Catherine Mary White Foster\u27s Eyewitness Account of the Battle of Gettysburg, with Background on the Foster Family Union Soldiers

Catherine Mary White Foster lived with her elderly parents in the red brick house on the northwest corner of Washington and High Streets in Gettysburg at the time of the battle, 1-3 July 1863. She was the only child of James White Foster and Catherine (nee Swope) Foster (a former resident of Lancaster county), who married on 11 May 1817 and settled in Gettysburg, Adams county, Pennsylvania. Her father, James White Foster, had served his country as a first lieutenant in the War of 1812. Her grandparents, James Foster and Catherine (nee White) Foster, had emigrated with her father and five older children from county Donegal, Ireland, in 1790, and settled near New Alexandria, Westmoreland county, Pennsylvania. [excerpt

Micro-meteoroid seismic uplift and regolith concentration on kilometric scale asteroids

Seismic shaking is an attractive mechanism to explain the destabilisation of regolith slopes and the regolith migration found on the surfaces of asteroids (Richardson et al. 2004; Miyamoto et al. 2007). Here, we use a continuum mechanics method to simulate the seismic wave propagation in an asteroid. Assuming that asteroids can be described by a cohesive core surrounded by a thin non-cohesive regolith layer, our numerical simulations of vibrations induced by micro-meteoroids suggest that the surface peak ground accelerations induced by micro-meteoroid impacts may have been previously under-estimated. Our lower bound estimate of vertical accelerations induced by seismic waves is about 50 times larger than previous estimates. It suggests that impact events triggering seismic activity are more frequent than previously assumed for asteroids in the kilometric and sub-kilometric size range. The regolith lofting is also estimated by a first order ballistic approximation. Vertical displacements are small, but lofting times are long compared to the duration of the seismic signals. The regolith movement has a non-linear dependence on the distance to the impact source which is induced by the type of seismic wave generating the first movement. The implications of regolith concentration in lows of surface acceleration potential are also discussed. We suggest that the resulting surface thermal inertia variations of small fast rotators may induce an increased sensitivity of these objects to the Yarkovsky effect.Comment: Accepted for publication in Icaru

Seismometer Detection of Dust Devil Vortices by Ground Tilt

We report seismic signals on a desert playa caused by convective vortices and dust devils. The long-period (10-100s) signatures, with tilts of ~10$^{-7}$ radians, are correlated with the presence of vortices, detected with nearby sensors as sharp temporary pressure drops (0.2-1 mbar) and solar obscuration by dust. We show that the shape and amplitude of the signals, manifesting primarily as horizontal accelerations, can be modeled approximately with a simple quasi-static point-load model of the negative pressure field associated with the vortices acting on the ground as an elastic half space. We suggest the load imposed by a dust devil of diameter D and core pressure {\Delta}Po is ~({\pi}/2){\Delta}PoD$^2$, or for a typical terrestrial devil of 5 m diameter and 2 mbar, about the weight of a small car. The tilt depends on the inverse square of distance, and on the elastic properties of the ground, and the large signals we observe are in part due to the relatively soft playa sediment and the shallow installation of the instrument. Ground tilt may be a particularly sensitive means of detecting dust devils. The simple point-load model fails for large dust devils at short ranges, but more elaborate models incorporating the work of Sorrells (1971) may explain some of the more complex features in such cases, taking the vortex winds and ground velocity into account. We discuss some implications for the InSight mission to Mars.Comment: Contributed Article for Bulletin of the Seismological Society of America, Accepted 29th August 201

Season of birth and risk of developing idiopathic Parkinson's disease

Peer reviewedPreprintPreprin

Adaptation of Turfgrasses in Hawaii

The major turfgrasses used in Hawaii are described in terms of their tolerances to shade, salt, weeds, and drought, and they are compared in their density, establishment rate, mowing factors, and other requirements

Augmentation of Visual Odometry using Radar

As UAVs become viable for more applications, pose estimation continues to be critical. All UAVs need to know where they are at all times, in order to avoid disaster. However, in the event that UAVs are deployed in an area with poor visual conditions, such as in many disaster scenarios, many localization algorithms have difficulties working. This thesis presents VIL-DSO, a visual odometry method as a pose estimation solution, combining several different algorithms in order to improve pose estimation and provide metric scale. This thesis also presents a method for automatically determining an accurate physical transform between radar and camera data, and in doing so, allow for the projection of radar information into the image plane. Finally, this thesis presents EVIL-DSO, a method for localization that fuses visual-inertial odometry with radar information. The proposed EVIL-DSO algorithm uses radar information projected into the image plane in order to create a depth map for odometry to directly observe depth of features, which can then be used as part of the odometry algorithm to remove the need to perform costly depth estimations. Trajectory analysis of the proposed algorithm on outdoor data, compared to differential GPS data, shows that the proposed algorithm is more accurate in terms of root-mean-square error, as well as having a lower percentage of scale error. Runtime analysis shows that the proposed algorithm updates more frequently than other, similar, algorithms

Comparative Morphology of Two Sympatric Species of Hedgehog in Ikh Nart Nature Reserve, Mongolia

Daurian hedgehog (Mesechinus dauuricus) and long-eared hedgehog (Hemiechinus auritus) inhabit Ikh Nart Nature Reserve, Mongolia and both species appear to occupy similar niches. We gathered morphological measurements to test for differences between species and sexes. We hoped to gain insight into the mechanisms that allow the species to coexist. We collected morphometric data from 10 long-eared hedgehogs (6 male, 4 female) and 18 Daurian hedgehogs (10 male, 7 female, and 1 unknown sex). Only total body length in Daurian hedgehogs differed significantly between males and females. Otherwise, we found no significant differences between morphometric measures of male and female hedgehogs of either species. Daurian hedgehogs were larger than long-eared hedgehogs for every measurement except for ear length; however, only girth, weight, and length of ear differed significantly. A general linear model found that animal girth best differentiated the two species. Coexistence of species that occupy similar niches generally occurs through the differential use of resources and may be inferred from morphological differentiation. We plan continued research to better explore resource partitioning between the two species

Comparative Morphology of Two Sympatric Species of Hedgehog in Ikh Nart Nature Reserve, Mongolia

Daurian hedgehog (Mesechinus dauuricus) and long-eared hedgehog (Hemiechinus auritus) inhabit Ikh Nart Nature Reserve, Mongolia and both species appear to occupy similar niches. We gathered morphological measurements to test for differences between species and sexes. We hoped to gain insight into the mechanisms that allow the species to coexist. We collected morphometric data from 10 long-eared hedgehogs (6 male, 4 female) and 18 Daurian hedgehogs (10 male, 7 female, and 1 unknown sex). Only total body length in Daurian hedgehogs differed significantly between males and females. Otherwise, we found no significant differences between morphometric measures of male and female hedgehogs of either species. Daurian hedgehogs were larger than long-eared hedgehogs for every measurement except for ear length; however, only girth, weight, and length of ear differed significantly. A general linear model found that animal girth best differentiated the two species. Coexistence of species that occupy similar niches generally occurs through the differential use of resources and may be inferred from morphological differentiation. We plan continued research to better explore resource partitioning between the two species

New Zealand’s COVID-19 Elimination Strategy – Is it Working?

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