ASSESSING THE IMPACTS OF CLIMATE CHANGE ON THE HYDROLOGY OF THE INDRAWATI RIVER BASIN, NEPAL

Abstract. This study details climate change assessment of the hydrological regime of Indrawati basin of Nepal. The study uses Soil and Water Assessment Tool (SWAT) model to delineate, discretize and parameterize the Indrawati basin to compute model's input parameters. The model was then run for 1990–2014 to simulate the discharge at the outlet (Dholalghat). The coefficient of determination R2 and Nash-Sutcliffe (ENS) were used to evaluate model calibration and validation. The results found were satisfactory for the gauging station R2 = 0.951 and ENS = 0.901 for calibration and R2 = 0.937 and. ENS = 0.906 for validation. The calibrated hydrological model was run for the future climate change scenario using the RegCM4-LMDZ4 data and the relative changes with the baseline scenarios were analyzed. The comparison suggests that the historical trend of flow is decreasing at the rate of 0.55 m3/s per year. According to RegCM4-LMDZ4 simulations, the trend is going to continue but at a flatter rate. The decreasing trend is observed to be very less. The characteristic peak flow month in the historical scenario is August but the RegCM4-LMDZ4 led simulated flows suggest a shift in monthly peak to October suggesting decrease in monsoon flows and a subsequent significant increase in flows from October to January

Follow-Up Chandra Observations of Three Candidate Tidal Disruption Events

Large-amplitude, high-luminosity soft X-ray flares were detected by the ROSAT All-Sky Survey in several galaxies with no evidence of Seyfert activity in their ground-based optical spectra. These flares had the properties predicted for a tidal disruption of a star by a central supermassive black hole. We report Chandra observations of three of these galaxies taken a decade after their flares that reveal weak nuclear X-ray sources that are from 240 to 6000 times fainter than their luminosities at peak, supporting the theory that these were special events and not ongoing active galactic nucleus (AGN) variability. The decline of RX J1624.9+7554 by a factor of 6000 is consistent with the (t-t_D)^(-5/3) decay predicted for the fall-back phase of a tidal disruption event, but only if ROSAT was lucky enough to catch the event exactly at its peak in 1990 October. RX J1242.6-1119A has declined by a factor of 240, also consistent with (t-t_D)^(-5/3). In the H II galaxy NGC 5905 we find only resolved, soft X-ray emission that is undoubtedly associated with starburst activity. When accounting for the starburst component, the ROSAT observations of NGC 5905, as well as the Chandra upper limit on its nuclear flux, are consistent with a (t-t_D)^(-5/3) decay by at least a factor of 1000. Although we found weak Seyfert~2 emission lines in Hubble Space Telescope spectra of NGC 5905, indicating that a low-luminosity AGN was present prior to the X-ray flare, we favor a tidal disruption explanation for the flare itself.Comment: 17 pages, 4 figures, to appear in ApJ April 1 200

ANOMALY DETECTION OF EVENTS IN CROWDED ENVIRONMENT AND STUDY OF VARIOUS BACKGROUND SUBTRACTION METHODS

Anomalous behavior detection and localization in videos of the crowded area that is specific from a dominant pattern are obtained. Appearance and motion information are taken into account to robustly identify different kinds of an anomaly considering a wide range of scenes. Our concept based on a histogram of oriented gradients and Markov random field easily captures varying dynamic of the crowded environment.Histogram of oriented gradients along with well-known Markov random field will effectively recognize and characterizes each frame of each scene. Anomaly detection using artificial neural network consist both appearance and motion features which extract within spatio temporal domain of moving pixels that ensures robustness to local noise and thus increases accuracy in detection of a local anomaly with low computational cost.To extract a region of interest we have to subtract background. Background subtraction is done by various methods like Weighted moving mean, Gaussian mixture model, Kernel density estimation.

Chandra Detects a Rapid Flare in the Gravitationally Lensed Mini-BALQSO RX J0911.4+0551

The mini Broad Absorption Line (BAL) quasar RX J0911.4+0551 was observed with the Advanced CCD Imaging Spectrometer (ACIS) of the Chandra X-ray Observatory for ~ 29 ks as part of a gravitational lens (GL) survey aimed at measuring time-delays. Timing analysis of the light-curve of the lensed image A2 shows a rapid flux variation with a duration of about 2000s. A Kolmogorov-Smirnov test shows that the probability that a constant-intensity source would produce the observed variability is less than ~ 0.2 percent. We discuss possible origins for the observed short-term X-ray variability. Our gravitational lens models for the RX J0911.4+0551 GL system predict a time-delay of less than a day between images A1 and A2. The rapid variability combined with the predicted short-time delay make RX J0911.4+0551 an ideal system to apply the GL method for estimating the Hubble constant. We describe the prospects of measuring H_0 within single X-ray observations of GL systems with relatively short time delays. Modeling of the spectrum of the mini-BAL quasar RX J0911.4+0551 suggests the presence of an intrinsic absorber. Partial covering models are slightly preferred over models that contain absorption due to intrinsic ionized or neutral gas.Comment: 17 pages, includes 5 figures, Accepted for publication in Ap

