Anat. 30:267-275, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Novel QTL at chromosome 6p22 for alcohol consumption: Implications for the genetic liability of alcohol use disorders

PubMed Central

Kos, Mark Z.; Glahn, David C.; Carless, Melanie A.; Olvera, Rene; McKay, D. Reese; Quillen, Ellen E.; Gelernter, Joel; Chen, Xiang-Ding; Deng, Hong-Wen; Kent, Jack W.; Dyer, Thomas D.; Göring, Harald H.H.; Curran, Joanne E.; Duggirala, Ravi; Blangero, John; Almasy, Laura

2014-01-01

Linkage studies of alcoholism have implicated several chromosome regions, leading to the successful identification of susceptibility genes, including ADH4 and GABRA2 on chromosome 4. Quantitative endophenotypes that are potentially closer to gene action than clinical endpoints offer a means of obtaining more refined linkage signals of genes that predispose alcohol use disorders (AUD). In this study we examine a self-reported measure of the maximum number of drinks consumed in a 24-hour period (abbreviated Max Drinks), a significantly heritable phenotype (h2 = 0.32 ± 0.05; P = 4.61 × 10−14) with a strong genetic correlation with AUD (ρg = 0.99 ± 0.13) for the San Antonio Family Study (n = 1,203). Genome-wide SNPs were analyzed using variance components linkage methods in the program SOLAR, revealing a novel, genome-wide significant QTL (LOD = 4.17; P = 5.85 × 10−6) for Max Drinks at chromosome 6p22.3, a region with a number of compelling candidate genes implicated in neuronal function and psychiatric illness. Joint analysis of Max Drinks and AUD status shows that the QTL has a significant non-zero effect on diagnosis (P = 4.04 × 10−3), accounting for 8.6% of the total variation. Significant SNP associations for Max Drinks were also identified at the linkage region, including one, rs7761213 (P = 2.14 × 10−4), obtained for an independent sample of Chinese families. Thus, our study identifies a potential risk locus for AUD at 6p22.3, with significant pleiotropic effects on the heaviness of alcohol consumption that may not be population specific. PMID:24692236

Double Arm Linkage precision Linear motion (DALL) Carriage, a simplified, rugged, high performance linear motion stage for the moving mirror of an Fourier Transform Spectrometer or other system requiring precision linear motion

NASA Astrophysics Data System (ADS)

Johnson, Kendall B.; Hopkins, Greg

2017-08-01

The Double Arm Linkage precision Linear motion (DALL) carriage has been developed as a simplified, rugged, high performance linear motion stage. Initially conceived as a moving mirror stage for the moving mirror of a Fourier Transform Spectrometer (FTS), it is applicable to any system requiring high performance linear motion. It is based on rigid double arm linkages connecting a base to a moving carriage through flexures. It is a monolithic design. The system is fabricated from one piece of material including the flexural elements, using high precision machining. The monolithic design has many advantages. There are no joints to slip or creep and there are no CTE (coefficient of thermal expansion) issues. This provides a stable, robust design, both mechanically and thermally and is expected to provide a wide operating temperature range, including cryogenic temperatures, and high tolerance to vibration and shock. Furthermore, it provides simplicity and ease of implementation, as there is no assembly or alignment of the mechanism. It comes out of the machining operation aligned and there are no adjustments. A prototype has been fabricated and tested, showing superb shear performance and very promising tilt performance. This makes it applicable to both corner cube and flat mirror FTS systems respectively.

Microsecond kinetics in model single- and double-stranded amylose polymers.

PubMed

Sattelle, Benedict M; Almond, Andrew

2014-05-07

Amylose, a component of starch with increasing biotechnological significance, is a linear glucose polysaccharide that self-organizes into single- and double-helical assemblies. Starch granule packing, gelation and inclusion-complex formation result from finely balanced macromolecular kinetics that have eluded precise experimental quantification. Here, graphics processing unit (GPU) accelerated multi-microsecond aqueous simulations are employed to explore conformational kinetics in model single- and double-stranded amylose. The all-atom dynamics concur with prior X-ray and NMR data while surprising and previously overlooked microsecond helix-coil, glycosidic linkage and pyranose ring exchange are hypothesized. In a dodecasaccharide, single-helical collapse was correlated with linkages and rings transitioning from their expected syn and (4)C1 chair conformers. The associated microsecond exchange rates were dependent on proximity to the termini and chain length (comparing hexa- and trisaccharides), while kinetic features of dodecasaccharide linkage and ring flexing are proposed to be a good model for polymers. Similar length double-helices were stable on microsecond timescales but the parallel configuration was sturdier than the antiparallel equivalent. In both, tertiary organization restricted local chain dynamics, implying that simulations of single amylose strands cannot be extrapolated to dimers. Unbiased multi-microsecond simulations of amylose are proposed as a valuable route to probing macromolecular kinetics in water, assessing the impact of chemical modifications on helical stability and accelerating the development of new biotechnologies.

Exploring linkages between research, policy and practice in the Netherlands: perspectives on sexual and reproductive health and rights knowledge flows.

PubMed

de Haas, Billie; van der Kwaak, Anke

2017-05-12

The attention to and demand for stronger linkages between research, policy and practice are increasing, especially in fields concerned with sensitive and challenging issues such as sexual and reproductive health and rights (SRHR). The study described in this article was conducted in the Netherlands among actors working in international development, especially the domain of SRHR. It explores the perceived flow of knowledge between research, policy and practice, the perceived impeding factors, and suggested strategies for improvement. A narrative literature review was performed and 28 key informants were interviewed between May and August 2015. Most interviewees were either active or passive members of Share-Net Netherlands, an SRHR knowledge platform. All interviews, which lasted 70 minutes on average, were recorded, transcribed verbatim and coded in MAXQDA. Linkages between research, policy and practice are many and diffuse. The demands for and supplies of knowledge within and across the fields vary and do not always match, which is shown by participants' research purposes and approaches. Participants identified various barriers to strengthening knowledge flows, including a lack of familiarity with practices in other fields, power relations and the undervaluation of tacit knowledge. They suggested a more visible and concrete demand for and supply of knowledge, the development of a joint knowledge agenda, more opportunities for the interdisciplinary creation of knowledge, and the development of a system for learning and sharing knowledge. This study shows the willingness to undertake, and the perceived advantages of, interdisciplinary dialogues and joint creation of knowledge to advance SRHR research, policies and practices. Whereas barriers to the flow of knowledge may maintain present understandings of knowledge and of whose knowledge is valid, enabling factors, such as interactions between research, policy and practice in knowledge-sharing activities, may challenge such perceptions and create an enabling environment for generating innovative knowledge and increasing knowledge use. Knowledge platforms are recommended to place more emphasis on sharing and documenting tacit knowledge through interdisciplinary dialogues, to address power relations and to set criteria for interdisciplinary funding.

3-D parallel program for numerical calculation of gas dynamics problems with heat conductivity on distributed memory computational systems (CS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sofronov, I.D.; Voronin, B.L.; Butnev, O.I.

1997-12-31

The aim of the work performed is to develop a 3D parallel program for numerical calculation of gas dynamics problem with heat conductivity on distributed memory computational systems (CS), satisfying the condition of numerical result independence from the number of processors involved. Two basically different approaches to the structure of massive parallel computations have been developed. The first approach uses the 3D data matrix decomposition reconstructed at temporal cycle and is a development of parallelization algorithms for multiprocessor CS with shareable memory. The second approach is based on using a 3D data matrix decomposition not reconstructed during a temporal cycle.more » The program was developed on 8-processor CS MP-3 made in VNIIEF and was adapted to a massive parallel CS Meiko-2 in LLNL by joint efforts of VNIIEF and LLNL staffs. A large number of numerical experiments has been carried out with different number of processors up to 256 and the efficiency of parallelization has been evaluated in dependence on processor number and their parameters.« less

A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI

PubMed Central

Lyu, Mengye; Liu, Yilong; Xie, Victor B.; Feng, Yanqiu; Guo, Hua; Wu, Ed X.

2017-01-01

PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient. PMID:28205602

A New Joint-Blade SENSE Reconstruction for Accelerated PROPELLER MRI.

PubMed

Lyu, Mengye; Liu, Yilong; Xie, Victor B; Feng, Yanqiu; Guo, Hua; Wu, Ed X

2017-02-16

PROPELLER technique is widely used in MRI examinations for being motion insensitive, but it prolongs scan time and is restricted mainly to T2 contrast. Parallel imaging can accelerate PROPELLER and enable more flexible contrasts. Here, we propose a multi-step joint-blade (MJB) SENSE reconstruction to reduce the noise amplification in parallel imaging accelerated PROPELLER. MJB SENSE utilizes the fact that PROPELLER blades contain sharable information and blade-combined images can serve as regularization references. It consists of three steps. First, conventional blade-combined images are obtained using the conventional simple single-blade (SSB) SENSE, which reconstructs each blade separately. Second, the blade-combined images are employed as regularization for blade-wise noise reduction. Last, with virtual high-frequency data resampled from the previous step, all blades are jointly reconstructed to form the final images. Simulations were performed to evaluate the proposed MJB SENSE for noise reduction and motion correction. MJB SENSE was also applied to both T2-weighted and T1-weighted in vivo brain data. Compared to SSB SENSE, MJB SENSE greatly reduced the noise amplification at various acceleration factors, leading to increased image SNR in all simulation and in vivo experiments, including T1-weighted imaging with short echo trains. Furthermore, it preserved motion correction capability and was computationally efficient.

Design, fabrication and characterization of a micro-fluxgate intended for parallel robot application

NASA Astrophysics Data System (ADS)

Kirchhoff, M. R.; Bogdanski, G.; Büttgenbach, S.

2009-05-01

This paper presents a micro-magnetometer based on the fluxgate principle. Fluxgates detect the magnitude and direction of DC and low-frequency AC magnetic fields. The detectable flux density typically ranges from several 10 nT to about 1 mT. The introduced fluxgate sensor is fabricated using MEMS-technologies, basically UV depth lithography and electroplating for manufacturing high aspect ratio structures. It consists of helical copper coils around a soft magnetic nickel-iron (NiFe) core. The core is designed in so-called racetrack geometry, whereby the directional sensitivity of the sensor is considerably higher compared to common ring-core fluxgates. The electrical operation is based on analyzing the 2nd harmonic of the AC output signal. Configuration, manufacturing and selected characteristics of the fluxgate magnetometer are discussed in this work. The fluxgate builds the basis of an innovative angular sensor system for a parallel robot with HEXA-structure. Integrated into the passive joints of the parallel robot, the fluxgates are combined with permanent magnets rotating on the joint shafts. The magnet transmits the angular information via its magnetic orientation. In this way, the angles between the kinematic elements are measured, which allows self-calibration of the robot and the fast analytical solution of direct kinematics for an advanced workspace monitoring.

A Parallel Finite Set Statistical Simulator for Multi-Target Detection and Tracking

NASA Astrophysics Data System (ADS)

Hussein, I.; MacMillan, R.

2014-09-01

Finite Set Statistics (FISST) is a powerful Bayesian inference tool for the joint detection, classification and tracking of multi-target environments. FISST is capable of handling phenomena such as clutter, misdetections, and target birth and decay. Implicit within the approach are solutions to the data association and target label-tracking problems. Finally, FISST provides generalized information measures that can be used for sensor allocation across different types of tasks such as: searching for new targets, and classification and tracking of known targets. These FISST capabilities have been demonstrated on several small-scale illustrative examples. However, for implementation in a large-scale system as in the Space Situational Awareness problem, these capabilities require a lot of computational power. In this paper, we implement FISST in a parallel environment for the joint detection and tracking of multi-target systems. In this implementation, false alarms and misdetections will be modeled. Target birth and decay will not be modeled in the present paper. We will demonstrate the success of the method for as many targets as we possibly can in a desktop parallel environment. Performance measures will include: number of targets in the simulation, certainty of detected target tracks, computational time as a function of clutter returns and number of targets, among other factors.

Powered orthosis and attachable power-assist device with Hydraulic Bilateral Servo System.

PubMed

Ohnishi, Kengo; Saito, Yukio; Oshima, Toru; Higashihara, Takanori

2013-01-01

This paper discusses the developments and control strategies of exoskeleton-type robot systems for the application of an upper limb powered orthosis and an attachable power-assist device for care-givers. Hydraulic Bilateral Servo System, which consist of a computer controlled motor, parallel connected hydraulic actuators, position sensors, and pressure sensors, are installed in the system to derive the joint motion of the exoskeleton arm. The types of hydraulic component structure and the control strategy are discussed in relation to the design philosophy and target joints motions.

A computational framework for simultaneous estimation of muscle and joint contact forces and body motion using optimization and surrogate modeling.

PubMed

Eskinazi, Ilan; Fregly, Benjamin J

2018-04-01

Concurrent estimation of muscle activations, joint contact forces, and joint kinematics by means of gradient-based optimization of musculoskeletal models is hindered by computationally expensive and non-smooth joint contact and muscle wrapping algorithms. We present a framework that simultaneously speeds up computation and removes sources of non-smoothness from muscle force optimizations using a combination of parallelization and surrogate modeling, with special emphasis on a novel method for modeling joint contact as a surrogate model of a static analysis. The approach allows one to efficiently introduce elastic joint contact models within static and dynamic optimizations of human motion. We demonstrate the approach by performing two optimizations, one static and one dynamic, using a pelvis-leg musculoskeletal model undergoing a gait cycle. We observed convergence on the order of seconds for a static optimization time frame and on the order of minutes for an entire dynamic optimization. The presented framework may facilitate model-based efforts to predict how planned surgical or rehabilitation interventions will affect post-treatment joint and muscle function. Copyright © 2018 IPEM. Published by Elsevier Ltd. All rights reserved.

Joint Services Electronics Program

DTIC Science & Technology

1991-03-05

Parallel Computing Network and Program Professor Abhiram Ranade with M.T. Raghunath and Robert Boothe The goal of our research is to develop high...References/Publications [1] M. T. Raghunath and A. 0. Ranade. "A Simulation-Based Comparison of Interconnection Networks," Proceedings of the 2nd IEEE

Effects of Wii balance board exercises on balance after posterior cruciate ligament reconstruction.

PubMed

Puh, Urška; Majcen, Nia; Hlebš, Sonja; Rugelj, Darja

2014-05-01

To establish the effects of training on Wii balance board (WBB) after posterior cruciate ligament (PCL) reconstruction on balance. Included patient injured her posterior cruciate ligament 22 months prior to the study. Training on WBB was performed 4 weeks, 6 times per week, 30-45 min per day. Center of pressure (CoP) sway during parallel and one-leg stance, and body weight distribution in parallel stance were measured. Additionally, measurements of joint range of motion and limb circumferences were taken before and after training. After training, the body weight was almost equally distributed on both legs. Decrease in CoP sway was most significant for one-leg stance with each leg on compliant surface with eyes open and closed. The knee joint range of motion increased and limb circumferences decreased. According to the results of this single case report, we might recommend the use of WBB for balance training after PCL reconstruction. Case series with no comparison group, Level IV.

Parallelization of a blind deconvolution algorithm

NASA Astrophysics Data System (ADS)

Matson, Charles L.; Borelli, Kathy J.

2006-09-01

Often it is of interest to deblur imagery in order to obtain higher-resolution images. Deblurring requires knowledge of the blurring function - information that is often not available separately from the blurred imagery. Blind deconvolution algorithms overcome this problem by jointly estimating both the high-resolution image and the blurring function from the blurred imagery. Because blind deconvolution algorithms are iterative in nature, they can take minutes to days to deblur an image depending how many frames of data are used for the deblurring and the platforms on which the algorithms are executed. Here we present our progress in parallelizing a blind deconvolution algorithm to increase its execution speed. This progress includes sub-frame parallelization and a code structure that is not specialized to a specific computer hardware architecture.

Leg kinematics and muscle activity during treadmill running in the cockroach, Blaberus discoidalis: I. Slow running.

PubMed

Watson, J T; Ritzmann, R E

1998-01-01

We have combined high-speed video motion analysis of leg movements with electromyogram (EMG) recordings from leg muscles in cockroaches running on a treadmill. The mesothoracic (T2) and metathoracic (T3) legs have different kinematics. While in each leg the coxa-femur (CF) joint moves in unison with the femurtibia (FT) joint, the relative joint excursions differ between T2 and T3 legs. In T3 legs, the two joints move through approximately the same excursion. In T2 legs, the FT joint moves through a narrower range of angles than the CF joint. In spite of these differences in motion, no differences between the T2 and T3 legs were seen in timing or qualitative patterns of depressor coxa and extensor tibia activity. The average firing frequencies of slow depressor coxa (Ds) and slow extensor tibia (SETi) motor neurons are directly proportional to the average angular velocity of their joints during stance. The average Ds and SETi firing frequency appears to be modulated on a cycle-by-cycle basis to control running speed and orientation. In contrast, while the frequency variations within Ds and SETi bursts were consistent across cycles, the variations within each burst did not parallel variations in the velocity of the relevant joints.

Co-development of Problem Gambling and Depression Symptoms in Emerging Adults: A Parallel-Process Latent Class Growth Model.

PubMed

Edgerton, Jason D; Keough, Matthew T; Roberts, Lance W

2018-02-21

This study examines whether there are multiple joint trajectories of depression and problem gambling co-development in a sample of emerging adults. Data were from the Manitoba Longitudinal Study of Young Adults (n = 679), which was collected in 4 waves across 5 years (age 18-20 at baseline). Parallel process latent class growth modeling was used to identified 5 joint trajectory classes: low decreasing gambling, low increasing depression (81%); low stable gambling, moderate decreasing depression (9%); low stable gambling, high decreasing depression (5%); low stable gambling, moderate stable depression (3%); moderate stable problem gambling, no depression (2%). There was no evidence of reciprocal growth in problem gambling and depression in any of the joint classes. Multinomial logistic regression analyses of baseline risk and protective factors found that only neuroticism, escape-avoidance coping, and perceived level of family social support were significant predictors of joint trajectory class membership. Consistent with the pathways model framework, we observed that individuals in the problem gambling only class were more likely using gambling as a stable way to cope with negative emotions. Similarly, high levels of neuroticism and low levels of family support were associated with increased odds of being in a class with moderate to high levels of depressive symptoms (but low gambling problems). The results suggest that interventions for problem gambling and/or depression need to focus on promoting more adaptive coping skills among more "at-risk" young adults, and such interventions should be tailored in relation to specific subtypes of comorbid mental illness.

[A case control study of perpendicular or parallel double plate for the treatment of young and middle-aged patients with type C fractures of distal humerus].

PubMed

Yu, Ye-Feng; Dai, Jia-Ping; Sheng, Jian-Ming; Zhou, Xiao

2017-06-25

To compare clinical outcomes of perpendicular or parallel double plate in treating type C fractures of distal humerus in adults. From March 2009 and March 2013, 40 adult patients with type C distal humerus fractures were treated. The patients were divided into two groups according to fixed form. In perpendicular group(group A), there were 13 males and 9 females with a mean age of (37.56±9.24) years old(ranged 18 to 56);while in parallel plating group(group B), including 11 males and 7 females, with a mean age of (41.35±9.03) year old(ranged 20 to 53). All fractures were fresh and closed without blood vessels or nerve damaged. Incision length, operating time, blood loss, hospital stay, preoperative and postoperative radiological change, range of activity of elbow joint, Mayo score, flexor and extensor elbow strength, and postoperative complications were observed and compared. All incisions were healed well. One patient occurred myositis ossificans between two groups. Two patients in group A and 1 patient in group B occurred elbow joint stiffness. All fractures were obtained bone union. Group A were followed up from 20 to 36 months with an average of (25.2±7.1) months, while group B were followed up from 18 to 35 months with an average of(24.3±6.0) months. There were significant differences in blood loss and operative time, while there was no obvious meaning in incision length, hospital stay, muscle strength, fracture healing time, range of activity of elbow joint. Mayo score of group A was 82.27±10.43, 6 cases obtained excellent results, 12 good, 3 moderate and 1 poor;in group B was 81.94±12.02, 5 cases obtained excellent results, 9 good, 3 moderate and 1 poor;and there were no statistical significance between two groups. There was no significant differences in clinical effects between perpendicular and parallel double plate for adult patients with type C distal humerus fractures, while the operation should choose according to facture and proficiency of operator.

Control of an optimal finger exoskeleton based on continuous joint angle estimation from EMG signals.

PubMed

Ngeo, Jimson; Tamei, Tomoya; Shibata, Tomohiro; Orlando, M F Felix; Behera, Laxmidhar; Saxena, Anupam; Dutta, Ashish

2013-01-01

Patients suffering from loss of hand functions caused by stroke and other spinal cord injuries have driven a surge in the development of wearable assistive devices in recent years. In this paper, we present a system made up of a low-profile, optimally designed finger exoskeleton continuously controlled by a user's surface electromyographic (sEMG) signals. The mechanical design is based on an optimal four-bar linkage that can model the finger's irregular trajectory due to the finger's varying lengths and changing instantaneous center. The desired joint angle positions are given by the predictive output of an artificial neural network with an EMG-to-Muscle Activation model that parameterizes electromechanical delay (EMD). After confirming good prediction accuracy of multiple finger joint angles we evaluated an index finger exoskeleton by obtaining a subject's EMG signals from the left forearm and using the signal to actuate a finger on the right hand with the exoskeleton. Our results show that our sEMG-based control strategy worked well in controlling the exoskeleton, obtaining the intended positions of the device, and that the subject felt the appropriate motion support from the device.

Fast l₁-SPIRiT compressed sensing parallel imaging MRI: scalable parallel implementation and clinically feasible runtime.

PubMed

Murphy, Mark; Alley, Marcus; Demmel, James; Keutzer, Kurt; Vasanawala, Shreyas; Lustig, Michael

2012-06-01

We present l₁-SPIRiT, a simple algorithm for auto calibrating parallel imaging (acPI) and compressed sensing (CS) that permits an efficient implementation with clinically-feasible runtimes. We propose a CS objective function that minimizes cross-channel joint sparsity in the wavelet domain. Our reconstruction minimizes this objective via iterative soft-thresholding, and integrates naturally with iterative self-consistent parallel imaging (SPIRiT). Like many iterative magnetic resonance imaging reconstructions, l₁-SPIRiT's image quality comes at a high computational cost. Excessively long runtimes are a barrier to the clinical use of any reconstruction approach, and thus we discuss our approach to efficiently parallelizing l₁-SPIRiT and to achieving clinically-feasible runtimes. We present parallelizations of l₁-SPIRiT for both multi-GPU systems and multi-core CPUs, and discuss the software optimization and parallelization decisions made in our implementation. The performance of these alternatives depends on the processor architecture, the size of the image matrix, and the number of parallel imaging channels. Fundamentally, achieving fast runtime requires the correct trade-off between cache usage and parallelization overheads. We demonstrate image quality via a case from our clinical experimentation, using a custom 3DFT spoiled gradient echo (SPGR) sequence with up to 8× acceleration via Poisson-disc undersampling in the two phase-encoded directions.

Fast ℓ1-SPIRiT Compressed Sensing Parallel Imaging MRI: Scalable Parallel Implementation and Clinically Feasible Runtime

PubMed Central

Murphy, Mark; Alley, Marcus; Demmel, James; Keutzer, Kurt; Vasanawala, Shreyas; Lustig, Michael

2012-01-01

We present ℓ1-SPIRiT, a simple algorithm for auto calibrating parallel imaging (acPI) and compressed sensing (CS) that permits an efficient implementation with clinically-feasible runtimes. We propose a CS objective function that minimizes cross-channel joint sparsity in the Wavelet domain. Our reconstruction minimizes this objective via iterative soft-thresholding, and integrates naturally with iterative Self-Consistent Parallel Imaging (SPIRiT). Like many iterative MRI reconstructions, ℓ1-SPIRiT’s image quality comes at a high computational cost. Excessively long runtimes are a barrier to the clinical use of any reconstruction approach, and thus we discuss our approach to efficiently parallelizing ℓ1-SPIRiT and to achieving clinically-feasible runtimes. We present parallelizations of ℓ1-SPIRiT for both multi-GPU systems and multi-core CPUs, and discuss the software optimization and parallelization decisions made in our implementation. The performance of these alternatives depends on the processor architecture, the size of the image matrix, and the number of parallel imaging channels. Fundamentally, achieving fast runtime requires the correct trade-off between cache usage and parallelization overheads. We demonstrate image quality via a case from our clinical experimentation, using a custom 3DFT Spoiled Gradient Echo (SPGR) sequence with up to 8× acceleration via poisson-disc undersampling in the two phase-encoded directions. PMID:22345529

Modeling of the interaction between grip force and vibration transmissibility of a finger.

PubMed

Wu, John Z; Welcome, Daniel E; McDowell, Thomas W; Xu, Xueyan S; Dong, Ren G

2017-07-01

It is known that the vibration characteristics of the fingers and hand and the level of grip action interacts when operating a power tool. In the current study, we developed a hybrid finger model to simulate the vibrations of the hand-finger system when gripping a vibrating handle covered with soft materials. The hybrid finger model combines the characteristics of conventional finite element (FE) models, multi-body musculoskeletal models, and lumped mass models. The distal, middle, and proximal finger segments were constructed using FE models, the finger segments were connected via three flexible joint linkages (i.e., distal interphalangeal joint (DIP), proximal interphalangeal joint (PIP), and metacarpophalangeal (MCP) joint), and the MCP joint was connected to the ground and handle via lumped parameter elements. The effects of the active muscle forces were accounted for via the joint moments. The bone, nail, and hard connective tissues were assumed to be linearly elastic whereas the soft tissues, which include the skin and subcutaneous tissues, were considered as hyperelastic and viscoelastic. The general trends of the model predictions agree well with the previous experimental measurements in that the resonant frequency increased from proximal to the middle and to the distal finger segments for the same grip force, that the resonant frequency tends to increase with increasing grip force for the same finger segment, especially for the distal segment, and that the magnitude of vibration transmissibility tends to increase with increasing grip force, especially for the proximal segment. The advantage of the proposed model over the traditional vibration models is that it can predict the local vibration behavior of the finger to a tissue level, while taking into account the effects of the active musculoskeletal force, the effects of the contact conditions on vibrations, the global vibration characteristics. Published by Elsevier Ltd.

Many-to-one form-to-function mapping weakens parallel morphological evolution.

PubMed

Thompson, Cole J; Ahmed, Newaz I; Veen, Thor; Peichel, Catherine L; Hendry, Andrew P; Bolnick, Daniel I; Stuart, Yoel E

2017-11-01

Evolutionary ecologists aim to explain and predict evolutionary change under different selective regimes. Theory suggests that such evolutionary prediction should be more difficult for biomechanical systems in which different trait combinations generate the same functional output: "many-to-one mapping." Many-to-one mapping of phenotype to function enables multiple morphological solutions to meet the same adaptive challenges. Therefore, many-to-one mapping should undermine parallel morphological evolution, and hence evolutionary predictability, even when selection pressures are shared among populations. Studying 16 replicate pairs of lake- and stream-adapted threespine stickleback (Gasterosteus aculeatus), we quantified three parts of the teleost feeding apparatus and used biomechanical models to calculate their expected functional outputs. The three feeding structures differed in their form-to-function relationship from one-to-one (lower jaw lever ratio) to increasingly many-to-one (buccal suction index, opercular 4-bar linkage). We tested for (1) weaker linear correlations between phenotype and calculated function, and (2) less parallel evolution across lake-stream pairs, in the many-to-one systems relative to the one-to-one system. We confirm both predictions, thus supporting the theoretical expectation that increasing many-to-one mapping undermines parallel evolution. Therefore, sole consideration of morphological variation within and among populations might not serve as a proxy for functional variation when multiple adaptive trait combinations exist. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Hey Wait! I Just Thought of Something Else! Advaita and Clinical Hypnosis.

PubMed

Amundson, Jon K; Ross, Marc W; Campbell, Debra

2018-07-01

While much has been made of the value of Buddhist mindfulness in clinical treatment, little attention has been given over to its parallels, if not antecedents in Hindu philosophy. Buddhist traditions in the vipassana, ch'an and zen tradition, and the practices associated, find their roots in Advaita philosophy and practice. This article looks at the useful/effective nature of Advaita and its specific application in clinical hypnosis. The linkage between traditional wisdom sources, psychological investigations of the self and contemporary hypnosis is articulated in the article which follows, and a case example, regarding clinical application, is provided.

A novel approach to multiple sequence alignment using hadoop data grids.

PubMed

Sudha Sadasivam, G; Baktavatchalam, G

2010-01-01

Multiple alignment of protein sequences helps to determine evolutionary linkage and to predict molecular structures. The factors to be considered while aligning multiple sequences are speed and accuracy of alignment. Although dynamic programming algorithms produce accurate alignments, they are computation intensive. In this paper we propose a time efficient approach to sequence alignment that also produces quality alignment. The dynamic nature of the algorithm coupled with data and computational parallelism of hadoop data grids improves the accuracy and speed of sequence alignment. The principle of block splitting in hadoop coupled with its scalability facilitates alignment of very large sequences.

Linkages from DOE's Solar Photovoltaic R&D to Commercial Renewable Power from Solar Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruegg, Rosalie; Thomas, Patrick

2011-04-01

DOE's Solar Photovoltaic R&D Subprogram promotes the development of cost-effective systems for directly converting solar energy into electricity for residential, commercial, and industrial applications. This study was commissioned to assess the extent to which the knowledge outputs of R&D funded by the DOE Solar PV subprogram are linked to downstream developments in commercial renewable power. A second purpose was to identify spillovers of the resulting knowledge to other areas of application. A third purpose was to lend support to a parallel benefit-cost study by contributing evidence of attribution of benefits to DOE.

Timber rivets in structural composite lumber

Treesearch

Ronald W. Wolfe; Marshall Begel; Bruce Craig

2004-01-01

Timber rivet connections, originally developed for use with glulam construction, may be a viable option for use with structural composite lumber (SCL) products. Tests were conducted on small samples to assess the performance and predictability of timber rivet connections in parallel strand lumber (PSL) and laminated strand lumber (LSL). The test joint configurations...

Introducing Differential Equations Students to the Fredholm Alternative--In Staggered Doses

ERIC Educational Resources Information Center

Savoye, Philippe

2011-01-01

The development, in an introductory differential equations course, of boundary value problems in parallel with initial value problems and the Fredholm Alternative. Examples are provided of pairs of homogeneous and nonhomogeneous boundary value problems for which existence and uniqueness issues are considered jointly. How this heightens students'…

Resident accuracy of joint line palpation using ultrasound verification.

PubMed

Rho, Monica E; Chu, Samuel K; Yang, Aaron; Hameed, Farah; Lin, Cindy Yuchin; Hurh, Peter J

2014-10-01

To determine the accuracy of knee and acromioclavicular (AC) joint line palpation in Physical Medicine and Rehabilitation (PM&R) residents using ultrasound (US) verification. Cohort study. PM&R residency program at an academic institution. Twenty-four PM&R residents participating in a musculoskeletal US course (7 PGY-2, 8 PGY-3, and 9 PGY4 residents). Twenty-four PM&R residents participating in an US course were asked to palpate the AC joint and lateral joint line of the knee in a female and male model before the start of the course. Once the presumed joint line was localized, the residents were asked to tape an 18-gauge, 1.5-inch, blunt-tip needle parallel to the joint line on the overlying skin. The accuracy of needle placement over the joint line was verified using US. US verification of correct needle placement over the joint line. Overall AC joint palpation accuracy was 16.7%, and knee lateral joint line palpation accuracy was 58.3%. Based on the resident level of education, using a value of P < .05, there were no statistically significant differences in the accuracy of joint line palpation. Residents in this study demonstrate poor accuracy of AC joint and lateral knee joint line identification by palpation, using US as the criterion standard for verification. There were no statistically significant differences in the accuracy rates of joint line palpation based on resident level of education. US may be a useful tool to use to advance the current methods of teaching the physical examination in medical education. Copyright © 2014 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

The E3 ubiquitin ligase NEDD4 enhances killing of membrane-perturbing intracellular bacteria by promoting autophagy

PubMed Central

Pei, Gang; Buijze, Hellen; Liu, Haipeng; Moura-Alves, Pedro; Goosmann, Christian; Brinkmann, Volker; Kawabe, Hiroshi; Dorhoi, Anca; Kaufmann, Stefan H. E.

2017-01-01

ABSTRACT The E3 ubiquitin ligase NEDD4 has been intensively studied in processes involved in viral infections, such as virus budding. However, little is known about its functions in bacterial infections. Our investigations into the role of NEDD4 in intracellular bacterial infections demonstrate that Mycobacterium tuberculosis and Listeria monocytogenes, but not Mycobacterium bovis BCG, replicate more efficiently in NEDD4 knockdown macrophages. In parallel, NEDD4 knockdown or knockout impaired basal macroautophagy/autophagy, as well as infection-induced autophagy. Conversely, NEDD4 expression promoted autophagy in an E3 catalytic activity-dependent manner, thereby restricting intracellular Listeria replication. Mechanistic studies uncovered that endogenous NEDD4 interacted with BECN1/Beclin 1 and this interaction increased during Listeria infection. Deficiency of NEDD4 resulted in elevated K48-linkage ubiquitination of endogenous BECN1. Further, NEDD4 mediated K6- and K27- linkage ubiquitination of BECN1, leading to elevated stability of BECN1 and increased autophagy. Thus, NEDD4 participates in killing of intracellular bacterial pathogens via autophagy by sustaining the stability of BECN1. PMID:29251248

The influence of joint parameters on normal fault evolution and geometry: a parameter study using analogue modeling

NASA Astrophysics Data System (ADS)

Kettermann, Michael; von Hagke, Christoph; Urai, Janos L.

2017-04-01

Dilatant faults often form in rocks containing pre-existing joints, but the effects of joints on fault segment linkage and fracture connectivity is not well understood. Studying evolution of dilatancy and influence of fractures on fault development provides insights into geometry of fault zones in brittle rocks and will eventually allow for predicting their subsurface appearance. In an earlier study we recognized the effect of different angles between strike direction of vertical joints and a basement fault on the geometry of a developing fault zone. We now systematically extend the results by varying geometric joint parameters such as joint spacing and vertical extent of the joints and measuring fracture density and connectivity. A reproducibility study shows a small error-range for the measurements, allowing for a confident use of the experimental setup. Analogue models were carried out in a manually driven deformation box (30x28x20 cm) with a 60° dipping pre-defined basement fault and 4.5 cm of displacement. To produce open joints prior to faulting, sheets of paper were mounted in the box to a depth of 5 cm at a spacing of 2.5 cm. We varied the vertical extent of the joints from 5 to 50 mm. Powder was then sieved into the box, embedding the paper almost entirely (column height of 19 cm), and the paper was removed. During deformation we captured structural information by time-lapse photography that allows particle imaging velocimetry analyses (PIV) to detect localized deformation at every increment of displacement. Post-mortem photogrammetry preserves the final 3-dimensional structure of the fault zone. A counterintuitive result is that joint depth is of only minor importance for the evolution of the fault zone. Even very shallow joints form weak areas at which the fault starts to form and propagate. More important is joint spacing. Very large joint spacing leads to faults and secondary fractures that form subparallel to the basement fault. In contrast, small joint spacing results in fault strands that only localize at the pre-existing joints, and secondary fractures that are oriented at high angles to the pre-existing joints. With this new set of experiments we can now quantitatively constrain how (i) the angle between joints and basement fault, (ii) the joint depth and (iii) the joint spacing affect fault zone parameters such as (1) the damage zone width, (2) the density of secondary fractures, (3) map-view area of open gaps or (4) the fracture connectivity. We apply these results to predict subsurface geometries of joint-fault networks in cohesive rocks, e.g. basaltic sequences in Iceland and sandstones in the Canyonlands NP, USA.

When the lowest energy does not induce native structures: parallel minimization of multi-energy values by hybridizing searching intelligences.

PubMed

Lü, Qiang; Xia, Xiao-Yan; Chen, Rong; Miao, Da-Jun; Chen, Sha-Sha; Quan, Li-Jun; Li, Hai-Ou

2012-01-01

Protein structure prediction (PSP), which is usually modeled as a computational optimization problem, remains one of the biggest challenges in computational biology. PSP encounters two difficult obstacles: the inaccurate energy function problem and the searching problem. Even if the lowest energy has been luckily found by the searching procedure, the correct protein structures are not guaranteed to obtain. A general parallel metaheuristic approach is presented to tackle the above two problems. Multi-energy functions are employed to simultaneously guide the parallel searching threads. Searching trajectories are in fact controlled by the parameters of heuristic algorithms. The parallel approach allows the parameters to be perturbed during the searching threads are running in parallel, while each thread is searching the lowest energy value determined by an individual energy function. By hybridizing the intelligences of parallel ant colonies and Monte Carlo Metropolis search, this paper demonstrates an implementation of our parallel approach for PSP. 16 classical instances were tested to show that the parallel approach is competitive for solving PSP problem. This parallel approach combines various sources of both searching intelligences and energy functions, and thus predicts protein conformations with good quality jointly determined by all the parallel searching threads and energy functions. It provides a framework to combine different searching intelligence embedded in heuristic algorithms. It also constructs a container to hybridize different not-so-accurate objective functions which are usually derived from the domain expertise.

When the Lowest Energy Does Not Induce Native Structures: Parallel Minimization of Multi-Energy Values by Hybridizing Searching Intelligences

PubMed Central

Lü, Qiang; Xia, Xiao-Yan; Chen, Rong; Miao, Da-Jun; Chen, Sha-Sha; Quan, Li-Jun; Li, Hai-Ou

2012-01-01

Background Protein structure prediction (PSP), which is usually modeled as a computational optimization problem, remains one of the biggest challenges in computational biology. PSP encounters two difficult obstacles: the inaccurate energy function problem and the searching problem. Even if the lowest energy has been luckily found by the searching procedure, the correct protein structures are not guaranteed to obtain. Results A general parallel metaheuristic approach is presented to tackle the above two problems. Multi-energy functions are employed to simultaneously guide the parallel searching threads. Searching trajectories are in fact controlled by the parameters of heuristic algorithms. The parallel approach allows the parameters to be perturbed during the searching threads are running in parallel, while each thread is searching the lowest energy value determined by an individual energy function. By hybridizing the intelligences of parallel ant colonies and Monte Carlo Metropolis search, this paper demonstrates an implementation of our parallel approach for PSP. 16 classical instances were tested to show that the parallel approach is competitive for solving PSP problem. Conclusions This parallel approach combines various sources of both searching intelligences and energy functions, and thus predicts protein conformations with good quality jointly determined by all the parallel searching threads and energy functions. It provides a framework to combine different searching intelligence embedded in heuristic algorithms. It also constructs a container to hybridize different not-so-accurate objective functions which are usually derived from the domain expertise. PMID:23028708

Serpentine Robot Model and Gait Design Using Autodesk Inventor and Simulink SimMechanics

NASA Astrophysics Data System (ADS)

Daniel; Iman Alamsyah, Mohammad; Erwin; Tan, Sofyan

2014-03-01

The authors introduce gaits of a serpentine robot with linear expansion mechanism where the robot varies its length using joints with three degrees of freedom. The 3D model of the serpentine robot is drawed in Autocad Inventor® and exported to SimMechanics® for straighforward modeling of the kinematics. The gaits are important for robots designed to explore ruins of disasters where the working spaces are very tight. For maximum flexibility of the serpentine robot, we adopted a joint design with three parallel actuators, where the joint is capable of linear movement in the forward axis, and rotational movements around two other axes. The designed linear expansion gaits is calculated for forward movement when the robot is posing straight or turning laterally.

Kinematics Simulation Analysis of Packaging Robot with Joint Clearance

NASA Astrophysics Data System (ADS)

Zhang, Y. W.; Meng, W. J.; Wang, L. Q.; Cui, G. H.

2018-03-01

Considering the influence of joint clearance on the motion error, repeated positioning accuracy and overall position of the machine, this paper presents simulation analysis of a packaging robot — 2 degrees of freedom(DOF) planar parallel robot based on the characteristics of high precision and fast speed of packaging equipment. The motion constraint equation of the mechanism is established, and the analysis and simulation of the motion error are carried out in the case of turning the revolute clearance. The simulation results show that the size of the joint clearance will affect the movement accuracy and packaging efficiency of the packaging robot. The analysis provides a reference point of view for the packaging equipment design and selection criteria and has a great significance on the packaging industry automation.

