2,237 research outputs found
Trajectory Generation for Stair Ascent Walking using Rayleigh Oscillator
This paper describes a trajectory generation technique for stair-ascent walking. The knee, hip and ankle joint trajectory during stair ascent are generated using mutually coupled, nonlinear oscillators. The parameters of the oscillators are tuned using the harmonic balance method, which converts the nonlinear differential equations to a set of algebraic equations. Fourier analysis of data generated by stair-ascent walking is performed to extract the amplitude and the phase of the dominant frequency components for each joint trajectory. The solution for the oscillator is assumed to be a sinusoidal wave and then by harmonic balance method the parameters of the oscillator are found. Each oscillator is responsible for generating a single frequency component with a specific phase and amplitude. The complete trajectory is obtained by summing the output of the oscillators that are relevant to one joint and the coupling maintains the phase relationship between the oscillators
Antigenotoxic and anticlastogenic potential of Agaricus bisporus against MMS induced toxicity in human lymphocyte cultures and in bone marrow cells of mice
The aim of the present study is to evaluate, for the first time, antigenotoxic potential of Agaricus bisporus against methyl methanesulphonate induced toxicity in human lymphocyte culture in vitro and in bone marrow cells of albino mice in vivo. The parameters studied included total aberrant cells and the frequencies of aberrations in the bone marrow cells at three exposure durations viz., 16, 24 and 32 h, and for the in vitro method using chromosomal aberrations, sister chromatid exchanges and replication indices as markers. The alcoholic extract of A. bisporus was taken in five increasing concentrations of 200, 250, 300, 350 and 400 mg/kg body weight for three in vivo exposure durations viz., 16, 24 and 32 h. Similarly, four doses of extracts viz., 150, 200, 250 and 300 lg/ ml of culture were taken for in vitro durations of 24, 48 and 72 h in the presence as well as the absence of S9-mix. The treatment reduced the total number of aberrant cells ranging from 10.0% to 46.15% and it reduced the total frequencies of aberrations ranging from 198 to 96 against very high aberrations i.e., 227 caused due to methyl methanesulphonate in vivo. The same trends were observed in the in vitro experiments i.e., it reduced chromosomal aberrations from (42.00%, 71.25%, and 83.00% to 20.00%, 39.50%, and 43.00%) at 24, 48, and 72 h of exposure respectively. However when experiments were carried out in the presence of liver S9 fraction, these values were respectively 52.38, 44.56, and 48.34% significant at <0.05 level, likewise it also reduced sister chromatid exchanges from 14.86 ± 1.44 down to 8.84 ±0.75 per cell, whereas the replication index got enhanced from 1.45 to 1.64
DESIGN, FACILE SYNTHESIS, AND BIOLOGICAL EVALUATION OF NOVEL 1,3-THIAZINE DERIVATIVES AS POTENTIAL ANTICONVULSANT AGENTS
Objective: Chalcones and their heterocyclic analogs represent an important class of small molecules having anticonvulsant activities. Therefore, inthis study, the synthesis and anticonvulsant activity of some new chalcones and 1,3-thiazines were described.Methods: The reaction of 1-acetylnaphthalene with substituted aromatic aldehydes in the presence of aq. NaOH afforded corresponding chalconeswhich upon further cyclization with thiourea resulted in 1,3-thiazine derivatives. The newly synthesized compounds were tested for anticonvulsantactivity by pentylenetetrazole-induced seizures method using diazepam as standard.Results: Most of the compounds showed good anticonvulsant activity but is less than diazepam. 1,3-thiazines were more potent than chalconesand among them, compound P4 containing 4-fluorophenyl substituents on the thiazine moiety was more potent as it has prolonged the onset ofconvulsions by 155.2 seconds.Conclusion: We described the synthesis and anticonvulsant activity of novel chalcones and 1,3-thiazine derivatives. 1,3-thiazines are more activeanticonvulsant agents than chalcones and in particular compounds with electron withdrawing substituents.Keywords: Chalcone, 1,3-thiazine, Pentylenetetrazole
A π-CLCL Type Immittance Converter for Constant Current and Dynamic Load Applications
