A Historian Views Spielberg’s Lincoln (2012)

Histor

A Southern Community In Crisis: Harrison County, Texas, 1850-1880

Continuity Over Change Randolph B. Mike Campbell\u27s study of Harrison County, Texas between 1850 and 1880 is an important work on Texas and the South during the Civil War and Reconstruction period, as well as a model for historians interested in social history methodology. Originally publi...

Fourier and Wavelet Representations of Functions

Representations of functions are compared using the traditional technique of Fourier series with a more modern technique using wavelets. Under certain conditions, a function can be represented with a sum of sine and cosine functions. Such a representation is called a Fourier series. This classical method is used in applications such as storage of sound waves and visual images on a computer. One problem with this sum is that it is infinite. In use, only a finite number of terms can be used. More accuracy requires more terms in the series, but more terms require more time to compute and more space to store. A new type of sum called a wavelet series was first introduced in the 1980’s. With these new series the same accuracy often takes fewer terms. Since wavelet representations can be more accurate and take less computer time, they are often more useful

On the physics behind coastal morphodynamic patterns

Peer ReviewedPostprint (published version

Informational Efficiency and the Reaction to Terrorism: A Financial Perspective

The purpose of this study is to measure the message terror organizations hope to convey using the financial markets as a proxy of measurement to determine patterns within the marketplace and the effects on the terrorists’ ability to deliver a desired message due to the increased use of digital devices and access to instantaneous news, seen over the past decade. Using death count, geographic location, and event type, this study identified 109 attacks between 1985 and 2015 to be analyzed against 5 market indices and 5 securities. Measuring the effects within a 10-day sample window from the time of the attack (+ or - 5 days) using average abnormal returns, standard deviation, Sharpe Ratio and the initial reactions in the market place as a percentage of total attacks, the effects on average abnormal returns on the market proxies were measured on three levels; The entire sample period from 1985 to 2015; the first half of the sample period 1985-1999; and the second half of the sample period 2000-2015. Analyzing trends in abnormal returns and standard deviation, the results of the study were inconclusive

Searching for the missing soldier: identifying casualties from the First World War

In recent years there has been an increase in the numbers of archaeologists and physical anthropologists involved in searching, locating and assisting in the identification of war casualties. These scientists have played an invaluable role within a larger team of professionals, working together to provide a dignified burial to those who fell for their country and remembering them. This paper reviews some of the work undertaken in Europe with regard to WWI casualties and how the war missing are located and ultimately identified when possible, bringing also some closure to their living relatives

Safe Low-Altitude Navigation in Steep Terrain with Fixed-Wing Aerial Vehicles

Fixed-wing aerial vehicles provide an efficient way to navigate long distances or cover large areas for environmental monitoring applications. By design, they also require large open spaces due to limited maneuverability. However, strict regulatory and safety altitude limits constrain the available space. Especially in complex, confined, or steep terrain, ensuring the vehicle does not enter an inevitable collision state(ICS) can be challenging. In this work, we propose a strategy to find safe paths that do not enter an ICS while navigating within tight altitude constraints. The method uses periodic paths to efficiently classify ICSs. A sampling-based planner creates collision-free and kinematically feasible paths that begin and end in safe periodic (circular) paths. We show that, in realistic terrain, using circular periodic paths can simplify the goal selection process by making it yaw agnostic and constraining yaw. We demonstrate our approach by dynamically planning safe paths in real-time while navigating steep terrain on a flight test in complex alpine terrain.Comment: Accepted to IEEE Robotics and Automation Letters (RA-L

Thymic Dendritic Cell Subsets Display Distinct Efficiencies and Mechanisms of Intercellular MHC Transfer

Thymic dendritic cells (DC) delete self-Ag-specific thymocytes, and drive development of FoxP3-expressing immunoregulatory T cells. Unlike medullary thymic epithelial cells (mTEC), which express and present peripheral self-Ag, DC must acquire self-Ag to mediate thymic negative selection. One such mechanism entails the transfer of surface MHC-self peptide complexes from mTEC to thymic DC. Despite the importance of thymic DC “cross-dressing” in negative selection, the factors that regulate the process, and the capacity of different thymic DC subsets to acquire MHC and stimulate thymocytes are poorly understood. Here intercellular MHC transfer by thymic DC subsets was studied using a MHC-mismatch-based in vitro system. Thymic conventional DC (cDC) subsets SIRPα+ and CD8α+ readily acquired MHC class I and II from TEC but plasmacytoid DC (pDC) were less efficient. Intercellular MHC transfer was donor cell-specific; thymic DC readily acquired MHC from TEC plus thymic or splenic DC, whereas thymic or splenic B cells were poor donors. Furthermore DC origin influenced cross-dressing; thymic versus splenic DC exhibited an increased capacity to capture TEC-derived MHC, which correlated with direct expression of EpCAM by DC. Despite similar capacities to acquire MHC-peptide complexes, thymic CD8α+ cDC elicited increased T cell stimulation relative to SIRPα+ cDC. DC cross-dressing was cell-contact dependent and unaffected by lipid raft disruption of donor TEC. Furthermore, blocking PI3K signaling reduced MHC acquisition by thymic CD8α+ cDC and pDC but not SIRPα+ cDC. These findings demonstrate that multiple parameters influence the efficiency of and distinct mechanisms drive intercellular MHC transfer by thymic DC subsets