A neural network for controlling the configuration of frame structure with elastic members

NASA Technical Reports Server (NTRS)

Tsutsumi, Kazuyoshi

1989-01-01

A neural network for controlling the configuration of frame structure with elastic members is proposed. In the present network, the structure is modeled not by using the relative angles of the members but by using the distances between the joint locations alone. The relationship between the environment and the joints is also defined by their mutual distances. The analog neural network attains the reaching motion of the manipulator as a minimization problem of the energy constructed by the distances between the joints, the target, and the obstacles. The network can generate not only the final but also the transient configurations and the trajectory. This framework with flexibility and parallelism is very suitable for controlling the Space Telerobotic systems with many degrees of freedom.

EUPDF-II: An Eulerian Joint Scalar Monte Carlo PDF Module : User's Manual

NASA Technical Reports Server (NTRS)

Raju, M. S.; Liu, Nan-Suey (Technical Monitor)

2004-01-01

EUPDF-II provides the solution for the species and temperature fields based on an evolution equation for PDF (Probability Density Function) and it is developed mainly for application with sprays, combustion, parallel computing, and unstructured grids. It is designed to be massively parallel and could easily be coupled with any existing gas-phase CFD and spray solvers. The solver accommodates the use of an unstructured mesh with mixed elements of either triangular, quadrilateral, and/or tetrahedral type. The manual provides the user with an understanding of the various models involved in the PDF formulation, its code structure and solution algorithm, and various other issues related to parallelization and its coupling with other solvers. The source code of EUPDF-II will be available with National Combustion Code (NCC) as a complete package.

Flexible All-Digital Receiver for Bandwidth Efficient Modulations

NASA Technical Reports Server (NTRS)

Gray, Andrew; Srinivasan, Meera; Simon, Marvin; Yan, Tsun-Yee

2000-01-01

An all-digital high data rate parallel receiver architecture developed jointly by Goddard Space Flight Center and the Jet Propulsion Laboratory is presented. This receiver utilizes only a small number of high speed components along with a majority of lower speed components operating in a parallel frequency domain structure implementable in CMOS, and can currently process up to 600 Mbps with standard QPSK modulation. Performance results for this receiver for bandwidth efficient QPSK modulation schemes such as square-root raised cosine pulse shaped QPSK and Feher's patented QPSK are presented, demonstrating the flexibility of the receiver architecture.

Radiating columnar joints in Gyeongju, Korea as a educational site

NASA Astrophysics Data System (ADS)

Woo, H.; Kim, J. H.; Jang, Y. D.

2015-12-01

Gyeongju is located in the central eastern part of South Korea. There are various directional columnar joint sets in Tertiary trachytic basalt formation along the shore. In particular, rare radiating columnar joints occur in this area. Columnar joints are parallel, prismatic columns that are formed as a result of contraction during the rapid cooling of lava flow, forming a three dimensional fracture network. In general, the radius and direction of the rock column represent the cooling rate and surface respectively. Radiating direction of columns here indicates that dome- or lobe-shaped lava was cooled from its surface to the core during the viscous lava flow. The fact that the trachytic textures of plagioclase laths are indistinct suggests that the radiating columnar joints are equivalent to the frontal end of the lava lobes. This area is currently has a shore trail course, which is being developed into a picturesque educational park. There are corresponding information boards on the trail near each type of columnar joints to explain not only the forming process and geological mechanisms but the importance of nature conservation to visitors, especially students. A variety of educational materials and educational programs linked to regular school curriculum are also being developed.

Considering Horn's Parallel Analysis from a Random Matrix Theory Point of View.

PubMed

Saccenti, Edoardo; Timmerman, Marieke E

2017-03-01

Horn's parallel analysis is a widely used method for assessing the number of principal components and common factors. We discuss the theoretical foundations of parallel analysis for principal components based on a covariance matrix by making use of arguments from random matrix theory. In particular, we show that (i) for the first component, parallel analysis is an inferential method equivalent to the Tracy-Widom test, (ii) its use to test high-order eigenvalues is equivalent to the use of the joint distribution of the eigenvalues, and thus should be discouraged, and (iii) a formal test for higher-order components can be obtained based on a Tracy-Widom approximation. We illustrate the performance of the two testing procedures using simulated data generated under both a principal component model and a common factors model. For the principal component model, the Tracy-Widom test performs consistently in all conditions, while parallel analysis shows unpredictable behavior for higher-order components. For the common factor model, including major and minor factors, both procedures are heuristic approaches, with variable performance. We conclude that the Tracy-Widom procedure is preferred over parallel analysis for statistically testing the number of principal components based on a covariance matrix.

A visual parallel-BCI speller based on the time-frequency coding strategy.

PubMed

Xu, Minpeng; Chen, Long; Zhang, Lixin; Qi, Hongzhi; Ma, Lan; Tang, Jiabei; Wan, Baikun; Ming, Dong

2014-04-01

Spelling is one of the most important issues in brain-computer interface (BCI) research. This paper is to develop a visual parallel-BCI speller system based on the time-frequency coding strategy in which the sub-speller switching among four simultaneously presented sub-spellers and the character selection are identified in a parallel mode. The parallel-BCI speller was constituted by four independent P300+SSVEP-B (P300 plus SSVEP blocking) spellers with different flicker frequencies, thereby all characters had a specific time-frequency code. To verify its effectiveness, 11 subjects were involved in the offline and online spellings. A classification strategy was designed to recognize the target character through jointly using the canonical correlation analysis and stepwise linear discriminant analysis. Online spellings showed that the proposed parallel-BCI speller had a high performance, reaching the highest information transfer rate of 67.4 bit min(-1), with an average of 54.0 bit min(-1) and 43.0 bit min(-1) in the three rounds and five rounds, respectively. The results indicated that the proposed parallel-BCI could be effectively controlled by users with attention shifting fluently among the sub-spellers, and highly improved the BCI spelling performance.

Genome-wide genetic investigation of serological measures of common infections

PubMed Central

Rubicz, Rohina; Yolken, Robert; Drigalenko, Eugene; Carless, Melanie A; Dyer, Thomas D; Kent Jr, Jack; Curran, Joanne E; Johnson, Matthew P; Cole, Shelley A; Fowler, Sharon P; Arya, Rector; Puppala, Sobha; Almasy, Laura; Moses, Eric K; Kraig, Ellen; Duggirala, Ravindranath; Blangero, John; Leach, Charles T; Göring, Harald HH

2015-01-01

Populations and individuals differ in susceptibility to infections because of a number of factors, including host genetic variation. We previously demonstrated that differences in antibody titer, which reflect infection history, are significantly heritable. Here we attempt to identify the genetic factors influencing variation in these serological phenotypes. Blood samples from >1300 Mexican Americans were quantified for IgG antibody level against 12 common infections, selected on the basis of their reported role in cardiovascular disease risk: Chlamydia pneumoniae; Helicobacter pylori; Toxoplasma gondii; cytomegalovirus; herpes simplex I virus; herpes simplex II virus; human herpesvirus 6 (HHV6); human herpesvirus 8 (HHV8); varicella zoster virus; hepatitis A virus (HAV); influenza A virus; and influenza B virus. Pathogen-specific quantitative antibody levels were analyzed, as were three measures of pathogen burden. Genome-wide linkage and joint linkage and association analyses were performed using ~1 million SNPs. Significant linkage (lod scores >3.0) was obtained for HHV6 (on chromosome 7), HHV8 (on chromosome 6), and HAV (on chromosome 13). SNP rs4812712 on chromosome 20 was significantly associated with C. pneumoniae (P=5.3 × 10−8). However, no genome-wide significant loci were obtained for the other investigated antibodies. We conclude that it is possible to localize host genetic factors influencing some of these antibody traits, but that further larger-scale investigations will be required to elucidate the genetic mechanisms contributing to variation in antibody levels. PMID:25758998

RECOGNIZING AND IDENTIFYING PEOPLE: A neuropsychological review

PubMed Central

Barton, Jason J S; Corrow, Sherryse L

2016-01-01

Recognizing people is a classic example of a cognitive function that involves multiple processing stages and parallel routes of information. Neuropsychological data have provided important evidence for models of this process, particularly from case reports; however, the quality and extent of the data varies widely between studies. In this review we first discuss the requirements and logical basis of the types of neuropsychological evidence to support conclusions about the modules in this process. We then survey the adequacy of the current body of reports to address two key issues. First is the question of which cognitive operation generates a sense of familiarity: the current debate revolves around whether familiarity arises in modality-specific recognition units or later amodal processes. Key evidence on this point comes from the search for dissociations between familiarity for faces, voices and names. The second question is whether lesions can differentially affect the abilities to link diverse sources of person information (e.g. face, voice, name, biographic data). Dissociations of these linkages may favour a distributed-only model of the organization of semantic knowledge, whereas a ‘person-hub’ model would predict uniform impairments of all linkages. While we conclude that there is reasonable evidence for dissociations in name, voice and face familiarity in regards to the first question, the evidence for or against dissociated linkages between information stores in regards to the second is tenuous at best. We identify deficiencies in the current literature that should motivate and inform the design of future studies. PMID:26773237

Factors related to the parallel use of complementary and alternative medicine with conventional medicine among patients with chronic conditions in South Korea.

PubMed

Choi, Byunghee; Han, Dongwoon; Na, Seonsam; Lim, Byungmook

2017-06-01

This study aims to examine the characteristics and behavioral patterns of patients with chronic conditions behind their parallel use of the conventional medicine (CM) and the complementary and alternative medicine (CAM) that includes traditional Korean Medicine (KM). This cross-sectional study used the self-administered anonymous survey method to obtain the results from inpatients who were staying in three hospitals in Gyeongnam province in Korea. Of the 423 participants surveyed, 334 participants (79.0%) used some form of CAM among which KM therapies were the most common modalities. The results of a logistic regression analysis showed that the parallel use pattern was most apparent in the groups aged over 40. Patients with hypertension or joint diseases were seen to have higher propensity to show the parallel use patterns, whereas patients with diabetes were not. In addition, many sociodemographic and health-related characteristics are related to the patterns of the parallel use of CAM and CM. In the rural area of Korea, most inpatients who used CM for the management of chronic conditions used CAM in parallel. KM was the most common in CAM modalities, and the aspect of parallel use varied according to the disease conditions.

Joint design of large-tip-angle parallel RF pulses and blipped gradient trajectories.

PubMed

Cao, Zhipeng; Donahue, Manus J; Ma, Jun; Grissom, William A

2016-03-01

To design multichannel large-tip-angle kT-points and spokes radiofrequency (RF) pulses and gradient waveforms for transmit field inhomogeneity compensation in high field magnetic resonance imaging. An algorithm to design RF subpulse weights and gradient blip areas is proposed to minimize a magnitude least-squares cost function that measures the difference between realized and desired state parameters in the spin domain, and penalizes integrated RF power. The minimization problem is solved iteratively with interleaved target phase updates, RF subpulse weights updates using the conjugate gradient method with optimal control-based derivatives, and gradient blip area updates using the conjugate gradient method. Two-channel parallel transmit simulations and experiments were conducted in phantoms and human subjects at 7 T to demonstrate the method and compare it to small-tip-angle-designed pulses and circularly polarized excitations. The proposed algorithm designed more homogeneous and accurate 180° inversion and refocusing pulses than other methods. It also designed large-tip-angle pulses on multiple frequency bands with independent and joint phase relaxation. Pulses designed by the method improved specificity and contrast-to-noise ratio in a finger-tapping spin echo blood oxygen level dependent functional magnetic resonance imaging study, compared with circularly polarized mode refocusing. A joint RF and gradient waveform design algorithm was proposed and validated to improve large-tip-angle inversion and refocusing at ultrahigh field. © 2015 Wiley Periodicals, Inc.

Chaperonin containing T-complex polypeptide subunit eta is a potential marker of joint contracture: an experimental study in the rat.

PubMed

He, Ronghan; Wang, Zhe; Lu, Yunxiang; Huang, Junqi; Ren, Jianhua; Wang, Kun

2015-11-01

Joint contracture is a fibroproliferative disorder that restricts joint mobility, resulting in tissue degeneration and deformity. However, the etiology of joint contracture is still unknown. Chaperonin containing T-complex polypeptide subunit eta (CCT-eta) is reported to increase in fibrotic diseases. The purpose of this study was to investigate whether CCT-eta is implicated in joint contracture and to determine the role of CCT-eta in the progression of joint contracture by analyzing a rat model. We immobilized the left knee joint of rat by internal fixation for 8 weeks. The non-immobilized right leg served as a control. The range of motion (ROM) of the knee was investigated. Fibroblasts were obtained from the posterior joint capsule of the joints. The outcome was followed by quantitative real-time polymerase chain reaction (qRT-PCR), Western blot, fibroblast migration assay, and collagen assay. The effect of CCT-eta on the functions of fibroblasts was observed by utilizing a short inhibitory RNA (siRNA) targeting CCT-eta. The ROM of the immobilized joints was significantly limited compared to the contralateral joints (p < 0.05). Fibroblasts derived from the contractive joints showed higher mRNA and protein expressions of CCT-eta in parallel with alpha-smooth muscle actin (α-SMA) compared to the cells from the contralateral knees (p < 0.05). siRNA-mediated downregulation of CCT-eta inhibited the expressions of both CCT-eta and α-SMA. Moreover, the reduction of CCT-eta also significantly decreased fibroblast functions such as cell mobility and collagen synthesis (all p < 0.05). Our findings indicate that CCT-eta appears to be a potential marker of joint contracture disease.

Linking morphology and motion: a test of a four-bar mechanism in seahorses.

PubMed

Roos, Gert; Leysen, Heleen; Van Wassenbergh, Sam; Herrel, Anthony; Jacobs, Patric; Dierick, Manuel; Aerts, Peter; Adriaens, Dominique

2009-01-01

Syngnathid fishes (seahorses, pipefish, and sea dragons) possess a highly modified cranium characterized by a long and tubular snout with minute jaws at its end. Previous studies indicated that these species are extremely fast suction feeders with their feeding strike characterized by a rapid elevation of the head accompanied by rotation of the hyoid. A planar four-bar model is proposed to explain the coupled motion of the neurocranium and the hyoid. Because neurocranial elevation as well as hyoid rotation are crucial for the feeding mechanism in previously studied Syngnathidae, a detailed evaluation of this model is needed. In this study, we present kinematic data of the feeding strike in the seahorse Hippocampus reidi. We combined these data with a detailed morphological analysis of the important linkages and joints involved in rotation of the neurocranium and the hyoid, and we compared the kinematic measurements with output of a theoretical four-bar model. The kinematic analysis shows that neurocranial rotation never preceded hyoid rotation, thus indicating that hyoid rotation triggers the explosive feeding strike. Our data suggest that while neurocranium and hyoid initially (first 1.5 ms) behave as predicted by the four-bar model, eventually, the hyoid rotation is underestimated by the model. Shortening, or a posterior displacement of the sternohyoid muscle (of which the posterior end is confluent with the hypaxial muscles in H. reidi), probably explains the discrepancy between the model and our kinematic measurements. As a result, while four-bar modeling indicates a clear coupling between hyoid rotation and neurocranial elevation, the detailed morphological determination of the linkages and joints of this four-bar model remain crucial in order to fully understand this mechanism in seahorse feeding.

Diagnostic Accuracy of an MRI Protocol of the Knee Accelerated Through Parallel Imaging in Correlation to Arthroscopy.

PubMed

Schnaiter, Johannes Walter; Roemer, Frank; McKenna-Kuettner, Axel; Patzak, Hans-Joachim; May, Matthias Stefan; Janka, Rolf; Uder, Michael; Wuest, Wolfgang

2018-03-01

 Parallel imaging allows for a considerable shortening of examination times. Limited data is available about the diagnostic accuracy of an accelerated knee MRI protocol based on parallel imaging evaluating all knee joint compartments in a large patient population compared to arthroscopy.  162 consecutive patients with a knee MRI (1.5 T, Siemens Aera) and arthroscopy were included. The total MRI scan time was less than 9 minutes. Meniscus and cartilage injuries, cruciate ligament lesions, loose joint bodies and medial patellar plicae were evaluated. Sensitivity (SE), specificity (SP), positive predictive value (PPV), and negative predictive value (NPV), as well as diagnostic accuracy were determined.  For the medial meniscus, the values were: SE 97 %, SP 88 %, PPV 94 %, and NPV 94 %. For the lateral meniscus the values were: SE 77 %, SP 99 %, PPV 98 %, and NPV 89 %. For cartilage injuries the values were: SE 72 %, SP 80 %, PPV 86 %, and NPV 61 %. For the anterior cruciate ligament the values were: SE 90 %, SP 94 %, PPV 77 %, and NPV 98 %, while all values were 100 % for the posterior cruciate ligament. For loose bodies the values were: SE 48 %, SP 96 %, PPV 62 %, and NPV 93 %, and for the medial patellar plicae the values were: SE 57 %, SP 88 %, PPV 18 %, and NPV 98 %.  A knee MRI examination with parallel imaging and a scan time of less than 9 minutes delivers reliable results with high diagnostic accuracy.   · An accelerated knee MRI protocol with parallel imaging allows for high diagnostic accuracy.. · Especially meniscal and cruciate ligament injuries are well depicted.. · Cartilage injuries seem to be overestimated.. · Schnaiter JW, Roemer F, McKenna-Kuettner A et al. Diagnostic Accuracy of an MRI Protocol of the Knee Accelerated Through Parallel Imaging in Correlation to Arthroscopy. Fortschr Röntgenstr 2018; 190: 265 - 272. © Georg Thieme Verlag KG Stuttgart · New York.

Heliophysical Explorers (HELEX): Solar Orbiter and Sentinels - Report of the Joint Science and Technology Definition Team (JSTDT)

NASA Technical Reports Server (NTRS)

2008-01-01

Heliophysical Explorers (HELEX) brings together and augments the unique capabilities of ESA's Solar Orbiter mission (near-Sun and out-of-ecliptic in-situ plus remote-sensing observations) with those of NASA's Inner Heliospheric Sentinels (in-situ observations from multiple platforms arrayed at varying radial distances and azimuthal locations in the near-ecliptic plane)to investigate, characterize, and understand how the Sun determines the environment of the inner solar system and, more broadly, generates the heliosphere itself. This joint ESA-NASA science program offers a unique opportunity for coordinated, correlative measurements, resulting in a combined observational capability and science return that far outweighs that of either mission alone. Building on the knowledge gained from missions like Helios and Ulysses, and STEREO, HELEX will bring to bear the power of multipoint, in-situ measurements using previously unavailable instrumental capabilities in combination with remote-sensing observations from a new, inner heliospheric perspective to answer fundamental questions about the Sun-heliosphere linkage.

On measures of association among genetic variables

PubMed Central

Gianola, Daniel; Manfredi, Eduardo; Simianer, Henner

2012-01-01

Summary Systems involving many variables are important in population and quantitative genetics, for example, in multi-trait prediction of breeding values and in exploration of multi-locus associations. We studied departures of the joint distribution of sets of genetic variables from independence. New measures of association based on notions of statistical distance between distributions are presented. These are more general than correlations, which are pairwise measures, and lack a clear interpretation beyond the bivariate normal distribution. Our measures are based on logarithmic (Kullback-Leibler) and on relative ‘distances’ between distributions. Indexes of association are developed and illustrated for quantitative genetics settings in which the joint distribution of the variables is either multivariate normal or multivariate-t, and we show how the indexes can be used to study linkage disequilibrium in a two-locus system with multiple alleles and present applications to systems of correlated beta distributions. Two multivariate beta and multivariate beta-binomial processes are examined, and new distributions are introduced: the GMS-Sarmanov multivariate beta and its beta-binomial counterpart. PMID:22742500

Cross-Population Joint Analysis of eQTLs: Fine Mapping and Functional Annotation

PubMed Central

Wen, Xiaoquan; Luca, Francesca; Pique-Regi, Roger

2015-01-01

Mapping expression quantitative trait loci (eQTLs) has been shown as a powerful tool to uncover the genetic underpinnings of many complex traits at molecular level. In this paper, we present an integrative analysis approach that leverages eQTL data collected from multiple population groups. In particular, our approach effectively identifies multiple independent cis-eQTL signals that are consistent across populations, accounting for population heterogeneity in allele frequencies and linkage disequilibrium patterns. Furthermore, by integrating genomic annotations, our analysis framework enables high-resolution functional analysis of eQTLs. We applied our statistical approach to analyze the GEUVADIS data consisting of samples from five population groups. From this analysis, we concluded that i) jointly analysis across population groups greatly improves the power of eQTL discovery and the resolution of fine mapping of causal eQTL ii) many genes harbor multiple independent eQTLs in their cis regions iii) genetic variants that disrupt transcription factor binding are significantly enriched in eQTLs (p-value = 4.93 × 10-22). PMID:25906321

A Simple Application of Compressed Sensing to Further Accelerate Partially Parallel Imaging

PubMed Central

Miao, Jun; Guo, Weihong; Narayan, Sreenath; Wilson, David L.

2012-01-01

Compressed Sensing (CS) and partially parallel imaging (PPI) enable fast MR imaging by reducing the amount of k-space data required for reconstruction. Past attempts to combine these two have been limited by the incoherent sampling requirement of CS, since PPI routines typically sample on a regular (coherent) grid. Here, we developed a new method, “CS+GRAPPA,” to overcome this limitation. We decomposed sets of equidistant samples into multiple random subsets. Then, we reconstructed each subset using CS, and averaging the results to get a final CS k-space reconstruction. We used both a standard CS, and an edge and joint-sparsity guided CS reconstruction. We tested these intermediate results on both synthetic and real MR phantom data, and performed a human observer experiment to determine the effectiveness of decomposition, and to optimize the number of subsets. We then used these CS reconstructions to calibrate the GRAPPA complex coil weights. In vivo parallel MR brain and heart data sets were used. An objective image quality evaluation metric, Case-PDM, was used to quantify image quality. Coherent aliasing and noise artifacts were significantly reduced using two decompositions. More decompositions further reduced coherent aliasing and noise artifacts but introduced blurring. However, the blurring was effectively minimized using our new edge and joint-sparsity guided CS using two decompositions. Numerical results on parallel data demonstrated that the combined method greatly improved image quality as compared to standard GRAPPA, on average halving Case-PDM scores across a range of sampling rates. The proposed technique allowed the same Case-PDM scores as standard GRAPPA, using about half the number of samples. We conclude that the new method augments GRAPPA by combining it with CS, allowing CS to work even when the k-space sampling pattern is equidistant. PMID:22902065

A wearable robotic orthosis with a spring-assist actuator.

PubMed

Seungmin Jung; Chankyu Kim; Jisu Park; Dongyoub Yu; Jaehwan Park; Junho Choi

2016-08-01

This paper introduces a wearable robotic orthosis with spring-assist actuators, which is designed to assist people who have difficulty in walking. The spring-assist actuator consists of an electrical motor and a spring, which are attached to a rotational axis in parallel to each other. The spring-assist actuator is developed based on the analysis on the stiffness of the knee and hip joints during walking. "COWALK-Mobile," which is a wearable robotic orthosis, is developed using the spring-assist actuators to reduce the required motor torque during walking. The COWALK-Mobile has active hip and knee joints and passive ankle joints to provide assistive torque to the wearer. The required joint torque is generated by the spring as well as the electrical motor, which results in a decrease of maximum required torque for the motor. In order to evaluate the performance of the spring-assist actuator, experiments are carried out. The experiments show that the spring-assist actuators reduced the required motor torque during walking.

Welding Wires To Thin Thermocouple Films

NASA Technical Reports Server (NTRS)

Holanda, Raymond; Kim, Walter S.; Danzey, Gerald A.; Pencil, Eric; Wadel, Mary

1993-01-01

Parallel-gap resistance welding yields joints surviving temperatures of about 1,000 degrees C. Much faster than thermocompression bonding. Also exceeds conductive-paste bonding and sputtering thin films through porous flame-sprayed insulation on prewelded lead wires. Introduces no foreign material into thermocouple circuit and does not require careful control of thickness of flame-sprayed material.

Joint Force Quarterly. Number 26, Autumn 2000

DTIC Science & Technology

2001-01-01

Compañía Impresora Ar- gentina, 1990). Caribbean, Central America, and Mex- ico, have become a parallel power to the state in controlling national terri...and regimen- tal service (1917–19); commanded 3d Battalion, 22d Infantry, in France (1919); assistant chief of staff, American Forces, Germany (1920–21

A Soft Parallel Kinematic Mechanism.

PubMed

White, Edward L; Case, Jennifer C; Kramer-Bottiglio, Rebecca

2018-02-01

In this article, we describe a novel holonomic soft robotic structure based on a parallel kinematic mechanism. The design is based on the Stewart platform, which uses six sensors and actuators to achieve full six-degree-of-freedom motion. Our design is much less complex than a traditional platform, since it replaces the 12 spherical and universal joints found in a traditional Stewart platform with a single highly deformable elastomer body and flexible actuators. This reduces the total number of parts in the system and simplifies the assembly process. Actuation is achieved through coiled-shape memory alloy actuators. State observation and feedback is accomplished through the use of capacitive elastomer strain gauges. The main structural element is an elastomer joint that provides antagonistic force. We report the response of the actuators and sensors individually, then report the response of the complete assembly. We show that the completed robotic system is able to achieve full position control, and we discuss the limitations associated with using responsive material actuators. We believe that control demonstrated on a single body in this work could be extended to chains of such bodies to create complex soft robots.

Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint

NASA Astrophysics Data System (ADS)

Zou, Yang; Li, Jianchun; Laloui, Lyesse; Zhao, Jian

2017-10-01

The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived based on Maxwell and Kelvin models which are, respectively, applied to describe the viscoelastic deformational behaviour of the rock joint and incorporated into the displacement discontinuity model (DDM). The proposed solutions are verified by comparing with the previous studies on harmonic waves, which are simulated by sinusoidal incident P- and S-waves. Comparison between the predicted transmitted waves and the experimental data for P-wave propagation across a joint filled with clay is conducted. The Maxwell is found to be more appropriate to describe the filled joint. The parametric studies show that wave propagation is affected by many factors, such as the stiffness and the viscosity of joints, the incident angle and the duration of incident waves. Furthermore, the dependences of the transmission and reflection coefficients on the specific joint stiffness and viscosity are different for the joints with Maxwell and Kelvin behaviours. The alternation of the reflected and transmitted waveforms is discussed, and the application scope of this study is demonstrated by an illustration of the effects of the joint thickness. The solutions are also extended for multiple parallel joints with the virtual wave source method and the time-domain recursive method. For an incident wave with arbitrary waveform, it is convenient to adopt the present approach to directly calculate wave propagation across a viscoelastic rock joint without additional mathematical methods such as the Fourier and inverse Fourier transforms.

Multifunctional Coatings to Simultaneously Promote Osseointegration and Prevent Infection of Orthopaedic Implants

PubMed Central

Raphel, Jordan; Holodniy, Mark; Goodman, Stuart B.; Heilshorn, Sarah C.

2016-01-01

The two leading causes of failure for joint arthroplasty prostheses are aseptic loosening and periprosthetic joint infection. With the number of primary and revision joint replacement surgeries on the rise, strategies to mitigate these failure modes have become increasingly important. Much of the recent work in this field has focused on the design of coatings either to prevent infection while ignoring bone mineralization or vice versa, to promote osseointegration while ignoring microbial susceptibility. However, both coating functions are required to achieve long-term success of the implant; therefore, these two modalities must be evaluated in parallel during the development of new orthopaedic coating strategies. In this review, we discuss recent progress and future directions for the design of multifunctional orthopaedic coatings that can inhibit microbial cells while still promoting osseointegration. PMID:26851394

Joint nociceptor nerve activity and pain in an animal model of acute gout and its modulation by intra-articular hyaluronan

PubMed Central

Marcotti, Aida; Miralles, Ana; Dominguez, Eduardo; Pascual, Eliseo; Gomis, Ana; Belmonte, Carlos; de la Peña, Elvira

2018-01-01

Abstract The mechanisms whereby deposition of monosodium urate (MSU) crystals in gout activates nociceptors to induce joint pain are incompletely understood. We tried to reproduce the signs of painful gouty arthritis, injecting into the knee joint of rats suspensions containing amorphous or triclinic, needle MSU crystals. The magnitude of MSU-induced inflammation and pain behavior signs were correlated with the changes in firing frequency of spontaneous and movement-evoked nerve impulse activity recorded in single knee joint nociceptor saphenous nerve fibers. Joint swelling, mechanical and cold allodynia, and hyperalgesia appeared 3 hours after joint injection of MSU crystals. In parallel, spontaneous and movement-evoked joint nociceptor impulse activity raised significantly. Solutions containing amorphous or needle-shaped MSU crystals had similar inflammatory and electrophysiological effects. Intra-articular injection of hyaluronan (HA, Synvisc), a high-MW glycosaminoglycan present in the synovial fluid with analgesic effects in osteoarthritis, significantly reduced MSU-induced behavioral signs of pain and decreased the enhanced joint nociceptor activity. Our results support the interpretation that pain and nociceptor activation are not triggered by direct mechanical stimulation of nociceptors by MSU crystals, but are primarily caused by the release of excitatory mediators by inflammatory cells activated by MSU crystals. Intra-articular HA decreased behavioral and electrophysiological signs of pain, possibly through its viscoelastic filtering effect on the mechanical forces acting over sensitized joint sensory endings and probably also by a direct interaction of HA molecules with the transducing channels expressed in joint nociceptor terminals. PMID:29319609

Microstructural and Compositional Features of the Fibrous and Hyaline Cartilage on the Medial Tibial Plateau Imply a Unique Role for the Hopping Locomotion of Kangaroo

PubMed Central

He, Bo; Wu, Jian Ping; Xu, Jiake; Day, Robert E.; Kirk, Thomas Brett

2013-01-01

Hopping provides efficient and energy saving locomotion for kangaroos, but it results in great forces in the knee joints. A previous study has suggested that a unique fibrous cartilage in the central region of the tibial cartilage could serve to decrease the peak stresses generated within kangaroo tibiofemoral joints. However, the influences of the microstructure, composition and mechanical properties of the central fibrous and peripheral hyaline cartilage on the function of the knee joints are still to be defined. The present study showed that the fibrous cartilage was thicker and had a lower chondrocyte density than the hyaline cartilage. Despite having a higher PG content in the middle and deep zones, the fibrous cartilage had an inferior compressive strength compared to the peripheral hyaline cartilage. The fibrous cartilage had a complex three dimensional collagen meshwork with collagen bundles parallel to the surface in the superficial zone, and with collagen bundles both parallel and perpendicular to the surface in the middle and deep zones. The collagen in the hyaline cartilage displayed a typical Benninghoff structure, with collagen fibres parallel to the surface in the superficial zone and collagen fibres perpendicular to the surface in the deep zone. Elastin fibres were found throughout the entire tissue depth of the fibrous cartilage and displayed a similar alignment to the adjacent collagen bundles. In comparison, the elastin fibres in the hyaline cartilage were confined within the superficial zone. This study examined for the first time the fibrillary structure, PG content and compressive properties of the central fibrous cartilage pad and peripheral hyaline cartilage within the kangaroo medial tibial plateau. It provided insights into the microstructure and composition of the fibrous and peripheral hyaline cartilage in relation to the unique mechanical properties of the tissues to provide for the normal activities of kangaroos. PMID:24058543

Microstructural and compositional features of the fibrous and hyaline cartilage on the medial tibial plateau imply a unique role for the hopping locomotion of kangaroo.

PubMed

He, Bo; Wu, Jian Ping; Xu, Jiake; Day, Robert E; Kirk, Thomas Brett

2013-01-01

Hopping provides efficient and energy saving locomotion for kangaroos, but it results in great forces in the knee joints. A previous study has suggested that a unique fibrous cartilage in the central region of the tibial cartilage could serve to decrease the peak stresses generated within kangaroo tibiofemoral joints. However, the influences of the microstructure, composition and mechanical properties of the central fibrous and peripheral hyaline cartilage on the function of the knee joints are still to be defined. The present study showed that the fibrous cartilage was thicker and had a lower chondrocyte density than the hyaline cartilage. Despite having a higher PG content in the middle and deep zones, the fibrous cartilage had an inferior compressive strength compared to the peripheral hyaline cartilage. The fibrous cartilage had a complex three dimensional collagen meshwork with collagen bundles parallel to the surface in the superficial zone, and with collagen bundles both parallel and perpendicular to the surface in the middle and deep zones. The collagen in the hyaline cartilage displayed a typical Benninghoff structure, with collagen fibres parallel to the surface in the superficial zone and collagen fibres perpendicular to the surface in the deep zone. Elastin fibres were found throughout the entire tissue depth of the fibrous cartilage and displayed a similar alignment to the adjacent collagen bundles. In comparison, the elastin fibres in the hyaline cartilage were confined within the superficial zone. This study examined for the first time the fibrillary structure, PG content and compressive properties of the central fibrous cartilage pad and peripheral hyaline cartilage within the kangaroo medial tibial plateau. It provided insights into the microstructure and composition of the fibrous and peripheral hyaline cartilage in relation to the unique mechanical properties of the tissues to provide for the normal activities of kangaroos.

[A network to promote health systems based on primary health care in the Region of the Americas].

PubMed

Herrera Vázquez, María Magdalena; Rodríguez Avila, Nuria; Nebot Adell, Carme; Montenegro, Hernán

2007-05-01

To identify the relational components of an international network of organizations that provide technical and financial assistance to promote the development of health systems based on primary health care in the countries of the Region of the Americas; to analyze the linkages that would allow the collaborating partners of the Pan American Health Organization (PAHO) to work together on health issues; and to determine the basic theoretical elements that can help to develop action strategies that support advocacy efforts by a network. This was a qualitative and quantitative cross-sectional study based on identifying key informants and on analyzing social networks. Ethnographic and relational information from 46 international organizations was collected through a self-administered semistructured questionnaire. From 46 international health cooperation organizations, 29 decision makers from 29 organizations participated (63.0% response rate). The structure and the strength of the network was evaluated in terms of density, closeness, clustering, and centralization. The statistical analysis was done using computer programs that included UCINET, Pajek, and Microsoft Access. We found a structurally centralized theoretical network, whose nodes were clustered into four central subgroups linked by a shared vision. The leadership, influence, and political interests reflected the formal and technical-cooperation linkages, the formal support for health systems based on primary health care, and the flow of resources being more often technical ones than financial ones. The interorganizational relational components and the social-action ties that were identified could help in the development and consolidation of a thematic network for advocacy and for the management of technical and financial assistance that supports primary health care in the Americas. The linkages for joint action that were identified could advance international cooperation in developing health systems based on primary health care, once PAHO formulates clear implementation strategies and takes a leadership position in mobilizing financial resources and in creating informal and interpersonal linkages for action.

A High-Resolution SNP Array-Based Linkage Map Anchors a New Domestic Cat Draft Genome Assembly and Provides Detailed Patterns of Recombination.

PubMed

Li, Gang; Hillier, LaDeana W; Grahn, Robert A; Zimin, Aleksey V; David, Victor A; Menotti-Raymond, Marilyn; Middleton, Rondo; Hannah, Steven; Hendrickson, Sher; Makunin, Alex; O'Brien, Stephen J; Minx, Pat; Wilson, Richard K; Lyons, Leslie A; Warren, Wesley C; Murphy, William J

2016-06-01

High-resolution genetic and physical maps are invaluable tools for building accurate genome assemblies, and interpreting results of genome-wide association studies (GWAS). Previous genetic and physical maps anchored good quality draft assemblies of the domestic cat genome, enabling the discovery of numerous genes underlying hereditary disease and phenotypes of interest to the biomedical science and breeding communities. However, these maps lacked sufficient marker density to order thousands of shorter scaffolds in earlier assemblies, which instead relied heavily on comparative mapping with related species. A high-resolution map would aid in validating and ordering chromosome scaffolds from existing and new genome assemblies. Here, we describe a high-resolution genetic linkage map of the domestic cat genome based on genotyping 453 domestic cats from several multi-generational pedigrees on the Illumina 63K SNP array. The final maps include 58,055 SNP markers placed relative to 6637 markers with unique positions, distributed across all autosomes and the X chromosome. Our final sex-averaged maps span a total autosomal length of 4464 cM, the longest described linkage map for any mammal, confirming length estimates from a previous microsatellite-based map. The linkage map was used to order and orient the scaffolds from a substantially more contiguous domestic cat genome assembly (Felis catus v8.0), which incorporated ∼20 × coverage of Illumina fragment reads. The new genome assembly shows substantial improvements in contiguity, with a nearly fourfold increase in N50 scaffold size to 18 Mb. We use this map to report probable structural errors in previous maps and assemblies, and to describe features of the recombination landscape, including a massive (∼50 Mb) recombination desert (of virtually zero recombination) on the X chromosome that parallels a similar desert on the porcine X chromosome in both size and physical location. Copyright © 2016 Li et al.

Estimation of Time-Varying, Intrinsic and Reflex Dynamic Joint Stiffness during Movement. Application to the Ankle Joint

PubMed Central

Guarín, Diego L.; Kearney, Robert E.

2017-01-01

Dynamic joint stiffness determines the relation between joint position and torque, and plays a vital role in the control of posture and movement. Dynamic joint stiffness can be quantified during quasi-stationary conditions using disturbance experiments, where small position perturbations are applied to the joint and the torque response is recorded. Dynamic joint stiffness is composed of intrinsic and reflex mechanisms that act and change together, so that nonlinear, mathematical models and specialized system identification techniques are necessary to estimate their relative contributions to overall joint stiffness. Quasi-stationary experiments have demonstrated that dynamic joint stiffness is heavily modulated by joint position and voluntary torque. Consequently, during movement, when joint position and torque change rapidly, dynamic joint stiffness will be Time-Varying (TV). This paper introduces a new method to quantify the TV intrinsic and reflex components of dynamic joint stiffness during movement. The algorithm combines ensemble and deterministic approaches for estimation of TV systems; and uses a TV, parallel-cascade, nonlinear system identification technique to separate overall dynamic joint stiffness into intrinsic and reflex components from position and torque records. Simulation studies of a stiffness model, whose parameters varied with time as is expected during walking, demonstrated that the new algorithm accurately tracked the changes in dynamic joint stiffness using as little as 40 gait cycles. The method was also used to estimate the intrinsic and reflex dynamic ankle stiffness from an experiment with a healthy subject during which ankle movements were imposed while the subject maintained a constant muscle contraction. The method identified TV stiffness model parameters that predicted the measured torque very well, accounting for more than 95% of its variance. Moreover, both intrinsic and reflex dynamic stiffness were heavily modulated through the movement in a manner that could not be predicted from quasi-stationary experiments. The new method provides the tool needed to explore the role of dynamic stiffness in the control of movement. PMID:28649196

Application of high-performance computing to numerical simulation of human movement

NASA Technical Reports Server (NTRS)

Anderson, F. C.; Ziegler, J. M.; Pandy, M. G.; Whalen, R. T.

1995-01-01

We have examined the feasibility of using massively-parallel and vector-processing supercomputers to solve large-scale optimization problems for human movement. Specifically, we compared the computational expense of determining the optimal controls for the single support phase of gait using a conventional serial machine (SGI Iris 4D25), a MIMD parallel machine (Intel iPSC/860), and a parallel-vector-processing machine (Cray Y-MP 8/864). With the human body modeled as a 14 degree-of-freedom linkage actuated by 46 musculotendinous units, computation of the optimal controls for gait could take up to 3 months of CPU time on the Iris. Both the Cray and the Intel are able to reduce this time to practical levels. The optimal solution for gait can be found with about 77 hours of CPU on the Cray and with about 88 hours of CPU on the Intel. Although the overall speeds of the Cray and the Intel were found to be similar, the unique capabilities of each machine are better suited to different portions of the computational algorithm used. The Intel was best suited to computing the derivatives of the performance criterion and the constraints whereas the Cray was best suited to parameter optimization of the controls. These results suggest that the ideal computer architecture for solving very large-scale optimal control problems is a hybrid system in which a vector-processing machine is integrated into the communication network of a MIMD parallel machine.

