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Knowledge of spatio-temporal couplings such as pulse-front tilt or curvature is important to determine the focused intensity of high-power lasers. Common techniques to diagnose these couplings are either qualitative or require hundreds of measurements. Here we present both a new algorithm for retrieving spatio-temporal couplings, as well as novel experimental implementations. Our method is based on the expression of the spatio-spectral phase in terms of a Zernike-Taylor basis, allowing us to directly quantify the coefficients for common spatio-temporal couplings. We take advantage of this method to perform quantitative measurements using a simple experimental setup, consisting of different bandpass filters in front of a Shack-Hartmann wavefront sensor. This fast acquisition of laser couplings using narrowband filters, abbreviated FALCON, is easy and cheap to implement in existing facilities. To this end, we present a measurement of spatio-temporal couplings at the ATLAS-3000 petawatt laser using our technique.

Bovine tuberculosis (bTB) is a chronic, infectious and zoonotic disease of domestic and wild animals caused mainly by Mycobacterium bovis. This study investigated farm management factors associated with recurrent bTB herd breakdowns (n = 2935) disclosed in the period 23 May 2016 to 21 May 2018 and is a follow-up to our 2020 paper which looked at long duration bTB herd breakdowns. A case control study design was used to construct an explanatory set of farm-level management factors associated with recurrent bTB herd breakdowns. In Northern Ireland, a Department of Agriculture Environment and Rural Affairs (DAERA) Veterinarian investigates bTB herd breakdowns using standardised guidelines to allocate a disease source. In this study, source was strongly linked to carryover of infection, suggesting that the diagnostic tests had failed to clear herd infection during the breakdown period. Other results from this study associated with recurrent bTB herd breakdowns were herd size and type (dairy herds 43% of cases), with both these variables intrinsically linked. Other associated risk factors were time of application of slurry, badger access to silage clamps, badger setts in the locality, cattle grazing silage fields immediately post-harvest, number of parcels of land the farmer associated with bTB, number of land parcels used for grazing and region of the country.

We present evidence for pressure-broadened sodium absorption and a steep scattering slope, using low-resolution optical transmission spectra of the hot Jupiter WASP-94Ab. Broad sodium is an indicator of a cloud-free atmosphere, suggesting the highly-inflated WASP-94Ab is an excellent target for molecular abundance determination using infrared spectroscopy. Our low-resolution study of the atmosphere of this exoplanet, a highly-inflated hot Jupiter with a radius of 1.7 Jupter radii and a mass of 0.5 Jupiter masses and an estimated equilibrium temperature of 1500 K in the wavelength range of 3800 - 7140 Å has revealed a clear atmosphere with a 4.9σ sodium absorption and a scattering slope through the LRG-BEASTS survey. It was measured with the EFOSC2 spectrograph on the ESO New Technology Telescope - the first time this instrument has been used for transmission spectroscopy. The ongoing work on high resolution observations from HARPS (taken as part of the HEARTS survey) is probing the Doppler shifts of the sodium line doublet., {"references":["Neveu-VanMalle, M. et al. (2014), A&A","Garhart, E. et al. (2020), AJ","Kirk, J. et al. (2017), MNRAS","Louden, T. et al. (2017), MNRAS","Kirk, J. et al. (2018), MNRAS","Kirk, J. et al. (2019), AJ","Alderson, L. et al. (2020), MNRAS","Kirk, J. et al. (2021), AJ","Zhang, M. et al. (2019), PASP","Ahrer, E. et al. (2022), MNRAS"]}

