Jensen-Shannon Information Based Characterization of the Generalization Error of Learning Algorithms

Generalization error bounds are critical to understanding the performance of machine learning models. In this work, we propose a new information-theoretic based generalization error upper bound applicable to supervised learning scenarios. We show that our general bound can specialize in various previous bounds. We also show that our general bound can be specialized under some conditions to a new bound involving the Jensen-Shannon information between a random variable modelling the set of training samples and another random variable modelling the hypothesis. We also prove that our bound can be tighter than mutual information-based bounds under some conditions.Comment: Accepted in ITW 2020 conferenc

Information-Theoretic Bounds on the Moments of the Generalization Error of Learning Algorithms

Generalization error bounds are critical to understanding the performance of machine learning models. In this work, building upon a new bound of the expected value of an arbitrary function of the population and empirical risk of a learning algorithm, we offer a more refined analysis of the generalization behaviour of a machine learning models based on a characterization of (bounds) to their generalization error moments. We discuss how the proposed bounds -- which also encompass new bounds to the expected generalization error -- relate to existing bounds in the literature. We also discuss how the proposed generalization error moment bounds can be used to construct new generalization error high-probability bounds

Ictal verbal help-seeking: Occurrence and the underlying etiology.

PURPOSE: Ictal verbal help-seeking has never been systematically studied before. In this study, we evaluated a series of patients with ictal verbal help-seeking to characterize its frequency and underlying etiology. METHODS: We retrospectively reviewed all the long-term video-EEG reports from Jefferson Comprehensive Epilepsy Center over a 12-year period (2004-2015) for the occurrence of the term help in the text body. All the extracted reports were reviewed and patients with at least one episode of documented ictal verbal help-seeking in epilepsy monitoring unit (EMU) were studied. For each patient, the data were reviewed from the electronic medical records, EMU report, and neuroimaging records. RESULTS: During the study period, 5133 patients were investigated in our EMU. Twelve patients (0.23%) had at least one episode of documented ictal verbal help-seeking. Nine patients (six women and three men) had epilepsy and three patients (two women and one man) had psychogenic nonepileptic seizures (PNES). Seven out of nine patients with epilepsy had temporal lobe epilepsy; six patients had right temporal lobe epilepsy. CONCLUSION: Ictal verbal help-seeking is a rare finding among patients evaluated in epilepsy monitoring units. Ictal verbal help-seeking may suggest that seizures arise in or propagate to the right temporal lobe

Development of de novo diabetes in long-term follow-up after bariatric surgery

Introduction: While bariatric surgery leads to significant prevention and improvement of type 2 diabetes, patients may rarely develop diabetes after bariatric surgery. The aim of this study was to determine the incidence and the characteristic of new-onset diabetes after bariatric surgery over a 17-year period at our institution. Methods: Non-diabetic patients who underwent bariatric surgery at a single academic center (1997–2013) and had a postoperative glycated hemoglobin (HbA1c) ≥ 6.5%, fasting blood glucose (FBG) ≥ 126 mg/dl, or positive glucose tolerance test were identified and studied. Results: Out of 2263 non-diabetic patients at the time of bariatric surgery, 11 patients had new-onset diabetes in the median follow-up time of 9 years (interquartile range [IQR], 4–12). Bariatric procedures performed were Roux-en-Y gastric bypass (n = 7), adjustable gastric banding (n = 3), and sleeve gastrectomy (n = 1). The median interval between surgery and diagnosis of diabetes was 6 years (IQR, 2–9). At the last follow-up, the median HbA1c and FBG values were 6.3% (IQR, 6.1–6.5) and 95 mg/dl (IQR, 85–122), respectively. Possible etiologic factors leading to diabetes were weight regain to baseline (n = 6, 55%), steroid-induced after renal transplantation (n = 1), pancreatic insufficiency after pancreatitis (n = 1), and unknown (n = 3). Conclusion: De novo diabetes after bariatric surgery is rare with an incidence of 0.4% based on our cohort. Weight regain was common (> 50%) in patients who developed new-onset diabetes suggesting recurrent severe obesity as a potential etiologic factor. All patients had good glycemic control (HbA1c ≤ 7%) in the long-term postoperative follow-up

