Genetic Mapping for QTL Associated with Seed Nickel and Molybdenum Accumulation in the Soybean 'Forrest' by 'Williams 82' RIL Population.

Understanding the genetic basis of seed Ni and Mo is essential. Since soybean is a major crop in the world and a major source for nutrients, including Ni and Mo, the objective of the current research was to map genetic regions (quantitative trait loci, QTL) linked to Ni and Mo concentrations in soybean seed. A recombinant inbred line (RIL) population was derived from a cross between 'Forrest' and 'Williams 82' (F × W82). A total of 306 lines was used for genotyping using 5405 single nucleotides polymorphism (SNP) markers using Infinium SNP6K BeadChips. A two-year experiment was conducted and included the parents and the RIL population. One experiment was conducted in 2018 in North Carolina (NC), and the second experiment was conducted in Illinois in 2020 (IL). Logarithm of the odds (LOD) of ≥2.5 was set as a threshold to report identified QTL using the composite interval mapping (CIM) method. A wide range of Ni and Mo concentrations among RILs was observed. A total of four QTL (qNi-01, qNi-02, and qNi-03 on Chr 2, 8, and 9, respectively, in 2018, and qNi-01 on Chr 20 in 2020) was identified for seed Ni. All these QTL were significantly (LOD threshold > 2.5) associated with seed Ni, with LOD scores ranging between 2.71-3.44, and with phenotypic variance ranging from 4.48-6.97%. A total of three QTL for Mo (qMo-01, qMo-02, and qMo-03 on Chr 1, 3, 17, respectively) was identified in 2018, and four QTL (qMo-01, qMo-02, qMo-03, and qMo-04, on Chr 5, 11, 14, and 16, respectively) were identified in 2020. Some of the current QTL had high LOD and significantly contributed to the phenotypic variance for the trait. For example, in 2018, Mo QTL qMo-01 on Chr 1 had LOD of 7.8, explaining a phenotypic variance of 41.17%, and qMo-03 on Chr 17 had LOD of 5.33, with phenotypic variance explained of 41.49%. In addition, one Mo QTL (qMo-03 on Chr 14) had LOD of 9.77, explaining 51.57% of phenotypic variance related to the trait, and another Mo QTL (qMo-04 on Chr 16) had LOD of 7.62 and explained 49.95% of phenotypic variance. None of the QTL identified here were identified twice across locations/years. Based on a search of the available literature and of SoyBase, the four QTL for Ni, identified on Chr 2, 8, 9, and 20, and the five QTL associated with Mo, identified on Chr 1, 17, 11, 14, and 16, are novel and not previously reported. This research contributes new insights into the genetic mapping of Ni and Mo, and provides valuable QTL and molecular markers that can potentially assist in selecting Ni and Mo levels in soybean seeds.

Acousto-optic holography.

Acousto-optic sensing is based on the interaction between sound and light: pressure waves induce density variations, which, in turn, alter the way light propagates in air. Pressure fields are, thus, characterized by measuring changes in light propagation induced by pressure waves. Although acousto-optic sensing provides a way of acquiring acoustic information noninvasively, its widespread application has been hindered by the use of reconstruction methods ill-suited for representing acoustic fields. In this study, an acousto-optic holography method is proposed in which the sound pressure in the near field of a source is captured via acousto-optic sensing. The acousto-optic measurements are expanded into propagating and evanescent waves, as in near-field acoustic holography, making it possible to completely characterize the radiated field noninvasively. An algebraic formulation of the wave expansion enables the use of arbitrary sets of projections. The proposed method is demonstrated experimentally by capturing the acoustic field radiated by a vibrating plate. Accurate holographic reconstructions of the pressure, particle velocity, and intensity fields are obtained using purely optical data. These results are particularly significant for the study of sound fields at mid and high frequencies, where using conventional transducers could perturb the measured field and spatial sampling requirements are challenging.

The Soybean High Density 'Forrest' by 'Williams 82' SNP-Based Genetic Linkage Map Identifies QTL and Candidate Genes for Seed Isoflavone Content.

