Inference of source signatures of merchant ships in shallow ocean environmentsa).

An ocean acoustics experiment in 2017 near a shipping lane on the New England continental shelf in about 75 m of water provided an opportunity to evaluate a methodology to extract source signatures of merchant ships in a bottom-limited environment. The data of interest are the received acoustic levels during approximately 20 min time intervals centered at the closest position of approach (CPA) time for each channel on two 16-element vertical line arrays. At the CPA ranges, the received levels exhibit a frequency-dependent peak and null structure, which possesses information about the geophysical properties of the seabed, such as the porosity and sediment thickness, and the characterization of the source, such as an effective source depth. The modeled seabed is represented by two sediment layers, parameterized with the viscous grain shearing (VGS) model, which satisfies causality, over a fixed deep layered structure. Inferred estimates of the implicit source levels require averaging an error function over the full 20 min time intervals. Within the 200-700 Hz band, the Wales-Heitmeyer model captures the inferred frequency dependence of the source levels.

Next-generation universal hereditary cancer screening: implementation of an automated hereditary cancer screening program for patients with advanced cancer undergoing tumor sequencing in a large HMO.

Variants in hereditary cancer risk genes are frequently identified following tumor-based DNA sequencing and represent an opportunity to diagnose hereditary cancer. We implemented an automated hereditary cancer screening program in a large HMO for all patients who underwent tumor-based DNA sequencing to identify patients with hereditary cancer and determine if this approach augmented existing genetic counseling approaches driven by personal/family history criteria. Regular automated searches of a centralized tumor DNA variant database were performed for ATM, BRCA1, BRCA2, MLH1, MSH2, MSH6, PALB2, and/or PMS2 variants, and germline hereditary cancer gene panel testing was offered to patients with tumor variants who had never undergone germline testing. Patients completing germline testing due to their tumor DNA test results were considered part of the tumor DNA safety net. Patients previously completing germline testing via traditional genetic counseling and tumor DNA safety net were compared for demographics, tumor type, presence of germline pathogenic/likely pathogenic (P/LP) variant, and whether NCCN criteria were met for hereditary cancer genetic testing. Germline P/LP variants were common in both groups. Patients who received germline testing through traditional genetic counseling were more likely to have cardinal hereditary tumors than the tumor DNA safety net group. Patients identified with hereditary cancer through traditional genetic counseling were more likely to meet NCCN personal/family history criteria for germline testing than the tumor DNA safety net group (99% versus 34%). A universal tumor DNA safety net screen is an important diagnostic strategy which augments traditional genetic counseling approaches based on personal/family history.

Geoacoustic inversion on the New England Mud Patch using warping and dispersion curves of high-order modes.

This paper presents single receiver geoacoustic inversion of a combustive sound source signal, recorded during the 2017 Seabed Characterization Experiment on the New England Mud Patch, in an area where water depth is around 70 m. There are two important features in this study. First, it is shown that high-order modes can be resolved and estimated using warping (up to mode number 18 over the frequency band 20-440 Hz). However, it is not possible to determine mode numbers from the data, so that classical inversion methods that require mode identification cannot be applied. To solve this issue, an inversion algorithm that jointly estimates geoacoustic properties and identifies mode number is proposed. It is successfully applied on a range-dependent track, and provides a reliable range-average estimation of geoacoustic properties of the mud layer, an important feature of the seabed on the experimental area.

Comment on "Glacial cycles drive variations in the production of oceanic crust".

Crowley et al. (Reports, 13 March 2015, p. 1237) propose that abyssal hill topography can be generated by variations in volcanism at mid-ocean ridges modulated by Milankovitch cycle-driven changes in sea level. Published values for abyssal hill characteristic widths versus spreading rate do not generally support this hypothesis. I argue that abyssal hills are primarily fault-generated rather than volcanically generated features.

Women's views and the impact of noninvasive prenatal testing on procedures in a managed care setting.