Nonuniform sampling of urodynamic signals: a comparison of different methods

Several different techniques for urodynamic signal compression have been proposed in the last few years. Using these techniques it is possible to reduce the requirements for digital storage or transmission. There are a number of applications where it is essential to use such techniques in diagnostic and ambulatory urodynamics. The purpose of this study is to compare different techniques of urodynamic data compression. The so-called FAN, voltage triggered, two point projection and second difference methods. The comparison between the methods is based on 65 pressure, 46 uroflow and 18 surface electromyogram signals. The reduction ratio achieved for different allowable errors between the original and compressed signals is calculated and compared for the different techniques. Results show that it is possible to store urodynamic signals accurately at a low sampling rate, where FAN and voltage triggered methods seem to be superior to the rest

The gait and balance of patients with diabetes can be improved: a randomised controlled trial

Aims/hypothesis: Gait characteristics and balance are altered in diabetic patients. Little is known about possible treatment strategies. This study evaluates the effect of a specific training programme on gait and balance of diabetic patients. Methods: This was a randomised controlled trial (n = 71) with an intervention (n = 35) and control group (n = 36). The intervention consisted of physiotherapeutic group training including gait and balance exercises with function-orientated strengthening (twice weekly over 12weeks). Controls received no treatment. Individuals were allocated to the groups in a central office. Gait, balance, fear of falls, muscle strength and joint mobility were measured at baseline, after intervention and at 6-month follow-up. Results: The trial is closed to recruitment and follow-up. After training, the intervention group increased habitual walking speed by 0.149m/s (p < 0.001) compared with the control group. Patients in the intervention group also significantly improved their balance (time to walk over a beam, balance index recorded on Biodex balance system), their performance-oriented mobility, their degree of concern about falling, their hip and ankle plantar flexor strength, and their hip flexion mobility compared with the control group. After 6months, all these variables remained significant except for the Biodex sway index and ankle plantar flexor strength. Two patients developed pain in their Achilles tendon: the progression for two related exercises was slowed down. Conclusions/interpretation: Specific training can improve gait speed, balance, muscle strength and joint mobility in diabetic patients. Further studies are needed to explore the influence of these improvements on the number of reported falls, patients' physical activity levels and quality of life. Trial registration:: ClinicalTrials.gov NCT00637546 Funding:: This work was supported by the Swiss National Foundation (SNF): PBSKP-123446/

Late relapse of diabetes after bariatric surgery should not be considered as a failure

Background: Although the impressive metabolic effects of bariatric surgery in patients with Type 2 Diabetes (T2DM) are known, bariatric surgery is criticized for late relapse of diabetes. Methods: Outcomes of 736 patients with T2DM who underwent Roux-en-Y Gastric Bypass (RYGB) and Sleeve Gastrectomy (SG) at an academic center (2004-2012) and had ≥5-year glycemic follow-up were assessed. Out of 736 patients, 425 (58%) experienced diabetes remission (HbA1c <6·5% off medications) in the first year after surgery. The latter subgroup was followed to characterize late relapse of T2DM which was defined as fasting glucose (FBG) or HbA1c in the diabetic range (≥126mg/dL and ≥6·5%, respectively) or need for antidiabetic medication after initial remission. Findings: The median postoperative follow-up time was 8 years (range, 5- 14). Of those 425 patients who initially achieved remission in shortterm, 136 (32%) had a late relapse of T2DM. Independent predictors of late relapse were the preoperative number of diabetes medications (OR:1·85,95%CI:1·35-2·53, p=0·0001), duration of T2DM (OR:1·08,95%CI:1·02- 1·15,p=0·012), and SG vs RYGB (OR:1·95,95%CI:1·00-3·70,p=0·049). In patients who experienced late relapse, a significant improvement in glycemic control, number of diabetes medications including the use of insulin, blood pressure, and lipid profile was still observed at longterm. Among patients with relapse, 77% maintained glycemic control (HbA1c <7%). Interpretation: While late relapse is a real phenomenon (one-third of our cohort), relapse of T2DM years after bariatric surgery should not be considered as a failure, as the trajectory of cardio-metabolic risk factors is changed by surgery. Earlier surgical intervention and RYGB (compared with SG) would be associated with less diabetes relapse in long-term