Isoflavones are secondary metabolites that are abundant in soybean and other legume seeds providing health and nutrition benefits for both humans and animals. The objectives of this study were to construct a single nucleotide polymorphism (SNP)-based genetic linkage map using the 'Forrest' by 'Williams 82' (F×W82) recombinant inbred line (RIL) population (n = 306); map quantitative trait loci (QTL) for seed daidzein, genistein, glycitein, and total isoflavone contents in two environments over two years (NC-2018 and IL-2020); identify candidate genes for seed isoflavone. The FXW82 SNP-based map was composed of 2075 SNPs and covered 4029.9 cM. A total of 27 QTL that control various seed isoflavone traits have been identified and mapped on chromosomes (Chrs.) 2, 4, 5, 6, 10, 12, 15, 19, and 20 in both NC-2018 (13 QTL) and IL-2020 (14 QTL). The six QTL regions on Chrs. 2, 4, 5, 12, 15, and 19 are novel regions while the other 21 QTL have been identified by other studies using different biparental mapping populations or genome-wide association studies (GWAS). A total of 130 candidate genes involved in isoflavone biosynthetic pathways have been identified on all 20 Chrs. And among them 16 have been identified and located within or close to the QTL identified in this study. Moreover, transcripts from four genes (Glyma.10G058200, Glyma.06G143000, Glyma.06G137100, and Glyma.06G137300) were highly abundant in Forrest and Williams 82 seeds. The identified QTL and four candidate genes will be useful in breeding programs to develop soybean cultivars with high beneficial isoflavone contents.

A Fourier transform formulation for radiation from an unbaffled cylinder.

A formulation based on the Fourier transform and generalized functions, and implemented with a fast Fourier transform, is developed to solve a classic acoustics problem: radiation from an unbaffled cylinder with flat endcaps. The endcaps as well as the cylindrical surface have a specified modal vibration pattern, and the problem is solved using the sum of two independent formulations based on the Fourier transform: (1) a vibrating cylinder with rigid endcaps and (2) a rigid cylindrical tube with vibrating diaphragms at its ends. The resulting nearfield solution correctly models the diffraction effects generated at the sharp ends of the cylinder. Calculation of the farfield radiated pressure follows directly from the nearfield solutions with a slight modification to the standard formulas. Results from the formulations are validated with a boundary element simulation and show excellent agreement with errors of less than 1%.

Bistatic scattering of an elastic object using the structural admittance and noise-based holographic measurements.

This paper presents a method to calculate the bistatic response of an elastic object immersed in a fluid using its structural Green's function (in vacuo structural admittance matrix), calculated by placing the object in a spatially random noise field in air. The field separation technique and equivalent source method are used to reconstruct pressure and velocity fields at the object's surface from pressure measurements recorded on two conformal holographic surfaces surrounding the object. Accurate reconstruction of the surface velocity requires subtraction of the rigid body response computed using a finite element approach. The velocity and pressure fields on the surface lead to the extraction of the in vacuo structural admittance matrix of the elastic object, which is manipulated to yield the farfield bistatic response for a fluid-loaded target for several angles of incidence. This method allows the computation of the scattering properties of an elastic object using exclusive information calculated on its surface (no knowledge of the internal structure required). A numerical experiment involving a cylindrical shell with hemispherical caps is presented, and its bistatic response in water shows excellent agreement with a finite element solution.

Endoscopic management of common bile duct stones: European Society of Gastrointestinal Endoscopy (ESGE) guideline.

ESGE recommends offering stone extraction to all patients with common bile duct stones, symptomatic or not, who are fit enough to tolerate the intervention.Strong recommendation, low quality evidence.ESGE recommends liver function tests and abdominal ultrasonography as the initial diagnostic steps for suspected common bile duct stones. Combining these tests defines the probability of having common bile duct stones.Strong recommendation, moderate quality evidence.ESGE recommends endoscopic ultrasonography or magnetic resonance cholangiopancreatography to diagnose common bile duct stones in patients with persistent clinical suspicion but insufficient evidence of stones on abdominal ultrasonography.Strong recommendation, moderate quality evidence.ESGE recommends the following timing for biliary drainage, preferably endoscopic, in patients with acute cholangitis, classified according to the 2018 revision of the Tokyo Guidelines:- severe, as soon as possible and within 12 hours for patients with septic shock- moderate, within 48 - 72 hours- mild, elective.Strong recommendation, low quality evidence.ESGE recommends endoscopic placement of a temporary biliary plastic stent in patients with irretrievable biliary stones that warrant biliary drainage.Strong recommendation, moderate quality of evidence.ESGE recommends limited sphincterotomy combined with endoscopic papillary large-balloon dilation as the first-line approach to remove difficult common bile duct stones. Strong recommendation, high quality evidence.ESGE recommends the use of cholangioscopy-assisted intraluminal lithotripsy (electrohydraulic or laser) as an effective and safe treatment of difficult bile duct stones.Strong recommendation, moderate quality evidence.ESGE recommends performing a laparoscopic cholecystectomy within 2 weeks from ERCP for patients treated for choledocholithiasis to reduce the conversion rate and the risk of recurrent biliary events. Strong recommendation, moderate quality evidence.

