10 research outputs found
Pair excitation-deexcitation coherent states
A class of coherent states defined in terms of the excitation and deexcitation of pairs of photons is studied with reference to its nonclassical and other quantum-statistical properties. These states supplement the other well-known two-mode states such as Caves-Schumaker states and pair coherent states and can be produced by dissipative processes involving emission and absorption of photons in pairs
Quantum singular oscillator as a model of two-ion trap: an amplification of transition probabilities due to small time variations of the binding potential
Following the paper by M. Combescure [Ann. Phys. (NY) 204, 113 (1990)], we
apply the quantum singular time dependent oscillator model to describe the
relative one dimensional motion of two ions in a trap. We argue that the model
can be justified for low energy excited states with the quantum numbers , provided that the dimensionless constant characterizing the
strength of the repulsive potential is large enough, . Time
dependent Gaussian-like wave packets generalizing odd coherent states of the
harmonic oscillator, and excitation number eigenstates are constructed. We show
that the relative motion of the ions, in contradistinction to its center of
mass counterpart, is extremely sensitive to the time dependence of the binding
harmonic potential, since the large value of results in a significant
amplification of the transition probabilities between energy eigenstate even
for slow time variations of the frequency.Comment: 19 pages, LaTeX, 5 eps-figures, to appear on Phys. Rev. A, one
reference correcte
Mixed excitation- and deexcitation-operator coherent states for the SU(1,1) group
Squeezed coherent states associated with the SU(1,1) group defined by (μa2+va° 2)|| Ψ>=λ|| Ψ>, ||μ||2-||v||2=1 are studied in detail. An explicit expression for the quasidistribution Q(α ,α ) in terms of the parabolic cylindrical functions is derived. The nonclassical properties of these states are discussed. The possibility of producing SU(1,1) squeezed coherent states using the down-conversion process is also demonstrated
RNA G-quadruplexes: G-quadruplexes with “U” turns
G-quadruplexes are non canonical secondary structures held together by Hoogsteen bonded planar guanine quartets formed in G-rich sequences in DNA and RNA. Considerable research over the past three decades has contributed to a great deal of understanding of these unusual structures in DNA. Various factors governing the stability of DNA quadruplexes coupled with their in vivo existence have been well documented. RNA has emerged as a key regulatory player in the functioning of the cell shifting the focus to RNA Gquadruplexes which were discovered recently. RNA G-quadruplexes demonstrate immense potential for in vivo existence and function due to their inherent chemistry. We have highlighted the major findings of the field and compared them to structural aspects of DNA quadruplexes. Further, the plausible functions of RNA G-quadruplexes such as translational suppression, splicing etc. are discussed in brief, suggesting scope for an extensive role of these structures in biological systems. As the field is growing, we endeavor to review the current knowledge and evaluate the various attributes of RNA G- quadruplex structure, stability, function and applications. We have also attempted to evaluate the physical and physiological role and relevance of these motifs
Oral Submucous Fibrosis- Correlation between Clinical Findings and Histopathological Grading
Introduction
Oral Submucous fibrosis (OSMF) occurs in young adults, who are in the habit of chewing tobacco mixed with areca nut and its various commercially available preparations. The disease results in progressive inability to open the mouth due to the submucosal fibrosis initiated by chronic inflammation affecting mainly oral mucosa. Authors undertook the present study to correlate the clinical features of OSMF to histopathological features and to find out aetiopathological factors of this condition.
Materials and Methods
A total of 123 clinically diagnosed OSMF patients, in the age range of 17 to 70 years were studied. Mouth opening was measured using a scale and was recorded in millimeters. Incisional biopsy was taken from the representative areas in the oral cavity. The patients were graded clinically and histopathologically and results were analyzed and discussed.
Result
Most of the patients were in the age group of 20-30 years (37.4%) with male predominance. The duration of either tobacco or areca nut chewing ranged from 1 to 35 yrs. Most patients had these habits for 6-19 yrs. Majority (55.3% & 54.5%) of the patients belonged to grade-2 (clinical grading) and intermediate grade (HPE grading) respectively. The HPE grading showed significant and direct association with duration of ill habits. The HPE grading showed significant and direct association with clinical grading (χ2=204.08, p<0.001).
