Sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease): a clinicoradiological profile of three cases including two with skeletal disease

International Nuclear Information System (INIS)

Gupta, Priya; Babyn, Paul

2008-01-01

Originally described as sinus histiocytosis with massive lymphadenopathy, Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder with a distinctive microscopic appearance. A rare entity, RDD is often under-diagnosed because of a low index of suspicion by both radiologist and pathologist. Through this article, we wish to apprise radiologists of the spectrum of disease that can be encountered in this disorder. RDD can mimic other common childhood skeletal diseases including benign Langerhans cell histiocytosis and lymphoma. The clinical and radiological manifestations of RDD vary depending upon organ involvement, and its imaging features are often confused with those of other disorders. RDD should be considered in the differential diagnosis of unifocal and multifocal skeletal involvement caused by granulomatous diseases, infections, pseudogranulomatous lesions and malignancy. As long-term outcome is usually good, a conservative approach is justified in most cases. Contrasted with its typical appearance, presenting with bilateral symmetrical cervical adenopathy (as shown in one patient), we also report extranodal involvement of bone in two patients. Extranodal disease occurs along with concomitant nodal disease in about 43% of patients. In 23% of patients, isolated extranodal RDD can be seen, most commonly in the head and neck. In two of our patients, we observed extranodal involvement with skeletal involvement away from the head and neck not associated with lymphadenopathy. Skeletal involvement in RDD without lymphadenopathy is rare, occurring only in 2% of all the patients reported to date. (orig.)

The disease related deaths due to differentiated thyroid carcinomas treated multidisciplinary, including radioiodine

International Nuclear Information System (INIS)

Stefanovic, Lj.; Kermeci, K.; Malesevic, M.; Mihailovic, J.; Srbovan, D.; Popadic, S.

2002-01-01

Aim: To analyse the disease related deaths of differentiated thyroid carcinoma (DTC) patients treated multidisciplinary, including radioiodine. Patients and Methods: 364 DTC patients were treated from 1977 to the end of 2000. All patients were operated, treated by radioiodine and by hormonal therapy, external radiotherapy was applied in 22 and chemotherapy in 6 of them. 54 treated patients were lost from the follow-up. The course of disease and outcomes are known in 310 patients, among them 53 patients died. The disease related deaths occurred in 33 (10.6%) patients. Results: Between 33 patients whose deaths were in relation with DTC the disease progression was the cause of deaths in 30 (9.7% of treated) patients (the locoregional disease in 10, distant metastases /M1/ in 17, locoregional disease + M1 in 3 patients). From the late complications of treatment died 3 (1%) patients (all of them were in complete remission to the deaths). The mean survival of these 33 patients from the diagnosis to the end of the life was 6.9 years, median 5.1 years, range 2 months to 23.9 years. The five years survived 54.6% of them, 10 years 21.2% and more than 20 years 3%. M1 had 72.7% of patients (lung and/or bone M1 were present in 91.7% of them), N1 had 69.7% and in 30.3% local tumor was T4. In relation to all treated patients died 14.6% men compared to 9% women (p<0.05), 15.7% of patients 45 years old or older compared to 4.4% of younger then 45 years (p<0.001) and 21.3% of patients with follicular type of DTC compared to 7.3% with papillary type (p<0.001). From all patients without radioiodine accumulation in tumor tissue died 60%. Conclusion: The DTC related deaths were the consequence of M1 and less frequently the result of locoregional disease (T4 and/or N1) in about 1/10 of all treated patients. The deaths as result of the late complications of treatment were exceptional. The deaths were significantly more frequent between males, patients 45 years old or older and patients

Diverticular disease: A therapeutic overview

Science.gov (United States)

Tursi, Antonio

2010-01-01

Formation of colonic diverticula, via herniation of the colonic wall, is responsible for the development of diverticulosis. When diverticulosis becomes symptomatic, it becomes diverticular disease. Diverticular disease is common in Western and industrialized countries, and it is associated with numerous abdominal symptoms (including pain, bloating, nausea, diarrhea, and constipation). Standard medical therapies with antibiotics are currently recommended for patients affected by diverticular disease. However, changing concepts on the pathophysiology of the disease suggest that diverticular disease may share many of the hallmarks of inflammatory bowel diseases. On this basis, the addition of therapies using mesalazine and probiotics may enhance treatment efficacy by shortening the course of the disease and preventing recurrences. PMID:21577292

2D Numerical Modelling of the Resin Injection Pultrusion Process Including Experimental Resin Kinetics and Temperature Validation

DEFF Research Database (Denmark)

Rasmussen, Filip Salling; Sonne, Mads Rostgaard; Larsen, Martin

In the present study, a two-dimensional (2D) transient Eulerian thermo-chemical analysis of a carbon fibre epoxy thermosetting Resin Injection Pultrusion (RIP) process is carried out. The numerical model is implemented using the well known unconditionally stable Alternating Direction Implicit (ADI......) scheme. The total heat of reaction and the cure kinetics of the epoxy thermosetting are determined using Differential Scanning Calorimetry (DSC). A very good agreement is observed between the fitted cure kinetic model and the experimental measurements. The numerical steady state temperature predictions...

Broader prevalence of Wolbachia in insects including potential human disease vectors.

Science.gov (United States)

de Oliveira, C D; Gonçalves, D S; Baton, L A; Shimabukuro, P H F; Carvalho, F D; Moreira, L A

2015-06-01

Wolbachia are intracellular, maternally transmitted bacteria considered the most abundant endosymbionts found in arthropods. They reproductively manipulate their host in order to increase their chances of being transmitted to the offspring, and currently are being used as a tool to control vector-borne diseases. Studies on distribution of Wolbachia among its arthropod hosts are important both for better understanding why this bacterium is so common, as well as for its potential use as a biological control agent. Here, we studied the incidence of Wolbachia in a broad range of insect species, collected from different regions of Brazil, using three genetic markers (16S rRNA, wsp and ftsZ), which varied in terms of their sensitivity to detect this bacterium. The overall incidence of Wolbachia among species belonging to 58 families and 14 orders was 61.9%. The most common positive insect orders were Coleoptera, Diptera, Hemiptera and Hymenoptera, with Diptera and Hemiptera having the highest numbers of Wolbachia-positive families. They included potential human disease vectors whose infection status has never been reported before. Our study further shows the importance of using quantitative polymerase chain reaction for high-throughput and sensitive Wolbachia screening.

[Emerging infectious diseases: complex, unpredictable processes].

Science.gov (United States)

Guégan, Jean-François

2016-01-01

In the light of a double approach, at first empirical, later theoretical and comparative, illustrated by the example of the Buruli ulcer and its mycobacterial agent Mycobacterium ulcerans on which I focused my research activity these last ten years by studying determinants and factors of emerging infectious or parasitic diseases, the complexity of events explaining emerging diseases will be presented. The cascade of events occurring at various levels of spatiotemporal scales and organization of life, which lead to the numerous observed emergences, nowadays requires better taking into account the interactions between host(s), pathogen(s) and the environment by including the behavior of both individuals and the population. In numerous research studies on emerging infectious diseases, microbial hazard is described rather than infectious disease risk, the latter resulting from the confrontation between an association of threatening phenomena, or hazards, and a susceptible population. Beyond, the theme of emerging infectious diseases and its links with global environmental and societal changes leads to reconsider some well-established knowledge in infectiology and parasitology. © Société de Biologie, 2017.

Numerical calculation of electromagnetic properties including chirality parameters for uniaxial bianisotropic media

International Nuclear Information System (INIS)

Amirkhizi, Alireza V; Nemat-Nasser, Sia

2008-01-01

Through the use of conductive straight wires or coils the electromagnetic properties of a composite material can be modified. The asymmetric geometry of the coils creates an overall chiral response. The polarization vectors rotate as an electromagnetic wave travels through such a medium. To calculate the chirality of a medium prior to its manufacturing, we developed a method to extract all four electromagnetic material parameter tensors for a general uniaxial bianisotropic composite based on the numerical simulation of the electromagnetic fields. Our method uses appropriate line and surface field averages in a single unit cell of the periodic structure of the composite material. These overall field quantities have physical meaning only when the microscopic variation of the electromagnetic fields in the scale of the unit cell is not important, that is when the wavelength of interest is significantly larger than the maximum linear dimension of the unit cell. The overall constitutive relations of the periodic structure can then be obtained from the relations among the average quantities

Semi-empirical γ-ray peak efficiency determination including self-absorption correction based on numerical integration

International Nuclear Information System (INIS)

Noguchi, M.; Takeda, K.; Higuchi, H.

1981-01-01

A method of γ-ray efficiency determination for extended (plane or bulk) samples based on numerical integration of point source efficiency is studied. The proposed method is widely applicable to samples of various shapes and materials. The geometrical factor in the peak efficiency can easily be corrected for by simply changing the integration region, and γ-ray self-absorption is also corrected by the absorption coefficients for the sample matrix. (author)

Global stability for infectious disease models that include immigration of infected individuals and delay in the incidence

Directory of Open Access Journals (Sweden)

Chelsea Uggenti

2018-03-01

Full Text Available We begin with a detailed study of a delayed SI model of disease transmission with immigration into both classes. The incidence function allows for a nonlinear dependence on the infected population, including mass action and saturating incidence as special cases. Due to the immigration of infectives, there is no disease-free equilibrium and hence no basic reproduction number. We show there is a unique endemic equilibrium and that this equilibrium is globally asymptotically stable for all parameter values. The results include vector-style delay and latency-style delay. Next, we show that previous global stability results for an SEI model and an SVI model that include immigration of infectives and non-linear incidence but not delay can be extended to systems with vector-style delay and latency-style delay.

Clinicopathological review of immunohistochemically defined Kikuchi-Fujimoto disease-including some interesting cases.

