Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “intercept”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 829 records · Page 46Linked to original sources
PubMed1993

Lactate breakpoint during slowly increasing work rates and irregular breathing.

The breakpoint (BP) in lactate (La) was determined using the noninvasive V-slope and VE/VO2 methods. Eight normal male subjects performed three maximal graded exercise tests (GXT) with 3-min work stages during normal breathing (NB) and during irregular breathing with hypoventilation (IB-HV). The IB-HV resulted in mild but significantly increased arterialized-venous PCO2, PETCO2 and irregular VE/VO2 and irregular breathing frequency. The correlation coefficients for linear regressions of the La BP with the V-slope and VE/VO2 BPs during NB were: 0.77 (p < 0.05) and 0.79 (p < 0.05), respectively, and during IB-HV the correlations coefficients were: 0.82 (p < 0.05) and -0.02 (p > 0.05) for V-slope and VE/VO2 BPs, respectively. The differences were more apparent from the regression coefficients with the La BP; the slopes with NB for V-slope and VE/VO2 BPs were 1.06 +/- 0.40 SEM and 1.38 +/- 0.43; the intercepts with NB were -0.22 +/- 0.24 and -0.67 +/- 0.33, respectively. During IB-HV the slopes for the V-slope and VE/VO2 were 1.02 +/- 0.29 and -0.02 +/- 0.47, and the intercepts were -0.11 +/- 0.40 and 1.57 +/- 0.64, respectively. The VE/VO2 slope and intercept with IB-HV were notably different. It was concluded that the V-slope and VE/VO2 methods determine the La BP with 3-min stages during NB, whereas only the V-slope method determined the La BP with IB-HV.

Adult↗
PubMed1982

Response of the aging hamster lung to elastase injury.

The effect of age on the induction of emphysema in hamsters was investigated by administering porcine pancreatic elastase endotracheally to old (18 months of age) and young (4 months of age) hamsters; age-matched untreated animals served as controls. Lung volumes, quasi-static deflation volume pressure relations, and mean linear intercept, an index of alveolar size, were measured. Elastase-treated young hamsters demonstrated an increased volume of air in the lungs at a transpulmonary pressure of 25 cm H2O and an increased mean linear intercept. The lungs of old elastase-treated animals showed less pronounced changes than those of young hamsters in lung volume at transpulmonary pressure of 25 cm H2O and in mean linear intercept. Untreated old hamsters had a larger lung volume at a transpulmonary pressure of 25 cm H2O and an 85% increase in total lung collagen. Age-related alterations in connective tissues may account for the increased resistance of old lungs to injury by pancreatic elastase.

Aging↗
PubMed1984

Reproducibility of CO2 response curves with ten minutes separating each rebreathing test.

It is unclear whether duration of the interval separating CO2 rebreathing tests has any effect on the CO2 response curve. In normal subjects, we compared slopes and intercepts, respectively, of CO2 response curves from 3 rebreathing tests separated by each of three different time intervals: 10, 20, and 30 min. The slopes and intercepts, respectively were no different from the first through third test with each interval and no different between tests from different intervals. Therefore, reproducibility of slope and intercept was not affected by the time interval separating each test. During each rebreathing test, heart rate and systolic blood pressure increased but diastolic blood pressure decreased. These effects resolved within 10 min after the test. We conclude that, in normal subjects, 3 CO2 rebreathing tests can be repeated rapidly with only 10 min of rest separating each test.

Adult↗
PubMed1979

Sodium taurocholate modifies the bile acid-independent fraction of canalicular bile flow in the rhesus monkey.