High-resolution spectroscopy is used to detect and characterise the atmospheres of transiting planets, giving us information about their chemical composition, temperature profiles, and the presence of clouds and winds, mainly in hot, giant planets. State-of-the-art instrumentation is pushing the precision of our measurements towards the detection of smaller exoplanets and their atmospheres (Neptune and Earth-sized planets). Of special interest are the few planets located in or close to the "Neptune desert", a lack of Neptune-size planets in close orbits around their host stars. The study of such planets can provide insight to their formation and evolution, and the existence of the desert. In this work, we study the presence of water vapour in the bloated super-Neptune WASP-166 b. This planet orbits an F9-type star in a close orbit of 5.4 days (0.06 AU) and is located in the Neptune desert. The presence of sodium in its atmosphere has recently been confirmed by our team using the same observations as here. Despite its close-in orbit, it preserved its atmosphere, making it a benchmark target for exoplanet atmosphere studies in the desert. We analyse two full transits observed in the visible with the high-resolution spectrograph ESPRESSO. We perform a principal component analysis on the observed spectra to remove telluric features from the Earth atmosphere and the stellar features, and then use the cross-correlation technique to try to isolate the planetary signal. To compute the cross-correlation, we employ a range of water models with different temperatures and cloud deck levels, as well as different line lists, but no model results in a significant detection. We use a Bayesian retrieval tool to simultaneously estimate limits on the abundance of water and the altitude of a cloud layer. This work provides further insight on the Neptune desert planet WASP-166 b, which in addition is scheduled to be observed with JWST.

We have searched the light curves of low mass stars with TESS 2 min cadence data in Cycles 1 & 2 for Quasi Periodic Pulsations (QPPs) in stellar flares. We identified 11 flares from 7 stars which have QPPs with periods ranging from ~10 min to 70 min. We use several methods for determining the loop length of the flares and find they can extend to a handful of stellar radius. Based on scaling relationships we determine the magnetic field strength in the coronal loops and compare the loop lengths to distance to the habitable zone for the host star., The work highlighted in this poster has been submitted to Solar Physics

Objective To evaluate outcome trends of neonates born very preterm in 11 high-income countries participating in the International Network for Evaluating Outcomes of neonates. Study design In a retrospective cohort study, we included 154 233 neonates admitted to 529 neonatal units between January 1, 2007, and December 31, 2015, at 24(0/7) to 31(6/7) weeks of gestational age and birth weight

© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. Objective To determine the accuracy of the National Institute of Child Health and Human Development (NICHD) calculator in predicting death and neurodevelopmental impairment in Australian and New Zealand infants. Design Population-based cohort study. setting Australia and New Zealand. Patients Preterm infants 22–25 completed weeks gestation. Interventions Comparison of NICHD calculator predicted rates of death and death or neurodevelopmental impairment, with actual rates recorded in the Australian and New Zealand Neonatal Network cohort. Main outcome measures Infant death and death or neurodevelopmental impairment rates. results A total of 714 infants were included in the study. Of these infants, 100 (14.0%) were

Background: The Healthy Aging Group Education Series was developed by interprofessional primary healthcare team and researchers to address the health needs and goals of nutrition, fitness and function, and advance care planning identified using data from a randomized controlled trial. Methods: Older adults from one family practice were invited to attend the series and participate in the descriptive evaluation. The series was developed based on aggregated patient-reported data on health goals; risks and needs gathered using a structured process. Surveys which included open-ended feedback and rated items of content and delivery evaluated the series. Program delivery expenses were itemized. Results: Of 69 people invited, a range of 26 to 37 people attended sessions. The overall series was rated positively with respect to meeting attendees’ expectations and being well-organized; 69.2% and 76.9% of attendees gave a positive rating respectively. Individual session feedback indicated a range of positive ratings (82.8-100%) for categories of effective and engaging presenters and providing new and relevant information. The majority of attendees (76.9%) indicated they would recommend the series to friends. The series continues to be offered regularly in the family practice. Conclusion: Unlike other types of group care, health goal information (and not disease diagnoses) was used to develop and deliver the program.

We studied the diet and prey selection of Desmognathus brimleyorum in southeastern Oklahoma relative to salamander size class and availability of prey. We found significant differences in prey consumed by large and small size classes. Also, by comparison with invertebrate samples taken in one salamander habitat, prey selected by D. brimleyorum was significantly disproportionate to its availability. Dipterans were taken more commonly than encountered in the habitat, and isopods taken less commonly.

