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1.
A wavelet-decomposition with soft-decision algorithm is used to estimate an approximate power-spectral density (PSD) of both accelerometer and surface EMG signals for the purpose of discrimination of Parkinson tremor from essential tremor. A soft-decision wavelet-based PSD estimation is used with 256 bands for a signal sampled at 800 Hz. The sum of the entropy of the PSD in band 6 (7.8125–9.375 Hz) and band 11 (15.625–17.1875 Hz) is used as a classification factor. The data has been recorded for diagnostic purposes in the Department of Neurology of the University of Kiel, Germany. Two sets of data are used. The training set, which consists of 21 essential-tremor (ET) subjects and 19 Parkinson-disease (PD) subjects, is used to obtain the threshold value of the classification factor differentiating between the two subjects. The test data set, which consists of 20 ET and 20 PD subjects, is used to test the technique and evaluate its performance. A “voting” between three results obtained from accelerometer signal and two EMG signals is applied to obtain the final discrimination. A total accuracy of discrimination of 85% is obtained.  相似文献   

2.
A modified Lorentzian distribution function is used to model peaks in two-dimensional (2D) 1H–13C heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectra. The model fit is used to determine accurate chemical shifts from genuine signals in complex metabolite mixtures such as blood. The algorithm can be used to extract features from a set of spectra from different samples for exploratory metabolomics. First a reference spectrum is created in which the peak intensities are given by the median value over all samples at each point in the 2D spectra so that 1H–13C correlations in any spectra are accounted for. The mathematical model provides a footprint for each peak in the reference spectrum, which can be used to bin the 1H–13C correlations in each HSQC spectrum. The binned intensities are then used as variables in multivariate analyses and those found to be discriminatory are rapidly identified by cross referencing the chemical shifts of the bins with a database of 13C and 1H chemical shift correlations from known metabolites.  相似文献   

3.
Objectives: To establish the association between changes in height and prevalence of obesity between 1996 and 2004 in Chilean preschool children. Research Methods and Procedures: Children registered in the Junta Nacional de Jardines Infantiles (JUNJI) preschool program were routinely measured three times a year and in consecutive years. Two indices [weight‐for‐height z‐scores (WHZ) and BMI centiles] were used to define obesity. Height‐for‐age z‐scores (HAZ) were used to define stature. Generalized estimating equations were used to describe the relationship between stature and obesity while controlling for repeated measurements in children. Results: The prevalence of obesity in Chilean preschool children has remained relatively constant over the past 9 years when either index is used. The prevalence of stunted (HAZ ≤2) children has decreased, while the proportion of children who are tall (HAZ >2) has increased. Using WHZ to define obesity, stunted children do not seem to be at increased risk of obesity when compared with children of normal height. Tall children were strongly protected from obesity when either criterion was used to define obesity. Discussion: The lack of association between stunting and obesity using WHZ ≥2 likely reflects the fact that Chile is in the post‐transitional phase of the nutrition transition, and stunting is no longer a risk factor for obesity; however, the associations observed between stunting and BMI suggest that either WHZ or BMI, or both, are inaccurate criteria to define overweight. Conclusions: There is a unique relationship between stature and obesity in preschool children that is different from that observed in older children in the same population.  相似文献   

4.
The beaded lizard (Heloderma horridum) is listed as a threatened species in Mexico. Scientific research has been limited to two sites within its range (Chamela and Valle Motagua) outside of these two regions there have not been adequate surveys to define range limits or measure environmental correlates for defining suitable habitat. We constructed an ensemble model (EM) for the distribution of suitable habitat for H. horridum in both Mexico and Guatemala and then used that model to identify potential areas to focus conservation. We used nine presence-only modeling methods, and selected three to generate our EM. We used the EM to evaluate the efficacy of the existing Protected Natural Areas (PNAs) in Mexico and Guatemala for H. horridum. Also we used the best individual predictive model (Maxent) to obtain the most important factors for H. horridum presence and used them to analyse the habitat use; finally we used our predictive model to calculate niche breath for the species. The estimated potential distribution of H. horridum is 370,474 km2; within this area we identified nine zones based on continuity and natural barriers. About 1.5% of the species distribution is under protection in the PNAs. The five most important factors for the presence of this species explained 78.2% of the generated model and are related to seasonality and soil cover, and these are used selectively. This species is closely associated with tropical deciduous forests, one of the most threatened ecosystems worldwide and is inadequately protected in both Mexico and Guatemala. Our results clearly show the necessity of a protection plan for this species.  相似文献   