Bile acid-independent secretion and the choleretic response to taurocholate were determined in rhesus monkeys fitted with indwelling silastic cannulas in the common bile ducts. Bile acids were infused intravenously in random order at 3.5, 7.0, or 10.5 mumol/min for 1.5 h each. When data were analyzed with a single regression line, bile flow increased in proportion to the level of bile acid secretion, although the y-intercepts (the conventional measurement of bile acid-independent secretion) varied widely (77.9+/-40.9 ml/24 h). The variation in y-intercepts was observed between animals and with repeated studies in the same animal and could not be explained by sex differences or the effects of the indwelling silastic cannulas, but seemed to be related to the order of bile acid infusion. With only two taurocholic acid infusion rates (7.0 and 3.5 mumol/min), [(14)C]erythritol clearance was greater per mole of secreted bile acid when the initial bile acid infusion was at the high level, but approached zero at low bile acid secretion rates, which suggests that so-called bile acid-independent canalicular flow is closely related to bile acid secretion or is small in size. The augmentation in [(14)C]erythritol clearance when the high infusion rate was given first was also associated with an increase in biliary clearance of [(3)H]inulin, which indicates that the premeability to inulin was also enhanced. Identical experiments which substituted equimolar infusions of a nonmicelle-forming bile acid (taurodehydrocholate) for taurocholate failed to demonstrate any difference in choleretic response or biliary clearance of [(3)H]inulin with the order of bile acid infusion. These experiments demonstrate that a micelleforming bile acid, taurocholate, can increase the permeability of the biliary system to large molecular weight solutes and simultaneously modify the y-intercept and the volume of bile secreted in response to the transported bile acid. Taurocholate may, therefore, modify its own choleretic response, perhaps by altering the structure or function of bile secretory membranes, and appears to be a major determinant of so-called bile acid-independent flow in rhesus monkeys.

Animals↗
PubMed1991

Electromyographic-force characteristics in the assessment of oral function.

The purpose of this investigation was to examine the utility of EMG-force characteristics as reliable and valid parameters by which to assess oral function. Masseter-muscle activity was recorded during controlled isometric biting exercises performed at various bite openings and force levels on two separate occasions. Measured muscle-activity levels, as well as the EMG-force characteristics of slope and y-intercept, were compared between bite openings and experimental trials. Sensitivity, assessed as the ability to detect statistically significant differences in muscle function due to changes in muscle length, was found to be acceptable for all measurements, except the y-intercept parameter, and during production of minimal forces. Reproducibility, evaluated as the correspondence between values recorded at different experimental sessions, was best for the EMG-force parameter of slope and during production of higher forces. The results from this study support the following conclusions: (1) Substantial variations in muscle function exist between individuals; (2) acceptable reliability and sensitivity of quantitative EMG values can be achieved, especially at higher muscle-activity levels, by rigidly controlling and quantifying functional activities during experimental trials; (3) the slope of an EMG-force curve is a reproducible, quantitative, and functionally sensitive measurement for assessment of muscle function; and (4) the EMG-force y-intercept is not a reliable quantity by which muscle-function characteristics may be studied.

Adult↗
PubMed1998

Clinical oxygen transfer comparison of the Terumo Capiox SX18 and SX25 membrane oxygenators.

The purpose of this current study was to compare the Terumo Capiox SX18 (1.8 m2) with the recently released Capiox SX25 (2.5 m2). Specifically, their oxygen transfer slopes, degree of blood shunting, extrapolated maximum oxygen transfer, blood side pressure drop and oxygen transfer consistency were compared. The lower intercept value (0.209 vs 0.236) coupled with the flatter slope (0.00171 vs 0.00225) of the oxygen transfer line for the SX25 is consistent with improved oxygen transfer performance. A lower FiO2 value would be predicted for the SX25, to achieve a specific PaO2 value, when the oxygen transfer requirement is equal for both devices. Extrapolated maximum oxygen transfer for the SX25 (462.6 ml O2/min) was 36.2% higher than that for the SX18 (339.6 ml O2/min). When indexed to membrane surface area, the SX18 (188.7 ml O2/m2/min performed 2.0% better than the SX25 (185.0 ml O2/m2/min). Both the slope (3.110 vs 3.744) and the intercept (4.595 vs 6.223) of the shunt fraction line were lower for the SX25, indicating that a lower shunt fraction would be predicted for all clinical blood flow rates. The slope (23.934 vs 22.443) and intercept values (-28.388 vs -22.650) of the pressure drop lines for the two devices indicate that the blood side pressure drop, over the range of clinical blood flows, were within 2% of each other. Oxygen transfer consistency, when expressed as the standard deviation of the oxygenator performance index and the percentage of predicted shunt, was not statistically different for the two devices.