BackgroundThe primary aim of this study is to assess, using individual participant data (IPD) meta-analysis, the effects of administration of antenatal magnesium sulphate given to women at risk of preterm birth on important clinical outcomes for their child such as death and neurosensory disability. The secondary aim is to determine whether treatment effects differ depending on important pre-specified participant and treatment characteristics, such as reasons at risk of preterm birth, gestational age, or type, dose and mode of administration of magnesium sulphate.MethodsDesignThe Antenatal Magnesium Individual Participant Data (IPD) International Collaboration: assessing the benefits for babies using the best level of evidence (AMICABLE) Group will perform an IPD meta-analysis to answer these important clinical questions.Setting/TimelineThe AMICABLE Group was formed in 2009 with data collection commencing late 2010.Inclusion CriteriaFive trials involving a total 6,145 babies are eligible for inclusion in the IPD meta-analysis.Primary study outcomesFor the infants/children: Death or cerebral palsy. For the women: Any severe maternal outcome potentially related to treatment (death, respiratory arrest or cardiac arrest).DiscussionResults are expected to be publicly available in 2012.

The objective of this paper is to compare market share forecasts using parameter estimates from three different arrangements of single source scanner data. The data arrangements are coupled with two different attraction models and a well known naive model. Each attraction model is specified with either autocorrelated errors or with a lagged attraction term on the right hand side. Forecasts are compared using data aggregated across stores and disaggregated by store. In the later case, parameters for each store are estimated and a composite (average) share forecast is formed or the data are pooled and a single set of estimated parameters provide the forecast. The study finds that the full cross effects model with an autocorrelated error structure fits the data better than alternative models. However, the differential effects model with an autocorrelated error structure provides the best forecasts. With respect to the alternative data arrangements, the data aggregated across stores (i.e. chain level data) provides the best forecasts.

Empirical research (as well as theoretical reasoning) has led to contradictory findings with regard to whether increases in brand advertising activities lead to increases or decreases in consumer price sensitivity. Lack of data to measure the exposure of individual households to advertisements and to capture competitive activities has been an important limitation to date. This study, using single source data for a midwestern US market, finds that increased advertising exposures are associated with increases in a household's brand choice price sensitivity for two frequently purchased consumer products. However, under high levels of advertising exposure, it is possible for a household's brand choice price sensitivity to decrease.

This pilot study assessed the effectiveness of external pneumatic compression (EPC) with gradient elastic stockings (GES) and low dose heparin (LDH) in the prevention of deep vein thrombosis (DVT) in acute spinal cord injured (SCI) patients in the first 14 days following injury. Twenty-one consecutive patients within 48 hrs of injury with acute C2 through T12 motor complete or nonfunctional motor incomplete spinal cord lesions were enrolled. 125 I fibrinogen scanning was performed daily. A positive scan was confirmed by venography. Thrombosis was demonstrated in 1/19 patients. A control group from a previous study confirmed thrombosis in 6/17 patients (p = 0.04). Comparison of extent of thrombosis demonstrated a reduction in the treated group (p = 0.02). This pilot study demonstrates that EPC with GES plus LDH may be an effective prophylactic regimen in these patients.

Published case histories of expansive soil/rock materials have historically reported the effects of vertical expansion, and the lessons learned from vertical expansion of soil/rock materials are numerous. In this case the abutment walls of the Las Colinas Bridge were constructed using the increasingly popular, top-down construction method which, while facilitating the construction process, restricts lateral earth movement. As a result of restraining the lateral earth movement, high horizontal stresses in the clay shale were transferred to the bridge resulting in significant structural problems in the bridge deck and guard rails. This is a case study of a bridge built over and contemporaneous to the development of the President George Bush Turnpike (PGBT) northwest of Dallas, Texas. The geologic formation that impacted this bridge is the Eagle Ford Group (Eagle Ford) a highly plastic, residual clay soil grading to clay shale at relatively shallow depths. This paper covers the studies of the in-situ lateral pressures using the Marchetti flat plate dilatometer test (DMT) in conjunction with monitoring soil mass movement using inclinometers. The paper compares its findings with information in the literature from studies and research that have experienced comparable lateral earth pressures.