Building of nested components by a double-nozzle droplet deposition process

NASA Astrophysics Data System (ADS)

Li, SuLi; Wei, ZhengYing; Du, Jun; Zhao, Guangxi; Wang, Xin; Lu, BingHeng

2016-07-01

According to the nested components jointed with multiple parts,a double-nozzle droplet deposition process was put forward in this paper, and the experimental system was developed. Through the research on the properties of support materials and the process of double-nozzle droplet deposition, the linkage control of the metal droplet deposition and the support material extrusion was realized, and a nested component with complex construction was fabricated directly. Compared with the traditional forming processes, this double-nozzle deposition process has the advantages of short cycle, low cost and so on. It can provide an approach way to build the nested parts.

Health and Environment Linked for Information Exchange (HELIX)-Atlanta: A CDC-NASA Joint Environmental Public Health Tracking Collaborative Project

NASA Technical Reports Server (NTRS)

Al-Hamdan, Mohammad; Luvall, Jeff; Crosson, Bill; Estes, Maury; Limaye, Ashutosh; Quattrochi, Dale; Rickman, Doug

2008-01-01

HELIX-Atlanta was developed to support current and future state and local EPHT programs to implement data linking demonstration projects which could be part of the CDC EPHT Network. HELIX-Atlanta is a pilot linking project in Atlanta for CDC to learn about the challenges the states will encounter. NASA/MSFC and the CDC are partners in linking environmental and health data to enhance public health surveillance. The use of NASA technology creates value added geospatial products from existing environmental data sources to facilitate public health linkages. Proving the feasibility of the approach is the main objective

Single Degree-of-Freedom Exoskeleton Mechanism Design for Thumb Rehabilitation*

PubMed Central

Yihun, Yimesker; Miklos, Robert; Perez-Gracia, Alba; Reinkensmeyer, David J.; Denney, Keith; Wolbrecht, Eric T.

2014-01-01

This paper presents the kinematic design of a spatial, 1-degree-of-freedom closed linkage to be used as an exoskeleton for thumb motion. Together with an already-designed finger mechanism, it forms a robotic device for hand therapy. The goal for the exoskeleton is to generate the desired grasping and pinching path of the thumb with one degree of freedom, rather than using a system actuating all its joints independently. In addition to the path of the thumb, additional constraints are added in order to control the position and size of the exoskeleton, reducing physical and sensory interference with the user. PMID:23366289

Coherent UDWDM PON with joint subcarrier reception at OLT.

PubMed

Kottke, Christoph; Fischer, Johannes Karl; Elschner, Robert; Frey, Felix; Hilt, Jonas; Schubert, Colja; Schmidt, Daniel; Wu, Zifeng; Lankl, Berthold

2014-07-14

In this contribution, we report on the experimental investigation of an ultra-dense wavelength-division multiplexing (UDWDM) upstream link with up to 700 × 2.488 Gb/s polarization-division multiplexing differential quadrature phase-shift keying parallel upstream user channels transmitted over 80 km of standard single-mode fiber. We discuss challenges of the digital signal processing in the optical line terminal arising from the joint reception of several upstream user channels. We present solutions for resource and cost-efficient realization of the required channel separation, matched filtering, down-conversion and decimation as well as realization of the clock recovery and polarization demultiplexing for each individual channel.

A Parallel Independent Component Analysis Approach to Investigate Genomic Influence on Brain Function

PubMed Central

Liu, Jingyu; Demirci, Oguz; Calhoun, Vince D.

2009-01-01

Relationships between genomic data and functional brain images are of great interest but require new analysis approaches to integrate the high-dimensional data types. This letter presents an extension of a technique called parallel independent component analysis (paraICA), which enables the joint analysis of multiple modalities including interconnections between them. We extend our earlier work by allowing for multiple interconnections and by providing important overfitting controls. Performance was assessed by simulations under different conditions, and indicated reliable results can be extracted by properly balancing overfitting and underfitting. An application to functional magnetic resonance images and single nucleotide polymorphism array produced interesting findings. PMID:19834575

A Parallel Independent Component Analysis Approach to Investigate Genomic Influence on Brain Function.

PubMed

Liu, Jingyu; Demirci, Oguz; Calhoun, Vince D

2008-01-01

Relationships between genomic data and functional brain images are of great interest but require new analysis approaches to integrate the high-dimensional data types. This letter presents an extension of a technique called parallel independent component analysis (paraICA), which enables the joint analysis of multiple modalities including interconnections between them. We extend our earlier work by allowing for multiple interconnections and by providing important overfitting controls. Performance was assessed by simulations under different conditions, and indicated reliable results can be extracted by properly balancing overfitting and underfitting. An application to functional magnetic resonance images and single nucleotide polymorphism array produced interesting findings.

A visual parallel-BCI speller based on the time-frequency coding strategy

NASA Astrophysics Data System (ADS)

Xu, Minpeng; Chen, Long; Zhang, Lixin; Qi, Hongzhi; Ma, Lan; Tang, Jiabei; Wan, Baikun; Ming, Dong

2014-04-01

Objective. Spelling is one of the most important issues in brain-computer interface (BCI) research. This paper is to develop a visual parallel-BCI speller system based on the time-frequency coding strategy in which the sub-speller switching among four simultaneously presented sub-spellers and the character selection are identified in a parallel mode. Approach. The parallel-BCI speller was constituted by four independent P300+SSVEP-B (P300 plus SSVEP blocking) spellers with different flicker frequencies, thereby all characters had a specific time-frequency code. To verify its effectiveness, 11 subjects were involved in the offline and online spellings. A classification strategy was designed to recognize the target character through jointly using the canonical correlation analysis and stepwise linear discriminant analysis. Main results. Online spellings showed that the proposed parallel-BCI speller had a high performance, reaching the highest information transfer rate of 67.4 bit min-1, with an average of 54.0 bit min-1 and 43.0 bit min-1 in the three rounds and five rounds, respectively. Significance. The results indicated that the proposed parallel-BCI could be effectively controlled by users with attention shifting fluently among the sub-spellers, and highly improved the BCI spelling performance.

Structural control on the emplacement of contemporaneous Sn-Ta-Nb mineralized LCT pegmatites and Sn bearing quartz veins: Insights from the Musha and Ntunga deposits of the Karagwe-Ankole Belt, Rwanda

NASA Astrophysics Data System (ADS)

Hulsbosch, Niels; Van Daele, Johanna; Reinders, Nathan; Dewaele, Stijn; Jacques, Dominique; Muchez, Philippe

2017-10-01

The Nb-Ta-Sn pegmatites and Sn quartz veins of the Rwamagana-Musha-Ntunga area in eastern Rwanda are part of the Mesoproterozoic Karagwe-Ankole Belt. These commodities are on a regional scale spatiotemporally associated to the early Neoproterozoic fertile G4-granite generation. Although a transition from the lithium-cesium-tantalum pegmatites to cassiterite-microcline-quartz veins has been observed in the Rwamagana-Musha-Ntunga area, the structural control and the paragenetic relationship between the mineralized pegmatites and the Sn bearing quartz veins is largely unknown. Consequently, this study investigates the occurrence of pegmatites and quartz veins and the structural and lithological controls on their emplacement. The metasediments in the area are affected by a regional compressional regime with a shortening direction oriented N70E, which resulted in a N20W-oriented fold sequence. The Lake Muhazi granite is present in center of the Karehe anticline. The structural orientations of pegmatites and quartz veins show that two important factors control their emplacement. The first control is the reactivation of pre-existing discontinuities such as the bedding, bedding-parallel joints or strike-slip fault planes. In view of the regional structural grain in the Rwamagana-Musha-Ntunga area, this corresponds with abundant N20W-oriented pegmatites and quartz veins. The reactivation is strongly related to the lithology of the host rocks. The Musha Formation, which mainly consists of decimeter- to meter-scale lithological alternations of metapelite, metasiltstone and metasandstone, represents the most suitable environment for bedding reactivation. This is reflected in the predominance of bedding-parallel pegmatites and quartz veins hosted by the Musha Formation. Strike-parallel joints were mainly observed in the competent lithologies. The second controlling factor is related to the regional post-compressional stress regime. New joints initiated upon emplacement of the pegmatites and quartz veins. The orientations of these joints are influenced by the regional stress regime and resulted in steep EW-oriented pegmatites and quartz veins in the Rwamagana-Musha-Ntunga area. The pegmatites and quartz veins are interpreted as being initiated upon emplacement under influence of the prevailing regional stress regime. This post-compressional stress regime is characterized by a subvertical maximum compressive stress.

No mixing of granulocytes and other lymphocytes in the inflamed joints of parabiosis mice with collagen-induced arthritis: possible in situ generation

PubMed Central

Nishizawa, Tetsuro; Kawamura, Toshihiko; Izumi, Nakao; Kawamura, Hiroki; Fujii, Katsuyuki; Abo, Toru

2005-01-01

Collagen-induced arthritis was evoked by an injection of lipopolysaccharide and anti-type II collagen antibody in mice. In parallel with the onset of arthritis, granulocytes with large light scatter and a Mac-1+ Gr-1+ phenotype expanded in the joints of these mice. Lymphocytes with a CD3− B220+ phenotype (i.e. B220+ B cells) were the major population among lymphocyte subsets in the joints, irrespective of disease. To determine the origin of these leucocyte populations in the joints and other organs, parabiotic experiments using CBF1Ly5.1 and CBF1Ly5.2 mice were conducted in mice with and without collagen-induced arthritis. As expected, leucocyte populations in the liver and spleen became a half-and-half mixture of their own cells and partner cells (e.g. ∼45% of Ly5.1+ cells in Ly5.2+ partner mice). However, such a mixture was extremely delayed in the joints and bone marrow, even in mice with arthritis. These results suggest that, because circulatory blood is not exchanged in the joints, granulocytes and other lymphocytes are generated in situ in the inflamed joints of mice with collagen-induced arthritis or are possibly supplied by the bone marrow. It is of interest that granulocytes in the joints expanded, even without a supply from another site, namely, the synovium. PMID:15606803

A Lossless Multichannel Bio-Signal Compression Based on Low-Complexity Joint Coding Scheme for Portable Medical Devices

PubMed Central

Kim, Dong-Sun; Kwon, Jin-San

2014-01-01

Research on real-time health systems have received great attention during recent years and the needs of high-quality personal multichannel medical signal compression for personal medical product applications are increasing. The international MPEG-4 audio lossless coding (ALS) standard supports a joint channel-coding scheme for improving compression performance of multichannel signals and it is very efficient compression method for multi-channel biosignals. However, the computational complexity of such a multichannel coding scheme is significantly greater than that of other lossless audio encoders. In this paper, we present a multichannel hardware encoder based on a low-complexity joint-coding technique and shared multiplier scheme for portable devices. A joint-coding decision method and a reference channel selection scheme are modified for a low-complexity joint coder. The proposed joint coding decision method determines the optimized joint-coding operation based on the relationship between the cross correlation of residual signals and the compression ratio. The reference channel selection is designed to select a channel for the entropy coding of the joint coding. The hardware encoder operates at a 40 MHz clock frequency and supports two-channel parallel encoding for the multichannel monitoring system. Experimental results show that the compression ratio increases by 0.06%, whereas the computational complexity decreases by 20.72% compared to the MPEG-4 ALS reference software encoder. In addition, the compression ratio increases by about 11.92%, compared to the single channel based bio-signal lossless data compressor. PMID:25237900

Clinical and ultrasound findings in patients with calcium pyrophosphate dihydrate deposition disease.

PubMed

Vele, Paulina; Simon, Siao-Pin; Damian, Laura; Felea, Ioana; Muntean, Laura; Filipescu, Ileana; Rednic, Simona

2018-05-02

To evaluate the presence and distribution of calcium pyrophosphate (CPP) deposits in joints commonly affected by CPP deposition (CPPD) disease (acromio-clavicular, gleno-humeral, wrists, hips, knees, ankles, and symphysis pubis joints) using ultrasound (US). Thirty consecutive patients fulfilling McCarty diagnostic criteria for CPPD were consecutively enrolled in the study. The data registered using the US included the affected joints, the calcification site, and the pattern of calcification (thin hyperechoic bands, parallel to the surface of the hyaline cartilage, hyperechoic spots, and hyperechoic nodular or oval deposits). The presence of CPP crystals in knees was confirmed by polarized light microscopy examination of the synovial fluid and radiographs of the knees were performed in all patients. In 30 patients, 390 joints were scanned, (13 joints in every patient). The mean±standard deviation number of joints with US CPPD evidence per patient was 2.93±1.8 (range 1-9). The knee was the most common joint involved both clinically and using US examination. The second US pattern (with hyperechoic spots) was the most frequent. Fibrocartilage calcifications were more common than hyaline calcification. Using radiography as reference method, the sensitivity and specificity of US for diagnosis CPPD in knees was 79.31%, 95CI(66.65%-88.83%), and 14.29%, 95CI(1.78%-42.81%), respectively. The knee is the most frequent joint affected by CPPD. The second ultrasound pattern is the most common. CPPD affects the fibrocartilage to a greater extent than the hyaline cartilage.

From Togetherness to Equal Partnership in Role Play.

ERIC Educational Resources Information Center

Hannikainen, Maritta

1998-01-01

Explored different kinds of participation in play and development of joint role play. Observed games and play sessions of a 2-year-old girl in a day care group. Found that the girl proceeded from a feeling of togetherness in a shared space through parallel and successive play actions to reciprocity and equal exchange of play actions. (JPB)

Results of Arthroscopic Ankle Arthrodesis with Fixation Using Two Parallel Headless Compression Screws in a Heterogenic Group of Patients

PubMed Central

Kolodziej, Lukas; Sadlik, Boguslaw; Sokolowski, Sebastian; Bohatyrewicz, Andrzej

2017-01-01

Background: As orthopedic surgeons become skilled in ankle arthroscopy technique and evidence -based data is supporting its use, arthroscopic ankle arthrodesis (AAA) will likely continue to increase, but stabilization methods have not been described clearly. We present a technique for two parallel 7.3-mm headless compression screws fixation (HCSs) for AAA in cases of ankle arthritis with different etiology, both traumatic and non-traumatic, including neuromuscular and inflammatory patients. Materials and Methods: We retrospectively verified 24 consecutive patients (25 ankles) who underwent AAA between 2011 and 2015. The average follow-up was 26 months (range 18 to 52 months). Arthrodesis was performed in 16 patients due to posttraumatic arthritis (in 5 as a sequela of pilon, 6 ankles, 3 tibia fractures, and 2 had arthritis due to chronic instability after lateral ligament injury), in 4 patients due to neuromuscular ankle joint deformities, and in 4 patients due to rheumatoid arthritis. Results: Fusion occurred in 23 joints (92%) over an average of 12 weeks (range 6 to 18 weeks). Ankle arthrodesis was not achieved in 2 joints (8%), both in post-pilon fracture patients. The correct foot alignment was not achieved in 4 feet (16%). None of the treated patients required hardware removal. Conclusion: The presented technique was effective in achieving a high fusion rate in a variety of diseases, decreasing intra- and post-operative hardware complications while maintaining adequate bone stability. PMID:28400871

Error modeling and sensitivity analysis of a parallel robot with SCARA(selective compliance assembly robot arm) motions

NASA Astrophysics Data System (ADS)

Chen, Yuzhen; Xie, Fugui; Liu, Xinjun; Zhou, Yanhua

2014-07-01

Parallel robots with SCARA(selective compliance assembly robot arm) motions are utilized widely in the field of high speed pick-and-place manipulation. Error modeling for these robots generally simplifies the parallelogram structures included by the robots as a link. As the established error model fails to reflect the error feature of the parallelogram structures, the effect of accuracy design and kinematic calibration based on the error model come to be undermined. An error modeling methodology is proposed to establish an error model of parallel robots with parallelogram structures. The error model can embody the geometric errors of all joints, including the joints of parallelogram structures. Thus it can contain more exhaustively the factors that reduce the accuracy of the robot. Based on the error model and some sensitivity indices defined in the sense of statistics, sensitivity analysis is carried out. Accordingly, some atlases are depicted to express each geometric error's influence on the moving platform's pose errors. From these atlases, the geometric errors that have greater impact on the accuracy of the moving platform are identified, and some sensitive areas where the pose errors of the moving platform are extremely sensitive to the geometric errors are also figured out. By taking into account the error factors which are generally neglected in all existing modeling methods, the proposed modeling method can thoroughly disclose the process of error transmission and enhance the efficacy of accuracy design and calibration.

A review of multivariate methods in brain imaging data fusion

NASA Astrophysics Data System (ADS)

Sui, Jing; Adali, Tülay; Li, Yi-Ou; Yang, Honghui; Calhoun, Vince D.

2010-03-01

On joint analysis of multi-task brain imaging data sets, a variety of multivariate methods have shown their strengths and been applied to achieve different purposes based on their respective assumptions. In this paper, we provide a comprehensive review on optimization assumptions of six data fusion models, including 1) four blind methods: joint independent component analysis (jICA), multimodal canonical correlation analysis (mCCA), CCA on blind source separation (sCCA) and partial least squares (PLS); 2) two semi-blind methods: parallel ICA and coefficient-constrained ICA (CC-ICA). We also propose a novel model for joint blind source separation (BSS) of two datasets using a combination of sCCA and jICA, i.e., 'CCA+ICA', which, compared with other joint BSS methods, can achieve higher decomposition accuracy as well as the correct automatic source link. Applications of the proposed model to real multitask fMRI data are compared to joint ICA and mCCA; CCA+ICA further shows its advantages in capturing both shared and distinct information, differentiating groups, and interpreting duration of illness in schizophrenia patients, hence promising applicability to a wide variety of medical imaging problems.

An 8-DOF dual-arm system for advanced teleoperation performance experiments

NASA Technical Reports Server (NTRS)

Bejczy, Antal K.; Szakaly, Zoltan F.

1992-01-01

This paper describes the electro-mechanical and control features of an 8-DOF manipulator manufactured by AAI Corporation and installed at the Jet Propulsion Lab. (JPL) in a dual-arm setting. The 8-DOF arm incorporates a variety of features not found in other lab or industrial manipulators. Some of the unique features are: 8-DOF revolute configuration with no lateral offsets at joint axes; 1 to 5 payload to weight ratio with 20 kg (44 lb) payload at a 1.75 m (68.5 in.) reach; joint position measurement with dual relative encoders and potentiometer; infinite roll of joint 8 with electrical and fiber optic slip rings; internal fiber optic link of 'smart' end effectors; four-axis wrist; graphite epoxy links; high link and joint stiffness; use of an upgraded JPL Universal Motor Controller (UMC) capable of driving up to 16 joints. The 8-DOF arm is equipped with a 'smart' end effector which incorporates a 6-DOF forcemoment sensor at the end effector base and grasp force sensors at the base of the parallel jaws. The 8-DOF arm is interfaced to a 6 DOF force reflecting hand controller. The same system is duplicated for and installed at NASA-Langley.

Implications of genome wide association studies for addiction: are our a priori assumptions all wrong?

PubMed

Hall, F Scott; Drgonova, Jana; Jain, Siddharth; Uhl, George R

2013-12-01

Substantial genetic contributions to addiction vulnerability are supported by data from twin studies, linkage studies, candidate gene association studies and, more recently, Genome Wide Association Studies (GWAS). Parallel to this work, animal studies have attempted to identify the genes that may contribute to responses to addictive drugs and addiction liability, initially focusing upon genes for the targets of the major drugs of abuse. These studies identified genes/proteins that affect responses to drugs of abuse; however, this does not necessarily mean that variation in these genes contributes to the genetic component of addiction liability. One of the major problems with initial linkage and candidate gene studies was an a priori focus on the genes thought to be involved in addiction based upon the known contributions of those proteins to drug actions, making the identification of novel genes unlikely. The GWAS approach is systematic and agnostic to such a priori assumptions. From the numerous GWAS now completed several conclusions may be drawn: (1) addiction is highly polygenic; each allelic variant contributing in a small, additive fashion to addiction vulnerability; (2) unexpected, compared to our a priori assumptions, classes of genes are most important in explaining addiction vulnerability; (3) although substantial genetic heterogeneity exists, there is substantial convergence of GWAS signals on particular genes. This review traces the history of this research; from initial transgenic mouse models based upon candidate gene and linkage studies, through the progression of GWAS for addiction and nicotine cessation, to the current human and transgenic mouse studies post-GWAS. © 2013.

Contribution of GLC3A locus to Primary Congenital Glaucoma in Pakistani population.

PubMed

Bashir, Rasheeda; Sanai, Mahrukh; Azeem, Adnan; Altaf, Imran; Saleem, Faiza; Naz, Sadaf

2014-01-01

To check the contribution of GLC3A locus to primary congenital glaucoma in the Pakistani population. We enrolled twenty-nine sporadic cases and three families with multiple individuals affected with recessive primary congenital glaucoma in the year 2013. It was a genetic linkage study accomplished jointly in Department of Biotechnology of Lahore College for Women University and School of Biological Sciences, University of the Punjab, Lahore. Samples from all affected individuals were checked for homozygosity for alleles of microsatellite markers spanning CYP1B1 at GLC3A locus. Genotyping was performed with fluorescently labeled primers by capillary electrophoresis. For familial cases, linkage was evaluated by checking the co-segregation of the phenotype with the genotypes. Two-point LOD score was calculated for each microsatellite marker with MLINK. Our study revealed that GLCA3 may contribute to glaucoma in 17% of the sporadic cases and patients in 2 of the 3 families. This data suggests that the GLC3A may make an important contribution to autosomal recessive primary congenital glaucoma in the Pakistani population. Genotyping and Sequencing of more families will be helpful to identify the common mutations in CYP1B1 in future.

Optimization of vehicle-trailer connection systems

NASA Astrophysics Data System (ADS)

Sorge, F.

2016-09-01

The three main requirements of a vehicle-trailer connection system are: en route stability, over- or under-steering restraint, minimum off-tracking along curved path. Linking the two units by four-bar trapeziums, wider stability margins may be attained in comparison with the conventional pintle-hitch for both instability types, divergent or oscillating. The stability maps are traced applying the Hurwitz method or the direct analysis of the characteristic equation at the instability threshold. Several types of four-bar linkages may be quickly tested, with the drawbars converging towards the trailer or the towing unit. The latter configuration appears preferable in terms of self-stability and may yield high critical speeds by optimising the geometrical and physical properties. Nevertheless, the system stability may be improved in general by additional vibration dampers in parallel with the connection linkage. Moreover, the four-bar connection may produce significant corrections of the under-steering or over-steering behaviour of the vehicle-train after a steering command from the driver. The off- tracking along the curved paths may be also optimized or kept inside prefixed margins of acceptableness. Activating electronic stability systems if necessary, fair results are obtainable for both the steering conduct and the off-tracking.

A passive exoskeleton with artificial tendons: design and experimental evaluation.

PubMed

van Dijk, Wietse; van der Kooij, Herman; Hekman, Edsko

2011-01-01

We developed a passive exoskeleton that was designed to minimize joint work during walking. The exoskeleton makes use of passive structures, called artificial tendons, acting in parallel with the leg. Artificial tendons are elastic elements that are able to store and redistribute energy over the human leg joints. The elastic characteristics of the tendons have been optimized to minimize the mechanical work of the human leg joints. In simulation the maximal reduction was 40 percent. The performance of the exoskeleton was evaluated in an experiment in which nine subjects participated. Energy expenditure and muscle activation were measured during three conditions: Normal walking, walking with the exoskeleton without artificial tendons, and walking with the exoskeleton with the artificial tendons. Normal walking was the most energy efficient. While walking with the exoskeleton, the artificial tendons only resulted in a negligibly small decrease in energy expenditure. © 2011 IEEE

Fault and joint geometry at Raft River Geothermal Area, Idaho

NASA Astrophysics Data System (ADS)

Guth, L. R.; Bruhn, R. L.; Beck, S. L.

1981-07-01

Raft River geothermal reservoir is formed by fractures in sedimentary strata of the Miocene and Pliocene salt lake formation. The fracturing is most intense at the base of the salt lake formation, along a decollement that dips eastward at less than 50 on top of metamorphosed precambrian and lower paleozoic rocks. Core taken from less than 200 m above the decollement contains two sets of normal faults. The major set of faults dips between 500 and 700. These faults occur as conjugate pairs that are bisected by vertical extension fractures. The second set of faults dips 100 to 200 and may parallel part of the basal decollement or reflect the presence of listric normal faults in the upper plate. Surface joints form two suborthogonal sets that dip vertically. East-northeast-striking joints are most frequent on the limbs of the Jim Sage anticline, a large fold that is associated with the geothermal field.

Wnt10b and Dkk-1 gene therapy differentially influenced trabecular bone architecture, soft tissue integrity, and osteophytosis in a skeletally mature rat model of osteoarthritis.

PubMed

Mason, Jeffrey B; Gurda, Brittney L; Hankenson, Kurt D; Harper, Lindsey R; Carlson, Cathy S; Wilson, James M; Richardson, Dean W

2017-11-01

Our goals in the current experiments were to determine if (a) upregulation of Wnt signaling would induce osteoarthritis changes in stable stifle joints and (b) if downregulation of Wnt signaling in destabilized joints would influence the progression of OA. At 37 weeks of age, rats were injected in the stifle joint with a recombinant adeno-associated viral vector containing the Wnt-inhibitor Dkk-1 or a Wnt10b transgene. At 40 weeks of age, rats underwent surgical destabilization of the joint. At 50 weeks of age, stifle joints were submitted for micro-computed tomography and histopathological analysis. Injection of either Wnt10b or Dkk-1 transgenes in stable joints improved bone architectural parameters, but worsened soft tissue integrity. Osteophytosis was decreased by Dkk-1, but unchanged by Wnt10b. Destabilization negatively influenced bone architecture, increased osteophytosis, and decreased soft tissue integrity. Dkk-1 exacerbated the negative effects of destabilization, whereas Wnt10b had little effect on these parameters. Osteophytosis was improved, whereas soft tissue integrity was worsened by both transgenes in destabilized joints. The Wnt-inhibitor Dkk-1 does not appear to completely inhibit the effects of Wnt signaling on bone remodeling. In vivo upregulation of Wnt10b and its inhibitor, Dkk-1, can produce both parallel or contrasting phenotypic responses depending on the specific parameter measured and the fidelity of the examined joint. These observations elucidate different roles for Wnt signaling in stable versus destabilized joints and may help to explain the conflicting results previously reported for the role of Dkk-1 in joint disease.

High Performance Computing Based Parallel HIearchical Modal Association Clustering (HPAR HMAC)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patlolla, Dilip R; Surendran Nair, Sujithkumar; Graves, Daniel A.

For many applications, clustering is a crucial step in order to gain insight into the makeup of a dataset. The best approach to a given problem often depends on a variety of factors, such as the size of the dataset, time restrictions, and soft clustering requirements. The HMAC algorithm seeks to combine the strengths of 2 particular clustering approaches: model-based and linkage-based clustering. One particular weakness of HMAC is its computational complexity. HMAC is not practical for mega-scale data clustering. For high-definition imagery, a user would have to wait months or years for a result; for a 16-megapixel image, themore » estimated runtime skyrockets to over a decade! To improve the execution time of HMAC, it is reasonable to consider an multi-core implementation that utilizes available system resources. An existing imple-mentation (Ray and Cheng 2014) divides the dataset into N partitions - one for each thread prior to executing the HMAC algorithm. This implementation benefits from 2 types of optimization: parallelization and divide-and-conquer. By running each partition in parallel, the program is able to accelerate computation by utilizing more system resources. Although the parallel implementation provides considerable improvement over the serial HMAC, it still suffers from poor computational complexity, O(N2). Once the maximum number of cores on a system is exhausted, the program exhibits slower behavior. We now consider a modification to HMAC that involves a recursive partitioning scheme. Our modification aims to exploit divide-and-conquer benefits seen by the parallel HMAC implementation. At each level in the recursion tree, partitions are divided into 2 sub-partitions until a threshold size is reached. When the partition can no longer be divided without falling below threshold size, the base HMAC algorithm is applied. This results in a significant speedup over the parallel HMAC.« less

Load Variation Influences on Joint Work During Squat Exercise in Reduced Gravity

NASA Technical Reports Server (NTRS)

DeWitt, John K.; Fincke, Renita S.; Logan, Rachel L.; Guilliams, Mark E.; Ploutz-Snyder, Lori L.

2011-01-01

Resistance exercises that load the axial skeleton, such as the parallel squat, are incorporated as a critical component of a space exercise program designed to maximize the stimuli for bone remodeling and muscle loading. Astronauts on the International Space Station perform regular resistance exercise using the Advanced Resistive Exercise Device (ARED). Squat exercises on Earth entail moving a portion of the body weight plus the added bar load, whereas in microgravity the body weight is 0, so all load must be applied via the bar. Crewmembers exercising in microgravity currently add approx.70% of their body weight to the bar load as compensation for the absence of the body weight. This level of body weight replacement (BWR) was determined by crewmember feedback and personal experience without any quantitative data. The purpose of this evaluation was to utilize computational simulation to determine the appropriate level of BWR in microgravity necessary to replicate lower extremity joint work during squat exercise in normal gravity based on joint work. We hypothesized that joint work would be positively related to BWR load.

Hand-handle interface force and torque measurement system for pneumatic assembly tool operations: suggested enhancement to ISO 6544.

PubMed

Lin, Jia-Hua; McGorry, Raymond W; Chang, Chien-Chi

2007-05-01

A hand-handle interface force and torque measurement system is introduced to fill the void acknowledged in the international standard ISO 6544, which governs pneumatic, assembly tool reaction torque and force measurement. This system consists of an instrumented handle with a sensor capable of measuring grip force and reaction hand moment when threaded, fastener-driving tools are used by operators. The handle is rigidly affixed to the tool in parallel to the original tool handle allowing normal fastener-driving operations with minimal interference. Demonstration of this proposed system was made with tools of three different shapes: pistol grip, right angle, and in-line. During tool torque buildup, the proposed system measured operators exerting greater grip force on the soft joint than on the hard joint. The system also demonstrated that the soft joint demanded greater hand moment impulse than the hard joint. The results demonstrate that the measurement system can provide supplemental data useful in exposure assessment with power hand tools as proposed in ISO 6544.

Shear Strength and Cracking Process of Non-persistent Jointed Rocks: An Extensive Experimental Investigation

NASA Astrophysics Data System (ADS)

Asadizadeh, Mostafa; Moosavi, Mahdi; Hossaini, Mohammad Farouq; Masoumi, Hossein

2018-02-01

In this paper, a number of artificial rock specimens with two parallel (stepped and coplanar) non-persistent joints were subjected to direct shearing. The effects of bridge length ( L), bridge angle ( γ), joint roughness coefficient (JRC) and normal stress ( σ n) on shear strength and cracking process of non-persistent jointed rock were studied extensively. The experimental program was designed based on Taguchi method, and the validity of the resulting data was assessed using analysis of variance. The results revealed that σ n and γ have the maximum and minimum effects on shear strength, respectively. Also, increase in L from 10 to 60 mm led to decrease in shear strength where high level of JRC profile and σ n led to the initiation of tensile cracks due to asperity interlocking. Such tensile cracks are known as "interlocking cracks" which normally initiate from the asperity and then propagate toward the specimen boundaries. Finally, the cracking process of specimens was classified into three categories, namely tensile cracking, shear cracking and combination of tension and shear or mixed mode tensile-shear cracking.

Providing a parallel and distributed capability for JMASS using SPEEDES

NASA Astrophysics Data System (ADS)

Valinski, Maria; Driscoll, Jonathan; McGraw, Robert M.; Meyer, Bob

2002-07-01

The Joint Modeling And Simulation System (JMASS) is a Tri-Service simulation environment that supports engineering and engagement-level simulations. As JMASS is expanded to support other Tri-Service domains, the current set of modeling services must be expanded for High Performance Computing (HPC) applications by adding support for advanced time-management algorithms, parallel and distributed topologies, and high speed communications. By providing support for these services, JMASS can better address modeling domains requiring parallel computationally intense calculations such clutter, vulnerability and lethality calculations, and underwater-based scenarios. A risk reduction effort implementing some HPC services for JMASS using the SPEEDES (Synchronous Parallel Environment for Emulation and Discrete Event Simulation) Simulation Framework has recently concluded. As an artifact of the JMASS-SPEEDES integration, not only can HPC functionality be brought to the JMASS program through SPEEDES, but an additional HLA-based capability can be demonstrated that further addresses interoperability issues. The JMASS-SPEEDES integration provided a means of adding HLA capability to preexisting JMASS scenarios through an implementation of the standard JMASS port communication mechanism that allows players to communicate.

Multi-GPU parallel algorithm design and analysis for improved inversion of probability tomography with gravity gradiometry data

NASA Astrophysics Data System (ADS)

Hou, Zhenlong; Huang, Danian

2017-09-01

In this paper, we make a study on the inversion of probability tomography (IPT) with gravity gradiometry data at first. The space resolution of the results is improved by multi-tensor joint inversion, depth weighting matrix and the other methods. Aiming at solving the problems brought by the big data in the exploration, we present the parallel algorithm and the performance analysis combining Compute Unified Device Architecture (CUDA) with Open Multi-Processing (OpenMP) based on Graphics Processing Unit (GPU) accelerating. In the test of the synthetic model and real data from Vinton Dome, we get the improved results. It is also proved that the improved inversion algorithm is effective and feasible. The performance of parallel algorithm we designed is better than the other ones with CUDA. The maximum speedup could be more than 200. In the performance analysis, multi-GPU speedup and multi-GPU efficiency are applied to analyze the scalability of the multi-GPU programs. The designed parallel algorithm is demonstrated to be able to process larger scale of data and the new analysis method is practical.

Rock face stability analysis and potential rockfall source detection in Yosemite Valley

NASA Astrophysics Data System (ADS)

Matasci, B.; Stock, G. M.; Jaboyedoff, M.; Oppikofer, T.; Pedrazzini, A.; Carrea, D.

2012-04-01

Rockfall hazard in Yosemite Valley is especially high owing to the great cliff heights (~1 km), the fracturing of the steep granitic cliffs, and the widespread occurrence of surface parallel sheeting or exfoliation joints. Between 1857 and 2011, 890 documented rockfalls and other slope movements caused 15 fatalities and at least 82 injuries. The first part of this study focused on realizing a structural study for Yosemite Valley at both regional (valley-wide) and local (rockfall source area) scales. The dominant joint sets were completely characterized by their orientation, persistence, spacing, roughness and opening. Spacing and trace length for each joint set were accurately measured on terrestrial laser scanning (TLS) point clouds with the software PolyWorks (InnovMetric). Based on this fundamental information the second part of the study aimed to detect the most important failure mechanisms leading to rockfalls. With the software Matterocking and the 1m cell size DEM, we calculated the number of possible failure mechanisms (wedge sliding, planar sliding, toppling) per cell, for several cliffs of the valley. Orientation, spacing and persistence measurements directly issued from field and TLS data were inserted in the Matterocking calculations. TLS point clouds are much more accurate than the 1m DEM and show the overhangs of the cliffs. Accordingly, with the software Coltop 3D we developed a methodology similar to the one used with Matterocking to identify on the TLS point clouds the areas of a cliff with the highest number of failure mechanisms. Exfoliation joints are included in this stability analysis in the same way as the other joint sets, with the only difference that their orientation is parallel to the local cliff orientation and thus variable. This means that, in two separate areas of a cliff, the exfoliation joint set is taken into account with different dip direction and dip, but its effect on the stability assessment is the same. Areas with a high density of possible failure mechanisms are shown to be more susceptible to rockfalls, demonstrating a link between high fracture density and rockfall susceptibility. This approach enables locating the most probable future rockfall sources and provides key elements needed to evaluate the potential volume and run-out distance of rockfall blocks. This information is used to improve rockfall hazard assessment in Yosemite Valley and elsewhere.

Introduction to the special issue on the joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics.

PubMed

Tsurumi, Takaaki

2011-09-01

The joint meeting of the 19th IEEE International Symposium on the Applications of Ferroelectrics and the 10th European Conference on the Applications of Polar Dielectrics took place in Edinburgh from August 9-12, 2010. The conference was attended by 390 delegates from more than 40 different countries. There were 4 plenary speakers, 56 invited speakers, and a further 222 contributed oral presentations in 7 parallel session. In addition there were 215 poster presentations. Key topics addressed at the conference included piezoelectric materials, leadfree piezoelectrics, and multiferroics.

Enhanced secure 4-D modulation space optical multi-carrier system based on joint constellation and Stokes vector scrambling.

PubMed

Liu, Bo; Zhang, Lijia; Xin, Xiangjun

2018-03-19

This paper proposes and demonstrates an enhanced secure 4-D modulation optical generalized filter bank multi-carrier (GFBMC) system based on joint constellation and Stokes vector scrambling. The constellation and Stokes vectors are scrambled by using different scrambling parameters. A multi-scroll Chua's circuit map is adopted as the chaotic model. Large secure key space can be obtained due to the multi-scroll attractors and independent operability of subcarriers. A 40.32Gb/s encrypted optical GFBMC signal with 128 parallel subcarriers is successfully demonstrated in the experiment. The results show good resistance against the illegal receiver and indicate a potential way for the future optical multi-carrier system.

Neural controller for adaptive movements with unforeseen payloads.

PubMed

Kuperstein, M; Wang, J

1990-01-01

A theory and computer simulation of a neural controller that learns to move and position a link carrying an unforeseen payload accurately are presented. The neural controller learns adaptive dynamic control from its own experience. It does not use information about link mass, link length, or direction of gravity, and it uses only indirect uncalibrated information about payload and actuator limits. Its average positioning accuracy across a large range of payloads after learning is 3% of the positioning range. This neural controller can be used as a basis for coordinating any number of sensory inputs with limbs of any number of joints. The feedforward nature of control allows parallel implementation in real time across multiple joints.

Assessment of modification factors for a row of bolts or timber connectors

Treesearch

Thomas Lee Wilkinson

1980-01-01

When bolts or timber connectors are used in a row, with load applied parallel to the row, load will be unequally distributed among the fasteners. This study assessed methods of predicting this unequal load distribution, looked at how joint variables can affect the distribution, and compared the predictions with data existing in the literature. Presently used design...

Final Report: PAGE: Policy Analytics Generation Engine

DTIC Science & Technology

2016-08-12

develop a parallel framework for it. We also developed policies and methods by which a group of defensive resources (e.g. checkpoints) could be...Sarit Kraus. Learning to Reveal Information in Repeated Human -Computer Negotiation, Human -Agent Interaction Design and Models Workshop 2012. 04-JUN...Joseph Keshet, Sarit Kraus. Predicting Human Strategic Decisions Using Facial Expressions, International Joint Conference on Artificial

Joint Services Electronics Program

DTIC Science & Technology

1992-03-05

Packaging Considerations M. T. Raghunath (Professor Abhiram Ranade) A central issue in massively parallel computation is the design of the interconnection...programs on promising network architectures. Publications: [1] M. T. Raghunath and A. G. Ranade, A Simulation-Based Compari- son of Interconnection Networks...more difficult analog function approximation task. Network Design Issues for Fast Global Communication Professor A. Ranade with M.T. Raghunath A

Overview 1993: Computational applications

NASA Technical Reports Server (NTRS)

Benek, John A.

1993-01-01

Computational applications include projects that apply or develop computationally intensive computer programs. Such programs typically require supercomputers to obtain solutions in a timely fashion. This report describes two CSTAR projects involving Computational Fluid Dynamics (CFD) technology. The first, the Parallel Processing Initiative, is a joint development effort and the second, the Chimera Technology Development, is a transfer of government developed technology to American industry.

Integrated configurable equipment selection and line balancing for mass production with serial-parallel machining systems

NASA Astrophysics Data System (ADS)

Battaïa, Olga; Dolgui, Alexandre; Guschinsky, Nikolai; Levin, Genrikh

2014-10-01

Solving equipment selection and line balancing problems together allows better line configurations to be reached and avoids local optimal solutions. This article considers jointly these two decision problems for mass production lines with serial-parallel workplaces. This study was motivated by the design of production lines based on machines with rotary or mobile tables. Nevertheless, the results are more general and can be applied to assembly and production lines with similar structures. The designers' objectives and the constraints are studied in order to suggest a relevant mathematical model and an efficient optimization approach to solve it. A real case study is used to validate the model and the developed approach.

