4,821 research outputs found
Neuro-Musculoskeletal Mapping for Man-Machine Interfacing.
We propose a myoelectric control method based on neural data regression and musculoskeletal modeling. This paradigm uses the timings of motor neuron discharges decoded by high-density surface electromyogram (HD-EMG) decomposition to estimate muscle excitations. The muscle excitations are then mapped into the kinematics of the wrist joint using forward dynamics. The offline tracking performance of the proposed method was superior to that of state-of-the-art myoelectric regression methods based on artificial neural networks in two amputees and in four out of six intact-bodied subjects. In addition to joint kinematics, the proposed data-driven model-based approach also estimated several biomechanical variables in a full feed-forward manner that could potentially be useful in supporting the rehabilitation and training process. These results indicate that using a full forward dynamics musculoskeletal model directly driven by motor neuron activity is a promising approach in rehabilitation and prosthetics to model the series of transformations from muscle excitation to resulting joint function
Toward a DNA Taxonomy of Alpine Rhithrogena (Ephemeroptera: Heptageniidae) Using a Mixed Yule-Coalescent Analysis of Mitochondrial and Nuclear DNA
Aquatic larvae of many Rhithrogena mayflies (Ephemeroptera)
inhabit sensitive Alpine environments. A number of species are on the IUCN Red
List and many recognized species have restricted distributions and are of
conservation interest. Despite their ecological and conservation importance,
ambiguous morphological differences among closely related species suggest that
the current taxonomy may not accurately reflect the evolutionary diversity of
the group. Here we examined the species status of nearly 50% of European
Rhithrogena diversity using a widespread sampling scheme of
Alpine species that included 22 type localities, general mixed Yule-coalescent
(GMYC) model analysis of one standard mtDNA marker and one newly developed nDNA
marker, and morphological identification where possible. Using sequences from
533 individuals from 144 sampling localities, we observed significant clustering
of the mitochondrial (cox1) marker into 31 GMYC species.
Twenty-one of these could be identified based on the presence of topotypes
(expertly identified specimens from the species' type locality) or
unambiguous morphology. These results strongly suggest the presence of both
cryptic diversity and taxonomic oversplitting in Rhithrogena.
Significant clustering was not detected with protein-coding nuclear PEPCK,
although nine GMYC species were congruent with well supported terminal clusters
of nDNA. Lack of greater congruence in the two data sets may be the result of
incomplete sorting of ancestral polymorphism. Bayesian phylogenetic analyses of
both gene regions recovered four of the six recognized
Rhithrogena species groups in our samples as monophyletic.
Future development of more nuclear markers would facilitate multi-locus analysis
of unresolved, closely related species pairs. The DNA taxonomy developed here
lays the groundwork for a future revision of the important but cryptic
Rhithrogena genus in Europe
Cooperative Algorithms for MIMO Amplify-and-Forward Relay Networks
Interference alignment is a signaling technique that provides high
multiplexing gain in the interference channel. It can be extended to multi-hop
interference channels, where relays aid transmission between sources and
destinations. In addition to coverage extension and capacity enhancement,
relays increase the multiplexing gain in the interference channel. In this
paper, three cooperative algorithms are proposed for a multiple-antenna
amplify-and-forward (AF) relay interference channel. The algorithms design the
transmitters and relays so that interference at the receivers can be aligned
and canceled. The first algorithm minimizes the sum power of enhanced noise
from the relays and interference at the receivers. The second and third
algorithms rely on a connection between mean square error and mutual
information to solve the end-to-end sum-rate maximization problem with either
equality or inequality power constraints via matrix-weighted sum mean square
error minimization. The resulting iterative algorithms converge to stationary
points of the corresponding optimization problems. Simulations show that the
proposed algorithms achieve higher end-to-end sum-rates and multiplexing gains
that existing strategies for AF relays, decode-and-forward relays, and direct
transmission. The first algorithm outperforms the other algorithms at high
signal-to-noise ratio (SNR) but performs worse than them at low SNR. Thanks to
power control, the third algorithm outperforms the second algorithm at the cost
of overhead.Comment: submitted to IEEE Transactions on Signal Processing in December 2011,
revised in April 2012 and in September 201
Simulation of tillage systems impact on soil biophysical properties using the SALUS model