Impedance-admittance converter is shortly termed as immittance converter. In this converter, the output current is proportional to the input voltage and the output voltage is proportional to the input current. The output current is thus independent of the load. This research evaluates the characteristics of a proposed π-CLCL immittance converter, which is a combination of the typical π- and T-type configurations, for constant current and dynamic load applications. The input-output characteristics and efficiency characteristics are analyzed and simulated. The characteristics are compared to that of the typical π- and T-type converters. The input-output characteristics and efficiency characteristics are then examined experimentally. It is observed that the experimental results agree with those of the simulation ones, and confirm that the π-CLCL configuration is more efficient than the typical π- and T-type immittance converters while maintaining a nearly constant output current and thus applicable for dynamic loads.DOI:http://dx.doi.org/10.11591/ijece.v4i5.595
Indigenous uses of medicinal plants in Tarikhet block of Kumaun Himalaya, India
Over 80% of the world population relies on vegetation for health care; more than
30% of the entire plant species are used for medicinal purposes. India displays
large topography and various climatic conditions which accommodates more than
45,000 species. Uttarakhand state known as the ‘natural reservoir of India’ is in
north-western Himalaya; it has 8000 vascular plants species, over 1748 of these
are known for their therapeutic properties. In hilly areas of Uttarakhand, local
communities still use the ethno-medicinal plants to cure various diseases and
ailments. Although several researchers have conducted surveys across different
areas of the Himalayan region, and to our knowledge, ethno-medicinal plants’
studies have not been conducted in Tarikhet block of Almora district, Uttarakhand.
In this study, a total of 155 individuals of different age groups (20–93 years) with
different socio-economic status (farmer, service man, ex-service man,
businessman, housewives, students) participated. A total of 72 medicinal plant
species were reported from which 31 were herbs, 20 trees, 15 shrubs and 6 were
climbers belonging to 44 families used in the treatment of various ailments.
Furthermore, we recorded that local people used various plant parts that is, leaves
(35), fruit (15), root (10), whole plant (5), seed (6), bark (6) stem (4), rhizome (3)
and others (4), to treat a wide range of health conditions. Thus, documenting the
ethno-medicinal plants and for conservation is of the upmost important not only
for cultural traditions and for biodiversity conservation. The study shows that
locals have extensive ethnobotanical knowledge and are highly dependent on the
forest for their livelihood. The valuable knowledge is anchored in cultural
practices and orally transmitted from one generation to another; however, the loss
is imminent as the new generation lacks the interest and the traditional
ethnobotanical knowledge is unprotected.info:eu-repo/semantics/publishedVersio
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Measles vaccination and antibody response in autism spectrum disorder
OBJECTIVE: To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls. DESIGN: Case-control study, community based. METHODS: A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum. RESULTS: No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis. CONCLUSION: No association between measles vaccination and ASD was shown
A study of the Space Station Freedom response to the disturbance environment
A relatively general formulation for studying the dynamics and control of an arbitrary spacecraft with interconnected flexible bodies has been developed. This self-contained and comprehensive numerical algorithm using system modes is applicable to a large class of spacecraft configurations of contemporary and future interest. Here, versatility of the approach is demonstrated through the dynamics and control studies aimed at the evolving Space Station Freedom
Evidence for a High Affinity, Saturable, Prenylation-Dependent p21(Ha- Ras) Binding Site in Plasma Membranes
Oncogenic p21(ras) proteins can only exert their stimulation of cellular proliferation when plasma membrane-associated. This membrane association has an absolute requirement for post-translational modification with isoprenoids. The mechanism by which isoprenoids participate in the specific association of p21(ras) with plasma membranes is the subject of this report. We present in vitro evidence for a plasma membrane binding protein for p21(ras) that can recognize the isoprenoid substituent and, therefore, may facilitate the localization of p21(ras)
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