A Maximum Entropy Resolution to the Wine/Water Paradox.

The Principle of Indifference ('PI': the simplest non-informative prior in Bayesian probability) has been shown to lead to paradoxes since Bertrand (1889). Von Mises (1928) introduced the 'Wine/Water Paradox' as a resonant example of a 'Bertrand paradox', which has been presented as demonstrating that the PI must be rejected. We now resolve these paradoxes using a Maximum Entropy (MaxEnt) treatment of the PI that also includes information provided by Benford's 'Law of Anomalous Numbers' (1938). We show that the PI should be understood to represent a family of informationally identical MaxEnt solutions, each solution being identified with its own explicitly justified boundary condition. In particular, our solution to the Wine/Water Paradox exploits Benford's Law to construct a non-uniform distribution representing the universal constraint of scale invariance, which is a physical consequence of the Second Law of Thermodynamics.

Relating a System's Hamiltonian to Its Entropy Production Using a Complex Time Approach.

We exploit the properties of complex time to obtain an analytical relationship based on considerations of causality between the two Noether-conserved quantities of a system: its Hamiltonian and its entropy production. In natural units, when complexified, the one is simply the Wick-rotated complex conjugate of the other. A Hilbert transform relation is constructed in the formalism of quantitative geometrical thermodynamics, which enables system irreversibility to be handled analytically within a framework that unifies both the microscopic and macroscopic scales, and which also unifies the treatment of both reversibility and irreversibility as complementary parts of a single physical description. In particular, the thermodynamics of two unitary entities are considered: the alpha particle, which is absolutely stable (that is, trivially reversible with zero entropy production), and a black hole whose unconditional irreversibility is characterized by a non-zero entropy production, for which we show an alternate derivation, confirming our previous one. The thermodynamics of a canonical decaying harmonic oscillator are also considered. In this treatment, the complexification of time also enables a meaningful physical interpretation of both "imaginary time" and "imaginary energy".

Adhesion-related readmissions after open and laparoscopic surgery: a retrospective cohort study (SCAR update).

BACKGROUND: Adhesions are the most common driver of long-term morbidity after abdominal surgery. Although laparoscopy can reduce adhesion formation, the effect of minimally invasive surgery on long-term adhesion-related morbidity remains unknown. We aimed to assess the impact of laparoscopy on adhesion-related readmissions in a population-based cohort. METHODS: We did a retrospective cohort study of patients of any age who had abdominal or pelvic surgery done using laparoscopic or open approaches between June 1, 2009, and June 30, 2011, using validated population data from the Scottish National Health Service. All patients who had surgery were followed up until Dec 31, 2017. The primary outcome measure was the incidence of hospital readmissions directly related to adhesions in the laparoscopic and open surgery cohorts at 5 years. Readmissions were categorised as directly related to adhesions, possibly related to adhesions, and readmissions for an operation that was potentially complicated by adhesions. We did subgroup analyses of readmissions by anatomical site of surgery and used Kaplan-Meier analyses to assess differences in survival across subgroups. We used multivariable Cox-regression analysis to determine whether surgical approach was an independent and significant risk factor for adhesion-related readmissions. FINDINGS: Between June 1, 2009, and June 30, 2011, 72 270 patients had an index abdominal or pelvic surgery, of whom 21 519 (29·8%) had laparoscopic index surgery and 50 751 (70·2%) had open surgery. Of the 72 270 patients who had surgery, 2527 patients (3·5%) were readmitted within 5 years of surgery for disorders directly related to adhesions, 12 687 (17·6%) for disorders possibly related to adhesions, and 9436 (13·1%) for operations potentially complicated by adhesions. Of the 21 519 patients who had laparoscopic surgery, 359 (1·7% [95% CI 1·5-1·9]) were readmitted for disorders directly related to adhesions compared with 2168 (4·3% [4·1-4·5]) of 50 751 patients in the open surgery cohort (p<0·0001). 3443 (16·0% [15·6-16·4]) of 21 519 patients in the laparoscopic surgery cohort were readmitted for disorders possibly related to adhesions compared with 9244 (18·2% [17·8-18·6]) of 50 751 patients in the open surgery cohort (p<0·005). In multivariate analyses, laparoscopy reduced the risk of directly related readmissions by 32% (hazard ratio [HR] 0·68, 95% CI 0·60-0·77), and of possibly related readmissions by 11% (HR 0·89, 0·85-0·94) compared with open surgery. Procedure type, malignancy, sex, and age were also independently associated with risk of adhesion-related readmissions. INTERPRETATION: Laparoscopic surgery reduces the incidence of adhesion-related readmissions. However, the overall burden of readmissions associated with adhesions remains high. With further increases in the use of laparoscopic surgery expected in the future, the effect at the population level might become larger. Further steps remain necessary to reduce the incidence of adhesion-related postsurgical complications. FUNDING: Dutch Adhesion Group and Nordic Pharma.

