Exploring the popularity, experiences, and beliefs surrounding gluten-free diets in nonceliac athletes.

PubMed

Lis, Dana M; Stellingwerff, Trent; Shing, Cecilia M; Ahuja, Kiran D K; Fell, James W

2015-02-01

Adherence to a gluten-free diet (GFD) for nonceliac athletes (NCA) has become increasingly popular despite a paucity of supportive medical or ergogenic evidence. This study aimed to quantify the demographics of NCA and determine associated experiences, perceptions, and sources of information related to GFD. Athletes (n = 910, female = 528, no gender selected = 5) completed a 17-question online survey. Forty-one percent of NCA respondents, including 18-world and/or Olympic medalists, follow a GFD 50-100% of the time (GFD > 50): only 13% for treatment of reported medical conditions with 57% self-diagnosing their gluten sensitivity. The GFD > 50 group characteristics included predominantly endurance sport athletes (70.0%) at the recreationally competitive level (32.3%), between 31 and 40 years of age (29.1%). Those who follow a GFD > 50 reported experiencing, abdominal/gastrointestinal (GI) symptoms alone (16.7%) or in conjunction with two (30.7%) or three (35.7%) additional symptoms (e.g., fatigue) believed to be triggered by gluten. Eighty-four percent of GFD > 50 indicated symptom improvement with gluten-removal. Symptom-based and non-symptom-based self-diagnosed gluten-sensitivity (56.7%) was the primary reason for adopting a GFD. Leading sources of GFD information were online (28.7%), trainer/coach (26.2%) and other athletes (17.4%). Although 5-10% of the general population is estimated to benefit clinically from a GFD a higher prevalence of GFD adherence was found in NCA (41.2%). Prescription of a GFD among many athletes does not result from evidence-based practice suggesting that adoption of a GFD in the majority of cases was not based on medical rationale and may be driven by perception that gluten removal provides health benefits and an ergogenic edge in NCA.

Is it gluten-free? Relationship between self-reported gluten-free diet adherence and knowledge of gluten content of foods.

PubMed

Silvester, Jocelyn A; Weiten, Dayna; Graff, Lesley A; Walker, John R; Duerksen, Donald R

2016-01-01

To assess the relationship between self-reported adherence to a gluten-free diet (GFD) and the ability to determine correctly the appropriateness of particular foods in a GFD. Persons with celiac disease were recruited through clinics and support groups. Participants completed a questionnaire with items related to GFD information sources, gluten content of 17 common foods (food to avoid, food allowed, and food to question), GFD adherence, and demographic characteristics. Diagnosis was self-reported. The 82 respondents (88% female) had a median of 6 y GFD experience. Most (55%) reported strict adherence, 18% reported intentional gluten consumption and 21% acknowledged rare unintentional gluten consumption. Cookbooks, advocacy groups, and print media were the most commonly used GFD information sources (85-92%). No participant identified correctly the gluten content of all 17 foods; only 30% identified at least 14 foods correctly. The median score on the Gluten-Free Diet Knowledge Scale (GFD-KS) was 11.5 (interquartile ratio, 10-13). One in five incorrect responses put the respondent at risk of consuming gluten. GFD-KS scores did not correlate with self-reported adherence or GFD duration. Patient advocacy group members scored significantly higher on the GFD-KS than non-members (12.3 versus 10.6; P < 0.005). Self-report measures which do not account for the possibility of unintentional gluten ingestion overestimate GFD adherence. Individuals who believe they are following a GFD are not readily able to correctly identify foods that are GF, which suggests ongoing gluten consumption may be occurring, even among patients who believe they are "strictly" adherent. The role of patient advocacy groups and education to improve outcomes through improved adherence to a GFD requires further research. Copyright © 2016 Elsevier Inc. All rights reserved.

Topical Review: Adherence Interventions for Youth on Gluten-Free Diets.

PubMed

Holbein, Christina E; Carmody, Julia K; Hommel, Kevin A

2018-05-01

To summarize gluten-free diet (GFD) nonadherence risk factors, nonadherence rates, and current intervention research within an integrative framework and to develop a research agenda for the development and implementation of evidence-based GFD adherence interventions. Topical review of literature published since 2008 investigating GFD adherence in pediatric samples. Reviews of pediatric studies indicate GFD nonadherence rates ranging from 19 to 56%. There are few evidence-based, published pediatric GFD adherence interventions. Novel assessments of GFD adherence are promising but require further study. Nonmodifiable and modifiable factors within individual, family, community, and health systems domains must be considered when developing future interventions. Clinical implications are discussed. Avenues for future research include development and refinement of adherence assessment tools and development of evidence-based GFD adherence interventions. Novel technologies (e.g., GFD mobile applications) require empirical study but present exciting opportunities for adherence intervention.

The gluten-free diet and its current application in coeliac disease and dermatitis herpetiformis

PubMed Central

Ciclitira, Paul; Hadjivassiliou, Marios; Kaukinen, Katri; Ludvigsson, Jonas F; McGough, Norma; Sanders, David S; Woodward, Jeremy; Leonard, Jonathan N; Swift, Gillian L

2015-01-01

Background A gluten-free diet (GFD) is currently the only available therapy for coeliac disease (CD). Objectives We aim to review the literature on the GFD, the gluten content in naturally gluten-free (GF) and commercially available GF food, standards and legislation concerning the gluten content of foods, and the vitamins and mineral content of a GFD. Methods We carried out a PubMed search for the following terms: Gluten, GFD and food, education, vitamins, minerals, calcium, Codex wheat starch and oats. Relevant papers were reviewed and for each topic a consensus among the authors was obtained. Conclusion Patients with CD should avoid gluten and maintain a balanced diet to ensure an adequate intake of nutrients, vitamins, fibre and calcium. A GFD improves symptoms in most patients with CD. The practicalities of this however, are difficult, as (i) many processed foods are contaminated with gluten, (ii) staple GF foods are not widely available, and (iii) the GF substitutes are often expensive. Furthermore, (iv) the restrictions of the diet may adversely affect social interactions and quality of life. The inclusion of oats and wheat starch in the diet remains controversial. PMID:25922672

A comparison of the nutritional status between adult celiac patients on a long-term, strictly gluten-free diet and healthy subjects.

PubMed

Barone, M; Della Valle, N; Rosania, R; Facciorusso, A; Trotta, A; Cantatore, F P; Falco, S; Pignatiello, S; Viggiani, M T; Amoruso, A; De Filippis, R; Di Leo, A; Francavilla, R

2016-01-01

There are conflicting data on the effect of a gluten-free diet (GFD) on the nutritional status of celiac patients. In the present study, we evaluated, in adult celiac patients, the influence of a long-term, strictly GFD on their nutritional status and compared it with matched healthy volunteers. Our study included 39 celiac patients and 39 healthy volunteers. The body mass index (BMI) of patients and controls was evaluated at enrollment, while the patients' BMI before the GFD was retrieved from clinical records. In addition, at enrollment, in both groups, we compared BMI, fat mass (FM), bone mineral density (BMD), as well as their dietary intake, recorded on a 7-day diary. At the time of diagnosis, the majority of celiac patients (82.0%) had a normal BMI or were overweight, while 10.3% were malnourished. After the GFD, patients with a normal BMI showed a significant weight increase (P=0.002), but none of them switched in the overweight or obese category. Two (50%) of the four malnourished patients achieved a normal BMI. Controls and patients on a GFD had a similar BMI, FM, BMD and total calorie intake, but the amount of lipids and fiber intake was significantly different in the two groups (P=0.003 and P<0.0001, respectively). Our study demonstrates that a GFD is able to improve the nutritional status of celiac patients without inducing overweight or obesity. Our findings are related to a celiac population adopting a GFD based on a Mediterranean-type diet.

Celiac disease, wheat allergy, and gluten sensitivity: when gluten free is not a fad.

PubMed

Pietzak, Michelle

2012-01-01

As the gluten-free diet (GFD) gains in popularity with the general public, health practitioners are beginning to question its real health benefits. For those patients with celiac disease (CD), the GFD is considered medical nutrition therapy, as well as the only proven treatment that results in improvements in symptomatology and small bowel histology. Those with wheat allergy also benefit from the GFD, although these patients often do not need to restrict rye, barley, and oats from their diet. Gluten sensitivity is a controversial subject, where patients who have neither CD nor wheat allergy have varying degrees of symptomatic improvement on the GFD. Conditions in this category include dermatitis herpetiformis (DH), irritable bowel syndrome (IBS), and neurologic diseases such as gluten-sensitive ataxia and autism. It is important for patients and healthcare practitioners to understand the differences between these conditions, even though they may all respond to a GFD. Patients with CD can experience comorbid nutrition deficiencies and are at higher risk for the development of cancers and other autoimmune conditions. Those with wheat allergy and gluten sensitivity are thought not to be at higher risk for these complications. Defining the symptoms and biochemical markers for gluten-sensitive conditions is an important area for future investigations, and high-quality, large-scale randomized trials are needed to prove the true benefits of the GFD in this evolving field.

Salivary and fecal microbiota and metabolome of celiac children under gluten-free diet.

PubMed

De Angelis, Maria; Vannini, Lucia; Di Cagno, Raffaella; Cavallo, Noemi; Minervini, Fabio; Francavilla, Ruggiero; Ercolini, Danilo; Gobbetti, Marco

2016-12-19

Celiac disease (CD) is an inflammatory autoimmune disorder resulting from the combination of genetic predisposition and gluten ingestion. A life-long gluten free diet (GFD) is the only therapeutic approach. Dysbiosis, which can precede the CD pathogenesis and/or persist when subjects are on GFD, is reviewed and discussed. Salivary microbiota and metabolome differed between healthy and celiac children treated under GFD (T-CD) for at least two years. The type of GFD (African- vs Italian-style) modified the microbiota and metabolome of Saharawi T-CD children. Different studies showed bacterial dysbiosis at duodenal and/or fecal level of patients with active untreated CD (U-CD) and T-CD compared to healthy subjects. The ratio of protective anti-inflammatory bacteria such as Lactobacillus-Bifidobacterium to potentially harmful Bacteroides-Enterobacteriaceae was the lowest in U-CD and T-CD children. In agreement with dysbiosis, serum, fecal and urinary metabolome from U-CD and T-CD patients showed altered levels of free amino acids and volatile organic compounds. However, consensus across studies defining specific bacteria and metabolites in U-CD or T-CD patients is still lacking. Future research efforts are required to determine the relationships between CD and oral and intestinal microbiotas to improve the composition of GFD for restoring the gut dysbiosis as a preventative or therapeutic approach for CD. Copyright © 2016 Elsevier B.V. All rights reserved.

Fecal Gluten Peptides Reveal Limitations of Serological Tests and Food Questionnaires for Monitoring Gluten-Free Diet in Celiac Disease Patients.

PubMed

Comino, Isabel; Fernández-Bañares, Fernando; Esteve, María; Ortigosa, Luís; Castillejo, Gemma; Fambuena, Blanca; Ribes-Koninckx, Carmen; Sierra, Carlos; Rodríguez-Herrera, Alfonso; Salazar, José Carlos; Caunedo, Ángel; Marugán-Miguelsanz, J M; Garrote, José Antonio; Vivas, Santiago; Lo Iacono, Oreste; Nuñez, Alejandro; Vaquero, Luis; Vegas, Ana María; Crespo, Laura; Fernández-Salazar, Luis; Arranz, Eduardo; Jiménez-García, Victoria Alejandra; Antonio Montes-Cano, Marco; Espín, Beatriz; Galera, Ana; Valverde, Justo; Girón, Francisco José; Bolonio, Miguel; Millán, Antonio; Cerezo, Francesc Martínez; Guajardo, César; Alberto, José Ramón; Rosinach, Mercé; Segura, Verónica; León, Francisco; Marinich, Jorge; Muñoz-Suano, Alba; Romero-Gómez, Manuel; Cebolla, Ángel; Sousa, Carolina

2016-10-01

Treatment for celiac disease (CD) is a lifelong strict gluten-free diet (GFD). Patients should be followed-up with dietary interviews and serology as CD markers to ensure adherence to the diet. However, none of these methods offer an accurate measure of dietary compliance. Our aim was to evaluate the measurement of gluten immunogenic peptides (GIP) in stools as a marker of GFD adherence in CD patients and compare it with traditional methods of GFD monitoring. We performed a prospective, nonrandomized, multicenter study including 188 CD patients on GFD and 84 healthy controls. Subjects were given a dietary questionnaire and fecal GIP quantified by enzyme-linked immunosorbent assay (ELISA). Serological anti-tissue transglutaminase (anti-tTG) IgA and anti-deamidated gliadin peptide (anti-DGP) IgA antibodies were measured simultaneously. Of the 188 celiac patients, 56 (29.8%) had detectable GIP levels in stools. There was significant association between age and GIP in stools that revealed increasing dietary transgressions with advancing age (39.2% in subjects ≥13 years old) and with gender in certain age groups (60% in men ≥13 years old). No association was found between fecal GIP and dietary questionnaire or anti-tTG antibodies. However, association was detected between GIP and anti-DGP antibodies, although 46 of the 53 GIP stool-positive patients were negative for anti-DGP. Detection of gluten peptides in stools reveals limitations of traditional methods for monitoring GFD in celiac patients. The GIP ELISA enables direct and quantitative assessment of gluten exposure early after ingestion and could aid in the diagnosis and clinical management of nonresponsive CD and refractory CD. Trial registration number NCT02711397.

The Effects of a Gluten-free Diet Versus a Hypocaloric Diet Among Patients With Fibromyalgia Experiencing Gluten Sensitivity-like Symptoms: A Pilot, Open-Label Randomized Clinical Trial.

PubMed

Slim, Mahmoud; Calandre, Elena P; Garcia-Leiva, Juan M; Rico-Villademoros, Fernando; Molina-Barea, Rocio; Rodriguez-Lopez, Carmen M; Morillas-Arques, Piedad

2017-07-01

Patients with fibromyalgia frequently present with symptoms similar to those experienced by patients with gluten-related disorders, raising the possibility that a subgroup of these patients could be experiencing underlying gluten sensitivity. This study aimed to evaluate the effects of a gluten-free diet (GFD) compared with a hypocaloric diet (HCD) among patients with fibromyalgia. Adult patients diagnosed with fibromyalgia were randomly allocated to receive a GFD or a HCD over a 24-week period. The primary outcome measure was the change in the number of gluten sensitivity symptoms. The following secondary outcomes were evaluated: body mass index, Revised Fibromyalgia Impact Questionnaire, Pittsburgh Sleep Quality Index, Brief Pain Inventory, Beck Depression Inventory-II, State-Trait Anxiety Inventory, Short-Form Health Survey, Patient Global Impression Scale of Severity, Patient Global Impression Scale of Improvement, and adverse events. Seventy-five subjects were randomly allocated to receive either a GFD (n=35) or an HCD (n=40). The least squares mean change in the total number of gluten sensitivity symptoms from baseline did not differ significantly between the GFD and HCD groups (-2.44±0.40 for the GFD; -2.10±0.37 for the HCD; P=0.343). Similarly, the 2 dietary interventions did not differ in any of the remaining measured secondary outcomes. Both dietary interventions were well tolerated. Both dietary interventions were associated with similar beneficial outcomes in reducing gluten sensitivity symptoms and other secondary outcomes. However, despite its specificity, GFD was not superior to HCD in reducing the number of gluten sensitivity symptoms or secondary outcomes.

Coeliac disease in adolescence: Coping strategies and personality factors affecting compliance with gluten-free diet.

PubMed

Wagner, Gudrun; Zeiler, Michael; Grylli, Vasileia; Berger, Gabriele; Huber, Wolf-Dietrich; Woeber, Christian; Rhind, Charlotte; Karwautz, Andreas

2016-06-01

Patients suffering from a chronic condition such as coeliac disease (CD) need to develop coping strategies in order to preserve emotional balance and psychosocial functioning while adhering to their obligatory life-long gluten free diet (GFD). However, this can be particularly challenging for adolescents and may lead to dietary transgressions. Little is currently known about the influence of coping strategies and personality factors on dietary compliance. This study aims to explore these factors for the first time in adolescents with biopsy-proven CD. We included 281 adolescents with CD and 95 healthy controls. We classified patients according to their GFD adherence status (adherent vs. non-adherent) and assessed coping strategies using the KIDCOPE and personality traits using the Junior-Temperament and Character Inventory (J-TCI). Adolescents with CD adherent to GFD used less emotional regulation and distraction as coping strategies than non-adherent patients. In terms of personality traits, adherent patients differed from non-adherent patients with respect to temperament, but not with respect to character, showing lower scores in novelty seeking, impulsivity and rule transgressions and higher scores in eagerness with work and perfectionism compared to non-adherent patients. No differences were found between healthy controls and adherent CD patients across these personality traits. Coping strategies and personality traits differ in adolescent patients with CD adherent to GFD from those not adherent, and may therefore relate to risk or protective factors in adherence. Targeting coping and temperament using psychological interventions may therefore be beneficial to support adolescents with CD and optimise their adherence to GFD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Living gluten-free: adherence, knowledge, lifestyle adaptations and feelings towards a gluten-free diet.

PubMed

Silvester, J A; Weiten, D; Graff, L A; Walker, J R; Duerksen, D R

2016-06-01

A gluten-free diet (GFD) requires tremendous dedication, involving substantive changes to diet and lifestyle that may have a significant impact upon quality of life. The present study aimed io assess dietary adherence, knowledge of a GFD, and the emotional and lifestyle impact of a GFD. Community dwelling adults following a GFD completed a questionnaire with items related to reasons for avoiding gluten, diagnostic testing, GFD adherence, knowledge and sources of information about a GFD, the Work and Social Adjustment Scale, and the effect of a GFD diet on lifestyle, feelings and behaviours. Strict GFD adherence among the 222 coeliac disease (CD) patients was 56%. Non-CD individuals (n = 38) were more likely to intentionally ingest gluten (odds ratio = 3.7; 95% confidence interval = 1.4-9.4). The adverse impact of a GFD was modest but most pronounced in the social domain. Eating shifted from the public to the domestic sphere and there were feelings of social isolation. Affective responses reflected resilience because acceptance and relief were experienced more commonly than anxiety or anger. Non-CD respondents were less knowledgeable and less likely to consult health professionals. They experienced less anger and depression and greater pleasure in eating than CD respondents. The findings obtained in the present suggest there is good potential for positive adaptation to the demands of a GFD; nevertheless, there is a measurable degree of social impairment that merits further study. The GFD may be a viable treatment option for conditions other than CD; however, education strategies regarding the need for diagnostic testing to exclude CD are required. © 2015 The British Dietetic Association Ltd.

Development and use of the Cytoscape app GFD-Net for measuring semantic dissimilarity of gene networks

PubMed Central

Diaz-Montana, Juan J.; Diaz-Diaz, Norberto

2014-01-01

Gene networks are one of the main computational models used to study the interaction between different elements during biological processes being widely used to represent gene–gene, or protein–protein interaction complexes. We present GFD-Net, a Cytoscape app for visualizing and analyzing the functional dissimilarity of gene networks. PMID:25400907

Assessing the proposed association between DED and gluten-free diet introduction in celiac children.

PubMed

de Queiroz, Alexandra Mussolino; Arid, Juliana; de Carvalho, Fabrício Kitazono; da Silva, Raquel Assed Bezerra; Küchler, Erika Calvano; Sawamura, Regina; da Silva, Lea Assed Bezerra; Nelson-Filho, Paulo

2017-07-01

A strong association between celiac disease (CD) and dental enamel defects (DEDs) have been extensively reported, however, the nature of this relationship is still unclear. The aim of this study was to evaluate DEDs phenotype in CD individuals according to the time they were introduced to a gluten-free diet (GFD). Forty-five CD individuals were examined by a pediatric dentist. DEDs were classified according to the type of affected teeth. CD individuals were classified into two groups (with or without DEDs) and the differences between these groups were tested using chi-square or Fisher´s exact tests and t-test to compare differences between means. The Pearson coefficient test was used to evaluate the degree of the correlation between the age of GFD introduction and number of affected teeth. Individuals with MIH were introduced earlier to the GFD (p = 0.038). An association was also observed for molar DED (p = 0.013). In conclusion, our study suggested an association between a specific type of DED and the time that CD individuals were introduced to a GFD. © 2017 Special Care Dentistry Association and Wiley Periodicals, Inc.

The Effect of Gluten-free Diet on Clinical Symptoms and the Intestinal Mucosa of Patients With Potential Celiac Disease.

PubMed

Mandile, Roberta; Discepolo, Valentina; Scapaticci, Serena; Del Vecchio, Maria Rosaria; Maglio, Maria Antonia; Greco, Luigi; Troncone, Riccardo; Auricchio, Renata

2018-04-01

In this prospective study, we evaluated the effect of gluten-free diet (GFD) in a cohort of 65 children with potential celiac disease. Patients received GFD for signs/symptoms (N = 47) or parents' choice (N = 18). Most frequent signs/symptoms were low body mass index (36%), recurrent abdominal pain (34%), and diarrhea (19%). Of the 35/47 patients followed-up on GFD, only 54% (19/35) showed a complete clinical response. In 9 of 65 patients an intestinal biopsy was also performed after at least 1 year of GFD. No significant differences were observed in terms of Marsh grade (P = 0.33), lamina propria CD25+ cells (P = 0.80), CD3+ (P = 0.9), and γδ+ (P = 0.59) intraepithelial lymphocytes density and intestinal anti-TG2 deposits (P = 0.60). In conclusion, caution is necessary before attributing all symptoms to gluten in this condition.

Celiac disease and the gluten-free diet: consequences and recommendations for improvement.

PubMed

Theethira, Thimmaiah G; Dennis, Melinda

2015-01-01

Celiac disease (CD) is a chronic small intestinal immune-mediated enteropathy precipitated by exposure to dietary gluten in genetically susceptible individuals. CD-related enteropathy leads to multiple nutritional deficiencies involving macro- and micronutrients. Currently, medical nutrition therapy consisting of the gluten-free diet (GFD) is the only accepted treatment for CD. The GFD is the cornerstone of treatment for CD. Prior published studies have concluded that maintenance of the GFD results in improvement of the majority of nutritional deficiencies. In the past, counseling for CD focused mainly on the elimination of gluten in the diet. However, the GFD is not without its inadequacies; compliance to the GFD may result in certain deficiencies such as fiber, B vitamins, iron, and trace minerals. Paucity of fortified gluten-free foods may be responsible for certain deficiencies which develop on the GFD. Weight gain and obesity have been added to the list of nutritional consequences while on the GFD and have been partially attributed to hypercaloric content of commercially available gluten-free foods. Follow-up of patients diagnosed with CD after starting the GFD has been reported to be irregular and, hence, less than ideal. Monitoring of the nutritional status using blood tests and use of appropriate gluten-free supplementation are integral components in the management of CD. The ideal GFD should be nutrient-dense with naturally gluten-free foods, balanced with macro- and micronutrients, reasonably priced, and easily accessible. Rotation of the pseudo-cereals provides a good source of complex carbohydrates, protein, fiber, fatty acids, vitamins and minerals. Fortification/enrichment of commonly consumed gluten-free commercial grain products should be encouraged. Dietitians specializing in CD play a critical role in the education and maintenance of the GFD for patients with CD. © 2015 S. Karger AG, Basel.

Larazotide acetate for persistent symptoms of celiac disease despite a gluten-free diet: a randomized controlled trial.

PubMed

Leffler, Daniel A; Kelly, Ciaran P; Green, Peter H R; Fedorak, Richard N; DiMarino, Anthony; Perrow, Wendy; Rasmussen, Henrik; Wang, Chao; Bercik, Premysl; Bachir, Natalie M; Murray, Joseph A

2015-06-01

Celiac disease (CeD) is a prevalent autoimmune condition. Recurrent signs and symptoms are common despite treatment with a gluten-free diet (GFD), yet no approved or proven nondietary treatment is available. In this multicenter, randomized, double-blind, placebo-controlled study, we assessed larazotide acetate 0.5, 1, or 2 mg 3 times daily to relieve ongoing symptoms in 342 adults with CeD who had been on a GFD for 12 months or longer and maintained their current GFD during the study. The study included a 4-week placebo run-in, 12 weeks of treatment, and a 4-week placebo run-out phase. The primary end point was the difference in average on-treatment Celiac Disease Gastrointestinal Symptom Rating Scale score. The primary end point was met with the 0.5-mg dose of larazotide acetate, with fewer symptoms compared with placebo by modified intention to treat (n = 340) (analysis of covariance, P = .022; mixed model for repeated measures, P = .005). The 0.5-mg dose showed an effect on exploratory end points including a 26% decrease in celiac disease patient-reported outcome symptomatic days (P = .017), a 31% increase in improved symptom days (P = .034), a 50% or more reduction from baseline of the weekly average abdominal pain score for 6 or more of 12 weeks of treatment (P = .022), and a decrease in the nongastrointestinal symptoms of headache and tiredness (P = .010). The 1- and 2-mg doses were no different than placebo for any end point. Safety was comparable with placebo. Larazotide acetate 0.5 mg reduced signs and symptoms in CeD patients on a GFD better than a GFD alone. Although results were mixed, this study was a successful trial of a novel therapeutic agent targeting tight junction regulation in patients with CeD who are symptomatic despite a GFD. Clinicaltrials.gov: NCT01396213. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

A possible role for ghrelin, leptin, brain-derived neurotrophic factor and docosahexaenoic acid in reducing the quality of life of coeliac disease patients following a gluten-free diet.

PubMed

Russo, Francesco; Chimienti, Guglielmina; Clemente, Caterina; Ferreri, Carla; Orlando, Antonella; Riezzo, Giuseppe

2017-03-01

A gluten-free diet (GFD) has been reported to negatively impact the quality of life (QoL) of coeliac disease (CD) patients. The gut-brain axis hormones ghrelin and leptin, with the brain-derived neurotrophic factor (BDNF), may affect QoL of CD patients undergoing GFD. Our aims were to evaluate whether: (a) the circulating concentrations of leptin, ghrelin and BDNF in CD patients were different from those in healthy subjects; (b) GFD might induce changes in their levels; (c) BDNF Val66Met polymorphism variability might affect BDNF levels; and (d) serum BDNF levels were related to dietary docosahexaenoic acid (DHA) as a neurotrophin modulator. Nineteen adult coeliac patients and 21 healthy controls were included. A QoL questionnaire was administered, and serum concentrations of ghrelin, leptin, BDNF and red blood cell membrane DHA levels were determined at the enrolment and after 1 year of GFD. BDNF Val66Met polymorphism was analysed. Results from the questionnaire indicated a decline in QoL after GFD. Ghrelin and leptin levels were not significantly different between groups. BDNF levels were significantly (p = 0.0213) lower in patients after GFD (22.0 ± 2.4 ng/ml) compared to controls (31.2 ± 2.2 ng/ml) and patients at diagnosis (25.0 ± 2.5 ng/ml). BDNF levels correlated with DHA levels (p = 0.008, r = 0.341) and the questionnaire total score (p = 0.041, r = 0.334). Ghrelin and leptin seem to not be associated with changes in QoL of patients undergoing dietetic treatment. In contrast, a link between BDNF reduction and the vulnerability of CD patients to psychological distress could be proposed, with DHA representing a possible intermediate.

Self-Reported Prevalence of Gluten-Related Disorders and Adherence to Gluten-Free Diet in Colombian Adult Population

PubMed Central

Franco-Aguilar, Alejandro; Magaña-Ordorica, Dalia

2016-01-01

Background. Celiac disease seems to be rare in Colombians, but there are currently no data about the prevalence rates of symptomatic adverse reactions to gluten or adherence to gluten-free diet (GFD) in this population. Aim. to evaluate the self-reported prevalence rates of adverse reactions to gluten, adherence to GFD, and gluten-related disorders at population level in Colombia. Methods. A self-administered questionnaire-based cross-sectional study was conducted in a population from Northwest Colombia. Results. The estimated prevalence rates were (95% CI) 7.9% (6.5–9.6) and 5.3% (4.1–6.7) for adverse and recurrent adverse reactions to wheat/gluten, respectively, adherence to GFD 5.9% (4.7–7.4), wheat allergy 0.74% (0.3–1.4), and nonceliac gluten sensitivity 4.5% (3.5–5.8). There were no self-reported cases of celiac disease. Prevalence of self-reported physician-diagnosis of gluten-related disorders was 0.41% (0.17–0.96). Most respondents reported adherence to GFD without a physician-diagnosis of gluten-related disorders (97.2%). The proportion of gluten avoiders was 17.2% (15.2–19.5). Most of them did not report recurrent adverse reactions to wheat/gluten (87.0%). Conclusions. Nonceliac gluten sensitivity is rarely formally diagnosed in Colombia, but this population has the highest prevalence rate of adherence to GFD reported to date. Consequently, most respondents were avoiding wheat- and/or gluten-based products for reasons other than health-related symptoms. PMID:27648068

Intraepithelial lymphocyte immunophenotype: a useful tool in the diagnosis of celiac disease.

PubMed

Saborido, Rebeca; Martinón, Nazareth; Regueiro, Alexandra; Crujeiras, Vanesa; Eiras, Pablo; Leis, Rosaura

2018-02-01

According to new ESPGHAN guidelines, gluten challenge is considered necessary when there is doubt about the initial diagnosis of celiac disease (CD). The main aim of this study was to quantify intraepithelial lymphocyte (IEL) immunophenotype on celiac patients on gluten-containing diet (GCD) compared to those on gluten-free diet (GFD). Another aim was to evaluate the clinical utility of IELs in the CD diagnosis, especially in selected patients on GFD where diagnostic uncertainty remains. IEL immunophenotype (TCRγδ and NK-like IELs) were studied by flow cytometry in 111 children with CD (81 children with CD on GCD and 30 celiac patients on GFD) and a control group (10 children). Duration of GFD was 5.4 ± 1.6 years. TCRγδ IELs in celiac patients receiving a GCD or GFD were significantly higher (p < 0.001) than in the control group. NK-like IELs in patients receiving a GCD or GFD were significantly lower than in the control group (p < 0.001). We observed a permanent decrease of NK-like IELs and an increment of TCRγδ IELs after following an adequate establishment and compliance of a long-term GFD in celiac patients. Recognition of IELs changes in the intestinal mucosa on celiac patients after long-term establishment of a GFD could constitute a useful tool for CD diagnosis in various situations: in which there is doubt about the initial diagnosis and repeat biopsy is necessary (avoiding the need of gluten challenges), and in those patients with symptoms/signs suggestive of CD who maintain a low gluten diet.

The progression of coeliac disease: its neurological and psychiatric implications.

PubMed

Campagna, Giovanna; Pesce, Mirko; Tatangelo, Raffaella; Rizzuto, Alessia; La Fratta, Irene; Grilli, Alfredo

2017-06-01

The aim of the paper is to show the various neurological and psychiatric symptoms in coeliac disease (CD). CD is a T cell-mediated, tissue-specific autoimmune disease which affects genetically susceptible individuals after dietary exposure to proline- and glutamine-rich proteins contained in certain cereal grains. Genetics, environmental factors and different immune systems, together with the presence of auto-antigens, are taken into account when identifying the pathogenesis of CD. CD pathogenesis is related to immune dysregulation, which involves the gastrointestinal system, and the extra-intestinal systems such as the nervous system, whose neurological symptoms are evidenced in CD patients. A gluten-free diet (GFD) could avoid cerebellar ataxia, epilepsy, neuropathies, migraine and mild cognitive impairment. Furthermore, untreated CD patients have more symptoms and psychiatric co-morbidities than those treated with a GFD. Common psychiatric symptoms in untreated CD adult patients include depression, apathy, anxiety, and irritability and schizophrenia is also common in untreated CD. Several studies show improvement in psychiatric symptoms after the start of a GFD. The present review discusses the state of the art regarding neurological and psychiatric complications in CD and highlights the evidence supporting a role for GFD in reducing neurological and psychiatric complications.

Safety of Adding Oats to a Gluten-Free Diet for Patients With Celiac Disease: Systematic Review and Meta-analysis of Clinical and Observational Studies.

PubMed

Pinto-Sánchez, María Inés; Causada-Calo, Natalia; Bercik, Premysl; Ford, Alexander C; Murray, Joseph A; Armstrong, David; Semrad, Carol; Kupfer, Sonia S; Alaedini, Armin; Moayyedi, Paul; Leffler, Daniel A; Verdú, Elena F; Green, Peter

2017-08-01

Patients with celiac disease should maintain a gluten-free diet (GFD), excluding wheat, rye, and barley. Oats might increase the nutritional value of a GFD, but their inclusion is controversial. We performed a systematic review and meta-analysis to evaluate the safety of oats as part of a GFD in patients with celiac disease. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE databases for clinical trials and observational studies of the effects of including oats in GFD of patients with celiac disease. The studies reported patients' symptoms, results from serology tests, and findings from histologic analyses. We used the GRADE approach to assess the quality of evidence. We identified 433 studies; 28 were eligible for analysis. Of these, 6 were randomized and 2 were not randomized controlled trials comprising a total of 661 patients-the remaining studies were observational. All randomized controlled trials used pure/uncontaminated oats. Oat consumption for 12 months did not affect symptoms (standardized mean difference: reduction in symptom scores in patients who did and did not consume oats, -0.22; 95% CI, -0.56 to 0.13; P = .22), histologic scores (relative risk for histologic findings in patients who consumed oats, 0.24; 95% CI, 0.01-4.8; P = .35), intraepithelial lymphocyte counts (standardized mean difference, 0.21; 95% CI, reduction of 1.44 to increase in 1.86), or results from serologic tests. Subgroup analyses of adults vs children did not reveal differences. The overall quality of evidence was low. In a systematic review and meta-analysis, we found no evidence that addition of oats to a GFD affects symptoms, histology, immunity, or serologic features of patients with celiac disease. However, there were few studies for many endpoints, as well as limited geographic distribution and low quality of evidence. Rigorous double-blind, placebo-controlled, randomized controlled trials, using commonly available oats sourced from different regions, are needed. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

[A national online survey applied to patients with celiac disease in Chile].

PubMed

Espino, Alberto; Castillo L, Cecilia; Guiraldes, Ernesto; Santibáñez, Helga; Miquel, Juan Francisco

2011-07-01

Celiac disease (CD) is an immune-mediated enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Its prevalence in Europe and the USA is 0.5 to 1%. To analyze epidemiological aspects and degree of compliance with gluten-free diet (GFD) among Chilean individuals with CD. Subjects with confirmed or suspected CD were invited to answer an online survey published on the web at www.fundacionconvivir.cl. The answers were reinforced with a telephone interview. The survey was answered by 1212 subjects (79% females). Median age at diagnosis was 25.8 years (range 1 to 84 years), with a bimodal curve with two peaks at less than 3 years and at 20 to 40 years of age. The diagnosis was made only by serologic markers in 9%, only by intestinal biopsy in 17.5%, and by a combination of both methods in 70%o. Conditions associated with CD were reported by 30% > of subjects and 20% > had relatives with CD. The GFD was strictly adhered to by 70% >, occasionally by 27% > and never by 3% >. Seventy five percent of subjects with a strict adherence to GFD had a favorable clinical response compared with 42% > of those with incomplete or lack of adherence (odds ratio 4.0, 95% > confidence intervals 2.8-5.7p < 0.01). In 30% of respondents, the diagnosis of CD was not confirmed according to international guidelines that require serology and duodenal biopsy. One third of subjects recognized a poor compliance with GFD. Those with a strict adherence to it had a more favorable clinical course. However, 25% > did not experience a clinical improvement despite a strict GFD, a finding which requires further study.

The Effect of Oligofructose-Enriched Inulin on Faecal Bacterial Counts and Microbiota-Associated Characteristics in Celiac Disease Children Following a Gluten-Free Diet: Results of a Randomized, Placebo-Controlled Trial

PubMed Central

Jarocka-Cyrta, Elżbieta; Markiewicz, Lidia Hanna

2018-01-01

Celiac disease (CD) is associated with intestinal microbiota alterations. The administration of prebiotics could be a promising method of restoring gut homeostasis in CD. The aim of this study was to evaluate the effect of prolonged oligofructose-enriched inulin (Synergy 1) administration on the characteristics and metabolism of intestinal microbiota in CD children following a gluten-free diet (GFD). Thirty-four paediatric CD patients (mean age 10 years; 62% females) on a GFD were randomized into two experimental groups receiving Synergy 1 (10 g/day) or placebo (maltodextrin; 7 g/day) for 3 months. The quantitative gut microbiota characteristics and short-chain fatty acids (SCFAs) concentration were analysed. In addition, side effects were monitored. Generally, the administration of Synergy 1 in a GFD did not cause any side effects. After the intervention period, Bifidobacterium count increased significantly (p < 0.05) in the Synergy 1 group. Moreover, an increase in faecal acetate and butyrate levels was observed in the prebiotic group. Consequently, total SCFA levels were 31% higher than at the baseline. The presented trial shows that Synergy 1 applied as a supplement of a GFD had a moderate effect on the qualitative characteristics of faecal microbiota, whereas it stimulated the bacterial metabolite production in CD children. PMID:29439526

The Effect of Oligofructose-Enriched Inulin on Faecal Bacterial Counts and Microbiota-Associated Characteristics in Celiac Disease Children Following a Gluten-Free Diet: Results of a Randomized, Placebo-Controlled Trial.

PubMed

Drabińska, Natalia; Jarocka-Cyrta, Elżbieta; Markiewicz, Lidia Hanna; Krupa-Kozak, Urszula

2018-02-12

Celiac disease (CD) is associated with intestinal microbiota alterations. The administration of prebiotics could be a promising method of restoring gut homeostasis in CD. The aim of this study was to evaluate the effect of prolonged oligofructose-enriched inulin (Synergy 1) administration on the characteristics and metabolism of intestinal microbiota in CD children following a gluten-free diet (GFD). Thirty-four paediatric CD patients (mean age 10 years; 62% females) on a GFD were randomized into two experimental groups receiving Synergy 1 (10 g/day) or placebo (maltodextrin; 7 g/day) for 3 months. The quantitative gut microbiota characteristics and short-chain fatty acids (SCFAs) concentration were analysed. In addition, side effects were monitored. Generally, the administration of Synergy 1 in a GFD did not cause any side effects. After the intervention period, Bifidobacterium count increased significantly ( p < 0.05) in the Synergy 1 group. Moreover, an increase in faecal acetate and butyrate levels was observed in the prebiotic group. Consequently, total SCFA levels were 31% higher than at the baseline. The presented trial shows that Synergy 1 applied as a supplement of a GFD had a moderate effect on the qualitative characteristics of faecal microbiota, whereas it stimulated the bacterial metabolite production in CD children.

Benefit on health-related quality of life of adherence to gluten-free diet in adult patients with celiac disease.

PubMed

Casellas, Francisco; Rodrigo, Luis; Lucendo, Alfredo J; Fernández-Bañares, Fernando; Molina-Infante, Javier; Vivas, Santiago; Rosinach, Mercé; Dueñas, Carmen; López-Vivancos, Josefa

2015-04-01

Celiac disease (CD) affects health-related quality of life (HRQOL) of patients suffering it. The exclusion of gluten from the diet (GFD) improves HRQOL, but involves difficulties in following the diet that could adversely affect HRQOL. To determine the effect of adherence to the diet on HRQOL of adult CD patients. A prospective, cross-sectional, multicenter study of CD patients treated with a GFD for longer than 1 year. Adherence to the GFD was measured using the Morisky scale, and health status using the specific CD-QOL questionnaire and the generic EuroQol-5D questionnaire. 366 patients from 7 hospitals were included: 71.5% of patients reported a perfect treatment adherence, 23.5% unintentional poor adherence and 5% intentional poor adherence. Good adherence to a GFD was related to a higher mean score onthe CD-QOL (75 vs. 68, respectively, p < 0.05) and EuroQol-5D (0.9 vs. 0.8, respectively, p < 0.05). Ease of adherence to a GFD was also related to a better HRQOL (total CD-QOL score of 82 vs. 67 in patients who consider the GFD difficult to follow, p < 0.05). Good symptom control was also related to a better HRQOL (total CD-QOL score of 78 vs. 67 in asymptomatic vs. symptomatic patients, p < 0.01). The worse scored dimension of CD-QOL was related to "inadequate treatment". In CD, good adherence to a GFD and adequate symptom control result in improved HRQOL. Many patients consider that the lack of therapeutic alternatives to diet worsens their quality of life.

Are patients with coeliac disease seeking alternative therapies to a gluten-free diet?

PubMed

Aziz, Imran; Evans, Kate E; Papageorgiou, Vasiliki; Sanders, David S

2011-03-01

The cornerstone of treatment for coeliac disease is a gluten-free diet (GFD). However, adherence to a GFD is variable. Recently investigators have been reporting their preliminary findings using novel therapies. In addition, there is a growing interest in the use of complementary or alternative medicine (CAM) in gastrointestinal illnesses. These observations suggest that patients with coeliac disease may be dissatisfied with a GFD and possibly are seeking/using alternative therapies for their disease. Our aim was to assess the satisfaction levels of adults with coeliac disease towards a GFD, their use of oral CAM and views regarding novel therapies. 310 patients with coeliac disease completed a questionnaire survey while attending their out-patient appointment. The control group comprised 477 individuals. Over 40% of patients with coeliac disease were dissatisfied with a GFD. The frequency of CAM use in patients with coeliac disease was 21.6% (67/310) vs 27% in the control group (129/477), p=0.09. All patients expressed an interest in novel therapies, with a vaccine being the first choice in 42% of patients, 35% and 23% for anti- zonulin and peptidases, respectively. Universally, patients placed genetically modified wheat as the lowest preference. A large proportion of patients with coeliac disease are dissatisfied with a GFD. Coeliac patients are not taking CAM any more than controls, suggesting they do not view CAM as an alternative to a GFD. However, all the patients in this survey were keen to consider novel therapies, with a vaccine being the most preferred option.

Quality of Life and Gastrointestinal Symptoms in Long-Term Treated Dermatitis Herpetiformis Patients: A Cross-Sectional Study in Finland.

PubMed

Pasternack, Camilla; Kaukinen, Katri; Kurppa, Kalle; Mäki, Markku; Collin, Pekka; Reunala, Timo; Huhtala, Heini; Salmi, Teea

2015-12-01

Dermatitis herpetiformis (DH) is a cutaneous manifestation of celiac disease. Both conditions are treated with a restrictive life-long gluten-free diet (GFD). Treated celiac disease patients have been shown to have more severe gastrointestinal symptoms and inferior quality of life compared with healthy controls, but evidence regarding quality of life in DH is lacking. The aim was to evaluate whether long-term GFD-treated DH patients suffer from persistent gastrointestinal symptoms and if they experience a drawdown in quality of life. Gastrointestinal symptoms and quality of life were assessed in 78 long-term GFD-treated DH patients using the validated Gastrointestinal Symptom Rating Scale, Psychological General Well-Being and Short Form 36 Health Survey questionnaires. The findings were compared with 110 healthy controls, population-based reference values and 371 treated celiac disease controls. The median age of the DH patients at the time of the study was 57 years, and 51 % were male. Significant differences in gastrointestinal symptoms or quality of life were not detected when treated DH patients were compared with healthy controls, but treated DH patients had less severe gastrointestinal symptoms and increased quality of life compared with celiac disease controls. Female DH patients had more severe gastrointestinal symptoms and reduced vitality compared with male DH patients. The presence of skin symptoms and the adherence to or duration of GFD did not have any influence on gastrointestinal symptoms or quality of life. We conclude that long-term GFD-treated DH patients do not suffer from the burden of dietary treatment and have a quality of life comparable to that of controls.

Swedish children with celiac disease comply well with a gluten-free diet, and most include oats without reporting any adverse effects: a long-term follow-up study.

PubMed

Tapsas, Dimitrios; Fälth-Magnusson, Karin; Högberg, Lotta; Hammersjö, Jan-Åke; Hollén, Elisabet

2014-05-01

The only known treatment for celiac disease is a gluten-free diet (GFD), which initially meant abstention from wheat, rye, barley, and oats. Recently, oats free from contamination with wheat have been accepted in the GFD. Yet, reports indicate that all celiac disease patients may not tolerate oats. We hypothesized that celiac children comply well with a GFD and that most have included oats in their diet. A food questionnaire was used to check our patients; 316 questionnaires were returned. Mean time on the GFD was 6.9 years, and 96.8% of the children reported that they were trying to keep a strict GFD. However, accidental transgressions occurred in 263 children (83.2%). In 2 of 3 cases, mistakes took place when the patients were not at home. Symptoms after incidental gluten intake were experienced by 162 (61.6%) patients, mostly (87.5%) from the gastrointestinal tract. Small amounts of gluten (<4 g) caused symptoms in 38% of the cases, and 68% reported symptoms during the first 3 hours after gluten consumption. Oats were included in the diet of 89.4% of the children for a mean of 3.4 years. Most (81.9%) ate purified oats, and 45.3% consumed oats less than once a week. Among those who did not consume oats, only 5.9% refrained because of symptoms. General compliance with the GFD was good. Only the duration of the GFD appeared to influence adherence to the diet. Most patients did not report adverse effects after long-term consumption of oats. Copyright © 2014 Elsevier Inc. All rights reserved.

Effect of gluten free diet on gastrointestinal and behavioral indices for children with autism spectrum disorders: a randomized clinical trial.

PubMed

Ghalichi, Faezeh; Ghaemmaghami, Jamal; Malek, Ayyoub; Ostadrahimi, Alireza

2016-11-01

Genetic and environmental factors are both responsible for the etiology of autism spectrum disorders (ASD). Although epidemiological studies have been conducted to clarify the association between restriction diets and ASD, the conclusion remains unclear. This study was undertaken to investigate the effect of gluten free diet (GFD) on gastrointestinal symptoms and behavioral indices in children with ASD. In this randomized clinical trial, 80 children diagnosed with ASD by the Autism Diagnostic Interview-Revised (ADI-R) were assigned into GFD (n=40) and regular diet (RD) (n=40) groups for 6 weeks. At the beginning and end of the intervention, the ROME Ш questionnaire for evaluating gastrointestinal symptoms and Gilliam Autism Rating Scale 2 questionnaire (GARS-2) for assessing psychometric properties were completed. Of the 80 children, 53.9% had gastrointestinal abnormalities. In the GFD group, the prevalence of gastrointestinal symptoms decreased significantly (P<0.05) after intake of GFD (40.57% vs. 17.10%) but increased insignificantly in the RD group (42.45% vs. 44.05%). GFD intervention resulted in a significant decrease in behavioral disorders (80.03±14.07 vs. 75.82±15.37, P<0.05) but an insignificant increase in the RD group (79.92±15.49 vs. 80.92±16.24). This study suggested that GFD may be effective in controlling gastrointestinal symptoms and ASD behaviors.

Is the Grass Always Greener? Comparing the Environmental Impact of Conventional, Natural and Grass-Fed Beef Production Systems.

PubMed

Capper, Judith L

2012-04-10

This study compared the environmental impact of conventional, natural and grass-fed beef production systems. A deterministic model based on the metabolism and nutrient requirements of the beef population was used to quantify resource inputs and waste outputs per 1.0 × 10⁸ kg of hot carcass weight beef in conventional (CON), natural (NAT) and grass-fed (GFD) production systems. Production systems were modeled using characteristic management practices, population dynamics and production data from U.S. beef production systems. Increased productivity (slaughter weight and growth rate) in the CON system reduced the cattle population size required to produce 1.0 × 10⁸ kg of beef compared to the NAT or GFD system. The CON system required 56.3% of the animals, 24.8% of the water, 55.3% of the land and 71.4% of the fossil fuel energy required to produce 1.0 × 10⁸ kg of beef compared to the GFD system. The carbon footprint per 1.0 × 10⁸ kg of beef was lowest in the CON system (15,989 × 10³ t), intermediate in the NAT system (18,772 × 10³ t) and highest in the GFD system (26,785 × 10³ t). The challenge to the U.S beef industry is to communicate differences in system environmental impacts to facilitate informed dietary choice.

[An analysis of clinical features of celiac disease patients in different ethnic].

PubMed

Geng, W; Qiao, X B; Ji, K Y; Wang, H F; Yang, A M

2016-08-01

To summarize the clinical features of different racial patients with celiac disease (CD) and analyze the disease prevalence, diagnosis and treatment in Chinese population. All the patients were diagnosed as CD and enrolled in Beijing United Family Hospital between January 2005 and July 2015.Clinical data including nationality, age, symptoms, endoscopic and pathological findings, outcome were collected and compared in patients from different countries. A total of 87 patients were enrolled including 63 Caucasians, 18 Asian patients and 6 Middle East patients.The peak age of disease onset was 40-60 years old.Patients with typical symptoms such as chronic diarrhea and weight loss only accounted for 20.7%(18/87) and 9.2%(8/87) respectively.Some patients presented with nonspecific symptoms such as abdominal pain and bloating [32.2%(28/87)], even constipation [5.7%(5/87)].13.8%(12/87) patients were previously diagnosed as irritable bowel syndrome.The incidence of abdominal pain, bloating, diarrhea and constipation between Asians and Caucasians had no statistical significance (P>0.05); but the proportions of weight loss, growth retardation, iron deficiency anemia and dermatitis herpetiformis in Asian group were significantly higher than that in Caucasian group (P<0.05). IgA type of anti-gliadin antibody (AGA), endomysium antibody (EMA) and tissue transglutaminase antibody (tTGA) were dominant autoimmune antibodies in patients with CD, which accounted for 58.6%(51/87), 44.8%(39/87) and 36.8%(32/87) respectively.The endoscopy showed that the lesion of CD was mainly located in small intestine, with reducing severity from the proximal to the distal small intestine.The lesions of duodenal bulb and descending duodenum appeared more significant in Asian group.Accordingly pathological intestinal atrophy and the degree of intraepithelial lymphocytosis were more severe in Asian patients.All 87 cases took the gluten-free diet (GFD). Eighty-one cases received serological follow up and 8 with endoscopic intestinal biopsy.The celiac disease antibodies in 47 patients turned negative from 6-9 months after GFD treatment, while 34 patients turned negative from 12-18 months after GFD.All patients reported disease remission to some extent.After 1 year GFD treatment, the pathology of endoscopic intestinal biopsy in 8 patients showed significant improvement of villous atrophy and lymphocyte infiltration. CD patients with typical clinical manifestations are not the majority.Serological celiac disease antibodies (AGA, EMA and tTGA) have a high diagnostic value.GFD treatment is effective on majority of celiac patients.Clinical manifestations, endoscopy, intestinal pathology, and response to GFD in Chinese patients are not the same as Caucasians.Clinicians need to pay attention to the differential diagnosis.

Gluten-Free Diet Indications, Safety, Quality, Labels, and Challenges.

PubMed

Rostami, Kamran; Bold, Justine; Parr, Alison; Johnson, Matt W

2017-08-08

A gluten-free diet (GFD) is the safest treatment modality in patient with coeliac disease (CD) and other gluten-related disorders. Contamination and diet compliance are important factors behind persistent symptoms in patients with gluten related-disorders, in particular CD. How much gluten can be tolerated, how safe are the current gluten-free (GF) products, what are the benefits and side effects of GFD? Recent studies published in Nutrients on gluten-free products' quality, availability, safety, as well as challenges related to a GFD are discussed.

Trace gluten contamination may play a role in mucosal and clinical recovery in a subgroup of diet-adherent non-responsive celiac disease patients

PubMed Central

2013-01-01

Background Patients with persistent symptoms and/or villous atrophy despite strict adherence to a gluten-free diet (GFD) have non-responsive celiac disease (NRCD). A subset of these patients has refractory celiac disease (RCD), yet some NRCD patients may simply be reacting to gluten cross-contamination. Here we describe the effects of a 3-6 month diet of whole, unprocessed foods, termed the Gluten Contamination Elimination Diet (GCED), on NRCD. We aim to demonstrate that this diet reclassifies the majority of patients thought to have RCD type 1 (RCD1). Methods We reviewed the records of all GFD-adherent NRCD patients cared for in our celiac center from 2005-2011 who were documented to have started the GCED. Response to the GCED was defined as being asymptomatic after the diet, with normal villous architecture on repeat biopsy, if performed. Results Prior to the GCED, all patients were interviewed by an experienced dietitian and no sources of hidden gluten ingestion were identified. 17 patients completed the GCED; 15 were female (88%). Median age at start of the GCED was 42 years (range 6-73). Fourteen patients (82%) responded to the GCED. Six patients met criteria for RCD prior to the GCED; 5 (83%) were asymptomatic after the GCED and no longer meet RCD criteria. Of the 14 patients who responded to the GCED, 11 (79%) successfully returned to a traditional GFD without resurgence of symptoms. Conclusions The GCED may be an effective therapeutic option for GFD-adherent NRCD patients. Response to this diet identifies a subgroup of patients, previously classified as RCD1, that is not truly refractory to dietary treatment. Preventing an inaccurate diagnosis of RCD1 avoids immunotherapy. Most patients are able to return to a traditional GFD without return of symptoms. PMID:23448408

Obesogenic habits among children and their families in response to initiation of gluten-free diet.

PubMed

Levran, Neriya; Wilschanski, Michael; Livovsky, Jessica; Shachar, Edna; Moskovitz, Moti; Assaf-Jabrin, Lama; Shteyer, Eyal

2018-06-01

Initiation of a lifelong, gluten-free diet (GFD) in children with celiac disease (CD) influences the child's life in many ways. The aim of this study was to assess the influence of GFD on the child and his/her family's eating habits and lifestyle behaviors. To study this, we asked children and their parents completed the Family Eating and Activity Habits Questionnaire (FEAHQ) at the time of diagnosis of CD and at least 6 months after initiation of GFD and a questionnaires assessing symptoms related to CD and adherence to the GFD diet. We analyzed questionnaires from 40 children with CD and their families. There were 21 females, ranging in age from 4 to 15.7 years (median age 7.4 years±2.8 years). The control group comprised 15 healthy children. After initiation of GFD the family ate more junk food including snacks and candies (p = 0.05), with the significant change reported by children and fathers (p = 0.001 and 0.03 respectively). All family members in the control group had significantly less snacks. Parents and children reported a significant increase in obesogenic eating styles, such as eating from the cooking pot and eating while doing other activities (mothers, p = 0.001; fathers, 0.02; and children, 0.02 respectively). Our study shows that initiation of GFD in children with CD leads to changes in eating habits and staple food eating that may lead to a more obesogenic environment. Care givers, pediatricians, gastroenterologists, and dieticians alike should be aware of these implications and educate families towards a healthier lifestyle and diet beyond the GFD itself. What's Known: • Gluten-free diet has been shown to affect various psychosocial aspects of children with celiac disease. • Obesity and celiac are associated. What is New: • Initiation of gluten-free diet led to increased eating of junk food both in the patient and his/her family. • After initiation of GFD pro-obesogenic eating habits is increased.

Internalizing the threat of risk-a qualitative study about adolescents’ experience living with screening-detected celiac disease 5 years after diagnosis

PubMed Central

2014-01-01

Background Mass screening could identify those with unrecognized celiac disease (CD), but the experience of being detected through screening and living with screening-detected CD should be explored before considering this as acceptable intervention. For this study we invited screening-detected adolescents to describe their experience living with screening-detected CD five years after diagnosis with the aim to explore how their perceptions, practices, and beliefs evolved. Methods Adolescents who were diagnosed through a population-based CD screening were invited to write narratives after being diagnosed. Of 153 adolescents who were eventually diagnosed through the screening, 91 wrote narratives one year after diagnosis and 72 five years after diagnosis. A qualitative content analysis resulted in a theme and categories that describe the experience living with screening-detected CD five years after diagnosis. Results The overall theme – Internalizing the threat of risk – illustrates that being detected through screening and the internalized threat of future health complications have impacted how these adolescents felt about the diagnosis, coped with the gluten-free diet (GFD), and thought about CD screening. This theme is supported by four categories: maintaining an imposed disease identity describes how they continued to define their diagnosis in relation to the screening. They also expressed moving from forced food changes to adapted diet routines by describing habits, routines, coping strategies, and the financial burden of the GFD. They had enduring beliefs of being spared negative consequences, however, even after five years, some doubted they had CD and worried that being detected and eating a GFD might not be beneficial, i.e. continuing to fear it is “all in vain”. Conclusions There was maintenance and evolution in the perceptions, practices, and beliefs of the adolescents after five years. Some have adjusted to the disease and adapted new habits and coping strategies to deal with the GFD, while others still doubt they have CD or that being detected was beneficial. The transition to adapting to the disease and GFD is ongoing, illustrating the importance of providing ongoing support for those with screening-detected CD as they adjust to this chronic disease and the GFD. PMID:24915870

Dietary compliance and life style of children with coeliac disease.

PubMed

Roma, E; Roubani, A; Kolia, E; Panayiotou, J; Zellos, A; Syriopoulou, V P

2010-04-01

Coeliac disease (CD) is common and requires a permanent strict gluten-free diet (GFD). However, data concerning how the situation is experienced by children are limited. The present study aimed to investigate the compliance with a GFD and the impact of CD and GFD on the lifestyle of patients and their families, together with proposed recommendations for improvement of quality of life. Children with biopsy confirmed CD were recruited consecutively from the outpatient gastroenterology clinic. Participants were evaluated by a special questionnaire for compliance with the GFD, patients' knowledge about CD, and the well-being and lifestyle of children and their families. Comparisons between discrete variables were performed by a chi-square test. Seventy-three children of median age 9.4 (interquartile range = 5-14.5) years were evaluated. Compliance to diet was reported by 58%. Reasons for noncompliance were: poor palatability (32%), dining outside home (17%), poor availability of products (11%), and asymptomatic disease diagnosed by screening (11%). The acceptance of the GFD was reported as good in 65%, whereas avoidance of travelling and restaurants was stated by 17% and 46% of families, respectively. Most families experienced difficulties detecting gluten from the food label. Proposed factors for improvement of quality of life were: better labelling of gluten-containing ingredients (76%) and more gluten-free (GF) foods in supermarkets (58%) and restaurants (42%). Children with CD have low compliance with the GFD. Better education about the disease, the availability of GF products, and appropriate food labelling could improve compliance and quality of life.

Practical insights into gluten-free diets.

PubMed

See, Jacalyn A; Kaukinen, Katri; Makharia, Govind K; Gibson, Peter R; Murray, Joseph A

2015-10-01

Coeliac disease is a global disease, and the only currently available treatment is a gluten-free diet (GFD). Although conceptually simple, the diet changes are substantial and have a profound effect on a patient's life. Untreated coeliac disease is associated with complications, including excess mortality, most of which can be avoided with a strict GFD. However, there are many barriers, including availability, cost and safety of gluten-free foods, and gluten cross-contamination. The GFD can be restrictive in social situations, leading to poor quality of life and, ultimately, nonadherence. As the number of patients with coeliac disease increases worldwide, clinicians need to be aware of the challenges patients face. Heightened awareness by physicians, dietitians and other providers can help maximize successful treatment, improve outcomes, and reduce health-care costs and disease burden. Routine follow-up is necessary to reinforce the need for a GFD, provide social and emotional support, and achieve mucosal healing, leading to reduced risk of complications. Unfortunately, there is wide variation in follow-up practices. The objective of this Review is to increase awareness of the challenges, management and follow-up of patients with coeliac disease to help them achieve GFD adherence and prevent complications whilst preserving their quality of life.

Gluten-Free Diet Indications, Safety, Quality, Labels, and Challenges

PubMed Central

Rostami, Kamran; Bold, Justine; Parr, Alison; Johnson, Matt W.

2017-01-01

A gluten-free diet (GFD) is the safest treatment modality in patient with coeliac disease (CD) and other gluten-related disorders. Contamination and diet compliance are important factors behind persistent symptoms in patients with gluten related-disorders, in particular CD. How much gluten can be tolerated, how safe are the current gluten-free (GF) products, what are the benefits and side effects of GFD? Recent studies published in Nutrients on gluten-free products’ quality, availability, safety, as well as challenges related to a GFD are discussed. PMID:28786929

Factors influencing the type, timing and severity of symptomatic responses to dietary gluten in patients with biopsy-proven coeliac disease.

PubMed

Barratt, Stephen M; Leeds, John S; Sanders, David S

2013-12-01

There is a paucity of data reflecting the symptomatic responses to dietary gluten (SRDG) in patients with Coeliac Disease (CD). We aimed to determine the type, timing and severity of SRDG with reference to a range of disease-related factors. Postal survey of 224 biopsy-proven patients including gluten-free diet (GFD) adherence, symptom checklist, ROME II criteria and The Hospital Anxiety & Depression Scale. Case-note review was also conducted. 26% of respondents were male. Full GFD adherence: n=159 (70%). Irritable bowel syndrome (IBS): n=50 (22%). Anxiety: n=30 (13%); Depression: n=33 (14%); Anxiety & Depression: n=72 (32%). Pruritus, fatigue and bloating were a more common SRDG in the partial/none GFD adherent group (p=ns). Co-existing IBS was associated with a greater prevalence of nausea and fatigue in response to gluten (p=<0.05). Fully GFD adherent patients are more likely to have SRDG <1hr than partial/none adherent (OR 4.8; p=0.004), as are a third of patients with co-existing IBS (OR 1.5; p=0.027) and those patients at risk of both anxiety and depression (OR 1.9; p=0.04). Inadvertent exposure to dietary gluten in the fully GFD adherent group is more likely to result in a severe SRDG in comparison to symptoms arising prior to consistent GFD adherence (OR 2.3; p=0.01). IBS sufferers are also more likely to rate their SRDG as severe in nature (OR 1.4; p=0.038). Patients with consistent GFD adherence experience a SRDG faster and more severe in comparison to prior gluten exposure possibly demonstrating an adept immunological response. Anxiety and depression also enhance the speed of symptom onset and co-existing visceral hypersensitivity is a risk factor for severe reactions to dietary gluten.

GO-based functional dissimilarity of gene sets.

PubMed

Díaz-Díaz, Norberto; Aguilar-Ruiz, Jesús S

2011-09-01

The Gene Ontology (GO) provides a controlled vocabulary for describing the functions of genes and can be used to evaluate the functional coherence of gene sets. Many functional coherence measures consider each pair of gene functions in a set and produce an output based on all pairwise distances. A single gene can encode multiple proteins that may differ in function. For each functionality, other proteins that exhibit the same activity may also participate. Therefore, an identification of the most common function for all of the genes involved in a biological process is important in evaluating the functional similarity of groups of genes and a quantification of functional coherence can helps to clarify the role of a group of genes working together. To implement this approach to functional assessment, we present GFD (GO-based Functional Dissimilarity), a novel dissimilarity measure for evaluating groups of genes based on the most relevant functions of the whole set. The measure assigns a numerical value to the gene set for each of the three GO sub-ontologies. Results show that GFD performs robustly when applied to gene set of known functionality (extracted from KEGG). It performs particularly well on randomly generated gene sets. An ROC analysis reveals that the performance of GFD in evaluating the functional dissimilarity of gene sets is very satisfactory. A comparative analysis against other functional measures, such as GS2 and those presented by Resnik and Wang, also demonstrates the robustness of GFD.

Self-compassion directly and indirectly predicts dietary adherence and quality of life among adults with celiac disease.

PubMed

Dowd, A Justine; Jung, Mary E

2017-06-01

Strict adherence to a gluten-free diet (GFD) is the only treatment for preventing both short- and long-term consequences of celiac disease. Given that following a strict GFD can be difficult, evidence-based strategies are needed to improve the psychological experience of living with celiac disease and following the GFD. Self-compassion appears to be an important component of effectively self-regulating one's behavior to cope with a chronic disease. The main goal of this study was to examine the relationships between self-compassion and management of celiac disease as assessed by (a) adherence to a strict GFD and (b) celiac-specific quality of life (CQoL). The secondary goal of this study was to explore self-regulatory efficacy (i.e., confidence in one's ability to self-manage behavior to follow a strict GFD) and concurrent self-regulatory efficacy (i.e., one's confidence to self-manage other valued life goals while following a strict GFD) as mediators of the relationship between self-compassion and the primary outcomes (adherence and CQoL). In this prospective study, 200 North American adults diagnosed with celiac disease completed online questionnaires at two time points (baseline and 1 month later). Self-compassion at baseline directly predicted stricter adherence (at Time 2; b = -0.63, p = 0.006) and enhanced CQoL (at Time 2; b = -0.50, p = 0.001). Further, self-compassion (at Time 1) also indirectly predicted stricter Time 2 adherence through self-regulatory efficacy (at Time 1; b = -0.26, 95% CI [-0.58, -0.04], R 2  = 0.29) and enhanced Time 2 CQoL through concurrent self-regulatory efficacy (at Time 1; b = -0.07, 95% CI [-0.14, -0.03], R 2  = 0.33). This was the first study to assess the effects of self-compassion in relation to the psychological experience of coping with celiac disease and following a GFD. The findings indicate that self-compassion, self-regulatory efficacy and concurrent self-regulatory efficacy are important cognitions in understanding adherence to a GFD and CQoL among adults with celiac disease. Copyright © 2017. Published by Elsevier Ltd.

Gluten-free diet in gluten-related disorders.

PubMed

Mulder, Chris J J; van Wanrooij, R L J; Bakker, S F; Wierdsma, N; Bouma, G

2013-01-01

A gluten-free diet (GFD) is recommended for all patients with coeliac disease (CD). The spectrum of gluten-related disorders in the early 1980s was simple: CD and dermatitis herpetiformis. In the last few years, wheat allergy, gluten ataxia and noncoeliac gluten sensitivity have become new gluten-related topics. Adherence to GFDs in CD is limited and factors influencing adherence are poorly understood. Noncoeliac gluten sensitivity has stimulated the GFD food industry not only in Australia but all over the world. This article provides an overview of GFD in daily practice. Copyright © 2013 S. Karger AG, Basel.

Bone mineral density and growth in children with coeliac disease on a gluten free-diet.

PubMed

Tuna Kırsaçlıoğlu, Ceyda; Kuloğlu, Zarife; Tanca, Aydan; Küçük, Nuriye Özlem; Aycan, Zehra; Öcal, Gönül; Ensari, Arzu; Kalaycı, Ayhan Gazi; Girgin, Nurten

2016-12-20

To evaluate changes in growth and bone metabolism during consumption of a gluten-free diet (GFD) in children with coeliac disease (CD). Thirty-seven children with CD (mean age of 8.8 ± 4.6 years, 21 girls) were enrolled. Anthropometric measurements, bone mineral density (BMD) in lumbar 2-4 vertebrae, and serum alkaline phosphatase, calcium, and phosphorus levels at diagnosis and at follow-up were recorded. The mean follow-up period was 3.5 ± 2.3 years. The BMD of patients was significantly lower than that of control subjects at the time of diagnosis but not after 1 year of the GFD. Incidence of low BMD with respect to z-scores for chronological age (CA) was significantly higher than z-scores for height age (HA) (P = 0.006). At the first year of GFD, BMD, BMD z-score, height-for-age z-scores, and weight-for-age z-scores were significantly increased compared with the baseline, but not after 1 year of the GFD. In CD, the first year of GFD is important in weight gain, linear growth, and improvement of BMD. A considerable relation of low BMD in children with CD, with respect to z-scores for CA, may be a result of misinterpretation of low BMD due to short stature.

Longitudinal changes in bone metabolism and bone mineral content in children with celiac disease during consumption of a gluten-free diet.

PubMed

Barera, Graziano; Beccio, Sabrina; Proverbio, Maria Carla; Mora, Stefano

2004-01-01

A gluten-free diet (GFD) rapidly corrects the bone mineral deficit of children with untreated celiac disease. The mechanisms underlying such changes are still poorly understood. In a longitudinal study, we monitored changes in bone metabolism during consumption of a GFD. We studied 22 white patients with celiac disease (11 girls) aged 10.5 +/- 1.0 y at the time of diagnosis. We compared bone metabolism and bone mass values in these patients with those in 428 healthy white children aged 11.3 +/- 0.2 y. Bone-specific alkaline phosphatase (a bone formation index) and N-terminal telopeptide of type I collagen (NTx; a bone resorption marker) were measured at the time of diagnosis and after 2, 6, and 12 mo of the GFD. Bone mineral content was measured at the lumbar spine and for the whole skeleton. The bone mineral content of patients was significantly lower than that of control subjects at the time of diagnosis but not after 1 y of the GFD. Serum bone-specific alkaline phosphatase concentrations of patients were significantly lower than those of control subjects at the time of diagnosis (P = 0.0064) and increased gradually and significantly during the GFD (ANOVA F = 4.71; P = 0.024). Conversely, patients with untreated disease had significantly higher urinary concentrations of NTx than did healthy control subjects (P < 0.0001). Urinary concentrations of NTx were not significantly affected by treatment (P = 0.37). The rate of bone metabolism is altered in children with untreated celiac disease, and these alterations may be the cause of osteopathy. Remarkable changes occur after the initiation of a GFD, and they result in a more balanced equilibrium.

Celiac disease: understanding the gluten-free diet.

PubMed

Bascuñán, Karla A; Vespa, María Catalina; Araya, Magdalena

2017-03-01

The only effective and safe treatment of celiac disease (CD) continues being strict exclusion of gluten for life, the so-called gluten-free diet (GFD). Although this treatment is highly successful, following strict GFD poses difficulties to patients in family, social and working contexts, deteriorating his/her quality of life. We aimed to review main characteristics of GFD with special emphasis on factors that may interfere with adherence to it. We conducted a search of various databases, such as PubMed, Google Scholar, Embase, and Scielo, with focus on key words such as "gluten-free diet", "celiac disease", "gluten" and "gluten-free diet adherence". Available literature has not reached definitive conclusions on the exact amount of gluten that is harmless to celiac patients, although international agreements establish cutoff points for gluten-free products and advise the use of clinical assessment to tailor the diet according to individual needs. Following GFD must include eliminating gluten as ingredient as well as hidden component and potential cross contamination in foods. There are numerous grains to substitute wheat but composition of most gluten-free products tends to include only a small number of them, especially rice. The diet must be not only free of gluten but also healthy to avoid nutrient, vitamins and minerals deficiencies or excess. Overweight/obesity frequency has increased among celiac patients so weight gain deserves attention during follow up. Nutritional education by a trained nutritionist is of great relevance to achieve long-term satisfactory health status and good compliance. A balanced GFD should be based on a combination of naturally gluten-free foods and certified processed gluten-free products. How to measure and improve adherence to GFD is still controversial and deserves further study.

[Treating coeliac disease. How do we measure adherence to the gluten-free diet?

PubMed

Aranda, Elisa A; Araya, Magdalena

Coeliac disease (CD) is a systemic autoimmune disorder triggered by gluten consumption in genetically susceptible individuals. It exhibits several clinical features, such as blood auto-antibodies (anti-endomysial antibodies EMA, anti-transglutaminase antibodies tTG, anti-deamidated gliadin peptides PGD), plus variable degrees of damage in the small intestinal mucosa. In Chile, tTG is positive in 0.76% in individuals >15 years, with the prevalence of CD being estimated at 0.6%. Approximately17% of first-degree relatives of coeliac patients have been reported tTG positive. To date, the gluten free diet (GFD) is the only known treatment for CD. To be effective, this must be lifelong, permanent, and strict. Gluten content in the GFD is not zero, but is limited to a cut-off of 3ppm (ormg/kg of product) in Chile. Mortality higher than that of the general population has been reported among coeliac patients, and poor adherence to GFD is associated with complications (mainly autoimmune processes and cancer). GFD is difficult to maintain strictly and poor adherence is by far the main cause of lack of response to treatment. Follow-up of adherence is also difficult because there are no objective measurements to assess it. In clinical practice determination of serum EMA, tTG and PGD is routinely used for these purposes, although more recently, the interview by an expert dietitian, validated questionnaires and measurement of faecal 33-mer peptide are being assessed as alternatives or complements to measure adherence to GFD. A review is presented with the current concepts on the available tools to follow up patients on GFD, emphasising those available in Chilel. Copyright © 2016 Sociedad Chilena de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Food label usage and reported difficulty with following a gluten-free diet among individuals in the USA with coeliac disease and those with noncoeliac gluten sensitivity.

PubMed

Verrill, L; Zhang, Y; Kane, R

2013-10-01

Individuals with coeliac disease (CD) and those with noncoeliac gluten sensitivity (GS) have reported difficulty following a gluten-free diet (GFD); however, few studies have explored the link between the food label, gluten-free (GF) claims and the difficulty associated with following a GFD. The present study surveyed adults with CD (n = 1,583) and adults with GS (n = 797) about their reported difficulty following a GFD, including assessing the role of food labels and GF claims, as well as other factors known to contribute to this difficulty. A two-sample t-test and chi-squared tests for equality of means or proportions were used for the descriptive data and ordinal logistic regression (OLR) was used to model associations. On average, individuals with GS reported slightly more difficulty following the GFD than did participants with CD. According to the OLR results, reading the food label often was significantly associated with less reported difficulty following a GFD, whereas consuming packaged processed foods and looking for GF claims more often were significantly associated with more reported difficulty for both respondent groups. Individuals with GS may rely more heavily on the GF claim for information about a product's gluten content. Individuals with CD, on the other hand, may be more experienced food label readers and may rely more on the ingredient list for finding GF foods. More studies are needed aiming to understand the role of the food label in facilitating consumers' ability to follow a GFD. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Oral health status and salivary properties in relation to gluten-free diet in children with celiac disease.

PubMed

Shteyer, Eyal; Berson, Tamar; Lachmanovitz, Odelia; Hidas, Ariela; Wilschanski, Michael; Menachem, Moti; Shachar, Edna; Shapira, Joseph; Steinberg, Doron; Moskovitz, Moti

2013-07-01

Patients with celiac disease (CD) have a wide variety of symptoms, from being asymptomatic to having chronic diarrhea, abdominal pain, and extraintestinal symptoms. In the oral cavity, enamel defects and recurrent aphthous stomatitis are the most common symptoms. The aim of the study was to assess oral health, bacterial colonization and salivary buffering capacity of patients with CD at diagnosis were compared with patients with CD receiving a gluten-free diet (GFD) and healthy children. Three groups were prospectively investigated: newly diagnosed CD, CD treated with GFD, and a control group. All of the children were examined by pediatric dentists, and saliva samples were collected for bacterial and pH analysis. Ninety children were enrolled in the study, 30 in each group. A higher prevalence of enamel hypoplasia (66%) was found in children with CD. Plaque index was significantly lower in the celiac-treated group, which correlated with oral health behavior: teeth brushing and frequency of eating between meals. Children receiving GFD brushed their teeth and used fluoride significantly more often than other children in the study. No difference between groups was found in snack consumption, mutans streptococci and lactobacilli counts in saliva, as well as pH and buffer capacity. A lower degree of plaque was found in children with CD receiving GFD. This finding could not be explained by salivary properties or bacteria, but rather by better oral hygiene. The results should raise the awareness of pediatric gastroenterologists toward oral health-related issues in children with CD.

Utility of Helicobacter spp. associated GFD markers for detecting avian fecal pollution in natural waters of two continents.

PubMed

Ahmed, W; Harwood, V J; Nguyen, K; Young, S; Hamilton, K; Toze, S

2016-01-01

Avian fecal droppings may negatively impact environmental water quality due to the presence of high concentrations of fecal indicator bacteria (FIB) and zoonotic pathogens. This study was aimed at evaluating the performance characteristics and utility of a Helicobacter spp. associated GFD marker by screening 265 fecal and wastewater samples from a range of avian and non-avian host groups from two continents (Brisbane, Australia and Florida, USA). The host-prevalence and -specificity of this marker among fecal and wastewater samples tested from Brisbane were 0.58 and 0.94 (maximum value of 1.00). These values for the Florida fecal samples were 0.30 (host-prevalence) and 1.00 (host-specificity). The concentrations of the GFD markers in avian and non-avian fecal nucleic acid samples were measured at a test concentration of 10 ng of nucleic acid at Brisbane and Florida laboratories using the quantitative PCR (qPCR) assay. The mean concentrations of the GFD marker in avian fecal nucleic acid samples (5.2 × 10(3) gene copies) were two orders of magnitude higher than non-avian fecal nucleic acid samples (8.6 × 10(1) gene copies). The utility of this marker was evaluated by testing water samples from the Brisbane River, Brisbane and a freshwater creek in Florida. Among the 18 water samples tested from the Brisbane River, 83% (n = 18) were positive for the GFD marker, and the concentrations ranged from 6.0 × 10(1)-3.2 × 10(2) gene copies per 100 mL water. In all, 92% (n = 25) water samples from the freshwater creek in Florida were also positive for the GFD marker with concentrations ranging from 2.8 × 10(1)-1.3 × 10(4) gene copies per 100 mL water. Based on the results, it can be concluded that the GFD marker is highly specific to avian host groups, and could be used as a reliable marker to detect the presence and amount of avian fecal pollution in environmental waters. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Adipokine profile in celiac patients: differences in comparison with patients suffering from diarrhea-predominant IBS and healthy subjects.

PubMed

Russo, Francesco; Chimienti, Guglielmina; Clemente, Caterina; D'Attoma, Benedetta; Linsalata, Michele; Orlando, Antonella; De Carne, Massimo; Cariola, Filomena; Semeraro, Francesco P; Pepe, Gabriella; Riezzo, Giuseppe

2013-12-01

OBJECTIVE. The role of adipokines such as resistin, leptin, and adiponectin could be pivotal in the molecular crosstalk between the inflamed intestine and the surrounding mesenteric adipose tissue. Our aims were to a) evaluate their circulating concentrations in patients with active celiac disease (ACD) and compare them to those in patients with diarrhea-predominant irritable bowel syndrome (IBS-d) and healthy subjects; b) establish the impact of genetic variability in resistin; and c) evaluate whether a 1-year gluten-free diet (GFD) modifies circulating concentrations of resistin, leptin, and adiponectin in celiac patients. MATERIAL AND METHODS. The study included 34 ACD patients, 29 IBS-d patients, and 27 healthy controls. Circulating concentrations of resistin, leptin, adiponectin, IL-6, and IL-8 were evaluated at the time of enrollment. Resistin +299 G/A polymorphism was also analysed. In CD patients, biochemical measurements were repeated after a 1-year GFD. RESULTS. Along with higher IL-6 and IL-8 plasma levels, higher resistin and adiponectin concentrations were found in ACD and IBS-d patients compared with controls (p: 0.0351 and p: 0.0020, respectively). Resistin values proved to be predictable from a linear combination of IL-8 and +299 polymorphism. GFD affected resistin (p: 0.0009), but not leptin and adiponectin concentrations. CONCLUSIONS. Our data suggest that these adipokines are involved in modulating inflammatory processes in both CD and IBS-d patients. Alterations in the adipokine profile as well as the higher prevalence of the resistin +299 G/A SNP A allele compared to controls support the hypothesis that, at least in well-defined cases of IBS, a genetic component may also be supposed.

Normal Bone Mineral Density Associates with Duodenal Mucosa Healing in Adult Patients with Celiac Disease on a Gluten-Free Diet.

PubMed

Larussa, Tiziana; Suraci, Evelina; Imeneo, Maria; Marasco, Raffaella; Luzza, Francesco

2017-01-31

Impairment of bone mineral density (BMD) is frequent in celiac disease (CD) patients on a gluten-free diet (GFD). The normalization of intestinal mucosa is still difficult to predict. We aim to investigate the relationship between BMD and duodenal mucosa healing (DMH) in CD patients on a GFD. Sixty-four consecutive CD patients on a GFD were recruited. After a median period of a 6-year GFD (range 2-33 years), patients underwent repeat duodenal biopsy and dual-energy X-ray absorptiometry (DXA) scan. Twenty-four patients (38%) displayed normal and 40 (62%) low BMD, 47 (73%) DMH, and 17 (27%) duodenal mucosa lesions. All patients but one with normal BMD (23 of 24, 96%) showed DMH, while, among those with low BMD, 24 (60%) did and 16 (40%) did not. At multivariate analysis, being older (odds ratio (OR) 1.1, 95% confidence interval (CI) 1.03-1.18) and having diagnosis at an older age (OR 1.09, 95% CI 1.03-1.16) were associated with low BMD; in turn, having normal BMD was the only variable independently associated with DMH (OR 17.5, 95% CI 1.6-192). In older CD patients and with late onset disease, BMD recovery is not guaranteed, despite a GFD. A normal DXA scan identified CD patients with DMH; thus, it is a potential tool in planning endoscopic resampling.

Fundamentals of Geophysical Fluid Dynamics

NASA Astrophysics Data System (ADS)

McWilliams, James C.

2006-07-01

Earth's atmosphere and oceans exhibit complex patterns of fluid motion over a vast range of space and time scales. These patterns combine to establish the climate in response to solar radiation that is inhomogeneously absorbed by the materials comprising air, water, and land. Spontaneous, energetic variability arises from instabilities in the planetary-scale circulations, appearing in many different forms such as waves, jets, vortices, boundary layers, and turbulence. Geophysical fluid dynamics (GFD) is the science of all these types of fluid motion. This textbook is a concise and accessible introduction to GFD for intermediate to advanced students of the physics, chemistry, and/or biology of Earth's fluid environment. The book was developed from the author's many years of teaching a first-year graduate course at the University of California, Los Angeles. Readers are expected to be familiar with physics and mathematics at the level of general dynamics (mechanics) and partial differential equations. Covers the essential GFD required for atmospheric science and oceanography courses Mathematically rigorous, concise coverage of basic theory and applications to both oceans and atmospheres Author is a world expert; this book is based on the course he has taught for many years Exercises are included, with solutions available to instructors from solutions@cambridge.org

The obestatin/ghrelin ratio and ghrelin genetics in adult celiac patients before and after a gluten-free diet, in irritable bowel syndrome patients and healthy individuals.

PubMed

Russo, Francesco; Chimienti, Guglielmina; Linsalata, Michele; Clemente, Caterina; Orlando, Antonella; Riezzo, Giuseppe

2017-02-01

Ghrelin levels and obestatin/ghrelin ratio have been proposed as activity markers in ulcerative colitis, but no data are available in celiac disease (CD) and irritable bowel syndrome (IBS). Our aims were as follows: (a) to assess obestatin and ghrelin concentrations in adult active CD patients, diarrhea-predominant IBS (IBS-d), and healthy controls (HC) in relation to intestinal permeability; (b) to evaluate the ghrelin-obestatin profile in CD patients after a 1-year gluten-free diet (GFD); and (c) to establish the impact of ghrelin genetics. The study included 31 CD patients, 28 IBS-d patients, and 19 HC. Intestinal permeability, assayed by high-performance liquid chromatography determination of urinary lactulose (La)/mannitol (Ma), and circulating concentrations of obestatin, ghrelin, and their ratio were evaluated at enrollment and after GFD. The ghrelin single nucleotide polymorphisms Arg51Gln (rs34911341), Leu72Met (rs696217), and Gln90Leu (rs4684677) were analyzed. Intestinal permeability was impaired in CD patients and ameliorated after GFD. Ghrelin was significantly (P=0.048) higher and the obestatin/ghrelin ratio was significantly (P=0.034) lower in CD patients compared with both IBS-d and HC, and GFD reduced the peptide levels, but without reaching the concentrations in HC. Significant differences (P<0.05) were found in the Leu72Met polymorphism among groups, with the reduction of the GT genotype and the T allele in both CD and IBS-d patients compared with HC. Intestinal permeability is altered in CD, but not in IBS-d patients, and ghrelin levels increase in CD patients as observed in other inflammatory conditions. Moreover, a role for ghrelin genetics is hypothesized in sustaining the many pathogenetic components of these different pathologies, but with a similar symptom profile.

Impact of gluten-free camp on quality of life of children and adolescents with celiac disease.

PubMed

Bongiovanni, Tasce R Simon; Clark, Ann L; Garnett, Elizabeth A; Wojcicki, Janet M; Heyman, Melvin B

2010-03-01

A gluten-free camp allows children with celiac disease (CD) to enjoy a camp experience without concern and preoccupation with foods they eat or the stigma of their underlying disease. The objective of this study was to evaluate the impact of gluten-free camp on quality-of-life indicators for children and adolescents with CD. Children aged 7 to 17 years with CD were administered a 14-question survey at the beginning and the end of a 7-day gluten-free camp. Surveys used a Likert scale to examine general well-being, emotional outlook, and self-perception for the week before each survey. Differences between the time points were compared. Data were analyzed by paired t test. Of the 104 campers who attended camp, 77 (21 male) completed the survey at both time points. Most (70%) had been on a gluten-free diet (GFD) for <4 years. All seemed to benefit from camp, no longer feeling different from other kids or feeling frustrated with a restricted diet. A more beneficial impact was found for campers who were on a GFD for <4 years. Overall, campers reported an improvement in 11 of 14 questions, statistically significant (P < .05) for 8 of those 11 questions. Improvement was observed in each of the 3 categories of questions: well-being, self-perception, and emotional outlook. Children who had CD and attended a week-long gluten-free camp demonstrated improvement in well-being, self-perception, and emotional outlook. The positive effects of camp were more apparent among campers who had been on a GFD for <4 years compared with those who had been on a GFD for > or =4 years, suggesting an adaptation to CD with time. A gluten-free camp that provides an environment of unrestricted foods can at least temporarily alleviate stress and anxiety around food and social interactions. Durability of these observations on return to daily life requires additional study.

Compliance with the gluten-free diet: the role of locus of control in celiac disease.

