Performance limitations of GaAs/AlGaAs infrared superlattices

The performance of the GaAs/AlGaAs superlattice as an infrared detecting material is modeled as a function of temperature for two cutoff wavelengths, namely, 8.3 and 10.0 µm. The results are compared with HgCdTe, the present industry standard material for infrared systems. The limiting performance of the GaAs/AlGaAs materials system is found to be orders of magnitude below that of HgCdTe for any specific cutoff wavelength and operating temperature

A Discussion of the Monetary Condition Index

The monetary conditions index (MCI) was developed in the early 1990s with the aim of capturing two of the important monetary transmission channels by combining both interest rates and exchange rates. This article examines the development of the MCI and explores the difficulties with implementing it as well as many of the problems associated with interpreting its results. These problems also need to be borne in mind with the recent interest in developing measures of how financial variables affect the economy through the development of financial condition indicators.

One-hundred years (and counting) of blast-associated traumatic brain injury

Blast-associated traumatic brain injury (TBI) has become one of the signature issues of modern warfare and is increasingly a concern in the civilian population due to a rise in terrorist attacks. Despite being a recognised feature of combat since the introduction of high explosives in conventional warfare over a century ago, only recently has there been interest in understanding the biology and pathology of blast TBI and the potential long-term consequences. Progress made has been slow and there remain remarkably few robust human neuropathology studies in this field. This article provides a broad overview of the history of blast TBI and reviews the pathology described in the limitedscientific studies found in the literature

Let Them Be Heroes

Since 1978, there is now a population of unique human entities unlike the world has ever seen before. This group numbers at more than 500,000 individuals (Grabill, 2007). Some are brand new, created only days ago; others have been around for decades. Yet these entities, all comprised of human embryos, are all developmentally the same age. They are five to six days old, frozen in liquid nitrogen until their fate is decided. And so a debate rages in our society. What should be done with all the frozen embryos? These are the excess or “left-over” embryos resulting from reproductive technologies, primarily in-vitro fertilization (IVF). There are five distinctly different potential fates: the embryos could be 1) implanted into the womb of their genetic parents, 2) implanted into the womb of an adoptive mother, 3) given up for research purposes, 4) thawed and thereby destroyed, or 5) simply left in a frozen state indefinitely. This will paper briefly discusses each possibility, and will give an ethical recommendation. Ultimately, this ethical dilemma is not one where we must choose the lesser of all evils; rather, it is an impasse where we must choose the greater of all goods

Changing Lives and Livelihoods: Culture, Capitalism and Contestation over Marine Resources in Island Melanesia

TThis thesis is both a contemporary and a longitudinal ethnographic case study of Brooker Islanders. Brooker Islanders are a sea-faring people that inhabit a large marine territory in the West Calvados Chain of the Louisiade Archipelago in Milne Bay Province of Papua New Guinea. In the late 19th Century, Brooker Islanders began to be incorporated into an emerging global economy through the production of various marine resources that were desired by mainly Australian capitalist interests. The most notable of these commodified marine resources was beche-de-mer. Beche-de-mer is the processed form of several sea cucumber species. The importance of the sea cucumber fishery for Brooker Islanders waned when World War I started. Following the rise of an increasingly affluent China in the early 1990s, the sea cucumber fishery and beche-de-mer trade once again became an important source of cash income for Brooker Islanders. With an increasing dependency on cash and a subsequent decline in sea cucumber stocks, a number of conflicts emerged across the Louisiade Archipelago due to competition to access areas that still held sea cucumbers stocks. In October 2009, the National Fisheries Authority imposed a moratorium on the sea cucumber fishery and beche-de-mer trade. This moratorium remained in place until April 2017. This moratorium caused major impacts on Brooker Islander livelihoods. Brooker Islanders have limited alternative income opportunities available and also have to contend with regular environmental shocks such as cyclones and El Nino associated droughts. An increasing population and projected impacts of climate change make for a very uncertain future for Brooker Islanders. This thesis is based on anthropological fieldwork, historical research and continued contact with Brooker Islanders that now spans a 22-year period from 1998 to the present. Using a historical political ecology approach, I argue that the incorporation of Brooker Islanders into the global economy and the unevenness of development has produced profound changes in their livelihoods, local marine tenureship arrangements and social relations with their island neighbours. This thesis provides a case study of the role that capitalism plays in changing livelihoods and institutions over time when market opportunities arise and consumer dependencies become essential to maintaining livelihoods. The contestation over commodified marine resources is also viewed in the context of changing political and legal domains. Issues of governability for the sustainability of sea cucumber stocks are also explored