505 research outputs found
Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators
We describe a flexible and modular delayed-feedback nonlinear oscillator that
is capable of generating a wide range of dynamical behaviours, from periodic
oscillations to high-dimensional chaos. The oscillator uses electrooptic
modulation and fibre-optic transmission, with feedback and filtering
implemented through real-time digital-signal processing. We consider two such
oscillators that are coupled to one another, and we identify the conditions
under which they will synchronize. By examining the rates of divergence or
convergence between two coupled oscillators, we quantify the maximum Lyapunov
exponents or transverse Lyapunov exponents of the system, and we present an
experimental method to determine these rates that does not require a
mathematical model of the system. Finally, we demonstrate a new adaptive
control method that keeps two oscillators synchronized even when the coupling
between them is changing unpredictably.Comment: 24 pages, 13 figures. To appear in Phil. Trans. R. Soc. A (special
theme issue to accompany 2009 International Workshop on Delayed Complex
Systems
Comparison of Radiovisiography and Digital volume tomography to direct surgical measurements in the detection of infrabony defects
Objectives: To compare the linear measurements of Radiovisiography (RVG) and Digital volume tomography
(DVT) to direct surgical measurements in the detection of periodontal infrabony defects.
Study design: RVG and DVT images were taken prior to periodontal surgery for 28 infrabony periodontal defects.
After defect debridement, direct bony defect measurements were made from the cemento enamel junction (CEJ) to
the base of the defect (CEJ-BD) and to the alveolar crest (CEJ-AC) with a periodontal probe. These same measurements
were made on the RVG and DVT images and then compared to the direct surgical values.
Results: DVT correlated strongly with surgical measurements, whereas RVG correlated less favorably (P=0.0109,
P=0.0193 respectively).No significant difference for CEJ-AC (P=0.0599) was seen between DVT and surgical
measurements; however, there was a significant difference for the distance CEJ-BD (P=0.0105).
Conclusion: DVT technique is significantly more accurate than RVG in the detection of infrabony periodontal
defects
Evaluation of holy basil mouthwash as an adjunctive plaque control agent in a four day plaque regrowth model
Objectives: Various antibacterial and antiplaque agents are used in chemical plaque control but none are without
their shortcomings. Chlorhexidine considered a gold standard, also has an array of side effects. To overcome these,
numerous herbal extracts have been tried and tested and one among them is holy basil. The present study evaluated
the antibacterial efficacy of holy basil in vitro against some periodontopathogens and its antiplaque ef
fect in vivo.
Study Design: Thirty periodontally healthy volunteers were randomly divided into three groups and refrained from
all mechanical oral hygiene measures for 4 days and used one of the randomly assigned mouthwash (1- chlor
-
hexidine; 2- holy basil; and 3- sterile water [placebo]) twice daily. The Plaque Index (PI) was assessed at days 0
and 5. Aqueous extract of holy basil was tested against
Prevotella intermedia
(
P. intermedia
) and
Fusobacterium
nucleatum
(
F.nucleatum
).
Results: Holy basil extract showed inhibition of both the tested periodontopathogens (
P.intermedia and F.nucleatum
)
at various concentrations. In all groups, the PI increased from baseline to day 5. There was a statistically significant
difference (
p
< .05) between the chlorhexidine and placebo rinse and the holy basil and placebo rinse, but no statis
-
tically significant difference was found between the chlorhexidine and holy basil rinse with respect to PI.
Conclusions: These results indicate that the holy basil mouthwash has an antiplaque effect and is efficacious against
P. intermedia
and
F. nucleatum
strains in vitro. Hence holy basil mouthwash may have potential as an antiplaque
mouthwash with prophylactic benefits
Multi component one pot synthesis and characterization of derivatives of 2-amino-7,7- dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile and study of anti-microbial activity
An efficient and convenient procedure has been described for one-pot multi-component synthesisof tetrahydrobenzo[b]pyrans known as 2-amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile which can be obtained from the reaction of substituted aromatic aldehydes, dimedone, malonitrile, in the presence of base such as potassium tertiary butoxide and THF in methanol as solvent at RT condition. All the compounds were examined by advanced spectroscopic data (1H NMR, 13C NMR and LCMS) and the structural determination was evaluated by elemental analysis. In addition to this, all the newly synthesized compounds were examined for their antibacterial activities and antifungal activity by disc diffusion method against the organism of Aspergillus niger and Candida ablicans L. KEY WORDS: Aromatic aldehydes, Dimedone, Malonitrile, Potasium tertiary butoxide, 2-Amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile, Anti-microbial activity Bull. Chem. Soc. Ethiop. 2018, 32(1), 133-138DOI: https://dx.doi.org/10.4314/bcse.v32i1.1
Radiographic imaging of metabolic bone disorders and their relative management