PubMed

Bellini, Anna; Zanchi, Chiara; Martelossi, Stefano; Di Leo, Grazia; Not, Tarcisio; Ventura, Alessandro

2011-03-01

To verify whether subjects with celiac disease (CD) have a different locus of control (LoC) compared with healthy subjects, and to evaluate the relationship between LoC and compliance with a prescribed gluten-free diet (GFD) and quality of life (QoL). We studied 156 subjects on a GFD (mean age, 10 years) and 353 healthy controls (mean age, 12 years). All subjects completed tests on the Nowicki-Strickland Locus of Control Scale; the subjects with CD also completed a questionnaire to measure compliance with dietary treatment and the disease's impact on QoL. There was no difference in LoC values between patients with CD and controls. Subjects with CD with good dietary compliance had a more internal LoC compared with those who were not compliant (P = .01). Patients who reported a satisfactory QoL had a more internal LoC compared with those who reported negative affects on QoL due to CD (P = .01). Our study confirms the usefulness of the LoC concept for identifying those patients who might be at risk for dietary transgression. Given the enhanced, psychological, and social well being that can result from adherence to a GFD, educational and psychological support can help internalize the LoC in those patients at risk for dietary transgression. Copyright © 2011 Mosby, Inc. All rights reserved.

Higher constitutive IL15Rα expression and lower IL-15 response threshold in coeliac disease patients

PubMed Central

Bernardo, D; Garrote, J A; Allegretti, Y; León, A; Gómez, E; Bermejo-Martin, J F; Calvo, C; Riestra, S; Fernández-Salazar, L; Blanco-Quirós, A; Chirdo, F; Arranz, E

2008-01-01

The IL-15 triggering effect of gliadin is not exclusive to coeliac disease (CD) patients, whereas the secondary response is CD specific. We have studied the expression of the IL-15 receptor, and the IL-15 response upon stimulation, in non-CD and CD patients, and the possible existence of a lower immunological threshold in the latter. Forty-two CD patients (20 on a gluten-containing diet, GCD, and 22 on gluten-free diet, GFD) and 24 non-CD healthy individuals were studied. IL15Rα mRNA expression, and tissue characterization, were assayed in the duodenum. Biopsies from six CD patients on GFD and 10 non-CD individuals were studied in vitro using organ culture in basal conditions, as well as after IL-15 stimulation discarding basal IL-15 production. Secretion of immune mediators was measured in the culture supernatants. IL15Rα mRNA expression was increased in CD patients, as compared with non-CD controls (on GFD P = 0·0334, on GCD P = 0·0062, respectively), and confirmed also by immunofluorescence. No differences were found between CD patients on GFD and on GCD. After in vitro IL-15 stimulation, IL15Rα expression was only triggered in non-CD controls (P = 0·0313), though it remained increased in CD patients. Moreover, IL-15 induced a more intense immunological response in CD patients after triggering the production of both nitrites and IFNγ (P = 0·0313, P = 0·0313, respectively). Gliadin-induced IL15 has a lower response threshold in CD patients, leading to the production of other immune mediators and the development of the intestinal lesion, and thus magnifying its effects within the CD intestine. PMID:18821940

The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) protocol: a randomised controlled study to evaluate treatment of asymptomatic coeliac disease in type 1 diabetes.

PubMed

Mahmud, Farid H; De Melo, Emilia N; Noordin, Karima; Assor, Esther; Sahota, Kamaljeet; Davies-Shaw, Jolie; Cutz, Ernest; Somers, Gino; Lawson, Margaret; Mack, David R; Gallego, Patricia; McDonald, Charlotte; Beaton, Melanie D; Bax, Kevin; Saibil, Fred; Gilbert, Jeremy; Kirsch, Susan; Perkins, Bruce A; Cino, Maria; Szentgyorgyi, Eva; Koltin, Dror; Parikh, Amish; Mukerji, Geetha; Advani, Andrew; Lou, Olivia; Marcon, Margaret A

2015-05-11

Coeliac disease (CD) is an autoimmune condition characterised by gluten-induced intestinal inflammation, and observed at a 5-10 fold greater prevalence in type 1 diabetes. While universal screening for CD in patients with diabetes is frequently advocated, objective data is limited as to benefits on diabetes control, bone health or quality of life related to the adoption of a gluten-free diet (GFD) in the large proportion of patients with diabetes with asymptomatic CD. The Celiac Disease and Diabetes-Dietary Intervention and Evaluation Trial (CD-DIET) study is a multicenter, randomised controlled trial to evaluate the efficacy and safety of a GFD in patients with type 1 diabetes with asymptomatic CD. Children and adults (8-45 years) with type 1 diabetes will be screened for asymptomatic CD. Eligible patients with biopsy-proven CD will be randomly assigned in a 1:1 ratio to treatment with a GFD for 1 year, or continue with a gluten-containing diet. The primary outcome will evaluate the impact of the GFD on change in glycated haemoglobin. Secondary outcomes will evaluate changes in bone mineral density, blood glucose variability and health-related quality of life between GFD-treated and the regular diet group over a 1-year period. The study was initiated in 2012 and has subsequently expanded to multiple paediatric and adult centres in Ontario, Canada. The findings from this study will provide high-quality evidence as to the impact of GFD treatment on glycaemic control and complications in asymptomatic children and adults with CD and type 1 diabetes. NCT01566110. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

HLA-DQ-Gluten Tetramer Blood Test Accurately Identifies Patients With and Without Celiac Disease in Absence of Gluten Consumption.

PubMed

Sarna, Vikas K; Lundin, Knut E A; Mørkrid, Lars; Qiao, Shuo-Wang; Sollid, Ludvig M; Christophersen, Asbjørn

2018-03-01

Celiac disease is characterized by HLA-DQ2/8-restricted responses of CD4+ T cells to cereal gluten proteins. A diagnosis of celiac disease based on serologic and histologic evidence requires patients to be on gluten-containing diets. The growing number of individuals adhering to a gluten-free diet (GFD) without exclusion of celiac disease complicates its detection. HLA-DQ-gluten tetramers can be used to detect gluten-specific T cells in blood of patients with celiac disease, even if they are on a GFD. We investigated whether an HLA-DQ-gluten tetramer-based assay accurately identifies patients with celiac disease. We produced HLA-DQ-gluten tetramers and added them to peripheral blood mononuclear cells isolated from 143 HLA-DQ2.5 + subjects (62 subjects with celiac disease on a GFD, 19 subjects without celiac disease on a GFD [due to self-reported gluten sensitivity], 10 subjects with celiac disease on a gluten-containing diet, and 52 presumed healthy individuals [controls]). T cells that bound HLA-DQ-gluten tetramers were quantified by flow cytometry. Laboratory tests and flow cytometry gating analyses were performed by researchers blinded to sample type, except for samples from subjects with celiac disease on a gluten-containing diet. Test precision analyses were performed using samples from 10 subjects. For the HLA-DQ-gluten tetramer-based assay, we combined flow-cytometry variables in a multiple regression model that identified individuals with celiac disease on a GFD with an area under the receiver operating characteristic curve value of 0.96 (95% confidence interval [CI] 0.89-1.00) vs subjects without celiac disease on a GFD. The assay detected individuals with celiac disease on a gluten-containing diet vs controls with an area under the receiver operating characteristic curve value of 0.95 (95% CI 0.90-1.00). Optimized cutoff values identified subjects with celiac disease on a GFD with 97% sensitivity (95% CI 0.92-1.00) and 95% specificity (95% CI 0.84-1.00) vs subjects without celiac disease on a GFD. The values identified subjects with celiac disease on a gluten-containing diet with 100% sensitivity (95% CI 1.00-1.00]) and 90% specificity (95% CI 0.83-0.98) vs controls. In an analysis of 4 controls with positive results from the HLA-DQ-gluten tetramer test, 2 had unrecognized celiac disease and the remaining 2 had T cells that proliferated in response to gluten antigen in vitro. An HLA-DQ-gluten tetramer-based assays that detects gluten-reactive T cells identifies patients with and without celiac disease with a high level of accuracy, regardless of whether the individuals are on a GFD. This test would allow individuals with suspected celiac disease to avoid gluten challenge and duodenal biopsy, but requires validation in a larger study. Clinicaltrials.gov no: NCT02442219. Copyright © 2018 AGA Institute. Published by Elsevier Inc. All rights reserved.

High fat consumption in children with celiac disease.

PubMed

Ferrara, P; Cicala, M; Tiberi, E; Spadaccio, C; Marcella, L; Gatto, A; Calzolari, P; Castellucci, G

2009-01-01

The purpose of this study was to estimate the caloric intake and fat consumption in children with celiac disease (CD) following a gluten-free diet (GFD). This study enrolled 100 subjects, including 50 children with CD on a gluten-free diet and a control group of 50 healthy children. Statistical analysis to compare groups was performed using one-way ANOVA. A significant increase in fat consumption was observed in children with CD as compared to healthy children. The daily fat intake was 72.5 +/- 37.2 g per 100 g of food in the CD group and 52.9 +/- 35.4 g per 100 g of food in the control group (p < 0.008). A significant difference in fat intake was found between celiac and healthy females (10.21 +/- 3.15 g/100 g in the celiac group vs 7.46 +/- 2.91 g/100 g in the control group), p = 0.004. This study describes a significantly higher fat consumption in patients with CD on GFD as compared to controls. This increase was more pronounced in females and during the puberal age. Based on these interesting preliminary results we estimate that further investigations are necessary, such as a randomized multicentre study on the long-term effects of GFD with particular attention to the imbalance in daily fat intake.

Serum zinc, copper and iron status of children with coeliac disease on three months of gluten-free diet with or without four weeks of zinc supplements: a randomised controlled trial.

PubMed

Negi, K; Kumar, R; Sharma, L; Datta, S P; Choudhury, M; Kumar, P

2018-04-01

Data about the effect of zinc supplementation with gluten-free diet on normalisation of plasma zinc, copper and iron in patients with coeliac disease are scanty. We evaluated the effect of zinc supplementation on serum zinc, copper and iron levels in patients with coeliac disease, by randomising 71 children newly diagnosed with coeliac disease into two groups: Group A = gluten-free diet (GFD); and Group B = gluten-free diet with zinc supplements (GFD +Zn). The rise in iron and zinc was significantly higher in the latter, but the mean rise of copper levels was slightly higher in the former, but the difference was not significant.

Economic burden made celiac disease an expensive and challenging condition for Iranian patients.

PubMed

Pourhoseingholi, Mohamad Amin; Rostami-Nejad, Mohammad; Barzegar, Farnoush; Rostami, Kamran; Volta, Umberto; Sadeghi, Amir; Honarkar, Zahra; Salehi, Niloofar; Asadzadeh-Aghdaei, Hamid; Baghestani, Ahmad Reza; Zali, Mohammad Reza

2017-01-01

The aim of this study was to estimate the economic burden of celiac disease (CD) in Iran. The assessment of burden of CD has become an important primary or secondary outcome measure in clinical and epidemiologic studies. Information regarding medical costs and gluten free diet (GFD) costs were gathered using questionnaire and checklists offered to the selected patients with CD. The data included the direct medical cost (including Doctor Visit, hospitalization, clinical test examinations, endoscopies, etc.), GFD cost and loss productivity cost (as the indirect cost) for CD patient were estimated. The factors used for cost estimation included frequency of health resource utilization and gluten free diet basket. Purchasing Power Parity Dollar (PPP$) was used in order to make inter-country comparisons. Total of 213 celiac patients entered to this study. The mean (standard deviation) of total cost per patient per year was 3377 (1853) PPP$. This total cost including direct medical cost, GFD costs and loss productivity cost per patients per year. Also the mean and standard deviation of medical cost and GFD cost were 195 (128) PPP$ and 932 (734) PPP$ respectively. The total costs of CD were significantly higher for male. Also GFD cost and total cost were higher for unmarried patients. In conclusion, our estimation of CD economic burden is indicating that CD patients face substantial expense that might not be affordable for a good number of these patients. The estimated economic burden may put these patients at high risk for dietary neglect resulting in increasing the risk of long term complications.

Beneficial effects of gluten free diet in potential coeliac disease in adult population.

PubMed

Imperatore, Nicola; Tortora, Raffaella; De Palma, Giovanni Domenico; Capone, Pietro; Gerbino, Nicolò; Donetto, Sara; Testa, Anna; Caporaso, Nicola; Rispo, Antonio

2017-08-01

To date, potential coeliac disease (PCD) occurring in adults remains an almost unexplored condition. To explore the prognostic role of Marsh grade in adult PCD patients, and to evaluate the effects of gluten-containing diet (GCD) in asymptomatic PCD patients. We retrospectively evaluated all consecutive adult PCD patients followed-up for at least 6 years. Patients were divided into: Group A (patients with Marsh 0 histology) and Group B (Marsh 1 patients). Symptomatic patients were started gluten-free diet (GFD), while asymptomatic subjects were kept on GCD and were followed-up. 56 PCD patients were enrolled (21 in Group A and 35 in Group B). Forty-three patients were symptomatic and started GFD. Of these, none of 15 patients in Group A and 8 of 28 patients in Group B developed immune-mediated disorders (IMD) during follow-up (P=0.03; OR=4.2). The 13 asymptomatic PCD patients were kept on GCD. During the follow-up, 9 patients developed CD-related symptoms, 6 villous atrophy and 8 IMD. At the end, patients kept on GCD were at higher risk of developing IMD than those following a GFD (61% vs 18%, P=0.03, OR=3.3). Although PCD with normal mucosa seems to be a milder disease, the continuation of GCD places patients at a high risk of developing villous atrophy and IMD compared to commencement of GFD. Adult PCD patients should start GFD even if not symptomatic. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Current and novel therapeutic strategies in celiac disease.

PubMed

Kurada, Satya; Yadav, Abhijeet; Leffler, Daniel A

2016-09-01

A gluten free diet (GFD) is the only available treatment for celiac disease (CD). However many patients fail to respond fully clinically or histologically. Several surveys highlight the psychosocial implications of adherence to a GFD. Hence, efforts are ongoing to develop therapeutic strategies beyond a GFD. We conducted a search of PubMed and clinicaltrials.gov to extract articles on CD using keywords including 'celiac disease' and 'refractory celiac disease' (RCD) and focused on articles conducting pathophysiologic and therapeutic research in/ex-vivo models and human trials. We highlight novel therapeutics that manipulate these mechanisms including tight junction regulators, glutenases, gluten sequestrants and immunotherapy using vaccines, nanoparticles that may serve as adjuncts to a GFD or more ambitiously to allow for gluten consumption. We also highlight the role of anti-inflammatories, immunosuppressants and monoclonal antibodies in RCD. Expert commentary: Therapeutics including tight junction regulators, glutenases have the potential to be approved for non-responsive CD or as gluten adjuncts. We expect results of various phase 1/2 trials using AMG 714, BL 7010, IgY antibodies to be published. In the interim, off-label use of 5 amino-salicylates, budesonide, nucleoside analogues and newer biologics developed for other inflammatory diseases will be used in RCD.

Investigational drug therapies for coeliac disease - where to from here?

PubMed

Haridy, James; Lewis, Diana; Newnham, Evan D

2018-03-01

Despite decades of research and a detailed knowledge of the immunopathological basis of coeliac disease (CD), adherence to a lifelong gluten-free diet (GFD) remains the single proven and available treatment. The increasing prevalence of CD combined with variable adherence to the GFD in a significant proportion of patients demands new therapeutic strategies. Areas covered: Trial registries, clinicaltrials.gov, pharmaceutical company website searches as well as published data from PubMed and conference proceedings were used to extract the most recent outcomes for CD therapeutics. This article aims to review the available therapies from a pathophysiological approach, and propose future directions in this interesting yet largely unfulfilled area of research. Expert opinion: Increasingly, the GFD is being challenged by its availability, palatability, practicality and now even efficacy in some populations. Whilst the causative antigens have been well described, it is clear that treatment based on the removal of these immunostimulatory peptides from the diet is far more complex than early experience in CD treatment implied. Despite burgeoning interest and research in experimental therapies for CD over the past twenty years, the only therapy showing promise as a true alternative to a GFD is that of the induction of tolerance via a vaccine.

Growth hormone impaired secretion and antipituitary antibodies in patients with coeliac disease and poor catch-up growth after a long gluten-free diet period: a causal association?

PubMed

Iughetti, Lorenzo; De Bellis, Annamaria; Predieri, Barbara; Bizzarro, Antonio; De Simone, Michele; Balli, Fiorella; Bellastella, Antonio; Bernasconi, Sergio

2006-12-01

Coeliac disease (CD) is usually associated with impaired growth in children. A gluten-free diet (GFD) induces a catch-up growth with the recovery of height in about 2 years. AIM AND DISCUSSION: The lack of the height improvement has been related to growth hormone (GH) secretion impairment. CD is an autoimmune disease often associated with other endocrine and non-endocrine autoimmune disease. The aim of this study was to evaluate antipituitary autoantibodies (APA) and antihypothalamus autoantibodies in CD children with poor clinical response to a GFD and growth hormone deficiency (GHD). We diagnosed CD on the basis of specific antibodies and endoscopic biopsies in 130 patients aged 1-15 years. Seven CD children, without catch-up growth after at least 12-months GFD, were tested for GH secretion and, in five out of seven patients, the diagnosis of GHD was made in the absence of metabolic and systemic diseases. APA and antihypothalamus antibodies were detected by the indirect immunofluorescence method in the seven CD children without catch-up growth factor and in 25 CD children without growth impairment matched for sex and age, and in 58 healthy children as control groups. APA resulted positive at high titres in four out of five CD-GHD patients and were also positive at low titres (<1:8) in three of only CD children and in two out of 58 controls. Hypothalamic-pituitary magnetic resonance imaging (MRI) was normal in all patients except in one with cystic pineal. APA have been previously detected not only in adults with GHD, but also in idiopathic GHD children, suggesting the occurrence of an autoimmune hypophysitis in these patients. In our study, the presence of APA in CD children without catch-up growth after GFD seems to be able to identify an autoimmune form of hypophysitis involving the somatotrophs cells.

Internalizing the threat of risk--a qualitative study about adolescents' experience living with screening-detected celiac disease 5 years after diagnosis.

PubMed

Nordyke, Katrina; Rosén, Anna; Emmelin, Maria; Ivarsson, Anneli

2014-06-11

Mass screening could identify those with unrecognized celiac disease (CD), but the experience of being detected through screening and living with screening-detected CD should be explored before considering this as acceptable intervention. For this study we invited screening-detected adolescents to describe their experience living with screening-detected CD five years after diagnosis with the aim to explore how their perceptions, practices, and beliefs evolved. Adolescents who were diagnosed through a population-based CD screening were invited to write narratives after being diagnosed. Of 153 adolescents who were eventually diagnosed through the screening, 91 wrote narratives one year after diagnosis and 72 five years after diagnosis. A qualitative content analysis resulted in a theme and categories that describe the experience living with screening-detected CD five years after diagnosis. The overall theme--Internalizing the threat of risk--illustrates that being detected through screening and the internalized threat of future health complications have impacted how these adolescents felt about the diagnosis, coped with the gluten-free diet (GFD), and thought about CD screening. This theme is supported by four categories: maintaining an imposed disease identity describes how they continued to define their diagnosis in relation to the screening. They also expressed moving from forced food changes to adapted diet routines by describing habits, routines, coping strategies, and the financial burden of the GFD. They had enduring beliefs of being spared negative consequences, however, even after five years, some doubted they had CD and worried that being detected and eating a GFD might not be beneficial, i.e. continuing to fear it is "all in vain". There was maintenance and evolution in the perceptions, practices, and beliefs of the adolescents after five years. Some have adjusted to the disease and adapted new habits and coping strategies to deal with the GFD, while others still doubt they have CD or that being detected was beneficial. The transition to adapting to the disease and GFD is ongoing, illustrating the importance of providing ongoing support for those with screening-detected CD as they adjust to this chronic disease and the GFD.

Increased Intraepithelial Vα24 Invariant NKT Cells in the Celiac Duodenum

PubMed Central

Montalvillo, Enrique; Bernardo, David; Martínez-Abad, Beatriz; Allegretti, Yessica; Fernández-Salazar, Luis; Calvo, Carmen; Chirdo, Fernando G.; Garrote, José A.; Arranz, Eduardo

2015-01-01

Celiac Disease (CD) is an interferon (IFN)γ-mediated duodenal hypersensitivity to wheat gluten occurring in genetically predisposed individuals. Gluten-free diet (GFD) leads to a complete remission of the disease. Vα24-restricted invariant NKT (iNKT) cells are important to maintain immune homeostasis in the gut mucosa because of their unique capacity to rapidly produce large quantities of both T-helper (Th)1 and Th2 cytokines upon stimulation. We studied the presence of these cells in the CD duodenum. Duodenal biopsies were obtained from 45 untreated-CD patients (uCD), 15 Gluten Free Diet-CD patients (GFD-CD), 44 non-inflamed non-CD controls (C-controls) and 15 inflamed non-CD controls (I-controls). Two populations from Spain and Argentina were recruited. Messenger RNA (mRNA) expression of Vα24-Jα18 (invariant TCRα chain of human iNKT cells), IFNγ and intracellular transcription factor Forkhead Box P3 (Foxp3), and flow cytometry intraepithelial lymphocyte (IEL) profile were determined. Both uCD and GFD-CD patients had higher Vα24-Jα18 mRNA levels than non-CD controls (I and C-controls). The expression of Vα24-Jα18 correlated with Marsh score for the severity of mucosal lesion and also with increased mRNA IFNγ levels. uCD and GFD-CD patients had decreased mRNA expression of FoxP3 but increased expression of Vα24-Jα18, which revealed a CD-like molecular profile. Increased numbers of iNKT cells were confirmed by flow cytometry within the intraepithelial lymphocyte compartment of uCD and GFD-CD patients and correlated with Vα24-Jα18 mRNA expression. In conclusion, we have found an increased number of iNKT cells in the duodenum from both uCD and GFD-CD patients, irrespective of the mucosal status. A CD-like molecular profile, defined by an increased mRNA expression of Vα24-Jα18 together with a decreased expression of FoxP3, may represent a pro-inflammatory signature of the CD duodenum. PMID:26529008

Increased Intraepithelial Vα24 Invariant NKT Cells in the Celiac Duodenum.

PubMed

Montalvillo, Enrique; Bernardo, David; Martínez-Abad, Beatriz; Allegretti, Yessica; Fernández-Salazar, Luis; Calvo, Carmen; Chirdo, Fernando G; Garrote, José A; Arranz, Eduardo

2015-10-30

Celiac Disease (CD) is an interferon (IFN)γ-mediated duodenal hypersensitivity to wheat gluten occurring in genetically predisposed individuals. Gluten-free diet (GFD) leads to a complete remission of the disease. Vα24-restricted invariant NKT (iNKT) cells are important to maintain immune homeostasis in the gut mucosa because of their unique capacity to rapidly produce large quantities of both T-helper (Th)1 and Th2 cytokines upon stimulation. We studied the presence of these cells in the CD duodenum. Duodenal biopsies were obtained from 45 untreated-CD patients (uCD), 15 Gluten Free Diet-CD patients (GFD-CD), 44 non-inflamed non-CD controls (C-controls) and 15 inflamed non-CD controls (I-controls). Two populations from Spain and Argentina were recruited. Messenger RNA (mRNA) expression of Vα24-Jα18 (invariant TCRα chain of human iNKT cells), IFNγ and intracellular transcription factor Forkhead Box P3 (Foxp3), and flow cytometry intraepithelial lymphocyte (IEL) profile were determined. Both uCD and GFD-CD patients had higher Vα24-Jα18 mRNA levels than non-CD controls (I and C-controls). The expression of Vα24-Jα18 correlated with Marsh score for the severity of mucosal lesion and also with increased mRNA IFNγ levels. uCD and GFD-CD patients had decreased mRNA expression of FoxP3 but increased expression of Vα24-Jα18, which revealed a CD-like molecular profile. Increased numbers of iNKT cells were confirmed by flow cytometry within the intraepithelial lymphocyte compartment of uCD and GFD-CD patients and correlated with Vα24-Jα18 mRNA expression. In conclusion, we have found an increased number of iNKT cells in the duodenum from both uCD and GFD-CD patients, irrespective of the mucosal status. A CD-like molecular profile, defined by an increased mRNA expression of Vα24-Jα18 together with a decreased expression of FoxP3, may represent a pro-inflammatory signature of the CD duodenum.

Age- and sex-related variations in the brain white matter fractal dimension throughout adulthood: an MRI study.

PubMed

Farahibozorg, S; Hashemi-Golpayegani, S M; Ashburner, J

2015-03-01

To observe age- and sex-related differences in the complexity of the global and hemispheric white matter (WM) throughout adulthood by means of fractal dimension (FD). A box-counting algorithm was used to extract FD from the WM magnetic resonance images of 209 healthy adults from three structural layers, including general (gFD), skeleton (sFD), and boundaries (bFD). Model selection algorithms and statistical analyses, respectively, were used to examine the patterns and significance of the changes. gFD and sFD showed inverse U-shape patterns with aging, with a slighter slope of increase from young to mid-age and a steeper decrease to the old. bFD was less affected by age. Sex differences were evident, specifically in gFD and sFD, with men showing higher FDs. Age × sex interaction was significant mainly in the hemispheric analysis, with men undergoing sharper age-related changes. After adjusting for the volume effect, age-related results remained approximately the same, but sex differences changed in most of the features, with women indicating higher values, specifically in the left hemisphere and boundaries. Right hemisphere was still more complex in men. This study is the first that investigates the WM FD spanning adulthood, treating age both as a continuous and categorical variable. We found positive correlations between FD and volume, and our results show similarities with those investigating small-world properties of the brain networks, as well as those of functional complexity and WM integrity. These suggest that FD could yield a highly compact description of the structural changes and also might inform us about functional and cognitive variations.

Prevalence of irritable bowel syndrome-type symptoms in patients with celiac disease: a meta-analysis.

PubMed

Sainsbury, Anita; Sanders, David S; Ford, Alexander C

2013-04-01

Patients with celiac disease (CD) often report symptoms compatible with irritable bowel syndrome (IBS). However, the prevalence of these symptoms in patients with CD and their relation to adherence to a gluten-free diet (GFD) have not been assessed systematically. We searched MEDLINE, EMBASE, and EMBASE Classic (through July 2012) to identify cross-sectional surveys or case-control studies reporting prevalence of IBS-type symptoms in adult patients (≥ 16 years old) with established CD. The number of individuals with symptoms meeting criteria for IBS was extracted for each study, according to case or control status and adherence to a GFD. Pooled prevalence and odds ratios (ORs), with 95% confidence intervals (CIs), were calculated. We analyzed data from 7 studies with 3383 participants. The pooled prevalence of IBS-type symptoms in all patients with CD was 38.0% (95% CI, 27.0%-50.0%). The pooled OR for IBS-type symptoms was higher in patients with CD than in controls (5.60; 95% CI, 3.23-9.70). In patients who were nonadherent with a GFD, the pooled OR for IBS-type symptoms, compared with those who were strictly adherent, was 2.69 (95% CI, 0.75-9.56). There was also a trend toward a higher OR for IBS-type symptoms among patients who did not adhere to the GFD, compared with controls (12.42; 95% CI, 6.84-11.75), compared with that observed for adherent CD patients vs controls (4.28; 95% CI, 1.56-11.75). IBS-type symptoms occur frequently in patients with CD and are more common than among controls. Adherence to a GFD might be associated with a reduction in symptoms. Copyright © 2013 AGA Institute. Published by Elsevier Inc. All rights reserved.

Coeliac disease and the liver: spectrum of liver histology, serology and treatment response at a tertiary referral centre.

PubMed

Majumdar, Kaushik; Sakhuja, Puja; Puri, Amarender Singh; Gaur, Kavita; Haider, Aiman; Gondal, Ranjana

2018-05-01

Coeliac disease (CD) is a gluten-sensitive enteropathy diagnosed on the basis of ESPGHAN criteria and clinical response to gluten-free diet (GFD). Histological abnormalities on liver biopsy have been noted in CD but have seldom been described. To assess the histological spectrum of 'coeliac hepatitis' and possibility of reversal of such features after a GFD. Twenty-five patients with concomitant CD and hepatic derangement were analysed for clinical profile, laboratory investigations and duodenal and liver biopsy. A histological comparison of pre- and post-GFD duodenal and liver biopsies was carried out, wherever possible. Fifteen patients presenting with CD subsequently developed abnormal liver function tests; 10 patients presenting with liver disease were found to have tissue positive transglutaminase in 70% and antigliadin antibodies in 60%. Serological markers for autoimmune liver disease (AILD) were positive in eight patients. Liver histology ranged from mild reactive hepatitis, chronic hepatitis, steatosis to cirrhosis. Liver biopsies after a GFD were available in six cases, of which five showed a decrease in steatosis, portal and lobular inflammation and fibrosis score. Coeliac hepatitis could be a distinct entity and the patients may present with either CD or secondary hepatic derangement. Evaluation for the presence of CD is recommended for patients presenting with AILD, unexplained transaminasaemia or anaemia. This is one of the very few studies demonstrating the continuum of liver histological changes in 'coeliac hepatitis'. Trial of a GFD may result in clinicopathological improvement of 'coeliac hepatitis'. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Adherence to the Gluten-free Diet and Health-related Quality of Life in an Ethnically Diverse Pediatric Population With Celiac Disease.

PubMed

Mager, Diana R; Marcon, Margaret; Brill, Herbert; Liu, Amanda; Radmanovich, Kristin; Mileski, Heather; Nasser, Roseann; Alzaben, Abeer; Carroll, Matthew W; Yap, Jason; Persad, Rabin; Turner, Justine M

2018-06-01

Celiac disease (CD) is an autoimmune disease that requires lifelong adherence to a gluten-free diet (GFD). Adherence to the GFD in childhood may be poor and adversely influence health-related quality of life (HRQOL). The study purpose was to determine sociodemographic and socioeconomic factors influencing adherence to the GFD and HRQOL in a multiethnic cohort of youth with CD. A multisite (Edmonton, Hamilton, Toronto) study examining child-parent HRQOL in youth with CD (n = 243) and/or mild gastrointestinal complaints (GI-CON; n = 148) was conducted. Sociodemographic (age, child-parental age/education/ethnicity/place of birth), anthropometric (weight, height, body mass index), disease (diagnosis, age at diagnosis, duration, Marsh score, serology), household characteristics (income, family size, region, number of children/total household size), HRQOL (Peds TM/KINDL and Celiac Disease DUX), GI Complaints (PedsQL: Gastrointestinal Symptom Scale) and gluten intake were measured. Younger age (<10 years), non-Caucasian ethnicity (parent/child), and presence of GI symptoms were associated with the highest rates of adherence to the GFD in CD children (P < 0.05). CD children (parent/child) had higher HRQOL (average, composite domains) than GI-CON (P < 0.05), but CD children were comparable to healthy children. Lack of GI symptoms, non-Caucasian ethnicity and age (<10 years) were associated with increased HRQOL in composite/average domains for CD (P < 0.05). Child-parent perceptions of HRQOL in a multiethnic population with CD are comparable to healthy reference populations, but significantly higher than in parent/child GI-CON. Adherence to the GFD in ethnically diverse youth with CD was related to GI symptoms, age of the child, and ethnicity of the parent-child.

Celiac Disease and Gluten-Free Oats: A Canadian Position Based on a Literature Review.

PubMed

La Vieille, Sébastien; Pulido, Olga M; Abbott, Michael; Koerner, Terence B; Godefroy, Samuel

2016-01-01

This paper provides an overview of the latest scientific data related to the safety of uncontaminated oats (<20 ppm of gluten) in the diet of individuals with celiac disease (CD). It updates the previous Health Canada position posted on the Health Canada website in 2007 and a related paper published in 2009. It considers a number of recent studies published between January 2008 and January 2015. While recognizing that a few people with celiac disease seem to be clinically intolerant to oats, this review concludes that oats uncontaminated by gluten-containing cereals (wheat, rye, and barley) can be safely ingested by most patients with celiac disease and that there is no conclusive evidence that the consumption of uncontaminated or specially produced oats containing no greater than 20 ppm gluten by patients with celiac disease should be limited to a specific daily amount. However, individuals with CD should observe a stabilization phase before introducing uncontaminated oats to the gluten-free diet (GFD). Oats uncontaminated with gluten should only be introduced after all symptoms of celiac disease have resolved and the individual has been on a GFD for a minimum of 6 months. Long-term regular medical follow-up of these patients is recommended but this is no different recommendation to celiac individuals on a GFD without oats.

Molecular and Immunological Characterization of Gluten Proteins Isolated from Oat Cultivars That Differ in Toxicity for Celiac Disease

PubMed Central

Real, Ana; Comino, Isabel; de Lorenzo, Laura; Merchán, Francisco; Gil-Humanes, Javier; Giménez, María J.; López-Casado, Miguel Ángel; Cebolla, Ángel; Sousa, Carolina; Barro, Francisco; Pistón, Fernando

2012-01-01

A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease (CD). Traditionally, treatment with a GFD has excluded wheat, barley and rye, while the presence of oats is a subject of debate. The most-recent research indicates that some cultivars of oats can be a safe part of a GFD. In order to elucidate the toxicity of the prolamins from oat varieties with low, medium, and high CD toxicity, the avenin genes of these varieties were cloned and sequenced, and their expression quantified throughout the grain development. At the protein level, we have accomplished an exhaustive characterization and quantification of avenins by RP-HPLC and an analysis of immunogenicity of peptides present in prolamins of different oat cultivars. Avenin sequences were classified into three different groups, which have homology with S-rich prolamins of Triticeae. Avenin proteins presented a lower proline content than that of wheat gliadin; this may contribute to the low toxicity shown by oat avenins. The expression of avenin genes throughout the development stages has shown a pattern similar to that of prolamins of wheat and barley. RP-HPLC chromatograms showed protein peaks in the alcohol-soluble and reduced-soluble fractions. Therefore, oat grains had both monomeric and polymeric avenins, termed in this paper gliadin- and glutenin-like avenins. We found a direct correlation between the immunogenicity of the different oat varieties and the presence of the specific peptides with a higher/lower potential immunotoxicity. The specific peptides from the oat variety with the highest toxicity have shown a higher potential immunotoxicity. These results suggest that there is wide range of variation of potential immunotoxicity of oat cultivars that could be due to differences in the degree of immunogenicity in their sequences. PMID:23284616

Going Gluten Free: the History and Nutritional Implications of Today's Most Popular Diet.

PubMed

Newberry, Carolyn; McKnight, Lindsay; Sarav, Menaka; Pickett-Blakely, Octavia

2017-09-25

The gluten-free diet (GFD) has become one of the most popular diets in modern history. Claims of improved health and increased energy fuel this popularity, though there is little evidence to substantiate these claims. The present review focuses on outlining known gluten-related disorders (GRD), discussing the GFD in the general population, exploring nutritional considerations, and providing advice for physicians in managing these patients. Currently, about a quarter of the population reports keeping a GFD despite GRDs affecting less than half of these individuals. Reduced intake of calcium, B vitamins, and fiber as well as enhanced consumption of fat and simple carbohydrates has consistently been reported and needs to be continually addressed. Although a necessity in proper management of GRDs, unforeseen nutritional complications may develop in patients who are gluten free for which enhanced physician awareness is vital to achieving optimal patient care.

Emerging drugs for coeliac disease.

PubMed

Mooney, Peter D; Hadjivassiliou, Marios; Sanders, David S

2014-12-01

Coeliac disease is an autoimmune gluten sensitive enteropathy and is now known to affect 1% of the adult population. A gluten-free diet (GFD) should be curative; however, up to 30% of patients have persistent symptoms and many patients find the diet difficult to fully adhere to. Currently, there are no licensed therapeutic options for patients with coeliac disease outside of a GFD. This review will outline the case for alternative treatments and discuss the potential therapeutic targets. The products in the most advanced stage of development will be discussed in detail. There is clearly an unmet need for alternatives to a GFD for the treatment of coeliac disease. Oral glutenase supplements to improve the degradation of gluten into non-toxic peptides appear to be the most likely to provide a breakthrough in the treatment of coeliac disease; however, other modalities such as a therapeutic vaccine or zonulin inhibitors to reduce intestinal permeability have shown promising results.

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

NASA Astrophysics Data System (ADS)

Gay-Balmaz, François; Holm, Darryl D.

2018-01-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

Stochastic Geometric Models with Non-stationary Spatial Correlations in Lagrangian Fluid Flows

NASA Astrophysics Data System (ADS)

Gay-Balmaz, François; Holm, Darryl D.

2018-06-01

Inspired by spatiotemporal observations from satellites of the trajectories of objects drifting near the surface of the ocean in the National Oceanic and Atmospheric Administration's "Global Drifter Program", this paper develops data-driven stochastic models of geophysical fluid dynamics (GFD) with non-stationary spatial correlations representing the dynamical behaviour of oceanic currents. Three models are considered. Model 1 from Holm (Proc R Soc A 471:20140963, 2015) is reviewed, in which the spatial correlations are time independent. Two new models, called Model 2 and Model 3, introduce two different symmetry breaking mechanisms by which the spatial correlations may be advected by the flow. These models are derived using reduction by symmetry of stochastic variational principles, leading to stochastic Hamiltonian systems, whose momentum maps, conservation laws and Lie-Poisson bracket structures are used in developing the new stochastic Hamiltonian models of GFD.

Metagenomics approach to the study of the gut microbiome structure and function in zebrafish Danio rerio fed with gluten formulated diet.

PubMed

Koo, Hyunmin; Hakim, Joseph A; Powell, Mickie L; Kumar, Ranjit; Eipers, Peter G; Morrow, Casey D; Crowley, Michael; Lefkowitz, Elliot J; Watts, Stephen A; Bej, Asim K

2017-04-01

In this study, we report the gut microbial composition and predictive functional profiles of zebrafish, Danio rerio, fed with a control formulated diet (CFD), and a gluten formulated diet (GFD) using a metagenomics approach and bioinformatics tools. The microbial communities of the GFD-fed D. rerio displayed heightened abundances of Legionellales, Rhizobiaceae, and Rhodobacter, as compared to the CFD-fed counterparts. Predicted metagenomics of microbial communities (PICRUSt) in GFD-fed D. rerio showed KEGG functional categories corresponding to bile secretion, secondary bile acid biosynthesis, and the metabolism of glycine, serine, and threonine. The CFD-fed D. rerio exhibited KEGG functional categories of bacteria-mediated cobalamin biosynthesis, which was supported by the presence of cobalamin synthesizers such as Bacteroides and Lactobacillus. Though these bacteria were absent in GFD-fed D. rerio, a comparable level of the cobalamin biosynthesis KEGG functional category was observed, which could be contributed by the compensatory enrichment of Cetobacterium. Based on these results, we conclude D. rerio to be a suitable alternative animal model for the use of a targeted metagenomics approach along with bioinformatics tools to further investigate the relationship between the gluten diet and microbiome profile in the gut ecosystem leading to gastrointestinal diseases and other undesired adverse health effects. Copyright © 2017. Published by Elsevier B.V.

Bifidobacterium infantis NLS Super Strain Reduces the Expression of α-Defensin-5, a Marker of Innate Immunity, in the Mucosa of Active Celiac Disease Patients.

PubMed

Pinto-Sánchez, Maria I; Smecuol, Edgardo C; Temprano, Maria P; Sugai, Emilia; González, Andrea; Moreno, María L; Huang, Xianxi; Bercik, Premysl; Cabanne, Ana; Vázquez, Horacio; Niveloni, Sonia; Mazure, Roberto; Mauriño, Eduardo; Verdú, Elena F; Bai, Julio C

2017-10-01

We have previously shown a reduction of gastrointestinal symptoms after the oral administration of Bifidobacterium infantis Natren Life Start super strain (NLS-SS) in untreated celiac disease (CD) patients. The symptomatic improvement was not associated with changes in intestinal permeability or serum levels of cytokines, chemokines, or growth factors. Therefore, we hypothesized that the beneficial symptomatic effect observed previously in patients with CD treated with B. infantis may be related to the modulation of innate immunity. To investigate the potential mechanisms of a probiotic B. infantis Natren Life Start super strain on the mucosal expression of innate immune markers in adult patients with active untreated CD compared with those treated with B. infantis×6 weeks and after 1 year of gluten-free diet (GFD). Numbers of macrophages and Paneth cells and α-defensin-5 expression were assessed by immunohistochemistry in duodenal biopsies. We showed that GFD decreases duodenal macrophage counts in CD patients more effectively than B. infantis. In contrast, B. infantis decreases Paneth cell counts and expression of α-defensin-5 in CD (P<0.001). The results identify differential innate immune effects of treatment with B. infantis compared with 1 year of GFD. Further studies are needed to investigate synergistic effects of GFD and B. infantis supplementation in CD.

The Effect of Depressive Symptoms on the Association between Gluten-Free Diet Adherence and Symptoms in Celiac Disease: Analysis of a Patient Powered Research Network

PubMed Central

Geller, Marilyn G.; Zylberberg, Haley M.; Green, Peter H. R.; Lebwohl, Benjamin

2018-01-01

Background: The prevalence of depression in celiac disease (CD) is high, and patients are often burdened socially and financially by a gluten-free diet. However, the relationship between depression, somatic symptoms and dietary adherence in CD is complex and poorly understood. We used a patient powered research network (iCureCeliac®) to explore the effect that depression has on patients’ symptomatic response to a gluten-free diet (GFD). Methods: We identified patients with biopsy-diagnosed celiac disease who answered questions pertaining to symptoms (Celiac Symptom Index (CSI)), GFD adherence (Celiac Dietary Adherence Test (CDAT)), and a 5-point, scaled question regarding depressive symptoms relating to patients’ celiac disease. We then measured the correlation between symptoms and adherence (CSI vs. CDAT) in patients with depression versus those without depression. We also tested for interaction of depression with regard to the association with symptoms using a multiple linear regression model. Results: Among 519 patients, 86% were female and the mean age was 40.9 years. 46% of patients indicated that they felt “somewhat,” “quite a bit,” or “very much” depressed because of their disorder. There was a moderate correlation between worsened celiac symptoms and poorer GFD adherence (r = 0.6, p < 0.0001). In those with a positive depression screen, there was a moderate correlation between worsening symptoms and worsening dietary adherence (r = 0.5, p < 0.0001) whereas in those without depression, the correlation was stronger (r = 0.64, p < 0.0001). We performed a linear regression analysis, which suggests that the relationship between CSI and CDAT is modified by depression. Conclusions: In patients with depressive symptoms related to their disorder, correlation between adherence and symptoms was weaker than those without depressive symptoms. This finding was confirmed with a linear regression analysis, showing that depressive symptoms may modify the effect of a GFD on celiac symptoms. Depressive symptoms may therefore mask the relationship between inadvertent gluten exposure and symptoms. Additional longitudinal and prospective studies are needed to further explore this potentially important finding. PMID:29701659

Dietary Factors and Mucosal Immune Response in Celiac Disease Patients Having Persistent Symptoms Despite a Gluten-free Diet.

PubMed

Laurikka, Pilvi; Lindfors, Katri; Oittinen, Mikko; Huhtala, Heini; Salmi, Teea; Lähdeaho, Marja-Leena; Ilus, Tuire; Mäki, Markku; Kaukinen, Katri; Kurppa, Kalle

2018-03-02

The aim of this study was to investigate the role of dietary factors, distinct small-bowel mucosal immune cell types, and epithelial integrity in the perpetuation of gastrointestinal symptoms in treated celiac disease patients. For unexplained reasons, many celiac disease patients suffer from persistent symptoms, despite a strict gluten-free diet (GFD) and recovered intestinal mucosa. We compared clinical and serological data and mucosal recovery in 22 asymptomatic and 25 symptomatic celiac patients on a long-term GFD. The density of CD3 and γδ intraepithelial lymphocytes (IELs), CD25 and FOXP3 regulatory T cells, and CD117 mast cells, and the expression of tight junction proteins claudin-3 and occludin, heat shock protein 60, interleukin 15, and Toll-like receptor 2 and 4 were evaluated in duodenal biopsies. All subjects kept a strict GFD and had negative celiac autoantibodies and recovered mucosal morphology. The asymptomatic patients had higher mean fiber intake (20.2 vs. 15.2 g/d, P=0.028) and density of CD3 IELs (59.3 vs. 45.0 cell/mm, P=0.045) than those with persistent symptoms. There was a similar but nonsignificant trend in γδ IELs (17.9 vs. 13.5, P=0.149). There were no differences between the groups in other parameters measured. Low fiber intake may predispose patients to persistent symptoms in celiac disease. There were no differences between the groups in the markers of innate immunity, epithelial stress or epithelial integrity. A higher number of IELs in asymptomatic subjects may indicate that the association between symptoms and mucosal inflammation is more complicated than previously thought.

The effect of oligofructose-enriched inulin supplementation on gut microbiota, nutritional status and gastrointestinal symptoms in paediatric coeliac disease patients on a gluten-free diet: study protocol for a pilot randomized controlled trial.

PubMed

Krupa-Kozak, Urszula; Drabińska, Natalia; Jarocka-Cyrta, Elżbieta

2017-08-22

A lifelong gluten-free diet (GFD) is regarded as the only proven and accepted therapy for coeliac disease (CD). However, even patients who strictly follow a GFD often suffer from intestinal symptoms and malabsorption. Selective modulation of intestinal microbiota with prebiotics could remedy various symptoms associated with CD. The use of prebiotics in the treatment of intestinal diseases remains insufficiently investigated. To our knowledge, this study makes the first attempt to evaluate the effect of prebiotic supplementation on gastrointestinal symptoms and nutritional status of children with CD. We hypothesized that adherence to a GFD supplemented with oligofructose-enriched inulin (Synergy 1) would deliver health benefits to children suffering from CD without any side effects, and that it would alleviate intestinal inflammation, restore and stabilize gut microbial balance and reverse nutritional deficiencies through enhanced absorption of vitamins and minerals. A randomized, placebo-controlled clinical trial was designed to assess the impact of the Synergy 1 on paediatric CD patients following a GFD. We randomized 34 children diagnosed with CD into an intervention group receiving 10 g of the Synergy 1 supplement daily and a placebo group (receiving maltodextrin) during a 12-week nutritional intervention. Selected biochemical parameters, nutritional status and the characteristics of faecal bacteria will be determined in samples collected before and after the intervention. Analysis of vitamins and amino acids concentration in biological fluids will allow to assess the dietary intake of crucial nutrients. The compliance to a GFD will be confirmed by a Food Frequency Questionnaire (FFQ-6) and the analysis of serum anti-tissue transglutaminase and faecal gluten immunogenic peptides (GIP). The identification of the beneficial effects of the Synergy 1 supplement on children with CD could have important implications for nutritional recommendations for CD patients and for alleviating the harmful effects of the disease. ClinicalTrials.gov Registration Number: NCT03064997 .

Trace gluten contamination may play a role in mucosal and clinical recovery in a subgroup of diet-adherent non-responsive celiac disease patients.

PubMed

Hollon, Justin R; Cureton, Pamela A; Martin, Margaret L; Puppa, Elaine L Leonard; Fasano, Alessio

2013-02-28

Patients with persistent symptoms and/or villous atrophy despite strict adherence to a gluten-free diet (GFD) have non-responsive celiac disease (NRCD). A subset of these patients has refractory celiac disease (RCD), yet some NRCD patients may simply be reacting to gluten cross-contamination. Here we describe the effects of a 3-6 month diet of whole, unprocessed foods, termed the Gluten Contamination Elimination Diet (GCED), on NRCD. We aim to demonstrate that this diet reclassifies the majority of patients thought to have RCD type 1 (RCD1). We reviewed the records of all GFD-adherent NRCD patients cared for in our celiac center from 2005-2011 who were documented to have started the GCED. Response to the GCED was defined as being asymptomatic after the diet, with normal villous architecture on repeat biopsy, if performed. Prior to the GCED, all patients were interviewed by an experienced dietitian and no sources of hidden gluten ingestion were identified. 17 patients completed the GCED; 15 were female (88%). Median age at start of the GCED was 42 years (range 6-73). Fourteen patients (82%) responded to the GCED. Six patients met criteria for RCD prior to the GCED; 5 (83%) were asymptomatic after the GCED and no longer meet RCD criteria. Of the 14 patients who responded to the GCED, 11 (79%) successfully returned to a traditional GFD without resurgence of symptoms. The GCED may be an effective therapeutic option for GFD-adherent NRCD patients. Response to this diet identifies a subgroup of patients, previously classified as RCD1, that is not truly refractory to dietary treatment. Preventing an inaccurate diagnosis of RCD1 avoids immunotherapy. Most patients are able to return to a traditional GFD without return of symptoms.

Frequency and Cause of Persistent Symptoms in Celiac Disease Patients on a Long-term Gluten-free Diet.

PubMed

Stasi, Elisa; Marafini, Irene; Caruso, Roberta; Soderino, Federica; Angelucci, Erika; Del Vecchio Blanco, Giovanna; Paoluzi, Omero A; Calabrese, Emma; Sedda, Silvia; Zorzi, Francesca; Pallone, Francesco; Monteleone, Giovanni

2016-03-01

To estimate the frequency and cause of nonresponsive celiac disease (CD). Treatment of CD is based on life-long adherence to a gluten-free diet (GFD). Some celiac patients experience persistence of symptoms despite a GFD. This condition is defined as nonresponsive CD. Celiac patients on a GFD for at least 12 months underwent diet compliance assessment, laboratory tests, breath tests, endoscopic, and histologic evaluations according to the symptoms/signs reported. Seventy of 321 (21.8%) patients had persistent or recurrent symptoms/signs. The cause of symptom persistence was evaluated in 56 of 70 patients. Thirteen of 56 (23%) patients were antiendomysial antibody positive. Among the patients with negative serology, 1 had fibromyalgia, and 3 had evidence that disproved the diagnosis of CD. The remaining 39 patients with negative serology underwent duodenal biopsy sampling, which evidenced histologic alterations in 24 patients. Among the 15 patients with normal histology 3 were lactose intolerant, 9 had irritable bowel syndrome, 2 had gastroesophageal reflux disease, and in 1 patient a cause for the persistent symptom was not identified. In patients with confirmed diagnosis of CD, exposure to dietary gluten was the main cause of persistence of symptoms/signs, and consistently after dietary modification, symptoms resolved in 63% of the patients at later time points during follow-up. Nonresponsive CD occurs in nearly one fifth of celiac patients on GFD and its occurrence suggests further investigations to optimize the management of celiac patients.

Nonceliac gluten sensitivity.

PubMed

Fasano, Alessio; Sapone, Anna; Zevallos, Victor; Schuppan, Detlef

2015-05-01

During the past decade there has been an impressive increase in popularity of the gluten-free diet (GFD)-now the most trendy alimentary habit in the United States and other countries. According to recent surveys, as many as 100 million Americans will consume gluten-free products within a year. Operating under the concept that the GFD benefits only individuals with celiac disease, health care professionals have struggled to separate the wheat from the chaff; there are claims that eliminating gluten from the diet increases health and helps with weight loss, or even that gluten can be harmful to every human being. However, apart from unfounded trends, a disorder related to ingestion of gluten or gluten-containing cereals, namely nonceliac gluten sensitivity (NCGS), has resurfaced in the literature, fueling a debate on the appropriateness of the GFD for people without celiac disease. Although there is clearly a fad component to the popularity of the GFD, there is also undisputable and increasing evidence for NCGS. However, we require a better understanding of the clinical presentation of NCGS, as well as its pathogenesis, epidemiology, management, and role in conditions such as irritable bowel syndrome, chronic fatigue, and autoimmunity. Before we can begin to identify and manage NCGS, there must be agreement on the nomenclature and definition of the disorder based on proper peer-reviewed scientific information. We review the most recent findings on NCGS and outline directions to dissipate some of the confusion related to this disorder. Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.

Administration of Bifidobacterium breve Decreases the Production of TNF-α in Children with Celiac Disease.

PubMed

Klemenak, Martina; Dolinšek, Jernej; Langerholc, Tomaž; Di Gioia, Diana; Mičetić-Turk, Dušanka

2015-11-01

Increasing evidence suggests that not only genetics, but also environmental factors like gut microbiota dysbiosis play an important role in the pathogenesis of celiac disease (CD). The aim of our study was to investigate the effect of two probiotic strains Bifidobacterium breve BR03 and B. breve B632 on serum production of anti-inflammatory cytokine interleukin 10 (IL-10) and pro-inflammatory cytokine tumor necrosis factor alpha (TNF-α) in children with CD. The study was a double-blinded, placebo-controlled trial that included 49 children with CD on gluten-free diet (GFD) randomized into two groups and 18 healthy children in the control group. The first group (24 children with CD) daily received B. breve BR03 and B632 (2 × 10(9) colony-forming units) and the second group (25 children with CD) received placebo for 3 months. TNF-α levels were significantly decreased in the first group after receiving B. breve for 3 months. On follow-up, 3 months after receiving probiotics, TNF-α levels increased again. Children with CD who were on GFD for less than 1 year showed similar baseline TNF-α levels as children who were on GFD for more than 1 year. IL-10 levels were in all groups of patients below detection level. Probiotic intervention with B. breve strains has shown a positive effect on decreasing the production of pro-inflammatory cytokine TNF-α in children with CD on GFD.

Diagnosis of Non-Celiac Gluten Sensitivity (NCGS): The Salerno Experts' Criteria.

PubMed

Catassi, Carlo; Elli, Luca; Bonaz, Bruno; Bouma, Gerd; Carroccio, Antonio; Castillejo, Gemma; Cellier, Christophe; Cristofori, Fernanda; de Magistris, Laura; Dolinsek, Jernej; Dieterich, Walburga; Francavilla, Ruggiero; Hadjivassiliou, Marios; Holtmeier, Wolfgang; Körner, Ute; Leffler, Dan A; Lundin, Knut E A; Mazzarella, Giuseppe; Mulder, Chris J; Pellegrini, Nicoletta; Rostami, Kamran; Sanders, David; Skodje, Gry Irene; Schuppan, Detlef; Ullrich, Reiner; Volta, Umberto; Williams, Marianne; Zevallos, Victor F; Zopf, Yurdagül; Fasano, Alessio

2015-06-18

Non-Celiac Gluten Sensitivity (NCGS) is a syndrome characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected by either celiac disease or wheat allergy. Given the lack of a NCGS biomarker, there is the need for standardizing the procedure leading to the diagnosis confirmation. In this paper we report experts' recommendations on how the diagnostic protocol should be performed for the confirmation of NCGS. A full diagnostic procedure should assess the clinical response to the gluten-free diet (GFD) and measure the effect of a gluten challenge after a period of treatment with the GFD. The clinical evaluation is performed using a self-administered instrument incorporating a modified version of the Gastrointestinal Symptom Rating Scale. The patient identifies one to three main symptoms that are quantitatively assessed using a Numerical Rating Scale with a score ranging from 1 to 10. The double-blind placebo-controlled gluten challenge (8 g/day) includes a one-week challenge followed by a one-week washout of strict GFD and by the crossover to the second one-week challenge. The vehicle should contain cooked, homogeneously distributed gluten. At least a variation of 30% of one to three main symptoms between the gluten and the placebo challenge should be detected to discriminate a positive from a negative result. The guidelines provided in this paper will help the clinician to reach a firm and positive diagnosis of NCGS and facilitate the comparisons of different studies, if adopted internationally.

Diagnosis of Non-Celiac Gluten Sensitivity (NCGS): The Salerno Experts’ Criteria

PubMed Central

Catassi, Carlo; Elli, Luca; Bonaz, Bruno; Bouma, Gerd; Carroccio, Antonio; Castillejo, Gemma; Cellier, Christophe; Cristofori, Fernanda; de Magistris, Laura; Dolinsek, Jernej; Dieterich, Walburga; Francavilla, Ruggiero; Hadjivassiliou, Marios; Holtmeier, Wolfgang; Körner, Ute; Leffler, Dan A.; Lundin, Knut E. A.; Mazzarella, Giuseppe; Mulder, Chris J.; Pellegrini, Nicoletta; Rostami, Kamran; Sanders, David; Skodje, Gry Irene; Schuppan, Detlef; Ullrich, Reiner; Volta, Umberto; Williams, Marianne; Zevallos, Victor F.; Zopf, Yurdagül; Fasano, Alessio

2015-01-01

Non-Celiac Gluten Sensitivity (NCGS) is a syndrome characterized by intestinal and extra-intestinal symptoms related to the ingestion of gluten-containing food, in subjects that are not affected by either celiac disease or wheat allergy. Given the lack of a NCGS biomarker, there is the need for standardizing the procedure leading to the diagnosis confirmation. In this paper we report experts’ recommendations on how the diagnostic protocol should be performed for the confirmation of NCGS. A full diagnostic procedure should assess the clinical response to the gluten-free diet (GFD) and measure the effect of a gluten challenge after a period of treatment with the GFD. The clinical evaluation is performed using a self-administered instrument incorporating a modified version of the Gastrointestinal Symptom Rating Scale. The patient identifies one to three main symptoms that are quantitatively assessed using a Numerical Rating Scale with a score ranging from 1 to 10. The double-blind placebo-controlled gluten challenge (8 g/day) includes a one-week challenge followed by a one-week washout of strict GFD and by the crossover to the second one-week challenge. The vehicle should contain cooked, homogeneously distributed gluten. At least a variation of 30% of one to three main symptoms between the gluten and the placebo challenge should be detected to discriminate a positive from a negative result. The guidelines provided in this paper will help the clinician to reach a firm and positive diagnosis of NCGS and facilitate the comparisons of different studies, if adopted internationally. PMID:26096570

Clinical Utility of Serologic Testing for Celiac Disease in Asymptomatic Patients

PubMed Central

2011-01-01

Executive Summary Objective The objective of this evidence-based analysis was to evaluate the clinical utility of serologic testing for celiac disease in asymptomatic individuals presenting with one of the non-gastrointestinal conditions evaluated in this report. The clinical utility was based on the effects of a gluten-free diet (GFD) on outcomes specific to each of these conditions. The prevalence of celiac disease in asymptomatic individuals and one of these non-gastrointestinal conditions was also evaluated. Clinical Need and Target Population Celiac Disease Celiac disease is an autoimmune disease characterized by a chronic inflammatory state of the proximal small bowel mucosa accompanied by structural and functional changes. Technology Under Evaluation Serologic Tests for Celiac Disease There are a number of serologic tests for celiac disease available. Serologic tests are automated with the exception of the anti-endomysial antibody test, which is more time-consuming and operator-dependent than the other tests. Research Questions What is the prevalence of asymptomatic celiac disease in patients presenting with one of the non-gastrointestinal conditions evaluated? What is the effect of the gluten-free diet on condition-specific outcomes in patients with asymptomatic celiac disease presenting with one of the non-gastrointestinal conditions evaluated? What is the clinical utility of serologic testing for celiac disease in asymptomatic patients presenting with one of the non-gastrointestinal conditions evaluated? The clinical utility was defined as the impact of the GFD on disease specific outcomes. What is the risk of all-cause mortality and lymphoma in individuals with asymptomatic celiac disease? What is the budget impact of serologic testing for celiac disease in asymptomatic subjects presenting with one of the non-gastrointestinal conditions evaluated? Research Methods Study Population The study population consisted of individuals with newly diagnosed celiac disease without any symptoms consistent with the disease presenting with one of the non-gastrointestinal conditions evaluated. When evaluating the risk of lymphoma and all-cause mortality, the study population consisted of asymptomatic individuals with a positive celiac disease serologic test and/or small bowel biopsy. Literature Search Search Strategy Literature searches were performed for each disease/condition evaluated between December 2010 and March 2011 using OVID MEDLINE, the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA). No restrictions for start date of search were used. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with an unknown eligibility were reviewed with a second clinical epidemiologist and then a group of epidemiologists until consensus was established. Inclusion Criteria Studies, systematic reviews, and meta-analyses that assessed the effects of a GFD in patients with newly diagnosed asymptomatic celiac disease presenting with one of the non-gastrointestinal conditions evaluated. If symptoms were not reported in the study but subjects were identified through screening for celiac disease the study was included. Studies, systematic reviews, and meta-analyses that assessed the prevalence of newly diagnosed asymptomatic celiac disease in patients with one of the non-gastrointestinal conditions evaluated. If symptoms were not reported in the study but subjects were identified through screening for celiac disease the study was included. Studies, systematic reviews, and meta-analyses that evaluated the risk of all-cause mortality or lymphoma in individuals with asymptomatic celiac disease. Sample size ≥ 10. Publications in English. Exclusion Criteria Studies that retrospectively assessed the prevalence of asymptomatic celiac disease. Studies that reported the prevalence of one of the non-gastrointestinal conditions evaluated in subjects already diagnosed with celiac disease. Studies in individuals with one of the non-gastrointestinal conditions evaluated if the condition could be explained by other causes. Studies in subjects with celiac disease and symptoms consistent with the disease. If the study included individuals with and without symptoms consistent with celiac disease and their results were analysed separately, the results in individuals without symptoms were included in the analysis. Studies in which individuals did not report any symptoms consistent with celiac disease at study start but that either retrospectively reported the presence of such symptoms after following a GFD, or that previously presented with symptoms consistent with celiac disease. Study results published in letters to the editor or comments about other studies. Studies with a sample size ≥ 10, however, in which less than 10 patients were included in the analysis. Outcomes of Interest The effects of a GFD on disease-specific outcomes for each condition evaluated in patients with asymptomatic celiac disease was assessed. The prevalence of asymptomatic celiac disease in patients presenting with one of the conditions evaluated was also assessed. Results of Evidence-Based Analysis Three eligible observational studies evaluated the effects of GFD on growth parameters in subjects with asymptomatic celiac disease and idiopathic short stature. Four eligible observational studies evaluated the effects of GFD on metabolic control in subjects with asymptomatic celiac disease and type 1 diabetes. Five eligible observational studies evaluated the risk of all-cause mortality and five eligible observational studies evaluated the risk of lymphoma in subjects with asymptomatic celiac disease. No eligible studies on the effects of the GFD for the other conditions evaluated were identified. Twenty-three eligible studies measured the prevalence of asymptomatic celiac disease in subjects presenting with one of the conditions evaluated. Prevalence of Celiac Disease in Asymptomatic Patients The prevalence of celiac disease in asymptomatic patients presenting with one of the conditions evaluated was analysed. Most studies also included a control group that generally consisted of individuals randomly selected from the general population. Although there was a trend to a higher prevalence of asymptomatic celiac disease in individuals with the conditions evaluated compared to the controls, it only reached statistical significance in type 1 diabetes. No eligible prevalence studies were identified in patients with amenorrhea, delayed puberty, alopecia, and depression. The Effects of a Gluten-Free Diet on Disease-Specific Outcomes in Patients with Asymptomatic Celiac Disease The effects of GFD on metabolic control in patients with asymptomatic celiac disease and Type 1 Diabetes The effects of a GFD on metabolic control (HbA1c, number of hypoglycemic episodes, and changes in insulin dosage) in subjects with asymptomatic celiac disease and type 1 diabetes were evaluated. One prospective case-control study reported an increase in HbA1c levels in cases with type 1 diabetes and asymptomatic celiac disease after the introduction of a GFD, however, the clinical significance of this change is unclear. Only one eligible retrospective case-control study evaluated the effects of a GFD on hypoglycemia episodes and since there were inadequate details in the study about both the ascertainment and severity of hypoglycemia episodes in both cases and controls, it is not possible to draw conclusions regarding the effects of a GFD on hypoglycemia episodes based on this study. One prospective case-control study did not show a statistically significant change in insulin dosage between cases with type 1 diabetes and asymptomatic celiac disease and controls with type 1 diabetes either before or after the introduction of a GFD. No eligible studies that evaluated the effects of a GFD on the long-term outcomes of type 1 diabetes such as cardiovascular or renal events in patients with asymptomatic celiac disease were identified. The effects of a Gluten-Free Diet in Patients with Idiopathic Short Stature and Asymptomatic Celiac Disease A total of 3 eligible studies were identified. All studies consisted of case series that compared growth parameters in subjects with asymptomatic celiac disease and idiopathic short stature before and after the celiac disease was diagnosed and the GFD was instituted. Most subjects included in the studies demonstrated an improvement in growth parameters. Compliance with the GFD was not reported in the studies. The results of the studies suggest an increase in growth velocity in pediatric patients with asymptomatic celiac disease and idiopathic short stature once a GFD is introduced. Risk of lymphoma in patients with asymptomatic celiac disease One retrospective cohort study evaluated the risk of lymphoma in patients with asymptomatic celiac disease. The authors concluded that the number of events identified was low during the long follow-up period and that the risk of overall malignancies was not increased among patients with asymptomatic celiac disease. Risk of Asymptomatic Celiac Disease in Patients with Lymphoma Four case-control studies, one of which retrospective, evaluated the risk of asymptomatic celiac disease in patients newly diagnosed with lymphoma. One retrospective cohort study did not show an increase in the risk of lymphoma among subjects with asymptomatic celiac disease. Three prospective case-control studies did not find a statistically significant risk of asymptomatic celiac disease in patients with newly diagnosed lymphoma. Risk of All-Cause Mortality in Patients with Asymptomatic Celiac Disease A total of 5 studies that evaluated the risk of all-cause mortality in asymptomatic patients with celiac disease were identified. There were 5 cohort studies, 2 prospective and 3 retrospective. The two prospective studies did not show an increased risk of all-cause mortality in subjects with asymptomatic celiac disease. Grading of Evidence The quality of the evidence for each serologic tests evaluated based on the GRADE Working Group criteria. Overall, the quality of the evidence ranged from low to very low depending on the outcome evaluated. The Clinical Utility of Serologic Testing for Celiac Disease in Asymptomatic Subjects Eligible studies that evaluated the effects of a GFD on disease-specific outcomes were only identified for two of the conditions evaluated, type 1 diabetes and idiopathic short stature. The clinical utility of serologic testing for celiac disease in patients with type 1 diabetes without symptoms consistent with celiac disease was not demonstrated since the studies identified did not provide evidence of the impact of the GFD on either metabolic control or long-term outcomes in these patients. The clinical utility of serologic testing for celiac disease in patients with idiopathic short stature without symptoms consistent with celiac disease was demonstrated since the studies identified showed an acceleration in growth once the diagnosis of celiac disease was made and a GFD was introduced. The Budget Impact of Serologic Testing for Celiac Disease in Asymptomatic Patients The budget impact of serologic testing for celiac disease in asymptomatic patients was calculated for the conditions for which clinical utility for serologic testing was demonstrated. The budget impact in patients with idiopathic short stature without symptoms consistent with celiac disease was estimated as C$552,000 as calculated by multiplying the number of individuals in Ontario with idiopathic short stature that may be eligible for the test by the cost of the serologic test for celiac disease. Conclusions Based on a review of the literature, there is an increased risk of asymptomatic celiac disease in patients with type 1 diabetes. Based on low quality evidence, in patients with idiopathic short stature and asymptomatic celiac disease there is an acceleration in growth once a gluten-free diet is introduced. With the exception of idiopathic short stature, there was no published evidence of clinical utility of celiac disease testing in asymptomatic patients with respect to a gluten-free diet intervention in the other conditions evaluated. Based on low to very low quality evidence, asymptomatic celiac disease does not confer an increased risk of lymphoma or mortality. Similarly, in patients with lymphoma there is no increased risk of asymptomatic celiac disease. PMID:23074415

Clinical impact of a gluten-free diet on health-related quality of life in seven fibromyalgia syndrome patients with associated celiac disease.

PubMed

Rodrigo, Luis; Blanco, Ignacio; Bobes, Julio; de Serres, Frederick J

2013-11-09

Celiac disease (CD) is an autoimmune disorder, characterized by the presence of gastrointestinal and multisystem symptoms, which occasionally mimic those of Irritable Bowel Syndrome (IBS) and Fibromyalgia Syndrome (FMS). To assess the effectiveness of a Gluten-Free Diet (GFD) in seven adult female screening-detected CD subjects, categorized as severe IBS and FMS patients. All subjects showed villous atrophy in duodenal biopsies, were HLA-DQ2/DQ8-positive, and fulfilled the Rome III and ACR 1990 criteria respectively for IBS and FMS classification. GFD effectiveness was assessed at baseline and after 1 year, examining the score changes in the Tender Points (TPs) test, Fibromyalgia Impact Questionnaire (FIQ), Health Assessment Questionnaire (HAQ), Short Form Health Survey (SF-36), Visual Analogue Scales (VAS) for gastrointestinal complaints, pain and tiredness, drug prescriptions and tissue-Trans-Glutaminase (tTG) serum levels. At baseline, all patients had poor Quality of Life and VAS scores, a high number of TPs and drug prescriptions, and increased tTG levels. After 1 year of GFD, all outcome measures significantly improved, with a decrease of 51-60% in TPs, FIQ, HAQ, and VAS scales, and in the number of prescribed drugs, accompanied by an increase of 48-60% in SF-36 Physical and Mental Component Summary scores, and a decrease of tTG to normal values. Results of this pilot study show that the adherence to a GFD by CD-related IBS/FMS patients can simultaneously improve CD and IBS/FMS symptoms, and indicate the merit of further research on a larger cohort.

Patient Perception of Treatment Burden is High in Celiac Disease Compared to Other Common Conditions

PubMed Central

Shah, Sveta; Akbari, Mona; Vanga, Rohini; Kelly, Ciaran P.; Hansen, Joshua; Theethira, Thimmaiah; Tariq, Sohaib; Dennis, Melinda; Leffler, Daniel A.

2014-01-01

Introduction The only treatment for celiac disease (CD) is life-long adherence to a gluten-free diet (GFD). Noncompliance is associated with signs and symptoms of celiac disease, yet long-term adherence rates are poor. It is not known how the burden of the GFD compares to other medical treatments, and there are limited data on the socio-economic factors influencing treatment adherence. In this study we compared treatment burden and health state in CD compared with other chronic illnesses and evaluated the relationship between treatment burden and adherence. Methods A survey was mailed to participants with: CD, gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), inflammatory bowel disease (IBD), hypertension (HTN), diabetes mellitus (DM), congestive heart failure (CHF), and end stage renal disease on dialysis (ESRD). Surveys included demographic information and visual analog scales measuring treatment burden, importance of treatment, disease-specific and overall health status. Results We collected surveys from 341 celiac and 368 non-celiac participants. Celiac participants reported high treatment burden, greater than participants with GERD or HTN and comparable to ESRD. Conversely, patients with CD reported the highest health state of all groups. Factors associated with high treatment burden in CD included poor adherence, concern regarding food cost, eating outside the home, higher income, lack of college education and time limitations in preparing food. Poor adherence in CD was associated with increased symptoms, income, and low perceived importance of treatment. Discussion Participants with CD have high treatment burden but also excellent overall health status in comparison with other chronic medical conditions. The significant burden of dietary therapy for celiac disease argues for the need for safe adjuvant treatment as well as interventions designed to lower the perceived burden of the GFD. PMID:24980880

Rare association of celiac disease with myasthenia gravis in a patient with other immune disorders: a case report.

PubMed

de Almeida Menezes, Marcela; Ribeiro Cabral, Vírginia Lúcia; Lorena, Sônia S; Nucci, Anamarli; Andrade Santana, Priscila; Queiroz Silva, Cecília

2016-09-01

Celiac disease is described in association with several autoimmune diseases, but rarely with myasthenia gravis. We describe the case of a 31-year-old white woman with celiac disease who presented manifestations related to a hyperactive immune system, including macroamylasemia, false-positive anti-HCV, positive antinuclear antibody, and Raynaud's phenomenon. The introduction of a gluten-free diet (GFD) resolved these features, but myasthenia gravis (MG) symptoms unexpectedly occurred on that occasion. The role of a GFD in the course of autoimmune diseases has been studied and improvement has been reported in many diseases. However, there is no consensus in the literature regarding the course of neurological disorders associated with celiac disease. In the present case, a GFD did not prevent the appearance of symptoms related to myasthenia gravis. There are few reports on the association of celiac disease with myasthenia gravis and therefore little is known about the course and time of onset of myasthenia in celiac patients. The present case increases the knowledge about this unusual autoimmune neurological disease associated with celiac disease.

Role of the gluten-free diet on neurological-EEG findings and sleep disordered breathing in children with celiac disease.

PubMed

Parisi, P; Pietropaoli, N; Ferretti, A; Nenna, R; Mastrogiorgio, G; Del Pozzo, M; Principessa, L; Bonamico, M; Villa, M P

2015-02-01

To determine whether celiac children are at risk for EEG-neurological features and sleep disordered breathing (SDB), and whether an appropriate gluten-free diet (GFD) influences these disorders. We consecutively enrolled 19 children with a new biopsy-proven celiac disease (CD) diagnosis. At CD diagnosis and after 6 months of GFD, each patient underwent a general and neurological examination, an electroencephalogram, a questionnaire about neurological features, and a validated questionnaire about SDB: OSA (obstructive sleep apnea) scores<0 predict normality; values>0 predict OSA. At CD diagnosis, 37% of patients complained headache that affected daily activities and 32% showed positive OSA score. The EEG examinations revealed abnormal finding in 48% of children. After 6 months of GFD headache disappeared in 72% of children and EEG abnormalities in 78%; all children showed negative OSA score. According to our preliminary data, in the presence of unexplained EEG abnormalities and/or other neurological disorders/SDB an atypical or silent CD should also be taken into account. Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Gluten free diet adherence in coeliac disease. The role of psychological symptoms in bridging the intention-behaviour gap.

PubMed

Sainsbury, Kirby; Mullan, Barbara; Sharpe, Louise

2013-02-01

This study examined the potential role of psychological symptoms in limiting the translation of positive intention into strict gluten free diet (GFD) adherence in coeliac disease (CD) within a theory of planned behaviour (TPB) framework. It was hypothesised that participants with more symptomatic psychological profiles would exhibit poorer adherence, primarily in the context of positive intentions. Coeliac disease participants (N=390) completed online measures of gluten free diet adherence, psychological symptoms, coping behaviour, and TPB items. Intention and behaviour were moderately correlated, confirming the existence of the intention-behaviour gap. Psychological symptoms accounted for additional variance over and above TPB variables in GFD adherence but not intention. Participants who failed to act on their positive intentions displayed more psychological symptoms and greater reliance on maladaptive coping strategies than those with consistent intention-behaviour relationships (p<.01). The heightened incidence of psychological symptoms in CD has a small but significant negative impact on the ability to translate positive intentions into strict adherence. Directions for future research including interventions to improve GFD adherence are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Tests for Serum Transglutaminase and Endomysial Antibodies Do Not Detect Most Patients With Celiac Disease and Persistent Villous Atrophy on Gluten-free Diets: a Meta-analysis.

PubMed

Silvester, Jocelyn A; Kurada, Satya; Szwajcer, Andrea; Kelly, Ciarán P; Leffler, Daniel A; Duerksen, Donald R

2017-09-01

Tests to measure serum endomysial antibodies (EMA) and antibodies to tissue transglutaminase (tTG) were developed to screen for celiac disease in patients consuming gluten. However, they are commonly used to monitor patients on a gluten-free diet (GFD). We conducted a meta-analysis to assess the sensitivity and specificity of tTG IgA and EMA IgA assays in identifying patients with celiac disease who have persistent villous atrophy despite a GFD. We searched PUBMED, EMBASE, BIOSIS, SCOPUS, clinicaltrials.gov, Science Citation Index, and Cochrane Library databases through November 2016. Inclusion criteria were studies of subjects with biopsy-confirmed celiac disease, follow-up biopsies, and measurement of serum antibodies on a GFD, biopsy performed on subjects regardless of symptoms, or antibody test results. Our analysis excluded subjects with refractory celiac disease, undergoing gluten challenge, or consuming a prescribed oats-containing GFD. Tests were considered to have positive or negative findings based on manufacturer cut-off values. Villous atrophy was defined as a Marsh 3 lesion or villous height:crypt depth ratio below 3.0. We constructed forest plots to determine the sensitivity and specificity of detection for individual studies. For the meta-analysis, a bivariate random effects model was used to jointly model sensitivity and specificity. Our search identified 5408 unique citations. Following review of abstracts, 442 articles were reviewed in detail. Only 26 studies (6 of tTG assays, 15 of EMA assays, and 5 of tTG and EMA assays) met our inclusion criteria. The most common reason studies were excluded from our analysis was inability to cross-tabulate histologic and serologic findings. The serum assays identified patients with persistent villous atrophy with high levels of specificity: 0.83 for the tTG IgA assay (95% CI, 0.79-0.87) and 0.91 for the EMA IgA assay (95% CI, 0.87-0.94). However, they detected villous atrophy with low levels of sensitivity: 0.50 for the tTG IgA assay (95% CI, 0.41-0.60) and 0.45 for the EMA IgA assay (95% CI, 0.34-0.57). The tests had similar levels of performance in pediatric and adult patients. In a meta-analysis of patients with biopsy-confirmed celiac disease undergoing follow-up biopsy on a GFD, we found that tests for serum tTG IgA and EMA IgA levels had low sensitivity (below 50%) in detection of persistent villous atrophy. We need more-accurate non-invasive markers of mucosal damage in children and adults with celiac disease who are following a GFD. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

The Long-Term Consumption of Oats in Celiac Disease Patients Is Safe: A Large Cross-Sectional Study

PubMed Central

Aaltonen, Katri; Laurikka, Pilvi; Huhtala, Heini; Mäki, Markku; Kaukinen, Katri; Kurppa, Kalle

2017-01-01

A strict gluten-free diet (GFD) can be diversified by non-contaminated oats, but there is a shortage of long-term studies concerning its safety. We compared long-term treatment outcomes and factors associated with the introduction of oats between celiac patients on a GFD with or without oats. Eight hundred sixty-nine previously diagnosed celiac patients were interviewed. The validated Gastrointestinal Symptom Rating Scale (GSRS), Psychological General Well-Being (PGWB), and Short-Form 36 Health Survey (SF-36) questionnaires were used to assess symptoms and quality of life, serological tests were performed, and results of histology were confirmed from patient records. We found the median duration of GFD to be 10 years and 82% using oats. Factors predicting the consumption of oats were diagnosis after the year 2000, advice from a dietitian, detection by screening, and mild clinical presentation. Oat consumers and non-consumers did not differ in dietary adherence (96.5% vs. 97.4%, p = 0.746), the prevalence of symptoms (22.9% vs. 22.5%, p = 0.931), positivity for endomysial antibodies (8.8% vs. 6.0%, p = 0.237), histological recovery after one year (63.1% vs. 60.0%, p = 0.773), malignancy (4.8% vs. 3.3%, p = 0.420), osteoporosis/osteopenia (9.2% vs. 11.0%, p = 0.489), or fractures (26.9% vs. 27.9%, p = 0.791). The oat consumers had better SF-36 physical role limitations and general health scores. Based on our results, the long-term consumption of oats in celiac disease patients is safe and may improve quality of life. PMID:28617328

Maintenance of a gluten free diet in coeliac disease: The roles of self-regulation, habit, psychological resources, motivation, support, and goal priority.

PubMed

Sainsbury, Kirby; Halmos, Emma P; Knowles, Simon; Mullan, Barbara; Tye-Din, Jason A

2018-06-01

A strict lifelong gluten free diet (GFD) is the only treatment for coeliac disease (CD). Theory-based research has focused predominantly on initiation, rational, and motivational processes in predicting adherence. The aim of this study was to evaluate an expanded collection of theoretical constructs specifically relevant to the maintenance of behaviour change, in the understanding and prediction of GFD adherence. Respondents with CD (N = 5573) completed measures of GFD adherence, psychological distress, intentions, self-efficacy, and the maintenance-relevant constructs of self-regulation, habit, temptation and intentional and unintentional lapses (cognitive and behavioural consequences of lowered or fluctuating psychological resources and self-control), motivation, social and environmental support, and goal priority, conflict, and facilitation. Correlations and multiple regression were used to determine their influence on adherence, over and above intention and self-efficacy, and how relationships changed in the presence of distress. Better adherence was associated with greater self-regulation, habit, self-efficacy, priority, facilitation, and support; and lower psychological distress, conflict, and fewer self-control lapses (e.g., when busy/stressed). Autonomous and wellbeing-based, but not controlled motivations, were related to adherence. In the presence of distress, the influence of self-regulation and intentional lapses on adherence were increased, while temptation and unintentional lapses were decreased. The findings point to the importance of considering intentional, volitional, automatic, and emotional processes in the understanding and prediction of GFD adherence. Behaviour change interventions and psychological support are now needed so that theoretical knowledge can be translated into evidence-based care, including a role for psychologists within the multi-disciplinary treatment team. Copyright © 2018 Elsevier Ltd. All rights reserved.

Gastrointestinal symptoms in children with type 1 diabetes screened for celiac disease.

PubMed

Narula, Priya; Porter, Lesley; Langton, Josephine; Rao, Veena; Davies, Paul; Cummins, Carole; Kirk, Jeremy; Barrett, Timothy; Protheroe, Susan

2009-09-01

The association between celiac disease (CD) and type 1 diabetes mellitus (DM) is recognized. Most cases of CD in patients with DM are reported to be asymptomatic. The objectives of this study were to (1) compare and audit our practice with the published standards for screening for CD in children with DM, (2) characterize the children with DM and biopsy-confirmed CD, in terms of growth and gastrointestinal symptoms, and compare them with children with DM and negative celiac serology, and (3) document the effects of a gluten-free diet (GFD) after 1 year of gastrointestinal symptoms, growth, and insulin requirement. We performed a retrospective case-note review of 22 children with DM, positive celiac serology +/- biopsy-confirmed CD, and 50 children with DM and negative celiac serology. Twenty-two children (3.9% of the total diabetic population) had positive celiac serology on screening, with 17 (3%) having biopsy-confirmed CD. Ninety-four percent of the children had standardized celiac serology testing. At diagnosis of CD, 13 of the 17 biopsy-positive children (76.4%) had > or =1 gastrointestinal symptom. The frequency of gastrointestinal symptoms in negative celiac serology diabetic children was 6% (3 of 50) (P < .0005). Symptoms resolved in all children after introduction of a GFD. A significant improvement in weight SD score (P = .008) and BMI SD score (P = .02) was noted in those compliant with a GFD after 1 year. Children with DM and CD have a higher frequency of gastrointestinal symptoms than their diabetic peers with negative celiac serology and are not truly asymptomatic. Institution of a GFD has a positive effect on nutritional status and symptom resolution in the short-term.

Occurrence of serum antibodies against wheat alpha-amylase inhibitor 0.19 in celiac disease.

PubMed

Sánchez, D; Štěpánová-Honzová, S; Hospodková, M; Hoffmanová, I; Hábová, V; Halada, P; Tlaskalová-Hogenová, H; Tučková, L

2018-05-10

The alcohol-soluble fraction of wheat gluten (gliadins) induces in genetically susceptible individuals immunologically mediated celiac disease (CLD). However, gliadins and related cereal proteins are not unique foodstuff targets of CLD patients´ immune system. Non-gluten wheat alpha-amylase inhibitor 0.19 (AAI 0.19) has been found to be capable of activating human monocyte-derived dendritic cells and inducing pro-inflammatory status in intestinal mucosa of patients with celiac disease (CLD). The possible contribution of this reactivity in incomplete remission of CLD patients on a gluten-free diet (GFD) is matter of contention. In an attempt to characterize the antigenicity of AAI 0.19 in patients with active CLD, patients on a GFD and healthy controls we developed ELISA employing wheat recombinant AAI 0.19. Using this test we revealed a significant (P<0.001) elevation of IgA anti-AAI 0.19 antibodies (Ab) in patients with active CLD (12 out of 30 patients were seropositive) but also in CLD patients on a GFD (15/46), in contrast to healthy controls (2/59). Anti-AAI 0.19 IgG Ab levels were increased (P<0.001) only in patients with active CLD (14/30) in contrast to the controls. Interestingly, the levels of anti-AAI 0.19 IgG Ab were decreased in CLD patients on a GFD (P<0.001, 1/46) compared to the controls (1/59). Notably, 20 out of 30 of patients with active CLD were positive either for IgA or for IgG anti-AAI 0.19 Ab. Thus, the majority of CLD patients developed a robust IgA and IgG Ab response against AAI 0.19. These findings may contribute to the broadening of the knowledge about CLD pathogenesis.

Serum alkylresorcinols as biomarkers of dietary gluten exposure in coeliac disease.

PubMed

Choung, R S; Murray, J A; Marietta, E V; Van Dyke, C T; Ross, A B

2017-03-01

Therapy for coeliac disease (CD) mainly relies on following a gluten-free diet (GFD); however, a serum marker for gluten intake has yet to be established. To evaluate the utility of alkylresorcinol concentrations for detecting gluten intake in studies of human and mouse. Alkylresorcinol concentrations were compared among treated patients with coeliac disease (n = 34), untreated coeliac disease patients (n = 36) and controls (n = 33). Furthermore, seven additional coeliac disease patients whose serum samples were available at diagnosis and after GFD were evaluated. In mice studies, alkylresorcinol concentrations were compared in the serum of five mice fed a regular chow and 10 mice fed lifelong with a gluten-free chow. In addition, the effect of adding gluten on changes of alkylresorcinol concentrations was also evaluated. Total alkylresorcinol concentrations were significantly lower in treated with coeliac disease [median (IQR), 3 (2-8) nmol/L], compared to untreated patients [median (IQR), 32 (11-74) nmol/L; P < 0.0001] or healthy controls [median (IQR), 54 (23-112) nmol/L; P < 0.0001]. Moreover, alkylresorcinol concentrations in coeliac disease patients significantly decreased after introduction of a GFD (median, 34 nmol/L at diagnosis vs. 5 nmol/L after GFD, P = 0.02). In the mice, median (IQR) total alkylresorcinol concentrations in serum samples of mice fed lifelong with a gluten-free chow was 1.8 (1.6-2.3) nmol/L, which was further significantly increased to 16 (11-22) nmol/L after 8 days of feeding with the gluten-free chow that had gluten added to it. (P = 0.008). Serum alkylresorcinol concentrations could be a useful marker for dietary gluten in coeliac disease. © 2017 John Wiley & Sons Ltd.