OBJECTIVE: To prospectively determine the impact of noninvasive prenatal testing (NIPT) on invasive procedure utilization in a managed care setting and to elucidate women's views. METHODS: Pregnant women at 10- 20 weeks' gestation with high-risk indications for fetal aneuploidy in the Kaiser Permanente Southern California organization were eligible. Enrolled patients received routine prenatal counseling, completed a questionnaire and were offered the option of NIPT by a genetic counselor. Downstream data through 28 weeks' gestation were collected from the electronic medical record (EMR). The EMR was also used to identify a matched historical cohort from 1 year prior to NIPT availability. Rates of invasive prenatal procedures were compared using McNemar's test. RESULTS: Two hundred women completed the questionnaire and underwent NIPT. Twenty-two subjects (11%) in the prospective cohort underwent an invasive prenatal procedure compared with 58 (29%) in the historical cohort (p<0.0001). Safety and accuracy were the most important factors in considering NIPT. At the time of survey, only 12% indicated being very comfortable with the possibility of undergoing amniocentesis. CONCLUSION: This prospective study demonstrates a 62% reduction in invasive prenatal procedures after NIPT testing and finds safety, accuracy, and personal beliefs key to women's decision-making.

Resource utilization before and during infliximab therapy in patients with inflammatory bowel disease.

OBJECTIVE: Although Remicade (infliximab) is costly relative to non-biologic therapy, its impact on healthcare resource utilization and mucosal healing may make it a cost-effective option. This study aimed to compare gastrointestinal (GI)-related healthcare resource utilization and severity of mucosal damage before and during infliximab therapy in Crohn's disease (CD) or ulcerative colitis (UC) patients. METHODS: A retrospective chart review was conducted at 14 gastroenterology practices from across the country, which varied in practice sizes and types. Patients were aged ≥18 years, diagnosed with CD or UC, and had an infliximab index date between January 1, 2005 and September 30, 2007. GI-related utilization 12 months before and 12 months after the index date was compared. Endoscopic disease severity was categorized based on blinded review of abstracted reports. RESULTS: Results from 268 patients indicated significantly lower rates of surgery (29.7% to 9.9%, p < 0.0001, CD; 24.4% to 12.8%, p = 0.042, UC) and colonoscopy (54.4% to 17.6%, p < 0.0001, CD; 50.0% to 22.1%, p = 0.0007, UC) during infliximab therapy. The rates of hospitalizations in UC (15.1% to 3.5%, p = 0.0124) and radiology assessments in CD (23.1% to 10.4%, p = 0.006) also decreased. Based on severity data from 183 procedures, greater proportions of patients had normal or mild ratings during infliximab treatment compared with pre-treatment. LIMITATIONS: This retrospective descriptive study is limited by the type and quantity of information available in patient charts from 14 gastroenterology clinics during the first year of infliximab treatment. In addition, the number of patients with pre-treatment and post-treatment disease severity information was too small to make comparisons among disease severity groups. Further information about the severity of disease and the extent of mucosal healing could be helpful in determining the effect of therapy on resource utilization in future research. CONCLUSIONS: GI-related resource utilization was significantly lower and attenuation of mucosal damage severity was observed during infliximab treatment compared with the pre-treatment period.

Stability of infliximab dosing in inflammatory bowel disease: results from a multicenter US chart review.

OBJECTIVE: Infliximab dosing for inflammatory bowel disease (IBD) is based on patient weight and treatment response. Understanding dosing patterns may provide insight into treatment response and predictability of treatment cost. The purpose of this medical record review was to assess dose and dose frequency of infliximab maintenance treatment in patients with IBD using patient chart data. METHODS: A retrospective chart review was conducted at 14 community gastroenterology clinics (GI clinics). Patients were aged ≥18 years, diagnosed with Crohn's disease (CD) or ulcerative colitis (UC), and had a first infliximab administration (index date) between January 1, 2005 and September 30, 2007. At least 24 months of continuous data availability were required with dosing data collected for 12 months after initiation of infliximab therapy. Patients with biologic use and/or participation in an IBD clinical trial within 12 months before the index date were excluded. RESULTS: Charts from 182 CD patients and 86 UC patients were analyzed. About half of the patients were female. Over 90% of patients initiated treatment with infliximab 5 mg/kg. Among CD patients and UC patients, respectively, 79% and 61% continued receiving this dose for maintenance therapy at stable intervals. LIMITATIONS: This retrospective descriptive study is limited by the type and quantity of information available in patient charts from 14 GI clinics during the first year of infliximab treatment. Further, non-anti-tumor necrosis factor medication data were intermittently collected in some charts and, therefore, did not allow for analysis. CONCLUSIONS: Weight-based dosing and, presumably, patient response enabled providers to find the effective infliximab dose for IBD patients. The maintenance dose and administration frequency remained stable during the initial year.