A general radiation model for sound fields and nearfield acoustical holography in wedge propagation spaces.

In this work an expression for the solution of the Helmholtz equation for wedge spaces is derived. Such propagation spaces represent scenarios for many acoustical problems where a free field assumption is not eligible. The proposed sound field model is derived from the general solution of the wave equation in cylindrical coordinates, using sets of orthonormal basis functions. The latter are modified to satisfy several boundary conditions representing the reflective behaviour of wedge-shaped propagation spaces. This formulation is then used in the context of nearfield acoustical holography (NAH) and to obtain the expression of the Neumann Green function. The model and its suitability for NAH is demonstrated through both numerical simulations and measured data, where the latter was acquired for the specific case of a loudspeaker on a hemi-cylindrical rigid baffle.

Experimental estimation of in vacuo structural admittance using random sources in a non-anechoic room.

Identification of unexploded ordinance buried in the sediment in the littoral waters throughout the world is a problem of great concern. When illuminated by low-frequency sonar some of these targets exhibit an elastic response that can be used to identify them. This elastic behavior is embodied and identified by a quantity called the in vacuo structural admittance matrix Ys, a relationship between the sonar-induced forces and resulting vibration on its surface. When it is known it can be combined with surface impedances to predict the three-dimensional bistatic scattering in any fluid-like media and for any burial state (depth and orientation). At the heart of this is the measurement of Ys and it is demonstrated in this paper that this can be accomplished by studying the target in a simple (acoustically unaltered) in-air laboratory environment. The target chosen in this study is a thick spherical shell that was illuminated by a nearly spatially isotropic array of remote loudspeakers. Ys is constructed from ensemble averages of the cross-correlations of eight collocated accelerometers and microphones placed on the surface of the object. The structural admittance determined from the data showed excellent agreement with theory.

Updated guideline on the management of common bile duct stones (CBDS).

Common bile duct stones (CBDS) are estimated to be present in 10-20% of individuals with symptomatic gallstones. They can result in a number of health problems, including pain, jaundice, infection and acute pancreatitis. A variety of imaging modalities can be employed to identify the condition, while management of confirmed cases of CBDS may involve endoscopic retrograde cholangiopancreatography, surgery and radiological methods of stone extraction. Clinicians are therefore confronted with a number of potentially valid options to diagnose and treat individuals with suspected CBDS. The British Society of Gastroenterology first published a guideline on the management of CBDS in 2008. Since then a number of developments in management have occurred along with further systematic reviews of the available evidence. The following recommendations reflect these changes and provide updated guidance to healthcare professionals who are involved in the care of adult patients with suspected or proven CBDS. It is not a protocol and the recommendations contained within should not replace individual clinical judgement.

Characterization of space dust using acoustic impact detection.

This paper describes studies leading to the development of an acoustic instrument for measuring properties of micrometeoroids and other dust particles in space. The instrument uses a pair of easily penetrated membranes separated by a known distance. Sensors located on these films detect the transient acoustic signals produced by particle impacts. The arrival times of these signals at the sensor locations are used in a simple multilateration calculation to measure the impact coordinates on each film. Particle direction and speed are found using these impact coordinates and the known membrane separations. This ability to determine particle speed, direction, and time of impact provides the information needed to assign the particle's orbit and identify its likely origin. In many cases additional particle properties can be estimated from the signal amplitudes, including approximate diameter and (for small particles) some indication of composition/morphology. Two versions of this instrument were evaluated in this study. Fiber optic displacement sensors are found advantageous when very thin membranes can be maintained in tension (solar sails, lunar surface). Piezoelectric strain sensors are preferred for thicker films without tension (long duration free flyers). The latter was selected for an upcoming installation on the International Space Station.