Adult↗
PubMedDate not supplied

In-vitro evaluation of a new inferior vena cava filter-the stent-filter.

Inferior vena cava filters are indicated for the prevention of pulmonary embolism when anticoagulation using heparin has failed or is contraindicated. The aim of this study was to assess in an in-vitro setting the efficiency of a new inferior vena cava filter to intercept emboli. The new filter, stent-filter, was inserted into a pulsating flow circuit. Then thrombi were produced by introducing sheep's blood into silicon tubes with 3 mm diameter. A combination of 9% saline solution with 40% glycerol was used as the isosmotic fluid in the circuit. A total of 150 thrombi were introduced into the circuit in 3 stages of 50 events each. The flow rate in each of the 3 stages was altered; initially a rate of 1.0 liter per minute was chosen, and after this, it was increased to 1.5 liters and finally 2.0 liters per minute. The percentage of interceptions was used for statistical analysis. In the in-vitro experiment, the filter captured 94%, 90%, and 92% of the thrombi at flow rates of 1.0, 1.5, and 2.0 liters per second, respectively. In conclusion the new filter was effective in the interception of the thrombi when it was evaluated in in-vitro conditions.

Animals↗
PubMed2005

Medication errors: a prospective cohort study of hand-written and computerised physician order entry in the intensive care unit.

INTRODUCTION: The study aimed to compare the impact of computerised physician order entry (CPOE) without decision support with hand-written prescribing (HWP) on the frequency, type and outcome of medication errors (MEs) in the intensive care unit. METHODS: Details of MEs were collected before, and at several time points after, the change from HWP to CPOE. The study was conducted in a London teaching hospital's 22-bedded general ICU. The sampling periods were 28 weeks before and 2, 10, 25 and 37 weeks after introduction of CPOE. The unit pharmacist prospectively recorded details of MEs and the total number of drugs prescribed daily during the data collection periods, during the course of his normal chart review. RESULTS: The total proportion of MEs was significantly lower with CPOE (117 errors from 2429 prescriptions, 4.8%) than with HWP (69 errors from 1036 prescriptions, 6.7%) (p < 0.04). The proportion of errors reduced with time following the introduction of CPOE (p < 0.001). Two errors with CPOE led to patient harm requiring an increase in length of stay and, if administered, three prescriptions with CPOE could potentially have led to permanent harm or death. Differences in the types of error between systems were noted. There was a reduction in major/moderate patient outcomes with CPOE when non-intercepted and intercepted errors were combined (p = 0.01). The mean baseline APACHE II score did not differ significantly between the HWP and the CPOE periods (19.4 versus 20.0, respectively, p = 0.71). CONCLUSION: Introduction of CPOE was associated with a reduction in the proportion of MEs and an improvement in the overall patient outcome score (if intercepted errors were included). Moderate and major errors, however, remain a significant concern with CPOE.

Chi-Square Distribution↗
PubMed2005

Pharmaceutical validation as a process of improving the quality of antineoplastic treatment.

