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PubMedDate not supplied

Dynamic monitoring of the dust pickup efficiency of vacuum cleaners.

This study evaluated a new method that uses an optical aerosol photometer for dynamically monitoring dust pickup efficiency during vacuuming. In the first stage of this study the new method was compared with built-in dirt sensors installed by vacuum cleaner manufacturers. Through parallel testing it has been shown that the widely available built-in dirt sensors are not sensitive enough to register small (< 53 microm) dust particles. Therefore, only the optical photometer was used in the rest of the experiments of this study to monitor the dust pickup efficiency while the vacuum cleaner was operated with different nozzles on clean and soiled carpet and vinyl sheet flooring. This method also was used to monitor dust pickup efficiency when vacuuming carpets originating from lead-contaminated homes. The dust pickup efficiencies obtained with the optical aerosol photometer have been compared with the surface lead concentrations found during different stages of cleaning. Results indicate that the dust mass concentration registered with the optical aerosol photometer at the nozzle outlet correlates well with the dust mass collected in the vacuum cleaner filter bag and with the surface lead level. Therefore, dynamic dust pickup monitoring can provide valuable information about the efficiency of cleaning when a vacuum cleaner is used. This suggests that a small aerosol photometer similar to a light-scattering smoke detector would be beneficial in vacuum cleaners used for cleaning surfaces contaminated with leaded dust and biological particles (including allergens).

Aerosols↗

PubMed2026

Screening for dual sgRNAs with comparable indel efficiencies enhances CRISPR-mediated large-fragment deletion.

CRISPR-mediated large-fragment deletion provides a powerful approach for gene clusters, noncoding regions and structural variants, but its broader application is limited by low and variable deletion efficiency. Here, we systematically designed and evaluated 78 sgRNAs targeting nine representative gene clusters (ttn.1-ttn.2 cluster, 7 hox clusters and nppb-nppa cluster), containing 31 large fragments (5 kb-340 kb) to investigate the determinants of deletion efficiency. We found two key rules for achieving high deletion efficiency: (i) using dual sgRNAs with similar indel efficiencies, and (ii) applying a single sgRNA pair rather than multiple sgRNAs. Based on those rules, a 340 kb deletion is detected in the progenies of 95% of founders. Whereas the deletion size showed no significant linear correlation with deletion efficiency within the tested range. Implementing these rules resulted in an average of 70% of founders transmitting deletions across all tested sgRNA pairs. Therefore, screening sgRNAs can effectively enhance CRISPR utility in deletions, thereby facilitating the application of genomic manipulation in vertebrates and other species.

CRISPR↗

PubMed1994

An assessment of efficiency of area agencies on aging in Virginia through data envelopment analysis.

This study investigates the efficiency of Area Agencies on Aging using Data Envelopment Analysis (DEA). Efficiency was calculated based on resources available and service units produced. Results demonstrated that extent of inefficiency in agencies and how efficiency of individual Area Agencies on Aging can be improved relative to their peer agencies. Analyses by organizational type, size, and rural-urban differences indicated governmental agencies and large agencies were more likely to be efficient. Rural agencies were about equally likely to be efficient as inefficient.

Aged↗

PubMed2001

Short-term efficiency and safety of gene delivery into canine kidneys.

