1,388 research outputs found
Using the GLOBE Program to Educate Students on the Interdependence of Professional Development?
We present how we have used GLOBE protocols and programs in a college undergraduate English course for science and non-science majors, âWriting in the Sciencesâ, and in a graduate-level field course for in-service teachers. Collecting land cover data and determining biomass in conjunction with a series of writing assignments allowed the English students to connect their work to research done in ecosystems throughout the world, and to specific environmental concerns such as carbon sequestration, biodiversity, and the impact of controlled burning on ecosystems. Teachers demonstrated increased knowledge of ecology, natural histories of various organisms, and awareness of environmental resources. A study conducted the following summer revealed that teachers valued the course and felt that their experiences helped them be more effective teachers. Six of the eight teachers had conducted field activities with their students, but also reported significant challenges associated with the effort
Advanced Diagnostics for the Study of Linearly Polarized Emission. II: Application to Diffuse Interstellar Radio Synchrotron Emission
Diagnostics of polarized emission provide us with valuable information on the
Galactic magnetic field and the state of turbulence in the interstellar medium,
which cannot be obtained from synchrotron intensity alone. In Paper I (Herron
et al. 2017b), we derived polarization diagnostics that are rotationally and
translationally invariant in the - plane, similar to the polarization
gradient. In this paper, we apply these diagnostics to simulations of ideal
magnetohydrodynamic turbulence that have a range of sonic and Alfv\'enic Mach
numbers. We generate synthetic images of Stokes and for these
simulations, for the cases where the turbulence is illuminated from behind by
uniform polarized emission, and where the polarized emission originates from
within the turbulent volume. From these simulated images we calculate the
polarization diagnostics derived in Paper I, for different lines of sight
relative to the mean magnetic field, and for a range of frequencies. For all of
our simulations, we find that the polarization gradient is very similar to the
generalized polarization gradient, and that both trace spatial variations in
the magnetoionic medium for the case where emission originates within the
turbulent volume, provided that the medium is not supersonic. We propose a
method for distinguishing the cases of emission coming from behind or within a
turbulent, Faraday rotating medium, and a method to partly map the rotation
measure of the observed region. We also speculate on statistics of these
diagnostics that may allow us to constrain the physical properties of an
observed turbulent region.Comment: 34 pages, 25 figures, accepted for publication in Ap
Rayleigh-LIDAR Observations of Mid-Latitude Mesospheric Densities
This research is an analysis of absolute densities throughout the mesosphere (45 km to 90 km). Although much research has gone into the study of temperatures and their variations occurring in our atmosphere, little has been done to research the densities and their variations. Due to the remoteness of the middle atmosphere there is a high degree of difficulty in making observations in the mesosphere. There are currently three major types of ground-based instruments used to sense the mesosphere remotely. They are atmospheric radars, LIDARs and optical spectrometers. As far as measuring density in the mesosphere LIDAR is the most efficient. A Rayleigh-scatter LIDAR operated at the Atmospheric LIDAR Observatory (ALO; 41.7 ° N, 111.8 ° W), as part of CASS (Center for Atmosphere and Space Studies), on the campus of Utah State University (USU) has collected extensive data between 1993 and 2004. This LIDAR is used to measure relative densities (which can be used to derive temperatures) throughout the mesosphere. An analysis is made with the absolute densities from the atmosphere reanalysis model ERA-20C (the European Reanalysis 20th century model.) by using the model densities at 45 km to calibrate the LIDAR observations made at USU. Thereby, converting the relative densities measured by the USU LIDAR into measurements of absolute densities. These densities are used to examine the density structure of the mesosphere, how it varies with altitude and time, possible atmospheric anomalies, along with annual or semiannual atmospheric variations. Monthly averages are used to compare density variations related to altitude and season. By normalizing the relative densities from the Rayleigh LIDAR observations to the absolute densities from the reanalysis models, these differences can be observed and analyzed to better characterize the neutral atmosphere and learn how it varies during the year