Prospects of Developing Medicinal Therapeutic Strategies and Pharmaceutical Design for Effective Gluten Intolerance Treatment.

PubMed

Savvateeva, Lyudmila V; Zamyatnin, Andrey A

2016-01-01

Gluten intolerance is an umbrella term for gluten-related disorders manifested in health decline as a result of the gluten ingestion. The spectrum of gluten-related disorders includes three major groups: autoimmune (mainly, Celiac Disease, CD, also known as Celiac Sprue, dermatitis herpetiformis, or gluten-sensitive ataxia), allergic (wheat allergy, WA), and non-autoimmune non-allergic (non-celiac gluten sensitivity, NCGS, or gluten sensitivity, GS). Pathogenesis and diagnostics of CD and WA are well established in contrast to NCGS, pathogenicity of which is still poorly understood and its symptoms are frequently misdiagnosed since most of the NCGS cases are currently identified via the process of CD and WA exclusion. By now, the only one proven effective way for CD treatment is gluten-free diet (GFD). However, such an increasingly gaining popularity diet is apparently unsuitable for NCGS treatment because in this case gluten does not always arise as the major or exclusive culprit of gastrointestinal disorder. Furthermore, it is some physicians' opinion that GFD can be deficient in fiber and in other vitamins and minerals. In many cases, GFD is commercially inaccessible for the most needy, whereas strict adherence to the diet is complicated by the presence of small amounts of the gluten components in some foods and even medicines. In this regard, a number of research groups and pharmaceutical companies are extensively developing alternative medicinal approaches to GFD for effective gluten intolerance treatment. This review summarizes our understanding of gluten-related disorders, possible mechanisms of gluten intolerance activation and advantages of gluten intolerance medicinal treatment using novel drug candidates obtained with a proper pharmaceutical design.

Vitamin D and K status influences bone mineral density and bone accrual in children and adolescents with celiac disease.

PubMed

Mager, D R; Qiao, J; Turner, J

2012-04-01

Children with celiac disease (CD) are at risk for decreased bone mineral density (BMD) because of fat-soluble vitamin malabsorption, inflammation and/or under-nutrition. The study objective was to determine the interrelationships between vitamin K/D status and lifestyle variables on BMD in children and adolescents with CD at diagnosis and after 1 year on the gluten-free diet (GFD). Children and adolescents aged 3-17 years with biopsy proven CD at diagnosis and after 1 year on the GFD were studied. BMD was measured using dual-energy X-ray absorptiometry. Relevant variables included: anthropometrics, vitamin D/K status, diet, physical activity and sunlight exposure. Whole-body and lumbar-spine BMD-z scores were low (< or = -1) at diagnosis (10-20%) and after 1 year (30-32%) in the children, independent of symptoms. Whole-body BMD-z scores (-0.55±0.7 versus 0.72±1.5) and serum levels of 25(OH) vitamin D (90.3±24.8 versus 70.5±19.8 nmol/l) were significantly lower in older children (>10 years) when compared with younger children (< or =10 years) (P<0.001). Forty-three percent had suboptimal vitamin D status (25(OH)-vitamin D <75 nmol/l) at diagnosis; resolving in nearly half after 1 year on the GFD. Twenty-five percent had suboptimal vitamin K status at diagnosis; all resolved after 1 year. Children and adolescents with CD are at risk for suboptimal bone health at time of diagnosis and after 1 year on GFD; likely due in part to suboptimal vitamin D/K status. Therapeutic strategies aimed at optimizing vitamin K/D intake may contribute to improved BMD in children with CD.

Quality of Life in Patients with Gluten Neuropathy: A Case-Controlled Study.

PubMed

Zis, Panagiotis; Sarrigiannis, Ptolemaios Georgios; Rao, Dasappaiah Ganesh; Hadjivassiliou, Marios

2018-05-23

Gluten neuropathy (GN) is defined as an otherwise idiopathic peripheral neuropathy in the presence of serological evidence of gluten sensitivity (positive native gliadin antibodies and/or transglutaminase or endomysium antibodies). We aimed to compare the quality of life (QoL) of GN patients with that of control subjects and to investigate the effects of a gluten-free diet (GFD) on the QoL. All consecutive patients with GN attending a specialist neuropathy clinic were invited to participate. The Overall Neuropathy Limitations Scale (ONLS) was used to assess the severity of the neuropathy. The 36-Item Short Form Survey (SF-36) questionnaire was used to measure participants’ QoL. A strict GFD was defined as effectively being able to eliminate all circulating gluten sensitivity-related antibodies. Fifty-three patients with GN and 53 age- and gender-matched controls were recruited. Compared to controls, GN patients showed significantly worse scores in the physical functioning, role limitations due to physical health, energy/fatigue, and general health subdomains of the SF-36. After adjusting for age, gender, and disease severity, being on a strict GFD correlated with better SF-36 scores in the pain domain of the SF-36 (beta 0.317, p = 0.019) and in the overall health change domain of the SF-36 (beta 0.306, p = 0.017). In GN patients, physical dysfunctioning is the major determinant of poor QoL compared to controls. Routine checking of the elimination of gluten sensitivity-related antibodies that results from a strict GFD should be encouraged, as such elimination ameliorates the overall pain and health scores, indicating a better QoL.

Follow-up of coeliac disease with the novel one-hour 13C-sorbitol breath test versus the H2-sorbitol breath test.

PubMed

Tveito, Kari; Hetta, Anne Kristine; Askedal, Mia; Brunborg, Cathrine; Sandvik, Leiv; Løberg, Else Marit; Skar, Viggo

2011-07-01

We recently developed a (13)C-sorbitol breath test ((13)C-SBT) as an alternative to the H(2)-sorbitol breath test (H(2)-SBT) for coeliac disease. In this study we compared the diagnostic properties of the H(2)-SBT and the (13)C-SBT in follow-up of coeliac disease. Twenty-seven coeliac patients on a gluten-free diet (GFD) performed the breath tests. All had been tested before treatment in the initial study of the (13)C-SBT, in which 39 untreated coeliac patients, 40 patient controls, and 26 healthy volunteers participated. Five gram sorbitol and 100 mg (13)C-sorbitol were dissolved in 250 ml tap water and given orally. H(2), CH(4) and (13)CO(2) were measured in end-expiratory breath samples every 30 min for 4 h. Increased H(2) concentration ≥20 ppm from basal values was used as cut-off for the H(2)-SBT. Sixty minutes values were used as diagnostic index in the (13)C-SBT. (13)CO(2) levels at 60 min increased in 20/26 treated coeliac patients (77%) after GFD, but were significantly lower than in control groups. Out of 20 patients who had a positive H(2)-SBT before GFD, 12 had a negative H(2)-SBT after GFD. Peak H(2) concentrations were not correlated with (13)C-SBT results. The study confirms the sensitivity of a one-hour (13)C-SBT for small intestinal malabsorption. The (13)C-SBT has superior diagnostic properties compared with the H(2)-SBT in follow-up of coeliac disease.

AMERICAN COLLEGE OF GASTROENTEROLOGY CLINICAL GUIDELINE: DIAGNOSIS AND MANAGEMENT OF CELIAC DISEASE

PubMed Central

Rubio-Tapia, Alberto; Hill, Ivor D; Kelly, Ciarán P; Calderwood, Audrey H; Murray, Joseph A

2013-01-01

This guideline presents recommendations for the diagnosis and management of patients with celiac disease. Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet. There has been a substantial increase in the prevalence of celiac disease over the last 50 years and an increase in the rate of diagnosis in the last 10 years. Celiac disease can present with many symptoms, including typical gastrointestinal symptoms (e.g. diarrhea, steatorrhea, weight loss, bloating, flatulence, abdominal pain) and also non-gastrointestinal abnormalities (e.g. abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations). Indeed, many individuals with celiac disease may have no symptoms at all. Celiac disease is usually detected by serologic testing of celiac-specific antibodies. The diagnosis is confirmed by duodenal mucosal biopsies. Both serology and biopsy should be performed on a gluten-containing diet. The treatment for celiac disease is primarily a gluten-free diet (GFD), which requires significant patient education, motivation, and follow-up. Non-responsive celiac disease occurs frequently, particularly in those diagnosed in adulthood. Persistent or recurring symptoms should lead to a review of the patient’s original diagnosis to exclude alternative diagnoses, a review of the GFD to ensure there is no obvious gluten contamination, and serologic testing to confirm adherence with the GFD. In addition, evaluation for disorders associated with celiac disease that could cause persistent symptoms, such as microscopic colitis, pancreatic exocrine dysfunction, and complications of celiac disease, such as enteropathy-associated lymphoma or refractory celiac disease, should be entertained. Newer therapeutic modalities are being studied in clinical trials, but are not yet approved for use in practice. Given the incomplete response of many patients to a GFD free diet as well as the difficulty of adherence to the GFD over the long term, development of new effective therapies for symptom control and reversal of inflammation and organ damage are needed. The prevalence of celiac disease is increasing worldwide and many patients with celiac disease remain undiagnosed, highlighting the need for improved strategies in the future for the optimal detection of patients. PMID:23609613

ACG clinical guidelines: diagnosis and management of celiac disease.

PubMed

Rubio-Tapia, Alberto; Hill, Ivor D; Kelly, Ciarán P; Calderwood, Audrey H; Murray, Joseph A

2013-05-01

This guideline presents recommendations for the diagnosis and management of patients with celiac disease. Celiac disease is an immune-based reaction to dietary gluten (storage protein for wheat, barley, and rye) that primarily affects the small intestine in those with a genetic predisposition and resolves with exclusion of gluten from the diet. There has been a substantial increase in the prevalence of celiac disease over the last 50 years and an increase in the rate of diagnosis in the last 10 years. Celiac disease can present with many symptoms, including typical gastrointestinal symptoms (e.g., diarrhea, steatorrhea, weight loss, bloating, flatulence, abdominal pain) and also non-gastrointestinal abnormalities (e.g., abnormal liver function tests, iron deficiency anemia, bone disease, skin disorders, and many other protean manifestations). Indeed, many individuals with celiac disease may have no symptoms at all. Celiac disease is usually detected by serologic testing of celiac-specific antibodies. The diagnosis is confirmed by duodenal mucosal biopsies. Both serology and biopsy should be performed on a gluten-containing diet. The treatment for celiac disease is primarily a gluten-free diet (GFD), which requires significant patient education, motivation, and follow-up. Non-responsive celiac disease occurs frequently, particularly in those diagnosed in adulthood. Persistent or recurring symptoms should lead to a review of the patient's original diagnosis to exclude alternative diagnoses, a review of the GFD to ensure there is no obvious gluten contamination, and serologic testing to confirm adherence with the GFD. In addition, evaluation for disorders associated with celiac disease that could cause persistent symptoms, such as microscopic colitis, pancreatic exocrine dysfunction, and complications of celiac disease, such as enteropathy-associated lymphoma or refractory celiac disease, should be entertained. Newer therapeutic modalities are being studied in clinical trials, but are not yet approved for use in practice. Given the incomplete response of many patients to a GFD-free diet as well as the difficulty of adherence to the GFD over the long term, development of new effective therapies for symptom control and reversal of inflammation and organ damage are needed. The prevalence of celiac disease is increasing worldwide and many patients with celiac disease remain undiagnosed, highlighting the need for improved strategies in the future for the optimal detection of patients.

Treatment of celiac disease: from gluten-free diet to novel therapies.

PubMed

Francavilla, R; Cristofori, F; Stella, M; Borrelli, G; Naspi, G; Castellaneta, S

2014-10-01

Gluten-free diet (GFD) is the cornerstone treatment for celiac disease (CD). This diet excludes the protein gluten a protein forum in in grains such as wheat, barley, rye and triticale. Gluten causes small intestines inflammation in patients with CD and eating a GFD helps these patients in controlling signs and symptoms and prevent complications. Following a GFD may be frustrating, however, it is important to know that plenty of foods are naturally gluten-free and nowadays is relatively easy to find substitutes for gluten-containing foods. Certain grains, such as oats, are generally safe but can be contaminated with wheat during growing and processing stages of production. For this reason, it is generally recommended avoiding oats unless they are specifically labelled gluten-free. Other products that may contain gluten include food additives, such as malt flavouring, modified food starch and some supplement and/or vitamins that use gluten as a binding agent. Cross-contamination occurs when gluten-free foods come into contact with foods that contain gluten. It can happen during the manufacturing process or if the same equipment is used to make a variety of products. Cross-contamination can also occur at home if foods are prepared on common surfaces or with utensils that have not been cleaned after being used to prepare gluten-containing foods (using a toaster for gluten-free and regular bread). Although safe and effective, the GFD is not ideal: it is expensive, of limited nutritional value, and not readily available in many countries. Consequently, a need exists for novel, non-dietary therapies for celiac disease. Advances in understanding the immunopathogenesis of CD have suggested several types of therapeutic strategies alternative to the GFD. Some of these strategies attempt to decrease the immunogenicity of gluten-containing grains by manipulating the grain itself or by using oral enzymes to break down immunogenic peptides that normally remain intact during digestion. Other strategies focus on preventing the absorption of these peptides, preventing tissue transglutaminase from rendering gluten peptides more immunogenic, or inhibiting their binding to CD-specific antigen-presenting molecules. Strategies that limit T cell migration to the small intestine or that re-establish mucosal homeostasis and tolerance to gluten antigens are also being explored.

Rapid anti-transglutaminase assay and patient interview for monitoring dietary compliance in celiac disease.

PubMed

Zanchi, Chiara; Ventura, Alessandro; Martelossi, Stefano; Di Leo, Grazia; Di Toro, Nicola; Not, Tarcisio

2013-06-01

The anti-transglutaminase antibodies (anti-tTG) play an important role in monitoring the celiacs' gluten-free diet (GFD). The authors propose to use the rapid IgA anti-tTG assay based on a whole blood drop to evaluate the compliance to GFD at the clinical ambulatory setting. The rapid test results were compared with those of the conventional ELISA assay and with dietary compliance reported by patients' interview. The authors showed that anti-tTG rapid test is reliable and easy to perform in the ambulatory setting to evaluate dietary compliance. Moreover, they proved that celiacs' interview is more sensitive than serology in identifying patients who transgress.

Bumble-bee learning selects for both early and long flowering in food-deceptive plants

PubMed Central

Internicola, Antonina I.; Harder, Lawrence D.

2012-01-01

Most rewardless orchids engage in generalized food-deception, exhibiting floral traits typical of rewarding species and exploiting the instinctive foraging of pollinators. Generalized food-deceptive (GFD) orchids compete poorly with rewarding species for pollinator services, which may be overcome by flowering early in the growing season when relatively more pollinators are naive and fewer competing plant species are flowering, and/or flowering for extended periods to enhance the chance of pollinator visits. We tested these hypotheses by manipulating flowering time and duration in a natural population of Calypso bulbosa and quantifying pollinator visitation based on pollen removal. Both early and long flowering increased bumble-bee visitation compared with late and brief flowering, respectively. To identify the cause of reduced visitation during late flowering, we tested whether negative experience with C. bulbosa (avoidance learning) and positive experience with a rewarding species, Arctostaphylos uva-ursi, (associative learning) by captive bumble-bees could reduce C. bulbosa's competitiveness. Avoidance learning explained the higher visitation of early- compared with late-flowering C. bulbosa. The resulting pollinator-mediated selection for early flowering may commonly affect GFD orchids, explaining their tendency to flower earlier than rewarding orchids. For dissimilar deceptive and rewarding sympatric species, associative learning may additionally favour early flowering by GFD species. PMID:22090384

Administration of Inulin-Supplemented Gluten-Free Diet Modified Calcium Absorption and Caecal Microbiota in Rats in a Calcium-Dependent Manner.

PubMed

Krupa-Kozak, Urszula; Markiewicz, Lidia H; Lamparski, Grzegorz; Juśkiewicz, Jerzy

2017-07-06

In coeliac disease (CD), the risk of adverse calcium balance and reduced bone density is induced mainly by the disease, but also by a gluten-free diet (GFD), the only accepted CD therapy. Prebiotics through the beneficial impact on intestinal microbiota may stimulate calcium (Ca) absorption. In the present study, we hypothesised that the dietary inulin in GFD would influence positively the intestinal microbiota, and by that will stimulate the absorption of calcium (Ca), especially in the conditions of Ca malnutrition. In a six-weeks nutritional experiment on growing a significant ( p < 0.05) luminal acidification, decrease in ammonia concentration and stimulation of short chain fatty acids formation indicated inulin-mediated beneficial effects on the caecal microbiota. However, the effect of inulin on characteristics of intestinal microbiota and mineral utilization depended on the dietary Ca intake from GFDs. Inulin stimulated bifidobacteria, in particular B. animalis species, only if a recommended amount of Ca was provided. Most benefits to mineral utilization from inulin consumption were seen in rats fed Ca-restricted GFD where it increased the relative Ca absorption. Administration of inulin to a GFDs could be a promising dietary strategy for beneficial modulation of intestinal ecosystem and by that for the improvement the Ca absorption.

Bumble-bee learning selects for both early and long flowering in food-deceptive plants.

PubMed

Internicola, Antonina I; Harder, Lawrence D

2012-04-22

Most rewardless orchids engage in generalized food-deception, exhibiting floral traits typical of rewarding species and exploiting the instinctive foraging of pollinators. Generalized food-deceptive (GFD) orchids compete poorly with rewarding species for pollinator services, which may be overcome by flowering early in the growing season when relatively more pollinators are naive and fewer competing plant species are flowering, and/or flowering for extended periods to enhance the chance of pollinator visits. We tested these hypotheses by manipulating flowering time and duration in a natural population of Calypso bulbosa and quantifying pollinator visitation based on pollen removal. Both early and long flowering increased bumble-bee visitation compared with late and brief flowering, respectively. To identify the cause of reduced visitation during late flowering, we tested whether negative experience with C. bulbosa (avoidance learning) and positive experience with a rewarding species, Arctostaphylos uva-ursi, (associative learning) by captive bumble-bees could reduce C. bulbosa's competitiveness. Avoidance learning explained the higher visitation of early- compared with late-flowering C. bulbosa. The resulting pollinator-mediated selection for early flowering may commonly affect GFD orchids, explaining their tendency to flower earlier than rewarding orchids. For dissimilar deceptive and rewarding sympatric species, associative learning may additionally favour early flowering by GFD species.

From coeliac disease to noncoeliac gluten sensitivity; should everyone be gluten free?

PubMed

Aziz, Imran; Dwivedi, Krit; Sanders, David S

2016-03-01

Gluten-free diets (GFDs) have seen a disproportional rise in use and popularity relative to the prevalence of established gluten-related disorders such as coeliac disease or immunoglobulin E wheat allergy. This entity has been termed noncoeliac gluten sensitivity (NCGS). This review aims to provide a current perspective on the emerging evidence for and against NCGS, along with the associated need for a GFD. NCGS and the benefits of a GFD are reported amongst patients with irritable bowel syndrome, inflammatory bowel disease, and nonintestinal disorders such as neuropsychiatric diseases and fibromyalgia. However, no reliable biomarkers currently exist to diagnose NCGS and hence confirmatory testing can only be performed using double-blind placebo-controlled gluten-based challenges. Unfortunately, such tests are not available in routine clinical practice. Furthermore, recent novel studies have highlighted the role of other gluten-based components in contributing to the symptoms of self-reported NCGS. These include fermentable oligo, di, mono-saccharides and polyols, amylase trypsin inhibitors, and wheat germ agglutinins. Therefore, NCGS is now seen as a spectrum encompassing several biological responses and terms such as 'noncoeliac wheat sensitivity' have been suggested as a wider label to define the condition. Despite the rising use of a GFD further studies are required to clearly establish the extent and exclusivity of gluten in NCGS.

Long-term response to gluten-free diet as evidence for non-celiac wheat sensitivity in one third of patients with diarrhea-dominant and mixed-type irritable bowel syndrome.

PubMed

Barmeyer, Christian; Schumann, Michael; Meyer, Tim; Zielinski, Christina; Zuberbier, Torsten; Siegmund, Britta; Schulzke, Jörg-Dieter; Daum, Severin; Ullrich, Reiner

2017-01-01

Irritable bowel syndrome (IBS) is common but therapies are unsatisfactory. Food is often suspected as cause by patients, but diagnostic procedures, apart from allergy testing, are limited. Based on the hypothesis of non-celiac wheat sensitivity (WS) in a subgroup of IBS patients, we tested the long-term response to a gluten-free diet (GFD) and investigated HLA-DQ2 or -DQ8 expression as a diagnostic marker for WS in diarrhea-dominant (IBS-D) and mixed-type IBS (IBS-M). The response to a GFD served as reference test for WS and HLA-DQ2/8 expression was determined as index test. Patients were classified as responders if they reported complete or considerable relief of IBS symptoms on at least 75 % of weeks over a 4-month period of gluten-free diet. Established questionnaires (IBS-Quality of Life (IBS-QoL), IBS Symptom Severity Scale (IBS-SSS), European Quality of Life-5 Dimensions (EQ-5D)) were used for secondary outcome measures. Thirty-five patients finished the study. Of these, 12 (34 %) were responders and classified as having WS (95 % CI 21-51 %). HLA-DQ2/8 expression had a specificity of 52 % (95 % CI 33-71 %) and sensitivity of 25 % (95 % CI 8-54 %) for WS. Responders showed improvement in quality of life and symptom scores. At 1-year follow-up, all responders and 55 % of non-responders were still on GFD and reported symptom relief. Using strict criteria as recommended for IBS studies, about one third of patients with IBS-D or IBS-M are wheat sensitive, with a similar proportion in both IBS types. Expression of HLA-DQ2/8 is not useful as diagnostic marker for WS. Long-term adherence to a GFD is high and can sustain symptomatic improvement.

Health-related quality of life in children with celiac disease: a study based on the Critical Incident Technique.

PubMed

Biagetti, Chiara; Naspi, Giulia; Catassi, Carlo

2013-11-12

Celiac Disease (CD) is a chronic autoimmune disease triggered by dietary gluten. Gluten avoidance, which is the only available treatment for CD, could impact on quality of life of children with CD. We present the results of a qualitative study on the emotional impact of gluten free diet (GFD) on the everyday life of children affected with CD. We investigated 76 celiac patients aged 2-18 years (average age: 9.5 years). By using the Critical Incident Technique (CIT), we defined emotions related to difficulties and awkward situations experienced by the patients. Written answers to open-ended questions from either children (older than 8 years) and parents (children younger than 8 years) were analyzed qualitatively. We found 80 dilemmas experienced in three different arenas (food situations at school, meals at home, meals outside) and characterized lived experiences of children with CD in everyday life (specific emotions, difficulties in relationships and in management of daily life). Children with CD experience strong emotions related to the GFD, permeating several aspects of everyday life. These dilemmas may be missed by a conventional, questionnaire-based approach to the psycho-social consequences of CD treatment.

Intakes of nutrients in Italian children with celiac disease and the role of commercially available gluten-free products.

PubMed

Zuccotti, G; Fabiano, V; Dilillo, D; Picca, M; Cravidi, C; Brambilla, P

2013-10-01

Celiac disease (CD) is a chronic gluten-sensitive enteropathy. Life-long gluten-free diet (GFD) is the only therapeutic option; however, it may contribute to the consumption of an unbalanced diet. The present study aimed to evaluate the dietary intake of CD affected children on a GFD and compare it with non-celiac children and with Italian nutritional intakes recommendations, as well as evaluate the contribution of commercially available gluten-free products (GFPs). Eighteen celiac children, median age 7.6 years, median GFD duration 4.2 years, and 18 non-celiac controls, were enrolled in a cross-sectional age-matched study. Dietary intakes of both groups were collected using a food frequency questionnaire and a 24-hour dietary recall. Nutritional intakes were compared between the group and controls and with Italian dietary reference values. The contribution of GFPs to energy and macronutrient intakes was evaluated. Median energy intake was significantly higher in CD patients than in controls (8961.8 and 5761.0 kJ day(-1); P < 0.001). CD subjects showed higher carbohydrate intakes and lower fat intakes compared to controls. Protein-derived energy did not differ. By contrast to control subjects, energy derived from carbohydrate intakes in CD children met the Italian recommendations. Both children groups showed higher protein and fat intakes than recommended in Italy. GFPs consumption accounted for 36.3% of daily total energy intake. Intakes of simple sugars, fats and protein exceeded the National recommendations for health. Children with CD had significantly higher energy intakes than controls, although body mass index was comparable across the groups. Lack of nutritional information for GFPs prevented complete dietary analysis of subfractions of fat and micronutrient intakes. This aspect need to be addressed if studies in this field are to be meaningful in the future. © 2012 The Authors Journal of Human Nutrition and Dietetics © 2012 The British Dietetic Association Ltd.

A comprehensive questionnaire for the assessment of health-related quality of life in coeliac disease (CDQL).

PubMed

Skjerning, Halfdan; Hourihane, Jonathan; Husby, Steffen; DunnGalvin, Audrey

2017-10-01

Coeliac disease (CD) is a chronic immune-mediated disease in genetically susceptible individuals, induced by ingested gluten. The treatment for CD is a lifelong gluten-free diet (GFD). The GFD involves restrictions in diet that may impact on a person's Health-Related Quality of Life (HRQoL). The aim of the present study was to develop the Coeliac Disease Quality of Life questionnaire (CDQL): a comprehensive CD-specific HRQoL measure that can be completed by children, adolescents, and adults or by proxy. The questionnaire was developed in three phases. In phase 1, focus group methods and qualitative analysis of verbatim transcripts generated CD-specific items for a prototype instrument to sensitively captured patient concerns. In phase 2, CD patients completed the prototype CDQL. The questionnaire was refined through analysis of data and cognitive interviewing. In phase 3, the final version of the CDQL was answered by Danish respondents. The psychometric properties of the CDQL were assessed, and the HRQoL data were analyzed. The CDQL was completed by 422 respondents. The CDQL has 12 patient background items, 2 generic HRQoL items, and 30 CD-specific HRQoL item. The CD-specific HRQoL items were distributed on eight scales with acceptable to excellent reliability. Comprehensiveness and understandability was shown by feedback from cognitive interviewing from children, adolescents, and adults. Content validity was ensured by involving patients and clinicians in the development of the questionnaire. Sensitivity of the questionnaire was demonstrated in differences found between children, adolescents, and adult's perception of their HRQoL in relation to having CD. The CDQL comprehensively measures HRQoL in CD, and is psychometrically robust. The questionnaire may prove useful in tracking HRQoL in CD across age groups.

Serum transglutaminase 3 antibodies correlate with age at celiac disease diagnosis.

PubMed

Salmi, Teea T; Kurppa, Kalle; Hervonen, Kaisa; Laurila, Kaija; Collin, Pekka; Huhtala, Heini; Saavalainen, Päivi; Sievänen, Harri; Reunala, Timo; Kaukinen, Katri

2016-06-01

Transglutaminase (TG)2 is the autoantigen in celiac disease, but also TG3 antibodies have been detected in the serum of celiac disease patients. To investigate the correlations between serum TG3 antibodies and clinical and histological manifestations of celiac disease and to assess gluten-dependency of TG3 antibodies. Correlations between serum TG3 antibody levels measured from 119 adults and children with untreated coeliac disease and the demographic data, clinical symptoms, celiac antibodies, histological data and results of laboratory tests and bone mineral densities were tested. TG3 antibodies were reinvestigated in 97 celiac disease patients after 12 months on a gluten-free diet (GFD). TG3 antibody titers were shown to correlate with the age at celiac disease diagnosis. Further, negative correlation with TG3 antibodies and intestinal γδ+ cells at diagnosis and on GFD was detected. Correlations were not detected with the clinical manifestation of celiac disease, TG2 or endomysial autoantibodies, laboratory values, severity of mucosal villous atrophy, associated diseases or complications. TG3 antibody titers decreased on GFD in 56% of the TG3 antibody positive patients. Serum TG3 antibody positivity in celiac disease increases as the diagnostic age rises. TG3 antibodies did not show similar gluten-dependency as TG2 antibodies. Copyright © 2016 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Gastroesophageal reflux symptoms in patients with celiac disease and the effects of a gluten-free diet.

PubMed

Nachman, Fabio; Vázquez, Horacio; González, Andrea; Andrenacci, Paola; Compagni, Liliana; Reyes, Hugo; Sugai, Emilia; Moreno, María Laura; Smecuol, Edgardo; Hwang, Hui Jer; Sánchez, Inés Pinto; Mauriño, Eduardo; Bai, Julio César

2011-03-01

Celiac disease (CD) patients often complain of symptoms consistent with gastroesophageal reflux disease (GERD). We aimed to assess the prevalence of GERD symptoms at diagnosis and to determine the impact of the gluten-free diet (GFD). We evaluated 133 adult CD patients at diagnosis and 70 healthy controls. Fifty-three patients completed questionnaires every 3 months during the first year and more than 4 years after diagnosis. GERD symptoms were evaluated using a subdimension of the Gastrointestinal Symptoms Rating Scale for heartburn and regurgitation domains. At diagnosis, celiac patients had a significantly higher reflux symptom mean score than healthy controls (P < .001). At baseline, 30.1% of CD patients had moderate to severe GERD (score >3) compared with 5.7% of controls (P < .01). Moderate to severe symptoms were significantly associated with the classical clinical presentation of CD (35.0%) compared with atypical/silent cases (15.2%; P < .03). A rapid improvement was evidenced at 3 months after initial treatment with a GFD (P < .0001) with reflux scores comparable to healthy controls from this time point onward. GERD symptoms are common in classically symptomatic untreated CD patients. The GFD is associated with a rapid and persistent improvement in reflux symptoms that resembles the healthy population. Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.

Geophysical fluid dynamics: whence, whither and why?

PubMed Central

2016-01-01

This article discusses the role of geophysical fluid dynamics (GFD) in understanding the natural environment, and in particular the dynamics of atmospheres and oceans on Earth and elsewhere. GFD, as usually understood, is a branch of the geosciences that deals with fluid dynamics and that, by tradition, seeks to extract the bare essence of a phenomenon, omitting detail where possible. The geosciences in general deal with complex interacting systems and in some ways resemble condensed matter physics or aspects of biology, where we seek explanations of phenomena at a higher level than simply directly calculating the interactions of all the constituent parts. That is, we try to develop theories or make simple models of the behaviour of the system as a whole. However, these days in many geophysical systems of interest, we can also obtain information for how the system behaves by almost direct numerical simulation from the governing equations. The numerical model itself then explicitly predicts the emergent phenomena—the Gulf Stream, for example—something that is still usually impossible in biology or condensed matter physics. Such simulations, as manifested, for example, in complicated general circulation models, have in some ways been extremely successful and one may reasonably now ask whether understanding a complex geophysical system is necessary for predicting it. In what follows we discuss such issues and the roles that GFD has played in the past and will play in the future. PMID:27616918

AP-Cloud: Adaptive particle-in-cloud method for optimal solutions to Vlasov–Poisson equation

DOE PAGES

Wang, Xingyu; Samulyak, Roman; Jiao, Xiangmin; ...

2016-04-19

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Here, simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

AP-Cloud: Adaptive Particle-in-Cloud method for optimal solutions to Vlasov–Poisson equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xingyu; Samulyak, Roman, E-mail: roman.samulyak@stonybrook.edu; Computational Science Initiative, Brookhaven National Laboratory, Upton, NY 11973

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

AP-Cloud: Adaptive particle-in-cloud method for optimal solutions to Vlasov–Poisson equation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Xingyu; Samulyak, Roman; Jiao, Xiangmin

We propose a new adaptive Particle-in-Cloud (AP-Cloud) method for obtaining optimal numerical solutions to the Vlasov–Poisson equation. Unlike the traditional particle-in-cell (PIC) method, which is commonly used for solving this problem, the AP-Cloud adaptively selects computational nodes or particles to deliver higher accuracy and efficiency when the particle distribution is highly non-uniform. Unlike other adaptive techniques for PIC, our method balances the errors in PDE discretization and Monte Carlo integration, and discretizes the differential operators using a generalized finite difference (GFD) method based on a weighted least square formulation. As a result, AP-Cloud is independent of the geometric shapes ofmore » computational domains and is free of artificial parameters. Efficient and robust implementation is achieved through an octree data structure with 2:1 balance. We analyze the accuracy and convergence order of AP-Cloud theoretically, and verify the method using an electrostatic problem of a particle beam with halo. Here, simulation results show that the AP-Cloud method is substantially more accurate and faster than the traditional PIC, and it is free of artificial forces that are typical for some adaptive PIC techniques.« less

Evidence of Avian and Possum Fecal Contamination in Rainwater Tanks as Determined by Microbial Source Tracking Approaches

PubMed Central

Hamilton, K. A.; Gyawali, P.; Toze, S.; Haas, C. N.

2016-01-01

ABSTRACT Avian and possum fecal droppings may negatively impact roof-harvested rainwater (RHRW) water quality due to the presence of zoonotic pathogens. This study was aimed at evaluating the performance characteristics of a possum feces-associated (PSM) marker by screening 210 fecal and wastewater samples from possums (n = 20) and a range of nonpossum hosts (n = 190) in Southeast Queensland, Australia. The host sensitivity and specificity of the PSM marker were 0.90 and 0.95 (maximum value, 1.00), respectively. The mean concentrations of the GFD marker in possum fecal DNA samples (8.8 × 107 gene copies per g of feces) were two orders of magnitude higher than those in the nonpossum fecal DNA samples (5.0 × 105 gene copies per g of feces). The host sensitivity, specificity, and concentrations of the avian feces-associated GFD marker were reported in our recent study (W. Ahmed, V. J. Harwood, K. Nguyen, S. Young, K. Hamilton, and S. Toze, Water Res 88:613–622, 2016, http://dx.doi.org/10.1016/j.watres.2015.10.050). The utility of the GFD and PSM markers was evaluated by testing a large number of tank water samples (n = 134) from the Brisbane and Currumbin areas. GFD and PSM markers were detected in 39 of 134 (29%) and 11 of 134 (8%) tank water samples, respectively. The GFD marker concentrations in PCR-positive samples ranged from 3.7 × 102 to 8.5 × 105 gene copies per liter, whereas the concentrations of the PSM marker ranged from 2.0 × 103 to 6.8 × 103 gene copies per liter of water. The results of this study suggest the presence of fecal contamination in tank water samples from avian and possum hosts. This study has established an association between the degradation of microbial tank water quality and avian and possum feces. Based on the results, we recommend disinfection of tank water, especially for tanks designated for potable use. IMPORTANCE The use of roof-harvested rainwater (RHRW) for domestic purposes is a globally accepted practice. The presence of pathogens in rainwater tanks has been reported by several studies, supporting the necessity for the management of potential health risks. The sources of fecal pollution in rainwater tanks are unknown. However, the application of microbial source tracking (MST) markers has the potential to identify the sources of fecal contamination in a rainwater tank. In this study, we provide evidence of avian and possum fecal contamination in tank water samples using molecular markers. This study established a potential link between the degradation of the microbial quality of tank water and avian and possum feces. PMID:27208100

The Effect of Depressive Symptoms on the Association between Gluten-Free Diet Adherence and Symptoms in Celiac Disease: Analysis of a Patient Powered Research Network.

PubMed

Joelson, Andrew M; Geller, Marilyn G; Zylberberg, Haley M; Green, Peter H R; Lebwohl, Benjamin

2018-04-26

The prevalence of depression in celiac disease (CD) is high, and patients are often burdened socially and financially by a gluten-free diet. However, the relationship between depression, somatic symptoms and dietary adherence in CD is complex and poorly understood. We used a patient powered research network (iCureCeliac ® ) to explore the effect that depression has on patients' symptomatic response to a gluten-free diet (GFD). We identified patients with biopsy-diagnosed celiac disease who answered questions pertaining to symptoms (Celiac Symptom Index (CSI)), GFD adherence (Celiac Dietary Adherence Test (CDAT)), and a 5-point, scaled question regarding depressive symptoms relating to patients' celiac disease. We then measured the correlation between symptoms and adherence (CSI vs. CDAT) in patients with depression versus those without depression. We also tested for interaction of depression with regard to the association with symptoms using a multiple linear regression model. Among 519 patients, 86% were female and the mean age was 40.9 years. 46% of patients indicated that they felt "somewhat," "quite a bit," or "very much" depressed because of their disorder. There was a moderate correlation between worsened celiac symptoms and poorer GFD adherence ( r = 0.6, p < 0.0001). In those with a positive depression screen, there was a moderate correlation between worsening symptoms and worsening dietary adherence ( r = 0.5, p < 0.0001) whereas in those without depression, the correlation was stronger ( r = 0.64, p < 0.0001). We performed a linear regression analysis, which suggests that the relationship between CSI and CDAT is modified by depression. In patients with depressive symptoms related to their disorder, correlation between adherence and symptoms was weaker than those without depressive symptoms. This finding was confirmed with a linear regression analysis, showing that depressive symptoms may modify the effect of a GFD on celiac symptoms. Depressive symptoms may therefore mask the relationship between inadvertent gluten exposure and symptoms. Additional longitudinal and prospective studies are needed to further explore this potentially important finding.

Ex-vivo whole blood secretion of interferon (IFN)-γ and IFN-γ-inducible protein-10 measured by enzyme-linked immunosorbent assay are as sensitive as IFN-γ enzyme-linked immunospot for the detection of gluten-reactive T cells in human leucocyte antigen (HLA)-DQ2·5+-associated coeliac disease

PubMed Central

Ontiveros, N; Tye-Din, J A; Hardy, M Y; Anderson, R P

2014-01-01

T cell cytokine release assays are used to diagnose infectious diseases, but not autoimmune or allergic disease. Coeliac disease (CD) is a common T cell-mediated disease diagnosed by the presence of gluten-dependent intestinal inflammation and serology. Many patients cannot be diagnosed with CD because they reduce dietary gluten before medical workup. Oral gluten challenge in CD patients treated with gluten-free diet (GFD) mobilizes gluten-reactive T cells measurable by interferon (IFN)-γ enzyme-linked immunospot (ELISPOT) or major histocompatibility complex (MHC) class II tetramers. Immunodominant peptides are quite consistent in the 90% of patients who possess HLA-DQ2·5. We aimed to develop whole blood assays to detect gluten-specific T cells. Blood was collected before and after gluten challenge from GFD donors confirmed to have CD (n = 27, all HLA-DQ2·5+), GFD donors confirmed not to have CD (n = 6 HLA-DQ2·5+, 11 HLA-DQ2·5−) and donors with CD not following GFD (n = 4, all HLA-DQ2·5+). Plasma IFN-γ and IFN-γ inducible protein-10 (IP-10) were measured by enzyme-linked immunosorbent assay (ELISA) after whole blood incubation with peptides or gliadin, and correlated with IFN-γ ELISPOT. No T cell assay could distinguish between CD patients and controls prior to gluten challenge, but after gluten challenge the whole blood IFN-γ ELISA and the ELISPOT were both 85% sensitive and 100% specific for HLA-DQ2·5+ CD patients; the whole blood IP-10 ELISA was 94% sensitive and 100% specific. We conclude that whole blood cytokine release assays are sensitive and specific for detection of gluten-reactive T cells in CD; further clinical studies addressing the utility of these tests in patients with an uncertain diagnosis of CD is warranted. PMID:24192268

Gluten-Free Flours from Different Raw Materials as the Source of Vitamin B1, B2, B3 and B6.

PubMed

Rybicka, Iga; Gliszczynska-Swiglo, Anna

2017-01-01

Gluten-free (GF) products are those with a natural absence or acceptable level (<20 mg/kg) of gluten. They should be a part of a diet for people with gluten-related disorders, like celiac disease. Recently the popularity of a gluten-free diet (GFD) has risen extremely, because a lot of healthy individuals exclude gluten from their menus. According to the literature data on nutritional deficiencies in the GFD, this trend seems to be risky. This paper describes the nutritional value of 14 flours from different GF raw materials from the aspect of B-group vitamin content (B 1 , B 2 , B 3 , B 6 ). Vitamins were determined using high performance liquid chromatography after enzymatic and acid hydrolysis of the samples. The vitamin contents significantly differed in the analysed flours. The content (in 100 g of the product) of vitamin B 1 ranged from 0.01 mg (amaranth flour) to 0.60 mg (teff flour), vitamin B 2 from 0.03 mg (GF flour with oats) to 0.22 mg (buckwheat flour), vitamin B 3 from below 0.01 mg (amaranth flour) to 6.02 mg (millet flour), and vitamin B 6 from 0.03 mg (acorn flour) to 0.69 mg (amaranth flour). The content of vitamins in the analysed GF flours was also compared to gluten-containing flours. Obtained results indicate that flours from teff, millet, chestnut, buckwheat, and amaranth are better sources of certain B-group vitamins than flours from corn, rice, and some flours with gluten.

Socioeconomic Risk Factors for Celiac Disease Burden and Symptoms.

PubMed

Oza, Sveta S; Akbari, Mona; Kelly, Ciarán P; Hansen, Joshua; Theethira, Thimmaiah; Tariq, Sohaib; Dennis, Melinda; Leffler, Daniel A

2016-04-01

Celiac disease (CD) affects approximately 1% of the population and negatively affects aspects of life including physical and social function. The relationship between socioeconomic (SE) factors, symptom severity, and perceived burden of living with CD is not well understood. The objective of this study was to assess the relationships between income, symptoms, and perceived burden of CD. In this survey study conducted at a tertiary care center, 773 patients 18 years of age or more with biopsy confirmed CD were eligible to participate. Patients completed a survey with information on SE data, the validated Celiac Symptom Index (CSI), and visual analog scales (VAS) assessing overall health, CD-related health, difficulty in following a gluten-free diet (GFD), and importance of following a GFD. Three hundred forty one patients completed the survey. Higher income predicted better overall health, better CD related health, and fewer symptoms. In the logistic regression model, low income was associated with greater CD symptoms (odds ratio=6.04, P=0.002). Other factors associated with greater symptoms were younger age, poor overall health state, and more physician visits. Factors associated with increased burden of CD included hospitalizations, more symptoms, poor overall health state, and burden of following a GFD. Patients with lower incomes have worse CD-related health and greater symptoms. Those with low income had 6 times the odds of greater symptoms compared with those with high income. Our data suggest that income is associated with perceived overall health, CD-related health, and CD symptoms.

Coeliac disease and the gluten-free diet: a review of the burdens; factors associated with adherence and impact on health-related quality of life, with specific focus on adolescence.

PubMed

White, L E; Bannerman, E; Gillett, P M

2016-10-01

Adherence and non-adherence to a gluten-free diet (GFD) may impact negatively on health-related quality of life (HRQoL). Understanding the factors that influence compliance could help inform management and also guide support. With a particular focus on adolescence, this narrative review critiques current literature on the burdens associated with following a GFD and the factors associated with adherence. Studies highlight a variety of burdens faced by individuals with coeliac disease, including the cost, access and availability of gluten-free (GF) foods, as well as the dilemmas experienced when eating out, travelling and socialising with friends. A number of studies report that adolescents face stigmatisation and feel isolated in social situations and at school. Additional burdens that are highlighted are a lack of knowledge regarding CD and GFD difficulties in interpreting food labels, as well as dissatisfaction with the organoleptic properties of GF foods. Factors associated with poor adherence in adolescence include older age, an absence of immediate symptoms, difficulties eating out and poor palatability of GF foods. Conversely, better emotional support and stronger organisation skills have been associated with superior adherence. Significant associations have been reported between HRQoL measures and adherence, although the findings are inconsistent. Limitations in research methodologies exist and data are restricted to just a few countries. Further research specific to adolescence is required to identify independent predictors of adherence. © 2016 The British Dietetic Association Ltd.

Differences in gluten metabolism among healthy volunteers, coeliac disease patients and first-degree relatives.

PubMed

Caminero, Alberto; Nistal, Esther; Herrán, Alexandra R; Pérez-Andrés, Jénifer; Ferrero, Miguel A; Vaquero Ayala, Luis; Vivas, Santiago; Ruiz de Morales, José M G; Albillos, Silvia M; Casqueiro, Francisco Javier

2015-10-28

Coeliac disease (CD) is an immune-mediated enteropathy resulting from exposure to gluten in genetically predisposed individuals. Gluten proteins are partially digested by human proteases generating immunogenic peptides that cause inflammation in patients carrying HLA-DQ2 and DQ8 genes. Although intestinal dysbiosis has been associated with patients with CD, bacterial metabolism of gluten has not been studied in depth thus far. The aim of this study was to analyse the metabolic activity of intestinal bacteria associated with gluten intake in healthy individuals, CD patients and first-degree relatives of CD patients. Faecal samples belonging to twenty-two untreated CD patients, twenty treated CD patients, sixteen healthy volunteers on normal diet, eleven healthy volunteers on gluten-free diet (GFD), seventy-one relatives of CD patients on normal diet and sixty-nine relatives on GFD were tested for several proteolytic activities, cultivable bacteria involved in gluten metabolism, SCFA and the amount of gluten in faeces. We detected faecal peptidasic activity against the gluten-derived peptide 33-mer. CD patients showed differences in faecal glutenasic activity (FGA), faecal tryptic activity (FTA), SCFA and faecal gluten content with respect to healthy volunteers. Alterations in specific bacterial groups metabolising gluten such as Clostridium or Lactobacillus were reported in CD patients. Relatives showed similar parameters to CD patients (SCFA) and healthy volunteers (FTA and FGA). Our data support the fact that commensal microbial activity is an important factor in the metabolism of gluten proteins and that this activity is altered in CD patients.

Probiotics and the Microbiome in Celiac Disease: A Randomised Controlled Trial

PubMed Central

Myers, Stephen P.; Rolfe, Margaret

2016-01-01

Background. There is limited research investigating the composition of the gastrointestinal microbiota in individuals with celiac disease (CoeD) reporting only partial symptom improvement despite adherence to a strict gluten-free diet (GFD). The aim of this research was to determine if the gastrointestinal microbiota could be altered by probiotic bacteria and provide a potential new therapy for this subgroup. Methods. A multicentre RCT was conducted between January and August 2011 in Australia. Participants included 45 people with CoeD reporting only partial symptom improvement despite adherence to a strict GFD for a minimum of 12 months. Participants took 5 g of VSL#™ probiotic formulation (n = 23) or 5 g placebo (n = 22) orally twice daily for 12 weeks. The main outcome measured was the efficacy of the probiotic formula in altering faecal microbiota counts between baseline and week 12. Safety was determined by safety blood and monitoring adverse events. Results. SPSS™ multivariate repeated measures analysis (95th confidence level) revealed no statistically significant changes between the groups in the faecal microbiota counts or blood safety measures over the course of the study. Conclusion. The probiotic formula when taken orally over the 12-week period did not significantly alter the microbiota measured in this population. The trial was registered with Australian and New Zealand Clinical Trials Register ACTRN12610000630011. PMID:27525027

Commercial Hype Versus Reality: Our Current Scientific Understanding of Gluten and Athletic Performance.

PubMed

Lis, Dana M; Fell, James W; Ahuja, Kiran D K; Kitic, Cecilia M; Stellingwerff, Trent

2016-01-01

Recent explosion in the prevalence of gluten-free athletes, exacerbated by unsubstantiated commercial health claims, has led to some professional athletes touting gluten-free diet as the secret to their success. Forty-one percent of athletes report adhering to a gluten-free diet (GFD), which is four-fold higher than the population-based clinical requirements. Many nonceliac athletes believe that gluten avoidance improves gastrointestinal well-being, reduces inflammation, and provides an ergogenic edge, despite the fact that limited data yet exist to support any of these benefits. There are several plausible associations between endurance-based exercise and gastrointestinal permeability whereby a GFD may be beneficial. However, the implications of confounding factors, including the risks of unnecessary dietary restriction, financial burden, food availability, psychosocial implications, alterations in short-chain carbohydrates (fermentable oligosaccharides, disaccharides, monosaccharides, and polyols), and other wheat constituents emphasize the need for further evaluation.

Celiac disease and obesity: need for nutritional follow-up after diagnosis.

PubMed

Valletta, E; Fornaro, M; Cipolli, M; Conte, S; Bissolo, F; Danchielli, C

2010-11-01

More than 20 years of serological approach to diagnosis of celiac disease (CD) has deeply changed the classical clinical presentation of the disease, and some reports indicate that CD and obesity can coexist in both childhood and adolescence. We reviewed clinical records of 149 children with CD followed in our institution between 1991 and 2007, considering weight, height and body mass index (BMI), both at diagnosis and after at least 12 months of gluten-free diet (GFD). In all, 11% of patients had BMI z-score >+1 and 3% were obese (z-score >+2) at presentation. In our population, there was a significant (P=0.008) increase in BMI z-score after GFD and the percentage of overweight (z-score >+1) subjects almost doubled (11 vs 21%, P=0.03). Our data suggest the need for a careful follow-up of nutritional status after diagnosis of CD, especially addressing those who are already overweight at presentation.

Celiac disease in normal-weight and overweight children: clinical features and growth outcomes following a gluten-free diet.

PubMed

Reilly, Norelle Rizkalla; Aguilar, Kathleen; Hassid, Benjamin G; Cheng, Jianfeng; Defelice, Amy R; Kazlow, Philip; Bhagat, Govind; Green, Peter H

2011-11-01

There are few data on pediatric celiac disease in the United States. The aim of our study was to describe the presentation of celiac disease among children with a normal and an elevated body mass index (BMI) for age, and to study their BMI changes following a gluten-free diet (GFD). One hundred forty-two children (age 13 months-19 years) with biopsy-proven celiac disease, contained in a registry of patients studied at our center from 2000 to 2008, had follow-up growth data available. Patients' height, weight, and BMI were converted to z scores for age and grouped by BMI as underweight, normal, and overweight. Compliance was confirmed using results of serological assays, and data of noncompliant patients were analyzed separately. Data were analyzed during the observation period and were expressed as change in height, weight, and BMI z score per month of dietary treatment. Nearly 19% of patients had an elevated BMI at diagnosis (12.6% overweight, 6% obese) and 74.5% presented with a normal BMI. The mean duration of follow-up was 35.6 months. Seventy-five percent of patients with an elevated BMI at diagnosis decreased their BMI z scores significantly after adherence to a GFD, normalizing it in 44% of cases. Of patients with a normal BMI at diagnosis, weight z scores increased significantly after treatment, and 13% became overweight. Both normal weight and overweight frequently occur in North American children presenting with celiac disease. A GFD may have a beneficial effect upon the BMI of overweight and obese children with celiac disease.

Gluten-induced symptoms in diarrhea-predominant irritable bowel syndrome are associated with increased myosin light chain kinase activity and claudin-15 expression

PubMed Central

Wu, Richard Licheng; Vazquez-Roque, Maria; Carlson, Paula; Burton, Duane; Grover, Madhusudan; Camilleri, Michael; Turner, Jerrold R.

2016-01-01

The mechanisms underlying diarrhea-predominant irritable bowel syndrome (IBS-D) are poorly understood, but increased intestinal permeability is thought to contribute to symptoms. A recent clinical trial of gluten-free diet (GFD) demonstrated symptomatic improvement, relative to gluten-containing diet (GCD), that was associated with reduced intestinal permeability in non-celiac disease IBS-D patients. The aim of this study was to characterize intestinal epithelial tight junction composition in IBS-D before and after dietary gluten challenge. Biopsies from 27 IBS-D patients (13 GFD; 14 GCD) were examined by H&E staining and semi-quantitative immunohistochemistry for phosphorylated myosin II regulatory light chain (MLC), MLC kinase, claudin-2, claudin-8, and claudin-15. Diet-induced changes were assessed and correlated with urinary mannitol excretion (after oral administration). In the small intestine, epithelial MLC phosphorylation was increased or decreased by GCD or GFD, respectively, and this correlated with increased intestinal permeability (P < 0.03). Colonocyte expression of the paracellular Na+ channel claudin-15 was also markedly augmented following GCD challenge (P < 0.05). Conversely, colonic claudin-2 expression correlated with reduced intestinal permeability (P < 0.03). Claudin-8 expression was not affected by dietary challenge. These data show that alterations in MLC phosphorylation and claudin-15 and claudin-2 expression are associated with gluten-induced symptomatology and intestinal permeability changes in IBS-D. The results provide new insight into IBS-D mechanisms and can explain permeability responses to gluten challenge in these patients. PMID:27869798

Total oxidant status, total antioxidant capacity and ischemia modified albumin levels in children with celiac disease.

PubMed

Sayar, Ersin; Özdem, Sebahat; Uzun, Gülbahar; İşlek, Ali; Yılmaz, Aygen; Artan, Reha

2015-01-01

In our study, we aimed to investigate ischemia modified albumin (IMA) as an oxidative stress marker, as well as other oxidant and antioxidant markers that have not been evaluated in children with celiac disease. A total of 37 pediatric patients who were diagnosed with celiac disease (CD) and 29 healthy children were enrolled in this prospective study. We evaluated the IMA, total oxidant status, total antioxidant capacity, sulfhydryl, and advanced oxidation protein products in all of the subjects. We also compared the levels at the time of the diagnosis, and following a gluten-free diet (GFD) in the children with CD. While the IMA and the other oxidant marker levels were significantly higher in the patient group compared to the control group, the antioxidant marker levels were found to be significantly lower in the patient group, compared to the control group. We also determined that the tissue transglutaminase IgA showed a highly positive correlation, and that the IMA showed a moderately positive correlation with the Marsh-Oberhuber histopathological stage. Additionally, the IMA and other oxidant marker levels were significantly lower, while the antioxidant marker levels were significantly higher after the GFD, compared to the pre-diet period. We detected that oxidative stress played a role in the pathogenesis of CD, and that this could be evaluated using oxidative stress markers, which would regress after the GFD. We also detected that IMA is a marker that shows a correlation with the histopathological stage, and may be used in the diagnosis.

Beyond Irritable Bowel Syndrome: The Efficacy of the Low Fodmap Diet for Improving Symptoms in Inflammatory Bowel Diseases and Celiac Disease.

PubMed

Testa, Anna; Imperatore, Nicola; Rispo, Antonio; Rea, Matilde; Tortora, Raffaella; Nardone, Olga Maria; Lucci, Lucia; Accarino, Grazia; Caporaso, Nicola; Castiglione, Fabiana

2018-05-15

To evaluate the usefulness of a low FODMAP (Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols) diet on patients with irritable bowel syndrome (IBS), non-active inflammatory bowel diseases (IBD), and celiac disease (CD) on a gluten-free diet (GFD). Dietetic interventional prospective study. IBS, IBD, and CD subjects were evaluated to check if they fulfilled the Rome III criteria. Each subject was educated to follow a low FODMAP diet after being evaluated by filling out questionnaires that assessed the quality of life (QoL) and symptoms experienced (IBS-SSS and SF-36), and was reevaluated after 1 and 3 months. One hundred twenty-seven subjects were enrolled: 56 with IBS, 30 with IBD, and 41 with CD. IBS-SSS showed that abdominal symptoms improved after 1 and 3 months of diet in all subjects, with significant difference among the 3 groups at T0 (average scores IBS: 293 ± 137, IBD: 206 ± 86, CD: 222 ± 65, p < 0.001), but no difference at T3 (IBS: 88 ± 54, IBD: 73 ± 45, CD: 77 ± 49, p = ns). By analyzing the SF-36 questionnaire, we did not observe any difference between the 3 groups, in terms of response to diet (p = ns), we observed a clinical improvement from T0 to T3 for most of the questionnaire's domains. A low FODMAP diet could be a valid option to counter -abdominal symptoms in patients with IBS, non-active IBD, or CD on a GFD, and thus, improve their QoL and social -relations. © 2018 S. Karger AG, Basel.

A new method for the prediction of combustion instability

NASA Astrophysics Data System (ADS)

Flanagan, Steven Meville

This dissertation presents a new approach to the prediction of combustion instability in solid rocket motors. Previous attempts at developing computational tools to solve this problem have been largely unsuccessful, showing very poor agreement with experimental results and having little or no predictive capability. This is due primarily to deficiencies in the linear stability theory upon which these efforts have been based. Recent advances in linear instability theory by Flandro have demonstrated the importance of including unsteady rotational effects, previously considered negligible. Previous versions of the theory also neglected corrections to the unsteady flow field of the first order in the mean flow Mach number. This research explores the stability implications of extending the solution to include these corrections. Also, the corrected linear stability theory based upon a rotational unsteady flow field extended to first order in mean flow Mach number has been implemented in two computer programs developed for the Macintosh platform. A quasi one-dimensional version of the program has been developed which is based upon an approximate solution to the cavity acoustics problem. The three-dimensional program applies Greens's Function Discretization (GFD) to the solution for the acoustic mode shapes and frequency. GFD is a recently developed numerical method for finding fully three dimensional solutions for this class of problems. The analysis of complex motor geometries, previously a tedious and time consuming task, has also been greatly simplified through the development of a drawing package designed specifically to facilitate the specification of typical motor geometries. The combination of the drawing package, improved acoustic solutions, and new analysis, results in a tool which is capable of producing more accurate and meaningful predictions than have been possible in the past.

No association between gluten sensitivity and amyotrophic lateral sclerosis.

PubMed

Visser, Anne E; Pazoki, Raha; Pulit, Sara L; van Rheenen, Wouter; Raaphorst, Joost; van der Kooi, Anneke J; Ricaño-Ponce, Isis; Wijmenga, Cisca; Otten, Henny G; Veldink, Jan H; van den Berg, Leonard H

2017-04-01

To examine evidence for a role of gluten sensitivity (GS) or celiac disease (CD) in ALS etiology, we included participants from a population-based case-control study in The Netherlands between January 2006 and December 2015. We compared levels and seroprevalence of IgA antibodies to tissue transglutaminase 6 (TG6) in 359 ALS patients and 359 controls, and to transglutaminase 2 (TG2) and endomysium (EMA) in 199 ALS patients and 199 controls. Questionnaire data on 1829 ALS patients and 3920 controls were examined for CD or gluten-free diets (GFD). Genetic correlation and HLA allele frequencies were analyzed using two genome-wide association studies: one on ALS (12,577 cases, 23,475 controls), and one on CD (4533 cases, 10,750 controls). We found one patient with TG6, TG2 and EMA antibodies who had typical ALS and no symptoms of GS. TG6 antibody concentrations and positivity, CD prevalence and adherence to a GFD were similar in patients and controls (p > 0.66) and in these patients disease progression was compatible with typical ALS. CD and ALS were not found to be genetically correlated (p > 0.37). CD-associated HLA allele frequencies were similar in patients and controls (p > 0.28). In conclusion, we found no serological evidence for involvement of gluten-related antibodies in ALS etiology nor did we observe an association between CD and ALS in medical history or genetic data, indicating that there is no evidence in our data for an association between the two diseases. Hence, a role for a GFD in the ALS treatment seems unlikely.

A Novel Patient-Derived Conceptual Model of the Impact of Celiac Disease in Adults: Implications for Patient-Reported Outcome and Health-Related Quality-of-Life Instrument Development.

PubMed

Leffler, Daniel A; Acaster, Sarah; Gallop, Katy; Dennis, Melinda; Kelly, Ciarán P; Adelman, Daniel C

2017-04-01

Celiac disease is a chronic inflammatory condition with wide ranging effects on individual's lives caused by a combination of symptoms and the burden of adhering to a gluten-free diet (GFD). To further understand patients' experience of celiac disease, the impact it has on health-related quality of life (HRQOL), and to develop a conceptual model describing this impact. Adults with celiac disease on a GFD reporting symptoms within the previous 3 months were included; patients with refractory celiac disease and confounding medical conditions were excluded. A semistructured discussion guide was developed exploring celiac disease symptoms and impact on patients' HRQOL. An experienced interviewer conducted in-depth interviews. The data set was coded and analyzed using thematic analysis to identify concepts, themes, and the inter-relationships between them. Data saturation was monitored and concepts identified formed the basis of the conceptual model. Twenty-one participants were recruited, and 32 distinct gluten-related symptoms were reported and data saturation was reached. Analysis identified several themes impacting patients' HRQOL: fears and anxiety, day-to-day management of celiac disease, physical functioning, sleep, daily activities, social activities, emotional functioning, and relationships. The conceptual model highlights the main areas of impact and the relationships between concepts. Both symptoms and maintaining a GFD have a substantial impact on patient functioning and HRQOL in adults with celiac disease. The conceptual model derived from these data may help to design future patient-reported outcomes as well as interventions to improve the quality of life in an individual with celiac disease. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Extraintestinal Manifestations of Celiac Disease: Effectiveness of the Gluten-Free Diet.

PubMed

Jericho, Hilary; Sansotta, Naire; Guandalini, Stefano

2017-07-01

The aim of the study was to evaluate the effectiveness of the gluten-free diet (GFD) on extraintestinal symptoms in pediatric and adult celiac populations at the University of Chicago. We conducted a retrospective chart review of the University of Chicago Celiac Center clinic charts from January 2002 to October 2014. Demographics, serologic testing, intestinal biopsies, and extraintestinal symptoms at presentation, 12, 24, and >24 months were recorded. Extraintestinal symptoms included abnormal liver enzymes, arthralgia/arthritis, dermatitis herpetiformis, alopecia, fatigue, headache, anemia, stomatitis, myalgias, psychiatric disorders, rashes, seizures, neuropathy, short stature, delayed puberty, osteoporosis, and infertility. A total of 737 patients with biopsy-confirmed celiac disease or skin biopsy-confirmed dermatitis herpetiformis were included. Patients lost to follow-up, or with insufficient data were excluded leaving 328 patients (157 pediatrics younger than 18 years). For pediatrics, the female to male ratio was 2:1 and the mean age at diagnosis was 8.9 years. For adults, 4:1 and 40.6 years old. Extraintestinal symptom rates were similar in children (60%) and adults (62%). Short stature (33%), fatigue (28%), and headache (20%) were most common in children. Iron deficiency anemia (48%), fatigue (37%), and headache/psychiatric disorders (24%) were common in adults. Children had faster/higher rates of symptom resolution compared with adults. Twenty-eight percent of children with unresolved short stature on a GFD were found to have other comorbidities. Children and adults with celiac disease have similar rates of extraintestinal manifestations. In children short stature, fatigue, and headache were most common, whereas anemia, fatigue, and headache/psychiatric disorders were most common in adults. Children on a strict GFD showed faster and higher rates of symptom resolution as compared to adults. Unresponsive children with short stature must be assessed for comorbidities.

Serological markers of enterocyte damage and apoptosis in patients with celiac disease, autoimmune diabetes mellitus and diabetes mellitus type 2.

PubMed

Hoffmanová, I; Sánchez, D; Hábová, V; Anděl, M; Tučková, L; Tlaskalová-Hogenová, H

2015-01-01

Impairment of mucosal barrier integrity of small intestine might be causative in immune-mediated gastrointestinal diseases. We tested the markers of epithelial apoptosis - cytokeratin 18 caspase-cleaved fragment (cCK-18), and enterocyte damage - intestinal fatty acid-binding protein (I-FABP) and soluble CD14 (sCD14) in sera of patients with untreated celiac disease (CLD), those on gluten-free diet (CLD-GFD), patients with autoimmune diabetes mellitus (T1D), T1D with insulitis (T1D/INS), and diabetes mellitus type 2 (T2D). We found elevated levels of cCK-18 (P<0.001), I-FABP (P<0.01) and sCD14 (P<0.05) in CLD when compared to healthy controls. However, the levels of cCK-18 (P<0.01) and I-FABP (P<0.01) in CLD-GFD were higher when compared with controls. Interestingly, elevated levels of cCK-18 and I-FABP were found in T2D and T1D (P<0.001), and T1D/INS (P<0.01, P<0.001). Twenty-two out of 43 CLD patients were seropositive for cCK-18, 19/43 for I-FABP and 11/43 for sCD14; 9/30 of T2D patients were positive for cCK-18 and 5/20 of T1D/INS for sCD14, while in controls only 3/41 were positive for cCK-18, 3/41 for I-FABP and 1/41 for sCD14. We documented for the first time seropositivity for sCD14 in CLD and potential usefulness of serum cCK-18 and I-FABP as markers of gut damage in CLD, CLD-GFD, and diabetes.

The effects of reduced gluten barley diet on humoral and cell-mediated systemic immune responses of gluten-sensitive rhesus macaques.

PubMed

Sestak, Karol; Thwin, Hazel; Dufour, Jason; Aye, Pyone P; Liu, David X; Moehs, Charles P

2015-03-06

Celiac disease (CD) affects approximately 1% of the general population while an estimated additional 6% suffers from a recently characterized, rapidly emerging, similar disease, referred to as non-celiac gluten sensitivity (NCGS). The only effective treatment of CD and NCGS requires removal of gluten sources from the diet. Since required adherence to a gluten-free diet (GFD) is difficult to accomplish, efforts to develop alternative treatments have been intensifying in recent years. In this study, the non-human primate model of CD/NCGS, e.g., gluten-sensitive rhesus macaque, was utilized with the objective to evaluate the treatment potential of reduced gluten cereals using a reduced gluten (RG; 1% of normal gluten) barley mutant as a model. Conventional and RG barleys were used for the formulation of experimental chows and fed to gluten-sensitive (GS) and control macaques to determine if RG barley causes a remission of dietary gluten-induced clinical and immune responses in GS macaques. The impacts of the RG barley diet were compared with the impacts of the conventional barley-containing chow and the GFD. Although remission of the anti-gliadin antibody (AGA) serum responses and an improvement of clinical diarrhea were noted after switching the conventional to the RG barley diet, production of inflammatory cytokines, e.g., interferon-gamma (IFN-γ), tumor necrosis factor (TNF) and interleukin-8 (IL-8) by peripheral CD4+ T helper lymphocytes, persisted during the RG chow treatment and were partially abolished only upon re-administration of the GFD. It was concluded that the RG barley diet might be used for the partial improvement of gluten-induced disease but its therapeutic value still requires upgrading-by co-administration of additional treatments.

The Effects of Reduced Gluten Barley Diet on Humoral and Cell-Mediated Systemic Immune Responses of Gluten-Sensitive Rhesus Macaques

PubMed Central

Sestak, Karol; Thwin, Hazel; Dufour, Jason; Aye, Pyone P.; Liu, David X.; Moehs, Charles P.

2015-01-01

Celiac disease (CD) affects approximately 1% of the general population while an estimated additional 6% suffers from a recently characterized, rapidly emerging, similar disease, referred to as non-celiac gluten sensitivity (NCGS). The only effective treatment of CD and NCGS requires removal of gluten sources from the diet. Since required adherence to a gluten-free diet (GFD) is difficult to accomplish, efforts to develop alternative treatments have been intensifying in recent years. In this study, the non-human primate model of CD/NCGS, e.g., gluten-sensitive rhesus macaque, was utilized with the objective to evaluate the treatment potential of reduced gluten cereals using a reduced gluten (RG; 1% of normal gluten) barley mutant as a model. Conventional and RG barleys were used for the formulation of experimental chows and fed to gluten-sensitive (GS) and control macaques to determine if RG barley causes a remission of dietary gluten-induced clinical and immune responses in GS macaques. The impacts of the RG barley diet were compared with the impacts of the conventional barley-containing chow and the GFD. Although remission of the anti-gliadin antibody (AGA) serum responses and an improvement of clinical diarrhea were noted after switching the conventional to the RG barley diet, production of inflammatory cytokines, e.g., interferon-gamma (IFN-γ), tumor necrosis factor (TNF) and interleukin-8 (IL-8) by peripheral CD4+ T helper lymphocytes, persisted during the RG chow treatment and were partially abolished only upon re-administration of the GFD. It was concluded that the RG barley diet might be used for the partial improvement of gluten-induced disease but its therapeutic value still requires upgrading—by co-administration of additional treatments. PMID:25756783

Acupuncture and a gluten-free diet relieve urticaria and eczema in a case of undiagnosed dermatitis herpetiformis and atypical or extraintestinal celiac disease: a case report.

PubMed

Ohlsen, Bahia A

2011-12-01

The purpose of this case report is to describe the use of acupuncture and a gluten-free diet (GFD) for urticaria and severe eczema in a patient with undiagnosed dermatitis herpetiformis and atypical or extraintestinal celiac disease. A 48-year-old woman presented with intense urticaria, eczema, worsening heartburn, chronic constipation, headaches, and an intense feeling of heat for 4 months. Results of punch biopsies of the skin lesions and laboratory tests were inconclusive. After the acupuncture sessions reported here ended, human leukocyte antigen blood typing revealed celiac disease and dermatitis herpetiformis-associated human leukocyte antigen DQ-8. Results of an endoscopy and colonoscopy were negative. The patient received 3 acupuncture treatments a week for 12 weeks. The patient's symptoms began in March 2008. She began using topical and oral steroids and felt that her symptoms were not responding. Acupuncture began in July 2008. At the end of the first 12 treatments, during which she was using topical and oral steroids, the urticaria and constipation resolved completely; and she had temporary relief from the heartburn. It is thought that the urticaria and constipation resolved because of the acupuncture as that was the only change. At the end of the second 12 treatments, during which time she had started Optifast, a GFD, the heartburn, headache, and eczema resolved. At the end of the third 12 treatments, all her symptoms remained resolved. Steroid treatment was discontinued after the first 12 treatments. Acupuncture and diet changes appeared to provide relief from the urticaria and eczema of dermatitis herpetiformis beyond that obtained by traditional treatment of a GFD alone.

Incompressible flow simulations on regularized moving meshfree grids

NASA Astrophysics Data System (ADS)

Vasyliv, Yaroslav; Alexeev, Alexander

2017-11-01

A moving grid meshfree solver for incompressible flows is presented. To solve for the flow field, a semi-implicit approximate projection method is directly discretized on meshfree grids using General Finite Differences (GFD) with sharp interface stencil modifications. To maintain a regular grid, an explicit shift is used to relax compressed pseudosprings connecting a star node to its cloud of neighbors. The following test cases are used for validation: the Taylor-Green vortex decay, the analytic and modified lid-driven cavities, and an oscillating cylinder enclosed in a container for a range of Reynolds number values. We demonstrate that 1) the grid regularization does not impede the second order spatial convergence rate, 2) the Courant condition can be used for time marching but the projection splitting error reduces the convergence rate to first order, and 3) moving boundaries and arbitrary grid distortions can readily be handled. Financial support provided by the National Science Foundation (NSF) Graduate Research Fellowship, Grant No. DGE-1148903.

Celiac disease: Prevalence, diagnosis, pathogenesis and treatment

PubMed Central

Gujral, Naiyana; Freeman, Hugh J; Thomson, Alan BR

2012-01-01

Celiac disease (CD) is one of the most common diseases, resulting from both environmental (gluten) and genetic factors [human leukocyte antigen (HLA) and non-HLA genes]. The prevalence of CD has been estimated to approximate 0.5%-1% in different parts of the world. However, the population with diabetes, autoimmune disorder or relatives of CD individuals have even higher risk for the development of CD, at least in part, because of shared HLA typing. Gliadin gains access to the basal surface of the epithelium, and interact directly with the immune system, via both trans- and para-cellular routes. From a diagnostic perspective, symptoms may be viewed as either “typical” or “atypical”. In both positive serological screening results suggestive of CD, should lead to small bowel biopsy followed by a favourable clinical and serological response to the gluten-free diet (GFD) to confirm the diagnosis. Positive anti-tissue transglutaminase antibody or anti-endomysial antibody during the clinical course helps to confirm the diagnosis of CD because of their over 99% specificities when small bowel villous atrophy is present on biopsy. Currently, the only treatment available for CD individuals is a strict life-long GFD. A greater understanding of the pathogenesis of CD allows alternative future CD treatments to hydrolyse toxic gliadin peptide, prevent toxic gliadin peptide absorption, blockage of selective deamidation of specific glutamine residues by tissue, restore immune tolerance towards gluten, modulation of immune response to dietary gliadin, and restoration of intestinal architecture. PMID:23155333

Independent genetic control of maize (Zea mays L.) kernel weight determination and its phenotypic plasticity.

PubMed

Alvarez Prado, Santiago; Sadras, Víctor O; Borrás, Lucas

2014-08-01

Maize kernel weight (KW) is associated with the duration of the grain-filling period (GFD) and the rate of kernel biomass accumulation (KGR). It is also related to the dynamics of water and hence is physiologically linked to the maximum kernel water content (MWC), kernel desiccation rate (KDR), and moisture concentration at physiological maturity (MCPM). This work proposed that principles of phenotypic plasticity can help to consolidated the understanding of the environmental modulation and genetic control of these traits. For that purpose, a maize population of 245 recombinant inbred lines (RILs) was grown under different environmental conditions. Trait plasticity was calculated as the ratio of the variance of each RIL to the overall phenotypic variance of the population of RILs. This work found a hierarchy of plasticities: KDR ≈ GFD > MCPM > KGR > KW > MWC. There was no phenotypic and genetic correlation between traits per se and trait plasticities. MWC, the trait with the lowest plasticity, was the exception because common quantitative trait loci were found for the trait and its plasticity. Independent genetic control of a trait per se and genetic control of its plasticity is a condition for the independent evolution of traits and their plasticities. This allows breeders potentially to select for high or low plasticity in combination with high or low values of economically relevant traits. © The Author 2014. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Quantitative Real-Time PCR Fecal Source Identification in the ...

EPA Pesticide Factsheets

Rivers in the Tillamook Basin play a vital role in supporting a thriving dairy and cheese-making industry, as well as providing a safe water resource for local human and wildlife populations. Historical concentrations of fecal bacteria in these waters are at times too high to allow for safe use leading to economic loss, endangerment of local wildlife, and poor conditions for recreational use. In this study, we employ host-associated qPCR methods for human (HF183/BacR287 and HumM2), ruminant (Rum2Bac), cattle (CowM2 and CowM3), canine (DG3 and DG37), and avian (GFD) fecal pollution combined with high-resolution geographic information system (GIS) land use data and general indicator bacteria measurements to elucidatewater quality spatial and temporal trends. Water samples (n=584) were collected over a 1-year period at 29 sites along the Trask, Kilchis, and Tillamook rivers and tributaries (Tillamook Basin, OR). A total of 16.6% of samples (n=97) yielded E. coli levels considered impaired based on Oregon Department of Environmental Quality bacteria criteria (406 MPN/100mL). Hostassociated genetic indicators were detected at frequencies of 39.2% (HF183/BacR287), 16.3% (HumM2), 74.6% (Rum2Bac), 13.0% (CowM2), 26.7% (CowM3), 19.8% (DG3), 3.2% (DG37), and 53.4% (GFD) across all water samples (n=584). Seasonal trends in avian, cattle, and human fecal pollution sources were evident over the study area. On a sample site basis, quantitative fecal source identification and

Anti-microbial antibodies in celiac disease: Trick or treat?

PubMed Central

Papp, Maria; Foldi, Ildiko; Altorjay, Istvan; Palyu, Eszter; Udvardy, Miklos; Tumpek, Judit; Sipka, Sandor; Korponay-Szabo, Ilma Rita; Nemes, Eva; Veres, Gabor; Dinya, Tamas; Tordai, Attila; Andrikovics, Hajnalka; Norman, Gary L; Lakatos, Peter Laszlo

2009-01-01

AIM: To determine the prevalence of a new set of anti-glycan and anti-outer membrane protein (anti-OMP) antibodies in a Hungarian cohort of adult Celiac disease (CD) patients. METHODS: 190 consecutive CD patients [M/F: 71/119, age:39.9 (SD:14.1) years], 100 healthy, and 48 gastrointestinal controls were tested for glycan anti-Saccharomyces cerevisiae (gASCA), anti-laminaribioside (ALCA), anti-chitobioside, anti-mannobioside, anti-OMP antibodies and major NOD2/CARD15 mutations. Thirty out of 82 CD patients enrolled at the time of diagnosis were re-evaluated for the same antibodies after longstanding gluten-free diet (GFD). RESULTS: 65.9% of the CD patients were positive for at least one of the tested antibodies at the time of the diagnosis. Except anti-OMP and ALCA, anti-microbial antibodies were exclusively seen in untreated CD; however, the overall sensitivity was low. Any glycan positivity (LR+: 3.13; 95% CI: 2.08-4.73) was associated with an increased likelihood ratio for diagnosing CD. Significant correlation was found between the levels of anti-glycan and anti-endomysial or anti-transglutaminase antibodies. Anti-glycan positivity was lost after longstanding GFD. Anti-glycan antibody titers were associated with symptoms at presentation, but not the presence of NOD2/CARD15 mutations. Patients with severe malabsorption more frequently had multiple antibodies at diagnosis (P = 0.019). CONCLUSION: The presence of anti-glycan antibodies in CD seems to be secondary to the impaired small bowel mucosa which can lead to increased antigen presentation. Furthermore, anti-glycan positivity may be considered an additional marker of CD and dietary adherence. PMID:19701969

Use of lipid-based nutrient supplements (LNS) to improve the nutrient adequacy of general food distribution rations for vulnerable sub-groups in emergency settings.

PubMed

Chaparro, Camila M; Dewey, Kathryn G

2010-01-01

The term 'lipid-based nutrient supplements' (LNS) refers generically to a range of fortified, lipid-based products, including products like Ready-to-Use Therapeutic Foods (RUTF) (a large daily ration with relatively low micronutrient concentration) as well as highly concentrated supplements (1-4 teaspoons/day, providing <100 kcal/day) to be used for 'point-of-use' fortification. RUTF have been successfully used for the management of severe acute malnutrition (SAM) among children in emergency settings. Recent research on smaller doses of LNS for prevention of malnutrition has created interest in their potential use in emergency settings to ensure a more nutritionally adequate ration for the most vulnerable groups [e.g. infants and children between 6 and 24 months of age, and pregnant and lactating women (PLW)]. Currently, the main food and nutrition interventions in emergency settings include general food distribution (GFD) rations, which are provided to the affected population as a whole, and selective (or supplementary) feeding programs (SFP), which are to be provided to nutritionally vulnerable or malnourished individuals. In addition to logistical and operational challenges that may limit the intended effect of these programs, the nutritional quality of the food commodities provided may be insufficient to meet the needs of infants and young children and PLW. Because these subgroups have particularly high nutrient needs for growth and development, meeting these needs is challenging in settings where the ration is limited to a few food commodities, with little access to a diverse diet and bioavailable sources of micronutrients. In recent years, there has been increased attention to adding micronutrient interventions, on top of the other food-based interventions (such as GFDs and SFPs), to fill micronutrient gaps in diets in emergency settings. The focus of this document is the potential role of LNS in meeting the nutritional needs of these vulnerable subgroups, with the goal of preventing malnutrition in emergency-affected populations. The document addresses the desired nutritional formulation of LNS for these target groups, taking into account the expected bioavailability of relevant nutrients and toxicity concerns. It also discusses the recommended chemical forms of the fortificants in LNS; stability and shelf-life considerations; production, packaging and distribution of LNS in the context of emergencies; and cost implications of the addition of LNS to current GFD rations for vulnerable groups. To develop the desired nutritional formulation of LNS for these purposes, we calculated the current nutrient content of commonly provided GFD rations and determined the nutritional 'gaps' (of both micro- and macronutrients) of these rations for each of the target groups (i.e. children 6-35 months of age and PLW). For fat and protein, both quantity and quality were evaluated. Through an iterative process, we determined the formulation of a small dose of LNS that would best meet the recommended nutrient intakes for each group in combination with other foods in the GFD ration [composed of a grain, pulse, oil, sugar and salt, but excluding a fortified blended food (FBF)], as well as breast milk for children 6-24 months of age, while avoiding excess levels of any one nutrient to the extent possible. The composition of the LNS used for these calculations is based on an existing LNS product (Nutributter, Malaunay, France, Nutriset), but with less sugar and more oil. Two different approaches were used: (1) developing two different formulations of LNS, one to be used for infants and children 6-35 months of age and a separate one for PLW; and (2) developing a single formulation that could be used for all of these subgroups. We used commodity cost data to estimate the cost of adding an LNS product to the GFD ration. The results indicate that the typical GFD ration currently provided in emergency settings--based on cereals, pulse, an FBF such as corn-soy blend (CSB), oil, salt and sugar-does not meet the nutritional needs of infants and young children and PLW. The hypothetical intake from a ration composed of food aid commodities (based on the current USAID/USDA specifications for exported food aid commodities used in emergency settings), and including breast milk for children 6-24 months of age, provided less than 75% of the recommended intake for several micronutrients for certain age/physiologic groups, including calcium, iron, zinc, B vitamins such as riboflavin, B6 and B12, and fat-soluble vitamins such as D, E and K. It also generally contained lower than recommended levels of fat and essential fatty acids. The initial LNS formulation for each target group was designed to provide 100% of the recommended amount (RDA or RNI) for most micronutrients per daily dose (20 g, approximately 118 kcal) of LNS. This would ensure consumption of the recommended levels of each nutrient even if the 'base' diet changed. However, because such a formulation could provide excess amounts of certain nutrients when consumed in combination with the 'base' diet (especially when the 'base' diet contains fortified foods), we made adjustments in the LNS formulation when there was a risk of greatly exceeding the Upper Level for certain subgroups and there were relevant concerns about adverse effects from chronic consumption of such amounts. For most nutrients, consumption of toxic amounts is highly unlikely with the proposed LNS formulations. The 'one-size' LNS formulation was designed so that one 'dose' (20 g) would be provided to infants and young children and two 'doses' (i.e. 40 g/day) would be provided to PLW. This 'one-size' formulation was based on the LNS formulation developed for children 6-35 months of age. Although the resulting formulation is not a perfect match for the unique nutritional needs of each subgroup, there are several practical advantages to using such an approach. As anticipated, addition of LNS to the GFD ration, even after eliminating the FBF (e.g. CSB), increases the cost. The 'revised' ration without CSB but with LNS would cost 34-52% more (food only) than the 'typical' GFD diet for a hypothetical mother-infant pair, depending on how many LNS 'doses' were provided to the mother. However, depending on the contribution of food costs to overall program costs, the overall increase in costs may be significantly less. Although cost is an important consideration, options to improve the nutritional quality of foods provided in emergency settings should also be assessed with regard to effectiveness in maintaining and improving nutritional outcomes. Another consideration is whether a specialized product like LNS is more easily targeted to the individuals for whom it is intended, thus reducing inter- and intra-household sharing, a common concern with other fortified products such as CSB. This could have substantial cost implications because programs usually compensate for sharing by inflating the amount of FBF provided. This document is intended to be a starting point for considering the incorporation of LNS in the food packages provided in emergency settings. Our goal was to examine the potential nutritional benefits but also the challenges of adopting such a strategy. There are many different options for emergency nutrition programs, and there are also many considerations governing which option to choose. This document is intended to encourage further evaluation of all of these options.

Leaky GFD problems

NASA Astrophysics Data System (ADS)

Chumakova, Lyubov; Rzeznik, Andrew; Rosales, Rodolfo R.

2017-11-01

In many dispersive/conservative wave problems, waves carry energy outside of the domain of interest and never return. Inside the domain of interest, this wave leakage acts as an effective dissipation mechanism, causing solutions to decay. In classical geophysical fluid dynamics problems this scenario occurs in the troposphere, if one assumes a homogeneous stratosphere. In this talk we present several classic GFD problems, where we seek the solution in the troposphere alone. Assuming that upward propagating waves that reach the stratosphere never return, we demonstrate how classic baroclinic modes become leaky, with characteristic decay time-scales that can be calculated. We also show how damping due to wave leakage changes the classic baroclinic instability problem in the presence of shear. This presentation is a part of a joint project. The mathematical approach used here relies on extending the classical concept of group velocity to leaky waves with complex wavenumber and frequency, which will be presented at this meeting by A. Rzeznik in the talk ``Group Velocity for Leaky Waves''. This research is funded by the Royal Soc. of Edinburgh, Scottish Government, and NSF.

Recognition and management of coeliac disease in children.

PubMed

Paul, Siba Prosad; Basude, Dharam

2013-12-01

Coeliac disease (CD) is an immune-mediated systemic disorder elicited by the ingestion of gluten (found in wheat, rye, and barley) in genetically susceptible individuals. It affects around 1% of children and leads to proximal small bowel enteropathy, although many cases may remain undiagnosed. CD classically presents with gastrointestinal symptoms of diarrhoea, abdominal pain and weight loss, although other symptoms such as iron deficiency anaemia, faltering growth, dental enamel defects, short stature, liver disease, arthropathy, mouth ulcers, etc may be the presenting feature. Breastfeeding is considered to have a beneficial role in preventing CD or at least delays onset. Community practitioners should remain aware of the classical gastrointestinal and other features of CD and make an early referral to medical professionals. Suspicion of CD should lead to antibody screening tests and the diagnosis is confirmed by an intestinal biopsy. A gluten-free diet (GFD) should always be started by paediatric dietitians and they play a vital role in educating and supporting families. Strict adherence to a GFD is essential to maintain good health and to prevent development of long-term complications.

Vegetarian, Gluten-Free, and Energy Restricted Diets in Female Athletes

PubMed Central

Cialdella-Kam, Lynn; Kulpins, Danielle; Manore, Melinda M.

2016-01-01

Female athletes who follow a diet that fails to meet energy and nutrient needs are at risk for musculoskeletal injuries, menstrual disturbances, and poor sports performance. Common nutritional concerns for the female athlete include low energy availability (EA) (i.e., energy intake from food remaining for metabolic processes after accounting for energy expended during exercise) and inadequate dietary intakes (i.e., not meeting sports nutrition guidelines) of carbohydrates, protein, essential fatty acids (EFAs), B-vitamins, calcium, iron, and vitamin D. Low EA and the associated nutrient deficiencies are more common in athletes who compete in weight-sensitive sports (i.e., aesthetic, gravitational, and weight category sports) because low body fat and mass confer a competitive advantage. Other athletes at risk for energy and nutrient deficits include athletes following a vegetarian or gluten-free diet (GFD). Careful dietary planning can help an athlete meet energy and nutrient needs. This review covers the nutrition issues associated with low EA and special diets (i.e., vegetarian and GFD) and describes strategies to help female athletes meet their energy and nutrient needs. PMID:29910298

Serum I-FABP Detects Gluten Responsiveness in Adult Celiac Disease Patients on a Short-Term Gluten Challenge.