Science.gov (United States)

Seong, Gil Myeong; Kim, Jo-Heon; Lim, Gil Chai; Kim, Jinseok

2012-10-01

Kikuchi-Fujimoto Disease (KFD) is a benign, self-limited disease characterized by tender regional lymphadenopathy with fever. KFD remains a poorly defined disease, and no clear diagnostic criteria are available. Here, we assess the clinical, laboratory, and histopathologic findings of KFD cases and report two unusual cases. Forty KFD patients that underwent lymph node (LN) biopsy and diagnosed by immunohistochemical staining, from January 2003 to November 2010, were enrolled in this retrospective study. The patients had a mean age of 29.3 years, and 29 (72.5 %) were women. Affected LNs were mainly located unilaterally in the cervical area. Mean LN size was 15.3 mm. Twenty-eight (70 %) patients had LN tenderness, and 25 (62.5 %) patients had fever. Leukopenia was observed in 18 of 35 evaluable patients. C-reactive protein and erythrocyte sedimentation rate were elevated in most patients. Anti-nuclear antibody was positive in four of 19 evaluable patients, but all had been diagnosed with concurrent systemic lupus erythematosus. Histologically, the 40 cases were classified into three types, that is, as proliferative (37.5 %), necrotizing (55.0 %), or xanthomatous (7.5 %). Interesting cases: Case 1 was a 35-year-old female with KFD and uveitis, retinal vasculitis, and superior sagittal sinus thrombosis. Case 2 was a 47-year-old male with KFD and bone marrow involvement and presented with severe bicytopenia. Although KFD is an uncommon self-limited benign disorder, it must be included in the differential diagnosis of lymphadenopathy with fever and cytopenia. It is important that the clinical features of KFD be understood to reach a correct diagnosis.

Introduction to precise numerical methods

CERN Document Server

Aberth, Oliver

2007-01-01

Precise numerical analysis may be defined as the study of computer methods for solving mathematical problems either exactly or to prescribed accuracy. This book explains how precise numerical analysis is constructed. The book also provides exercises which illustrate points from the text and references for the methods presented. All disc-based content for this title is now available on the Web. · Clearer, simpler descriptions and explanations ofthe various numerical methods· Two new types of numerical problems; accurately solving partial differential equations with the included software and computing line integrals in the complex plane.

Hip and pelvis diseases on lumbar AP radiographs including both hip joints

Energy Technology Data Exchange (ETDEWEB)

Lim, Hyun Soo; Juhng, Seon Kwan; Kim, Eun A; Kim, Jeong Ho; Song, Ha Heon; Shim, Dae Moo [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

2002-12-01

To determine the frequency of disease, and to evaluate the methods used for lumbar spine radiography in Korea. Sixty university and training hospitals were randomly selected and asked to describe the projections, film size and radiographic techniques employed for routine radiography in patients with suspected disease of the lumbar spine. Plain radiographs of 1215 patients, taken using 14x17 inch film and depicting both hip joints and the lumbar region, were analysed between March 1999 and February 2000. In 15 patients (1.2%), the radiographs revealed hip or pelvic lesion, confirmed as follows: avascular necrosis of the femoral head (n=11, with bilateral lesion in four cases); sustained ankylosing spondylitis (n=2); acetabular dysplasia (n=1); and insufficiency fracture of the pubic rami secondary to osteoporosis (n=1). In 11 or the 20 hospitals which responded, 14{sup x}17{sup f}ilm was being used for lumbar radiography, while in the other nine, film size was smaller. Plain radiography of the lumbar spine including both hip joints, may be a useful way to simultaneously evaluate lesions not only of the lumbar spine but also of the hip and/or pelvis.

A novel method of including Landau level mixing in numerical studies of the quantum Hall effect

International Nuclear Information System (INIS)

Wooten, Rachel; Quinn, John; Macek, Joseph

2013-01-01

Landau level mixing should influence the quantum Hall effect for all except the strongest applied magnetic fields. We propose a simple method for examining the effects of Landau level mixing by incorporating multiple Landau levels into the Haldane pseudopotentials through exact numerical diagonalization. Some of the resulting pseudopotentials for the lowest and first excited Landau levels will be presented

Numerical problems in physics

CERN Document Server

Singh, Devraj

2015-01-01

Numerical Problems in Physics, Volume 1 is intended to serve the need of the students pursuing graduate and post graduate courses in universities with Physics and Materials Science as subject including those appearing in engineering, medical, and civil services entrance examinations. KEY FEATURES: * 29 chapters on Optics, Wave & Oscillations, Electromagnetic Field Theory, Solid State Physics & Modern Physics * 540 solved numerical problems of various universities and ompetitive examinations * 523 multiple choice questions for quick and clear understanding of subject matter * 567 unsolved numerical problems for grasping concepts of the various topic in Physics * 49 Figures for understanding problems and concept

Src family kinases in chronic kidney disease.

Science.gov (United States)

Wang, Jun; Zhuang, Shougang

2017-09-01

Src family kinases (SFKs) belong to nonreceptor protein tyrosine kinases and have been implicated in the regulation of numerous cellular processes, including cell proliferation, differentiation, migration and invasion, and angiogenesis. The role and mechanisms of SFKs in tumorgenesis have been extensively investigated, and some SFK inhibitors are currently under clinical trials for tumor treatment. Recent studies have also demonstrated the importance of SFKs in regulating the development of various fibrosis-related chronic diseases (e.g., idiopathic pulmonary fibrosis, liver fibrosis, renal fibrosis, and systemic sclerosis). In this article, we summarize the roles of SFKs in various chronic kidney diseases, including glomerulonephritis, diabetic nephropathy, human immunodeficiency virus-associated nephropathy, autosomal dominant form of polycystic kidney disease, and obesity-associated kidney disease, and discuss the mechanisms involved. Copyright © 2017 the American Physiological Society.

An introduction to mathematical modeling of infectious diseases

CERN Document Server

Li, Michael Y

2018-01-01

This text provides essential modeling skills and methodology for the study of infectious diseases through a one-semester modeling course or directed individual studies.  The book includes mathematical descriptions of epidemiological concepts, and uses classic epidemic models to introduce different mathematical methods in model analysis.  Matlab codes are also included for numerical implementations. It is primarily written for upper undergraduate and beginning graduate students in mathematical sciences who have an interest in mathematical modeling of infectious diseases.  Although written in a rigorous mathematical manner, the style is not unfriendly to non-mathematicians.

Numerical calculations in quantum field theories

International Nuclear Information System (INIS)

Rebbi, C.

1984-01-01

Four lecture notes are included: (1) motivation for numerical calculations in Quantum Field Theory; (2) numerical simulation methods; (3) Monte Carlo studies of Quantum Chromo Dynamics; and (4) systems with fermions. 23 references

Extracellular Vesicles in Heart Disease: Excitement for the Future?

Directory of Open Access Journals (Sweden)

Kirsty M. Danielson

2014-01-01

Full Text Available Extracellular vesicles (EV, including exosomes, microvesicles and apoptotic bodies, are released from numerous cell types and are involved in intercellular communication, physiological functions and the pathology of disease. They have been shown to carry and transfer a wide range of cargo including proteins, lipids and nucleic acids. The role of EVs in cardiac physiology and heart disease is an emerging field that has produced intriguing findings in recent years. This review will outline what is currently known about EVs in the cardiovascular system, including cellular origins, functional roles and utility as biomarkers and potential therapeutics.

Kikuchi-Fujimoto disease (histiocytic necrotizing lymphadenitis)

International Nuclear Information System (INIS)

Escribano, J.; Ruza, M.; Gonzalez, J.; Acosta, A.

2000-01-01

Kikuchi-Fujimoto's disease is a rare but increasingly frequent cause of cervical adenopathy. It usually affects young women who also present fever and weight loss. ultrasonography and computed tomography of adenopathies usually show findings typical of benign disease (they are numerous, homogeneous, slightly or moderately increased in size, their normal echo structure is unchanged, they are clearly delimited and the surrounding tissues present no alterations, although in a few cases central necrosis has been described). Diagnosis is by ganglion biopsy showing typical findings. The disease is benign and self-limiting and treatment is not required. We believe that the disease should be included in the differential diagnosis of adenopathies, especially cervical adenophathies in young patients. (Author) 14 refs

The Relationship Between Fatty Liver Disease and Periodontal Disease

Science.gov (United States)

2017-03-22

Periodontitis is a highly prevalent and destructive chronic disease. Numerous studies support an association between periodontal disease and other...destruction seen in periodontal disease. The association between the two diseases has never been investigated. A reasonable mechanism in which periodontal ...disease may play a role in the destruction seen in NAFLD is the remote site infection of periodontal disease. Chewing and oral hygiene measures lead to

Rivastigmine in Alzheimer's disease and Parkinson's disease dementia: an ADAS-cog factor analysis.

Science.gov (United States)

Weintraub, Daniel; Somogyi, Monique; Meng, Xiangyi

2011-09-01

Rivastigmine treatment is associated with significant improvements on the cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS-cog) in patients with mild-to-moderate Alzheimer's disease (AD) and Parkinson's disease dementia (PDD). Both AD and PDD are purported to have different profiles of cognitive impairment, which may respond differentially to rivastigmine treatment. This was a retrospective analysis of 3 randomized, double-blind, rivastigmine trial databases (Investigation of transDermal Exelon in ALzheimer's disease [IDEAL; AD], EXelon in PaRkinson's disEaSe dementia Study [EXPRESS; PDD], and Alzheimer's Disease with ENA 713 [ADENA; AD]). Factor analyses of the 11 baseline ADAS-cog items derived the same factors in the 2 diseases, that is, "memory" and "language". Rivastigmine-treated AD and PDD patients showed significant improvements (P < .0001 versus placebo) on both factors. For both AD and PDD, rivastigmine had a numerically greater effect on memory than language. Treatment effect sizes were numerically greater in PDD compared with AD. Rivastigmine treatment is associated with improvement in memory and language in AD and PDD. The numerically greater response in PDD is consistent with greater cholinergic deficits in this disease state.