This paper presents a framework for organizing and discussing factors influencing consumer choice dynamics, how these factors may be incorporated into models of buyer behavior and problems that may arise in estimating such models. The paper identifies research issues and delineates possible approaches.

We investigate the improved detection of extrasolar planets around eclipsing binaries using eclipse minima timing, and extrasolar moons around transiting planets using transit timing, offered by the upcoming COROT (ESA, 2005), Kepler (NASA, 2007), and Eddington (ESA 2008) spacecraft missions. Hundreds of circum-binary planets should be discovered, and a thorough survey of moons around transiting planets will be accomplished by these missions., Comment: 4 pages, pdf only, submitted to IAU Symp. Vol. S-213, BIOASTRONOMY 2002: LIFE AMONG THE STARS, ed. Ray Norris

For the eclipsing binary system CM Draconis, eclipse minimum times have been monitored with high precision between 1994 and 1999. Periodic deviations of minimum times from a linear ephemeris may indicate the presence of an orbiting third body. Individual measurements of 41 eclipse minimum times result in a standard deviation from linear ephemeris of 5.74 seconds. A power spectral analysis of the residuals reveals only one periodicity with more then 2 seconds amplitude. This feature, with a periodicity between 750 and 1050 days has an amplitude of 2.8+-0.5 seconds, and is also present with similar phases if the power spectral analysis is performed independently for primary and secondary eclipses. It would be compatible with a planet of 1.5-3 Jupiter masses at an orbital distance of 1.1-1.45 AU to the binary barycenter. The assignation of a planet to the CM Dra system can however only be upheld if this periodicity can be followed in future observations for several years. For low-mass eclipsing binary stars, the method of eclipse minimum timing allows one to reach mass limits for the detection of third bodies well below that feasible by radial velocity measurements., Comment: 4 pages, 4 figures. Update on 2 may 2000: following referee comments added figure for powerspectra phase, elaborate on precision of ephemeris, fixed typos

Numerical model studies were conducted to assist the U.S. Army Engineer District, Wilmington, in evaluating potential plans for modifying the Cape Fear River entrance channel and in preparing General Reevaluation Reports. The offshore wave climate was evaluated, and Wave Information Studies hindcasts from 1976-1995 were used as the incident wave climate. Wave transformation around Frying Pan Shoals and nearshore bathymetry were modeled with the spectral wave model STWAVE. Wave climate was estimated in existing and plan navigation channels and along the Brunswick County, North Carolina, coast west of Cape Fear. Since potential areas for offshore disposal of dredged material are included in the wave model coverage, wave climate in the finally selected offshore dredged material site can be estimated from study results as needed. Nearshore wave climate and littoral transport were estimated for existing conditions between Cape Fear and the middle of Ocean Isle Beach to the west. Other bathymetric conditions studied in the more localized area between Cape Fear and the middle of Long Beach are historical 1872 bathymetry, a plan navigation channel, and the plan channel with adjusted ebb-tide shoals representing a long-term equilibrium with the relocated channel. Potential longshore annual transport rates were computed at approximately 55-m (180-ft) intervals along these coasts.

