3,596 research outputs found
A Program Evaluation of the Document-Based Question Project
Only 1% of students scored in the exceeding range on the Eighth Grade Writing Assessment in a rural Southeastern school district. The purpose of this program evaluation was to explore the effectiveness of the Document-Based Question (DBQ) project in improving student writing. Using interview protocols, work artifacts, and archival student data, a decision-based program evaluation of the DBQ project was conducted using the CIPP model. Administrators and teachers from elementary and middle schools who attended district DBQ project training were invited to participate in this study. One elementary and 1 middle school administrator, 5 elementary teachers, and 7 middle school teachers were selected to participate to create a balanced representation across grade levels. Using the Coding Analysis Toolkit (CAT), interview responses about context, input, process, and product evaluation were analyzed. Analysis of patterns in the data identified 10 strengths and 10 opportunities for improvement of the DBQ project, and led to 6 suggested recommendations to create a more customized fit for its implementation in the school system under study. Overall, it was determined that the DBQ project is an effective program for improving student-constructed responses in writing; it was also determined that expository writing skills of students in Grades 3 through 8 can be improved with explicit instruction in thesis development and text citation supporting ideas. Impacts on social change include students\u27 improvements in formulation, justification, and communication of opinions and the ability to revise positions or demonstrate tolerance for ideas opposing their own. School officials and teachers will benefit from the study results as they continue seeking and refining ways to improve student writing through the use of the DBQ project
Coal Blooded Action Toolkit
With this toolkit, your community now has the necessary framework and tools to build a foundation for eliminating pollution from coal, one of the most important steps we can take, in our march to advance Environmental and Climate Justice. Whether you are a leader, partner or participant in a coal campaign, your role is critical to creating change. By following the modules in the Coal Blooded Action Toolkit, your unit will experience writing letters to decision makers, using the media to advance your cause, organizing community meetings, negotiating with plant owners, etc., towards the ends of reduction of harmful pollution, improving health outcomes, increasing investment in energy efficiency and renewable energy, creating sustainable, healthy jobs/careers, and more. These activities were designed for communities to succeed and most importantly, use them as tools to do so
On the metric dimension of corona product graphs
Given a set of vertices of a connected graph , the
metric representation of a vertex of with respect to is the vector
, where ,
denotes the distance between and . is a resolving set for if
for every pair of vertices of , . The metric
dimension of , , is the minimum cardinality of any resolving set for
. Let and be two graphs of order and , respectively. The
corona product is defined as the graph obtained from and by
taking one copy of and copies of and joining by an edge each
vertex from the -copy of with the -vertex of . For any
integer , we define the graph recursively from
as . We give several results on the metric
dimension of . For instance, we show that given two connected
graphs and of order and , respectively, if the
diameter of is at most two, then .
Moreover, if and the diameter of is greater than five or is
a cycle graph, then $dim(G\odot^k H)=n_1(n_2+1)^{k-1}dim(K_1\odot H).
Standing Self-Manipulation for a Legged Robot
On challenging, uneven terrain a legged robotâs open loop posture will almost inevitably be inefficient, due to uncoordinated support of gravitational loads with coupled internal torques. By reasoning about certain structural properties governing the infinitesimal kinematics of the closed chains arising from a typical stance, we have developed a computationally trivial self-manipulation behavior that can minimize both internal and external torques absent any terrain information. The key to this behavior is a change of basis in torque space that approximates the partially decoupled nature of the two types of disturbances. The new coordinates reveal how to use actuator current measurements as proprioceptive sensors for the approximate gradients of both the internal and external task potential fields, without recourse to further modeling. The behavior is derived using a manipulation framework informed by the dual relationship between a legged robot and a multifingered hand. We implement the reactive posture controller resulting from simple online descent along these proprioceptively sensed gradients on the X-RHex robot to document the significant savings in standing power.