Discussion
The HPE grading showed significant and direct association with duration of ill habits and also with clinical findings of restriction of mouth opening and inter incisal distance. The HPE findings showed significant and direct association with clinical grading i.e. when the clinical grading increases, the histopathological grading also increases.
Conclusion
OSMF is a disease with a high incidence. It also carries a significant risk of transformation to oral cancer. As no effective medical and surgical treatment is available for this condition; it is desirable to diagnose OSMF at early stages
Oral Submucous Fibrosis- Correlation between Clinical Findings and Histopathological Grading
Introduction
Oral Submucous fibrosis (OSMF) occurs in young adults, who are in the habit of chewing tobacco mixed with areca nut and its various commercially available preparations. The disease results in progressive inability to open the mouth due to the submucosal fibrosis initiated by chronic inflammation affecting mainly oral mucosa. Authors undertook the present study to correlate the clinical features of OSMF to histopathological features and to find out aetiopathological factors of this condition.
Materials and Methods
A total of 123 clinically diagnosed OSMF patients, in the age range of 17 to 70 years were studied. Mouth opening was measured using a scale and was recorded in millimeters. Incisional biopsy was taken from the representative areas in the oral cavity. The patients were graded clinically and histopathologically and results were analyzed and discussed.
Result
Most of the patients were in the age group of 20-30 years (37.4%) with male predominance. The duration of either tobacco or areca nut chewing ranged from 1 to 35 yrs. Most patients had these habits for 6-19 yrs. Majority (55.3% & 54.5%) of the patients belonged to grade-2 (clinical grading) and intermediate grade (HPE grading) respectively. The HPE grading showed significant and direct association with duration of ill habits. The HPE grading showed significant and direct association with clinical grading (χ2=204.08, p<0.001).
Discussion
The HPE grading showed significant and direct association with duration of ill habits and also with clinical findings of restriction of mouth opening and inter incisal distance. The HPE findings showed significant and direct association with clinical grading i.e. when the clinical grading increases, the histopathological grading also increases.
Conclusion
OSMF is a disease with a high incidence. It also carries a significant risk of transformation to oral cancer. As no effective medical and surgical treatment is available for this condition; it is desirable to diagnose OSMF at early stages
Not Available
Not AvailableThis article presents a robust contact-type weed eradicator based on position sensing, digital image processing
and microcontroller for weed control in row crops. The imaging system determines the weed density between
the crop rows using an image analyser developed in Visual Studio Open computer vision platform for use under varying illumination levels. Graphic user interface was developed for parametric adjustments of the image analyser. The image analyser conducts image analysis after image acquisition and the data is sent via computer serial to microcontroller for pulse width modulation controlled chemical release. Solenoid valves are employed for liquid release on sponge rollers. The contact-type technique overcomes losses due to chemical drift and percolation resulting in an efficient application. The machine locomotion sensing is done through an inductive type proximity switch. The developed system was calibrated in laboratory, followed by extensive field tests. The average weeding efficiency reported was 90.30% with lowest plant damage of 5.74% and 7.91% and high yield coefficients of 26.15 g/plant and 581.74 g/plant in two selected crops of groundnut and maize plantation. The technology saved about 79.50% of herbicide marking it as a robust and eco-friendly technology.Not Availabl
InSane 2016-2
Very
fast magic-angle spinning (MAS > 80 kHz) NMR combined with
high-field magnets has enabled the acquisition of proton-detected
spectra in fully protonated solid samples with sufficient resolution
and sensitivity. One of the primary challenges in structure determination
of protein is observing long-range <sup>1</sup>H–<sup>1</sup>H contacts. Here we use band-selective spin-lock pulses to obtain
selective <sup>1</sup>H–<sup>1</sup>H contacts (e.g., H<sup>N</sup>–H<sup>N</sup>) on the order of 5–6 Å in
fully protonated proteins at 111 kHz MAS. This approach is a major
advancement in structural characterization of proteins given that
magnetization can be selectively transferred between protons that
are 5–6 Å apart despite the presence of other protons
at shorter distance. The observed contacts are similar to those previously
observed only in perdeuterated proteins with selective protonation.
Simulations and experiments show the proposed method has performance
that is superior to that of the currently used methods. The method
is demonstrated on GB1 and a β-barrel membrane protein, AlkL