5.
Both Schisandra sphenanthera (S. sphenanthera) and Schisandra chinensis (S. chinensis) are used as traditional Chinese medicines, but they have different medicinal properties. Because S. sphenanthera is cheaper, it is often used as a counterfeit product for S. chinensis. In the present study, an electronic tongue (e-tongue) was used for discrimination of the two Schisandraceae species. In addition, the contents of schisandrin, schizandrol B, schisantherin A, deoxyschizandrin, and schisandrin B were determined simultaneously by ultra-performance liquid chromatography. Principal component analysis (PCA) and discriminant factor analysis (DFA) were used to establish the mathematical models for species identification, and the classification rates for both methods reached 100%. The e-tongue coupled with multivariate analysis exhibited the excellent performance and classification accuracy, and this was validated by the ultra-performance liquid chromatography results. This simple e-tongue technique could be useful for rapid and accurate identification of S. sphenanthera and S. chinensis.  相似文献   

6.
The development of a competitive ELISA for the detection of brucella-specific antibodies in bovines is described. Anti-brucella guinea pig serum was used as a source of competing antibodies. Lipo-polysaccharide purified from inactivated B. abortus S19 culture was used as antigen for the development of the assay. Sera from cattle were used in the competitive ELISA, rose bengal test and a commercial indirect ELISA. The following cattle sera were tested: (i) known positive sera (n = 80) (ii) known negative sera (n = 100) and (iii) field sera (n = 1184). Based on the receiver operating characteristics curve analysis and frequency distribution of the percentage of inhibition, 30% inhibition was considered the cut-off for positive and negative results. The sensitivity and specificity estimate on comparison with the commercial indirect ELISA was 94.87 and 92.12% respectively. The competitive ELISA described is a simple method for the routine screening of animal sera for detecting Brucella-specific antibodies.  相似文献   

7.
The statistical method for the analysis of frequency tables which has been published by GRIZZLE, STARMER, and KOCH (1969) is outlined for the case of linear functions of relative frequencies. Its use for the analysis of aggregate time series data under the model of simple MARKOV chains is suggested. Weighty objections against the resulting test statistics were grounds for the planning and performance of a Monte Carlo study. The results of the study demonstrated that the test statistic SS ( Cb =0) which is used for the comparison of different MARKOV chains is in fact X2-distributed. The test statistic SS ( F (p) = Xb ) for evaluation of the lack of fit of the model also follows a X2-distribution when a simple MARKOV chain is used instead of the observed time series can be determined by simply iterating the original GSK algorithm.  相似文献   

8.
Introduction: The aim of this work is to validate the dose calculated by the TPS at the dose build-up region when the treatment beam irradiates the patient (skin surface) through the CF couch. The accuracy of dose calculated by TPS for these situations depends on the type of algorithm used.Methods: In order to validate the TPS for the situation mentioned earlier, we have used BEAMnrc MC Simulation and Parallel Plate (PP) chamber measurements as a benchmark. The three measurement set-ups used in   相似文献   

