1,944 research outputs found
Hidden in Plain Sight: Homeless Students In America's Public Schools
Student homelessness is on the rise, with more than 1.3 million homeless students identified during the 2013-14 school year. This is a 7 percent increase from the previous year and more than double the number of homeless students in 2006-07. As high as these numbers seem, they are almost certainly undercounts.Despite increasing numbers, these students - as well as the school liaisons and state coordinators who support them - report that student homelessness remains an invisible and extremely disruptive problem.Students experiencing homelessness struggle to stay in school, to perform well, and to form meaningful connections with peers and adults. Ultimately, they are much more likely to fall off track and eventually drop out of school more often than their non-homeless peers.This study:provides an overview of existing research on homeless students,sheds light on the challenges homeless students face and the supports they say they need to succeed,reports on the challenges adults - local liaisons and state coordinators - face in trying to help homeless students, andrecommends changes in policy and practice at the school, community, state and national level to help homeless students get on a path to adult success.This is a critical and timely topic. The recent reauthorization of the Every Student Succeeds Act (ESSA) provides many new and stronger provisions for homeless students (effective Oct. 1, 2016); requires states, district and schools for the first time to report graduation rates for homeless students (effective beginning with the 2016-17 school year); and affirms the urgency and importance of dealing with homelessness so that all children can succeed
Evaluation of Hybrid-III 6YO ATD chest jacket shape and position
In previous work, belt fit on the Hybrid-III six-year-old (6YO) anthropomorphic test device (ATD) was found to depend on the positioning of the chest jacket of the ATD. Moreover, differences were noted between jackets manufactured by Denton-ATD and First Technology Safety Systems (FTSS). The objective of this study was to quantify differences between the manufacturers’ jackets by detailed measurements of exemplar jackets and to assess the effects of jacket installation procedure on jacket position.
A custom fixture was designed to hold rigidly the thorax, pelvis, and head of a 6YO ATD while allowing the chest jacket to be installed and removed. Testing was conducted with two jackets from FTSS and one from Denton. In pilot testing, jacket position was affected by the installation procedure and by the initial position of the shoulder components. Detailed measurements were made using a portable surface measurement device (laser
scanner) with each jacket in six conditions defined by initial shoulder position and the manner in which the jacket was installed. Quantitative comparisons in jacket position and shape were conducted in software using the laserscan data. Notable differences in jacket shape were observed between the FTSS and Denton jackets, with the FTSS jacket having a wider, flatter profile in the lateral shoulder area and the Denton jacket extending more forward in the upper chest area. However, the effects of jacket positioning were much larger than differences between manufacturers in jacket shape. Pulling the jacket down firmly resulted in jacket shoulder positions relative to the spine differing by more than 25 mm from those obtained by pulling the jacket down lightly, with results dependent on the initial positions of the shoulder components.
The results of this study indicate that careful attention to jacket positioning is needed to obtain a consistent relationship between the chest and shoulder surfaces and the ATD skeleton. Pulling the jacket down firmly after initially placing the shoulder components in a downward/rearward position is suggested. Monitoring and adjusting the location of reference points on the jacket relative to specified hard points on the ATD skeletonprovides a means for ensuring that the jacket is consistently placed for static or dynamic testing.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89865/1/102811.pd
Resuscitation of the trauma patient: tell me a trigger for early haemostatic resuscitation please!
The management of trauma-related coagulopathy and haemorrhage is changing from a reactive strategy to a proactive early intervention with blood products and haemostatic agents. Although major haemorrhage and massive transfusion are associated with higher mortality, the pattern of this association with modern trauma care is poorly described. In addition, early predictors of massive transfusion, which might trigger a proactive haemostatic resuscitation strategy, are not currently available. We review recent literature relating to predictors of massive transfusions and the relationship between transfusion and mortality
Net Returns for Grain Sorghum and Corn under Alternative Irrigation Systems in Western Kansas
This study evaluates seven irrigation systems for use in production of grain sorghum and corn. These systems are medium pressure center-pivot (MPCP), low pressure center-pivot (LPCP), low drift nozzle center-pivot (LDN) , low energy precision application center-pivot (LEPA), furrow flood (FF) , surge flood (SF), and subsurface drip (SD). After-tax net present value estimates from investing in and using each system over a 10-year period to produce grain sorghum and corn are compared. The surge flood system, has the highest net returns under typical conditions for irrigation of both grain sorghum and corn. The furrow flood system generates the next highest net returns for both crops, followed by the subsurface drip system. The medium pressure center-pivot system is the least profitable for both crops. Of the center-pivot systems, the low pressure system has the highest net return, but is followed very closely by the low drift nozzle system. The results of the sensitivity analysis indicate that the net return estimates and ranking of the subsurface drip system are very sensitive to the yield response to irrigation. Lower than average crop prices also have a substantial impact on the ranking of this system. The original investment cost is also an important determinant of its net return.Crop Production/Industries,
Effects of obesity on seat belt fit
Obesity has been shown to increase the risk of some types of injury in crashes. One hypothesis is that obesity adversely effects belt fit by changing the routing of the belt relative to the underlying skeletal structures. To evaluate this hypothesis, belt fit was measured in a laboratory study of 54 men and women, 48 percent of whom
were obese, with a body mass index (BMI) of 30 kg/m2 or greater. Test conditions included a wide range of upper and lower belt anchorage locations and ranges of seat height, seat cushion angle, and seat back angle spanning a large fraction of current vehicle front and rear seats. In some conditions, foot position was restricted
to simulate the typical situation in the second row of a small sedan. Across individuals, an increase in BMI of