OBJECTIVE: To quantify the improvement added by standardization of pharmaceutical validation (PV) of antineoplastic treatment to the processes of prescription and preparation of the pharmacotherapeutic sequence, in terms of prevention and reduction of medication errors (ME). DESIGN: Prospective cohort study during two years (from 2001-2002) for oncohaematologic patients (inpatients and outpatients) that compared the percentage of medication errors detected and resolved and the number of medication errors with potential clinical significance (severity value >or=4) intercepted during PV in both years. RESULTS: During the PV processes, 202 ME were identified and resolved, which is the equivalent of 16.88 ME/1,000 patient-days. In 2001 14.08 ME/1,000 patient-days were detected and 19.83 ME/1,000 patient-days in 2002. This means that the effectiveness of the identification method increased by 41%. The number of ME intercepted with clinical significance (severity value >or=4) increased in a statistically significant manner by 2.18 times in 2002. CONCLUSION: This study shows that the standardization of PV is an effective method of improving the quality of antineoplastic treatment use, by increasing the ability to intercept ME.

Adult↗
PubMed2001

Designing multidrug-resistance modulators circumventing the reverse pH gradient in tumours.

Multidrug-resistant tumours often exhibit a reverse pH gradient (acid outside), as they have an acid extracellular pH (pHe) and a neutral alkaline intracellular pH (pHi). This study was designed to test the hypothesis that the ability of lipophilic drugs to mediate multidrug resistance (MDR) reversal by interacting with the membrane phospholipids may be correlated with pH in resistant tumours. The permeation properties of five MDR modulators were therefore studied at 37 degrees C by quantifying their ability to induce the leakage of Sulfan blue through unilamellar anionic liposomes, over the range pH 6.5-7.7, and in the absence of any membrane potential (pHe = pHi). The dye leakage induced by two calcium blockers (diltiazem and verapamil) and two antiparasitic agents (thioacridine derivative and mepacrine) was found to significantly increase with the pH of the medium (P < 0.001), whereas that induced by a non-ionic detergent (Triton X-100) showed almost no pH-dependent variations. This process was a cooperative one (0.8 < Hill coefficient < 8.5) and the permeation doses inducing 50% dye leakage (PD50) ranged from 1.6 to 36.0 mM. The permeation ability of the MDR modulators (log(1/PD50)) significantly increased with their octanol-buffer distributions (logD) (slope = 0.35+/-0.06; y intercept = 1.65 +/- 0.14; P < 0.0001) and significantly decreased with their net electric charge (z) (slope = -0.48+/-0.07; y intercept = 2.85+/-0.08; P < 0.0001). A highly significant multiple correlation was found to exist between the variations of log(1/PD50) with those of logD and z (dlog(1/PD50)/dlogD = 0.21 +/- 0.05; dlog(1/PD50)/dz = -0.34+/-0.07; y intercept = 2.27+/-0.17; P < 0.000001). The results provide evidence that in resistant tumours (acid pHe and neutral alkaline pHi), the MDR reversal might be enhanced by favourable drug-membrane interactions if the modulators are designed in the form of highly lipophilic (logP approximately equals 4) mono-basic drugs with a near neutral pKa (pKa approximately equals 7-8).

Antineoplastic Agents↗
PubMed1996

Wear in retrieved Charnley acetabular sockets.

One hundred and twenty-nine Charnley acetabular components were acquired at the time of revision surgery and a tribological investigation undertaken. The relative occurrence of pitting in the unworn and worn regions of the sockets suggest that most of the cement ingress occurs during the early part of the service life. The penetration depth of the explanted sockets was determined using the shadowgraph technique. Observation of the profiles in the wear planes suggest that, in general, the creep component was not a significant proportion of the overall change in the inner bore of the socket. Using weighted ordinary least squares regression, in which the intercept was not assumed to be zero, mean penetration and wear volume rates of 0.02 (SE = 0.02) mm/year and 55 (SE = 5) mm3/year, respectively, were recorded and are in agreement with other retrieval studies. In neither case was the intercept found to be significantly different from zero. A mean clinical wear factor, Kclinical, equal to 2.1 (SE = 0.2) x 10(-6) mm3/N m was calculated which is considerably larger than that found in laboratory experiments which purport to reflect in vivo conditions. In this analysis, a significant positive intercept was observed [96 (SE = 36) mm3] and may be evidence of the small initial penetration due to creep reported in simulator experiments. A strong positive association between kclinical and the arithmetical mean roughness, Ra, of the femoral head was also demonstrated although the rate of change was not as great as that cited for laboratory experiments.

