1,988 research outputs found
Global science literacy : definition, needs assessment and concerns for Cyprus
Global Science Literacy has as its goals to stimulate an interest in
science, represent modern technological goals of science, develop international
understanding, relate science to social needs, and develop thinking and
problem-solving skills for the 21st Century. Such an approach is proposed as
viable on an international basis for conceptual strength in integrated science
courses. Assessment of GSL’s potential in Cyprus serves as an example of
preparations needed and concerns to be addressed if GSL is to become the basis
of the science curriculum. Toward this end, a survey of teachers throughout
Cyprus identified teachers’ priorities for environmental issues and system
science concepts their students should know, the teachers’ knowledge of those
concepts and issues, and their current levels of teaching them. This paper will
discuss the teachers’ relative perceptions of local and global understandings,
Earth systems science, and teacher education issues involved in fostering
Global Science Literacy.peer-reviewe
The Policy of Enforcement: Red Light Cameras and Racial Profiling
The article of record as published may be located at http://dx.doi.org/10.1177/1098611115586174We explore the question of whether some of the often conflicting evidence of
racial profiling can be cleared up using red light camera observations to measure
racial disparities in traffic violations. Using data from cameras at intersections
matched to census data, we find that although citations from the red light cameras
are issued to a disproportionate number of minorities based on the racial composition
of the surrounding location, the racial composition of the violator is consistent
with the racial composition of the block group in which they reside. Our study
indicates that red light cameras may have a present and future role in assisting
public policy makers on issues of racial profiling thresholds
A continuous Flaring- to Normal-branch transition in Sco X-1
We report the first resolved rapid transition from a Flaring Branch
Oscillation to a Normal Branch Oscillation in the RXTE data of the Z source Sco
X-1. The transition took place on a time scale of ~100 seconds and was clearly
associated to the Normal Branch-Flaring Branch vertex in the color-color
diagram. We discuss the results in the context of the possible association of
the Normal Branch Oscillation with other oscillations known both in
Neutron-Star and Black-Hole systems, concentrating on the similarities with the
narrow 4-6 Hz oscillations observed at high flux in Black-Hole Candidates.Comment: 5 pages, 4 figures, accepted for publication in Astronomy &
Astrophysic
Azo-Dye-Functionalized Polycarbonate Membranes for Textile Dye and Nitrate Ion Removal
Challenges exist in the wastewater treatment of dyes produced by the world’s growing textiles industry. Common problems facing traditional wastewater treatments include low retention values and breaking the chemical bonds of some dye molecules, which in some cases can release byproducts that can be more harmful than the original dye. This research illustrates that track-etched polycarbonate filtration membranes with 100-nanometer diameter holes can be functionalized with azo dye direct red 80 at 1000 µM, creating a filter that can then be used to remove the entire negatively charged azo dye molecule for a 50 µM solution of the same dye, with a rejection value of 96.4 ± 1.4%, at a stable flow rate of 114 ± 5 µL/min post-functionalization. Post-functionalization, Na+ and NO3− ions had on average 17.9%, 26.0%, and 31.1% rejection for 750, 500, and 250 µM sodium nitrate solutions, respectively, at an average flow rate of 177 ± 5 µL/min. Post-functionalization, similar 50 µM azo dyes had increases in rejection from 26.3% to 53.2%. Rejection measurements were made using ultraviolet visible-light spectroscopy for dyes, and concentration meters using ion selective electrodes for Na+ and NO3− ions
PCN51 HEALTH CARE COSTS ASSOCIATED WITH ANGIOGENESIS INHIBITORS (AIS) AND MTOR INHIBITORS (MTORS) IN PATIENTS WITH METASTATIC RENAL CELL CARCINOMA (MRCC) TREATED AT US COMMUNITY ONCOLOGY CLINICS
Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign
Volatile organic compounds (VOCs) were measured by proton transfer reaction – mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative – Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.