PubMed

Adriaanse, Marlou P M; Leffler, Daniel A; Kelly, Ciaran P; Schuppan, Detlef; Najarian, Robert M; Goldsmith, Jeffrey D; Buurman, Wim A; Vreugdenhil, Anita C E

2016-07-01

Response to gluten challenge (GC) is a key feature in diagnostic algorithms and research trials in celiac disease (CD). Currently, autoantibody titers, late responders to GC, and invasive duodenal biopsies are used to evaluate gluten responsiveness. This study investigated the accuracy of serum intestinal-fatty acid binding protein (I-FABP), a marker for intestinal epithelial damage, to predict intestinal damage during GC in patients with CD. Twenty adult CD patients in remission underwent a two-week GC with 3 or 7.5 g of gluten daily. Study visits occurred at day -14, 0, 3, 7, 14, and 28. Serum I-FABP, antibodies to tissue transglutaminase (tTG-IgA), deamidated gliadin peptides (IgA-DGP), and anti-actin (AAA-IgA) were assessed at each visit. Villous-height to crypt-depth ratio (Vh:Cd) and intraepithelial lymphocyte (IEL) count were evaluated at day -14, 3, and 14. Forty-three CD-serology negative individuals were included to compare serum I-FABP levels in CD patients on a gluten-free diet (GFD) with those in healthy subjects. Serum I-FABP levels increased significantly during a two-week GC. In contrast, the most pronounced autoantibody increase was found at day 28, when patients had already returned to a GFD for two weeks. IgA-AAA titers were only significantly elevated at day 28. I-FABP levels and IEL count correlated at baseline (r=0.458, P=0.042) and at day 14 (r=0.654, P=0.002) of GC. Neither gluten dose nor time on a GFD influenced I-FABP change during GC. Serum I-FABP levels increased significantly during a two-week GC in adult CD patients and correlated with IEL count. The data suggest that serum I-FABP is an early marker of gluten-induced enteropathy in celiac patients and may be of use in both clinical and research settings.

Clinical and Microbiological Effect of a Multispecies Probiotic Supplementation in Celiac Patients With Persistent IBS-type Symptoms: A Randomized, Double-Blind, Placebo-controlled, Multicenter Trial.

PubMed

Francavilla, Ruggiero; Piccolo, Maria; Francavilla, Antonio; Polimeno, Lorenzo; Semeraro, Francesco; Cristofori, Fernanda; Castellaneta, Stefania; Barone, Michele; Indrio, Flavia; Gobbetti, Marco; De Angelis, Maria

2018-04-23

The goals of this study were to evaluate the efficacy and safety of a probiotic mixture in patients with celiac disease (CD) with irritable bowel syndrome (IBS)-type symptoms despite a strict gluten-free diet (GFD). About 30% of patients with CD adherent to a GFD suffer from IBS-type symptoms; a possible cause resides in the imbalances of the intestinal microbiota in CD. Probiotics may represent a potential treatment. CD patients with IBS-type symptoms entered a prospective, double-blind, randomized placebo-controlled study. A 6-week treatment period was preceded by a 2-week run-in and followed by a 6-week follow-up phase. Clinical data were monitored throughout the study by validated questionnaires: IBS Severity Scoring System (IBS-SSS); Gastrointestinal Symptom Rating Scale (GSRS); Bristol Stool Form Scale (BSFS); and IBS Quality of Life Questionnaire (IBS-QOL). The fecal microbiota were assayed using plate counts and 16S rRNA gene-based analysis. In total, 109 patients were randomized to probiotics (n=54) or placebo (n=55). IBS-SSS and GSRS decreased significantly in probiotics, as compared with placebo [(-15.9%±14.8% vs. 8.2%±25.9%; P<0.001) and (-19.8%±16.6% vs. 12.9%±31.6%; P<0.001)], respectively. Treatment success was significantly higher in patients receiving probiotics, as compared with placebo (15.3% vs. 3.8%; P<0.04). Presumptive lactic acid bacteria, Staphylococcus and Bifidobacterium, increased in patients receiving probiotic treatment. No adverse events were reported. A 6-week probiotic treatment is effective in improving the severity of IBS-type symptoms, in CD patients on strict GFD, and is associated with a modification of gut microbiota, characterized by an increase of bifidobacteria.

Evaluation of magma mixing in the subvolcanic rocks of Ghansura Felsic Dome of Chotanagpur Granite Gneiss Complex, eastern India

NASA Astrophysics Data System (ADS)

Gogoi, Bibhuti; Saikia, Ashima; Ahmad, Mansoor; Ahmad, Talat

2018-06-01

The subvolcanic rocks exposed in the Ghansura Felsic Dome (GFD) of the Bathani volcano-sedimentary sequence at the northern fringe of the Rajgir fold belt in the Proterozoic Chotanagpur Granite Gneiss Complex preserves evidence of magma mixing and mingling in mafic (dolerite), felsic (microgranite) and intermediate (hybrid) rocks. Structures like crenulated margins of mafic enclaves, felsic microgranular enclaves and ocelli with reaction surfaces in mafic rocks, hybrid zones at mafic-felsic contacts, back-veining and mafic flows in the granitic host imply magma mingling phenomena. Textural features like quartz and titanite ocelli, acicular apatite, rapakivi and anti-rapakivi feldspar intergrowths, oscillatory zoned plagioclase, plagioclase with resorbed core and intact rim, resorbed crystals, mafic clots and mineral transporting veins are interpreted as evidence of magma mixing. Three distinct hybridized rocks have formed due to varied interactions of the intruding mafic magma with the felsic host, which include porphyritic diorite, mingled rocks and intermediate rocks containing felsic ocelli. Geochemical signatures confirm that the hybrid rocks present in the study area are mixing products formed due to the interaction of mafic and felsic magmas. Physical parameters like temperature, viscosity, glass transition temperature and fragility calculated for different rock types have been used to model the relative contributions of mafic and felsic end-member magmas in forming the porphyritic diorite. From textural and geochemical investigations it appears that the GFD was a partly solidified magma chamber when mafic magma intruded it leading to the formation of a variety of hybrid rock types.

Folate Insufficiency Due to Celiac Disease in a 49-Year-Old Woman of Southeast Asian-Indian Ethnicity

PubMed Central

Datta Mitra, Ananya; Gupta, Asha; Jialal, Ishwarlal

2016-01-01

The clinical presentation of celiac disease has evolved from chronic diarrhea and malnutrition to mild nutrient insufficiencies. Recently diagnosed adults with celiac disease should be assessed for micronutrient deficiencies because early institution of a gluten-free diet (GFD) prevents morbidity and reduces the incidence of gastrointestinal malignant neoplasms and osteoporosis. In this report, we present the case of a 49-year-old woman of Southeast Asian–Indian descent living in the United States who had folate insufficiency, as manifested by low serum and red blood cell (RBC) folate levels. Further investigation, including serologic testing and intestinal biopsy, confirmed a diagnosis of celiac disease and other nutrient deficiencies. Managing the condition of this patient with folate supplements and implementation of a recommended GFD reversed the folate insufficiency. In conclusion, when serum and/or RBC levels are low in a person of Southeast Asian-Indian descent living in a country with folate fortification of the grain supply, such as the United States, the medical team needs to look for an organic cause, as in our patient, to diagnose and manage celiac disease early and, hopefully, forestall complications. PMID:27406144

Double-blind randomized controlled trial of rifaximin for persistent symptoms in patients with celiac disease.

PubMed

Chang, Matthew S; Minaya, Maria T; Cheng, Jianfeng; Connor, Bradley A; Lewis, Suzanne K; Green, Peter H R

2011-10-01

Small intestinal bacterial overgrowth (SIBO) is one cause of a poor response to a gluten-free diet (GFD) and persistent symptoms in celiac disease. Rifaximin has been reported to improve symptoms in non-controlled trials. To determine the effect of rifaximin on gastrointestinal symptoms and lactulose-hydrogen breath tests in patients with poorly responsive celiac disease. A single-center, double-blind, randomized, controlled trial of patients with biopsy-proven celiac disease and persistent gastrointestinal symptoms despite a GFD was conducted. Patients were randomized to placebo (n = 25) or rifaximin (n = 25) 1,200 mg daily for 10 days. They completed the Gastrointestinal Symptom Rating Scale (GSRS) and underwent lactulose-hydrogen breath tests at weeks 0, 2, and 12. An abnormal breath test was defined as: (1) a rise in hydrogen of ≥20 parts per million (ppm) within 100 min, or (2) two peaks ≥20 ppm over baseline. GSRS scores were unaffected by treatment with rifaximin, regardless of baseline breath tests. In a multivariable regression model, the duration of patients' gastrointestinal symptoms significantly predicted their overall GSRS scores (estimate 0.029, p < 0.006). According to criteria 1 and 2, respectively, SIBO was present in 55 and 8% of patients at baseline, intermittently present in 28 and 20% given placebo, and 28 and 12% given rifaximin. There was no difference in the prevalence of SIBO between placebo and treatment groups at weeks 2 and 12. Rifaximin does not improve patients' reporting of gastrointestinal symptoms and hydrogen breath tests do not reliably identify who will respond to antibiotic therapy.

Intestinal Microbiota and Celiac Disease: Cause, Consequence or Co-Evolution?

PubMed

Cenit, María Carmen; Olivares, Marta; Codoñer-Franch, Pilar; Sanz, Yolanda

2015-08-17

It is widely recognized that the intestinal microbiota plays a role in the initiation and perpetuation of intestinal inflammation in numerous chronic conditions. Most studies report intestinal dysbiosis in celiac disease (CD) patients, untreated and treated with a gluten-free diet (GFD), compared to healthy controls. CD patients with gastrointestinal symptoms are also known to have a different microbiota compared to patients with dermatitis herpetiformis and controls, suggesting that the microbiota is involved in disease manifestation. Furthermore, a dysbiotic microbiota seems to be associated with persistent gastrointestinal symptoms in treated CD patients, suggesting its pathogenic implication in these particular cases. GFD per se influences gut microbiota composition, and thus constitutes an inevitable confounding factor in studies conducted in CD patients. To improve our understanding of whether intestinal dysbiosis is the cause or consequence of disease, prospective studies in healthy infants at family risk of CD are underway. These studies have revealed that the CD host genotype selects for the early colonizers of the infant's gut, which together with environmental factors (e.g., breast-feeding, antibiotics, etc.) could influence the development of oral tolerance to gluten. Indeed, some CD genes and/or their altered expression play a role in bacterial colonization and sensing. In turn, intestinal dysbiosis could promote an abnormal response to gluten or other environmental CD-promoting factors (e.g., infections) in predisposed individuals. Here, we review the current knowledge of host-microbe interactions and how host genetics/epigenetics and environmental factors shape gut microbiota and may influence disease risk. We also summarize the current knowledge about the potential mechanisms of action of the intestinal microbiota and specific components that affect CD pathogenesis.

Effect of oxygen plasma treatment on the electrochemical performance of the rayon and polyacrylonitrile based carbon felt for the vanadium redox flow battery application

NASA Astrophysics Data System (ADS)

Dixon, D.; Babu, D. J.; Langner, J.; Bruns, M.; Pfaffmann, L.; Bhaskar, A.; Schneider, J. J.; Scheiba, F.; Ehrenberg, H.

2016-11-01

Oxygen plasma treatment was applied on commercially available graphite felt electrodes based on rayon (GFA) and polyacrylonitrile (GFD). The formation of functional groups on the surface of the felt was confirmed by X-ray photoelectron spectroscopy measurements. The BET studies of the plasma treated electrodes showed no significant increase in surface area for both the rayon as well as the PAN based felts. Both plasma treated electrodes showed significantly enhanced V3+/V2+ redox activity compared to the pristine electrodes. Since an increase of the surface area has been ruled out for plasma treated electrode the enhanced activity could be attributed to surface functional groups. Interestingly, plasma treated GFD felts showed less electrochemical activity towards V5+/V4+ compared to the pristine electrode. Nevertheless, an overall increase of the single cell performance was still observed as the negative electrode is known to be the performance limiting electrode. Thus, to a great extent the present work helps to preferentially understand the importance of functional groups on the electrochemical activity of negative and positive redox reaction. The study emphasizes the need of highly active electrodes especially at the negative electrode side as inactive electrodes can still facilitate hydrogen evolution and degrade the electrolyte in VRFBs.

Gastrointestinal symptoms and well-being of adults living on a gluten-free diet: a case for nursing in celiac disease.

PubMed

Roos, Susanne; Kärner, Anita; Hallert, Claes

2009-01-01

Women with celiac disease (CD) living on a gluten-free diet (GFD) show a lower health-related quality of life and report a higher rate of gastrointestinal (GI) symptoms than men with CD. Uncertainty exists as to whether GI symptoms may explain the poorer treatment outcome of women with CD. This study was designed to explore relationships of GI symptoms and psychological well-being in men and women with long-standing CD. Patients with CD (n = 108; 59% women), aged 45-64 years, treated with a GFD for at least 8 years were evaluated by the Gastrointestinal Symptom Rating Scale and the Psychological General Well-Being index. The results show that women with a high rate of GI symptoms have no lower level of psychological well-being than corresponding men with CD and that women with CD with reduced psychological well-being have no more GI symptoms than corresponding men. Our results fail to support the notion that the reduced subjective health in CD is explained by GI symptoms. They may be secondary to perceived difficulties in managing everyday life, suggesting that launching a nurse-led follow-up may be helpful, as has been proven to be useful in other lifelong disorders.

The Role of Celiac Disease in Severity of Liver Disorders and Effect of a Gluten Free Diet on Diseases Improvement

PubMed Central

Rostami-Nejad, Mohammad; Haldane, Thea; AlDulaimi, David; Alavian, Seyed Moayed; Zali, Mohammad Reza; Rostami, Kamran

2013-01-01

Context Celiac disease (CD) is defined as a permanent intolerance to ingested gluten. The intolerance to gluten results in immune-mediated damage of small intestine mucosa manifested by villous atrophy and crypt hyperplasia. These abnormalities resolve with initiationa gluten-free diet. Evidence Acquisition PubMed, Ovid, and Google were searched for full text articles published between 1963 and 2012. The associated keywords were used, and papers described particularly the impact of celiac disease on severity of liver disorder were identified. Results Recently evidence has emerged revealingthat celiac disease not only is associated with small intestine abnormalities and malabsorption, but is also a multisystem disorder affecting other systems outside gastrointestinal tract, including musculo-skeletal, cardiovascular and nervous systems. Some correlations have been assumed between celiac and liver diseases. In particular, celiac disease is associated with changes in liver biochemistry and linked to alter the prognosis of other disorders. This review will concentrate on the effect of celiac disease and gluten-free diets on the severity of liver disorders. Conclusions Although GFD effect on the progression of CD associated liver diseases is not well defined, it seems that GFD improves liver function tests in patients with a hypertransaminasemia. PMID:24348636

Group Velocity for Leaky Waves

NASA Astrophysics Data System (ADS)

Rzeznik, Andrew; Chumakova, Lyubov; Rosales, Rodolfo

2017-11-01

In many linear dispersive/conservative wave problems one considers solutions in an infinite medium which is uniform everywhere except for a bounded region. In general, localized inhomogeneities of the medium cause partial internal reflection, and some waves leak out of the domain. Often one only desires the solution in the inhomogeneous region, with the exterior accounted for by radiation boundary conditions. Formulating such conditions requires definition of the direction of energy propagation for leaky waves in multiple dimensions. In uniform media such waves have the form exp (d . x + st) where d and s are complex and related by a dispersion relation. A complex s is required since these waves decay via radiation to infinity, even though the medium is conservative. We present a modified form of Whitham's Averaged Lagrangian Theory along with modulation theory to extend the classical idea of group velocity to leaky waves. This allows for solving on the bounded region by representing the waves as a linear combination of leaky modes, each exponentially decaying in time. This presentation is part of a joint project, and applications of these results to example GFD problems will be presented by L. Chumakova in the talk ``Leaky GFD Problems''. This work is partially supported by NSF Grants DMS-1614043, DMS-1719637, and 1122374, and by the Hertz Foundation.

Toolbox Approaches Using Molecular Markers and 16S rRNA Gene Amplicon Data Sets for Identification of Fecal Pollution in Surface Water

PubMed Central

Staley, C.; Sadowsky, M. J.; Gyawali, P.; Sidhu, J. P. S.; Palmer, A.; Beale, D. J.; Toze, S.

2015-01-01

In this study, host-associated molecular markers and bacterial 16S rRNA gene community analysis using high-throughput sequencing were used to identify the sources of fecal pollution in environmental waters in Brisbane, Australia. A total of 92 fecal and composite wastewater samples were collected from different host groups (cat, cattle, dog, horse, human, and kangaroo), and 18 water samples were collected from six sites (BR1 to BR6) along the Brisbane River in Queensland, Australia. Bacterial communities in the fecal, wastewater, and river water samples were sequenced. Water samples were also tested for the presence of bird-associated (GFD), cattle-associated (CowM3), horse-associated, and human-associated (HF183) molecular markers, to provide multiple lines of evidence regarding the possible presence of fecal pollution associated with specific hosts. Among the 18 water samples tested, 83%, 33%, 17%, and 17% were real-time PCR positive for the GFD, HF183, CowM3, and horse markers, respectively. Among the potential sources of fecal pollution in water samples from the river, DNA sequencing tended to show relatively small contributions from wastewater treatment plants (up to 13% of sequence reads). Contributions from other animal sources were rarely detected and were very small (<3% of sequence reads). Source contributions determined via sequence analysis versus detection of molecular markers showed variable agreement. A lack of relationships among fecal indicator bacteria, host-associated molecular markers, and 16S rRNA gene community analysis data was also observed. Nonetheless, we show that bacterial community and host-associated molecular marker analyses can be combined to identify potential sources of fecal pollution in an urban river. This study is a proof of concept, and based on the results, we recommend using bacterial community analysis (where possible) along with PCR detection or quantification of host-associated molecular markers to provide information on the sources of fecal pollution in waterways. PMID:26231650

Remote visualization and scale analysis of large turbulence datatsets

NASA Astrophysics Data System (ADS)

Livescu, D.; Pulido, J.; Burns, R.; Canada, C.; Ahrens, J.; Hamann, B.

2015-12-01

Accurate simulations of turbulent flows require solving all the dynamically relevant scales of motions. This technique, called Direct Numerical Simulation, has been successfully applied to a variety of simple flows; however, the large-scale flows encountered in Geophysical Fluid Dynamics (GFD) would require meshes outside the range of the most powerful supercomputers for the foreseeable future. Nevertheless, the current generation of petascale computers has enabled unprecedented simulations of many types of turbulent flows which focus on various GFD aspects, from the idealized configurations extensively studied in the past to more complex flows closer to the practical applications. The pace at which such simulations are performed only continues to increase; however, the simulations themselves are restricted to a small number of groups with access to large computational platforms. Yet the petabytes of turbulence data offer almost limitless information on many different aspects of the flow, from the hierarchy of turbulence moments, spectra and correlations, to structure-functions, geometrical properties, etc. The ability to share such datasets with other groups can significantly reduce the time to analyze the data, help the creative process and increase the pace of discovery. Using the largest DOE supercomputing platforms, we have performed some of the biggest turbulence simulations to date, in various configurations, addressing specific aspects of turbulence production and mixing mechanisms. Until recently, the visualization and analysis of such datasets was restricted by access to large supercomputers. The public Johns Hopkins Turbulence database simplifies the access to multi-Terabyte turbulence datasets and facilitates turbulence analysis through the use of commodity hardware. First, one of our datasets, which is part of the database, will be described and then a framework that adds high-speed visualization and wavelet support for multi-resolution analysis of turbulence will be highlighted. The addition of wavelet support reduces the latency and bandwidth requirements for visualization, allowing for many concurrent users, and enables new types of analyses, including scale decomposition and coherent feature extraction.

Impact of type 1 diabetes mellitus and celiac disease on nutrition and quality of life.

PubMed

Nunes-Silva, J G; Nunes, V S; Schwartz, R P; Mlss Trecco, S; Evazian, D; Correa-Giannella, M L; Nery, M; Queiroz, M S

2017-01-09

Type 1 diabetes mellitus (T1DM) and celiac disease (CD) are autoimmune diseases and have similar genetic patterns. T1DM treatment is based on diet, physical activity and insulin therapy, whereas CD depends on dietary changes with restriction of wheat, rye and barley. The aim of the study was to evaluate the quality of life (QoL) of individuals with the association of T1DM and CD, to characterize their nutritional status and to compare it with those with only one disease and healthier controls. Sixty patients controlled by sex, age and body mass index (BMI) were stratified by previous diagnosis in: T1DM and CD (DMCD group); T1DM (DM group); CD (CD group); or healthy participants (HC). The SF-36 questionnaire was applied to assess psychological well being and results were compared with glycemic control and presence of complications related to diabetes, adhesion to gluten-free diet (GFD). Nutritional status and body mass composition were determined by BMI, waist circumference, bioimpedance, general laboratory tests and whole-body densitometry. The time of diagnosis of T1DM was similar between DMCD and DM groups; however, the duration of CD was significantly higher in the CD group compared with DMCD. The SF-36 analysis revealed statistically significant differences between DM and HC groups in two domains: general health (P=0.042) and energy/vitality (P=0.012). QoL was also correlated with compliance to a GFD, and scores were similar in both groups: DMCD and CD. Forty percent of individuals in the CD group had visceral fat area above 100 cm 2 , as opposed to 20% in the other groups. Individuals of DMCD group had similar scores to DM, CD and HC on QoL, as well as on their nutritional status and bone metabolism. Thereby, we should conclude that the association of T1DM and CD did not deteriorate their health status.

What a practitioner needs to know about celiac disease?

PubMed

Garg, Kapil; Gupta, R K

2015-02-01

Celiac disease (CD) is an immune-mediated systemic disorder elicited by gluten and related prolamines in genetically susceptible individuals and is characterized by the presence of a variable combination of gluten-dependent clinical manifestations, CD-specific antibodies, HLA-DQ2 or HLA-DQ8 haplotypes and enteropathy. CD is triggered by wheat gluten and related prolamines in barley and rye. Worldwide, the disease affects approximately 1 % of the general population. Clinical features of CD vary considerably. Intestinal symptoms are more common in young children. In older children extra intestinal manifestations affecting almost all organs are seen. IgA tTG antibody, upper GI endoscopy with histological analysis of multiple biopsies of the duodenum and in selected cases HLA DQ2 and DQ8 positivity and endomysial antibodies (EMA) are needed for diagnosis. Currently, the only treatment for CD is a life-long gluten-free diet (GFD). Strict avoidance of wheat, rye, barley and their derivatives will result in intestinal healing and relief of symptoms for the majority of individuals with CD. The GFD is simple in principle, however, completely eliminating all foods and ingredients containing wheat, rye, barley, and most commercial oats can be very challenging. Newly diagnosed CD children should undergo testing and treatment for micronutrient deficiencies specially iron, folic acid, vitamin D, and vitamin B12. Long-term monitoring and follow up of patients with CD is necessary.

2008 Program of Study: Perspectives and Challenges in GFD (Geophysical Fluid Dynamics)

DTIC Science & Technology

2009-03-01

half of the complex k- plane , and Φ− is similarly well defined in the lower half of 338 PSfrag replacements Im k Re k−i +i Figure 2: Branch cuts in...domains ⊕ and , which include, respectively, the upper and lower half k- planes . The full Fourier transform of φ (and of h, d, etc.) is then well defined in...contour at infinity in the lower half k- plane ; the solution will only contain waves arising from poles located in the

Toolbox Approaches Using Molecular Markers and 16S rRNA Gene Amplicon Data Sets for Identification of Fecal Pollution in Surface Water.

PubMed

Ahmed, W; Staley, C; Sadowsky, M J; Gyawali, P; Sidhu, J P S; Palmer, A; Beale, D J; Toze, S

2015-10-01

In this study, host-associated molecular markers and bacterial 16S rRNA gene community analysis using high-throughput sequencing were used to identify the sources of fecal pollution in environmental waters in Brisbane, Australia. A total of 92 fecal and composite wastewater samples were collected from different host groups (cat, cattle, dog, horse, human, and kangaroo), and 18 water samples were collected from six sites (BR1 to BR6) along the Brisbane River in Queensland, Australia. Bacterial communities in the fecal, wastewater, and river water samples were sequenced. Water samples were also tested for the presence of bird-associated (GFD), cattle-associated (CowM3), horse-associated, and human-associated (HF183) molecular markers, to provide multiple lines of evidence regarding the possible presence of fecal pollution associated with specific hosts. Among the 18 water samples tested, 83%, 33%, 17%, and 17% were real-time PCR positive for the GFD, HF183, CowM3, and horse markers, respectively. Among the potential sources of fecal pollution in water samples from the river, DNA sequencing tended to show relatively small contributions from wastewater treatment plants (up to 13% of sequence reads). Contributions from other animal sources were rarely detected and were very small (<3% of sequence reads). Source contributions determined via sequence analysis versus detection of molecular markers showed variable agreement. A lack of relationships among fecal indicator bacteria, host-associated molecular markers, and 16S rRNA gene community analysis data was also observed. Nonetheless, we show that bacterial community and host-associated molecular marker analyses can be combined to identify potential sources of fecal pollution in an urban river. This study is a proof of concept, and based on the results, we recommend using bacterial community analysis (where possible) along with PCR detection or quantification of host-associated molecular markers to provide information on the sources of fecal pollution in waterways. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Latiglutenase Improves Symptoms in Seropositive Celiac Disease Patients While on a Gluten-Free Diet.

PubMed

Syage, Jack A; Murray, Joseph A; Green, Peter H R; Khosla, Chaitan

2017-09-01

Celiac disease (CD) is a widespread condition triggered by dietary gluten and treated with a lifelong gluten-free diet (GFD); however, inadvertent exposure to gluten can result in episodic symptoms. A previous trial of latiglutenase (clinicaltrials.gov; NCT01917630), an orally administered mixture of two recombinant gluten-specific proteases, was undertaken in symptomatic subjects with persistent injury. The primary endpoint for histologic improvement was not met, presumably due to a trial effect. In this post hoc analysis, we investigated the efficacy of latiglutenase for reducing symptoms in subgroups of the study participants based on their seropositivity. The study involved symptomatic CD patients following a GFD for at least one year prior to randomization. Patients were treated for 12 weeks with latiglutenase or placebo. Of 398 completed patients, 173 (43%) were seropositive at baseline. Symptoms were recorded daily, and weekly symptom scores were compiled. p values were calculated by analysis of covariance. A statistically significant, dose-dependent reduction was detected in the severity and frequency of symptoms in seropositive but not seronegative patients. The severity of abdominal pain and bloating was reduced by 58 and 44%, respectively, in the cohort receiving the highest latiglutenase dose (900 mg, n = 14) relative to placebo (n = 54). Symptom improvement increased from week 6 to week 12. There was also a trend toward greater symptom improvement with greater baseline symptom severity. Seropositive CD patients show symptomatic improvement from latiglutenase taken with meals and would benefit from the availability of this treatment.

Observations of speciated atmospheric mercury at three sites in Nevada: Evidence for a free tropospheric source of reactive gaseous mercury

NASA Astrophysics Data System (ADS)

Weiss-Penzias, Peter; Gustin, Mae Sexauer; Lyman, Seth N.

2009-07-01

Air mercury (Hg) speciation was measured for 11 weeks (June-August 2007) at three sites simultaneously in Nevada, USA. Mean reactive gaseous Hg (RGM) concentrations were elevated at all sites relative to those reported for locations not directly influenced by known point sources. RGM concentrations at all sites displayed a regular diel pattern and were positively correlated with ozone (O3) and negatively correlated with elemental Hg (Hg0) and dew point temperature (Tdp). Superimposed on the diel changes were 2- to 7-day periods when RGM concentrations increased across all three sites, producing significant intersite correlations of RGM daily means (r = 0.53-0.76, p < 0.0001). During these periods, enhanced O3 concentrations and lower Tdp were also observed. Back trajectories were applied to develop gridded frequency distribution (GFD) plots and determine trajectory residence times (TRT) in specific source boxes. The GFD for the upper-quartile RGM daily means at one site showed a contributing airflow regime from the high-altitude subtropics with little precipitation, while that developed for the lower-quartile RGM concentrations indicated predominantly lower-altitude westerly flow and precipitation. Daily mean TRT in a subtropical high-altitude source box (>2 km and <35°N) explained a component of the daily mean RGM at two sites (r2 = 0.37 and 0.27, p < 0.05). These observations indicate that long-range transport of RGM from the free troposphere is a potentially important component of Hg input to rural areas of the western United States.

Long-term mucosal recovery and healing in celiac disease is the rule - not the exception.

PubMed

Hære, Petter; Høie, Ole; Schulz, Tom; Schönhardt, Irina; Raki, Melinda; Lundin, Knut E A

2016-12-01

The prevalence of persistent villous atrophy (VA) in patients with celiac disease (CD) on a gluten-free diet (GFD) varies greatly between studies. Most studies show a relatively high prevalence of mucosal atrophy and inflammation in treated patients, a finding which have led to a concept of non-responsive CD. Few studies have examined the prevalence of long-term mucosal healing. Our study aimed to determine the extent of mucosal healing in a cohort of Norwegian patients with CD treated with GFD for several years. Adult patients diagnosed with VA between 1989 and 2009 were included. We performed a follow-up gastroscopy with duodenal biopsies. Two pathologists evaluated the biopsies according to the Marsh-Oberhuber classification. Mucosal healing was defined as Marsh 0 while mucosal recovery was defined as Marsh 0-2. Duodenal biopsies were obtained from 127 adult patients with established CD. After a follow-up time of 8.1 years (median, range 2.3-22.3), 103 (81%) of the patients showed mucosal healing, 120 patients (94%) showed mucosal recovery, and 7 patients (6%) showed persistent VA. In addition, 103 of the 127 patients (81%) had undergone a routine follow-up biopsy 12.6 months (median, range 5.2-28.8) after diagnosis. At the time of the routine follow-up, only 52 of these patients (50.5%) had achieved mucosal recovery. Although half of the patients had persistent VA at the time of routine follow-up, both long-term mucosal recovery and healing is possible for the vast majority of adult patients with CD.

Consumption of gluten with gluten-degrading enzyme by celiac patients: A pilot-study

PubMed Central

Tack, Greetje J; van de Water, Jolanda MW; Bruins, Maaike J; Kooy-Winkelaar, Engelina MC; van Bergen, Jeroen; Bonnet, Petra; Vreugdenhil, Anita CE; Korponay-Szabo, Ilma; Edens, Luppo; von Blomberg, B Mary E; Schreurs, Marco WJ; Mulder, Chris J; Koning, Frits

2013-01-01

AIM: To assesses the safety and efficacy of Aspergillus niger prolyl endoprotease (AN-PEP) to mitigate the immunogenic effects of gluten in celiac patients. METHODS: Patients with initial diagnosis of celiac disease as confirmed by positive serology with subtotal or total villous atrophy on duodenal biopsies who adhere to a strict gluten-free diet (GFD) resulting in normalised antibodies and mucosal healing classified as Marsh 0 or I were included. In a randomised double-blind placebo-controlled pilot study, patients consumed toast (approximately 7 g/d gluten) with AN-PEP for 2 wk (safety phase). After a 2-wk washout period with adherence of the usual GFD, 14 patients were randomised to gluten intake with either AN-PEP or placebo for 2 wk (efficacy phase). Measurements at baseline included complaints, quality-of-life, serum antibodies, immunophenotyping of T-cells and duodenal mucosa immunohistology. Furthermore, serum and quality of life questionnaires were collected during and after the safety, washout and efficacy phase. Duodenal biopsies were collected after the safety phase and after the efficacy phase. A change in histological evaluation according to the modified Marsh classification was the primary endpoint. RESULTS: In total, 16 adults were enrolled in the study. No serious adverse events occurred during the trial and no patients withdrew during the trial. The mean score for the gastrointestinal subcategory of the celiac disease quality (CDQ) was relatively high throughout the study, indicating that AN-PEP was well tolerated. In the efficacy phase, the CDQ scores of patients consuming gluten with placebo or gluten with AN-PEP did not significantly deteriorate and moreover no differences between the groups were observed. During the efficacy phase, neither the placebo nor the AN-PEP group developed significant antibody titers. The IgA-EM concentrations remained negative in both groups. Two patients were excluded from entering the efficacy phase as their mucosa showed an increase of two Marsh steps after the safety phase, yet with undetectable serum antibodies, while 14 patients were considered histologically stable on gluten with AN-PEP. Also after the efficacy phase, no significant deterioration was observed regarding immunohistological and flow cytometric evaluation in the group consuming placebo compared to the group receiving AN-PEP. Furthermore, IgA-tTG deposit staining increased after 2 wk of gluten compared to baseline in four out of seven patients on placebo. In the seven patients receiving AN-PEP, one patient showed increased and one showed decreased IgA-tTG deposits. CONCLUSION: AN-PEP appears to be well tolerated. However, the primary endpoint was not met due to lack of clinical deterioration upon placebo, impeding an effect of AN-PEP. PMID:24124328

Structure and Electrochemistry of Copper Fluoride Nanocomposites Utilizing Mixed Conducting Matrices

DTIC Science & Technology

2007-01-01

similar to the conversion reaction of the metal fluoride. Attractive materials such as V2O5 , MoS2, and MoO3-δ can be utilized. Examples of metal...fluorides enabled by these MCM matrices are nanocomposites of FeF3 ( V2O5 ),2 BiF3 (MoS2),15 and as discussed herein, CuF2 (MoO3). In all cases, the...filled dry box using Whatman GF/D glass fiber separators saturated with 1M LiPF6 in 1:1 vol/vol ethylene carbonate:dimethyl carbonate elec- trolyte

Spectrum of gluten-related disorders: consensus on new nomenclature and classification.

PubMed

Sapone, Anna; Bai, Julio C; Ciacci, Carolina; Dolinsek, Jernej; Green, Peter H R; Hadjivassiliou, Marios; Kaukinen, Katri; Rostami, Kamran; Sanders, David S; Schumann, Michael; Ullrich, Reiner; Villalta, Danilo; Volta, Umberto; Catassi, Carlo; Fasano, Alessio

2012-02-07

A decade ago celiac disease was considered extremely rare outside Europe and, therefore, was almost completely ignored by health care professionals. In only 10 years, key milestones have moved celiac disease from obscurity into the popular spotlight worldwide. Now we are observing another interesting phenomenon that is generating great confusion among health care professionals. The number of individuals embracing a gluten-free diet (GFD) appears much higher than the projected number of celiac disease patients, fueling a global market of gluten-free products approaching $2.5 billion (US) in global sales in 2010. This trend is supported by the notion that, along with celiac disease, other conditions related to the ingestion of gluten have emerged as health care concerns. This review will summarize our current knowledge about the three main forms of gluten reactions: allergic (wheat allergy), autoimmune (celiac disease, dermatitis herpetiformis and gluten ataxia) and possibly immune-mediated (gluten sensitivity), and also outline pathogenic, clinical and epidemiological differences and propose new nomenclature and classifications.

Spectrum of gluten-related disorders: consensus on new nomenclature and classification

PubMed Central

2012-01-01

A decade ago celiac disease was considered extremely rare outside Europe and, therefore, was almost completely ignored by health care professionals. In only 10 years, key milestones have moved celiac disease from obscurity into the popular spotlight worldwide. Now we are observing another interesting phenomenon that is generating great confusion among health care professionals. The number of individuals embracing a gluten-free diet (GFD) appears much higher than the projected number of celiac disease patients, fueling a global market of gluten-free products approaching $2.5 billion (US) in global sales in 2010. This trend is supported by the notion that, along with celiac disease, other conditions related to the ingestion of gluten have emerged as health care concerns. This review will summarize our current knowledge about the three main forms of gluten reactions: allergic (wheat allergy), autoimmune (celiac disease, dermatitis herpetiformis and gluten ataxia) and possibly immune-mediated (gluten sensitivity), and also outline pathogenic, clinical and epidemiological differences and propose new nomenclature and classifications. PMID:22313950

The Gluten-Free Diet: Testing Alternative Cereals Tolerated by Celiac Patients

PubMed Central

Comino, Isabel; de Lourdes Moreno, María; Real, Ana; Rodríguez-Herrera, Alfonso; Barro, Francisco; Sousa, Carolina

2013-01-01

A strict gluten-free diet (GFD) is the only currently available therapeutic treatment for patients with celiac disease, an autoimmune disorder of the small intestine associated with a permanent intolerance to gluten proteins. The complete elimination of gluten proteins contained in cereals from the diet is the key to celiac disease management. However, this generates numerous social and economic repercussions due to the ubiquity of gluten in foods. The research presented in this review focuses on the current status of alternative cereals and pseudocereals and their derivatives obtained by natural selection, breeding programs and transgenic or enzymatic technology, potential tolerated by celiac people. Finally, we describe several strategies for detoxification of dietary gluten. These included enzymatic cleavage of gliadin fragment by Prolyl endopeptidases (PEPs) from different organisms, degradation of toxic peptides by germinating cereal enzymes and transamidation of cereal flours. This information can be used to search for and develop cereals with the baking and nutritional qualities of toxic cereals, but which do not exacerbate this condition. PMID:24152755

Evidence for the Presence of Non-Celiac Gluten Sensitivity in Patients with Functional Gastrointestinal Symptoms: Results from a Multicenter Randomized Double-Blind Placebo-Controlled Gluten Challenge.

PubMed

Elli, Luca; Tomba, Carolina; Branchi, Federica; Roncoroni, Leda; Lombardo, Vincenza; Bardella, Maria Teresa; Ferretti, Francesca; Conte, Dario; Valiante, Flavio; Fini, Lucia; Forti, Edoardo; Cannizzaro, Renato; Maiero, Stefania; Londoni, Claudio; Lauri, Adriano; Fornaciari, Giovanni; Lenoci, Nicoletta; Spagnuolo, Rocco; Basilisco, Guido; Somalvico, Francesco; Borgatta, Bruno; Leandro, Gioacchino; Segato, Sergio; Barisani, Donatella; Morreale, Gaetano; Buscarini, Elisabetta

2016-02-08

Non-celiac gluten sensitivity (NCGS) is characterized by the onset of symptoms after eating gluten-containing food. We aimed to single out NCGS subjects among subjects with functional gastrointestinal symptoms. Patients were enrolled in a multicenter double-blind placebo-controlled trial with crossover. Symptoms and quality of life were evaluated by means of 10-cm VAS and SF36. Iron parameters, transaminases and C reactive protein (CRP) were evaluated. After a three-week-long gluten-free diet (GFD), responsive patients were randomly assigned to gluten intake (5.6 g/day) or placebo for seven days, followed by crossover. The primary endpoint was the worsening of symptoms (VAS increase ≥3 cm) during gluten ingestion compared to placebo. One hundred and forty patients were enrolled and 134 (17 males, mean age 39.1 ± 11.7 years, BMI 22.4 ± 3.8) completed the first period. A total of 101 subjects (10 males, mean age 39.3 ± 11.0 years, BMI 22.3 ± 4.0) reported a symptomatic improvement (VAS score 2.3 ± 1.2 vs. 6.5 ± 2.2 before and after GFD, p = 0.001). 98 patients underwent the gluten challenge and 28 (all females, mean age 38.9 ± 12.7 years, BMI 22.0 ± 2.9) reported a symptomatic relapse and deterioration of quality of life. No parameters were found to be statistically associated with positivity to the challenge. However, 14 patients responded to the placebo ingestion. Taking into account this finding, about 14% of patients responding to gluten withdrawal showed a symptomatic relapse during the gluten challenge. This group is suspected to have NCGS.

A novel uPAg-KPI fusion protein inhibits the growth and invasion of human ovarian cancer cells in vitro.

PubMed

Zhao, Li-Ping; Xu, Tian-Min; Kan, Mu-Jie; Xiao, Ye-Chen; Cui, Man-Hua

2016-05-01

Urokinase-type plasminogen activator (uPA) acts by breaking down the basement membrane and is involved in cell proliferation, migration and invasion. These actions are mediated by binding to the uPA receptor (uPAR) via its growth factor domain (GFD). The present study evaluated the effects of uPAg-KPI, a fusion protein of uPA-GFD and a kunitz protease inhibitor (KPI) domain that is present in the amyloid β-protein precursor. Using SKOV-3 cells, an ovarian cancer cell line, we examined cell viability, migration, invasion and also protein expression. Furthermore, we examined wound healing, and migration and invasion using a Transwell assay. Our data showed that uPAg-KPI treatment reduced the viability of ovarian cancer SKOV-3 cells in both a concentration and time-dependent manner by arresting tumor cells at G1/G0 phase of the cell cycle. The IC50 of uPAg-KPI was 0.5 µg/µl after 48 h treatment. At this concentration, uPAg-KPI also inhibited tumor cell colony formation, wound closure, as well as cell migration and invasion capacity. At the protein level, western blot analysis demonstrated that uPAg-KPI exerted no significant effect on the expression of total extracellular signal-regulated kinase (ERK)1/ERK2 and AKT, whereas it suppressed levels of phosphorylated ERK1/ERK2 and AKT. Thus, we suggest that this novel uPAg-KPI fusion protein reduced cell viability, colony formation, wound healing and the invasive ability of human ovarian cancer SKOV-3 cells in vitro by regulating ERK and AKT signaling. Further studies using other cell lines will confirm these findings.

A novel uPAg-KPI fusion protein inhibits the growth and invasion of human ovarian cancer cells in vitro

PubMed Central

ZHAO, LI-PING; XU, TIAN-MIN; KAN, MU-JIE; XIAO, YE-CHEN; CUI, MAN-HUA

2016-01-01

Urokinase-type plasminogen activator (uPA) acts by breaking down the basement membrane and is involved in cell proliferation, migration and invasion. These actions are mediated by binding to the uPA receptor (uPAR) via its growth factor domain (GFD). The present study evaluated the effects of uPAg-KPI, a fusion protein of uPA-GFD and a kunitz protease inhibitor (KPI) domain that is present in the amyloid β-protein precursor. Using SKOV-3 cells, an ovarian cancer cell line, we examined cell viability, migration, invasion and also protein expression. Furthermore, we examined wound healing, and migration and invasion using a Transwell assay. Our data showed that uPAg-KPI treatment reduced the viability of ovarian cancer SKOV-3 cells in both a concentration and time-dependent manner by arresting tumor cells at G1/G0 phase of the cell cycle. The IC50 of uPAg-KPI was 0.5 µg/µl after 48 h treatment. At this concentration, uPAg-KPI also inhibited tumor cell colony formation, wound closure, as well as cell migration and invasion capacity. At the protein level, western blot analysis demonstrated that uPAg-KPI exerted no significant effect on the expression of total extracellular signal-regulated kinase (ERK)1/ERK2 and AKT, whereas it suppressed levels of phosphorylated ERK1/ERK2 and AKT. Thus, we suggest that this novel uPAg-KPI fusion protein reduced cell viability, colony formation, wound healing and the invasive ability of human ovarian cancer SKOV-3 cells in vitro by regulating ERK and AKT signaling. Further studies using other cell lines will confirm these findings. PMID:27035617

Improved Xenobiotic Metabolism and Reduced Susceptibility to Cancer in Gluten-Sensitive Macaques upon Introduction of a Gluten-Free Diet

PubMed Central

Sestak, Karol; Conroy, Lauren; Aye, Pyone P.; Mehra, Smriti; Doxiadis, Gaby G.; Kaushal, Deepak

2011-01-01

Background A non-human primate (NHP) model of gluten sensitivity was employed to study the gene perturbations associated with dietary gluten changes in small intestinal tissues from gluten-sensitive rhesus macaques (Macaca mulatta). Methodology Stages of remission and relapse were accomplished in gluten-sensitive animals by administration of gluten-free (GFD) and gluten-containing (GD) diets, as described previously. Pin-head-sized biopsies, obtained non-invasively by pediatric endoscope from duodenum while on GFD or GD, were used for preparation of total RNA and gene profiling, using the commercial Rhesus Macaque Microarray (Agilent Technologies),targeting expression of over 20,000 genes. Principal Findings When compared with normal healthy control, gluten-sensitive macaques showed differential gene expressions induced by GD. While observed gene perturbations were classified into one of 12 overlapping categories - cancer, metabolism, digestive tract function, immune response, cell growth, signal transduction, autoimmunity, detoxification of xenobiotics, apoptosis, actin-collagen deposition, neuronal and unknown function - this study focused on cancer-related gene networks such as cytochrome P450 family (detoxification function) and actin-collagen-matrix metalloproteinases (MMP) genes. Conclusions/Significance A loss of detoxification function paralleled with necessity to metabolize carcinogens was revealed in gluten-sensitive animals while on GD. An increase in cancer-promoting factors and a simultaneous decrease in cancer-preventing factors associated with altered expression of actin-collagen-MMP gene network were noted. In addition, gluten-sensitive macaques showed reduced number of differentially expressed genes including the cancer-associated ones upon withdrawal of dietary gluten. Taken together, these findings indicate potentially expanded utility of gluten-sensitive rhesus macaques in cancer research. PMID:21533263

Evidence for the Presence of Non-Celiac Gluten Sensitivity in Patients with Functional Gastrointestinal Symptoms: Results from a Multicenter Randomized Double-Blind Placebo-Controlled Gluten Challenge

PubMed Central

Elli, Luca; Tomba, Carolina; Branchi, Federica; Roncoroni, Leda; Lombardo, Vincenza; Bardella, Maria Teresa; Ferretti, Francesca; Conte, Dario; Valiante, Flavio; Fini, Lucia; Forti, Edoardo; Cannizzaro, Renato; Maiero, Stefania; Londoni, Claudio; Lauri, Adriano; Fornaciari, Giovanni; Lenoci, Nicoletta; Spagnuolo, Rocco; Basilisco, Guido; Somalvico, Francesco; Borgatta, Bruno; Leandro, Gioacchino; Segato, Sergio; Barisani, Donatella; Morreale, Gaetano; Buscarini, Elisabetta

2016-01-01

Non-celiac gluten sensitivity (NCGS) is characterized by the onset of symptoms after eating gluten-containing food. We aimed to single out NCGS subjects among subjects with functional gastrointestinal symptoms. Patients were enrolled in a multicenter double-blind placebo-controlled trial with crossover. Symptoms and quality of life were evaluated by means of 10-cm VAS and SF36. Iron parameters, transaminases and C reactive protein (CRP) were evaluated. After a three-week-long gluten-free diet (GFD), responsive patients were randomly assigned to gluten intake (5.6 g/day) or placebo for seven days, followed by crossover. The primary endpoint was the worsening of symptoms (VAS increase ≥3 cm) during gluten ingestion compared to placebo. One hundred and forty patients were enrolled and 134 (17 males, mean age 39.1 ± 11.7 years, BMI 22.4 ± 3.8) completed the first period. A total of 101 subjects (10 males, mean age 39.3 ± 11.0 years, BMI 22.3 ± 4.0) reported a symptomatic improvement (VAS score 2.3 ± 1.2 vs. 6.5 ± 2.2 before and after GFD, p = 0.001). 98 patients underwent the gluten challenge and 28 (all females, mean age 38.9 ± 12.7 years, BMI 22.0 ± 2.9) reported a symptomatic relapse and deterioration of quality of life. No parameters were found to be statistically associated with positivity to the challenge. However, 14 patients responded to the placebo ingestion. Taking into account this finding, about 14% of patients responding to gluten withdrawal showed a symptomatic relapse during the gluten challenge. This group is suspected to have NCGS. PMID:26867199

Nitrogen Nutrition Improves the Potential of Wheat (Triticum aestivum L.) to Alleviate the Effects of Drought Stress during Vegetative Growth Periods.

PubMed

Abid, Muhammad; Tian, Zhongwei; Ata-Ul-Karim, Syed Tahir; Cui, Yakun; Liu, Yang; Zahoor, Rizwan; Jiang, Dong; Dai, Tingbo

2016-01-01

Efficient nitrogen (N) nutrition has the potential to alleviate drought stress in crops by maintaining metabolic activities even at low tissue water potential. This study was aimed to understand the potential of N to minimize the effects of drought stress applied/occur during tillering (Feekes stage 2) and jointing (Feekes stage 6) growth stages of wheat by observing the regulations and limitations of physiological activities, crop growth rate during drought periods as well as final grain yields at maturity. In present study, pot cultured plants of a wheat cultivar Yangmai-16 were exposed to three water levels [severe stress at 35-40% field capacity (FC), moderate stress at 55-60% FC and well-watered at 75-80% FC] under two N rates (0.24 g and 0.16 g/kg soil). The results showed that the plants under severe drought stress accompanied by low N exhibited highly downregulated photosynthesis, and chlorophyll (Chl) fluorescence during the drought stress periods, and showed an accelerated grain filling rate with shortened grain filling duration (GFD) at post-anthesis, and reduced grain yields. Severe drought-stressed plants especially at jointing, exhibited lower Chl and Rubisco contents, lower efficiency of photosystem II and greater grain yield reductions. In contrast, drought-stressed plants under higher N showed tolerance to drought stress by maintaining higher leaf water potential, Chl and Rubisco content; lower lipid peroxidation associated with higher superoxide dismutase and ascorbate peroxidase activities during drought periods. The plants under higher N showed delayed senescence, increased GFD and lower grain yield reductions. The results of the study suggested that higher N nutrition contributed to drought tolerance in wheat by maintaining higher photosynthetic activities and antioxidative defense system during vegetative growth periods.

Label-free SPR detection of gluten peptides in urine for non-invasive celiac disease follow-up.

PubMed

Soler, Maria; Estevez, M-Carmen; Moreno, Maria de Lourdes; Cebolla, Angel; Lechuga, Laura M

2016-05-15

Motivated by the necessity of new and efficient methods for dietary gluten control of celiac patients, we have developed a simple and highly sensitive SPR biosensor for the detection of gluten peptides in urine. The sensing methodology enables rapid and label-free quantification of the gluten immunogenic peptides (GIP) by using G12 mAb. The overall performance of the biosensor has been in-depth optimized and evaluated in terms of sensitivity, selectivity and reproducibility, reaching a limit of detection of 0.33 ng mL(-1). Besides, the robustness and stability of the methodology permit the continuous use of the biosensor for more than 100 cycles with excellent repeatability. Special efforts have been focused on preventing and minimizing possible interferences coming from urine matrix enabling a direct analysis in this fluid without requiring extraction or purification procedures. Our SPR biosensor has proven to detect and identify gluten consumption by evaluating urine samples from healthy and celiac individuals with different dietary gluten conditions. This novel biosensor methodology represents a novel approach to quantify the digested gluten peptides in human urine with outstanding sensitivity in a rapid and non-invasive manner. Our technique should be considered as a promising opportunity to develop Point-of-Care (POC) devices for an efficient, simple and accurate gluten free diet (GFD) monitoring as well as therapy follow-up of celiac disease patients. Copyright © 2015 Elsevier B.V. All rights reserved.

Notes on the 1978 summer study program on dynamo models of geomagnetism in geophysical fluid dynamics at the Woods Hole Oceanographic Institution. Technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malkus, W.V.R.; Thayer, M.

1978-11-01

This volume contains the manuscripts of research lectures by the eleven fellows of the summer program. Five of the lectures overlap significantly with the central summer theme of geomagnetism. The other six lectures cover a broad range of current G.F.D. topics from collective instability to strange attractors. Several of these research efforts are quite polished and probably will appear in journals soon. The middle half represent reports of sound progress on studies of thesis calibre. A few of the lectures report on only the very first consequences of a novel idea.

Rhabdomyolysis and coeliac disease: A causal or casual association? A case report and review of literature.

PubMed

Mandato, Claudia; Rossi, Alessandro; Caldore, Mariano; Lamba, Marta; Rocco, Michele; Auricchio, Renata; Vajro, Pietro; Siani, Paolo

2018-02-01

Rhabdomyolysis is a rare, potentially life-threatening condition, caused by multiple disorders. The association with Coeliac Disease (CD) has been rarely reported and in these cases muscular damage was imputed to hypokalemia. Herein we describe a new case of severe rhabdomyolysis in a child subsequently diagnosed as affected by CD, and review previous reports. A 3-year-old boy was referred for diarrhea, brown urine, muscular pain/weakness, and no history of muscular trauma. At entry, laboratory tests showed elevated levels of creatine kinase (CK) (x100 unv) and aspartate aminotransferase (AST) (x10 unv), alanine aminotrasferase (ALT) (x5 unv); electrolytes were within the reference range. Twenty-four hours after admission serum CK peaked 115,000 U/L and transaminases increased up to 30 times unv. Hyperhydration treatment was started with renal function monitoring. Urine output decreased little, while serum creatinine and urea nitrogen stayed within the reference range. Serum potassium levels went down to 2.8 mEq/L at day 3, in spite of supplementation. The patient completely recovered at day 16. Main metabolic causes of rhabdomyolysis were ruled out by appropriate tests. Because of rarely reported cases of CD/rhabdomyolysis, anti-tissue transglutaminase (tTG) antibodies were measured and found positive (IgA 34 U/mL, unv <9). HLA typing was DQA1 05:02, DQB1 03:02. As jejunal biopsy showed patchy villous atrophy, gluten free diet (GFD) was prescribed. One year after starting GFD, histology was normal. Literature (search engines: PUB MED and GOOGLE SCHOLAR) from 1980 to 2016 retrieved 8 cases (age range: 12 to 75 years old) previously described. The present case suggests to check for CD in children with severe rhabdomyolysis. Because severe rhabdomyolysis itself may elevate the serum potassium levels, hypokalemia might go unrecognized as the cause of muscular damage. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Self-reported dietary adherence, disease-specific symptoms, and quality of life are associated with healthcare provider follow-up in celiac disease.

PubMed

Hughey, Jacob J; Ray, Bonnie K; Lee, Anne R; Voorhees, Kristin N; Kelly, Ciaran P; Schuppan, Detlef

2017-12-11

The only treatment for celiac disease (CeD) is a lifelong gluten-free diet (GFD). The restrictive nature of the GFD makes adherence a challenge. As an integral part of CeD management, multiple professional organizations recommend regular follow-up with a healthcare provider (HCP). Many CeD patients also participate in patient advocacy groups (PAGs) for education and support. Previous work found that follow-up of CeD patients is highly variable. Here we investigated the self-reported factors associated with HCP follow-up among individuals diagnosed with CeD who participate in a PAG. We conducted a survey of members of Beyond Celiac (a PAG), collecting responses from 1832 U.S. adults ages 19-65 who reported having CeD. The survey queried HCP follow-up related to CeD and included validated instruments for dietary adherence (CDAT), disease-specific symptoms (CSI), and quality of life (CD-QOL). Overall, 27% of respondents diagnosed with CeD at least five years ago reported that they had not visited an HCP about CeD in the last five years. The most frequent reason for not visiting an HCP was "doing fine on my own" (47.6%). Using multiple logistic regression, we identified significant associations between whether a respondent reported visiting an HCP about CeD in the last five years and the scores for all three validated instruments. In particular, as disease-specific symptoms and quality of life worsened, the probability of having visited an HCP increased. Conversely, as dietary adherence worsened, the probability decreased. Our results suggest that many individuals with CeD manage their disease without ongoing support from an HCP. Our results thus emphasize the need for greater access to high quality CeD care, and highlight an opportunity for PAGs to bring together patients and HCPs to improve management of CeD.

Are we diagnosing too many people with coeliac disease?

PubMed

Aziz, Imran; Sanders, David S

2012-11-01

This review will try to address the question of whether we are diagnosing too many people with coeliac disease. The key reasons for diagnosing coeliac disease may be that it is a common condition affecting up to 1% of the adult population. Delays in diagnosis are common. The average time delay reported by Coeliac UK (National Medical Patient Charity), for patients with symptoms prior to the diagnosis being made is 13 years. For every adult case detected, it is estimated that there are eight cases not detected. Patients with coeliac disease have an associated morbidity and mortality. In addition, quality of life studies suggest that the majority of patients benefit from a gluten-free diet (GFD). Furthermore, the GFD reduces or alleviates the risk of the associated complications. All of these facts could even be used to support the argument for screening! However, conversely the tests for coeliac disease are not 100% sensitive and specific. In addition, we do not know whether patients with milder symptoms will derive less benefit from treatment and are at less risk of complications. Furthermore, evidence presented in this review suggests that actual outcomes for screening studies in an adult population have revealed poor uptake and subsequently difficulties with adherence. What little published data that are available also infers that individuals recognised through screening programmes could have been detected if carefully questioned for symptoms. There is evidence to suggest that diagnosing celiac disease is cost-effective and that the diagnostic costs are offset by reduced medical expenditures, reduced hospital and general practice attendances, but this view depends on the population prevalence of coeliac disease. We believe on the basis of the evidence presented in this review that we are not diagnosing too many adults with coeliac disease. However, the authors consider case-finding with a low threshold for serological testing to be the optimal approach. If you look for coeliac disease you will find it.

Dermatitis herpetiformis: a cutaneous manifestation of coeliac disease.

PubMed

Collin, Pekka; Salmi, Teea T; Hervonen, Kaisa; Kaukinen, Katri; Reunala, Timo

2017-02-01

Dermatitis herpetiformis (DH) is an itchy blistering skin disease with predilection sites on elbows, knees, and buttocks. Diagnosis is confirmed by showing granular immunoglobulin A deposits in perilesional skin. DH is one manifestation of coeliac disease; the skin symptoms heal with gluten free diet (GFD) and relapse on gluten challenge. Of the first-degree relatives, 5% may be affected by either condition. Tissue transglutaminase (TG2) is the autoantigen in coeliac disease and epidermal transglutaminase (TG3) in DH. Both diseases conditions exhibit TG2-specific autoantibodies in serum and small bowel mucosa; patients with DH have IgA-TG3 in the skin. There are some divergencies between these two phenotypes. One-fourth of DH patients do not have small bowel mucosal villous atrophy, but virtually all have coeliac-type inflammatory changes. The skin symptoms respond slowly to GFD. The incidence of coeliac disease is increasing, whereas the opposite is true for DH. A female predominance is evident in coeliac disease, while DH may be more common in males. Coeliac disease carries the risk of small intestinal T-cell lymphoma; in DH B-cell lymphomas at any site may prevail. Adult coeliac disease carries a slightly increased elevated mortality risk, whereas in DH, the relative mortality rate is significantly decreased. Key messages Dermatitis herpetiformis is a cutaneous manifestation of coeliac disease; both conditions are genetically determined and gluten-dependent. Gastrointestinal symptoms and the degree of villous atrophy are less obvious in dermatitis herpetiformis than in coeliac disease. Both show tissue transglutaminase (TG2) specific autoantibodies in serum and small bowel mucosa. In addition, TG3-targeted IgA antibodies are found in the skin of DH patients Both conditions carry an increased elevated risk of lymphoma, in coeliac disease small intestinal T-cell lymphoma, in dermatitis herpetiformis mainly B-cell lymphoma at various sites. Coeliac disease is currently eight times more common that DH; the incidence of DH is decreasing in contrast to that of coeliac disease, where it is increasing.

Neighborhood diversity of potentially pathogenic bacteria in drinking water from the city of Maroua, Cameroon.

PubMed

Healy-Profitós, Jessica; Lee, Seungjun; Mouhaman, Arabi; Garabed, Rebecca; Moritz, Mark; Piperata, Barbara; Lee, Jiyoung

2016-06-01

This study examined the spatial variation of potential gastrointestinal pathogens within drinking water sources and home storage containers in four neighborhoods in Maroua, Cameroon. Samples were collected from source (n = 28) and home containers (n = 60) in each study neighborhood. Pathogen contamination was assessed using quantitative polymerase chain reaction, targeting Campylobacter spp., Shiga toxin producing Escherichia coli (virulence genes, stx1 and stx2), and Salmonella spp. Microbial source tracking (MST) targeted three different host-specific markers: HF183 (human), Rum2Bac (ruminant) and GFD (poultry) to identify contamination sources. Staphylococcus aureus and the tetracycline-resistance gene (tetQ) were assessed to measure human hand contact and presence of antibiotic-resistant bacteria. Pathogen/MST levels were compared statistically and spatially, and neighborhood variation was compared with previously collected demographic information. All the test fecal markers and pathogens (except Arcobacter) were detected in home and source samples. Two neighborhoods tested positive for most pathogens/MST while the others only tested positive for one or two. Spatial variation of pathogens/MST existed between sources, storage containers, and neighborhoods. Differing population density and ethno-economic characteristics could potentially explain variation. Future research should explore the influence of demographic and ethno-economic factors on water quality during microbial risk assessments in urban Africa.

Mapping QTLs for grain yield components in wheat under heat stress.

PubMed

Bhusal, Nabin; Sarial, Ashok Kumar; Sharma, Pradeep; Sareen, Sindhu

2017-01-01

The current perspective of increasing global temperature makes heat stress as a major threat to wheat production worldwide. In order to identify quantitative trait loci (QTLs) associated with heat tolerance, 251 recombinant inbred lines (RILs) derived from a cross between HD2808 (heat tolerant) and HUW510 (heat susceptible) were evaluated under timely sown (normal) and late sown (heat stress) conditions for two consecutive crop seasons; 2013-14 and 2014-15. Grain yield (GY) and its components namely, grain weight/spike (GWS), grain number/spike (GNS), thousand grain weight (TGW), grain filling rate (GFR) and grain filling duration (GFD) were recorded for both conditions and years. The data collected for both timely and late sown conditions and heat susceptibility index (HSI) of these traits were used as phenotypic data for QTL identification. The frequency distribution of HSI for all the studied traits was continuous during both the years and also included transgressive segregants. Composite interval mapping identified total 24 QTLs viz., 9 (timely sown traits), 6 (late sown traits) and 9 (HSI of traits) mapped on linkage groups 2A, 2B, and 6D during both the crop seasons 2013-14 and 2014-15. The QTLs were detected for GWS (6), GNS (6), GFR (4), TGW (3), GY (3) and GFD (2). The LOD score of identified QTLs varied from 3.03 (Qtgns.iiwbr-6D) to 21.01 (Qhsitgw.iiwbr-2A) during 2014-15, explaining 11.2 and 30.6% phenotypic variance, respectively. Maximum no of QTLs were detected in chromosome 2A followed by 6D and 2B. All the QTL detected under late sown and HSI traits were identified on chromosome 2A except for QTLs associated with GFD. Fifteen out of 17 QTL detected on chromosome 2A were clustered within the marker interval between gwm448 and wmc296 and showed tight linkage with gwm122 and these were localized in 49-52 cM region of Somers consensus map of chromosome 2A i.e. within 18-59.56 cM region of chromosome 2A where no QTL related to heat stress were reported earlier. Besides, three consistent QTLs, Qgws.iiwbr-2A, Qgns.iiwbr-2A and Qgns.iiwbr-2A were also detected in all the environments in this region. The nearest QTL detected in earlier studies, QFv/Fm.cgb-2A was approximately 6cM below the presently identified QTLs region, respectively Additionally, QTLs for physiological and phenological traits and plant height under late sown and HSI of these traits were also detected on chromosome 2A. QTL for HSI of plant height and physiological maturity were located in the same genomic region of chromosome 2Awhereas QTLs for physiological and phonological traits under late sown were located 8cM and 33.5 cM below the genomic location associated with grain traits, respectively in consensus map of Somers. This QTL hot-spot region with consistent QTLs could be used to improve heat tolerance after validation.

Recognising and Managing Refractory Coeliac Disease: A Tertiary Centre Experience.

PubMed

Nasr, Ikram; Nasr, Iman; Beyers, Carl; Chang, Fuju; Donnelly, Suzanne; Ciclitira, Paul J

2015-12-01

Refractory coeliac disease (RCD) is a rare complication of coeliac disease (CD) and involves malabsorption and villous atrophy despite adherence to a strict gluten-free diet (GFD) for at least 12 months in the absence of another cause. RCD is classified based on the T-cells in the intra-epithelial lymphocyte (IEL) morphology into type 1 with normal IEL and type 2 with aberrant IEL (clonal) by PCR (polymerase chain reaction) for T cell receptors (TCR) at the β/γ loci. RCD type 1 is managed with strict nutritional and pharmacological management. RCD type 2 can be complicated by ulcerative jejunitis or enteropathy associated lymphoma (EATL), the latter having a five-year mortality of 50%. Management options for RCD type 2 and response to treatment differs across centres and there have been debates over the best treatment option. Treatment options that have been used include azathioprine and steroids, methotrexate, cyclosporine, campath (an anti CD-52 monoclonal antibody), and cladribine or fluadribine with or without autologous stem cell transplantation. We present a tertiary centre's experience in the treatment of RCD type 2 where treatment with prednisolone and azathioprine was used, and our results show good response with histological recovery in 56.6% of treated individuals.

Proto-Typing Research Aimed for Secondary School Students and Teachers

NASA Astrophysics Data System (ADS)

Walker, C. E.; Fersch, A.; Barringer, D.; Pompea, S. M.

2011-12-01

In workshops on GLOBE at Night, teacher professional development has begun on using night sky brightness data and bat telemetry data to do scientific research in the classroom. The study looks at the effects of light pollution on the flight paths of threatened and endangered (T&E) bats between their day roosts and night foraging areas. A jump-start in getting secondary school students involved was the BioBlitz event in Tucson, Arizona in October 2011. During the 24-hour event, night Sky Quality Meter (SQM) data was taken across the Saguaro National Park West, through Tucson and across the Saguaro National Park East. The program had its beginning with a pair of Research Experiences for Undergraduates (REU) students and their advisor. Through the collaboration of the National Science Foundation's REU program, the National Optical Astronomy Observatory's GLOBE at Night program and the U.S. Arizona Game and Fish Department (AzGFD), two REU students along with their advisor used data from the GLOBE at Night project and telemetry tracking data of lesser long-nosed bats to study the effects of light pollution on the flight paths of the bats between their day roosts and night foraging areas around the city of Tucson, AZ. During the summer of 2010, the first REU student used the visual limiting magnitude data from GLOBE at Night and, with the assistance of the AzGFD, ran compositional analyses with respect to the bats' flight paths to determine whether the bats were selecting for or against flight through regions of particular night sky brightness levels. The bats selected for the regions in which the limiting sky magnitudes fell between the ranges of 2.8-3.0 to 3.6-3.8 and 4.4-4.6 to 5.0-5.2, suggesting that the lesser long-nosed bat can tolerate a fair degree of urbanization. Three areas of systematic uncertainty were identified of which 2 could be addressed the following summer. Due to a relatively large uncertainty in each individually measured visual limiting magnitude, Sky Quality Meter (SQM) measurements were subsequently used as a more objective source of data. In addition, the area over which the data was taken was expanded to redress spurious edge effects in making contour maps. During the summer of 2011, the second REU student took more SQM data and, with the SQM database from GLOBE at Night and the assistance of the AzGFD, performed a logistic regression analysis with respect to the bats' flight paths to determine whether the bats preferred or avoided flight through regions of particular night sky brightness levels. During the presentation, we will provide more on the analysis and conclusions of the research, as well as the extension of the program to secondary students and teachers. Should the conclusion be that the bats are preferentially staying in darker areas, a next step for students and teachers would include helping to maintain a dark corridor where the T&E lesser long nosed bats travel between roosts and foraging areas. Should this prototype project succeed, it will be used as a template for other REU and secondary school research projects on endangered animals across the U.S. affected by light pollution. Teacher professional development will play a big role in the program's future success.

Cardiovascular involvement in celiac disease

PubMed Central

Ciaccio, Edward J; Lewis, Suzanne K; Biviano, Angelo B; Iyer, Vivek; Garan, Hasan; Green, Peter H

2017-01-01

Celiac disease (CD) is an autoimmune response to ingestion of gluten protein, which is found in wheat, rye, and barley grains, and results in both small intestinal manifestations, including villous atrophy, as well as systemic manifestations. The main treatment for the disease is a gluten-free diet (GFD), which typically results in the restoration of the small intestinal villi, and restoration of other affected organ systems, to their normal functioning. In an increasing number of recently published studies, there has been great interest in the occurrence of alterations in the cardiovascular system in untreated CD. Herein, published studies in which CD and cardiovascular terms appear in the title of the study were reviewed. The publications were categorized into one of several types: (1) articles (including cohort and case-control studies); (2) reviews and meta-analyses; (3) case studies (one to three patient reports); (4) letters; (5) editorials; and (6) abstracts (used when no full-length work had been published). The studies were subdivided as either heart or vascular studies, and were further characterized by the particular condition that was evident in conjunction with CD. Publication information was determined using the Google Scholar search tool. For each publication, its type and year of publication were tabulated. Salient information from each article was then compiled. It was determined that there has been a sharp increase in the number of CD - cardiovascular studies since 2000. Most of the publications are either of the type “article” or “case study”. The largest number of documents published concerned CD in conjunction with cardiomyopathy (33 studies), and there have also been substantial numbers of studies published on CD and thrombosis (27), cardiovascular risk (17), atherosclerosis (13), stroke (12), arterial function (11), and ischemic heart disease (11). Based on the published research, it can be concluded that many types of cardiovascular issues can occur in untreated CD patients, but that most tend to resolve on a GFD, often in conjunction with the healing of small intestinal villous atrophy. However, in some cases the alterations are irreversible, underscoring the need for CD screening and treatment when cardiovascular issues arise of unknown etiology. PMID:28932354

CYP3A4-catalyzed simvastatin metabolism as a non-invasive marker of small intestinal health in celiac disease.

PubMed

Morón, Belén; Verma, Anil K; Das, Prasenjit; Taavela, Juha; Dafik, Laila; Diraimondo, Thomas R; Albertelli, Megan A; Kraemer, Thomas; Mäki, Markku; Khosla, Chaitan; Rogler, Gerhard; Makharia, Govind K

2013-08-01

Histological examination of duodenal biopsies is the gold standard for assessing intestinal damage in celiac disease (CD). A noninvasive marker of disease status is necessary, because obtaining duodenal biopsies is invasive and not suitable for routine monitoring of CD patients. As the small intestine is a major site of cytochrome P450 3A4 (CYP3A4) activity and also the location of the celiac lesion, we investigated whether patients with active CD display abnormal pharmacokinetics of an orally administered CYP3A4 substrate, simvastatin (SV), which could potentially be used for noninvasive assessment of their small intestinal health. Preclinical experiments were performed in CYP3A4-humanized mice to examine the feasibility of the test. Subsequently, a clinical trial was undertaken with 11 healthy volunteers, 18 newly diagnosed patients with CD, and 25 celiac patients who had followed a gluten-free diet (GFD) for more than 1 year. The maximum concentration (Cmax) of orally administered SV plus its major non-CYP3A4-derived metabolite SV acid (SV equivalent (SVeq)) was measured, and compared with clinical, histological, and serological parameters. In CYP3A4-humanized mice, a marked decrease in SV metabolism was observed in response to enteropathy. In the clinical setting, untreated celiac patients displayed a significantly higher SVeq Cmax (46±24 nM) compared with treated patients (21±16 nM, P<0.001) or healthy subjects (19±11 nM, P<0.005). SVeq Cmax correctly predicted the diagnosis in 16/18 untreated celiac patients, and also the recovery status of all follow-up patients that exhibited normal or near-normal biopsies (Marsh 0-2). All patients with abnormal SVeq Cmax showed a reduction in the value after 1 year of following a GFD. SVeq Cmax is a promising noninvasive marker for assessment of small intestinal health. Further studies are warranted to establish its clinical utility for assessing gut status of patients with CD.

Recognising and Managing Refractory Coeliac Disease: A Tertiary Centre Experience

PubMed Central

Nasr, Ikram; Nasr, Iman; Beyers, Carl; Chang, Fuju; Donnelly, Suzanne; Ciclitira, Paul J.

2015-01-01

Refractory coeliac disease (RCD) is a rare complication of coeliac disease (CD) and involves malabsorption and villous atrophy despite adherence to a strict gluten-free diet (GFD) for at least 12 months in the absence of another cause. RCD is classified based on the T-cells in the intra-epithelial lymphocyte (IEL) morphology into type 1 with normal IEL and type 2 with aberrant IEL (clonal) by PCR (polymerase chain reaction) for T cell receptors (TCR) at the β/γ loci. RCD type 1 is managed with strict nutritional and pharmacological management. RCD type 2 can be complicated by ulcerative jejunitis or enteropathy associated lymphoma (EATL), the latter having a five-year mortality of 50%. Management options for RCD type 2 and response to treatment differs across centres and there have been debates over the best treatment option. Treatment options that have been used include azathioprine and steroids, methotrexate, cyclosporine, campath (an anti CD-52 monoclonal antibody), and cladribine or fluadribine with or without autologous stem cell transplantation. We present a tertiary centre’s experience in the treatment of RCD type 2 where treatment with prednisolone and azathioprine was used, and our results show good response with histological recovery in 56.6% of treated individuals. PMID:26633478

Coeliac Disease – New Pathophysiological Findings and Their Implications for Therapy

PubMed Central

Stein, Jürgen; Schuppan, Detlef

2014-01-01

Summary Coeliac disease (CD) is one of the most common diseases worldwide, resulting from a combination of environmental (gluten) and genetic (human leucocyte antigen (HLA) and non-HLA genes) factors. Depending on the geographical location, the prevalence of CD has been estimated to approximate 0.5-1%. The only treatment currently available for CD is a gluten-free diet (GFD) excluding gluten-containing cereals such as wheat, rye, and barley, and other foodstuffs with natural or added gluten. However, adherence rates and patient acceptance are often poor. Moreover, even in fully adherent patients, the diet may fail to induce clinical or histological improvement. Hence, it is unsurprising that studies show CD patients to be highly interested in non-dietary alternatives. The following review focuses on current pathophysiological concepts of CD, spotlighting those pathways which may serve as new possible, non-dietary therapeutic targets in the treatment of CD. PMID:26288589

Analysis of Taiwan patents for the medicinal mushroom "Niu-Chang- Chih".

PubMed

Chen, Yu-Fen; Lu, Wen-Ling; Wu, Ming-Der; Yuan, Gwo-Fang

2013-04-01

"Niu-Chang-Chih" (Antrodia cinnanomea) is a medicinal mushroom that has only been collected from the aromatic tree, Cinnamomum kanehirai, which is native to Taiwan. A total of 105 Taiwan patent applications and patents for "Niu-Chang-Chih" were collected and analyzed. Patent applications and granted patents claiming newly identified functional components from "Niu-Chang-Chih," biologically pure cultures of the mushroom strain, and cultivation of "Niu-Chang-Chih" were examined. Several applications and patents claim identified active compounds from "Niu-Chang- Chih," which provide better patent protection. These newly identified functional compounds include cyclohexanones, maleic and succinic acid derivatives, labdane diterpenoids, and benzenoids. Newly identified functional proteins include a glutathione-dependent formaldehyde dehydrogenase (GFD), a glycoprotein named ACA1, and a laccase. Newly identified functional polysaccharides include ACP1, ACP2, and ACP3. The number of patents for newly identified compounds and their uses are expected to continue growing.

Dietary Gluten-Induced Gut Dysbiosis Is Accompanied by Selective Upregulation of microRNAs with Intestinal Tight Junction and Bacteria-Binding Motifs in Rhesus Macaque Model of Celiac Disease.

PubMed

Mohan, Mahesh; Chow, Cheryl-Emiliane T; Ryan, Caitlin N; Chan, Luisa S; Dufour, Jason; Aye, Pyone P; Blanchard, James; Moehs, Charles P; Sestak, Karol

2016-10-28

The composition of the gut microbiome reflects the overall health status of the host. In this study, stool samples representing the gut microbiomes from 6 gluten-sensitive (GS) captive juvenile rhesus macaques were compared with those from 6 healthy, age- and diet-matched peers. A total of 48 samples representing both groups were studied using V4 16S rRNA gene DNA analysis. Samples from GS macaques were further characterized based on type of diet administered: conventional monkey chow, i.e., wheat gluten-containing diet (GD), gluten-free diet (GFD), barley gluten-derived diet (BOMI) and reduced gluten barley-derived diet (RGB). It was hypothesized that the GD diet would lower the gut microbial diversity in GS macaques. This is the first report illustrating the reduction of gut microbial alpha-diversity ( p < 0.05) following the consumption of dietary gluten in GS macaques. Selected bacterial families (e.g., Streptococcaceae and Lactobacillaceae ) were enriched in GS macaques while Coriobacteriaceae was enriched in healthy animals. Within several weeks after the replacement of the GD by the GFD diet, the composition (beta-diversity) of gut microbiome in GS macaques started to change ( p = 0.011) towards that of a normal macaque. Significance for alpha-diversity however, was not reached by the day 70 when the feeding experiment ended. Several inflammation-associated microRNAs (miR-203, -204, -23a, -23b and -29b) were upregulated ( p < 0.05) in jejunum of 4 biopsied GS macaques fed GD with predicted binding sites on 16S ribosomal RNA of Lactobacillus reuteri (accession number: NR_025911), Prevotella stercorea (NR_041364) and Streptococcus luteciae (AJ297218) that were overrepresented in feces. Additionally, claudin-1, a validated tight junction protein target of miR-29b was significantly downregulated in jejunal epithelium of GS macaques. Taken together, we predict that with the introduction of effective treatments in future studies the diversity of gut microbiomes in GS macaques will approach those of healthy individuals. Further studies are needed to elucidate the regulatory pathways of inflammatory miRNAs in intestinal mucosa of GS macaques and to correlate their expression with gut dysbiosis.

Tooth Wear Is Frequent in Adult Patients with Celiac Disease

PubMed Central

Amato, Massimo; Zingone, Fabiana; Iovino, Paola; Bucci, Cristina; Ciacci, Carolina

2017-01-01

(1) Background: Celiac disease (CD) patients can be affected by mouth and tooth disorders, which are influenced by their gluten-free diet. The aim of our research was to evaluate the pathological conditions of the stomatognathic system observed in celiac patients on a gluten-free diet. (2) Methods: we consecutively recruited celiac patients on a gluten-free diet at our celiac center, as well as healthy volunteers. Two dentists examined all patients/controls and checked them for any mouth disorder. (3) Results: Forty-nine patients affected by celiac disease (age at test 31.8 ± 11.58, time on GFD 8.73 ± 7.7) and 51 healthy volunteers (age at test 30.5 ± 8.7) were included. Recurrent aphthous stomatitis was reported in 26 patients (53.0%) and in 13 (25.5%) controls (p = 0.005). Dental enamel disorders were reported in 7 patients (14.3%) and in 0 controls (p = 0.002), with none having geographic tongue. We found non-specific tooth wear, characterized by loss of the mineralized tissue of the teeth, in 9 patients (18.3%) and in 3 (5.9%) controls (p = 0.05). (4) Conclusion: Recurrent aphthous stomatitis and enamel hypoplasia are “risk indicators” that may suggest that an individual has CD. We detected a high prevalence of non-specific tooth wear that can be caused by several factors such as malocclusion, sleep bruxism, parafunctional activity, and age. PMID:29207559

Celiac disease or non-celiac gluten sensitivity? An approach to clinical differential diagnosis.

PubMed

Kabbani, Toufic A; Vanga, Rohini R; Leffler, Daniel A; Villafuerte-Galvez, Javier; Pallav, Kumar; Hansen, Joshua; Mukherjee, Rupa; Dennis, Melinda; Kelly, Ciaran P

2014-05-01

Differentiating between celiac disease (CD) and non-celiac gluten sensitivity (NCGS) is important for appropriate management but is often challenging. We retrospectively reviewed records from 238 patients who presented for the evaluation of symptoms responsive to gluten restriction without prior diagnosis or exclusion of CD. Demographics, presenting symptoms, serologic, genetic, and histologic data, nutrient deficiencies, personal history of autoimmune diseases, and family history of CD were recorded. NCGS was defined as symptoms responsive to a gluten-free diet (GFD) in the setting of negative celiac serology and duodenal biopsies while on a gluten-containing diet or negative human leukocyte antigen (HLA) DQ2/DQ8 testing. Of the 238 study subjects, 101 had CD, 125 had NCGS, 9 had non-celiac enteropathy, and 3 had indeterminate diagnosis. CD subjects presented with symptoms of malabsorption 67.3% of the time compared with 24.8% of the NCGS subjects (P<0.0001). In addition, CD subjects were significantly more likely to have a family history of CD (P=0.004), personal history of autoimmune diseases (P=0.002), or nutrient deficiencies (P<0.0001). The positive likelihood ratio for diagnosis of CD of a >2× upper limit of normal IgA trans-glutaminase antibody (tTG) or IgA/IgG deaminated gliadan peptide antibody (DGP) with clinical response to GFD was 130 (confidence interval (CI): 18.5-918.3). The positive likelihood ratio of the combination of gluten-responsive symptoms and negative IgA tTG or IgA/IgG DGP on a regular diet for NCGS was 9.6 (CI: 5.5-16.9). When individuals with negative IgA tTG or IgA/IgG DGP also lacked symptoms of malabsorption (weight loss, diarrhea, and nutrient deficiencies) and CD risk factors (personal history of autoimmune diseases and family history of CD), the positive likelihood ratio for NCGS increased to 80.9. On the basis of our findings, we have developed a diagnostic algorithm to differentiate CD from NCGS. Subjects with negative celiac serologies (IgA tTG or IgA/IgG DGP) on a regular diet are unlikely to have CD. Those with negative serology who also lack clinical evidence of malabsorption and CD risk factors are highly likely to have NCGS and may not require further testing. Those with equivocal serology should undergo HLA typing to determine the need for biopsy.

[Reproductive disorders in women with celiac disease. Effect of the etiotropic therapy].

PubMed

Bykova, S V; Sabel'nikova, E A; Parfenov, A I; Gudkova, R B; Krums, L M; Chikunova, B Z

2011-01-01

Violation of reproductive function in patients with celiac disease can manifest as delayed puberty, infertility, amenorrhea, premature menopause, spontaneous abortion, low birth weight. The aim of the study was to establish the frequency and nature of reproductive function violation in patients with CD in the Russian Federation. The study included 132 women (average age 38,5 +/- 1,17 years) with CD observed in CSRIG in the period from 2000 to 2010. Comparison group consisted 105 women (average age 38,7 +/- 1,6 years) with predominantly functional bowel disorders (irritable bowel syndrome, functional constipation, functional bloating, inert colon). Were took into account information regarding obstetric history, physical and laboratory signs of malabsorption syndrome (MS) study of antibodies to alpha-gliadin immunoglobulin (IG) A class (AGA) and tissue transglutaminase (AtTG). The average age of onset of menses was 14,3 +/- 1,4 years, and in the control group - 13,0 +/- 1,3 years (p > 0.05), half of patients with C (43.9%) had menstruation begun at age 15 years and older, while 7.6% of the women--aged 17 and older. In the comparison group menses beginning after 15 years was only at 13.3% of women. In 61.3% of patients with CD was irregular menstrual cycle while in the comparison group such violations were noted in 13.3% (p < 0.001). Prolonged periods of amenorrhea we observed in women with newly diagnosed GC 3 times more likely than the comparison group: 43.9% and 11.4% respectively (p < 0.01). They also had nearly 3 times more likely to occur spontaneous miscarriage: at 46.9% and 14.3% respectively (p < 0.01). The frequency of dead children birth was about the same: 2.3% and 1.9% respectively (p > 0.05). The frequency of reproductive disorders increased with the growth of the severity of MS. In 43% of women after 6-8 months of strict adherence to a gluten-free diet (GFD) had disappeared amenorrhea and there were regular menses. Three women of childbearing age, strictly abided the GFD and had a history of repeated spontaneous abortion during the year managed to get pregnant and give birth to healthy full-term baby. Reproductive disorders in women with celiac disease are significantly more likely than at women with functional bowel disease. One of the reasons of reproductive disorders in patients with CD can be malabsorption of necessary nutrients in the small intestine. The presence of reproductive disorders should be considered as a risk factor for celiac disease, so these women should be screened for celiac disease.

Emerging concepts: from coeliac disease to non-coeliac gluten sensitivity.

PubMed

Aziz, Imran; Sanders, David S

2012-11-01

The rise in gluten consumption over time has led to the increasing recognition of coeliac disease (CD) with associated complications. However, only recently has there been an appreciation that the spectrum of gluten-related disorders is greater than just CD, which may explain the growing global popularity in gluten-free products. Current literature suggests that a newly recognised clinical entity in the form of non-coeliac gluten sensitivity (NCGS) may be the most common gluten-related disorder encountered by healthcare professionals, although its exact prevalence is as yet unknown. This article will review the historical relationship between mankind and gluten as well as the progressive recognition that it is possible for gluten to have a deleterious effect on our health. To this effect we discuss the prevalence, diagnosis and complications of CD including the benefits derived from a gluten-free diet (GFD). Finally, we discuss our current understanding of NCGS, in addition to highlighting the need for further research to determine the extent, clinicopathological features and serological biomarkers to help recognise this emerging condition in clinical practice.

Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities.