Endoscopist-directed administration of propofol: a worldwide safety experience.

BACKGROUND & AIMS: Endoscopist-directed propofol sedation (EDP) remains controversial. We sought to update the safety experience of EDP and estimate the cost of using anesthesia specialists for endoscopic sedation. METHODS: We reviewed all published work using EDP. We contacted all endoscopists performing EDP for endoscopy that we were aware of to obtain their safety experience. These complications were available in all patients: endotracheal intubations, permanent neurologic injuries, and death. RESULTS: A total of 646,080 (223,656 published and 422,424 unpublished) EDP cases were identified. Endotracheal intubations, permanent neurologic injuries, and deaths were 11, 0, and 4, respectively. Deaths occurred in 2 patients with pancreatic cancer, a severely handicapped patient with mental retardation, and a patient with severe cardiomyopathy. The overall number of cases requiring mask ventilation was 489 (0.1%) of 569,220 cases with data available. For sites specifying mask ventilation risk by procedure type, 185 (0.1%) of 185,245 patients and 20 (0.01%) of 142,863 patients required mask ventilation during their esophagogastroduodenoscopy or colonoscopy, respectively (P < .001). The estimated cost per life-year saved to substitute anesthesia specialists in these cases, assuming they would have prevented all deaths, was $5.3 million. CONCLUSIONS: EDP thus far has a lower mortality rate than that in published data on endoscopist-delivered benzodiazepines and opioids and a comparable rate to that in published data on general anesthesia by anesthesiologists. In the cases described here, use of anesthesia specialists to deliver propofol would have had high costs relative to any potential benefit.

Observations of the R reflector and sediment interface reflection at the Shallow Water '06 Central Site.

Acoustic bottom-interacting measurements from the Shallow Water '06 experiment experiment (frequency range 1-20 kHz) are presented. These are co-located with coring and stratigraphic studies showing a thin (approximately 20 cm) higher sound speed layer overlaying a thicker (approximately 20 m) lower sound speed layer ending at a high-impedance reflector (R reflector). Reflections from the R reflector and analysis of the bottom reflection coefficient magnitude for the upper two sediment layers confirm both these features. Geoacoustic parameters are estimated, dispersion effects addressed, and forward modeling using the parabolic wave equation undertaken. The reflection coefficient measurements suggest a nonlinear attenuation law for the thin layer of sandy sediments.

Does obesity confer an increased risk and/or more severe course of post-ERCP pancreatitis?: a retrospective, multicenter study.

BACKGROUND: Pancreatitis is the most common major complication of endoscopic retrograde cholangiopancreatography (ERCP). Recent studies have suggested that obesity may serve as a prognostic indicator of poor outcome in non-ERCP-induced acute pancreatitis. However, to our knowledge, no one has ever investigated the potential association of obesity and ERCP-induced pancreatitis. Thus, the purpose of our study was to determine whether obesity conferred an increased risk and/or more severe course of post-ERCP pancreatitis. METHODS: A 160 variable database was prospectively collected by a defined protocol on patients undergoing diagnostic or therapeutic ERCP at 15 centers in the Midwest Pancreaticobiliary Group and participating in a randomized controlled study, evaluating whether prophylactic corticosteroids reduces the incidence of post-ERCP pancreatitis. Body mass indices (BMIs) were available on 964 of the 1115 patients from the original study. A BMI > or = 30 kg/m2 was defined as obese (World Health Organization) and used as a cutoff point in this study. BMIs were analyzed in a retrospective fashion to determine whether obesity confers an increased risk and/or more severe course of post-ERCP pancreatitis. Data were collected before the ERCP, at the time of procedure, and 24 to 72 hours after discharge. Standardized criteria were used to diagnose and grade the severity of postprocedure pancreatitis. RESULTS: Nine hundred sixty four patients were enrolled in the study. Pancreatitis occurred in 149 patients (15.5%) and was graded as mild in 101 (67.8%), moderate in 42 (28.2%), and severe in 6 (4.0%). The patients were categorized by BMI (kg/m2) using the following breakdowns: BMI < 20, 20 to < 25, 25 to < 30, and > or = 30, as well as BMI < 30 or > or = 30. The groups were similar with respect to the patient and procedure risk factors for post-ERCP pancreatitis except the group with BMI > or = 30 had a higher frequency of females, were younger, had less frequent chronic pancreatitis, a lower number of pancreatic duct injections, and fewer patients received more than 2 pancreatic duct injections. Of the patients with a BMI < 30, 119 (16.4%) developed post-ERCP pancreatitis compared with 30 (12.5%) of those with a BMI > or = 30 (P=0.14). There was no association between the presence of obesity and the severity of pancreatitis (P=0.74). Patients with a BMI < 20, 20 to < 25, 25 to < 30, and > or = 30 had a similar incidence of post-ERCP pancreatitis. CONCLUSIONS: Obesity did not seem to confer an increased risk for ERCP-induced pancreatitis. A statistically significant association between obesity and the severity of ERCP-induced pancreatitis was not apparent.

