Search

OBJECTIVE To examine associations among objectively measured physical activity (PA), body mass index (BMI), waist circumference (WC), and cardiorespiratory fitness (CRF) in firefighters. METHODS Career firefighters (n = 29; male = 100%) wore accelerometers to assess PA. BMI and WC classified obesity. Each participant completed a stage-graded exercise test to determine maximal oxygen uptake ((Equation is included in full-text article.)). RESULTS Two linear regression models were used to investigate whether PA intensities, step count, BMI, or WC were predictive of "true" (Equation is included in full-text article.). Vigorous physical activity (VPA) was predictive of "true" (Equation is included in full-text article.)(F[1,27] = 7.89, R = 0.23, P

INTRODUCTION: Microgravity leads to a progressive loss in muscular strength, endurance, and aerobic capacity (Vo2peak). Blood flow restricted (BFR) exercise has been shown to elicit rapid gains in muscular strength and Vo2peak. Rowing exercise combined with BFR could be a supplemental countermeasure to maintain preflight muscle function and Vo2peak, especially within future space vehicles with restricted physical volume.METHODS: There were 20 men who completed 19 min of rowing exercise during CON or BFR in a randomized order. Exercise intensity for all sets was 30% of peak work load achieved during a separate incremental maximal exercise test. Kaatsu training cuffs were inflated around each leg during BFR. Muscle oxygen saturation (Smo₂) and heart rate (HR) were measured throughout exercise and rest. Rate of perceived exertion (RPE) and muscle activation, using surface electromyography (sEMG), were measured during the last 30 s of each exercise set. Blood pressure (BP) and whole blood lactate ([La-]b) were measured at rest and postexercise.RESULTS: Smo₂ declined significantly in BFR during exercise and rest by 13% and 14%, respectively. HR and RPE showed significant increases during BFR (120.5 ± 5.53 vs. 128.9 ± 9.86 bts · min-1) (9.8 ± 1.85 vs. 11.8 ± 1.88 arbitrary units). No differences were observed for BP, [La-]b, and sEMG.DISCUSSION: Findings indicate exercise intensity and cuff pressure elicited acute muscular, cardiovascular, and perceptual responses. BFR rowing exercise could be advantageous as an adjunct for future exercise countermeasures where aerobic and anaerobic exercise may be performed on one device or in limited physical space.Mahoney SJ, Dicks ND, Lyman KJ, Christensen BK, Hackney KJ. Acute cardiovascular, metabolic, and muscular responses to blood flow restricted rowing exercise. Aerosp Med Hum Perform. 2019; 90(5):440-446.

Introduction The purpose of the current study was to examine if isometric peak force and rate of force development (RFD) were related to the ability to successfully perform a simulated casualty evacuation task in both unweighted and weighted conditions. Methods Eighteen male participants from Army Reserve Officers’ Training Corps (ROTC) completed a maximum isometric deadlift on a force plate (IRB#HE16227). Isometric peak force and RFD were calculated from ground reaction force. Two simulated casualty evacuation performance trials were then completed. The unweighted trial consisted of lifting and carrying a 75 kg dummy as quickly as possible for 50 m. The weighted trial was similar except 9 kg vests were added to both the simulation dummy and the participant to represent 18 kg of duty gear. Independent sample t-tests and Pearson correlations were performed to compare the characteristics of those who passed and failed the weighted trial. Results All of the participants (n = 18) completed the unweighted casualty evacuation trial, while 72% (n = 13) were able to complete the weighted casualty evacuation trial. The participants that successfully completed the weighted evacuation trial had significantly (p < 0.05) greater isometric peak force (1420 ± 165 vs. 1076 ± 256 N) and lean mass (74.18 ± 3.89 vs. 65.34 ± 3.89 kg) when compared to participants (n = 5) that could not complete the weighted evacuating task trial. Additionally, greater Army Physical Fitness Test scores (288 ± 13 vs. 269 ± 16 arbitrary units) and significantly faster (30.34 ± 4.41 vs. 44.92 ± 10.62 seconds) unweighted evacuation trial times were observed in participants that could complete the weighted evacuation task. Peak force was also significantly correlated with lean mass (r = 0.51, p < 0.05). There was no relationship between RFD and performance of the unweighted or weight trial. Conclusion Isometric deadlift peak force represents an important determinant for the success of a simulated casualty evacuation task and may be a useful marker to include in periodic fitness evaluations of military personnel.