A sustainable land management has been defined as the management system that allows for production, while minimizing risk, maintaining quality of soil and water. Tillage systems can significantly decrease soil carbon storage and influence the soil environment of a crop. Crop growth models can be useful tools in evaluating the impact of different tillage systems on soil biophysical properties and on the growth and final yield of the crops. The objectives of this paper were i) to illustrate the SALUS model and its tillage component; ii) to evaluate the effects of different tillage systems on water infiltration and time to ponding, iii) to simulate the effect of tillage systems on some soil biophysical properties. The SALUS (System Approach to Land Use Sustainability) model is designed to simulate continuous crop, soil, water and nutrient conditions under different tillage and crop residues management strategies for multiple years. Predictions of changes in surface residue, bulk density, runoff, drainage and evaporation were consistent with expected behaviours of these parameters as described in the literature. The experiment to estimate the time to ponding curve under different tillage system confirmed the theory and showed the beneficial effects of the residue on soil surface with respect to water infiltration. It also showed that the no-tillage system is a more appropriate system to adopt in areas characterized by high intensity rainfal
Postmenopausal Urinary Disorders: Clinical And Urodynamic Evaluation
Purpose: to evaluate the frequency of urinary disorders and variation of the urodynamic parameters according to the time of post-menopause. Method: two hundred forty-two post-menopausal women with urinary complaints were studied at the Division of Gynecology, Escola Paulista de Medicina, UNIFESP. They were grouped according to the time of post-menopause: group A - up to 4 years; group B - 5 to 9 years and group C - more than 10 years. They were submitted to anamnesis, gynecological examination and urodynamic study. The frequency of urinary alterations and the variation of the urodynamic parameters were analyzed, such as voiding volume; flow time; maximum flow rate, average flow rate; residual urine; vesical capacity at the first desire to void; maximum bladder capacity; maximum urethral closure pressure and functional profile length, with full and empty bladder. The data were statistically analyzed. Results: the most common clinical diagnosis was stress urinary incontinence in the three groups, but the longer the time of post-menopause, the more frequently urinary urgency was observed. Regarding urodynamic diagnosis, 93.6%, 84.6% and 90.7% of the patients of the groups A, B and C, respectively, presented stress urinary incontinence, while 4.8%, 13.5% and 6.2% revealed detrusor instability. There was a decrease in the following urodynamic parameters, according to the time of post-menopause: flow time, maximum flow rate and vesical capacity at the first desire to void, and an increase of the residual urine. Conclusion: in spite of the high incidence of urinary symptoms such as urgency incontinence, stress urinary incontinence was the main urinary problem we have found in post-menopause.Objetivos: avaliar a freqüência dos distúrbios urinários e a variação dos parâmetros urodinâmicos segundo o tempo de pós-menopausa. Métodos: foram estudadas 242 mulheres menopausadas atendidas nos Setores de Climatério e de Uroginecologia e Cirurgia Vaginal da Disciplina de Ginecologia da Escola Paulista de Medicina, UNIFESP, que apresentavam queixas urinárias. As pacientes foram agrupadas segundo o tempo de pós-menopausa em: grupo A - até 4 anos; grupo B - de 5 a 9 anos e grupo C - mais de 10 anos. Todas foram submetidas a anamnese, exame ginecológico e estudo urodinâmico. Analisamos a freqüência de alterações urinárias e a variação dos parâmetros urodinâmicos, como volume urinário (VOL); tempo total de micção (TTM); fluxos urinário máximo (FMAX) e médio (FM); resÃduo pós-miccional (RES); capacidade vesical no primeiro desejo miccional (CV1D); capacidade vesical máxima (CVM); pressão máxima de fechamento uretral e comprimento funcional da uretra, com bexiga cheia e vazia (PMCH, PMV, CFUCH, CFV). Os dados foram analisados estatisticamente. Resultados: o diagnóstico clÃnico mais comum foi de incontinência urinária de esforço (IUE) nos três grupos, porém observou-se maior incidência de urgência miccional com o evoluir do tempo de pós-menopausa. Em relação ao diagnóstico urodinâmico, 93,6%, 84,6% e 90,7%, respectivamente, das pacientes dos grupos A, B e C apresentaram IUE, ao passo que 4,8%, 13,5% e 6,2% revelaram instabilidade vesical. Houve diminuição dos seguintes parâmetros urodinâmicos, segundo o tempo de pós-menopausa: TTM, FMAX e CV1D, além de aumento do resÃduo pós-miccional. Conclusões: apesar da elevada incidência de sintomas urinários irritativos, como urgência incontinência, a IUE foi a principal afecção urinária nesta faixa etária.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Setor de Uroginecologia e Cirurgia VaginalUNIFESP, EPM, Setor de Uroginecologia e Cirurgia VaginalSciEL
Boschi vetusti e riserve forestali nel Veneto: patrimoni di biodiversita\u300
Vengono sintetizzate le criticita\u300 emergenti legate alle dinamiche di cambiamento della biodiversita\u300 nelle foreste del Veneto anche esaminando i dati delle politiche forestali degli ultimi decenni e delle trasformazioni di boschi e foreste di montagna, collina e pianura conseguenti all\u2019abbandono colturale e ad iniziative locali di contrasto alle alterazioni del paesaggio forestale, di miglioramento ambientale ed estetico e di difesa della biodiversita\u300 forestale e naturalistica dei territori del Veneto.
