Estudio económico de los Estados Unidos, 1988 = Economic survey of the United States of America, 1988

Incluye Bibliografía

Book Review of Twilight of the Mammoths: Ice Age Extinctions and the Rewilding of America</i> by Paul S. Martin

Applying ecological studies to the adaptations of prehistoric human hunter-gatherer groups has greatly increased our abilities to interpret effects of an ever-changing environment and our access to critical resources on these populations. The Pleistocene/Holocene transition, its climate and human genesis in the new world, draws intensive interest from a number of scientific communities. In Twilight of the Mammoths, Paul Martin adds his views, which are of no surprise, on the megafaunal extirpations during a cultural period referred to in North America as Clovis.

Driver Safety in Far-side and Far-oblique Crashes: A Study of Patrol Vehicles in the United States of America

The dissertation titled "Driver Safety in Far-side and Far-oblique Crashes" presents a novel approach to assessing vehicle cockpit safety by integrating Human Factors and Applied Mechanics. The methodology of this approach is aimed at improving safety in compact mobile workspaces such as patrol vehicle cockpits. A statistical analysis performed using Michigan state's traffic crash data to assess various contributing factors that affect the risk of severe driver injuries showed that the risk was greater for unrestrained drivers (OR=3.38, p<0.0001) and for incidents involving front and far-side crashes without seatbelts (OR=8.0 and 23.0 respectively, p<0.005). Statistics also showed that near-side and far-side crashes pose similar threat to driver injury severity. A Human Factor survey was conducted to assess various Human-Machine/Human-Computer Interaction aspects in patrol vehicle cockpits. Results showed that tasks requiring manual operation, especially the usage of laptop, would require more attention and potentially cause more distraction. A vehicle survey conducted to evaluate ergonomics-related issues revealed that some of the equipment was in airbag deployment zones. In addition, experiments were conducted to assess the effects on driver distraction caused by changing the position of in-car accessories. A driving simulator study was conducted to mimic HMI/HCI in a patrol vehicle cockpit (20 subjects, average driving experience = 5.35 years, s.d. = 1.8). It was found that the mounting locations of manual tasks did not result in a significant change in response times. Visual displays resulted in response times less than 1.5sec. It can also be concluded that the manual task was equally distracting regardless of mounting positions (average response time was 15 secs). Average speeds and lane deviations did not show any significant results. Data from 13 full-scale sled tests conducted to simulate far-side impacts at 70 PDOF and 40 PDOF was used to analyze head injuries and HIC/AIS values. It was found that accelerations generated by the vehicle deceleration alone were high enough to cause AIS 3 - AIS 6 injuries. Pretensioners could mitigated injuries only in 40 PDOF (oblique) impacts but are useless in 70 PDOF impacts. Seat belts were ineffective in protecting the driver's head from injuries. Head would come in contact with the laptop during a far-oblique (40 PDOF) crash and far-side door for an angle-type crash (70 PDOF). Finite Element analysis head-laptop impact interaction showed that the contact velocity was the most crucial factor in causing a severe (and potentially fatal) head injury. Results indicate that no equipment may be mounted in driver trajectory envelopes. A very narrow band of space is left in patrol vehicles for installation of manual-task equipment to be both safe and ergonomic. In case of a contact, the material stiffness and damping properties play a very significant role in determining the injury outcome. Future work may be done on improving the interiors' material properties to better absorb and dissipate kinetic energy of the head. The design of seat belts and pretensioners may also be seen as an essential aspect to be further improved.

Improving Conditions of Latino Children Brightens the Future of America

An introduction to the inaugural issue of the Journal of Applied Research on Children.

An exploratory investigation of America's most costly delinquents: Juvenile firesetters

This study focused on the instruments that are currently being used by fire department personnel to identify and classify juvenile firesetters, these instruments, as published by the Federal Emergency Management Agency (F.E.M.A.) have never been empirically validated as to their ability to discriminate between first time and multiple firesetters and to predict the degree of risk for future firesetting by juveniles that come to the attention of authorities for firesetting behaviors. The study was descriptive in nature and not designed to test the validity of these instruments. The study was designed to test the ability of the instruments to discriminate between first time and multiple firesetters and to categorize known firesetters, based on the motive for firesetting, as to their degree or risk for future firesetting.^ The results suggest that the F.E.M.A. instruments are of little use in discriminating between first time and multiple firesetters. The F.E.M.A. instruments were not able to categorize juvenile firesetters as to their potential risk for future firesetting. A subset of variables from the F.E.M.A. instruments was identified that may be useful in discriminating between youth that are troubled firesetters and those that are not. ^

The voice of America on Kishineff

ed. by Cyrus Adler

The Jews in the making of America

by George Cohen