Objective The purpose of this study was to examine the effects of 3 different elastic therapeutic taping methods on the subacromial joint space in healthy adults. Methods Pre-/post-test laboratory study method was used in this study. Forty-eight healthy adults with no prior history of shoulder injury or surgery and no history of dominant shoulder pain in the past 6 months were enrolled in the study. Participants were placed into 3 groups (8 males and 8 females per group) on the basis of a consecutively assigned allocation design. A baseline measurement of the acromiohumeral distance (AHD) was taken by using diagnostic ultrasonography for every participant. On the basis of group assignment, participants were then taped according to the Kinesio Tape (Kinesio Tex Classic Tape) guidelines in one of 3 conditions: (1) taping of the supraspinatus from insertion to origin; (2) taping of the anterior and posterior deltoids from insertion to origin; and (3) a combination of both techniques. After a 5-minute wait period, the AHD was remeasured with the tape intervention in place, with each participant serving as his or her own control. Results Data analysis showed a statistically significant increase in AHD when using the taping technique over the anterior and posterior deltoids (Condition 2). The subacromial space increased in both males and females when the supraspinatus was taped from insertion to origin (Condition 1), but not at a statistically significant level. Condition 3, in which both taping techniques were used simultaneously, did not show an increase at a statistically significant level. Conclusions The application of the Kinesio Tape from insertion to muscle origin of the supraspinatus or the anterior and posterior deltoid increased the subacromial joint space.

The purpose of this original research was to survey high school coaches in four states in the Midwest region of the United States regarding their knowledge of first aid, cardiopulmonary resuscitation (CPR), and use of an Automated External Defibrillator (AED) as well as confidence in managing/treating emergency situations. Responses to general knowledge inquiries revealed that coaches were able to accurately answer questions related to return to play, level of consciousness, external bleeding, and cardiac arrest. However, coaches were unable to correctly answer questions specific to rest, ice, compression, and elevation (RICE) and also misidentified information related to pediatric AED use. Because sudden cardiac death is the leading cause of death and has been linked to lack of bystander intervention, the results of this project should be considered by coaches and administrators to implement certification and continuing education for high school coaches. Finally, coaches who were certified in first aid, CPR, and AED were more confident in treating an individual who required care compared with coaches not certified. Therefore, individuals who coach at all levels of sport and recreational activities should consider formal training and certification.

OBJECTIVE The aim of this study was to validate a (Equation is included in full-text article.)O2max protocol designed specifically for the occupational demands of firefighters by incorporating the use of personal protective equipment (PPE). METHODS Career firefighters completed a stage-graded exercise test (GXT) with submaximal square-wave verification bout while wearing PPE (pants and boots) to determine (Equation is included in full-text article.)O2max. Using the self-reported Physical Activity-Rating (PA-R) scale and an estimated nonexercise regression equation of (Equation is included in full-text article.)O2max for comparison to measured. RESULTS Twenty-eight male, career firefighters performed the GXT and square-wave bout. (Equation is included in full-text article.)O2 values (mean ± SD) from the GXT and the square-wave verification bout were 41.04 ± 6.98 and 39.74 ± 6.42 mL/kg/min, respectively (ICC = 0.98, typical error = 0.96 mL/kg/min, CV = 2.4%). CONCLUSION Our data suggest an incremental treadmill protocol that incorporates PPE and square-wave verification as an occupational-specific tool to measure cardiovascular fitness in firefighters.

Context:Allied health care professionals commonly apply cryotherapy as treatment for acute musculoskeletal trauma and the associated symptoms. Understanding the impact of a tape barrier on intramuscular temperature can assist in determining treatment duration for effective cryotherapy.Objective:To determine whether Kinesio®Tape acts as a barrier that affects intramuscular temperature during cryotherapy application.Design:A repeated-measures, counterbalanced design in which the independent variable was tape application and the dependent variable was muscle temperature as measured by thermocouples placed 1 cm beneath the adipose layer. Additional covariates for robustness were body mass index and adipose thickness.Setting:University research laboratory.Participants:Nineteen male college students with no contraindications to cryotherapy, no known sensitivity to Kinesio®Tape, and no reported quadriceps injury within the past 6 months.Intervention:Topical cryotherapy: cubed ice bags of 1 kg and 0.5 kg.Main Outcome Measures:Intramuscular temperature.Results:The tape barrier had no statistically significant effect on muscle temperature. The pattern of temperature change was indistinguishable between participants with and without tape application.Conclusions:Findings suggest that health care professionals can combine cryotherapy with a Kinesio®Tape application without any need for adjustments to cryotherapy duration.

Attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopy of hair fibres shows a discrete transition zone (DTZ) between the hard protective cuticle layer and the softer elongated cortical cells of the cortex. The DTZ is composed of flattened orthocortical cells located on the outer perimeter of the cortex and appears to range in thickness between 2 and 3.6 μm. The inner surface of the DTZ, adjacent to the elongated cortical cells that make up the core of the hair fibre, is irregular. ATR-FT-IR analyses of these flattened orthocortical cells indicate major changes in the molecular structure of keratins found in this transition zone. Other studies have identified cells that produce keratins that are distinct from alpha keratins found in the elongated heterocortical cells in the hair fibre core. These distinct keratins appear to be produced in the lower region of the hair follicle at the interface between the cuticle and cortex. The DTZ is also the region where ATR-FT-IR spectroscopy studies identified changes in C-H bending of lipid esters indicative of breast cancer. Lipid ester absorption bands at 1738 and 1732 cm-1, present in non-cancer hair, are absent in the cancer hair and a new ester band absorbing at 1736 cm-1 is observed. When the breast cancer is clinically removed, the 1736 cm-1 ester band absorption and the increase in the 1446-1456 C-H-bending absorption ratio are no longer observed. This suggests that biomarkers produced by the breast cancer interact with stem or other cells near the lower region of the follicle, controlling the amount and type of lipid esters in the DTZ.

AimTo assess plasma zinc and copper concentration in individuals with autism and correlate these levels with symptom severity.Subjects and MethodsPlasma from 102 autistic individuals, and 18 neurotypical controls, were tested for plasma zinc and copper using inductively-coupled plasma-mass spectrometry. Copper and zinc levels and Cu/Zn were analyzed for possible correlation with severity of 19 symptoms.ResultsAutistic individuals had elevated plasma levels of copper and Cu/Zn and lower, but not significantly lower, plasma Zn compared to neurotypical controls. There was a correlation between Cu/Zn and expressive language, receptive language, focus attention, hyperactivity, fine motor skills, gross motor skills and Tip Toeing. There was a negative correlation between plasma zinc concentration and hyperactivity, and fine motor skills severity.DiscussionThese results suggest an association between plasma Cu/Zn and severity of symptoms associated with autism.

Many undergraduate students in exercise science (EXSC) will enter professions that serve older adults (e.g., cardiac rehabilitation, physical therapy), professions projected to grow the next 10 years. However, no research yet has explored whether EXSC students are even interested in working with older adults. Therefore, the purpose of this study was to explore EXSC students’ perceptions and attitudes towards working with older adult patients. A total of 225 students (140 female; 143 Caucasian) from EXSC programs across the United States completed scales about ageism and perceptions of working with older patients (Cary et al., 2017; Nolan et al., 2006), and questions about coursework, prior experiences, and demographics. Questionnaire order was manipulated to explore the possibility of a priming effect. Overall, 119 students (52.89%) self-reported interest in working with older adults. Responses indicated moderately low levels of ageism (M = 2.89, SD = 0.79) and moderately positive perceptions of work with older adults (M = 3.73, SD = 0.44). No effect of priming was observed (p > .14). Students reporting regular contact with older adults had more positive perceptions (t = -2.69, p = .008) and were less ageist compared to those who did not (t = 2.30, p = .022), but older adult coursework was unimportant (p > .170). Results indicate that many EXSC students are open to older adult patients, particularly compared to other majors (e.g., Chonody & Wang, 2014), an encouraging result given how many professionals with a background in exercise and human movement will be needed.

In narrow vein mining it is often not possible to limit stope width to the vein width when utilising blasting for rock breakage. A probabilistic benchmarking method is used to estimate benchmark stability stoping widths and benchmark average stoping width for three commonly used narrow vein longhole blast patterns. Average stoping widths for inline, staggered and dice-5 blast patterns have been estimated at 1˙3, 1˙5 and 1˙7 m respectively. Average stoping width can be used to assess planned and unplanned dilution. Additionally, a concept termed the benchmark stability stoping width has been defined and quantified for the three blasting patterns. Stability stoping widths for inline, staggered and dice-5 have been estimated at 1˙6, 2˙0 and 2˙1 m respectively. Narrow vein stopes within these limits after blasting can be regarded as stable.

A concept has been developed where characteristic load cycles of longwall shields can describe most of the interaction between a longwall support and the roof. A characteristic load cycle is the change in support pressure with time from setting the support against the roof to the next release and movement of the support. The concept has been validated through the back-analysis of more than 500 000 individual load cycles in five longwall panels at four mines and seven geotechnical domains. The validation process depended upon the development of new software capable of both handling the large quantity of data emanating from a modern longwall and accurately delineating load cycles. Existing software was found not to be capable of delineating load cycles to a sufficient accuracy. Load-cycle analysis can now be used quantitatively to assess the adequacy of support capacity and the appropriateness of set pressure for the conditions under which a longwall is being operated. When linked to a description of geotechnical conditions, this has allowed the development of a database for support selection for greenfield sites. For existing sites, the load-cycle characteristic concept allows for a diagnosis of strata-support problem areas, enabling changes to be made to set pressure and mining strategies to manage better, or avoid, strata control problems. With further development of the software, there is the prospect of developing a system that is able to respond to changes in strata-support interaction in real time.

