Search

A new approach for budgeting building construction projects is presented as an alternative to the traditional cost per gross square foot basis. The new method calls for the preparation of a complete budget based on the design program data, criteria, design parameters and quality standards set by the project's principal. It is shown that this budgeting technique is significantly more effective in terms of cost control.

Enteral or tube feeding is a commonly used method for providing nutrition to patients who are seriously ill. However, enteral feedings are accompanied by a high incidence of diarrhea (which has been reported in 32 to 68 percent of enteral feeding patients). Although this diarrhea is thought to be caused by a complex of different factors, the underlying mechanisms are not well understood. The present experiment investigates the value of using an aseptic (sterile) delivery mechanism of enteral solution to one group of adult patients in various intensive care units of a hospital. The rate of diarrhea in this group was compared to that of a group who received conventional enteral support. Samples of the enteral fluid fed to both groups was also sampled and analyzed for bacterial contamination. There was no significant difference in the incidence of diarrhea between the two groups; consequently, bacterial contamination of feeding formulas is not considered to be a major source of diarrhea in enterally fed patients. The rate of bacterial contamination, however, was found to be higher in the group who received conventional enteral feedings than in the aseptically fed group. Other factors, such as the severity of the patients' illness, the osmolarity of the solution, and the rate of formula administration, were found to have no effect on the incidence of diarrhea. In general, the findings demonstrate that the use of closed sterile bags (which do not require further handling) reduces the rate of bacterial contamination of enteral formula, and this method is recommended for patients who require enteral feedings. (Consumer Summary produced by Reliance Medical Information, Inc.)

The article discusses the significance of vestibular apparatus to scientific experimentation. Its role is to respond to accelerations of the head. The vestibular apparatus have two kinds of receptors, namely, the otolith and the semicircular canals. These apparatus can be shared by vertebrate animals and man. Cesar Fernandez and Jay M. Goldberg of the University of Chicago, have investigated a second class of neurons in the vestibular system.

Purpose An arteriovenous fistulas (AVF) is the preferred vascular access for hemodialysis and is associated with lower mortality, morbidity and cost when compared with grafts and particularly with central venous dialysis catheters. This study reviews a series of new patients where an autogenous access was constructed for each individual utilizing surgeon-performed ultrasound (SP-US).Methods Consecutive new patients referred for a permanent vascular access during an 11-year period were retrospectively reviewed. In addition to physical examination, each patient underwent SP-US evaluation for preoperative vessel mapping and post-operative evaluation for access maturation. SP-US was also used in the evaluation of access dysfunction in mature AVFs.Results We identified 1874 patients. Ages were 8-94 years (mean 60 years). Of these, 51% were female and 59% were diabetic; 33% had previous failed access operations. Follow-up was 3-127 months (mean 23 months). An autogenous access was constructed for each individual. No grafts were used. Direct AVFs were constructed in 1240 (66%) patients and 634 (34%) individuals required a transposition or translocation procedure. Primary and cumulative patency rates were 60.0% and 93.0% at 12 months and 47.3% and 90.2% at 24 months, respectively. AVF arterial inflow was most commonly supplied by the proximal radial artery (67%).Conclusions Creating a functional autogenous vascular access is possible for most patients. No grafts were used in this series of 1874 consecutive new patients. Important elements for success included SP-US evaluation, utilization of the many vascular access options available, establishing radial artery AVF inflow when feasible, and prompt intervention when indicated.

Simulator sickness (SS)-virtual environment (VE) sickness is expected to become increasingly troublesome as VE technology evolves. This paper investigated using an independent visual background (IVB) to reduce SS and VE sickness. The IVB is a visual scene component that provides visual motion and orientation cues that match those from the vestibular receptors. In this study, the IVB was stationary, fixed with respect to inertial space. Two experiments were conducted. The first experiment examined the differences in visual motion-induced postural disturbance as a function of simultaneous exposure to an IVB. Subjects exhibited less balance disturbance when the IVB was presented. An expected statistically significant interaction between IVB presence-absence and visual scene motion oscillation frequency was observed. In the second experiment, subjects reported less SS when the IVB was presented during the VE exposure. We suggest that an IVB may alleviate disturbance when conflicting visual and inertial cues evoke SS.

Postural disturbance following virtual environment (VE) exposure has been reported in many studies. Some suggest that postural disturbance could be a pre-cursor of or highly related to simulator sickness (SS). Few studies have addressed long duration exposure and multi-sessions in SS and postural disturbance. This study investigated effects of long duration and repeated exposure to an immersive VE on postural disturbance. The results suggested larger postural disturbance 24 hours and 48 hours after the first VE exposure. However, differences between postural disturbance magnitudes pre- and post- exposure within a day decreased after 48 hours. Differential effects were associated with different postural stances were also found. Suggestions for further research are addressed.

Several studies indicated that an independent visual background (IVB) reduced simulator sickness (SS) and balance disturbance associated with exposure to virtual environments (VEs) and motion simulators. A recent study showed that an IVB comprised of an earth-fixed grid was less effective in a complex driving simulator than in a simple VE. Subjects' post-experiment reports indicated that the VE motion “induced” motion of the earth-fixed grid IVB. This led to the suggestion that an IVB comprised of clouds would be less subject to induced motion and therefore would alleviate nausea more effectively than a grid IVB. Clouds are “natural” and are usually perceived as relatively stable, whereas a gird has no inherent stability. Twelve subjects were exposed to complex motion through a simulated environment in a driving simulator under 3 IVB conditions: grid, less clouds, and many clouds. They reported less nausea when the many-cloud IVB was used relative to the grid IVB condition.