Numerical methods in software and analysis

CERN Document Server

Rice, John R

1992-01-01

Numerical Methods, Software, and Analysis, Second Edition introduces science and engineering students to the methods, tools, and ideas of numerical computation. Introductory courses in numerical methods face a fundamental problem-there is too little time to learn too much. This text solves that problem by using high-quality mathematical software. In fact, the objective of the text is to present scientific problem solving using standard mathematical software. This book discusses numerous programs and software packages focusing on the IMSL library (including the PROTRAN system) and ACM Algorithm

[Infectious pathology: vulvovaginitis, sexually transmitted diseases, pelvic inflammatory disease, tubo-ovarian abscesses].

Science.gov (United States)

Ibarrola Vidaurre, M; Benito, J; Azcona, B; Zubeldía, N

2009-01-01

Sexually transmitted diseases are those where the principal path of infection is through intimate contact. Numerous patients attend Accidents and emergencies for this reason, both because of the clinical features and because of social implications. The most frequent symptoms are lower abdominal pain, vaginal bleeding or excessive or troubling vaginal flow. Vulvovaginites are one of the principal problems in the everyday clinical practice of gynaecology. A genital ulcer whose principal aetiology is herpes, followed by syphilis and chancroid, increases the risk of contracting HIV infection and alters the course of other sexually transmitted diseases. Inflammatory pelvic disease encompasses infections of the upper female genital tract. The importance of early diagnosis and suitable treatment is both due to the complications in its acute phase and to its sequels, which include chronic pain and sterility.

Genetics of Valvular Heart Disease

Science.gov (United States)

LaHaye, Stephanie; Lincoln, Joy

2015-01-01

Valvular heart disease is associated with significant morbidity and mortality and often the result of congenital malformations. However, the prevalence is increasing in adults not only because of the growing aging population, but also because of improvements in the medical and surgical care of children with congenital heart valve defects. The success of the Human Genome Project and major advances in genetic technologies, in combination with our increased understanding of heart valve development, has led to the discovery of numerous genetic contributors to heart valve disease. These have been uncovered using a variety of approaches including the examination of familial valve disease and genome-wide association studies to investigate sporadic cases. This review will discuss these findings and their implications in the treatment of valvular heart disease. PMID:24743897

Glyphosate, pathways to modern diseases II: Celiac sprue and gluten intolerance

OpenAIRE

Samsel, Anthony; Seneff, Stephanie

2013-01-01

Celiac disease, and, more generally, gluten intolerance, is a growing problem worldwide, but especially in North America and Europe, where an estimated 5% of the population now suffers from it. Symptoms include nausea, diarrhea, skin rashes, macrocytic anemia and depression. It is a multifactorial disease associated with numerous nutritional deficiencies as well as reproductive issues and increased risk to thyroid disease, kidney failure and cancer. Here, we propose that glyphosate, the activ...

Newcastle disease: An in-depth review including epidemiology and molecular diagnostics

Science.gov (United States)

Infections of birds with strains of avian paramyxovirus serotype 1 (APMV-1), (synonyms: Newcastle disease virus (NDV), pigeon PMV-1 (PPMV-1)) are associated with two clinical outcomes: 1) Newcastle disease (ND) results from infections with virulent APMV-1, and is also called Exotic ND (END) in U. S...

Development of orthogonal 2-dimensional numerical code TFC2D for fluid flow with various turbulence models and numerical schemes

Energy Technology Data Exchange (ETDEWEB)

Park, Ju Yeop; In, Wang Kee; Chun, Tae Hyun; Oh, Dong Seok [Korea Atomic Energy Research Institute, Taejeon (Korea)

2000-02-01

The development of orthogonal 2-dimensional numerical code is made. The present code contains 9 kinds of turbulence models that are widely used. They include a standard k-{epsilon} model and 8 kinds of low Reynolds number ones. They also include 6 kinds of numerical schemes including 5 kinds of low order schemes and 1 kind of high order scheme such as QUICK. To verify the present numerical code, pipe flow, channel flow and expansion pipe flow are solved by this code with various options of turbulence models and numerical schemes and the calculated outputs are compared to experimental data. Furthermore, the discretization error that originates from the use of standard k-{epsilon} turbulence model with wall function is much more diminished by introducing a new grid system than a conventional one in the present code. 23 refs., 58 figs., 6 tabs. (Author)

Plants used to treat skin diseases

Science.gov (United States)

Tabassum, Nahida; Hamdani, Mariya

2014-01-01

Skin diseases are numerous and a frequently occurring health problem affecting all ages from the neonates to the elderly and cause harm in number of ways. Maintaining healthy skin is important for a healthy body. Many people may develop skin diseases that affect the skin, including cancer, herpes and cellulitis. Some wild plants and their parts are frequently used to treat these diseases. The use of plants is as old as the mankind. Natural treatment is cheap and claimed to be safe. It is also suitable raw material for production of new synthetic agents. A review of some plants for the treatment of skin diseases is provided that summarizes the recent technical advancements that have taken place in this area during the past 17 years. PMID:24600196

Numerical computations with GPUs

CERN Document Server

Kindratenko, Volodymyr

2014-01-01

This book brings together research on numerical methods adapted for Graphics Processing Units (GPUs). It explains recent efforts to adapt classic numerical methods, including solution of linear equations and FFT, for massively parallel GPU architectures. This volume consolidates recent research and adaptations, covering widely used methods that are at the core of many scientific and engineering computations. Each chapter is written by authors working on a specific group of methods; these leading experts provide mathematical background, parallel algorithms and implementation details leading to

Numerical investigation of a double-junction a:SiGe thin-film solar cell including the multi-trench region

International Nuclear Information System (INIS)

Kacha, K.; Djeffal, F.; Ferhati, H.; Arar, D.; Meguellati, M.

2015-01-01

We present a new approach based on the multi-trench technique to improve the electrical performances, which are the fill factor and the electrical efficiency. The key idea behind this approach is to introduce a new multi-trench region in the intrinsic layer, in order to modulate the total resistance of the solar cell. Based on 2-D numerical investigation and optimization of amorphous SiGe double-junction (a-Si:H/a-SiGe:H) thin film solar cells, in the present paper numerical models of electrical and optical parameters are developed to explain the impact of the multi-trench technique on the improvement of the double-junction solar cell electrical behavior for high performance photovoltaic applications. In this context, electrical characteristics of the proposed design are analyzed and compared with conventional amorphous silicon double-junction thin-film solar cells. (paper)

Prevention of metabolic diseases: fruits (including fruit sugars) vs. vegetables.

Science.gov (United States)

Kuzma, Jessica N; Schmidt, Kelsey A; Kratz, Mario

2017-07-01

To discuss recent evidence from observational and intervention studies on the relationship between fruit and vegetable (F&V) consumption and metabolic disease. Observational studies have consistently demonstrated a modest inverse association between the intake of fruit and leafy green vegetables, but not total vegetables, and biomarkers of metabolic disease as well as incident type 2 diabetes mellitus. This is in contrast to limited evidence from recently published randomized controlled dietary intervention trials, which - in sum - suggests little to no impact of increased F&V consumption on biomarkers of metabolic disease. Evidence from observational studies that fruit and leafy green vegetable intake is associated with lower type 2 diabetes risk and better metabolic health could not be confirmed by dietary intervention trials. It is unclear whether this discrepancy is because of limitations inherent in observational studies (e.g., subjective dietary assessment methods, residual confounding) or due to limitations in the few available intervention studies (e.g., short duration of follow-up, interventions combining whole fruit and fruit juice, or lack of compliance). Future studies that attempt to address these limitations are needed to provide more conclusive insight into the impact of F&V consumption on metabolic health.

Numerical Hydrodynamics in General Relativity

Directory of Open Access Journals (Sweden)

Font José A.

2003-01-01

Full Text Available The current status of numerical solutions for the equations of ideal general relativistic hydrodynamics is reviewed. With respect to an earlier version of the article, the present update provides additional information on numerical schemes, and extends the discussion of astrophysical simulations in general relativistic hydrodynamics. Different formulations of the equations are presented, with special mention of conservative and hyperbolic formulations well-adapted to advanced numerical methods. A large sample of available numerical schemes is discussed, paying particular attention to solution procedures based on schemes exploiting the characteristic structure of the equations through linearized Riemann solvers. A comprehensive summary of astrophysical simulations in strong gravitational fields is presented. These include gravitational collapse, accretion onto black holes, and hydrodynamical evolutions of neutron stars. The material contained in these sections highlights the numerical challenges of various representative simulations. It also follows, to some extent, the chronological development of the field, concerning advances on the formulation of the gravitational field and hydrodynamic equations and the numerical methodology designed to solve them.

Numerical simulation of sand jet in water

Energy Technology Data Exchange (ETDEWEB)

Azimi, A.H.; Zhu, D.; Rajaratnam, N. [Alberta Univ., Edmonton, AB (Canada). Dept. of Civil and Environmental Engineering

2008-07-01

A numerical simulation of sand jet in water was presented. The study involved a two-phase flow using two-phase turbulent jets. A literature review was also presented, including an experiment on particle laden air jet using laser doppler velocimetry (LDV); experiments on the effect of particle size and concentration on solid-gas jets; an experimental study of solid-liquid jets using particle image velocimetry (PIV) technique where mean velocity and fluctuations were measured; and an experimental study on solid-liquid jets using the laser doppler anemometry (LDA) technique measuring both water axial and radial velocities. Other literature review results included a photographic study of sand jets in water; a comparison of many two-phase turbulent flow; and direct numerical simulation and large-eddy simulation to study the effect of particle in gas jet flow. The mathematical model and experimental setup were also included in the presentation along with simulation results for sand jets, concentration, and kinetic energy. The presentation concluded with some proposed future studies including numerical simulation of slurry jets in water and numerical simulation of slurry jets in MFT. tabs., figs.

