3,306 research outputs found
Automatic identification of gait events using an instrumented sock
Background: textile-based transducers are an emerging technology in which piezo-resistive properties of materials
are used to measure an applied strain. By incorporating these sensors into a sock, this technology offers the
potential to detect critical events during the stance phase of the gait cycle. This could prove useful in several
applications, such as functional electrical stimulation (FES) systems to assist gait.
Methods: we investigated the output of a knitted resistive strain sensor during walking and sought to determine
the degree of similarity between the sensor output and the ankle angle in the sagittal plane. In addition, we
investigated whether it would be possible to predict three key gait events, heel strike, heel lift and toe off, with a
relatively straight-forward algorithm. This worked by predicting gait events to occur at fixed time offsets from
specific peaks in the sensor signal.
Results: our results showed that, for all subjects, the sensor output exhibited the same general characteristics as
the ankle joint angle. However, there were large between-subjects differences in the degree of similarity between
the two curves. Despite this variability, it was possible to accurately predict gait events using a simple algorithm.
This algorithm displayed high levels of trial-to-trial repeatability.
Conclusions: this study demonstrates the potential of using textile-based transducers in future devices that provide active gait assistance
Evidence for Allelopathic Activity of Mikania micrantha H.B.K. on Three Weed Species
Laboratory, greenhouse and field studies were conducted to determine the allelopathic potential of Mikania micrantha H.B.K. on the germination and growth
of three weed species, A.systasia gangetica (L.) T. Anders., Chrysopogon aciculatus
(Ritz.) Trin and Paspalum conjugatum Berg. Germination and fresh weight of all
three weeds decreased progressively when exposed to increasing concentrations
of aqueous leaf or root extract of Mikania. The phytotoxic effect of root extract
on the radicle elongation of the test species was greater than that of leaf extract.
The dry weight and rate of emergence of the bioassay species used were affected
when Mikania debris (leaf or root) were placed on soil surfaces or incorporated into the soil. P. conjugatum emergence was strongly affected when Mikania (root
orleaf) was incorporated into the soil. Soil collectedfrom the field where Mikania
had been growing had no effecton the final germination of the three weed species.
However, dry weights of A. gangetica and P. conjugatum were significantly reduced
when grown in the Mikanilt-infested so
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The cardiomyocyte "redox rheostat": Redox signalling via the AMPK-mTOR axis and regulation of gene and protein expression balancing survival and death.
Reactive oxygen species (ROS) play a key role in development of heart failure but, at a cellular level, their effects range from cytoprotection to induction of cell death. Understanding how this is regulated is crucial to develop novel strategies to ameliorate only the detrimental effects. Here, we revisited the fundamental hypothesis that the level of ROS per se is a key factor in the cellular response by applying different concentrations of H2O2 to cardiomyocytes. High concentrations rapidly reduced intracellular ATP and inhibited protein synthesis. This was associated with activation of AMPK which phosphorylated and inhibited Raptor, a crucial component of mTOR complex-1 that regulates protein synthesis. Inhibition of protein synthesis by high concentrations of H2O2 prevents synthesis of immediate early gene products required for downstream gene expression, and such mRNAs (many encoding proteins required to deal with oxidant stress) were only induced by lower concentrations. Lower concentrations of H2O2 promoted mTOR phosphorylation, associated with differential recruitment of some mRNAs to the polysomes for translation. Some of the upregulated genes induced by low H2O2 levels are cytoprotective. We identified p21Cip1/WAF1 as one such protein, and preventing its upregulation enhanced the rate of cardiomyocyte apoptosis. The data support the concept of a "redox rheostat" in which different degrees of ROS influence cell energetics and intracellular signalling pathways to regulate mRNA and protein expression. This sliding scale determines cell fate, modulating survival vs death