Results from a photometric search for extrasolar planetary transits across the eclipsing binary CM Dra are presented. The TEP (Transits of Extrasolar Planets) network has observed this star since 1994, and a lightcurve with 617 hours of coverage has been obtained. The data give a complete phase coverage of the CM Dra system at each of the 3 years of observations, with a noise of less than 5 mmag. New epoch and period values for CM Dra are derived, and a low flare rate of 0.025/hr has been confirmed. The absence of periodic variations in eclipse minimum times excludes the presence of very massive planets with periods of less than a few years. The lightcurve was visually scanned for the presence of unusual events which may be indicative of transits of extrasolar planets with 'massive earth' sizes. Six suspicious events were found which are being followed up for future transits, by planets with sizes between 1.5 and 2.5 RE (Earth Radii). However, none of these events has amplitudes compatible with planets larger than 2.5 RE. Coplanar planets larger than 2.5 RE and with orbital periods of less than 60 days can therefore be ruled out with a confidence of about 80%. Planets smaller than 1.5 RE cannot be detected in the data without a sub-noise detection algorithm. A preliminary signal detection analysis shows that there is a 50% detection confidence for 2 RE planets with a period from 10 to 30 days with the current data. This data-set demonstrates that it is possible to detect terrestrial sized planets with ground based photometry, and that strong constraints on the sizes of planets orbiting in the plane of the CM Dra system can be set., Comment: 12 pages, 8 figures (in 11 individual ps or eps files), to be published in A&A

Solar’s Mares 100LS industrial gas turbine rated at 11.2 MW (15,000 hp) and 34% thermal efficiency at ISO conditions is the latest model Mars gas turbine evolved from an ongoing program of planned continuous product improvement. Since the Mars gas turbine was introduced in 1978, over 250 units have been ordered and approximately 4 million hours of field experience have been logged with packages designed for gas compression, pump drive, and electrical power generation. This paper updates the description of the Mars gas turbine to include the three latest enhancements: redesign of the first two compressor stages for increased output power and efficiency; SoLoNOx (dry low NOx, antipollution) combustion system: and a new low speed power turbine to improve output drive versatility.Copyright © 1994 by ASME

In February 1996, the United States Department of Agriculture Forest Service completed a renovation project at Horsethief Spring, LeFlore County, Oklahoma. This spring is located on the north face of Winding Stair Mountain along the Talimena Scenic Drive (State Highway 1; T3N R25E Sec. 7). Renovations included paving the existing parking area, installing a restroom facility and picnic site above the spring, resurfacing the existing horse trail that crosses just below the spring origin, reconstructing a stone wall next to the lower parking area, and removing riparian vegetation along the upper portion of the spring. The area of vegetation removal was approximately 0.1 acres. Although this may seem to be a small-scale disturbance, we were concerned about the potential impacts on sensitive salamander species that depend on the spring habitat.

In 1964, Palda published the results of the first application of lagged-variable regression models to the question of advertising's sales effectiveness. In doing this he supplied the first empirically supported quantification of the salesadvertising relationship. The purpose of this paper is to reexamine some of the issues which have been raised subsequent to Palda's research and to focus directly on some of the structural issues associated with the class of models examined by Palda (see Schmalensee 1972). As such this paper will focus on these issues by comparing results from the following models: (1) Palda's (1964) original distributed-lag model; (2) a current-effects model (Clarke and McCann 1973); (3) an extension of the above model utilizing a second-order autoregressive structure; (4) a brand-loyalty model, structured after early work by Kuehn (1961); and (5) several Pascal lag distributions (see Kmenta 1971).

The authors briefly review the literature associated with the autocorrelated current effects model and present a simple procedure that recovers its parameters from time-aggregated data when the level of aggregation is known. The procedure is based partly on the estimation of a first-order autocorrelation coefficient. The procedure is illustrated and its properties are compared with those of a GLS procedure by means of a Monte Carlo experiment. In many of the tested cases, there is good recovery of the microparameters with aggregated data.