Risk factors for post-ERCP pancreatitis: a prospective multicenter study.

OBJECTIVES: Pancreatitis is the most common and serious complication of diagnostic and therapeutic ERCP. The aim of this study is to examine the potential patient- and procedure-related risk factors for post-ERCP pancreatitis in a prospective multicenter study. METHODS: A 160-variable database was prospectively collected by a defined protocol on patients undergoing diagnostic or therapeutic ERCP at 15 centers in the Midwest Pancreaticobiliary Group and participating in a randomized controlled study evaluating whether prophylactic corticosteroids will reduce the incidence of post-ERCP pancreatitis. Data were collected prior to the procedure, at the time of procedure, and 24-72 h after discharge. Post-ERCP pancreatitis was diagnosed and its severity graded according to consensus criteria. RESULTS: Of the 1,115 patients enrolled, diagnostic ERCP with or without sphincter of Oddi manometry (SOM) was performed in 536 (48.1%) and therapeutic ERCP in 579 (51.9%). Suspected sphincter of Oddi dysfunction (SOD) was the indication for the ERCP in 378 patients (33.9%). Pancreatitis developed in 168 patients (15.1%) and was graded mild in 112 (10%), moderate in 45 (4%), and severe in 11(1%). There was no difference in the incidence of pancreatitis or the frequency of investigated potential pancreatitis risk factors between the corticosteroid and placebo groups. By univariate analysis, the incidence of post-ERCP pancreatitis was significantly higher in 19 of 30 investigated variables. In the multivariate risk model, significant risk factors with adjusted odds ratios (OR) were: minor papilla sphincterotomy (OR: 3.8), suspected SOD (OR: 2.6), history of post-ERCP pancreatitis (OR: 2.0), age <60 yr (OR: 1.6), > or =2 contrast injections into the pancreatic duct (OR: 1.5), and trainee involvement (OR: 1.5). Female gender, history of recurrent idiopathic pancreatitis, pancreas divisum, SOM, difficult cannulation, and major papilla sphincterotomy (either biliary or pancreatic) were not multivariate risk factors for post-ERCP pancreatitis. CONCLUSION: This study emphasizes the role of patient factors (age, SOD, prior history of post-ERCP pancreatitis) and technical factors (number of PD injections, minor papilla sphincterotomy, and operator experience) as the determining high-risk predictors for post-ERCP pancreatitis.

Oral allopurinol does not prevent the frequency or the severity of post-ERCP pancreatitis.

BACKGROUND: Pancreatitis is the most common major complication of ERCP. Efforts have been made to identify pharmacologic agents capable of reducing its incidence and severity. The aim of this trial was to determine whether prophylactic allopurinol, an inhibitor of oxygen-derived free radical production, would reduce the frequency and severity of post-ERCP pancreatitis. Methods A total of 701 patients were randomized to receive either allopurinol or placebo 4 hours and 1 hour before ERCP. A database was prospectively collected by a defined protocol on patients who underwent ERCP. Standardized criteria were used to diagnose and grade the severity of postprocedure pancreatitis. RESULTS: The groups were similar with regard to patient demographics and to patient and procedure risk factors for pancreatitis. The overall incidence of pancreatitis was 12.55%. It occurred in 46 of 355 patients in the allopurinol group (12.96%) and in 42 of 346 patients in the control group (12.14%; p = 0.52). The pancreatitis was graded mild in 7.89%, moderate in 4.51%, and severe in 0.56% of the allopurinol group, and mild in 6.94%, moderate in 4.62%, and severe in 0.58% of the control group. There was no significant difference between the groups in the frequency or the severity of pancreatitis. CONCLUSIONS: Prophylactic oral allopurinol did not reduce the frequency or the severity of post-ERCP pancreatitis.

