729 research outputs found

    Exploring the extended density-dependent Skyrme effective forces for normal and isospin-rich nuclei to neutron stars

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    We parameterize the recently proposed generalized Skyrme effective force (GSEF) containing extended density dependence. The parameters of the GSEF are determined by the fit to several properties of the normal and isospin-rich nuclei. We also include in our fit a realistic equation of state for the pure neutron matter up to high densities so that the resulting Skyrme parameters can be suitably used to model the neutron star with the "canonical" mass (1.4M\sim 1.4 M_\odot). For the appropriate comparison we generate a parameter set for the standard Skyrme effective force (SSEF) using exactly the same set of the data as employed to determine the parameters of the GSEF. We find that the GSEF yields larger values for the neutron skin thickness which are closer to the recent predictions based on the isospin diffusion data. The Skyrme parameters so obtained are employed to compute the strength function for the isoscalar giant monopole, dipole and quadrupole resonances. It is found that in the case of GSEF, due to the the larger value of the nucleon effective mass the values of centroid energies for the isoscalar giant resonances are in better agreement with the corresponding experimental data in comparison to those obtained using the SSEF. We also present results for some of the key properties associated with the neutron star of "canonical" mass and for the one with the maximum mass.Comment: 45pages, 16 figure

    Prosody Modifications for Voice Conversion

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    Generally defined, speech modification is the process of changing certain perceptual properties of speech while leaving other properties unchanged. Among the many types of speech information that may be altered are rate of articulation, pitch and formant characteristics.Modifying the speech parameters like pitch, duration and strength of excitation by desired factor is termed as prosody modification. In this thesis prosody modifications for voice conversion framework are presented. Among all the speech modifications for prosody two things are important firstly modification of duartion and pauses (Time scale modification) in a speech utterance and secondly modification of the pitch(pitch scale modification).Prosody modification involves changing the pitch and duration of speech without affecting the message and naturalness.In this work time scale and pitch scale modifications of speech are discussed using two methods Time Domain Pitch Synchronous Overlapped-Add (TD-PSOLA) and epoch based approach.In order to apply desired speech modifications TD-PSOLA discussed in this thesis works directly on speech in time domian although there are many variations of TD-PSOLA.The epoch based approach involves modifications of LP-residual

    STUDY ON AGE RELATED MACULAR DEGENERATION (DRY TYPE) IN CONTEXT TO PITTA VIDAGDHA DRISHTI AND ITS AYURVEDIC MANAGEMENT

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    Age Related Macular Degeneration (ARMD) is the leading cause of the vision loss and blindness in people above 50 years of age. ARMD is characterised by central vision loss, distorted or blurred vision, decreased visual acuity, Central or para-central blind spot (scotoma). An almost similar clinical condition to ARMD is seen in Pitta Vidagdha Dristi. Dry ARMD is more prevalent (90%) and slower in progress than Wet ARMD. The Ayurvedic management of Pitta Vidagdha Drishti is similar to Pittaja Abhishyanda. With this background a specific line of treatment for the Pitta Vidagdha Drisht in Sushruta Samhita is adopted. In this study, total 22 patients, 12 in group A (Triphala Ghrita, Saptamrita Lauha, Rasayana Churna and Shatavari etc.) & 10 in Group B (Control) were registered. The duration of therapy was of 3 months in both the groups. Group A showed better results on ARMD when compared with that of Group B especially on perception of flashes of light (72.23%) & dim light adaptation problem (45.23%). So ARMD (Dry type) can be better managed by Ayurvedic treatment group than the Modern multivitamin group

    Novel speech duration modifier for packet based communication system

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    In this paper, we propose a real-time method for duration modification of speech for packet based communication system. While there is rich literature available on duration modification, it fails to clearly address the issues in real-time implementation of the same. Most of the duration modification methods rely on accurate estimation of pitch marks, which is not feasible in a real-time scenario. The proposed method modifies the duration of Linear Prediction residual of individual frames without using any look-ahead delay and knowledge of pitch marks. In this method, multiples of pitch period is repeated or removed from a frame depending on a scheduling algorithm. The subjective quality of the proposed method was found to be better than waveform similarity overlap and add (WSOLA) technique as well as Linear Prediction Pitch Synchronous Overlap and Add (LP-PSOLA) technique

    On the role of different Skyrme forces and surface corrections in exotic cluster-decay

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    We present cluster decay studies of 56^{56}Ni^* formed in heavy-ion collisions using different Skyrme forces. Our study reveals that different Skyrme forces do not alter the transfer structure of fractional yields significantly. The cluster decay half-lives of different clusters lies within \pm 10% for PCM and \pm 15% for UFM.Comment: 13 pages,6 figures and 1 table; in press Pramana Journal of Physics (2010