For more information: Kod*La
Disturbance Detection, Identification, and Recovery by Gait Transition in Legged Robots
We present a framework for detecting, identifying, and recovering within stride from faults and other leg contact disturbances encountered by a walking hexapedal robot. Detection is achieved by means of a software contactevent sensor with no additional sensing hardware beyond the commercial actuatorsâ standard shaft encoders. A simple finite state machine identifies disturbances as due either to an expected ground contact, a missing ground contact indicating leg fault, or an unexpected âwallâ contact. Recovery proceeds as necessary by means of a recently developed topological gait transition coordinator. We demonstrate the efficacy of this system by presenting preliminary data arising from two reactive behaviors â wall avoidance and leg-break recovery. We believe that extensions of this framework will enable reactive behaviors allowing the robot to function with guarded autonomy under widely varying terrain and self-health conditions
Hydroxyurea and zileuton differentially modulate cell proliferation and interleukin-2 secretion by murine spleen cells: Possible implication on the immune function and risk of pain crisis in patients with sickle cell disease
Background: Hydroxyurea (HU) reduces major complications associated with sickle cell disease in part because of the induction of fetal hemoglobin. However, because of its antiproliferative property, its long-term use may impair immunity. Zileuton, a derivative of HU, also induces fetal hemoglobin and has antiinflammatory properties, a feature that can reduce the risk of sickling. Our goal was to investigate the capacity of both drugs to modulate the secretion of interleukin-2 (IL-2), a regulatory cytokine for immune responses. Methods: Spleen cells obtained from 11 4-month-old C57BL/6 female mice were incubated without and with 10 ”/mL HU or zileuton, 2.5 ”/mL concanavalin A (ConA), 20 ”/mL phytohemagglutinin (PHA), and 50 ng/mL anti-CD3 antibody for 12-48 h. IL-2 was measured in the supernatant by enzyme-linked immunosorbent assay and cell proliferation byH-thymidine uptake. Results: While HU reduced lymphocyte proliferation in response to mitogens (
Education of Children with Disabilities: Voices from Around the World
Education of Children with Disabilities: Voices from Around the World combines research on children with disabilities and women/girls with disabilities. These projects provided opportunities to interview disability professionals, policy-makers and persons with disabilities from around the world with the purpose of learning about needs, issues and services, in diverse countries. A unique international analysis, this research compares various cultural responses on the education of children with disabilities emphasizing the girl child. Discussion includes findings based on 177 interviews of disability professionals from over 57 countries including the stated reasons and consequences of lost educational opportunities. Techniques locating participants included internet searches, literature reviews, and personal referrals. Interviewees were selected based on their experiences with childhood disabilities and/or women and girls with disabilities. Many interviewees were persons with disabilities who shared their personal experiences.
Through a qualitative analysis of the interviews some of the most prevalent themes that emerged were the importance of education and the disproportionate negative effect of disability on females. To measure the strength of these themes, an electronic survey was created using a Likert scale to measure the strength of agreement of each participant with the issues identified. Survey ratings added quantitative confirmation to the rich qualitative interviews. The education themes identified include school exclusion and barriers to education with a particular focus on the girl child, education quality and inclusive education
Gas, Stars, and Star Formation in ALFALFA Dwarf Galaxies
We examine the global properties of the stellar and H I components of 229 low H_I mass dwarf galaxies extracted from the ALFALFA survey, including a complete sample of 176 galaxies with H_I masses <10^(7.7) M_â and H_I line widths <80 km s^(â1). Sloan Digital Sky Survey (SDSS) data are combined with photometric properties derived from Galaxy Evolution Explorer to derive stellar masses (M_*) and star formation rates (SFRs) by fitting their UV-optical spectral energy distributions (SEDs). In optical images, many of the ALFALFA dwarfs are faint and of low surface brightness; only 56% of those within the SDSS footprint have a counterpart in the SDSS spectroscopic survey. A large fraction of the dwarfs have high specific star formation rates (SSFRs), and estimates of their SFRs and M_* obtained by SED fitting are systematically smaller than ones derived via standard formulae assuming a constant SFR. The increased dispersion of the SSFR distribution at M_* âČ 10^8 M_â is driven by a set of dwarf galaxies that have low gas fractions and SSFRs; some of these are dE/dSphs in the Virgo Cluster. The imposition of an upper H_I mass limit yields the selection of a sample with lower gas fractions for their M_* than found for the overall ALFALFA population. Many of the ALFALFA dwarfs, particularly the Virgo members, have H_I depletion timescales shorter than a Hubble time. An examination of the dwarf galaxies within the full ALFALFA population in the context of global star formation (SF) laws is consistent with the general assumptions that gas-rich galaxies have lower SF efficiencies than do optically selected populations and that H_I disks are more extended than stellar ones
Approximation Algorithms for the Capacitated Domination Problem
We consider the {\em Capacitated Domination} problem, which models a
service-requirement assignment scenario and is also a generalization of the
well-known {\em Dominating Set} problem. In this problem, given a graph with
three parameters defined on each vertex, namely cost, capacity, and demand, we
want to find an assignment of demands to vertices of least cost such that the
demand of each vertex is satisfied subject to the capacity constraint of each
vertex providing the service. In terms of polynomial time approximations, we
present logarithmic approximation algorithms with respect to different demand
assignment models for this problem on general graphs, which also establishes
the corresponding approximation results to the well-known approximations of the
traditional {\em Dominating Set} problem. Together with our previous work, this
closes the problem of generally approximating the optimal solution. On the
other hand, from the perspective of parameterization, we prove that this
problem is {\it W[1]}-hard when parameterized by a structure of the graph
called treewidth. Based on this hardness result, we present exact
fixed-parameter tractable algorithms when parameterized by treewidth and
maximum capacity of the vertices. This algorithm is further extended to obtain
pseudo-polynomial time approximation schemes for planar graphs
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