Pulmonary microRNA profiling: implications in upper lobe predominant lung disease

OpenAIRE

Armstrong, David A.; Nymon, Amanda B.; Ringelberg, Carol S.; Lesseur, Corina; Hazlett, Haley F.; Howard, Louisa; Marsit, Carmen J.; Ashare, Alix

2017-01-01

Background Numerous pulmonary diseases manifest with upper lobe predominance including cystic fibrosis, smoking-related chronic obstructive pulmonary disease, and tuberculosis. Zonal hypoxia, characteristic of these pulmonary maladies, and oxygen stress in general is known to exert profound effects on various important aspects of cell biology. Lung macrophages are major participants in the pulmonary innate immune response and regional differences in macrophage responsiveness to hypoxia may co...

Numerically and experimentally analysis of creep

International Nuclear Information System (INIS)

Fontanive, J.A.

1982-11-01

The problems of creep in concrete are analyzed experimentally and numerically, comparing with classical methods and suggesting a numerical procedure for the solution of these problems. Firstly, fundamentals of viscoelasticity and its application to concrete behaviour representation are presented. Then the theories of Dischinger and Arutyunyan are studied, and a computing numerical solutions are compared in several examples. Finally, experiences on creep and relaxation are described, and its result are analyzed. Some coments on possible future developments are included. (Author) [pt

Theory and applications of numerical analysis

CERN Document Server

Phillips, G M

1996-01-01

This text is a self-contained Second Edition, providing an introductory account of the main topics in numerical analysis. The book emphasizes both the theorems which show the underlying rigorous mathematics andthe algorithms which define precisely how to program the numerical methods. Both theoretical and practical examples are included.* a unique blend of theory and applications* two brand new chapters on eigenvalues and splines* inclusion of formal algorithms* numerous fully worked examples* a large number of problems, many with solutions

Oxidative Stress in Oral Diseases: Understanding Its Relation with Other Systemic Diseases

Directory of Open Access Journals (Sweden)

Jaya Kumar

2017-09-01

Full Text Available Oxidative stress occurs in diabetes, various cancers, liver diseases, stroke, rheumatoid arthritis, chronic inflammation, and other degenerative diseases related to the nervous system. The free radicals have deleterious effect on various organs of the body. This is due to lipid peroxidation and irreversible protein modification that leads to cellular apoptosis or programmed cell death. During recent years, there is a rise in the oral diseases related to oxidative stress. Oxidative stress in oral disease is related to other systemic diseases in the body such as periodontitis, cardiovascular, pancreatic, gastric, and liver diseases. In the present review, we discuss the various pathways that mediate oxidative cellular damage. Numerous pathways mediate oxidative cellular damage and these include caspase pathway, PERK/NRF2 pathway, NADPH oxidase 4 pathways and JNK/mitogen-activated protein (MAP kinase pathway. We also discuss the role of inflammatory markers, lipid peroxidation, and role of oxygen species linked to oxidative stress. Knowledge of different pathways, role of inflammatory markers, and importance of low-density lipoprotein, fibrinogen, creatinine, nitric oxide, nitrates, and highly sensitive C-reactive proteins may be helpful in understanding the pathogenesis and plan better treatment for oral diseases which involve oxidative stress.

Numerical Feedback Stabilization with Applications to Networks

Directory of Open Access Journals (Sweden)

Simone Göttlich

2017-01-01

Full Text Available The focus is on the numerical consideration of feedback boundary control problems for linear systems of conservation laws including source terms. We explain under which conditions the numerical discretization can be used to design feedback boundary values for network applications such as electric transmission lines or traffic flow systems. Several numerical examples illustrate the properties of the results for different types of networks.

Cost of tobacco-related diseases, including passive smoking, in Hong Kong.

Science.gov (United States)

McGhee, S M; Ho, L M; Lapsley, H M; Chau, J; Cheung, W L; Ho, S Y; Pow, M; Lam, T H; Hedley, A J

2006-04-01

Costs of tobacco-related disease can be useful evidence to support tobacco control. In Hong Kong we now have locally derived data on the risks of smoking, including passive smoking. To estimate the health-related costs of tobacco from both active and passive smoking. Using local data, we estimated active and passive smoking-attributable mortality, hospital admissions, outpatient, emergency and general practitioner visits for adults and children, use of nursing homes and domestic help, time lost from work due to illness and premature mortality in the productive years. Morbidity risk data were used where possible but otherwise estimates based on mortality risks were used. Utilisation was valued at unit costs or from survey data. Work time lost was valued at the median wage and an additional costing included a value of USD 1.3 million for a life lost. In the Hong Kong population of 6.5 million in 1998, the annual value of direct medical costs, long term care and productivity loss was USD 532 million for active smoking and USD 156 million for passive smoking; passive smoking accounted for 23% of the total costs. Adding the value of attributable lives lost brought the annual cost to USD 9.4 billion. The health costs of tobacco use are high and represent a net loss to society. Passive smoking increases these costs by at least a quarter. This quantification of the costs of tobacco provides strong motivation for legislative action on smoke-free areas in the Asia Pacific Region and elsewhere.

Numerical modeling of AA2024-T3 friction stir welding process for residual stress evaluation, including softening effects

DEFF Research Database (Denmark)

Sonne, Mads Rostgaard; Carlone, Pierpaolo; Palazzo, Gaetano S.

2014-01-01

In the present paper, a numerical finite element model of the precipitation hardenable AA2024-T3 aluminum alloy, consisting of a heat transfer analysis based on the Thermal Pseudo Mechanical model for heat generation, and a sequentially coupled quasi-static stress analysis is proposed. Metallurgi...

Numerical modeling and experimental validation of the acoustic transmission of aircraft's double-wall structures including sound package

Science.gov (United States)

Rhazi, Dilal

In the field of aeronautics, reducing the harmful effects of acoustics constitutes a major concern at the international level and justifies the call for further research, particularly in Canada where aeronautics is a key economic sector, which operates in a context of global competition. Aircraft sidewall structure is usually of a double wall construction with a curved ribbed metallic skin and a lightweight composite or sandwich trim separated by a cavity filled with a noise control treatment. The latter is of a great importance in the transport industry, and continues to be of interest in many engineering applications. However, the insertion loss noise control treatment depends on the excitation of the supporting structure. In particular, Turbulent Boundary Layer is of interest to several industries. This excitation is difficult to simulate in laboratory conditions, given the prohibiting costs and difficulties associated with wind tunnel and in-flight tests. Numerical simulation is the only practical way to predict the response to such excitations and to analyze effects of design changes to the response to such excitation. Another kinds of excitations encountered in industrial are monopole, rain on the Roof and diffuse acoustic field. Deterministic methods can calculate in each point the spectral response of the system. Most known are numerical methods such as finite elements and boundary elements methods. These methods generally apply to the low frequency where modal behavior of the structure dominates. However, the high limit of calculation in frequency of these methods cannot be defined in a strict way because it is related to the capacity of data processing and to the nature of the studied mechanical system. With these challenges in mind, and with limitations of the main numerical codes on the market, the manufacturers have expressed the need for simple models immediately available as early as the stage of preliminary drafts. This thesis represents an attempt

Numerical investigation of flow parameters for solid rigid spheroidal particle in a pulsatile pipe flow

Science.gov (United States)

Varghese, Joffin; Jayakumar, J. S.

2017-09-01

Quantifying, forecasting and analysing the displacement rates of suspended particles are essential while discussing about blood flow analysis. Because blood is one of the major organs in the body, which enables transport phenomena, comprising of numerous blood cells. In order to model the blood flow, a flow domain was created and numerically simulated. Flow field velocity in the stream is solved utilizing Finite Volume Method utilizing FVM unstructured solver. In pulsatile flow, the effect of parameters such as average Reynolds number, tube radius, particle size and Womersley number are taken into account. In this study spheroidal particle trajectory in axial direction is simulated at different values of pulsating frequency including 1.2 Hz, 3.33 Hz and 4.00 Hz and various densities including 1005 kg/m3 and 1025 kg/m3 for the flow domain. The analysis accomplishes the interaction study of blood constituents for different flow situations which have applications in diagnosis and treatment of cardio vascular related diseases.

SIRT1 gene is associated with cardiovascular disease in the Iranian ...

African Journals Online (AJOL)

Background: Sirtuins (SIRT) have recently been identified as the pivotal regulators of lifespan and health. SIRT1 has protective effects against cardiovascular disease (CVD) and through its deacetylase activity it regulates numerous essential pathways including regulating blood pressure, reducing atherosclerosis, heart ...

Introduction to numerical analysis

CERN Document Server

Hildebrand, F B

1987-01-01

Well-known, respected introduction, updated to integrate concepts and procedures associated with computers. Computation, approximation, interpolation, numerical differentiation and integration, smoothing of data, other topics in lucid presentation. Includes 150 additional problems in this edition. Bibliography.

Disease-Related Detection with Electrochemical Biosensors: A Review.

Science.gov (United States)

Huang, Ying; Xu, Jin; Liu, Junjie; Wang, Xiangyang; Chen, Bin

2017-10-17

Rapid diagnosis of diseases at their initial stage is critical for effective clinical outcomes and promotes general public health. Classical in vitro diagnostics require centralized laboratories, tedious work and large, expensive devices. In recent years, numerous electrochemical biosensors have been developed and proposed for detection of various diseases based on specific biomarkers taking advantage of their features, including sensitivity, selectivity, low cost and rapid response. This article reviews research trends in disease-related detection with electrochemical biosensors. Focus has been placed on the immobilization mechanism of electrochemical biosensors, and the techniques and materials used for the fabrication of biosensors are introduced in details. Various biomolecules used for different diseases have been listed. Besides, the advances and challenges of using electrochemical biosensors for disease-related applications are discussed.

Grover's Disease after Heart Transplantation: A Case Report

Directory of Open Access Journals (Sweden)

Giovanbattista Ippoliti

2012-01-01

Full Text Available Grover's disease is a transient acantholytic dermatosis of unknown cause, manifesting clinically as a papular skin eruption that is usually located on the anterior chest and abdomen. Histologically characterized by an acantholytic pattern, it has been associated with numerous disorders, including hematologic malignancies, chronic renal failure, and HIV infection, as well as with chemotherapy and bone marrow and/or kidney transplant. Evaluation of followup and treatment is often complicated by spontaneous remission and the occasionally fluctuant course of the disease. Here we report the case of a patient with sudden onset of Grover's disease after heart transplantation. To the best of our knowledge, this is the first observation of Grover's disease as diagnosed after heart transplantation.

