1,936 research outputs found
Tunable far infrared studies of molecular parameters in support of stratospheric measurements
Lab studies were made in support of far infrared spectroscopy of the stratosphere using the Tunable Far InfraRed (TuFIR) method of ultrahigh resolution spectroscopy and, more recently, spectroscopic and retrieval calculations performed in support of satellite-based atmospheric measurement programs: the Global Ozone Monitoring Experiment (GOME), and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY)
How well do activity monitors estimate energy expenditure? A systematic review and meta-analysis of the validity of current technologies
How do electronic carriers cross Si-bound alkyl monolayers?
Electron transport through Si-C bound alkyl chains, sandwiched between n-Si
and Hg, is characterized by two distinct types of barriers, each dominating in
a different voltage range. At low voltage, current depends strongly on
temperature but not on molecular length, suggesting transport by thermionic
emission over a barrier in the Si. At higher voltage, the current decreases
exponentially with molecular length, suggesting tunneling through the
molecules. The tunnel barrier is estimated, from transport and photoemission
data, to be ~1.5 eV with a 0.25me effective mass.Comment: 13 pages, 3 figure
Sheep productivity in an Astrebla grassland of south-west Queensland
A grazing study conducted between 1979 and 1983 assessed the seasonal trends of ewe productivity in Astrebla grassland in southwestern Queensland. This study was designed originally to compare productivity on two pastures with different compositions, however, these differences in pastures composition were not achieved.
Large differences in liveweight, wool growth and reproductive performance occurred between years in response to differences in pasture growth resulting from large variation in the seasonal incidence of rainfall. Rainfall effective for plant growth, both forbs and grasses, resulted in a high quality diet which resulted, in turn, in increased sheep productivity. Reproductive performance was particularly sensitive to the quality of the ewes diet around the time of lambing through the effect of diet quality on lamb survival and growth rate.
It is suggested that the effect of rainfall on reproductive performance is of greater importance than the yield of forbs present in the pasture
The Role of Self-as-Doer Identity in Physical Activity: Increasing Behaviors by Increasing Self-Efficacy for Overcoming Barriers to Physical Activity
https://openriver.winona.edu/urc2018/1054/thumbnail.jp
Cosmic ray short burst observed with the Global Muon Detector Network (GMDN) on June 22, 2015
We analyze the short cosmic ray intensity increase ("cosmic ray burst": CRB)
on June 22, 2015 utilizing a global network of muon detectors and derive the
global anisotropy of cosmic ray intensity and the density (i.e. the
omnidirectional intensity) with 10-minute time resolution. We find that the CRB
was caused by a local density maximum and an enhanced anisotropy of cosmic rays
both of which appeared in association with Earth's crossing of the heliospheric
current sheet (HCS). This enhanced anisotropy was normal to the HCS and
consistent with a diamagnetic drift arising from the spatial gradient of cosmic
ray density, which indicates that cosmic rays were drifting along the HCS from
the north of Earth. We also find a significant anisotropy along the HCS,
lasting a few hours after the HCS crossing, indicating that cosmic rays
penetrated into the inner heliosphere along the HCS. Based on the latest
geomagnetic field model, we quantitatively evaluate the reduction of the
geomagnetic cut-off rigidity and the variation of the asymptotic viewing
direction of cosmic rays due to a major geomagnetic storm which occurred during
the CRB and conclude that the CRB is not caused by the geomagnetic storm, but
by a rapid change in the cosmic ray anisotropy and density outside the
magnetosphere.Comment: accepted for the publication in the Astrophysical Journa
A comparison of alternative assays to measure DNA damage in stallion spermatozoa: TUNEL test versus ‘Nicoletti assay’
The aberrations of sperm DNA may cause various problems and have negative consequences on fertility. These influence embryonic development or might lead to early embryo loss. Sperm Chromatin Structure Assay (SCSA) is the flow cytometric method most often used for the detection of DNA lesions; however, some studies using that method reached confusing conclusions. The aim of this pilot study was to adjust and compare two alternative tests, namely the TUNEL test and the Nicoletti assay. The above-mentioned two flow cytometric methods capable of detecting the fragmented DNA of sperm were tested on 12 frozen-thawed stallion semen samples. The TUNEL test demonstrated much higher DNA fragmentation ratio than the Nicoletti assay (mean ± SD: 30.77 ± 13.03% vs. 1.93 ± 0.89%, respectively). A fluorescent microscopic check of the samples showed that TUNEL labelled the plasma membrane and the mitochondria in a nonspecific way, rather than detecting only the fragmented DNA, thus eventually resulting in a false positive sign. The Nicoletti assay is simpler, quicker and does not detect nonspecific binding; however, further analyses are required to determine its diagnostic value
Solar Magnetic Polarity Effect on Neutron Monitor Count Rates: Comparing Latitude Surveys and Antarctic Stations
The Galactic cosmic ray spectrum manifests pronounced variations over the
11-year sunspot cycle and more subtle variations over the 22-year solar
magnetic cycle. An important tool to study these variations is repeated
latitude surveys with neutron monitors (NMs) onboard icebreakers in conjunction
with land-based references. We revisit 13 annual latitude surveys from 1994 to
2007 using reference data from the Mawson NM instead of McMurdo NM (which
closed in 2017). We then consider two more latitude surveys (2018 and 2019)
with a monitor similar to the 3NM64 in the previous surveys but without lead
rings around the central tube, a so-called ``semi-leaded neutron monitor.'' The
new surveys extend the linear relationship among data taken at different cutoff
rigidity ranges. They also confirm the ``crossover'' measured near solar minima
during epochs of opposite solar magnetic polarity and the absence of a
crossover for epochs having the same solar magnetic polarity.Comment: Accepted for publication in Astrophys.
Vibrational Enhancement of the Effective Donor - Acceptor Coupling
The paper deals with a simple three sites model for charge transfer phenomena
in an one-dimensional donor (D) - bridge (B) - acceptor (A) system coupled with
vibrational dynamics of the B site. It is found that in a certain range of
parameters the vibrational coupling leads to an enhancement of the effective
donor - acceptor electronic coupling as a result of the formation of the
polaron on the B site. This enhancement of the charge transfer efficiency is
maximum at the resonance, where the effective energy of the fluctuating B site
coincides with the donor (acceptor) energy.Comment: 5 pages, 3 figure
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