Estimated Success Rate Research Articles

Estimating the Value of 'Going for It' (When No One Does)

This paper estimates success rates and the value of going for it on fourth down using three alternative approaches. First, the paper uses actual fourth down attempts from all regular season NFL games played in 1998, 1999 and 2000. It uses early quarter data and functional form assumptions to estimate success rates at various to distances. It also uses all fourth down attempts and a Heckman selection model to account for the selection bias in the data. Second, the paper estimates success rates at various positions and to distances from simulated data using Madden NFL 07. Third, the paper estimates a game theoretic structural model of fourth down attempts using actual third down data and estimated expected points. Romer (2006) claims to demonstrate that American football teams systematically err in their choice of whether to punt or go for it on fourth down, and uses those results to argue that firms do not maximize profits. The analysis below calls into question whether Romer indeed successfully demonstrated that football teams punt too often, which in turn casts doubt on the more general conclusions he drew from his results.

Genetic Signatures of Coancestry within Surnames

Surnames are cultural markers of shared ancestry within human populations. The Y chromosome, like many surnames, is paternally inherited, so men sharing surnames might be expected to share similar Y chromosomes as a signature of coancestry. Such a relationship could be used to connect branches of family trees, to validate population genetic studies based on isonymy, and to predict surname from crime-scene samples in forensics. However, the link may be weak or absent due to multiple independent founders for many names, adoptions, name changes and nonpaternities, and mutation of Y haplotypes. Here, rather than focusing on a single name, we take a general approach by seeking evidence for a link in a sample of 150 randomly ascertained pairs of males who each share a British surname. We show that sharing a surname significantly elevates the probability of sharing a Y-chromosomal haplotype and that this probability increases as surname frequency decreases. Within our sample, we estimate that up to 24% of pairs share recent ancestry and that a large surname-based forensic database might contribute to the intelligence-led investigation of up to approximately 70 rapes and murders per year in the UK. This approach would be applicable to any society that uses patrilineal surnames of reasonable time-depth.

A quasi-dense approach to surface reconstruction from uncalibrated images

This paper proposes a quasi-dense approach to 3D surface model acquisition from uncalibrated images. First, correspondence information and geometry are computed based on new quasi-dense point features that are resampled subpixel points from a disparity map. The quasi-dense approach gives more robust and accurate geometry estimations than the standard sparse approach. The robustness is measured as the success rate of full automatic geometry estimation with all involved parameters fixed. The accuracy is measured by a fast gauge-free uncertainty estimation algorithm. The quasi-dense approach also works for more largely separated images than the sparse approach, therefore, it requires fewer images for modeling. More importantly, the quasidense approach delivers a high density of reconstructed 3D points on which a surface representation can be reconstructed. This fills the gap of insufficiency of the sparse approach for surface reconstruction, essential for modeling and visualization applications. Second, surface reconstruction methods from the given quasi-dense geometry are also developed. The algorithm optimizes new unified functionals integrating both 3D quasi-dense points and 2D image information, including silhouettes. Combining both 3D data and 2D images is more robust than the existing methods using only 2D information or only 3D data. An efficient bounded regularization method is proposed to implement the surface evolution by level-set methods. Its properties are discussed and proven for some cases. As a whole, a complete automatic and practical system of 3D modeling from raw images captured by hand-held cameras to surface representation is proposed. Extensive experiments demonstrate the superior performance of the quasi-dense approach with respect to the standard sparse approach in robustness, accuracy, and applicability.

Organic hyperinsulinism and endoscopic surgery

Experience with minimally invasive surgery for organic hyperinsulinism is limited. No criteria for patient selection with special regard to sporadic, hereditary, multiple and malignant tumors have been defined. The estimated success rate of endoscopic surgery was retrospectively calculated by analysing 34 consecutive patients with organic hyperinsulinism operated on by open surgery. A literature search was undertaken to better define indications for endoscopic procedures. Differences in postoperative outcome (morbidity) between endoscopic and open procedures were analysed. Twenty-eight of 31 patients (90%) with solitary insulinomas and one of three patients with multiple insulinomas were correctly localized preoperatively. Twenty-six enucleations (76%) and eight distal resections (24%) including one endoscopic tail resection were performed. Theoretically only 14 out of 34 patients (41%) would have been suitable for endoscopic surgery (8 enucleations and 6 patients for distal resections which were enucleated using an open approach). Pancreatic fistulas were documented in three patients (9%). Reviewing 34 publications, 49 enucleations, 36 distal resections and 15 conversions to open surgery were performed, showing a higher proportion of distal resections in endoscopic surgery. The spleen was preserved in 88% of cases. Fourteen fistulas occurred after enucleations. Only solitary insulinomas localized in the pancreatic tail or superficially in the body or head may be candidates for endoscopic procedures. Patients with multiple insulinomas, MEN-1 syndrome or malignancy should undergo open surgery.

