2,841 research outputs found
English Literacy Development for English Language Learners: Does Spanish Instruction Promote or Hinder?
In this brief, the authors consider whether instruction in a child\u27s native language (particularly Spanish) hinders or promotes learning of literacy in English. The authors conduct a four-step process for identifying research on this topic, examining this literature, and then determining the answer to this clinical question. The results suggest that supporting a child\u27s home/native language promotes rather than hinders development of English literacy skills
Safety
Wildlife damage management (WDM) is an exciting field with many opportunities to provide solutions to the complex issues involved in human-wildlife interactions. In addition, WDM wildlife control operators (WCO) face a variety of threats to their physical well-being. Injuries can result from misused (Figure 1), faulty, or poorly maintained equipment, inexperience, mishandled wildlife, harsh weather, and dangerous situations, such as electrical lines. The goals of this publication are to: * Develop an awareness of safety issues and adopt a mindset of “Safety First”, * Review the major safety threats that WCOs face, * Provide basic information for WCOs to protect themselves, and * List resources for further information and training.
Although no statistics are available for the WDM industry in particular, the authors are aware of several instances where WCOs have lost their lives or suffered serious injuries while performing WDM.
While accidents do happen, most are preventable and occur due to hurried behavior, neglect of procedures, or lack of attention to the task at hand. The United States, Canada, and Mexico have agencies tasked with setting and enforcing standards to assure safe and healthful conditions for workers. The U.S. agency is the Occupational Safety and Health Administration (OSHA). In Canada, it is the Labour Program, and in Mexico, the Ministry of Labor and Social Welfare governs workplace requirements. Readers are encouraged to keep abreast of government safety regulations not only to follow the law, but also to maintain a safe working environment. Safety is an extremely broad and complex topic. The number and diversity of situations that pose safety risks to WCOs are numerous. This publication focuses specifically on safety risks to the WCOs’ physical wellbeing, such as injuries. Safety concerns pertaining to organizational design, worker supervision, disease, environmental or social catastrophes, or pesticides are beyond its scope.
Work in WDM poses many safety risks to those involved. Awareness, planning, and deliberate action can eliminate or reduce many threats. As the industry continues to develop, WCOs must keep up with new threats and safety practices to maintain their well-being. Following safe work practices helps to ensure WCOs remain on-the-job and injury free
Finite-Temperature Auxiliary-Field Quantum Monte Carlo for Bose-Fermi Mixtures
We present a quantum Monte Carlo (QMC) technique for calculating the exact
finite-temperature properties of Bose-Fermi mixtures. The Bose-Fermi
Auxiliary-Field Quantum Monte Carlo (BF-AFQMC) algorithm combines two methods,
a finite-temperature AFQMC algorithm for bosons and a variant of the standard
AFQMC algorithm for fermions, into one algorithm for mixtures. We demonstrate
the accuracy of our method by comparing its results for the Bose-Hubbard and
Bose-Fermi-Hubbard models against those produced using exact diagonalization
for small systems. Comparisons are also made with mean-field theory and the
worm algorithm for larger systems. As is the case with most fermion
Hamiltonians, a sign or phase problem is present in BF-AFQMC. We discuss the
nature of these problems in this framework and describe how they can be
controlled with well-studied approximations to expand BF-AFQMC's reach. The new
algorithm can serve as an essential tool for answering many unresolved
questions about many-body physics in mixed Bose-Fermi systems.Comment: 19 pages, 6 figure
The Long Wait for an Improbable Death: A Look at Delays in Executions in Kansas and Possible Reforms to Capital Punishment
This article uses Kansas as a case study to show how in Kansas, as in many other states in the United States, the execution of a death sentence is so improbable, and the delays that precede it so extraordinary, that any arguable deterrent or retributive effect capital punishment might once have had has been severely diminished. This article considers possible reforms to the capital punishment system aimed at reducing the delay between sentencing and execution, and the risks that would accompany those reforms. This article also considers whether capital punishment should still be considered a viable option for states in this position
Activism Among College Students with Disabilities and the Move Beyond Compliance to Full Inclusion
This article discusses two case studies of activism by college students with disabilities that have successfully moved disability issues beyond regulatory compliance to a conversation of equity. The two case studies are compared to identify strategies that promoted the success of the campaigns. The article concludes with a discussion of the usage of student activism to ensure equality of opportunity
Modeling \u3ci\u3eEscherichia coli\u3c/i\u3e in the Missouri River near Omaha, Nebraska, 2012–16
The city of Omaha, Nebraska, has a combined sewer system in some areas of the city. In Omaha, Nebr., a moderate amount of rainfall will lead to the combination of stormwater and untreated sewage or wastewater being discharged directly into the Missouri River and Papillion Creek and is called a combined sewer overflow (CSO) event. In 2009, the city of Omaha began the implementation of their Long Term Control Plan (LTCP) to mitigate the effects of CSOs on the Missouri River and Papillion Creek. As part of the LTCP, the city partnered with the U.S. Geological Survey (USGS) in 2012 to begin monitoring in the Missouri River. Since 2012, monthly discrete water-quality samples for many constituents have been collected from the Missouri River at four sites. At 3 of the 4 sites, water quality has been monitored continuously for selected constituents and physical properties. These discrete water-quality samples and continuous water-quality monitoring data (from July 2012 to 2020) have been collected to better understand the water