A comparative study of Fourier transform infrared attenuated total reflection (FTIR-ATR) spectra of 32 scalp and pubic hair samples from individuals diagnosed with breast cancer and those who were negative for breast cancer showed increases in the β-sheet/disorder structures (relative to α-helix structures) and C–H lipid content of hair from breast cancer patients. Thus, the presence of breast cancer appears to alter the hair growth process, resulting in changes in the composition and conformation of cell membrane and matrix materials of hair fiber. These appear to be consistent with the changes observed in X-ray diffraction patterns for hair from breast cancer patients. A blind study of 12 additional hair samples using these FTIR-ATR spectral differences as markers correctly identified all four hair samples from cancer patients (100%). Two of these samples were from breast cancer patients. Of the remaining two samples analyzing positive for cancer, one was from a prostate cancer patient and one from a lung cancer patient. Thus, it appears that the mechanism that alters hair fiber synthesis in the three types of cancer may be similar. The blind study incorrectly identified as positive for cancer three hair samples from two apparently healthy individuals and one patient considered cured from prostate cancer.

As medical care for spinal cord injuries (SCI) continues to improve, coronary artery disease (CAD) has emerged as a major cause of morbidity and mortality. Patients with SCI particularly are at risk for CAD because of the changes in cardiovascular physiology, glucose homeostasis, decreased HDL cholesterol, proportionally increased body fat, and physical inactivity that accompany SCI. Management of cardiac disease in SCI includes surveillance for silent ischemia, the careful prescription of an appropriate diet, aerobic exercise, medications, and stress reduction. Rehabilitation after myocardial infarction (MI) requires modifications for mobility impairments, attention to risks for autonomic hypotension, and autonomic dysreflexia.

An anomalous hot spot, which occurs when the motion of the Leksell Gamma Unit is halted, was investigated. A series of measurements indicated that the source of this hot spot is the focusing property of the primary collimator. It was determined that this effect is unlikely to result in serious consequences to the patient, even in the event of failure of the hydraulic unit.

A substantial research project on the performance of a 600 tonne per hour Batac jig involved removing large bed samples from four locations across the bed in the first compartment. The bed was sampled as four or more layers of constant thickness. In order to arrive at estimates of the continuous variation of bulk density and concentrations of particle size and density fractions with depth in a bed, a new method of interpolation, the basis of which is developed in the first paper in this series, was applied to the data. While it was not possible to determine trends in stratification with operating conditions of the jig, the work provided insight into bed stratification. A new jig bed stratification index was devised to quantify the state of stratification of the bed. The use of the interpolation method made possible the objective estimation of stratification.

The first paper in this series' presented the mathematical basis and computational procedures for problems of interpolation of sizing and density data commonly encountered in coal preparation problems. Robust methods having the desirable property that the interpolations reduce exactly to the original data were developed. This work discusses the application of the method to two-dimensional interpolation of size-by-size density and ash data. The primary application of the method is in consistently recalculating washability information to some chosen set of size and density intervals, given sets of data defined on a different set of intervals. Such a problem occurs when preparing drill core or bulk sample data for washery calculations. No ‘model’ of coal properties or assumptions regarding the forms of the mass or ash distribution are involved. The method is consistent, objective and computationally robust.coal preparation, Coal, density distribution, interpolation, size distribution, washability.

Fifteen patients were treated in the Gamma Knife Unit and followed for 18 months or longer. Four patients had Cushing's disease, 4 had acromegaly, 3 had Nelson's syndrome and 3 had prolactinomas. One patient had no endocrinopathy. One of the patients with acromegaly and 2 of those with prolactinomas had been operated prior to Gamma Knife treatment. Radiological tumor localization was not an insuperable problem in this series. The effect of Gamma Knife treatment on the anterior pituitary neoplasia, as such, was consistently successful. All the tumors which received 10 Gy or more to the edge showed either a reduction in volume or at least cessation of growth. On the other hand, the effect of the treatment was less consistent in respect to the endocrinopathies. These results are discussed in respect of dose and tumor size. It is suggested that the role of the Gamma Knife in the treatment of pituitary adenomas requires further clarification, based on prospective studies.