Nonlinear PP and PS joint inversion based on the exact Zoeppritz equations: a two-stage procedure

NASA Astrophysics Data System (ADS)

Zhi, Lixia; Chen, Shuangquan; Song, Baoshan; Li, Xiang-yang

2018-04-01

S-velocity and density are very important parameters in distinguishing lithology and estimating other petrophysical properties. A reliable estimate of S-velocity and density is very difficult to obtain, even from long-offset gather data. Joint inversion of PP and PS data provides a promising strategy for stabilizing and improving the results of inversion in estimating elastic parameters and density. For 2D or 3D inversion, the trace-by-trace strategy is still the most widely used method although it often suffers from a lack of clarity because of its high efficiency, which is due to parallel computing. This paper describes a two-stage inversion method for nonlinear PP and PS joint inversion based on the exact Zoeppritz equations. There are several advantages for our proposed methods as follows: (1) Thanks to the exact Zoeppritz equation, our joint inversion method is applicable for wide angle amplitude-versus-angle inversion; (2) The use of both P- and S-wave information can further enhance the stability and accuracy of parameter estimation, especially for the S-velocity and density; (3) The two-stage inversion procedure proposed in this paper can achieve a good compromise between efficiency and precision. On the one hand, the trace-by-trace strategy used in the first stage can be processed in parallel so that it has high computational efficiency. On the other hand, to deal with the indistinctness of and undesired disturbances to the inversion results obtained from the first stage, we apply the second stage—total variation (TV) regularization. By enforcing spatial and temporal constraints, the TV regularization stage deblurs the inversion results and leads to parameter estimation with greater precision. Notably, the computation consumption of the TV regularization stage can be ignored compared to the first stage because it is solved using the fast split Bregman iterations. Numerical examples using a well log and the Marmousi II model show that the proposed joint inversion is a reliable method capable of accurately estimating the density parameter as well as P-wave velocity and S-wave velocity, even when the seismic data is noisy with signal-to-noise ratio of 5.

Evaluating Intra-Articular Drug Delivery for the Treatment of Osteoarthritis in a Rat Model

PubMed Central

Allen, Kyle D.; Adams, Samuel B.

2010-01-01

Osteoarthritis (OA) is a degenerative joint disease that can result in joint pain, loss of joint function, and deleterious effects on activity levels and lifestyle habits. Current therapies for OA are largely aimed at symptomatic relief and may have limited effects on the underlying cascade of joint degradation. Local drug delivery strategies may provide for the development of more successful OA treatment outcomes that have potential to reduce local joint inflammation, reduce joint destruction, offer pain relief, and restore patient activity levels and joint function. As increasing interest turns toward intra-articular drug delivery routes, parallel interest has emerged in evaluating drug biodistribution, safety, and efficacy in preclinical models. Rodent models provide major advantages for the development of drug delivery strategies, chiefly because of lower cost, successful replication of human OA-like characteristics, rapid disease development, and small joint volumes that enable use of lower total drug amounts during protocol development. These models, however, also offer the potential to investigate the therapeutic effects of local drug therapy on animal behavior, including pain sensitivity thresholds and locomotion characteristics. Herein, we describe a translational paradigm for the evaluation of an intra-articular drug delivery strategy in a rat OA model. This model, a rat interleukin-1β overexpression model, offers the ability to evaluate anti-interleukin-1 therapeutics for drug biodistribution, activity, and safety as well as the therapeutic relief of disease symptoms. Once the action against interleukin-1 is confirmed in vivo, the newly developed anti-inflammatory drug can be evaluated for evidence of disease-modifying effects in more complex preclinical models. PMID:19943805

Social and spatial processes associated with childhood diarrheal disease in Matlab, Bangladesh.

PubMed

Perez-Heydrich, Carolina; Furgurson, Jill M; Giebultowicz, Sophia; Winston, Jennifer J; Yunus, Mohammad; Streatfield, Peter Kim; Emch, Michael

2013-01-01

We develop novel methods for conceptualizing geographic space and social networks to evaluate their respective and combined contributions to childhood diarrheal incidence. After defining maternal networks according to direct familial linkages between females, and road networks using satellite imagery of the study area, we use a spatial econometrics model to evaluate the significance of correlation terms relating childhood diarrheal incidence to the incidence observed within respective networks. Disease was significantly clustered within road networks across time, but only inconsistently correlated within maternal networks. These methods could be widely applied to systems in which both social and spatial processes jointly influence health outcomes. Copyright © 2012 Elsevier Ltd. All rights reserved.

Cycle life machine for AX-5 space suit

NASA Technical Reports Server (NTRS)

Schenberger, Deborah S.

1990-01-01

In order to accurately test the AX-5 space suit, a complex series of motions needed to be performed which provided a unique opportunity for mechanism design. The cycle life machine design showed how 3-D computer images can enhance mechanical design as well as help in visualizing mechanisms before manufacturing them. In the early stages of the design, potential problems in the motion of the joint and in the four bar linkage system were resolved using CAD. Since these problems would have been very difficult and tedious to solve on a drawing board, they would probably not have been addressed prior to fabrication, thus limiting the final design or requiring design modification after fabrication.

Influence of urban morphology on total noise pollution: multifractal description.

PubMed

Ariza-Villaverde, Ana B; Jiménez-Hornero, Francisco J; Gutiérrez De Ravé, Eduardo

2014-02-15

Exposure to ambient noise levels above 65 dB can cause public health problems. The spatial distribution of this kind of pollution is linked to various elements which make up the urban form, such as construction density, the existence of open spaces and the shape and physical position of buildings. Since urban morphology displays multifractal behaviour, the present research studies for the first time the relationship between total noise pollution and urban features, such as street width and building height by means of a joint multifractal spectrum in two neighbourhoods of the city of Cordoba (Andalusia, Spain). According to the results, the joint multifractal spectrum reveals a positive correlation between the total noise pollution and the street width to building height ratio, this being more evident when urban morphology is regular. The information provided by the multifractal analysis completes the description obtained by using urban indexes and landscape metrics and might be useful for urban planning once the linkage between both frameworks has been done. Copyright © 2013 Elsevier B.V. All rights reserved.

Experimental Study of Hybrid Fractures and the Transition From Joints to Faults

NASA Astrophysics Data System (ADS)

Ramsey, J. M.; Chester, F. M.

2003-12-01

Joints and faults are end members of a continuous spectrum of brittle fractures including the hybrid fractures, hypothesized to form under mixed compressive and tensile stress. However, unequivocal evidence for the existence of hybrid fractures has not been presented. To investigate this transition, we have conducted triaxial extension experiments on dog-bone shaped cylindrical samples of Carrara marble at room temperature, an axial extension rate of 2x10-2 mm s-1, and confining pressures between 7.5 and 170 MPa. Two parallel suites of experiments were completed, one using very weak, latex jacketing to obtain accurate failure strength, and another using copper foil jacketing to preserve fracture surfaces. The combined data set provides strong evidence for the existence of hybrid fractures on the basis of the progressive change in failure strength, fracture orientation, and fracture surface morphology from joints to faults. At the lowest confining pressures (7.5 to 60 MPa), fractures are oriented approximately parallel to the maximum principal compressive stress, form at a tensile axial stress of approximately -7.75 MPa (i.e. the uniaxial tensile strength), and display fracture surfaces characterized by many reflective grain-scale cleavage faces, consistent with jointing. At the highest confining pressures (130 to 170 MPa), fractures are oriented from 13.4 to 21.6 degrees to the maximum principal compressive stress, form under completely compressive stress states where the axial stress is between 0 and 4.3 MPa, and are characterized by short slip lineations and powdery, finely comminuted grains consistent with faulting. At intermediate confining pressures (70 to 120 MPa), fractures are oriented from 3.7 to 12.4 degrees to the maximum principal compressive stress, form under mixed stress conditions with the axial stress ranging from -10.6 to -3.0 MPa, and display both reflective cleavage faces and short slip lineations with comminuted grains, consistent with hybrid fracturing.

Toward the identification of causal genes in complex diseases: a gene-centric joint test of significance combining genomic and transcriptomic data.

PubMed

Charlesworth, Jac C; Peralta, Juan M; Drigalenko, Eugene; Göring, Harald Hh; Almasy, Laura; Dyer, Thomas D; Blangero, John

2009-12-15

Gene identification using linkage, association, or genome-wide expression is often underpowered. We propose that formal combination of information from multiple gene-identification approaches may lead to the identification of novel loci that are missed when only one form of information is available. Firstly, we analyze the Genetic Analysis Workshop 16 Framingham Heart Study Problem 2 genome-wide association data for HDL-cholesterol using a "gene-centric" approach. Then we formally combine the association test results with genome-wide transcriptional profiling data for high-density lipoprotein cholesterol (HDL-C), from the San Antonio Family Heart Study, using a Z-transform test (Stouffer's method). We identified 39 genes by the joint test at a conservative 1% false-discovery rate, including 9 from the significant gene-based association test and 23 whose expression was significantly correlated with HDL-C. Seven genes identified as significant in the joint test were not independently identified by either the association or expression tests. This combined approach has increased power and leads to the direct nomination of novel candidate genes likely to be involved in the determination of HDL-C levels. Such information can then be used as justification for a more exhaustive search for functional sequence variation within the nominated genes. We anticipate that this type of analysis will improve our speed of identification of regulatory genes causally involved in disease risk.

TIMEDELN: A programme for the detection and parametrization of overlapping resonances using the time-delay method

NASA Astrophysics Data System (ADS)

Little, Duncan A.; Tennyson, Jonathan; Plummer, Martin; Noble, Clifford J.; Sunderland, Andrew G.

2017-06-01

TIMEDELN implements the time-delay method of determining resonance parameters from the characteristic Lorentzian form displayed by the largest eigenvalues of the time-delay matrix. TIMEDELN constructs the time-delay matrix from input K-matrices and analyses its eigenvalues. This new version implements multi-resonance fitting and may be run serially or as a high performance parallel code with three levels of parallelism. TIMEDELN takes K-matrices from a scattering calculation, either read from a file or calculated on a dynamically adjusted grid, and calculates the time-delay matrix. This is then diagonalized, with the largest eigenvalue representing the longest time-delay experienced by the scattering particle. A resonance shows up as a characteristic Lorentzian form in the time-delay: the programme searches the time-delay eigenvalues for maxima and traces resonances when they pass through different eigenvalues, separating overlapping resonances. It also performs the fitting of the calculated data to the Lorentzian form and outputs resonance positions and widths. Any remaining overlapping resonances can be fitted jointly. The branching ratios of decay into the open channels can also be found. The programme may be run serially or in parallel with three levels of parallelism. The parallel code modules are abstracted from the main physics code and can be used independently.

Genetic variants associated with susceptibility to psychosis in late-onset Alzheimer's disease families.

PubMed

Barral, Sandra; Vardarajan, Badri N; Reyes-Dumeyer, Dolly; Faber, Kelley M; Bird, Thomas D; Tsuang, Debby; Bennett, David A; Rosenberg, Roger; Boeve, Bradley F; Graff-Radford, Neill R; Goate, Alison M; Farlow, Martin; Lantigua, Rafael; Medrano, Martin Z; Wang, Xinbing; Kamboh, M Ilyas; Barmada, Mahmud Muhiedine; Schaid, Daniel J; Foroud, Tatiana M; Weamer, Elise A; Ottman, Ruth; Sweet, Robert A; Mayeux, Richard

2015-11-01

Psychotic symptoms are frequent in late-onset Alzheimer's disease (LOAD) patients. Although the risk for psychosis in LOAD is genetically mediated, no genes have been identified. To identify loci potentially containing genetic variants associated with risk of psychosis in LOAD, a total of 263 families from the National Institute of Aging-LOAD cohort were classified into psychotic (LOAD+P, n = 215) and nonpsychotic (LOAD-P, n = 48) families based on the presence/absence of psychosis during the course of LOAD. The LOAD+P families yielded strong evidence of linkage on chromosome 19q13 (two-point [2-pt] ​logarithm of odds [LOD] = 3.8, rs2285513 and multipoint LOD = 2.7, rs541169). Joint linkage and association in 19q13 region detected strong association with rs2945988 (p = 8.7 × 10(-7)). Linkage results for the LOAD-P families yielded nonsignificant 19q13 LOD scores. Several 19q13 single-nucleotide polymorphisms generalized the association of LOAD+P in a Caribbean Hispanic (CH) cohort, and the strongest signal was rs10410711 (pmeta = 5.1 × 10(-5)). A variant located 24 kb upstream of rs10410711 and rs10421862 was strongly associated with LOAD+P (pmeta = 1.0 × 10(-5)) in a meta-analysis of the CH cohort and an additional non-Hispanic Caucasian dataset. Identified variants rs2945988 and rs10421862 affect brain gene expression levels. Our results suggest that genetic variants in genes on 19q13, some of which are involved in brain development and neurodegeneration, may influence the susceptibility to psychosis in LOAD patients. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Testing for Turkeys Faith-Based Community HIV Testing Initiative: An Update.

PubMed

DeGrezia, Mary; Baker, Dorcas; McDowell, Ingrid

2018-06-04

Testing for Turkeys (TFT) HIV/hepatitis C virus (HCV) and sexually transmitted infection (STI) testing initiative is a joint effort between Older Women Embracing Life (OWEL), Inc., a nonprofit faith-based community HIV support and advocacy organization; the Johns Hopkins University Regional Partner MidAtlantic AIDS Education and Training Center (MAAETC); and the University of Maryland, Baltimore JACQUES Initiative (JI), and is now in its 11th year of providing HIV outreach, testing, and linkage to care. Since 2008, the annual TFT daylong community HIV testing and linkage to care initiative has been held 2 weeks before Thanksgiving at a faith-based center in Baltimore, Maryland, in a zip code where one in 26 adults and adolescents ages 13 years and older are living with HIV (Maryland Department of Health, Center for HIV Surveillance, Epidemiology, and Evaluation, 2017). TFT includes a health fair with vendors that supply an abundance of education information (handouts, videos, one-on-one counseling) and safer sex necessities, including male and female condoms, dental dams, and lube. Nutritious boxed lunches and beverages are provided to all attendees and volunteers. Everyone tested for HIV who stays to obtain their results is given a free frozen turkey as they exit. The Baltimore City Health Department is on hand with a confidential no-test list (persons in the state already known to have HIV) to diminish retesting of individuals previously diagnosed with HIV. However, linkage to care is available to everyone: newly diagnosed individuals and those previously diagnosed and currently out of care. Copyright © 2018 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Development, Interaction and Linkage of Normal Fault Segments along the 100-km Bilila-Mtakataka Fault, Malawi

NASA Astrophysics Data System (ADS)

Fagereng, A.; Hodge, M.; Biggs, J.; Mdala, H. S.; Goda, K.

2016-12-01

Faults grow through the interaction and linkage of isolated fault segments. Continuous fault systems are those where segments interact, link and may slip synchronously, whereas non-continuous fault systems comprise isolated faults. As seismic moment is related to fault length (Wells and Coppersmith, 1994), understanding whether a fault system is continuous or not is critical in evaluating seismic hazard. Maturity may be a control on fault continuity: immature, low displacement faults are typically assumed to be non-continuous. Here, we study two overlapping, 20 km long, normal fault segments of the N-S striking Bilila-Mtakataka fault, Malawi, in the southern section of the East African Rift System. Despite its relative immaturity, previous studies concluded the Bilila-Mtakataka fault is continuous for its entire 100 km length, with the most recent event equating to an Mw8.0 earthquake (Jackson and Blenkinsop, 1997). We explore whether segment geometry and relationship to pre-existing high-grade metamorphic foliation has influenced segment interaction and fault development. Fault geometry and scarp height is constrained by DEMs derived from SRTM, Pleiades and `Structure from Motion' photogrammetry using a UAV, alongside direct field observations. The segment strikes differ on average by 10°, but up to 55° at their adjacent tips. The southern segment is sub-parallel to the foliation, whereas the northern segment is highly oblique to the foliation. Geometrical surface discontinuities suggest two isolated faults; however, displacement-length profiles and Coulomb stress change models suggest segment interaction, with potential for linkage at depth. Further work must be undertaken on other segments to assess the continuity of the entire fault, concluding whether an earthquake greater than that of the maximum instrumentally recorded (1910 M7.4 Rukwa) is possible.

Increased Probability of Co-Occurrence of Two Rare Diseases in Consanguineous Families and Resolution of a Complex Phenotype by Next Generation Sequencing

PubMed Central

Lal, Dennis; Neubauer, Bernd A.; Toliat, Mohammad R.; Altmüller, Janine; Thiele, Holger; Nürnberg, Peter; Kamrath, Clemens; Schänzer, Anne; Sander, Thomas; Hahn, Andreas; Nothnagel, Michael

2016-01-01

Massively parallel sequencing of whole genomes and exomes has facilitated a direct assessment of causative genetic variation, now enabling the identification of genetic factors involved in rare diseases (RD) with Mendelian inheritance patterns on an almost routine basis. Here, we describe the illustrative case of a single consanguineous family where this strategy suffered from the difficulty to distinguish between two etiologically distinct disorders, namely the co-occurrence of hereditary hypophosphatemic rickets (HRR) and congenital myopathies (CM), by their phenotypic manifestation alone. We used parametric linkage analysis, homozygosity mapping and whole exome-sequencing to identify mutations underlying HRR and CM. We also present an approximate approach for assessing the probability of co-occurrence of two unlinked recessive RD in a single family as a function of the degree of consanguinity and the frequency of the disease-causing alleles. Linkage analysis and homozygosity mapping yielded elusive results when assuming a single RD, but whole-exome sequencing helped to identify two mutations in two genes, namely SLC34A3 and SEPN1, that segregated independently in this family and that have previously been linked to two etiologically different diseases. We assess the increase in chance co-occurrence of rare diseases due to consanguinity, i.e. under circumstances that generally favor linkage mapping of recessive disease, and show that this probability can increase by several orders of magnitudes. We conclude that such potential co-occurrence represents an underestimated risk when analyzing rare or undefined diseases in consanguineous families and should be given more consideration in the clinical and genetic evaluation. PMID:26789268

Flexible Learning: Proceedings of the National Academy for Integration of Research, Teaching and Learning Annual Conference (4th, Dublin, Ireland, October 6-7, 2010)

ERIC Educational Resources Information Center

National Academy for Integration of Research, Teaching and Learning (NJ1), 2011

2011-01-01

This volume presents 64 abstracts of keynote and parallel paper presentations of the Irish National Academy for Integration of Research, Teaching and Learning's (NAIRTL) conference on the theme of flexible learning. The Flexible Learning conference was a joint initiative by NAIRTL and the Learning Innovation Network. The keynote presentations can…

Of Small Beauties and Large Beasts: The Quality of Distractors on Multiple-Choice Tests Is More Important than Their Quantity

ERIC Educational Resources Information Center

Papenberg, Martin; Musch, Jochen

2017-01-01

In multiple-choice tests, the quality of distractors may be more important than their number. We therefore examined the joint influence of distractor quality and quantity on test functioning by providing a sample of 5,793 participants with five parallel test sets consisting of items that differed in the number and quality of distractors.…

A Parallel Multigrid Solver for Viscous Flows on Anisotropic Structured Grids

DTIC Science & Technology

2001-10-01

the US-Spain Joint Commission for Scienti c and Technological Cooperation. yDepartamento Arquitectura de Computadores y Automatica, Universidad...Complutense, 28040 Madrid, Spain. E-mail: mpmatias@dacya.ucm.es zDepartamento Arquitectura de Computadores y Automatica, Universidad Complutense, 28040...Madrid, Spain. E-mail: rubensm@dacya.ucm.es xDepartamento Arquitectura de Computadores y Automatica, Universidad Complutense, 28040 Madrid, Spain. E-mail

ENVIRONMENTAL TECHNOLOGY VERIFICATION: JOINT (NSF-EPA) VERIFICATION STATEMENT AND REPORT FOR THE UV DISINFECTION OF SECONDARY EFFLUENTS, SUNTEC, INC. MODEL LPX200 DISINFECTION SYSTEM - 03/09/WQPC-SWP

EPA Science Inventory

Verification testing of the SUNTEC LPX200 UV Disinfection System to develop the UV delivered dose flow relationship was conducted at the Parsippany-Troy Hills wastewater treatment plant test site in Parsippany, New Jersey. Two lamp modules were mounted parallel in a 6.5-meter lon...

Coupled Monte Carlo Probability Density Function/ SPRAY/CFD Code Developed for Modeling Gas-Turbine Combustor Flows

NASA Technical Reports Server (NTRS)

1995-01-01

The success of any solution methodology for studying gas-turbine combustor flows depends a great deal on how well it can model various complex, rate-controlling processes associated with turbulent transport, mixing, chemical kinetics, evaporation and spreading rates of the spray, convective and radiative heat transfer, and other phenomena. These phenomena often strongly interact with each other at disparate time and length scales. In particular, turbulence plays an important role in determining the rates of mass and heat transfer, chemical reactions, and evaporation in many practical combustion devices. Turbulence manifests its influence in a diffusion flame in several forms depending on how turbulence interacts with various flame scales. These forms range from the so-called wrinkled, or stretched, flamelets regime, to the distributed combustion regime. Conventional turbulence closure models have difficulty in treating highly nonlinear reaction rates. A solution procedure based on the joint composition probability density function (PDF) approach holds the promise of modeling various important combustion phenomena relevant to practical combustion devices such as extinction, blowoff limits, and emissions predictions because it can handle the nonlinear chemical reaction rates without any approximation. In this approach, mean and turbulence gas-phase velocity fields are determined from a standard turbulence model; the joint composition field of species and enthalpy are determined from the solution of a modeled PDF transport equation; and a Lagrangian-based dilute spray model is used for the liquid-phase representation with appropriate consideration of the exchanges of mass, momentum, and energy between the two phases. The PDF transport equation is solved by a Monte Carlo method, and existing state-of-the-art numerical representations are used to solve the mean gasphase velocity and turbulence fields together with the liquid-phase equations. The joint composition PDF approach was extended in our previous work to the study of compressible reacting flows. The application of this method to several supersonic diffusion flames associated with scramjet combustor flow fields provided favorable comparisons with the available experimental data. A further extension of this approach to spray flames, three-dimensional computations, and parallel computing was reported in a recent paper. The recently developed PDF/SPRAY/computational fluid dynamics (CFD) module combines the novelty of the joint composition PDF approach with the ability to run on parallel architectures. This algorithm was implemented on the NASA Lewis Research Center's Cray T3D, a massively parallel computer with an aggregate of 64 processor elements. The calculation procedure was applied to predict the flow properties of both open and confined swirl-stabilized spray flames.

Joint association between body fat and its distribution with all-cause mortality: A data linkage cohort study based on NHANES (1988-2011)

PubMed Central

Peng, Yang; Wang, Zhiqiang; Adegbija, Odewumi; Hu, Jie; Ma, Jun; Ma, Ying-Hua

2018-01-01

Objective Although obesity is recognized as an important risk of mortality, how the amount and distribution of body fat affect mortality risk is unclear. Furthermore, whether fat distribution confers any additional risk of mortality in addition to fat amount is not understood. Methods This data linkage cohort study included 16415 participants (8554 females) aged 18 to 89 years from National Health and Nutrition Examination Survey III (1988–1994) and its linked mortality data (31 December 2011). Cox proportional hazard models and parametric survival models were used to estimate the association between body fat percentage (BF%), based on bioelectrical impedance analysis, and waist-hip ratio (WHR) with mortality. Results A total of 4999 deaths occurred during 19-year follow-up. A U-shaped association between BF% and mortality was found in both sexes, with the adjusted hazard ratios for other groups between 1.02 (95% confidence interval: 0.89, 1.18) and 2.10 (1.47, 3.01) when BF% groups of 25–30% in males and 30–35% in females were used as references. A non-linear relationship between WHR and mortality was detected in males, with the adjusted hazard ratios among other groups ranging from 1.05 (0.94, 1.18) to 1.52 (1.15, 2.00) compared with the WHR category of 0.95–1.0. However in females, the death risk constantly increased across the WHR spectrum. Joint impact of BF% and WHR suggested males with BF% of 25–30% and WHR of 0.95–1.0 and females with BF% of 30–35% and WHR <0.9 were associated with the lowest mortality risk and longest survival age compared with their counterparts in other categories. Conclusions This study supported the use of body fat distribution in addition to fat amount in assessing the risk of all-cause mortality. PMID:29474498

Joint association between body fat and its distribution with all-cause mortality: A data linkage cohort study based on NHANES (1988-2011).

PubMed

Dong, Bin; Peng, Yang; Wang, Zhiqiang; Adegbija, Odewumi; Hu, Jie; Ma, Jun; Ma, Ying-Hua

2018-01-01

Although obesity is recognized as an important risk of mortality, how the amount and distribution of body fat affect mortality risk is unclear. Furthermore, whether fat distribution confers any additional risk of mortality in addition to fat amount is not understood. This data linkage cohort study included 16415 participants (8554 females) aged 18 to 89 years from National Health and Nutrition Examination Survey III (1988-1994) and its linked mortality data (31 December 2011). Cox proportional hazard models and parametric survival models were used to estimate the association between body fat percentage (BF%), based on bioelectrical impedance analysis, and waist-hip ratio (WHR) with mortality. A total of 4999 deaths occurred during 19-year follow-up. A U-shaped association between BF% and mortality was found in both sexes, with the adjusted hazard ratios for other groups between 1.02 (95% confidence interval: 0.89, 1.18) and 2.10 (1.47, 3.01) when BF% groups of 25-30% in males and 30-35% in females were used as references. A non-linear relationship between WHR and mortality was detected in males, with the adjusted hazard ratios among other groups ranging from 1.05 (0.94, 1.18) to 1.52 (1.15, 2.00) compared with the WHR category of 0.95-1.0. However in females, the death risk constantly increased across the WHR spectrum. Joint impact of BF% and WHR suggested males with BF% of 25-30% and WHR of 0.95-1.0 and females with BF% of 30-35% and WHR <0.9 were associated with the lowest mortality risk and longest survival age compared with their counterparts in other categories. This study supported the use of body fat distribution in addition to fat amount in assessing the risk of all-cause mortality.

Same day ART initiation versus clinic-based pre-ART assessment and counselling for individuals newly tested HIV-positive during community-based HIV testing in rural Lesotho - a randomized controlled trial (CASCADE trial).

PubMed

Labhardt, Niklaus Daniel; Ringera, Isaac; Lejone, Thabo Ishmael; Masethothi, Phofu; Thaanyane, T'sepang; Kamele, Mashaete; Gupta, Ravi Shankar; Thin, Kyaw; Cerutti, Bernard; Klimkait, Thomas; Fritz, Christiane; Glass, Tracy Renée

2016-04-14

Achievement of the UNAIDS 90-90-90 targets in Sub-Sahara Africa is challenged by a weak care-cascade with poor linkage to care and retention in care. Community-based HIV testing and counselling (HTC) is widely used in African countries. However, rates of linkage to care and initiation of antiretroviral therapy (ART) in individuals who tested HIV-positive are often very low. A frequently cited reason for non-linkage to care is the time-consuming pre-ART assessment often requiring several clinic visits before ART-initiation. This two-armed open-label randomized controlled trial compares in individuals tested HIV-positive during community-based HTC the proposition of same-day community-based ART-initiation to the standard of care pre-ART assessment at the clinic. Home-based HTC campaigns will be conducted in catchment areas of six clinics in rural Lesotho. Households where at least one individual tested HIV positive will be randomized. In the standard of care group individuals receive post-test counselling and referral to the nearest clinic for pre-ART assessment and counselling. Once they have started ART the follow-up schedule foresees monthly clinic visits. Individuals randomized to the intervention group receive on the spot point-of-care pre-ART assessment and adherence counselling with the proposition to start ART that same day. Once they have started ART, follow-up clinic visits will be less frequent. First primary outcome is linkage to care (individual presents at the clinic at least once within 3 months after the HIV test). The second primary outcome is viral suppression 12 months after enrolment in the study. We plan to enrol a minimum of 260 households with 1:1 allocation and parallel assignment into both arms. This trial will show if in individuals tested HIV-positive during community-based HTC campaigns the proposition of same-day ART initiation in the community, combined with less frequent follow-up visits at the clinic could be a pragmatic approach to improve the care cascade in similar settings. NCT02692027 , registered February 21, 2016.

Development of a persistent superconducting joint between Bi-2212/Ag-alloy multifilamentary round wires

NASA Astrophysics Data System (ADS)

Chen, Peng; Trociewitz, Ulf P.; Davis, Daniel S.; Bosque, Ernesto S.; Hilton, David K.; Kim, Youngjae; Abraimov, Dmytro V.; Starch, William L.; Jiang, Jianyi; Hellstrom, Eric E.; Larbalestier, David C.

2017-02-01

Superconducting joints are one of the key components needed to make Ag-alloy clad Bi2Sr2CaCu2O8+x (Bi-2212) superconducting round wire (RW) successful for high-field, high-homogeneity magnet applications, especially for nuclear magnetic resonance magnets in which persistent current mode operation is highly desired. In this study, a procedure for fabricating superconducting joints between Bi-2212 RWs during coil reaction was developed. Melting temperatures of Bi-2212 powder with different amounts of Ag addition were investigated by differential thermal analysis so as to provide information for selecting the proper joint matrix. Test joints of 1.3 mm dia. wires heat treated in 1 bar flowing oxygen using the typical partial melt Bi-2212 heat treatment (HT) had transport critical currents I c of ˜900 A at 4.2 K and self-field, decreasing to ˜480 A at 14 T evaluated at 0.1 μV cm-1 at 4.2 K. Compared to the I c of the open-ended short conductor samples with identical 1 bar HT, the I c values of the superconducting joint are ˜20% smaller than that of conductor samples measured in parallel field but ˜20% larger than conductor samples measured in perpendicular field. Microstructures examined by scanning electron microscopy clearly showed the formation of a superconducting Bi-2212 interface between the two Bi-2212 RWs. Furthermore, a Bi-2212 RW closed-loop solenoid with a superconducting joint heat treated in 1 bar flowing oxygen showed an estimated joint resistance below 5 × 10-12 Ω based on its field decay rate. This value is sufficiently low to demonstrate the potential for persistent operation of large inductance Bi-2212 coils.

A Cadaveric Study on Sacroiliac Joint Injection

PubMed Central

Zou, Yu-Cong; Li, Yi-Kai; Yu, Cheng-Fu; Yang, Xian-Wen; Chen, Run-Qi

2015-01-01

The scope of this study was to explore the possibility as well as the feasibility of sacroiliac joint injection following simple X-ray clip location. For the cadaveric study, 10 fixed sacroiliac joint (SIJ) sectional specimens, 4 dried cadaveric pelvises and 21 embalmed adult cadaveric pelvises were dissected, followed by an injection of contrast agent into the joint. The irrigation of the agent was observed through CT scanning. For the radiologic study, 188 CT scans of ankylosing spondylitis patients (143 male, 45 female) were collected from 2010 to 2012, in Nanfang Hospital. What was measured was (1) Distance between the posterior midline and sagittal synovium; (2) Length of the sagittal synovium; (3) Distance between the midpoint of the sagittal synovium and posterior superior iliac spine; and (4) Distance between the superficial skin vertical to the sagittal synovium point were measured. For the practice-based study: 20 patients (17 males and 3 females) with early ankylosing spondylitis, from Nanfang Hospital affiliated with Southern Medical University were recruited, and sacroiliac joint unguided injections were done on the basis of the cadaveric and radiologic study. Only the inferior 1/3rd portion parallel to the posterior midline could be injected into since the superior 2/3rd portion were filled with interosseous ligaments. Thirteen of the 20 patients received successful injections as identified by CT scan using the contrast agent. Sacroiliac joint injection following simple X-ray clip location is possible and feasible if the operation is performed by trained physicians familiar with the sacroiliac joint and its surrounding anatomic structures. PMID:25692437

Joint radius-length distribution as a measure of anisotropic pore eccentricity: an experimental and analytical framework.

PubMed

Benjamini, Dan; Basser, Peter J

2014-12-07

In this work, we present an experimental design and analytical framework to measure the nonparametric joint radius-length (R-L) distribution of an ensemble of parallel, finite cylindrical pores, and more generally, the eccentricity distribution of anisotropic pores. Employing a novel 3D double pulsed-field gradient acquisition scheme, we first obtain both the marginal radius and length distributions of a population of cylindrical pores and then use these to constrain and stabilize the estimate of the joint radius-length distribution. Using the marginal distributions as constraints allows the joint R-L distribution to be reconstructed from an underdetermined system (i.e., more variables than equations), which requires a relatively small and feasible number of MR acquisitions. Three simulated representative joint R-L distribution phantoms corrupted by different noise levels were reconstructed to demonstrate the process, using this new framework. As expected, the broader the peaks in the joint distribution, the less stable and more sensitive to noise the estimation of the marginal distributions. Nevertheless, the reconstruction of the joint distribution is remarkably robust to increases in noise level; we attribute this characteristic to the use of the marginal distributions as constraints. Axons are known to exhibit local compartment eccentricity variations upon injury; the extent of the variations depends on the severity of the injury. Nonparametric estimation of the eccentricity distribution of injured axonal tissue is of particular interest since generally one cannot assume a parametric distribution a priori. Reconstructing the eccentricity distribution may provide vital information about changes resulting from injury or that occurred during development.

Adaptation of an Evidence-Based Arthritis Program for Breast Cancer Survivors on Aromatase Inhibitor Therapy Who Experience Joint Pain

PubMed Central

Callahan, Leigh F.; Rini, Christine; Altpeter, Mary; Hackney, Betsy; Schecher, Arielle; Wilson, Anne; Muss, Hyman B.

2015-01-01

Adding aromatase inhibitors (AIs) to adjuvant treatment of postmenopausal women with hormone-receptor–positive breast cancer significantly reduces cancer recurrence. A common side effect of AIs is noninflammatory joint pain and stiffness (arthralgia) similar to arthritis symptoms. An evidence-based walking program developed by the Arthritis Foundation — Walk With Ease (WWE) — reduces arthritis-related joint symptoms. We hypothesized that WWE may also reduce AI-associated arthralgia. However, the potential for different barriers and facilitators to physical activity for these 2 patient populations suggested a need to adapt WWE before testing it with breast cancer survivors. We conducted qualitative research with 46 breast cancer survivors to explore program modification and inform the development of materials for an adapted program (Walk With Ease-Breast Cancer). Our process parallels the National Cancer Institute’s Research-Tested Intervention Programs (RTIPs) guidelines for adapting evidence-based programs for cancer populations. Findings resulted in a customized 8-page brochure to supplement existing WWE materials. PMID:26068412

Distributed computer system enhances productivity for SRB joint optimization

NASA Technical Reports Server (NTRS)

Rogers, James L., Jr.; Young, Katherine C.; Barthelemy, Jean-Francois M.

1987-01-01

Initial calculations of a redesign of the solid rocket booster joint that failed during the shuttle tragedy showed that the design had a weight penalty associated with it. Optimization techniques were to be applied to determine if there was any way to reduce the weight while keeping the joint opening closed and limiting the stresses. To allow engineers to examine as many alternatives as possible, a system was developed consisting of existing software that coupled structural analysis with optimization which would execute on a network of computer workstations. To increase turnaround, this system took advantage of the parallelism offered by the finite difference technique of computing gradients to allow several workstations to contribute to the solution of the problem simultaneously. The resulting system reduced the amount of time to complete one optimization cycle from two hours to one-half hour with a potential of reducing it to 15 minutes. The current distributed system, which contains numerous extensions, requires one hour turnaround per optimization cycle. This would take four hours for the sequential system.

Characteristics of AZ31 Mg alloy joint using automatic TIG welding

NASA Astrophysics Data System (ADS)

Liu, Hong-tao; Zhou, Ji-xue; Zhao, Dong-qing; Liu, Yun-teng; Wu, Jian-hua; Yang, Yuan-sheng; Ma, Bai-chang; Zhuang, Hai-hua

2017-01-01

The automatic tungsten-inert gas welding (ATIGW) of AZ31 Mg alloys was performed using a six-axis robot. The evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction. The ATIGW process resulted in coarse recrystallized grains in the heat affected zone (HAZ) and epitaxial growth of columnar grains in the fusion zone (FZ). Substantial changes of texture between the base material (BM) and the FZ were detected. The {0002} basal plane in the BM was largely parallel to the sheet rolling plane, whereas the c-axis of the crystal lattice in the FZ inclined approximately 25° with respect to the welding direction. The maximum pole density increased from 9.45 in the BM to 12.9 in the FZ. The microhardness distribution, tensile properties, and fracture features of the AZ31 auto-welded joints were also investigated.

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

PubMed Central

Milano, Elizabeth R.; Lowry, David B.; Juenger, Thomas E.

2016-01-01

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mapping population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes. PMID:27613751

Linkage analysis in a family with Stickler syndrome leads to the exclusion of the COL2A1 locus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mottes, M.; Zolezzi, F.; Pignatti, P.F.

1994-09-01

Hereditary arthro-ophtalmopathy (AO) or Stickler Syndrome (MIM No. 10830) is a dominantly inherited disorder characterized by vitro-retinal degeneration and other connective tissue disturbances. Mutations in the COL2A1 gene, coding for type II collagen chains, have been described in a few patients. The wide spectrum of clinical manifestations is presumably due to genetic heterogeneity, since only about 50% of the Stickler families so far studied show cosegregation of the disease with the COL2A1 locus. We have investigated a large pedigree (19 individuals of whom 9 are affected) in which severe myopia with vitro-retinal degeneration consegregated with joint laxity, recurrent inguinal hernias,more » and degenerative changes of the hip and the knee. The 3{prime} end COL2A1 VNTR polymorphism was utilized for linkage analysis. In order to get the maximum informativity, we have analyzed the allelic microheterogeneity of this VNTR, due to the repeat sequence variation, by means of a single strand polymorphism. Mendelian inheritance of the different single strands was observed as expected. Discordance of segregation between the disease and the COL2A1 locus was thus established inequivocally in this family.« less

Determining the trophic guilds of fishes and macroinvertebrates in a seagrass food web

USGS Publications Warehouse

Luczkovich, J.J.; Ward, G.P.; Johnson, J.C.; Christian, R.R.; Baird, D.; Neckles, H.; Rizzo, W.M.

2002-01-01

We established trophic guilds of macroinvertebrate and fish taxa using correspondence analysis and a hierarchical clustering strategy for a seagrass food web in winter in the northeastern Gulf of Mexico. To create the diet matrix, we characterized the trophic linkages of macroinvertebrate and fish taxa present in Halodule wrightii seagrass habitat areas within the St. Marks National Wildlife Refuge (Florida) using binary data, combining dietary links obtained from relevant literature for macroinvertebrates with stomach analysis of common fishes collected during January and February of 1994. Heirarchical average-linkage cluster analysis of the 73 taxa of fishes and macroinvertebrates in the diet matrix yielded 14 clusters with diet similarity ??? 0.60. We then used correspondence analysis with three factors to jointly plot the coordinates of the consumers (identified by cluster membership) and of the 33 food sources. Correspondence analysis served as a visualization tool for assigning each taxon to one of eight trophic guilds: herbivores, detritivores, suspension feeders, omnivores, molluscivores, meiobenthos consumers, macrobenthos consumers, and piscivores. These trophic groups, cross-classified with major taxonomic groups, were further used to develop consumer compartments in a network analysis model of carbon flow in this seagrass ecosystem. The method presented here should greatly improve the development of future network models of food webs by providing an objective procedure for aggregating trophic groups.