Atmos. Chem. Phys., 9, 467–481, 2009.Robert A. Welch Foundation (Grant A-1417)Texas A & M University. Center for Atmospheric Chemistry and EnvironmentNational Science Foundation (U.S.) (ATM-0528227
Measurements of HNO 3 and N 2 O 5 using ion drift-chemical ionization mass spectrometry during the MILAGRO/MCMA-2006 campaign
Reverse Monte Carlo modeling of amorphous silicon
An implementation of the Reverse Monte Carlo algorithm is presented for the
study of amorphous tetrahedral semiconductors. By taking into account a number
of constraints that describe the tetrahedral bonding geometry along with the
radial distribution function, we construct a model of amorphous silicon using
the reverse monte carlo technique. Starting from a completely random
configuration, we generate a model of amorphous silicon containing 500 atoms
closely reproducing the experimental static structure factor and bond angle
distribution and in improved agreement with electronic properties. Comparison
is made to existing Reverse Monte Carlo models, and the importance of suitable
constraints beside experimental data is stressed.Comment: 6 pages, 4 PostScript figure
Resection of the liver for colorectal carcinoma metastases - A multi-institutional study of long-term survivors
In this review of a collected series of patients undergoing hepatic resection for colorectal metastases, 100 patients were found to have survived greater than five years from the time of resection. Of these 100 long-term survivors, 71 remain disease-free through the last follow-up, 19 recurred prior to five years, and ten recurred after five years. Patient characteristics that may have contributed to survival were examined. Procedures performed included five trisegmentectomies, 32 lobectomies, 16 left lateral segmentectomies, and 45 wedge resections. The margin of resection was recorded in 27 patients, one of whom had a positive margin, nine of whom had a less than or equal to 1-cm margin, and 17 of whom had a greater than 1-cm margin. Eighty-one patients had a solitary metastasis to the liver, 11 patients had two metastases, one patient had three metastases, and four patients had four metastases. Thirty patients had Stage C primary carcinoma, 40 had Stage B primary carcinoma, and one had Stage A primarycarcinoma. The disease-free interval from the time of colon resection to the time of liver resection was less than one year in 65 patients, and greater than one year in 34 patients. Three patients had bilobar metastases. Four of the patients had extrahepatic disease resected simultaneously with the liver resection. Though several contraindications to hepatic resection have been proposed in the past, five-year survival has been found in patients with extrahepatic disease resected simultaneously, patients with bilobar metastases, patients with multiple metastases, and patients with positive margins. Five-year disease-free survivors are also present in each of these subsets. It is concluded that five-year survival is possible in the presence of reported contraindications to resection, and therefore that the decision to resect the liver must be individualized. © 1988 American Society of Colon and Rectal Surgeons
Targeting mitochondrial oxidative stress with MitoQ reduces NET formation and kidney disease in lupus-prone MRL-lpr mice.
OBJECTIVES: Recent investigations in humans and mouse models with lupus have revealed evidence of mitochondrial dysfunction and production of mitochondrial reactive oxygen species (mROS) in T cells and neutrophils. This can provoke numerous cellular changes including oxidation of nucleic acids, proteins, lipids and even induction of cell death. We have previously observed that in T cells from patients with lupus, the increased mROS is capable of provoking oligomerisation of mitochondrial antiviral stimulator (MAVS) and production of type I interferon (IFN-I). mROS in SLE neutrophils also promotes the formation of neutrophil extracellular traps (NETs), which are increased in lupus and implicated in renal damage. As a result, in addition to traditional immunosuppression, more comprehensive treatments for lupus may also include non-immune therapy, such as antioxidants. METHODS: Lupus-prone MRL-lpr mice were treated from weaning for 11 weeks with the mitochondria-targeted antioxidant, MitoQ (200 µM) in drinking water. Mice were then assessed for ROS production in neutrophils, NET formation, MAVS oligomerisation, serum IFN-I, autoantibody production and renal function. RESULTS: MitoQ-treated mice manifested reduced neutrophil ROS and NET formation, decreased MAVS oligomerisation and serum IFN-I, and reduced immune complex formation in kidneys, despite no change in serum autoantibody . CONCLUSIONS: These findings reveal the potential utility of targeting mROS in addition to traditional immunosuppressive therapy for lupus
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