The outcome of self-expanding metal stents in elderly patients.

BACKGROUND AND OBJECTIVES: Emergency surgery for large bowel obstruction is associated with high morbidity and mortality rates, especially in elderly patients. Colonic self-expanding metal stents may provide temporary relief of obstructions and enable preoperative evaluation. The aim of this retrospective study was to assess the clinical outcomes of emergency stenting in elderly patients with large bowel obstructions. METHODS: Between 1997 and 2010, patients presenting with large bowel obstructions were treated predominantly with self-expanding metal stent insertion. Clinical data, including age, site of obstruction, success rate, and surgery and mortality rates, were collected. Patients were divided into 3 groups (I, II, and III) according to age: <69, 70 to 79, or >80 years. RESULTS: One hundred thirty-two consecutive patients underwent stent implantation, with a mean age of 72.1 years (range, 28-95 years). Similar diversity of sex, indication, and stricture location was found. There were no significant differences in clinical success (88.7%, 73.8%, and 78.4%, P=.16) and stent-related mortality (2.1%, 3.3%, and 3.6%, P=1.00). Similar rates of stoma creation were also found (59.3%, 46.7%, and 60.0%, P=.76). In contrast, rates of surgery were lower in older patients (50.9%, 38.1%, and 13.5%, P=.0013), and mortality during the same admission was significantly higher in patients>70 years of age (4.0%, 15.0%, and 22.2%, P=.027). Kaplan-Meier 30-day survival curves for the 3 groups showed a trend toward earlier death among patients>70 years of age. CONCLUSIONS: This study demonstrates that stenting provides similar success rates in all age groups but is associated with higher mortality rates in older patients.

Self-expandable metal stents for obstructing colonic and extracolonic cancer: European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline.

This Guideline is an official statement of the European Society of Gastrointestinal Endoscopy (ESGE). This Guideline was also reviewed and endorsed by the Governing Board of the American Society for Gastrointestinal Endoscopy (ASGE). 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 The following recommendations should only be applied after a thorough diagnostic evaluation including a contrast-enhanced computed tomography (CT) scan. 1 Prophylactic colonic stent placement is not recommended. Colonic stenting should be reserved for patients with clinical symptoms and imaging evidence of malignant large-bowel obstruction, without signs of perforation (strong recommendation, low quality evidence). 2 Colonic self-expandable metal stent (SEMS) placement as a bridge to elective surgery is not recommended as a standard treatment of symptomatic left-sided malignant colonic obstruction (strong recommendation, high quality evidence). 3 For patients with potentially curable but obstructing left-sided colonic cancer, stent placement may be considered as an alternative to emergency surgery in those who have an increased risk of postoperative mortality, I. e. American Society of Anesthesiologists (ASA) Physical Status ≥ III and/or age > 70 years (weak recommendation, low quality evidence). 4 SEMS placement is recommended as the preferred treatment for palliation of malignant colonic obstruction (strong recommendation, high quality evidence), except in patients treated or considered for treatment with antiangiogenic drugs (e. g. bevacizumab) (strong recommendation, low quality evidence).

Management of asymptomatic inguinal hernia: a systematic review of the evidence.

OBJECTIVE: To establish a literature-based surgical approach to asymptomatic inguinal hernia (IH). DATA SOURCES: PubMed, the Cochrane Library database, Embase, national guidelines (including the National Library of Guidelines Specialist Library), National Institute for Health and Clinical Excellence guidelines, and the National Research Register were searched for prospective randomized trials comparing surgical treatment of patients with asymptomatic IH with conservative treatment. STUDY SELECTION: The literature search retrieved 216 article headlines, and these articles were analyzed. Of those studies, a total of 41 articles were found to be relevant and 2 large well-conducted randomized controlled studies that published their results in several articles were reviewed. DATA EXTRACTION: The pain and discomfort, general health status, complications, and life-threatening events of patients with asymptomatic IH managed by surgery or watchful waiting were determined. DATA SYNTHESIS: No significant difference in pain scores and general health status were found when comparing the patients who were followed up with the patients who had surgery. A significant crossover ratio ranging between 23% and 72% from watchful waiting to surgery was found. In patients with watchful waiting, the rates of IH strangulation were 0.27% after 2 years of follow-up and 0.55% after 4 years of follow-up. In patients who underwent elective surgery, the range of operative complications was 0% to 22.3% and the recurrence rate was 2.1%. CONCLUSION: Both treatment options for asymptomatic IH are safe, but most patients will develop symptoms (mainly pain) over time and will require operation.