Attempts have been made to correlate small-diameter vascular graft patency with compliance matching between the graft and the host artery. Without knowledge about the mechanisms of failure by compliance mismatch, however, such correlations remain empirical. We have developed a flow system which mimics the flow in peripheral arteries and techniques to model a compliance mismatch in a straight elastic tube, as might occur with vascular repair. Our goal was to investigate one proposed mechanism of graft failure by compliance mismatch, that of a blood flow disturbance. Flow visualization experiments showed that, under pulsatile flow, a compliance mismatch caused trapping of 40 μm microspheres at the wall near the distal or downstream anastomosis. This suggests that the presence of a microscopic flow separation or stagnant zone in vivo may contribute to the intimal hyperplasia and thrombosis seen in failed grafts.

The jig in its variety of forms applied in coal preparation has been a major unit in coal washeries for one hundred years; yet the principles of jigging are still less well understood than those governing many other coal preparation unit operations. Jig control has also been viewed as an art rather than a science until recently. This review considers some of the history of jigs and the theories that have been advanced to explain their operation. Special emphasis is placed on discussion of the means of control of jigs, starting from the traditional means and working towards the novel methods that have been proposed recently. It is clear that our understanding of jigs and the means by which they will be controlled in the future will benefit from our rapidly increasing engineering computational power and will make much fuller use of microprocessor control and modern instrumentation.

Seven signals were accurately measured and data logged in exhaustive experiments using a highly instrumented and controlled pilot scale Baum jig. These signals provide a basis for understanding the effect of the operating parameters on the air and water behaviour in the jigging process. The measurements include the air pressure, water pressures and displacement, the hutch water flowrate. A Fourier decomposition method was applied to remove signal noise and smooth the signals. Water velocities and accelerations are calculated from the smoothed displacement data. The frequency of pulsation, air pressure in the accumulator and inlet period of the air cycle play significant roles in determining the air and water behaviour in the jigging process. The bed thickness. expansion period of the air cycle, hutch water flowrate and the rate of opening of the inlet valve are less important. The characteristics of four typical air cycles, namely, the conventional Baum jig cycle. Mayer cycle. Jeffrey/Bird cycle ...

This study examined memory for common odors and odors names that were encoded with visual, verbal, and olfactory elaboration.

The compliance hypothesis states that the compliance of vascular grafts should match that of the host artery for optimal patency. Although this has not been proven, the literature shows that much effort has gone into measuring compliance. Uniaxial circumferential tensile tests are simpler than compliance tests, but do not give the compliance (a multiaxial property) directly. Therefore, we have used mechanical models to correlate the two. Simple models suffer from inappropriate simplifying assumptions. In a clinically useful range, a Laplace law model and an incremental elasticity model do not predict the compliance from the rigidity as well as does a model derived from finite elasticity. This latter model has helped locate sources of errors. Variations in graft thickness, diameter, and anisotropy may be responsible for scatter in the experimental correlations between compliance and uniaxial rigidity.

Rehabilitative medicine and curative medicine differ significantly. Rehabilitative medicine forcuses on compensation, using intact residual functions in the presence of permanent damage to improve impaired functions, whereas curative medicine aims to restore the body to normal functioning in various ways. For its part, rehabilitative medicine is an excellent example of a multidisciplinary activity, which is also true of supervisory control. Rasmussen's familiar three–level classification (1983) of complex cognitive behaviors into Skill–based, Rule–based, and Knowledge–based behaviors provides a perspective with three hierarchically ordered levels, as does the classification of Wood and Badley (1985) regarding rehabilitation concerns into impairment, disability, and handicap. Similarities between the two disciplines are varied and significant. They include: a) the cybernetic modelling approaches and techniques used; b) the description of human behavior; c) the design of man–machine interfaces (MMIf); d) the use of human decision support systems and field evaluation studies; and e) the functional interaction of the disabled person/supervisor with his/her physical environment. At the same time, the two fields are characterized as well by significant differences. For example, in rehabilitative medicine: a) phycho–social considerations are far more pervasive and significant; b) intra– and inter–subject variability are often sufficiently great to warrant individualized solutions; c) financial mechanisms and motives are different, as are the economic consequences of achieving successful solutions; and d) it is the more multidisciplinary field. Two case studies will be reported in detail by way of illustration. These include an application of expert systems and the development of treatment support systems, and alternative communication devices and assistive devices for visually impaired individuals. A prognosis for the developing field of rehabilitation will be given. We will discuss how the current emphasis on information technology and the change of our society into an information society may affect various disability groups differentially, affecting the prognosis for visually impaired, hearing impaired and motorically impaired individuals. The discussion characterizes likely directions of the field in several selected countries, including the Netherlands, the USA, and Japan. Finally, we argue the the Man–Machine Systems aspects of industry and rehabilitation should be more closely allied and integrated, not only as a challenge, but of necessity to specialists in both fields.