9.
Jan Vymazal 《Hydrobiologia》2011,674(1):133-156
The presence of macrophytes is one of the most conspicuous features of wetlands and their presence distinguishes constructed wetlands from unplanted soil filters or lagoons. The macrophytes growing in constructed wetlands have several properties in relation to the treatment process that make them an essential component of the design. However, only several roles of macrophytes apply to constructed wetlands with horizontal subsurface flow (HF CWs). The plants used in HF CWs designed for wastewater treatment should therefore: (1) be tolerant of high organic and nutrient loadings, (2) have rich belowground organs (i.e. roots and rhizomes) in order to provide substrate for attached bacteria and oxygenation (even very limited) of areas adjacent to roots and rhizomes and (3) have high aboveground biomass for winter insulation in cold and temperate regions and for nutrient removal via harvesting. The comparison of treatment efficiency of vegetated HF CWs and unplanted filters is not unanimous but most studies have shown that systems with plants achieve higher treatment efficiency. The vegetation has mostly a positive effect, i.e. supports higher treatment efficiency, for organics and nutrients like nitrogen and phosphorus. By far the most frequently used plant around the globe is Phragmites australis (Common reed). Species of the genera Typha (latifolia, angustifolia, domingensis, orientalis and glauca) and Scirpus (e.g. lacustris, validus, californicus and acutus) spp. are other commonly used species. In many countries, and especially in the tropics and subtropics, local plants including ornamental species are used for HF CWs.  相似文献   

10.
Herein, we disclose the design of a model Ni(II) complex of glycine Schiff base possessing single‐nitrogen stereogenic center, which was successfully used for high‐performance liquid chromatography (HPLC)‐assisted assessment of its configurational stability. The major finding is that the configurational stability of the Ni(II)‐coordinated nitrogen is profoundly dependent on the reaction conditions used, in particular the solvent, and can range from inconsequential (t½ less than 5 min) to virtually completely stable (t½ 90 y). The discovery reported in this study most likely to be of certain theoretical and synthetic value.  相似文献   

11.
(1)Where grinding or maceration of plant tissue is impractical, immersion in methanol should be used. (2)The adaption to aqueous methanol of existing techniqus for distinguishing chlorophyll and phaeophytin in aqueous acetone was studied in detail. In methanol the spectra of both phaeophytin a and b were found to be pH sensitive. A method developed involving changes in absorbance at 665 nm is less precise than similar methods using acetone. (3)The spectra of phaeophytin b in methanol at different pH levels are anomalous. Changes in absorbance between 440 and 410 nm cannot be used for the estimation of phaeophytin. (4)Plant pigments can be transferred from methanol to aqueous acetone without degradation of chlorophyll. Modified standard techniques may then be used to measure chlorophyll a and phaeophytin a content.  相似文献   

12.
On the interpretation of some planktonology equations   总被引:1,自引:0,他引:1  
D. A. Voronov 《Oecologia》1991,88(2):303-304
Summary The concept of the mean value of a function is used to interpret some population-dynamics equations. The well-known formula for the per capita growth rate r gives a precise mean value for any (not only exponentially growing) populations. This result is used to derive the birth and death rate equations of Paloheimo (1974) with minimal initial limitations.Abbreviations t time - N number of animals - E number of eggs - r specific (i.e. per capita) population growth rate - b specific birth rate - d specific death rate - D duration of embryonic development  相似文献   

13.
In this research, the B3LYP density functional and Stevens effective core potentials are used to compare carbon-hydrogen and carbon-heteroatom bond activation by an iridium(I) complex. Of particular importance is to address the kinetic (transition state) and thermodynamic (ground state) selectivity. The complex Ir(PH3)2(H) with CH3-X (X=F, Cl, OH, SH, NH2, PH2) as the substrate has been used as a model. Good agreement in geometries is obtained between the target molecules and experimental models. The resultant products of C-H and C-X oxidative addition are Y-shaped minima (i.e., a distorted trigonal bipyramid with one acute and two obtuse angles among the equatorial ligands). Oxidative addition of the C-X bond to the substrate is exothermic for groups 16 and 17, but endothermic for group 15. A significant thermodynamic preference for C-X activation over C-H activation is observed for these Ir(I) complexes. However, analysis of the transition states for oxidative addition suggests that there is a kinetic preference for C-H activation.  相似文献   