Papillary cannulation and sphincterotomy techniques at ERCP: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). It provides practical advice on how to achieve successful cannulation and sphincterotomy at minimum risk to the patient. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system was adopted to define the strength of recommendations and the quality of evidence. Main recommendations 1 ESGE suggests that difficult biliary cannulation is defined by the presence of one or more of the following: more than 5 contacts with the papilla whilst attempting to cannulate; more than 5 minutes spent attempting to cannulate following visualization of the papilla; more than one unintended pancreatic duct cannulation or opacification (low quality evidence, weak recommendation). 2 ESGE recommends the guidewire-assisted technique for primary biliary cannulation, since it reduces the risk of post-ERCP pancreatitis (moderate quality evidence, strong recommendation). 3 ESGE recommends using pancreatic guidewire (PGW)-assisted biliary cannulation in patients where biliary cannulation is difficult and repeated unintentional access to the main pancreatic duct occurs (moderate quality evidence, strong recommendation). ESGE recommends attempting prophylactic pancreatic stenting in all patients with PGW-assisted attempts at biliary cannulation (moderate quality evidence, strong recommendation). 4 ESGE recommends needle-knife fistulotomy as the preferred technique for precutting (moderate quality evidence, strong recommendation). ESGE suggests that precutting should be used only by endoscopists who achieve selective biliary cannulation in more than 80 % of cases using standard cannulation techniques (low quality evidence, weak recommendation). When access to the pancreatic duct is easy to obtain, ESGE suggests placement of a pancreatic stent prior to precutting (moderate quality evidence, weak recommendation). 5 ESGE recommends that in patients with a small papilla that is difficult to cannulate, transpancreatic biliary sphincterotomy should be considered if unintentional insertion of a guidewire into the pancreatic duct occurs (moderate quality evidence, strong recommendation).In patients who have had transpancreatic sphincterotomy, ESGE suggests prophylactic pancreatic stenting (moderate quality evidence, strong recommendation). 6 ESGE recommends that mixed current is used for sphincterotomy rather than pure cut current alone, as there is a decreased risk of mild bleeding with the former (moderate quality evidence, strong recommendation). 7 ESGE suggests endoscopic papillary balloon dilation (EPBD) as an alternative to endoscopic sphincterotomy (EST) for extracting CBD stones < 8 mm in patients without anatomical or clinical contraindications, especially in the presence of coagulopathy or altered anatomy (moderate quality evidence, strong recommendation). 8 ESGE does not recommend routine biliary sphincterotomy for patients undergoing pancreatic sphincterotomy, and suggests that it is reserved for patients in whom there is evidence of coexisting bile duct obstruction or biliary sphincter of Oddi dysfunction (moderate quality evidence, weak recommendation). 9 In patients with periampullary diverticulum (PAD) and difficult cannulation, ESGE suggests that pancreatic duct stent placement followed by precut sphincterotomy or needle-knife fistulotomy are suitable options to achieve cannulation (low quality evidence, weak recommendation).ESGE suggests that EST is safe in patients with PAD. In cases where EST is technically difficult to complete as a result of a PAD, large stone removal can be facilitated by a small EST combined with EPBD or use of EPBD alone (low quality evidence, weak recommendation). 10 For cannulation of the minor papilla, ESGE suggests using wire-guided cannulation, with or without contrast, and sphincterotomy with a pull-type sphincterotome or a needle-knife over a plastic stent (low quality evidence, weak recommendation).When cannulation of the minor papilla is difficult, ESGE suggests secretin injection, which can be preceded by methylene blue spray in the duodenum (low quality evidence, weak recommendation). 11 In patients with choledocholithiasis who are scheduled for elective cholecystectomy, ESGE suggests intraoperative ERCP with laparoendoscopic rendezvous (moderate quality evidence, weak recommendation). ESGE suggests that when biliary cannulation is unsuccessful with a standard retrograde approach, anterograde guidewire insertion either by a percutaneous or endoscopic ultrasound (EUS)-guided approach can be used to achieve biliary access (low quality evidence, weak recommendation). 12 ESGE suggests that in patients with Billroth II gastrectomy ERCP should be performed in referral centers, with the side-viewing endoscope as a first option; forward-viewing endoscopes are the second choice in cases of failure (low quality evidence, weak recommendation). A straight standard ERCP catheter or an inverted sphincterotome, with or without the guidewire, is recommended by ESGE for biliopancreatic cannulation in patients who have undergone Billroth II gastrectomy (low quality evidence, strong recommendation). Endoscopic papillary ballon dilation (EPBD) is suggested as an alternative to sphincterotomy for stone extraction in the setting of patients with Billroth II gastrectomy (low quality evidence, weak recommendation).In patients with complex post-surgical anatomy ESGE suggests referral to a center where device-assisted enteroscopy techniques are available (very low quality evidence, weak recommendation).