Rayleigh-LIDAR Observations of Mesospheric Densities
The goal of this project is to take relative densities of the mesosphere (altitude 45-90 km) from data that has been collected and convert them into absolute densities. It is then possible to look at how these densities vary with altitude and season. The data was collected using a Rayleigh-scatter LIDAR at the Atmospheric LIDAR Observatory. This is a part of the Center for Atmospheric and Space Sciences and is located on the Utah State University Campus. It spans a total of 11 years beginning in 1993 and ending in 2004. The collected data is used to create a composite year and is then normalized to a constant at an attitude of 45 km. It is then compared to an absolute density measurement at 45 km that is calculated using the European Reanalysis 20th Century (ERA-20C) model. This density is then used to convert all of the relative mesospheric densities into absolute densities
The Co-occurrence of child and intimate partner maltreatment in the family: characteristics of the violent perpetrators
This study considers the characteristics associated with mothers and fathers who maltreat their child and each other in comparison to parents who only maltreat their child. One hundred and sixty-two parents who had allegations of child maltreatment made against them were considered. The sample consisted of 43 fathers (Paternal FamilyâPF) and 23 mothers (Maternal FamilyâMF) who perpetrated both partner and child maltreatment, together with 23 fathers (Paternal ChildâPC) and 26 mothers (Maternal ChildâMC) who perpetrated child maltreatment only. In addition, 2 fathers (Paternal VictimâPV) and 23 mothers (Maternal VictimâMV) were victims of intimate partner maltreatment and perpetrators of child maltreatment and 7 fathers (Paternal Non-abusive CarerâPNC) and 15 mothers (Maternal Non-abusive CarerâMNC) did not maltreat the child but lived with an individual who did. Within their family unit, 40.7% of parents perpetrated both intimate partner and child maltreatment. However, fathers were significantly more likely to maltreat both their partner and child than mothers and mothers were significantly more likely to be victims of intimate partner violence than fathers. PF fathers conducted the highest amount of physical and/or sexual child maltreatment while MC and MV mothers perpetrated the highest amount of child neglect. Few significant differences between mothers were found. PF fathers had significantly more factors associated with development of a criminogenic lifestyle than PC fathers. Marked sex differences were demonstrated with PF fathers demonstrating significantly more antisocial characteristics, less mental health problems and fewer feelings of isolation than MF mothers. MC mothers had significantly more childhood abuse, mental health problems, parenting risk factors and were significantly more likely to be biologically related to the child than PC fathers. This study suggests that violent families should be assessed and treated in a holistic manner, considering the effects of partner violence upon all family members, rather than exclusively intervening with the violent man
Estimation of ultrasonic attenuation and mean backscatterer size via digital signal processing
The backscattered rf signals from the lungs of fetal sheep during their last trimester of development were digitized and processed in an attempt to correlate ultrasonic parameters with measured functional parameters related to lung maturation. The broad-band, post-TGC, rf signal of a commercial B-mode ultrasonic scanner was digitized at a sampling rate of 25 MHz. Sorting excluded data from regions of rib shadowing and other nonlung structures from analysis. The sorted data were used to estimate the slope of the ultrasonic attenuation coefficient with respect to frequency via linear regression on the average difference of the logarithm of power spectra from separated data segments. The power spectra were also corrected for attenuation, averaged and used to compute the power cepstrum of the backscattered signal which can be related to mean backscatterer radius. Results are presented for eight fetal sheep.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24941/1/0000368.pd
Synthesis of CdS and CdSe nanocrystallites using a novel single-molecule precursors approach
The synthesis of CdS and CdSe nanocrystallites using the thermolysis of several dithioor
diselenocarbamato complexes of cadmium in trioctylphosphine oxide (TOPO) is reported.
