Body image in middle school students

This study was conducted to investigate the body images of Middle School aged students. A population of 62 students (37 males, 25 females) was given a survey that questioned their level of body image, their practice of weight-control behaviors, and the various potential influences on these areas. The results showed that this particular population had a higher level of body image than previous studies indicate. It also showed that students at this age are engaging in weight-control behaviors. The major influences on body image and weight-control behaviors were found to be peers and the media. This research, along with previous studies, implicates the need for prevention and intervention programs at this age level

A neural network controller for automated composite manufacturing

At McDonnell Douglas Aerospace (MDA), an artificial neural network based control system has been developed and implemented to control laser heating for the fiber placement composite manufacturing process. This neurocontroller learns an approximate inverse model of the process on-line to provide performance that improves with experience and exceeds that of conventional feedback control techniques. When untrained, the control system behaves as a proportional plus integral (PI) controller. However after learning from experience, the neural network feedforward control module provides control signals that greatly improve temperature tracking performance. Faster convergence to new temperature set points and reduced temperature deviation due to changing feed rate have been demonstrated on the machine. A Cerebellar Model Articulation Controller (CMAC) network is used for inverse modeling because of its rapid learning performance. This control system is implemented in an IBM compatible 386 PC with an A/D board interface to the machine

Local Area Damage Detection in Composite Structures Using Piezoelectric Transducers

An integrated and automated smart structures approach for structural health monitoring is presented, utilizing an array of piezoelectric transducers attached to or embedded within the structure for both actuation and sensing. The system actively interrogates the structure via broadband excitation of multiple actuators across a desired frequency range. The structure's vibration signature is then characterized by computing the transfer functions between each actuator/sensor pair, and compared to the baseline signature. Experimental results applying the system to local area damage detection in a MD Explorer rotorcraft composite flexbeam are presented.Comment: 7 page

The ion-beam reactive sputtering process for deposition of niobium nitride thin films

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1990.Vita.Includes bibliographical references (leaves 284-290).by Daniel Jenner Lichtenwalner.Ph.D

Avian oncogenesis induced by lymphoproliferative disease virus: a neglected or emerging retroviral pathogen?

Lymphoproliferative disease virus (LPDV) is an exogenous oncogenic retrovirus that induces lymphoid tumors in some galliform species of birds. Historically, outbreaks of LPDV have been reported from Europe and Israel. Although the virus has previously never been detected in North America, herein we describe the widespread distribution, genetic diversity, pathogenesis, and evolution of LPDV in the United States. Characterization of the provirus genome of the index LPDV case from North America demonstrated an 88% nucleotide identity to the Israeli prototype strain. Although phylogenetic analysis indicated that the majority of viruses fell into a single North American lineage, a small subset of viruses from South Carolina were most closely related to the Israeli prototype. These results suggest that LPDV was transferred between continents to initiate outbreaks of disease. However, the direction (New World to Old World or vice versa), mechanism, and time frame of the transcontinental spread currently remain unknown

ECHINOCOCCUS GRANULOSUS GENOTYPE G8 IN MAINE MOOSE (ALCES ALCES)

During a 2012 survey of harvested moose (Alces alces) in Maine (USA), an incidental finding of hydatid cysts was found in 39% (21 of 54) of lung sets examined. Cytology of cyst contents was consistent with Echinococcus granulosus. The G8 genotype was identified based on PCR and DNA sequencing of a 470 base pair region of the NADH dehydrogenase subunit 1 (NAD1) mitochondrial gene. The hydatid cysts were the northern, or cervid genotype and this is the first confirmed report of E. granulosus in Maine moose. The Atlantic regions of the northern USA and Canada were not previously thought to be endemic regions for E. granulosus. It is presumed that either domestic dogs or eastern coyotes (Canis latrans) are the definitive host

Replacing neocortical neurons after stroke

No abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56007/1/21088_ftp.pd

Origin of multiplexing capabilities of multifrequency magnetic ratchets

Through a combination of theory, numerical simulation, and experiment, we investigate the motion of magnetic beads on the surface of a magnetic ratchet driven by multifrequency fields. Here, we focus on the influence of static forcing terms, which were not included in previous models, and we derive analytical models that show why the static forcing terms are responsible for inducing beads of two different sizes to move in opposite directions on the same ratchet potential. We begin our analysis with the simplest possible forcing model, and we show that the main effect of the static forcing terms is to delay the phase of flux reversal. From there, we move onto the full analysis and theoretically derive the phase range for which opposite motion among two different bead types is achieved. Based on these theoretical results, we conduct experimental investigations that explore the effects of bead size and static forcing coefficient on the direction of bead motion, which confirm most of the expected trends. These results shed light both on past experimental work both by ourselves and others, as well as elucidate the more general multiplexing capabilities of ratchets