Characterization of Batch-Microfabricated Scanning Electrochemical-Atomic Force Microscopy Probes

A procedure for the batch microfabrication of scanning electrochemical-atomic force microscopy (SECM-AFM) probes is described. The process yields sharp AFM tips, incorporating a triangular-shaped electrode (base width 1 microm, height 0.65 microm) at the apex. Microfabrication was typically carried out on (1)/(4) 3-in. wafers, yielding 60 probes in each run. The measured spring constant of the probes was in the range 1-1.5 N m(-1). To date, processing has been carried out twice successfully, with an estimated success rate for the fabrication process in excess of 80%, based on field emission-scanning electron microscopy imaging of all probes and current-voltage measurements on a random selection of approximately 30 probes. Steady-state voltammetric measurements for the reduction of Ru(NH(3))(6)(3+) in aqueous solution indicate that the electrode response is well-defined, reproducible, and quantitative, based on a comparison of the experimental diffusion-limited current with finite element simulations of the corresponding mass transport (diffusion) problem. Topographical imaging of a sputtered Au film with the SECM-AFM probes demonstrates lateral resolution comparable to that of conventional Si(3)N(4) AFM probes. Combined electrochemical-topographical imaging studies have been carried out on two model substrates: a 10-microm-diameter disk ultramicroelectrode (UME) and an array of 1-microm-diameter UMEs, spaced 12.5 microm apart (center to center). In both cases, an SECM-AFM probe was first employed to image the topography of the substrates. The tip was then moved back a defined distance from the surface and use to detect Ru(NH(3))(6)(2+) produced at the substrate, biased at a potential to reduce Ru(NH(3))(6)(3+), present in bulk solution, at a diffusion-controlled rate (substrate generation-tip collection mode). These studies establish the success of the batch process for the mass microfabrication of SECM-AFM tips.

Perceptions of Gastroenterology Fellows Regarding ERCP Competency and Training

Background: The adequacy of ERCP training in the United States may be suboptimal because many training programs do not provide fellows with the exposure to the procedures necessary to achieve competence. Methods: A short survey questionnaire, which assesses the training program, the personal ERCP experience, the perceptions regarding training adequacy, and the post-training practice plans, was sent to all fellows graduating from gastroenterology training programs. Results: Graduating fellows performed a median of 140 ERCPs and 35 sphincterotomies during training, with an associated median comfort level for independently performing sphincterotomy of 7.5 on a scale of 1 to 10. The median estimated success rate for independent free cannulation was 75%. Based on nonparametric correlation and regression analysis, 180 ERCPs would be necessary to achieve a free cannulation rate of 80% and 69 sphincterotomies to achieve a comfort level of 8 on a scale of 1 to 10. Thirty-six percent of fellows achieved the number of procedures and cannulation success determined by this study to indicate procedural competence. Sixty-four percent of fellows did not achieve procedural competence and 33% reported inadequate ERCP training. Nevertheless, 91% of fellows expected to perform unsupervised ERCP after training. Conclusions: The results of this study are consistent with those of previously published studies demonstrating that 160 to 200 ERCP procedures are necessary to achieve competence to perform ERCP. The majority of graduating fellows do not achieve an acceptable success rate during training, yet still intend to perform ERCP after training.

EM‐MODE in high‐resolution DOA estimation for nonuniform array

AbstractRecently, the superresolution method has attracted significant attention as a high‐resolution method of estimation of the electromagnetic wave propagation environment for mobile communications as well as various kinds of wireless communications. With regard to the array shape used in the estimation problem of direction of arrival, various array configurations in addition to equally spaced arrays have been studied. Weiss and colleagues have proposed a method of realizing a virtual equally spaced array by applying the EM method and the IQML method to nonuniform arrays. In this paper, the EM‐MODE method based on this algorithm is proposed for estimation of the direction of arrival of the coherent wave by a nonuniform array and for improved processing. It is shown that improvement of the estimation success rate is possible by applying the improved processing in cases where estimation by the conventional EM‐MODE method is difficult. The errors in estimation of the direction of arrival when this method is applied are studied. It is shown that much better characteristics can be obtained than when real elements are equally spaced. © 2002 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 85(8): 47–56, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.1117

Treatment options for chronic immune (idiopathic) thrombocytopenia purpura in children