Acetabulum↗
PubMed2006

Reproductive effects of ethnomedicinal formulation of tape-vine leaves in female rats.

Documented ethno-contraceptive use of Tape-vine or Stephania japonica (THUNB.) MIERS., Syn. Stephania hernandifolia (WILLD.) WALP. leaves is evaluated with regards to post-coital pregnancy interceptive activity of its aqueous extract (AE) and an ethnomedicinal formulation (EF) in Wistar rats. EF at 500 and 250 mg/kg doses induced 66.7% and 33.3% post-coital pregnancy interception respectively and the higher dose exhibited significant reduction in number of litters born and also anti-implantation property. In contrast, none of the dose levels of AE interfered in pregnancy but significant anti-implantation property was observed at doses of 2 and 1 g/kg, even as the higher dose produced significant reduction in number of litters born as well. EF at 500 mg/kg also exhibited significant uterotrophic activity and histological changes in uterus. Pair-wise comparison of sex hormone-levels exhibited significant increment in serum estradiol, LH and FSH but decrease in progesterone levels. Assessed blood lipid-carbohydrate profile exhibited substantial decrease in glucose, cholesterol, VLDL and triglyceride contents and significant increase in HDL. It is concluded that EF probably acts as better post-coital pregnancy interceptive agent through restriction of implantation by alteration of gonadal hormone levels and decline in blood-glucose levels that possibly disrupts oxidative energy metabolism in uterus during implantation. High surge in LH and FSH suggests negligible interference in ovulatory mechanism. This preparation also seems to be free of cardiovascular risk factors. HPTLC and HPLC analysis of both EF and AE exhibited marked chemical differences.

Animals↗
PubMed2005

Skinfold prediction equation for athletes developed using a four-component model.

INTRODUCTION: Skinfold (SKF) equations exist to predict percent body fat (%BF) in athletes; however, none have been derived from multicomponent model reference measures. PURPOSE: To develop and cross-validate a %BF prediction equation based on SKF in athletes using a four-component model as the reference measure. METHODS: Subjects were 132 collegiate athletes (20.7 +/- 2.0 yr; 78 males: 28 black, 50 white; 54 females: 10 black, 44 white). Four-component model estimates of %BF (%BF4C) included measures of total body water from deuterium dilution, bone mineral by dual- energy x-ray absorptiometry (DXA), and body density by densitometry using underwater weighing. SKF measures included subscapular, triceps, chest, midaxillary, suprailiac, abdominal, and thigh sites (7SKF). A prediction equation was developed on 102 athletes using 7SKF, race, and gender as predictor variables. Cross-validation was performed on a representative holdout sample of 30 athletes. RESULTS: The equation cross-validated well (slope and intercept both not different (P > 0.05) from the line of identity (LOI); r(YY') = 0.85, total error (TE) = 3.76%BF) and was better than the existing athlete SKF equations (intercept and slope both different from LOI (P < 0.01); r(YY') = 0.76, TE = 4.51%BF). Notably, a prediction equation developed using 3SKF sites (abdomen, thigh, and triceps) produced a similar accuracy (intercept and slope both not different from LOI (P > 0.05); r(YY') = 0.85, TE = 3.66%BF). CONCLUSIONS: The new 7SKF equation improved on SKF equations developed using densitometry. The final equation based on the whole sample was %BF' = 10.566 + 0.12077*(7SKF) - 8.057*(gender) - 2.545*(race). Moreover, a 3SKF equation was comparable in accuracy to the 7SKF equation: BF' = 8.997 + 0.24658*(3SKF) - 6.343*(gender) - 1.998*(race).