Numerical calculations near spatial infinity

International Nuclear Information System (INIS)

Zenginoglu, Anil

2007-01-01

After describing in short some problems and methods regarding the smoothness of null infinity for isolated systems, I present numerical calculations in which both spatial and null infinity can be studied. The reduced conformal field equations based on the conformal Gauss gauge allow us in spherical symmetry to calculate numerically the entire Schwarzschild-Kruskal spacetime in a smooth way including spacelike, null and timelike infinity and the domain close to the singularity

Probabilistic numerics and uncertainty in computations.

Science.gov (United States)

Hennig, Philipp; Osborne, Michael A; Girolami, Mark

2015-07-08

We deliver a call to arms for probabilistic numerical methods : algorithms for numerical tasks, including linear algebra, integration, optimization and solving differential equations, that return uncertainties in their calculations. Such uncertainties, arising from the loss of precision induced by numerical calculation with limited time or hardware, are important for much contemporary science and industry. Within applications such as climate science and astrophysics, the need to make decisions on the basis of computations with large and complex data have led to a renewed focus on the management of numerical uncertainty. We describe how several seminal classic numerical methods can be interpreted naturally as probabilistic inference. We then show that the probabilistic view suggests new algorithms that can flexibly be adapted to suit application specifics, while delivering improved empirical performance. We provide concrete illustrations of the benefits of probabilistic numeric algorithms on real scientific problems from astrometry and astronomical imaging, while highlighting open problems with these new algorithms. Finally, we describe how probabilistic numerical methods provide a coherent framework for identifying the uncertainty in calculations performed with a combination of numerical algorithms (e.g. both numerical optimizers and differential equation solvers), potentially allowing the diagnosis (and control) of error sources in computations.

Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies.

Directory of Open Access Journals (Sweden)

Ryoko Katagiri

Full Text Available Although several reports concerning the association of iodine excess and thyroid disease have appeared, no systematic review of the association between iodine excess intake and thyroid diseases, especially hyperthyroidism and hypothyroidism, has yet been reported.We conducted a systematic search of Ovid MEDLINE, PubMed, Cochrane Central Register of Controlled Trials databases, Ichushi-Web and CiNii database for intervention trials and observational studies. Search terms were constructed from related words for excess AND iodine intake or excretion AND thyroid hormones or diseases AND study designs. After considering the qualitative heterogeneity among studies, a meta-analysis was conducted and odds ratios and 95% confidence intervals (CI were estimated in random-effects models. A protocol was registered with PROSPERO (No. CRD42015028081.50 articles were included, including three intervention trials, six case-control studies, six follow-up studies and 35 cross-sectional studies. Three cross-sectional studies in adults included in meta-analysis. Odds ratio of overt and subclinical hypothyroidism between excess and adequate populations were 2.78 (CI:1.47 to 5.27 and 2.03 (CI:1.58 to 2.62 in adults, respectively. Source of excess iodine status was mainly iodized salt or water in included studies.Although universal salt iodization has improved goiter rates, chronic exposure to excess iodine from water or poorly monitored salt are risk factors for hypothyroidism in free-living populations. Monitoring of both iodine concentration in salt as well as the iodine concentration in local drinking water are essential to preventing thyroid diseases. Hypothyroidism should be also carefully monitored in areas with excess iodine. Because of the low quality and limited number of included studies, further evidence and review are required.

Patients with neuromyelitis optica have a more severe disease than patients with relapsingremitting multiple sclerosis, including higher risk of dying of a demyelinating disease

Directory of Open Access Journals (Sweden)

Denis Bernardi Bichuetti

2013-05-01

Full Text Available Although neuromyelitis optica (NMO is known to be a more severe disease than relapsing-remitting multiple sclerosis (RRMS, few studies comparing both conditions in a single center have been done. Methods: Comparison of our previously published cohort of 41 NMO patients with 177 RRMS patients followed in the same center, from 1994 to 2007. Results: Mean age of onset was 32.6 for NMO and 30.2 for RRMS (p=0.2062 with mean disease duration of 7.4 years for NMO and 10.3 years for RRMS. Patients with NMO had a higher annualized relapse rate (1.0 versus 0.8, p=0.0013 and progression index (0.9 versus 0.6, p≪0.0001, with more patients reaching expanded disability status scale (EDSS 6.0 (39 versus 17%, p=0.0036. The odds ratio for reaching EDSS 6.0 and being deceased due to NMO in comparison to RRMS were, respectively, 3.14 and 12.15. Conclusion: Patients with NMO have a more severe disease than patients with RRMS, including higher risk of dying of a demyelinating disease.

Numerical simulation of mechatronic sensors and actuators

CERN Document Server

Kaltenbacher, Manfred

2007-01-01

Focuses on the physical modeling of mechatronic sensors and actuators and their precise numerical simulation using the Finite Element Method (FEM). This book discusses the physical modeling as well as numerical computation. It also gives a comprehensive introduction to finite elements, including their computer implementation.

Do Mitochondrial Replacement Techniques Affect Qualitative or Numerical Identity?

Science.gov (United States)

Liao, S Matthew

2017-01-01

Mitochondrial replacement techniques (MRTs), known in the popular media as 'three-parent' or 'three-person' IVFs, have the potential to enable women with mitochondrial diseases to have children who are genetically related to them but without such diseases. In the debate regarding whether MRTs should be made available, an issue that has garnered considerable attention is whether MRTs affect the characteristics of an existing individual or whether they result in the creation of a new individual, given that MRTs involve the genetic manipulation of the germline. In other words, do MRTs affect the qualitative identity or the numerical identity of the resulting child? For instance, a group of panelists on behalf of the UK Human Fertilisation and Embryology Authority (HFEA) has claimed that MRTs affect only the qualitative identity of the resulting child, while the Working Group of the Nuffield Council on Bioethics (NCOB) has argued that MRTs would create a numerically distinct individual. In this article, I shall argue that MRTs do create a new and numerically distinct individual. Since my explanation is different from the NCOB's explanation, I shall also offer reasons why my explanation is preferable to the NCOB's explanation. © 2016 John Wiley & Sons Ltd.

Combined scintigraphic and radiographic diagnosis of bone and joint diseases. Including gamma correction interpretation. 4. rev. and enl. ed.

Energy Technology Data Exchange (ETDEWEB)

Bahk, Yong-Whee [Sung Ae General Hospital, Seoul (Korea, Republic of). Dept. of Nuclear Medicine and Radiology

2013-07-01

In this fourth edition of Combined Scintigraphic and Radiographic Diagnosis of Bone and Joint Diseases, the text has been thoroughly amended, updated, and partially rearranged to reflect the latest advances. In addition to discussing the role of pinhole imaging in the range of disorders previously covered, the new edition pays detailed attention to the novel diagnostic use of gamma correction pinhole bone scan in a broad spectrum of skeletal disorders, including physical, traumatic, and sports injuries, infectious and non-infectious bone diseases, benign and malignant bone tumors, and soft tissue diseases. A large number of state of the art pinhole scans and corroborative CT, MRI, and/or ultrasound images are presented side by side. The book has been enlarged to encompass various new topics, including occult fractures; cervical sprain and whiplash trauma; bone marrow edema; microfractures of trabeculae; evident, gaping, and stress fractures; and differential diagnosis. This new edition will be essential reading for practitioners and researchers in not only nuclear medicine but also radiology, orthopedic surgery, and pathology.

Combined scintigraphic and radiographic diagnosis of bone and joint diseases. Including gamma correction interpretation. 4. rev. and enl. ed.

International Nuclear Information System (INIS)

Bahk, Yong-Whee

2013-01-01

In this fourth edition of Combined Scintigraphic and Radiographic Diagnosis of Bone and Joint Diseases, the text has been thoroughly amended, updated, and partially rearranged to reflect the latest advances. In addition to discussing the role of pinhole imaging in the range of disorders previously covered, the new edition pays detailed attention to the novel diagnostic use of gamma correction pinhole bone scan in a broad spectrum of skeletal disorders, including physical, traumatic, and sports injuries, infectious and non-infectious bone diseases, benign and malignant bone tumors, and soft tissue diseases. A large number of state of the art pinhole scans and corroborative CT, MRI, and/or ultrasound images are presented side by side. The book has been enlarged to encompass various new topics, including occult fractures; cervical sprain and whiplash trauma; bone marrow edema; microfractures of trabeculae; evident, gaping, and stress fractures; and differential diagnosis. This new edition will be essential reading for practitioners and researchers in not only nuclear medicine but also radiology, orthopedic surgery, and pathology.

Description of an oral Chagas disease outbreak in Venezuela, including a vertically transmitted case.

Science.gov (United States)

Noya, Belkisyolé Alarcón de; Pérez-Chacón, Gladymar; Díaz-Bello, Zoraida; Dickson, Sonia; Muñoz-Calderón, Arturo; Hernández, Carlos; Pérez, Yadira; Mauriello, Luciano; Moronta, Eyleen

2017-08-01

We describe the eleventh major outbreak of foodborne Trypanosoma cruzi transmission in urban Venezuela, including evidence for vertical transmission from the index case to her fetus. After confirming fetal death at 24 weeks of gestation, pregnancy interruption was performed. On direct examination of the amniotic fluid, trypomastigotes were detected. T. cruzi specific-polymerase chain reaction (PCR) also proved positive when examining autopsied fetal organs. Finally, microscopic fetal heart examination revealed amastigote nests. Acute orally transmitted Chagas disease can be life threatening or even fatal for pregnant women and unborn fetuses owing to vertical transmission. There is therefore an urgent need to improve national epidemiologic control measures.

