2,871 research outputs found
Chrysomelidae of Arkansas
A list of Chrysomelidae of Arkansas is brought up to date by inclusion of species in the reference collection in the University of Arkansas, the collection in the Zoological Institute of Leningrad, and the private collection of L. Medvedev, as well as those reported in the literature. The list consists of 232 species, subspecies, and varieties and the ecological data where known. One new species and one new variety are included
Do Accountability and Voucher Threats Improve Low-Performing Schools?
In this paper we study the effects of the threat of school vouchers and school stigma in Florida on the performance of "low-performing" schools using student-level data from a subset of districts. Estimates of the change in school-level high-stakes test scores from the first year of the reform are consistent with the early results used by the state of Florida to claim large-scale improvements associated with the threat of voucher assignment. However, we also find that much of this estimated effect may be due to other factors. While we estimate a small relative improvement in reading scores on the high-stakes test for voucher-threatened/stigmatized schools, we estimate a much smaller relative improvement on a lower-stakes, nationally norm-referenced, test. Further, the relative gains in reading scores are explained largely by changing student characteristics. We find more evidence for a positive differential effect on math test scores on both the low- and highstakes tests, however, the results from the lower-stakes test appear primarily limited to students in the high-stakes grade. Finally, we find some evidence that the relative improvements following the introduction of the A Plan by low-performing schools were more due to the stigma of receiving the low grade rather than the threat of vouchers.
Postbuckling behavior of graphite-epoxy panels
Structurally efficient fuselage panels are often designed to allow buckling to occur at applied loads below ultimate. Interest in applying graphite-epoxy materials to fuselage primary structure led to several studies of the post-buckling behavior of graphite-epoxy structural components. Studies of the postbuckling behavior of flat and curved, unstiffened and stiffened graphite-epoxy panels loaded in compression and shear were summarized. The response and failure characteristics of specimens studied experimentally were described, and analytical and experimental results were compared. The specimens tested in the studies described were fabricated from commercially available 0.005-inch-thick unidirectional graphite-fiber tapes preimpregnated with 350 F cure thermosetting epoxy resins
Assessment ‘ResponsAbilities’ in the Basic Course: Evaluating Public Speaking Rubrics
Procedures and practices that are ableist in the educational system have been long overlooked. Speakers having differing abilities than neurotypical or able-bodied individuals is often not something that is considered in basic course assessment tools. This is important to address because although there are institutional policies and procedures in place to help students with differing abilities, instructors of public speaking have the autonomy or power to determine how such accommodations will affect the speech grade determined by the assessment tool. Power relations are significantly complicated in educational settings when strict hierarchies are imposed, and when instructors abuse their authority, which might lead to unequal power dynamics, especially at the beginning of a course, because the instructor holds power in shaping the course. Additionally, since assessment tools such as rubrics reinforce societal norms, they can also encourage bias from the instructor (Ashby-King et al., 2021). This analysis will examine current assessment tools used by instructors in the public speaking course from a critical disability lens paired with rhetorical content analysis to uncover ableist perspectives
Using Margin Elevation with Bonded Ceramics: A Case Report.
