Intra- and Inter-Seasonal Variability of Supra-Glacial 1 Streams and Lakes over the West Greenland Ice Sheet 2 from High-Resolution Satellite Optical Data

The Greenland ice sheet (GrIS) is one of the largest glacial ice masses on Earth, second only to the Antarctic ice sheet. The surface hydrology of the GrIS plays a crucial role on the surface energy and mass balance budgets of the ice sheet as a whole. Surface water, known as supra-glacial water, is seasonally found in the ablation zone and feeds the en-glacial and sub-glacial hydrological environments of the ice sheet. The spatial distribution of surface streams is poorly understood and their temporal variability is (to our knowledge) unknown. One of the reasons for the lack of knowledge on the temporal variability of such streams is related to the historical unavailability of satellite data that could spatially resolve the presence and associated properties of the streams. In recent years, however, multispectral commercial satellite data in the visible and infra-red bands have been made available to the scientific community. These newly accessible data sets are provided at spatial resolutions on the order of 2 meters, allowing to perform accurate spatial and temporal analysis of surface streams (and small lakes and ponds that cannot be resolved with other sensors such as those on board MODIS or LANDSAT). In this thesis, I report results concerning the intra- and inter-seasonal variability of surface streams over a selected area on the west Greenland ice sheet. Using multispectral high-resolution imagery from World View - 2 and Quickbird - 2 satellites applied to ArcGIS® software, surface streams were identified through band math algorithms, threshold classifications, and morphological operations. I also provide depth estimations and corresponding volume estimations for the surface water features identified. The supra-glacial hydrology network over the study area was created both with and without lakes for each month. The stream networks created during the melt season (at several different stages of melting) were compared and discussed as well as the networks mapped between consecutive years for proximate dates

An ALMA Constraint on the GSC 6214-210 B Circum-Substellar Accretion Disk Mass

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of GSC 6214-210 A and B, a solar-mass member of the 5-10 Myr Upper Scorpius association with a 15 $\pm$ 2 Mjup companion orbiting at $\approx$330 AU (2.2"). Previous photometry and spectroscopy spanning 0.3-5 $\mu$m revealed optical and thermal excess as well as strong H$\alpha$ and Pa~$\beta$ emission originating from a circum-substellar accretion disk around GSC 6214-210 B, making it the lowest mass companion with unambiguous evidence of a subdisk. Despite ALMA's unprecedented sensitivity and angular resolution, neither component was detected in our 880 $\mu$m (341 GHz) continuum observations down to a 3-$\sigma$ limit of 0.22 mJy/beam. The corresponding constraints on the dust mass and total mass are <0.15 Mearth and <0.05 Mjup, respectively, or <0.003% and <0.3% of the mass of GSC 6214-210 B itself assuming a 100:1 gas-to-dust ratio and characteristic dust temperature of 10-20 K. If the host star possesses a putative circum-stellar disk then at most it is a meager 0.0015% of the primary mass, implying that giant planet formation has certainly ceased in this system. Considering these limits and its current accretion rate, GSC 6214-210 B appears to be at the end stages of assembly and is not expected to gain any appreciable mass over the next few Myr.Comment: Accepted to ApJ

Strength gain at little cost? Feasibility of \u27low load\u27 eccentric cycling as a tool for strength gain in sedentary men

Symptomatic reporting is a common issue in exercise rehabilitation. When traditional concentric aerobic exercise is used as an exercise stimulus, dyspnoea and fatigue are often reported by elderly5 and by cohorts with cardiorespiratory pathology3. Among the unique attributes of eccentric aerobic exercise is lower metabolic and cardiovascular demand for a given workload 1 ,2. This makes eccentric aerobic exercise more suitable for long-term adherence in rehabilitation. Although, extremely \u27high load\u27 eccentric cycling interventions have shown improvements in strength measurements4, no \u27low load\u27 eccentric cycling studies have been performed to determine if strength adaptations are feasible. Therefore, this study determined if \u27low load\u27 eccentric cycling can stimulate strength adaptations

Neurobehavioral Symptoms in Mild Primary Hyperparathyroidism: Related to Hypercalcemia but not Improved by Parathyroidectomy

The neurobehavioral symptomatology of severe primary hyperparathyroidism (PHPT) has been thoroughly described. Less is known about more mild cases. We evaluated 34 patients with mild PHPT and followed 19 for an average of six months. Of those cases followed, ten had parathyroidectomy (PTX). Patients with no neurobehavioral abnormalities had the lowest serum calcium levels (10.9 ± 0.88 mg/dL), patients with signs of affective disorder had intermediate levels (11.25 ± 0.66 mg/dL), and patients with signs of cerebral dysfunction had the highest levels (12.17 ± 1.17 mg/dL). Serum calcium significantly correlated with motor speed, psychomotor speed, fluid intelligence, and short term memory. However, in the follow-up of patients, PTX seemed to have no effect on their behavior Serum calcium correlates with both type and severity of the neurobehavioral abnormalities found in mild PHPT. However, most of the evidence indicates that PTX does not produce any improvement of these abnormalities, even when the hypercalcemia elevation is corrected

Referral Patterns, Procedures, and Outcomes of a Large Community- Based Urology Group: a Retrospective Chart Review

In 2012 The United States Preventive Services Task Force (USPSTF) recommended against prostate cancer (Pca) screening. The purpose of our study is to assess the effects of the USPSTF grade D recommendation for PSA based screening on new PCa diagnoses within a large-community based private practice setting. We completed a retrospective chart review of men with an elevated PSA seen in our clinic between May 2009–May 2015 who had undergone a prostate biopsy and were diagnosed with PCa. We observed that following the 2012 USPSTF recommendations, there was a significant increase in patients with clinically significant prostate cancer GG ≥ 2, with the majority being 55-65 years of age. In addition we observed a decrease in the diagnosis of very low and low risk PCa with an increased incidence of intermediate and high risk PCa