14.
《Microbiological research》2014,169(12):940-947
The recent emergence of multidrug-resistant bacteria over the last decade has led to a renewal in the discovery of new antimicrobial drugs. Streptomyces members are practically unlimited sources of new antibiotics. However, the identification of Streptomyces species is difficult and time-consuming. Therefore, there is a need for alternative methods for their rapid identification. In this study, an efficient protocol of identification using Matrix-Assisted Laser Desorption Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF MS) was developed and applied for the rapid identification of Streptomyces isolates from the El Kala lakes in northeastern Algeria. A collection of 48 Streptomyces isolates were used for this study. The optimized procedure allowed us to obtain specific and reproducible protein spectra for each Streptomyces isolate tested. The spectra generated were used to build a preliminary local database based on their initial 16S rRNA identification. The blind test used for the identification of 20 Streptomyces strains already available in our created database and 20 unknown Streptomyces isolates showed that all (100%) of the Streptomyces strains listed in the database were rapidly (<30 min) identified with high scores of up to 2.8. Here, for the first time we showed that MALDI-TOF MS could be used as a cost-effective tool for the rapid identification of Streptomyces isolates.  相似文献   

15.
Rücker's walk count (WC) indices are well-known topological indices (TIs) used in Chemoinformatics to quantify the molecular structure of drugs represented by a graph in Quantitative structure–activity/property relationship (QSAR/QSPR) studies. In this work, we introduce for the first time the higher-order (kth order) analogues (WCk) of these indices using Markov chains. In addition, we report new QSPR models for large complex networks of different Bio-Systems useful in Parasitology and Neuroinformatics. The new type of QSPR models can be used for model checking to calculate numerical scores S(Lij) for links Lij (checking or re-evaluation of network connectivity) in large networks of all these fields. The method may be summarized as follows: (i) first, the WCk(j) values are calculated for all jth nodes in a complex network already created; (ii) A linear discriminant analysis (LDA) is used to seek a linear equation that discriminates connected or linked (Lij = 1) pairs of nodes experimentally confirmed from non-linked ones (Lij = 0); (iii) The new model is validated with external series of pairs of nodes; (iv) The equation obtained is used to re-evaluate the connectivity quality of the network, connecting/disconnecting nodes based on the quality scores calculated with the new connectivity function. The linear QSPR models obtained yielded the following results in terms of overall test accuracy for re-construction of complex networks of different Bio-Systems: parasite–host networks (93.14%), NW Spain fasciolosis spreading networks (71.42/70.18%) and CoCoMac Brain Cortex co-activation network (86.40%). Thus, this work can contribute to the computational re-evaluation or model checking of connectivity (collation) in complex systems of any science field.  相似文献   

16.
The present study was aimed to explore the traditional knowledge of Irula tribal people who are practicing herbal medicine in Walayar valley, the Southern Western Ghats, India. A total number of 146 species of plants distributed in 122 genera belonging to 58 families were identified as commonly used ethnomedicinal plants by them. Interestingly, 26 new claims were also made in the present study. Through the data obtained from Irula tribal healers, the herbs were mostly used for medicine (40.4%) followed by trees (26.7%) and climbers (18.5%). In addition leaves were highly used for medicinal purposes, collected from 55 species (38%) followed by multiple parts from 18 species (12%). Acorus calamus is the species of higher use value (1.80) assessed to be prescribed most commonly for the treatment of cough. High informant consensus factor (1.0) obtained for insecticidal uses and cooling agent indicates that the usage of Canarium strictum and Melia dubia, and Mimosa pudica and Sesamum indicum respectively for that purposes had obtained high degree of agreement among the healers in using these species for the respective purposes. The most commonly used method of preparation was decoction (63%) followed by raw form (23%), paste (12%) and powder (2%). Therefore, it is suggested to take-up pharmacological and phytochemical studies to evaluate the species to confirm the traditional knowledge of Irulas on medicinal plants.  相似文献   