PosterThirty years ago, glass ionomer was first used as a means of bonding resin matrix composite to dentin. Today this method is used to elevate the margin of a preparation to a level which gives the clinician more access to the operating field. This technique has been described in the dental literature with resin composites bonded with resin adhesives. There are still inherent problems with this approach, however, since resin adhesives are subject to hydrolysis, marginal leakage, and recurrent caries. Studies have demonstrated the ability of glass ionomer to chemically bond to dentin; glass ionomer can also be dissolved/etched by phosphoric acid and predictably bonded to resin composites, eliminating the problem of hybrid layer hydrolysis which occurs with resin bonding agents. Margin elevation takes advantage of the favorable properties of glass ionomer cements (adhesion through chemical bond to dentin, fluoride release, biocompatibility, coefficient of thermal expansion similar to tooth structure, and decreased interfacial bacteria penetration/caries activity) while allowing overlaying of a suitable direct or indirect restorative material. This technique should be utilized when a preparation stands an increased risk of contamination or has a gingival margin on dentin/cementum. This case describes restoration of a tooth with a deep subgingival margin located on cervical dentin. The tooth was prepared for a ceramic onlay. Resin-modified glass ionomer was then inserted into the mesial proximal box and re-prepared with the occlusal wall of the glass ionomer becoming the new gingival margin, allowing significantly increased access and isolation. The tooth was then restored with an e.max onlay and cemented with RelyX Unicem. The restoration has been examined at a 6-month recall. With proper case selection and attention to detail, glass ionomer margin elevation is an excellent technique for bonding ceramics to teeth which cannot be isolated adequately for impression and/or resin bonding
Psychological Issues in Online Adaptive Task Allocation
Adaptive aiding is an idea that offers potential for improvement over many current approaches to aiding in human-computer systems. The expected return of tailoring the system to fit the user could be in the form of improved system performance and/or increased user satisfaction. Issues such as the manner in which information is shared between human and computer, the appropriate division of labor between them, and the level of autonomy of the aid are explored. A simulated visual search task was developed. Subjects are required to identify targets in a moving display while performing a compensatory sub-critical tracking task. By manipulating characteristics of the situation such as imposed task-related workload and effort required to communicate with the computer, it is possible to create conditions in which interaction with the computer would be more or less desirable. The results of preliminary research using this experimental scenario are presented, and future directions for this research effort are discussed
Pilot interaction with automated airborne decision making systems
The use of advanced software engineering methods (e.g., from artificial intelligence) to aid aircraft crews in procedure selection and execution is investigated. Human problem solving in dynamic environments as effected by the human's level of knowledge of system operations is examined. Progress on the development of full scale simulation facilities is also discussed
Pilot interaction with automated airborne decision making systems
Two project areas were pursued: the intelligent cockpit and human problem solving. The first area involves an investigation of the use of advanced software engineering methods to aid aircraft crews in procedure selection and execution. The second area is focused on human problem solving in dynamic environments, particulary in terms of identification of rule-based models land alternative approaches to training and aiding. Progress in each area is discussed
Neural reconstruction of bone-eating <i>Osedax</i> spp. (Annelida) and evolution of the siboglinid nervous system
BACKGROUND: Bone-devouring Osedax worms were described over a decade ago from deep-sea whale falls. The gutless females (and in one species also the males) have a unique root system that penetrates the bone and nourishes them via endosymbiotic bacteria. Emerging from the bone is a cylindrical trunk, which is enclosed in a transparent tube, that generally gives rise to a plume of four palps (or tentacles). In most Osedax species, dwarf males gather in harems along the female’s trunk and the nervous system of these microscopic forms has been described in detail. Here, the nervous system of bone-eating Osedax forms are described for the first time, allowing for hypotheses on how the abberant ventral brain and nervous system of Siboglinidae may have evolved from a ganglionated nervous system with a dorsal brain, as seen in most extant annelids. RESULTS: The intraepidermal nervous systems of four female Osedax spp. and the bone-eating O. priapus male were reconstructed in detail by a combination of immunocytochemistry, CLSM, histology and TEM. They all showed a simple nervous system composed of an anterior ventral brain, connected with anteriorly directed paired palp and gonoduct nerves, and four main pairs of posteriorly directed longitudinal nerves (2 ventral, 2 ventrolateral, 2 sets of dorso-lateral, 2 dorsal). Transverse peripheral nerves surround the trunk, ovisac and root system. The nervous system of Osedax resembles that of other siboglinids, though possibly presenting additional lateral and dorsal longitudinal nerves. It differs from most Sedentaria in the presence of an intraepidermal ventral brain, rather than a subepidermal dorsal brain, and by having an intraepidermal nerve cord with several plexi and up to three main commissures along the elongated trunk, which may comprise two indistinct segments. CONCLUSIONS: Osedax shows closer neuroarchitectural resemblance to Vestimentifera + Sclerolinum (= Monilifera) than to Frenulata. The intraepidermal nervous system with widely separated nerve cords, double brain commissures, double palp nerves and other traits found in Osedax can all be traced to represent ancestral states of Siboglinidae. A broader comparison of the nervous system and body regions across Osedax and other siboglinids allows for a reinterpretation of the anterior body region in the group
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