Herschel/PACS View Of Disks Around Low-Mass Stars And Brown Dwarfs In The TW Hydrae Association

We conducted Herschel/PACS observations of five very low-mass stars or brown dwarfs located in the TW Hya association with the goal of characterizing the properties of disks in the low stellar mass regime. We detected all five targets at 70 mu m and 100 mu m and three targets at 160 mu m. Our observations, combined with previous photometry from 2MASS, WISE, and SCUBA-2, enabled us to construct spectral energy distributions (SEDs) with extended wavelength coverage. Using sophisticated radiative transfer models, we analyzed the observed SEDs of the five detected objects with a hybrid fitting strategy that combines the model grids and the simulated annealing algorithm and evaluated the constraints on the disk properties via the Bayesian inference method. The modeling suggests that disks around low-mass stars and brown dwarfs are generally flatter than their higher mass counterparts, but the range of disk mass extends to well below the value found in T Tauri stars, and the disk scale heights are comparable in both groups. The inferred disk properties (i.e., disk mass, flaring, and scale height) in the low stellar mass regime are consistent with previous findings from large samples of brown dwarfs and very low-mass stars. We discuss the dependence of disk properties on their host stellar parameters and find a significant correlation between the Herschel far-IR fluxes and the stellar effective temperatures, probably indicating that the scaling between the stellar and disk masses (i.e., M-disk proportional to M-star) observed mainly in low-mass stars may extend down to the brown dwarf regime.Natural Science Foundation of Jiangsu Province of China BK20141046Youth Qianren Program of the National Science Foundation of ChinaNational Aeronautics and Space AdministrationStrategic Priority Research Program >The Emergence of Cosmological Structures> of the Chinese Academy of Sciences XDB09000000Astronom

Chandra X-ray spectroscopy of the focused wind in the Cygnus X-1 system III. Dipping in the low/hard state

We present an analysis of three Chandra High Energy Transmission Gratings observations of the black hole binary Cyg X-1/HDE 226868 at different orbital phases. The stellar wind that is powering the accretion in this system is characterized by temperature and density inhomogeneities including structures, or "clumps", of colder, more dense material embedded in the photoionized gas. As these clumps pass our line of sight, absorption dips appear in the light curve. We characterize the properties of the clumps through spectral changes during various dip stages. Comparing the silicon and sulfur absorption line regions (1.6-2.7 keV $\equiv$ 7.7-4.6 {\AA}) in four levels of varying column depth reveals the presence of lower ionization stages, i.e., colder or denser material, in the deeper dip phases. The Doppler velocities of the lines are roughly consistent within each observation, varying with the respective orbital phase. This is consistent with the picture of a structure that consists of differently ionized material, in which shells of material facing the black hole shield the inner and back shells from the ionizing radiation. The variation of the Doppler velocities compared to a toy model of the stellar wind, however, does not allow us to pin down an exact location of the clump region in the system. This result, as well as the asymmetric shape of the observed lines, point at a picture of a complex wind structure.Comment: 19 pages, 15 figures, accepted for publication in A&

Optical Measurements at the Combustor Exit of the HIFiRE 2 Ground Test Engine

The development of optical techniques capable of measuring in-stream flow properties of air breathing hypersonic engines is a goal of the Aerospace Propulsion Division at AFRL. Of particular interest are techniques such as tunable diode laser absorption spectroscopy that can be implemented in both ground and flight test efforts. We recently executed a measurement campaign at the exit of the combustor of the HIFiRE 2 ground test engine during Phase II operation of the engine. Data was collected in anticipation of similar data sets to be collected during the flight experiment. The ground test optical data provides a means to evaluate signal processing algorithms particularly those associated with limited line of sight tomography. Equally important, this in-stream data was collected to compliment data acquired with surface-mounted instrumentation and the accompanying flowpath modeling efforts-both CFD and lower order modeling. Here we discuss the specifics of hardware and data collection along with a coarse-grained look at the acquired data and our approach to processing and analyzing it

High-accuracy comparison of numerical relativity simulations with post-Newtonian expansions

Numerical simulations of 15 orbits of an equal-mass binary black hole system are presented. Gravitational waveforms from these simulations, covering more than 30 cycles and ending about 1.5 cycles before merger, are compared with those from quasi-circular zero-spin post-Newtonian (PN) formulae. The cumulative phase uncertainty of these comparisons is about 0.05 radians, dominated by effects arising from the small residual spins of the black holes and the small residual orbital eccentricity in the simulations. Matching numerical results to PN waveforms early in the run yields excellent agreement (within 0.05 radians) over the first $\sim 15$ cycles, thus validating the numerical simulation and establishing a regime where PN theory is accurate. In the last 15 cycles to merger, however, {\em generic} time-domain Taylor approximants build up phase differences of several radians. But, apparently by coincidence, one specific post-Newtonian approximant, TaylorT4 at 3.5PN order, agrees much better with the numerical simulations, with accumulated phase differences of less than 0.05 radians over the 30-cycle waveform. Gravitational-wave amplitude comparisons are also done between numerical simulations and post-Newtonian, and the agreement depends on the post-Newtonian order of the amplitude expansion: the amplitude difference is about 6--7% for zeroth order and becomes smaller for increasing order. A newly derived 3.0PN amplitude correction improves agreement significantly ($<1$ amplitude difference throughout most of the run, increasing to 4% near merger) over the previously known 2.5PN amplitude terms.Comment: Updated to agree with published version (various minor clarifications; added description of AH finder in Sec IIB; added discussion of tidal heating in Sec VC