17.
Rifampicin (Rif) is a first line drug used for tuberculosis treatment. However, the emergence of drug resistant strains has necessitated synthesis and testing of newer analogs of Rif. Mycobacterium smegmatis is often used as a surrogate for M. tuberculosis. However, the presence of an ADP ribosyltransferase (Arr) in M. smegmatis inactivates Rif, rendering it impractical for screening of Rif analogs or other compounds when used in conjunction with them (Rif/Rif analogs). Rifampicin is also used in studying the role of various DNA repair enzymes by analyzing mutations in RpoB (a subunit of RNA polymerase) causing Rif resistance. These analyses use high concentrations of Rif when M. smegmatis is used as model. Here, we have generated M. smegmatis strains by deleting arr (Δarr). The M. smegmatis Δarr strains show minimum inhibitory concentration (MIC) for Rif which is similar to that for M. tuberculosis. The MICs for isoniazid, pyrazinamide, ethambutol, ciprofloxacin and streptomycin were essentially unaltered for M. smegmatis Δarr. The growth profiles and mutation spectrum of Δarr and, Δarr combined with ΔudgB (udgB encodes a DNA repair enzyme that excises uracil) strains were similar to their counterparts wild-type for arr. However, the mutation spectrum of ΔfpgΔarr strain differed somewhat from that of the Δfpg strain (fpg encodes a DNA repair enzyme that excises 8-oxo-G). Our studies suggest M. smegmatis Δarr strain as an ideal model system in drug testing and mutation spectrum determination in DNA repair studies.  相似文献   

18.
Schizonepeta tenuifolia (Korean name “Hyung-Gae”) is an oriental medicinal plant that is widely used in Korea, China and Japan. S. tenuifolia (Hyung-Gae) has many pharmacological activities and is mostly used for many medicinal preparations. The dried aerial part (spikes and stems) of three oriental medicinal plants, S. tenuifolia (Hyung-Gae), Agastache rugosa (Kwhak-Hyang) and Elsholtzia ciliata (Hyang-Yoo) belonging to the same family, mint family Labiaceae, have such similar shape and smell that it is difficult to differentiate between them. The trnL-F regions of chloroplast DNA of the three medicinal plants were sequenced and used as targets in multiplex PCR reaction to identify S. tenuifolia. After alignment of trnL-F sequences of the authenticated plant samples, one single nucleotide polymorphism (SNP) specific to S. tenuifolia was found. Based on this SNP, a new primer was designed that specifically amplifies the trnL-F region of S. tenuifolia. The established multiplex-PCR was proven to be effective in the differentiation of commercial S. tenuifolia samples from A. rugosa and E. ciliata. This rapid and accurate molecular method is highly promising for use in the food industry.  相似文献   

19.
Multienzyme reaction systems with simultaneous coenzyme regeneration have been investigated in a continuously operated membrane reactor at bench scale. NAD(H) covalently bound to polyethylene glycol with a molecular weight of 104 [PEG-10,000-NAD(H)] was used as coenzyme. It could be retained in the membrane reactor together with the enzymes. L -leucine dehydrogenase (LEUDH) was used as catalyze for the reductive amination of α-ketoisocaproate (2-oxo-4-methylpentanoic acid) to L -leucine. Format dehydrogenease (FDH) was used for the regeneration of NADH. Kinetic experiments were carried out to obtain data which could be used in a kinetic model in order to predict the performance of an enzyme membrane reactor for the continuous production of L -leucine. The kinetic constants Vmax and Km of enzymes are all in the same range regardless of whether native NAD(H) or PEG-10,000-NAD(H) is used as coenzyme. L -leucine was produced continuously out of α-ketoisocaproate for 48 days; a maximal conversion of 99.7% was reached. The space-time yield was 324 mmol/L day (or 42.5 g/L day).  相似文献   

20.
《Biomarkers》2013,18(7):571-577
Abstract

The cerebrospinal fluid (CSF) used for identification of molecular biomarkers in amyotrophic lateral sclerosis (ALS) is mainly obtained from lumbar puncture (LP) performed to exclude other causes of motor neuron damage.

Aim: The aim of the study was to analyze whether CSF of ALS patients obtained for diagnostic purposes is suitable for biomarker studies in the entire ALS population.

Material and methods: We analyzed the medical data, LP frequency and CSF parameters in 568 ALS patients.

Results: LP was performed in 34% of cases. Patients who underwent LP were significantly younger and more frequently presented limb onset ALS, there were no differences in the clinical phenotypes.

Conclusion: CSF obtained for diagnostic purposes can be used for biomarkers studies in ALS.  相似文献   

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