This study demonstrates the application of a scientific method of reinforcer selection for children and tests the hypothesis that reinforcer preference fits a hierarchical or developmental progression model. A paired-comparison questionnaire was administered to second-, fourth-, and sixth-grade boys and girls ({N = 398). who were asked to choose the reinforcer they most preferred from each item pair. The data were analyzed using Schonemann and Wang's (1972) model for multidimensional analysis of paired comparisons data. For each group of students. preference ratings (BTL values) were determined for each of 20 stimuli. The two major dimensions influencing reinforcer preference were (a) physical or sedentary activities and (b) immediate or delayed gratification of the reinforcer. In addition, two minor dimensions influencing reinforcer preference were identified: (a) whether a reinforcer was social or tangible in nature and (b) peer value and activity.

Linear aggregation models employing unit and equal weights have been shown to be superior to human decisions in a surprising range of decision situations. In addition, decisions based on these models have often been found to be superior to those based on linear regression models (LRMs). This general issue was explored for repetitive decisions in production planning. The problem considered differs in several aspects from the types of problems investigated previously: (1) the problem is dynamic rather than static; (2) a set (or vector) of interactive decisions dependent on previous decisions is required to be made, where a decision in stage t , the dependent variable, becomes an independent variable in stage t + 1; and (3) the criterion function is cost with a quadratic loss function (rather than the correlation measure of R 2 ). Moreover, since repetitive decisions were involved, the parameters of the models were estimated using past human decisions. These were used to predict specific values of the decision variables (rather than rank order), which in turn were employed recursively to predict values of the decision variables at subsequent stages. While decisions from equal weighting rules were found to be superior to human decisions and not greatly inferior to decisions from linear regression models, decisions from unit weighting rules performed poorly. The rationale for such performance is discussed, indicating that previous theoretical and empirical research on linear weighting models is not generally applicable to dynamic, multivariate interactive decisions problems with lagged variables.

This article reports the findings of an empirical investigation into the movement of competitive market share. Palda's cumulative advertising model is adapted to include a price variable, and the analysis is extended to a multibrand market. The statistical methodology employed in the investigation overtly recognizes the competitive interdependence of the brands studied and exploits this interdependence in its estimation procedures.

Griliches’ test is not completely adequate for discriminating among several popular models of advertising effectiveness and, as a result, its use by several researchers in that area has produced inconclusive results. The authors review some past applications of Griliches’ test and develop a testing procedure which will properly discriminate between models of current and cumulative advertising effects. Finally, an empirical example of the proposed procedure is presented.

The authors investigate the measurement of the sales-advertising relationship with temporally aggregated data. Previous work has produced encouraging results for recovering micro-level parameters of the brand loyal model from data aggregated over time, but the Koyck model has not been studied in this context. The authors develop methods for recovering micro parameters of the Koyck model and extend the results for the brand loyal model. The results are supported by simulation experiments examining both asymptotic and small-sample properties.

Forty-four subjects were assigned to a High or Low Abuse Potential Group based upon their Child Abuse Potential (CAP) Inventory's abuse scale scores. Each subject's heart rate (HR) and skin conductance (SC) were monitored while the subject was viewing videotape presentations of an infant smiling, crying, or quiescent. The High Abuse Potential Group had a faster peak HR throughout the videotape presentations with no significant differences among videotape segments. The Low Abuse Potential Group had a slower peak HR and had a significantly lower HR during the Smile and Cry segments than in the second Quiescent segment. The males accounted for most of the significant SC variability among tape segments. The pattern of SC responses revealed that the males were less aroused than the females, the Low Abuse Potential Group was less aroused than the High Abuse Potential group, and all four groups showed a decrease in arousal toward the end of the videotape presentations. The results provide support for the concurrent validity of the CAP inventory.

In a well-known article, Blattberg and Jeuland (Blattberg, R. C., A. P. Jeuland. 1981. A micromodeling approach to investigate the advertising-sales relationship. Management Sci. 27 (September) 988–1005.) apply nonlinear estimation to a market level model based on aggregation of an individual level model of consumer response to advertising. In this paper, a simpler estimation technique is developed and successfully employed for that same model.