PubMed

Balakireva, Anastasia V; Zamyatnin, Andrey A

2016-10-18

Theterm gluten intolerance may refer to three types of human disorders: autoimmune celiac disease (CD), allergy to wheat and non-celiac gluten sensitivity (NCGS). Gluten is a mixture of prolamin proteins present mostly in wheat, but also in barley, rye and oat. Gluten can be subdivided into three major groups: S-rich, S-poor and high molecular weight proteins. Prolamins within the groups possess similar structures and properties. All gluten proteins are evolutionarily connected and share the same ancestral origin. Gluten proteins are highly resistant to hydrolysis mediated by proteases of the human gastrointestinal tract. It results in emergence of pathogenic peptides, which cause CD and allergy in genetically predisposed people. There is a hierarchy of peptide toxicity and peptide recognition by T cells. Nowadays, there are several ways to detoxify gluten peptides: the most common is gluten-free diet (GFD), which has proved its effectiveness; prevention programs, enzymatic therapy, correction of gluten pathogenicity pathways and genetically modified grains with reduced immunotoxicity. A deep understanding of gluten intolerance underlying mechanisms and detailed knowledge of gluten properties may lead to the emergence of novel effective approaches for treatment of gluten-related disorders.

Properties of Gluten Intolerance: Gluten Structure, Evolution, Pathogenicity and Detoxification Capabilities

PubMed Central

Balakireva, Anastasia V.; Zamyatnin, Andrey A.

2016-01-01

Theterm gluten intolerance may refer to three types of human disorders: autoimmune celiac disease (CD), allergy to wheat and non-celiac gluten sensitivity (NCGS). Gluten is a mixture of prolamin proteins present mostly in wheat, but also in barley, rye and oat. Gluten can be subdivided into three major groups: S-rich, S-poor and high molecular weight proteins. Prolamins within the groups possess similar structures and properties. All gluten proteins are evolutionarily connected and share the same ancestral origin. Gluten proteins are highly resistant to hydrolysis mediated by proteases of the human gastrointestinal tract. It results in emergence of pathogenic peptides, which cause CD and allergy in genetically predisposed people. There is a hierarchy of peptide toxicity and peptide recognition by T cells. Nowadays, there are several ways to detoxify gluten peptides: the most common is gluten-free diet (GFD), which has proved its effectiveness; prevention programs, enzymatic therapy, correction of gluten pathogenicity pathways and genetically modified grains with reduced immunotoxicity. A deep understanding of gluten intolerance underlying mechanisms and detailed knowledge of gluten properties may lead to the emergence of novel effective approaches for treatment of gluten-related disorders. PMID:27763541

Intentional and inadvertent non-adherence in adult coeliac disease. A cross-sectional survey.

PubMed

Hall, Nicola J; Rubin, Gregory P; Charnock, Anne

2013-09-01

Adherence to a gluten-free diet is the mainstay of treatment for coeliac disease. Non-adherence is common as the diet is restrictive and can be difficult to follow. This study aimed to determine the rates of intentional and inadvertent non-adherence in adult coeliac disease and to examine the factors associated with both. A self-completion questionnaire was mailed to adult coeliac patients identified from the computer records of 31 family practices within the North East of England. We received 287 responses after one reminder. Intentional gluten consumption was reported by 115 (40%) of respondents. 155 (54%) had made at least one known mistaken lapse over the same period and 82 (29%) reported neither intentional nor mistaken gluten consumption. Using logistic regression analysis, low self-efficacy, perceptions of tolerance to gluten and intention were found to be independently predictive of intentional gluten consumption. A statistical model predicted 71.8% of cases reporting intentional lapses. Intentional non-adherence to the GFD was found to be common but not as frequent as inadvertent lapses. Distinguishing the factors influencing both intentional and inadvertent non-adherence is useful in understanding dietary self-management in coeliac disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Bone morphogenetic protein (BMP)1-3 enhances bone repair.

PubMed

Grgurevic, Lovorka; Macek, Boris; Mercep, Mladen; Jelic, Mislav; Smoljanovic, Tomislav; Erjavec, Igor; Dumic-Cule, Ivo; Prgomet, Stefan; Durdevic, Dragan; Vnuk, Drazen; Lipar, Marija; Stejskal, Marko; Kufner, Vera; Brkljacic, Jelena; Maticic, Drazen; Vukicevic, Slobodan

2011-04-29

Members of the astacin family of metalloproteinases such as human bone morphogenetic protein 1 (BMP-1) regulate morphogenesis by processing precursors to mature functional extracellular matrix (ECM) proteins and several growth factors including TGFβ, BMP2, BMP4 and GFD8. We have recently discovered that BMP1-3 isoform of the Bmp-1 gene circulates in the human plasma and is significantly increased in patients with acute bone fracture. We hypothesized that circulating BMP1-3 might have an important role in bone repair and serve as a novel bone biomarker. When administered systemically to rats with a long bone fracture and locally to rabbits with a critical size defect of the ulna, recombinant human BMP1-3 enhanced bone healing. In contrast, neutralization of the endogenous BMP1-3 by a specific polyclonal antibody delayed the bone union. Invitro BMP1-3 increased the expression of collagen type I and osteocalcin in MC3T3-E(1) osteoblast like cells, and enhanced the formation of mineralized bone nodules from bone marrow mesenchymal stem cells. We suggest that BMP1-3 is a novel systemic regulator of bone repair. Copyright © 2011 Elsevier Inc. All rights reserved.

Microbial source tracking in shellfish harvesting waters in the Gulf of Nicoya, Costa Rica.

PubMed

Symonds, E M; Young, S; Verbyla, M E; McQuaig-Ulrich, S M; Ross, E; Jiménez, J A; Harwood, V J; Breitbart, M

2017-03-15

Current microbial water quality monitoring is generally limited to culture-based measurements of fecal indicator bacteria (FIB). Given the many possible sources of fecal pollution within a watershed and extra-intestinal FIB reservoirs, it is important to determine source(s) of fecal pollution as a means to improve water quality and protect public health. The principal objective of this investigation was to characterize the microbial water quality of shellfish harvesting areas in the Gulf of Nicoya, Costa Rica during 2015. In order to achieve this objective, the specificity and sensitivity of 11 existing microbial source tracking (MST) PCR assays, associated with cows (BacCow), dogs (BacCan, DogBac), domestic wastewater (PMMoV), general avian (GFD), gulls (Gull2), horses (HorseBac, HoF), humans (HF183, HPyV), and pigs (PF), were evaluated using domestic wastewater and animal fecal samples collected from the region. The sensitivity of animal-associated assays ranged from 13 to 100%, while assay specificity ranged from 38 to 100%. The specificity of pepper mild mottle virus (PMMoV) and human polyomavirus (HPyV) was 100% for domestic wastewater, as compared to 94% specificity of the HF183 Bacteroidales marker. PMMoV was identified as a useful domestic wastewater-associated marker, with concentrations as high as 1.1 × 10 5 copies/ml and 100% sensitivity and specificity. Monthly surface water samples collected from four shellfish harvesting areas were analyzed using culture-based methods for Escherichia coli as well as molecular methods for FIB and a suite of MST markers, which were selected for their specificity in the region. While culturable E. coli results suggested possible fecal pollution during the monitoring period, the absence of human/domestic wastewater-associated markers and low FIB concentrations determined using molecular methods indicated sufficient microbial water quality for shellfish harvesting. This is the first study to our knowledge to test the performance of MST markers in Costa Rica as well as in Central America. Given the lack of wastewater treatment and the presence of secondary sources of FIB, this study highlights the importance of an MST toolbox approach to characterize water quality in tropical regions. Furthermore, it confirms and extends the geographic range of PMMoV as an effective tool for monitoring domestic wastewater pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cutaneous Manifestations of Non-Celiac Gluten Sensitivity: Clinical Histological and Immunopathological Features.

PubMed

Bonciolini, Veronica; Bianchi, Beatrice; Del Bianco, Elena; Verdelli, Alice; Caproni, Marzia

2015-09-15

The dermatological manifestations associated with intestinal diseases are becoming more frequent, especially now when new clinical entities, such as Non-Celiac Gluten Sensitivity (NCGS), are identified. The existence of this new entity is still debated. However, many patients with diagnosed NCGS that present intestinal manifestations have skin lesions that need appropriate characterization. We involved 17 patients affected by NCGS with non-specific cutaneous manifestations who got much better after a gluten free diet. For a histopathological and immunopathological evaluation, two skin samples from each patient and their clinical data were collected. The median age of the 17 enrolled patients affected by NCGS was 36 years and 76% of them were females. On the extensor surfaces of upper and lower limbs in particular, they all presented very itchy dermatological manifestations morphologically similar to eczema, psoriasis or dermatitis herpetiformis. This similarity was also confirmed histologically, but the immunopathological analysis showed the prevalence of deposits of C3 along the dermo-epidermal junction with a microgranular/granular pattern (82%). The exact characterization of new clinical entities such as Cutaneous Gluten Sensitivity and NCGS is an important objective both for diagnostic and therapeutic purposes, since these are patients who actually benefit from a GFD (Gluten Free Diet) and who do not adopt it only for fashion.

Efficiency of several micro-fiber glass filters for recovery of poliovirus from tape water.

PubMed Central

Payment, P; Trudel, M

1979-01-01

Micro-fiber glass filters from Gelman, Filterite, Johns-Manville, and Whatman were compared with Millipore membrane filters on the basis of their virus adsorbancy, flow rate, clogging resistance, and virus concentration efficiency by using tap water at 2 nephelometric turbidity units. As virus adsorbants the Johns-Manville D39, Filterite 0.25-micron, Filterite 0.45-micron, and Millipore 0.45-micron filters were the most efficient, retaining more than 99% of the added virus in water at pH 3.5 and 0.0005 M aluminum chloride. The Johns-Manville D79 and D49 filters retained 92 and 96% of the virus, respectively, whereas the Whatman GF-D, Whatman GF-F, Gelman A-E, and Millipore AP-20 filters retained only 28, 78, 56, and 34% of the virus, respectively. The best flow rate and clogging resistance were obtained with the Johns-Manville D79 filter or with this filter acting as a prefilter to the Johns-Manville D49, Johns-Manville D39, or Filterite 0.45-micron filter. Finally, poliovirus experimentally seeded in 20 liters of tape water was recovered from Johns-Manville D79-Johns-Manville D39 or Johns-Manville D79-Filterite 0.45 micron 142-mm filter combinations was a efficiencies of 86 and 85%, respectively. PMID:231414

Validation of a French Version of the Quality of Life “Celiac Disease Questionnaire”

PubMed Central

Pouchot, Jacques; Despujol, Carole; Malamut, Georgia; Ecosse, Emmanuel; Coste, Joël; Cellier, Christophe

2014-01-01

Background and Objective Celiac disease (CD) is a common chronic autoimmune disorder. Both the manifestations of the disease and the burden of the compulsory life-long gluten-free diet (GFD) have been shown to be associated with impairment of health-related quality of life. The objectives of this study were to provide a cross-cultural adaptation of the specific quality of life “Celiac Disease Questionnaire” (CDQ) and to analyze its psychometric properties. Materials and Methods A cross-cultural French adaptation of the CDQ (F-CDQ) was obtained according to the revised international guidelines. The questionnaire was administered at baseline to 211 patients with biopsy proven CD followed-up in a single tertiary referral centre. The questionnaire was also administered after 7 days and 6 months. Reliability (intraclass correlation coefficients (ICC), Cronbach's alpha and Bland and Altman graphical analysis), validity (factorial structure and Rasch analysis, convergent validity), and responsiveness (effect size) of the F-CDQ were studied. Results The reliability of the F-CDQ was excellent with ICC and Cronbach's alpha coefficients being between 0.79 and 0.94 for the four subscales and the total score. The factorial structure and the Rasch analysis showed that the four dimensions of the original instrument were retained. Correlations with external measures (a generic measure of quality of life, an anxiety and depression instrument, a self-assessed disease severity, and clinical manifestations) were all in the expected direction confirming the validity of the instrument. Responsiveness was studied and effect sizes ≥0.20 were demonstrated for most of the subscales for patients who reported improvement or deterioration after 6 months. Conclusion The F-CDQ retains the psychometric properties of the original instrument and should be useful in cross-national surveys and to assess outcome in clinical trials involving patients with CD. PMID:24788794

Effect of Bifidobacterium breve on the Intestinal Microbiota of Coeliac Children on a Gluten Free Diet: A Pilot Study.

PubMed

Quagliariello, Andrea; Aloisio, Irene; Bozzi Cionci, Nicole; Luiselli, Donata; D'Auria, Giuseppe; Martinez-Priego, Llúcia; Pérez-Villarroya, David; Langerholc, Tomaž; Primec, Maša; Mičetić-Turk, Dušanka; Di Gioia, Diana

2016-10-22

Coeliac disease (CD) is associated with alterations of the intestinal microbiota. Although several Bifidobacterium strains showed anti-inflammatory activity and prevention of toxic gliadin peptides generation in vitro, few data are available on their efficacy when administered to CD subjects. This study evaluated the effect of administration for three months of a food supplement based on two Bifidobacterium breve strains (B632 and BR03) to restore the gut microbial balance in coeliac children on a gluten free diet (GFD). Microbial DNA was extracted from faeces of 40 coeliac children before and after probiotic or placebo administration and 16 healthy children (Control group). Sequencing of the amplified V3-V4 hypervariable region of 16S rRNA gene as well as qPCR of Bidobacterium spp., Lactobacillus spp., Bacteroides fragilis group Clostridium sensu stricto and enterobacteria were performed. The comparison between CD subjects and Control group revealed an alteration in the intestinal microbial composition of coeliacs mainly characterized by a reduction of the Firmicutes/Bacteroidetes ratio, of Actinobacteria and Euryarchaeota . Regarding the effects of the probiotic, an increase of Actinobacteria was found as well as a re-establishment of the physiological Firmicutes/Bacteroidetes ratio. Therefore, a three-month administration of B. breve strains helps in restoring the healthy percentage of main microbial components.

Application of ceramic membranes with pre-ozonation for treatment of secondary wastewater effluent.

PubMed

Lehman, S Geno; Liu, Li

2009-04-01

Membrane fouling is an inevitable problem when microfiltration (MF) and ultrafiltraion (UF) are used to treat wastewater treatment plant (WWTP) effluent. While historically the use of MF/UF for water and wastewater treatment has been almost exclusively focused on polymeric membranes, new generation ceramic membranes were recently introduced in the market and they possess unique advantages over currently available polymeric membranes. Ceramic membranes are mechanically superior and are more resistant to severe chemical and thermal environments. Due to the robustness of ceramic membranes, strong oxidants such as ozone can be used as pretreatment to reduce the membrane fouling. This paper presents results of a pilot study designed to investigate the application of new generation ceramic membranes for WWTP effluent treatment. Ozonation and coagulation pretreatment were evaluated to optimize the membrane operation. The ceramic membrane demonstrated stable performance at a filtration flux of 100 gfd (170LMH) at 20 degrees C with pretreatment using PACl (1mg/L as Al) and ozone (4 mg/L). To understand the effects of ozone and coagulation pretreatment on organic foulants, natural organic matter (NOM) in four waters - raw, ozone treated, coagulation treated, and ozone followed by coagulation treated wastewaters - were characterized using high performance size exclusion chromatography (HPSEC). The HPSEC analysis demonstrated that ozone treatment is effective at degrading colloidal NOMs which are likely responsible for the majority of membrane fouling.

Current and Emerging Therapy for Celiac Disease

PubMed Central

Makharia, Govind K.

2014-01-01

At present, strict and lifelong gluten-free diet is the only effective treatment for celiac disease. Even small amounts of gluten (50 mg/day) can be immunogenic; therefore all food and food items and drugs that contain gluten and its derivatives must be eliminated completely from the diet. While prescribing gluten-free diet is easy; the key to the success is the dietary counseling by a nutrition specialist and maintenance of adherence to GFD by the patient. In recent times, a number of targets to halt the process of immunological injury have been explored to find out alternative treatment for celiac disease. These targets include exploration of ancient wheat if they are less immunogenic, intra-luminal digestion of gluten using prolylendopeptidases, pretreatment of whole gluten with bacterial-derived peptidase before ingestion; prevention of passage of immunogenic peptides through the tight junctions such as zonulin antagonists, Blocking of HLA-DQ2 to prevent binding of immunogenic peptides, inhibition of transglutaminase 2, immune-modulation, and induction of tolerance to gluten using gluten tolerizing vaccines, use of gluten-sequestering polymers, use of anti-inflammatory drugs (glucocorticoids, budesonides) and anti-cytokines such as anti TNF-α, and anti-interleukin-15. While many of these targets are still in the pre-clinical phase, some of them including zonulin antagonist and endopeptidases have already reached phase II and phase III clinical trials. Furthermore, while these targets appear very exciting; they at best are likely to be used as adjunctive therapy rather than a complete replacement for gluten-free diet. PMID:25705619

Selected Probiotic Lactobacilli Have the Capacity To Hydrolyze Gluten Peptides during Simulated Gastrointestinal Digestion.

PubMed

Francavilla, Ruggiero; De Angelis, Maria; Rizzello, Carlo Giuseppe; Cavallo, Noemi; Dal Bello, Fabio; Gobbetti, Marco

2017-07-15

The aim of this study was to demonstrate the capacity of probiotic lactobacilli to hydrolyze immunogenic gluten peptides. Eighteen commercial strains of probiotic lactobacilli with highly variable peptidase activity (i.e., aminopeptidase N, iminopeptidase, prolyl endopeptidyl peptidase, tripeptidase, prolidase, prolinase, and dipeptidase), including toward Pro-rich peptides, were tested in this study. Ten probiotic strains were selected on the basis of their specific enzyme activity. When pooled, these 10 strains provided the peptidase portfolio that is required to completely degrade the immunogenic gluten peptides involved in celiac disease (CD). The selected probiotic mixture was able to completely hydrolyze well-known immunogenic epitopes, including the gliadin 33-mer peptide, the peptide spanning residues 57 to 68 of the α9-gliadin (α9-gliadin peptide 57-68), A-gliadin peptide 62-75, and γ-gliadin peptide 62-75. During digestion under simulated gastrointestinal conditions, the pool of 10 selected probiotic lactobacilli strongly hydrolyzed the wheat bread gluten (ca. 18,000 ppm) to less than 10 ppm after 360 min of treatment. As determined by multidimensional chromatography (MDLC) coupled to nanoelectrospray ionization (nano-ESI)-tandem mass spectrometry (MS/MS), no known immunogenic peptides were detected in wheat bread that was digested in the presence of the probiotics. Accordingly, the level of cytokines (interleukin 2 [IL-2], IL-10, and interferon gamma [IFN-γ]) produced by duodenal biopsy specimens from CD patients who consumed wheat bread digested by probiotics was similar to the baseline value (negative control). Probiotics that specifically hydrolyze gluten polypeptides could also be used to hydrolyze immunogenic peptides that contaminate gluten-free products. This could provide a new and safe adjunctive therapy alternative to the gluten-free diet (GFD). IMPORTANCE This study confirmed that probiotic Lactobacillus strains have different enzymatic abilities for hydrolyzing polypeptides, including the Pro-rich epitopes involved in the pathology of CD. Ten lactobacilli with complementary peptidase activities that hydrolyze gluten peptides during simulated gastrointestinal digestion were selected and tested. The results collected showed the potential of probiotic formulas as novel dietary treatments for CD patients. Copyright © 2017 American Society for Microbiology.

Application of variational principles and adjoint integrating factors for constructing numerical GFD models

NASA Astrophysics Data System (ADS)

Penenko, Vladimir; Tsvetova, Elena; Penenko, Alexey

2015-04-01

The proposed method is considered on an example of hydrothermodynamics and atmospheric chemistry models [1,2]. In the development of the existing methods for constructing numerical schemes possessing the properties of total approximation for operators of multiscale process models, we have developed a new variational technique, which uses the concept of adjoint integrating factors. The technique is as follows. First, a basic functional of the variational principle (the integral identity that unites the model equations, initial and boundary conditions) is transformed using Lagrange's identity and the second Green's formula. As a result, the action of the operators of main problem in the space of state functions is transferred to the adjoint operators defined in the space of sufficiently smooth adjoint functions. By the choice of adjoint functions the order of the derivatives becomes lower by one than those in the original equations. We obtain a set of new balance relationships that take into account the sources and boundary conditions. Next, we introduce the decomposition of the model domain into a set of finite volumes. For multi-dimensional non-stationary problems, this technique is applied in the framework of the variational principle and schemes of decomposition and splitting on the set of physical processes for each coordinate directions successively at each time step. For each direction within the finite volume, the analytical solutions of one-dimensional homogeneous adjoint equations are constructed. In this case, the solutions of adjoint equations serve as integrating factors. The results are the hybrid discrete-analytical schemes. They have the properties of stability, approximation and unconditional monotony for convection-diffusion operators. These schemes are discrete in time and analytic in the spatial variables. They are exact in case of piecewise-constant coefficients within the finite volume and along the coordinate lines of the grid area in each direction on a time step. In each direction, they have tridiagonal structure. They are solved by the sweep method. An important advantage of the discrete-analytical schemes is that the values of derivatives at the boundaries of finite volume are calculated together with the values of the unknown functions. This technique is particularly attractive for problems with dominant convection, as it does not require artificial monotonization and limiters. The same idea of integrating factors is applied in temporal dimension to the stiff systems of equations describing chemical transformation models [2]. The proposed method is applicable for the problems involving convection-diffusion-reaction operators. The work has been partially supported by the Presidium of RAS under Program 43, and by the RFBR grants 14-01-00125 and 14-01-31482. References: 1. V.V. Penenko, E.A. Tsvetova, A.V. Penenko. Variational approach and Euler's integrating factors for environmental studies// Computers and Mathematics with Applications, (2014) V.67, Issue 12, P. 2240-2256. 2. V.V.Penenko, E.A.Tsvetova. Variational methods of constructing monotone approximations for atmospheric chemistry models // Numerical analysis and applications, 2013, V. 6, Issue 3, pp 210-220.

Angiogenesis-related gene expression analysis in celiac disease.

PubMed

Castellanos-Rubio, Ainara; Caja, Sergio; Irastorza, Iñaki; Fernandez-Jimenez, Nora; Plaza-Izurieta, Leticia; Vitoria, Juan Carlos; Maki, Markku; Lindfors, Katri; Bilbao, Jose Ramon

2012-05-01

Celiac disease (CD) involves disturbance of the small-bowel mucosal vascular network, and transglutaminase autoantibodies (TGA) have been related to angiogenesis disturbance, a complex phenomenon probably also influenced by common genetic variants in angiogenesis-related genes. A set of genes with "angiogenesis" GO term identified in a previous expression microarray experiment (SCG2, STAB1, TGFA, ANG, ERBB2, GNA13, PML, CASP8, ECGF1, JAG1, HIF1A, TNFSF13 and TGM2) was selected for genetic and functional studies. SNPs that showed a trend for association with CD in the first GWAS were genotyped in 555 patients and 541 controls. Gene expression of all genes was quantified in 15 pairs of intestinal biopsies (diagnosis vs. GFD) and in three-dimensional HUVEC and T84 cell cultures incubated with TGA-positive and negative serum. A regulatory SNP in TNFSF13 (rs11552708) is associated with CD (p = 0.01, OR = 0.7). Expression changes in biopsies pointed to TGM2 and PML as up-regulated antiangiogenic genes and to GNA13, TGFA, ERBB2 and SCG2 as down-regulated proangiogenic factors in CD. TGA seem to enhance TGM2 expression in both cell models, but PML expression was induced only in T84 enterocytes while GNA13 and ERBB2 were repressed in HUVEC endothelial cells, with several genes showing discordant effects in each model, highlighting the complexity of gene interactions in the pathogenesis of CD. Finally, cell culture models are useful tools to help dissect complex responses observed in human explants.

Testing Mechanisms of Mercury Retention in GFD Products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beatty, W.L.; Schroeder, K.T.; Kairies, C.L.

2007-07-01

The natural mode of retention of Hg in FGD products is a key issue in the utilization of coal byproducts as environmentally acceptable resources. This is being investigated with a sequential extraction scheme that subjects FGD material to a series of phase-targeted reagents. Mineral phases with the greatest affinity for Hg and the form in which Hg is naturally immobilized can be discovered by observing the amount of Hg mobilized by each successive extracting solution. The extraction procedure consists of a prolonged water rinse in a continuously stirred tank extractor to dissolve CaSO4 followed by a series of batch extractions.more » These extraction include: a water rinse of the resulting residue to remove any remaining water soluble and loosely sorbed ions, 0.11M acetic acid to target carbonate minerals and exchangeable ions, 0.1 M hydroxylamine hydrochloride to dissolve manganese oxides and hydroxides, 0.25 M hydroxylamine hydrochloride in 0.25 M HCl to dissolve iron oxides and hydroxides, and hydrogen peroxide and 0.1 M ammonium acetate to oxidize organic matter and dissolve sulfide minerals. Analysis of the supernatant after each extraction step includes ICP-OES or ICP-MS for major and trace elemental composition and CVAF for mercury. Initial results indicate that Hg is associated with two distinct fractions of FGD materials. Although most of the solubilized Hg is extracted by the iron oxide and hydroxide dissolution reagent, ICP analysis suggests an association with clay minerals present in this fraction. The organic matter and sulfide minerals fraction typically yields lower but still significant amounts of Hg.« less

Celiac Crisis: A Rare Or Rarely Recognized Disease.

PubMed

Waheed, Nadia; Cheema, Huma Arshad; Suleman, Hassan; Fayyaz, Zafar; Mushtaq, Iqra; Muhammad; Hashmi, Almas

2016-01-01

Celiac crisis is a serious life threatening complication of celiac disease characterized by profuse diarrhoea, severe dehydration and metabolic disturbances leading to neuromuscular weakness, cardiac arrhythmias and sudden death. It has been described as rare condition and not well documented in the literature. To improve awareness and facilitate diagnosis of this condition, we studied risk factors, pattern of presentation and management plans of celiac crisis. It was a descriptive cross sectional study. Patients presenting in emergency room(ER) with profuse diarrhoea leading to severe dehydration, neuromuscular weakness, and metabolic acidosis and electrolyte abnormalities enrolled in the studies after positive serology and small bowel biopsy suggestive of celiac disease. Total 126 patients out of 350 fulfilled the criteria including 54 (42.8%) male and 71 (56.3%) female. The mean age at presentation was 5.25±1.18 years. Risk factors were poor social status (97.60%), consanguinity (96.77%), early weaning with gluten contained diet (93.54%), and Presenting complaints were loose motion (100%), loss of neck holding (96.77%), dehydration (96.77%), polyuria (95.96%), inability to walk (67.74%), abdominal distension (85.86%). Electrolytes imbalances were hypokalaemia (2.4±0.55), hypocalcaemia (7.29±0.66), hypomagnesaemia (1.89±0.50), hypophosphatemia (2.8±0.68), hypoalbuminemia (3.05±0.48) and metabolic acidosis (96%). One hundred & twenty patients were stabilized with GFD and correction of dehydration, acidosis and electrolyte imbalance. Six patients needed parenteral steroids ant total parenteral nutrition (TPN). Recovery time from crisis was mean 5.4±2.73 days (range 3-20 days). Celiac crisis is a common but under recognized problem in developing countries. Commonest presenting feature is neuromuscular paralysis and biochemical abnormality is hypokalaemia.

Smog chamber study on aging of combustion soot in isoprene/SO2/NOx system: Changes of mass, size, effective density, morphology and mixing state

NASA Astrophysics Data System (ADS)

Li, Kangwei; Chen, Linghong; Han, Ke; Lv, Biao; Bao, Kaiji; Wu, Xuecheng; Gao, Xiang; Cen, Kefa

2017-02-01

Atmospheric soot aging process is always accompanied by secondary particle formation, which is a comprehensive environmental issue that deserves great attention. On one hand, aging of primary soot could change its own physicochemical properties; on the other hand, complex air pollution caused by pollutant emission from various sources (e.g., vehicle exhausts, coal-fired flue gases and biogenic VOCs emission) may contribute to secondary particle formation onto primary particle surface. In this study, aging of combustion soot in isoprene/SO2/NOx system was investigated under controlled laboratory conditions in several smog chamber experiments. During the evolution of soot, several physical properties such as mass, size, effective density, morphology and mixing state were determined simultaneously by an integrated aerosol analytical system of Scanning Mobility Particle Sizer (SMPS), Differential Mobility Analyzer-Aerosol Particle Mass Analyzer-Condensation Particle Counter (DMA-APM-CPC) and Transmission Electron Microscopy coupled with Energy-dispersive X-ray Spectrometry (TEM/EDX) techniques. Here, based on the experimental results of soot aging under different gas-phase composition and relative humidity (RH), we firstly proposed possible aging pathways of soot in isoprene/SO2/NOx system. A synergetic effect was speculated to exist between SO2 and isoprene on soot aging process, which led to more secondary particle formation. At the same time, TEM/EDX analysis showed that a competitive mechanism between H2SO4(g) and isoprene oxidation vapor may exist: H2SO4(g) firstly condensed onto fresh soot, then an acceleration of isoprene oxidation products formed onto H2SO4 pre-coated soot. In isoprene/SO2/NOx system, high RH conditions could contribute to soot aging and new particle formation. The changes of effective density and dynamic shape factor of soot also indicated that high RH conditions could accelerate soot aging process, and led chain-like soot into more spherical morphology, which was further confirmed from the STEM image. Moreover, it was found that volume equivalent coating thickness (Δrve) could also be applied to normalized characterize soot aging parameters like diameter growth factor (Gfd) and mass growth factor (Gfm) in a complex reaction system like isoprene/SO2/NOx. Our results revealed the dual mechanism (competitive effect&cooperative effect) of isoprene and SO2 on photochemical aging of soot, which is of significance for improving understanding of complex air pollution in China.

Supplementation of Reduced Gluten Barley Diet with Oral Prolyl Endopeptidase Effectively Abrogates Enteropathy-Associated Changes in Gluten-Sensitive Macaques.

PubMed

Sestak, Karol; Thwin, Hazel; Dufour, Jason; Liu, David X; Alvarez, Xavier; Laine, David; Clarke, Adam; Doyle, Anthony; Aye, Pyone P; Blanchard, James; Moehs, Charles P

2016-06-28

Celiac disease (CD) is an autoimmune disorder that affects approximately three million people in the United States. Furthermore, non-celiac gluten sensitivity (NCGS) affects an estimated additional 6% of the population, e.g., 20 million in the U.S. The only effective treatment of CD and NCGS requires complete removal of gluten sources from the diet. While required adherence to a gluten-free diet (GFD) is extremely difficult to accomplish, efforts to develop additional supportive treatments are needed. To facilitate these efforts, we developed a gluten-sensitive (GS) rhesus macaque model to study the effects of novel therapies. Recently reported results from phase one of this project suggest that partial improvement-but not remission-of gluten-induced disease can be accomplished by 100-fold reduction of dietary gluten, i.e., 200 ppm-by replacement of conventional dietary sources of gluten with a mutant, reduced gluten (RG) barley (lys3a)-derived source. The main focus of this (phase two) study was to determine if the inflammatory effects of the residual gluten in lys3a mutant barley grain could be further reduced by oral supplementation with a prolylendopeptidase (PE). Results reveal that PE supplementation of RG barley diet induces more complete immunological, histopathological and clinical remission than RG barley diet alone. The combined effects of RG barley diet and PE supplementation resulted in a further decrease of inflammatory mediators IFN-γ and TNF secretion by peripheral lymphocytes, as well as decreased plasma anti-gliadin and anti-intestinal tissue transglutaminase (TG2) antibodies, diminished active caspase production in small intestinal mucosa, and eliminated clinical diarrhea-all comparable with a gluten-free diet induced remission. In summary, the beneficial results of a combined RG barley and PE administration in GS macaques may warrant the investigation of similar synergistic approaches.

Supplementation of Reduced Gluten Barley Diet with Oral Prolyl Endopeptidase Effectively Abrogates Enteropathy-Associated Changes in Gluten-Sensitive Macaques

PubMed Central

Sestak, Karol; Thwin, Hazel; Dufour, Jason; Liu, David X.; Alvarez, Xavier; Laine, David; Clarke, Adam; Doyle, Anthony; Aye, Pyone P.; Blanchard, James; Moehs, Charles P.

2016-01-01

Celiac disease (CD) is an autoimmune disorder that affects approximately three million people in the United States. Furthermore, non-celiac gluten sensitivity (NCGS) affects an estimated additional 6% of the population, e.g., 20 million in the U.S. The only effective treatment of CD and NCGS requires complete removal of gluten sources from the diet. While required adherence to a gluten-free diet (GFD) is extremely difficult to accomplish, efforts to develop additional supportive treatments are needed. To facilitate these efforts, we developed a gluten-sensitive (GS) rhesus macaque model to study the effects of novel therapies. Recently reported results from phase one of this project suggest that partial improvement—but not remission—of gluten-induced disease can be accomplished by 100-fold reduction of dietary gluten, i.e., 200 ppm—by replacement of conventional dietary sources of gluten with a mutant, reduced gluten (RG) barley (lys3a)-derived source. The main focus of this (phase two) study was to determine if the inflammatory effects of the residual gluten in lys3a mutant barley grain could be further reduced by oral supplementation with a prolylendopeptidase (PE). Results reveal that PE supplementation of RG barley diet induces more complete immunological, histopathological and clinical remission than RG barley diet alone. The combined effects of RG barley diet and PE supplementation resulted in a further decrease of inflammatory mediators IFN-γ and TNF secretion by peripheral lymphocytes, as well as decreased plasma anti-gliadin and anti-intestinal tissue transglutaminase (TG2) antibodies, diminished active caspase production in small intestinal mucosa, and eliminated clinical diarrhea—all comparable with a gluten-free diet induced remission. In summary, the beneficial results of a combined RG barley and PE administration in GS macaques may warrant the investigation of similar synergistic approaches. PMID:27367722

Celiac disease and celiac crisis in children.

PubMed

Babar, Masud Iqbal; Ahmad, Irfan; Rao, Muhammad Suleman; Iqbal, Raghib; Asghar, Shakeel; Saleem, Mazhar

2011-08-01

To determine the frequency of clinical features of Celiac disease (CD) and Celiac crisis in children. Case series. Paediatrics Unit, Sheikh Zayed Medical College and Hospital, Rahim Yar Khan, from September 2009 to September 2010. Forty children aged between 4 to 13 years of either gender, presenting with complaints of recurrent diarrhea, abdominal distention, severe emaciation and dehydration were included. The information about breast feeding, weaning diets, age of introduction of wheat diets, onset of diarrhea, characteristics and frequency of stools, growth, vaccination status, symptoms in 1st degree relatives, restriction of Gluten diet in the past and anthropometric measures were recorded. Serological tests against anti-Tissue Transglultaminase (anti-tTG) antibodies were obtained in all cases. Upper gastrointestinal endoscopies were performed and multiple biopsies were taken from distal parts of duodenum. Among the forty children, twenty four (60%) were females and 16 were males (40%). The mean age was 6.35 ± 2.83 years. Thirty five (87.5%) parents were cousins. Breast feeding was not exclusively given and the Gluten containing weaning diets were given as early as 3.5 months of age. Thirty (75%) children presented with typical sign and symptoms of CD. Celiac crisis presented with profuse diarrhea, severe dehydration; abdominal distention; pedal edema, carpopedal spasm due to tetany; wasted muscles; head drop and inability to stand. The serum TtG antibodies in thirty-eight cases (95%) were above the cut off level of 7 u/ml ranging from 35-99 u/ml. The histopathology of specimens from distal duodenum revealed lesions of M3 type in thirteen (32.5%) and M2 type in eighteen cases (45%). All cases recovered and improved on follow-up after strict adherence to gluten-free diet (GFD). Majority of children with Celiac disease presented with typical symptom, while Celiac crisis was characterized by severe dehydration, weakness and calcium deficiency signs. Most were the product of consanguineous marriages and were given Gluten-containing weaning foods as early as the 4th month of life.

Gdf11 is a negative regulator of chondrogenesis and myogenesis in the developing chick limb.

PubMed

Gamer, L W; Cox, K A; Small, C; Rosen, V

2001-01-15

GDF11, a new member of the TGF-beta gene superfamily, regulates anterior/posterior patterning in the axial skeleton during mouse embryogenesis. Gdf11 null mice display skeletal abnormalities that appear to represent anterior homeotic transformations of vertebrae consistent with high levels of Gdf11 expression in the primitive streak, presomitic mesoderm, and tail bud. However, despite strong Gdf11 expression in the limb throughout development, this structure does not appear to be affected in the knockout mice. In order to understand this dichotomy of Gdf11 expression versus Gdf11 function, we identified the chicken Gdf11 gene and studied its role during limb formation. In the early limb bud, Gdf11 transcripts are detected in the subectodermal mesoderm at the distal tip, in a region overlapping the progress zone. At these stages, Gdf11 is excluded from the central core mesenchyme where precartilaginous condensations will form. Later in development, Gdf11 continues to be expressed in the distal most mesenchyme and can also be detected more proximally, in between the forming skeletal elements. When beads incubated in GDF11 protein were implanted into the early wing bud, GDF11 caused severe truncations of the limb that affected both the cartilage elements and the muscle. Limb shortening appeared to be the result of an inhibition of chondrogenesis and myogenesis and using an in vitro micromass assay, we confirmed the negative effects of GDF11 on both myogenic and chondrogenic cell differentiation. Analysis of molecular markers of skeletal patterning revealed that GDF11 induced ectopic expression of Hoxd-11 and Hoxd-13, but not of Hoxa-11, Hoxa-13, or the Msx genes. These data suggest that GDF11 may be involved in controlling the late distal expression of the Hoxd genes during limb development and that misregulation of these Hox genes by excess GDF11 may cause some of the observed alterations in skeletal element shape. In addition, GDF11 induced the expression of its own antagonist follistatin, indicating that the activity of GFD11 may be limited by a negative feedback mechanism. The data from our studies in the chick suggest that Gdf11 plays a role in the formation and development of the avian limb skeleton.

Clinical Utility of Serologic Testing for Celiac Disease in Ontario

PubMed Central

2010-01-01

Executive Summary Objective of Analysis The objective of this evidence-based evaluation is to assess the accuracy of serologic tests in the diagnosis of celiac disease in subjects with symptoms consistent with this disease. Furthermore the impact of these tests in the diagnostic pathway of the disease and decision making was also evaluated. Celiac Disease Celiac disease is an autoimmune disease that develops in genetically predisposed individuals. The immunological response is triggered by ingestion of gluten, a protein that is present in wheat, rye, and barley. The treatment consists of strict lifelong adherence to a gluten-free diet (GFD). Patients with celiac disease may present with a myriad of symptoms such as diarrhea, abdominal pain, weight loss, iron deficiency anemia, dermatitis herpetiformis, among others. Serologic Testing in the Diagnosis Celiac Disease There are a number of serologic tests used in the diagnosis of celiac disease. Anti-gliadin antibody (AGA) Anti-endomysial antibody (EMA) Anti-tissue transglutaminase antibody (tTG) Anti-deamidated gliadin peptides antibodies (DGP) Serologic tests are automated with the exception of the EMA test, which is more time-consuming and operator-dependent than the other tests. For each serologic test, both immunoglobulin A (IgA) or G (IgG) can be measured, however, IgA measurement is the standard antibody measured in celiac disease. Diagnosis of Celiac Disease According to celiac disease guidelines, the diagnosis of celiac disease is established by small bowel biopsy. Serologic tests are used to initially detect and to support the diagnosis of celiac disease. A small bowel biopsy is indicated in individuals with a positive serologic test. In some cases an endoscopy and small bowel biopsy may be required even with a negative serologic test. The diagnosis of celiac disease must be performed on a gluten-containing diet since the small intestine abnormalities and the serologic antibody levels may resolve or improve on a GFD. Since IgA measurement is the standard for the serologic celiac disease tests, false negatives may occur in IgA-deficient individuals. Incidence and Prevalence of Celiac Disease The incidence and prevalence of celiac disease in the general population and in subjects with symptoms consistent with or at higher risk of celiac disease based on systematic reviews published in 2004 and 2009 are summarized below. Incidence of Celiac Disease in the General Population Adults or mixed population: 1 to 17/100,000/year Children: 2 to 51/100,000/year In one of the studies, a stratified analysis showed that there was a higher incidence of celiac disease in younger children compared to older children, i.e., 51 cases/100,000/year in 0 to 2 year-olds, 33/100,000/year in 2 to 5 year-olds, and 10/100,000/year in children 5 to 15 years old. Prevalence of Celiac Disease in the General Population The prevalence of celiac disease reported in population-based studies identified in the 2004 systematic review varied between 0.14% and 1.87% (median: 0.47%, interquartile range: 0.25%, 0.71%). According to the authors of the review, the prevalence did not vary by age group, i.e., adults and children. Prevalence of Celiac Disease in High Risk Subjects Type 1 diabetes (adults and children): 1 to 11% Autoimmune thyroid disease: 2.9 to 3.3% First degree relatives of patients with celiac disease: 2 to 20% Prevalence of Celiac Disease in Subjects with Symptoms Consistent with the Disease The prevalence of celiac disease in subjects with symptoms consistent with the disease varied widely among studies, i.e., 1.5% to 50% in adult studies, and 1.1% to 17% in pediatric studies. Differences in prevalence may be related to the referral pattern as the authors of a systematic review noted that the prevalence tended to be higher in studies whose population originated from tertiary referral centres compared to general practice. Research Questions What is the sensitivity and specificity of serologic tests in the diagnosis celiac disease? What is the clinical validity of serologic tests in the diagnosis of celiac disease? The clinical validity was defined as the ability of the test to change diagnosis. What is the clinical utility of serologic tests in the diagnosis of celiac disease? The clinical utility was defined as the impact of the test on decision making. What is the budget impact of serologic tests in the diagnosis of celiac disease? What is the cost-effectiveness of serologic tests in the diagnosis of celiac disease? Methods Literature Search A literature search was performed on November 13th, 2009 using OVID MEDLINE, MEDLINE In-Process and Other Non-Indexed Citations, EMBASE, the Cumulative Index to Nursing & Allied Health Literature (CINAHL), the Cochrane Library, and the International Agency for Health Technology Assessment (INAHTA) for studies published from January 1st 2003 and November 13th 2010. Abstracts were reviewed by a single reviewer and, for those studies meeting the eligibility criteria, full-text articles were obtained. Reference lists were also examined for any additional relevant studies not identified through the search. Articles with unknown eligibility were reviewed with a second clinical epidemiologist, then a group of epidemiologists until consensus was established. The quality of evidence was assessed as high, moderate, low or very low according to GRADE methodology. Inclusion Criteria Inclusion Criteria Exclusion Criteria Studies that evaluated diagnostic accuracy, i.e., both sensitivity and specificity of serology tests in the diagnosis of celiac disease. Study population consisted of untreated patients with symptoms consistent with celiac disease. Studies in which both serologic celiac disease tests and small bowel biopsy (gold standard) were used in all subjects. Systematic reviews, meta-analyses, randomized controlled trials, prospective observational studies, and retrospective cohort studies. At least 20 subjects included in the celiac disease group. English language. Human studies. Studies published from 2000 on. Clearly defined cut-off value for the serology test. If more than one test was evaluated, only those tests for which a cut-off was provided were included. Description of small bowel biopsy procedure clearly outlined (location, number of biopsies per patient), unless if specified that celiac disease diagnosis guidelines were followed. Patients in the treatment group had untreated CD. Studies on screening of the general asymptomatic population. Studies that evaluated rapid diagnostic kits for use either at home or in physician’s offices. Studies that evaluated diagnostic modalities other than serologic tests such as capsule endoscopy, push enteroscopy, or genetic testing. Cut-off for serologic tests defined based on controls included in the study. Study population defined based on positive serology or subjects pre-screened by serology tests. Celiac disease status known before study enrolment. Sensitivity or specificity estimates based on repeated testing for the same subject. Non-peer-reviewed literature such as editorials and letters to the editor. Population The population consisted of adults and children with untreated, undiagnosed celiac disease with symptoms consistent with the disease. Serologic Celiac Disease Tests Evaluated Anti-gliadin antibody (AGA) Anti-endomysial antibody (EMA) Anti-tissue transglutaminase antibody (tTG) Anti-deamidated gliadin peptides antibody (DGP) Combinations of some of the serologic tests listed above were evaluated in some studies Both IgA and IgG antibodies were evaluated for the serologic tests listed above. Outcomes of Interest Sensitivity Specificity Positive and negative likelihood ratios Diagnostic odds ratio (OR) Area under the sROC curve (AUC) Small bowel biopsy was used as the gold standard in order to estimate the sensitivity and specificity of each serologic test. Statistical Analysis Pooled estimates of sensitivity, specificity and diagnostic odds ratios (DORs) for the different serologic tests were calculated using a bivariate, binomial generalized linear mixed model. Statistical significance for differences in sensitivity and specificity between serologic tests was defined by P values less than 0.05, where “false discovery rate” adjustments were made for multiple hypothesis testing. The bivariate regression analyses were performed using SAS version 9.2 (SAS Institute Inc.; Cary, NC, USA). Using the bivariate model parameters, summary receiver operating characteristic (sROC) curves were produced using Review Manager 5.0.22 (The Nordiac Cochrane Centre, The Cochrane Collaboration, 2008). The area under the sROC curve (AUC) was estimated by bivariate mixed-efects binary regression modeling framework. Model specification, estimation and prediction are carried out with xtmelogit in Stata release 10 (Statacorp, 2007). Statistical tests for the differences in AUC estimates could not be carried out. The study results were stratified according to patient or disease characteristics such as age, severity of Marsh grade abnormalities, among others, if reported in the studies. The literature indicates that the diagnostic accuracy of serologic tests for celiac disease may be affected in patients with chronic liver disease, therefore, the studies identified through the systematic literature review that evaluated the diagnostic accuracy of serologic tests for celiac disease in patients with chronic liver disease were summarized. The effect of the GFD in patiens diagnosed with celiac disease was also summarized if reported in the studies eligible for the analysis. Summary of Findings Published Systematic Reviews Five systematic reviews of studies that evaluated the diagnostic accuracy of serologic celiac disease tests were identified through our literature search. Seventeen individual studies identified in adults and children were eligible for this evaluation. In general, the studies included evaluated the sensitivity and specificity of at least one serologic test in subjects with symptoms consistent with celiac disease. The gold standard used to confirm the celiac disease diagnosis was small bowel biopsy. Serologic tests evaluated included tTG, EMA, AGA, and DGP, using either IgA or IgG antibodies. Indirect immunoflurorescence was used for the EMA serologic tests whereas enzyme-linked immunosorbent assay (ELISA) was used for the other serologic tests. Common symptoms described in the studies were chronic diarrhea, abdominal pain, bloating, unexplained weight loss, unexplained anemia, and dermatitis herpetiformis. The main conclusions of the published systematic reviews are summarized below. IgA tTG and/or IgA EMA have a high accuracy (pooled sensitivity: 90% to 98%, pooled specificity: 95% to 99% depending on the pooled analysis). Most reviews found that AGA (IgA or IgG) are not as accurate as IgA tTG and/or EMA tests. A 2009 systematic review concluded that DGP (IgA or IgG) seems to have a similar accuracy compared to tTG, however, since only 2 studies identified evaluated its accuracy, the authors believe that additional data is required to draw firm conclusions. Two systematic reviews also concluded that combining two serologic celiac disease tests has little contribution to the accuracy of the diagnosis. MAS Analysis Sensitivity The pooled analysis performed by MAS showed that IgA tTG has a sensitivity of 92.1% [95% confidence interval (CI) 88.0, 96.3], compared to 89.2% (83.3, 95.1, p=0.12) for IgA DGP, 85.1% (79.5, 94.4, p=0.07) for IgA EMA, and 74.9% (63.6, 86.2, p=0.0003) for IgA AGA. Among the IgG-based tests, the results suggest that IgG DGP has a sensitivity of 88.4% (95% CI: 82.1, 94.6), 44.7% (30.3, 59.2) for tTG, and 69.1% (56.0, 82.2) for AGA. The difference was significant when IgG DGP was compared to IgG tTG but not IgG AGA. Combining serologic celiac disease tests yielded a slightly higher sensitivity compared to individual IgA-based serologic tests. IgA deficiency The prevalence of total or severe IgA deficiency was low in the studies identified varying between 0 and 1.7% as reported in 3 studies in which IgA deficiency was not used as a referral indication for celiac disease serologic testing. The results of IgG-based serologic tests were positive in all patients with IgA deficiency in which celiac disease was confirmed by small bowel biopsy as reported in four studies. Specificity The MAS pooled analysis indicates a high specificity across the different serologic tests including the combination strategy, pooled estimates ranged from 90.1% to 98.7% depending on the test. Likelihood Ratios According to the likelihood ratio estimates, both IgA tTG and serologic test combinationa were considered very useful tests (positive likelihood ratio above ten and the negative likelihood ratio below 0.1). Moderately useful tests included IgA EMA, IgA DGP, and IgG DGP (positive likelihood ratio between five and ten and the negative likelihood ratio between 0.1 and 0.2). Somewhat useful tests: IgA AGA, IgG AGA, generating small but sometimes important changes from pre- to post-test probability (positive LR between 2 and 5 and negative LR between 0.2 and 0.5) Not Useful: IgG tTG, altering pre- to post-test probability to a small and rarely important degree (positive LR between 1 and 2 and negative LR between 0.5 and 1). Diagnostic Odds Ratios (DOR) Among the individual serologic tests, IgA tTG had the highest DOR, 136.5 (95% CI: 51.9, 221.2). The statistical significance of the difference in DORs among tests was not calculated, however, considering the wide confidence intervals obtained, the differences may not be statistically significant. Area Under the sROC Curve (AUC) The sROC AUCs obtained ranged between 0.93 and 0.99 for most IgA-based tests with the exception of IgA AGA, with an AUC of 0.89. Sensitivity and Specificity of Serologic Tests According to Age Groups Serologic test accuracy did not seem to vary according to age (adults or children). Sensitivity and Specificity of Serologic Tests According to Marsh Criteria Four studies observed a trend towards a higher sensitivity of serologic celiac disease tests when Marsh 3c grade abnormalities were found in the small bowel biopsy compared to Marsh 3a or 3b (statistical significance not reported). The sensitivity of serologic tests was much lower when Marsh 1 grade abnormalities were found in small bowel biopsy compared to Marsh 3 grade abnormalities. The statistical significance of these findings were not reported in the studies. Diagnostic Accuracy of Serologic Celiac Disease Tests in Subjects with Chronic Liver Disease A total of 14 observational studies that evaluated the specificity of serologic celiac disease tests in subjects with chronic liver disease were identified. All studies evaluated the frequency of false positive results (1-specificity) of IgA tTG, however, IgA tTG test kits using different substrates were used, i.e., human recombinant, human, and guinea-pig substrates. The gold standard, small bowel biopsy, was used to confirm the result of the serologic tests in only 5 studies. The studies do not seem to have been designed or powered to compare the diagnostic accuracy among different serologic celiac disease tests. The results of the studies identified in the systematic literature review suggest that there is a trend towards a lower frequency of false positive results if the IgA tTG test using human recombinant substrate is used compared to the guinea pig substrate in subjects with chronic liver disease. However, the statistical significance of the difference was not reported in the studies. When IgA tTG with human recombinant substrate was used, the number of false positives seems to be similar to what was estimated in the MAS pooled analysis for IgA-based serologic tests in a general population of patients. These results should be interpreted with caution since most studies did not use the gold standard, small bowel biopsy, to confirm or exclude the diagnosis of celiac disease, and since the studies were not designed to compare the diagnostic accuracy among different serologic tests. The sensitivity of the different serologic tests in patients with chronic liver disease was not evaluated in the studies identified. Effects of a Gluten-Free Diet (GFD) in Patients Diagnosed with Celiac Disease Six studies identified evaluated the effects of GFD on clinical, histological, or serologic improvement in patients diagnosed with celiac disease. Improvement was observed in 51% to 95% of the patients included in the studies. Grading of Evidence Overall, the quality of the evidence ranged from moderate to very low depending on the serologic celiac disease test. Reasons to downgrade the quality of the evidence included the use of a surrogate endpoint (diagnostic accuracy) since none of the studies evaluated clinical outcomes, inconsistencies among study results, imprecise estimates, and sparse data. The quality of the evidence was considered moderate for IgA tTg and IgA EMA, low for IgA DGP, and serologic test combinations, and very low for IgA AGA. Clinical Validity and Clinical Utility of Serologic Testing in the Diagnosis of Celiac Disease The clinical validity of serologic tests in the diagnosis of celiac disease was considered high in subjects with symptoms consistent with this disease due to High accuracy of some serologic tests. Serologic tests detect possible celiac disease cases and avoid unnecessary small bowel biopsy if the test result is negative, unless an endoscopy/ small bowel biopsy is necessary due to the clinical presentation. Serologic tests support the results of small bowel biopsy. The clinical utility of serologic tests for the diagnosis of celiac disease, as defined by its impact in decision making was also considered high in subjects with symptoms consistent with this disease given the considerations listed above and since celiac disease diagnosis leads to treatment with a gluten-free diet. Economic Analysis A decision analysis was constructed to compare costs and outcomes between the tests based on the sensitivity, specificity and prevalence summary estimates from the MAS Evidence-Based Analysis (EBA). A budget impact was then calculated by multiplying the expected costs and volumes in Ontario. The outcome of the analysis was expected costs and false negatives (FN). Costs were reported in 2010 CAD$. All analyses were performed using TreeAge Pro Suite 2009. Four strategies made up the efficiency frontier; IgG tTG, IgA tTG, EMA and small bowel biopsy. All other strategies were dominated. IgG tTG was the least costly and least effective strategy ($178.95, FN avoided=0). Small bowel biopsy was the most costly and most effective strategy ($396.60, FN avoided =0.1553). The cost per FN avoided were $293, $369, $1,401 for EMA, IgATTG and small bowel biopsy respectively. One-way sensitivity analyses did not change the ranking of strategies. All testing strategies with small bowel biopsy are cheaper than biopsy alone however they also result in more FNs. The most cost-effective strategy will depend on the decision makers’ willingness to pay. Findings suggest that IgA tTG was the most cost-effective and feasible strategy based on its Incremental Cost-Effectiveness Ratio (ICER) and convenience to conduct the test. The potential impact of IgA tTG test in the province of Ontario would be $10.4M, $11.0M and $11.7M respectively in the following three years based on past volumes and trends in the province and basecase expected costs. The panel of tests is the commonly used strategy in the province of Ontario therefore the impact to the system would be $13.6M, $14.5M and $15.3M respectively in the next three years based on past volumes and trends in the province and basecase expected costs. Conclusions The clinical validity and clinical utility of serologic tests for celiac disease was considered high in subjects with symptoms consistent with this disease as they aid in the diagnosis of celiac disease and some tests present a high accuracy. The study findings suggest that IgA tTG is the most accurate and the most cost-effective test. AGA test (IgA) has a lower accuracy compared to other IgA-based tests Serologic test combinations appear to be more costly with little gain in accuracy. In addition there may be problems with generalizability of the results of the studies included in this review if different test combinations are used in clinical practice. IgA deficiency seems to be uncommon in patients diagnosed with celiac disease. The generalizability of study results is contingent on performing both the serologic test and small bowel biopsy in subjects on a gluten-containing diet as was the case in the studies identified, since the avoidance of gluten may affect test results. PMID:23074399

Functional magnetic resonance imaging of visual object construction and shape discrimination : relations among task, hemispheric lateralization, and gender.

PubMed

Georgopoulos, A P; Whang, K; Georgopoulos, M A; Tagaris, G A; Amirikian, B; Richter, W; Kim, S G; Uğurbil, K

2001-01-01

We studied the brain activation patterns in two visual image processing tasks requiring judgements on object construction (FIT task) or object sameness (SAME task). Eight right-handed healthy human subjects (four women and four men) performed the two tasks in a randomized block design while 5-mm, multislice functional images of the whole brain were acquired using a 4-tesla system using blood oxygenation dependent (BOLD) activation. Pairs of objects were picked randomly from a set of 25 oriented fragments of a square and presented to the subjects approximately every 5 sec. In the FIT task, subjects had to indicate, by pushing one of two buttons, whether the two fragments could match to form a perfect square, whereas in the SAME task they had to decide whether they were the same or not. In a control task, preceding and following each of the two tasks above, a single square was presented at the same rate and subjects pushed any of the two keys at random. Functional activation maps were constructed based on a combination of conservative criteria. The areas with activated pixels were identified using Talairach coordinates and anatomical landmarks, and the number of activated pixels was determined for each area. Altogether, 379 pixels were activated. The counts of activated pixels did not differ significantly between the two tasks or between the two genders. However, there were significantly more activated pixels in the left (n = 218) than the right side of the brain (n = 161). Of the 379 activated pixels, 371 were located in the cerebral cortex. The Talairach coordinates of these pixels were analyzed with respect to their overall distribution in the two tasks. These distributions differed significantly between the two tasks. With respect to individual dimensions, the two tasks differed significantly in the anterior--posterior and superior--inferior distributions but not in the left--right (including mediolateral, within the left or right side) distribution. Specifically, the FIT distribution was, overall, more anterior and inferior than that of the SAME task. A detailed analysis of the counts and spatial distributions of activated pixels was carried out for 15 brain areas (all in the cerebral cortex) in which a consistent activation (in > or = 3 subjects) was observed (n = 323 activated pixels). We found the following. Except for the inferior temporal gyrus, which was activated exclusively in the FIT task, all other areas showed activation in both tasks but to different extents. Based on the extent of activation, areas fell within two distinct groups (FIT or SAME) depending on which pixel count (i.e., FIT or SAME) was greater. The FIT group consisted of the following areas, in decreasing FIT/SAME order (brackets indicate ties): GTi, GTs, GC, GFi, GFd, [GTm, GF], GO. The SAME group consisted of the following areas, in decreasing SAME/FIT order : GOi, LPs, Sca, GPrC, GPoC, [GFs, GFm]. These results indicate that there are distributed, graded, and partially overlapping patterns of activation during performance of the two tasks. We attribute these overlapping patterns of activation to the engagement of partially shared processes. Activated pixels clustered to three types of clusters : FIT-only (111 pixels), SAME-only (97 pixels), and FIT + SAME (115 pixels). Pixels contained in FIT-only and SAME-only clusters were distributed approximately equally between the left and right hemispheres, whereas pixels in the SAME + FIT clusters were located mostly in the left hemisphere. With respect to gender, the left-right distribution of activated pixels was very similar in women and men for the SAME-only and FIT + SAME clusters but differed for the FIT-only case in which there was a prominent left side preponderance for women, in contrast to a right side preponderance for men. We conclude that (a) cortical mechanisms common for processing visual object construction and discrimination involve mostly the left hemisphere, (b) cortical mechanisms specific for these tasks engage both hemispheres, and (c) in object construction only, men engage predominantly the right hemisphere whereas women show a left-hemisphere preponderance.

The Relation of Finite Element and Finite Difference Methods

NASA Technical Reports Server (NTRS)

Vinokur, M.

1976-01-01

Finite element and finite difference methods are examined in order to bring out their relationship. It is shown that both methods use two types of discrete representations of continuous functions. They differ in that finite difference methods emphasize the discretization of independent variable, while finite element methods emphasize the discretization of dependent variable (referred to as functional approximations). An important point is that finite element methods use global piecewise functional approximations, while finite difference methods normally use local functional approximations. A general conclusion is that finite element methods are best designed to handle complex boundaries, while finite difference methods are superior for complex equations. It is also shown that finite volume difference methods possess many of the advantages attributed to finite element methods.

Evaluation of finite difference and FFT-based solutions of the transport of intensity equation.

PubMed

Zhang, Hongbo; Zhou, Wen-Jing; Liu, Ying; Leber, Donald; Banerjee, Partha; Basunia, Mahmudunnabi; Poon, Ting-Chung

2018-01-01

A finite difference method is proposed for solving the transport of intensity equation. Simulation results show that although slower than fast Fourier transform (FFT)-based methods, finite difference methods are able to reconstruct the phase with better accuracy due to relaxed assumptions for solving the transport of intensity equation relative to FFT methods. Finite difference methods are also more flexible than FFT methods in dealing with different boundary conditions.

Improved methods of vibration analysis of pretwisted, airfoil blades

NASA Technical Reports Server (NTRS)

Subrahmanyam, K. B.; Kaza, K. R. V.

1984-01-01

Vibration analysis of pretwisted blades of asymmetric airfoil cross section is performed by using two mixed variational approaches. Numerical results obtained from these two methods are compared to those obtained from an improved finite difference method and also to those given by the ordinary finite difference method. The relative merits, convergence properties and accuracies of all four methods are studied and discussed. The effects of asymmetry and pretwist on natural frequencies and mode shapes are investigated. The improved finite difference method is shown to be far superior to the conventional finite difference method in several respects. Close lower bound solutions are provided by the improved finite difference method for untwisted blades with a relatively coarse mesh while the mixed methods have not indicated any specific bound.

A new method of time difference measurement: The time difference method by dual phase coincidence points detection

NASA Technical Reports Server (NTRS)

Zhou, Wei

1993-01-01

In the high accurate measurement of periodic signals, the greatest common factor frequency and its characteristics have special functions. A method of time difference measurement - the time difference method by dual 'phase coincidence points' detection is described. This method utilizes the characteristics of the greatest common factor frequency to measure time or phase difference between periodic signals. It can suit a very wide frequency range. Measurement precision and potential accuracy of several picoseconds were demonstrated with this new method. The instrument based on this method is very simple, and the demand for the common oscillator is low. This method and instrument can be used widely.

Mixed Methods, Triangulation, and Causal Explanation

ERIC Educational Resources Information Center

Howe, Kenneth R.

2012-01-01

This article distinguishes a disjunctive conception of mixed methods/triangulation, which brings different methods to bear on different questions, from a conjunctive conception, which brings different methods to bear on the same question. It then examines a more inclusive, holistic conception of mixed methods/triangulation that accommodates…

Examining mixing methods in an evaluation of a smoking cessation program.

PubMed

Betzner, Anne; Lawrenz, Frances P; Thao, Mao

2016-02-01

Three different methods were used in an evaluation of a smoking cessation study: surveys, focus groups, and phenomenological interviews. The results of each method were analyzed separately and then combined using both a pragmatic and dialectic stance to examine the effects of different approaches to mixing methods. Results show that the further apart the methods are philosophically, the more diverse the findings. Comparisons of decision maker opinions and costs of the different methods are provided along with recommendations for evaluators' uses of different methods. Copyright © 2015. Published by Elsevier Ltd.

Task exposures in an office environment: a comparison of methods.

PubMed

Van Eerd, Dwayne; Hogg-Johnson, Sheilah; Mazumder, Anjali; Cole, Donald; Wells, Richard; Moore, Anne

2009-10-01

Task-related factors such as frequency and duration are associated with musculoskeletal disorders in office settings. The primary objective was to compare various task recording methods as measures of exposure in an office workplace. A total of 41 workers from different jobs were recruited from a large urban newspaper (71% female, mean age 41 years SD 9.6). Questionnaire, task diaries, direct observation and video methods were used to record tasks. A common set of task codes was used across methods. Different estimates of task duration, number of tasks and task transitions arose from the different methods. Self-report methods did not consistently result in longer task duration estimates. Methodological issues could explain some of the differences in estimates seen between methods observed. It was concluded that different task recording methods result in different estimates of exposure likely due to different exposure constructs. This work addresses issues of exposure measurement in office environments. It is of relevance to ergonomists/researchers interested in how to best assess the risk of injury among office workers. The paper discusses the trade-offs between precision, accuracy and burden in the collection of computer task-based exposure measures and different underlying constructs captures in each method.

Finite difference and Runge-Kutta methods for solving vibration problems

NASA Astrophysics Data System (ADS)

Lintang Renganis Radityani, Scolastika; Mungkasi, Sudi

2017-11-01

The vibration of a storey building can be modelled into a system of second order ordinary differential equations. If the number of floors of a building is large, then the result is a large scale system of second order ordinary differential equations. The large scale system is difficult to solve, and if it can be solved, the solution may not be accurate. Therefore, in this paper, we seek for accurate methods for solving vibration problems. We compare the performance of numerical finite difference and Runge-Kutta methods for solving large scale systems of second order ordinary differential equations. The finite difference methods include the forward and central differences. The Runge-Kutta methods include the Euler and Heun methods. Our research results show that the central finite difference and the Heun methods produce more accurate solutions than the forward finite difference and the Euler methods do.

Unmanned Tactical Autonomous Control and Collaboration Threat and Vulnerability Assessment

DTIC Science & Technology

2015-06-01

they are evaluated separately 15 from each other [19]. One major difference between this classification method and the FIPS 199 is that no...both technical and nontechnical methods ” [31]. These different methods will enable the UTACC system to effectively mitigate vulnerabilities that...team. Marines on the battlefield communicate with each other in many different and unique methods . UTACC must be adaptable to these different methods

Convergence and divergence across construction methods for human brain white matter networks: an assessment based on individual differences.

PubMed

Zhong, Suyu; He, Yong; Gong, Gaolang

2015-05-01

Using diffusion MRI, a number of studies have investigated the properties of whole-brain white matter (WM) networks with differing network construction methods (node/edge definition). However, how the construction methods affect individual differences of WM networks and, particularly, if distinct methods can provide convergent or divergent patterns of individual differences remain largely unknown. Here, we applied 10 frequently used methods to construct whole-brain WM networks in a healthy young adult population (57 subjects), which involves two node definitions (low-resolution and high-resolution) and five edge definitions (binary, FA weighted, fiber-density weighted, length-corrected fiber-density weighted, and connectivity-probability weighted). For these WM networks, individual differences were systematically analyzed in three network aspects: (1) a spatial pattern of WM connections, (2) a spatial pattern of nodal efficiency, and (3) network global and local efficiencies. Intriguingly, we found that some of the network construction methods converged in terms of individual difference patterns, but diverged with other methods. Furthermore, the convergence/divergence between methods differed among network properties that were adopted to assess individual differences. Particularly, high-resolution WM networks with differing edge definitions showed convergent individual differences in the spatial pattern of both WM connections and nodal efficiency. For the network global and local efficiencies, low-resolution and high-resolution WM networks for most edge definitions consistently exhibited a highly convergent pattern in individual differences. Finally, the test-retest analysis revealed a decent temporal reproducibility for the patterns of between-method convergence/divergence. Together, the results of the present study demonstrated a measure-dependent effect of network construction methods on the individual difference of WM network properties. © 2015 Wiley Periodicals, Inc.

A simulation-based evaluation of methods for inferring linear barriers to gene flow

Treesearch

Christopher Blair; Dana E. Weigel; Matthew Balazik; Annika T. H. Keeley; Faith M. Walker; Erin Landguth; Sam Cushman; Melanie Murphy; Lisette Waits; Niko Balkenhol

2012-01-01

Different analytical techniques used on the same data set may lead to different conclusions about the existence and strength of genetic structure. Therefore, reliable interpretation of the results from different methods depends on the efficacy and reliability of different statistical methods. In this paper, we evaluated the performance of multiple analytical methods to...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowe, M.D.; Pierce, B.L.

This report presents results of tests of different final site selection methods used for siting large-scale facilities such as nuclear power plants. Test data are adapted from a nuclear power plant siting study conducted on Long Island, New York. The purpose of the tests is to determine whether or not different final site selection methods produce different results, and to obtain some understanding of the nature of any differences found. Decision rules and weighting methods are included. Decision rules tested are Weighting Summation, Power Law, Decision Analysis, Goal Programming, and Goal Attainment; weighting methods tested are Categorization, Ranking, Rating Ratiomore » Estimation, Metfessel Allocation, Indifferent Tradeoff, Decision Analysis lottery, and Global Evaluation. Results show that different methods can, indeed, produce different results, but that the probability that they will do so is controlled by the structure of differences among the sites being evaluated. Differences in weights and suitability scores attributable to methods have reduced significance if the alternatives include one or two sites that are superior to all others in many attributes. The more tradeoffs there are among good and bad levels of different attributes at different sites, the more important are the specifics of methods to the final decision. 5 refs., 14 figs., 19 tabs.« less

Testing and Validation of Computational Methods for Mass Spectrometry.

PubMed

Gatto, Laurent; Hansen, Kasper D; Hoopmann, Michael R; Hermjakob, Henning; Kohlbacher, Oliver; Beyer, Andreas

2016-03-04

High-throughput methods based on mass spectrometry (proteomics, metabolomics, lipidomics, etc.) produce a wealth of data that cannot be analyzed without computational methods. The impact of the choice of method on the overall result of a biological study is often underappreciated, but different methods can result in very different biological findings. It is thus essential to evaluate and compare the correctness and relative performance of computational methods. The volume of the data as well as the complexity of the algorithms render unbiased comparisons challenging. This paper discusses some problems and challenges in testing and validation of computational methods. We discuss the different types of data (simulated and experimental validation data) as well as different metrics to compare methods. We also introduce a new public repository for mass spectrometric reference data sets ( http://compms.org/RefData ) that contains a collection of publicly available data sets for performance evaluation for a wide range of different methods.

Estimating the mediating effect of different biomarkers on the relation of alcohol consumption with the risk of type 2 diabetes.

PubMed

Beulens, Joline W J; van der Schouw, Yvonne T; Moons, Karel G M; Boshuizen, Hendriek C; van der A, Daphne L; Groenwold, Rolf H H

2013-04-01

Moderate alcohol consumption is associated with a reduced type 2 diabetes risk, but the biomarkers that explain this relation are unknown. The most commonly used method to estimate the proportion explained by a biomarker is the difference method. However, influence of alcohol-biomarker interaction on its results is unclear. G-estimation method is proposed to accurately assess proportion explained, but how this method compares with the difference method is unknown. In a case-cohort study of 2498 controls and 919 incident diabetes cases, we estimated the proportion explained by different biomarkers on the relation between alcohol consumption and diabetes using the difference method and sequential G-estimation method. Using the difference method, high-density lipoprotein cholesterol explained the relation between alcohol and diabetes by 78% (95% confidence interval [CI], 41-243), whereas high-sensitivity C-reactive protein (-7.5%; -36.4 to 1.8) or blood pressure (-6.9; -26.3 to -0.6) did not explain the relation. Interaction between alcohol and liver enzymes led to bias in proportion explained with different outcomes for different levels of liver enzymes. G-estimation method showed comparable results, but proportions explained were lower. The relation between alcohol consumption and diabetes may be largely explained by increased high-density lipoprotein cholesterol but not by other biomarkers. Ignoring exposure-mediator interactions may result in bias. The difference and G-estimation methods provide similar results. Copyright © 2013 Elsevier Inc. All rights reserved.

Psychological traits underlying different killing methods among Malaysian male murderers.

PubMed

Kamaluddin, Mohammad Rahim; Shariff, Nadiah Syariani; Nurfarliza, Siti; Othman, Azizah; Ismail, Khaidzir H; Mat Saat, Geshina Ayu

2014-04-01

Murder is the most notorious crime that violates religious, social and cultural norms. Examining the types and number of different killing methods that used are pivotal in a murder case. However, the psychological traits underlying specific and multiple killing methods are still understudied. The present study attempts to fill this gap in knowledge by identifying the underlying psychological traits of different killing methods among Malaysian murderers. The study adapted an observational cross-sectional methodology using a guided self-administered questionnaire for data collection. The sampling frame consisted of 71 Malaysian male murderers from 11 Malaysian prisons who were selected using purposive sampling method. The participants were also asked to provide the types and number of different killing methods used to kill their respective victims. An independent sample t-test was performed to establish the mean score difference of psychological traits between the murderers who used single and multiple types of killing methods. Kruskal-Wallis tests were carried out to ascertain the psychological trait differences between specific types of killing methods. The results suggest that specific psychological traits underlie the type and number of different killing methods used during murder. The majority (88.7%) of murderers used a single method of killing. Multiple methods of killing was evident in 'premeditated' murder compared to 'passion' murder, and revenge was a common motive. Examples of multiple methods are combinations of stabbing and strangulation or slashing and physical force. An exception was premeditated murder committed with shooting, when it was usually a single method, attributed to the high lethality of firearms. Shooting was also notable when the motive was financial gain or related to drug dealing. Murderers who used multiple killing methods were more aggressive and sadistic than those who used a single killing method. Those who used multiple methods or slashing also displayed a higher level of minimisation traits. Despite its limitations, this study has provided some light on the underlying psychological traits of different killing methods which is useful in the field of criminology.

Mobile micro-colorimeter and micro-spectrometer sensor modules as enablers for the replacement of subjective inspections by objective measurements for optically clear colored liquids in-field

NASA Astrophysics Data System (ADS)

Dittrich, Paul-Gerald; Grunert, Fred; Ehehalt, Jörg; Hofmann, Dietrich

2015-03-01

Aim of the paper is to show that the colorimetric characterization of optically clear colored liquids can be performed with different measurement methods and their application specific multichannel spectral sensors. The possible measurement methods are differentiated by the applied types of multichannel spectral sensors and therefore by their spectral resolution, measurement speed, measurement accuracy and measurement costs. The paper describes how different types of multichannel spectral sensors are calibrated with different types of calibration methods and how the measurement values can be used for further colorimetric calculations. The different measurement methods and the different application specific calibration methods will be explained methodically and theoretically. The paper proofs that and how different multichannel spectral sensor modules with different calibration methods can be applied with smartpads for the calculation of measurement results both in laboratory and in field. A given practical example is the application of different multichannel spectral sensors for the colorimetric characterization of petroleum oils and fuels and their colorimetric characterization by the Saybolt color scale.

[Preliminary study on correlation between diversity of soluble proteins and producing area of Cordyceps sinensis].

PubMed

Ren, Yan; Qiu, Yi; Wan, De-Guang; Lu, Xian-Ming; Guo, Jin-Lin

2013-05-01

To analyze the content and type of soluble proteins in Cordyceps sinensis from different producing areas and processed with different methods with bradford method and 2-DE technology, in order to discover significant differences in soluble proteins in C. sinensis processed with different methods and from different producing areas. The preliminary study indicated that the content and diversity of soluble proteins were related to producing areas and processing methods to some extent.

[Measuring the blood pressure in both arms is of little use; longitudinal study into blood pressure differences between both arms and its reproducibility in patients with diabetes mellitus type 2].

PubMed

Kleefstra, N; Houweling, S T; Meyboom-de Jong, B; Bilo, H J G

2007-07-07

To determine the prevalence of inter-arm blood pressure differences > 10 mmHg in patients with diabetes mellitus type 2 (DM2) and to determine whether these differences are consistent over time. Descriptive. In an evaluation study of 169 DM2 patients from 5 general practices in 2003 and 2004, different methods of oscillatory measurement were used to investigate inter-arm blood pressure differences > 10 mmHg systolic or diastolic. These methods were: one measurement in each arm non-simultaneously (method A), one measurement simultaneously (B) and the mean of two simultaneous measurements (C). With method A an inter-arm blood pressure difference was found in 33% of patients. This percentage diminished to 9 with method C. In 44% (n = 7) of the patients in whom method C detected a relevant blood pressure difference, this difference was not found with method A. In 79% of patients the inter-arm blood pressure difference was not reproduced after one year. In daily practice, one non-simultaneous blood pressure measurement in each arm (method A) was of little value for identification of patients with inter-arm blood pressure differences. The reproducibility was poor one year later. Bilateral blood pressure measurement is therefore of little value.

Spectral difference Lanczos method for efficient time propagation in quantum control theory

NASA Astrophysics Data System (ADS)

Farnum, John D.; Mazziotti, David A.

2004-04-01

Spectral difference methods represent the real-space Hamiltonian of a quantum system as a banded matrix which possesses the accuracy of the discrete variable representation (DVR) and the efficiency of finite differences. When applied to time-dependent quantum mechanics, spectral differences enhance the efficiency of propagation methods for evolving the Schrödinger equation. We develop a spectral difference Lanczos method which is computationally more economical than the sinc-DVR Lanczos method, the split-operator technique, and even the fast-Fourier-Transform Lanczos method. Application of fast propagation is made to quantum control theory where chirped laser pulses are designed to dissociate both diatomic and polyatomic molecules. The specificity of the chirped laser fields is also tested as a possible method for molecular identification and discrimination.

Different methods to analyze stepped wedge trial designs revealed different aspects of intervention effects.

PubMed

Twisk, J W R; Hoogendijk, E O; Zwijsen, S A; de Boer, M R

2016-04-01

Within epidemiology, a stepped wedge trial design (i.e., a one-way crossover trial in which several arms start the intervention at different time points) is increasingly popular as an alternative to a classical cluster randomized controlled trial. Despite this increasing popularity, there is a huge variation in the methods used to analyze data from a stepped wedge trial design. Four linear mixed models were used to analyze data from a stepped wedge trial design on two example data sets. The four methods were chosen because they have been (frequently) used in practice. Method 1 compares all the intervention measurements with the control measurements. Method 2 treats the intervention variable as a time-independent categorical variable comparing the different arms with each other. In method 3, the intervention variable is a time-dependent categorical variable comparing groups with different number of intervention measurements, whereas in method 4, the changes in the outcome variable between subsequent measurements are analyzed. Regarding the results in the first example data set, methods 1 and 3 showed a strong positive intervention effect, which disappeared after adjusting for time. Method 2 showed an inverse intervention effect, whereas method 4 did not show a significant effect at all. In the second example data set, the results were the opposite. Both methods 2 and 4 showed significant intervention effects, whereas the other two methods did not. For method 4, the intervention effect attenuated after adjustment for time. Different methods to analyze data from a stepped wedge trial design reveal different aspects of a possible intervention effect. The choice of a method partly depends on the type of the intervention and the possible time-dependent effect of the intervention. Furthermore, it is advised to combine the results of the different methods to obtain an interpretable overall result. Copyright © 2016 Elsevier Inc. All rights reserved.

[Influence of different processing methods and mature stages on 3,29-dibenzoyl rarounitriol of Trichosanthes kirilowii seeds].

PubMed

Liu, Jin-Na; Xie, Xiao-Liang; Yang, Tai-Xin; Zhang, Cun-Li; Jia, Dong-Sheng; Liu, Ming; Wen, Chun-Xiu

2014-04-01

To study the different mature stages and the best processing methods on the quality of Trichosanthes kirilowii seeds. The content of 3,29-dibenzoyl rarounitriol in Trichosanthes kirilowii seeds was determined by HPLC. The sample of different mature stages such as immature, near mature and fully mature and processed by different methods were studied. Fully mature Trichosanthes kirilowii seeds were better than the immatured, and the best processing method was dried under 60degrees C, the content of 3,29-dibenzoyl rarounitriol reached up to 131.63microlg/mL. Different processing methods and different mature stages had a significant influence on the quality of Trichosanthes kirilowii seeds.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ji, Changyoon, E-mail: changyoon@yonsei.ac.kr; Hong, Taehoon, E-mail: hong7@yonsei.ac.kr

Previous studies have proposed several methods for integrating characterized environmental impacts as a single index in life cycle assessment. Each of them, however, may lead to different results. This study presents internal and external normalization methods, weighting factors proposed by panel methods, and a monetary valuation based on an endpoint life cycle impact assessment method as the integration methods. Furthermore, this study investigates the differences among the integration methods and identifies the causes of the differences through a case study in which five elementary school buildings were used. As a result, when using internal normalization with weighting factors, the weightingmore » factors had a significant influence on the total environmental impacts whereas the normalization had little influence on the total environmental impacts. When using external normalization with weighting factors, the normalization had more significant influence on the total environmental impacts than weighing factors. Due to such differences, the ranking of the five buildings varied depending on the integration methods. The ranking calculated by the monetary valuation method was significantly different from that calculated by the normalization and weighting process. The results aid decision makers in understanding the differences among these integration methods, and, finally, help them select the method most appropriate for the goal at hand.« less

Comparison of preprocessing methods and storage times for touch DNA samples

PubMed Central

Dong, Hui; Wang, Jing; Zhang, Tao; Ge, Jian-ye; Dong, Ying-qiang; Sun, Qi-fan; Liu, Chao; Li, Cai-xia

2017-01-01

Aim To select appropriate preprocessing methods for different substrates by comparing the effects of four different preprocessing methods on touch DNA samples and to determine the effect of various storage times on the results of touch DNA sample analysis. Method Hand touch DNA samples were used to investigate the detection and inspection results of DNA on different substrates. Four preprocessing methods, including the direct cutting method, stubbing procedure, double swab technique, and vacuum cleaner method, were used in this study. DNA was extracted from mock samples with four different preprocessing methods. The best preprocess protocol determined from the study was further used to compare performance after various storage times. DNA extracted from all samples was quantified and amplified using standard procedures. Results The amounts of DNA and the number of alleles detected on the porous substrates were greater than those on the non-porous substrates. The performances of the four preprocessing methods varied with different substrates. The direct cutting method displayed advantages for porous substrates, and the vacuum cleaner method was advantageous for non-porous substrates. No significant degradation trend was observed as the storage times increased. Conclusion Different substrates require the use of different preprocessing method in order to obtain the highest DNA amount and allele number from touch DNA samples. This study provides a theoretical basis for explorations of touch DNA samples and may be used as a reference when dealing with touch DNA samples in case work. PMID:28252870

Digital photography and transparency-based methods for measuring wound surface area.

PubMed

Bhedi, Amul; Saxena, Atul K; Gadani, Ravi; Patel, Ritesh

2013-04-01

To compare and determine a credible method of measurement of wound surface area by linear, transparency, and photographic methods for monitoring progress of wound healing accurately and ascertaining whether these methods are significantly different. From April 2005 to December 2006, 40 patients (30 men, 5 women, 5 children) admitted to the surgical ward of Shree Sayaji General Hospital, Baroda, had clean as well as infected wound following trauma, debridement, pressure sore, venous ulcer, and incision and drainage. Wound surface areas were measured by these three methods (linear, transparency, and photographic methods) simultaneously on alternate days. The linear method is statistically and significantly different from transparency and photographic methods (P value <0.05), but there is no significant difference between transparency and photographic methods (P value >0.05). Photographic and transparency methods provided measurements of wound surface area with equivalent result and there was no statistically significant difference between these two methods.

K-nearest neighbors based methods for identification of different gear crack levels under different motor speeds and loads: Revisited

NASA Astrophysics Data System (ADS)

Wang, Dong

2016-03-01

Gears are the most commonly used components in mechanical transmission systems. Their failures may cause transmission system breakdown and result in economic loss. Identification of different gear crack levels is important to prevent any unexpected gear failure because gear cracks lead to gear tooth breakage. Signal processing based methods mainly require expertize to explain gear fault signatures which is usually not easy to be achieved by ordinary users. In order to automatically identify different gear crack levels, intelligent gear crack identification methods should be developed. The previous case studies experimentally proved that K-nearest neighbors based methods exhibit high prediction accuracies for identification of 3 different gear crack levels under different motor speeds and loads. In this short communication, to further enhance prediction accuracies of existing K-nearest neighbors based methods and extend identification of 3 different gear crack levels to identification of 5 different gear crack levels, redundant statistical features are constructed by using Daubechies 44 (db44) binary wavelet packet transform at different wavelet decomposition levels, prior to the use of a K-nearest neighbors method. The dimensionality of redundant statistical features is 620, which provides richer gear fault signatures. Since many of these statistical features are redundant and highly correlated with each other, dimensionality reduction of redundant statistical features is conducted to obtain new significant statistical features. At last, the K-nearest neighbors method is used to identify 5 different gear crack levels under different motor speeds and loads. A case study including 3 experiments is investigated to demonstrate that the developed method provides higher prediction accuracies than the existing K-nearest neighbors based methods for recognizing different gear crack levels under different motor speeds and loads. Based on the new significant statistical features, some other popular statistical models including linear discriminant analysis, quadratic discriminant analysis, classification and regression tree and naive Bayes classifier, are compared with the developed method. The results show that the developed method has the highest prediction accuracies among these statistical models. Additionally, selection of the number of new significant features and parameter selection of K-nearest neighbors are thoroughly investigated.

More than Method?: A Discussion of Paradigm Differences within Mixed Methods Research

ERIC Educational Resources Information Center

Harrits, Gitte Sommer

2011-01-01

This article challenges the idea that mixed methods research (MMR) constitutes a coherent research paradigm and explores how different research paradigms exist within MMR. Tracing paradigmatic differences at the level of methods, ontology, and epistemology, two MMR strategies are discussed: nested analysis, recently presented by the American…

Comparing 3D foot scanning with conventional measurement methods.

PubMed

Lee, Yu-Chi; Lin, Gloria; Wang, Mao-Jiun J

2014-01-01

Foot dimension information on different user groups is important for footwear design and clinical applications. Foot dimension data collected using different measurement methods presents accuracy problems. This study compared the precision and accuracy of the 3D foot scanning method with conventional foot dimension measurement methods including the digital caliper, ink footprint and digital footprint. Six commonly used foot dimensions, i.e. foot length, ball of foot length, outside ball of foot length, foot breadth diagonal, foot breadth horizontal and heel breadth were measured from 130 males and females using four foot measurement methods. Two-way ANOVA was performed to evaluate the sex and method effect on the measured foot dimensions. In addition, the mean absolute difference values and intra-class correlation coefficients (ICCs) were used for precision and accuracy evaluation. The results were also compared with the ISO 20685 criteria. The participant's sex and the measurement method were found (p < 0.05) to exert significant effects on the measured six foot dimensions. The precision of the 3D scanning measurement method with mean absolute difference values between 0.73 to 1.50 mm showed the best performance among the four measurement methods. The 3D scanning measurements showed better measurement accuracy performance than the other methods (mean absolute difference was 0.6 to 4.3 mm), except for measuring outside ball of foot length and foot breadth horizontal. The ICCs for all six foot dimension measurements among the four measurement methods were within the 0.61 to 0.98 range. Overall, the 3D foot scanner is recommended for collecting foot anthropometric data because it has relatively higher precision, accuracy and robustness. This finding suggests that when comparing foot anthropometric data among different references, it is important to consider the differences caused by the different measurement methods.

Validated univariate and multivariate spectrophotometric methods for the determination of pharmaceuticals mixture in complex wastewater

NASA Astrophysics Data System (ADS)

Riad, Safaa M.; Salem, Hesham; Elbalkiny, Heba T.; Khattab, Fatma I.