Seppur in un confronto europeo l'Italia e\u300 forse uno degli stati piu\u300 virtuosi nella gestione del patrimonio boschivo, sia in termini di risparmio di biomassa (35% di prelievo sull'incremento contro la media europea di oltre 60%) che per modalita\u300 di prelievo (e\u300 uno dei pochi stati dove il taglio a raso e\u300 vietato e, a differenza di molti paesi europei, non ammette l'imboschimento con specie esotiche), in questo approfondimento vengono esaminati gli scenari possibili di riferimento per una programmazione piu\u300 mirata, incisiva ed innovativa delle politiche di tutela della biodiversita\u300 forestale del Veneto, guardando ad alcune esperienze europee volte alla tutela e valorizzazione dei boschi antichi o vetusti.
Boschi e foreste si stanno espandendo nel Veneto anche in pianura: ma questo trend e\u300 frutto dell\u2019abbandono colturale e/o conseguenza di una programmazione territoriale adeguata? Si propongono linee guida per iniziative locali di contrasto alla banalizzazione estetica ed ambientale del paesaggio e per contro di miglioramento della difesa della biodiversita\u300 forestale e naturalistica dei territori del Veneto partendo dalla tutela del patrimonio genetico dei \u201cboschi vetusti\u201d
Level-3 Calorimetric Resolution available for the Level-1 and Level-2 CDF Triggers
As the Tevatron luminosity increases sophisticated selections are required to
be efficient in selecting rare events among a very huge background. To cope
with this problem, CDF has pushed the offline calorimeter algorithm
reconstruction resolution up to Level 2 and, when possible, even up to Level 1,
increasing efficiency and, at the same time, keeping under control the rates.
The CDF Run II Level 2 calorimeter trigger is implemented in hardware and is
based on a simple algorithm that was used in Run I. This system has worked well
for Run II at low luminosity. As the Tevatron instantaneous luminosity
increases, the limitation due to this simple algorithm starts to become clear:
some of the most important jet and MET (Missing ET) related triggers have large
growth terms in cross section at higher luminosity. In this paper, we present
an upgrade of the Level 2 Calorimeter system which makes the calorimeter
trigger tower information available directly to a CPU allowing more
sophisticated algorithms to be implemented in software. Both Level 2 jets and
MET can be made nearly equivalent to offline quality, thus significantly
improving the performance and flexibility of the jet and MET related triggers.
However in order to fully take advantage of the new L2 triggering capabilities
having at Level 1 the same L2 MET resolution is necessary. The new Level-1 MET
resolution is calculated by dedicated hardware. This paper describes the
design, the hardware and software implementation and the performance of the
upgraded calorimeter trigger system both at Level 2 and Level 1.Comment: 5 pages, 5 figures,34th International Conference on High Energy
Physics, Philadelphia, 200
Effect of toroidal field ripple on plasma rotation in JET
Dedicated experiments on TF ripple effects on the performance of tokamak plasmas have been carried out at JET. The TF ripple was found to have a profound effect on the plasma rotation. The central Mach number, M, defined as the ratio of the rotation velocity and the thermal velocity, was found to drop as a function of TF ripple amplitude (3) from an average value of M = 0.40-0.55 for operations at the standard JET ripple of 6 = 0.08% to M = 0.25-0.40 for 6 = 0.5% and M = 0.1-0.3 for delta = 1%. TF ripple effects should be considered when estimating the plasma rotation in ITER. With standard co-current injection of neutral beam injection (NBI), plasmas were found to rotate in the co-current direction. However, for higher TF ripple amplitudes (delta similar to 1%) an area of counter rotation developed at the edge of the plasma, while the core kept its co-rotation. The edge counter rotation was found to depend, besides on the TF ripple amplitude, on the edge temperature. The observed reduction of toroidal plasma rotation with increasing TF ripple could partly be explained by TF ripple induced losses of energetic ions, injected by NBI. However, the calculated torque due to these losses was insufficient to explain the observed counter rotation and its scaling with edge parameters. It is suggested that additional TF ripple induced losses of thermal ions contribute to this effect
Barley foliage diseases, Field pea diseases
A. Experimental Notes. Barley foliage diseases: B. Scald: Effect of various fungicides. c. Scald: Response of cultivars to fungicides. D. Scald: Effect of seeding rate on infection and yield. E. Scald: Testing of fungicides S3308L. F. Net blotch: Potential yield losses. G. Net blotch: Screening fungicides. H. Spot type net blotch: Simulated stubble retention. I. Spot type net blotch: Potential yield losses. J. Powdery mildew: Effect of simulated stubble retention. K. Powdery mildew: Time of fungicide application. L. Powdery mildew: Comparing fungicides. M. Powdery mildew: Testing fungicide S3308L. N. Powdery mildew: Response to Erex in farmer\u27s crops. o. Disease development and yield in barley cultivars. P. Response to Bayleton in farmer\u27s crops. Q. Disease resistance in stage 4 barley cultivars. Field pea diseases R. Black spot: Seed dressing and spray timing. S. Field Pea disease survey
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