Adolescent↗
PubMed2006

Career education: an application of latent growth curve modelling to career information-seeking behaviour of school pupils.

BACKGROUND: This study applied the theory of planned behaviour (TPB) in an attempt to predict longitudinal growth of career exploratory behaviour in school pupils. The importance of information for making considered career decisions is indicated in theories of career development and choice, career education programmes, and concepts of career maturity. AIMS: The study aimed to initially model individual and group levels of career exploratory behaviour and then to identify psychological variables that predicted such behaviour. SAMPLE: Longitudinal data from a sample of 325 adolescents (mean age 16.4 years, SD = 0.77, 45% were male) was collected at three points in time. METHOD: A latent growth curve model was specified to account for initial status and subsequent linear growth of career exploratory behaviour. Variables representing the TPB were included in the model to explain the variation in the intercept and slope factors. RESULTS: The latent growth curve model was found to be an acceptable description of the data, and indicated that there was significant individual variability in terms of the intercept and slope factors. Behavioural intention was found to be a significant predictor of the intercept factor, but not of the slope factor. CONCLUSIONS: It was concluded that the TPB remains a useful theoretical framework from which to explain career information-seeking behaviour.

Adolescent↗
PubMed2001

Alkaline phosphatase activity: new assay for the Reflotron system. Results of the evaluation in eight clinical laboratories.

A new reagent carrier, Reflotron ALP, has been developed for the Reflotron system, allowing easy and rapid measurement (in less than 3 minutes) of alkaline phosphatase (ALP) activity in capillary blood, venous blood, heparinized plasma or serum. The evaluation of the analytical performance of the assay was carried out at eight clinical laboratories. The study of the imprecision using the measurements in human samples resulted in coefficients of variation ranging from 1.3% to 4.6% (within-run) and from 3.2% to 4.0% (day-to-day). The analytical specificity of the Reflotron ALP assay agrees well with ALP methods using a N-methyl-D-glucamine buffer solution. The calibration of the Reflotron ALP assay, however, is related to the reference intervals for ALP methods using a diethanolamine buffer solution. Method comparisons were performed with the ALP method on Hitachi instruments using diethanolamine buffer. Reflotron ALP measurements in blood and plasma in 157 randomly selected split samples showed excellent agreement (slope: 0.99; intercept: 0.7 U/l; median bias: 2.3%; median difference from the comparison method: -0.3%). Specimens from pregnant women and adolescents were excluded from this study. Differing values were obtained in a method comparison using 48 samples containing predominantly the ALP bone isoform (slope: 0.81; intercept: 31.5 U/l; median bias: 5.7%; median difference from the comparison method: -12.2%). Regression analysis of the results from 21 sera with prevailing placental ALP gave a slope of 1.51, and an intercept of -41.1 U/l (median bias: 8.6%; median difference from the comparison method: 35.6%). Reflotron ALP was compared with three different wet chemistry procedures using different buffer compounds: N-methyl-D-glucamine or diethanolamine or 2-amino-2-methyl-1-propanol. In samples containing predominantly ALP isoforms not of liver origin, the measurements with N-methyl-D-glucamine buffer gave the best fit with respect to Reflotron. In an interference study with 18 drugs, no effect on the test results could be detected. Total bilirubin up to 750 micromol/l and hemolysis up to 1.7 g/l free hemoglobin did not influence the test. Reflotron ALP proved to be an easy and rapid method with excellent precision. The accuracy related to an ALP method using diethanolamine buffer was good. The systematic differences for ALP in samples from pregnant women and adolescents have to be taken into account. The assay is well suited for differential diagnosis of hepatic diseases in decentralized testing.

Alkaline Phosphatase↗
PubMed2001

Inhibitors of platelet signal transduction as anti-aggregatory drugs.