quality of the Missouri River, how it is changing with time, how it changes upstream from the city of Omaha to downstream, and how it varies during base-flow conditions and during periods of runoff. The purpose of this report is to document the development of Escherichia coli (E. coli) concentration models for these four Missouri River sites. Analysis was completed using the first 5 years of data (through 2016) to determine if the current approach is sufficient to meet future analysis goals and to understand if proposed models such as Load Estimator (LOADEST) models will be able to represent water-quality changes in the Missouri River. Multiple linear regression models were developed to estimate E. coli concentration using LOADEST as implemented in the rloadest package in the R statistical software program. A set of explanatory variables, including streamflow and streamflow anomalies, precipitation, information about CSOs, and continuous water quality, were evaluated for potential inclusion in regression models. The best model at Missouri River at NP Dodge Park at Omaha, Nebr. (USGS station 412126095565201; hereafter “NP Dodge”) included basin explanatory variables of upstream antecedent precipitation index measured at Tekamah, Nebr.; decimal time; season; and turbidity. The best model at Missouri River at Freedom Park Omaha, Nebr. (USGS station 411636095535401; hereafter “Freedom Park”) included the same explanatory variables as the NP Dodge model with the addition of turbidity anomalies and flow anomalies. The best models at the two downstream sites (Missouri River near Council Bluffs, Iowa, USGS station 06610505 and Missouri River near La Platte, Nebr., USGS station 410333095530101) included the same explanatory variables as the Freedom Park model with the addition of local antecedent precipitation index as measured at Eppley Airport in Omaha, Nebr., and additional turbidity and flow anomalies. The final selected models were the best models given our modeling design constraint in which explanatory variables included in the model for the upstream site were included in the downstream models. Explanatory variables currently (2020) being collected and included in the selected models through 2016 explained 64–75 percent of the variability of E. coli concentration in the Missouri River. Explaining 64–75 percent of the variability might be considered low when working with physical constituents (total nitrogen or sediment), but with the natural variability of biological constituents such as E. coli, the uncertainty of E. coli laboratory measurements, and the added complexity of modeling in a large drainage basin with multiple sources, these results are adequate and indicate that the explanatory variables being collected and models such as LOADEST can represent water-quality changes in the Missouri River for E. coli concentration from 2012 to 2016
ALMA Observations of Asymmetric Molecular Gas Emission from a Protoplanetary Disk in the Orion Nebula
We present Atacama Large Millimeter/submillimeter Array (ALMA) observations
of molecular line emission from d216-0939, one of the largest and most massive
protoplanetary disks in the Orion Nebula Cluster (ONC). We model the spectrally
resolved HCO (4--3), CO (3--2), and HCN (4--3) lines observed at 0\farcs5
resolution to fit the temperature and density structure of the disk. We also
weakly detect and spectrally resolve the CS (7--6) line but do not model it.
The abundances we derive for CO and HCO are generally consistent with
expected values from chemical modeling of protoplanetary disks, while the HCN
abundance is higher than expected. We dynamically measure the mass of the
central star to be which is inconsistent with the
previously determined spectral type of K5. We also report the detection of a
spatially unresolved high-velocity blue-shifted excess emission feature with a
measurable positional offset from the central star, consistent with a Keplerian
orbit at . Using the integrated flux of the feature in
HCO (4--3), we estimate the total H gas mass of this feature to be at
least , depending on the assumed temperature. The
feature is due to a local temperature and/or density enhancement consistent
with either a hydrodynamic vortex or the expected signature of the envelope of
a forming protoplanet within the disk.Comment: 19 pages, 12 figures, accepted for publication in A
ALMA Observations of the Largest Proto-Planetary Disk in the Orion Nebula, 114-426: A CO Silhouette
We present ALMA observations of the largest protoplanetary disk in the Orion
Nebula, 114-426. Detectable 345 GHz (856 micron) dust continuum is produced
only in the 350 AU central region of the ~1000 AU diameter silhouette seen
against the bright H-alpha background in HST images. Assuming optically thin
dust emission at 345 GHz, a gas-to-dust ratio of 100, and a grain temperature
of 20 K, the disk gas-mass is estimated to be 3.1 +/- 0.6 Jupiter masses. If
most solids and ices have have been incorporated into large grains, however,
this value is a lower limit. The disk is not detected in dense-gas tracers such
as HCO+ J=4-3, HCN J=4-3, or CS =7-6. These results may indicate that the
114-426 disk is evolved and depleted in some light organic compounds found in
molecular clouds. The CO J=3-2 line is seen in absorption against the bright 50
to 80 K background of the Orion A molecular cloud over the full spatial extent
and a little beyond the dust continuum emission. The CO absorption reaches a
depth of 27 K below the background CO emission at VLSR ~6.7 km/s about 0.52
arcseconds (210 AU) northeast and 12 K below the background CO emission at VLSR
~ 9.7 km/s about 0.34 arcseconds (140 AU) southwest of the suspected location
of the central star, implying that the embedded star has a mass less than 1
Solar mass .Comment: 20 pages, 4 figure
SNS programming environment user's guide
The computing environment is briefly described for the Supercomputing Network Subsystem (SNS) of the Central Scientific Computing Complex of NASA Langley. The major SNS computers are a CRAY-2, a CRAY Y-MP, a CONVEX C-210, and a CONVEX C-220. The software is described that is common to all of these computers, including: the UNIX operating system, computer graphics, networking utilities, mass storage, and mathematical libraries. Also described is file management, validation, SNS configuration, documentation, and customer services
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