Susy theories and QCD: numerical approaches

International Nuclear Information System (INIS)

Ita, Harald

2011-01-01

We review on-shell and unitarity methods and discuss their application to precision predictions for Large Hadron Collider (LHC) physics. Being universal and numerically robust, these methods are straightforward to automate for next-to-leading-order computations within standard model and beyond. Several state-of-the-art results including studies of (W/Z+3)-jet and (W+4)-jet production have explicitly demonstrated the effectiveness of the unitarity method for describing multi-parton scattering. Here we review central ideas needed to obtain efficient numerical implementations. This includes on-shell loop-level recursions, the unitarity method, color management and further refined tricks. (review)

Role of curcumin in health and disease.

Science.gov (United States)

Pari, Leelavinothan; Tewas, Daniel; Eckel, Juergen

2008-04-01

Curcumin (diferuloylmethane) is an orange-yellow component of turmeric (Curcuma longa), a spice often found in curry powder. In recent years, considerable interest has been focused on curcumin due to its use to treat a wide variety of disorders without any side effects. It is one of the major curcuminoids of turmeric, which impart its characteristic yellow colour. It was used in ancient times on the Indian subcontinent to treat various illnesses such as rheumatism, body ache, skin diseases, intestinal worms, diarrhoea, intermittent fevers, hepatic disorders, biliousness, urinary discharges, dyspepsia, inflammations, constipation, leukoderma, amenorrhea, and colic. Curcumin has the potential to treat a wide variety of inflammatory diseases including cancer, diabetes, cardiovascular diseases, arthritis, Alzheimer's disease, psoriasis, etc, through modulation of numerous molecular targets. This article reviews the use of curcumin for the chemoprevention and treatment of various diseases.

Average-case analysis of numerical problems

CERN Document Server

2000-01-01

The average-case analysis of numerical problems is the counterpart of the more traditional worst-case approach. The analysis of average error and cost leads to new insight on numerical problems as well as to new algorithms. The book provides a survey of results that were mainly obtained during the last 10 years and also contains new results. The problems under consideration include approximation/optimal recovery and numerical integration of univariate and multivariate functions as well as zero-finding and global optimization. Background material, e.g. on reproducing kernel Hilbert spaces and random fields, is provided.

Disease-Related Detection with Electrochemical Biosensors: A Review

Directory of Open Access Journals (Sweden)

Ying Huang

2017-10-01

Full Text Available Rapid diagnosis of diseases at their initial stage is critical for effective clinical outcomes and promotes general public health. Classical in vitro diagnostics require centralized laboratories, tedious work and large, expensive devices. In recent years, numerous electrochemical biosensors have been developed and proposed for detection of various diseases based on specific biomarkers taking advantage of their features, including sensitivity, selectivity, low cost and rapid response. This article reviews research trends in disease-related detection with electrochemical biosensors. Focus has been placed on the immobilization mechanism of electrochemical biosensors, and the techniques and materials used for the fabrication of biosensors are introduced in details. Various biomolecules used for different diseases have been listed. Besides, the advances and challenges of using electrochemical biosensors for disease-related applications are discussed.

Predicting cognitive decline in Alzheimer's disease: an integrated analysis

DEFF Research Database (Denmark)

Lopez, Oscar L; Schwam, Elias; Cummings, Jeffrey

2010-01-01

Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined.......Numerous patient- and disease-related factors increase the risk of rapid cognitive decline in patients with Alzheimer's disease (AD). The ability of pharmacological treatment to attenuate this risk remains undefined....

Numerical modelling of mine workings.

CSIR Research Space (South Africa)

Lightfoot, N

1999-03-01

Full Text Available to cover most of what is required for a practising rock mechanics engineer to be able to use any of these five programs to solve practical mining problems. The chapters on specific programs discuss their individual strengths and weaknesses and highlight... and applications of numerical modelling in the context of the South African gold and platinum mining industries. This includes an example that utilises a number of different numerical 3 modelling programs to solve a single problem. This particular example...

CT features of lymphobronchial tuberculosis in children, including complications and associated abnormalities

Energy Technology Data Exchange (ETDEWEB)

Lucas, Susan; Andronikou, Savvas [Faculty of Health Sciences, University of the Witwatersrand, Department of Radiology, Johannesburg (South Africa); Goussard, Pierre; Gie, Robert [Stellenbosch University, Department Paediatrics, Stellenbosch (South Africa)

2012-08-15

Lymphobronchial tuberculosis (TB) is tuberculous lymphadenopathy involving the airways, which is particularly common in children. To describe CT findings of lymphobronchial TB in children, the parenchymal complications and associated abnormalities. CT scans of children with lymphobronchial TB were reviewed retrospectively. Lymphadenopathy, bronchial narrowing, parenchymal complications and associations were documented. Infants comprised 51% of patients. The commonest site of lymphadenopathy was the subcarinal mediastinum (97% of patients). Bronchial compression was seen in all children (259 bronchi, of these 28% the bronchus intermedius) with severe or complete stenosis in 23% of affected bronchi. Parenchymal complications were present in 94% of patients, including consolidation (88%), breakdown (42%), air trapping (38%), expansile pneumonia (28%), collapse (17%) and bronchiectasis (9%), all predominantly on the right side (63%). Associated abnormalities included ovoid lesions, miliary nodules, pleural disease and intracavitary bodies. Airway compression was more severe in infants and most commonly involved the bronchus intermedius. Numerous parenchymal complications were documented, all showing right-side predominance. (orig.)

Cardiorenal metabolic syndrome in the African diaspora: rationale for including chronic kidney disease in the metabolic syndrome definition.

Science.gov (United States)

Lea, Janice P; Greene, Eddie L; Nicholas, Susanne B; Agodoa, Lawrence; Norris, Keith C

2009-01-01

Chronic kidney disease (CKD) is more likely to progress to end-stage renal disease (ESRD) in African Americans while the reasons for this are unclear. The metabolic syndrome is a risk factor for the development of diabetes, cardiovascular disease, and has been recently linked to incident CKD. Historically, fewer African Americans meet criteria for the definition of metabolic syndrome, despite having higher rates of cardiovascular mortality than Caucasians. The presence of microalbuminuria portends increased cardiovascular risks and has been shown to cluster with the metabolic syndrome. We recently reported that proteinuria is a predictor of CKD progression in African American hypertensives with metabolic syndrome. In this review we explore the potential value of including CKD markers--microalbuminuria/proteinuria or low glomerular filtration rate (GFR)-in refining the cluster of factors defined as metabolic syndrome, ie, "cardiorenal metabolic syndrome."

Tree shrew (Tupaia belangeri as a novel laboratory disease animal model

Directory of Open Access Journals (Sweden)

Ji Xiao

2017-05-01

Full Text Available The tree shrew (Tupaia belangeri is a promising laboratory animal that possesses a closer genetic relationship to primates than to rodents. In addition, advantages such as small size, easy breeding, and rapid reproduction make the tree shrew an ideal subject for the study of human disease. Numerous tree shrew disease models have been generated in biological and medical studies in recent years. Here we summarize current tree shrew disease models, including models of infectious diseases, cancers, depressive disorders, drug addiction, myopia, metabolic diseases, and immune-related diseases. With the success of tree shrew transgenic technology, this species will be increasingly used in biological and medical studies in the future.

Numerical relativity

International Nuclear Information System (INIS)

Piran, T.

1982-01-01

There are many recent developments in numerical relativity, but there remain important unsolved theoretical and practical problems. The author reviews existing numerical approaches to solution of the exact Einstein equations. A framework for classification and comparison of different numerical schemes is presented. Recent numerical codes are compared using this framework. The discussion focuses on new developments and on currently open questions, excluding a review of numerical techniques. (Auth.)

Inflammatory diseases of the brain

International Nuclear Information System (INIS)

Haehnel, Stefan

2009-01-01

This book provides a comprehensive overview of inflammatory brain diseases from a neuroradiological point of view. Such diseases may be either infectious (e.g., viral encephalitis and pyogenic brain abscess) or non-infectious (e.g., multiple sclerosis), and many of these entities are becoming increasingly important for differential diagnosis, particularly in immunocompromised persons. Neuroimaging contributes greatly to the differentiation of infectious and noninfectious brain diseases and to the distinction between brain inflammation and other, for instance neoplastic, diseases. In order to ensure a standardized approach throughout the book, each chapter is subdivided into three principal sections: epidemiology, clinical presentation and therapy; imaging; and differential diagnosis. A separate chapter addresses technical and methodological issues and imaging protocols. All of the authors are recognized experts in their fields, and numerous high-quality and informative illustrations are included. This book will be of great value not only to neuroradiologists but also to neurologists, neuropediatricians, and general radiologists. (orig.)

Inflammatory diseases of the brain

Energy Technology Data Exchange (ETDEWEB)

Haehnel, Stefan (ed.) [University of Heidelberg Medical Center (Germany). Div. of Neuroradiology

2009-07-01

This book provides a comprehensive overview of inflammatory brain diseases from a neuroradiological point of view. Such diseases may be either infectious (e.g., viral encephalitis and pyogenic brain abscess) or non-infectious (e.g., multiple sclerosis), and many of these entities are becoming increasingly important for differential diagnosis, particularly in immunocompromised persons. Neuroimaging contributes greatly to the differentiation of infectious and noninfectious brain diseases and to the distinction between brain inflammation and other, for instance neoplastic, diseases. In order to ensure a standardized approach throughout the book, each chapter is subdivided into three principal sections: epidemiology, clinical presentation and therapy; imaging; and differential diagnosis. A separate chapter addresses technical and methodological issues and imaging protocols. All of the authors are recognized experts in their fields, and numerous high-quality and informative illustrations are included. This book will be of great value not only to neuroradiologists but also to neurologists, neuropediatricians, and general radiologists. (orig.)

Periodontal Disease, Tooth Loss, and Cancer Risk.