Long range acoustic imaging of the continental shelf environment: the Acoustic Clutter Reconnaissance Experiment 2001.

An active sonar system is used to image wide areas of the continental shelf environment by long-range echo sounding at low frequency. The bistatic system, deployed in the STRATAFORM area south of Long Island in April-May of 2001, imaged a large number of prominent clutter events over ranges spanning tens of kilometers in near real time. Roughly 3000 waveforms were transmitted into the water column. Wide-area acoustic images of the ocean environment were generated in near real time for each transmission. Between roughly 10 to more than 100 discrete and localized scatterers were registered for each image. This amounts to a total of at least 30000 scattering events that could be confused with those from submerged vehicles over the period of the experiment. Bathymetric relief in the STRATAFORM area is extremely benign, with slopes typically less than 0.5 degrees according to high resolution (30 m sampled) bathymetric data. Most of the clutter occurs in regions where the bathymetry is locally level and does not coregister with seafloor features. No statistically significant difference is found in the frequency of occurrence per unit area of repeatable clutter inside versus outside of areas occupied by subsurface river channels.

Does prophylactic administration of corticosteroid reduce the risk and severity of post-ERCP pancreatitis: a randomized, prospective, multicenter study.

BACKGROUND: Pancreatitis is the most common major complication of diagnostic and therapeutic ERCP. There have been continuing efforts to identify a pharmacologic agent capable of reducing the frequency and severity of this complication. On the basis of several case reports, experimental data, and knowledge of their mechanism of action, corticosteroids might be effective in this regard. The aim of this randomized, double-blind, controlled trial was to determine whether prophylactic, orally administered corticosteroid reduces the frequency and/or severity of post-ERCP pancreatitis. METHODS: A total of 1115 patients were randomized to receive either prednisone (40 mg) or a placebo orally 15 hours and 3 hours before ERCP. A 160 variable database was prospectively collected according to a defined protocol on patients undergoing diagnostic or therapeutic ERCP at 15 centers in the Midwest Pancreaticobiliary Group. Standardized criteria were used to diagnose and grade the severity of postprocedure pancreatitis. RESULTS: The overall frequency of pancreatitis was 15.07%. It occurred in 92 of 555 patients in the corticosteroid group (16.6%), and in 76 of 560 patients in the control group (13.6%; p = 0.19). The pancreatitis was mild in 10.04%, moderate in 4.04%, and severe in 0.99%. There was no difference between the groups with regard to the severity of pancreatitis. Moreover, the groups were similar with regard to age, gender, body mass index, frequency of prior pancreatitis, type of procedure performed (diagnostic or therapeutic), difficulty of cannulation, frequency of pre-cut sphincterotomy, pancreatic sphincterotomy, sphincter of Oddi dysfunction, sphincter of Oddi manometry, pancreatic acinarization, chronic pancreatitis, number of pancreatic duct injections, and bile duct diameter. CONCLUSION: Prophylactic orally administered corticosteroid did not reduce the frequency or severity of post-ERCP pancreatitis.

Fixed three-dimensional holographic images.

Three-dimensional holograms were recorded in a cerium-doped, strontium barium niobate (SBN:75) photorefractive crystal. These holograms are shown to not degrade after more than one week of continuous readout and to reconstruct reproductions of the original object with an observable field of view of approximately 35 degrees.

The Stretta procedure for the treatment of GERD: 6 and 12 month follow-up of the U.S. open label trial.

BACKGROUND: This multicenter prospective study investigated the longer-term (12 month) safety and efficacy of radiofrequency energy delivery for the treatment of GERD. METHODS: A prospective study was conducted of 118 patients with chronic heartburn and/or regurgitation who required antisecretory medication daily and had demonstrated pathologic esophageal acid exposure, a sliding hiatal hernia (