Contribution of GLC3A locus to Primary Congenital Glaucoma in Pakistani population

PubMed Central

Bashir, Rasheeda; Sanai, Mahrukh; Azeem, Adnan; Altaf, Imran; Saleem, Faiza; Naz, Sadaf

2014-01-01

Objectives: To check the contribution of GLC3A locus to primary congenital glaucoma in the Pakistani population. Methods: We enrolled twenty-nine sporadic cases and three families with multiple individuals affected with recessive primary congenital glaucoma in the year 2013. It was a genetic linkage study accomplished jointly in Department of Biotechnology of Lahore College for Women University and School of Biological Sciences, University of the Punjab, Lahore. Samples from all affected individuals were checked for homozygosity for alleles of microsatellite markers spanning CYP1B1 at GLC3A locus. Genotyping was performed with fluorescently labeled primers by capillary electrophoresis. For familial cases, linkage was evaluated by checking the co-segregation of the phenotype with the genotypes. Two-point LOD score was calculated for each microsatellite marker with MLINK. Results: Our study revealed that GLCA3 may contribute to glaucoma in 17% of the sporadic cases and patients in 2 of the 3 families. Conclusions: This data suggests that the GLC3A may make an important contribution to autosomal recessive primary congenital glaucoma in the Pakistani population. Genotyping and Sequencing of more families will be helpful to identify the common mutations in CYP1B1 in future. PMID:25674135

A Study for Adjustable Riding Position of the Innovation Bicycle Design

NASA Astrophysics Data System (ADS)

Huang, Yu-Che; Huang, Tai-Shen

2018-04-01

This research is about the analysis and design of the user in a wheelchair use posture can be changed. So user can through different sitting posture changes to provide different needs, so the folding design patents for the existing data collection and classification, through the analysis of advantages and disadvantages, further to find the innovative design approach. Finally through the multi linkage mechanism system, change the seat, handlebars and rear position, provide different posture context. In order to reduce the cost, this study is designed to integrate the innovation input mechanism, multi linkage system, through the construction of 10 joints and degrees of freedom of the bicycle frame. Then use 3D software to design of bicycle the size of the frame of innovation, through the three-dimensional CAD model to simulate the mechanism between movement and interference, and to evaluate the 3D The virtual prototype can meet the requirement. It will also enable CAE to analyze and determine the strength and the safety of the bicycle frame structure of ANSYS11.0 stress. Finally, we have integrated design through CAID to make a product appearance, the focus of research is mainly a study of CAD, CAE, CAID integration the production and the completion of a prototype.

Analyzing structural variations along strike in a deep-water thrust belt

NASA Astrophysics Data System (ADS)

Totake, Yukitsugu; Butler, Robert W. H.; Bond, Clare E.; Aziz, Aznan

2018-03-01

We characterize a deep-water fold-thrust arrays imaged by a high-resolution 3D seismic dataset in the offshore NW Borneo, Malaysia, to understand the kinematics behind spatial arrangement of structural variations throughout the fold-thrust system. The seismic volume used covers two sub-parallel fold trains associated with a series of fore-thrusts and back-thrusts. We measured fault heave, shortening value, fold geometries (forelimb dip, interlimb angle and crest depth) along strike in individual fold trains. Heave plot on strike projection allows to identify individual thrust segments showing semi-elliptical to triangular to bimodal patterns, and linkages of these segments. The linkage sites are marked by local minima in cumulative heave. These local heave minima are compensated by additional structures, such as small imbricate thrusts and tight folds indicated by large forelimb dip and small interlimb angle. Complementary profiles of the shortening amount for the two fold trains result in smoother gradient of total shortening across the structures. We interpret this reflects kinematic interaction between two fold-thrust trains. This type of along-strike variation analysis provides comprehensive understanding of a fold-thrust system and may provide an interpretative strategy for inferring the presence of complex multiple faults in less well-imaged parts of seismic volumes.

A comparison of the genetic basis of wing size divergence in three parallel body size clines of Drosophila melanogaster.

PubMed Central

Gilchrist, A S; Partridge, L

1999-01-01

Body size clines in Drosophila melanogaster have been documented in both Australia and South America, and may exist in Southern Africa. We crossed flies from the northern and southern ends of each of these clines to produce F(1), F(2), and first backcross generations. Our analysis of generation means for wing area and wing length produced estimates of the additive, dominance, epistatic, and maternal effects underlying divergence within each cline. For both females and males of all three clines, the generation means were adequately described by these parameters, indicating that linkage and higher order interactions did not contribute significantly to wing size divergence. Marked differences were apparent between the clines in the occurrence and magnitude of the significant genetic parameters. No cline was adequately described by a simple additive-dominance model, and significant epistatic and maternal effects occurred in most, but not all, of the clines. Generation variances were also analyzed. Only one cline was described sufficiently by a simple additive variance model, indicating significant epistatic, maternal, or linkage effects in the remaining two clines. The diversity in genetic architecture of the clines suggests that natural selection has produced similar phenotypic divergence by different combinations of gene action and interaction. PMID:10581284

MSH6 and MSH3 are rarely involved in genetic predisposition to nonpolypotic colon cancer.

PubMed

Huang, J; Kuismanen, S A; Liu, T; Chadwick, R B; Johnson, C K; Stevens, M W; Richards, S K; Meek, J E; Gao, X; Wright, F A; Mecklin, J P; Järvinen, H J; Grönberg, H; Bisgaard, M L; Lindblom, A; Peltomäki, P

2001-02-15

A set of 90 nonpolypotic colon cancer families in which germ-line mutations of MSH2 and MLH1 had been excluded were screened for mutations in two additional DNA mismatch repair genes, MSH6 and MSH3. Kindreds fulfilling and not fulfilling the Amsterdam I criteria, showing early and late onset colorectal (and other) cancers, and having microsatellite stable and unstable tumors were included. Two partly parallel approaches were used: genetic linkage analysis (19 large families) and the protein truncation test (85, mostly smaller, families). Whereas MSH3 was not involved in any family, a large Amsterdam-positive, late-onset family showed a novel germ-line mutation in MSH6 (deletion of CT at nucleotide 3052 in exon 4). The mutation was identified through genetic linkage (multipoint lod score 2.4) and subsequent sequencing of MSH6. Furthermore, the entire MSH6 gene was sequenced exon by exon in families with frameshift mutations in the (C)8 tract in tumors, previously suggested as a predictor of MSH6 germ-line mutations; no mutations were found. We conclude that germ-line involvement of MSH6 and MSH3 is rare and that other genes are likely to account for a majority of MSH2-, MLH1-mutation negative families with nonpolypotic colon cancer.

Inverse Kinematics for Upper Limb Compound Movement Estimation in Exoskeleton-Assisted Rehabilitation.

PubMed

Cortés, Camilo; de Los Reyes-Guzmán, Ana; Scorza, Davide; Bertelsen, Álvaro; Carrasco, Eduardo; Gil-Agudo, Ángel; Ruiz-Salguero, Oscar; Flórez, Julián

2016-01-01

Robot-Assisted Rehabilitation (RAR) is relevant for treating patients affected by nervous system injuries (e.g., stroke and spinal cord injury). The accurate estimation of the joint angles of the patient limbs in RAR is critical to assess the patient improvement. The economical prevalent method to estimate the patient posture in Exoskeleton-based RAR is to approximate the limb joint angles with the ones of the Exoskeleton. This approximation is rough since their kinematic structures differ. Motion capture systems (MOCAPs) can improve the estimations, at the expenses of a considerable overload of the therapy setup. Alternatively, the Extended Inverse Kinematics Posture Estimation (EIKPE) computational method models the limb and Exoskeleton as differing parallel kinematic chains. EIKPE has been tested with single DOF movements of the wrist and elbow joints. This paper presents the assessment of EIKPE with elbow-shoulder compound movements (i.e., object prehension). Ground-truth for estimation assessment is obtained from an optical MOCAP (not intended for the treatment stage). The assessment shows EIKPE rendering a good numerical approximation of the actual posture during the compound movement execution, especially for the shoulder joint angles. This work opens the horizon for clinical studies with patient groups, Exoskeleton models, and movements types.

Practical aspects of prestack depth migration with finite differences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ober, C.C.; Oldfield, R.A.; Womble, D.E.

1997-07-01

Finite-difference, prestack, depth migrations offers significant improvements over Kirchhoff methods in imaging near or under salt structures. The authors have implemented a finite-difference prestack depth migration algorithm for use on massively parallel computers which is discussed. The image quality of the finite-difference scheme has been investigated and suggested improvements are discussed. In this presentation, the authors discuss an implicit finite difference migration code, called Salvo, that has been developed through an ACTI (Advanced Computational Technology Initiative) joint project. This code is designed to be efficient on a variety of massively parallel computers. It takes advantage of both frequency and spatialmore » parallelism as well as the use of nodes dedicated to data input/output (I/O). Besides giving an overview of the finite-difference algorithm and some of the parallelism techniques used, migration results using both Kirchhoff and finite-difference migration will be presented and compared. The authors start out with a very simple Cartoon model where one can intuitively see the multiple travel paths and some of the potential problems that will be encountered with Kirchhoff migration. More complex synthetic models as well as results from actual seismic data from the Gulf of Mexico will be shown.« less

The influence of foot position on scrum kinetics during machine scrummaging.

PubMed

Bayne, Helen; Kat, Cor-Jacques

2018-05-23

The purpose of this study was to investigate the effect of variations in the alignment of the feet on scrum kinetics during machine scrummaging. Twenty nine rugby forwards from amateur-level teams completed maximal scrum efforts against an instrumented scrum machine, with the feet in parallel and non-parallel positions. Three-dimensional forces, the moment about the vertical axis and sagittal plane joint angles were measured during the sustained pushing phase. There was a decrease in the magnitude of the resultant force and compression force in both of the non-parallel conditions compared to parallel and larger compression forces were associated with more extended hip and knee angles. Scrummaging with the left foot forward resulted in the lateral force being directed more towards the left and the turning moment becoming more clockwise. These directional changes were reversed when scrummaging with the right foot forward. Scrummaging with the right foot positioned ahead of the left may serve to counteract the natural clockwise wheel of the live scrum and could be used to achieve an anti-clockwise rotation of the scrum for tactical reasons. However, this would be associated with lower resultant forces and a greater lateral shear force component directed towards the right.

Heel anatomy for retrograde tibiotalocalcaneal roddings: a roentgenographic and anatomic analysis.

PubMed

Flock, T J; Ishikawa, S; Hecht, P J; Wapner, K L

1997-04-01

There is an increased interest in load-sharing devices for tibiotalocalcaneal arthrodesis. Although the neurovascular anatomy of the heel has been well described, the purpose of this study is to consider heel anatomy as it relates to plantar heel incisions and to well-defined fluoroscopic landmarks to prevent complications during these procedures. Twenty lateral radiographs of normal feet while standing were evaluated by two observers. The distance from the calcaneocuboid (CC) joint to a line parallel to the center of the intramedullary canal of the tibia was calculated. In the second part of the study, 14 dissections of the arterial and neural anatomy were performed. The distances from the CC joint to structures crossing the heel proximal to the CC joint were studied. In the 20 standing radiographs, the mean distance from the CC joint to the middle of the intramedullary canal of the tibia was 2.1 cm (standard deviation, 0.55 cm). In the dissections, the only artery or nerve found to cross the plantar surface proximal to the CC joint was the nerve to the abductor digiti quinti (NAbDQ). The mean distance from the CC joint to the NAbDQ was 3.1 cm (standard deviation, 1.36 cm). Assuming reaming to 12 mm, NAbDQ would be at risk 42% of the time. We recommend careful dissection of the heel during retrograde roddings to avoid damage to NAbDQ and subsequent neurogenic heel pain.

The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints.

PubMed

Fattahi, Farnaz; Hashemi Ardakani, Zahra; Hashemi Ardakani, Maryam

2015-12-01

Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (p< 0.05). The mean tensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint.

JESPP: Joint Experimentation on Scalable Parallel Processors Supercomputers

DTIC Science & Technology

2010-03-01

were for the relatively small market of scientific and engineering applications. Contrast this with GPUs that are designed to improve the end- user...experience in mass- market arenas such as gaming. In order to get meaningful speed-up using the GPU, it was determined that the data transfer and...Included) Conference Year Effectively using a Large GPGPU-Enhanced Linux Cluster HPCMP UGC 2009 FLOPS per Watt: Heterogeneous-Computing’s Approach

Summary of Research 1997, Department of Computer Science.

DTIC Science & Technology

1999-01-01

Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704...contains summaries of research projects in the Department of Computer Science . A list of recent publications is also included which consists of conference...parallel programming. Recently, in a joint research project between NPS and the Russian Academy of Sciences Systems Programming Insti- tute in Moscow

Search and Determine Integrated Environment (SADIE)

NASA Astrophysics Data System (ADS)

Sabol, C.; Schumacher, P.; Segerman, A.; Coffey, S.; Hoskins, A.

2012-09-01

A new and integrated high performance computing software applications package called the Search and Determine Integrated Environment (SADIE) is being jointly developed and refined by the Air Force and Naval Research Laboratories (AFRL and NRL) to automatically resolve uncorrelated tracks (UCTs) and build a more complete space object catalog for improved Space Situational Awareness (SSA). The motivation for SADIE is to respond to very challenging needs identified and guidance received from Air Force Space Command (AFSPC) and other senior leaders to develop this technology to support the evolving Joint Space Operations Center (JSpOC) and Alternate Space Control Center (ASC2)-Dahlgren. The JSpOC and JMS SSA mission requirements and threads flow down from the United States Strategic Command (USSTRATCOM). The SADIE suite includes modification and integration of legacy applications and software components that include Search And Determine (SAD), Satellite Identification (SID), and Parallel Catalog (Parcat), as well as other utilities and scripts to enable end-to-end catalog building and maintenance in a parallel processing environment. SADIE is being developed to handle large catalog building challenges in all orbit regimes and includes the automatic processing of radar, fence, and optical data. Real data results are provided for the processing of Air Force Space Surveillance System fence observations and for the processing of Space Surveillance Telescope optical data.

Optimism and hope as predictors of subjective health in post-myocardial infarction patients: A comparison of the role of coping strategies.

PubMed

Wlodarczyk, Dorota

2017-03-01

This study explored the effects intervening in the linkages of optimism and hope with subjective health in the short term after myocardial infarction. A two-wave study design was used. The sample consisted of 222 myocardial infarction survivors. When adopting a cross-sectional design, optimism and hope predicted subjective health at Time 1 and Time 2. After controlling for baseline subjective health, they were no longer significant predictors of subjective health at Time 2. Parallel indirect effects of seeking social support and problem solving were significant for both optimism and hope. After controlling for the shared variance between optimism and hope, these effects remained significant only for optimism.

The R package "sperrorest" : Parallelized spatial error estimation and variable importance assessment for geospatial machine learning

NASA Astrophysics Data System (ADS)

Schratz, Patrick; Herrmann, Tobias; Brenning, Alexander

2017-04-01

Computational and statistical prediction methods such as the support vector machine have gained popularity in remote-sensing applications in recent years and are often compared to more traditional approaches like maximum-likelihood classification. However, the accuracy assessment of such predictive models in a spatial context needs to account for the presence of spatial autocorrelation in geospatial data by using spatial cross-validation and bootstrap strategies instead of their now more widely used non-spatial equivalent. The R package sperrorest by A. Brenning [IEEE International Geoscience and Remote Sensing Symposium, 1, 374 (2012)] provides a generic interface for performing (spatial) cross-validation of any statistical or machine-learning technique available in R. Since spatial statistical models as well as flexible machine-learning algorithms can be computationally expensive, parallel computing strategies are required to perform cross-validation efficiently. The most recent major release of sperrorest therefore comes with two new features (aside from improved documentation): The first one is the parallelized version of sperrorest(), parsperrorest(). This function features two parallel modes to greatly speed up cross-validation runs. Both parallel modes are platform independent and provide progress information. par.mode = 1 relies on the pbapply package and calls interactively (depending on the platform) parallel::mclapply() or parallel::parApply() in the background. While forking is used on Unix-Systems, Windows systems use a cluster approach for parallel execution. par.mode = 2 uses the foreach package to perform parallelization. This method uses a different way of cluster parallelization than the parallel package does. In summary, the robustness of parsperrorest() is increased with the implementation of two independent parallel modes. A new way of partitioning the data in sperrorest is provided by partition.factor.cv(). This function gives the user the possibility to perform cross-validation at the level of some grouping structure. As an example, in remote sensing of agricultural land uses, pixels from the same field contain nearly identical information and will thus be jointly placed in either the test set or the training set. Other spatial sampling resampling strategies are already available and can be extended by the user.

Cartilage degradation biomarkers predict efficacy of a novel, highly selective matrix metalloproteinase 13 inhibitor in a dog model of osteoarthritis: confirmation by multivariate analysis that modulation of type II collagen and aggrecan degradation peptides parallels pathologic changes.

PubMed

Settle, Steven; Vickery, Lillian; Nemirovskiy, Olga; Vidmar, Tom; Bendele, Alison; Messing, Dean; Ruminski, Peter; Schnute, Mark; Sunyer, Teresa

2010-10-01

To demonstrate that the novel highly selective matrix metalloproteinase 13 (MMP-13) inhibitor PF152 reduces joint lesions in adult dogs with osteoarthritis (OA) and decreases biomarkers of cartilage degradation. The potency and selectivity of PF152 were evaluated in vitro using 16 MMPs, TACE, and ADAMTS-4 and ADAMTS-5, as well as ex vivo in human cartilage explants. In vivo effects were evaluated at 3 concentrations in mature beagles with partial medial meniscectomy. Gross and histologic changes in the femorotibial joints were evaluated using various measures of cartilage degeneration. Biomarkers of cartilage turnover were examined in serum, urine, or synovial fluid. Results were analyzed individually and in combination using multivariate analysis. The potent and selective MMP-13 inhibitor PF152 decreased human cartilage degradation ex vivo in a dose-dependent manner. PF152 treatment of dogs with OA reduced cartilage lesions and decreased biomarkers of type II collagen (type II collagen neoepitope) and aggrecan (peptides ending in ARGN or AGEG) degradation. The dose required for significant inhibition varied with the measure used, but multivariate analysis of 6 gross and histologic measures indicated that all doses differed significantly from vehicle but not from each other. Combined analysis of cartilage degradation markers showed similar results. This highly selective MMP-13 inhibitor exhibits chondroprotective effects in mature animals. Biomarkers of cartilage degradation, when evaluated in combination, parallel the joint structural changes induced by the MMP-13 inhibitor. These data support the potential therapeutic value of selective MMP-13 inhibitors and the use of a set of appropriate biomarkers to predict efficacy in OA clinical trials.

A novel biomarker in patients with knee osteoarthritis: adropin.

PubMed

Gundogdu, Gulsah; Gundogdu, Koksal

2018-03-16

Adropin is newly discovered peptide hormone. Osteoarthritis (OA) is a kind of joint disease characterized by progressive joint cartilage loss and joint pain. The present study was carried out to investigate adropin and tumor necrosis factor alpha (TNF-α) levels and the relationship between adropin in patients with knee OA classified by Kellgren-Lawrence (KL). A total of 60 knee OA patients and 30 healthy controls were included in this study. KL grading was carried out using the radiographic findings. Demographic characteristics and laboratory parameters were recorded. Adropin and TNF-α levels were determined by using enzyme-linked immunosorbent assay (ELISA). Adropin level was lower in the knee OA patients compared with the healthy controls (p < 0.001), whereas TNF-α level was higher (p < 0.001). Adropin level was negatively correlated with TNF-α level, blood white blood cell (WBC) count, and neutrophil-lymphocyte ratio (NLR). However, there was a significant decrease in adropin level and an increase in TNF-α level parallel to the increase in the KL grade. In addition, serum adropin level was found to be significantly lower in KL grade 1 groups compared with healthy controls (p < 0.01). There was a decrease in adropin level parallel to the increase in the body mass index (BMI), and there was a statistically significant decrease in adropin level in knee OA patients higher than BMI > 30 (p < 0.01). Mean NLR of KL grade 4 was significantly increased compared with other grades (p < 0.05). The consequence of the present study suggested that serum adropin level could be used as a new biomarker indicating the early grade of knee OA.

The gap technique does not rotate the femur parallel to the epicondylar axis.

PubMed

Matziolis, Georg; Boenicke, Hinrich; Pfiel, Sascha; Wassilew, Georgi; Perka, Carsten

2011-02-01

In the analysis of painful total knee replacements, the surgical epicondylar axis (SEA) has become established as a standard in the diagnosis of femoral component rotation. It remains unclear whether the gap technique widely used to determine femoral rotation, when applied correctly, results in a rotation parallel to the SEA. In this prospective study, 69 patients (69 joints) were included who received a navigated bicondylar surface replacement due to primary arthritis of the knee joint. In 67 cases in which a perfect soft-tissue balancing of the extension gap (<1° asymmetry) was achieved, the flexion gap and the rotation of the femoral component necessary for its symmetry was determined and documented. The femoral component was implanted additionally taking into account the posterior condylar axis and the Whiteside's line. Postoperatively, the rotation of the femoral component to the SEA was determined and this was used to calculate the angle between a femur implanted according to the gap technique and the SEA. If the gap technique had been used consistently, it would have resulted in a deviation of the femoral components by -0.6° ± 2.9° (-7.4°-5.9°) from the SEA. The absolute deviation would have been 2.4° ± 1.8°, with a range between 0.2° and 7.4°. Even if the extension gap is perfectly balanced, the gap technique does not lead to a parallel alignment of the femoral component to the SEA. Since the clinical results of this technique are equivalent to those of the femur first technique in the literature, an evaluation of this deviation as a malalignment must be considered critically.

A three-degree-of-freedom parallel manipulator for concentrated solar power towers: Modeling, simulation and design

NASA Astrophysics Data System (ADS)

Ghosal, Ashitava; Shyam, R. B. Ashith

2016-05-01

There is an increased thrust to harvest solar energy in India to meet increasing energy requirements and to minimize imported fossil fuels. In a solar power tower system, an array of tracking mirrors or heliostats are used to concentrate the incident solar energy on an elevated stationary receiver and then the thermal energy converted to electricity using a heat engine. The conventional method of tracking are the Azimuth-Elevation (Az-El) or Target-Aligned (T-A) mount. In both the cases, the mirror is rotated about two mutually perpendicular axes and is supported at the center using a pedestal which is fixed to the ground. In this paper, a three degree-of-freedom parallel manipulator, namely the 3-RPS, is proposed for tracking the sun in a solar power tower system. We present modeling, simulation and design of the 3-RPS parallel manipulator and show its advantages over conventional Az-El and T-A mounts. The 3-RPS manipulator consists of three rotary (R), three prismatic (P) and three spherical (S) joints and the mirror assembly is mounted at three points in contrast to the Az-El and T-A mounts. The kinematic equations for sun tracking are derived for the 3-RPS manipulator and from the simulations, we obtain the range of motion of the rotary, prismatic and spherical joints. Since the mirror assembly is mounted at three points, the wind load and self-weight are distributed and as a consequence, the deflections due to loading are smaller than in conventional mounts. It is shown that the weight of the supporting structure is between 15% and 65% less than that of conventional systems. Hence, even though one additional actuator is used, the larger area mirrors can be used and costs can be reduced.

Three-way parallel independent component analysis for imaging genetics using multi-objective optimization.

PubMed

Ulloa, Alvaro; Jingyu Liu; Vergara, Victor; Jiayu Chen; Calhoun, Vince; Pattichis, Marios

2014-01-01

In the biomedical field, current technology allows for the collection of multiple data modalities from the same subject. In consequence, there is an increasing interest for methods to analyze multi-modal data sets. Methods based on independent component analysis have proven to be effective in jointly analyzing multiple modalities, including brain imaging and genetic data. This paper describes a new algorithm, three-way parallel independent component analysis (3pICA), for jointly identifying genomic loci associated with brain function and structure. The proposed algorithm relies on the use of multi-objective optimization methods to identify correlations among the modalities and maximally independent sources within modality. We test the robustness of the proposed approach by varying the effect size, cross-modality correlation, noise level, and dimensionality of the data. Simulation results suggest that 3p-ICA is robust to data with SNR levels from 0 to 10 dB and effect-sizes from 0 to 3, while presenting its best performance with high cross-modality correlations, and more than one subject per 1,000 variables. In an experimental study with 112 human subjects, the method identified links between a genetic component (pointing to brain function and mental disorder associated genes, including PPP3CC, KCNQ5, and CYP7B1), a functional component related to signal decreases in the default mode network during the task, and a brain structure component indicating increases of gray matter in brain regions of the default mode region. Although such findings need further replication, the simulation and in-vivo results validate the three-way parallel ICA algorithm presented here as a useful tool in biomedical data decomposition applications.

Dynamic modeling and optimal joint torque coordination of advanced robotic systems

NASA Astrophysics Data System (ADS)

Kang, Hee-Jun

The development is documented of an efficient dynamic modeling algorithm and the subsequent optimal joint input load coordination of advanced robotic systems for industrial application. A closed-form dynamic modeling algorithm for the general closed-chain robotic linkage systems is presented. The algorithm is based on the transfer of system dependence from a set of open chain Lagrangian coordinates to any desired system generalized coordinate set of the closed-chain. Three different techniques for evaluation of the kinematic closed chain constraints allow the representation of the dynamic modeling parameters in terms of system generalized coordinates and have no restriction with regard to kinematic redundancy. The total computational requirement of the closed-chain system model is largely dependent on the computation required for the dynamic model of an open kinematic chain. In order to improve computational efficiency, modification of an existing open-chain KIC based dynamic formulation is made by the introduction of the generalized augmented body concept. This algorithm allows a 44 pct. computational saving over the current optimized one (O(N4), 5995 when N = 6). As means of resolving redundancies in advanced robotic systems, local joint torque optimization is applied for effectively using actuator power while avoiding joint torque limits. The stability problem in local joint torque optimization schemes is eliminated by using fictitious dissipating forces which act in the necessary null space. The performance index representing the global torque norm is shown to be satisfactory. In addition, the resulting joint motion trajectory becomes conservative, after a transient stage, for repetitive cyclic end-effector trajectories. The effectiveness of the null space damping method is shown. The modular robot, which is built of well defined structural modules from a finite-size inventory and is controlled by one general computer system, is another class of evolving, highly versatile, advanced robotic systems. Therefore, finally, a module based dynamic modeling algorithm is presented for the dynamic coordination of such reconfigurable modular robotic systems. A user interactive module based manipulator analysis program (MBMAP) has been coded in C language running on 4D/70 Silicon Graphics.

Assessment of the relationship between stress and temporomandibular joint disorder in female students before university entrance exam (Konkour exam).

PubMed

Mottaghi, Ahmad; Razavi, S Mohammad; Pozveh, Elham Zamani; Jahangirmoghaddam, Milad

2011-12-01

Temporomandibular joint is one of the most complicated joints of the body and plays an important role in the head and neck system. One of the factors affecting the temporomandibular joint and lead to temporomandibular disorder is anxiety with all the events causing it. The aim of this study was to determine a relationship between anxiety and temporomandibular disorders. In this prospective study, subjects were randomly selected. One hundred and thirty pre-university students in Isfahan were evaluated with Ketel's test of anxiety, exam stress test and temporomandibular disorder questionnaires. The evaluation was done in two stages 10 months and 1 month prior to the university entrance exam (Konkour), clinical assessments consisted of masticatory muscles and sternocleidomastoid muscle palpation, temporomandibular joint palpation for pain and noise and its movement, and mouth opening limitations. The Wilcoxon rank test and paired t-test were used to analyze the data and the P value under 0.05 was considered significant. The level of anxiety and occurrence of temporomandibular disorders were increased between two stages and had the highest level in the second stage. There was a significant increase between two stages (P<0.001). The parallel increase of temporomandibular disorders and anxiety between the two stages can suggest a possible relationship between anxiety and temporomandibular disorders. Therefore, the effect of anxiety in triggering temporomandibular disorder symptoms is probable.

A stochastic Iwan-type model for joint behavior variability modeling

NASA Astrophysics Data System (ADS)

Mignolet, Marc P.; Song, Pengchao; Wang, X. Q.

2015-08-01

This paper focuses overall on the development and validation of a stochastic model to describe the dissipation and stiffness properties of a bolted joint for which experimental data is available and exhibits a large scatter. An extension of the deterministic parallel-series Iwan model for the characterization of the force-displacement behavior of joints is first carried out. This new model involves dynamic and static coefficients of friction differing from each other and a broadly defined distribution of Jenkins elements. Its applicability is next investigated using the experimental data, i.e. stiffness and dissipation measurements obtained in harmonic testing of 9 nominally identical bolted joints. The model is found to provide a very good fit of the experimental data for each bolted joint notwithstanding the significant variability of their behavior. This finding suggests that this variability can be simulated through the randomization of only the parameters of the proposed Iwan-type model. The distribution of these parameters is next selected based on maximum entropy concepts and their corresponding parameters, i.e. the hyperparameters of the model, are identified using a maximum likelihood strategy. Proceeding with a Monte Carlo simulation of this stochastic Iwan model demonstrates that the experimental data fits well within the uncertainty band corresponding to the 5th and 95th percentiles of the model predictions which well supports the adequacy of the modeling effort.

Enhanced control of a flexure-jointed micromanipulation system using a vision-based servoing approach

NASA Astrophysics Data System (ADS)

Chuthai, T.; Cole, M. O. T.; Wongratanaphisan, T.; Puangmali, P.

2018-01-01

This paper describes a high-precision motion control implementation for a flexure-jointed micromanipulator. A desktop experimental motion platform has been created based on a 3RUU parallel kinematic mechanism, driven by rotary voice coil actuators. The three arms supporting the platform have rigid links with compact flexure joints as integrated parts and are made by single-process 3D printing. The mechanism overall size is approximately 250x250x100 mm. The workspace is relatively large for a flexure-jointed mechanism, being approximately 20x20x6 mm. A servo-control implementation based on pseudo-rigid-body models (PRBM) of kinematic behavior combined with nonlinear-PID control has been developed. This is shown to achieve fast response with good noise-rejection and platform stability. However, large errors in absolute positioning occur due to deficiencies in the PRBM kinematics, which cannot accurately capture flexure compliance behavior. To overcome this problem, visual servoing is employed, where a digital microscopy system is used to directly measure the platform position by image processing. By adopting nonlinear PID feedback of measured angles for the actuated joints as inner control loops, combined with auxiliary feedback of vision-based measurements, the absolute positioning error can be eliminated. With controller gain tuning, fast dynamic response and low residual vibration of the end platform can be achieved with absolute positioning accuracy within ±1 micron.

ParallABEL: an R library for generalized parallelization of genome-wide association studies.

PubMed

Sangket, Unitsa; Mahasirimongkol, Surakameth; Chantratita, Wasun; Tandayya, Pichaya; Aulchenko, Yurii S

2010-04-29

Genome-Wide Association (GWA) analysis is a powerful method for identifying loci associated with complex traits and drug response. Parts of GWA analyses, especially those involving thousands of individuals and consuming hours to months, will benefit from parallel computation. It is arduous acquiring the necessary programming skills to correctly partition and distribute data, control and monitor tasks on clustered computers, and merge output files. Most components of GWA analysis can be divided into four groups based on the types of input data and statistical outputs. The first group contains statistics computed for a particular Single Nucleotide Polymorphism (SNP), or trait, such as SNP characterization statistics or association test statistics. The input data of this group includes the SNPs/traits. The second group concerns statistics characterizing an individual in a study, for example, the summary statistics of genotype quality for each sample. The input data of this group includes individuals. The third group consists of pair-wise statistics derived from analyses between each pair of individuals in the study, for example genome-wide identity-by-state or genomic kinship analyses. The input data of this group includes pairs of SNPs/traits. The final group concerns pair-wise statistics derived for pairs of SNPs, such as the linkage disequilibrium characterisation. The input data of this group includes pairs of individuals. We developed the ParallABEL library, which utilizes the Rmpi library, to parallelize these four types of computations. ParallABEL library is not only aimed at GenABEL, but may also be employed to parallelize various GWA packages in R. The data set from the North American Rheumatoid Arthritis Consortium (NARAC) includes 2,062 individuals with 545,080, SNPs' genotyping, was used to measure ParallABEL performance. Almost perfect speed-up was achieved for many types of analyses. For example, the computing time for the identity-by-state matrix was linearly reduced from approximately eight hours to one hour when ParallABEL employed eight processors. Executing genome-wide association analysis using the ParallABEL library on a computer cluster is an effective way to boost performance, and simplify the parallelization of GWA studies. ParallABEL is a user-friendly parallelization of GenABEL.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, Janine Camille; Thompson, David; Pebay, Philippe Pierre

Statistical analysis is typically used to reduce the dimensionality of and infer meaning from data. A key challenge of any statistical analysis package aimed at large-scale, distributed data is to address the orthogonal issues of parallel scalability and numerical stability. Many statistical techniques, e.g., descriptive statistics or principal component analysis, are based on moments and co-moments and, using robust online update formulas, can be computed in an embarrassingly parallel manner, amenable to a map-reduce style implementation. In this paper we focus on contingency tables, through which numerous derived statistics such as joint and marginal probability, point-wise mutual information, information entropy,more » and {chi}{sup 2} independence statistics can be directly obtained. However, contingency tables can become large as data size increases, requiring a correspondingly large amount of communication between processors. This potential increase in communication prevents optimal parallel speedup and is the main difference with moment-based statistics (which we discussed in [1]) where the amount of inter-processor communication is independent of data size. Here we present the design trade-offs which we made to implement the computation of contingency tables in parallel. We also study the parallel speedup and scalability properties of our open source implementation. In particular, we observe optimal speed-up and scalability when the contingency statistics are used in their appropriate context, namely, when the data input is not quasi-diffuse.« less

Questa Baseline and Premining Ground-Water Quality Investigation 18. Characterization of Brittle Structures in the Questa Caldera and Their Potential Influence on Bedrock Ground-Water Flow, Red River Valley, New Mexico

USGS Publications Warehouse

Caine, Jonathan S.

2006-01-01

This report presents a field-based characterization of fractured and faulted crystalline bedrock in the southern portion of the Questa caldera and its margin. The focus is (1) the identification and description of brittle geological structures and (2) speculation on the potential effects and controls that these structures might have on the potential fluxes of paleo to present-day ground water in relation to natural or mining-related metal and acid loads to surface and ground water. The entire study area is pervasively jointed with a few distinctive patterns such as orthogonal, oblique orthogonal, and conjugate joint sets. Joint intensity, the number of joints measured per unit line length, is high to extreme. Three types of fault zones are present that include partially silicified, low- and high-angle faults with well-developed damage zones and clay-rich cores and high-angle, unsilicified open faults. Conceptually, the joint networks can be thought of as providing the background porosity and permeability structure of the bedrock aquifer system. This background is cut by discrete entities such as the faults with clay-rich cores and open faults that may act as important hydrologic heterogeneities. The southern caldera margin runs parallel to the course of the Red River Valley, whose incision has left an extreme topographic gradient at high angles to the river. Many of the faults and fault intersections run parallel to this assumed hydraulic gradient; thus, these structures have great potential to provide paleo and present-day, discrete and anisotropic pathways for solute transport within the otherwise relatively low porosity and permeability bedrock background aquifer system. Although brittle fracture networks and faults are pervasive and complex, simple Darcy calculations are used to estimate the hydraulic conductivity and potential ground-water discharges of the bedrock aquifer, caldera margin, and other faults in order to gain insight into the potential contributions of these features to the ground-water and surface-water flow systems. These calculations show that, because all of these features are found along the Red River in the Cabin Springs-Columbine Park-Goat Hill fan area, their combined effect increases the probability that the bedrock aquifer ground-water flow system provides discharge to the Red River along this reach.

MARE2DEM: a 2-D inversion code for controlled-source electromagnetic and magnetotelluric data

NASA Astrophysics Data System (ADS)

Key, Kerry

2016-10-01

This work presents MARE2DEM, a freely available code for 2-D anisotropic inversion of magnetotelluric (MT) data and frequency-domain controlled-source electromagnetic (CSEM) data from onshore and offshore surveys. MARE2DEM parametrizes the inverse model using a grid of arbitrarily shaped polygons, where unstructured triangular or quadrilateral grids are typically used due to their ease of construction. Unstructured grids provide significantly more geometric flexibility and parameter efficiency than the structured rectangular grids commonly used by most other inversion codes. Transmitter and receiver components located on topographic slopes can be tilted parallel to the boundary so that the simulated electromagnetic fields accurately reproduce the real survey geometry. The forward solution is implemented with a goal-oriented adaptive finite-element method that automatically generates and refines unstructured triangular element grids that conform to the inversion parameter grid, ensuring accurate responses as the model conductivity changes. This dual-grid approach is significantly more efficient than the conventional use of a single grid for both the forward and inverse meshes since the more detailed finite-element meshes required for accurate responses do not increase the memory requirements of the inverse problem. Forward solutions are computed in parallel with a highly efficient scaling by partitioning the data into smaller independent modeling tasks consisting of subsets of the input frequencies, transmitters and receivers. Non-linear inversion is carried out with a new Occam inversion approach that requires fewer forward calls. Dense matrix operations are optimized for memory and parallel scalability using the ScaLAPACK parallel library. Free parameters can be bounded using a new non-linear transformation that leaves the transformed parameters nearly the same as the original parameters within the bounds, thereby reducing non-linear smoothing effects. Data balancing normalization weights for the joint inversion of two or more data sets encourages the inversion to fit each data type equally well. A synthetic joint inversion of marine CSEM and MT data illustrates the algorithm's performance and parallel scaling on up to 480 processing cores. CSEM inversion of data from the Middle America Trench offshore Nicaragua demonstrates a real world application. The source code and MATLAB interface tools are freely available at http://mare2dem.ucsd.edu.

Coupled Multi-physics analysis of Caprock Integrity and Fault Reactivation during CO2 Sequestration*

NASA Astrophysics Data System (ADS)

Newell, P.; Martinez, M. J.; Bishop, J.

2012-12-01

Structural/stratigraphic trapping beneath a low-permeable caprock layer is the primary trapping mechanism for long-term subsurface sequestration of CO2. Pre-existing fracture networks, injection induced fractures, and faults are of concern for possible CO2 leakage both during and after injection. In this work we model the effects of both caprock jointing and a fault on the caprock sealing integrity during various injection scenarios. The modeling effort uses a three-dimensional finite-element based coupled multiphase flow and geomechanics simulator. The joints within the caprock are idealized as equally spaced and parallel. Both the mechanical and flow behavior of the joint network are treated within an effective continuum formulation. The mechanical behavior of the joint network is linear elastic in shear and nonlinear elastic in the normal direction. The flow behavior of the joint network is treated using the classical cubic-law relating flow rate and aperture. The flow behavior is then upscaled to obtain an effective permeability. The fault is modeled as a finite-thickness layer with multiple joint sets. The joint sets within the fault region are modeled following the same mechanical and flow formulation as the joints within the caprock. Various injection schedules as well as fault and caprock jointing configurations within a proto-typical sequestration site have been investigated. The resulting leakage rates through the caprock and fault are compared to those assuming intact material. The predicted leakage rates are a strong nonlinear function of the injection rate. *This material is based upon work supported as part of the Center for Frontiers of Subsurface Energy Security, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001114. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energys National Nuclear Security Administration under Contract DE-AC04-94AL85000.

Design of smart prosthetic knee utilizing magnetorheological damper

NASA Astrophysics Data System (ADS)

Gao, F.; Liu, Y. N.; Liao, W. H.

2017-04-01

In this study, based on human knee's kinetics, a smart prosthetic knee employing springs, DC motor and magnetorheological (MR) damper is designed. The MR damper is coupled in series with the springs that are mounted in parallel with the DC motor. The working principle of the prosthesis during level-ground walking is presented. During stance phase, the MR damper is powered on. The springs will store and release the negative mechanical energy for restoring the function of human knee joint. In swing phase, the MR damper is powered off for disengaging the springs. In this phase, the work of knee joint is negative. For improving the system energy efficiency, the DC motor will work as a power generator to supply required damping torque and harvest electrical energy. Finally, the design of MR damper is introduced.

A discrete decentralized variable structure robotic controller

NASA Technical Reports Server (NTRS)

Tumeh, Zuheir S.

1989-01-01

A decentralized trajectory controller for robotic manipulators is designed and tested using a multiprocessor architecture and a PUMA 560 robot arm. The controller is made up of a nominal model-based component and a correction component based on a variable structure suction control approach. The second control component is designed using bounds on the difference between the used and actual values of the model parameters. Since the continuous manipulator system is digitally controlled along a trajectory, a discretized equivalent model of the manipulator is used to derive the controller. The motivation for decentralized control is that the derived algorithms can be executed in parallel using a distributed, relatively inexpensive, architecture where each joint is assigned a microprocessor. Nonlinear interaction and coupling between joints is treated as a disturbance torque that is estimated and compensated for.