Science.gov (United States)

Michaud, Dominique S; Fu, Zhuxuan; Shi, Jian; Chung, Mei

2017-01-01

Periodontal disease, which includes gingivitis and periodontitis, is highly prevalent in adults and disease severity increases with age. The relationship between periodontal disease and oral cancer has been examined for several decades, but there is increasing interest in the link between periodontal disease and overall cancer risk, with systemic inflammation serving as the main focus for biological plausibility. Numerous case-control studies have addressed the role of oral health in head and neck cancer, and several cohort studies have examined associations with other types of cancers over the past decade. For this review, we included studies that were identified from either 11 published reviews on this topic or an updated literature search on PubMed (between 2011 and July 2016). A total of 50 studies from 46 publications were included in this review. Meta-analyses were conducted on cohort and case-control studies separately when at least 4 studies could be included to determine summary estimates of the risk of cancer in relation to 1) periodontal disease or 2) tooth number (a surrogate marker of periodontal disease) with adjustment for smoking. Existing data provide support for a positive association between periodontal disease and risk of oral, lung, and pancreatic cancers; however, additional prospective studies are needed to better inform on the strength of these associations and to determine whether other cancers are associated with periodontal disease. Future studies should include sufficiently large sample sizes, improved measurements for periodontal disease, and thorough adjustment for smoking and other risk factors. © The Author 2017. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Extraction of gravitational waves in numerical relativity.

Science.gov (United States)

Bishop, Nigel T; Rezzolla, Luciano

2016-01-01

A numerical-relativity calculation yields in general a solution of the Einstein equations including also a radiative part, which is in practice computed in a region of finite extent. Since gravitational radiation is properly defined only at null infinity and in an appropriate coordinate system, the accurate estimation of the emitted gravitational waves represents an old and non-trivial problem in numerical relativity. A number of methods have been developed over the years to "extract" the radiative part of the solution from a numerical simulation and these include: quadrupole formulas, gauge-invariant metric perturbations, Weyl scalars, and characteristic extraction. We review and discuss each method, in terms of both its theoretical background as well as its implementation. Finally, we provide a brief comparison of the various methods in terms of their inherent advantages and disadvantages.

Neoclassical transport including collisional nonlinearity.

Science.gov (United States)

Candy, J; Belli, E A

2011-06-10

In the standard δf theory of neoclassical transport, the zeroth-order (Maxwellian) solution is obtained analytically via the solution of a nonlinear equation. The first-order correction δf is subsequently computed as the solution of a linear, inhomogeneous equation that includes the linearized Fokker-Planck collision operator. This equation admits analytic solutions only in extreme asymptotic limits (banana, plateau, Pfirsch-Schlüter), and so must be solved numerically for realistic plasma parameters. Recently, numerical codes have appeared which attempt to compute the total distribution f more accurately than in the standard ordering by retaining some nonlinear terms related to finite-orbit width, while simultaneously reusing some form of the linearized collision operator. In this work we show that higher-order corrections to the distribution function may be unphysical if collisional nonlinearities are ignored.

[Tick-borne diseases].

Science.gov (United States)

Tissot Dupont, H; Raoult, D

1993-05-01

Due to their worldwide distribution, from hottest to coldest climates, and due to their behaviour, ticks are capable of transmitting numerous human and animal bacterial viral or parasitous diseases. Depending on the disease, they play the role of biological vector or intermediate host. In France, six tick borne diseases are of epidemiologic importance. Q fever (not often tick-borne), Mediterranean Spotted Fever, Lyme disease, Turalemia (human and animal), Babesiosis and Tick-borne Viral Encephalitis.

A literature survey on numerical heat transfer

Science.gov (United States)

Shih, T. M.

1982-12-01

Technical papers in the area of numerical heat transfer published from 1977 through 1981 are reviewed. The journals surveyed include: (1) ASME Journal of Heat Transfer, (2) International Journal of Heat and Mass Transfer, (3) AIAA Journal, (4) Numerical Heat Transfer, (5) Computers and Fluids, (6) International Journal for Numerical Methods in Engineering, (7) SIAM Journal of Numerical Analysis, and (8) Journal of Computational Physics. This survey excludes experimental work in heat transfer and numerical schemes that are not applied to equations governing heat transfer phenomena. The research work is categorized into the following areas: (A) conduction, (B) boundary-layer flows, (C) momentum and heat transfer in cavities, (D) turbulent flows, (E) convection around cylinders and spheres or within annuli, (F) numerical convective instability, (G) radiation, (H) combustion, (I) plumes, jets, and wakes, (J) heat transfer in porous media, (K) boiling, condensation, and two-phase flows, (L) developing and fully developed channel flows, (M) combined heat and mass transfer, (N) applications, (O) comparison and properties of numerical schemes, and (P) body-fitted coordinates and nonuniform grids.

Leptospirosis in dogs and cats: epidemiology, clinical disease, zoonotic implications and prevention

NARCIS (Netherlands)

Azocar-Aedo, L.; Smits, H. L.; Monti, G.

2014-01-01

Leptospirosis is a zoonotic disease of worldwide distribution caused by spirochetes of the genus Leptospira. The genus includes a large number of serovars that may be sheed in the urine of infected animals creating a highly infectious source of transmission. Numerous species of wild and domestic

Infectious disease modeling a hybrid system approach

CERN Document Server

Liu, Xinzhi

2017-01-01

This volume presents infectious diseases modeled mathematically, taking seasonality and changes in population behavior into account, using a switched and hybrid systems framework. The scope of coverage includes background on mathematical epidemiology, including classical formulations and results; a motivation for seasonal effects and changes in population behavior, an investigation into term-time forced epidemic models with switching parameters, and a detailed account of several different control strategies. The main goal is to study these models theoretically and to establish conditions under which eradication or persistence of the disease is guaranteed. In doing so, the long-term behavior of the models is determined through mathematical techniques from switched systems theory. Numerical simulations are also given to augment and illustrate the theoretical results and to help study the efficacy of the control schemes.

Numerical relativity

CERN Document Server

Shibata, Masaru

2016-01-01

This book is composed of two parts: First part describes basics in numerical relativity, that is, the formulations and methods for a solution of Einstein's equation and general relativistic matter field equations. This part will be helpful for beginners of numerical relativity who would like to understand the content of numerical relativity and its background. The second part focuses on the application of numerical relativity. A wide variety of scientific numerical results are introduced focusing in particular on the merger of binary neutron stars and black holes.

Numerical analysis

CERN Document Server

Khabaza, I M

1960-01-01

Numerical Analysis is an elementary introduction to numerical analysis, its applications, limitations, and pitfalls. Methods suitable for digital computers are emphasized, but some desk computations are also described. Topics covered range from the use of digital computers in numerical work to errors in computations using desk machines, finite difference methods, and numerical solution of ordinary differential equations. This book is comprised of eight chapters and begins with an overview of the importance of digital computers in numerical analysis, followed by a discussion on errors in comput

Hemodynamic effect of bypass geometry on intracranial aneurysm: A numerical investigation.

Science.gov (United States)

Kurşun, Burak; Uğur, Levent; Keskin, Gökhan

2018-05-01

Hemodynamic analyzes are used in the clinical investigation and treatment of cardiovascular diseases. In the present study, the effect of bypass geometry on intracranial aneurysm hemodynamics was investigated numerically. Pressure, wall shear stress (WSS) and velocity distribution causing the aneurysm to grow and rupture were investigated and the best conditions were tried to be determined in case of bypassing between basilar (BA) and left/right posterior arteries (LPCA/RPCA) for different values of parameters. The finite volume method was used for numerical solutions and calculations were performed with the ANSYS-Fluent software. The SIMPLE algorithm was used to solve the discretized conservation equations. Second Order Upwind method was preferred for finding intermediate point values in the computational domain. As the blood flow velocity changes with time, the blood viscosity value also changes. For this reason, the Carreu model was used in determining the viscosity depending on the velocity. Numerical study results showed that when bypassed, pressure and wall shear stresses reduced in the range of 40-70% in the aneurysm. Numerical results obtained are presented in graphs including the variation of pressure, wall shear stress and velocity streamlines in the aneurysm. Considering the numerical results for all parameter values, it is seen that the most important factors affecting the pressure and WSS values in bypassing are the bypass position on the basilar artery (L b ) and the diameter of the bypass vessel (d). Pressure and wall shear stress reduced in the range of 40-70% in the aneurysm in the case of bypass for all parameters. This demonstrates that pressure and WSS values can be greatly reduced in aneurysm treatment by bypassing in cases where clipping or coil embolization methods can not be applied. Copyright © 2018 Elsevier B.V. All rights reserved.

FCDD: A Database for Fruit Crops Diseases.

Science.gov (United States)

Chauhan, Rupal; Jasrai, Yogesh; Pandya, Himanshu; Chaudhari, Suman; Samota, Chand Mal

2014-01-01

Fruit Crops Diseases Database (FCDD) requires a number of biotechnology and bioinformatics tools. The FCDD is a unique bioinformatics resource that compiles information about 162 details on fruit crops diseases, diseases type, its causal organism, images, symptoms and their control. The FCDD contains 171 phytochemicals from 25 fruits, their 2D images and their 20 possible sequences. This information has been manually extracted and manually verified from numerous sources, including other electronic databases, textbooks and scientific journals. FCDD is fully searchable and supports extensive text search. The main focus of the FCDD is on providing possible information of fruit crops diseases, which will help in discovery of potential drugs from one of the common bioresource-fruits. The database was developed using MySQL. The database interface is developed in PHP, HTML and JAVA. FCDD is freely available. http://www.fruitcropsdd.com/

Numerical Analysis Objects

Science.gov (United States)

Henderson, Michael

1997-08-01

The Numerical Analysis Objects project (NAO) is a project in the Mathematics Department of IBM's TJ Watson Research Center. While there are plenty of numerical tools available today, it is not an easy task to combine them into a custom application. NAO is directed at the dual problems of building applications from a set of tools, and creating those tools. There are several "reuse" projects, which focus on the problems of identifying and cataloging tools. NAO is directed at the specific context of scientific computing. Because the type of tools is restricted, problems such as tools with incompatible data structures for input and output, and dissimilar interfaces to tools which solve similar problems can be addressed. The approach we've taken is to define interfaces to those objects used in numerical analysis, such as geometries, functions and operators, and to start collecting (and building) a set of tools which use these interfaces. We have written a class library (a set of abstract classes and implementations) in C++ which demonstrates the approach. Besides the classes, the class library includes "stub" routines which allow the library to be used from C or Fortran, and an interface to a Visual Programming Language. The library has been used to build a simulator for petroleum reservoirs, using a set of tools for discretizing nonlinear differential equations that we have written, and includes "wrapped" versions of packages from the Netlib repository. Documentation can be found on the Web at "http://www.research.ibm.com/nao". I will describe the objects and their interfaces, and give examples ranging from mesh generation to solving differential equations.