The objective was to examine possible reasons for delamination observed in tibial inserts of the porous-coated anatomic (PCA) knee replacement. To date, 33 PCA inserts have been forwarded to the authors' labs. Of these 33, 52% showed severe delamination within four years of implantation. Visual, structural, and mechanical analyses were conducted and data compared on the heat-pressed PCA type and the common machined inserts. Twenty inserts of the two different types were examined. Visual data using polarized light microscopy showed the presence of a surface layer separated from the middle region of the heat-pressed inserts by a line of demarcation 250-580 microns beneath the articulating surface. This anomaly was not observed in machined inserts. Structural analysis showed the new heat-pressed inserts had increased crystallinity in the surface layer when compared to new machined inserts. The retrieved heat-pressed inserts showed increased crystallinity in the surface and middle regions. There was a slight increase in surface crystallinity in the retrieved machined inserts. Microhardness data showed that there was an increased hardness associated with the crystallinity seen on the heat-pressed inserts. Orthopedic surgeons should be aware of early delamination and surface failure in heat-pressed inserts.

Poetry groups are providing opportunities for older people to reminisce and integrate Important life experiences related to cultural identity. This paper describes a poetry group experience for older Navajo Indian people which promotes their reminiscence of "sheepherdmg" youth experiences. Group members have identi- fied the challenges they faced and the knowledge they acquired while "sheepherding" and the ways in which these themes have and are currently impacting their life experiences.

Stereotactic irradiation appears to be effective in causing partial or complete thrombosis of AVM that are not surgically resectable. Use of heavy particles generated in a cyclotron allows better spatial definition and dose distribution than do other methods, allowing larger AVM to be treated [1–3]. From these preliminary results, it is evident that heavy-partiele irradiation therapy, like proton beam therapy, does not offer protection from recurrent hemorrhage for at least 12 months, nor is it devoid of major complications; it does offer a noninvasive mode of therapy for AVM that are difficult to treat surgically, however.

To carry out washery optimization calculations in a digital computer, both the raw coal feed characteristics and separator efficiency performance must be reduced to a form that is both accurate and easv to translate into code. A systematic analysis has been made of mathematical representation for partition curves and separation characteristics for froth flotation machines. A number of representations of the partition curves have been found to be useful. The programs developed accept conventional partition data or modelled partition curve parameters. Flotation performance is specified according to a two-rate constant kinetic model. Feed coal characteristics used are typical for coal preparations plants in China. Optimization of the process is carried out by maximization of yield, and three programs have been developed for the purpose. The programs can deal with any one of seven plant flowsheets commonly used in China. One program can be applied to determine the optimal ash content of clean coal for either each category of separator or each coal feed group. The other two programs are very useful to determine the optimal cut points of separators being installed in a plant. The computing techniques applied in both the programs are the Rosenbrock pattern search and the so-called “Replacement Method”. The cubic spline interpolation techniques have been applied in a number of calculations with success. All the programs have been proved to be effective and convenient tools for the design and operation of coal preparation plants.

The effects of various encoding tasks on long-term recognition of odours were examined. Different groups of subjects were instructed (a) to form visual images of the source of the odour, (b) to generate the name of the odour and provide a dictionary-like definition, or (c) to describe a life episode of which the odour reminded them. A no-strategy control was simply told to try to remember the odours for a subsequent recognition test. One week later, subjects performed a yes–no recognition test for the odours. The second and third groups displayed significantly higher recognition than the controls. The visual imagery group did not differ significantly from the control group. The results seem to be accounted for best by dual coding theory.

The purpose of this study was to determine if older adults have more difficulty than younger adults in judging either the distance or speed of approaching vehicles. Eighteen elderly and 27 younger adults made judgements of the speed and distance of a video-taped automobile. Velocity judgements were made of 5 s segments of the car moving at 20, 30, 40, 50, and 60 mph. Distance judgements were based on 5 static sequences of the same test vehicle at 190, 235, 300, 360, and 480 ft. It was found that older women gave significantly higher estimates of car velocity than did younger ones. Older males also gave disproportionately high estimates of the car's distance. To the extent that these simulation data can be generalized to real-life settings, they suggest that older drivers and pedestrians (particularly older males) would view it as relatively safer than younger drivers to enter or cross the lane of an approaching car. Future research might be directed to a determination of age differences in distance perception under three-dimensional viewing conditions.

