142 research outputs found
The development of the cotton rat, Sigmodon hispidus Texianus (Audubon and Bachman, 1853), through the first nine and one half days of gestation
Dissertation (Ph.D.)--University of Kansas, Zoology, 1952
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Stomatal activity patterns in provenance plantations of Abies concolor and Abies grandis
Seedlings from 25 provenances of Abies grandis and Abies
concolor were studied at two plantations, 12 at Philomath, Oregon,
and 13 at Camino, California. Native seedlings were studied at four
of the provenances' field sites. Stomatal infiltration pressure
measurements and plant moisture stress measurements were made
throughout one summer on the plantation seedlings to identify their
patterns of stomatal response to moisture stress. Stomatal distribution
on the needle surface was used to determine the degree of
resemblance of each provenance to the two Abies species. Seedlings
from four provenances were also studied during December to determine
which seedlings would retain the freshest Christmas tree characteristics
after being cut, transported, stored and displayed, and whether
'heir response could be predicted from stomatal behavior.
Three aspects of the stomatal response patterns differed from
one provenance to another: (1) occurrence of daily stomatal closure
or nonclosure, (2) time of closure and (3) degree of closure. The
stomata of the Abies grandis provenances tended to close daily while
the stomata of Abies concolor-influenced provenances remained open
during the day. The Abies grandis stomata also tended to close
earlier in the day than those in provenances mildly influenced by
Abies concolor, which did close daily to some degree. The provenances
represented at Camino could be grouped as to their degree
of stomatal closure. The members of each group were generally
morphologically similar, indicating genetic relationship. The
stomatal response data suggest that some genetic control of stomatal
response to moisture stress does exist. These genetically controlled
responses conceivably could affect the establishment of seedlings of
certain genotypes in particular habitats.
The Christmas tree keepability experiment resulted in one provenance,
20, retaining its favorable characteristics relatively well,
certainly better than the other provenances. Provenance 20 seedlings
are, therefore, recommended to be used as Christmas trees due to
their ability to retain fresh Christmas tree characteristics. Keepability
was not predictable from the summer stomatal response, but
was correlated with moisture stresses during display of the trees
EOS-AM1 Nickel Hydrogen Cell Interim Life Test Report
This paper reports the interim results Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missiles and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of the tests is to verify that the EOS-AM-1 cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 18202 LEO cycles completed as of September 1, 1997. Each cycle consists of a 64-minute charge (VT at 1,507 volts per cell, 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5 percent DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60 percent DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 amperes (VT at 1.54 volts per cell to 1.90 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three, 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battery, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (minus 5 deg) cold plate. The entire assembly is located in a thermal chamber operating at plus 3 deg. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at plus 10 deg. The real-time LEO life test battery has met all performance requirements through the first 18,202 cycles, including: end of charge and discharge cell voltages and voltage gradients; end of charge and discharge cells pressures; within cell and between cell temperature gradients dischare capacity; current and power levels; and all charge parameters. The accelerated stress test battery has completed 11998 cycles when the test was terminated. The stress test unit met all test parameters. This paper reports battery performances as a function of cycle life for both the real-time LEO and the accelerated life test regimes
EOS-AM1 Nickel Hydrogen Cell
This paper reports the interim results of the Earth Observing System AM-1 project (EOS-AM-1) nickel hydrogen cell life test being conducted under contract to National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) at the Lockheed Martin Missile and Space (LMMS) facility in East Windsor, NJ; and at COMSAT Labs., Clarksburg, MD. The purpose of die tests is to verify that the EOS-AM-1 cell design can meet five years of real-time Low Earth Orbit (LEO) cycling. The tests include both real-time LEO and accelerated stress tests. At LMMS, the first real-time LEO simulated 99 minute orbital cycle started on February 7, 1994 and the test has been running continuously since that time, with 18,202 LEO cycles completed as of September 1, 1997. Each cycle consists of a 64 minute charge (VT at 1.507 volts per cell, 1.06 C/D ratio, followed by 0.6 ampere trickle charge) and a 35 minute constant power discharge at 177 watts (22.5% DOD). At COMSAT, the accelerated stress test consists of 90 minute orbital cycles at 60% DOD with a 30 minute discharge at 60 amperes and a 60 minute charge at 40 amperes (VT at 1.54 volts per cell to 1.09 C/D ratio, followed by 0.6 ampere trickle charge). The real-time LEO life test battery consists of seven, 50AH (nameplate rating) Eagle-Picher, Inc. (EPI) Mantech cells manufactured into three, 3-cell pack assemblies (there are two place holder cells that are not part of the life test electrical circuit). The test pack is configured to simulate the conductive thermal design of the spacecraft battery, including: conductive aluminum sleeves, 3-cell pack aluminum baseplate, and honeycomb panel all mounted to a liquid (-5 C) cold plate. The entire assembly is located in a thermal chamber operating at +30 C. The accelerated stress test unit consists of five cells mounted in machined aluminum test sleeves and is operating at +10 C. The real-time LEO life test battery has met all performance requirements through the first 18,202 cycles, including: end of charge mid discharge cell voltages and voltage gradients; end of charge and discharge cell pressures; within cell and between cell temperature gradients; discharge capacity; current and power levels; and all charge parameters. The accelerated stress test battery has completed 11,998 cycles when the test was terminated. The stress test unit met all test parameters. This paper reports battery perfortnances as a funcfion of cycle life for both the real-time LEO and the accelerated life test regimes
Panel Discussion On Lipid Metabolism In Cardiovascular Diseaseâ
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111126/1/jgs00741.pd