10-kg/m2 was associated with a lap belt positioned 43 mm further forward and 21 mm higher relative to the anterior-superior iliac spines of the pelvis. Each 10-kg/m2 increase in BMI was associated with an increase in lap belt webbing length of 130 mm. The worsening of lap belt fit with restricted foot position was slightly greater
for obese participants. Obesity was associated with a more-inboard shoulder belt routing across a wide range of upper belt anchorage locations, and the shoulder belt webbing length between the D-ring and latchplate increased by an average of 60 mm with each 10-kg/m2 increase in BMI. The results suggest that obesity effectively
introduces slack in the seat belt system by routing the belt further away from the skeleton. Particularly in frontal
crashes, but also in rollovers and other scenarios, this slack will result in increased excursions and an increased
likelihood and severity of contacts with the interior. The higher routing of the lap belt with respect to the pelvis also increases the likelihood of submarining in frontal crashes.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89867/1/102813.pd
Comparison of child body dimensions with rear seat geometry
2006 SAE World Congress, Detroit, Michigan, April 3-6, 2006Children who are too large for harness restraints but too small to obtain good restraint from a vehicle seatbelt alone should be seated in a belt-positioning booster. Boosters have been shown to significantly reduce abdominal injuries caused by seatbelts. This effectiveness may be due in part to the fact that boosters reduce the effective seat cushion length, allowing children to sit more comfortably without slouching. NHTSA recommends that children who do not use harness restraints use boosters until they are at least 145 cm tall. In this paper, data from several sources were combined to assess how well children fit on rear seat cushions. Data from NASS-GES were analyzed to determine the age distribution of rear-seat occupants. Anthropometric data from several sources were analyzed to determine the distribution of buttock-popliteal length, a measure of thigh length that is a key determinant of seat fit, as a function of age and gender. Second- and third-row cushion lengths were measured on a convenience sample of 56 late-model vehicles. Comparing the distribution of body size for rear-seat occupants with the seat cushion lengths showed that most cushions are too long for most rear-seat occupants, using commonly applied standards of seat fit. Given that most rear-seat occupants in the U.S. are children, rear-seat design standards should consider the smaller body dimensions and different restraint needs of this population.http://deepblue.lib.umich.edu/bitstream/2027.42/65015/1/102222.pd
Improving the repeatability and reproducibility of belt fit measurement with 6YO and 10YO ATDs
In previous work, researchers at the University of Michigan Transportation Research Institute (UMTRI) developed a method for quantifying the belt fit provided by belt-positioning boosters by measuring the belt location relative to the six- and ten-year-old Hybrid-III dummies. In another study, the torso and lap belt scores
obtained by this method were found to be closely related to the belt fit obtained by similar-size children across a wide range of booster and belt conditions. The Insurance Institute for Highway Safety (IIHS) adapted the UMTRI procedure to develop a rating system for booster belt fit, but adoption by other labs has been slowed by difficulty in obtaining repeatable results.
The current study was undertaken to improve the repeatability and reproducibility across operators of the procedure. The modifications made by IIHS were studied and most incorporated, and a number of other issues were examined through pilot testing. A revised version of the procedure was tested with repeated measurements
by three operators in six boosters. The results were analyzed to quantify the variance associated with the operators, the installation of the booster and dummy, and the routing of the belt.
The results show that trained operators can perform the procedure with minimal systematic bias across boosters.
The variability within booster varies considerably, with some boosters producing higher precision measurements due to the design of their belt-routing features. For any particular booster, the booster and dummy installation process accounts for about half the variability in the belt fit scores with the remainder due to variability in the belt routing and other measurement variability.
Based on these findings, multiple measurements of belt fit in each booster are recommended to establish the desired level of confidence in the true belt fit. Straightforward statistical methods involving confidence intervals are recommended for establishing objective test methods. More testing will be needed to determine the reproducibility of the method across laboratories.National Highway Traffic Safety Administrationhttp://deepblue.lib.umich.edu/bitstream/2027.42/89866/1/102812.pd
Core excitations across the neutron shell gap in ²⁰⁷Tl
The single closed-neutron-shell, one proton-hole nucleus 207Tl was populated in deep-inelastic collisions of a 208Pb beam with a 208Pb target. The yrast and near-yrast level scheme has been established up to high excitation energy, comprising an octupol
Dynamical locality of the nonminimally coupled scalar field and enlarged algebra of Wick polynomials
We discuss dynamical locality in two locally covariant quantum field
theories, the nonminimally coupled scalar field and the enlarged algebra of
Wick polynomials. We calculate the relative Cauchy evolution of the enlarged
algebra, before demonstrating that dynamical locality holds in the nonminimally
coupled scalar field theory. We also establish dynamical locality in the
enlarged algebra for the minimally coupled massive case and the conformally
coupled massive case.Comment: 39p
Development of surrogate child restraints for testing occupant sensing and classification systems
This paper describes the design and development of a family of surrogate child restraints that are intended for
use in developing and testing occupant sensing and classification systems. Detailed measurements were made of the geometry and mass distribution characteristics of 34 commercial child restraints, including infant restraints, convertibles, combination
restraints, and boosters. The restraints were installed in three test seats with appropriately sized crash dummies to obtain data on seat-surface pressure patterns and the position and orientation of the restraint with belt loading. The data were used to construct two surrogates with
removable components. The convertible surrogate can be used to represent a rear-facing infant restraint with or
without a base, a rear-facing convertible, or a forwardfacing convertible. The booster surrogate can represent a high-back belt-positioning booster, a backless booster,
or a forward-facing-only restraint with a five-point harness. The surrogates were designed to meet geometric and mass targets obtained by taking the mean values for analogous dimensions in each of the restraint
categories. Data analyses showed that the dimensions and performance of the surrogates are quantitatively representative of the commercial restraints.http://deepblue.lib.umich.edu/bitstream/2027.42/65014/1/97843_A07.pd
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