The purpose of this report is to discuss, explain, and position the more notable literature on logically consistent market share demand models. More specifically, the report explains and provides examples for the analysis by McGuire et al., discusses the recent paper by Naert and Bultez, and comments on a recent related article by Beckwith.

This article reports the results of a demand analysis investigating the underlying structure and price responsiveness of a consumer product market. The analysis employs a non-linear demand model arising directly from recent empirical research on individual consumer behavior and is concerned with the determinants of market share in a competitive environment. The empirical investigation focuses on the form of the relationship relating price and adverstising expenditures to market share, and in this interest a number of linear models relating these variables were fitted to provide a reference for the results obtained with the non-linear model. Finally, the results of the study were put into perspective and related to the relevant literature.

Analysis of market share movements for a low-cost, frequently purchased consumer product. An examination of the influence of price and advertising on sales is presented.

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MATE (Marketing Analysis Training Exercise) simulates a market for one multi-branded product—packaged detergents— in form of a game. It can be used to train marketing students and junior executives as well as to screen and experiment with marketing strategies prior to trial runs in the actual market, thus paralleling the use of a pilot plant.

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Abstract Total fluid production and hence oil production can be increased significantly by production can be increased significantly by evaluating and modifying presently installed gas lift system. Many gas lift systems were improperly designed initially, and as a system was expanded, the inefficiencies were compounded. The more critical design features of a continuous gas lift system are tubing sizes, operating gas lift pressure, proper valve design, and surface back pressure. The optimization of any one of these features will improve a system, but the proper design of all four will result in the most efficient system. This paper will show how production from a 6,000 ft, well was increased from 620 bbl/D to 2,280 bbl/D by optimizing the gas lift system. The effects of changing the tubing to a larger size are graphically illustrated. Streamlining of wellheads, flow lines and separator headers are shown to be a necessity in reducing excessive surface pressure. A discussion of an efficient lift valve design is included. The changing of a gas lift system from some eight valves to fourteen valves and placing them in a so-called stacked condition is one of the more important features in increasing production. A discussion of gas lift valve choke sizes is included as well as the necessity for a high system pressure. In this case, pressure was increased from 900 psi to 1300 psi, thereby providing a lower gas injection point required for maximum production. point required for maximum production. By the proper analysis of a high volume gas lift System, production can be increased as much as 200% by carefully analyzing the following features: - tubing size, - operating pressure, - surface wellhead restrictions, and - the number and spacing of gas lift valves. Once a system is considered to be operating at its maximum efficiency, it should not be neglected. Proper monitoring is as important as the initial design and installation. At least bimonthly well production tests should be conducted with complete production information recorded. This then provides necessary information prior to a workover whereby a complete system prior to a workover whereby a complete system analysis can be applied for the purpose of increasing production. production. Many beneficial changes can be made with very little expense if a Proper evaluation is conducted and analyzed.

To assess dynamic magnetic resonance angiography (MRA) as an alternative to catheter angiography in patients with popliteal artery entrapment syndrome (PAES).Nine patients with surgically proven PAES underwent provocation digital subtraction angiography (DSA) and 2-dimensional time-of-flight dynamic MRA of the popliteal fossae (total of 17 limbs). Eight normal volunteers also underwent dynamic MRA (total of 16 limbs). Two observers blinded to the surgical findings and the results of DSA independently evaluated the 33 limbs of the 17 subjects on the basis of maximum-intensity projection images and transverse MRA source images. The degree of stenosis was graded and compared with that indicated by DSA.Among the 17 limbs of patients with surgically proven PAES, dynamic MRA suggested the correct diagnosis in 13 (76%) by indicating stenosis greater than 50%. Dynamic MRA indicated stenosis of 1% to 50% for 4 (25%) of the 16 normal limbs and no stenosis in the other 12 normal limbs (i.e., no false positive results).Catheter angiography is not necessary if dynamic MRA indicates stenosis of greater than 50% in patients with clinical suspicion of PAES, but is recommended if dynamic MRA indicates stenosis of 1% to 50%.