The nanodispersed materials obtained show quantum size effects in their optical spectra
and exhibit near band-edge luminescence. The influence of experimental parameters on
the properties of the nanocrystallites is discussed. HRTEM images of these materials show
well-defined, crystalline nanosized particles. Standard size fractionation procedures can
be performed in order to narrow the size dispersion of the samples. The TOPO-capped CdS
and CdSe nanocrystallites and simple organic bridging ligands, such as 2,2Âą-bipyrimidine,
are used as the starting materials for the preparation of novel nanocomposites. The optical
properties shown by these new nanocomposites are compared with those of the starting
nanodispersed materials
LIFE BEEF CARBON: a common framework for quantifying grass and corn based beef farmsâ carbon footprints
peer-reviewedEuropeâs roadmap to a low-carbon economy aims to cut greenhouse gas (GHG) emissions 80% below 1990 levels by 2050. Beef
production is an important source of GHG emissions and is expected to increase as the world population grows. LIFE BEEF CARBON
is a voluntary European initiative that aims to reduce GHG emissions per unit of beef (carbon footprint) by 15% over a 10-year
period on 2172 farms in four large beef-producing countries. Changes in farms beef carbon footprint are normally estimated via
simulation modelling, but the methods current models apply differ. Thus, our initial goal was to develop a common modelling
framework to estimate beef farms carbon footprint. The framework was developed for a diverse set of Western Europe farms
located in Ireland, Spain, Italy and France. Whole farm and life cycle assessment (LCA) models were selected to quantify emissions
for the different production contexts and harmonized. Carbon Audit was chosen for Ireland, Bovid-CO2 for Spain and CAPâ2ER for
France and Italy. All models were tested using 20 case study farms, that is, 5 per country and quantified GHG emissions associated
with on-farm live weight gain. The comparison showed the ranking of beef systems gross carbon footprint was consistent across the
three models. Suckler to weaning or store systems generally had the highest carbon footprint followed by suckler to beef systems
and fattening beef systems. When applied to the same farm, Carbon Auditâs footprint estimates were slightly lower than CAPâ2ER,
but marginally higher than Bovid-CO2. These differences occurred because the models were adapted to a specific regionâs production
circumstances, which meant their emission factors for key sources; that is, methane from enteric fermentation and GHG emissions
from concentrates were less accurate when used outside their target region. Thus, for the common modelling framework, regionspecific
LCA models were chosen to estimate beef carbon footprints instead of a single generic model. Additionally, the Carbon
Audit and Bovid-CO2 models were updated to include carbon removal by soil and other environmental metrics included in CAPâ2ER,
for example, acidification. This allows all models to assess the effect carbon mitigation strategies have on other potential pollutants.
Several options were identified to reduce beef farms carbon footprint, for example, improving genetic merit. These options were
assessed for beef systems, and a mitigation plan was created by each nation. The cumulative mitigation effect of the LIFE BEEF
CARBON plan was estimated to exceed the projects reduction target (â15%)
Anti-cancer effects and mechanism of actions of aspirin analogues in the treatment of glioma cancer
INTRODUCTION: In the past 25 years only modest advancements in glioma treatment have been made, with patient prognosis and median survival time following diagnosis only increasing from 3 to 7 months. A substantial body of clinical and preclinical evidence has suggested a role for aspirin in the treatment of cancer with multiple mechanisms of action proposed including COX 2 inhibition, down regulation of EGFR expression, and NF-ÎșB signaling affecting Bcl-2 expression. However, with serious side effects such as stroke and gastrointestinal bleeding, aspirin analogues with improved potency and side effect profiles are being developed. METHOD: Effects on cell viability following 24 hr incubation of four aspirin derivatives (PN508, 517, 526 and 529) were compared to cisplatin, aspirin and di-aspirin in four glioma cell lines (U87 MG, SVG P12, GOS â 3, and 1321N1), using the PrestoBlue assay, establishing IC50 and examining the time course of drug effects. RESULTS: All compounds were found to decrease cell viability in a concentration and time dependant manner. Significantly, the analogue PN517 (IC50 2mM) showed approximately a twofold increase in potency when compared to aspirin (3.7mM) and cisplatin (4.3mM) in U87 cells, with similar increased potency in SVG P12 cells. Other analogues demonstrated similar potency to aspirin and cisplatin. CONCLUSION: These results support the further development and characterization of novel NSAID derivatives for the treatment of glioma
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