The possibility that drugs administered to Skylab 3 (SL-3) and 4 (SL-4) crewmen for space motion sickness may have interfered with their biomedical evaluation in space was investigated. Healthy volunteers received combinations of Scopolamine/Dexedrine for four days in regimens similar to those used in these missions. Urine samples, heart rate, body temperature, mood and performance were analyzed for drug-related changes. Twenty-four hour urine samples were analyzed by the same procedures as those used to analyze the flight samples. Hormone concentrations determined included cortisol, epinephrine, norepinephrine, aldosterone and antidiuretic hormone (ADH). In addition, volume, specific gravity, osmolarity, sodium (Na), potassium (K), calcium (Ca), magnesium (Mg), chloride (Cl), inorganic phosphate, uric acid and creatinine were measured. Performance was not affected by the Scopolamine/Dexedrine. The drug combination increased daily mean heart rate (HR) significantly in all the subjects and daily mean rectal temperature (RT) in some of the subjects. A 2-4 hr phase shift in the HR circadian rhythm was also observed which indicates that internal circadian synchrony was disturbed by the drugs. Psychological and subjective evaluation indicated that the subjects could usually identify which days they were given the drugs by an increase in tension and anxiety, decreased patience, restlessness, decreased appetite, difficulty in sleeping and feelings of increased heart rate and body temperature. Urinary electrolytes were not changed significantly by the drug, but marked and significant changes occurred in urine volume and hormone excretion patterns. Scopolamine/Dexedrine caused consistent elevations in urinary cortisol and epinephrine and a transient elevation in ADH. Norepinephrine excretion was decreased, but there was no significant change in aldosterone excretion or in 24 hr urine volume. A comparison of these findings with the first four days of inflight data from the SL-3 and SL-4 missions leads to the conclusion that the dramatic increases in aldosterone excretion during the first three days of spaceflight probably can be directly attributed to weightlessness, whereas the antimotion sickness medication could have substantially contributed to the early increased excretion of epinephrine and cortisol during these missions.

Models which have been presented in the literature consider only selected aspects of dense medium cyclone operation, are empirical in nature and generally relate only to severely limited ranges of operating parameters. This paper reports progress towards development of a more comprehensive and robust model. The data base consists of partitioning parameters developed using density tracers and conventional coal sampling and analysis techniques, together with recordings of parameters such as cyclone dimensions, feed pressure, medium size distribution and product media densities. These data were drawn from 15 Australian coal preparation plants. To eludicate the effects of important operating parameters on medium behaviour and on the partitioning of large particles a series of pilot scale tests were also conducted. The present model consists of eight sub-models which relate to particular aspects of dense medium cyclone operation such as medium flowrates and densities, or size-by-size separation densit...

Foveal and peripheral target detection were compared in young adults (M age = 22 years) and older adults (M age = 66 years) who were optically corrected for the viewing distance. In a two-alternative, forced-choice task, target letters were presented at 0 degree to 10.5 degrees from fixation. Targets were presented alone, flanked on each side by one noise element (i.e., nontarget letter), or embedded in a horizontal row of 19 noise elements. An Age X Noise Level X Location interaction was obtained, wherein age differences were largest for peripheral targets presented in noise. Slope analyses of latency data showed that the performance of young adults in the high-noise condition was most similar to that of older adults in the low-noise condition. At the functional level, results indicated that aging is associated with a restricted useful field of view. In addition, the data suggest that age differences in search can be described by a model in which older adults take smaller perceptual samples from the visual scene and scan these samples more slowly than do the young adults.

A new solid-wall vascular graft which has a compliance approximating that of the natural artery has been prepared from a copolyether-urethane material. Six of nine of these compliant grafts implanted in dogs were patent on removal, the longest implant time being 77 days for a 4-mm I.D. femoral artery graft. This is in contrast to noncompliant grafts of the same copolyurethane in which failure usually occurred within 48 hr.

The density tracer technique has for some years been utilised for determination of the separation efficiencies of density separators in the diamond and iron ore industries. At the Julius Kruttschnitt Mineral Research Centre (JKMRC), the technique has been adapted for studies of coal separation, and refined to a point where a Tromp or partition curve for a dense medium cyclone module can be determined quickly and accurately. Test programs using 33 mm tracers in seven Australian coal washeries are reported, and the effects of selected operating variables on separator performances are examined. The density tracer technique is shown to have substantial potential in improvement of day to day washery operation and the detection of unusual operating conditions, and in coal preparation research.