Image quality issues such as field of view (FOV) and resolution are important for evaluating “presence” and simulator sickness (SS) in virtual environments (VEs). This research examined effects on postural stability of varying FOV, image resolution, and scene content in an immersive visual display. Two different scenes (a photograph of a fountain and a simple radial pattern) at two different resolutions were tested using six FOVs (30, 60, 90, 120, 150, and 180 deg.). Both postural stability, recorded by force plates, and subjective difficulty ratings varied as a function of FOV, scene content, and image resolution. Subjects exhibited more balance disturbance and reported more difficulty in maintaining posture in the wide-FOV, highresolution, and natural scene conditions.

Simulator sickness (SS) is a major impediment to use of virtual environments (VEs). Procedures to alleviate SS have been of limited value. The ‘independent visual background’ (IVB) may reduce SS when people use a VE. Optimum characteristics of IVBs remain to be determined. In this study, balance was disturbed by roll oscillation of a black and white radial pattern. Disturbance was reduced by simultaneous presentation of an IVB. Effects of locating the IVB in the foreground or background relative to the moving radial pattern using a stereographic display were determined. Nine subjects were tested at two IVB luminance levels and three different IVB conditions using a within-subjects design. An expected statistically significant difference between the IVB and no-IVB conditions was observed. No effect of IVB location was obtained. Effects of foreground / background manipulations on spatial orientation are addressed.

A possible relation between vection and presence is discussed. Two experiments examined the hypothesis that “presence” is enhanced by manipulations which facilitate interpreting visual scenes as “background.” A total of 39 participants in two experiments engaged in a pursuit game while in a virtual visual environment generated by an HMD and rated their experience of “presence” on 5 questions. Experiment 1 compared two viewing conditions: visual scene masking at the eye and a paper mask mounted on the screen with the same 60° FOV, and showed that presence was enhanced by eye masking relative to screen masking. Experiment 2 replicated these findings with a double-blind experimental design.

Little research exists that explores subcortical function in people who stutter. One study suggested that auditory middle latency response Wave Pb was prolonged in subjects who stutter as compared to controls. Other studies have suggested that Pb was generated within the thalamic portion of the reticular system. MLRs were recorded from 10 males who stutter and 10 controls using a variety of filter passbands in response to clicks presented binaurally at various rates. The latency of Pb was found to be significantly shorter in the group of subjects who stutter.

This article presents the concept of a spatial orientation/motion perceptual system, the contributions of the vestibular receptors to this system, and apparatus and training procedures and observations to allow astronauts to preadapt to weightlessness. The author also discusses perceptual reactions to prolonged weightlessness.

Two part‐task preflight adaptation trainers (PATs) are being developed at the NASA Johnson Space Center to preadapt astronauts to novel sensory stimulus conditions similar to those present in microgravity to facilitate adaptation to microgravity and readaptation to Earth. This activity is a major component of a general effort to develop countermeasures aimed at minimizing sensory and sensorimotor disturbances and Space Motion Sickness (SMS) associated with adaptation to microgravity and readaptation to Earth. Design principles for the development of the two trainers are discussed, along with a detailed description of both devices. In addition, a summary of four ground‐based investigations using one of the trainers to determine the extent to which various novel sensory stimulus conditions produce changes in compensatory eye movement responses, postural equilibrium, motion sickness symptoms, and electrogastric responses are presented. Finally, a brief description of the general concept of dual‐adapted states that underly the development of the PATs, and ongoing and future operational and basic research activities is presented.

Four astronauts experienced passive whole-body rotation in a number of test sessions during a 7-day orbital mission. Pitch (Y-axis) and roll (X-axis) rotation required subject orientations on the rotator in which the otolith system was at radius of 0.5 m. Thus subjects experienced a constant -0.22 Gzstimulus to the otoliths during the 60 s constant-velocity segments of “pitch” and “roll” ramp profiles. The Gzstimulus, a radius-dependent vector ranging from -0.22 Gzat the otoliths to +0.36 Gzat the feet, generated sensory information that was not interpreted as inversion in any of the 16 tests carried out in flight (12 in pitch and 4 in roll orientation). None of the subjects was rotated with head off-center during the first 33 h of the mission. In the state of orbital adaptation of these subjects, a -0.22 Gzotolith stimulus did not provide a vertical reference in the presence of a gradient of -Gzstimuli to the trunk and legs.

The research described in this paper is intended to support development and evaluation of preflight adaptation training (PAT) apparatus and procedures. Successful training depends on appropriate manipulation of visual and inertial stimuli that control perception of self-motion and self-orientation. For one part of this process, astronauts are trained to report their self-motion and self-orientation experiences. Before their space mission, they are exposed to the altered sensory environments produced by the PAT trainers. During and after the mission, they report their motion and orientation experiences. Subsequently, they are again exposed to the PAT trainers and are asked to describe relationships between their experiences in microgravity and following entry and their experiences in the trainers.

Inflight and post-landing “immunity” to the “coriolis sickness susceptibility test”, observed during the Skylab M131 experiment, suggests that the otolith organs play a major role in space motion sickness (SMS). This view is supported by the report that ocular counter-torsion asymmetries correlate with SMS incidence and severity. Further data indicate that sensory-motor adaptation to microgravity includes a process whereby central interpretation of otolith signals is biased from “tilt” toward translation. However, unexpected responses to linear acceleration suggest the importance of graviceptors distributed throughout the body in addition to the vestibular otolith organs. Research is needed to assess distributed graviceptor effects.