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Papers by jayant Bhalerao

Essentials of Clinical Cardiology, 2013

Genomics, 1997

The Wnt gene family consists of at least 15 structuret al., 1994). Wnt genes have been shown to f... more The Wnt gene family consists of at least 15 structuret al., 1994). Wnt genes have been shown to function ally related genes that encode secreted extracellular in a wide variety of biological processes, including cell signaling factors. Wnt proteins function in a range of fate determination and patterning in early embryos, critical developmental processes in both vertebrates and in growth and/or differentiation of the brain, kidand invertebrates and are implicated in regulation of neys, limbs, somites, and mammary glands (Nusse and cell growth and differentiation in certain adult mam-Varmus, 1992; Parr and McMahon, 1994; Moon et al., malian tissues, including the mammary gland. We have 1997). Two of the first known Wnt genes, Wnt1 and isolated a number of WNT sequences from human ge-Wnt3, were discovered as oncogenes activated by the nomic DNA, two of which, designated WNT14 and mouse mammary tumor virus in virus-induced carcino-WNT15, represent novel members of the Wnt gene fammas (Nusse and Varmus, 1982; Roelink et al., 1990; ily. We also isolated WNT sequences from human mam-Nusse, 1991). Recent studies showing that WNT family mary cDNA and present evidence that WNT13 is exmembers are overexpressed in a proportion of breast pressed in human breast tissue, in addition to those and colon cancers now suggest that WNT genes may previously described. WNT14 and WNT15 appear to also contribute to cancer in humans (Huguet et al., have originated from an ancestral branch of the Wnt

The Astrophysical Journal, 2020

The soft γ-ray repeater (SGR) 0526-66 is the first-identified magnetar, and is projected within t... more The soft γ-ray repeater (SGR) 0526-66 is the first-identified magnetar, and is projected within the supernova remnant N49 in the Large Magellanic Cloud. Based on our ∼50 ks NuSTAR observation, we detect the quiescent-state 0526-66 for the first time in the 10-40 keV band. Based on the joint analysis of our NuSTAR and the archival Chandra ACIS data, we firmly establish the presence of the nonthermal component in the X-ray spectrum of 0526-66 in addition to the thermal emission. In the best-fit blackbody (BB) plus power law (PL) model, the slope of the PL component (photon index Γ = 2.1) is steeper than those (Γ ∼ < 1.5) for other magnetars. The soft part of the X-ray spectrum can be described with a BB component with the temperature of kT = 0.43 keV. The best-fit radius (R = 6.5 km) of the X-ray-emitting area is smaller than the canonical size of a neutron star. If we assume an underlying cool BB component with the canonical radius of R = 10 km for the neutron star in addition to the hot BB component (2BB + PL model), a lower BB temperature of kT = 0.24 keV is obtained for the passively cooling neutron star's surface, while the hot spot emission with kT = 0.46 keV dominates the thermal spectrum (∼85% of the thermal luminosity in the 0.5-5 keV band). The nonthermal component (Γ ∼ 1.8) is still required.

The Astrophysical Journal, 2020

We report our measurements of the bulk radial velocity from a sample of small, metal-rich ejecta ... more We report our measurements of the bulk radial velocity from a sample of small, metal-rich ejecta knots in Kepler's Supernova Remnant (SNR). We measure the Doppler shift of the He-like Si Kα line center energy in the spectra of these knots based on our Chandra High-Energy Transmission Grating Spectrometer (HETGS) observation to estimate their radial velocities. We estimate high radial velocities of up to ∼ 8,000 km s-1 for some of these ejecta knots. We also measure proper motions for our sample based on the archival Chandra Advanced CCD Imaging Spectrometer (ACIS) data taken in 2000, 2006, and 2014. Our measured radial velocities and proper motions indicate that some of these ejecta knots are almost freely-expanding after ∼ 400 years since the explosion. The fastest moving knots show proper motions up to ∼ 0.2 arcseconds per year. Assuming that these high velocity ejecta knots are traveling ahead of the forward shock of the SNR, we estimate the distance to Kepler's SNR d ∼ 4.4 to 7.5 kpc. We find that the ejecta knots in our sample have an average space velocity of v s ∼ 4,600 km s-1 (at a distance of 6 kpc). We note that 8 out of the 15 ejecta knots from our sample show a statistically significant (at the 90% confidence level) redshifted spectrum, compared to only two with a blueshifted spectrum. This may suggest an asymmetry in the ejecta distribution in Kepler's SNR along the line of sight, however a larger sample size is required to confirm this result.

The Astrophysical Journal, 2019

G292.0+1.8 (G292) is a young (∼3000 yr), Galactic textbook-type core-collapse supernova remnant (... more G292.0+1.8 (G292) is a young (∼3000 yr), Galactic textbook-type core-collapse supernova remnant (CCSNR). It is characterized by X-ray, optical and infrared emission from ejecta and circumstellar medium (CSM) features, and contains a pulsar (PSR J1124-5916) and pulsar wind nebula that have been observed in X-rays and radio. Previous studies have revealed a complex, dynamically evolving, oxygen-rich remnant, a striking relic from the explosion of a massive star. Here, using our deep (530 ks) Chandra ACIS data, we present high spatial-resolution maps (based on a regional grid size of a few arcsec) of the shocked CSM and metal-rich ejecta in G292. We make the first Chandra-detection of Fe-rich ejecta in G292. We identify the X-ray counterpart of the northern equatorial belt, a component of a ring-like CSM structure identified earlier in the infrared band. We show the detailed spatial distributions of ejecta enriched in O, Ne, Mg, Si, S and Fe. We find that the bulk of the Si, S and Fe-rich X-ray-emitting ejecta are located in the northwestern hemisphere of the remnant, opposite to the pulsar's projected angular displacement to the southeast from the SNR's center. This suggests that the pulsar's kick may have originated from gravitational and hydrodynamic forces during an asymmetric explosion, rather than from anisotropic neutrino emission. Based on abundance ratios and our estimated CSM and ejecta masses, we constrain the progenitor mass to 13 M M 30 M

The Astrophysical Journal, 2015

We report on the results from the analysis of our 114 ks Chandra High Energy Transmision Grating ... more We report on the results from the analysis of our 114 ks Chandra High Energy Transmision Grating Spectrometer observation of the Galactic core-collapse supernova remnant G292.0+1.8. To probe the three-dimensional structure of the clumpy X-ray emitting ejecta material in this remnant, we measured Doppler shifts in emission lines from metal-rich ejecta knots projected at different radial distances from the expansion center. We estimate radial velocities of ejecta knots in the range of −2300 v r 1400 km s −1. The distribution of ejecta knots in velocity versus projected-radius space suggests an expanding ejecta shell with a projected angular thickness of ∼90 (corresponding to ∼3 pc at d = 6 kpc). Based on this geometrical distribution of the ejecta knots, we estimate the location of the reverse shock approximately at the distance of ∼4 pc from the center of the supernova remnant, putting it in close proximity to the outer boundary of the radio pulsar wind nebula. Based on our observed remnant dynamics and the standard explosion energy of 10 51 erg, we estimate the total ejecta mass to be 8 M , and we propose an upper limit of 35 M on the progenitor's mass.

Essentials of Clinical Cardiology, 2013

Genomics, 1997

The Astrophysical Journal, 2020

The Astrophysical Journal, 2019

The Astrophysical Journal, 2015

Essentials of Clinical Cardiology, 2013