On band gap predictions for multiresonant metamaterials on plates.

Recently wide frequency band gaps were observed in an experimental realization of a multiresonant metamaterial for Lamb waves propagating in thin plates. The band gaps rose from hybridization between the flexural plate (A0 Lamb waves) and longitudinal resonances in rods attached perpendicularly. Shortly thereafter a theory based on considering a one-dimensional periodic array of rods and the scattering matrix for a single rod successfully described the observations. This letter presents an alternative simpler theory, arguably accurate at high rod density, that treats the full two-dimensional array of rods and makes no assumption of periodicity. This theory also fits the measurements.

Convolution formulations for non-negative intensity.

Previously unknown spatial convolution formulas for a variant of the active normal intensity in planar coordinates have been derived that use measured pressure or normal velocity near-field holograms to construct a positive-only (outward) intensity distribution in the plane, quantifying the areas of the vibrating structure that produce radiation to the far-field. This is an extension of the outgoing-only (unipolar) intensity technique recently developed for arbitrary geometries by Steffen Marburg. The method is applied independently to pressure and velocity data measured in a plane close to the surface of a point-driven, unbaffled rectangular plate in the laboratory. It is demonstrated that the sound producing regions of the structure are clearly revealed using the derived formulas and that the spatial resolution is limited to a half-wavelength. A second set of formulas called the hybrid-intensity formulas are also derived which yield a bipolar intensity using a different spatial convolution operator, again using either the measured pressure or velocity. It is demonstrated from the experiment results that the velocity formula yields the classical active intensity and the pressure formula an interesting hybrid intensity that may be useful for source localization. Computations are fast and carried out in real space without Fourier transforms into wavenumber space.

District general hospital networks can provide safe and effective hepatitis C treatment: results of a 5-year audit.

INTRODUCTION: Chronic hepatitis C treatment is well described in randomized-controlled trials (RCTs). We aimed to determine whether these findings can be extrapolated to treatment programmes delivered by nurse specialists in district general hospitals (DGHs). MATERIALS AND METHODS: Within the Dorset viral hepatitis network, chronic hepatitis C patients were treated in three DGHs by nurse specialists working under the supervision of four lead clinicians. Between January 2007 and January 2012, standard of care was ribavirin and pegylated interferon-α2a administered for 24 weeks (G2/3) and 48 weeks (G1/4). Retrospective analysis of the network's database was carried out and comparisons were made with a multicentre RCT. RESULTS: In total, 242 completed patient episodes were available for analysis. Ninety per cent (219) were treatment naive. G1 patients represented 49% (107) of this cohort; 2% (six) were hepatitis B/HIV coinfected and 97% (212) were Whites. Overall, 11% (23) were lost to follow-up within 24 weeks of completing treatment. On the basis of the intention to treat, the sustained virological response rates were 45 (48/107), 60 (63/105) and 57% (4/7) for patients infected with hepatitis C virus G1, G2/3 and G4, respectively. These results are comparable with RCT data (P=0.4973, 0.1359 and 0.9552). Treatment was discontinued in 3.7% (eight) of patients because of a laboratory abnormality and 9.6% (21) because of other medical complications or side-effect intolerance. These proportions are similar to those observed in the RCT (P=0.0873 and 0.5613). CONCLUSION: Specialist nurses supported by a network of DGHs can deliver a high-quality hepatitis C service across a broad geographical area.

Prediction of a body's structural impedance and scattering properties using correlation of random noise.

This paper derives a method to estimate the structural or surface impedance matrix (or equivalently the inverse of the structural Green's function) for an elastic body by placing it in an encompassing and spatially random noise field and cross-correlating pressure and normal velocity measurements taken on its surface. A numerical experiment is presented that utilizes a cross-correlation method to determine the structural impedance matrix for an infinite cylindrical shell excited by a spatially random noise field. It is shown that the correlation method produces the exact analytic form of the structural impedance matrix. Furthermore, using standard impedance formulations of the scattered and incident pressure fields at the object surface that are based on the equivalent source method and using this estimated structural impedance, a prediction of the scattered acoustic field at any position outside of the object can be made for any given incident field. An example is presented for a point (line) source near a cylindrical shell and when compared with the analytical result, excellent agreement is found between the scattered fields at a radius close to the shell.