    Astrophysical S_{17}(0) factor from a measurement of d(7Be,8B)n reaction at E_{c.m.} = 4.5 MeV

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    Angular distribution measurements of 2^2H(7^7Be,7^7Be)2^2H and 2^2H(7^7Be,8^8B)nn reactions at Ec.m.E_{c.m.}\sim~4.5 MeV were performed to extract the astrophysical S17(0)S_{17}(0) factor using the asymptotic normalization coefficient (ANC) method. For this purpose a pure, low emittance 7^7Be beam was separated from the primary 7^7Li beam by a recoil mass spectrometer operated in a novel mode. A beam stopper at 0^{\circ} allowed the use of a higher 7^7Be beam intensity. Measurement of the elastic scattering in the entrance channel using kinematic coincidence, facilitated the determination of the optical model parameters needed for the analysis of the transfer data. The present measurement significantly reduces errors in the extracted 7^7Be(p,γ\gamma) cross section using the ANC method. We get S17S_{17}~(0)~=~20.7~±\pm~2.4 eV~b.Comment: 15 pages including 3 eps figures, one figure removed and discussions updated. Version to appear in Physical Review

    Epigenetic distortion to VDR transcriptional regulation in prostate cancer cells

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    AbstractThe current study aimed to examine the gene specific mechanisms by which the actions of the vitamin D receptor (VDR) are distorted in prostate cancer. Transcriptional responses toward the VDR ligand, 1α,25(OH)2D3, were examined in non-malignant prostate epithelial cells (RWPE-1) and compared to the 1α,25(OH)2D3-recalcitrant prostate cancer cells (PC-3). Time resolved transcriptional studies for two VDR target genes revealed selective attenuation and repression of VDR transcriptional responses in PC-3 cells. For example, responses in PC-3 cells revealed suppressed responsiveness of IGFBP3 and G0S2. Furthermore, Chromatin Immunoprecipitation (ChIP) assays revealed that suppressed transcriptional responses in PC-3 cells of IGFBP3 and G0S2 were associated with selective VDR-induced NCOR1 enrichment at VDR-binding regions on target-gene promoter regions. We propose that VDR inappropriately recruits co-repressors in prostate cancer cells. Subsequent direct and indirect mechanisms may induce local DNA methylation and stable transcriptional silencing. Thus a transient epigenetic process mediated by co-repressor binding, namely, the control of H3K9 acetylation, is distorted to favor a more stable epigenetic event, namely DNA methylation.This article is part of a Special Issue entitled ‘Vitamin D Workshop’

    Influence of B - site Disorder in La0.5Ca0.5Mn1xBxO3La_{0.5}Ca_{0.5}Mn_{1-x}B_{x}O_{3} (B = Fe, Ru, Al and Ga) Manganites

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    We have investigated the influence of B - site doping on the crystal and magnetic structure in La0.5Ca0.5Mn1xBxO3La_{0.5}Ca_{0.5}Mn_{1-x}B_{x}O_{3} (B= Fe, Ru, Al and Ga) compounds using neutron diffraction, SANS, magnetization and resistivity techniques. The B - site doped samples are isostructural and possess an orthorhombic structure in \textit{Pnma} space group at 300K. A structural transition from orthorhombic to monoclinic is found to precede the magnetic transition to CE - type antiferromagnetic state in few of these samples. On doping with Fe, charge and orbitally ordered CE - type antiferromagnetic state is suppressed, followed by the growth in ferromagnetic insulating phase in 0.02x0.060.02\leq x\leq0.06 compounds. At higher Fe doping in x>0.06x>0.06, the ferromagnetic state is also suppressed and no evidence of long range magnetic ordering is observed. In Ru doped samples (0.01x0.05)(0.01\leq x\leq0.05), the ferromagnetic metallic state is favored at TC200KT{}_{C}\approx200K and TMI125KT_{MI}\approx125K and no significant change in TCT_{C} and TMIT_{MI} as a function of Ru doping is found. In contrast, with non magnetic Al substitution for 0.01x0.030.01\leq x\leq0.03, the charge ordered CE - type antiferromagnetic state coexists with the ferromagnetic metallic phase. With further increase in Al doping (0.05x0.07)(0.05\leq x\leq0.07), both CE - type antiferromagnetic and ferromagnetic phases are gradually suppressed. This behavior is accompanied by the evolution of A - type antiferromagnetic insulating state. Eventually, at higher Al doping (0.10x0.13)(0.10\leq x\leq0.13), this phase is also suppressed and signature of spin glass like transition are evident in M(T). Likewise, substitution with Ga is observed to induce similar effects as described for Al doped samples. The presence of short ranged ferromagnetic ordering has been further explored using SANS measurements in few of the selected samples.Comment: To appear in Journal of Physics: Condensed Matte
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