In the treatment and prevention of cardiovascular diseases, inhibition of platelet aggregation is of fundamental importance. Inhibition of platelet aggregation can be achieved by either inhibition of membrane receptors or by interception of signalling pathways. While receptor antagonism provides high specificity, the inhibition of platelet signal transduction is more effective. The effectiveness results from the inhibition of platelets, regardless of the cause of activation. These common pathway inhibitors are either intercepting platelet activating mechanisms or amplifying the action of endogenous platelet inhibitors. The physiological anti-aggregants are the endothelial factors NO and prostacyclin, which elevate intracellular cGMP or cAMP content, respectively. By administration of NO-releasing agents, prostacyclin analogues or other cyclic nucleotide elevating drugs the platelet anti-aggregatory action of endothelial factors can be effectively mimicked. Besides antiplatelet activity these drugs also act on vascular smooth muscle causing relaxation and therefore vasodilation, an additional beneficial effect. Inhibition of phosphodiesterases causes elevation of platelet cyclic nucleotide content and thus inhibits platelet aggregation and causes vasodilation. Another relevant target for anti-aggregatory treatment is the arachidonic acid metabolic pathway. This pathway can be intercepted by blockade of either cyclooxygenase-1 (COX-1) or thromboxane synthase. Inhibition of these enzymes may be further amplified by additional antagonism of the thromboxane receptor thus not only preventing formation of thromboxane but also activation of thromboxane receptor by thromboxane precursors, which were particularly effective in clinical trials. In vivo these precursors may be metabolised to prostacyclin in the endothelium and consequently provide additional platelet anti-aggregatory activity. A rather new target for platelet anti-aggregatory treatment is the ecto-nucleotidase CD-39 which limits the plasma level of nucleotides. While several of the novel anti-aggregatory drugs were disappointing in clinical studies combinations of drugs with different effector enzymes showed potent antithrombotic efficacy.

Animals↗
PubMed2002

Impact of aviation highway-in-the-sky displays on pilot situation awareness.

Thirty-six pilots (31 men, 5 women) were tested in a flight simulator on their ability to intercept a pathway depicted on a highway-in-the-sky (HITS) display. While intercepting and flying the pathway, pilots were required to watch for traffic outside the cockpit. Additionally, pilots were tested on their awareness of speed, altitude, and heading during the flight. Results indicated that the presence of a flight guidance cue significantly improved flight path awareness while intercepting the pathway, but significant practice effects suggest that a guidance cue might be unnecessary if pilots are given proper training. The amount of time spent looking outside the cockpit while using the HITS display was significantly less than when using conventional aircraft instruments. Additionally, awareness of flight information present on the HITS display was poor. Actual or potential applications of this research include guidance for the development of perspective flight display standards and as a basis for flight training requirements.

Adult↗
PubMed2000

Simulated insect defoliation on soybean: influence of row width.

An ongoing change in soybean production gaining popularity in the United States is a reduction in row spacing. Plant canopy closure is quicker and leaf area index is greater, thus yield is usually higher. Because yield response to insect defoliation is primarily a function of how defoliation causes changes in light interception, the possibility exists that the insect-injury-yield-loss relationship might differ among row widths. Soybean was grown in four states using similar methodologies. Insect defoliation was simulated by picking leaflets based on an insect defoliation model. Plant growth measurements were taken immediately following the end of defoliation. Numerous independent variables were measured or calculated, including percentage light interception, leaf area index, percentage defoliation, and leaf area per plot. Analyses of covariance were conducted on the resultant data to determine whether insect-injury-yield-loss relationships interact with row width. A significant interaction would indicate that the impact of the variables on yield was dependent on the row width, whereas a nonsignificant interaction would suggest that the relationship between the variables and yield is similar at all row widths. Few significant interactions were obtained, indicating that the impact of the variables on yield is similar across row widths. Because of the lack of significant interactions, the insect-injury-yield-loss relationships previously developed should be usable across varying row widths. Thus, treatment decisions based on light interception and leaf area indices, both considered more appropriated measures of insect injury, should be applicable for all row spacings.

Agriculture↗