Chandra X-ray Observations of the Quadruply Lensed Quasar RX J0911.4+0551

We present results from X-ray observations of the quadruply lensed quasar RX J0911.4+0551 using data obtained with the Advanced CCD Imaging Spectrometer (ACIS) on board the Chandra X-ray Observatory. The 29 ks observation detects a total of ~404 X-ray photons (0.3 to 7.0 keV) from the four images of the lensed quasar. Deconvolution of the aspect corrected data resolves all four lensed images, with relative positions in good agreement with optical measurements. When compared to contemporaneous optical data, one of the lensed images (component A3) is dimmer by a factor of ~6 in X-rays with respect to the 2 brighter images (components A1 and A2). Spectral fitting for the combined images shows significant intrinsic absorption in the soft (0.2 to 2.4 keV) energy band, consistent with the mini-BAL nature of this quasar, while a comparison with ROSAT PSPC observations from 1990 shows a drop of ~6.5 in the total soft bandpass flux. The observations also detect ~157 X-ray photons arising from extended emission of the nearby cluster (peaked ~42" SW of RXJ0911.4+0551) responsible for the large external shear present in the system. The Chandra observation reveals the cluster emission to be complex and non-spherical, and yields a cluster temperature of kT = 2.3^{+1.8}_{-0.8} keV and a 2.0 to 10 keV cluster luminosity within a 1 Mpc radius of L_X = 7.6_{-0.2}^{+0.6} x 10^{43} ergs/s (error bars denote 90% confidence limits). Our mass estimate of the cluster within its virial radius is 2.3^{+1.8}_{-0.7} x 10^{14} solar, and is a factor of 2 smaller than, although consistent with, previous mass estimates based on the observed cluster velocity dispersion.Comment: 16 pages, 3 figures (figure 1 is color ps). Accepted by Ap

A Study of CO Emission in High Redshift QSOs Using the Owens Valley Millimeter Array

Searches for CO emission in high-redshift objects have traditionally suffered from the accuracy of optically-derived redshifts due to lack of bandwidth in correlators at radio observatories. This problem has motivated the creation of the new COBRA continuum correlator, with 4 GHz available bandwidth, at the Owens Valley Radio Observatory Millimeter Array. Presented here are the first scientific results from COBRA. We report detections of redshifted CO(J=3-2) emission in the QSOs SMM J04135+10277 and VCV J140955.5+562827, as well as a probable detection in RX J0911.4+0551. At redshifts of z=2.846, z=2.585, and z=2.796, we find integrated CO flux densities of 5.4 Jy km/s, 2.4 Jy km/s, and 2.9 Jy km/s for SMM J04135+10277, VCV J140955.5+562827, and RX J0911.4+0551, respectively, over linewidths of Delta(V_{FWHM}) ~ 350 km/s. These measurements, when corrected for gravitational lensing, correspond to molecular gas masses of order M(H_2) ~ 10^{9.6-11.1} solar masses, and are consistent with previous CO observations of high-redshift QSOs. We also report 3-sigma upper limits on CO(3-2) emission in the QSO LBQS 0018-0220 of 1.3 Jy km/s. We do not detect significant 3mm continuum emission from any of the QSOs, with the exception of a tentative (3-sigma) detection in RX J0911.4+0551 of S_{3mm}=0.92 mJy/beam.Comment: 18 pages, 5 figures, 2 tables, accepted to ApJ. Changes made for version 2: citations added, 2 objects added to Table 2 and Figure

Unified Field Theory From Enlarged Transformation Group. The Covariant Derivative for Conservative Coordinate Transformations and Local Frame Transformations

Pandres has developed a theory in which the geometrical structure of a real four-dimensional space-time is expressed by a real orthonormal tetrad, and the group of diffeomorphisms is replaced by a larger group called the conservation group. This paper extends the geometrical foundation for Pandres' theory by developing an appropriate covariant derivative which is covariant under all local Lorentz (frame) transformations, including complex Lorentz transformations, as well as conservative transformations. After defining this extended covariant derivative, an appropriate Lagrangian and its resulting field equations are derived. As in Pandres' theory, these field equations result in a stress-energy tensor that has terms which may automatically represent the electroweak field. Finally, the theory is extended to include 2-spinors and 4-spinors.Comment: Aug 25 replacement has corrected margin width

Chronic subdural haematoma: A retrospective 232 cases review - a comparison of a single centre between a population aged under 75 and above 75 years old

Chronic subdural haematoma represents a major problem in the neurosurgical field concerning population both under and above 75 years old. It is not only a matter of prevalence or pure statistics but it embodies true understanding of how the pathology a?ects older patients, their life expectancy and quality when reliable factors are implied such as comorbidities, relation with the moment of surgery, the existence of anticoagulation therapy, and many more. We target these challenges in a study on 232 cases of treated chronic subdural haematomas with impact on two major categories - those under and above 75 years old in the Neurosurgery Department, County Hospital “Pius Branzeu” Timisoara, Romania

Divergent platforms

Models of electoral competition between two opportunistic, office-motivated parties typically predict that both parties become indistinguishable in equilibrium. I show that this strong connection between the office motivation of parties and their equilibrium choice of identical platforms depends on two—possibly false—assumptions: (1) Issue spaces are uni-dimensional and (2) Parties are unitary actors whose preferences can be represented by expected utilities. I provide an example of a two-party model in which parties offer substantially different equilibrium platforms even though no exogenous differences between parties are assumed. In this example, some voters’ preferences over the 2-dimensional issue space exhibit non-convexities and parties evaluate their actions with respect to a set of beliefs on the electorate