Estimasi Daya Dukung Lingkungan Pesisir untuk Pengembangan Areal Tambak Berdasarkan Laju Biodegradasi Limbah Tambak di Perairan Pesisir Kabupaten Serang
Penelitian ini bertujuan untuk mengestimasi daya dukung lingkungan pesisir Kabupaten Serang untuk pengembangan budidaya tambak berdasarkan laju biodegradasi limbah organik tambak di perairan pesisir. Laju biodegradasi OSS adalah 10.78 ppm/hari untuk perlakuan T0 (kontrol), 14.24 ppm/hari untuk perlakuan T1 (TSS 100 ppm, OSS 58.08 ppm), 12.75 ppm/hari untuk perlakuan T2 (TSS 200 ppm, OSS 145.72 ppm),11.34 ppm/hari untuk perlakuan T3 (TSS 300 ppm, OSS 234.22 ppm), 9.38 ppm/hari untuk perlakuan T4(TSS 400 ppm, OSS 321.86 ppm), dan 8.40 ppm/hari untuk perlakuan T5 (TSS 500 ppm, OSS 410.35 ppm). Dengan musim tanam udang 2 kali dan laju biodegradasi OSS 14.76 ppm/hari, daya dukung maksimum lingkungan pesisir Kabupaten Serang untuk budidaya tambak udang adalah 1 090.55 ha untuk tambak intensif,2 220.82 ha untuk tambak semi intensif, dan 12 595.07 ha untuk tambak tradisional plus. Kombinasi optimum luas tambak yang sesuai dengan potensi lahan tambak adalah 149.16 ha (13.6%)tambak intensif, 975.61 ha (42.6%) tambak semi intensif, dan 5 875.23 ha (43.8%) tambak tradisional plus
Potency of Vibrio Isolates for Biocontrol of Vibriosis in Tiger Shrimp (Penaeus Monodon) Larvae
This study was carried out to obtain Vibrio isolates able to function as biocontrol of vibriosis in shrimp hatchery. Thirty one Vibrio isolates were isolated from tiger shrimp larvae and hatchery environments, i.e. Labuan, Pangandaran, and Lampung, Indonesia. Pathogenic V. harveyi MR5339 was obtained from Maros, South-Sulawesi and was made as a rifampicin resistant mutant (RFR) to screen for those 31 Vibrio isolates in in vitro assays and to allow us to monitor their presence in shrimp larvae and larval rearing water. Almost all Vibrio isolates could inhibit the growth of pathogenic V. harveyi MR5339 RFR. SKT-b isolate from Skeletonema was the most effective to inhibit the growth of V. harveyi MR5339 Rf* and significantly reduced larval mortality in pathogen challenge assays. These prospective biocontrol bacteria, at concentration of 10" CFU/ml, did not show pathogenicity to shrimp larvae. SKT-b was Gram negative, short rod-shape, exhibited yellow colonies on TCBS and swarming on SWC-agar media, motile, utilized glucose and sucrose but not lactose: produced extra-cellular protease and amylase, but did not produce chitmase. Partial sequencing of 16S-rRNA gene SKT-b showed SKT-b similarity to Vibrio alginofyticus
Spontaneous Interlayer Charge Transfer near the Magnetic Quantum Limit
Experiments reveal that a confined electron system with two equally-populated
layers at zero magnetic field can spontaneously break this symmetry through an
interlayer charge transfer near the magnetic quantum limit. New fractional
quantum Hall states at unusual total filling factors such as \nu = 11/15 (= 1/3
+ 2/5) stabilize as signatures that the system deforms itself, at substantial
electrostatic energy cost, in order to gain crucial correlation energy by
"locking in" separate incompressible liquid phases at unequal fillings in the
two layers (e.g., layered 1/3 and 2/5 states in the case of \nu = 11/15).Comment: 4 pages, 4 figures (1 color) included in text. Related papers at
http://www.ee.princeton.edu/~hari/papers.htm
Essai d'appréciation de l'importance épidémiologique des concentrations hivernales d'étourneaux sansonnets (Sturnus vulgaris L.) dans la région portuaire de Brest, Finistère
Observation of Quantized Hall Drag in a Strongly Correlated Bilayer Electron System
The frictional drag between parallel two-dimensional electron systems has
been measured in a regime of strong interlayer correlations. When the bilayer
system enters the excitonic quantized Hall state at total Landau level filling
factor \nu_T=1 the longitudinal component of the drag vanishes but a strong
Hall component develops. The Hall drag resistance is observed to be accurately
quantized at h/e^2.Comment: 4 pages, 3 figures. Version accepted for publication in Physical
Review Letters. Improved discussion of experimental and theoretical issues,
added references, correction to figure
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