Surface decomposition method for near-field acoustic holography.

Near-field acoustic holography reconstruction of the acoustic field at the surface of an arbitrarily shaped radiating structure from pressure measurements at a nearby conformal surface is obtained from the solution of a boundary integral equation. This integral equation is discretized using the equivalent source method and transformed into a matrix system that can be solved using iterative regularization methods that counteract the effect of noise on the measurements. This work considers the case when the resultant matrix system is so large that it cannot be explicitly formed and iterative methods of solution cannot be directly implemented. In this case the method of surface decomposition is proposed, where the measurement surface is divided into smaller nonoverlapping subsurfaces. Each subsurface is used to form a smaller matrix system that is solved and the result joined together to generate a global solution to the original matrix system. Numerically generated data are used to study the use of subsurface extensions to increase the continuity of the global solution, and investigate the size of the subsurfaces, as well as the distance between the measurement and the vibrating surface. Finally a vibrating ship hull structure is considered as a physical example to apply and validate the proposed methodology.

Vector intensity reconstructions in a volume surrounding a rigid spherical microphone array.

A technique is described to image the vector intensity in the near field of a spherical array of microphones flush mounted in a rigid sphere. The spatially measured pressure is decomposed into Fourier harmonics in order to reconstruct the volumetric vector intensity outside the sphere. The theory for this reconstruction is developed in this paper. The resulting intensity images are very successful at locating and quantifying unknown exterior acoustic sources, ideal for application in noise control problems in interior spaces such as automobiles and airplanes. Arrays of varying numbers of microphones and radii are considered and compared and errors are computed for both theory and experiment. It is demonstrated that this is an ill-posed problem below a cutoff frequency depending on array design, requiring Tikhonov regularization below cutoff. There is no low frequency limit on operation, although the signal-to-noise ratio is the determining factor for high-spatial resolution at low frequencies. It is shown that the upper frequency limit is set by the number of microphones in the array and is independent of noise. The accuracy of the approach is assessed by considering the exact solution for the scattering of a point source by a rigid sphere. Several field experiments are presented to demonstrate the utility of the technique. In these experiments, the partial field decomposition technique is used and holograms of multiple exterior sources are separated and their individual volumetric intensity fields imaged. In this manner, the intensity fields of two uncorrelated tube sources in an anechoic chamber are isolated from one another and separated intensity maps are obtained from over a broad frequency range. In a practical application, the vector intensity field in the interior of an automobile cabin is mapped at the fundamental of the engine vibration using the rigid sphere positioned at the driver's head. The source regions contributing to the interior cabin noise are identified.

Consenting patients for endoscopic retrograde cholangiopancreatography: results of a survey of 182 UK endoscopists and 2059 of their patients.

OBJECTIVES: To describe the endoscopic retrograde cholangiopancreatography (ERCP) consent process. METHOD: A prospective, multicentre study of ERCP, supplemented by questionnaires administered to participating endoscopists and their patients. RESULTS: A total 165 of 182 (91%) endoscopists completed a questionnaire describing personal practice with 140 of 165 (85%) routinely providing written information to patients; 120 of 165 (73%) routinely acquiring verbal consent on the day of ERCP; 23 of 165 (14%) delegating acquisition of consent to another team member and 59 of 165 (36%) usually/always describing alternative treatments to patients. Types of complication disclosed (and percentage of incidence quoted) varied significantly. A total of 2059 of 4561 (45%) patients completed the questionnaire following their first recorded procedure, at a mean of 11 days post-ERCP. Most (1968/2059; 96%) patients were satisfied with the explanation provided; they understood why ERCP was recommended (1935/2059; 94%) and recalled being informed of complications (1745/2059; 85%). Regression analysis of first-ever (nonurgent) ERCP suggested that patients were more likely to recall being informed of risk (odds ratio; 95% confidence interval) if they were younger (1.04 per 5-year decrease, 1.02-1.05), had an American Society of Anesthesiology score of less than 3 (2.0; 1.18-3.4); or had verbally consented more than 1 week in advance of ERCP (2.41, 1.02-5.71, when compared with those who consented on the day of ERCP). After ERCP 964 of 2059 (47%) patients were warned of specific symptoms that could arise. CONCLUSION: The ERCP consent process could be improved by consistent disclosure of risk, acquisition of verbal consent well in advance of the procedure, provision of information after ERCP and increased attention to older and more sick patients.