One-degree-of-freedom spherical model for the passive motion of the human ankle joint.

PubMed

Sancisi, Nicola; Baldisserri, Benedetta; Parenti-Castelli, Vincenzo; Belvedere, Claudio; Leardini, Alberto

2014-04-01

Mathematical modelling of mobility at the human ankle joint is essential for prosthetics and orthotic design. The scope of this study is to show that the ankle joint passive motion can be represented by a one-degree-of-freedom spherical motion. Moreover, this motion is modelled by a one-degree-of-freedom spherical parallel mechanism model, and the optimal pivot-point position is determined. Passive motion and anatomical data were taken from in vitro experiments in nine lower limb specimens. For each of these, a spherical mechanism, including the tibiofibular and talocalcaneal segments connected by a spherical pair and by the calcaneofibular and tibiocalcaneal ligament links, was defined from the corresponding experimental kinematics and geometry. An iterative procedure was used to optimize the geometry of the model, able to predict original experimental motion. The results of the simulations showed a good replication of the original natural motion, despite the numerous model assumptions and simplifications, with mean differences between experiments and predictions smaller than 1.3 mm (average 0.33 mm) for the three joint position components and smaller than 0.7° (average 0.32°) for the two out-of-sagittal plane rotations, once plotted versus the full flexion arc. The relevant pivot-point position after model optimization was found within the tibial mortise, but not exactly in a central location. The present combined experimental and modelling analysis of passive motion at the human ankle joint shows that a one degree-of-freedom spherical mechanism predicts well what is observed in real joints, although its computational complexity is comparable to the standard hinge joint model.

Multibody Kinematics Optimization for the Estimation of Upper and Lower Limb Human Joint Kinematics: A Systematized Methodological Review.

PubMed

Begon, Mickaël; Andersen, Michael Skipper; Dumas, Raphaël

2018-03-01

Multibody kinematics optimization (MKO) aims to reduce soft tissue artefact (STA) and is a key step in musculoskeletal modeling. The objective of this review was to identify the numerical methods, their validation and performance for the estimation of the human joint kinematics using MKO. Seventy-four papers were extracted from a systematized search in five databases and cross-referencing. Model-derived kinematics were obtained using either constrained optimization or Kalman filtering to minimize the difference between measured (i.e., by skin markers, electromagnetic or inertial sensors) and model-derived positions and/or orientations. While hinge, universal, and spherical joints prevail, advanced models (e.g., parallel and four-bar mechanisms, elastic joint) have been introduced, mainly for the knee and shoulder joints. Models and methods were evaluated using: (i) simulated data based, however, on oversimplified STA and joint models; (ii) reconstruction residual errors, ranging from 4 mm to 40 mm; (iii) sensitivity analyses which highlighted the effect (up to 36 deg and 12 mm) of model geometrical parameters, joint models, and computational methods; (iv) comparison with other approaches (i.e., single body kinematics optimization and nonoptimized kinematics); (v) repeatability studies that showed low intra- and inter-observer variability; and (vi) validation against ground-truth bone kinematics (with errors between 1 deg and 22 deg for tibiofemoral rotations and between 3 deg and 10 deg for glenohumeral rotations). Moreover, MKO was applied to various movements (e.g., walking, running, arm elevation). Additional validations, especially for the upper limb, should be undertaken and we recommend a more systematic approach for the evaluation of MKO. In addition, further model development, scaling, and personalization methods are required to better estimate the secondary degrees-of-freedom (DoF).

Design of Mechanism for Assisting Standing Movement Using Planar Linkage and Gear Train

NASA Astrophysics Data System (ADS)

Nango, Jun; Yoshizawa, Hisato; Liu, Jiajun

The number of people who are in need of nursing care due to difficulties they experience with performing various activities of daily living is increasing. In particular, the action of standing up is performed frequently in daily life, and this action starts to induce pain in joints as people age. In this research, we develop a device whose seat plate follows the movement of the thigh in the action of standing up for the purpose of relieving the burden from the joints and reducing the effort associated with nursing care. The device is designed by using a planar five-link mechanism and a gear train, and only a single input is needed to drive the device. The respective lengths of the links are determined by comparing the movement of the seat plate of the device with the movement of the human thigh in the action of standing up. In addition, this device is expected to be useful for assisting users in standing up in a natural manner, including in the case when the body remains supported by the seat plate, as well as for guiding the individual movements of users in the action of standing up.

Polarity effect of electromigration on mechanical properties of lead-free solder joints

NASA Astrophysics Data System (ADS)

Ren, Fei

The trend of electronic packaging is to package the chips and the associated interconnections in a compact way that allows high speed operation; that allows for sufficient heat removal; that can withstand the thermal cycling associated with the turning on and turning off of the circuits; and that protects the circuits from environmental attack. These goals require that flip chip solder joints have higher resistance to electromigration, stronger mechanical property to sustain thermal mechanical stress, and are lead-free materials to satisfy environment and health concern. With lots of work on chemical reaction, electromigration and mechanical study in flip chip solder joints, however, the interaction between different driving forces is still little known. As a matter of fact, the combination study of chemical, electrical and mechanical is more and more significant to the understanding of the behavior of flip chip solder joints. In this dissertation, I developed one dimensional Cu (wire)-eutectic SnAgCu(ball)-Cu(wire) structure to investigate the interaction between electrical and mechanical force in lead-free solder joints. Electromigration was first conducted. The mechanical behaviors of solder joints before, after, and during electromigration were examined. Electrical current and mechanical stress were applied either in serial or in parallel to the solder joints. Tensile, creep, and drop tests, combined with different electrical current densities (1˜5x10 3A/cm2) and different stressing time (3˜144 hours), have been performed to study the effect of electromigration on the mechanical behavior of solder joints. Nano-indentation test was conducted to study the localized mechanical property of IMC at both interfaces in nanometer scale. Fracture images help analyze the failure mechanism of solder joints driven by both electrical and mechanical forces. The combination study shows a strain build-up during electromigration. Furthermore, a ductile-to-brittle transition in flip chip solder joints induced by electromigration is observed, in which the fracture position migrates from the middle to the cathode interface of the joint with increasing current density and time. The transition is explained by the polarity effect of electromigration, particular due to the accumulation of vacancies at the cathode interface.

Knee Joint Kinetics in Relation to Commonly Prescribed Squat Loads and Depths

PubMed Central

Cotter, Joshua A.; Chaudhari, Ait M.; Jamison, Steve T.; Devor, Steven T.

2014-01-01

Controversy exists regarding the safety and performance benefits of performing the squat exercise to depths beyond 90° of knee flexion. Our aim was to compare the net peak external knee flexion moments (pEKFM) experienced over typical ranges of squat loads and depths. Sixteen recreationally trained males (n = 16; 22.7 ± 1.1 yrs; 85.4 ± 2.1 kg; 177.6 ± 0.96 cm; mean ± SEM) with no previous lower limb surgeries or other orthopedic issues and at least one year of consistent resistance training experience while utilizing the squat exercise performed single repetition squat trials in a random order at squat depths of above parallel, parallel, and below parallel. Less than one week before testing, one repetition maximum (1RM) values were found for each squat depth. Subsequent testing required subjects to perform squats at the three depths with three different loads: unloaded, 50% 1RM, and 85% 1RM (nine total trials). Force platform and kinematic data were collected to calculate pEKFM. To assess differences among loads and depths, a two-factor (load and depth) repeated-measures ANOVA with significance set at the P < 0.05 level was used. Squat 1RM significantly decreased 13.6% from the above parallel to parallel squat and another 3.6% from the parallel to the below parallel squat (P < 0.05). Net peak external knee flexion moments significantly increased as both squat depth and load were increased (P ≤ 0.02). Slopes of pEKFM were greater from unloaded to 50% 1RM than when progressing from 50% to 85% 1RM (P < 0.001). The results suggest that that typical decreases in squat loads used with increasing depths are not enough to offset increases in pEKFM. PMID:23085977

Online System for Faster Multipoint Linkage Analysis via Parallel Execution on Thousands of Personal Computers

PubMed Central

Silberstein, M.; Tzemach, A.; Dovgolevsky, N.; Fishelson, M.; Schuster, A.; Geiger, D.

2006-01-01

Computation of LOD scores is a valuable tool for mapping disease-susceptibility genes in the study of Mendelian and complex diseases. However, computation of exact multipoint likelihoods of large inbred pedigrees with extensive missing data is often beyond the capabilities of a single computer. We present a distributed system called “SUPERLINK-ONLINE,” for the computation of multipoint LOD scores of large inbred pedigrees. It achieves high performance via the efficient parallelization of the algorithms in SUPERLINK, a state-of-the-art serial program for these tasks, and through the use of the idle cycles of thousands of personal computers. The main algorithmic challenge has been to efficiently split a large task for distributed execution in a highly dynamic, nondedicated running environment. Notably, the system is available online, which allows computationally intensive analyses to be performed with no need for either the installation of software or the maintenance of a complicated distributed environment. As the system was being developed, it was extensively tested by collaborating medical centers worldwide on a variety of real data sets, some of which are presented in this article. PMID:16685644

Function-based payment model for inpatient medical rehabilitation: an evaluation.

PubMed

Sutton, J P; DeJong, G; Wilkerson, D

1996-07-01

To describe the components of a function-based prospective payment model for inpatient medical rehabilitation that parallels diagnosis-related groups (DRGs), to evaluate this model in relation to stakeholder objectives, and to detail the components of a quality of care incentive program that, when combined with this payment model, creates an incentive for provides to maximize functional outcomes. This article describes a conceptual model, involving no data collection or data synthesis. The basic payment model described parallels DRGs. Information on the potential impact of this model on medical rehabilitation is gleaned from the literature evaluating the impact of DRGs. The conceptual model described is evaluated against the results of a Delphi Survey of rehabilitation providers, consumers, policymakers, and researchers previously conducted by members of the research team. The major shortcoming of a function-based prospective payment model for inpatient medical rehabilitation is that it contains no inherent incentive to maximize functional outcomes. Linkage of reimbursement to outcomes, however, by withholding a fixed proportion of the standard FRG payment amount, placing that amount in a "quality of care" pool, and distributing that pool annually among providers whose predesignated, facility-level, case-mix-adjusted outcomes are attained, may be one strategy for maximizing outcome goals.

A model for cytoplasmic rheology consistent with magnetic twisting cytometry.

PubMed

Butler, J P; Kelly, S M

1998-01-01

Magnetic twisting cytometry is gaining wide applicability as a tool for the investigation of the rheological properties of cells and the mechanical properties of receptor-cytoskeletal interactions. Current technology involves the application and release of magnetically induced torques on small magnetic particles bound to or inside cells, with measurements of the resulting angular rotation of the particles. The properties of purely elastic or purely viscous materials can be determined by the angular strain and strain rate, respectively. However, the cytoskeleton and its linkage to cell surface receptors display elastic, viscous, and even plastic deformation, and the simultaneous characterization of these properties using only elastic or viscous models is internally inconsistent. Data interpretation is complicated by the fact that in current technology, the applied torques are not constant in time, but decrease as the particles rotate. This paper describes an internally consistent model consisting of a parallel viscoelastic element in series with a parallel viscoelastic element, and one approach to quantitative parameter evaluation. The unified model reproduces all essential features seen in data obtained from a wide variety of cell populations, and contains the pure elastic, viscoelastic, and viscous cases as subsets.

Two degrees of freedom parallel linkageto track solarthermal platforms installed on ships

NASA Astrophysics Data System (ADS)

Visa, I.; Cotorcea, A.; Moldovan, M.; Neagoe, M.

2016-08-01

Transportation is responsible at global level for one third of the total energy consumption. Solutions to reduce conventional fuel consumption are under research, to improve the systems’ efficiency and to replace the current fossil fuels. There already are several applications, usually onsmall maritime vehicles, using photovoltaic systems to cover the electric energy demand on-board andto support the owners’ commitment towards sustainability. In most cases, these systems are fixed, parallely aligned with the deck; thus, the amount of solar energy received is heavily reduced (down to 50%) as compared to the available irradiance. Large scale, feasible applications require to maximize the energy output of the solar convertors implemented on ships; using solar tracking systems is an obvious path, allowing a gain up to 35...40% in the output energy, as compared to fixed systems. Spatial limitations, continuous movement of the ship and harsh navigation condition are the main barriers in implementation. This paper proposes a solar tracking system with two degrees of freedom, for a solar thermal platform, based on a parallel linkage with sphericaljoints, considered as Multibody System. The analytical model for mobile platform position, pressure angles and a numerical example are given in the paper.

Stress-Strain Properties of SIFCON in Uniaxial Compression and Tension

DTIC Science & Technology

1988-08-01

direction act as contacting beams whereas fibers aligned parallel to the loading direction act as individual columns . The combination of fiber-to-fiber...applicable to the study of SIFCON. These include such topics as the influence of strain rate on composite behavior, cyclic loading response, fiber-to-matrix...the specimen are shown in Figure 17. The grips consisted of self-clamping steel plates and a universal joint connection to the loading machine which

Proceedings of the 27th International Group for the Psychology of Mathematics Education Conference Held Jointly with the 25th PME-NA Conference (Honolulu, Hawaii, July 13-18, 2003). Volume 2

ERIC Educational Resources Information Center

Pateman, Neil A., Ed.; Dougherty, Barbara J., Ed.; Zilliox, Joseph T., Ed.

2003-01-01

This volume of the 27th International Group for the Psychology of Mathematics Education Conference presents the following research reports: (1) Text Talk, Body Talk, Table Talk: A Design of Ratio and Proportion as Classroom Parallel Events (Dor Abrahamson); (2) Generalizing the Context and Generalising the Calculation (Janet Ainley); (3) Interview…

Operation Corporate: Parallels of the Joint Operational Access Concept

DTIC Science & Technology

2013-04-04

To) 04-04-2013 Master of Military Studies Research Paper September 2012 - April 2013 4. TITLE AND SUBTITLE Sa. CONTRACT NUMBER Operation Corporate...amphibious operations. Discussion: Many books, periodicals, and papers have been written about the Falklands War. Most of these cover a broad...periodicals, and papers have been written about the Falklands War. Most of these cover a broad overview of the air, naval, and ground campaign, or are very

Prophylaxis usage, bleeding rates, and joint outcomes of hemophilia, 1999 to 2010: a surveillance project

PubMed Central

Soucie, J. Michael; Gill, Joan Cox

2017-01-01

This analysis of the US Hemophilia Treatment Center Network and the Centers for Disease Control and Prevention surveillance registry assessed trends in prophylaxis use and its impact on key indicators of arthropathy across the life-span among participants with severe hemophilia A. Data on demographics, clinical characteristics, and outcomes were collected prospectively between 1999 and 2010 at annual clinical visits to 134 hemophilia treatment centers. Trends in treatment and outcomes were evaluated using cross-sectional and longitudinal analyses. Data analyzed included 26 614 visits for 6196 males; mean age at first registry visit was 17.7 years; and median was 14 (range, 2 to 69). During this time, prophylaxis use increased from 31% to 59% overall, and by 2010, 75% of children and youths <20 years were on prophylaxis. On cross-sectional analysis, bleeding rates decreased dramatically for the entire population (P < .001) in parallel with increased prophylaxis usage, possibly because frequent bleeders adopted prophylaxis. Joint bleeding decreased proportionately with prophylaxis (22%) and nonprophylaxis (23%), and target joints decreased more with prophylaxis (80% vs 61%). Joint, total, and target joint bleeding on prophylaxis were 33%, 41%, and 27%, respectively, compared with nonprophylaxis. On longitudinal analysis of individuals over time, prophylaxis predicted decreased bleeding at any age (P < .001), but only prophylaxis initiation prior to age 4 years and nonobesity predicted preservation of joint motion (P < .001 for each). Using a national registry, care providers in a specialized health care network for a rare disorder were able to detect and track trends in outcomes over time. PMID:28183693

Fracturesis Jointitis: Causes, Symptoms, and Treatment in Groundwater Communities.

PubMed

Manda, Alex K; Horsman, Eric

2015-01-01

Fracturesis Jointitis is a grammatical disorder characterized by failure or inability to understand the difference between overarching and specific terms of brittle deformation features. The disorder leads to the use of the word "fracture" as a specific type of discontinuity rather than as an overarching term for mechanical breaks in rocks. This condition appears to be prevalent among groundwater practitioners working with fractured rocks. Common signs and symptoms of Fracturesis Jointitis include the use of terms such as "joints and fractures" and "joints, faults and fractures" when describing fractures in rocks. At best, such terms imply that a "fracture" is one of many kinds of features like joints and faults, and at worst that joints and faults are not fractures but something else. Using proper terms to identify specific fracture types is critical because fractures may act as either barriers to groundwater flow (e.g., faults or deformation bands) or conduits for flow (e.g., faults and joints), The treatment for Fracturesis Jointitis involves an education campaign highlighting to the groundwater community the different fracture types that exist, the modes by which fractures propagate and the role that these fractures play in facilitating or hindering groundwater flow. Those afflicted by Fracturesis Jointitis can be cured of the condition by avoiding the word "fractures" in phrases such as "joints and fractures" or by adding descriptive words before the word "fractures" to specify fracture types (e.g., "foliation-parallel" fractures). Only with a concerted education campaign can we rid our community of Fracturesis Jointitis. © 2014, National Ground Water Association.

The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints

PubMed Central

Fattahi, Farnaz; Hashemi Ardakani, Zahra; Hashemi Ardakani, Maryam

2015-01-01

Statement of the Problem Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. Purpose The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. Materials and Method A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (p< 0.05). Results The mean tensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). Conclusion Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint. PMID:26636118

Spatiotemporal distribution of location and object effects in reach-to-grasp kinematics

PubMed Central

Rouse, Adam G.

2015-01-01

In reaching to grasp an object, the arm transports the hand to the intended location as the hand shapes to grasp the object. Prior studies that tracked arm endpoint and grip aperture have shown that reaching and grasping, while proceeding in parallel, are interdependent to some degree. Other studies of reaching and grasping that have examined the joint angles of all five digits as the hand shapes to grasp various objects have not tracked the joint angles of the arm as well. We, therefore, examined 22 joint angles from the shoulder to the five digits as monkeys reached, grasped, and manipulated in a task that dissociated location and object. We quantified the extent to which each angle varied depending on location, on object, and on their interaction, all as a function of time. Although joint angles varied depending on both location and object beginning early in the movement, an early phase of location effects in joint angles from the shoulder to the digits was followed by a later phase in which object effects predominated at all joint angles distal to the shoulder. Interaction effects were relatively small throughout the reach-to-grasp. Whereas reach trajectory was influenced substantially by the object, grasp shape was comparatively invariant to location. Our observations suggest that neural control of reach-to-grasp may occur largely in two sequential phases: the first determining the location to which the arm transports the hand, and the second shaping the entire upper extremity to grasp and manipulate the object. PMID:26445870

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

PubMed Central

Kuiken, Todd A; Hargrove, Levi J

2014-01-01

Objective Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main Results Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts' Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts' Law tasks with high levels of path efficiency. Significance These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control. PMID:25394366

Real-time simultaneous and proportional myoelectric control using intramuscular EMG

NASA Astrophysics Data System (ADS)

Smith, Lauren H.; Kuiken, Todd A.; Hargrove, Levi J.

2014-12-01

Objective. Myoelectric prostheses use electromyographic (EMG) signals to control movement of prosthetic joints. Clinically available myoelectric control strategies do not allow simultaneous movement of multiple degrees of freedom (DOFs); however, the use of implantable devices that record intramuscular EMG signals could overcome this constraint. The objective of this study was to evaluate the real-time simultaneous control of three DOFs (wrist rotation, wrist flexion/extension, and hand open/close) using intramuscular EMG. Approach. We evaluated task performance of five able-bodied subjects in a virtual environment using two control strategies with fine-wire EMG: (i) parallel dual-site differential control, which enabled simultaneous control of three DOFs and (ii) pattern recognition control, which required sequential control of DOFs. Main results. Over the course of the experiment, subjects using parallel dual-site control demonstrated increased use of simultaneous control and improved performance in a Fitts’ Law test. By the end of the experiment, performance using parallel dual-site control was significantly better (up to a 25% increase in throughput) than when using sequential pattern recognition control for tasks requiring multiple DOFs. The learning trends with parallel dual-site control suggested that further improvements in performance metrics were possible. Subjects occasionally experienced difficulty in performing isolated single-DOF movements with parallel dual-site control but were able to accomplish related Fitts’ Law tasks with high levels of path efficiency. Significance. These results suggest that intramuscular EMG, used in a parallel dual-site configuration, can provide simultaneous control of a multi-DOF prosthetic wrist and hand and may outperform current methods that enforce sequential control.

Design, calibration and validation of a novel 3D printed instrumented spatial linkage that measures changes in the rotational axes of the tibiofemoral joint.

PubMed

Bonny, Daniel P; Hull, M L; Howell, S M

2014-01-01

An accurate axis-finding technique is required to measure any changes from normal caused by total knee arthroplasty in the flexion-extension (F-E) and longitudinal rotation (LR) axes of the tibiofemoral joint. In a previous paper, we computationally determined how best to design and use an instrumented spatial linkage (ISL) to locate the F-E and LR axes such that rotational and translational errors were minimized. However, the ISL was not built and consequently was not calibrated; thus the errors in locating these axes were not quantified on an actual ISL. Moreover, previous methods to calibrate an ISL used calibration devices with accuracies that were either undocumented or insufficient for the device to serve as a gold-standard. Accordingly, the objectives were to (1) construct an ISL using the previously established guidelines,(2) calibrate the ISL using an improved method, and (3) quantify the error in measuring changes in the F-E and LR axes. A 3D printed ISL was constructed and calibrated using a coordinate measuring machine, which served as a gold standard. Validation was performed using a fixture that represented the tibiofemoral joint with an adjustable F-E axis and the errors in measuring changes to the positions and orientations of the F-E and LR axes were quantified. The resulting root mean squared errors (RMSEs) of the calibration residuals using the new calibration method were 0.24, 0.33, and 0.15 mm for the anterior-posterior, medial-lateral, and proximal-distal positions, respectively, and 0.11, 0.10, and 0.09 deg for varus-valgus, flexion-extension, and internal-external orientations, respectively. All RMSEs were below 0.29% of the respective full-scale range. When measuring changes to the F-E or LR axes, each orientation error was below 0.5 deg; when measuring changes in the F-E axis, each position error was below 1.0 mm. The largest position RMSE was when measuring a medial-lateral change in the LR axis (1.2 mm). Despite the large size of the ISL, these calibration residuals were better than those for previously published ISLs, particularly when measuring orientations, indicating that using a more accurate gold standard was beneficial in limiting the calibration residuals. The validation method demonstrated that this ISL is capable of accurately measuring clinically important changes (i.e. 1 mm and 1 deg) in the F-E and LR axes.

Development of a mechatronic platform and validation of methods for estimating ankle stiffness during the stance phase of walking.

PubMed

Rouse, Elliott J; Hargrove, Levi J; Perreault, Eric J; Peshkin, Michael A; Kuiken, Todd A

2013-08-01

The mechanical properties of human joints (i.e., impedance) are constantly modulated to precisely govern human interaction with the environment. The estimation of these properties requires the displacement of the joint from its intended motion and a subsequent analysis to determine the relationship between the imposed perturbation and the resultant joint torque. There has been much investigation into the estimation of upper-extremity joint impedance during dynamic activities, yet the estimation of ankle impedance during walking has remained a challenge. This estimation is important for understanding how the mechanical properties of the human ankle are modulated during locomotion, and how those properties can be replicated in artificial prostheses designed to restore natural movement control. Here, we introduce a mechatronic platform designed to address the challenge of estimating the stiffness component of ankle impedance during walking, where stiffness denotes the static component of impedance. The system consists of a single degree of freedom mechatronic platform that is capable of perturbing the ankle during the stance phase of walking and measuring the response torque. Additionally, we estimate the platform's intrinsic inertial impedance using parallel linear filters and present a set of methods for estimating the impedance of the ankle from walking data. The methods were validated by comparing the experimentally determined estimates for the stiffness of a prosthetic foot to those measured from an independent testing machine. The parallel filters accurately estimated the mechatronic platform's inertial impedance, accounting for 96% of the variance, when averaged across channels and trials. Furthermore, our measurement system was found to yield reliable estimates of stiffness, which had an average error of only 5.4% (standard deviation: 0.7%) when measured at three time points within the stance phase of locomotion, and compared to the independently determined stiffness values of the prosthetic foot. The mechatronic system and methods proposed in this study are capable of accurately estimating ankle stiffness during the foot-flat region of stance phase. Future work will focus on the implementation of this validated system in estimating human ankle impedance during the stance phase of walking.

Agonist-antagonist active knee prosthesis: a preliminary study in level-ground walking.

PubMed

Martinez-Villalpando, Ernesto C; Herr, Hugh

2009-01-01

We present a powered knee prosthesis with two series-elastic actuators positioned in parallel in an agonist-antagonist arrangement. To motivate the knee's design, we developed a prosthetic knee model that comprises a variable damper and two series-elastic clutch units that span the knee joint. Using human gait data to constrain the model's joint to move biologically, we varied model parameters using an optimization scheme that minimized the sum over time of the squared difference between the model's joint torque and biological knee values. We then used these optimized values to specify the mechanical and control design of the prosthesis for level-ground walking. We hypothesized that a variable-impedance control design could produce humanlike knee mechanics during steady-state level-ground walking. As a preliminary evaluation of this hypothesis, we compared the prosthetic knee mechanics of an amputee walking at a self-selected gait speed with those of a weight- and height-matched nonamputee. We found qualitative agreement between prosthetic and human knee mechanics. Because the knee's motors never perform positive work on the knee joint throughout the level-ground gait cycle, the knee's electrical power requirement is modest in walking (8 W), decreasing the size of the onboard battery required to power the prosthesis.

Novel actuation design of a gait trainer with shadow leg approach.

PubMed

Meuleman, Jos; Meuleman, Jos; van Asseldonk, Edwin H F; van der Kooij, Herman

2013-06-01

Robotic gait training has developed since the end of the 20(th) century, yet there is much room for improvement in the design of the robots. With the conventional exoskeleton structures, donning of patients in a gait trainer usually is a cumbersome process due to the need of joint alignments and normal walking is often hindered due to obstructed arm swing. Our goal was to design a gait training robots that overcomes these limitations. We propose a novel design in which these drawbacks are reduced to a great amount. By using a parallel structure behind the patient (shadow leg) that is connected to the patient joints with rods, little alignment is needed, the area lateral to the hip is left free, and thus arm swing is not obstructed. The construction is lightweight, because the actuators are mounted on a fixed base and the transmission of power is executed with light weight rods. An end stop in the shadow leg prevents hyper extension of the patient's knee. The relationship between motor displacement and human joint rotations is nonlinear. In this paper we derive the nonlinear relationships between motors and patient joints and verify these. calculations with a measurement. The device has been built, now tests with subjects are required to assess if subjects can indeed walk normally in the robot.

Elbow joint variability for different hand positions of the round off in gymnastics.

PubMed

Farana, Roman; Irwin, Gareth; Jandacka, Daniel; Uchytil, Jaroslav; Mullineaux, David R

2015-02-01

The aim of the present study was to conduct within-gymnast analyses of biological movement variability in impact forces, elbow joint kinematics and kinetics of expert gymnasts in the execution of the round-off with different hand positions. Six international level female gymnasts performed 10 trials of the round-off from a hurdle step to a back-handspring using two hand potions: parallel and T-shape. Two force plates were used to determine ground reaction forces. Eight infrared cameras were employed to collect the kinematic data automatically. Within gymnast variability was calculated using biological coefficient of variation (BCV) discretely for ground reaction force, kinematic and kinetic measures. Variability of the continuous data was quantified using coefficient of multiple correlations (CMC). Group BCV and CMC were calculated and T-test with effect size statistics determined differences between the variability of the two techniques examined in this study. The major observation was a higher level of biological variability in the elbow joint abduction angle and adduction moment of force in the T-shaped hand position. This finding may lead to a reduced repetitive abduction stress and thus protect the elbow joint from overload. Knowledge of the differences in biological variability can inform clinicians and practitioners with effective skill selection. Copyright © 2014 Elsevier B.V. All rights reserved.

Inverse Kinematics for Upper Limb Compound Movement Estimation in Exoskeleton-Assisted Rehabilitation

PubMed Central

Cortés, Camilo; de los Reyes-Guzmán, Ana; Scorza, Davide; Bertelsen, Álvaro; Carrasco, Eduardo; Gil-Agudo, Ángel; Ruiz-Salguero, Oscar; Flórez, Julián

2016-01-01

Robot-Assisted Rehabilitation (RAR) is relevant for treating patients affected by nervous system injuries (e.g., stroke and spinal cord injury). The accurate estimation of the joint angles of the patient limbs in RAR is critical to assess the patient improvement. The economical prevalent method to estimate the patient posture in Exoskeleton-based RAR is to approximate the limb joint angles with the ones of the Exoskeleton. This approximation is rough since their kinematic structures differ. Motion capture systems (MOCAPs) can improve the estimations, at the expenses of a considerable overload of the therapy setup. Alternatively, the Extended Inverse Kinematics Posture Estimation (EIKPE) computational method models the limb and Exoskeleton as differing parallel kinematic chains. EIKPE has been tested with single DOF movements of the wrist and elbow joints. This paper presents the assessment of EIKPE with elbow-shoulder compound movements (i.e., object prehension). Ground-truth for estimation assessment is obtained from an optical MOCAP (not intended for the treatment stage). The assessment shows EIKPE rendering a good numerical approximation of the actual posture during the compound movement execution, especially for the shoulder joint angles. This work opens the horizon for clinical studies with patient groups, Exoskeleton models, and movements types. PMID:27403420

Joint reconstruction of PET-MRI by exploiting structural similarity

NASA Astrophysics Data System (ADS)

Ehrhardt, Matthias J.; Thielemans, Kris; Pizarro, Luis; Atkinson, David; Ourselin, Sébastien; Hutton, Brian F.; Arridge, Simon R.

2015-01-01

Recent advances in technology have enabled the combination of positron emission tomography (PET) with magnetic resonance imaging (MRI). These PET-MRI scanners simultaneously acquire functional PET and anatomical or functional MRI data. As function and anatomy are not independent of one another the images to be reconstructed are likely to have shared structures. We aim to exploit this inherent structural similarity by reconstructing from both modalities in a joint reconstruction framework. The structural similarity between two modalities can be modelled in two different ways: edges are more likely to be at similar positions and/or to have similar orientations. We analyse the diffusion process generated by minimizing priors that encapsulate these different models. It turns out that the class of parallel level set priors always corresponds to anisotropic diffusion which is sometimes forward and sometimes backward diffusion. We perform numerical experiments where we jointly reconstruct from blurred Radon data with Poisson noise (PET) and under-sampled Fourier data with Gaussian noise (MRI). Our results show that both modalities benefit from each other in areas of shared edge information. The joint reconstructions have less artefacts and sharper edges compared to separate reconstructions and the ℓ2-error can be reduced in all of the considered cases of under-sampling.

Fast Face-Recognition Optical Parallel Correlator Using High Accuracy Correlation Filter

NASA Astrophysics Data System (ADS)

Watanabe, Eriko; Kodate, Kashiko

2005-11-01

We designed and fabricated a fully automatic fast face recognition optical parallel correlator [E. Watanabe and K. Kodate: Appl. Opt. 44 (2005) 5666] based on the VanderLugt principle. The implementation of an as-yet unattained ultra high-speed system was aided by reconfiguring the system to make it suitable for easier parallel processing, as well as by composing a higher accuracy correlation filter and high-speed ferroelectric liquid crystal-spatial light modulator (FLC-SLM). In running trial experiments using this system (dubbed FARCO), we succeeded in acquiring remarkably low error rates of 1.3% for false match rate (FMR) and 2.6% for false non-match rate (FNMR). Given the results of our experiments, the aim of this paper is to examine methods of designing correlation filters and arranging database image arrays for even faster parallel correlation, underlining the issues of calculation technique, quantization bit rate, pixel size and shift from optical axis. The correlation filter has proved its excellent performance and higher precision than classical correlation and joint transform correlator (JTC). Moreover, arrangement of multi-object reference images leads to 10-channel correlation signals, as sharply marked as those of a single channel. This experiment result demonstrates great potential for achieving the process speed of 10000 face/s.

Application of viscous and Iwan modal damping models to experimental measurements from bolted structures

DOE PAGES

Deaner, Brandon J.; Allen, Matthew S.; Starr, Michael James; ...

2015-01-20

Measurements are presented from a two-beam structure with several bolted interfaces in order to characterize the nonlinear damping introduced by the joints. The measurements (all at force levels below macroslip) reveal that each underlying mode of the structure is well approximated by a single degree-of-freedom (SDOF) system with a nonlinear mechanical joint. At low enough force levels, the measurements show dissipation that scales as the second power of the applied force, agreeing with theory for a linear viscously damped system. This is attributed to linear viscous behavior of the material and/or damping provided by the support structure. At larger forcemore » levels, the damping is observed to behave nonlinearly, suggesting that damping from the mechanical joints is dominant. A model is presented that captures these effects, consisting of a spring and viscous damping element in parallel with a four-parameter Iwan model. As a result, the parameters of this model are identified for each mode of the structure and comparisons suggest that the model captures the stiffness and damping accurately over a range of forcing levels.« less

Optimal design and control of an electromechanical transfemoral prosthesis with energy regeneration.

PubMed

Rohani, Farbod; Richter, Hanz; van den Bogert, Antonie J

2017-01-01

In this paper, we present the design of an electromechanical above-knee active prosthesis with energy storage and regeneration. The system consists of geared knee and ankle motors, parallel springs for each motor, an ultracapacitor, and controllable four-quadrant power converters. The goal is to maximize the performance of the system by finding optimal controls and design parameters. A model of the system dynamics was developed, and used to solve a combined trajectory and design optimization problem. The objectives of the optimization were to minimize tracking error relative to human joint motions, as well as energy use. The optimization problem was solved by the method of direct collocation, based on joint torque and joint angle data from ten subjects walking at three speeds. After optimization of controls and design parameters, the simulated system could operate at zero energy cost while still closely emulating able-bodied gait. This was achieved by controlled energy transfer between knee and ankle, and by controlled storage and release of energy throughout the gait cycle. Optimal gear ratios and spring parameters were similar across subjects and walking speeds.

Identifying the control structure of multijoint coordination during pistol shooting.

PubMed

Scholz, J P; Schöner, G; Latash, M L

2000-12-01

The question of degrees of freedom in the control of multijoint movement is posed as the problem of discovering how the motor control system constrains the many possible combinations of joint postures to stabilize task-dependent essential variables. Success at a task can be achieved, in principle, by always adopting a particular joint combination. In contrast, we propose a more selective control strategy: variations of the joint configuration that leave the values of essential task variables unchanged are predicted to be less controlled (i.e., stabilized to a lesser degree) than joint configuration changes that shift the values of the task variables. Our experimental task involved shooting with a laser pistol at a target under four conditions. The seven joint angles of the arm were obtained from the recorded positions of markers on the limb segments. The joint configurations observed at each point in normalized time were analyzed with respect to trial-to-trial variability. Different hypotheses about relevant task variables were used to define sets of joint configurations ("uncontrolled manifolds" or UCMs) that, if realized, would leave essential task variables unchanged. The variability of joint configurations was decomposed into components lying parallel to those sets and components lying in their complement. The orientation of the gun's barrel relative to a vector pointing from the gun to the target was the task variable most successful at showing a difference between the two components of joint variability. This variable determines success at the task. Throughout the movement, not only while the gun was pointing at the target, fluctuations of joint configuration that affected this variable were much reduced compared with fluctuations that did not affect this variable. The UCM principle applied to relative gun orientation thus captures the structure of the motor control system across different parts of joint configuration space as the movement evolves in time. This suggests a specific control strategy in which changes of joint configuration that are irrelevant to success at the task are selectively released from control. By contrast, constraints representing an invariant spatial position of the gun or of the arm's center of mass structured joint configuration variability in the early and mid-portion of the movement trajectory, but not at the time of shooting. This specific control strategy is not trivial, because a target can be hit successfully also by controlling irrelevant directions in joint space equally to relevant ones. The results indicate that the method can be successfully used to determine the structure of coordination in joint space that underlies the control of the essential variables for a given task.

Lower limb joint angles and ground reaction forces in forefoot strike and rearfoot strike runners during overground downhill and uphill running.

PubMed

Kowalski, Erik; Li, Jing Xian

2016-11-01

This study investigated the normal and parallel ground reaction forces during downhill and uphill running in habitual forefoot strike and habitual rearfoot strike (RFS) runners. Fifteen habitual forefoot strike and 15 habitual RFS recreational male runners ran at 3 m/s ± 5% during level, uphill and downhill overground running on a ramp mounted at 6° and 9°. Results showed that forefoot strike runners had no visible impact peak in all running conditions, while the impact peaks only decreased during the uphill conditions in RFS runners. Active peaks decreased during the downhill conditions in forefoot strike runners while active loading rates increased during downhill conditions in RFS runners. Compared to the level condition, parallel braking peaks were larger during downhill conditions and parallel propulsive peaks were larger during uphill conditions. Combined with previous biomechanics studies, our findings suggest that forefoot strike running may be an effective strategy to reduce impacts, especially during downhill running. These findings may have further implications towards injury management and prevention.

Trajectory Tracking of a Planer Parallel Manipulator by Using Computed Force Control Method

NASA Astrophysics Data System (ADS)

Bayram, Atilla

2017-03-01

Despite small workspace, parallel manipulators have some advantages over their serial counterparts in terms of higher speed, acceleration, rigidity, accuracy, manufacturing cost and payload. Accordingly, this type of manipulators can be used in many applications such as in high-speed machine tools, tuning machine for feeding, sensitive cutting, assembly and packaging. This paper presents a special type of planar parallel manipulator with three degrees of freedom. It is constructed as a variable geometry truss generally known planar Stewart platform. The reachable and orientation workspaces are obtained for this manipulator. The inverse kinematic analysis is solved for the trajectory tracking according to the redundancy and joint limit avoidance. Then, the dynamics model of the manipulator is established by using Virtual Work method. The simulations are performed to follow the given planar trajectories by using the dynamic equations of the variable geometry truss manipulator and computed force control method. In computed force control method, the feedback gain matrices for PD control are tuned with fixed matrices by trail end error and variable ones by means of optimization with genetic algorithm.

A Noncoding, Regulatory Mutation Implicates HCFC1 in Nonsyndromic Intellectual Disability

PubMed Central

Huang, Lingli; Jolly, Lachlan A.; Willis-Owen, Saffron; Gardner, Alison; Kumar, Raman; Douglas, Evelyn; Shoubridge, Cheryl; Wieczorek, Dagmar; Tzschach, Andreas; Cohen, Monika; Hackett, Anna; Field, Michael; Froyen, Guy; Hu, Hao; Haas, Stefan A.; Ropers, Hans-Hilger; Kalscheuer, Vera M.; Corbett, Mark A.; Gecz, Jozef

2012-01-01

The discovery of mutations causing human disease has so far been biased toward protein-coding regions. Having excluded all annotated coding regions, we performed targeted massively parallel resequencing of the nonrepetitive genomic linkage interval at Xq28 of family MRX3. We identified in the binding site of transcription factor YY1 a regulatory mutation that leads to overexpression of the chromatin-associated transcriptional regulator HCFC1. When tested on embryonic murine neural stem cells and embryonic hippocampal neurons, HCFC1 overexpression led to a significant increase of the production of astrocytes and a considerable reduction in neurite growth. Two other nonsynonymous, potentially deleterious changes have been identified by X-exome sequencing in individuals with intellectual disability, implicating HCFC1 in normal brain function. PMID:23000143

Enterovirus Control of Translation and RNA Granule Stress Responses.

PubMed

Lloyd, Richard E

2016-03-30

Enteroviruses such as poliovirus (PV) and coxsackievirus B3 (CVB3) have evolved several parallel strategies to regulate cellular gene expression and stress responses to ensure efficient expression of the viral genome. Enteroviruses utilize their encoded proteinases to take over the cellular translation apparatus and direct ribosomes to viral mRNAs. In addition, viral proteinases are used to control and repress the two main types of cytoplasmic RNA granules, stress granules (SGs) and processing bodies (P-bodies, PBs), which are stress-responsive dynamic structures involved in repression of gene expression. This review discusses these processes and the current understanding of the underlying mechanisms with respect to enterovirus infections. In addition, the review discusses accumulating data suggesting linkage exists between RNA granule formation and innate immune sensing and activation.

