962 research outputs found
The effects of training on errors of perceived direction in perspective displays
An experiment was conducted to determine the effects of training on the characteristic direction errors that are observed when subjects estimate exocentric directions on perspective displays. Changes in five subjects' perceptual errors were measured during a training procedure designed to eliminate the error. The training was provided by displaying to each subject both the sign and the direction of his judgment error. The feedback provided by the error display was found to decrease but not eliminate the error. A lookup table model of the source of the error was developed in which the judgement errors were attributed to overestimates of both the pitch and the yaw of the viewing direction used to produce the perspective projection. The model predicts the quantitative characteristics of the data somewhat better than previous models did. A mechanism is proposed for the observed learning, and further tests of the model are suggested
Savage and Bloody Footsteps Through the Valley : The Wyoming Massacre in the American Imagination
Along the banks of the Susquehanna River in early July 1778, a force of about 600 Loyalist and Native American raiders won a lopsided victory against 400 overwhelmed Patriot militiamen and regulars in the Wyoming Valley of Pennsylvania. While not well-known today, this battleāthe Battle of Wyomingāhad profound effects on the Revolutionary War and American culture and politics. Quite familiar to early Americans, this battleās remembrance influenced the formation of national identity and informed Americansā perceptions of their past and present over the course of the eighteenth and nineteenth centuries.
From the beginning, however, Americansā understanding of what occurred in the Wyoming Valley in July 1778 was strongly influenced by reports from partisans not present at the battle, reports which wildly differed from eyewitness accounts. In the aftermath of the battle, a fabricated myth about Loyalists and Native Americans massacring women, children, and wounded soldiers quickly took root in the public imagination and influenced the Patriot war effort. Despite having no evidence backing it up, the myth eventually outlasted its Revolutionary context, coming back to shape political dialogue and popular culture in the early nineteenth century. Indeed, this Revolutionary fabrication was only the beginning of the historical distortion related to the Battle of Wyoming. By mid-century, a whole new myth about the battle arose, featuring a Native American woman known as Queen Esther who murdered prisoners around a rock. Made possible by the cultural atmosphere of the period, this myth proved equally sensational.
This thesis explores how these myths about the battle formed, spread, and influenced American society on national and local levels from 1778 to around 1878. Tracing and analyzing how Americans have remembered and misremembered the Battle of Wyoming, more popularly known as the Wyoming Massacre, its primary focus is to look at the meaning behind the narratives that formed around this event and what those meanings say about the individuals and cultures that created them. It also scrutinizes some of the ways Americans have tailored their remembrances of Wyoming to speak to their present. Ultimately, this thesis points to how historical distortions can easily enmesh themselves into popular memory and how they can influence national and local identities
Sex ratios at birth vary with environmental harshness but not maternal condition
The sex ratio at birth (SRB) may be patterned by maternal condition and/or environmental stressors. However, despite decades of research, empirical results from across the social and biological sciences are equivocal on this topic. Using longitudinal individual-level data from a US population during the interwar period (1918Ć¢ā¬ā1939), inclusive of three distinct eras (Spanish Flu, Roaring Ć¢ā¬Ė20Ć¢ā¬ā°s, and the Great Depression), we evaluate predictions from two theoretical frameworks used to study patterning in SRB Ć¢ā¬ā (1) Ć¢ā¬Ėfrail malesĆ¢ā¬ā¢ and (2) adaptive sex-biased investment theory (Trivers-Willard). The first approach centers on greater male susceptibility to exogenous stressors and argues that offspring survival should be expected to differ between Ć¢ā¬ĖgoodĆ¢ā¬ā¢ and Ć¢ā¬ĖbadĆ¢ā¬ā¢ times. The second approach contends that mothers themselves play a direct role in manipulating offspring SRB, and that those in better condition should invest more in sons. In-line with Ć¢ā¬Ėfrail maleĆ¢ā¬ā¢ predictions, we find that boys are less likely to be born during the environmentally challenging times of the Spanish Flu and Great Depression. However, we find no evidence that maternal condition is associated with sex ratios at birth, a result inconsistent with the Trivers-Willard hypothesis
Teaching Guide for Ninth Grade General Science
General science became a part of the curriculum in the early part of the century to satisfy the needs of those students who had to leave school before taking the high school science courses. Its secondary function was a foundation for later study. This report is concerned with the present role of general science in the modern secondary school, and its need for imporvement to meet the aims for such a course in a modern secondary school. This report presents a teaching guide in four parts (1) a general outline of the course, (2) laboratory activities, (3) supplementary material composed of industrial literature and audio-visual materials, and (4) a bibliography of outside reading. Although the course is a composite of several courses, it is taught as though it were one course with each major subject treated as a unit. These units are correlated in such a way as to present the science of the environment. There is an abundance of industrial literature available to illustrate the use of the basic scientific principles. The addition of these materials to the curriculum gives an effective, modern science course for all students.Natural Scienc
Endobronchial Perineurioma: An Unusual Soft Tissue Lesion in an Unreported Location
We report the first case of an endobronchial perineurioma, a rare benign neoplasm typically occurring in soft tissue. A 53-year-old nonsmoking female presented with a three-month history of persistent bronchitis. A CT scan followed by bronchoscopy demonstrated an endobronchial lesion involving the left mainstem bronchus. Removal of the lesion by bronchoscopy was accomplished. The tumor was composed of bland spindle cells in a variably collagenized stroma. These cells had long cytoplasmic processes. No mitotic activity or necrosis was observed. Neoplastic cells were immunoreactive for epithelial membrane antigen (EMA), CD34, and claudin-1. Smooth muscle actin (SMA), desmin, and S-100 immunostains were all negative. Based on the morphologic appearance and immunophenotype, a diagnosis of perineurioma was rendered
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Simulation of barrier heterogeneity and preferential flow effects on the performance of shallow land burial facilities
Compacted soil barriers constructed at landfill sites have some degree of heterogeneity in hydraulic properties that may lead to a decline in barrier integrity and performance. A computer modeling study of the water dynamics of compacted soil barriers for a mesic site in eastem Tennessee was undertaken to identify possible situations that could lead to barrier failure. A water dynamics model for soil-plant systems (UTM) was applied to three landful construction scenarios, and varying degrees of heterogeneity of hydraulic properties for the cap and liner were introduced with a scaling procedure. Simulations were conducted for three annual contrasting rainfall conditions, and sensitivity analysis and Monte Carlo methods were used in the investigation
Just picking it up? Young children learning with technology at home
We describe a two-year empirical investigation of three- and four-year-old children's uses of technology at home, based on a survey of 346 families and 24 case studies. Using a sociocultural approach, we discuss the range of technologies children encounter in the home, the different forms their learning takes, the roles of adults and other children, and how family practices support this learning. Many parents believed that they do not teach children how to use technology. We discuss parents' beliefs that their children 'pick up' their competences with technology and identify trial and error, copying and demonstration as typical modes of learning. Parents tend to consider that their children are mainly self-taught and underestimate their own role in supporting learning and the extent to which learning with technology is culturally transmitted within the family
Roles of residues 3 and 4 in cyclic tetrapeptide ligand recognition by the Ī -opioid receptor
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75723/1/j.1399-3011.2005.00220.x.pd
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