BACKGROUND: Gene delivery of biologically active molecules to the kidney may have potential therapeutic applications in renal and cardiovascular diseases. Recombinant adenovirus is one of the most efficient vectors for in vivo gene delivery. However, in vivo toxicity at the site of administration has to be evaluated for the successful use of adenovirus-mediated gene transfer. The aim of this study was to document precisely the short-term safety of different routes of intra-renal adenoviral administration and to compare their transduction efficiency. METHODS: Dog puppies were injected with an adenoviral vector expressing the beta-galactosidase reporter gene in both kidneys via three different routes, i.e. intra-renal-ureteral route (IU) and intra-renal-arterial route with (IAC) or without (IA) clamping of the renal vein. Toxicity of viral administration was assayed on day 4 at both physiological and histological levels. Renal samples were monitored for the presence of nuclear beta-galactosidase-expressing cells. RESULTS: All renal physiological parameters (glomerular filtration rate, effective renal plasma flow, and electrolyte excretion fractions) remained stable whatever the route of viral administration. No histological lesion was detected in any of the haematoxylin-eosin-stained kidney sections, and there was no evidence of ischaemia-reperfusion injury in the kidneys subjected to venous clamping. Efficient transgene expression was obtained in dog kidneys following IAC and IU injection of adenoviral vectors. Gene transfer via the IAC route induced gene expression predominantly in the cortical interstitial cells. Retrograde IU adenoviral injection resulted in reduced transduction efficiency compared with the IAC route, with transgene expression occurring mainly in the distal tubular and pyelic epithelial cells. CONCLUSIONS: The two major findings of this study were (i) the absence of acute histological and functional renal alteration following intra-arterial and intra-ureteral injections of adenoviral vectors in both kidneys of healthy dogs, and (ii) the efficiency of transgene expression with specific cellular targeting according to the route of administration.

Adenoviridae↗

PubMed1990

Matching and efficiency in cohort studies.

Contrary to the impression given in some textbooks, matching can reduce the efficiency of a cohort study, even when it produces no sample-size reduction and even if the matching variable is a confounder. The authors illustrate this along with some additional points regarding cohort matching. First, the impact of matching on efficiency can be in opposite directions for different measures of effect; as a consequence, criteria for deciding whether to match must depend on whether one wishes to estimate relative or absolute effects. Second, the commonly drawn analogy between blocking in randomized trials and matching in cohort studies is misleading when one considers the impact of matching on covariate distributions. Third, the conditions for efficiency overmatching in a cohort study are different from the conditions in a case-control study. It appears that, under an additive model, matching will usually increase the efficiency of both risk-difference and risk-ratio estimation, and the power of the Mantel-Haenszel test. Under a multiplicative model, the impact of matching is not as consistently beneficial. The authors present some approximate criteria which allow one to use a priori information to predict whether cohort matching is likely to improve efficiency.

Adult↗

PubMed2002

How to schedule elective surgical cases into specific operating rooms to maximize the efficiency of use of operating room time.

UNLABELLED: We considered elective case scheduling at hospitals and surgical centers at which surgeons and patients choose the day of surgery, cases are not turned away, and anesthesia and nursing staffing are adjusted to maximize the efficiency of use of operating room (OR) time. We investigated scheduling a new case into an OR by using two patient-scheduling rules: Earliest Start Time or Latest Start Time. By using several scenarios, we showed that the use of Earliest Start Time is rational economically at such facilities. Specifically, it maximizes OR efficiency when a service has nearly filled its regularly scheduled hours of OR time. However, Latest Start Time will perform better at balancing workload among services' OR time. We then used historical case duration data from two facilities in computer simulations to investigate the effect of errors in predicting case durations on the performance of these two heuristics. The achievable incremental reduction in overtime by having perfect information on case duration versus using historical case durations was only a few minutes per OR. The differences between Earliest Start Time and Latest Start Time were also only a few minutes per OR. We conclude that for facilities at which the goals are, in order of importance, safety, patient and surgeon access to OR time, and then efficiency, few restrictions need to be placed on patient scheduling to achieve an efficient use of OR time. IMPLICATIONS: We showed how elective cases should be scheduled to maximize the efficiency of use of operating room time. The analysis applies to surgical suites at which surgeons and patients have access to operating room time every workday.

Ambulatory Surgical Procedures↗

PubMed1996

The economics of independent living: efficiency, equity and ethics.