Synthetic biology tools for environmental protection

Synthetic biology transforms the way we perceive biological systems. Emerging technologies in this field affect many disciplines of science and engineering. Traditionally, synthetic biology approaches were commonly aimed at developing cost-effective microbial cell factories to produce chemicals from renewable sources. Based on this, the immediate beneficial impact of synthetic biology on the environment came from reducing our oil dependency. However, synthetic biology is starting to play a more direct role in environmental protection. Toxic chemicals released by industries and agriculture endanger the environment, disrupting ecosystem balance and biodiversity loss. This review highlights synthetic biology approaches that can help environmental protection by providing remediation systems capable of sensing and responding to specific pollutants. Remediation strategies based on genetically engineered microbes and plants are discussed. Further, an overview of computational approaches that facilitate the design and application of synthetic biology tools in environmental protection is presented

Metabolic Effects Of Duodenojejunal Bypass Surgery In A Rat Model Of Type 1 Diabetes

Background Metabolic surgery has beneficial metabolic effects, including remission of type 2 diabetes. We hypothesized that duodenojejunal bypass (DJB) surgery can protect against development of type 1 diabetes (T1D) by enhancing regulation of cellular and molecular pathways that control glucose homeostasis. Methods BBDP/Wor rats, which are prone to develop spontaneous autoimmune T1D, underwent loop DJB (n = 15) or sham (n = 15) surgery at a median age of 41 days, before development of diabetes. At T1D diagnosis, a subcutaneous insulin pellet was implanted, oral glucose tolerance test was performed 21 days later, and tissues were collected 25 days after onset of T1D. Pancreas and liver tissues were assessed by histology and RT-qPCR. Fecal microbiota composition was analyzed by 16S V4 sequencing. Results Postoperatively, DJB rats weighed less than sham rats (287.8 vs 329.9 g,P = 0.04). In both groups, 14 of 15 rats developed T1D, at similar age of onset (87 days in DJB vs 81 days in sham,P = 0.17). There was no difference in oral glucose tolerance, fasting and stimulated plasma insulin and c-peptide levels, and immunohistochemical analysis of insulin-positive cells in the pancreas. DJB rats needed 1.3 +/- 0.4 insulin implants vs 1.9 +/- 0.5 in sham rats (P = 0.002). Fasting and glucose stimulated glucagon-like peptide 1 (GLP-1) secretion was elevated after DJB surgery. DJB rats had reduced markers of metabolic stress in liver. After DJB, the fecal microbiome changed significantly, including increases inAkkermansiaandRuminococcus, while the changes were minimal in sham rats. Conclusion DJB does not protect against autoimmune T1D in BBDP/Wor rats, but reduces the need for exogenous insulin and facilitates other metabolic benefits including weight loss, increased GLP-1 secretion, reduced hepatic stress, and altered gut microbiome

Studies on the host range of Septoria species on cereals and some wild grasses in Iran

In an attempt to determine the host range of Septoria species, 27 species/varieties of cereals and certain wild grasses were examined with inoculation experiments under controlled conditions. Most Septoria species were each pathogenic only on a particular host plant, and wild grasses played only a minor role as alternative hosts for these fungi. Septoria tritici isolates from Triticum aestivum infected T. aestivum, T. durum, T. dicoccum and T. compactum, species that may provide a primary inoculum source for S. tritici. Septoria isolates from Aegilops tauschii, Lolium loliaceum, Lophochloa phleoides, Phalaris paradoxa and Hordeum glaucum were pathogenic only on their original hosts. S. passerinii isolates from Hordeum vulgare and H. distichon were pathogenic on all Hordeum species/cultivars tested except H. glaucum. Thus various Hordeum species may play a role in the epidemiology of Septoria diseases on barley