4,450 research outputs found
Nutrient chemistry of a large, deep lake in subarctic Alaska
Project Officer
Eldor W. Schallock
Assessment and Criteria Development Division
Corvallis Environmental Research Laboratory
Corvallis, Oregon 97330;Corvallis Environmental Research Laboratory
Office of Research and Development
U. S. Environmental Protection Agency
Corvallis, Oregon 97330; R800276The primary objective of this project was to assess the state of the
water quality of Harding Lake, and to attempt to predict the effects of
future development within its watershed. Since the major effect of degradation
of water quality due to human activity is the promotion of nuisance
growths of plants, the major emphasis was placed on measurements of plant
growth and concentrations of the major nutrients they require. Planktonic
algal growth was found to be low, below 95.6 gm/m2/year, and the growth of
submerged rooted plants was found to be relatively less important at approximately
1.35 gm/m2/year. Measurements of the growth of attached algae were
not conducted, therefore the relative importance of their growth is currently
unknown.
A model for predicting the effect of future real estate development in
the watershed was modified and applied to this lake. This model adequately
describes current water quality conditions, and is assumed to have some
predictive ability, but several cautions concerning application of this
model to Harding Lake are discussed.
A secondary objective was to study the thermal regime of a deep subarctic
lake. Intensive water temperature measurements were made throughout
one year and less intensive measurements were conducted during two additional
years. The possibility that this lake may occasionally stratify thermally
under the ice and not mix completely in the spring was discovered. The
implications of this possibility are discussed for management of subarctic
lakes. Hydrologic and energy budgets of this lake are attempted; the annual
heat budget is estimated at 1.96 x 104 Âą 1.7 x 103 cal/cm2.
The results of a study of domestic water supply and waste disposal
alternatives in the watershed, and the potential for enteric bacterial contamination
of the lake water are presented. Limited work on the zooplankton,
fishes, and benthic macroinvertebrates of this lake is also presented
Physics Potential of Very Intense Conventional Neutrino Beams
The physics potential of high intensity conventional beams is explored. We
consider a low energy super beam which could be produced by a proposed new
accelerator at CERN, the Super Proton Linac. Water Cherenkov and liquid oil
scintillator detectors are studied as possible candidates for a neutrino
oscillation experiment which could improve our current knowledge of the
atmospheric parameters and measure or severely constrain the parameter
connecting the atmospheric and solar realms. It is also shown that a very large
water detector could eventually observe leptonic CP violation. The reach of
such an experiment to the neutrino mixing parameters would lie in-between the
next generation of neutrino experiments (MINOS, OPERA, etc) and a future
neutrino factory.Comment: Talk given at the Venice Conference on Neutrino Telescopes, Venice,
March, 200
A âhealthy babyâ: The double imperative of preimplantation genetic diagnosis
This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2010 The Authors.This article reports from a study exploring the social processes, meanings and institutions that frame and produce âethical problemsâ and clinical dilemmas for practitioners, scientists and others working in the specialty of preimplantation genetic diagnosis (PGD). A major topic in the data was that, in contrast to IVF, the aim of PGD is to transfer to the womanâs womb only those embryos likely to be unaffected by serious genetic disorders; that is, to produce âhealthy babiesâ. Staff described the complex processes through which embryos in each treatment cycle must meet a double imperative: they must be judged viable by embryologists and âunaffectedâ by geneticists. In this article, we focus on some of the ethical, social and occupational issues for staff ensuing from PGDâs double imperative.The Wellcome Trus
Brain-specific tropomyosins TMBr-1 and TMBr-3 have distinct patterns of expression during development and in adult brain
In this study we report on the developmental and regional expression of two brain-specific isoforms of tropomyosin, TMBr-1 and TMBr-3, that are generated from the rat alpha-tropomyosin gene via the use of alternative promoters and alternative RNA splicing. Western blot analysis using an exon-specific peptide polyclonal antibody revealed that the two isoforms are differentially expressed in development with TMBr-3 appearing in the embryonic brain at 16 days of gestation, followed by the expression of TMBr-1 at 20 days after birth. TMBr-3 was detected in all brain regions examined, whereas TMBr-1 was detected predominantly in brain areas that derived from the prosencephalon. Immunocytochemical studies on mixed primary cultures made from rat embryonic midbrain indicate that expression of the brain-specific epitope is restricted to neurons. The developmental pattern and neuronal localization of these forms of tropomyosin suggest that these isoforms have a specialized role in the development and plasticity of the nervous system
Physics Potential of the SPL Super Beam
Performances of a neutrino beam generated by the CERN SPL proton driver are
computed considering a 440 kton water Cerenkov detector at 130 km from the
target. sensitivity down to and a
sensitivity comparable to a Neutrino Factory, for ,
are within the reach of such a project.Comment: Invited talk at the Nufact02 Workshop, Imperial College of Science,
Technology and Medicine, London, July 200
Measuring the to Ratio in a High Statistics Atmospheric Neutrino Experiment
By exploiting differences in muon lifetimes it is possible to distinguish
from charged current interactions in underground
neutrino detectors. Such observations would be a useful tool in understanding
the source of the atmospheric neutrino anomaly.Comment: 6 pages no figure
- âŚ