Immune (idiopathic) thrombocytopenic purpura (ITP) in children is usually acute and self-limiting, but may become chronic in 10% to 30% of patients. Salient issues in the treatment of childhood chronic ITP (cITP) include the following: the choice of immunomodulatory agent; the child's desire for unrestricted physical activity; interventions to avoid or defer splenectomy; and, finally, choosing when (and how) to perform splenectomy. Treatment for children with cITP during childhood usually is extrapolated from that for acute ITP. Treatment with pooled intravenous immunoglobulin (IVIg) and anti-D immunoglobulin often gives an acute response followed by a predictable decay of platelet count. Corticosteroids usually lead to a platelet increase; however, the associated adverse effects of chronic usage are generally unsatisfactory for most children and adolescents. With pulsed, high-dose corticosteroids, a durable platelet response is the exception, not the rule. More aggressive immunosuppression is usually reserved for patients who are symptomatic and refractory to the above treatments, including splenectomy. Although the estimated success rate ranges from 70% to 90%, the long-term outcome of splenectomy in children with cITP in not well described. In addition, the risk of fatal postsplenectomy infections is significant. A familiar initial strategy among pediatric hematologists thus involves deferral of splenectomy with the reasonable possibility of spontaneous recovery. Corticosteroids, anti-D, and IVIg are effective, temporizing medical alternatives to splenectomy in treating cITP in children. Quality-of-life measurements in children with cITP may help to stimulate the development of new approaches.

Update on the Subconjunctival THC:YAG (Holmium) Laser Sclerostomy Ab Externo Clinical Trial: A 4-Year Report

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create 93 thermal sclerostomies ab externo in 81 glaucomatous eyes of 76 patients. Pulse energies of 80 to 120 mJ were used, with a repetition rate of 5 pulses per second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Estimated probability of success was 0.66 at 12 months and 0.57 up to 30 months. The mean intraocular pressure in the successful cases was 12.8 +/- 4.0 mm Hg.

Effects of supplemental mass pollination (SMP) in a young and a mature seed orchard of Pinus sylvestris

The effects of supplemental mass pollination (SMP) were studied in two Pinus sylvestris seed orchards differing in pollen production. Pollen was dusted over the whole tree during the period of peak female receptivity using a pressurized backpack sprayer. The success of SMP was assessed by means of allozyme markers. In the orchard with high pollen production, detectable differences in SMP success rate were found between clones, but the success rate was not influenced by the number of pollinations per day. The average estimated success rate of SMP was 19%. In the orchard with low pollen production, no significant differences in SMP success rate were found between years (22 versus 34%) or between clones. The SMP success rate in the low pollen production orchard varied between 14 and 69%.

REVERSAL OF VASECTOMY AND THE GENERAL SURGEON

SUMMARY Reversal of vasectomy is a difficult procedure. Most surgeons still perform a macroscopic vasovasostomy. However, there is a little guidance in the current literature on the results that can be expected from such procedures. Patients may therefore be given unrealistic expectations preoperatively. Our study shows the results of macroscopic reversals of vasectomy performed over a 9‐year period. A survey of Welsh surgeons is also presented concerning their preferred techniques and estimated success rates for reversals. The study clearly shows that a macroscopic vasovasostomy is the commonest method employed, with a wide variation in estimated success rates. Patients considering a macroscopic reversal of vasectomy should be warned of a less than 20% success rate.

Success rate of supplemental mass pollination in a seed orchard ofPinus sylvestrisL.

Two experiments (Expt 1, Expt 2) with supplemental mass pollination (SMP) were carried out in a seed orchard of Pinus sylvestris L. in order to assess the biological and operational prospects for SMP. The success of the SMP was studied by means of allozyme markers. In Expt 1 the pollen mix was applied very close to each female strobilus. The estimated success rates for treatments varied between 66% and 84%. When supplemental pollination was done at peak receptivity, one single pollination was enough to obtain high success rates. In Expt 2 the pollen mix was dusted over clusters of receptive strobili on whole‐trees. The estimated success rates for treatments varied between 10% and 23%. The success rates improved when the trees were pollinated on more than one occasion per day during the receptive period. The overall conclusion is that SMP is practical for P. sylvestris seed orchards.

Endodontic treatment of teeth with periapical radiolucent areas in a general dental practice

Clinical details of 192 teeth with preoperative periapical radiolucent areas, treated endodontically, are described. The presenting signs and symptoms as well as some postoperative observations are listed. Periapical radiolucent areas were most frequently found related to maxillary teeth: 55 percent were adjacent to teeth with a single root canal and 30 percent related to teeth with three root canals. Radiographic follow-up 1 or more years after therapy was possible in 124 of the root-filled teeth: of those teeth, 59 percent showed disappearance of the radiolucent area and 29 percent exhibited a decrease in size of the area. The degree of success did not appear to be related to the number of root canals filled per tooth but, rather, to whether or not the root filling was short of the radiographic apex. In addition, the prognosis made at the time of root filling was accurate in most cases when compared to the estimated success rates.

A Note on the Applicability of the Method of Oddments to 3 x 3 Two Person Zero Sum Games

This paper examines a short-cut method for the solution of two person zero-sum games. The method of oddments always works for 2 x 2 games which do not exhibit saddle points. When larger games are examined, the method is not universally successful. The paper examines the estimated success rate for the method of oddments using 3 x 3 matrices whose elements have been randomly selected from a uniform probability distribution.