7,726 research outputs found
Determination of Chemical Composition of Wood Pulp Hydrolyzates by Paper Chromatography
The available literature on paper chromatography was surveyed. Special attention was given to those techniques dealing with the analysis of wood pulp hydrolyzates. Five hardwood pulp hydrolyzates were analyzed by paper chromatographic means. All hardwood pulp hydrolyzates analyzed tended to fall in a relatively narrow range of chemical composition. Glucose and xylose were found to be the main constituents with traces of mannose and galactose present in some pulp hydrolyzates
Partial Trajectory: The Story of the Altered Nuclear Transfer-Oocyte Assisted Reprogramming (ANT-OAR) Proposal
This essay aims to tell the story of the âaltered nuclear transfer-oocyte assisted reprogramming,â or ANT-OAR, proposalâfrom its conception by Professor William Hurlbut of the Presidentâs Council on Bioethicsâto its adoption and promotion by a group of conservative, mostly Catholic philosophers, theologians and scientistsâto its eventual demise in Congress. It also will give some reflections on how ANT-OAR promotes a genetically deterministic view of the human organism and can lead down a slippery slope into a future in which human cloning and human genetic engineering are more acceptable. For these reasons, it will be argued, ANT-OAR should be opposed by all who are against human genetic modification regardless of their political orientation
Climate Justice, Hurricane Katrina, and African American Environmentalism
The images of human suffering from New Orleans in the aftermath of Hurricane Katrina remain seared in our nation's collective memory. More than 8 years on, the city and its African-American population still have not recovered fully. This reality highlights an important truth: the disturbances that accompany climate change will first and foremost affect minority communities, many of whom are economically disadvantaged. This paper: (1) describes how Hurricane Katrina, an example of the type of natural disaster that will become more prevalent with intensifying climate change, has impacted the black community of New Orleans; (2) explores the notion that African Americans, in the midst of racial oppression, have developed a unique and powerful brand of environmental thought that has much to contribute to mainstream environmentalism; and (3) argues that the voice of the black community, which has a vested interest in climate outcomes, is critically needed in today's climate debate
An investigation of pre-launch and in-flight STS range safety radio signal degradation and dropout
The range safety system (RSS) transmitters operate at a frequency of 416.500 MHz. The transmitting antennas transmit left circularly polarized waves, and the shuttle range safety system (SRSS) receiving antennas onboard the shuttle vehicle receive left circular polarization. Preliminary explanations are proposed for many of the observed fluctuations in signal levels. It is recommended that experiments and further investigation be performed to test the validity of certain of these explanations
A study of radar cross section measurement techniques
Past, present, and proposed future technologies for the measurement of radar cross section were studied. The purpose was to determine which method(s) could most advantageously be implemented in the large microwave anechoic chamber facility which is operated at the antenna test range site. The progression toward performing radar cross section measurements of space vehicles with which the Orbital Maneuvering Vehicle will be called upon to rendezvous and dock is a natural outgrowth of previous work conducted in recent years of developing a high accuracy range and velocity sensing radar system. The radar system was designed to support the rendezvous and docking of the Orbital Maneuvering Vehicle with various other space vehicles. The measurement of radar cross sections of space vehicles will be necessary in order to plan properly for Orbital Maneuvering Vehicle rendezvous and docking assignments. The methods which were studied include: standard far-field measurements; reflector-type compact range measurements; lens-type compact range measurement; near field/far field transformations; and computer predictive modeling. The feasibility of each approach is examined
The Physics of 2-d Stringy Spacetimes
We examine the two-dimensional spacetimes that emerge from string theory. We
find all the solutions with no tachyons, and show that the only non-trivial
solution is the black hole spacetime. We examine the role of duality in this
picture. We then explore the thermodynamics of these solutions which is
complicated by the fact that only in two spacetime dimensions is it impossible
to redefine the dilaton field in terms of a canonical scalar field. Finally, we
extend our analysis to the heterotic string, and briefly comment on exact, as
opposed to perturbative, solutions
Determinants of visitor expenditure at a major sports event
This paper develops a model of the determinants of visitor expenditure at a one day repeated major sporting event in Edinburgh, Scotland. An econometric model is developed that combines both macroeconomic data and socio-economic information derived from over 1,000 visitor interviews. This allows us to control for individual characteristics and estimate the derived elasticities for the macroeconomic determinants of expenditure. The findings suggest that socio-economic characteristics of individuals may be more significant than macroeconomic indicators in explaining variations in visitor expenditure. Among individual characteristics, the region of origin, length of stay, type of accommodation, type of expenditure and personal income are associated with the level of per capita visitor expenditure. This should assist regional policy formulation in attracting higher spending visitors and thereby maximising the income and employment benefits from sporting events and other areas of tourism.
Pulse of inflammatory proteins in the pregnant uterus of European polecats (Mustela putorius) leading to the time of implantation
Uterine secretory proteins protect the uterus and conceptuses against infection, facilitate implantation, control cellular damage resulting from implantation, and supply pre-implantation embryos with nutrients. Unlike in humans, the early conceptus of the European polecat (Mustela putorius; ferret) grows and develops free in the uterus until implanting at about 12 days after mating. We found that the proteins appearing in polecat uteri changed dramatically with time leading to implantation. Several of these proteins have also been found in pregnant uteri of other eutherian mammals. However, we found a combination of two increasingly abundant proteins that have not been recorded before in pre-placentation uteri. First, the broad-spectrum proteinase inhibitor α2-macroglobulin rose to dominate the protein profile by the time of implantation. Its functions may be to limit damage caused by the release of proteinases during implantation or infection, and to control other processes around sites of implantation. Second, lipocalin-1 (also known as tear lipocalin) also increased substantially in concentration. This protein has not previously been recorded as a uterine secretion in pregnancy in any species. If polecat lipocalin-1 has similar biological properties to that of humans, then it may have a combined function in antimicrobial protection and transporting or scavenging lipids. The changes in the uterine secretory protein repertoire of European polecats is therefore unusual, and may be representative of pre-placentation supportive uterine secretions in mustelids (otters, weasels, badgers, mink, wolverines) in general
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