[Occupational exposure in cancer of the mouth, pharynx and larynx].

PubMed

Oreggia, F; de Stefani, E; Correa, P; Rivero, S; Fernández, G; Leiva, J; Zavala, D

1989-01-01

The AA. have scheduled a case-control study in order to assess the ambient hazards factors in these cancers, through the evaluation of its occupational risk. The program cover 242 cases of the epidermoid type of carcinoma (positive biopsy), and the group was parallelled with another group of 322 (after the age) admitted at the same Hospital, but affected with several processes. Were excluded the cancer of the lung, bladder, pancreas and kidney because of the causal link with tobacco smokers. In oral and pharyngeal cancer the AA. found out that the workers of high risk were butchers, blacksmiths, masons, drivers, electricians and railwaymen. Regarding the cancer of the larynx mechanics, plumbers, farmers, textile workers and drivers showed the greatest linkage. These findings are in accordance with those published in previous papers.

Growth and linkage of the quaternary Ubrique Normal Fault Zone, Western Gibraltar Arc: role on the along-strike relief segmentation

NASA Astrophysics Data System (ADS)

Jiménez-Bonilla, Alejandro; Balanya, Juan Carlos; Exposito, Inmaculada; Diaz-Azpiroz, Manuel; Barcos, Leticia

2015-04-01

Strain partitioning modes within migrating orogenic arcs may result in arc-parallel stretching that produces along-strike structural and topographic discontinuities. In the Western Gibraltar Arc, arc-parallel stretching has operated from the Lower Miocene up to recent times. In this study, we have reviewed the Colmenar Fault, located at the SW end of the Subbetic ranges, previously interpreted as a Middle Miocene low-angle normal fault. Our results allow to identify younger normal fault segments, to analyse their kinematics, growth and segment linkage, and to discuss its role on the structural and relief drop at regional scale. The Colmenar Fault is folded by post-Serravallian NE-SW buckle folds. Both the SW-dipping fault surfaces and the SW-plunging fold axes contribute to the structural relief drop toward the SW. Nevertheless, at the NW tip of the Colmenar Fault, we have identified unfolded normal faults cutting quaternary soils. They are grouped into a N110˚E striking brittle deformation band 15km long and until 3km wide (hereafter Ubrique Normal Fault Zone; UNFZ). The UNFZ is divided into three sectors: (a) The western tip zone is formed by normal faults which usually dip to the SW and whose slip directions vary between N205˚E and N225˚E. These segments are linked to each other by left-lateral oblique faults interpreted as transfer faults. (b) The central part of the UNFZ is composed of a single N115˚E striking fault segment 2,4km long. Slip directions are around N190˚E and the estimated throw is 1,25km. The fault scarp is well-conserved reaching up to 400m in its central part and diminishing to 200m at both segment terminations. This fault segment is linked to the western tip by an overlap zone characterized by tilted blocks limited by high-angle NNE-SSW and WNW-ESE striking faults interpreted as "box faults" [1]. (c) The eastern tip zone is formed by fault segments with oblique slip which also contribute to the downthrown of the SW block. This kinematic pattern seems to be related to other strike-slip fault systems developed to the E of the UNFZ. The structural revision together with updated kinematic data suggest that the Colmenar Fault is cut and downthrown by a younger normal fault zone, the UNFZ, which would have contributed to accommodate arc-parallel stretching until the Quaternary. This stretching provokes along-strike relief segmentation, being the UNFZ the main fault zone causing the final drop of the Subbetic ranges towards the SW within the Western Gibraltar Arc. Our results show displacement variations in each fault segment of the UNFZ, diminishing to their tips. This suggests fault segment linkage finally evolved to build the nearly continuous current fault zone. The development of current large through-going faults linked inside the UNFZ is similar to those ones simulated in some numerical modelling of rift systems [2]. Acknowledgements: RNM-415 and CGL-2013-46368-P [1]Peacock, D.C.P., Knipe, R.J., Sanderson, D.J., 2000. Glossary of normal faults. Journal Structural Geology, 22, 291-305. [2]Cowie, P.A., Gupta, S., Dawers, N.H., 2000. Implications of fault array evolution for synrift depocentre development: insights from a numerical fault growth model. Basin Research, 12, 241-261.

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE PAGES

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

2016-09-09

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

The evolution of recombination in a heterogeneous environment.

PubMed Central

Lenormand, T; Otto, S P

2000-01-01

Most models describing the evolution of recombination have focused on the case of a single population, implicitly assuming that all individuals are equally likely to mate and that spatial heterogeneity in selection is absent. In these models, the evolution of recombination is driven by linkage disequilibria generated either by epistatic selection or drift. Models based on epistatic selection show that recombination can be favored if epistasis is negative and weak compared to directional selection and if the recombination modifier locus is tightly linked to the selected loci. In this article, we examine the joint effects of spatial heterogeneity in selection and epistasis on the evolution of recombination. In a model with two patches, each subject to different selection regimes, we consider the cases of mutation-selection and migration-selection balance as well as the spread of beneficial alleles. We find that including spatial heterogeneity extends the range of epistasis over which recombination can be favored. Indeed, recombination can be favored without epistasis, with negative and even with positive epistasis depending on environmental circumstances. The selection pressure acting on recombination-modifier loci is often much stronger with spatial heterogeneity, and even loosely linked modifiers and free linkage may evolve. In each case, predicting whether recombination is favored requires knowledge of both the type of environmental heterogeneity and epistasis, as none of these factors alone is sufficient to predict the outcome. PMID:10978305

Determining the trophic guilds of fishes and macroinvertebrates in a seagrass food web

USGS Publications Warehouse

Luczkovich, J.J.; Ward, G.P.; Johnson, J.C.; Christian, R.R.; Baird, D.; Neckles, H.; Rizzo, W.M.

2002-01-01

We established trophic guilds of macroinvertebrate and fish taxa using correspondence analysis and a hierarchical clustering strategy for a seagrass food web in winter in the northeastern Gulf of Mexico. To create the diet matrix, we characterized the trophic linkages of macroinvertebrate and fish taxa. present in Hatodule wrightii seagrass habitat areas within the St. Marks National Wildlife Refuge (Florida) using binary data, combining dietary links obtained from relevant literature for macroinvertebrates with stomach analysis of common fishes collected during January and February of 1994. Heirarchical average-linkage cluster analysis of the 73 taxa of fishes and macroinvertebrates in the diet matrix yielded 14 clusters with diet similarity greater than or equal to 0.60. We then used correspondence analysis with three factors to jointly plot the coordinates of the consumers (identified by cluster membership) and of the 33 food sources. Correspondence analysis served as a visualization tool for assigning each taxon to one of eight trophic guilds: herbivores, detritivores, suspension feeders, omnivores, molluscivores, meiobenthos consumers, macrobenthos consumers, and piscivores. These trophic groups, cross-classified with major taxonomic groups, were further used to develop consumer compartments in a network analysis model of carbon flow in this seagrass ecosystem. The method presented here should greatly improve the development of future network models of food webs by providing an objective procedure for aggregating trophic groups.

The Genetic Basis of Upland/Lowland Ecotype Divergence in Switchgrass (Panicum virgatum)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milano, E. R.; Lowry, D. B.; Juenger, T. E.

The evolution of locally adapted ecotypes is a common phenomenon that generates diversity within plant species. However, we know surprisingly little about the genetic mechanisms underlying the locally adapted traits involved in ecotype formation. The genetic architecture underlying locally adapted traits dictates how an organism will respond to environmental selection pressures, and has major implications for evolutionary ecology, conservation, and crop breeding. To understand the genetic architecture underlying the divergence of switchgrass (Panicum virgatum) ecotypes, we constructed a genetic mapping population through a four-way outbred cross between two northern upland and two southern lowland accessions. Trait segregation in this mappingmore » population was largely consistent with multiple independent loci controlling the suite of traits that characterizes ecotype divergence. We assembled a joint linkage map using ddRADseq, and mapped quantitative trait loci (QTL) for traits that are divergent between ecotypes, including flowering time, plant size, physiological processes, and disease resistance. Overall, we found that most QTL had small to intermediate effects. While we identified colocalizing QTL for multiple traits, we did not find any large-effect QTL that clearly controlled multiple traits through pleiotropy or tight physical linkage. These results indicate that ecologically important traits in switchgrass have a complex genetic basis, and that similar loci may underlie divergence across the geographic range of the ecotypes.« less

Lack of segregation of a Marfan-like phenotype associating marfanoie habitus and mitral valve disease with fibrillin gene on chromosome 15

DOE Office of Scientific and Technical Information (OSTI.GOV)

VanMaldergen, L.; Hilbert, P.; Gillerot, Y.

1994-09-01

Apart from typical Marfan syndrome (MS), several Marfan-like conditions are known. One of those is the MASS syndrome (Mitral involvement, Aortic dilatation, Skin and Skeletal abnormalities) defined by Pyeritz et al. Among these, a dominantly inherited mitral valve prolapse with marfanoid habitus have also been reported. Until now, except for a Marfan-like condition described by Boileau et al., all Marfan families are linked to fib 15. A large Belgian pedigree with 25 affected patients among 62 at risk subjects spanning four generations is described. A syndrome including marfanoid skeletal dysplasia (tall stature, dolichostenomelia, arachnodactyly, pectus carinatum joint dislocation), prolapse and/ormore » myxomatous degeneration of the mitral valve, but without aortic dilatation of eye involvement was observed. Although the phenotype fulfills Berlin diagnostic criteria for MS, it closely resembles MASS syndrome. Preliminary linkage results show discordance aggregation insertion in the fib 15 gene, as evaluated by intragenic microsatellite fib 15. Since Dietz et al. described a similar patient with fib 15 gene, we suggest that this variant of Marfan syndrome is genetically heterogeneous and caused by mutations, some of which are allelic to classical Marfan syndrome plus a subtype, some of which are not. Linkage studies are under way to further characterize the gene involved in the present family.« less

A Wolff in sheep's clothing: trabecular bone adaptation in response to changes in joint loading orientation.

PubMed

Barak, Meir M; Lieberman, Daniel E; Hublin, Jean-Jacques

2011-12-01

This study tests Wolff's law of trabecular bone adaptation by examining if induced changes in joint loading orientation cause corresponding adjustments in trabecular orientation. Two groups of sheep were exercised at a trot, 15 min/day for 34 days on an inclined (7°) or level (0°) treadmills. Incline trotting caused the sheep to extend their tarsal joints by 3-4.5° during peak loading (P<0.01) but has no effect on carpal joint angle (P=0.984). Additionally, tarsal joint angle in the incline group sheep were maintained more extended throughout the day using elevated platform shoes on their forelimbs. A third "sedentary group" group did not run but wore platform shoes throughout the day. As predicted by Wolff's law, trabecular orientation in the distal tibia (tarsal joint) were more obtuse by 2.7 to 4.3° in the incline group compared to the level group; trabecular orientation was not significantly different in the sedentary and level groups. In addition, trabecular orientations in the distal radius (carpal joint) of the sedentary, level and incline groups did not differ between groups, and were aligned almost parallel to the radius long axis, corresponding to the almost straight carpal joint angle at peak loading. Measurements of other trabecular bone parameters revealed additional responses to loading, including significantly higher bone volume fraction (BV/TV), Trabecular number (Tb.N) and trabecular thickness (Tb.Th), lower trabecular spacing (Tb.Sp), and less rod-shaped trabeculae (higher structure model index, SMI) in the exercised than sedentary sheep. Overall, these results demonstrate that trabecular bone dynamically adjusts and realigns itself in very precise relation to changes in peak loading direction, indicating that Wolff's law is not only accurate but also highly sensitive. Copyright © 2011 Elsevier Inc. All rights reserved.

Coupled Viscous Fluid Flow and Joint Deformation Analysis for Grout Injection in a Rock Joint

NASA Astrophysics Data System (ADS)

Kim, Hyung-Mok; Lee, Jong-Won; Yazdani, Mahmoud; Tohidi, Elham; Nejati, Hamid Reza; Park, Eui-Seob

2018-02-01

Fluid flow modeling is a major area of interest within the field of rock mechanics. The main objective of this study is to gain insight into the performance of grout injection inside jointed rock masses by numerical modeling of grout flow through a single rock joint. Grout flow has been widely simulated using non-Newtonian Bingham fluid characterized by two main parameters of dynamic viscosity and shear yield strength both of which are time dependent. The increasing value of these properties with injection time will apparently affect the parameters representing the grouting performance including grout penetration length and volumetric injection rate. In addition, through hydromechanical coupling a mutual influence between the injection pressure from the one side and the joint opening/closing behavior and the aperture profile variation on the other side is anticipated. This is capable of producing a considerable impact on grout spread within the rock joints. In this study based on the Bingham fluid model, a series of numerical analysis has been conducted using UDEC to simulate the flow of viscous grout in a single rock joint with smooth parallel surfaces. In these analyses, the time-dependent evolution of the grout fluid properties and the hydromechanical coupling have been considered to investigate their impact on grouting performance. In order to verify the validity of these simulations, the results of analyses including the grout penetration length and the injection flow rate were compared with a well-known analytical solution which is available for the simple case of constant grout properties and non-coupled hydraulic analysis. The comparison demonstrated that the grout penetration length can be overestimated when the time-dependent hardening of grout material is not considered. Moreover, due to the HM coupling, it was shown that the joint opening induced by injection pressure may have a considerable increasing impression on the values of penetration length and injected grout volume.

Biodegradation of coal-related model compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Campbell, J.A.; Stewart, D.L.; McCulloch, M.

1988-06-01

We have studied the reactions of model compounds having coal-related functionalities (ester linkages, ether linkages, PAH) with the intact organism, cell-free filtrate, and cell-free enzyme of C. versicolor to better understand the process of biosolubilization. Many of the degradation products have been identified by gas chromatography/mass spectroscopy (GC/MS). Results indicate that the two compounds tested with the intact fungal organism were completely degraded. Complete degradation refers to no recovery of model compound. We can probably assume that the other two would also be totally degraded, since we have not yet found a simple compound that will survive long-term exposure tomore » the intact fungus. The ease of degradation with the cell-free filtrate appears to be in the order: phenylbenzoate > benzylbenzoate > benzyl ether > methoxybenzophenone. Esters and ethers that are activated by aromatic rings appear to be susceptible to the fungal extract; however, aromatic ketones are not affected by the extract. From the limited results we have obtained from the isolated enzyme, it appears that the activity may parallel the cell-free filtrate. When the cell-free extract was tested with the model compounds indole, dibenzothiophene, and bibenzyl, no degradation with the enzyme was noted: however, exposure of these compounds to the intact organism resulted in complete degradation. Analysis of the controls indicated no degradation. 8 refs., 1 fig., 1 tab.« less

Charge line quad pulser

DOEpatents

Booth, R.

1996-10-08

A quartet of parallel coupled planar triodes is removably mounted in a quadrahedron shaped PCB structure. Releasable brackets and flexible means attached to each triode socket make triode cathode and grid contact with respective conductive coatings on the PCB and a detachable cylindrical conductive element enclosing and contacting the triode anodes jointly permit quick and easy replacement of faulty triodes. By such orientation, the quad pulser can convert a relatively low and broad pulse into a very high and narrow pulse. 16 figs.

Charge line quad pulser

DOEpatents

Booth, Rex

1996-01-01

A quartet of parallel coupled planar triodes is removably mounted in a quadrahedron shaped PCB structure. Releasable brackets and flexible means attached to each triode socket make triode cathode and grid contact with respective conductive coatings on the PCB and a detachable cylindrical conductive element enclosing and contacting the triode anodes jointly permit quick and easy replacement of faulty triodes. By such orientation, the quad pulser can convert a relatively low and broad pulse into a very high and narrow pulse.

Systematic generation of multibody equations of motion suitable for recursive and parallel manipulation

NASA Technical Reports Server (NTRS)

Nikravesh, Parviz E.; Gim, Gwanghum; Arabyan, Ara; Rein, Udo

1989-01-01

The formulation of a method known as the joint coordinate method for automatic generation of the equations of motion for multibody systems is summarized. For systems containing open or closed kinematic loops, the equations of motion can be reduced systematically to a minimum number of second order differential equations. The application of recursive and nonrecursive algorithms to this formulation, computational considerations and the feasibility of implementing this formulation on multiprocessor computers are discussed.

Multiscale implementation of infinite-swap replica exchange molecular dynamics.

PubMed

Yu, Tang-Qing; Lu, Jianfeng; Abrams, Cameron F; Vanden-Eijnden, Eric

2016-10-18

Replica exchange molecular dynamics (REMD) is a popular method to accelerate conformational sampling of complex molecular systems. The idea is to run several replicas of the system in parallel at different temperatures that are swapped periodically. These swaps are typically attempted every few MD steps and accepted or rejected according to a Metropolis-Hastings criterion. This guarantees that the joint distribution of the composite system of replicas is the normalized sum of the symmetrized product of the canonical distributions of these replicas at the different temperatures. Here we propose a different implementation of REMD in which (i) the swaps obey a continuous-time Markov jump process implemented via Gillespie's stochastic simulation algorithm (SSA), which also samples exactly the aforementioned joint distribution and has the advantage of being rejection free, and (ii) this REMD-SSA is combined with the heterogeneous multiscale method to accelerate the rate of the swaps and reach the so-called infinite-swap limit that is known to optimize sampling efficiency. The method is easy to implement and can be trivially parallelized. Here we illustrate its accuracy and efficiency on the examples of alanine dipeptide in vacuum and C-terminal β-hairpin of protein G in explicit solvent. In this latter example, our results indicate that the landscape of the protein is a triple funnel with two folded structures and one misfolded structure that are stabilized by H-bonds.

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

An efficient parallel sampling technique for Multivariate Poisson-Lognormal model: Analysis with two crash count datasets

DOE PAGES

Zhan, Xianyuan; Aziz, H. M. Abdul; Ukkusuri, Satish V.

2015-11-19

Our study investigates the Multivariate Poisson-lognormal (MVPLN) model that jointly models crash frequency and severity accounting for correlations. The ordinary univariate count models analyze crashes of different severity level separately ignoring the correlations among severity levels. The MVPLN model is capable to incorporate the general correlation structure and takes account of the over dispersion in the data that leads to a superior data fitting. But, the traditional estimation approach for MVPLN model is computationally expensive, which often limits the use of MVPLN model in practice. In this work, a parallel sampling scheme is introduced to improve the original Markov Chainmore » Monte Carlo (MCMC) estimation approach of the MVPLN model, which significantly reduces the model estimation time. Two MVPLN models are developed using the pedestrian vehicle crash data collected in New York City from 2002 to 2006, and the highway-injury data from Washington State (5-year data from 1990 to 1994) The Deviance Information Criteria (DIC) is used to evaluate the model fitting. The estimation results show that the MVPLN models provide a superior fit over univariate Poisson-lognormal (PLN), univariate Poisson, and Negative Binomial models. Moreover, the correlations among the latent effects of different severity levels are found significant in both datasets that justifies the importance of jointly modeling crash frequency and severity accounting for correlations.« less

Drainage lineaments in late Quaternary sediments, Ascension and East Baton Rouge Parishes, Louisiana

DOE Office of Scientific and Technical Information (OSTI.GOV)

Birdseye, R.U.; Christians, G.L.; Olson, J.L.

1988-09-01

Analysis of conventional aerial photographs, NHAP imagery, and topographic maps covering Ascension and East Baton Rouge Parishes in southeastern Louisiana reveals fine-textured parallel sets of drainage lineaments and numerous fluvial anomalies. Linear physiographic features include stream channels, natural levees, stream valleys, rectangular drainage patterns, and terrace scarps. Late Pleistocene and Holocene surfaces are involved, but only small drainages are affected and no such control is exerted on the Mississippi river. Most lineaments show preferred northeast and northwest trends. Orientations of mapped joint systems are similar to lineament orientations, which suggests that trends of physiographic lineaments are controlled by underlying structure.more » Several surface faults are mapped in the northern portion of the region, all of which strike essentially east-west. Salt domes are located in the subsurface to the south; however, they have no geomorphic expression and do not seem to be associated with the lineaments. Therefore, joints rather than faults or salt diapirs are a likely structural control. Joints may provide paths of weakness along which surface drainage might develop preferentially. Thus, joints probably exert an important control on the geomorphology of the region. The joint pattern appears to be related to the local distribution of the Mesozoic and Cenozoic strata, and may result from regional subsidence due to the thick accumulation of deltaic sediments. Conclusive subsurface data are currently unavailable, and shallow seismic surveys in the future may strengthen the case for an interpretation of structural control of drainage.« less

Functionally deficient mesenchymal stem cells reside in the bone marrow niche with M2-macrophages and amyloid-β protein adjacent to loose total joint implants.

PubMed

Margulies, Bryan S; DeBoyace, Sean D; Parsons, Adrienne M; Policastro, Connor G; Ee, Jessica S S; Damron, Timothy S

2015-05-01

We sought to demonstrate whether there is a difference in the local mesenchymal stem cells (MSC) niche obtained from patients undergoing their first total joint replacement surgery versus those patients undergoing a revision surgery for an failing total joint implant. Bone marrow aspirates collected from patients undergoing revision total joint arthroplasty were observed to be less clonal and the expression of PDGFRα, CD51, ALCAM, endoglin, CXCL12, nestin, and nucleostemin were decreased. Revision MSC were also less able to commit to an osteoblast-lineage or an adipocyte-lineage. Further, in revision MSC, OPG, and IL6 expression were increased. Monocytes, derived from revision whole marrow aspirates, were less capable of differentiating into osteoclasts, the cells implicated in the pathologic degradation of bone. Osteoclasts were also not observed in tissue samples collected adjacent to the implants of revision patients; however, the alternatatively activated M2-macrophage phenotype was observed in parallel with pathologic accumulations of amyloid-β, τ-protien and 3-nitrotyrosine. Despite the limited numbers of patients examined, our data suggest that nucleostemin may be a useful functional marker for MSC while the observation of M2-macrophage infiltration around the implant lays the foundation for future investigation into a novel mechanism that we propose is associated with loose total joint implants. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Monitoring of fatigue damage in composite lap-joints using guided waves and FBG sensors

NASA Astrophysics Data System (ADS)

Karpenko, Oleksii; Khomenko, Anton; Koricho, Ermias; Haq, Mahmoodul; Udpa, Lalita

2016-02-01

Adhesive bonding is being increasingly employed in many applications as it offers possibility of light-weighting and efficient multi-material joining along with reduction in time and cost of manufacturing. However, failure initiation and progression in critical components like joints, specifically in fatigue loading is not well understood, which necessitates reliable NDE and SHM techniques to ensure structural integrity. In this work, concurrent guided wave (GW) and fiber Bragg grating (FBG) sensor measurements were used to monitor fatigue damage in adhesively bonded composite lap-joints. In the present set-up, one FBG sensor was strategically embedded in the adhesive bond-line of a lap-joint, while two other FBGs were bonded on the surface of the adherends. Full spectral responses of FBG sensors were collected and compared at specific intervals of fatigue loading. In parallel, guided waves were actuated and sensed using PZT wafers mounted on the composite adherends. Experimental results demonstrated that time-of-flight (ToF) of the fundamental modes transmitted through the bond-line and spectral response of FBG sensors were sensitive to fatigue loading and damage. Combination of guided wave and FBG measurements provided the desired redundancy and synergy in the data to evaluate the degradation in bond-line properties. Measurements taken in the presence of continuously applied load replicated the in-situ/service conditions. The approach shows promise in understanding the behavior of bonded joints subjected to complex loading.

Joint estimation of 2D-DOA and frequency based on space-time matrix and conformal array.

PubMed

Wan, Liang-Tian; Liu, Lu-Tao; Si, Wei-Jian; Tian, Zuo-Xi

2013-01-01

Each element in the conformal array has a different pattern, which leads to the performance deterioration of the conventional high resolution direction-of-arrival (DOA) algorithms. In this paper, a joint frequency and two-dimension DOA (2D-DOA) estimation algorithm for conformal array are proposed. The delay correlation function is used to suppress noise. Both spatial and time sampling are utilized to construct the spatial-time matrix. The frequency and 2D-DOA estimation are accomplished based on parallel factor (PARAFAC) analysis without spectral peak searching and parameter pairing. The proposed algorithm needs only four guiding elements with precise positions to estimate frequency and 2D-DOA. Other instrumental elements can be arranged flexibly on the surface of the carrier. Simulation results demonstrate the effectiveness of the proposed algorithm.

NASA Tech Briefs, August 2003

NASA Technical Reports Server (NTRS)

2003-01-01

Topics covered include: Stable, Thermally Conductive Fillers for Bolted Joints; Connecting to Thermocouples with Fewer Lead Wires; Zipper Connectors for Flexible Electronic Circuits; Safety Interlock for Angularly Misdirected Power Tool; Modular, Parallel Pulse-Shaping Filter Architectures; High-Fidelity Piezoelectric Audio Device; Photovoltaic Power Station with Ultracapacitors for Storage; Time Analyzer for Time Synchronization and Monitor of the Deep Space Network; Program for Computing Albedo; Integrated Software for Analyzing Designs of Launch Vehicles; Abstract-Reasoning Software for Coordinating Multiple Agents; Software Searches for Better Spacecraft-Navigation Models; Software for Partly Automated Recognition of Targets; Antistatic Polycarbonate/Copper Oxide Composite; Better VPS Fabrication of Crucibles and Furnace Cartridges; Burn-Resistant, Strong Metal-Matrix Composites; Self-Deployable Spring-Strip Booms; Explosion Welding for Hermetic Containerization; Improved Process for Fabricating Carbon Nanotube Probes; Automated Serial Sectioning for 3D Reconstruction; and Parallel Subconvolution Filtering Architectures.

Experimental signatures of the inverted phase in InAs/GaSb coupled quantum wells

NASA Astrophysics Data System (ADS)

Karalic, Matija; Mueller, Susanne; Mittag, Christopher; Pakrouski, Kiryl; Wu, QuanSheng; Soluyanov, Alexey A.; Troyer, Matthias; Tschirky, Thomas; Wegscheider, Werner; Ensslin, Klaus; Ihn, Thomas

2016-12-01

Transport measurements are performed on InAs/GaSb double quantum wells at zero and finite magnetic fields applied parallel and perpendicular to the quantum wells. We investigate a sample in the inverted regime where electrons and holes coexist, and compare it with another sample in the noninverted semiconducting regime. The activated behavior in conjunction with a strong suppression of the resistance peak at the charge neutrality point in a parallel magnetic field attest to the topological hybridization gap between electron and hole bands in the inverted sample. We observe an unconventional Landau level spectrum with energy gaps modulated by the magnetic field applied perpendicular to the quantum wells. This is caused by a strong spin-orbit interaction provided jointly by the InAs and the GaSb quantum wells.

Improving record linkage performance in the presence of missing linkage data.

PubMed

Ong, Toan C; Mannino, Michael V; Schilling, Lisa M; Kahn, Michael G

2014-12-01

Existing record linkage methods do not handle missing linking field values in an efficient and effective manner. The objective of this study is to investigate three novel methods for improving the accuracy and efficiency of record linkage when record linkage fields have missing values. By extending the Fellegi-Sunter scoring implementations available in the open-source Fine-grained Record Linkage (FRIL) software system we developed three novel methods to solve the missing data problem in record linkage, which we refer to as: Weight Redistribution, Distance Imputation, and Linkage Expansion. Weight Redistribution removes fields with missing data from the set of quasi-identifiers and redistributes the weight from the missing attribute based on relative proportions across the remaining available linkage fields. Distance Imputation imputes the distance between the missing data fields rather than imputing the missing data value. Linkage Expansion adds previously considered non-linkage fields to the linkage field set to compensate for the missing information in a linkage field. We tested the linkage methods using simulated data sets with varying field value corruption rates. The methods developed had sensitivity ranging from .895 to .992 and positive predictive values (PPV) ranging from .865 to 1 in data sets with low corruption rates. Increased corruption rates lead to decreased sensitivity for all methods. These new record linkage algorithms show promise in terms of accuracy and efficiency and may be valuable for combining large data sets at the patient level to support biomedical and clinical research. Copyright © 2014 Elsevier Inc. All rights reserved.

Privacy preserving interactive record linkage (PPIRL).

PubMed

Kum, Hye-Chung; Krishnamurthy, Ashok; Machanavajjhala, Ashwin; Reiter, Michael K; Ahalt, Stanley

2014-01-01

Record linkage to integrate uncoordinated databases is critical in biomedical research using Big Data. Balancing privacy protection against the need for high quality record linkage requires a human-machine hybrid system to safely manage uncertainty in the ever changing streams of chaotic Big Data. In the computer science literature, private record linkage is the most published area. It investigates how to apply a known linkage function safely when linking two tables. However, in practice, the linkage function is rarely known. Thus, there are many data linkage centers whose main role is to be the trusted third party to determine the linkage function manually and link data for research via a master population list for a designated region. Recently, a more flexible computerized third-party linkage platform, Secure Decoupled Linkage (SDLink), has been proposed based on: (1) decoupling data via encryption, (2) obfuscation via chaffing (adding fake data) and universe manipulation; and (3) minimum information disclosure via recoding. We synthesize this literature to formalize a new framework for privacy preserving interactive record linkage (PPIRL) with tractable privacy and utility properties and then analyze the literature using this framework. Human-based third-party linkage centers for privacy preserving record linkage are the accepted norm internationally. We find that a computer-based third-party platform that can precisely control the information disclosed at the micro level and allow frequent human interaction during the linkage process, is an effective human-machine hybrid system that significantly improves on the linkage center model both in terms of privacy and utility.

Next Generation Mapping of Enological Traits in an F2 Interspecific Grapevine Hybrid Family

PubMed Central

Sun, Qi; Manns, David C.; Sacks, Gavin L.; Mansfield, Anna Katharine; Luby, James J.; Londo, Jason P.; Reisch, Bruce I.; Cadle-Davidson, Lance E.; Fennell, Anne Y.

2016-01-01

In winegrapes (Vitis spp.), fruit quality traits such as berry color, total soluble solids content (SS), malic acid content (MA), and yeast assimilable nitrogen (YAN) affect fermentation or wine quality, and are important traits in selecting new hybrid winegrape cultivars. Given the high genetic diversity and heterozygosity of Vitis species and their tendency to exhibit inbreeding depression, linkage map construction and quantitative trait locus (QTL) mapping has relied on F1 families with the use of simple sequence repeat (SSR) and other markers. This study presents the construction of a genetic map by single nucleotide polymorphisms identified through genotyping-by-sequencing (GBS) technology in an F2 mapping family of 424 progeny derived from a cross between the wild species V. riparia Michx. and the interspecific hybrid winegrape cultivar, ‘Seyval’. The resulting map has 1449 markers spanning 2424 cM in genetic length across 19 linkage groups, covering 95% of the genome with an average distance between markers of 1.67 cM. Compared to an SSR map previously developed for this F2 family, these results represent an improved map covering a greater portion of the genome with higher marker density. The accuracy of the map was validated using the well-studied trait berry color. QTL affecting YAN, MA and SS related traits were detected. A joint MA and SS QTL spans a region with candidate genes involved in the malate metabolism pathway. We present an analytical pipeline for calling intercross GBS markers and a high-density linkage map for a large F2 family of the highly heterozygous Vitis genus. This study serves as a model for further genetic investigations of the molecular basis of additional unique characters of North American hybrid wine cultivars and to enhance the breeding process by marker-assisted selection. The GBS protocols for identifying intercross markers developed in this study can be adapted for other heterozygous species. PMID:26974672

Aβ-affected pathogenic induction of S-nitrosylation of OGT and identification of Cys-NO linkage triplet.

PubMed

Ryu, In-Hyun; Lee, Ki-Young; Do, Su-Il

2016-05-01

Mechanistic link of protein hypo-O-GlcNAcylation to the pathogenesis of Alzheimer's disease (AD) remains unclear. Here, we found that S-nitrosylation of O-linked N-acetylglucosaminyltransferase (SNO-OGT) was induced by β-amyloid peptide (Aβ) exposure to SK-N-MC and SK-N-SH human neuroblastoma cells. Subsequently, Aβ-induced SNO-OGT led to protein hypo-O-GlcNAcylation globally including tau hypo-O-GlcNAcylation. Our results support that underlying mechanism for induction of SNO-OGT comprises the concerted action of Aβ-triggered Ca2+ entry into cells and nNOS-catalyzed NO production. Intriguingly, OGT was found to be associated with nNOS and its association was enhanced during Aβ treatment. In parallel with SNO-OGT-mediated tau hypo-O-GlcNAcylation, Aβ led to SNO-Akt-mediated GSK3β activation for tau phosphorylation, suggesting that tau hyperphosphorylation is established by synergistic connection between SNO-OGT and GSK3β activation. We also observed that Aβ-neurotoxicity including both reactive oxygen species (ROS) production and cell death was amplified with DON treatment, whereas it was restored by PUGNAc treatment, GlcNH2 treatment or OGT overexpression. Early time-course Aβ-monitoring assay revealed that premaintained hyper-O-GlcNAcylation inside cells blocked not only Aβ-triggered Ca2+ entry into cells but also induction of SNO-OGT and SNO-Akt. Together, these findings suggest that induction of SNO-OGT by Aβ exposure is a pathogenic mechanism to cause cellular hypo-O-GlcNAcylation by which Aβ neurotoxicity is executed, and conversely, hyper-O-GlcNAcylation within cells can defend against Aβ neurotoxicity. Furthermore, our Cys mapping demonstrates that cysteine-nitric oxide (Cys-NO) linkages in SNO-OGT occur at triple Cys845, Cys921, and Cys965 residues in C-terminal catalytic domain (C-CAT), suggesting that Cys-NO linkage triplet in SNO-OGT is associated with null OGT activity. Copyright © 2016 Elsevier B.V. All rights reserved.

Linkage and related analyses of Barrett's esophagus and its associated adenocarcinomas.

PubMed

Sun, Xiangqing; Elston, Robert; Falk, Gary W; Grady, William M; Faulx, Ashley; Mittal, Sumeet K; Canto, Marcia I; Shaheen, Nicholas J; Wang, Jean S; Iyer, Prasad G; Abrams, Julian A; Willis, Joseph E; Guda, Kishore; Markowitz, Sanford; Barnholtz-Sloan, Jill S; Chandar, Apoorva; Brock, Wendy; Chak, Amitabh

2016-07-01

Familial aggregation and segregation analysis studies have provided evidence of a genetic basis for esophageal adenocarcinoma (EAC) and its premalignant precursor, Barrett's esophagus (BE). We aim to demonstrate the utility of linkage analysis to identify the genomic regions that might contain the genetic variants that predispose individuals to this complex trait (BE and EAC). We genotyped 144 individuals in 42 multiplex pedigrees chosen from 1000 singly ascertained BE/EAC pedigrees, and performed both model-based and model-free linkage analyses, using S.A.G.E. and other software. Segregation models were fitted, from the data on both the 42 pedigrees and the 1000 pedigrees, to determine parameters for performing model-based linkage analysis. Model-based and model-free linkage analyses were conducted in two sets of pedigrees: the 42 pedigrees and a subset of 18 pedigrees with female affected members that are expected to be more genetically homogeneous. Genome-wide associations were also tested in these families. Linkage analyses on the 42 pedigrees identified several regions consistently suggestive of linkage by different linkage analysis methods on chromosomes 2q31, 12q23, and 4p14. A linkage on 15q26 is the only consistent linkage region identified in the 18 female-affected pedigrees, in which the linkage signal is higher than in the 42 pedigrees. Other tentative linkage signals are also reported. Our linkage study of BE/EAC pedigrees identified linkage regions on chromosomes 2, 4, 12, and 15, with some reported associations located within our linkage peaks. Our linkage results can help prioritize association tests to delineate the genetic determinants underlying susceptibility to BE and EAC.

Probabilistic record linkage

PubMed Central

Sayers, Adrian; Ben-Shlomo, Yoav; Blom, Ashley W; Steele, Fiona

2016-01-01

Abstract Studies involving the use of probabilistic record linkage are becoming increasingly common. However, the methods underpinning probabilistic record linkage are not widely taught or understood, and therefore these studies can appear to be a ‘black box’ research tool. In this article, we aim to describe the process of probabilistic record linkage through a simple exemplar. We first introduce the concept of deterministic linkage and contrast this with probabilistic linkage. We illustrate each step of the process using a simple exemplar and describe the data structure required to perform a probabilistic linkage. We describe the process of calculating and interpreting matched weights and how to convert matched weights into posterior probabilities of a match using Bayes theorem. We conclude this article with a brief discussion of some of the computational demands of record linkage, how you might assess the quality of your linkage algorithm, and how epidemiologists can maximize the value of their record-linked research using robust record linkage methods. PMID:26686842

Privacy preserving interactive record linkage (PPIRL)

PubMed Central

Kum, Hye-Chung; Krishnamurthy, Ashok; Machanavajjhala, Ashwin; Reiter, Michael K; Ahalt, Stanley

2014-01-01

Objective Record linkage to integrate uncoordinated databases is critical in biomedical research using Big Data. Balancing privacy protection against the need for high quality record linkage requires a human–machine hybrid system to safely manage uncertainty in the ever changing streams of chaotic Big Data. Methods In the computer science literature, private record linkage is the most published area. It investigates how to apply a known linkage function safely when linking two tables. However, in practice, the linkage function is rarely known. Thus, there are many data linkage centers whose main role is to be the trusted third party to determine the linkage function manually and link data for research via a master population list for a designated region. Recently, a more flexible computerized third-party linkage platform, Secure Decoupled Linkage (SDLink), has been proposed based on: (1) decoupling data via encryption, (2) obfuscation via chaffing (adding fake data) and universe manipulation; and (3) minimum information disclosure via recoding. Results We synthesize this literature to formalize a new framework for privacy preserving interactive record linkage (PPIRL) with tractable privacy and utility properties and then analyze the literature using this framework. Conclusions Human-based third-party linkage centers for privacy preserving record linkage are the accepted norm internationally. We find that a computer-based third-party platform that can precisely control the information disclosed at the micro level and allow frequent human interaction during the linkage process, is an effective human–machine hybrid system that significantly improves on the linkage center model both in terms of privacy and utility. PMID:24201028

A Novel Concept for Safe, Stiffness-Controllable Robot Links.

PubMed

Stilli, Agostino; Wurdemann, Helge A; Althoefer, Kaspar

2017-03-01

The recent decade has seen an astounding increase of interest and advancement in a new field of robotics, aimed at creating structures specifically for the safe interaction with humans. Softness, flexibility, and variable stiffness in robotics have been recognized as highly desirable characteristics for many applications. A number of solutions were proposed ranging from entirely soft robots (such as those composed mainly from soft materials such as silicone), via flexible continuum and snake-like robots, to rigid-link robots enhanced by joints that exhibit an elastic behavior either implemented in hardware or achieved purely by means of intelligent control. Although these are very good solutions paving the path to safe human-robot interaction, we propose here a new approach that focuses on creating stiffness controllability for the linkages between the robot joints. This article proposes a replacement for the traditionally rigid robot link-the new link is equipped with an additional capability of stiffness controllability. With this added feature, a robot can accurately carry out manipulation tasks (high stiffness), but can virtually instantaneously reduce its stiffness when a human is nearby or in contact with the robot. The key point of the invention described here is a robot link made of an airtight chamber formed by a soft and flexible, but high-strain resistant combination of a plastic mesh and silicone wall. Inflated with air to a high pressure, the mesh silicone chamber behaves like a rigid link; reducing the air pressure, softens the link and rendering the robot structure safe. This article investigates a number of link prototypes and shows the feasibility of the new concept. Stiffness tests have been performed, showing that a significant level of stiffness can be achieved-up to 40 N reaction force along the axial direction, for a 25-mm-diameter sample at 60 kPa, at an axial deformation of 5 mm. The results confirm that this novel concept to linkages for robot manipulators exhibits the beam-like behavior of traditional rigid links when fully pressurized and significantly reduced stiffness at low pressure. The proposed concept has the potential to easily create safe robots, augmenting traditional robot designs.