2015-04-01

Five, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its λmax 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p = 0.05.

Validated univariate and multivariate spectrophotometric methods for the determination of pharmaceuticals mixture in complex wastewater.

PubMed

Riad, Safaa M; Salem, Hesham; Elbalkiny, Heba T; Khattab, Fatma I

2015-04-05

Five, accurate, precise, and sensitive univariate and multivariate spectrophotometric methods were developed for the simultaneous determination of a ternary mixture containing Trimethoprim (TMP), Sulphamethoxazole (SMZ) and Oxytetracycline (OTC) in waste water samples collected from different cites either production wastewater or livestock wastewater after their solid phase extraction using OASIS HLB cartridges. In univariate methods OTC was determined at its λmax 355.7 nm (0D), while (TMP) and (SMZ) were determined by three different univariate methods. Method (A) is based on successive spectrophotometric resolution technique (SSRT). The technique starts with the ratio subtraction method followed by ratio difference method for determination of TMP and SMZ. Method (B) is successive derivative ratio technique (SDR). Method (C) is mean centering of the ratio spectra (MCR). The developed multivariate methods are principle component regression (PCR) and partial least squares (PLS). The specificity of the developed methods is investigated by analyzing laboratory prepared mixtures containing different ratios of the three drugs. The obtained results are statistically compared with those obtained by the official methods, showing no significant difference with respect to accuracy and precision at p=0.05. Copyright © 2015 Elsevier B.V. All rights reserved.

Finite difference methods for transient signal propagation in stratified dispersive media

NASA Technical Reports Server (NTRS)

Lam, D. H.

1975-01-01

Explicit difference equations are presented for the solution of a signal of arbitrary waveform propagating in an ohmic dielectric, a cold plasma, a Debye model dielectric, and a Lorentz model dielectric. These difference equations are derived from the governing time-dependent integro-differential equations for the electric fields by a finite difference method. A special difference equation is derived for the grid point at the boundary of two different media. Employing this difference equation, transient signal propagation in an inhomogeneous media can be solved provided that the medium is approximated in a step-wise fashion. The solutions are generated simply by marching on in time. It is concluded that while the classical transform methods will remain useful in certain cases, with the development of the finite difference methods described, an extensive class of problems of transient signal propagating in stratified dispersive media can be effectively solved by numerical methods.

Confident difference criterion: a new Bayesian differentially expressed gene selection algorithm with applications.

PubMed

Yu, Fang; Chen, Ming-Hui; Kuo, Lynn; Talbott, Heather; Davis, John S

2015-08-07

Recently, the Bayesian method becomes more popular for analyzing high dimensional gene expression data as it allows us to borrow information across different genes and provides powerful estimators for evaluating gene expression levels. It is crucial to develop a simple but efficient gene selection algorithm for detecting differentially expressed (DE) genes based on the Bayesian estimators. In this paper, by extending the two-criterion idea of Chen et al. (Chen M-H, Ibrahim JG, Chi Y-Y. A new class of mixture models for differential gene expression in DNA microarray data. J Stat Plan Inference. 2008;138:387-404), we propose two new gene selection algorithms for general Bayesian models and name these new methods as the confident difference criterion methods. One is based on the standardized differences between two mean expression values among genes; the other adds the differences between two variances to it. The proposed confident difference criterion methods first evaluate the posterior probability of a gene having different gene expressions between competitive samples and then declare a gene to be DE if the posterior probability is large. The theoretical connection between the proposed first method based on the means and the Bayes factor approach proposed by Yu et al. (Yu F, Chen M-H, Kuo L. Detecting differentially expressed genes using alibrated Bayes factors. Statistica Sinica. 2008;18:783-802) is established under the normal-normal-model with equal variances between two samples. The empirical performance of the proposed methods is examined and compared to those of several existing methods via several simulations. The results from these simulation studies show that the proposed confident difference criterion methods outperform the existing methods when comparing gene expressions across different conditions for both microarray studies and sequence-based high-throughput studies. A real dataset is used to further demonstrate the proposed methodology. In the real data application, the confident difference criterion methods successfully identified more clinically important DE genes than the other methods. The confident difference criterion method proposed in this paper provides a new efficient approach for both microarray studies and sequence-based high-throughput studies to identify differentially expressed genes.

[Mahalanobis distance based hyperspectral characteristic discrimination of leaves of different desert tree species].

PubMed

Lin, Hai-jun; Zhang, Hui-fang; Gao, Ya-qi; Li, Xia; Yang, Fan; Zhou, Yan-fei

2014-12-01

The hyperspectral reflectance of Populus euphratica, Tamarix hispida, Haloxylon ammodendron and Calligonum mongolicum in the lower reaches of Tarim River and Turpan Desert Botanical Garden was measured by using the HR-768 field-portable spectroradiometer. The method of continuum removal, first derivative reflectance and second derivative reflectance were used to deal with the original spectral data of four tree species. The method of Mahalanobis Distance was used to select the bands with significant differences in the original spectral data and transform spectral data to identify the different tree species. The progressive discrimination analyses were used to test the selective bands used to identify different tree species. The results showed that The Mahalanobis Distance method was an effective method in feature band extraction. The bands for identifying different tree species were most near-infrared bands. The recognition accuracy of four methods was 85%, 93.8%, 92.4% and 95.5% respectively. Spectrum transform could improve the recognition accuracy. The recognition accuracy of different research objects and different spectrum transform methods were different. The research provided evidence for desert tree species classification, monitoring biodiversity and the analysis of area in desert by using large scale remote sensing method.

Simultaneous determination of binary mixture of amlodipine besylate and atenolol based on dual wavelengths

NASA Astrophysics Data System (ADS)

Lamie, Nesrine T.

2015-10-01

Four, accurate, precise, and sensitive spectrophotometric methods are developed for simultaneous determination of a binary mixture of amlodipine besylate (AM) and atenolol (AT). AM is determined at its λmax 360 nm (0D), while atenolol can be determined by four different methods. Method (A) is absorption factor (AF). Method (B) is the new ratio difference method (RD) which measures the difference in amplitudes between 210 and 226 nm. Method (C) is novel constant center spectrophotometric method (CC). Method (D) is mean centering of the ratio spectra (MCR) at 284 nm. The methods are tested by analyzing synthetic mixtures of the cited drugs and they are applied to their commercial pharmaceutical preparation. The validity of results is assessed by applying standard addition technique. The results obtained are found to agree statistically with those obtained by official methods, showing no significant difference with respect to accuracy and precision.

Financial time series analysis based on information categorization method

NASA Astrophysics Data System (ADS)

Tian, Qiang; Shang, Pengjian; Feng, Guochen

2014-12-01

The paper mainly applies the information categorization method to analyze the financial time series. The method is used to examine the similarity of different sequences by calculating the distances between them. We apply this method to quantify the similarity of different stock markets. And we report the results of similarity in US and Chinese stock markets in periods 1991-1998 (before the Asian currency crisis), 1999-2006 (after the Asian currency crisis and before the global financial crisis), and 2007-2013 (during and after global financial crisis) by using this method. The results show the difference of similarity between different stock markets in different time periods and the similarity of the two stock markets become larger after these two crises. Also we acquire the results of similarity of 10 stock indices in three areas; it means the method can distinguish different areas' markets from the phylogenetic trees. The results show that we can get satisfactory information from financial markets by this method. The information categorization method can not only be used in physiologic time series, but also in financial time series.

Elevation data fitting and precision analysis of Google Earth in road survey

NASA Astrophysics Data System (ADS)

Wei, Haibin; Luan, Xiaohan; Li, Hanchao; Jia, Jiangkun; Chen, Zhao; Han, Leilei

2018-05-01

Objective: In order to improve efficiency of road survey and save manpower and material resources, this paper intends to apply Google Earth to the feasibility study stage of road survey and design. Limited by the problem that Google Earth elevation data lacks precision, this paper is focused on finding several different fitting or difference methods to improve the data precision, in order to make every effort to meet the accuracy requirements of road survey and design specifications. Method: On the basis of elevation difference of limited public points, any elevation difference of the other points can be fitted or interpolated. Thus, the precise elevation can be obtained by subtracting elevation difference from the Google Earth data. Quadratic polynomial surface fitting method, cubic polynomial surface fitting method, V4 interpolation method in MATLAB and neural network method are used in this paper to process elevation data of Google Earth. And internal conformity, external conformity and cross correlation coefficient are used as evaluation indexes to evaluate the data processing effect. Results: There is no fitting difference at the fitting point while using V4 interpolation method. Its external conformity is the largest and the effect of accuracy improvement is the worst, so V4 interpolation method is ruled out. The internal and external conformity of the cubic polynomial surface fitting method both are better than those of the quadratic polynomial surface fitting method. The neural network method has a similar fitting effect with the cubic polynomial surface fitting method, but its fitting effect is better in the case of a higher elevation difference. Because the neural network method is an unmanageable fitting model, the cubic polynomial surface fitting method should be mainly used and the neural network method can be used as the auxiliary method in the case of higher elevation difference. Conclusions: Cubic polynomial surface fitting method can obviously improve data precision of Google Earth. The error of data in hilly terrain areas meets the requirement of specifications after precision improvement and it can be used in feasibility study stage of road survey and design.

Development of a Thermal Desorption Gas Chromatography-Mass Spectrometry Analysis Method for Airborne Dichlorodiphenyltrichloroethane

DTIC Science & Technology

2013-05-28

span of 1-250 ng DDT. Furthermore, laboratory and field experiments utilizing this method confirmed that significant DDT concentration differences ... different between the two sample introduction methods when comparing the same DDT mass which may be due to differences in the precision of split...degradation of DDT was significantly different between the liquid and TD methods (t-test; p < 0.001). For TD analyses the relative percent

a Method of Time-Series Change Detection Using Full Polsar Images from Different Sensors

NASA Astrophysics Data System (ADS)

Liu, W.; Yang, J.; Zhao, J.; Shi, H.; Yang, L.

2018-04-01

Most of the existing change detection methods using full polarimetric synthetic aperture radar (PolSAR) are limited to detecting change between two points in time. In this paper, a novel method was proposed to detect the change based on time-series data from different sensors. Firstly, the overall difference image of a time-series PolSAR was calculated by ominous statistic test. Secondly, difference images between any two images in different times ware acquired by Rj statistic test. Generalized Gaussian mixture model (GGMM) was used to obtain time-series change detection maps in the last step for the proposed method. To verify the effectiveness of the proposed method, we carried out the experiment of change detection by using the time-series PolSAR images acquired by Radarsat-2 and Gaofen-3 over the city of Wuhan, in China. Results show that the proposed method can detect the time-series change from different sensors.

Stability and retention of micronutrients in fortified rice prepared using different cooking methods.

PubMed

Wieringa, Frank T; Laillou, Arnaud; Guyondet, Christophe; Jallier, Vincent; Moench-Pfanner, Regina; Berger, Jacques

2014-09-01

Fortified rice holds great potential for bringing essential micronutrients to a large part of the world population. However, it is unknown whether differences in cooking methods or in production of rice premix affect the final amount of micronutrient consumed. This paper presents a study that quantified the losses of five different micronutrients (vitamin A, iron, zinc, folic acid, and vitamin B12) in fortified rice that was produced using three different techniques (hot extrusion, cold extrusion, and coating) during cooking and five different cooking methods (absorption method with or without soaking, washing before cooking, cooking in excess water, and frying rice before cooking). Fortified rice premix from six different producers (two for each technique) was mixed with normal rice in a 1:100 ratio. Each sample was prepared in triplicate, using the five different cooking methods, and retention of iron, zinc, vitamin A, vitamin B12, and folic acid was determined. It was found that the overall retention of iron, zinc, vitamin B12, and folic acid was between 75% and 100% and was unaffected by cooking method, while the retention of vitamin A was significantly affected by cooking method, with retention ranging from 0% (excess water) to 80% (soaking), depending on the cooking method and producer of the rice premix. No systematic differences between the different production methods were observed. We conclude that different cooking methods of rice as used in different regions of the world do not lead to a major loss of most micronutrients, with the exception of vitamin A. The factors involved in protecting vitamin A against losses during cooking need to be identified. All production techniques of rice premix yielded similar results, showing that coating is not inferior to extrusion techniques. Standard overages (50%) for vitamin B12 and folic acid are too high. © 2014 New York Academy of Sciences.

Differences in the Stimulus Accommodative Convergence/Accommodation Ratio using Various Techniques and Accommodative Stimuli.

PubMed

Satou, Tsukasa; Ito, Misae; Shinomiya, Yuma; Takahashi, Yoshiaki; Hara, Naoto; Niida, Takahiro

2018-04-04

To investigate differences in the stimulus accommodative convergence/accommodation (AC/A) ratio using various techniques and accommodative stimuli, and to describe a method for determining the stimulus AC/A ratio. A total of 81 subjects with a mean age of 21 years (range, 20-23 years) were enrolled. The relationship between ocular deviation and accommodation was assessed using two methods. Ocular deviation was measured by varying the accommodative requirement using spherical plus/minus lenses to create an accommodative stimulus of 10.00 diopters (D) (in 1.00 D steps). Ocular deviation was assessed using the alternate prism cover test in method 1 at distance (5 m) and near (1/3 m), and the major amblyoscope in method 2. The stimulus AC/A ratios obtained using methods 1 and 2 were calculated and defined as the stimulus AC/A ratios with low and high accommodation, respectively, using the following analysis method. The former was calculated as the difference between the convergence response to an accommodative stimulus of 3 D and 0 D, divided by 3. The latter was calculated as the difference between the convergence response to a maximum (max) accommodative stimulus with distinct vision of the subject and an accommodative stimulus of max minus 3.00 D, divided by 3. The median stimulus AC/A ratio with low accommodation (1.0 Δ/D for method 1 at distance, 2.0 Δ/D for method 1 at near, and 2.7 Δ/D for method 2) differed significantly among the measurement methods (P < 0.01). Differences in the median stimulus AC/A ratio with high accommodation (4.0 Δ/D for method 1 at distance, 3.7 Δ/D for method 1 at near, and 4.7 Δ/D for method 2) between method 1 at distance and method 2 were statistically significant (P < 0.05), while method 1 at near was not significantly different compared with other methods. Differences in the stimulus AC/A ratio value were significant according to measurement technique and accommodative stimuli. However, differences caused by measurement technique may be reduced by using a high accommodative stimulus during measurements.

[Comparison of different methods in dealing with HIV viral load data with diversified missing value mechanism on HIV positive MSM].

PubMed

Jiang, Z; Dou, Z; Song, W L; Xu, J; Wu, Z Y

2017-11-10

Objective: To compare results of different methods: in organizing HIV viral load (VL) data with missing values mechanism. Methods We used software SPSS 17.0 to simulate complete and missing data with different missing value mechanism from HIV viral loading data collected from MSM in 16 cities in China in 2013. Maximum Likelihood Methods Using the Expectation and Maximization Algorithm (EM), regressive method, mean imputation, delete method, and Markov Chain Monte Carlo (MCMC) were used to supplement missing data respectively. The results: of different methods were compared according to distribution characteristics, accuracy and precision. Results HIV VL data could not be transferred into a normal distribution. All the methods showed good results in iterating data which is Missing Completely at Random Mechanism (MCAR). For the other types of missing data, regressive and MCMC methods were used to keep the main characteristic of the original data. The means of iterating database with different methods were all close to the original one. The EM, regressive method, mean imputation, and delete method under-estimate VL while MCMC overestimates it. Conclusion: MCMC can be used as the main imputation method for HIV virus loading missing data. The iterated data can be used as a reference for mean HIV VL estimation among the investigated population.

[Do different interpretative methods used for evaluation of checkerboard synergy test affect the results?].

PubMed

Ozseven, Ayşe Gül; Sesli Çetin, Emel; Ozseven, Levent

2012-07-01

In recent years, owing to the presence of multi-drug resistant nosocomial bacteria, combination therapies are more frequently applied. Thus there is more need to investigate the in vitro activity of drug combinations against multi-drug resistant bacteria. Checkerboard synergy testing is among the most widely used standard technique to determine the activity of antibiotic combinations. It is based on microdilution susceptibility testing of antibiotic combinations. Although this test has a standardised procedure, there are many different methods for interpreting the results. In many previous studies carried out with multi-drug resistant bacteria, different rates of synergy have been reported with various antibiotic combinations using checkerboard technique. These differences might be attributed to the different features of the strains. However, different synergy rates detected by checkerboard method have also been reported in other studies using the same drug combinations and same types of bacteria. It was thought that these differences in synergy rates might be due to the different methods of interpretation of synergy test results. In recent years, multi-drug resistant Acinetobacter baumannii has been the most commonly encountered nosocomial pathogen especially in intensive-care units. For this reason, multidrug resistant A.baumannii has been the subject of a considerable amount of research about antimicrobial combinations. In the present study, the in vitro activities of frequently preferred combinations in A.baumannii infections like imipenem plus ampicillin/sulbactam, and meropenem plus ampicillin/sulbactam were tested by checkerboard synergy method against 34 multi-drug resistant A.baumannii isolates. Minimum inhibitory concentration (MIC) values for imipenem, meropenem and ampicillin/sulbactam were determined by the broth microdilution method. Subsequently the activity of two different combinations were tested in the dilution range of 4 x MIC and 0.03 x MIC in 96-well checkerboard plates. The results were obtained separately using the four different interpretation methods frequently preferred by researchers. Thus, it was aimed to detect to what extent the rates of synergistic, indifferent and antagonistic interactions were affected by different interpretation methods. The differences between the interpretation methods were tested by chi-square analysis for each combination used. Statistically significant differences were detected between the four different interpretation methods for the determination of synergistic and indifferent interactions (p< 0.0001). Highest rates of synergy were observed with both combinations by the method that used the lowest fractional inhibitory concentration index of all the non-turbid wells along the turbidity/non-turbidity interface. There was no statistically significant difference between the four methods for the detection of antagonism (p> 0.05). In conclusion although there is a standard procedure for checkerboard synergy testing it fails to exhibit standard results owing to different methods of interpretation of the results. Thus, there is a need to standardise the interpretation method for checkerboard synergy testing. To determine the most appropriate method of interpretation further studies investigating the clinical benefits of synergic combinations and additionally comparing the consistency of the results obtained from the other standard combination tests like time-kill studies, are required.

Relation between financial market structure and the real economy: comparison between clustering methods.

PubMed

Musmeci, Nicoló; Aste, Tomaso; Di Matteo, T

2015-01-01

We quantify the amount of information filtered by different hierarchical clustering methods on correlations between stock returns comparing the clustering structure with the underlying industrial activity classification. We apply, for the first time to financial data, a novel hierarchical clustering approach, the Directed Bubble Hierarchical Tree and we compare it with other methods including the Linkage and k-medoids. By taking the industrial sector classification of stocks as a benchmark partition, we evaluate how the different methods retrieve this classification. The results show that the Directed Bubble Hierarchical Tree can outperform other methods, being able to retrieve more information with fewer clusters. Moreover,we show that the economic information is hidden at different levels of the hierarchical structures depending on the clustering method. The dynamical analysis on a rolling window also reveals that the different methods show different degrees of sensitivity to events affecting financial markets, like crises. These results can be of interest for all the applications of clustering methods to portfolio optimization and risk hedging [corrected].

Relation between Financial Market Structure and the Real Economy: Comparison between Clustering Methods

PubMed Central

Musmeci, Nicoló; Aste, Tomaso; Di Matteo, T.

2015-01-01

We quantify the amount of information filtered by different hierarchical clustering methods on correlations between stock returns comparing the clustering structure with the underlying industrial activity classification. We apply, for the first time to financial data, a novel hierarchical clustering approach, the Directed Bubble Hierarchical Tree and we compare it with other methods including the Linkage and k-medoids. By taking the industrial sector classification of stocks as a benchmark partition, we evaluate how the different methods retrieve this classification. The results show that the Directed Bubble Hierarchical Tree can outperform other methods, being able to retrieve more information with fewer clusters. Moreover, we show that the economic information is hidden at different levels of the hierarchical structures depending on the clustering method. The dynamical analysis on a rolling window also reveals that the different methods show different degrees of sensitivity to events affecting financial markets, like crises. These results can be of interest for all the applications of clustering methods to portfolio optimization and risk hedging. PMID:25786703

Development of a Double Glass Mounting Method Using Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) and its Evaluation for Permanent Mounting of Small Nematodes

PubMed Central

ZAHABIUN, Farzaneh; SADJJADI, Seyed Mahmoud; ESFANDIARI, Farideh

2015-01-01

Background: Permanent slide preparation of nematodes especially small ones is time consuming, difficult and they become scarious margins. Regarding this problem, a modified double glass mounting method was developed and compared with classic method. Methods: A total of 209 nematode samples from human and animal origin were fixed and stained with Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) followed by double glass mounting and classic dehydration method using Canada balsam as their mounting media. The slides were evaluated in different dates and times, more than four years. Different photos were made with different magnification during the evaluation time. Results: The double glass mounting method was stable during this time and comparable with classic method. There were no changes in morphologic structures of nematodes using double glass mounting method with well-defined and clear differentiation between different organs of nematodes in this method. Conclusion: Using this method is cost effective and fast for mounting of small nematodes comparing to classic method. PMID:26811729

Evaluation of a visual layering methodology for colour coding control room displays.

PubMed

Van Laar, Darren; Deshe, Ofer

2002-07-01

Eighteen people participated in an experiment in which they were asked to search for targets on control room like displays which had been produced using three different coding methods. The monochrome coding method displayed the information in black and white only, the maximally discriminable method contained colours chosen for their high perceptual discriminability, the visual layers method contained colours developed from psychological and cartographic principles which grouped information into a perceptual hierarchy. The visual layers method produced significantly faster search times than the other two coding methods which did not differ significantly from each other. Search time also differed significantly for presentation order and for the method x order interaction. There was no significant difference between the methods in the number of errors made. Participants clearly preferred the visual layers coding method. Proposals are made for the design of experiments to further test and develop the visual layers colour coding methodology.

Comparison of Molecular Typing Methods Useful for Detecting Clusters of Campylobacter jejuni and C. coli Isolates through Routine Surveillance

PubMed Central

Taboada, Eduardo; Grant, Christopher C. R.; Blakeston, Connie; Pollari, Frank; Marshall, Barbara; Rahn, Kris; MacKinnon, Joanne; Daignault, Danielle; Pillai, Dylan; Ng, Lai-King

2012-01-01

Campylobacter spp. may be responsible for unreported outbreaks of food-borne disease. The detection of these outbreaks is made more difficult by the fact that appropriate methods for detecting clusters of Campylobacter have not been well defined. We have compared the characteristics of five molecular typing methods on Campylobacter jejuni and C. coli isolates obtained from human and nonhuman sources during sentinel site surveillance during a 3-year period. Comparative genomic fingerprinting (CGF) appears to be one of the optimal methods for the detection of clusters of cases, and it could be supplemented by the sequencing of the flaA gene short variable region (flaA SVR sequence typing), with or without subsequent multilocus sequence typing (MLST). Different methods may be optimal for uncovering different aspects of source attribution. Finally, the use of several different molecular typing or analysis methods for comparing individuals within a population reveals much more about that population than a single method. Similarly, comparing several different typing methods reveals a great deal about differences in how the methods group individuals within the population. PMID:22162562

Advances in NMR Spectroscopy for Lipid Oxidation Assessment

USDA-ARS?s Scientific Manuscript database

Although there are many analytical methods developed for the assessment of lipid oxidation, different analytical methods often give different, sometimes even contradictory, results. The reason for this inconsistency is that although there are many different kinds of oxidation products, most methods ...

Are LOD and LOQ Reliable Parameters for Sensitivity Evaluation of Spectroscopic Methods?

PubMed

Ershadi, Saba; Shayanfar, Ali

2018-03-22

The limit of detection (LOD) and the limit of quantification (LOQ) are common parameters to assess the sensitivity of analytical methods. In this study, the LOD and LOQ of previously reported terbium sensitized analysis methods were calculated by different methods, and the results were compared with sensitivity parameters [lower limit of quantification (LLOQ)] of U.S. Food and Drug Administration guidelines. The details of the calibration curve and standard deviation of blank samples of three different terbium-sensitized luminescence methods for the quantification of mycophenolic acid, enrofloxacin, and silibinin were used for the calculation of LOD and LOQ. A comparison of LOD and LOQ values calculated by various methods and LLOQ shows a considerable difference. The significant difference of the calculated LOD and LOQ with various methods and LLOQ should be considered in the sensitivity evaluation of spectroscopic methods.

Influence of the antagonist material on the wear of different composites using two different wear simulation methods.

PubMed

Heintze, S D; Zellweger, G; Cavalleri, A; Ferracane, J

2006-02-01

The aim of the study was to evaluate two ceramic materials as possible substitutes for enamel using two wear simulation methods, and to compare both methods with regard to the wear results for different materials. Flat specimens (OHSU n=6, Ivoclar n=8) of one compomer and three composite materials (Dyract AP, Tetric Ceram, Z250, experimental composite) were fabricated and subjected to wear using two different wear testing methods and two pressable ceramic materials as stylus (Empress, experimental ceramic). For the OHSU method, enamel styli of the same dimensions as the ceramic stylus were fabricated additionally. Both wear testing methods differ with regard to loading force, lateral movement of stylus, stylus dimension, number of cycles, thermocycling and abrasive medium. In the OHSU method, the wear facets (mean vertical loss) were measured using a contact profilometer, while in the Ivoclar method (maximal vertical loss) a laser scanner was used for this purpose. Additionally, the vertical loss of the ceramic stylus was quantified for the Ivoclar method. The results obtained from each method were compared by ANOVA and Tukey's test (p<0.05). To compare both wear methods, the log-transformed data were used to establish relative ranks between material/stylus combinations and assessed by applying the Pearson correlation coefficient. The experimental ceramic material generated significantly less wear in Tetric Ceram and Z250 specimens compared to the Empress stylus in the Ivoclar method, whereas with the OHSU method, no difference between the two ceramic antagonists was found with regard to abrasion or attrition. The wear generated by the enamel stylus was not statistically different from that generated by the other two ceramic materials in the OHSU method. With the Ivoclar method, wear of the ceramic stylus was only statistically different when in contact with Tetric Ceram. There was a close correlation between the attrition wear of the OHSU and the wear of the Ivoclar method (Pearson coefficient 0.83, p=0.01). Pressable ceramic materials can be used as a substitute for enamel in wear testing machines. However, material ranking may be affected by the type of ceramic material chosen. The attrition wear of the OHSU method was comparable with the wear generated with the Ivoclar method.

Analysis of vestibular schwannoma size in multiple dimensions: a comparative cohort study of different measurement techniques.

PubMed

Varughese, J K; Wentzel-Larsen, T; Vassbotn, F; Moen, G; Lund-Johansen, M

2010-04-01

In this volumetric study of the vestibular schwannoma, we evaluated the accuracy and reliability of several approximation methods that are in use, and determined the minimum volume difference that needs to be measured for it to be attributable to an actual difference rather than a retest error. We also found empirical proportionality coefficients for the different methods. DESIGN/SETTING AND PARTICIPANTS: Methodological study with investigation of three different VS measurement methods compared to a reference method that was based on serial slice volume estimates. These volume estimates were based on: (i) one single diameter, (ii) three orthogonal diameters or (iii) the maximal slice area. Altogether 252 T1-weighted MRI images with gadolinium contrast, from 139 VS patients, were examined. The retest errors, in terms of relative percentages, were determined by undertaking repeated measurements on 63 scans for each method. Intraclass correlation coefficients were used to assess the agreement between each of the approximation methods and the reference method. The tendency for approximation methods to systematically overestimate/underestimate different-sized tumours was also assessed, with the help of Bland-Altman plots. The most commonly used approximation method, the maximum diameter, was the least reliable measurement method and has inherent weaknesses that need to be considered. This includes greater retest errors than area-based measurements (25% and 15%, respectively), and that it was the only approximation method that could not easily be converted into volumetric units. Area-based measurements can furthermore be more reliable for smaller volume differences than diameter-based measurements. All our findings suggest that the maximum diameter should not be used as an approximation method. We propose the use of measurement modalities that take into account growth in multiple dimensions instead.

Social network extraction based on Web: 1. Related superficial methods

NASA Astrophysics Data System (ADS)

Khairuddin Matyuso Nasution, Mahyuddin

2018-01-01

Often the nature of something affects methods to resolve the related issues about it. Likewise, methods to extract social networks from the Web, but involve the structured data types differently. This paper reveals several methods of social network extraction from the same sources that is Web: the basic superficial method, the underlying superficial method, the description superficial method, and the related superficial methods. In complexity we derive the inequalities between methods and so are their computations. In this case, we find that different results from the same tools make the difference from the more complex to the simpler: Extraction of social network by involving co-occurrence is more complex than using occurrences.

A different approach to estimate nonlinear regression model using numerical methods

NASA Astrophysics Data System (ADS)

Mahaboob, B.; Venkateswarlu, B.; Mokeshrayalu, G.; Balasiddamuni, P.

2017-11-01

This research paper concerns with the computational methods namely the Gauss-Newton method, Gradient algorithm methods (Newton-Raphson method, Steepest Descent or Steepest Ascent algorithm method, the Method of Scoring, the Method of Quadratic Hill-Climbing) based on numerical analysis to estimate parameters of nonlinear regression model in a very different way. Principles of matrix calculus have been used to discuss the Gradient-Algorithm methods. Yonathan Bard [1] discussed a comparison of gradient methods for the solution of nonlinear parameter estimation problems. However this article discusses an analytical approach to the gradient algorithm methods in a different way. This paper describes a new iterative technique namely Gauss-Newton method which differs from the iterative technique proposed by Gorden K. Smyth [2]. Hans Georg Bock et.al [10] proposed numerical methods for parameter estimation in DAE’s (Differential algebraic equation). Isabel Reis Dos Santos et al [11], Introduced weighted least squares procedure for estimating the unknown parameters of a nonlinear regression metamodel. For large-scale non smooth convex minimization the Hager and Zhang (HZ) conjugate gradient Method and the modified HZ (MHZ) method were presented by Gonglin Yuan et al [12].

Interaction of depth probes and style of depiction

PubMed Central

van Doorn, Andrea J.; Koenderink, Jan J.; Leyssen, Mieke H. R.; Wagemans, Johan

2012-01-01

We study the effect of stylistic differences on the nature of pictorial spaces as they appear to an observer when looking into a picture. Four pictures chosen from diverse styles of depiction were studied by 2 different methods. Each method addresses pictorial depth but draws on a different bouquet of depth cues. We find that the depth structures are very similar for 8 observers, apart from an idiosyncratic depth scaling (up to a factor of 3). The differences between observers generalize over (very different) pictures and (very different) methods. They are apparently characteristic of the person. The differences between depths as sampled by the 2 methods depend upon the style of the picture. This is the case for all observers except one. PMID:23145306

Analytical investigation of different mathematical approaches utilizing manipulation of ratio spectra

NASA Astrophysics Data System (ADS)

Osman, Essam Eldin A.

2018-01-01

This work represents a comparative study of different approaches of manipulating ratio spectra, applied on a binary mixture of ciprofloxacin HCl and dexamethasone sodium phosphate co-formulated as ear drops. The proposed new spectrophotometric methods are: ratio difference spectrophotometric method (RDSM), amplitude center method (ACM), first derivative of the ratio spectra (1DD) and mean centering of ratio spectra (MCR). The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitations and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

Cluster detection methods applied to the Upper Cape Cod cancer data.

PubMed

Ozonoff, Al; Webster, Thomas; Vieira, Veronica; Weinberg, Janice; Ozonoff, David; Aschengrau, Ann

2005-09-15

A variety of statistical methods have been suggested to assess the degree and/or the location of spatial clustering of disease cases. However, there is relatively little in the literature devoted to comparison and critique of different methods. Most of the available comparative studies rely on simulated data rather than real data sets. We have chosen three methods currently used for examining spatial disease patterns: the M-statistic of Bonetti and Pagano; the Generalized Additive Model (GAM) method as applied by Webster; and Kulldorff's spatial scan statistic. We apply these statistics to analyze breast cancer data from the Upper Cape Cancer Incidence Study using three different latency assumptions. The three different latency assumptions produced three different spatial patterns of cases and controls. For 20 year latency, all three methods generally concur. However, for 15 year latency and no latency assumptions, the methods produce different results when testing for global clustering. The comparative analyses of real data sets by different statistical methods provides insight into directions for further research. We suggest a research program designed around examining real data sets to guide focused investigation of relevant features using simulated data, for the purpose of understanding how to interpret statistical methods applied to epidemiological data with a spatial component.

Image and Imaging an Emergency Department: Expense and Benefit of Different Quality Assessment Methods

PubMed Central

Pfortmueller, Carmen Andrea; Keller, Michael; Mueller, Urs; Zimmermann, Heinz; Exadaktylos, Aristomenis Konstantinos

2013-01-01

Introduction. In this era of high-tech medicine, it is becoming increasingly important to assess patient satisfaction. There are several methods to do so, but these differ greatly in terms of cost, time, and labour and external validity. The aim of this study is to describe and compare the structure and implementation of different methods to assess the satisfaction of patients in an emergency department. Methods. The structure and implementation of the different methods to assess patient satisfaction were evaluated on the basis of a 90-minute standardised interview. Results. We identified a total of six different methods in six different hospitals. The average number of patients assessed was 5012, with a range from 230 (M5) to 20 000 patients (M2). In four methods (M1, M3, M5, and M6), the questionnaire was composed by a specialised external institute. In two methods, the questionnaire was created by the hospital itself (M2, M4).The median response rate was 58.4% (range 9–97.8%). With a reminder, the response rate increased by 60% (M3). Conclusion. The ideal method to assess patient satisfaction in the emergency department setting is to use a patient-based, in-emergency department-based assessment of patient satisfaction, planned and guided by expert personnel. PMID:23984073

Comparison of Video Head Impulse Test (vHIT) Gains Between Two Commercially Available Devices and by Different Gain Analytical Methods.

PubMed

Lee, Sang Hun; Yoo, Myung Hoon; Park, Jun Woo; Kang, Byung Chul; Yang, Chan Joo; Kang, Woo Suk; Ahn, Joong Ho; Chung, Jong Woo; Park, Hong Ju

2018-06-01

To evaluate whether video head impulse test (vHIT) gains are dependent on the measuring device and method of analysis. Prospective study. vHIT was performed in 25 healthy subjects using two devices simultaneously. vHIT gains were compared between these instruments and using five different methods of comparing position and velocity gains during head movement intervals. The two devices produced different vHIT gain results with the same method of analysis. There were also significant differences in the vHIT gains measured using different analytical methods. The gain analytic method that compares the areas under the velocity curve (AUC) of the head and eye movements during head movements showed lower vHIT gains than a method that compared the peak velocities of the head and eye movements. The former method produced the vHIT gain with the smallest standard deviation among the five procedures tested in this study. vHIT gains differ in normal subjects depending on the device and method of analysis used, suggesting that it is advisable for each device to have its own normal values. Gain calculations that compare the AUC of the head and eye movements during the head movements show the smallest variance.

Development of a Double Glass Mounting Method Using Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) and its Evaluation for Permanent Mounting of Small Nematodes.

PubMed

Zahabiun, Farzaneh; Sadjjadi, Seyed Mahmoud; Esfandiari, Farideh

2015-01-01

Permanent slide preparation of nematodes especially small ones is time consuming, difficult and they become scarious margins. Regarding this problem, a modified double glass mounting method was developed and compared with classic method. A total of 209 nematode samples from human and animal origin were fixed and stained with Formaldehyde Alcohol Azocarmine Lactophenol (FAAL) followed by double glass mounting and classic dehydration method using Canada balsam as their mounting media. The slides were evaluated in different dates and times, more than four years. Different photos were made with different magnification during the evaluation time. The double glass mounting method was stable during this time and comparable with classic method. There were no changes in morphologic structures of nematodes using double glass mounting method with well-defined and clear differentiation between different organs of nematodes in this method. Using this method is cost effective and fast for mounting of small nematodes comparing to classic method.

Comparison of methods used to estimate conventional undiscovered petroleum resources: World examples

USGS Publications Warehouse

Ahlbrandt, T.S.; Klett, T.R.

2005-01-01

Various methods for assessing undiscovered oil, natural gas, and natural gas liquid resources were compared in support of the USGS World Petroleum Assessment 2000. Discovery process, linear fractal, parabolic fractal, engineering estimates, PETRIMES, Delphi, and the USGS 2000 methods were compared. Three comparisons of these methods were made in: (1) the Neuquen Basin province, Argentina (different assessors, same input data); (2) provinces in North Africa, Oman, and Yemen (same assessors, different methods); and (3) the Arabian Peninsula, Arabian (Persian) Gulf, and North Sea (different assessors, different methods). A fourth comparison (same assessors, same assessment methods but different geologic models), between results from structural and stratigraphic assessment units in the North Sea used only the USGS 2000 method, and hence compared the type of assessment unit rather than the method. In comparing methods, differences arise from inherent differences in assumptions regarding: (1) the underlying distribution of the parent field population (all fields, discovered and undiscovered), (2) the population of fields being estimated; that is, the entire parent distribution or the undiscovered resource distribution, (3) inclusion or exclusion of large outlier fields; (4) inclusion or exclusion of field (reserve) growth, (5) deterministic or probabilistic models, (6) data requirements, and (7) scale and time frame of the assessment. Discovery process, Delphi subjective consensus, and the USGS 2000 method yield comparable results because similar procedures are employed. In mature areas such as the Neuquen Basin province in Argentina, the linear and parabolic fractal and engineering methods were conservative compared to the other five methods and relative to new reserve additions there since 1995. The PETRIMES method gave the most optimistic estimates in the Neuquen Basin. In less mature areas, the linear fractal method yielded larger estimates relative to other methods. A geologically based model, such as one using the total petroleum system approach, is preferred in that it combines the elements of petroleum source, reservoir, trap and seal with the tectono-stratigraphic history of basin evolution with petroleum resource potential. Care must be taken to demonstrate that homogeneous populations in terms of geology, geologic risk, exploration, and discovery processes are used in the assessment process. The USGS 2000 method (7th Approximation Model, EMC computational program) is robust; that is, it can be used in both mature and immature areas, and provides comparable results when using different geologic models (e.g. stratigraphic or structural) with differing amounts of subdivisions, assessment units, within the total petroleum system. ?? 2005 International Association for Mathematical Geology.

Numerical solution of nonlinear partial differential equations of mixed type. [finite difference approximation

NASA Technical Reports Server (NTRS)

Jameson, A.

1976-01-01

A review is presented of some recently developed numerical methods for the solution of nonlinear equations of mixed type. The methods considered use finite difference approximations to the differential equation. Central difference formulas are employed in the subsonic zone and upwind difference formulas are used in the supersonic zone. The relaxation method for the small disturbance equation is discussed and a description is given of difference schemes for the potential flow equation in quasi-linear form. Attention is also given to difference schemes for the potential flow equation in conservation form, the analysis of relaxation schemes by the time dependent analogy, the accelerated iterative method, and three-dimensional calculations.

How to Quantify Penile Corpus Cavernosum Structures with Histomorphometry: Comparison of Two Methods

PubMed Central

Felix-Patrício, Bruno; De Souza, Diogo Benchimol; Gregório, Bianca Martins; Costa, Waldemar Silva; Sampaio, Francisco José

2015-01-01

The use of morphometrical tools in biomedical research permits the accurate comparison of specimens subjected to different conditions, and the surface density of structures is commonly used for this purpose. The traditional point-counting method is reliable but time-consuming, with computer-aided methods being proposed as an alternative. The aim of this study was to compare the surface density data of penile corpus cavernosum trabecular smooth muscle in different groups of rats, measured by two observers using the point-counting or color-based segmentation method. Ten normotensive and 10 hypertensive male rats were used in this study. Rat penises were processed to obtain smooth muscle immunostained histological slices and photomicrographs captured for analysis. The smooth muscle surface density was measured in both groups by two different observers by the point-counting method and by the color-based segmentation method. Hypertensive rats showed an increase in smooth muscle surface density by the two methods, and no difference was found between the results of the two observers. However, surface density values were higher by the point-counting method. The use of either method did not influence the final interpretation of the results, and both proved to have adequate reproducibility. However, as differences were found between the two methods, results obtained by either method should not be compared. PMID:26413547

How to Quantify Penile Corpus Cavernosum Structures with Histomorphometry: Comparison of Two Methods.

PubMed

Felix-Patrício, Bruno; De Souza, Diogo Benchimol; Gregório, Bianca Martins; Costa, Waldemar Silva; Sampaio, Francisco José

2015-01-01

The use of morphometrical tools in biomedical research permits the accurate comparison of specimens subjected to different conditions, and the surface density of structures is commonly used for this purpose. The traditional point-counting method is reliable but time-consuming, with computer-aided methods being proposed as an alternative. The aim of this study was to compare the surface density data of penile corpus cavernosum trabecular smooth muscle in different groups of rats, measured by two observers using the point-counting or color-based segmentation method. Ten normotensive and 10 hypertensive male rats were used in this study. Rat penises were processed to obtain smooth muscle immunostained histological slices and photomicrographs captured for analysis. The smooth muscle surface density was measured in both groups by two different observers by the point-counting method and by the color-based segmentation method. Hypertensive rats showed an increase in smooth muscle surface density by the two methods, and no difference was found between the results of the two observers. However, surface density values were higher by the point-counting method. The use of either method did not influence the final interpretation of the results, and both proved to have adequate reproducibility. However, as differences were found between the two methods, results obtained by either method should not be compared.

Effects of observers using different methods upon the total population estimates of two resident island birds

Treesearch

Sheila Conant; Mark S. Collins; C. John Ralph

1981-01-01

During a 5-week study of the Nihoa Millerbird and Nihoa Finch, we censused birds using these techniques: two line transect methods, a variable-distance circular plot method, and spot-mapping of territories (millerbirds only). Densities derived from these methods varied greatly. Due to differences in behavior, it appeared that the two species reacted differently to the...

Methods for comparing 3D surface attributes

NASA Astrophysics Data System (ADS)

Pang, Alex; Freeman, Adam

1996-03-01

A common task in data analysis is to compare two or more sets of data, statistics, presentations, etc. A predominant method in use is side-by-side visual comparison of images. While straightforward, it burdens the user with the task of discerning the differences between the two images. The user if further taxed when the images are of 3D scenes. This paper presents several methods for analyzing the extent, magnitude, and manner in which surfaces in 3D differ in their attributes. The surface geometry are assumed to be identical and only the surface attributes (color, texture, etc.) are variable. As a case in point, we examine the differences obtained when a 3D scene is rendered progressively using radiosity with different form factor calculation methods. The comparison methods include extensions of simple methods such as mapping difference information to color or transparency, and more recent methods including the use of surface texture, perturbation, and adaptive placements of error glyphs.

Latency as a region contrast: Measuring ERP latency differences with Dynamic Time Warping.

PubMed

Zoumpoulaki, A; Alsufyani, A; Filetti, M; Brammer, M; Bowman, H

2015-12-01

Methods for measuring onset latency contrasts are evaluated against a new method utilizing the dynamic time warping (DTW) algorithm. This new method allows latency to be measured across a region instead of single point. We use computer simulations to compare the methods' power and Type I error rates under different scenarios. We perform per-participant analysis for different signal-to-noise ratios and two sizes of window (broad vs. narrow). In addition, the methods are tested in combination with single-participant and jackknife average waveforms for different effect sizes, at the group level. DTW performs better than the other methods, being less sensitive to noise as well as to placement and width of the window selected. © 2015 Society for Psychophysiological Research.

Comparison of the calculation QRS angle for bundle branch block detection

NASA Astrophysics Data System (ADS)

Goeirmanto, L.; Mengko, R.; Rajab, T. L.

2016-04-01

QRS angle represent condition of blood circulation in the heart. Normally QRS angle is between -30 until 90 degree. Left Axis Defiation (LAD) and Right Axis Defiation (RAD) are abnormality conditions that lead to Bundle Branch Block. QRS angle is calculated using common method from physicians and compared to mathematical method using difference amplitudos and difference areas. We analyzed the standard 12 lead electrocardiogram data from MITBIH physiobank database. All methods using lead I and lead avF produce similar QRS angle and right QRS axis quadrant. QRS angle from mathematical method using difference areas is close to common method from physician. Mathematical method using difference areas can be used as a trigger for detecting heart condition.

Using mark-recapture distance sampling methods on line transect surveys

USGS Publications Warehouse

Burt, Louise M.; Borchers, David L.; Jenkins, Kurt J.; Marques, Tigao A

2014-01-01

Synthesis and applications. Mark–recapture DS is a widely used method for estimating animal density and abundance when detection of animals at distance zero is not certain. Two observer configurations and three statistical models are described, and it is important to choose the most appropriate model for the observer configuration and target species in question. By way of making the methods more accessible to practicing ecologists, we describe the key ideas underlying MRDS methods, the sometimes subtle differences between them, and we illustrate these by applying different kinds of MRDS method to surveys of two different target species using different survey configurations.

Finite elements and finite differences for transonic flow calculations

NASA Technical Reports Server (NTRS)

Hafez, M. M.; Murman, E. M.; Wellford, L. C.

1978-01-01

The paper reviews the chief finite difference and finite element techniques used for numerical solution of nonlinear mixed elliptic-hyperbolic equations governing transonic flow. The forms of the governing equations for unsteady two-dimensional transonic flow considered are the Euler equation, the full potential equation in both conservative and nonconservative form, the transonic small-disturbance equation in both conservative and nonconservative form, and the hodograph equations for the small-disturbance case and the full-potential case. Finite difference methods considered include time-dependent methods, relaxation methods, semidirect methods, and hybrid methods. Finite element methods include finite element Lax-Wendroff schemes, implicit Galerkin method, mixed variational principles, dual iterative procedures, optimal control methods and least squares.

Rupture Dynamics Simulation for Non-Planar fault by a Curved Grid Finite Difference Method

NASA Astrophysics Data System (ADS)

Zhang, Z.; Zhu, G.; Chen, X.

2011-12-01

We first implement the non-staggered finite difference method to solve the dynamic rupture problem, with split-node, for non-planar fault. Split-node method for dynamic simulation has been used widely, because of that it's more precise to represent the fault plane than other methods, for example, thick fault, stress glut and so on. The finite difference method is also a popular numeric method to solve kinematic and dynamic problem in seismology. However, previous works focus most of theirs eyes on the staggered-grid method, because of its simplicity and computational efficiency. However this method has its own disadvantage comparing to non-staggered finite difference method at some fact for example describing the boundary condition, especially the irregular boundary, or non-planar fault. Zhang and Chen (2006) proposed the MacCormack high order non-staggered finite difference method based on curved grids to precisely solve irregular boundary problem. Based upon on this non-staggered grid method, we make success of simulating the spontaneous rupture problem. The fault plane is a kind of boundary condition, which could be irregular of course. So it's convinced that we could simulate rupture process in the case of any kind of bending fault plane. We will prove this method is valid in the case of Cartesian coordinate first. In the case of bending fault, the curvilinear grids will be used.

On the wavelet optimized finite difference method

NASA Technical Reports Server (NTRS)

Jameson, Leland

1994-01-01

When one considers the effect in the physical space, Daubechies-based wavelet methods are equivalent to finite difference methods with grid refinement in regions of the domain where small scale structure exists. Adding a wavelet basis function at a given scale and location where one has a correspondingly large wavelet coefficient is, essentially, equivalent to adding a grid point, or two, at the same location and at a grid density which corresponds to the wavelet scale. This paper introduces a wavelet optimized finite difference method which is equivalent to a wavelet method in its multiresolution approach but which does not suffer from difficulties with nonlinear terms and boundary conditions, since all calculations are done in the physical space. With this method one can obtain an arbitrarily good approximation to a conservative difference method for solving nonlinear conservation laws.

Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods.

PubMed

Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

2016-01-01

Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community.

Clustering Scientific Publications Based on Citation Relations: A Systematic Comparison of Different Methods

PubMed Central

Šubelj, Lovro; van Eck, Nees Jan; Waltman, Ludo

2016-01-01

Clustering methods are applied regularly in the bibliometric literature to identify research areas or scientific fields. These methods are for instance used to group publications into clusters based on their relations in a citation network. In the network science literature, many clustering methods, often referred to as graph partitioning or community detection techniques, have been developed. Focusing on the problem of clustering the publications in a citation network, we present a systematic comparison of the performance of a large number of these clustering methods. Using a number of different citation networks, some of them relatively small and others very large, we extensively study the statistical properties of the results provided by different methods. In addition, we also carry out an expert-based assessment of the results produced by different methods. The expert-based assessment focuses on publications in the field of scientometrics. Our findings seem to indicate that there is a trade-off between different properties that may be considered desirable for a good clustering of publications. Overall, map equation methods appear to perform best in our analysis, suggesting that these methods deserve more attention from the bibliometric community. PMID:27124610

A robust algorithm for optimisation and customisation of fractal dimensions of time series modified by nonlinearly scaling their time derivatives: mathematical theory and practical applications.

PubMed

Fuss, Franz Konstantin

2013-01-01

Standard methods for computing the fractal dimensions of time series are usually tested with continuous nowhere differentiable functions, but not benchmarked with actual signals. Therefore they can produce opposite results in extreme signals. These methods also use different scaling methods, that is, different amplitude multipliers, which makes it difficult to compare fractal dimensions obtained from different methods. The purpose of this research was to develop an optimisation method that computes the fractal dimension of a normalised (dimensionless) and modified time series signal with a robust algorithm and a running average method, and that maximises the difference between two fractal dimensions, for example, a minimum and a maximum one. The signal is modified by transforming its amplitude by a multiplier, which has a non-linear effect on the signal's time derivative. The optimisation method identifies the optimal multiplier of the normalised amplitude for targeted decision making based on fractal dimensions. The optimisation method provides an additional filter effect and makes the fractal dimensions less noisy. The method is exemplified by, and explained with, different signals, such as human movement, EEG, and acoustic signals.

A Robust Algorithm for Optimisation and Customisation of Fractal Dimensions of Time Series Modified by Nonlinearly Scaling Their Time Derivatives: Mathematical Theory and Practical Applications

PubMed Central

2013-01-01

Standard methods for computing the fractal dimensions of time series are usually tested with continuous nowhere differentiable functions, but not benchmarked with actual signals. Therefore they can produce opposite results in extreme signals. These methods also use different scaling methods, that is, different amplitude multipliers, which makes it difficult to compare fractal dimensions obtained from different methods. The purpose of this research was to develop an optimisation method that computes the fractal dimension of a normalised (dimensionless) and modified time series signal with a robust algorithm and a running average method, and that maximises the difference between two fractal dimensions, for example, a minimum and a maximum one. The signal is modified by transforming its amplitude by a multiplier, which has a non-linear effect on the signal's time derivative. The optimisation method identifies the optimal multiplier of the normalised amplitude for targeted decision making based on fractal dimensions. The optimisation method provides an additional filter effect and makes the fractal dimensions less noisy. The method is exemplified by, and explained with, different signals, such as human movement, EEG, and acoustic signals. PMID:24151522

CompareSVM: supervised, Support Vector Machine (SVM) inference of gene regularity networks.

PubMed

Gillani, Zeeshan; Akash, Muhammad Sajid Hamid; Rahaman, M D Matiur; Chen, Ming

2014-11-30

Predication of gene regularity network (GRN) from expression data is a challenging task. There are many methods that have been developed to address this challenge ranging from supervised to unsupervised methods. Most promising methods are based on support vector machine (SVM). There is a need for comprehensive analysis on prediction accuracy of supervised method SVM using different kernels on different biological experimental conditions and network size. We developed a tool (CompareSVM) based on SVM to compare different kernel methods for inference of GRN. Using CompareSVM, we investigated and evaluated different SVM kernel methods on simulated datasets of microarray of different sizes in detail. The results obtained from CompareSVM showed that accuracy of inference method depends upon the nature of experimental condition and size of the network. For network with nodes (<200) and average (over all sizes of networks), SVM Gaussian kernel outperform on knockout, knockdown, and multifactorial datasets compared to all the other inference methods. For network with large number of nodes (~500), choice of inference method depend upon nature of experimental condition. CompareSVM is available at http://bis.zju.edu.cn/CompareSVM/ .

[Comparision of Different Methods of Area Measurement in Irregular Scar].

PubMed

Ran, D; Li, W J; Sun, Q G; Li, J Q; Xia, Q

2016-10-01

To determine a measurement standard of irregular scar area by comparing the advantages and disadvantages of different measurement methods in measuring same irregular scar area. Irregular scar area was scanned by digital scanning and measured by coordinate reading method, AutoCAD pixel method, Photoshop lasso pixel method, Photoshop magic bar filled pixel method and Foxit PDF reading software, and some aspects of these methods such as measurement time, repeatability, whether could be recorded and whether could be traced were compared and analyzed. There was no significant difference in the scar areas by the measurement methods above. However, there was statistical difference in the measurement time and repeatability by one or multi performers and only Foxit PDF reading software could be traced back. The methods above can be used for measuring scar area, but each one has its advantages and disadvantages. It is necessary to develop new measurement software for forensic identification. Copyright© by the Editorial Department of Journal of Forensic Medicine

Dangerous gas detection based on infrared video

NASA Astrophysics Data System (ADS)

Ding, Kang; Hong, Hanyu; Huang, Likun

2018-03-01

As the gas leak infrared imaging detection technology has significant advantages of high efficiency and remote imaging detection, in order to enhance the detail perception of observers and equivalently improve the detection limit, we propose a new type of gas leak infrared image detection method, which combines background difference methods and multi-frame interval difference method. Compared to the traditional frame methods, the multi-frame interval difference method we proposed can extract a more complete target image. By fusing the background difference image and the multi-frame interval difference image, we can accumulate the information of infrared target image of the gas leak in many aspect. The experiment demonstrate that the completeness of the gas leakage trace information is enhanced significantly, and the real-time detection effect can be achieved.

An empirical investigation of methods for nonsymmetric linear systems

NASA Technical Reports Server (NTRS)

Sherman, A. H.

1981-01-01

The present investigation is concerned with a comparison of methods for solving linear algebraic systems which arise from finite difference discretizations of the elliptic convection-diffusion equation in a planar region Omega with Dirichlet boundary conditions. Such linear systems are typically of the form Ax = b where A is an N x N sparse nonsymmetric matrix. In a discussion of discretizations, it is assumed that a regular rectilinear mesh of width h has been imposed on Omega. The discretizations considered include central differences, upstream differences, and modified upstream differences. Six methods for solving Ax = b are considered. Three variants of Gaussian elimination have been chosen as representatives of state-of-the-art software for direct methods under different assumptions about pivoting. Three iterative methods are also included.

The Influence of Different Processing Methods on Component Content of Sophora japonica

NASA Astrophysics Data System (ADS)

Ji, Y. B.; Zhu, H. J.; Xin, G. S.; Wei, C.

2017-12-01

The purpose of this experiment is to understand the effect of different processing methods on the content of active ingredients in Sophora japonica, and to determine the content of rutin and quercetin in Sophora japonica under different processing methods by UV spectrophotometry of the content determination. So as to compare the effect of different processing methods on the active ingredient content of Sophora japonica. Experiments can be seen in the rutin content: Fried Sophora japonica>Vinegar sunburn Sophora> Health products Sophora japonica> Charred sophora flower, Vinegar sunburn Sophora and Fried Sophora japonica difference is not obvious; Quercetin content: Charred sophora flower> Fried Sophora japonica> Vinegar sunburn Sophora>Health products Sophora japonica. It is proved that there are some differences in the content of active ingredients in Sophora japonica in different processing methods. The content of rutin increased with the increase of the processing temperature, but the content decreased after a certain temperature; Quercetin content will increase gradually with time.

Review of Hull Structural Monitoring Systems for Navy Ships

DTIC Science & Technology

2013-05-01

generally based on the same basic form of S-N curve, different correction methods are used by the various classification societies. ii. Methods for...Likewise there are a number of different methods employed for temperature compensation and these vary depending on the type of gauge, although typically...Analysis, Inc.[30] Figure 8. Examples of different methods of temperature compensation of fibre-optic strain sensors. It is noted in NATO

Comparison of four different methods for detection of biofilm formation by uropathogens.

PubMed

Panda, Pragyan Swagatika; Chaudhary, Uma; Dube, Surya K

2016-01-01

Urinary tract infection (UTI) is one of the most common infectious diseases encountered in clinical practice. Emerging resistance of the uropathogens to the antimicrobial agents due to biofilm formation is a matter of concern while treating symptomatic UTI. However, studies comparing different methods for detection of biofilm by uropathogens are scarce. To compare four different methods for detection of biofilm formation by uropathogens. Prospective observational study conducted in a tertiary care hospital. Totally 300 isolates from urinary samples were analyzed for biofilm formation by four methods, that is, tissue culture plate (TCP) method, tube method (TM), Congo Red Agar (CRA) method and modified CRA (MCRA) method. Chi-square test was applied when two or more set of variables were compared. P < 0.05 considered as statistically significant. Considering TCP to be a gold standard method for our study we calculated other statistical parameters. The rate of biofilm detection was 45.6%, 39.3% and 11% each by TCP, TM, CRA and MCRA methods, respectively. The difference between TCP and only CRA/MCRA was significant, but not that between TCP and TM. There was no difference in the rate of biofilm detection between CRA and MCRA in other isolates, but MCRA is superior to CRA for detection of the staphylococcal biofilm formation. TCP method is the ideal method for detection of bacterial biofilm formation by uropathogens. MCRA method is superior only to CRA for detection of staphylococcal biofilm formation.

Comparing four non-invasive methods to determine the ventilatory anaerobic threshold during cardiopulmonary exercise testing in children with congenital heart or lung disease.

PubMed

Visschers, Naomi C A; Hulzebos, Erik H; van Brussel, Marco; Takken, Tim

2015-11-01

The ventilatory anaerobic threshold (VAT) is an important method to assess the aerobic fitness in patients with cardiopulmonary disease. Several methods exist to determine the VAT; however, there is no consensus which of these methods is the most accurate. To compare four different non-invasive methods for the determination of the VAT via respiratory gas exchange analysis during a cardiopulmonary exercise test (CPET). A secondary objective is to determine the interobserver reliability of the VAT. CPET data of 30 children diagnosed with either cystic fibrosis (CF; N = 15) or with a surgically corrected dextro-transposition of the great arteries (asoTGA; N = 15) were included. No significant differences were found between conditions or among testers. The RER = 1 method differed the most compared to the other methods, showing significant higher results in all six variables. The PET-O2 method differed significantly on five of six and four of six exercise variables with the V-slope method and the VentEq method, respectively. The V-slope and the VentEq method differed significantly on one of six exercise variables. Ten of thirteen ICCs that were >0.80 had a 95% CI > 0.70. The RER = 1 method and the V-slope method had the highest number of significant ICCs and 95% CIs. The V-slope method, the ventilatory equivalent method and the PET-O2 method are comparable and reliable methods to determine the VAT during CPET in children with CF or asoTGA. © 2014 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Multiple-algorithm parallel fusion of infrared polarization and intensity images based on algorithmic complementarity and synergy

NASA Astrophysics Data System (ADS)

Zhang, Lei; Yang, Fengbao; Ji, Linna; Lv, Sheng

2018-01-01

Diverse image fusion methods perform differently. Each method has advantages and disadvantages compared with others. One notion is that the advantages of different image methods can be effectively combined. A multiple-algorithm parallel fusion method based on algorithmic complementarity and synergy is proposed. First, in view of the characteristics of the different algorithms and difference-features among images, an index vector-based feature-similarity is proposed to define the degree of complementarity and synergy. This proposed index vector is a reliable evidence indicator for algorithm selection. Second, the algorithms with a high degree of complementarity and synergy are selected. Then, the different degrees of various features and infrared intensity images are used as the initial weights for the nonnegative matrix factorization (NMF). This avoids randomness of the NMF initialization parameter. Finally, the fused images of different algorithms are integrated using the NMF because of its excellent data fusing performance on independent features. Experimental results demonstrate that the visual effect and objective evaluation index of the fused images obtained using the proposed method are better than those obtained using traditional methods. The proposed method retains all the advantages that individual fusion algorithms have.

Radiometer calibration methods and resulting irradiance differences: Radiometer calibration methods and resulting irradiance differences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habte, Aron; Sengupta, Manajit; Andreas, Afshin

Accurate solar radiation measured by radiometers depends on instrument performance specifications, installation method, calibration procedure, measurement conditions, maintenance practices, location, and environmental conditions. This study addresses the effect of different calibration methodologies and resulting differences provided by radiometric calibration service providers such as the National Renewable Energy Laboratory (NREL) and manufacturers of radiometers. Some of these methods calibrate radiometers indoors and some outdoors. To establish or understand the differences in calibration methodologies, we processed and analyzed field-measured data from radiometers deployed for 10 months at NREL's Solar Radiation Research Laboratory. These different methods of calibration resulted in a difference ofmore » +/-1% to +/-2% in solar irradiance measurements. Analyzing these differences will ultimately assist in determining the uncertainties of the field radiometer data and will help develop a consensus on a standard for calibration. Further advancing procedures for precisely calibrating radiometers to world reference standards that reduce measurement uncertainties will help the accurate prediction of the output of planned solar conversion projects and improve the bankability of financing solar projects.« less

Detection of oral HPV infection - Comparison of two different specimen collection methods and two HPV detection methods.

PubMed

de Souza, Marjorie M A; Hartel, Gunter; Whiteman, David C; Antonsson, Annika

2018-04-01

Very little is known about the natural history of oral HPV infection. Several different methods exist to collect oral specimens and detect HPV, but their respective performance characteristics are unknown. We compared two different methods for oral specimen collection (oral saline rinse and commercial saliva kit) from 96 individuals and then analyzed the samples for HPV by two different PCR detection methods (single GP5+/6+ PCR and nested MY09/11 and GP5+/6+ PCR). For the oral rinse samples, the oral HPV prevalence was 10.4% (GP+ PCR; 10% repeatability) vs 11.5% (nested PCR method; 100% repeatability). For the commercial saliva kit samples, the prevalences were 3.1% vs 16.7% with the GP+ PCR vs the nested PCR method (repeatability 100% for both detection methods). Overall the agreement was fair or poor between samples and methods (kappa 0.06-0.36). Standardizing methods of oral sample collection and HPV detection would ensure comparability between future oral HPV studies. Copyright © 2017 Elsevier Inc. All rights reserved.

Simulation of 2D rarefied gas flows based on the numerical solution of the Boltzmann equation

NASA Astrophysics Data System (ADS)

Poleshkin, Sergey O.; Malkov, Ewgenij A.; Kudryavtsev, Alexey N.; Shershnev, Anton A.; Bondar, Yevgeniy A.; Kohanchik, A. A.

2017-10-01

There are various methods for calculating rarefied gas flows, in particular, statistical methods and deterministic methods based on the finite-difference solutions of the Boltzmann nonlinear kinetic equation and on the solutions of model kinetic equations. There is no universal method; each has its disadvantages in terms of efficiency or accuracy. The choice of the method depends on the problem to be solved and on parameters of calculated flows. Qualitative theoretical arguments help to determine the range of parameters of effectively solved problems for each method; however, it is advisable to perform comparative tests of calculations of the classical problems performed by different methods and with different parameters to have quantitative confirmation of this reasoning. The paper provides the results of the calculations performed by the authors with the help of the Direct Simulation Monte Carlo method and finite-difference methods of solving the Boltzmann equation and model kinetic equations. Based on this comparison, conclusions are made on selecting a particular method for flow simulations in various ranges of flow parameters.

The Comparison of Matching Methods Using Different Measures of Balance: Benefits and Risks Exemplified within a Study to Evaluate the Effects of German Disease Management Programs on Long-Term Outcomes of Patients with Type 2 Diabetes.

PubMed

Fullerton, Birgit; Pöhlmann, Boris; Krohn, Robert; Adams, John L; Gerlach, Ferdinand M; Erler, Antje

2016-10-01

To present a case study on how to compare various matching methods applying different measures of balance and to point out some pitfalls involved in relying on such measures. Administrative claims data from a German statutory health insurance fund covering the years 2004-2008. We applied three different covariance balance diagnostics to a choice of 12 different matching methods used to evaluate the effectiveness of the German disease management program for type 2 diabetes (DMPDM2). We further compared the effect estimates resulting from applying these different matching techniques in the evaluation of the DMPDM2. The choice of balance measure leads to different results on the performance of the applied matching methods. Exact matching methods performed well across all measures of balance, but resulted in the exclusion of many observations, leading to a change of the baseline characteristics of the study sample and also the effect estimate of the DMPDM2. All PS-based methods showed similar effect estimates. Applying a higher matching ratio and using a larger variable set generally resulted in better balance. Using a generalized boosted instead of a logistic regression model showed slightly better performance for balance diagnostics taking into account imbalances at higher moments. Best practice should include the application of several matching methods and thorough balance diagnostics. Applying matching techniques can provide a useful preprocessing step to reveal areas of the data that lack common support. The use of different balance diagnostics can be helpful for the interpretation of different effect estimates found with different matching methods. © Health Research and Educational Trust.

Evaluation method on steering for the shape-shifting robot in different configurations

NASA Astrophysics Data System (ADS)

Chang, Jian; Li, Bin; Wang, Chong; Zheng, Huaibing; Li, Zhiqiang

2016-01-01

The evaluation method on steering is based on qualitative manner in existence, which causes the result inaccurate and fuzziness. It reduces the efficiency of process execution. So the method by quantitative manner for the shape-shifting robot in different configurations is proposed. Comparing to traditional evaluation method, the most important aspects which can influence the steering abilities of the robot in different configurations are researched in detail, including the energy, angular velocity, time and space. In order to improve the robustness of system, the ideal and slippage conditions are all considered by mathematical model. Comparing to the traditional weighting confirming method, the extent of robot steering method is proposed by the combination of subjective and objective weighting method. The subjective weighting method can show more preferences of the experts and is based on five-grade scale. The objective weighting method is based on information entropy to determine the factors. By the sensors fixed on the robot, the contract force between track grouser and ground, the intrinsic motion characteristics of robot are obtained and the experiment is done to prove the algorithm which is proposed as the robot in different common configurations. Through the method proposed in the article, fuzziness and inaccurate of the evaluation method has been solved, so the operators can choose the most suitable configuration of the robot to fulfil the different tasks more quickly and simply.

Digital image color analysis compared to direct dental CIE colorimeter assessment under different ambient conditions.

PubMed

Knösel, Michael; Attin, Rengin; Jung, Klaus; Brunner, Edgar; Kubein-Meesenburg, Dietmar; Attin, Thomas

2009-04-01

To evaluate the concordance and repeatability of two in vivo methods for dental color assessment and to clarify the influence of different ambient light conditions and subject's head position on the assessed color variables. Color assessments were performed by two examiners on 16 arbitrarily selected subjects under two different, standardized conditions of illumination and at two different standardized head angulations. CIE (L*a*b*) data for upper and lower central incisors were recorded in two different ways: (1) by an intra-oral contact dental colorimeter and (2) by processing digital images for performing color calculation using Adobe Photoshop software. The influence of the different ambient conditions on both methods, as well as the concordance of measurements was analyzed statistically using several mixed linear models. Ambient light as a single factor had no significant influence on maxillary L*, a* and b* values, but it did have an effect on mandible assessments. Head angulation variation resulted in significant L* value differences using the photo method. The operator had a significant influence on values a* and b* for the photo method and on a* values for the colorimeter method. In fully lit ambient condition, the operator had a significant influence on the segregated L*, a*, and b* values. With dimmed lights, head angulation became significant, but not the operator. Evaluation of segregated L* values was error prone in both methods. Comparing both methods, deltaE values did not exceed 2.85 units, indicating that color differences between methods and recorded under varying ambient conditions were well below the sensitivity of the naked eye.

Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

PubMed

Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

2015-11-05

Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

The Effects of Different Standard Setting Methods and the Composition of Borderline Groups: A Study within a Law Curriculum

ERIC Educational Resources Information Center

Dochy, Filip; Kyndt, Eva; Baeten, Marlies; Pottier, Sofie; Veestraeten, Marlies; Leuven, K. U.

2009-01-01

The aim of this study was to examine the effect of different standard setting methods on the size and composition of the borderline group, on the discrimination between different types of students and on the types of students passing with one method but failing with another. A total of 107 university students were classified into 4 different types…

Prototype Procedures to Describe Army Jobs

DTIC Science & Technology

2010-07-01

ratings for the same MOS. Consistent with a multi-trait multi- method framework, high profile similarities (or low mean differences ) among different ...rater types for the same MOS would indicate convergent validity. That is, different methods (i.e., rater types) yield converging results for the same... different methods of data collection depends upon the type of data collected. For example, it could be that data on work-oriented descriptors are most

Hospitalization costs of severe bacterial pneumonia in children: comparative analysis considering different costing methods

PubMed Central

Nunes, Sheila Elke Araujo; Minamisava, Ruth; Vieira, Maria Aparecida da Silva; Itria, Alexander; Pessoa, Vicente Porfirio; de Andrade, Ana Lúcia Sampaio Sgambatti; Toscano, Cristiana Maria

2017-01-01

ABSTRACT Objective To determine and compare hospitalization costs of bacterial community-acquired pneumonia cases via different costing methods under the Brazilian Public Unified Health System perspective. Methods Cost-of-illness study based on primary data collected from a sample of 59 children aged between 28 days and 35 months and hospitalized due to bacterial pneumonia. Direct medical and non-medical costs were considered and three costing methods employed: micro-costing based on medical record review, micro-costing based on therapeutic guidelines and gross-costing based on the Brazilian Public Unified Health System reimbursement rates. Costs estimates obtained via different methods were compared using the Friedman test. Results Cost estimates of inpatient cases of severe pneumonia amounted to R$ 780,70/$Int. 858.7 (medical record review), R$ 641,90/$Int. 706.90 (therapeutic guidelines) and R$ 594,80/$Int. 654.28 (Brazilian Public Unified Health System reimbursement rates). Costs estimated via micro-costing (medical record review or therapeutic guidelines) did not differ significantly (p=0.405), while estimates based on reimbursement rates were significantly lower compared to estimates based on therapeutic guidelines (p<0.001) or record review (p=0.006). Conclusion Brazilian Public Unified Health System costs estimated via different costing methods differ significantly, with gross-costing yielding lower cost estimates. Given costs estimated by different micro-costing methods are similar and costing methods based on therapeutic guidelines are easier to apply and less expensive, this method may be a valuable alternative for estimation of hospitalization costs of bacterial community-acquired pneumonia in children. PMID:28767921

Estimating Soil Organic Carbon Stocks and Spatial Patterns with Statistical and GIS-Based Methods

PubMed Central

Zhi, Junjun; Jing, Changwei; Lin, Shengpan; Zhang, Cao; Liu, Qiankun; DeGloria, Stephen D.; Wu, Jiaping

2014-01-01

Accurately quantifying soil organic carbon (SOC) is considered fundamental to studying soil quality, modeling the global carbon cycle, and assessing global climate change. This study evaluated the uncertainties caused by up-scaling of soil properties from the county scale to the provincial scale and from lower-level classification of Soil Species to Soil Group, using four methods: the mean, median, Soil Profile Statistics (SPS), and pedological professional knowledge based (PKB) methods. For the SPS method, SOC stock is calculated at the county scale by multiplying the mean SOC density value of each soil type in a county by its corresponding area. For the mean or median method, SOC density value of each soil type is calculated using provincial arithmetic mean or median. For the PKB method, SOC density value of each soil type is calculated at the county scale considering soil parent materials and spatial locations of all soil profiles. A newly constructed 1∶50,000 soil survey geographic database of Zhejiang Province, China, was used for evaluation. Results indicated that with soil classification levels up-scaling from Soil Species to Soil Group, the variation of estimated SOC stocks among different soil classification levels was obviously lower than that among different methods. The difference in the estimated SOC stocks among the four methods was lowest at the Soil Species level. The differences in SOC stocks among the mean, median, and PKB methods for different Soil Groups resulted from the differences in the procedure of aggregating soil profile properties to represent the attributes of one soil type. Compared with the other three estimation methods (i.e., the SPS, mean and median methods), the PKB method holds significant promise for characterizing spatial differences in SOC distribution because spatial locations of all soil profiles are considered during the aggregation procedure. PMID:24840890

Child Mortality Estimation 2013: An Overview of Updates in Estimation Methods by the United Nations Inter-Agency Group for Child Mortality Estimation

PubMed Central

Alkema, Leontine; New, Jin Rou; Pedersen, Jon; You, Danzhen

2014-01-01

Background In September 2013, the United Nations Inter-agency Group for Child Mortality Estimation (UN IGME) published an update of the estimates of the under-five mortality rate (U5MR) and under-five deaths for all countries. Compared to the UN IGME estimates published in 2012, updated data inputs and a new method for estimating the U5MR were used. Methods We summarize the new U5MR estimation method, which is a Bayesian B-spline Bias-reduction model, and highlight differences with the previously used method. Differences in UN IGME U5MR estimates as published in 2012 and those published in 2013 are presented and decomposed into differences due to the updated database and differences due to the new estimation method to explain and motivate changes in estimates. Findings Compared to the previously used method, the new UN IGME estimation method is based on a different trend fitting method that can track (recent) changes in U5MR more closely. The new method provides U5MR estimates that account for data quality issues. Resulting differences in U5MR point estimates between the UN IGME 2012 and 2013 publications are small for the majority of countries but greater than 10 deaths per 1,000 live births for 33 countries in 2011 and 19 countries in 1990. These differences can be explained by the updated database used, the curve fitting method as well as accounting for data quality issues. Changes in the number of deaths were less than 10% on the global level and for the majority of MDG regions. Conclusions The 2013 UN IGME estimates provide the most recent assessment of levels and trends in U5MR based on all available data and an improved estimation method that allows for closer-to-real-time monitoring of changes in the U5MR and takes account of data quality issues. PMID:25013954

THREE-POINT BACKWARD FINITE DIFFERENCE METHOD FOR SOLVING A SYSTEM OF MIXED HYPERBOLIC-PARABOLIC PARTIAL DIFFERENTIAL EQUATIONS. (R825549C019)

EPA Science Inventory

A three-point backward finite-difference method has been derived for a system of mixed hyperbolic_¯¯parabolic (convection_¯¯diffusion) partial differential equations (mixed PDEs). The method resorts to the three-point backward differenci...

Comparison of different methods to quantify fat classes in bakery products.

PubMed

Shin, Jae-Min; Hwang, Young-Ok; Tu, Ock-Ju; Jo, Han-Bin; Kim, Jung-Hun; Chae, Young-Zoo; Rhu, Kyung-Hun; Park, Seung-Kook

2013-01-15

The definition of fat differs in different countries; thus whether fat is listed on food labels depends on the country. Some countries list crude fat content in the 'Fat' section on the food label, whereas other countries list total fat. In this study, three methods were used for determining fat classes and content in bakery products: the Folch method, the automated Soxhlet method, and the AOAC 996.06 method. The results using these methods were compared. Fat (crude) extracted by the Folch and Soxhlet methods was gravimetrically determined and assessed by fat class using capillary gas chromatography (GC). In most samples, fat (total) content determined by the AOAC 996.06 method was lower than the fat (crude) content determined by the Folch or automated Soxhlet methods. Furthermore, monounsaturated fat or saturated fat content determined by the AOAC 996.06 method was lowest. Almost no difference was observed between fat (crude) content determined by the Folch method and that determined by the automated Soxhlet method for nearly all samples. In three samples (wheat biscuits, butter cookies-1, and chocolate chip cookies), monounsaturated fat, saturated fat, and trans fat content obtained by the automated Soxhlet method was higher than that obtained by the Folch method. The polyunsaturated fat content obtained by the automated Soxhlet method was not higher than that obtained by the Folch method in any sample. Copyright © 2012 Elsevier Ltd. All rights reserved.

Content based Image Retrieval based on Different Global and Local Color Histogram Methods: A Survey

NASA Astrophysics Data System (ADS)

Suhasini, Pallikonda Sarah; Sri Rama Krishna, K.; Murali Krishna, I. V.

2017-02-01

Different global and local color histogram methods for content based image retrieval (CBIR) are investigated in this paper. Color histogram is a widely used descriptor for CBIR. Conventional method of extracting color histogram is global, which misses the spatial content, is less invariant to deformation and viewpoint changes, and results in a very large three dimensional histogram corresponding to the color space used. To address the above deficiencies, different global and local histogram methods are proposed in recent research. Different ways of extracting local histograms to have spatial correspondence, invariant colour histogram to add deformation and viewpoint invariance and fuzzy linking method to reduce the size of the histogram are found in recent papers. The color space and the distance metric used are vital in obtaining color histogram. In this paper the performance of CBIR based on different global and local color histograms in three different color spaces, namely, RGB, HSV, L*a*b* and also with three distance measures Euclidean, Quadratic and Histogram intersection are surveyed, to choose appropriate method for future research.

Titanium Hydroxide - a Volatile Species at High Temperature

NASA Technical Reports Server (NTRS)

Nguyen, QuynhGiao N.

2010-01-01

An alternative method of low-temperature plasma functionalization of carbon nanotubes provides for the simultaneous attachment of molecular groups of multiple (typically two or three) different species or different mixtures of species to carbon nanotubes at different locations within the same apparatus. This method is based on similar principles, and involves the use of mostly the same basic apparatus, as those of the methods described in "Low-Temperature Plasma Functionalization of Carbon Nanotubes" (ARC-14661-1), NASA Tech Briefs, Vol. 28, No. 5 (May 2004), page 45. The figure schematically depicts the basic apparatus used in the aforementioned method, with emphasis on features that distinguish the present alternative method from the other. In this method, one exploits the fact that the composition of the deposition plasma changes as the plasma flows from its source in the precursor chamber toward the nanotubes in the target chamber. As a result, carbon nanotubes mounted in the target chamber at different flow distances (d1, d2, d3 . . .) from the precursor chamber become functionalized with different species or different mixtures of species.

Effect of Different In Vitro Aging Methods on Color Stability of a Dental Resin-Based Composite Using CIELAB and CIEDE2000 Color-Difference Formulas.

PubMed

de Oliveira, Dayane Carvalho Ramos Salles; Ayres, Ana Paula Almeida; Rocha, Mateus Garcia; Giannini, Marcelo; Puppin Rontani, Regina Maria; Ferracane, Jack L; Sinhoreti, Mario Alexandre Coelho

2015-01-01

To evaluate the effect of different in vitro aging methods on color change (CC) of an experimental dental resin-based composite using CIELAB (ΔEab ) and CIEDE2000 (ΔE00 ) color-difference formulas. The CC was evaluated with a spectrophotometer (CM700d, Konica Minolta, Tokyo, Japan) according to the CIE chromatic space. Disk-shaped specimens (Φ = 5 × 1 mm thick) (N = 10) were submitted to different in vitro aging methods: 30 days of water aging (WA); 120 hours of ultraviolet light aging (UVA); or 300 hours of an accelerated artificial aging (AAA) method with cycles of 4 hours of UV-B light exposure and 4 hours of moisture condensation to induce CC. The temperature was standardized at 37°C for all aging methods. CC was evaluated with ΔEab and ΔE00 formulas. Differences in individual Lab coordinates were also calculated. Data for the individual color parameters were submitted to one-way analysis of variance and Tukey's test for multiple comparisons (α = 0.05). All in vitro aging methods tested induced CC, in the following order: WA: ΔEab = 0.83 (0.1); ΔE00  = 1.15 (0.1) < AAA: ΔEab  = 5.64 (0.2); ΔE00  = 5.01 (0.1) < UVA: ΔEab  = 6.74 (0.2); ΔE00  = 6.03 (0.4). No changes in L* or a* coordinates were ≥1; the methods with UV aging showed a yellowing effect due a large positive change in b*. All in vitro aging methods tested induced a CC, but to different extents. Changes in color followed similar trends, but with different absolute values when calculated with the CIELAB and the CIEDE2000 formulas. Establishing the efficacy of different artificial aging methods and differences between color change using CIELAB and CIEDE2000 formulas are important to standardize color stability evaluations and facilitate the comparison of outcomes from different studies in the literature. © 2015 Wiley Periodicals, Inc.

The Adams formulas for numerical integration of differential equations from 1st to 20th order

NASA Technical Reports Server (NTRS)

Kirkpatrick, J. C.

1976-01-01

The Adams Bashforth predictor coefficients and the Adams Moulton corrector coefficients for the integration of differential equations are presented for methods of 1st to 20th order. The order of the method as presented refers to the highest order difference formula used in Newton's backward difference interpolation formula, on which the Adams method is based. The Adams method is a polynomial approximation method derived from Newton's backward difference interpolation formula. The Newton formula is derived and expanded to 20th order. The Adams predictor and corrector formulas are derived and expressed in terms of differences of the derivatives, as well as in terms of the derivatives themselves. All coefficients are given to 18 significant digits. For the difference formula only, the ratio coefficients are given to 10th order.

Contaminants | Hydrogen and Fuel Cells | NREL

Science.gov Websites

-Derived Contaminants Overview Materials Methods Data Tool Partners Publications System Contaminants using several screening methods. The materials are from different manufacturers, comprise different Characterization Methods A flowchart graphic that shows the experimental methods used in the system contaminants

A FINITE-DIFFERENCE, DISCRETE-WAVENUMBER METHOD FOR CALCULATING RADAR TRACES

EPA Science Inventory

A hybrid of the finite-difference method and the discrete-wavenumber method is developed to calculate radar traces. The method is based on a three-dimensional model defined in the Cartesian coordinate system; the electromagnetic properties of the model are symmetric with respect ...

Space methods in oceanology

NASA Technical Reports Server (NTRS)

Bolshakov, A. A.

1985-01-01

The study of Earth from space with specialized satellites, and from manned orbiting stations, has become important in the space programs. The broad complex of methods used for probing Earth from space are different methods of the study of ocean, dynamics. The different methods of ocean observation are described.

Accuracy of tree diameter estimation from terrestrial laser scanning by circle-fitting methods

NASA Astrophysics Data System (ADS)

Koreň, Milan; Mokroš, Martin; Bucha, Tomáš

2017-12-01

This study compares the accuracies of diameter at breast height (DBH) estimations by three initial (minimum bounding box, centroid, and maximum distance) and two refining (Monte Carlo and optimal circle) circle-fitting methods The circle-fitting algorithms were evaluated in multi-scan mode and a simulated single-scan mode on 157 European beech trees (Fagus sylvatica L.). DBH measured by a calliper was used as reference data. Most of the studied circle-fitting algorithms significantly underestimated the mean DBH in both scanning modes. Only the Monte Carlo method in the single-scan mode significantly overestimated the mean DBH. The centroid method proved to be the least suitable and showed significantly different results from the other circle-fitting methods in both scanning modes. In multi-scan mode, the accuracy of the minimum bounding box method was not significantly different from the accuracies of the refining methods The accuracy of the maximum distance method was significantly different from the accuracies of the refining methods in both scanning modes. The accuracy of the Monte Carlo method was significantly different from the accuracy of the optimal circle method in only single-scan mode. The optimal circle method proved to be the most accurate circle-fitting method for DBH estimation from point clouds in both scanning modes.

Seismic wavefield modeling based on time-domain symplectic and Fourier finite-difference method

NASA Astrophysics Data System (ADS)

Fang, Gang; Ba, Jing; Liu, Xin-xin; Zhu, Kun; Liu, Guo-Chang

2017-06-01

Seismic wavefield modeling is important for improving seismic data processing and interpretation. Calculations of wavefield propagation are sometimes not stable when forward modeling of seismic wave uses large time steps for long times. Based on the Hamiltonian expression of the acoustic wave equation, we propose a structure-preserving method for seismic wavefield modeling by applying the symplectic finite-difference method on time grids and the Fourier finite-difference method on space grids to solve the acoustic wave equation. The proposed method is called the symplectic Fourier finite-difference (symplectic FFD) method, and offers high computational accuracy and improves the computational stability. Using acoustic approximation, we extend the method to anisotropic media. We discuss the calculations in the symplectic FFD method for seismic wavefield modeling of isotropic and anisotropic media, and use the BP salt model and BP TTI model to test the proposed method. The numerical examples suggest that the proposed method can be used in seismic modeling of strongly variable velocities, offering high computational accuracy and low numerical dispersion. The symplectic FFD method overcomes the residual qSV wave of seismic modeling in anisotropic media and maintains the stability of the wavefield propagation for large time steps.

Numerical solution of the Saint-Venant equations by an efficient hybrid finite-volume/finite-difference method

NASA Astrophysics Data System (ADS)

Lai, Wencong; Khan, Abdul A.

2018-04-01

A computationally efficient hybrid finite-volume/finite-difference method is proposed for the numerical solution of Saint-Venant equations in one-dimensional open channel flows. The method adopts a mass-conservative finite volume discretization for the continuity equation and a semi-implicit finite difference discretization for the dynamic-wave momentum equation. The spatial discretization of the convective flux term in the momentum equation employs an upwind scheme and the water-surface gradient term is discretized using three different schemes. The performance of the numerical method is investigated in terms of efficiency and accuracy using various examples, including steady flow over a bump, dam-break flow over wet and dry downstream channels, wetting and drying in a parabolic bowl, and dam-break floods in laboratory physical models. Numerical solutions from the hybrid method are compared with solutions from a finite volume method along with analytic solutions or experimental measurements. Comparisons demonstrates that the hybrid method is efficient, accurate, and robust in modeling various flow scenarios, including subcritical, supercritical, and transcritical flows. In this method, the QUICK scheme for the surface slope discretization is more accurate and less diffusive than the center difference and the weighted average schemes.

Age adjustment in ecological studies: using a study on arsenic ingestion and bladder cancer as an example.