Adhesions after abdominal surgery in children.

PURPOSE: The objective of this study is to quantify the overall burden (operative and nonoperative) of small bowel obstruction caused by adhesions after laparotomy in children. METHODS: Data from the Scottish National Health Service Medical Record Linkage database were used to assess risk of an adhesion-related readmission in the 5 years after open abdominal surgery in children and adolescents younger than 16 years from April 1996 to March 1997. RESULTS: A total of 1581 children underwent abdominal surgery (ie, from duodenum downward). Patients undergoing surgery on the ileum had the highest risk of readmission because of adhesions in the subsequent 5 years after surgery (9.2%)--formation/closure of ileostomy had the greatest risk (25%); 6.5% of children were readmitted after general laparotomy, 4.7% after duodenal surgery, and 2.1% after colonic surgery. The incidence of readmissions was 0.3% after appendicectomy. The overall readmission rate was 5.3% (if appendicectomy was excluded) and 1.1% (if appendicectomy was included). CONCLUSION: This population-based study has demonstrated that children have a high incidence of readmissions owing to adhesions after lower abdominal surgery. The risks are related to the site and the type of the original surgery. The risk of further readmissions was highest in the first year but continued with time. The data enable surgeons to target antiadhesion strategies at procedures that lead to a high risk of adhesions.

Population-based analysis of the risk of adhesion-related readmissions after abdominal surgery in children.

PURPOSE: The aim of this study was to quantify the risk of adhesion-related readmissions after abdominal surgery in children. METHODS: This was a population-based study. One thousand five hundred eighty-one children younger than 16 years underwent laparotomy in 1996. Patients were identified from the Scottish Morbidity Records database and followed up for 4 years. RESULTS: In children younger than 5 years, 4.2% had a readmission "directly" owing to adhesions. In children younger than 16 years, 1.1% had a readmission directly owing to adhesions. The highest risk of readmission followed surgery on the small intestine (9.3%), followed by abdominal wall surgery (5.8%), duodenal surgery (2.6%), colonic surgery (2.1%), and appendicectomy (0.3%). 55% of all readmissions occurred in the first year. CONCLUSION: There was no difference in readmission rates between younger and older children when comparing the organ on which surgery was initially performed. The highest readmission rate followed small intestinal surgery and the lowest followed appendicectomy. The risk of readmission was highest in the first year.

Long-term survival from gastrocolic fistula secondary to adenocarcinoma of the transverse colon.

BACKGROUND: Gastrocolic fistula is a rare presentation of both benign and malignant diseases of the gastrointestinal tract. Malignant gastrocolic fistula is most commonly associated with adenocarcinoma of the transverse colon in the Western World. Despite radical approaches to treatment, long-term survival is rarely documented. CASE PRESENTATION: We report a case of a 24-year-old woman who presented with the classic triad of symptoms associated with gastrocolic fistula. Radical en-bloc surgery and adjuvant chemotherapy were performed. She is still alive ten years after treatment. CONCLUSIONS: Gastrocolic fistula is an uncommon presentation of adenocarcinoma of the transverse colon. Radical en-bloc surgery with adjuvant chemotherapy may occasionally produce long-term survival.

Pseudomyxoma extraperitonei occurring 35 years after appendicectomy: a case report and review of literature.

BACKGROUND: Pseudomyxoma peritonei is a rare condition consisting of mucinous ascites, most commonly arising from mucinous tumors of the appendix and occasionally from the ovary. Very rarely mucinous implants arise in the retroperitoneum without any intra-peritoneal involvement. This has been termed as pseudomyxoma extraperitonei. CASE PRESENTATION: We report a case of a 57 year old man who developed pseudomyxoma extraperitonei, 35 years after undergoing an appendicectomy for a perforated appendix. CONCLUSIONS: Pseudomyxoma extraperitonei has been previously reported, however we report the longest incubation period of 35 years for this condition.

Zoned microstructure fiber for low-dispersion waveguiding and coupling to photonic crystals.

We describe a zoned microstructure fiber that exhibits low dispersion and virtually zero spherical aberration because of its optimized piecewise Gaussian index profile. We present results of a nine-zone design that has an average refractive index of 2.3, a refractive-index contrast of 0.1, a first zone radius of 1.67 microm, and a maximum core radius of 5 microm. It has an in-fiber focal length of 8.88 microm and can focus light to a spot size of radius 315 nm, facilitating efficient coupling between single-mode fiber and photonic crystals.

Epidemiology of adhesions: the burden.

Until recently the epidemiology of adhesion-related disease was unclear and lack of awareness of the clinical impact and extent of the problem has been cited as the greatest impediment to reducing adhesion formation. The clinical consequences and burden of disease are reviewed.