Users' guide on socket heat fusion joining of polyethylene gas pipes. Volume 1. Topical report, September 1989-September 1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.

1991-03-01

The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setups for conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less

Technical reference on socket heat fusion joining of polyethylene gas pipes. Volume 2. Topical Report, September 1989-September 1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pimputkar, S.M.; McCoy, J.K.; Stets, J.A.

1991-03-01

The integrity of a pipeline system is determined by its weakest links which may be the joints. Heat fusion is the most common method for joining gas distribution polyethylene (PE) piping. There are procedural, thermal, and mechanical aspects of making fusion joints. Acceptable procedural aspects, such as heater calibration and cleanliness, can be assured by rigorous training and certification of the operators. Thermal and mechanical aspects consist of specifying joining conditions such as the heater temperature, heating time, and joining pressure. In the absence of procedural errors, the strength of a fusion joint should depend on the pipe material, pipemore » dimensions, and the thermal and mechanical joining conditions. Socket heat fusion was studied both experimentally and analytically to determine how the strength of the joint varied with the conditions under which it was made. The standard tensile impact test was modified to test socket fusion joint samples in shear. The developed shear impact energy test data were found to be reliable measures of strength if the setup conditions were meticulously identical. A parameter, termed the socket joining parameter, was found to characterize the joining conditions. It is a strong function of melt volume at the end of the heating phase, and, physically, it is polyethylene transported parallel to the axis during insertion. The results for three resins are presented in the form of three nomographs. The nomographs may be used to select the required heater temperature or the heating time, for a given ambient temperature and a PE resin, to ensure a structurally sound socket heat fusion joint.« less

Intelligent Robotic Systems Study (IRSS), phase 2

NASA Technical Reports Server (NTRS)

1990-01-01

Under the Intelligent Robotics System Study (IRSS) contract, a generalized robotic control architecture was developed for use with the ProtoFlight Manipulator Arm (PFMA). The controller built for the PFMA provides localized position based force control, teleoperation and advanced path recording and playback capabilities. Various hand controllers can be used with the system in conjunction with a synthetic time delay capability to provide a realistic test bed for typical satellite servicing tasks. The configuration of the IRSS system is illustrated and discussed. The PFMA has six computer controllable degrees of freedom (DOF) plus a seventh manually indexable DOF, making the manipulator a pseudo 7 DOF mechanism. Because the PFMA was not developed to operate in a gravity field, but rather in space, it is counter balanced at the shoulder, elbow and wrist and a spring counterbalance has been added near the wrist to provide additional support. Built with long slender intra-joint linkages, the PFMA has a workspace nearly 2 meters deep and possesses sufficient dexterity to perform numerous satellite servicing tasks. The manipulator is arranged in a shoulder-yaw, pitch, elbow-pitch, and wrist-pitch, yaw, roll configuration, with an indexable shoulder roll joint. Digital control of the PFMA is implemented using a variety of single board computers developed by Heurikon Corporation and other manufacturers. The IRSS controller is designed to be a multi-rate, multi-tasking system. Independent joint servos run at a 134 Hz rate and position based impedance control functions at 67 Hz. Autonomous path generation and hand controller inputs are processed at a 33 Hz.

Linkages: Effective Keys to Success.

ERIC Educational Resources Information Center

Tindall, Lloyd W.

1986-01-01

Discusses various elements of linkages: informal agreements; formal written agreements; making agreements work; the non-financial agreement; how linkages work at the elementary, secondary, and postsecondary levels in Wisconsin; mandated linkages; and the importance of linkages in the vocational education and training arena. (CT)

Biomechanical Comparison of External Fixation and Compression Screws for Transverse Tarsal Joint Arthrodesis.

PubMed

Latt, L Daniel; Glisson, Richard R; Adams, Samuel B; Schuh, Reinhard; Narron, John A; Easley, Mark E

2015-10-01

Transverse tarsal joint arthrodesis is commonly performed in the operative treatment of hindfoot arthritis and acquired flatfoot deformity. While fixation is typically achieved using screws, failure to obtain and maintain joint compression sometimes occurs, potentially leading to nonunion. External fixation is an alternate method of achieving arthrodesis site compression and has the advantage of allowing postoperative compression adjustment when necessary. However, its performance relative to standard screw fixation has not been quantified in this application. We hypothesized that external fixation could provide transverse tarsal joint compression exceeding that possible with screw fixation. Transverse tarsal joint fixation was performed sequentially, first with a circular external fixator and then with compression screws, on 9 fresh-frozen cadaveric legs. The external fixator was attached in abutting rings fixed to the tibia and the hindfoot and a third anterior ring parallel to the hindfoot ring using transverse wires and half-pins in the tibial diaphysis, calcaneus, and metatarsals. Screw fixation comprised two 4.3 mm headless compression screws traversing the talonavicular joint and 1 across the calcaneocuboid joint. Compressive forces generated during incremental fixator foot ring displacement to 20 mm and incremental screw tightening were measured using a custom-fabricated instrumented miniature external fixator spanning the transverse tarsal joint. The maximum compressive force generated by the external fixator averaged 186% of that produced by the screws (range, 104%-391%). Fixator compression surpassed that obtainable with screws at 12 mm of ring displacement and decreased when the tibial ring was detached. No correlation was found between bone density and the compressive force achievable by either fusion method. The compression across the transverse tarsal joint that can be obtained with a circular external fixator including a tibial ring exceeds that which can be obtained with 3 headless compression screws. Screw and external fixator performance did not correlate with bone mineral density. This study supports the use of external fixation as an alternative method of generating compression to help stimulate fusion across the transverse tarsal joints. The findings provide biomechanical evidence to support the use of external fixation as a viable option in transverse tarsal joint fusion cases in which screw fixation has failed or is anticipated to be inadequate due to suboptimal bone quality. © The Author(s) 2015.

The effect of subject measurement error on joint kinematics in the conventional gait model: Insights from the open-source pyCGM tool using high performance computing methods.

PubMed

Schwartz, Mathew; Dixon, Philippe C

2018-01-01

The conventional gait model (CGM) is a widely used biomechanical model which has been validated over many years. The CGM relies on retro-reflective markers placed along anatomical landmarks, a static calibration pose, and subject measurements as inputs for joint angle calculations. While past literature has shown the possible errors caused by improper marker placement, studies on the effects of inaccurate subject measurements are lacking. Moreover, as many laboratories rely on the commercial version of the CGM, released as the Plug-in Gait (Vicon Motion Systems Ltd, Oxford, UK), integrating improvements into the CGM code is not easily accomplished. This paper introduces a Python implementation for the CGM, referred to as pyCGM, which is an open-source, easily modifiable, cross platform, and high performance computational implementation. The aims of pyCGM are to (1) reproduce joint kinematic outputs from the Vicon CGM and (2) be implemented in a parallel approach to allow integration on a high performance computer. The aims of this paper are to (1) demonstrate that pyCGM can systematically and efficiently examine the effect of subject measurements on joint angles and (2) be updated to include new calculation methods suggested in the literature. The results show that the calculated joint angles from pyCGM agree with Vicon CGM outputs, with a maximum lower body joint angle difference of less than 10-5 degrees. Through the hierarchical system, the ankle joint is the most vulnerable to subject measurement error. Leg length has the greatest effect on all joints as a percentage of measurement error. When compared to the errors previously found through inter-laboratory measurements, the impact of subject measurements is minimal, and researchers should rather focus on marker placement. Finally, we showed that code modifications can be performed to include improved hip, knee, and ankle joint centre estimations suggested in the existing literature. The pyCGM code is provided in open source format and available at https://github.com/cadop/pyCGM.

Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters.

PubMed

Macionis, Valdas

2013-01-09

Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. The paper goniometer and the standard goniometer can be used interchangeably by non-professional raters for evaluation of normal finger joints. The obtained results warrant further research to assess clinical performance of the paper strip technique.

Reliability of the standard goniometry and diagrammatic recording of finger joint angles: a comparative study with healthy subjects and non-professional raters

PubMed Central

2013-01-01

Background Diagrammatic recording of finger joint angles by using two criss-crossed paper strips can be a quick substitute to the standard goniometry. As a preliminary step toward clinical validation of the diagrammatic technique, the current study employed healthy subjects and non-professional raters to explore whether reliability estimates of the diagrammatic goniometry are comparable with those of the standard procedure. Methods The study included two procedurally different parts, which were replicated by assigning 24 medical students to act interchangeably as 12 subjects and 12 raters. A larger component of the study was designed to compare goniometers side-by-side in measurement of finger joint angles varying from subject to subject. In the rest of the study, the instruments were compared by parallel evaluations of joint angles similar for all subjects in a situation of simulated change of joint range of motion over time. The subjects used special guides to position the joints of their left ring finger at varying angles of flexion and extension. The obtained diagrams of joint angles were converted to numerical values by computerized measurements. The statistical approaches included calculation of appropriate intraclass correlation coefficients, standard errors of measurements, proportions of measurement differences of 5 or less degrees, and significant differences between paired observations. Results Reliability estimates were similar for both goniometers. Intra-rater and inter-rater intraclass correlation coefficients ranged from 0.69 to 0.93. The corresponding standard errors of measurements ranged from 2.4 to 4.9 degrees. Repeated measurements of a considerable number of raters fell within clinically non-meaningful 5 degrees of each other in proportions comparable with a criterion value of 0.95. Data collected with both instruments could be similarly interpreted in a simulated situation of change of joint range of motion over time. Conclusions The paper goniometer and the standard goniometer can be used interchangeably by non-professional raters for evaluation of normal finger joints. The obtained results warrant further research to assess clinical performance of the paper strip technique. PMID:23302419

The effect of subject measurement error on joint kinematics in the conventional gait model: Insights from the open-source pyCGM tool using high performance computing methods

PubMed Central

Dixon, Philippe C.

2018-01-01

The conventional gait model (CGM) is a widely used biomechanical model which has been validated over many years. The CGM relies on retro-reflective markers placed along anatomical landmarks, a static calibration pose, and subject measurements as inputs for joint angle calculations. While past literature has shown the possible errors caused by improper marker placement, studies on the effects of inaccurate subject measurements are lacking. Moreover, as many laboratories rely on the commercial version of the CGM, released as the Plug-in Gait (Vicon Motion Systems Ltd, Oxford, UK), integrating improvements into the CGM code is not easily accomplished. This paper introduces a Python implementation for the CGM, referred to as pyCGM, which is an open-source, easily modifiable, cross platform, and high performance computational implementation. The aims of pyCGM are to (1) reproduce joint kinematic outputs from the Vicon CGM and (2) be implemented in a parallel approach to allow integration on a high performance computer. The aims of this paper are to (1) demonstrate that pyCGM can systematically and efficiently examine the effect of subject measurements on joint angles and (2) be updated to include new calculation methods suggested in the literature. The results show that the calculated joint angles from pyCGM agree with Vicon CGM outputs, with a maximum lower body joint angle difference of less than 10-5 degrees. Through the hierarchical system, the ankle joint is the most vulnerable to subject measurement error. Leg length has the greatest effect on all joints as a percentage of measurement error. When compared to the errors previously found through inter-laboratory measurements, the impact of subject measurements is minimal, and researchers should rather focus on marker placement. Finally, we showed that code modifications can be performed to include improved hip, knee, and ankle joint centre estimations suggested in the existing literature. The pyCGM code is provided in open source format and available at https://github.com/cadop/pyCGM. PMID:29293565

Association between marijuana exposure and pulmonary function over 20 years.

PubMed

Pletcher, Mark J; Vittinghoff, Eric; Kalhan, Ravi; Richman, Joshua; Safford, Monika; Sidney, Stephen; Lin, Feng; Kertesz, Stefan

2012-01-11

Marijuana smoke contains many of the same constituents as tobacco smoke, but whether it has similar adverse effects on pulmonary function is unclear. To analyze associations between marijuana (both current and lifetime exposure) and pulmonary function. The Coronary Artery Risk Development in Young Adults (CARDIA) study, a longitudinal study collecting repeated measurements of pulmonary function and smoking over 20 years (March 26, 1985-August 19, 2006) in a cohort of 5115 men and women in 4 US cities. Mixed linear modeling was used to account for individual age-based trajectories of pulmonary function and other covariates including tobacco use, which was analyzed in parallel as a positive control. Lifetime exposure to marijuana joints was expressed in joint-years, with 1 joint-year of exposure equivalent to smoking 365 joints or filled pipe bowls. Forced expiratory volume in the first second of expiration (FEV(1)) and forced vital capacity (FVC). Marijuana exposure was nearly as common as tobacco exposure but was mostly light (median, 2-3 episodes per month). Tobacco exposure, both current and lifetime, was linearly associated with lower FEV(1) and FVC. In contrast, the association between marijuana exposure and pulmonary function was nonlinear (P < .001): at low levels of exposure, FEV(1) increased by 13 mL/joint-year (95% CI, 6.4 to 20; P < .001) and FVC by 20 mL/joint-year (95% CI, 12 to 27; P < .001), but at higher levels of exposure, these associations leveled or even reversed. The slope for FEV(1) was -2.2 mL/joint-year (95% CI, -4.6 to 0.3; P = .08) at more than 10 joint-years and -3.2 mL per marijuana smoking episode/mo (95% CI, -5.8 to -0.6; P = .02) at more than 20 episodes/mo. With very heavy marijuana use, the net association with FEV(1) was not significantly different from baseline, and the net association with FVC remained significantly greater than baseline (eg, at 20 joint-years, 76 mL [95% CI, 34 to 117]; P < .001). Occasional and low cumulative marijuana use was not associated with adverse effects on pulmonary function.

Parallel, staged opening switch power conditioning techniques for flux compression generator applications

NASA Astrophysics Data System (ADS)

Reinovsky, R. E.; Levi, P. S.; Bueck, J. C.; Goforth, J. H.

The Air Force Weapons Laboratory, working jointly with Los Alamos National Laboratory, has conducted a series of experiments directed at exploring composite, or staged, switching techniques for use in opening switches in applications which require the conduction of very high currents (or current densities) with very low losses for relatively long times (several tens of microseconds), and the interruption of these currents in much shorter times (ultimately a few hundred nanoseconds). The results of those experiments are reported.

Seismicity, shear failure and modes of deformation in deep subduction zones

NASA Technical Reports Server (NTRS)

Lundgren, Paul R.; Giardini, Domenico

1992-01-01

The joint hypocentral determination method is used to relocate deep seismicity reported in the International Seismological Center catalog for earthquakes deeper than 400 km in the Honshu, Bonin, Mariannas, Java, Banda, and South America subduction zones. Each deep seismic zone is found to display planar features of seismicity parallel to the Harvard centroid-moment tensor nodal planes, which are identified as planes of shear failure. The sense of displacement on these planes is one of resistance to deeper penetration.

ParallABEL: an R library for generalized parallelization of genome-wide association studies

PubMed Central

2010-01-01

Background Genome-Wide Association (GWA) analysis is a powerful method for identifying loci associated with complex traits and drug response. Parts of GWA analyses, especially those involving thousands of individuals and consuming hours to months, will benefit from parallel computation. It is arduous acquiring the necessary programming skills to correctly partition and distribute data, control and monitor tasks on clustered computers, and merge output files. Results Most components of GWA analysis can be divided into four groups based on the types of input data and statistical outputs. The first group contains statistics computed for a particular Single Nucleotide Polymorphism (SNP), or trait, such as SNP characterization statistics or association test statistics. The input data of this group includes the SNPs/traits. The second group concerns statistics characterizing an individual in a study, for example, the summary statistics of genotype quality for each sample. The input data of this group includes individuals. The third group consists of pair-wise statistics derived from analyses between each pair of individuals in the study, for example genome-wide identity-by-state or genomic kinship analyses. The input data of this group includes pairs of SNPs/traits. The final group concerns pair-wise statistics derived for pairs of SNPs, such as the linkage disequilibrium characterisation. The input data of this group includes pairs of individuals. We developed the ParallABEL library, which utilizes the Rmpi library, to parallelize these four types of computations. ParallABEL library is not only aimed at GenABEL, but may also be employed to parallelize various GWA packages in R. The data set from the North American Rheumatoid Arthritis Consortium (NARAC) includes 2,062 individuals with 545,080, SNPs' genotyping, was used to measure ParallABEL performance. Almost perfect speed-up was achieved for many types of analyses. For example, the computing time for the identity-by-state matrix was linearly reduced from approximately eight hours to one hour when ParallABEL employed eight processors. Conclusions Executing genome-wide association analysis using the ParallABEL library on a computer cluster is an effective way to boost performance, and simplify the parallelization of GWA studies. ParallABEL is a user-friendly parallelization of GenABEL. PMID:20429914

A guide to evaluating linkage quality for the analysis of linked data.

PubMed

Harron, Katie L; Doidge, James C; Knight, Hannah E; Gilbert, Ruth E; Goldstein, Harvey; Cromwell, David A; van der Meulen, Jan H

2017-10-01

Linked datasets are an important resource for epidemiological and clinical studies, but linkage error can lead to biased results. For data security reasons, linkage of personal identifiers is often performed by a third party, making it difficult for researchers to assess the quality of the linked dataset in the context of specific research questions. This is compounded by a lack of guidance on how to determine the potential impact of linkage error. We describe how linkage quality can be evaluated and provide widely applicable guidance for both data providers and researchers. Using an illustrative example of a linked dataset of maternal and baby hospital records, we demonstrate three approaches for evaluating linkage quality: applying the linkage algorithm to a subset of gold standard data to quantify linkage error; comparing characteristics of linked and unlinked data to identify potential sources of bias; and evaluating the sensitivity of results to changes in the linkage procedure. These approaches can inform our understanding of the potential impact of linkage error and provide an opportunity to select the most appropriate linkage procedure for a specific analysis. Evaluating linkage quality in this way will improve the quality and transparency of epidemiological and clinical research using linked data. © The Author 2017. Published by Oxford University Press on behalf of the International Epidemiological Association.

Environmental Public Health Survelliance for Exposure to Respiratory Health Hazards: A Joint NASA/CDC Project to Use Remote Sensing Data for Estimating Airborne Particulate Matter Over the Atlanta, Georgia Metropolitan Area

NASA Technical Reports Server (NTRS)

Quattrochi, Dale A.; Rickman, Douglas; Mohammad, Al-Hamdan; Crosson, William; Estes, Maurice, Jr.; Limaye, Ashutosh; Qualters, Judith

2008-01-01

Describes the public health surveillance efforts of NASA, in a joint effort with the Center for Disease Control (CDC). NASA/MSFC and the CDC are partners in linking nvironmental and health data to enhance public health surveillance. The use of NASA technology creates value - added geospatial products from existing environmental data sources to facilitate public health linkages. The venture sought to provide remote sensing data for the 5-country Metro-Atlanta area and to integrate this environmental data with public health data into a local network, in an effort to prevent and control environmentally related health effects. Remote sensing data used environmental data (Environmental Protection Agency [EPA] Air Quality System [AQS] ground measurements and MODIS Aerosol Optical Depth [AOD]) to estimate airborne particulate matter over Atlanta, and linked this data with health data related to asthma. The study proved the feasibility of linking environmental data (MODIS particular matter estimates and AQS) with health data (asthma). Algorithms were developed for QC, bias removal, merging MODIS and AQS particulate matter data, as well as for other applications. Additionally, a Business Associate Agreement was negotiated for a health care provider to enable sharing of Protected Health Information.

The role of implementation intention formation in promoting hepatitis B vaccination uptake among men who have sex with men.

PubMed

Vet, Raymond; de Wit, John B F; Das, Enny

2014-02-01

This study assessed the separate and joint effects of having a goal intention and the completeness of implementation intention formation on the likelihood of attending an appointment to obtain vaccination against the hepatitis B virus among men who have sex with men (MSM) in the Netherlands. Extending previous research, it was hypothesized that to be effective in promoting vaccination, implementation intention formation not only requires a strong goal intention, but also complete details specifying when, where and how to make an appointment to obtain hepatitis B virus vaccination among MSM. MSM at risk for hepatitis B virus (N = 616), with strong or weak intentions to obtain hepatitis B virus vaccination, were randomly assigned to form an implementation intention or not. Completeness of implementation intentions was rated and hepatitis B virus uptake was assessed through data linkage with the joint vaccination registry of the collaborating Public Health Services. Having a strong goal intention to obtain hepatitis B virus vaccination and forming an implementation intention, each significantly and independently increased the likelihood of MSM obtaining hepatitis B virus vaccination. In addition, MSM who formed complete implementation intentions were more successful in obtaining vaccination (p < 0.01). The formation of complete implementation intentions was promoted by strong goal intentions (p < 0.01).

Rheumatoid arthritis: identifying and characterising polymorphisms using rat models

PubMed Central

2016-01-01

ABSTRACT Rheumatoid arthritis is a chronic inflammatory joint disorder characterised by erosive inflammation of the articular cartilage and by destruction of the synovial joints. It is regulated by both genetic and environmental factors, and, currently, there is no preventative treatment or cure for this disease. Genome-wide association studies have identified ∼100 new loci associated with rheumatoid arthritis, in addition to the already known locus within the major histocompatibility complex II region. However, together, these loci account for only a modest fraction of the genetic variance associated with this disease and very little is known about the pathogenic roles of most of the risk loci identified. Here, we discuss how rat models of rheumatoid arthritis are being used to detect quantitative trait loci that regulate different arthritic traits by genetic linkage analysis and to positionally clone the underlying causative genes using congenic strains. By isolating specific loci on a fixed genetic background, congenic strains overcome the challenges of genetic heterogeneity and environmental interactions associated with human studies. Most importantly, congenic strains allow functional experimental studies be performed to investigate the pathological consequences of natural genetic polymorphisms, as illustrated by the discovery of several major disease genes that contribute to arthritis in rats. We discuss how these advances have provided new biological insights into arthritis in humans. PMID:27736747

Biomechanical model of batoid (skates and rays) pectoral fins predicts the influence of skeletal structure on fin kinematics: implications for bio-inspired design.

PubMed

Russo, R S; Blemker, S S; Fish, F E; Bart-Smith, H

2015-06-16

Growing interest in the development of bio-inspired autonomous underwater vehicles (AUVs) has motivated research in understanding the mechanisms behind the propulsion systems of marine animals. For example, the locomotive behavior of rays (Batoidea) by movement of the pectoral fins is of particular interest due to their superior performance characteristics over contemporary AUV propulsion systems. To better understand the mechanics of pectoral fin propulsion, this paper introduces a biomechanical model that simulates how batoid skeletal structures function to achieve the swimming locomotion observed in nature. Two rays were studied, Dasyatis sabina (Atlantic ray), and Rhinoptera bonasus (cownose ray). These species were selected because they exhibit very different swimming styles (undulation versus oscillation), but all use primarily their pectoral fins for propulsion (unlike electric rays or guitarfishes). Computerized tomography scans of each species were taken to image the underlying structure, which reveal a complex system of cartilaginous joints and linkages. Data collected from these images were used to quantify the complete skeletal morphometry of each batoid fin. Morphological differences were identified in the internal cartilage arrangement between each species including variations in the orientation of the skeletal elements, or radials, and the joint patterns between them, called the inter-radial joint pattern. These data were used as the primary input into the biomechanical model to couple a given ray skeletal structure with various swimming motions. A key output of the model is an estimation of the uniaxial strain that develops in the skeletal connective tissue in order for the structure to achieve motions observed during swimming. Tensile load tests of this connective tissue were conducted to further investigate the implications of the material strain predictions. The model also demonstrates that changes in the skeletal architecture (e.g., joint positioning) will effect fin deformation characteristics. Ultimately, the results of this study can be used to guide the design of optimally performing bio-inspired AUVs.

Are Subject-Specific Musculoskeletal Models Robust to the Uncertainties in Parameter Identification?

PubMed Central

Valente, Giordano; Pitto, Lorenzo; Testi, Debora; Seth, Ajay; Delp, Scott L.; Stagni, Rita; Viceconti, Marco; Taddei, Fulvia

2014-01-01

Subject-specific musculoskeletal modeling can be applied to study musculoskeletal disorders, allowing inclusion of personalized anatomy and properties. Independent of the tools used for model creation, there are unavoidable uncertainties associated with parameter identification, whose effect on model predictions is still not fully understood. The aim of the present study was to analyze the sensitivity of subject-specific model predictions (i.e., joint angles, joint moments, muscle and joint contact forces) during walking to the uncertainties in the identification of body landmark positions, maximum muscle tension and musculotendon geometry. To this aim, we created an MRI-based musculoskeletal model of the lower limbs, defined as a 7-segment, 10-degree-of-freedom articulated linkage, actuated by 84 musculotendon units. We then performed a Monte-Carlo probabilistic analysis perturbing model parameters according to their uncertainty, and solving a typical inverse dynamics and static optimization problem using 500 models that included the different sets of perturbed variable values. Model creation and gait simulations were performed by using freely available software that we developed to standardize the process of model creation, integrate with OpenSim and create probabilistic simulations of movement. The uncertainties in input variables had a moderate effect on model predictions, as muscle and joint contact forces showed maximum standard deviation of 0.3 times body-weight and maximum range of 2.1 times body-weight. In addition, the output variables significantly correlated with few input variables (up to 7 out of 312) across the gait cycle, including the geometry definition of larger muscles and the maximum muscle tension in limited gait portions. Although we found subject-specific models not markedly sensitive to parameter identification, researchers should be aware of the model precision in relation to the intended application. In fact, force predictions could be affected by an uncertainty in the same order of magnitude of its value, although this condition has low probability to occur. PMID:25390896

A Simple Sequence Repeat- and Single-Nucleotide Polymorphism-Based Genetic Linkage Map of the Brown Planthopper, Nilaparvata lugens

PubMed Central

Jairin, Jirapong; Kobayashi, Tetsuya; Yamagata, Yoshiyuki; Sanada-Morimura, Sachiyo; Mori, Kazuki; Tashiro, Kosuke; Kuhara, Satoru; Kuwazaki, Seigo; Urio, Masahiro; Suetsugu, Yoshitaka; Yamamoto, Kimiko; Matsumura, Masaya; Yasui, Hideshi

2013-01-01

In this study, we developed the first genetic linkage map for the major rice insect pest, the brown planthopper (BPH, Nilaparvata lugens). The linkage map was constructed by integrating linkage data from two backcross populations derived from three inbred BPH strains. The consensus map consists of 474 simple sequence repeats, 43 single-nucleotide polymorphisms, and 1 sequence-tagged site, for a total of 518 markers at 472 unique positions in 17 linkage groups. The linkage groups cover 1093.9 cM, with an average distance of 2.3 cM between loci. The average number of marker loci per linkage group was 27.8. The sex-linkage group was identified by exploiting X-linked and Y-specific markers. Our linkage map and the newly developed markers used to create it constitute an essential resource and a useful framework for future genetic analyses in BPH. PMID:23204257

Smooth adaptive sliding mode vibration control of a flexible parallel manipulator with multiple smart linkages in modal space

NASA Astrophysics Data System (ADS)

Zhang, Quan; Li, Chaodong; Zhang, Jiantao; Zhang, Jianhui

2017-12-01

This paper addresses the dynamic model and active vibration control of a rigid-flexible parallel manipulator with three smart links actuated by three linear ultrasonic motors. To suppress the vibration of three flexible intermediate links under high speed and acceleration, multiple Lead Zirconium Titanate (PZT) sensors and actuators are collocated mounted on each link, forming a smart structure which can achieve self-sensing and self-actuating. The dynamic characteristics and equations of the flexible link incorporated with the PZT sensors and actuator are analyzed and formulated. The smooth adaptive sliding mode based active vibration control is proposed to suppress the vibration of the smart links, and the first and second modes of the three links are targeted to be suppressed in modal space to avoid the spillover phenomenon. Simulations and experiments are implemented to validate the effectiveness of the smart structures and the proposed control laws. Experimental results show that the vibration of the first mode around 92 Hz and the second mode around 240 Hz of the three smart links are reduced respectively by 64.98%, 59.47%, 62.28%, and 45.80%, 36.79%, 33.33%, which further verify the multi-mode vibration control ability of the smooth adaptive sliding mode control law.

Capping Parallel β-Sheets of Acetyl(Ala)6NH2 with an Acetyl(Ala)5ProNH2 Can Arrest the Growth of the Sheet, Suggesting a Potential for Curtailing Amyloid Growth. An ONIOM and Density Functional Theory Study

PubMed Central

2015-01-01

We present ONIOM calculations using B3LYP/d95(d,p) as the high level and AM1 as the medium level on parallel β-sheets containing four strands of Ac-AAAAAA-NH2 capped with either Ac-AAPAAA-NH2 or Ac-AAAPAA-NH2. Because Pro can form H-bonds from only one side of the peptide linkage (that containing the C=O H-bond acceptor), only one of the two Pro-containing strands can favorably add to the sheet on each side. Surprisingly, when the sheet is capped with AAPAAA-NH2 at one edge, the interaction between the cap and sheet is slightly more stabilizing than that of another all Ala strand. Breaking down the interaction enthalpies into H-bonding and distortion energies shows the favorable interaction to be due to lower distortion energies in both the strand and the four-stranded sheet. Because another strand would be inhibited for attachment to the other side of the capping (Pro-containing) strand, we suggest the possible use of Pro residues in peptides designed to arrest the growth of many amyloids. PMID:24422496

Three d10 coordination polymers assembled from 3,5-bis(imidazole-1-yl)pyridine and different polycarboxylates: Syntheses, structures and luminescence properties

NASA Astrophysics Data System (ADS)

Pan, Jie; Zhang, Di; Xue, Zhen-Zhen; Wei, Li; Han, Song-De; Wang, Guo-Ming

2017-11-01

Three novel Zn(II)/Cd(II) coordination polymers, [Cd2(bip)2(m-bdc)2(H2O)2·3H2O]n (1), [Zn2(bip)2(p-bdc)2·2.5H2O]n (2) and [Zn(bip) (p-bdc)·3H2O]n (3), where bip = 3,5-bis(imidazole-1-yl)pyridine, m-H2bdc = 1,3-benzenedicarboxylic acid, p-H2bdc = 1,4-benzenedicarboxylic acid, have been successfully synthesized under solvothermal conditions. The linkage of different ligands with Cd(II) ions in compound 1 affords a (3,5)-connected layer. Furthermore, 2D→3D parallel polycatenation occurs wherein the layers are polycatenated with the adjacent two parallel layers to form a 3D framework. In 2 and 3, the polycarboxylates act as pillars to combine the metal-bip chains, yielding the layered structures. These 2D networks are extended to the final 3D supramolecular architectures by π-π stacking interactions. The results show that bip can act as a versatile building block for the construction of various coordination polymers. Moreover, the fluorescent properties of 1-3 in the solid state at room temperature have been investigated.

Rock cities, periglacial mass-wasting, and honeycomb weathering in Warren County, northwestern Pennsylvania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Inners, J.D.; Sevon, W.D.; Moore, M.E.

1993-03-01

Imposing hilltop rock-cities developed from widely jointed outcrops of Olean conglomerate (Lower Pennsylvanian) create picturesque scenery on the Allegheny High Plateau in Warren Co., Pa. At least six such rock cities 2 to 5 acres in extent are associated with the Late Wisconsinan glacial border in the northern half of the county. Farther to the south, jumbled Olean and Knapp (Lower Mississippian) joint blocks occur on steep slopes below valley-wall cliffs. The rock cities and accumulations of displaced joint blocks are largely relics of Late Wisconsinan periglacial mass-wasting. Frost splitting initiated opening of bedrock joints to form buildings. Gravity, soilmore » wedging, and possibly gelifluction then widened the fissures into streets. Gelifluction moved blocks downslope and oriented their long axes parallel with slope (Warren Rocks). Forward toppling of high, unstable blocks contributed to mass-movement on some steep slopes (Rimrock). Today, rock cities and downslope blocks are stable in areas of gentle (less than 10 percent) slopes, but toppling, solifluction, creep, and debris flows cause continued slow movement of large blocks on moderately steep to steep (greater than 30 percent) slopes. Blocks of Olean and Knapp conglomerate have both stratabound pitting and intricate honeycomb weathering. Deep pitting is controlled largely by variations in silica cementation. Honeycomb weathering is most evident in sandy layers and results from patterns of iron-oxide impregnation. Both are Holocene surface-weathering processes.« less

Musculoskeletal modelling of human ankle complex: Estimation of ankle joint moments.

PubMed

Jamwal, Prashant K; Hussain, Shahid; Tsoi, Yun Ho; Ghayesh, Mergen H; Xie, Sheng Quan

2017-05-01

A musculoskeletal model for the ankle complex is vital in order to enhance the understanding of neuro-mechanical control of ankle motions, diagnose ankle disorders and assess subsequent treatments. Motions at the human ankle and foot, however, are complex due to simultaneous movements at the two joints namely, the ankle joint and the subtalar joint. The musculoskeletal elements at the ankle complex, such as ligaments, muscles and tendons, have intricate arrangements and exhibit transient and nonlinear behaviour. This paper develops a musculoskeletal model of the ankle complex considering the biaxial ankle structure. The model provides estimates of overall mechanical characteristics (motion and moments) of ankle complex through consideration of forces applied along ligaments and muscle-tendon units. The dynamics of the ankle complex and its surrounding ligaments and muscle-tendon units is modelled and formulated into a state space model to facilitate simulations. A graphical user interface is also developed during this research in order to include the visual anatomical information by converting it to quantitative information on coordinates. Validation of the ankle model was carried out by comparing its outputs with those published in literature as well as with experimental data obtained from an existing parallel ankle rehabilitation robot. Qualitative agreement was observed between the model and measured data for both, the passive and active ankle motions during trials in terms of displacements and moments. Copyright © 2017 Elsevier Ltd. All rights reserved.

Signal-domain optimization metrics for MPRAGE RF pulse design in parallel transmission at 7 tesla.

PubMed

Gras, V; Vignaud, A; Mauconduit, F; Luong, M; Amadon, A; Le Bihan, D; Boulant, N

2016-11-01

Standard radiofrequency pulse design strategies focus on minimizing the deviation of the flip angle from a target value, which is sufficient but not necessary for signal homogeneity. An alternative approach, based directly on the signal, here is proposed for the MPRAGE sequence, and is developed in the parallel transmission framework with the use of the k T -points parametrization. The flip angle-homogenizing and the proposed methods were investigated numerically under explicit power and specific absorption rate constraints and tested experimentally in vivo on a 7 T parallel transmission system enabling real time local specific absorption rate monitoring. Radiofrequency pulse performance was assessed by a careful analysis of the signal and contrast between white and gray matter. Despite a slight reduction of the flip angle uniformity, an improved signal and contrast homogeneity with a significant reduction of the specific absorption rate was achieved with the proposed metric in comparison with standard pulse designs. The proposed joint optimization of the inversion and excitation pulses enables significant reduction of the specific absorption rate in the MPRAGE sequence while preserving image quality. The work reported thus unveils a possible direction to increase the potential of ultra-high field MRI and parallel transmission. Magn Reson Med 76:1431-1442, 2016. © 2015 International Society for Magnetic Resonance in Medicine. © 2015 International Society for Magnetic Resonance in Medicine.

Program Responses to Acute and Chronic Malnutrition: Divergences and Convergences123

PubMed Central

Bergeron, Gilles; Castleman, Tony

2012-01-01

Program approaches for addressing acute malnutrition and those for addressing chronic malnutrition have grown in different directions. Their specialization has led to productive advances in the efficacy of specific interventions but has also created divergences in implementation. Greater convergence and integration between the 2 sets of approaches would help programs respond to the diversity of conditions faced in the field and enable a more comprehensive continuum of care from prevention to treatment. After reviewing the causes of the differences in approach, this paper examines programmatic and scientific challenges to greater convergence and suggests steps to promote effective integration of acute and chronic malnutrition services. Steps include strengthening community linkages between program platforms, assessing the degree and type of integration needed in various situations, identifying cost efficiencies, and developing joint tools where possible. PMID:22516735

Can health feasibly be considered as part of the planning process in Scotland?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Higgins, Martin; Douglas, Margaret; Muirie, Jill

2005-10-15

The planning system is significant because of its capacity to determine the quality of the built environment as well as the health, well-being and quality of life of the individuals and communities therein. Development planning is especially important because of the long-term impact of the decisions. This paper was developed in response to increasing recognition amongst HIA practitioners in Scotland of the importance of planning for health. It focuses on the relationship between the planning system in Scotland, specifically the Development Planning element of it, and population health and considers how the health impact assessment (HIA) approach can facilitate andmore » support joint working with planners. In particular, consideration is given to the potential impact of the introduction of Strategic Environmental Assessment (SEA) on the linkages between health, HIA and planning.« less

The postnatal development of the temporal part of the human temporomandibular joint. A quantitative study on skulls.

PubMed

Dibbets, J M; Dijkman, G E

1997-12-01

The morphology of the temporal part of the human temporomandibular joint (TMJ) changes drastically during postnatal development. The glenoid fossa will acquire its characteristic S shape and a tubercle will develop. The combined results of the literature and of this study allow a reconstruction of the actual growth processes. The roof of the glenoid fossa appears to enlarge forward by remodeling while sagittal and vertical growth is mainly achieved by deposition at the top of the tubercle. These latter changes result in a steeper slope of the eminence and take place in 3 phases, parallelling the eruption of the first incisors, the permanent first molars and the permanent second molars. While the zygomatic arch thickens by deposition at all surfaces, it also remodels downward relative to the external meatus. As a result, the neonate anulus occupies a lower position relative to this arch than does the adult meatus.

A robot conditioned reflex system modeled after the cerebellum.

NASA Technical Reports Server (NTRS)

Albus, J. S.

1972-01-01

Reduction of a theory of cerebellar function to computer software for the control of a mechanical manipulator. This reduction is achieved by considering the cerebellum, along with the higher-level brain centers which control it, as a type of finite-state machine with input entering the cerebellum via mossy fibers from the periphery and output from the cerebellum occurring via Purkinje cells. It is hypothesized that the cerebellum learns by an error-correction system similar to Perceptron training algorithms. An electromechanical model of the cerebellum is then developed for the control of a mechanical arm. The problem of modeling the granular layer which selects the set of parallel fibers which are active at any instant of time is considered, and a relevance matrix is constructed to model the relative degree of influence which mossy fibers from the various joints have on the sets of granule cells unique to each joint.

Finite-frequency wave propagation through outer rise fault zones and seismic measurements of upper mantle hydration

USGS Publications Warehouse

Miller, Nathaniel; Lizarralde, Daniel

2016-01-01

Effects of serpentine-filled fault zones on seismic wave propagation in the upper mantle at the outer rise of subduction zones are evaluated using acoustic wave propagation models. Modeled wave speeds depend on azimuth, with slowest speeds in the fault-normal direction. Propagation is fastest along faults, but, for fault widths on the order of the seismic wavelength, apparent wave speeds in this direction depend on frequency. For the 5–12 Hz Pn arrivals used in tomographic studies, joint-parallel wavefronts are slowed by joints. This delay can account for the slowing seen in tomographic images of the outer rise upper mantle. At the Middle America Trench, confining serpentine to fault zones, as opposed to a uniform distribution, reduces estimates of bulk upper mantle hydration from ~3.5 wt % to as low as 0.33 wt % H2O.

The Goal of the IAU/IAG Joint Working Group on the Theory of Earth Rotation

NASA Technical Reports Server (NTRS)

Ferrandiz, J. M.; Gross, R. S.

2013-01-01

In 2012 the International Association of Geodesy (IAG) and the International Astronomical Union (IAU) initiated a process to establish a Joint Working Group (JWG) on theory of Earth rotation with the purpose of promoting the development of improved theories of the Earth rotation which reach the accuracy required to meet the needs of the near future as recommended by, e.g. GGOS, the Global Geodetic Observing System of the IAG. The JWG was approved by both organizations in April 2013 with the chairs being the two authors of this paper. Its structure comprises three Sub Working Groups (SWGs) addressing Precession/Nutation, Polar Motion and UT1, the Numerical Solutions and Validation, respectively. The SWGs should work in parallel for the sake of efficiency, but should keep consistency as an overall goal. This paper offers a view of the objectives and scope of the JWG and reports about its initial activities and plans.