PubMed

Guo, How-Ran

2011-10-20

Despite its limitations, ecological study design is widely applied in epidemiology. In most cases, adjustment for age is necessary, but different methods may lead to different conclusions. To compare three methods of age adjustment, a study on the associations between arsenic in drinking water and incidence of bladder cancer in 243 townships in Taiwan was used as an example. A total of 3068 cases of bladder cancer, including 2276 men and 792 women, were identified during a ten-year study period in the study townships. Three methods were applied to analyze the same data set on the ten-year study period. The first (Direct Method) applied direct standardization to obtain standardized incidence rate and then used it as the dependent variable in the regression analysis. The second (Indirect Method) applied indirect standardization to obtain standardized incidence ratio and then used it as the dependent variable in the regression analysis instead. The third (Variable Method) used proportions of residents in different age groups as a part of the independent variables in the multiple regression models. All three methods showed a statistically significant positive association between arsenic exposure above 0.64 mg/L and incidence of bladder cancer in men and women, but different results were observed for the other exposure categories. In addition, the risk estimates obtained by different methods for the same exposure category were all different. Using an empirical example, the current study confirmed the argument made by other researchers previously that whereas the three different methods of age adjustment may lead to different conclusions, only the third approach can obtain unbiased estimates of the risks. The third method can also generate estimates of the risk associated with each age group, but the other two are unable to evaluate the effects of age directly.

Effect of DNA Extraction Methods and Sampling Techniques on the Apparent Structure of Cow and Sheep Rumen Microbial Communities

PubMed Central

Henderson, Gemma; Cox, Faith; Kittelmann, Sandra; Miri, Vahideh Heidarian; Zethof, Michael; Noel, Samantha J.; Waghorn, Garry C.; Janssen, Peter H.

2013-01-01

Molecular microbial ecology techniques are widely used to study the composition of the rumen microbiota and to increase understanding of the roles they play. Therefore, sampling and DNA extraction methods that result in adequate yields of microbial DNA that also accurately represents the microbial community are crucial. Fifteen different methods were used to extract DNA from cow and sheep rumen samples. The DNA yield and quality, and its suitability for downstream PCR amplifications varied considerably, depending on the DNA extraction method used. DNA extracts from nine extraction methods that passed these first quality criteria were evaluated further by quantitative PCR enumeration of microbial marker loci. Absolute microbial numbers, determined on the same rumen samples, differed by more than 100-fold, depending on the DNA extraction method used. The apparent compositions of the archaeal, bacterial, ciliate protozoal, and fungal communities in identical rumen samples were assessed using 454 Titanium pyrosequencing. Significant differences in microbial community composition were observed between extraction methods, for example in the relative abundances of members of the phyla Bacteroidetes and Firmicutes. Microbial communities in parallel samples collected from cows by oral stomach-tubing or through a rumen fistula, and in liquid and solid rumen digesta fractions, were compared using one of the DNA extraction methods. Community representations were generally similar, regardless of the rumen sampling technique used, but significant differences in the abundances of some microbial taxa such as the Clostridiales and the Methanobrevibacter ruminantium clade were observed. The apparent microbial community composition differed between rumen sample fractions, and Prevotellaceae were most abundant in the liquid fraction. DNA extraction methods that involved phenol-chloroform extraction and mechanical lysis steps tended to be more comparable. However, comparison of data from studies in which different sampling techniques, different rumen sample fractions or different DNA extraction methods were used should be avoided. PMID:24040342

Effect of DNA extraction methods and sampling techniques on the apparent structure of cow and sheep rumen microbial communities.

PubMed

Henderson, Gemma; Cox, Faith; Kittelmann, Sandra; Miri, Vahideh Heidarian; Zethof, Michael; Noel, Samantha J; Waghorn, Garry C; Janssen, Peter H

2013-01-01

Molecular microbial ecology techniques are widely used to study the composition of the rumen microbiota and to increase understanding of the roles they play. Therefore, sampling and DNA extraction methods that result in adequate yields of microbial DNA that also accurately represents the microbial community are crucial. Fifteen different methods were used to extract DNA from cow and sheep rumen samples. The DNA yield and quality, and its suitability for downstream PCR amplifications varied considerably, depending on the DNA extraction method used. DNA extracts from nine extraction methods that passed these first quality criteria were evaluated further by quantitative PCR enumeration of microbial marker loci. Absolute microbial numbers, determined on the same rumen samples, differed by more than 100-fold, depending on the DNA extraction method used. The apparent compositions of the archaeal, bacterial, ciliate protozoal, and fungal communities in identical rumen samples were assessed using 454 Titanium pyrosequencing. Significant differences in microbial community composition were observed between extraction methods, for example in the relative abundances of members of the phyla Bacteroidetes and Firmicutes. Microbial communities in parallel samples collected from cows by oral stomach-tubing or through a rumen fistula, and in liquid and solid rumen digesta fractions, were compared using one of the DNA extraction methods. Community representations were generally similar, regardless of the rumen sampling technique used, but significant differences in the abundances of some microbial taxa such as the Clostridiales and the Methanobrevibacter ruminantium clade were observed. The apparent microbial community composition differed between rumen sample fractions, and Prevotellaceae were most abundant in the liquid fraction. DNA extraction methods that involved phenol-chloroform extraction and mechanical lysis steps tended to be more comparable. However, comparison of data from studies in which different sampling techniques, different rumen sample fractions or different DNA extraction methods were used should be avoided.

The Role of Psychological and Physiological Factors in Decision Making under Risk and in a Dilemma

PubMed Central

Fooken, Jonas; Schaffner, Markus

2016-01-01

Different methods to elicit risk attitudes of individuals often provide differing results despite a common theory. Reasons for such inconsistencies may be the different influence of underlying factors in risk-taking decisions. In order to evaluate this conjecture, a better understanding of underlying factors across methods and decision contexts is desirable. In this paper we study the difference in result of two different risk elicitation methods by linking estimates of risk attitudes to gender, age, and personality traits, which have been shown to be related. We also investigate the role of these factors during decision-making in a dilemma situation. For these two decision contexts we also investigate the decision-maker's physiological state during the decision, measured by heart rate variability (HRV), which we use as an indicator of emotional involvement. We found that the two elicitation methods provide different individual risk attitude measures which is partly reflected in a different gender effect between the methods. Personality traits explain only relatively little in terms of driving risk attitudes and the difference between methods. We also found that risk taking and the physiological state are related for one of the methods, suggesting that more emotionally involved individuals are more risk averse in the experiment. Finally, we found evidence that personality traits are connected to whether individuals made a decision in the dilemma situation, but risk attitudes and the physiological state were not indicative for the ability to decide in this decision context. PMID:26834591

Temperature Profiles of Different Cooling Methods in Porcine Pancreas Procurement

PubMed Central

Weegman, Brad P.; Suszynski, Thomas M.; Scott, William E.; Ferrer, Joana; Avgoustiniatos, Efstathios S.; Anazawa, Takayuki; O’Brien, Timothy D.; Rizzari, Michael D.; Karatzas, Theodore; Jie, Tun; Sutherland, David ER.; Hering, Bernhard J.; Papas, Klearchos K.

2014-01-01

Background Porcine islet xenotransplantation is a promising alternative to human islet allotransplantation. Porcine pancreas cooling needs to be optimized to reduce the warm ischemia time (WIT) following donation after cardiac death, which is associated with poorer islet isolation outcomes. Methods This study examines the effect of 4 different cooling Methods on core porcine pancreas temperature (n=24) and histopathology (n=16). All Methods involved surface cooling with crushed ice and chilled irrigation. Method A, which is the standard for porcine pancreas procurement, used only surface cooling. Method B involved an intravascular flush with cold solution through the pancreas arterial system. Method C involved an intraductal infusion with cold solution through the major pancreatic duct, and Method D combined all 3 cooling Methods. Results Surface cooling alone (Method A) gradually decreased core pancreas temperature to < 10 °C after 30 minutes. Using an intravascular flush (Method B) improved cooling during the entire duration of procurement, but incorporating an intraductal infusion (Method C) rapidly reduced core temperature 15–20 °C within the first 2 minutes of cooling. Combining all methods (Method D) was the most effective at rapidly reducing temperature and providing sustained cooling throughout the duration of procurement, although the recorded WIT was not different between Methods (p=0.36). Histological scores were different between the cooling Methods (p=0.02) and the worst with Method A. There were differences in histological scores between Methods A and C (p=0.02) and Methods A and D (p=0.02), but not between Methods C and D (p=0.95), which may highlight the importance of early cooling using an intraductal infusion. Conclusions In conclusion, surface cooling alone cannot rapidly cool large (porcine or human) pancreata. Additional cooling with an intravascular flush and intraductal infusion results in improved core porcine pancreas temperature profiles during procurement and histopathology scores. These data may also have implications on human pancreas procurement since use of an intraductal infusion is not common practice. PMID:25040217

Efficiency trade-offs of steady-state methods using FEM and FDM. [iterative solutions for nonlinear flow equations

NASA Technical Reports Server (NTRS)

Gartling, D. K.; Roache, P. J.

1978-01-01

The efficiency characteristics of finite element and finite difference approximations for the steady-state solution of the Navier-Stokes equations are examined. The finite element method discussed is a standard Galerkin formulation of the incompressible, steady-state Navier-Stokes equations. The finite difference formulation uses simple centered differences that are O(delta x-squared). Operation counts indicate that a rapidly converging Newton-Raphson-Kantorovitch iteration scheme is generally preferable over a Picard method. A split NOS Picard iterative algorithm for the finite difference method was most efficient.

A real-time TV logo tracking method using template matching

NASA Astrophysics Data System (ADS)

Li, Zhi; Sang, Xinzhu; Yan, Binbin; Leng, Junmin

2012-11-01

A fast and accurate TV Logo detection method is presented based on real-time image filtering, noise eliminating and recognition of image features including edge and gray level information. It is important to accurately extract the optical template using the time averaging method from the sample video stream, and then different templates are used to match different logos in separated video streams with different resolution based on the topology features of logos. 12 video streams with different logos are used to verify the proposed method, and the experimental result demonstrates that the achieved accuracy can be up to 99%.

Differences between Cheddar cheese manufactured by the milled-curd and stirred-curd methods using different commercial starters.

PubMed

Shakeel-ur-Rehman; Drake, M A; Farkye, N Y

2008-01-01

Traditionally, Cheddar cheese is made by the milled-curd method. However, because of the mechanization of cheese making and time constraints, the stirred-curd method is more commonly used by many large-scale commercial manufacturers. This study was undertaken to evaluate quality differences during ripening (at 2 and 8 degrees C) of Cheddar cheese made by the milled-curd and stirred-curd methods, using 4 different commercial starters. Twenty-four vats (4 starters x 2 methods x 3 replicates) were made, with approximately 625 kg of pasteurized (72 degrees C x 16 s) whole milk in each vat. Fat, protein, and salt contents of the cheeses were not affected by the starter. Starter cell densities in cheese were not affected by the method of manufacture. Nonstarter lactic acid bacteria counts at 90, 180, and 270 d were influenced by the manufacturing method, with a higher trend in milled-curd cheeses. Proteolysis in cheese (percentage of water-soluble N) was influenced by the starter and manufacturing method (270 d). Sensory analysis by a trained descriptive panel (n = 8) revealed differences in cooked, whey, sulfur, brothy, milk fat, umami, and bitter attributes caused by the starter, whereas only brothy flavor was influenced by storage temperature. The method of manufacture influenced diacetyl, sour, and salty flavors.

Quantifying distinct associations on different temporal scales: comparison of DCCA and Pearson methods

NASA Astrophysics Data System (ADS)

Piao, Lin; Fu, Zuntao

2016-11-01

Cross-correlation between pairs of variables takes multi-time scale characteristic, and it can be totally different on different time scales (changing from positive correlation to negative one), e.g., the associations between mean air temperature and relative humidity over regions to the east of Taihang mountain in China. Therefore, how to correctly unveil these correlations on different time scales is really of great importance since we actually do not know if the correlation varies with scales in advance. Here, we compare two methods, i.e. Detrended Cross-Correlation Analysis (DCCA for short) and Pearson correlation, in quantifying scale-dependent correlations directly to raw observed records and artificially generated sequences with known cross-correlation features. Studies show that 1) DCCA related methods can indeed quantify scale-dependent correlations, but not Pearson method; 2) the correlation features from DCCA related methods are robust to contaminated noises, however, the results from Pearson method are sensitive to noise; 3) the scale-dependent correlation results from DCCA related methods are robust to the amplitude ratio between slow and fast components, while Pearson method may be sensitive to the amplitude ratio. All these features indicate that DCCA related methods take some advantages in correctly quantifying scale-dependent correlations, which results from different physical processes.

Quantifying distinct associations on different temporal scales: comparison of DCCA and Pearson methods.

PubMed

Piao, Lin; Fu, Zuntao

2016-11-09

Cross-correlation between pairs of variables takes multi-time scale characteristic, and it can be totally different on different time scales (changing from positive correlation to negative one), e.g., the associations between mean air temperature and relative humidity over regions to the east of Taihang mountain in China. Therefore, how to correctly unveil these correlations on different time scales is really of great importance since we actually do not know if the correlation varies with scales in advance. Here, we compare two methods, i.e. Detrended Cross-Correlation Analysis (DCCA for short) and Pearson correlation, in quantifying scale-dependent correlations directly to raw observed records and artificially generated sequences with known cross-correlation features. Studies show that 1) DCCA related methods can indeed quantify scale-dependent correlations, but not Pearson method; 2) the correlation features from DCCA related methods are robust to contaminated noises, however, the results from Pearson method are sensitive to noise; 3) the scale-dependent correlation results from DCCA related methods are robust to the amplitude ratio between slow and fast components, while Pearson method may be sensitive to the amplitude ratio. All these features indicate that DCCA related methods take some advantages in correctly quantifying scale-dependent correlations, which results from different physical processes.

Comparison of Chemical Constituents in Scrophulariae Radix Processed by Different Methods based on UFLC-MS Combined with Multivariate Statistical Analysis.

PubMed

Wang, Shengnan; Hua, Yujiao; Zou, Lisi; Liu, Xunhong; Yan, Ying; Zhao, Hui; Luo, Yiyuan; Liu, Juanxiu

2018-02-01

Scrophulariae Radix is one of the most popular traditional Chinese medicines (TCMs). Primary processing of Scrophulariae Radix is an important link which closely related to the quality of products in this TCM. The aim of this study is to explore the influence of different processing methods on chemical constituents in Scrophulariae Radix. The difference of chemical constituents in Scrophulariae Radix processed by different methods was analyzed by using ultra fast liquid chromatography-triple quadrupole-time of flight mass spectrometry coupled with principal component analysis and orthogonal partial least squares discriminant analysis. Furthermore, the contents of 12 index differential constituents in Scrophulariae Radix processed by different methods were simultaneously determined by using ultra fast liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry. Gray relational analysis was performed to evaluate the different processed samples according to the contents of 12 constituents. All of the results demonstrated that the quality of Scrophulariae Radix processed by "sweating" method was better. This study will provide the basic information for revealing the change law of chemical constituents in Scrophulariae Radix processed by different methods and facilitating selection of the suitable processing method of this TCM. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A FINITE-DIFFERENCE, DISCRETE-WAVENUMBER METHOD FOR CALCULATING RADAR TRACES

EPA Science Inventory

A hybrid of the finite-difference method and the discrete-wavenumber method is developed to calculate radar traces. The method is based on a three-dimensional model defined in the Cartesian coordinate system; the electromag-netic properties of the model are symmetric with respect...

Palmprint Recognition Across Different Devices.

PubMed

Jia, Wei; Hu, Rong-Xiang; Gui, Jie; Zhao, Yang; Ren, Xiao-Ming

2012-01-01

In this paper, the problem of Palmprint Recognition Across Different Devices (PRADD) is investigated, which has not been well studied so far. Since there is no publicly available PRADD image database, we created a non-contact PRADD image database containing 12,000 grayscale captured from 100 subjects using three devices, i.e., one digital camera and two smart-phones. Due to the non-contact image acquisition used, rotation and scale changes between different images captured from a same palm are inevitable. We propose a robust method to calculate the palm width, which can be effectively used for scale normalization of palmprints. On this PRADD image database, we evaluate the recognition performance of three different methods, i.e., subspace learning method, correlation method, and orientation coding based method, respectively. Experiments results show that orientation coding based methods achieved promising recognition performance for PRADD.

Palmprint Recognition across Different Devices

PubMed Central

Jia, Wei; Hu, Rong-Xiang; Gui, Jie; Zhao, Yang; Ren, Xiao-Ming

2012-01-01

In this paper, the problem of Palmprint Recognition Across Different Devices (PRADD) is investigated, which has not been well studied so far. Since there is no publicly available PRADD image database, we created a non-contact PRADD image database containing 12,000 grayscale captured from 100 subjects using three devices, i.e., one digital camera and two smart-phones. Due to the non-contact image acquisition used, rotation and scale changes between different images captured from a same palm are inevitable. We propose a robust method to calculate the palm width, which can be effectively used for scale normalization of palmprints. On this PRADD image database, we evaluate the recognition performance of three different methods, i.e., subspace learning method, correlation method, and orientation coding based method, respectively. Experiments results show that orientation coding based methods achieved promising recognition performance for PRADD. PMID:22969380

A highly accurate finite-difference method with minimum dispersion error for solving the Helmholtz equation

NASA Astrophysics Data System (ADS)

Wu, Zedong; Alkhalifah, Tariq

2018-07-01

Numerical simulation of the acoustic wave equation in either isotropic or anisotropic media is crucial to seismic modeling, imaging and inversion. Actually, it represents the core computation cost of these highly advanced seismic processing methods. However, the conventional finite-difference method suffers from severe numerical dispersion errors and S-wave artifacts when solving the acoustic wave equation for anisotropic media. We propose a method to obtain the finite-difference coefficients by comparing its numerical dispersion with the exact form. We find the optimal finite difference coefficients that share the dispersion characteristics of the exact equation with minimal dispersion error. The method is extended to solve the acoustic wave equation in transversely isotropic (TI) media without S-wave artifacts. Numerical examples show that the method is highly accurate and efficient.

Microbial composition during Chinese soy sauce koji-making based on culture dependent and independent methods.

PubMed

Yan, Yin-zhuo; Qian, Yu-lin; Ji, Feng-di; Chen, Jing-yu; Han, Bei-zhong

2013-05-01

Koji-making is a key process for production of high quality soy sauce. The microbial composition during koji-making was investigated by culture-dependent and culture-independent methods to determine predominant bacterial and fungal populations. The culture-dependent methods used were direct culture and colony morphology observation, and PCR amplification of 16S/26S rDNA fragments followed by sequencing analysis. The culture-independent method was based on the analysis of 16S/26S rDNA clone libraries. There were differences between the results obtained by different methods. However, sufficient overlap existed between the different methods to identify potentially significant microbial groups. 16 and 20 different bacterial species were identified using culture-dependent and culture-independent methods, respectively. 7 species could be identified by both methods. The most predominant bacterial genera were Weissella and Staphylococcus. Both 6 different fungal species were identified using culture-dependent and culture-independent methods, respectively. Only 3 species could be identified by both sets of methods. The most predominant fungi were Aspergillus and Candida species. This work illustrated the importance of a comprehensive polyphasic approach in the analysis of microbial composition during soy sauce koji-making, the knowledge of which will enable further optimization of microbial composition and quality control of koji to upgrade Chinese traditional soy sauce product. Copyright © 2013 Elsevier Ltd. All rights reserved.

Sawing SHOLO logs: three methods

Treesearch

Ronald E. Coleman; Hugh W. Reynolds

1973-01-01

Three different methods of sawing the SHOLO log were compared on a board-foot yield basis. Using sawmill simulation, all three methods of sawing were performed on the same sample of logs, eliminating differences due to sapling. A statistical test was made to determine whether or not there were any real differences between the board-foot yields. Two of the sawing...

Methods of Suicide by Age: Sex and Race Differences among the Young and Old.

ERIC Educational Resources Information Center

McIntosh, John L.; Santos, John F.

1986-01-01

Annual official statistics for specific methods of suicide (firearms, hanging, poisons) by age for different sex and racial groups (Whites, Blacks, non-Whites excluding Black) were examined from 1960 to 1978. Comparisons among the age-sex-race groups, along with trends over time and differences in the methods employed, were noted. (Author/ABL)

Examining the Value Master's and PhD Students Place on Various Instructional Methods in Educational Leadership Preparation

ERIC Educational Resources Information Center

Gordon, Stephen P.; Oliver, John

2015-01-01

The purpose of this study was to determine the value that graduate students place on different types of instructional methods used by professors in educational leadership preparation programs, and to determine if master's and doctoral students place different values on different instructional methods. The participants included 87 graduate…

Diabat Interpolation for Polymorph Free-Energy Differences.

PubMed

Kamat, Kartik; Peters, Baron

2017-02-02

Existing methods to compute free-energy differences between polymorphs use harmonic approximations, advanced non-Boltzmann bias sampling techniques, and/or multistage free-energy perturbations. This work demonstrates how Bennett's diabat interpolation method ( J. Comput. Phys. 1976, 22, 245 ) can be combined with energy gaps from lattice-switch Monte Carlo techniques ( Phys. Rev. E 2000, 61, 906 ) to swiftly estimate polymorph free-energy differences. The new method requires only two unbiased molecular dynamics simulations, one for each polymorph. To illustrate the new method, we compute the free-energy difference between face-centered cubic and body-centered cubic polymorphs for a Gaussian core solid. We discuss the justification for parabolic models of the free-energy diabats and similarities to methods that have been used in studies of electron transfer.

Methods for Synthesizing Findings on Moderation Effects Across Multiple Randomized Trials

PubMed Central

Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

2011-01-01

This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis, and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design. PMID:21360061

Methods for synthesizing findings on moderation effects across multiple randomized trials.

PubMed

Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

2013-04-01

This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design.

Distortion analysis of subband adaptive filtering methods for FMRI active noise control systems.

PubMed

Milani, Ali A; Panahi, Issa M; Briggs, Richard

2007-01-01

Delayless subband filtering structure, as a high performance frequency domain filtering technique, is used for canceling broadband fMRI noise (8 kHz bandwidth). In this method, adaptive filtering is done in subbands and the coefficients of the main canceling filter are computed by stacking the subband weights together. There are two types of stacking methods called FFT and FFT-2. In this paper, we analyze the distortion introduced by these two stacking methods. The effect of the stacking distortion on the performance of different adaptive filters in FXLMS algorithm with non-minimum phase secondary path is explored. The investigation is done for different adaptive algorithms (nLMS, APA and RLS), different weight stacking methods, and different number of subbands.

Child mortality estimation 2013: an overview of updates in estimation methods by the United Nations Inter-agency Group for Child Mortality Estimation.

PubMed

Alkema, Leontine; New, Jin Rou; Pedersen, Jon; You, Danzhen

2014-01-01

In September 2013, the United Nations Inter-agency Group for Child Mortality Estimation (UN IGME) published an update of the estimates of the under-five mortality rate (U5MR) and under-five deaths for all countries. Compared to the UN IGME estimates published in 2012, updated data inputs and a new method for estimating the U5MR were used. We summarize the new U5MR estimation method, which is a Bayesian B-spline Bias-reduction model, and highlight differences with the previously used method. Differences in UN IGME U5MR estimates as published in 2012 and those published in 2013 are presented and decomposed into differences due to the updated database and differences due to the new estimation method to explain and motivate changes in estimates. Compared to the previously used method, the new UN IGME estimation method is based on a different trend fitting method that can track (recent) changes in U5MR more closely. The new method provides U5MR estimates that account for data quality issues. Resulting differences in U5MR point estimates between the UN IGME 2012 and 2013 publications are small for the majority of countries but greater than 10 deaths per 1,000 live births for 33 countries in 2011 and 19 countries in 1990. These differences can be explained by the updated database used, the curve fitting method as well as accounting for data quality issues. Changes in the number of deaths were less than 10% on the global level and for the majority of MDG regions. The 2013 UN IGME estimates provide the most recent assessment of levels and trends in U5MR based on all available data and an improved estimation method that allows for closer-to-real-time monitoring of changes in the U5MR and takes account of data quality issues.

MPN estimation of qPCR target sequence recoveries from whole cell calibrator samples.

PubMed

Sivaganesan, Mano; Siefring, Shawn; Varma, Manju; Haugland, Richard A

2011-12-01

DNA extracts from enumerated target organism cells (calibrator samples) have been used for estimating Enterococcus cell equivalent densities in surface waters by a comparative cycle threshold (Ct) qPCR analysis method. To compare surface water Enterococcus density estimates from different studies by this approach, either a consistent source of calibrator cells must be used or the estimates must account for any differences in target sequence recoveries from different sources of calibrator cells. In this report we describe two methods for estimating target sequence recoveries from whole cell calibrator samples based on qPCR analyses of their serially diluted DNA extracts and most probable number (MPN) calculation. The first method employed a traditional MPN calculation approach. The second method employed a Bayesian hierarchical statistical modeling approach and a Monte Carlo Markov Chain (MCMC) simulation method to account for the uncertainty in these estimates associated with different individual samples of the cell preparations, different dilutions of the DNA extracts and different qPCR analytical runs. The two methods were applied to estimate mean target sequence recoveries per cell from two different lots of a commercially available source of enumerated Enterococcus cell preparations. The mean target sequence recovery estimates (and standard errors) per cell from Lot A and B cell preparations by the Bayesian method were 22.73 (3.4) and 11.76 (2.4), respectively, when the data were adjusted for potential false positive results. Means were similar for the traditional MPN approach which cannot comparably assess uncertainty in the estimates. Cell numbers and estimates of recoverable target sequences in calibrator samples prepared from the two cell sources were also used to estimate cell equivalent and target sequence quantities recovered from surface water samples in a comparative Ct method. Our results illustrate the utility of the Bayesian method in accounting for uncertainty, the high degree of precision attainable by the MPN approach and the need to account for the differences in target sequence recoveries from different calibrator sample cell sources when they are used in the comparative Ct method. Published by Elsevier B.V.

Safety training for working youth: Methods used versus methods wanted.

PubMed

Zierold, Kristina M

2016-04-07

Safety training is promoted as a tool to prevent workplace injury; however, little is known about the safety training experiences young workers get on-the-job. Furthermore, nothing is known about what methods they think would be the most helpful for learning about safe work practices. To compare safety training methods teens get on the job to those safety training methods teens think would be the best for learning workplace safety, focusing on age differences. A cross-sectional survey was administered to students in two large high schools in spring 2011. Seventy percent of working youth received safety training. The top training methods that youth reported getting at work were safety videos (42%), safety lectures (25%), and safety posters/signs (22%). In comparison to the safety training methods used, the top methods youth wanted included videos (54%), hands-on (47%), and on-the-job demonstrations (34%). This study demonstrated that there were differences in training methods that youth wanted by age; with older youth seemingly wanting more independent methods of training and younger teens wanting more involvement. Results indicate that youth want methods of safety training that are different from what they are getting on the job. The differences in methods wanted by age may aid in developing training programs appropriate for the developmental level of working youth.

High-Order Entropy Stable Finite Difference Schemes for Nonlinear Conservation Laws: Finite Domains

NASA Technical Reports Server (NTRS)

Fisher, Travis C.; Carpenter, Mark H.

2013-01-01

Developing stable and robust high-order finite difference schemes requires mathematical formalism and appropriate methods of analysis. In this work, nonlinear entropy stability is used to derive provably stable high-order finite difference methods with formal boundary closures for conservation laws. Particular emphasis is placed on the entropy stability of the compressible Navier-Stokes equations. A newly derived entropy stable weighted essentially non-oscillatory finite difference method is used to simulate problems with shocks and a conservative, entropy stable, narrow-stencil finite difference approach is used to approximate viscous terms.

Drying method has no substantial effect on δ(15)N or δ(13)C values of muscle tissue from teleost fishes.

PubMed

Bessey, Cindy; Vanderklift, Mathew A

2014-02-15

Stable isotope analysis (SIA) is a powerful tool in many fields of research that enables quantitative comparisons among studies, if similar methods have been used. The goal of this study was to determine if three different drying methods commonly used to prepare samples for SIA yielded different δ(15)N and δ(13)C values. Muscle subsamples from 10 individuals each of three teleost species were dried using three methods: (i) oven, (ii) food dehydrator, and (iii) freeze-dryer. All subsamples were analysed for δ(15)N and δ(13)C values, and nitrogen and carbon content, using a continuous flow system consisting of a Delta V Plus mass spectrometer and a Flush 1112 elemental analyser via a Conflo IV universal interface. The δ(13)C values were normalized to constant lipid content using the equations proposed by McConnaughey and McRoy. Although statistically significant, the differences in δ(15)N values between the drying methods were small (mean differences ≤0.21‰). The differences in δ(13)C values between the drying methods were not statistically significant, and normalising the δ(13)C values to constant lipid content reduced the mean differences for all treatments to ≤0.65‰. A statistically significant difference of ~2% in C content existed between tissues dried in a food dehydrator and those dried in a freeze-dryer for two fish species. There was no significant effect of fish size on the differences between methods. No substantial effect of drying method was found on the δ(15)N or δ(13)C values of teleost muscle tissue. Copyright © 2013 John Wiley & Sons, Ltd.

Two Project Methods: Preliminary Observations on the Similarities and Differences between William Heard Kilpatrick's Project Method and John Dewey's Problem-Solving Method

ERIC Educational Resources Information Center

Sutinen, Ari

2013-01-01

The project method became a famous teaching method when William Heard Kilpatrick published his article "Project Method" in 1918. The key idea in Kilpatrick's project method is to try to explain how pupils learn things when they work in projects toward different common objects. The same idea of pupils learning by work or action in an…

The Comparative Method of Language Acquisition Research: A Mayan Case Study

ERIC Educational Resources Information Center

Pye, Clifton; Pfeiler, Barbara

2014-01-01

This article demonstrates how the Comparative Method can be applied to cross-linguistic research on language acquisition. The Comparative Method provides a systematic procedure for organizing and interpreting acquisition data from different languages. The Comparative Method controls for cross-linguistic differences at all levels of the grammar and…

Automatic frequency and phase alignment of in vivo J-difference-edited MR spectra by frequency domain correlation.

PubMed

Wiegers, Evita C; Philips, Bart W J; Heerschap, Arend; van der Graaf, Marinette

2017-12-01

J-difference editing is often used to select resonances of compounds with coupled spins in 1 H-MR spectra. Accurate phase and frequency alignment prior to subtracting J-difference-edited MR spectra is important to avoid artefactual contributions to the edited resonance. In-vivo J-difference-edited MR spectra were aligned by maximizing the normalized scalar product between two spectra (i.e., the correlation over a spectral region). The performance of our correlation method was compared with alignment by spectral registration and by alignment of the highest point in two spectra. The correlation method was tested at different SNR levels and for a broad range of phase and frequency shifts. In-vivo application of the proposed correlation method showed reduced subtraction errors and increased fit reliability in difference spectra as compared with conventional peak alignment. The correlation method and the spectral registration method generally performed equally well. However, better alignment using the correlation method was obtained for spectra with a low SNR (down to ~2) and for relatively large frequency shifts. Our correlation method for simultaneously phase and frequency alignment is able to correct both small and large phase and frequency drifts and also performs well at low SNR levels.

SOME NEW FINITE DIFFERENCE METHODS FOR HELMHOLTZ EQUATIONS ON IRREGULAR DOMAINS OR WITH INTERFACES

PubMed Central

Wan, Xiaohai; Li, Zhilin

2012-01-01

Solving a Helmholtz equation Δu + λu = f efficiently is a challenge for many applications. For example, the core part of many efficient solvers for the incompressible Navier-Stokes equations is to solve one or several Helmholtz equations. In this paper, two new finite difference methods are proposed for solving Helmholtz equations on irregular domains, or with interfaces. For Helmholtz equations on irregular domains, the accuracy of the numerical solution obtained using the existing augmented immersed interface method (AIIM) may deteriorate when the magnitude of λ is large. In our new method, we use a level set function to extend the source term and the PDE to a larger domain before we apply the AIIM. For Helmholtz equations with interfaces, a new maximum principle preserving finite difference method is developed. The new method still uses the standard five-point stencil with modifications of the finite difference scheme at irregular grid points. The resulting coefficient matrix of the linear system of finite difference equations satisfies the sign property of the discrete maximum principle and can be solved efficiently using a multigrid solver. The finite difference method is also extended to handle temporal discretized equations where the solution coefficient λ is inversely proportional to the mesh size. PMID:22701346

SOME NEW FINITE DIFFERENCE METHODS FOR HELMHOLTZ EQUATIONS ON IRREGULAR DOMAINS OR WITH INTERFACES.

PubMed

Wan, Xiaohai; Li, Zhilin

2012-06-01

Solving a Helmholtz equation Δu + λu = f efficiently is a challenge for many applications. For example, the core part of many efficient solvers for the incompressible Navier-Stokes equations is to solve one or several Helmholtz equations. In this paper, two new finite difference methods are proposed for solving Helmholtz equations on irregular domains, or with interfaces. For Helmholtz equations on irregular domains, the accuracy of the numerical solution obtained using the existing augmented immersed interface method (AIIM) may deteriorate when the magnitude of λ is large. In our new method, we use a level set function to extend the source term and the PDE to a larger domain before we apply the AIIM. For Helmholtz equations with interfaces, a new maximum principle preserving finite difference method is developed. The new method still uses the standard five-point stencil with modifications of the finite difference scheme at irregular grid points. The resulting coefficient matrix of the linear system of finite difference equations satisfies the sign property of the discrete maximum principle and can be solved efficiently using a multigrid solver. The finite difference method is also extended to handle temporal discretized equations where the solution coefficient λ is inversely proportional to the mesh size.

Comparison of three explicit multigrid methods for the Euler and Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Chima, Rodrick V.; Turkel, Eli; Schaffer, Steve

1987-01-01

Three explicit multigrid methods, Ni's method, Jameson's finite-volume method, and a finite-difference method based on Brandt's work, are described and compared for two model problems. All three methods use an explicit multistage Runge-Kutta scheme on the fine grid, and this scheme is also described. Convergence histories for inviscid flow over a bump in a channel for the fine-grid scheme alone show that convergence rate is proportional to Courant number and that implicit residual smoothing can significantly accelerate the scheme. Ni's method was slightly slower than the implicitly-smoothed scheme alone. Brandt's and Jameson's methods are shown to be equivalent in form but differ in their node versus cell-centered implementations. They are about 8.5 times faster than Ni's method in terms of CPU time. Results for an oblique shock/boundary layer interaction problem verify the accuracy of the finite-difference code. All methods slowed considerably on the stretched viscous grid but Brandt's method was still 2.1 times faster than Ni's method.

Chosen interval methods for solving linear interval systems with special type of matrix

NASA Astrophysics Data System (ADS)

Szyszka, Barbara

2013-10-01

The paper is devoted to chosen direct interval methods for solving linear interval systems with special type of matrix. This kind of matrix: band matrix with a parameter, from finite difference problem is obtained. Such linear systems occur while solving one dimensional wave equation (Partial Differential Equations of hyperbolic type) by using the central difference interval method of the second order. Interval methods are constructed so as the errors of method are enclosed in obtained results, therefore presented linear interval systems contain elements that determining the errors of difference method. The chosen direct algorithms have been applied for solving linear systems because they have no errors of method. All calculations were performed in floating-point interval arithmetic.

Taste intensities of ten vegetables commonly consumed in the Netherlands.

PubMed

van Stokkom, V L; Teo, P S; Mars, M; de Graaf, C; van Kooten, O; Stieger, M

2016-09-01

Bitterness has been suggested to be the main reason for the limited palatability of several vegetables. Vegetable acceptance has been associated with preparation method. However, the taste intensity of a variety of vegetables prepared by different methods has not been studied yet. The objective of this study is to assess the intensity of the five basic tastes and fattiness of ten vegetables commonly consumed in the Netherlands prepared by different methods using the modified Spectrum method. Intensities of sweetness, sourness, bitterness, umami, saltiness and fattiness were assessed for ten vegetables (cauliflower, broccoli, leek, carrot, onion, red bell pepper, French beans, tomato, cucumber and iceberg lettuce) by a panel (n=9) trained in a modified Spectrum method. Each vegetable was assessed prepared by different methods (raw, cooked, mashed and as a cold pressed juice). Spectrum based reference solutions were available with fixed reference points at 13.3mm (R1), 33.3mm (R2) and 66.7mm (R3) for each taste modality on a 100mm line scale. For saltiness, R1 and R3 differed (16.7mm and 56.7mm). Mean intensities of all taste modalities and fattiness for all vegetables were mostly below R1 (13.3mm). Significant differences (p<0.05) within vegetables between preparation methods were found. Sweetness was the most intensive taste, followed by sourness, bitterness, fattiness, umami and saltiness. In conclusion, all ten vegetables prepared by different methods showed low mean intensities of all taste modalities and fattiness. Preparation method affected taste and fattiness intensity and the effect differed by vegetable type. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of four different reduction methods for anterior dislocation of the shoulder.

PubMed

Guler, Olcay; Ekinci, Safak; Akyildiz, Faruk; Tirmik, Uzeyir; Cakmak, Selami; Ugras, Akin; Piskin, Ahmet; Mahirogullari, Mahir

2015-05-28

Shoulder dislocations account for almost 50% of all major joint dislocations and are mainly anterior. The aim is a comparative retrospective study of different reduction maneuvers without anesthesia to reduce the dislocated shoulder. Patients were treated with different reduction maneuvers, including various forms of traction and external rotation, in the emergency departments of four training hospitals between 2009 and 2012. Each of the four hospitals had different treatment protocols for reduction and applying one of four maneuvers: Spaso, Chair, Kocher, and Matsen methods. Thirty-nine patients were treated by the Spaso method, 47 by the Chair reduction method, 40 by the Kocher method, and 27 patients by Matsen's traction-countertraction method. All patients' demographic data were recorded. Dislocation number, reduction time, time interval between dislocation and reduction, and associated complications, pre- and post-reduction period, were recorded prospectively. No anesthetic method was used for the reduction. All of the methods used included traction and some external rotation. The Chair method had the shortest reduction time. All surgeons involved in the study agreed that the Kocher and Matsen methods needed more force for the reduction. Patients could contract their muscles because of the pain in these two methods. The Spaso method includes flexion of the shoulder and blocks muscle contraction somewhat. The Chair method was found to be the easiest because the patients could not contract their muscles while sitting on a chair with the affected arm at their side. We suggest that the Chair method is an effective and fast reduction maneuver that may be an alternative for the treatment of anterior shoulder dislocations. Further prospective studies with larger sample size are needed to compare safety of different reduction techniques.

Comparative study between recent methods manipulating ratio spectra and classical methods based on two-wavelength selection for the determination of binary mixture of antazoline hydrochloride and tetryzoline hydrochloride

NASA Astrophysics Data System (ADS)

Abdel-Halim, Lamia M.; Abd-El Rahman, Mohamed K.; Ramadan, Nesrin K.; EL Sanabary, Hoda F. A.; Salem, Maissa Y.

2016-04-01

A comparative study was developed between two classical spectrophotometric methods (dual wavelength method and Vierordt's method) and two recent methods manipulating ratio spectra (ratio difference method and first derivative of ratio spectra method) for simultaneous determination of Antazoline hydrochloride (AN) and Tetryzoline hydrochloride (TZ) in their combined pharmaceutical formulation and in the presence of benzalkonium chloride as a preservative without preliminary separation. The dual wavelength method depends on choosing two wavelengths for each drug in a way so that the difference in absorbance at those two wavelengths is zero for the other drug. While Vierordt's method, is based upon measuring the absorbance and the absorptivity values of the two drugs at their λmax (248.0 and 219.0 nm for AN and TZ, respectively), followed by substitution in the corresponding Vierordt's equation. Recent methods manipulating ratio spectra depend on either measuring the difference in amplitudes of ratio spectra between 255.5 and 269.5 nm for AN and 220.0 and 273.0 nm for TZ in case of ratio difference method or computing first derivative of the ratio spectra for each drug then measuring the peak amplitude at 250.0 nm for AN and at 224.0 nm for TZ in case of first derivative of ratio spectrophotometry. The specificity of the developed methods was investigated by analyzing different laboratory prepared mixtures of the two drugs. All methods were applied successfully for the determination of the selected drugs in their combined dosage form proving that the classical spectrophotometric methods can still be used successfully in analysis of binary mixture using minimal data manipulation rather than recent methods which require relatively more steps. Furthermore, validation of the proposed methods was performed according to ICH guidelines; accuracy, precision and repeatability are found to be within the acceptable limits. Statistical studies showed that the methods can be competitively applied in quality control laboratories.

Comparison of lipid and calorie loss from donor human milk among 3 methods of simulated gavage feeding: one-hour, 2-hour, and intermittent gravity feedings.

PubMed

Brooks, Christine; Vickers, Amy Manning; Aryal, Subhash

2013-04-01

The objective of this study was to compare the differences in lipid loss from 24 samples of banked donor human milk (DHM) among 3 feeding methods: DHM given by syringe pump over 1 hour, 2 hours, and by bolus/gravity gavage. Comparative, descriptive. There were no human subjects. Twenty-four samples of 8 oz of DHM were divided into four 60-mL aliquots. Timed feedings were given by Medfusion 2001 syringe pumps with syringes connected to narrow-lumened extension sets designed for enteral feedings and connected to standard silastic enteral feeding tubes. Gravity feedings were given using the identical syringes connected to the same silastic feeding tubes. All aliquots were analyzed with the York Dairy Analyzer. Univariate repeated-measures analyses of variance were used for the omnibus testing for overall differences between the feeding methods. Lipid content expressed as grams per deciliter at the end of each feeding method was compared with the prefed control samples using the Dunnett's test. The Tukey correction was used for other pairwise multiple comparisons. The univariate repeated-measures analysis of variance conducted to test for overall differences between feeding methods showed a significant difference between the methods (F = 58.57, df = 3, 69, P < .0001). Post hoc analysis using the Dunnett's approach revealed that there was a significant difference in fat content between the control sample and the 1-hour and 2-hours feeding methods (P < .0001), but we did not find any significant difference in fat content between the control and the gravity feeding methods (P = .3296). Pairwise comparison using the Tukey correction revealed a significant difference between both gravity and 1-hour feeding methods (P < .0001), and gravity and 2-hour feeding method (P < .0001). There was no significant difference in lipid content between the 1-hour and 2-hour feeding methods (P = .2729). Unlike gravity feedings, the timed feedings resulted in a statistically significant loss of fat as compared with their controls. These findings should raise questions about how those infants in the neonatal intensive care unit are routinely gavage fed.

Evaluating the Effects of Differences in Group Abilities on the Tucker and the Levine Observed-Score Methods for Common-Item Nonequivalent Groups Equating. ACT Research Report Series 2010-1

ERIC Educational Resources Information Center

Chen, Hanwei; Cui, Zhongmin; Zhu, Rongchun; Gao, Xiaohong

2010-01-01

The most critical feature of a common-item nonequivalent groups equating design is that the average score difference between the new and old groups can be accurately decomposed into a group ability difference and a form difficulty difference. Two widely used observed-score linear equating methods, the Tucker and the Levine observed-score methods,…

Microphone Array

NASA Astrophysics Data System (ADS)

Bader, Rolf

This chapter deals with microphone arrays. It is arranged according to the different methods available to proceed through the different problems and through the different mathematical methods. After discussing general properties of different array types, such as plane arrays, spherical arrays, or scanning arrays, it proceeds to the signal processing tools that are most used in speech processing. In the third section, backpropagating methods based on the Helmholtz-Kirchhoff integral are discussed, which result in spatial radiation patterns of vibrating bodies or air.

Kinds of access: different methods for report reveal different kinds of metacognitive access

PubMed Central

Overgaard, Morten; Sandberg, Kristian

2012-01-01

In experimental investigations of consciousness, participants are asked to reflect upon their own experiences by issuing reports about them in different ways. For this reason, a participant needs some access to the content of her own conscious experience in order to report. In such experiments, the reports typically consist of some variety of ratings of confidence or direct descriptions of one's own experiences. Whereas different methods of reporting are typically used interchangeably, recent experiments indicate that different results are obtained with different kinds of reporting. We argue that there is not only a theoretical, but also an empirical difference between different methods of reporting. We hypothesize that differences in the sensitivity of different scales may reveal that different types of access are used to issue direct reports about experiences and metacognitive reports about the classification process. PMID:22492747

Impact of enumeration method on diversity of Escherichia coli genotypes isolated from surface water.

PubMed

Martin, E C; Gentry, T J

2016-11-01

There are numerous regulatory-approved Escherichia coli enumeration methods, but it is not known whether differences in media composition and incubation conditions impact the diversity of E. coli populations detected by these methods. A study was conducted to determine if three standard water quality assessments, Colilert ® , USEPA Method 1603, (modified mTEC) and USEPA Method 1604 (MI), detect different populations of E. coli. Samples were collected from six watersheds and analysed using the three enumeration approaches followed by E. coli isolation and genotyping. Results indicated that the three methods generally produced similar enumeration data across the sites, although there were some differences on a site-by-site basis. The Colilert ® method consistently generated the least diverse collection of E. coli genotypes as compared to modified mTEC and MI, with those two methods being roughly equal to each other. Although the three media assessed in this study were designed to enumerate E. coli, the differences in the media composition, incubation temperature, and growth platform appear to have a strong selective influence on the populations of E. coli isolated. This study suggests that standardized methods of enumeration and isolation may be warranted if researchers intend to obtain individual E. coli isolates for further characterization. This study characterized the impact of three USEPA-approved Escherichia coli enumeration methods on observed E. coli population diversity in surface water samples. Results indicated that these methods produced similar E. coli enumeration data but were more variable in the diversity of E. coli genotypes observed. Although the three methods enumerate the same species, differences in media composition, growth platform, and incubation temperature likely contribute to the selection of different cultivable populations of E. coli, and thus caution should be used when implementing these methods interchangeably for downstream applications which require cultivated isolates. © 2016 The Society for Applied Microbiology.

A seismic analysis for masonry constructions: The different schematization methods of masonry walls

NASA Astrophysics Data System (ADS)

Olivito, Renato. S.; Codispoti, Rosamaria; Scuro, Carmelo

2017-11-01

Seismic analysis of masonry structures is usually analyzed through the use of structural calculation software based on equivalent frames method or to macro-elements method. In these approaches, the masonry walls are divided into vertical elements, masonry walls, and horizontal elements, so-called spandrel elements, interconnected by rigid nodes. The aim of this work is to make a critical comparison between different schematization methods of masonry wall underlining the structural importance of the spandrel elements. In order to implement the methods, two different structural calculation software were used and an existing masonry building has been examined.

Mass, height of burst, and source–receiver distance constraints on the acoustic coda phase delay method

DOE Office of Scientific and Technical Information (OSTI.GOV)

Albert, Sarah; Bowman, Daniel; Rodgers, Arthur

Here, this research uses the acoustic coda phase delay method to estimate relative changes in air temperature between explosions with varying event masses and heights of burst. It also places a bound on source–receiver distance for the method. Previous studies used events with different shapes, height of bursts, and masses and recorded the acoustic codas at source–receiver distances less than 1 km. This research further explores the method using explosions that differ in mass (by up to an order of magnitude) and are placed at varying heights. Source–receiver distances also cover an area out to 7 km. Relative air temperaturemore » change estimates are compared to complementary meteorological observations. Results show that two explosions that differ by an order of magnitude cannot be used with this method because their propagation times in the near field and their fundamental frequencies are different. These differences are expressed as inaccuracies in the relative air temperature change estimates. An order of magnitude difference in mass is also shown to bias estimates higher. Small differences in height of burst do not affect the accuracy of the method. Finally, an upper bound of 1 km on source–receiver distance is provided based on the standard deviation characteristics of the estimates.« less

Mass, height of burst, and source–receiver distance constraints on the acoustic coda phase delay method

DOE PAGES

Albert, Sarah; Bowman, Daniel; Rodgers, Arthur; ...

2018-04-23

Here, this research uses the acoustic coda phase delay method to estimate relative changes in air temperature between explosions with varying event masses and heights of burst. It also places a bound on source–receiver distance for the method. Previous studies used events with different shapes, height of bursts, and masses and recorded the acoustic codas at source–receiver distances less than 1 km. This research further explores the method using explosions that differ in mass (by up to an order of magnitude) and are placed at varying heights. Source–receiver distances also cover an area out to 7 km. Relative air temperaturemore » change estimates are compared to complementary meteorological observations. Results show that two explosions that differ by an order of magnitude cannot be used with this method because their propagation times in the near field and their fundamental frequencies are different. These differences are expressed as inaccuracies in the relative air temperature change estimates. An order of magnitude difference in mass is also shown to bias estimates higher. Small differences in height of burst do not affect the accuracy of the method. Finally, an upper bound of 1 km on source–receiver distance is provided based on the standard deviation characteristics of the estimates.« less

An Unsupervised Change Detection Method Using Time-Series of PolSAR Images from Radarsat-2 and GaoFen-3.

PubMed

Liu, Wensong; Yang, Jie; Zhao, Jinqi; Shi, Hongtao; Yang, Le

2018-02-12

The traditional unsupervised change detection methods based on the pixel level can only detect the changes between two different times with same sensor, and the results are easily affected by speckle noise. In this paper, a novel method is proposed to detect change based on time-series data from different sensors. Firstly, the overall difference image of the time-series PolSAR is calculated by omnibus test statistics, and difference images between any two images in different times are acquired by R j test statistics. Secondly, the difference images are segmented with a Generalized Statistical Region Merging (GSRM) algorithm which can suppress the effect of speckle noise. Generalized Gaussian Mixture Model (GGMM) is then used to obtain the time-series change detection maps in the final step of the proposed method. To verify the effectiveness of the proposed method, we carried out the experiment of change detection using time-series PolSAR images acquired by Radarsat-2 and Gaofen-3 over the city of Wuhan, in China. Results show that the proposed method can not only detect the time-series change from different sensors, but it can also better suppress the influence of speckle noise and improve the overall accuracy and Kappa coefficient.

Wavefront reconstruction for multi-lateral shearing interferometry using difference Zernike polynomials fitting

NASA Astrophysics Data System (ADS)

Liu, Ke; Wang, Jiannian; Wang, Hai; Li, Yanqiu

2018-07-01

For the multi-lateral shearing interferometers (multi-LSIs), the measurement accuracy can be enhanced by estimating the wavefront under test with the multidirectional phase information encoded in the shearing interferogram. Usually the multi-LSIs reconstruct the test wavefront from the phase derivatives in multiple directions using the discrete Fourier transforms (DFT) method, which is only suitable to small shear ratios and relatively sensitive to noise. To improve the accuracy of multi-LSIs, wavefront reconstruction from the multidirectional phase differences using the difference Zernike polynomials fitting (DZPF) method is proposed in this paper. For the DZPF method applied in the quadriwave LSI, difference Zernike polynomials in only two orthogonal shear directions are required to represent the phase differences in multiple shear directions. In this way, the test wavefront can be reconstructed from the phase differences in multiple shear directions using a noise-variance weighted least-squares method with almost no extra computational burden, compared with the usual recovery from the phase differences in two orthogonal directions. Numerical simulation results show that the DZPF method can maintain high reconstruction accuracy in a wider range of shear ratios and has much better anti-noise performance than the DFT method. A null test experiment of the quadriwave LSI has been conducted and the experimental results show that the measurement accuracy of the quadriwave LSI can be improved from 0.0054 λ rms to 0.0029 λ rms (λ = 632.8 nm) by substituting the DFT method with the proposed DZPF method in the wavefront reconstruction process.

Formulation and application of optimal homotopty asymptotic method to coupled differential-difference equations.

PubMed

Ullah, Hakeem; Islam, Saeed; Khan, Ilyas; Shafie, Sharidan; Fiza, Mehreen

2015-01-01

In this paper we applied a new analytic approximate technique Optimal Homotopy Asymptotic Method (OHAM) for treatment of coupled differential-difference equations (DDEs). To see the efficiency and reliability of the method, we consider Relativistic Toda coupled nonlinear differential-difference equation. It provides us a convenient way to control the convergence of approximate solutions when it is compared with other methods of solution found in the literature. The obtained solutions show that OHAM is effective, simpler, easier and explicit.

Formulation and Application of Optimal Homotopty Asymptotic Method to Coupled Differential - Difference Equations

PubMed Central

Ullah, Hakeem; Islam, Saeed; Khan, Ilyas; Shafie, Sharidan; Fiza, Mehreen

2015-01-01

In this paper we applied a new analytic approximate technique Optimal Homotopy Asymptotic Method (OHAM) for treatment of coupled differential- difference equations (DDEs). To see the efficiency and reliability of the method, we consider Relativistic Toda coupled nonlinear differential-difference equation. It provides us a convenient way to control the convergence of approximate solutions when it is compared with other methods of solution found in the literature. The obtained solutions show that OHAM is effective, simpler, easier and explicit. PMID:25874457

Cryopreservation of in vitro grown shoot tips of Diospyros kaki thunb. using different methods.

PubMed

Niu, Y L; Luo, Z R; Zhang, Y F; Zhang, Q L

2012-01-01

The objective of this study was to compare the potential of different cryopreservation strategies for in vitro shoot tips of Diospyros kaki Thunb. The treatments consisted of three different cryopreservation methods: vitrification, droplet-vitrification and modified droplet-vitrification. The following variables were assessed: cold acclimation, sucrose concentration in the preculture medium and PVS2 treatment time. A higher average survival level was obtained using the modified droplet-vitrification method compared to the other two methods.

Nicotine Metabolite Ratio (3-hydroxycotinine/cotinine) in Plasma and Urine by Different Analytical Methods and Laboratories: Implications for Clinical Implementation

PubMed Central

Tanner, Julie-Anne; Novalen, Maria; Jatlow, Peter; Huestis, Marilyn A.; Murphy, Sharon E.; Kaprio, Jaakko; Kankaanpää, Aino; Galanti, Laurence; Stefan, Cristiana; George, Tony P.; Benowitz, Neal L.; Lerman, Caryn; Tyndale, Rachel F.

2015-01-01

Background The highly genetically variable enzyme CYP2A6 metabolizes nicotine to cotinine (COT) and COT to trans-3′-hydroxycotinine (3HC). The nicotine metabolite ratio (NMR, 3HC/COT) is commonly used as a biomarker of CYP2A6 enzymatic activity, rate of nicotine metabolism, and total nicotine clearance; NMR is associated with numerous smoking phenotypes, including smoking cessation. Our objective was to investigate the impact of different measurement methods, at different sites, on plasma and urinary NMR measures from ad libitum smokers. Methods Plasma (n=35) and urine (n=35) samples were sent to eight different laboratories, which employed similar and different methods of COT and 3HC measurements to derive the NMR. We used Bland-Altman analysis to assess agreement, and Pearson correlations to evaluate associations, between NMR measured by different methods. Results Measures of plasma NMR were in strong agreement between methods according to Bland-Altman analysis (ratios 0.82–1.16) and were highly correlated (all Pearson r>0.96, P<0.0001). Measures of urinary NMR were in relatively weaker agreement (ratios 0.62–1.71) and less strongly correlated (Pearson r values of 0.66–0.98, P<0.0001) between different methods. Plasma and urinary COT and 3HC concentrations, while weaker than NMR, also showed good agreement in plasma, which was better than in urine, as was observed for NMR. Conclusions Plasma is a very reliable biological source for the determination of NMR, robust to differences in these analytical protocols or assessment site. Impact Together this indicates a reduced need for differential interpretation of plasma NMR results based on the approach used, allowing for direct comparison of different studies. PMID:26014804

Methods for specifying the target difference in a randomised controlled trial: the Difference ELicitation in TriAls (DELTA) systematic review.

PubMed

Hislop, Jenni; Adewuyi, Temitope E; Vale, Luke D; Harrild, Kirsten; Fraser, Cynthia; Gurung, Tara; Altman, Douglas G; Briggs, Andrew H; Fayers, Peter; Ramsay, Craig R; Norrie, John D; Harvey, Ian M; Buckley, Brian; Cook, Jonathan A

2014-05-01

Randomised controlled trials (RCTs) are widely accepted as the preferred study design for evaluating healthcare interventions. When the sample size is determined, a (target) difference is typically specified that the RCT is designed to detect. This provides reassurance that the study will be informative, i.e., should such a difference exist, it is likely to be detected with the required statistical precision. The aim of this review was to identify potential methods for specifying the target difference in an RCT sample size calculation. A comprehensive systematic review of medical and non-medical literature was carried out for methods that could be used to specify the target difference for an RCT sample size calculation. The databases searched were MEDLINE, MEDLINE In-Process, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Methodology Register, PsycINFO, Science Citation Index, EconLit, the Education Resources Information Center (ERIC), and Scopus (for in-press publications); the search period was from 1966 or the earliest date covered, to between November 2010 and January 2011. Additionally, textbooks addressing the methodology of clinical trials and International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) tripartite guidelines for clinical trials were also consulted. A narrative synthesis of methods was produced. Studies that described a method that could be used for specifying an important and/or realistic difference were included. The search identified 11,485 potentially relevant articles from the databases searched. Of these, 1,434 were selected for full-text assessment, and a further nine were identified from other sources. Fifteen clinical trial textbooks and the ICH tripartite guidelines were also reviewed. In total, 777 studies were included, and within them, seven methods were identified-anchor, distribution, health economic, opinion-seeking, pilot study, review of the evidence base, and standardised effect size. A variety of methods are available that researchers can use for specifying the target difference in an RCT sample size calculation. Appropriate methods may vary depending on the aim (e.g., specifying an important difference versus a realistic difference), context (e.g., research question and availability of data), and underlying framework adopted (e.g., Bayesian versus conventional statistical approach). Guidance on the use of each method is given. No single method provides a perfect solution for all contexts.

Comparing Indirect Effects in Different Groups in Single-Group and Multi-Group Structural Equation Models

PubMed Central

Ryu, Ehri; Cheong, Jeewon

2017-01-01

In this article, we evaluated the performance of statistical methods in single-group and multi-group analysis approaches for testing group difference in indirect effects and for testing simple indirect effects in each group. We also investigated whether the performance of the methods in the single-group approach was affected when the assumption of equal variance was not satisfied. The assumption was critical for the performance of the two methods in the single-group analysis: the method using a product term for testing the group difference in a single path coefficient, and the Wald test for testing the group difference in the indirect effect. Bootstrap confidence intervals in the single-group approach and all methods in the multi-group approach were not affected by the violation of the assumption. We compared the performance of the methods and provided recommendations. PMID:28553248

Estimation of the impacts of different homogenization approaches on the variability of temperature series in Catalonia (North Eastern-Spain), Andorra and South Eastern - France. An experiment under the umbrella of the HOME-COST action.

NASA Astrophysics Data System (ADS)

Aguilar, E.; Prohom, M.; Mestre, O.; Esteban, P.; Kuglitsch, F. G.; Gruber, C.; Herrero, M.

2008-12-01

The almost unanimously accepted fact of climate change has brought many scientists to investigate the seasonal and interannual variability and change in instrumental climatic records. Unfortunately, these records are nearly always affected by homogeneity problems caused by changes in the station or its environment. The European Cooperation in the Field of Scientific and Technical Research (COST) is sponsoring the action COST-ES0601: Advances in homogenisation methods of climate series: an integrated approach (HOME), which aims amongst others to investigate the impacts of different homogenisation ap-proaches on the observed data series. In this work, we apply different detection/correction methods (SNHT, RhTest, Caussinus-Mestre, Vincent Interpolation Method, HOM Method) to annual, sea-sonal, monthly and daily data of a multi-country quality controlled dataset (17 stations in Catalonia (NE Spain); 3 stations in Andorra and 11 stations in SE France). The different outputs are analysed and the differences in the final se-ries studied. After this experiment, we can state that - although all the applied methods im-prove the homogeneity of the original series - the conclusions extracted from the analysis of the homogenised annual, seasonal, monthly data and extreme indices derived from daily data demonstrate important differences. As an exam-ple, some methods (SNHT) tend to detect fewer breakpoints than others (Caussinus-Mestre). Even if metadata or a pre-identified list of breakpoints is available, the correction factors calculated by the different approaches differ both in annual, seasonal, monthly and daily scales. In the latter case, some methods like HOM - based on the modelling of a candidate series against a reference series - present a richest solution than others based on the mere in-terpolation of monthly factors (Vincent Method), although the former are not al-ways applicable due to lack of good reference stations. In order to identify the best performing method (or suite of methods) COST-HOME action is conducting an intensive testing of the different homogenisation methods over simulated, surrogated and real series. At the end of the action (2011), we expect to present a significant contribution to a better evaluation of seasonal and interannual variability and change.

A Preliminary Study of the Effectiveness of Different Recitation Teaching Methods

NASA Astrophysics Data System (ADS)

Endorf, Robert J.; Koenig, Kathleen M.; Braun, Gregory A.

2006-02-01

We present preliminary results from a comparative study of student understanding for students who attended recitation classes which used different teaching methods. Student volunteers from our introductory calculus-based physics course attended a special recitation class that was taught using one of four different teaching methods. A total of 272 students were divided into approximately equal groups for each method. Students in each class were taught the same topic, "Changes in energy and momentum," from Tutorials in Introductory Physics. The different teaching methods varied in the amount of student and teacher engagement. Student understanding was evaluated through pretests and posttests given at the recitation class. Our results demonstrate the importance of the instructor's role in teaching recitation classes. The most effective teaching method was for students working in cooperative learning groups with the instructors questioning the groups using Socratic dialogue. These results provide guidance and evidence for the teaching methods which should be emphasized in training future teachers and faculty members.

Comparison study of two procedures for the determination of emamectin benzoate in medicated fish feed.

PubMed

Farer, Leslie J; Hayes, John M

2005-01-01

A new method has been developed for the determination of emamectin benzoate in fish feed. The method uses a wet extraction, cleanup by solid-phase extraction, and quantitation and separation by liquid chromatography (LC). In this paper, we compare the performance of this method with that of a previously reported LC assay for the determination of emamectin benzoate in fish feed. Although similar to the previous method, the new procedure uses a different sample pretreatment, wet extraction, and quantitation method. The performance of the new method was compared with that of the previously reported method by analyses of 22 medicated feed samples from various commercial sources. A comparison of the results presented here reveals slightly lower assay values obtained with the new method. Although a paired sample t-test indicates the difference in results is significant, this difference is within the method precision of either procedure.

An improved algorithm of mask image dodging for aerial image

NASA Astrophysics Data System (ADS)

Zhang, Zuxun; Zou, Songbai; Zuo, Zhiqi

2011-12-01

The technology of Mask image dodging based on Fourier transform is a good algorithm in removing the uneven luminance within a single image. At present, the difference method and the ratio method are the methods in common use, but they both have their own defects .For example, the difference method can keep the brightness uniformity of the whole image, but it is deficient in local contrast; meanwhile the ratio method can work better in local contrast, but sometimes it makes the dark areas of the original image too bright. In order to remove the defects of the two methods effectively, this paper on the basis of research of the two methods proposes a balance solution. Experiments show that the scheme not only can combine the advantages of the difference method and the ratio method, but also can avoid the deficiencies of the two algorithms.

Body Segment Differences in Surface Area, Skin Temperature and 3D Displacement and the Estimation of Heat Balance during Locomotion in Hominins

PubMed Central

Cross, Alan; Collard, Mark; Nelson, Andrew

2008-01-01

The conventional method of estimating heat balance during locomotion in humans and other hominins treats the body as an undifferentiated mass. This is problematic because the segments of the body differ with respect to several variables that can affect thermoregulation. Here, we report a study that investigated the impact on heat balance during locomotion of inter-segment differences in three of these variables: surface area, skin temperature and rate of movement. The approach adopted in the study was to generate heat balance estimates with the conventional method and then compare them with heat balance estimates generated with a method that takes into account inter-segment differences in surface area, skin temperature and rate of movement. We reasoned that, if the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement affect heat balance during locomotion is correct, the estimates yielded by the two methods should be statistically significantly different. Anthropometric data were collected on seven adult male volunteers. The volunteers then walked on a treadmill at 1.2 m/s while 3D motion capture cameras recorded their movements. Next, the conventional and segmented methods were used to estimate the volunteers' heat balance while walking in four ambient temperatures. Lastly, the estimates produced with the two methods were compared with the paired t-test. The estimates of heat balance during locomotion yielded by the two methods are significantly different. Those yielded by the segmented method are significantly lower than those produced by the conventional method. Accordingly, the study supports the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement impact heat balance during locomotion. This has important implications not only for current understanding of heat balance during locomotion in hominins but also for how future research on this topic should be approached. PMID:18560580

Body segment differences in surface area, skin temperature and 3D displacement and the estimation of heat balance during locomotion in hominins.

PubMed

Cross, Alan; Collard, Mark; Nelson, Andrew

2008-06-18

The conventional method of estimating heat balance during locomotion in humans and other hominins treats the body as an undifferentiated mass. This is problematic because the segments of the body differ with respect to several variables that can affect thermoregulation. Here, we report a study that investigated the impact on heat balance during locomotion of inter-segment differences in three of these variables: surface area, skin temperature and rate of movement. The approach adopted in the study was to generate heat balance estimates with the conventional method and then compare them with heat balance estimates generated with a method that takes into account inter-segment differences in surface area, skin temperature and rate of movement. We reasoned that, if the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement affect heat balance during locomotion is correct, the estimates yielded by the two methods should be statistically significantly different. Anthropometric data were collected on seven adult male volunteers. The volunteers then walked on a treadmill at 1.2 m/s while 3D motion capture cameras recorded their movements. Next, the conventional and segmented methods were used to estimate the volunteers' heat balance while walking in four ambient temperatures. Lastly, the estimates produced with the two methods were compared with the paired t-test. The estimates of heat balance during locomotion yielded by the two methods are significantly different. Those yielded by the segmented method are significantly lower than those produced by the conventional method. Accordingly, the study supports the hypothesis that inter-segment differences in surface area, skin temperature and rate of movement impact heat balance during locomotion. This has important implications not only for current understanding of heat balance during locomotion in hominins but also for how future research on this topic should be approached.

Effect of different drying methods on the composition of steviol glycosides in Stevia rebaudiana Bertoni leaves

NASA Astrophysics Data System (ADS)

Aranda-González, Irma; Betancur-Ancona, David; Chel-Guerrero, Luis; Moguel-Ordóñez, Yolanda

2017-01-01

Drying techniques can modify the composition of certain plant compounds. Therefore, the aim of the study was to assess the effect of different drying methods on steviol glycosides in Stevia rebaudiana Bertoni leaves. Four different drying methods were applied to Stevia rebaudiana Bertoni leaves, which were then subjected to aqueous extraction. Radiation or convection drying was performed in stoves at 60°C, whereas shade or sun drying methods were applied at 29.7°C and 70% of relative humidity. Stevioside, rebaudioside A, rebaudioside B, rebaudioside C, rebaudioside D, dulcoside A, and steviolbioside were quantified by a validated HPLC method. Among steviol glycosides, the content (g 100 g-1 dry basis) of stevioside, rebaudioside A, rebaudioside B, and rebaudioside C varied according to the drying method. The total glycoside content was higher in sun-dried samples, with no significant differences compared to shade or convection drying, whereas radiation drying adversely affected the content of rebaudioside A and rebaudioside C (p <0.01) and was therefore a method lowering total glycoside content. The effect of the different drying methods was also reflected in the proportion of the sweetener profile. Convection drying could be suitable for modern food processing industries while shadow or sun drying may be a low-cost alternative for farmers.

Machine learning of swimming data via wisdom of crowd and regression analysis.

PubMed

Xie, Jiang; Xu, Junfu; Nie, Celine; Nie, Qing

2017-04-01

Every performance, in an officially sanctioned meet, by a registered USA swimmer is recorded into an online database with times dating back to 1980. For the first time, statistical analysis and machine learning methods are systematically applied to 4,022,631 swim records. In this study, we investigate performance features for all strokes as a function of age and gender. The variances in performance of males and females for different ages and strokes were studied, and the correlations of performances for different ages were estimated using the Pearson correlation. Regression analysis show the performance trends for both males and females at different ages and suggest critical ages for peak training. Moreover, we assess twelve popular machine learning methods to predict or classify swimmer performance. Each method exhibited different strengths or weaknesses in different cases, indicating no one method could predict well for all strokes. To address this problem, we propose a new method by combining multiple inference methods to derive Wisdom of Crowd Classifier (WoCC). Our simulation experiments demonstrate that the WoCC is a consistent method with better overall prediction accuracy. Our study reveals several new age-dependent trends in swimming and provides an accurate method for classifying and predicting swimming times.

Factors affecting the relationship between quantitative polymerase chain reaction (qPCR) and culture-based enumeration of Enterococcus in environmental waters.

PubMed

Raith, M R; Ebentier, D L; Cao, Y; Griffith, J F; Weisberg, S B

2014-03-01

To determine the extent to which discrepancies between qPCR and culture-based results in beach water quality monitoring can be attributed to: (i) within-method variability, (ii) between-method difference within each method class (qPCR or culture) and (iii) between-class difference. We analysed 306 samples using two culture-based (EPA1600 and Enterolert) and two qPCR (Taqman and Scorpion) methods, each in duplicate. Both qPCR methods correlated with EPA1600, but regression analyses indicated approximately 0·8 log10 unit overestimation by qPCR compared to culture methods. Differences between methods within a class were less than half of this and were minimal for between-replicate within a method. Using the 104 Enterococcus per 100 ml management decision threshold, Taqman qPCR indicated the same decisions as EPA1600 for 87% of the samples, but indicated beach posting for unhealthful water when EPA1600 did not for 12% of the samples. After accounting for within-method and within-class variability, 8% of the samples exhibited true between-class discrepancy where both qPCR methods indicated beach posting while both culture methods did not. Measurement target difference (DNA vs growth) accounted for the majority of the qPCR-vs-culture discrepancy, but its influence on monitoring application is outweighed by frequent incorrect posting with culture methods due to incubation time delay. This is the first study to quantify the frequency with which culture-vs-qPCR discrepancies can be attributed to target difference - vs - method variability. © 2013 The Society for Applied Microbiology.

Evaluating fMRI methods for assessing hemispheric language dominance in healthy subjects.

PubMed

Baciu, Monica; Juphard, Alexandra; Cousin, Emilie; Bas, Jean François Le

2005-08-01

We evaluated two methods for quantifying the hemispheric language dominance in healthy subjects, by using a rhyme detection (deciding whether couple of words rhyme) and a word fluency (generating words starting with a given letter) task. One of methods called "flip method" (FM) was based on the direct statistical comparison between hemispheres' activity. The second one, the classical lateralization indices method (LIM), was based on calculating lateralization indices by taking into account the number of activated pixels within hemispheres. The main difference between methods is the statistical assessment of the inter-hemispheric difference: while FM shows if the difference between hemispheres' activity is statistically significant, LIM shows only that if there is a difference between hemispheres. The robustness of LIM and FM was assessed by calculating correlation coefficients between LIs obtained with each of these methods and manual lateralization indices MLI obtained with Edinburgh inventory. Our results showed significant correlation between LIs provided by each method and the MIL, suggesting that both methods are robust for quantifying hemispheric dominance for language in healthy subjects. In the present study we also evaluated the effect of spatial normalization, smoothing and "clustering" (NSC) on the intra-hemispheric location of activated regions and inter-hemispheric asymmetry of the activation. Our results have shown that NSC did not affect the hemispheric specialization but increased the value of the inter-hemispheric difference.

Comparative analysis for strength serum sodium and potassium in three different methods: Flame photometry, ion-selective electrode (ISE) and colorimetric enzymatic.

PubMed

Garcia, Rafaela Alvim; Vanelli, Chislene Pereira; Pereira Junior, Olavo Dos Santos; Corrêa, José Otávio do Amaral

2018-06-19

Hydroelectrolytic disorders are common in clinical situations and may be harmful to the patient, especially those involving plasma sodium and potassium dosages. Among the possible methods for the dosages are flame photometry, ion-selective electrode (ISE) and colorimetric enzymatic method. We analyzed 175 samples in the three different methods cited from patients attending the laboratory of the University Hospital of the Federal University of Juiz de Fora. The values obtained were statistically treated using SPSS 19.0 software. The present study aims to evaluate the impact of the use of these different methods in the determination of plasma sodium and potassium. The averages obtained for sodium and potassium measurements by flame photometry were similar (P > .05) to the means obtained for the two electrolytes by ISE. The averages obtained by the colorimetric enzymatic method presented statistical difference in relation to ISE, both for sodium and potassium. In the correlation analysis, both flame photometry and colorimetric enzymatic showed a strong correlation with the ISE method for both dosages. At the first time in the same work sodium and potassium were analyzed by three different methods and the results allowed us to conclude that the methods showed a positive and strong correlation, and can be applied in the clinical routine. © 2018 Wiley Periodicals, Inc.

49 CFR 105.35 - Serving documents in PHMSA proceedings.

Code of Federal Regulations, 2010 CFR

2010-10-01

... following methods, except where a different method of service is specifically required: (1) Registered or... document by one of the following methods, except where a different method of service is specifically... at http://www.regulations.gov. [67 FR 42951, June 25, 2002, as amended at 72 FR 55682, Oct. 1, 2007] ...

Choosing Learning Methods Suitable for Teaching and Learning in Computer Science

ERIC Educational Resources Information Center

Taylor, Estelle; Breed, Marnus; Hauman, Ilette; Homann, Armando

2013-01-01

Our aim is to determine which teaching methods students in Computer Science and Information Systems prefer. There are in total 5 different paradigms (behaviorism, cognitivism, constructivism, design-based and humanism) with 32 models between them. Each model is unique and states different learning methods. Recommendations are made on methods that…

Novel ratio difference at coabsorptive point spectrophotometric method for determination of components with wide variation in their absorptivities.

PubMed

Saad, Ahmed S; Abo-Talib, Nisreen F; El-Ghobashy, Mohamed R

2016-01-05

Different methods have been introduced to enhance selectivity of UV-spectrophotometry thus enabling accurate determination of co-formulated components, however mixtures whose components exhibit wide variation in absorptivities has been an obstacle against application of UV-spectrophotometry. The developed ratio difference at coabsorptive point method (RDC) represents a simple effective solution for the mentioned problem, where the additive property of light absorbance enabled the consideration of the two components as multiples of the lower absorptivity component at certain wavelength (coabsorptive point), at which their total concentration multiples could be determined, whereas the other component was selectively determined by applying the ratio difference method in a single step. Mixture of perindopril arginine (PA) and amlodipine besylate (AM) figures that problem, where the low absorptivity of PA relative to AM hinders selective spectrophotometric determination of PA. The developed method successfully determined both components in the overlapped region of their spectra with accuracy 99.39±1.60 and 100.51±1.21, for PA and AM, respectively. The method was validated as per the USP guidelines and showed no significant difference upon statistical comparison with reported chromatographic method. Copyright © 2015 Elsevier B.V. All rights reserved.

Detection of admittivity anomaly on high-contrast heterogeneous backgrounds using frequency difference EIT.

PubMed

Jang, J; Seo, J K

2015-06-01

This paper describes a multiple background subtraction method in frequency difference electrical impedance tomography (fdEIT) to detect an admittivity anomaly from a high-contrast background conductivity distribution. The proposed method expands the use of the conventional weighted frequency difference EIT method, which has been used limitedly to detect admittivity anomalies in a roughly homogeneous background. The proposed method can be viewed as multiple weighted difference imaging in fdEIT. Although the spatial resolutions of the output images by fdEIT are very low due to the inherent ill-posedness, numerical simulations and phantom experiments of the proposed method demonstrate its feasibility to detect anomalies. It has potential application in stroke detection in a head model, which is highly heterogeneous due to the skull.

The research progress of perforating gun inner wall blind hole machining method

NASA Astrophysics Data System (ADS)

Wang, Zhe; Shen, Hongbing

2018-04-01

Blind hole processing method has been a concerned technical problem in oil, electronics, aviation and other fields. This paper introduces different methods for blind hole machining, focus on machining method for perforating gun inner wall blind hole processing. Besides, the advantages and disadvantages of different methods are also discussed, and the development trend of blind hole processing were introduced significantly.

A comparison of five partial volume correction methods for Tau and Amyloid PET imaging with [18F]THK5351 and [11C]PIB.

PubMed

Shidahara, Miho; Thomas, Benjamin A; Okamura, Nobuyuki; Ibaraki, Masanobu; Matsubara, Keisuke; Oyama, Senri; Ishikawa, Yoichi; Watanuki, Shoichi; Iwata, Ren; Furumoto, Shozo; Tashiro, Manabu; Yanai, Kazuhiko; Gonda, Kohsuke; Watabe, Hiroshi

2017-08-01

To suppress partial volume effect (PVE) in brain PET, there have been many algorithms proposed. However, each methodology has different property due to its assumption and algorithms. Our aim of this study was to investigate the difference among partial volume correction (PVC) method for tau and amyloid PET study. We investigated two of the most commonly used PVC methods, Müller-Gärtner (MG) and geometric transfer matrix (GTM) and also other three methods for clinical tau and amyloid PET imaging. One healthy control (HC) and one Alzheimer's disease (AD) PET studies of both [ 18 F]THK5351 and [ 11 C]PIB were performed using a Eminence STARGATE scanner (Shimadzu Inc., Kyoto, Japan). All PET images were corrected for PVE by MG, GTM, Labbé (LABBE), Regional voxel-based (RBV), and Iterative Yang (IY) methods, with segmented or parcellated anatomical information processed by FreeSurfer, derived from individual MR images. PVC results of 5 algorithms were compared with the uncorrected data. In regions of high uptake of [ 18 F]THK5351 and [ 11 C]PIB, different PVCs demonstrated different SUVRs. The degree of difference between PVE uncorrected and corrected depends on not only PVC algorithm but also type of tracer and subject condition. Presented PVC methods are straight-forward to implement but the corrected images require careful interpretation as different methods result in different levels of recovery.

Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys

PubMed Central

Hund, Lauren; Bedrick, Edward J.; Pagano, Marcello

2015-01-01

Lot quality assurance sampling (LQAS) surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we compare these latter cluster LQAS methodologies and provide recommendations for choosing a cluster LQAS design. We compare technical differences in the three methods and determine situations in which the choice of method results in a substantively different design. We consider two different aspects of the methods: the distributional assumptions and the clustering parameterization. Further, we provide software tools for implementing each method and clarify misconceptions about these designs in the literature. We illustrate the differences in these methods using vaccination and nutrition cluster LQAS surveys as example designs. The cluster methods are not sensitive to the distributional assumptions but can result in substantially different designs (sample sizes) depending on the clustering parameterization. However, none of the clustering parameterizations used in the existing methods appears to be consistent with the observed data, and, consequently, choice between the cluster LQAS methods is not straightforward. Further research should attempt to characterize clustering patterns in specific applications and provide suggestions for best-practice cluster LQAS designs on a setting-specific basis. PMID:26125967

Choosing a Cluster Sampling Design for Lot Quality Assurance Sampling Surveys.

PubMed

Hund, Lauren; Bedrick, Edward J; Pagano, Marcello

2015-01-01

Lot quality assurance sampling (LQAS) surveys are commonly used for monitoring and evaluation in resource-limited settings. Recently several methods have been proposed to combine LQAS with cluster sampling for more timely and cost-effective data collection. For some of these methods, the standard binomial model can be used for constructing decision rules as the clustering can be ignored. For other designs, considered here, clustering is accommodated in the design phase. In this paper, we compare these latter cluster LQAS methodologies and provide recommendations for choosing a cluster LQAS design. We compare technical differences in the three methods and determine situations in which the choice of method results in a substantively different design. We consider two different aspects of the methods: the distributional assumptions and the clustering parameterization. Further, we provide software tools for implementing each method and clarify misconceptions about these designs in the literature. We illustrate the differences in these methods using vaccination and nutrition cluster LQAS surveys as example designs. The cluster methods are not sensitive to the distributional assumptions but can result in substantially different designs (sample sizes) depending on the clustering parameterization. However, none of the clustering parameterizations used in the existing methods appears to be consistent with the observed data, and, consequently, choice between the cluster LQAS methods is not straightforward. Further research should attempt to characterize clustering patterns in specific applications and provide suggestions for best-practice cluster LQAS designs on a setting-specific basis.

Comparing deflection measurements of a magnetically steerable catheter using optical imaging and MRI

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lillaney, Prasheel, E-mail: Prasheel.Lillaney@ucsf.edu; Caton, Curtis; Martin, Alastair J.

2014-02-15

Purpose: Magnetic resonance imaging (MRI) is an emerging modality for interventional radiology, giving clinicians another tool for minimally invasive image-guided interventional procedures. Difficulties associated with endovascular catheter navigation using MRI guidance led to the development of a magnetically steerable catheter. The focus of this study was to mechanically characterize deflections of two different prototypes of the magnetically steerable catheterin vitro to better understand their efficacy. Methods: A mathematical model for deflection of the magnetically steerable catheter is formulated based on the principle that at equilibrium the mechanical and magnetic torques are equal to each other. Furthermore, two different image basedmore » methods for empirically measuring the catheter deflection angle are presented. The first, referred to as the absolute tip method, measures the angle of the line that is tangential to the catheter tip. The second, referred to the base to tip method, is an approximation that is used when it is not possible to measure the angle of the tangent line. Optical images of the catheter deflection are analyzed using the absolute tip method to quantitatively validate the predicted deflections from the mathematical model. Optical images of the catheter deflection are also analyzed using the base to tip method to quantitatively determine the differences between the absolute tip and base to tip methods. Finally, the optical images are compared to MR images using the base to tip method to determine the accuracy of measuring the catheter deflection using MR. Results: The optical catheter deflection angles measured for both catheter prototypes using the absolute tip method fit very well to the mathematical model (R{sup 2} = 0.91 and 0.86 for each prototype, respectively). It was found that the angles measured using the base to tip method were consistently smaller than those measured using the absolute tip method. The deflection angles measured using optical data did not demonstrate a significant difference from the angles measured using MR image data when compared using the base to tip method. Conclusions: This study validates the theoretical description of the magnetically steerable catheter, while also giving insight into different methods and modalities for measuring the deflection angles of the prototype catheters. These results can be used to mechanically model future iterations of the design. Quantifying the difference between the different methods for measuring catheter deflection will be important when making deflection measurements in future studies. Finally, MR images can be used to reliably measure deflection angles since there is no significant difference between the MR and optical measurements.« less

Comparison of six methods for isolating mycobacteria from swine lymph nodes.

PubMed

Thoen, C O; Richards, W D; Jarnagin, J L

1974-03-01

Six laboratory methods were compared for isolating acid-fast bacteria. Tuberculous lymph nodes from each of 48 swine as identified by federal meat inspectors were processed by each of the methods. Treated tissue suspensions were inoculated onto each of eight media which were observed at 7-day intervals for 9 weeks. There were no statistically significant differences between the number of Mycobacterium avium complex bacteria isolated by each of the six methods. Rapid tissue preparation methods involving treatment with 2% sodium hydroxide or treatment with 0.2% zephiran required only one-third to one-fourth the processing time as a standard method. There were small differences in the amount of contamination among the six methods, but no detectable differences in the time of first appearance of M. avium complex colonies.

Methods for Specifying the Target Difference in a Randomised Controlled Trial: The Difference ELicitation in TriAls (DELTA) Systematic Review

PubMed Central

Hislop, Jenni; Adewuyi, Temitope E.; Vale, Luke D.; Harrild, Kirsten; Fraser, Cynthia; Gurung, Tara; Altman, Douglas G.; Briggs, Andrew H.; Fayers, Peter; Ramsay, Craig R.; Norrie, John D.; Harvey, Ian M.; Buckley, Brian; Cook, Jonathan A.

2014-01-01

Background Randomised controlled trials (RCTs) are widely accepted as the preferred study design for evaluating healthcare interventions. When the sample size is determined, a (target) difference is typically specified that the RCT is designed to detect. This provides reassurance that the study will be informative, i.e., should such a difference exist, it is likely to be detected with the required statistical precision. The aim of this review was to identify potential methods for specifying the target difference in an RCT sample size calculation. Methods and Findings A comprehensive systematic review of medical and non-medical literature was carried out for methods that could be used to specify the target difference for an RCT sample size calculation. The databases searched were MEDLINE, MEDLINE In-Process, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Methodology Register, PsycINFO, Science Citation Index, EconLit, the Education Resources Information Center (ERIC), and Scopus (for in-press publications); the search period was from 1966 or the earliest date covered, to between November 2010 and January 2011. Additionally, textbooks addressing the methodology of clinical trials and International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) tripartite guidelines for clinical trials were also consulted. A narrative synthesis of methods was produced. Studies that described a method that could be used for specifying an important and/or realistic difference were included. The search identified 11,485 potentially relevant articles from the databases searched. Of these, 1,434 were selected for full-text assessment, and a further nine were identified from other sources. Fifteen clinical trial textbooks and the ICH tripartite guidelines were also reviewed. In total, 777 studies were included, and within them, seven methods were identified—anchor, distribution, health economic, opinion-seeking, pilot study, review of the evidence base, and standardised effect size. Conclusions A variety of methods are available that researchers can use for specifying the target difference in an RCT sample size calculation. Appropriate methods may vary depending on the aim (e.g., specifying an important difference versus a realistic difference), context (e.g., research question and availability of data), and underlying framework adopted (e.g., Bayesian versus conventional statistical approach). Guidance on the use of each method is given. No single method provides a perfect solution for all contexts. Please see later in the article for the Editors' Summary PMID:24824338

Comparison of different wind data interpolation methods for a region with complex terrain in Central Asia

NASA Astrophysics Data System (ADS)

Reinhardt, Katja; Samimi, Cyrus

2018-01-01

While climatological data of high spatial resolution are largely available in most developed countries, the network of climatological stations in many other regions of the world still constitutes large gaps. Especially for those regions, interpolation methods are important tools to fill these gaps and to improve the data base indispensible for climatological research. Over the last years, new hybrid methods of machine learning and geostatistics have been developed which provide innovative prospects in spatial predictive modelling. This study will focus on evaluating the performance of 12 different interpolation methods for the wind components \\overrightarrow{u} and \\overrightarrow{v} in a mountainous region of Central Asia. Thereby, a special focus will be on applying new hybrid methods on spatial interpolation of wind data. This study is the first evaluating and comparing the performance of several of these hybrid methods. The overall aim of this study is to determine whether an optimal interpolation method exists, which can equally be applied for all pressure levels, or whether different interpolation methods have to be used for the different pressure levels. Deterministic (inverse distance weighting) and geostatistical interpolation methods (ordinary kriging) were explored, which take into account only the initial values of \\overrightarrow{u} and \\overrightarrow{v} . In addition, more complex methods (generalized additive model, support vector machine and neural networks as single methods and as hybrid methods as well as regression-kriging) that consider additional variables were applied. The analysis of the error indices revealed that regression-kriging provided the most accurate interpolation results for both wind components and all pressure heights. At 200 and 500 hPa, regression-kriging is followed by the different kinds of neural networks and support vector machines and for 850 hPa it is followed by the different types of support vector machine and ordinary kriging. Overall, explanatory variables improve the interpolation results.