People with disabilities are routinely denied the exercise of choice in their daily lives. There are strong efficiency arguments for the promotion of greater choice and autonomy for disabled people. There are equally strong moral arguments for an investment in the capabilities of disabled people to allow them to participate in both the educational system and the labour market. This investment will not come cheaply nor will the pay-off always be of such magnitude to justify the expenditure on narrow cost-benefit criteria. Those who value efficiency above everything else must, however, set out the system of justice implied by such a choice. The conclusions of a narrow efficiency argument may turn out to be unacceptable to the majority of citizens. Likewise, however, those who value equity at all costs must consider the implications of their approach for individual freedom, economic growth and technical efficiency. This paper is an attempt to explore the meaning of efficiency and equity in the context of independent-living programmes for people with disabilities.

Activities of Daily Living↗

PubMedDate not supplied

Do different case-mix measures affect assessments of provider efficiency? Lessons from the Department of Veterans Affairs.

Although case-mix adjustment is critical for provider profiling, little is known regarding whether different case-mix measures affect assessments of provider efficiency. We examine whether two case-mix measures, Adjusted Clinical Groups (ACGs) and Diagnostic Cost Groups (DCGs), result in different assessments of efficiency across service networks within the Department of Veterans Affairs (VA). Three profiling indicators examine variation in resource use. Although results from the ACGs and DCGs generally agree on which networks have greater or lesser efficiency than average, assessments of individual network efficiency vary depending upon the case-mix measure used. This suggests that caution should be used so that providers are not misclassified based on reported efficiency.

Aged↗

PubMed1995

The effects of ownership, operating environment, and strategic choices on nursing home efficiency.

This article reports on a study of the labor efficiency of 461 nursing homes located in Pennsylvania. Data envelopment analysis was used to estimate efficiency scores. Tobit equations were estimated for the entire sample and for subsamples consisting of for-profit (FP) and not-for-profit (NFP) nursing homes. The authors found that the major factors explaining efficiency were managerial and environmental characteristics such as ownership, occupancy rate, size, payment source, wage rate, and per capita income, rather than quality characteristics of nursing homes. Analysis of the FP and NFP subsamples suggests that many NFP homes may respond to environmental pressures by increasing their efficiency, whereas FP homes tend to operate at a high level of efficiency irrespective of environmental and regulatory pressures.

Bed Occupancy↗

PubMed2004

Effectiveness and efficiency of opportunistic cervical cancer screening: comparison with organized screening.

BACKGROUND: Several countries have adopted nationally organized cervical screening programs, but many continue with opportunistic screening. Comparison of the effectiveness and efficiency of the 2 systems is important for informing policy. OBJECTIVES: The objectives of this study were to assess the effectiveness and efficiency of an opportunistic cervical screening system, and to compare this with what could be achieved through an organized program. RESEARCH DESIGN: We propose a model for estimating the effectiveness and efficiency of opportunistic screening systems and demonstrate it using data from a cross-sectional study of 1826 women in Hong Kong. We estimated the coverage and frequency of screening and used this to estimate effectiveness (number of cases of invasive cervical cancer potentially prevented) and efficiency (tests per case prevented) of the current system. Similar estimates were made for various organized programs with different screening intervals and coverage. RESULTS: Ever screening coverage in this opportunistic system was 44%, resulting in 26% to 31% reduction in potential new cases (n = 144-183). Compared with this, a 3-yearly or 5-yearly screening policy aiming for 80% coverage would prevent an additional 46% (equivalent to 254 new cases out of a population of 2.3 million women per year) and 41% (222 per year), respectively. This could be achieved with more efficient use of resources, reducing the number of tests per case prevented from 2018 to 1545 and 1007, respectively. CONCLUSIONS: At best, the effectiveness of this opportunistic system is equivalent to an organized program with 10-yearly screening and 50% coverage but at much greater cost. Poor coverage and over screening of a minority of women contributes to its inefficiency.

Adult↗

PubMed1987

A new measure of teeth-cleaning efficiency and periodontal disease.