Background: Bone is a strong dynamic organ of the endoskeleton playing a vital role in structural integrity envisaging to keep proper shape and maintenance of the body, mineral reservoirs, blood production, coagulation and immunity. Metabolic bone diseases are a heterogeneous group of disorders that interrupt the normal homeostasis of bone formation and resorption. Bone regulates as well as acts as a host for hematopoiesis by providing niche for proliferation and differentiation of hematopoietic cell. Bone is a dynamic tissue but metabolically active as it is being constantly formed (modelling) and reformed (remodelling). Metabolic bone diseases comprise of a broad spectrum of inherited and acquired disorders characterized by abnormalities in calcium metabolism and bone cell physiology- that lead to an altered serum calcium concentration and skeletal failure.Methods: After taking a properly informed written consent and complete history, thorough clinical examination was done and these patients were subjected to radiographic imaging and biochemical analysis.Results: Serum alkaline phosphatase is a good marker in rickets and osteomalacia, ICTP in osteoporosis, pyridinoline, deoxypyridinoline in primary hyperparathyroidism, serum PICP in renal osteodystrophy.Conclusions: In cases of rickets and osteomalacia either decreased or normal values of serum calcium and serum phosphorus were obtained. But the cases pertaining to renal failure with rickets values of serum phosphorous were found to be raised. However, in all cases of rickets and osteomalacia values of serum alkaline phosphatase were also found to be raised
Effect of Yoga on Human Aggression and Violent Behavior - A Review of the Indian Yoga Scriptures and Scientific Studies
Among the deviant human behaviors, aggression appears to be the most prevalent and disturbing one, affecting one and all. Uncontrolled aggression/violent behavior could cause a significant toll, equally affecting both involved and the non-involved. This delinquent human behavior has been well addressed in Indian yogic scriptures. It provides a theoretical framework to understand the causes, ill-effects, need for peace, harmony, and ways to correct the aggression behavior. It is also claimed that yoga is a way for inner bliss and external coherence; and with this time-tested technique, it is possible to bring about a sense of inner peace and emotional stability, thus having potential to correct aggressive behaviors. This review paper brings out the studies made to find out effect of yoga on human aggression/violent behavior
Concordance between chest X ray (CXR) and point of care ultrasound (POCUS) findings in children diagnosed with RSV infection by nasopharyngeal RT-PCR: the Zambia experience
NIHhttp://www.cs.bu.edu/faculty/betke/papers/Camelo-et-alRSV-POCUS-vs-CXR-Poster.pdfAccepted manuscrip
Radiographic imaging of metabolic bone disorders in consonance with biochemical parameters
Background: Bone is a strong dynamic organ of the endoskeleton playing a vital role in structural integrity envisaging keeping proper shape and maintenance of the body, mineral reservoirs, blood production, coagulation and immunity. Metabolic bone diseases are a heterogeneous group of disorders that interrupt the normal homeostasis of bone formation and resorption. Bone regulates as well as acts as a host for hematopoiesis by providing niche for proliferation and differentiation of hematopoietic cell. Bone is a dynamic tissue but metabolically active as it is being constantly formed (modelling) and reformed (remodelling). Metabolic bone diseases comprise of a broad spectrum of inherited and acquired disorders characterized by abnormalities in calcium metabolism and bone cell physiology- that lead to an altered serum calcium concentration and skeletal failure.Methods: After taking a properly informed written consent and complete history, thorough clinical examination was done and these patients were subjected to radiographic imaging and biochemical analysis.Results: With regards to fracture relating to different skeletal structures frequency was more in vertebra (38%), the maximum to be reported in 38 cases followed by hip fractures (17%) in 17 cases. Pelvis fractures were reported as (11%) in 11 cases and tibia fractures were reported to be only (7%) in meagre population of 7 cases, while remaining skeletal organs had (27%) fractures with subject to realisation in other 27 cases.Conclusions: In all the osteoporotic cases irrespective to age of patients, values of serum calcium, serum alkaline phosphatase, serum phosphorus, serum potassium, serum sodium, serum calcidiol were within normal limits
Testing quantum correlations in a confined atomic cloud by scattering fast atoms
We suggest measuring one-particle density matrix of a trapped ultracold
atomic cloud by scattering fast atoms in a pure momentum state off the cloud.
The lowest-order probability of the inelastic process, resulting in a pair of
outcoming fast atoms for each incoming one, turns out to be given by a Fourier
transform of the density matrix. Accordingly, important information about
quantum correlations can be deduced directly from the differential scattering
cross-section. A possible design of the atomic detector is also discussed.Comment: 5 RevTex pages, no figures, submitted to PR
Morphoanatomy and phytochemical screening of entire fruits of Momordica tuberosa Cogn. (Cucurbitaceae)
Momordica tuberosa (Cucurbitaceae) is traditionally used as abortifacient in India. Morphoanatomy, physicochemical and phytochemical nature of fruits and seeds of this plant were studied in order to contribute to complete the profile of these parts to aid in their identification and avoid confusion in taxanomic species. Macroscopic and microscopic characters were established using light microscopy, WHO recommendations and standard physicochemical and phytochemical procedures. Fruits presented the typical characters of Cucurbitaceae plants possessing ridges with 1 mm thickness and pericarp 550 µm thick. Phytochemical screening revealed the presence of flavonoids, steroids, triterpenes and alkaloids in various extracts. The findings from morphoanatomy, microscopy and physicochemical characters may be used to establish the authenticity of fruits of this plant.Colegio de Farmacéuticos de la Provincia de Buenos Aire
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