New Laboratory Methods for Characterizing the Immersion Factors for Irradiance

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Zibordi, Giuseppe; DAlimonte, Davide; vaderLinde, Dirk; Brown, James W.

2003-01-01

The experimental determination of the immersion factor, I(sub f)(lambda), of irradiance collectors is a requirement of any in-water radiometer. The eighth SeaWiFS Intercalibration Round-Robin Experiment (SIRREX-8) showed different implementations, at different laboratories, of the same I(sub f)(lambda) measurement protocol. The different implementations make use of different setups, volumes, and water types. Consequently, they exhibit different accuracies and require different execution times for characterizing an irradiance sensor. In view of standardizing the characterization of I(sub f)(lambda) values for in-water radiometers, together with an increase in the accuracy of methods and a decrease in the execution time, alternative methods are presented, and assessed versus the traditional method. The proposed new laboratory methods include: a) the continuous method, in which optical measurements taken with discrete water depths are substituted by continuous profiles created by removing the water from the water vessel at a constant flow rate (which significantly reduces the time required for the characterization of a single radiometer); and b) the Compact Portable Advanced Characterization Tank (ComPACT) method, in which the commonly used large tanks are replaced by a small water vessel, thereby allowing the determination of I(sub f)(lambda) values with a small water volume, and more importantly, permitting I(sub f)(lambda) characterizations with pure water. Intercomparisons between the continuous and the traditional method showed results within the variance of I(sub f) (lambda) determinations. The use of the continuous method, however, showed a much shorter realization time. Intercomparisons between the ComPACT and the traditional method showed generally higher I(sub f)(lambda) values for the former. This is in agreement with the generalized expectations of a reduction in scattering effects, because of the use of pure water with the ComPACT method versus the use of tap water with the traditional method.

Star sub-pixel centroid calculation based on multi-step minimum energy difference method

NASA Astrophysics Data System (ADS)

Wang, Duo; Han, YanLi; Sun, Tengfei

2013-09-01

The star's centroid plays a vital role in celestial navigation, star images which be gotten during daytime, due to the strong sky background, have a low SNR, and the star objectives are nearly submerged in the background, takes a great trouble to the centroid localization. Traditional methods, such as a moment method, weighted centroid calculation method is simple but has a big error, especially in the condition of a low SNR. Gaussian method has a high positioning accuracy, but the computational complexity. Analysis of the energy distribution in star image, a location method for star target centroids based on multi-step minimum energy difference is proposed. This method uses the linear superposition to narrow the centroid area, in the certain narrow area uses a certain number of interpolation to pixels for the pixels' segmentation, and then using the symmetry of the stellar energy distribution, tentatively to get the centroid position: assume that the current pixel is the star centroid position, and then calculates and gets the difference of the sum of the energy which in the symmetric direction(in this paper we take the two directions of transverse and longitudinal) and the equal step length(which can be decided through different conditions, the paper takes 9 as the step length) of the current pixel, and obtain the centroid position in this direction when the minimum difference appears, and so do the other directions, then the validation comparison of simulated star images, and compare with several traditional methods, experiments shows that the positioning accuracy of the method up to 0.001 pixel, has good effect to calculate the centroid of low SNR conditions; at the same time, uses this method on a star map which got at the fixed observation site during daytime in near-infrared band, compare the results of the paper's method with the position messages which were known of the star, it shows that :the multi-step minimum energy difference method achieves a better effect.

Proposed Modifications to Engineering Design Guidelines Related to Resistivity Measurements and Spacecraft Charging

NASA Technical Reports Server (NTRS)

Dennison, J. R.; Swaminathan, Prasanna; Jost, Randy; Brunson, Jerilyn; Green, Nelson; Frederickson, A. Robb

2005-01-01

A key parameter in modeling differential spacecraft charging is the resistivity of insulating materials. This determines how charge will accumulate and redistribute across the spacecraft, as well as the time scale for charge transport and dissipation. Existing spacecraft charging guidelines recommend use of tests and imported resistivity data from handbooks that are based principally upon ASTM methods that are more applicable to classical ground conditions and designed for problems associated with power loss through the dielectric, than for how long charge can be stored on an insulator. These data have been found to underestimate charging effects by one to four orders of magnitude for spacecraft charging applications. A review is presented of methods to measure the resistive of highly insulating materials, including the electrometer-resistance method, the electrometer-constant voltage method, the voltage rate-of-change method and the charge storage method. This is based on joint experimental studies conducted at NASA Jet Propulsion Laboratory and Utah State University to investigate the charge storage method and its relation to spacecraft charging. The different methods are found to be appropriate for different resistivity ranges and for different charging circumstances. A simple physics-based model of these methods allows separation of the polarization current and dark current components from long duration measurements of resistivity over day- to month-long time scales. Model parameters are directly related to the magnitude of charge transfer and storage and the rate of charge transport. The model largely explains the observed differences in resistivity found using the different methods and provides a framework for recommendations for the appropriate test method for spacecraft materials with different resistivities and applications. The proposed changes to the existing engineering guidelines are intended to provide design engineers more appropriate methods for consideration and measurements of resistivity for many typical spacecraft charging scenarios.

Comparison of Chemical Extraction Methods for Determination of Soil Potassium in Different Soil Types

NASA Astrophysics Data System (ADS)

Zebec, V.; Rastija, D.; Lončarić, Z.; Bensa, A.; Popović, B.; Ivezić, V.

2017-12-01

Determining potassium supply of soil plays an important role in intensive crop production, since it is the basis for balancing nutrients and issuing fertilizer recommendations for achieving high and stable yields within economic feasibility. The aim of this study was to compare the different extraction methods of soil potassium from arable horizon of different types of soils with ammonium lactate method (KAL), which is frequently used as analytical method for determining the accessibility of nutrients and it is a common method used for issuing fertilizer recommendations in many Europe countries. In addition to the ammonium lactate method (KAL, pH 3.75), potassium was extracted with ammonium acetate (KAA, pH 7), ammonium acetate ethylenediaminetetraacetic acid (KAAEDTA, pH 4.6), Bray (KBRAY, pH 2.6) and with barium chloride (K_{BaCl_2 }, pH 8.1). The analyzed soils were extremely heterogeneous with a wide range of determined values. Soil pH reaction ( {pH_{H_2 O} } ) ranged from 4.77 to 8.75, organic matter content ranged from 1.87 to 4.94% and clay content from 8.03 to 37.07%. In relation to KAL method as the standard method, K_{BaCl_2 } method extracts 12.9% more on average of soil potassium, while in relation to standard method, on average KAA extracts 5.3%, KAAEDTA 10.3%, and KBRAY 27.5% less of potassium. Comparison of analyzed extraction methods of potassium from the soil is of high precision, and most reliable comparison was KAL method with KAAEDTA, followed by a: KAA, K_{BaCl_2 } and KBRAY method. Extremely significant statistical correlation between different extractive methods for determining potassium in the soil indicates that any of the methods can be used to accurately predict the concentration of potassium in the soil, and that carried out research can be used to create prediction model for concentration of potassium based on different methods of extraction.

Improved Estimation of Cardiac Function Parameters Using a Combination of Independent Automated Segmentation Results in Cardiovascular Magnetic Resonance Imaging.

PubMed

Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe; Frouin, Frederique; Garreau, Mireille

2015-01-01

This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert.

Improved Estimation of Cardiac Function Parameters Using a Combination of Independent Automated Segmentation Results in Cardiovascular Magnetic Resonance Imaging

PubMed Central

Lebenberg, Jessica; Lalande, Alain; Clarysse, Patrick; Buvat, Irene; Casta, Christopher; Cochet, Alexandre; Constantinidès, Constantin; Cousty, Jean; de Cesare, Alain; Jehan-Besson, Stephanie; Lefort, Muriel; Najman, Laurent; Roullot, Elodie; Sarry, Laurent; Tilmant, Christophe

2015-01-01

This work aimed at combining different segmentation approaches to produce a robust and accurate segmentation result. Three to five segmentation results of the left ventricle were combined using the STAPLE algorithm and the reliability of the resulting segmentation was evaluated in comparison with the result of each individual segmentation method. This comparison was performed using a supervised approach based on a reference method. Then, we used an unsupervised statistical evaluation, the extended Regression Without Truth (eRWT) that ranks different methods according to their accuracy in estimating a specific biomarker in a population. The segmentation accuracy was evaluated by estimating six cardiac function parameters resulting from the left ventricle contour delineation using a public cardiac cine MRI database. Eight different segmentation methods, including three expert delineations and five automated methods, were considered, and sixteen combinations of the automated methods using STAPLE were investigated. The supervised and unsupervised evaluations demonstrated that in most cases, STAPLE results provided better estimates than individual automated segmentation methods. Overall, combining different automated segmentation methods improved the reliability of the segmentation result compared to that obtained using an individual method and could achieve the accuracy of an expert. PMID:26287691

Comparison of methods of DNA extraction for real-time PCR in a model of pleural tuberculosis.

PubMed

Santos, Ana; Cremades, Rosa; Rodríguez, Juan Carlos; García-Pachón, Eduardo; Ruiz, Montserrat; Royo, Gloria

2010-01-01

Molecular methods have been reported to have different sensitivities in the diagnosis of pleural tuberculosis and this may in part be caused by the use of different methods of DNA extraction. Our study compares nine DNA extraction systems in an experimental model of pleural tuberculosis. An inoculum of Mycobacterium tuberculosis was added to 23 pleural liquid samples with different characteristics. DNA was subsequently extracted using nine different methods (seven manual and two automatic) for analysis with real-time PCR. Only two methods were able to detect the presence of M. tuberculosis DNA in all the samples: extraction using columns (Qiagen) and automated extraction with the TNAI system (Roche). The automatic method is more expensive, but requires less time. Almost all the false negatives were because of the difficulty involved in extracting M. tuberculosis DNA, as in general, all the methods studied are capable of eliminating inhibitory substances that block the amplification reaction. The method of M. tuberculosis DNA extraction used affects the results of the diagnosis of pleural tuberculosis by molecular methods. DNA extraction systems that have been shown to be effective in pleural liquid should be used.

Evaluation of multivariate calibration models with different pre-processing and processing algorithms for a novel resolution and quantitation of spectrally overlapped quaternary mixture in syrup

NASA Astrophysics Data System (ADS)

Moustafa, Azza A.; Hegazy, Maha A.; Mohamed, Dalia; Ali, Omnia

2016-02-01

A novel approach for the resolution and quantitation of severely overlapped quaternary mixture of carbinoxamine maleate (CAR), pholcodine (PHL), ephedrine hydrochloride (EPH) and sunset yellow (SUN) in syrup was demonstrated utilizing different spectrophotometric assisted multivariate calibration methods. The applied methods have used different processing and pre-processing algorithms. The proposed methods were partial least squares (PLS), concentration residuals augmented classical least squares (CRACLS), and a novel method; continuous wavelet transforms coupled with partial least squares (CWT-PLS). These methods were applied to a training set in the concentration ranges of 40-100 μg/mL, 40-160 μg/mL, 100-500 μg/mL and 8-24 μg/mL for the four components, respectively. The utilized methods have not required any preliminary separation step or chemical pretreatment. The validity of the methods was evaluated by an external validation set. The selectivity of the developed methods was demonstrated by analyzing the drugs in their combined pharmaceutical formulation without any interference from additives. The obtained results were statistically compared with the official and reported methods where no significant difference was observed regarding both accuracy and precision.

Sector Identification in a Set of Stock Return Time Series Traded at the London Stock Exchange

NASA Astrophysics Data System (ADS)

Coronnello, C.; Tumminello, M.; Lillo, F.; Micciche, S.; Mantegna, R. N.

2005-09-01

We compare some methods recently used in the literature to detect the existence of a certain degree of common behavior of stock returns belonging to the same economic sector. Specifically, we discuss methods based on random matrix theory and hierarchical clustering techniques. We apply these methods to a portfolio of stocks traded at the London Stock Exchange. The investigated time series are recorded both at a daily time horizon and at a 5-minute time horizon. The correlation coefficient matrix is very different at different time horizons confirming that more structured correlation coefficient matrices are observed for long time horizons. All the considered methods are able to detect economic information and the presence of clusters characterized by the economic sector of stocks. However, different methods present a different degree of sensitivity with respect to different sectors. Our comparative analysis suggests that the application of just a single method could not be able to extract all the economic information present in the correlation coefficient matrix of a stock portfolio.

Evaluation of methods for the extraction of DNA from drinking water distribution system biofilms.

PubMed

Hwang, Chiachi; Ling, Fangqiong; Andersen, Gary L; LeChevallier, Mark W; Liu, Wen-Tso

2012-01-01

While drinking water biofilms have been characterized in various drinking water distribution systems (DWDS), little is known about the impact of different DNA extraction methods on the subsequent analysis of microbial communities in drinking water biofilms. Since different DNA extraction methods have been shown to affect the outcome of microbial community analysis in other environments, it is necessary to select a DNA extraction method prior to the application of molecular tools to characterize the complex microbial ecology of the DWDS. This study compared the quantity and quality of DNA yields from selected DWDS bacteria with different cell wall properties using five widely used DNA extraction methods. These were further selected and evaluated for their efficiency and reproducibility of DNA extraction from DWDS samples. Terminal restriction fragment length analysis and the 454 pyrosequencing technique were used to interpret the differences in microbial community structure and composition, respectively, from extracted DNA. Such assessments serve as a concrete step towards the determination of an optimal DNA extraction method for drinking water biofilms, which can then provide a reliable comparison of the meta-analysis results obtained in different laboratories.

A total variation diminishing finite difference algorithm for sonic boom propagation models

NASA Technical Reports Server (NTRS)

Sparrow, Victor W.

1993-01-01

It is difficult to accurately model the rise phases of sonic boom waveforms with traditional finite difference algorithms because of finite difference phase dispersion. This paper introduces the concept of a total variation diminishing (TVD) finite difference method as a tool for accurately modeling the rise phases of sonic booms. A standard second order finite difference algorithm and its TVD modified counterpart are both applied to the one-way propagation of a square pulse. The TVD method clearly outperforms the non-TVD method, showing great potential as a new computational tool in the analysis of sonic boom propagation.

Study of EEG during Sternberg Tasks with Different Direction of Arrangement for Letters

NASA Astrophysics Data System (ADS)

Kamihoriuchi, Kenji; Nuruki, Atsuo; Matae, Tadashi; Kurono, Asutsugu; Yunokuchi, Kazutomo

In previous study, we recorded electroencephalogram (EEG) of patients with dementia and healthy subjects during Sternberg task. But, only one presentation method of Sternberg task was considered in previous study. Therefore, we examined whether the EEG was different in two different presentation methods wrote letters horizontally and wrote letters vertically in this study. We recorded EEG of six healthy subjects during Sternberg task using two different presentation methods. The result was not different in EEG topography of all subjects. In all subjects, correct rate increased in case of vertically arranged letters.

Evaluation of Alternative Difference-in-Differences Methods

ERIC Educational Resources Information Center

Yu, Bing

2013-01-01

Difference-in-differences (DID) strategies are particularly useful for evaluating policy effects in natural experiments in which, for example, a policy affects some schools and students but not others. However, the standard DID method may produce biased estimation of the policy effect if the confounding effect of concurrent events varies by…

Gestalt Therapy: Its Inheritance from Gestalt Psychology.

ERIC Educational Resources Information Center

Yontef, Gary M.

When adequately elaborated, the basic method of Gestalt therapy can be traced to the phenomenological field theory of Gestalt psychology. Gestalt therapy differs from Gestalt psychology not because of a difference in philosophy or method, but because of different contexts; the clinical context has different demands than those of basic research.…

State of the art of immunoassay methods for B-type natriuretic peptides: An update.

PubMed

Clerico, Aldo; Franzini, Maria; Masotti, Silvia; Prontera, Concetta; Passino, Claudio

2015-01-01

The aim of this review article is to give an update on the state of the art of the immunoassay methods for the measurement of B-type natriuretic peptide (BNP) and its related peptides. Using chromatographic procedures, several studies reported an increasing number of circulating peptides related to BNP in human plasma of patients with heart failure. These peptides may have reduced or even no biological activity. Furthermore, other studies have suggested that, using immunoassays that are considered specific for BNP, the precursor of the peptide hormone, proBNP, constitutes a major portion of the peptide measured in plasma of patients with heart failure. Because BNP immunoassay methods show large (up to 50%) systematic differences in values, the use of identical decision values for all immunoassay methods, as suggested by the most recent international guidelines, seems unreasonable. Since proBNP significantly cross-reacts with all commercial immunoassay methods considered specific for BNP, manufacturers should test and clearly declare the degree of cross-reactivity of glycosylated and non-glycosylated proBNP in their BNP immunoassay methods. Clinicians should take into account that there are large systematic differences between methods when they compare results from different laboratories that use different BNP immunoassays. On the other hand, clinical laboratories should take part in external quality assessment (EQA) programs to evaluate the bias of their method in comparison to other BNP methods. Finally, the authors believe that the development of more specific methods for the active peptide, BNP1-32, should reduce the systematic differences between methods and result in better harmonization of results.

Age and Gender Differences in the Use of Various Poisoning Methods for Deliberate Parasuicide Cases Admitted to Loghman Hospital in Tehran (2000-2004)

ERIC Educational Resources Information Center

Ghazinour, Mehdi; Emami, Habib; Richter, Jorg; Abdollahi, Mohammad; Pazhumand, Abdolkarim

2009-01-01

Different methods of poisoning used by individuals with the diagnosis of parasuicide admitted to the Loghman Hospital, Tehran, from 2000 to 2004 were investigated, with particular focus on gender and age differences. Drugs, pesticides, and other agricultural chemicals (women: 12.7%, men: 9%) were the most commonly used methods. In males, the…

What Are Reasons for the Large Gender Differences in the Lethality of Suicidal Acts? An Epidemiological Analysis in Four European Countries

PubMed Central

Heinrichs, Katherina; Székely, András; Tóth, Mónika Ditta; Coyne, James; Quintão, Sónia; Arensman, Ella; Coffey, Claire; Maxwell, Margaret; Värnik, Airi; van Audenhove, Chantal; McDaid, David; Sarchiapone, Marco; Schmidtke, Armin; Genz, Axel; Gusmão, Ricardo; Hegerl, Ulrich

2015-01-01

Background In Europe, men have lower rates of attempted suicide compared to women and at the same time a higher rate of completed suicides, indicating major gender differences in lethality of suicidal behaviour. The aim of this study was to analyse the extent to which these gender differences in lethality can be explained by factors such as choice of more lethal methods or lethality differences within the same suicide method or age. In addition, we explored gender differences in the intentionality of suicide attempts. Methods and Findings Methods. Design: Epidemiological study using a combination of self-report and official data. Setting: Mental health care services in four European countries: Germany, Hungary, Ireland, and Portugal. Data basis: Completed suicides derived from official statistics for each country (767 acts, 74.4% male) and assessed suicide attempts excluding habitual intentional self-harm (8,175 acts, 43.2% male). Main Outcome Measures and Data Analysis. We collected data on suicidal acts in eight regions of four European countries participating in the EU-funded “OSPI-Europe”-project (www.ospi-europe.com). We calculated method-specific lethality using the number of completed suicides per method * 100 / (number of completed suicides per method + number of attempted suicides per method). We tested gender differences in the distribution of suicidal acts for significance by using the χ2-test for two-by-two tables. We assessed the effect sizes with phi coefficients (φ). We identified predictors of lethality with a binary logistic regression analysis. Poisson regression analysis examined the contribution of choice of methods and method-specific lethality to gender differences in the lethality of suicidal acts. Findings Main Results Suicidal acts (fatal and non-fatal) were 3.4 times more lethal in men than in women (lethality 13.91% (regarding 4106 suicidal acts) versus 4.05% (regarding 4836 suicidal acts)), the difference being significant for the methods hanging, jumping, moving objects, sharp objects and poisoning by substances other than drugs. Median age at time of suicidal behaviour (35–44 years) did not differ between males and females. The overall gender difference in lethality of suicidal behaviour was explained by males choosing more lethal suicide methods (odds ratio (OR) = 2.03; 95% CI = 1.65 to 2.50; p < 0.000001) and additionally, but to a lesser degree, by a higher lethality of suicidal acts for males even within the same method (OR = 1.64; 95% CI = 1.32 to 2.02; p = 0.000005). Results of a regression analysis revealed neither age nor country differences were significant predictors for gender differences in the lethality of suicidal acts. The proportion of serious suicide attempts among all non-fatal suicidal acts with known intentionality (NFSAi) was significantly higher in men (57.1%; 1,207 of 2,115 NFSAi) than in women (48.6%; 1,508 of 3,100 NFSAi) (χ2 = 35.74; p < 0.000001). Main limitations of the study Due to restrictive data security regulations to ensure anonymity in Ireland, specific ages could not be provided because of the relatively low absolute numbers of suicide in the Irish intervention and control region. Therefore, analyses of the interaction between gender and age could only be conducted for three of the four countries. Attempted suicides were assessed for patients presenting to emergency departments or treated in hospitals. An unknown rate of attempted suicides remained undetected. This may have caused an overestimation of the lethality of certain methods. Moreover, the detection of attempted suicides and the registration of completed suicides might have differed across the four countries. Some suicides might be hidden and misclassified as undetermined deaths. Conclusions Men more often used highly lethal methods in suicidal behaviour, but there was also a higher method-specific lethality which together explained the large gender differences in the lethality of suicidal acts. Gender differences in the lethality of suicidal acts were fairly consistent across all four European countries examined. Males and females did not differ in age at time of suicidal behaviour. Suicide attempts by males were rated as being more serious independent of the method used, with the exceptions of attempted hanging, suggesting gender differences in intentionality associated with suicidal behaviour. These findings contribute to understanding of the spectrum of reasons for gender differences in the lethality of suicidal behaviour and should inform the development of gender specific strategies for suicide prevention. PMID:26147965

The method of space-time and conservation element and solution element: A new approach for solving the Navier-Stokes and Euler equations

NASA Technical Reports Server (NTRS)

Chang, Sin-Chung

1995-01-01

A new numerical framework for solving conservation laws is being developed. This new framework differs substantially in both concept and methodology from the well-established methods, i.e., finite difference, finite volume, finite element, and spectral methods. It is conceptually simple and designed to overcome several key limitations of the above traditional methods. A two-level scheme for solving the convection-diffusion equation is constructed and used to illuminate the major differences between the present method and those previously mentioned. This explicit scheme, referred to as the a-mu scheme, has two independent marching variables.

Ensemble Methods for MiRNA Target Prediction from Expression Data.

PubMed

Le, Thuc Duy; Zhang, Junpeng; Liu, Lin; Li, Jiuyong

2015-01-01

microRNAs (miRNAs) are short regulatory RNAs that are involved in several diseases, including cancers. Identifying miRNA functions is very important in understanding disease mechanisms and determining the efficacy of drugs. An increasing number of computational methods have been developed to explore miRNA functions by inferring the miRNA-mRNA regulatory relationships from data. Each of the methods is developed based on some assumptions and constraints, for instance, assuming linear relationships between variables. For such reasons, computational methods are often subject to the problem of inconsistent performance across different datasets. On the other hand, ensemble methods integrate the results from individual methods and have been proved to outperform each of their individual component methods in theory. In this paper, we investigate the performance of some ensemble methods over the commonly used miRNA target prediction methods. We apply eight different popular miRNA target prediction methods to three cancer datasets, and compare their performance with the ensemble methods which integrate the results from each combination of the individual methods. The validation results using experimentally confirmed databases show that the results of the ensemble methods complement those obtained by the individual methods and the ensemble methods perform better than the individual methods across different datasets. The ensemble method, Pearson+IDA+Lasso, which combines methods in different approaches, including a correlation method, a causal inference method, and a regression method, is the best performed ensemble method in this study. Further analysis of the results of this ensemble method shows that the ensemble method can obtain more targets which could not be found by any of the single methods, and the discovered targets are more statistically significant and functionally enriched. The source codes, datasets, miRNA target predictions by all methods, and the ground truth for validation are available in the Supplementary materials.

Ensemble Methods for MiRNA Target Prediction from Expression Data

PubMed Central

Le, Thuc Duy; Zhang, Junpeng; Liu, Lin; Li, Jiuyong

2015-01-01

Background microRNAs (miRNAs) are short regulatory RNAs that are involved in several diseases, including cancers. Identifying miRNA functions is very important in understanding disease mechanisms and determining the efficacy of drugs. An increasing number of computational methods have been developed to explore miRNA functions by inferring the miRNA-mRNA regulatory relationships from data. Each of the methods is developed based on some assumptions and constraints, for instance, assuming linear relationships between variables. For such reasons, computational methods are often subject to the problem of inconsistent performance across different datasets. On the other hand, ensemble methods integrate the results from individual methods and have been proved to outperform each of their individual component methods in theory. Results In this paper, we investigate the performance of some ensemble methods over the commonly used miRNA target prediction methods. We apply eight different popular miRNA target prediction methods to three cancer datasets, and compare their performance with the ensemble methods which integrate the results from each combination of the individual methods. The validation results using experimentally confirmed databases show that the results of the ensemble methods complement those obtained by the individual methods and the ensemble methods perform better than the individual methods across different datasets. The ensemble method, Pearson+IDA+Lasso, which combines methods in different approaches, including a correlation method, a causal inference method, and a regression method, is the best performed ensemble method in this study. Further analysis of the results of this ensemble method shows that the ensemble method can obtain more targets which could not be found by any of the single methods, and the discovered targets are more statistically significant and functionally enriched. The source codes, datasets, miRNA target predictions by all methods, and the ground truth for validation are available in the Supplementary materials. PMID:26114448

Detecting and Analyzing Corrosion Spots on the Hull of Large Marine Vessels Using Colored 3d LIDAR Point Clouds

NASA Astrophysics Data System (ADS)

Aijazi, A. K.; Malaterre, L.; Tazir, M. L.; Trassoudaine, L.; Checchin, P.

2016-06-01

This work presents a new method that automatically detects and analyzes surface defects such as corrosion spots of different shapes and sizes, on large ship hulls. In the proposed method several scans from different positions and viewing angles around the ship are registered together to form a complete 3D point cloud. The R, G, B values associated with each scan, obtained with the help of an integrated camera are converted into HSV space to separate out the illumination invariant color component from the intensity. Using this color component, different surface defects such as corrosion spots of different shapes and sizes are automatically detected, within a selected zone, using two different methods depending upon the level of corrosion/defects. The first method relies on a histogram based distribution whereas the second on adaptive thresholds. The detected corrosion spots are then analyzed and quantified to help better plan and estimate the cost of repair and maintenance. Results are evaluated on real data using different standard evaluation metrics to demonstrate the efficacy as well as the technical strength of the proposed method.

Experiments to Evaluate and Implement Passive Tracer Gas Methods to Measure Ventilation Rates in Homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lunden, Melissa; Faulkner, David; Heredia, Elizabeth

2012-10-01

This report documents experiments performed in three homes to assess the methodology used to determine air exchange rates using passive tracer techniques. The experiments used four different tracer gases emitted simultaneously but implemented with different spatial coverage in the home. Two different tracer gas sampling methods were used. The results characterize the factors of the execution and analysis of the passive tracer technique that affect the uncertainty in the calculated air exchange rates. These factors include uncertainties in tracer gas emission rates, differences in measured concentrations for different tracer gases, temporal and spatial variability of the concentrations, the comparison betweenmore » different gas sampling methods, and the effect of different ventilation conditions.« less

Accessibility to primary health care in Belgium: an evaluation of policies awarding financial assistance in shortage areas

PubMed Central

2013-01-01

Background In many countries, financial assistance is awarded to physicians who settle in an area that is designated as a shortage area to prevent unequal accessibility to primary health care. Today, however, policy makers use fairly simple methods to define health care accessibility, with physician-to-population ratios (PPRs) within predefined administrative boundaries being overwhelmingly favoured. Our purpose is to verify whether these simple methods are accurate enough for adequately designating medical shortage areas and explore how these perform relative to more advanced GIS-based methods. Methods Using a geographical information system (GIS), we conduct a nation-wide study of accessibility to primary care physicians in Belgium using four different methods: PPR, distance to closest physician, cumulative opportunity, and floating catchment area (FCA) methods. Results The official method used by policy makers in Belgium (calculating PPR per physician zone) offers only a crude representation of health care accessibility, especially because large contiguous areas (physician zones) are considered. We found substantial differences in the number and spatial distribution of medical shortage areas when applying different methods. Conclusions The assessment of spatial health care accessibility and concomitant policy initiatives are affected by and dependent on the methodology used. The major disadvantage of PPR methods is its aggregated approach, masking subtle local variations. Some simple GIS methods overcome this issue, but have limitations in terms of conceptualisation of physician interaction and distance decay. Conceptually, the enhanced 2-step floating catchment area (E2SFCA) method, an advanced FCA method, was found to be most appropriate for supporting areal health care policies, since this method is able to calculate accessibility at a small scale (e.g. census tracts), takes interaction between physicians into account, and considers distance decay. While at present in health care research methodological differences and modifiable areal unit problems have remained largely overlooked, this manuscript shows that these aspects have a significant influence on the insights obtained. Hence, it is important for policy makers to ascertain to what extent their policy evaluations hold under different scales of analysis and when different methods are used. PMID:23964751

Band selection method based on spectrum difference in targets of interest in hyperspectral imagery

NASA Astrophysics Data System (ADS)

Zhang, Xiaohan; Yang, Guang; Yang, Yongbo; Huang, Junhua

2016-10-01

While hyperspectral data shares rich spectrum information, it has numbers of bands with high correlation coefficients, causing great data redundancy. A reasonable band selection is important for subsequent processing. Bands with large amount of information and low correlation should be selected. On this basis, according to the needs of target detection applications, the spectral characteristics of the objects of interest are taken into consideration in this paper, and a new method based on spectrum difference is proposed. Firstly, according to the spectrum differences of targets of interest, a difference matrix which represents the different spectral reflectance of different targets in different bands is structured. By setting a threshold, the bands satisfying the conditions would be left, constituting a subset of bands. Then, the correlation coefficients between bands are calculated and correlation matrix is given. According to the size of the correlation coefficient, the bands can be set into several groups. At last, the conception of normalized variance is used on behalf of the information content of each band. The bands are sorted by the value of its normalized variance. Set needing number of bands, and the optimum band combination solution can be get by these three steps. This method retains the greatest degree of difference between the target of interest and is easy to achieve by computer automatically. Besides, false color image synthesis experiment is carried out using the bands selected by this method as well as other 3 methods to show the performance of method in this paper.

A spring system method for a mesh generation problem

NASA Astrophysics Data System (ADS)

Romanov, A.

2018-04-01

A new direct method for the 2d-mesh generation for a simply-connected domain using a spring system is observed. The method can be used with other methods to modify a mesh for growing solid problems. Advantages and disadvantages of the method are shown. Different types of boundary conditions are explored. The results of modelling for different target domains are given. Some applications for composite materials are studied.

Comparison of Three Different Methods for Pile Integrity Testing on a Cylindrical Homogeneous Polyamide Specimen

NASA Astrophysics Data System (ADS)

Lugovtsova, Y. D.; Soldatov, A. I.

2016-01-01

Three different methods for pile integrity testing are proposed to compare on a cylindrical homogeneous polyamide specimen. The methods are low strain pile integrity testing, multichannel pile integrity testing and testing with a shaker system. Since the low strain pile integrity testing is well-established and standardized method, the results from it are used as a reference for other two methods.

Accurate Simulation and Detection of Coevolution Signals in Multiple Sequence Alignments

PubMed Central

Ackerman, Sharon H.; Tillier, Elisabeth R.; Gatti, Domenico L.

2012-01-01

Background While the conserved positions of a multiple sequence alignment (MSA) are clearly of interest, non-conserved positions can also be important because, for example, destabilizing effects at one position can be compensated by stabilizing effects at another position. Different methods have been developed to recognize the evolutionary relationship between amino acid sites, and to disentangle functional/structural dependencies from historical/phylogenetic ones. Methodology/Principal Findings We have used two complementary approaches to test the efficacy of these methods. In the first approach, we have used a new program, MSAvolve, for the in silico evolution of MSAs, which records a detailed history of all covarying positions, and builds a global coevolution matrix as the accumulated sum of individual matrices for the positions forced to co-vary, the recombinant coevolution, and the stochastic coevolution. We have simulated over 1600 MSAs for 8 protein families, which reflect sequences of different sizes and proteins with widely different functions. The calculated coevolution matrices were compared with the coevolution matrices obtained for the same evolved MSAs with different coevolution detection methods. In a second approach we have evaluated the capacity of the different methods to predict close contacts in the representative X-ray structures of an additional 150 protein families using only experimental MSAs. Conclusions/Significance Methods based on the identification of global correlations between pairs were found to be generally superior to methods based only on local correlations in their capacity to identify coevolving residues using either simulated or experimental MSAs. However, the significant variability in the performance of different methods with different proteins suggests that the simulation of MSAs that replicate the statistical properties of the experimental MSA can be a valuable tool to identify the coevolution detection method that is most effective in each case. PMID:23091608

Further Insight and Additional Inference Methods for Polynomial Regression Applied to the Analysis of Congruence

ERIC Educational Resources Information Center

Cohen, Ayala; Nahum-Shani, Inbal; Doveh, Etti

2010-01-01

In their seminal paper, Edwards and Parry (1993) presented the polynomial regression as a better alternative to applying difference score in the study of congruence. Although this method is increasingly applied in congruence research, its complexity relative to other methods for assessing congruence (e.g., difference score methods) was one of the…

Colorimetric characterization of digital cameras with unrestricted capture settings applicable for different illumination circumstances

NASA Astrophysics Data System (ADS)

Fang, Jingyu; Xu, Haisong; Wang, Zhehong; Wu, Xiaomin

2016-05-01

With colorimetric characterization, digital cameras can be used as image-based tristimulus colorimeters for color communication. In order to overcome the restriction of fixed capture settings adopted in the conventional colorimetric characterization procedures, a novel method was proposed considering capture settings. The method calculating colorimetric value of the measured image contains five main steps, including conversion from RGB values to equivalent ones of training settings through factors based on imaging system model so as to build the bridge between different settings, scaling factors involved in preparation steps for transformation mapping to avoid errors resulted from nonlinearity of polynomial mapping for different ranges of illumination levels. The experiment results indicate that the prediction error of the proposed method, which was measured by CIELAB color difference formula, reaches less than 2 CIELAB units under different illumination levels and different correlated color temperatures. This prediction accuracy for different capture settings remains the same level as the conventional method for particular lighting condition.

Newton's method applied to finite-difference approximations for the steady-state compressible Navier-Stokes equations

NASA Technical Reports Server (NTRS)

Bailey, Harry E.; Beam, Richard M.

1991-01-01

Finite-difference approximations for steady-state compressible Navier-Stokes equations, whose two spatial dimensions are written in generalized curvilinear coordinates and strong conservation-law form, are presently solved by means of Newton's method in order to obtain a lifting-airfoil flow field under subsonic and transonnic conditions. In addition to ascertaining the computational requirements of an initial guess ensuring convergence and the degree of computational efficiency obtainable via the approximate Newton method's freezing of the Jacobian matrices, attention is given to the need for auxiliary methods assessing the temporal stability of steady-state solutions. It is demonstrated that nonunique solutions of the finite-difference equations are obtainable by Newton's method in conjunction with a continuation method.

Computationally efficient finite-difference modal method for the solution of Maxwell's equations.

PubMed

Semenikhin, Igor; Zanuccoli, Mauro

2013-12-01

In this work, a new implementation of the finite-difference (FD) modal method (FDMM) based on an iterative approach to calculate the eigenvalues and corresponding eigenfunctions of the Helmholtz equation is presented. Two relevant enhancements that significantly increase the speed and accuracy of the method are introduced. First of all, the solution of the complete eigenvalue problem is avoided in favor of finding only the meaningful part of eigenmodes by using iterative methods. Second, a multigrid algorithm and Richardson extrapolation are implemented. Simultaneous use of these techniques leads to an enhancement in terms of accuracy, which allows a simple method such as the FDMM with a typical three-point difference scheme to be significantly competitive with an analytical modal method.

A New Moving Object Detection Method Based on Frame-difference and Background Subtraction

NASA Astrophysics Data System (ADS)

Guo, Jiajia; Wang, Junping; Bai, Ruixue; Zhang, Yao; Li, Yong

2017-09-01

Although many methods of moving object detection have been proposed, moving object extraction is still the core in video surveillance. However, with the complex scene in real world, false detection, missed detection and deficiencies resulting from cavities inside the body still exist. In order to solve the problem of incomplete detection for moving objects, a new moving object detection method combined an improved frame-difference and Gaussian mixture background subtraction is proposed in this paper. To make the moving object detection more complete and accurate, the image repair and morphological processing techniques which are spatial compensations are applied in the proposed method. Experimental results show that our method can effectively eliminate ghosts and noise and fill the cavities of the moving object. Compared to other four moving object detection methods which are GMM, VIBE, frame-difference and a literature's method, the proposed method improve the efficiency and accuracy of the detection.

Comprehensive Numerical Analysis of Finite Difference Time Domain Methods for Improving Optical Waveguide Sensor Accuracy

PubMed Central

Samak, M. Mosleh E. Abu; Bakar, A. Ashrif A.; Kashif, Muhammad; Zan, Mohd Saiful Dzulkifly

2016-01-01

This paper discusses numerical analysis methods for different geometrical features that have limited interval values for typically used sensor wavelengths. Compared with existing Finite Difference Time Domain (FDTD) methods, the alternating direction implicit (ADI)-FDTD method reduces the number of sub-steps by a factor of two to three, which represents a 33% time savings in each single run. The local one-dimensional (LOD)-FDTD method has similar numerical equation properties, which should be calculated as in the previous method. Generally, a small number of arithmetic processes, which result in a shorter simulation time, are desired. The alternating direction implicit technique can be considered a significant step forward for improving the efficiency of unconditionally stable FDTD schemes. This comparative study shows that the local one-dimensional method had minimum relative error ranges of less than 40% for analytical frequencies above 42.85 GHz, and the same accuracy was generated by both methods.

Numerical simulation using vorticity-vector potential formulation

NASA Technical Reports Server (NTRS)

Tokunaga, Hiroshi

1993-01-01

An accurate and efficient computational method is needed for three-dimensional incompressible viscous flows in engineering applications. On solving the turbulent shear flows directly or using the subgrid scale model, it is indispensable to resolve the small scale fluid motions as well as the large scale motions. From this point of view, the pseudo-spectral method is used so far as the computational method. However, the finite difference or the finite element methods are widely applied for computing the flow with practical importance since these methods are easily applied to the flows with complex geometric configurations. However, there exist several problems in applying the finite difference method to direct and large eddy simulations. Accuracy is one of most important problems. This point was already addressed by the present author on the direct simulations on the instability of the plane Poiseuille flow and also on the transition to turbulence. In order to obtain high efficiency, the multi-grid Poisson solver is combined with the higher-order, accurate finite difference method. The formulation method is also one of the most important problems in applying the finite difference method to the incompressible turbulent flows. The three-dimensional Navier-Stokes equations have been solved so far in the primitive variables formulation. One of the major difficulties of this method is the rigorous satisfaction of the equation of continuity. In general, the staggered grid is used for the satisfaction of the solenoidal condition for the velocity field at the wall boundary. However, the velocity field satisfies the equation of continuity automatically in the vorticity-vector potential formulation. From this point of view, the vorticity-vector potential method was extended to the generalized coordinate system. In the present article, we adopt the vorticity-vector potential formulation, the generalized coordinate system, and the 4th-order accurate difference method as the computational method. We present the computational method and apply the present method to computations of flows in a square cavity at large Reynolds number in order to investigate its effectiveness.

Evaluation of two-phase flow solvers using Level Set and Volume of Fluid methods

NASA Astrophysics Data System (ADS)

Bilger, C.; Aboukhedr, M.; Vogiatzaki, K.; Cant, R. S.

2017-09-01

Two principal methods have been used to simulate the evolution of two-phase immiscible flows of liquid and gas separated by an interface. These are the Level-Set (LS) method and the Volume of Fluid (VoF) method. Both methods attempt to represent the very sharp interface between the phases and to deal with the large jumps in physical properties associated with it. Both methods have their own strengths and weaknesses. For example, the VoF method is known to be prone to excessive numerical diffusion, while the basic LS method has some difficulty in conserving mass. Major progress has been made in remedying these deficiencies, and both methods have now reached a high level of physical accuracy. Nevertheless, there remains an issue, in that each of these methods has been developed by different research groups, using different codes and most importantly the implementations have been fine tuned to tackle different applications. Thus, it remains unclear what are the remaining advantages and drawbacks of each method relative to the other, and what might be the optimal way to unify them. In this paper, we address this gap by performing a direct comparison of two current state-of-the-art variations of these methods (LS: RCLSFoam and VoF: interPore) and implemented in the same code (OpenFoam). We subject both methods to a pair of benchmark test cases while using the same numerical meshes to examine a) the accuracy of curvature representation, b) the effect of tuning parameters, c) the ability to minimise spurious velocities and d) the ability to tackle fluids with very different densities. For each method, one of the test cases is chosen to be fairly benign while the other test case is expected to present a greater challenge. The results indicate that both methods can be made to work well on both test cases, while displaying different sensitivity to the relevant parameters.

Method for Non-Invasive Determination of Chemical Properties of Aqueous Solutions

NASA Technical Reports Server (NTRS)

Jones, Alan (Inventor); Thomas, Nathan A. (Inventor); Todd, Paul W. (Inventor)

2016-01-01

A method for non-invasively determining a chemical property of an aqueous solution is provided. The method provides the steps of providing a colored solute having a light absorbance spectrum and transmitting light through the colored solute at two different wavelengths. The method further provides the steps of measuring light absorbance of the colored solute at the two different transmitted light wavelengths, and comparing the light absorbance of the colored solute at the two different wavelengths to determine a chemical property of an aqueous solution.

Temperature profiles of different cooling methods in porcine pancreas procurement.

PubMed

Weegman, Bradley P; Suszynski, Thomas M; Scott, William E; Ferrer Fábrega, Joana; Avgoustiniatos, Efstathios S; Anazawa, Takayuki; O'Brien, Timothy D; Rizzari, Michael D; Karatzas, Theodore; Jie, Tun; Sutherland, David E R; Hering, Bernhard J; Papas, Klearchos K

2014-01-01

Porcine islet xenotransplantation is a promising alternative to human islet allotransplantation. Porcine pancreas cooling needs to be optimized to reduce the warm ischemia time (WIT) following donation after cardiac death, which is associated with poorer islet isolation outcomes. This study examines the effect of four different cooling Methods on core porcine pancreas temperature (n = 24) and histopathology (n = 16). All Methods involved surface cooling with crushed ice and chilled irrigation. Method A, which is the standard for porcine pancreas procurement, used only surface cooling. Method B involved an intravascular flush with cold solution through the pancreas arterial system. Method C involved an intraductal infusion with cold solution through the major pancreatic duct, and Method D combined all three cooling Methods. Surface cooling alone (Method A) gradually decreased core pancreas temperature to <10 °C after 30 min. Using an intravascular flush (Method B) improved cooling during the entire duration of procurement, but incorporating an intraductal infusion (Method C) rapidly reduced core temperature 15-20 °C within the first 2 min of cooling. Combining all methods (Method D) was the most effective at rapidly reducing temperature and providing sustained cooling throughout the duration of procurement, although the recorded WIT was not different between Methods (P = 0.36). Histological scores were different between the cooling Methods (P = 0.02) and the worst with Method A. There were differences in histological scores between Methods A and C (P = 0.02) and Methods A and D (P = 0.02), but not between Methods C and D (P = 0.95), which may highlight the importance of early cooling using an intraductal infusion. In conclusion, surface cooling alone cannot rapidly cool large (porcine or human) pancreata. Additional cooling with an intravascular flush and intraductal infusion results in improved core porcine pancreas temperature profiles during procurement and histopathology scores. These data may also have implications on human pancreas procurement as use of an intraductal infusion is not common practice. © 2014 John Wiley & Sons A/S Published by John Wiley & Sons Ltd.

System and method employing a minimum distance and a load feature database to identify electric load types of different electric loads

DOEpatents

Lu, Bin; Yang, Yi; Sharma, Santosh K; Zambare, Prachi; Madane, Mayura A

2014-12-23

A method identifies electric load types of a plurality of different electric loads. The method includes providing a load feature database of a plurality of different electric load types, each of the different electric load types including a first load feature vector having at least four different load features; sensing a voltage signal and a current signal for each of the different electric loads; determining a second load feature vector comprising at least four different load features from the sensed voltage signal and the sensed current signal for a corresponding one of the different electric loads; and identifying by a processor one of the different electric load types by determining a minimum distance of the second load feature vector to the first load feature vector of the different electric load types of the load feature database.

A simple and rapid method for preparing the whole section of starchy seed to investigate the morphology and distribution of starch in different regions of seed.

PubMed

Zhao, Lingxiao; Pan, Ting; Guo, Dongwei; Wei, Cunxu

2018-01-01

Storage starch in starchy seed influences the seed weight and texture, and determines its applications in food and nonfood industries. Starch granules from different plant sources have significantly different shapes and sizes, and even more the difference exists in the different regions of the same tissue. Therefore, it is very important to in situ investigate the morphology and distribution of starch in the whole seed. However, a simple and rapid method is deficient to prepare the whole section of starchy seed for investigating the morphology and distribution of starch in the whole seeds for a large number of samples. A simple and rapid method was established to prepare the whole section of starchy seed, especially for floury seed, in this study. The whole seeds of translucent and chalky rice, vitreous and floury maize, and normal barley and wheat were sectioned successfully using the newly established method. The iodine-stained section clearly exhibited the shapes and size of starch granules in different regions of seed. The starch granules with different morphologies and iodine-staining colors existed regionally in the seeds of high-amylose rice and maize. The sections of lotus and kidney bean seeds also showed the feasibility of this method for starchy non-cereal seeds. The simple and rapid method was proven effective for preparing the whole sections of starchy seeds. The whole section of seed could be used to investigate the morphology and distribution of starch granules in different regions of the whole seed. The method was especially suitable for large sample numbers to investigate the starch morphology in short time.

Energy stable and high-order-accurate finite difference methods on staggered grids

NASA Astrophysics Data System (ADS)

O'Reilly, Ossian; Lundquist, Tomas; Dunham, Eric M.; Nordström, Jan

2017-10-01

For wave propagation over distances of many wavelengths, high-order finite difference methods on staggered grids are widely used due to their excellent dispersion properties. However, the enforcement of boundary conditions in a stable manner and treatment of interface problems with discontinuous coefficients usually pose many challenges. In this work, we construct a provably stable and high-order-accurate finite difference method on staggered grids that can be applied to a broad class of boundary and interface problems. The staggered grid difference operators are in summation-by-parts form and when combined with a weak enforcement of the boundary conditions, lead to an energy stable method on multiblock grids. The general applicability of the method is demonstrated by simulating an explosive acoustic source, generating waves reflecting against a free surface and material discontinuity.

Shear Strength of Remoulding Clay Samples Using Different Methods of Moulding

NASA Astrophysics Data System (ADS)

Norhaliza, W.; Ismail, B.; Azhar, A. T. S.; Nurul, N. J.

2016-07-01

Shear strength for clay soil was required to determine the soil stability. Clay was known as a soil with complex natural formations and very difficult to obtain undisturbed samples at the site. The aim of this paper was to determine the unconfined shear strength of remoulded clay on different methods in moulding samples which were proctor compaction, hand operated soil compacter and miniature mould methods. All the samples were remoulded with the same optimum moisture content (OMC) and density that were 18% and 1880 kg/m3 respectively. The unconfined shear strength results of remoulding clay soils for proctor compaction method was 289.56kPa with the strain 4.8%, hand operated method was 261.66kPa with the strain 4.4% and miniature mould method was 247.52kPa with the strain 3.9%. Based on the proctor compaction method, the reduction percentage of unconfined shear strength of remoulded clay soil of hand operated method was 9.66%, and for miniature mould method was 14.52%. Thus, because there was no significant difference of reduction percentage of unconfined shear strength between three different methods, so it can be concluded that remoulding clay by hand operated method and miniature mould method were accepted and suggested to perform remoulding clay samples by other future researcher. However for comparison, the hand operated method was more suitable to form remoulded clay sample in term of easiness, saving time and less energy for unconfined shear strength determination purposes.

Assessing the stock market volatility for different sectors in Malaysia by using standard deviation and EWMA methods

NASA Astrophysics Data System (ADS)

Saad, Shakila; Ahmad, Noryati; Jaffar, Maheran Mohd

2017-11-01

Nowadays, the study on volatility concept especially in stock market has gained so much attention from a group of people engaged in financial and economic sectors. The applications of volatility concept in financial economics can be seen in valuation of option pricing, estimation of financial derivatives, hedging the investment risk and etc. There are various ways to measure the volatility value. However for this study, two methods are used; the simple standard deviation and Exponentially Weighted Moving Average (EWMA). The focus of this study is to measure the volatility on three different sectors of business in Malaysia, called primary, secondary and tertiary by using both methods. The daily and annual volatilities of different business sector based on stock prices for the period of 1 January 2014 to December 2014 have been calculated in this study. Result shows that different patterns of the closing stock prices and return give different volatility values when calculating using simple method and EWMA method.

[An attempt for standardization of serum CA19-9 levels, in order to dissolve the gap between three different methods].

PubMed

Hayashi, Kuniki; Hoshino, Tadashi; Yanai, Mitsuru; Tsuchiya, Tatsuyuki; Kumasaka, Kazunari; Kawano, Kinya

2004-06-01

It is well known that serious method-related differences exist in results of serum CA19-9, and the necessity of standardization has been pointed out. In this study, differences of serum tumor marker CA19-9 levels obtained by various immunoassay kits (CLEIA, FEIA, LPIA and RIA) were evaluated in sixty-seven clinical samples and five calibrators and the possibility to improve the inter-methodological differences were observed not only for clinical samples but also for calibrators. We supposed an assumed standard material using by a calibrator. We calculated the serum levels of CA19-9 when using the assumed standard material for three different measurement methods. We approximate the CA19-9 values using by this method. It is suggested that the obtained CA19-9 values could be approximated by recalculation with the assumed standard material would be able to correct between-method and between-laboratory discrepancies in particular systematic errors.

Standardised Benchmarking in the Quest for Orthologs

PubMed Central

Altenhoff, Adrian M.; Boeckmann, Brigitte; Capella-Gutierrez, Salvador; Dalquen, Daniel A.; DeLuca, Todd; Forslund, Kristoffer; Huerta-Cepas, Jaime; Linard, Benjamin; Pereira, Cécile; Pryszcz, Leszek P.; Schreiber, Fabian; Sousa da Silva, Alan; Szklarczyk, Damian; Train, Clément-Marie; Bork, Peer; Lecompte, Odile; von Mering, Christian; Xenarios, Ioannis; Sjölander, Kimmen; Juhl Jensen, Lars; Martin, Maria J.; Muffato, Matthieu; Gabaldón, Toni; Lewis, Suzanna E.; Thomas, Paul D.; Sonnhammer, Erik; Dessimoz, Christophe

2016-01-01

The identification of evolutionarily related genes across different species—orthologs in particular—forms the backbone of many comparative, evolutionary, and functional genomic analyses. Achieving high accuracy in orthology inference is thus essential. Yet the true evolutionary history of genes, required to ascertain orthology, is generally unknown. Furthermore, orthologs are used for very different applications across different phyla, with different requirements in terms of the precision-recall trade-off. As a result, assessing the performance of orthology inference methods remains difficult for both users and method developers. Here, we present a community effort to establish standards in orthology benchmarking and facilitate orthology benchmarking through an automated web-based service (http://orthology.benchmarkservice.org). Using this new service, we characterise the performance of 15 well-established orthology inference methods and resources on a battery of 20 different benchmarks. Standardised benchmarking provides a way for users to identify the most effective methods for the problem at hand, sets a minimal requirement for new tools and resources, and guides the development of more accurate orthology inference methods. PMID:27043882

A probabilistic method for testing and estimating selection differences between populations

PubMed Central

He, Yungang; Wang, Minxian; Huang, Xin; Li, Ran; Xu, Hongyang; Xu, Shuhua; Jin, Li

2015-01-01

Human populations around the world encounter various environmental challenges and, consequently, develop genetic adaptations to different selection forces. Identifying the differences in natural selection between populations is critical for understanding the roles of specific genetic variants in evolutionary adaptation. Although numerous methods have been developed to detect genetic loci under recent directional selection, a probabilistic solution for testing and quantifying selection differences between populations is lacking. Here we report the development of a probabilistic method for testing and estimating selection differences between populations. By use of a probabilistic model of genetic drift and selection, we showed that logarithm odds ratios of allele frequencies provide estimates of the differences in selection coefficients between populations. The estimates approximate a normal distribution, and variance can be estimated using genome-wide variants. This allows us to quantify differences in selection coefficients and to determine the confidence intervals of the estimate. Our work also revealed the link between genetic association testing and hypothesis testing of selection differences. It therefore supplies a solution for hypothesis testing of selection differences. This method was applied to a genome-wide data analysis of Han and Tibetan populations. The results confirmed that both the EPAS1 and EGLN1 genes are under statistically different selection in Han and Tibetan populations. We further estimated differences in the selection coefficients for genetic variants involved in melanin formation and determined their confidence intervals between continental population groups. Application of the method to empirical data demonstrated the outstanding capability of this novel approach for testing and quantifying differences in natural selection. PMID:26463656

78 FR 9 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-02

... AD adds repetitive inspections for cracking using different inspection methods and inspecting... cracking using different inspection methods and would inspect additional areas, and corrective actions if... an acceptable method for accomplishing the inspections in areas covered by non-terminating repairs as...

Educating Instructional Designers: Different Methods for Different Outcomes.

ERIC Educational Resources Information Center

Rowland, Gordon; And Others

1994-01-01

Suggests new methods of teaching instructional design based on literature reviews of other design fields including engineering, architecture, interior design, media design, and medicine. Methods discussed include public presentations, visiting experts, competitions, artifacts, case studies, design studios, and internships and apprenticeships.…

New non-invasive safe, quick, economical method of detecting various cancers was found using QRS complex or rising part of T-wave of recorded ECGs. Cancers can be screened along with their biochemical parameters & therapeutic effects of any cancer treatments can be evaluated using recorded ECGs of the same individual.

PubMed

Omura, Yoshiaki; Lu, Dominic; O'Young, Brian; Jones, Marilyn; Nihrane, Abdallah; Duvvi, Harsha; Shimotsuura, Yasuhiro; Ohki, Motomu

2015-01-01

There are many methods of detecting cancers including detection of cancer markers by blood test, (which is invasive, time consuming and relatively expensive), detection of cancers by non-invasive methods such as X-Ray, CT scan, and MRI & PET Scan (which are non-invasive and quick but very expensive). Our research was performed to develop new non-invasive, safe, quick economical method of detecting cancers and the 1st author already developed for clinically important non-invasive new methods including early stage of present method using his method of localizing accurate organ representation areas of face, eyebrows, upper lip, lower lip, surface and dorsal part of the tongue, surface backs, and palm side of the hands. This accurate localization of the organ representation area of the different parts of the body was performed using electromagnetic field resonance phenomenon between 2 identical molecules or tissues based on our US patented non-invasive method in 1993. Since year 2000, we developed the following non-invasive diagnostic methods that can be quickly identified by the patented simple non-invasive method without using expensive or bulky instrument at any office or field where there is no electricity or instrument available. The following are examples of non-invasive quick method of diagnosis and treatment of cancers using different approaches: 1) Soft red laser beam scanning of different parts of body; 2) By speaking voice; 3) Visible and invisible characteristic abnormalities on different organ representation areas of the different parts of the body, and 4) Mouth, Hand, and Foot Writings of both right and left side of the body. As a consequence of our latest research, we were able to develop a simple method of detecting cancer from existing recorded electrocardiograms. In this article, we are going to describe the method and result of clinical applications on many different cancers of different organs including lung, esophagus, breast, stomach, colon, uterus, ovary, prostate gland, as well as common bone marrow related malignancies such as Hodgkin's Lymphoma, Non-Hodgkin's Lymphoma, Multiple Myeloma as well as Leukemia.

Laboratory based instruction in Pakistan: Comparative evaluation of three laboratory instruction methods in biological science at higher secondary school level

NASA Astrophysics Data System (ADS)

Cheema, Tabinda Shahid

This study of laboratory based instruction at higher secondary school level was an attempt to gain some insight into the effectiveness of three laboratory instruction methods: cooperative group instruction method, individualised instruction method and lecture demonstration method on biology achievement and retention. A Randomised subjects, Pre-test Post-test Comparative Methods Design was applied. Three groups of students from a year 11 class in Pakistan conducted experiments using the different laboratory instruction methods. Pre-tests, achievement tests after the experiments and retention tests one month later were administered. Results showed no significant difference between the groups on total achievement and retention, nor was there any significant difference on knowledge and comprehension test scores or skills performance. Future research investigating a similar problem is suggested.

Chemometrics Methods for Specificity, Authenticity and Traceability Analysis of Olive Oils: Principles, Classifications and Applications

PubMed Central

Messai, Habib; Farman, Muhammad; Sarraj-Laabidi, Abir; Hammami-Semmar, Asma; Semmar, Nabil

2016-01-01

Background. Olive oils (OOs) show high chemical variability due to several factors of genetic, environmental and anthropic types. Genetic and environmental factors are responsible for natural compositions and polymorphic diversification resulting in different varietal patterns and phenotypes. Anthropic factors, however, are at the origin of different blends’ preparation leading to normative, labelled or adulterated commercial products. Control of complex OO samples requires their (i) characterization by specific markers; (ii) authentication by fingerprint patterns; and (iii) monitoring by traceability analysis. Methods. These quality control and management aims require the use of several multivariate statistical tools: specificity highlighting requires ordination methods; authentication checking calls for classification and pattern recognition methods; traceability analysis implies the use of network-based approaches able to separate or extract mixed information and memorized signals from complex matrices. Results. This chapter presents a review of different chemometrics methods applied for the control of OO variability from metabolic and physical-chemical measured characteristics. The different chemometrics methods are illustrated by different study cases on monovarietal and blended OO originated from different countries. Conclusion. Chemometrics tools offer multiple ways for quantitative evaluations and qualitative control of complex chemical variability of OO in relation to several intrinsic and extrinsic factors. PMID:28231172

Research on the Calculation Method of Optical Path Difference of the Shanghai Tian Ma Telescope

NASA Astrophysics Data System (ADS)

Dong, J.; Fu, L.; Jiang, Y. B.; Liu, Q. H.; Gou, W.; Yan, F.

2016-03-01

Based on the Shanghai Tian Ma Telescope (TM), an optical path difference calculation method of the shaped Cassegrain antenna is presented in the paper. Firstly, the mathematical model of the TM optics is established based on the antenna reciprocity theorem. Secondly, the TM sub-reflector and main reflector are fitted by the Non-Uniform Rational B-Splines (NURBS). Finally, the method of optical path difference calculation is implemented, and the expanding application of the Ruze optical path difference formulas in the TM is researched. The method can be used to calculate the optical path difference distributions across the aperture field of the TM due to misalignment like the axial and lateral displacements of the feed and sub-reflector, or the tilt of the sub-reflector. When the misalignment quantity is small, the expanding Ruze optical path difference formulas can be used to calculate the optical path difference quickly. The paper supports the real-time measurement and adjustment of the TM structure. The research has universality, and can provide reference for the optical path difference calculation of other radio telescopes with shaped surfaces.

Assessment of four methods to estimate surface UV radiation using satellite data, by comparison with ground measurements from four stations in Europe

NASA Astrophysics Data System (ADS)

Arola, Antti; Kalliskota, S.; den Outer, P. N.; Edvardsen, K.; Hansen, G.; Koskela, T.; Martin, T. J.; Matthijsen, J.; Meerkoetter, R.; Peeters, P.; Seckmeyer, G.; Simon, P. C.; Slaper, H.; Taalas, P.; Verdebout, J.

2002-08-01

Four different satellite-UV mapping methods are assessed by comparing them against ground-based measurements. The study includes most of the variability found in geographical, meteorological and atmospheric conditions. Three of the methods did not show any significant systematic bias, except during snow cover. The mean difference (bias) in daily doses for the Rijksinstituut voor Volksgezondheid en Milieu (RIVM) and Joint Research Centre (JRC) methods was found to be less than 10% with a RMS difference of the order of 30%. The Deutsches Zentrum für Luft- und Raumfahrt (DLR) method was assessed for a few selected months, and the accuracy was similar to the RIVM and JRC methods. It was additionally used to demonstrate how spatial averaging of high-resolution cloud data improves the estimation of UV daily doses. For the Institut d'Aéronomie Spatiale de Belgique (IASB) method the differences were somewhat higher, because of their original cloud algorithm. The mean difference in daily doses for IASB was about 30% or more, depending on the station, while the RMS difference was about 60%. The cloud algorithm of IASB has been replaced recently, and as a result the accuracy of the IASB method has improved. Evidence is found that further research and development should focus on the improvement of the cloud parameterization. Estimation of daily exposures is likely to be improved if additional time-resolved cloudiness information is available for the satellite-based methods. It is also demonstrated that further development work should be carried out on the treatment of albedo of snow-covered surfaces.

A comparison of five approaches to measurement of anatomic knee alignment from radiographs.

PubMed

McDaniel, G; Mitchell, K L; Charles, C; Kraus, V B

2010-02-01

The recent recognition of the correlation of the hip-knee-ankle angle (HKA) with femur-tibia angle (FTA) on a standard knee radiograph has led to the increasing inclusion of FTA assessments in OA studies due to its clinical relevance, cost effectiveness and minimal radiation exposure. Our goal was to investigate the performance metrics of currently used methods of FTA measurement to determine whether a specific protocol could be recommended based on these results. Inter- and intra-rater reliability of FTA measurements were determined by intraclass correlation coefficient (ICC) of two independent analysts. Minimal detectable differences were determined and the correlation of FTA and HKA was analyzed by linear regression. Differences among methods of measuring HKA were assessed by ANOVA. All five methods of FTA measurement demonstrated high precision by inter- and intra-rater reproducibility (ICCs>or=0.93). All five methods displayed good accuracy, but after correction for the offset of FTA from HKA, the femoral notch landmark method was the least accurate. However, the methods differed according to their minimal detectable differences; the FTA methods utilizing the center of the base of the tibial spines or the center of the tibial plateau as knee center landmarks yielded the smallest minimal detectable differences (1.25 degrees and 1.72 degrees, respectively). All methods of FTA were highly reproducible, but varied in their accuracy and sensitivity to detect meaningful differences. Based on these parameters we recommend standardizing measurement angles with vertices at the base of the tibial spines or the center of the tibia and comparing single-point and two-point methods in larger studies. Copyright 2009 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Stochastic rainfall synthesis for urban applications using different regionalization methods

NASA Astrophysics Data System (ADS)

Callau Poduje, A. C.; Leimbach, S.; Haberlandt, U.

2017-12-01

The proper design and efficient operation of urban drainage systems require long and continuous rainfall series in a high temporal resolution. Unfortunately, these time series are usually available in a few locations and it is therefore suitable to develop a stochastic precipitation model to generate rainfall in locations without observations. The model presented is based on an alternating renewal process and involves an external and an internal structure. The members of these structures are described by probability distributions which are site specific. Different regionalization methods based on site descriptors are presented which are used for estimating the distributions for locations without observations. Regional frequency analysis, multiple linear regressions and a vine-copula method are applied for this purpose. An area located in the north-west of Germany is used to compare the different methods and involves a total of 81 stations with 5 min rainfall records. The site descriptors include information available for the whole region: position, topography and hydrometeorologic characteristics which are estimated from long term observations. The methods are compared directly by cross validation of different rainfall statistics. Given that the model is stochastic the evaluation is performed based on ensembles of many long synthetic time series which are compared with observed ones. The performance is as well indirectly evaluated by setting up a fictional urban hydrological system to test the capability of the different methods regarding flooding and overflow characteristics. The results show a good representation of the seasonal variability and good performance in reproducing the sample statistics of the rainfall characteristics. The copula based method shows to be the most robust of the three methods. Advantages and disadvantages of the different methods are presented and discussed.

Evaluation of Four Methods for Predicting Carbon Stocks of Korean Pine Plantations in Heilongjiang Province, China

PubMed Central

Gao, Huilin; Dong, Lihu; Li, Fengri; Zhang, Lianjun

2015-01-01

A total of 89 trees of Korean pine (Pinus koraiensis) were destructively sampled from the plantations in Heilongjiang Province, P.R. China. The sample trees were measured and calculated for the biomass and carbon stocks of tree components (i.e., stem, branch, foliage and root). Both compatible biomass and carbon stock models were developed with the total biomass and total carbon stocks as the constraints, respectively. Four methods were used to evaluate the carbon stocks of tree components. The first method predicted carbon stocks directly by the compatible carbon stocks models (Method 1). The other three methods indirectly predicted the carbon stocks in two steps: (1) estimating the biomass by the compatible biomass models, and (2) multiplying the estimated biomass by three different carbon conversion factors (i.e., carbon conversion factor 0.5 (Method 2), average carbon concentration of the sample trees (Method 3), and average carbon concentration of each tree component (Method 4)). The prediction errors of estimating the carbon stocks were compared and tested for the differences between the four methods. The results showed that the compatible biomass and carbon models with tree diameter (D) as the sole independent variable performed well so that Method 1 was the best method for predicting the carbon stocks of tree components and total. There were significant differences among the four methods for the carbon stock of stem. Method 2 produced the largest error, especially for stem and total. Methods 3 and Method 4 were slightly worse than Method 1, but the differences were not statistically significant. In practice, the indirect method using the mean carbon concentration of individual trees was sufficient to obtain accurate carbon stocks estimation if carbon stocks models are not available. PMID:26659257

Comparative study between recent methods manipulating ratio spectra and classical methods based on two-wavelength selection for the determination of binary mixture of antazoline hydrochloride and tetryzoline hydrochloride.

PubMed

Abdel-Halim, Lamia M; Abd-El Rahman, Mohamed K; Ramadan, Nesrin K; El Sanabary, Hoda F A; Salem, Maissa Y

2016-04-15

A comparative study was developed between two classical spectrophotometric methods (dual wavelength method and Vierordt's method) and two recent methods manipulating ratio spectra (ratio difference method and first derivative of ratio spectra method) for simultaneous determination of Antazoline hydrochloride (AN) and Tetryzoline hydrochloride (TZ) in their combined pharmaceutical formulation and in the presence of benzalkonium chloride as a preservative without preliminary separation. The dual wavelength method depends on choosing two wavelengths for each drug in a way so that the difference in absorbance at those two wavelengths is zero for the other drug. While Vierordt's method, is based upon measuring the absorbance and the absorptivity values of the two drugs at their λ(max) (248.0 and 219.0 nm for AN and TZ, respectively), followed by substitution in the corresponding Vierordt's equation. Recent methods manipulating ratio spectra depend on either measuring the difference in amplitudes of ratio spectra between 255.5 and 269.5 nm for AN and 220.0 and 273.0 nm for TZ in case of ratio difference method or computing first derivative of the ratio spectra for each drug then measuring the peak amplitude at 250.0 nm for AN and at 224.0 nm for TZ in case of first derivative of ratio spectrophotometry. The specificity of the developed methods was investigated by analyzing different laboratory prepared mixtures of the two drugs. All methods were applied successfully for the determination of the selected drugs in their combined dosage form proving that the classical spectrophotometric methods can still be used successfully in analysis of binary mixture using minimal data manipulation rather than recent methods which require relatively more steps. Furthermore, validation of the proposed methods was performed according to ICH guidelines; accuracy, precision and repeatability are found to be within the acceptable limits. Statistical studies showed that the methods can be competitively applied in quality control laboratories. Copyright © 2016 Elsevier B.V. All rights reserved.

Vulnerability to cavitation in Olea europaea current-year shoots: further evidence of an open-vessel artifact associated with centrifuge and air-injection techniques.

PubMed

Torres-Ruiz, José M; Cochard, Hervé; Mayr, Stefan; Beikircher, Barbara; Diaz-Espejo, Antonio; Rodriguez-Dominguez, Celia M; Badel, Eric; Fernández, José Enrique

2014-11-01

Different methods have been devised to analyze vulnerability to cavitation of plants. Although a good agreement between them is usually found, some discrepancies have been reported when measuring samples from long-vesseled species. The aim of this study was to evaluate possible artifacts derived from different methods and sample sizes. Current-year shoot segments of mature olive trees (Olea europaea), a long-vesseled species, were used to generate vulnerability curves (VCs) by bench dehydration, pressure collar and both static- and flow-centrifuge methods. For the latter, two different rotors were used to test possible effects of the rotor design on the curves. Indeed, high-resolution computed tomography (HRCT) images were used to evaluate the functional status of xylem at different water potentials. Measurements of native embolism were used to validate the methods used. The pressure collar and the two centrifugal methods showed greater vulnerability to cavitation than the dehydration method. The shift in vulnerability thresholds in centrifuge methods was more pronounced in shorter samples, supporting the open-vessel artifact hypothesis as a higher proportion of vessels were open in short samples. The two different rotor designs used for the flow-centrifuge method revealed similar vulnerability to cavitation. Only the bench dehydration or HRCT methods produced VCs that agreed with native levels of embolism and water potential values measured in the field. © 2014 Scandinavian Plant Physiology Society.

A factorial design experiment as a pilot study for noninvasive genetic sampling.

PubMed

Renan, Sharon; Speyer, Edith; Shahar, Naama; Gueta, Tomer; Templeton, Alan R; Bar-David, Shirli

2012-11-01

Noninvasive genetic sampling has increasingly been used in ecological and conservation studies during the last decade. A major part of the noninvasive genetic literature is dedicated to the search for optimal protocols, by comparing different methods of collection, preservation and extraction of DNA from noninvasive materials. However, the lack of quantitative comparisons among these studies and the possibility that different methods are optimal for different systems make it difficult to decide which protocol to use. Moreover, most studies that have compared different methods focused on a single factor - collection, preservation or extraction - while there could be interactions between these factors. We designed a factorial experiment, as a pilot study, aimed at exploring the effect of several collection, preservation and extraction methods, and the interactions between them, on the quality and amplification success of DNA obtained from Asiatic wild ass (Equus hemionus) faeces in Israel. The amplification success rates of one mitochondrial DNA and four microsatellite markers differed substantially as a function of collection, preservation and extraction methods and their interactions. The most efficient combination for our system integrated the use of swabs as a collection method with preservation at -20 °C and with the Qiagen DNA Stool Kit with modifications as the DNA extraction method. The significant interaction found between the collection, preservation methods and the extraction methods reinforces the importance of conducting a factorial design experiment, rather than examining each factor separately, as a pilot study before initiating a full-scale noninvasive research project. © 2012 Blackwell Publishing Ltd.

Statistical evaluation of fatty acid profile and cholesterol content in fish (common carp) lipids obtained by different sample preparation procedures.

PubMed

Spiric, Aurelija; Trbovic, Dejana; Vranic, Danijela; Djinovic, Jasna; Petronijevic, Radivoj; Matekalo-Sverak, Vesna

2010-07-05

Studies performed on lipid extraction from animal and fish tissues do not provide information on its influence on fatty acid composition of the extracted lipids as well as on cholesterol content. Data presented in this paper indicate the impact of extraction procedures on fatty acid profile of fish lipids extracted by the modified Soxhlet and ASE (accelerated solvent extraction) procedure. Cholesterol was also determined by direct saponification method, too. Student's paired t-test used for comparison of the total fat content in carp fish population obtained by two extraction methods shows that differences between values of the total fat content determined by ASE and modified Soxhlet method are not statistically significant. Values obtained by three different methods (direct saponification, ASE and modified Soxhlet method), used for determination of cholesterol content in carp, were compared by one-way analysis of variance (ANOVA). The obtained results show that modified Soxhlet method gives results which differ significantly from the results obtained by direct saponification and ASE method. However the results obtained by direct saponification and ASE method do not differ significantly from each other. The highest quantities for cholesterol (37.65 to 65.44 mg/100 g) in the analyzed fish muscle were obtained by applying direct saponification method, as less destructive one, followed by ASE (34.16 to 52.60 mg/100 g) and modified Soxhlet extraction method (10.73 to 30.83 mg/100 g). Modified Soxhlet method for extraction of fish lipids gives higher values for n-6 fatty acids than ASE method (t(paired)=3.22 t(c)=2.36), while there is no statistically significant difference in the n-3 content levels between the methods (t(paired)=1.31). The UNSFA/SFA ratio obtained by using modified Soxhlet method is also higher than the ratio obtained using ASE method (t(paired)=4.88 t(c)=2.36). Results of Principal Component Analysis (PCA) showed that the highest positive impact to the second principal component (PC2) is recorded by C18:3 n-3, and C20:3 n-6, being present in a higher amount in the samples treated by the modified Soxhlet extraction, while C22:5 n-3, C20:3 n-3, C22:1 and C20:4, C16 and C18 negatively influence the score values of the PC2, showing significantly increased level in the samples treated by ASE method. Hotelling's paired T-square test used on the first three principal components for confirmation of differences in individual fatty acid content obtained by ASE and Soxhlet method in carp muscle showed statistically significant difference between these two data sets (T(2)=161.308, p<0.001). Copyright 2010 Elsevier B.V. All rights reserved.

High order spectral difference lattice Boltzmann method for incompressible hydrodynamics

NASA Astrophysics Data System (ADS)

Li, Weidong

2017-09-01

This work presents a lattice Boltzmann equation (LBE) based high order spectral difference method for incompressible flows. In the present method, the spectral difference (SD) method is adopted to discretize the convection and collision term of the LBE to obtain high order (≥3) accuracy. Because the SD scheme represents the solution as cell local polynomials and the solution polynomials have good tensor-product property, the present spectral difference lattice Boltzmann method (SD-LBM) can be implemented on arbitrary unstructured quadrilateral meshes for effective and efficient treatment of complex geometries. Thanks to only first oder PDEs involved in the LBE, no special techniques, such as hybridizable discontinuous Galerkin method (HDG), local discontinuous Galerkin method (LDG) and so on, are needed to discrete diffusion term, and thus, it simplifies the algorithm and implementation of the high order spectral difference method for simulating viscous flows. The proposed SD-LBM is validated with four incompressible flow benchmarks in two-dimensions: (a) the Poiseuille flow driven by a constant body force; (b) the lid-driven cavity flow without singularity at the two top corners-Burggraf flow; and (c) the unsteady Taylor-Green vortex flow; (d) the Blasius boundary-layer flow past a flat plate. Computational results are compared with analytical solutions of these cases and convergence studies of these cases are also given. The designed accuracy of the proposed SD-LBM is clearly verified.

The legal aspects of parental rights in assisted reproductive technology.

PubMed

Ciccarelli, John K; Ciccarelli, Janice C

2005-03-01

This paper provides an overview of the different legal approaches that are used in various jurisdictions to determine parental rights and obligations of the parties involved in third party assisted reproduction. Additionally, the paper explores the differing legal models that are used depending on the method of surrogacy being utilized. The data demonstrates that a given method of surrogacy may well result in different procedures and outcomes regarding parental rights in different jurisdictions. This suggests the need for a uniform method to resolve parental rights where assisted reproductive technology is involved.

20170824 - Enhancing the Application of Alternative Methods Through Global Cooperation (WC10)

EPA Science Inventory

Progress towards the development and translation of alternative testing methods to safety-related decision making is a common goal that crosses organizational, stakeholder, and international boundaries. The challenge is that different organizations have different missions, differ...

Influence of the Extractive Method on the Recovery of Phenolic Compounds in Different Parts of Hymenaea martiana Hayne

PubMed Central

Oliveira, Fernanda Granja da Silva; de Lima-Saraiva, Sarah Raquel Gomes; Oliveira, Ana Paula; Rabêlo, Suzana Vieira; Rolim, Larissa Araújo; Almeida, Jackson Roberto Guedes da Silva

2016-01-01

Background: Popularly known as “jatobá,” Hymenaea martiana Hayne is a medicinal plant widely used in the Brazilian Northeast for the treatment of various diseases. Objective: The aim of this study was to evaluate the influence of different extractive methods in the production of phenolic compounds from different parts of H. martiana. Materials and Methods: The leaves, bark, fruits, and seeds were dried, pulverized, and submitted to maceration, ultrasound, and percolation extractive methods, which were evaluated for yield, visual aspects, qualitative phytochemical screening, phenolic compound content, and total flavonoids. Results: The highest results of yield were obtained from the maceration of the leaves, which may be related to the contact time between the plant drug and solvent. The visual aspects of the extracts presented some differences between the extractive methods. The phytochemical screening showed consistent data with other studies of the genus. Both the vegetal part as the different extractive methods influenced significantly the levels of phenolic compounds, and the highest content was found in the maceration of the barks, even more than the content found previously. No differences between the levels of total flavonoids were significant. The highest concentration of total flavonoids was found in the ultrasound of the barks, followed by maceration on this drug. According to the results, the barks of H. martiana presented the highest total flavonoid contents. Conclusion: The results demonstrate that both the vegetable and the different extractive methods influenced significantly various parameters obtained in the various extracts, demonstrating the importance of systematic comparative studies for the development of pharmaceuticals and cosmetics. SUMMARY The phytochemical screening showed consistent data with other studies of the genus HymenaeaBoth the vegetable part and the different extractive methods influenced significantly various parameters obtained in the various extracts, including the levels of phenolic compoundsThe barks of H. martiana presented the highest total phenolic and flavonoid contents. PMID:27695267

[A clinical study on different decompression methods in cervical spondylosis].

PubMed

Ma, Xun; Zhao, Xiao-fei; Zhao, Yi-bo

2009-04-15

To analyze the different decompression methods to treat cervical spondylosis based on imageological evaluation. Two hundred and sixty three consecutive patients with cervical spondylosis between Nov. 2004 and Oct. 2007 were involved in this study. Patients were distributed to different operation groups based on the preoperative imageological evaluation, including anterior or posterior decompression methods. The Anterior method is to use the discectomy of one to three segments, autogenous iliac graft or titanium mesh or cage fusion and titanium plate fixation, or subtotal vertebrectomy of one to two segments autogenous iliac graft or titanium mesh fusion and titanium plate fixation, or discectomy plus subtotal vertebrectomy, The posterior expansive single open door laminoplasty and other operation types. All the patients were divided into different groups by the preoperative imageological evaluation, age, sex and course of diseases. Then we collected each group's preoperative and postoperative JOA scores and mean improvement rate to evaluate the postoperative effect by different decompression methods. Two hundred and thirty five patients were followed up with a mean period of 18 months (range, 4 to 36 months). JOA scores of all patients were improved by different degrees after operations. Anterior and posterior decompression methods both can achieve higher mean improvement rates. There were no significant differences in mean improvement rates between anterior groups, and so did male and female (P > 0.05). The effect will decrease as age increases or the course of disease prolongs. Statistical significance existed among the different age groups and between course groups (P < 0.05). Anterior and posterior decompression methods both can achieve good effect. The key point is to choose the surgical indication correctly, decompress thoroughly, and make the fusion reliable and fixation firm. In regard to the patients' imageological evaluation, the methods should be differentiated. The anterior operation type included discectomy of one to three segments, subtotal vertebrectomy of one to two segments and discectomy plus subtotal vertebra ectomy.

[The Misgav-Ladach method for cesarean section compared to the Pfannenstiel technique].

PubMed

Studziński, Zbigniew

2002-08-01

The aim of the study was to evaluate the outcome of two different methods of cesarean section. To determine whether the Misgav-Ladach caesarean technique can offer benefits when compared with conventional Pfannenstiel caesarean section technique. This study describes operative details and the postoperative course of 110 patients who underwent caesarean section in May 2000 to December 2000 in Department of Gynecology and Obstetrics in Regional Hospital in Slupsk, Poland. One group (50 women) was operated with the Misgav-Ladach method for caesarean section and the other group (60 women) with Pfannenstiel method. Operating time was significantly different between the two methods, with an average of 20.2 minutes with the Misgav-Ladach method and 47.3 minutes with the Pfannenstiel method (p < 0.001). Time of child delivery was with average 1.1 minutes with the Misgav-Ladach method and 3.8 minutes with the Pfannenstiel method (p < 0.001). The amount of blood loss different significantly, with 336 ml and 483 ml respectively (p < 0.001). No significant difference was found in Apgar scores. No difference was found in overall postoperative complications, wound infection, febrile illness, febrile morbidity, wound dehiscence affected by the new technique. Significantly less suture material was used during Misgav-Ladach caesarean section compared to Pfannenstiel technique (p < 0.001). The Misgav-Ladach method of caesarean section has advantages over the Pfannenstiel technique by being significantly quicker to perform, with the reduced amounts of bleeding and suture material. The women were satisfied with the appearance of their scars. In this study no negative effects of the new operation technique were discovered.

Nonlinear mixed effects dose response modeling in high throughput drug screens: application to melanoma cell line analysis.

PubMed

Ding, Kuan-Fu; Petricoin, Emanuel F; Finlay, Darren; Yin, Hongwei; Hendricks, William P D; Sereduk, Chris; Kiefer, Jeffrey; Sekulic, Aleksandar; LoRusso, Patricia M; Vuori, Kristiina; Trent, Jeffrey M; Schork, Nicholas J

2018-01-12

Cancer cell lines are often used in high throughput drug screens (HTS) to explore the relationship between cell line characteristics and responsiveness to different therapies. Many current analysis methods infer relationships by focusing on one aspect of cell line drug-specific dose-response curves (DRCs), the concentration causing 50% inhibition of a phenotypic endpoint (IC 50 ). Such methods may overlook DRC features and do not simultaneously leverage information about drug response patterns across cell lines, potentially increasing false positive and negative rates in drug response associations. We consider the application of two methods, each rooted in nonlinear mixed effects (NLME) models, that test the relationship relationships between estimated cell line DRCs and factors that might mitigate response. Both methods leverage estimation and testing techniques that consider the simultaneous analysis of different cell lines to draw inferences about any one cell line. One of the methods is designed to provide an omnibus test of the differences between cell line DRCs that is not focused on any one aspect of the DRC (such as the IC 50 value). We simulated different settings and compared the different methods on the simulated data. We also compared the proposed methods against traditional IC 50 -based methods using 40 melanoma cell lines whose transcriptomes, proteomes, and, importantly, BRAF and related mutation profiles were available. Ultimately, we find that the NLME-based methods are more robust, powerful and, for the omnibus test, more flexible, than traditional methods. Their application to the melanoma cell lines reveals insights into factors that may be clinically useful.

Effectiveness of different tutorial recitation teaching methods and its implications for TA training

NASA Astrophysics Data System (ADS)

Koenig, Kathleen M.; Endorf, Robert J.; Braun, Gregory A.

2007-06-01

We present results from a comparative study of student understanding for students who attended recitation classes that used different teaching methods. Student volunteers from our introductory calculus-based physics course attended a special recitation class that was taught using one of four different teaching methods. A total of 272 students were divided into approximately equal groups for each method. Students in each class were taught the same topic, “Changes in Energy and Momentum,” from Tutorials in Introductory Physics. The different teaching methods varied in the amount of student and teacher engagement. Student understanding was evaluated through pre- and post-tests. Our results demonstrate the importance of the instructor’s role in teaching recitation classes. The most effective teaching method was for students working in cooperative learning groups with the instructors questioning the groups using Socratic dialogue. In addition, we investigated student preferences for modes of instruction through an open-ended survey. Our results provide guidance and evidence for the teaching methods that should be emphasized in training course instructors.

A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: Derivative spectrophotometry versus wavelet transform

NASA Astrophysics Data System (ADS)

Salem, Hesham; Lotfy, Hayam M.; Hassan, Nagiba Y.; El-Zeiny, Mohamed B.; Saleh, Sarah S.

2015-01-01

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.

A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: derivative spectrophotometry versus wavelet transform.

PubMed

Salem, Hesham; Lotfy, Hayam M; Hassan, Nagiba Y; El-Zeiny, Mohamed B; Saleh, Sarah S

2015-01-25

This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision. Copyright © 2014 Elsevier B.V. All rights reserved.