This paper presents a new measure of teeth-cleaning efficiency based on information from a random sample of 400 factory employees and a separate (non-random) sample of some 400 skilled manual workers and their wives. Regression analysis showed that only 1/3 of the variance in calculus levels in the random sample was explained by age, frequency of visits to a dentist, socioeconomic group and smoking habits (other variables tested--gender, date of last dental visit, frequency of teeth-brushing and sugar consumption--were not significant). The corresponding regression for the skilled manual sample gave a broadly similar result, though the proportion of explained variance (1/5) was lower than for the random sample. These results indicated the presence of one or more additional factors, of which teeth-cleaning efficiency is likely to be the most important. A new measure of cleaning efficiency was then constructed by expressing the actual calculus level as a proportion of the level estimated from the regression equation, and deducting this proportion from unity. If this new measure is, indeed, a genuine indicator of teeth-cleaning efficiency, then one should expect it to be an important element in an explanation of the level of periodontal disease, but not of dental caries (which is a resultant essentially of dietary habits). This hypothesis was tested and confirmed by multiple regression analysis. Though the new measure of teeth cleaning efficiency is essentially experimental, and has yet to be validated by clinical testing.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1972

The mechanical efficiency of treadmill running against a horizontal impeding force.

1. A method for determining the apparent mechanical efficiency of running against a horizontal impeding force is described. The results of studies on three well trained athletes have been summarized.2. A linear relation was found between metabolic rate and external work rate. The apparent mechanical efficiency was calculated as the inverse of the slope of the linear regression line of metabolic rate on external work rate x 10(2) (percentage).3. The over-all mean for apparent load-running efficiency (LRE) was 36.1%. The differences in LRE between subjects were not statistically significant. No measurable change in LRE occurred with habituation.4. Values are given for E(k), the net energy cost of unloaded horizontal treadmill running per kilogram of bodyweight and per kilometre of distance covered. The over-all mean for E(k) was 0.83 kcal. kg(-1). km(-1).5. The efficiency values obtained are discussed and compared with other values of running efficiency obtained by different methods, and with studies on isolated muscle.

Adult↗

PubMed2001

Comparative efficiency of national health systems: cross national econometric analysis.

OBJECTIVE: To improve the evidence base for health policy by devising a method to measure and monitor the performance of health systems. DESIGN: Estimation of the relation between levels of population health and the inputs used to produce health. SETTING: 191 countries. MAIN OUTCOME MEASURE: Health system efficiency (performance). RESULTS: Estimated efficiency varied from nearly fully efficient to nearly fully inefficient. Countries with a history of civil conflict or high prevalence of HIV and AIDS were less efficient. Performance increased with health expenditure per capita. CONCLUSIONS: Increasing the resources for health systems is critical to improving health in poor countries, but important gains can be made in most countries by using existing resources more efficiently.

Delivery of Health Care↗

PubMed1977

Efficiency and daily work effort in sugar cane cutters.

Productivity (metric tons (tonnes)/day), efficiency (kg cane cut/litre Vo2), and effort (percent Vo2 max sustained during an 8-hour workday) have been measured in 54 Colombian sugar cane cutters. In workers who sustained less than 40% Vo2 max during the workday, the effort expended was related to productivity (4 = 0-71) but efficiency and productivity were not significantly correlated. In 16 workers sustaining a greater than 40% Vo2 max during the workday, productivity and effort were not related and efficiency was significantly reduced. Subjects using less than 40% Vo2 max were divided into good, average and poor producers and compared with the men with low efficiencies. In general, these inefficient men had the anthropometric and physical fitness characteristics of low productivity workers (smaller stature, weight and Vo2 max). However, the frequency of good, average, and poor cutters in the inefficient group did not differ from that of the men expending less than 40% of their maximum effort nor was their average productivity different. No obvious reasons for the differences in efficiency and effort of these men were found.

Adult↗

PubMed1995

Delta efficiency of uphill roller skiing with the double pole and diagonal stride techniques.

