Statistics of non-linear stochastic dynamical systems under L\'evy noises by a convolution quadrature approach

This paper describes a novel numerical approach to find the statistics of the non-stationary response of scalar non-linear systems excited by L\'evy white noises. The proposed numerical procedure relies on the introduction of an integral transform of Wiener-Hopf type into the equation governing the characteristic function. Once this equation is rewritten as partial integro-differential equation, it is then solved by applying the method of convolution quadrature originally proposed by Lubich, here extended to deal with this particular integral transform. The proposed approach is relevant for two reasons: 1) Statistics of systems with several different drift terms can be handled in an efficient way, independently from the kind of white noise; 2) The particular form of Wiener-Hopf integral transform and its numerical evaluation, both introduced in this study, are generalizations of fractional integro-differential operators of potential type and Gr\"unwald-Letnikov fractional derivatives, respectively.Comment: 20 pages, 5 figure

Diagnostic accuracy of fecal calprotectin assay in distinguishing organic causes of chronic diarrhea from irritable bowel syndrome: a prospective study in adults and children

Fecal calprotectin (FC) has been proposed as a marker of inflammatory bowel disease (IBD), but few studies have evaluated its usefulness in patients with chronic diarrhea of various causes. We evaluated the diagnostic accuracy of a FC assay in identifying "organic" causes of chronic diarrhea in consecutive adults and children

ADVANCED ENDOSCOPIC IMAGING FOR SURVEILLANCE FOR DYSPLASIA AND COLORECTAL CANCER IN INFLAMMATORY BOWEL DISEASE: COULD THE PATHOLOGIST BE FURTHER HELPED?

Patients with inflammatory bowel disease (IBD) have an increased risk of developing intestinal cancer. The magnitude of that increased risk as well as how best to mitigate it remain a topic of ongoing investigation in the field. It is important to quantify the risk of colorectal cancer in association with IBD. The reported risk varies widely between studies. This is partly due to the different methodologies used in the studies. Because of the limitations of surveillance strategies based on the detection of dysplasia, advanced endoscopic imaging and techniques involving the detection of alterations in mucosal antigens and genetic abnormalities are being investigated. Development of new biomarkers, predicting future occurrence of colonic neoplasia may lead to more biomarker-based surveillance. There are promising results that may lead to more efficient surveillance in IBD patients and more general acceptance of its use. A multidisciplinary approach, involving in particular endoscopists and pathologists, together with a centralized patient management, could help to optimize treatments and follow-up measures, both of which could help to reduce the IBD-associated cancer risk

COLORECTAL CANCER IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: PRELIMINARY RESULTS FROM AN ONGOING CASE-CONTROL STUDY

Background and Aim:Understanding the risk factors for colorectal cancer (CRC) is crucial to the development of effective strategies for its prevention. meta-analysis and epidemiological studies have already shown that type 2 diabetes mellitus (DM) is associated with an increased risk of CRC and have provided data to support a positive relationship between these diseases. Material and Methods: We retrospectively evaluated 741 consecutive caucasian patients with type 2 DM who underewnt colonoscopic screening cof CRC and followed in our tertiary referrral center in 200-208 for incidence of CRC. Patients were stratified based on gender, age, body mass index (MBI), alchool and NSAIDS assumption, family history for cancer blood glycated hemoglobin levels, hypertension, hypertrigliceridemia, age at diabetes onset and duration, treatment with insulin or other hypoglicemic drugs. A total of 257 consecutive control patients were selected from a cohort of patients followed as outpatients for thyroid diseases. Results: At a median follow-up of 132,5 months (range 33,3-175,7) 56 cases of cancer (prevalence 7,56%) occurred; among these, 14 cases of CRC were reported (prevalence 18,8%) among the diabetic patients, while only one case (prevalence 0,004%) occurred in the control group, although this difference is not statistically significant (chi-square 2,9, P=0,08). Median duration of DM to CRC diagnosis was 156 months (range 1-768). At the univariate analysis older age (p=0,001), and diabetes duration (p=0,001) were related to higher risk of cancer, while metformin seems to be protective towards cancer (p=0,058). in the subset of patients with CRC, older age (p=0,001) and diabetes duration (p=0,001) were related to higher risk of CRC, such as treatment with sulphonylureas (p=0,01). Conclusions: Our preliminbar data show that the prevalence of CRC in the cohort of patients with type 2 DM was higher compared to that from our control group, and to that from the National Tumor Register up 2010 (0,5%). Furthermore we could interestingly hypotize that sulphonylureas may play a role in CRC carcinogenesis altering the physiological insulin secretion

NUTRITION, MALNUTRITION AND DIETARY INTERVENTIONS IN INFLAMMATORY BOWEL DISEASE

Inflammatory Bowel Disease (IBD), which includes both Crohn's disease (CD) and Ulcerative Colitis (UC), is a chronic idiopathic inflammatory disorder affecting the gastrointestinal tract. Diet, as a source of luminal antigens, is thought to be an important factor in the pathogenesis of IBD. often the nutritional status of patients is significantly compromised, particularly in CD. several factors, including drug-nutrient interactions, disease location, symptoms, and dietary restriction can lead to protein energy malnutrition and specific nutritional deficiencies. solid evidence regarding the accountability of certain dietary components in the etiology of IBD are lacking. With regard to malnutrition, its consequence are growth failure, weight loss, bone disease, and/or micronutrient deficiencies, although micronutrient deficiency in IBD in most cases does not tend to have any evident clinical manifestation, except with regardo of iron, folic acid, and vitamin B. Nutritional supplemantation is essential for patients with evidence of malnutrition to increase calorie, and protein intake. Nutritional supplementation can also have efficacy in the induction and maintenance of remission in adults with CD, however it does not replace other treatments. Aim of this review is to discuss the role of nutrition and nutrients' deficiencies in the clinical setting of IBD, and to analyze efficacy and safety of the dietary interventions in patients with IBD