Summary Rehabilitative medicine and curative medicine differ significantly. Rehabilitative medicine forcuses on compensation, using intact residual functions in the presence of permanent damage to improve impaired functions, whereas curative medicine aims to restore the body to normal functioning in various ways. For its part, rehabilitative medicine is an excellent example of a multidisciplinary activity, which is also true of supervisory control. Rasmussen’s familiar three–level classification (1983) of complex cognitive behaviors into Skill–based, Rule–based, and Knowledge–based behaviors provides a perspective with three hierarchically ordered levels, as does the classification of Wood and Badley (1985) regarding rehabilitation concerns into impairment, disability, and handicap. Similarities between the two disciplines are varied and significant. They include: a) the cybernetic modelling approaches and techniques used; b) the description of human behavior; c) the design of man-machine interfaces (MMIf); d) the use of human decision support systems and field evaluation studies; and e) the functional interaction of the disabled person/supervisor with his/her physical environment. At the same time, the two fields are characterized as well by significant differences. For example, in rehabilitative medicine: a) phycho–social considerations are far more pervasive and significant; b) intra– and inter–subject variability are often sufficiently great to warrant individualized solutions; c) financial mechanisms and motives are different, as are the economic consequences of achieving successful solutions; and d) it is the more multidisciplinary field. Two case studies will be reported in detail by way of illustration. These include an application of expert systems and the development of treatment support systems, and alternative communication devices and assistive devices for visually impaired individuals. A prognosis for the developing field of rehabilitation will be given. We will discuss how the current emphasis on information technology and the change of our society into an information society may affect various disability groups differentially, affecting the prognosis for visually impaired, hearing impaired and motorically impaired individuals. The discussion characterizes likely directions of the field in several selected countries, including the Netherlands, the USA, and Japan. Finally, we argue the the Man–Machine Systems aspects of industry and rehabilitation should be more closely allied and integrated, not only as a challenge, but of necessity to specialists in both fields.

The line scan camera, or LSC, is an inexpensive and easily applied technique for optical strain measurement of soft biomaterials. The LSC is based on a linear array of photodiodes; in gauging applications, where measurements between dark/light interfaces are important, the digital nature of the array can be exploited. Advantages of the LSC include low cost, high frequency response, applicability to front- or back-lighted samples, insensitivity to stray and nonuniform lighting as well as to accidental overexposure, ease and linearity of calibration, and lack of temperature sensitivity. With the 1024 element arrays used herein, the relative resolution is theoretically limited to 1 part in 1024, or 0.1%; in practice, the relative resolution is somewhat poorer. LSCs have been successfully used in mechanical tests to measure the diameter of arteries and compliant vascular grafts, the longitudinal strain of vascular grafts, and the dynamic diameter of elastic tube models of graft/artery systems in pulsatile flow visualization experiments.

Systems for the routine on-line determination of ash content of process streams in coal preparation plants and handling systems have been in use in Australia for over four years. More recently, monitors for on-line moisture measurements have been developed to complement the ash measurement function. The technology for these systems is reviewed briefly. The development of reliable ash and moisture monitors has made the implementation of automatic systems of coal quality control practical. The emerging philosophies of automatic control in Australian preparation plants are examined with particular emphasis on systems involving dense medium circuit regulation. Related developments in flotation control and coal sorting are noted to complete this overview.

Heavy oil mining is a promising technology that may increase ultimate oil recovery from existing reservoirs from 35–40% to 90% of the original oil in place. If successful, mining for heavy oil could effectively double or even triple the quantity of oil recovered from the known resources in the United States and throughout the world. Current estimates of these known world resources are several thousand billion barrels. Three mining methods appear to offer technical feasibility for heavy oil recovery: surface extractive mining, underground extractive mining and underground mining for access. These three methods have been attempted in several projects worldwide during the past century, and have demonstrated the technical feasibility of each method. Each project has failed economically in the past due to competition from oil produced from traditional surface wells. Successful implementation of the theories behind heavy oil production using mining techniques will require the cooperation of several diverse disciplines including petroleum geology, petroleum engineering, mining engineering, civil engineering and environmental sciences.

In the operation of an electric power distributing system involving various kinds of networks, a fundamental necessity is that each transforming and transmitting unit carry a reasonable share of the total load. In the case of a single system that has been developed in a coordinated manner the problem of load division has not in general been troublesome and has been solved by judicious selection of parallel circuits, use of reactors, proper system set-up, etc. The advent of inter-company connections has brought together systems of varying characteristics, changed the relation between the basic elements involved, and in some cases has made difficult the control of power flow over tie lines small in comparison to the systems which they unite. It is the purpose of this paper to discuss the case of load control where closed rings or parallel path circuits are involved. After briefly reviewing the principles of voltage phase angle and power flow, a description is given of some actual tests performed on a very large interconnected system with a 250-mi. transmission loop, involving five power companies and a total generator capacity well over 1,000,000 kw. The results of these measurements are analyzed for the purpose of checking theoretical against actual values and forming a basis for the solution of problems of a similar nature.