Delta efficiencies for uphill roller skiing with the double pole (DP) and diagonal stride (DS) techniques were determined among 4 female and 4 male cross-country ski racers in order to examine for differences between techniques and between the sexes. Each skier roller-skied on a motorized ski-treadmill at 1.7% and 7.1% grades with both techniques at 2 to 4 different speeds. Steady-state oxygen uptake values were used to calculate the differences in metabolic requirements for roller skiing at the 2 grades (delta E). The differences in external work rates between the 2 grades (delta W) were calculated from the work rates for overcoming rolling resistance and elevating the transported mass against gravity. Delta efficiencies (delta W/ delta E) ranged from 14 to 36%, were significantly greater (p < 0.001) for DS than DP, and showed a significant (p < 0.01) velocity effect for DS. Delta efficiencies were 27% greater (p < 0.05) for the women compared with the men for DP, and significant (p < 0.05) correlations were found between efficiency for DP and body mass. This suggests that the higher efficiency with DP for female skiers is at least partially due to their lower body mass.

Adipose Tissue↗

PubMed1988

Efficiency of energy transfer from pressure-volume area to external mechanical work increases with contractile state and decreases with afterload in the left ventricle of the anesthetized closed-chest dog.

We studied the effects of ventricular end-systolic elastance (Ees) and effective arterial elastance (Ea) on the efficiency of energy transfer from pressure-volume area (PVA) to external mechanical work (EW) in the left ventricle of anesthetized closed-chest dogs. PVA represents the total mechanical energy generated by ventricular contraction, which is an intermediate form of energy between oxygen consumption, the total energy input, and EW, the effective energy output. PVA and EW were determined from ventricular pressure and volume, which were continuously measured with a volumetric conductance catheter. Measurements of Ees were obtained by transiently increasing afterload by an inflation of a Fogarty catheter in the thoracic descending aorta. Ea was determined as the ratio of end-systolic pressure to stroke volume. The EW/PVA efficiency of a steady-state contraction increased from 55% to 64%, with a 58% increase in Ees after dobutamine. Ees, which was smaller than Ea before dobutamine, became nearly equal to Ea after dobutamine, maximizing EW for a given end-diastolic volume. EW/PVA efficiency decreased with an abrupt increase in afterload before and after dobutamine. The sensitivity of the decrease in the EW/PVA efficiency to an increase in end-systolic pressure was significantly less after than before dobutamine. We could account for all these changes in EW/PVA efficiency by the relative changes in Ees and Ea in the pressure-volume diagram.

Animals↗

PubMed1991

Changes in rates of unscheduled hospital readmissions and changes in efficiency following the introduction of the Medicare prospective payment system. An analysis using risk-adjusted data.

The purpose of this study was to analyze changes in rates of unscheduled readmissions and changes in technical efficiency following the introduction of the Medicare Prospective Payment System (PPS). We developed the Risk-Adjusted Readmissions Index (RARI), which allowed us to make comparisons in rates of unanticipated readmissions across hospitals and over time. Data envelopment analysis (DEA), a linear programming technique, was used to measure changes in technical efficiency by comparing the inputs used and the outputs produced across a cohort of hospitals, while adjusting for changes over time in case mix and case complexity. Rates of unscheduled readmissions and efficiency scores were computed for a sample of 245 hospitals for each year. Although both readmission rates and efficiency scores increased for most hospitals, there was no evidence that those hospitals that experienced the greatest increases in efficiency had the largest increases in their rates of unscheduled readmissions.

Abstracting and Indexing↗

PubMed2001

On the efficiency of public, welfare and private hospitals in Germany over time: a sectoral data envelopment analysis study.

This paper examines the efficiency of the German hospital sector over time and the relative efficiency of public, welfare (both nonprofit) and private (for-profit) hospital sectors using data from the Federal Statistics Office of German hospitals. Efficiency scores were computed using data envelopment analysis. The absolute efficiency of the hospital sector as a whole was found to have improved between 1991 and 1996. In this comparison, the empirical results showed that the hospitals in the public and welfare sector are relatively more efficient than private hospitals. Our results suggest that public, welfare and private hospital sectors have different best-practice frontiers; and that public and welfare hospital sectors appear to use relatively fewer resources than private hospitals. These results suggest differences in quality of care arising from ownership.

Efficiency, Organizational↗