The Geostationary Carbon Process Mapper
The Geostationary Carbon Process Mapper (GCPM) is an earth science mission to measure key atmospheric trace gases and process tracers related to climate change and human activity. The measurement strategy delivers a process based understanding of the carbon cycle that is accurate and extensible from city to regional and continental scales. This understanding comes from contiguous maps of carbon dioxide (CO2), methane (CH4), carbon monoxide (CO), and chlorophyll fluorescence (CF) collected up to 10 times per day at high spatial resolution (~4km Ă 4km) from geostationary orbit (GEO). These measurements will capture the spatial and temporal variability of the carbon cycle across diurnal, synoptic, seasonal and interannual time scales. The CO2/CH4/CO/CF measurement suite has been specifically selected because their combination provides the information needed to disentangle natural and anthropogenic contributions to atmospheric carbon concentrations and to minimize key uncertainties in the flow of carbon between the atmosphere and surface since they place constraints on both biogenic uptake and release as well as on combustion emissions. Additionally, GCPM's combination of high-resolution mapping and high measurement frequency provide quasi-continuous monitoring, effectively eliminating atmospheric transport uncertainties from source/sink inversion modeling. GCPM uses a single instrument, the âGeostationary Fourier Transform Spectrometer (GeoFTS)â to make measurements in the near infrared spectral region at high spectral resolution. The GeoFTS is a half meter cube size instrument designed to be a secondary âhostedâ payload on a commercial GEO satellite. NASA and other government agencies have adopted the hosted payload implementation approach because it substantially reduces the overall mission cost. This paper presents a hosted payload implementation approach for measuring the major carbon-containing gases in the atmosphere from the geostationary vantage point, to affordably advance the scientific understating of carbon cycle processes and climate change
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Explaining disappearances as a tool of political terror
Despite the widespread use of disappearances as a central tool of terror in recent decades, little is known about the emergence of the phenomenon or its underlying rationale. We argue that growing international accountability norms, coupled with the improved quality of reporting human rights abuses, paradoxically reshaped the repressive strategies of certain regimes and pushed them to deploy more clandestine and extrajudicial forms of repression, predominantly disappearances. We also explore the timing of disappearances: when a state decides to deploy a particular instrument of terror can greatly benefit our understanding of why it was used. We show that repressive regimes tend to use disappearances in the first period after a coup, taking advantage of the general confusion and opacity to secure strategic benefits and protect the regime from external scrutiny and future accountability. Our findings contribute to the growing literature on human rights and political repression by highlighting an âunintended consequenceâ of international accountability norms: repressive regimes turn to clandestine crimes
A tool to balance benefit and harm when deciding about adjuvant therapy
Adjuvant therapy aims to prevent outgrowth of residual disease but can induce serious side effects. Weighing conflicting treatment effects and communicating this information with patients is not elementary. This study presents a scheme balancing benefit and harm of adjuvant therapy vs no adjuvant therapy. It is illustrated by the available evidence on adjuvant pelvic external beam radiotherapy (RT) for intermediate-risk stage I endometrial carcinoma patients. The scheme comprises five outcome possibilities of adjuvant therapy: patients who benefit from adjuvant therapy (some at the cost of complications) vs those who neither benefit nor contract complications, those who do not benefit but contract severe complications, or those who die. Using absolute risk differences, a fictive cohort of 1000 patients receiving adjuvant RT is categorised. Three large randomised clinical trials were included. Recurrences will be prevented by adjuvant RT in 60 patients, a majority of 908 patients will neither benefit nor suffer severe radiation-induced harm but 28 patients will suffer severe complications due to adjuvant RT and an expected four patients will die. This scheme readily summarises the different possible treatment outcomes and can be of practical value for clinicians and patients in decision making about adjuvant therapies
Linking a dermal permeation and an inhalation model to a simple pharmacokinetic model to study airborne exposure to di(n-butyl) phthalate
Six males clad only in shorts were exposed to high levels of airborne di(n-butyl) phthalate (DnBP) and diethyl phthalate (DEP) in chamber experiments conducted in 2014. In two 6âh sessions, the subjects were exposed only dermally while breathing clean air from a hood, and both dermally and via inhalation when exposed without a hood. Full urine samples were taken before, during, and for 48âh after leaving the chamber and measured for key DnBP and DEP metabolites. The data clearly demonstrated high levels of DnBP and DEP metabolite excretions while in the chamber and during the first 24âh once leaving the chamber under both conditions. The data for DnBP were used in a modeling exercise linking dose models for inhalation and transdermal permeation with a simple pharmacokinetic model that predicted timing and mass of metabolite excretions. These models were developed and calibrated independent of these experiments. Tests included modeling of the âhood-onâ (transdermal penetration only), âhood-offâ (both inhalation and transdermal) scenarios, and a derived âinhalation-onlyâ scenario. Results showed that the linked model tended to duplicate the pattern of excretion with regard to timing of peaks, decline of concentrations over time, and the ratio of DnBP metabolites. However, the transdermal model tended to overpredict penetration of DnBP such that predictions of metabolite excretions were between 1.1 and 4.5 times higher than the cumulative excretion of DnBP metabolites over the 54âh of the simulation. A similar overprediction was not seen for the âinhalation-onlyâ simulations. Possible explanations and model refinements for these overpredictions are discussed. In a demonstration of the linked model designed to characterize general population exposures to typical airborne indoor concentrations of DnBP in the United States, it was estimated that up to one-quarter of total exposures could be due to inhalation and dermal uptake
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