Complement, a target for therapy in inflammatory and degenerative diseases.

Science.gov (United States)

Morgan, B Paul; Harris, Claire L

2015-12-01

The complement system is a key innate immune defence against infection and an important driver of inflammation; however, these very properties can also cause harm. Inappropriate or uncontrolled activation of complement can cause local and/or systemic inflammation, tissue damage and disease. Complement provides numerous options for drug development as it is a proteolytic cascade that involves nine specific proteases, unique multimolecular activation and lytic complexes, an arsenal of natural inhibitors, and numerous receptors that bind to activation fragments. Drug design is facilitated by the increasingly detailed structural understanding of the molecules involved in the complement system. Only two anti-complement drugs are currently on the market, but many more are being developed for diseases that include infectious, inflammatory, degenerative, traumatic and neoplastic disorders. In this Review, we describe the history, current landscape and future directions for anti-complement therapies.

Valvular Heart Disease in Heart Failure

Directory of Open Access Journals (Sweden)

Giuseppe MC Rosano

2017-01-01

Full Text Available Structural valvular heart disease may be the cause of heart failure or may worsen the clinical status of patients with heart failure. Heart failure may also develop in patients treated with valve surgery. Patients with heart failure with valvular heart disease are at increased risk of events including sudden cardiac death. Before considering intervention (surgical or percutaneous all patients should receive appropriate medical and device therapy taking into account that vasodilators must be used with caution in patients with severe aortic stenosis. Numerous percutaneous and/or hybrid procedures have been introduced in the past few years and they are changing the management of valvular heart disease. In patients with heart failure and valvular heart disease, either primary or functional, the whole process of decision-making should be staged through a comprehensive evaluation of the risk– benefit ratio of different treatment strategies and should be made by a multidisciplinary ‘heart team’ with a particular expertise in valvular heart disease. The heart team should include heart failure cardiologists, cardiac surgeons/structural valve interventionists, imaging specialists, anaesthetists, geriatricians and intensive care specialists. This article will review recent developments and distill practical guidance in the management of this important heart failure co-morbidity.

[Evolutionary medicine: A new look on health and disease].

Science.gov (United States)

Bauduer, F

2017-03-01

Evolutionary medicine represents an innovative approach deriving from evolutionary biology. It includes the initial Darwin's view, its actualization in the light of progresses in genetics and also dissident theories (i.e. non gene-based) particularly epigenetics. This approach enables us to reconsider the pathophysiology of numerous diseases, as for instance, infection, and our so-called diseases of civilization especially obesity, type 2 diabetes, allergy or cancer. Evolutionary medicine may also improve our knowledge regarding inter-individual variation in susceptibility to disease or drugs. Furthermore, it points out the impact of our behaviors and environment on the genesis of a series of diseases. Copyright © 2016 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

Recruitment of subjects into clinical trials for Alzheimer disease.

Science.gov (United States)

Knebl, Janice A; Patki, Deepti

2010-09-01

Alzheimer disease is a devastating neurodegenerative disorder affecting millions of Americans. It reduces the ability of the individual to remain independent, places a burden on caregivers, and substantially increases healthcare costs. New treatments are being tested in numerous clinical trials with the goal of preventing or delaying the onset of Alzheimer disease, slowing or modifying the disease's course, or finding a cure for patients with the disease. Alzheimer disease research can successfully proceed only if individuals who have this illness are willing to participate in clinical trials. However, recruitment and retention of subjects in clinical trials for Alzheimer disease is a challenging task. Furthermore, because of reductions in decision-making capacities of individuals with Alzheimer disease, clinical trials also need to involve caregivers. The present article delineates unique hurdles encountered in the recruitment process for Alzheimer disease clinical trials. The article also identifies strategies for effective recruitment of subjects in Alzheimer disease clinical trials, including guidelines to help principal investigators and clinical research coordinators reach recruitment goals.

Numerical MHD study for plasmoid instability in uniform resistivity

Science.gov (United States)

Shimizu, Tohru; Kondoh, Koji; Zenitani, Seiji

2017-11-01

The plasmoid instability (PI) caused in uniform resistivity is numerically studied with a MHD numerical code of HLLD scheme. It is shown that the PI observed in numerical studies may often include numerical (non-physical) tearing instability caused by the numerical dissipations. By increasing the numerical resolutions, the numerical tearing instability gradually disappears and the physical tearing instability remains. Hence, the convergence of the numerical results is observed. Note that the reconnection rate observed in the numerical tearing instability can be higher than that of the physical tearing instability. On the other hand, regardless of the numerical and physical tearing instabilities, the tearing instability can be classified into symmetric and asymmetric tearing instability. The symmetric tearing instability tends to occur when the thinning of current sheet is stopped by the physical or numerical dissipations, often resulting in the drastic changes in plasmoid chain's structure and its activity. In this paper, by eliminating the numerical tearing instability, we could not specify the critical Lundquist number Sc beyond which PI is fully developed. It suggests that Sc does not exist, at least around S = 105.

Numerical methods for metamaterial design

CERN Document Server

2013-01-01

This book describes a relatively new approach for the design of electromagnetic metamaterials.  Numerical optimization routines are combined with electromagnetic simulations to tailor the broadband optical properties of a metamaterial to have predetermined responses at predetermined wavelengths. After a review of both the major efforts within the field of metamaterials and the field of mathematical optimization, chapters covering both gradient-based and derivative-free design methods are considered.  Selected topics including surrogate-base optimization, adaptive mesh search, and genetic algorithms are shown to be effective, gradient-free optimization strategies.  Additionally, new techniques for representing dielectric distributions in two dimensions, including level sets, are demonstrated as effective methods for gradient-based optimization.  Each chapter begins with a rigorous review of the optimization strategy used, and is followed by numerous examples that combine the strategy with either electromag...

Numerical integration of asymptotic solutions of ordinary differential equations

Science.gov (United States)

Thurston, Gaylen A.

1989-01-01

Classical asymptotic analysis of ordinary differential equations derives approximate solutions that are numerically stable. However, the analysis also leads to tedious expansions in powers of the relevant parameter for a particular problem. The expansions are replaced with integrals that can be evaluated by numerical integration. The resulting numerical solutions retain the linear independence that is the main advantage of asymptotic solutions. Examples, including the Falkner-Skan equation from laminar boundary layer theory, illustrate the method of asymptotic analysis with numerical integration.

Arthropods vector grapevine trunk disease pathogens.

Science.gov (United States)

Moyo, P; Allsopp, E; Roets, F; Mostert, L; Halleen, F

2014-10-01

Arthropod-mediated dispersal of pathogens is known in many cropping systems but has never been demonstrated for grapevine trunk disease pathogens. Arthropods from vineyards were screened for the presence of pathogens associated with Petri disease and esca using cultural and molecular techniques. The ability of the most abundant pathogen-carrying species to inoculate healthy grapevine vascular tissues was also determined. Millipedes and ants were allowed to associate with a DsRed- Express-transformed Phaeomoniella chlamydospora, after which they were exposed to freshly pruned healthy grapevines under controlled conditions and wounds were monitored for subsequent infection. In addition, the possibility of millipede excreta, commonly found on pruning wounds in the field, to act as inoculum source was determined. A diverse arthropod fauna was associated with declining grapevines and many of these carried trunk disease pathogens. However, spiders, the ant Crematogaster peringueyi, and the millipede Ommattoiulus moreleti were the most abundant pathogen carriers. The ant and millipede species fed on pruning wound sap and effectively transmitted trunk disease pathogens. Millipede excreta contained viable spores of Phaeomoniella chlamydospora and may serve as an inoculum source. Numerous arthropods, including beneficial predators, are potential vectors of grapevine trunk disease pathogens. Our results highlight the need for an integrated approach, including targeted management of ants and millipedes at the time of pruning, to limit the spread of grapevine trunk diseases.

Kinetic models of gene expression including non-coding RNAs

Energy Technology Data Exchange (ETDEWEB)

Zhdanov, Vladimir P., E-mail: zhdanov@catalysis.r

2011-03-15

In cells, genes are transcribed into mRNAs, and the latter are translated into proteins. Due to the feedbacks between these processes, the kinetics of gene expression may be complex even in the simplest genetic networks. The corresponding models have already been reviewed in the literature. A new avenue in this field is related to the recognition that the conventional scenario of gene expression is fully applicable only to prokaryotes whose genomes consist of tightly packed protein-coding sequences. In eukaryotic cells, in contrast, such sequences are relatively rare, and the rest of the genome includes numerous transcript units representing non-coding RNAs (ncRNAs). During the past decade, it has become clear that such RNAs play a crucial role in gene expression and accordingly influence a multitude of cellular processes both in the normal state and during diseases. The numerous biological functions of ncRNAs are based primarily on their abilities to silence genes via pairing with a target mRNA and subsequently preventing its translation or facilitating degradation of the mRNA-ncRNA complex. Many other abilities of ncRNAs have been discovered as well. Our review is focused on the available kinetic models describing the mRNA, ncRNA and protein interplay. In particular, we systematically present the simplest models without kinetic feedbacks, models containing feedbacks and predicting bistability and oscillations in simple genetic networks, and models describing the effect of ncRNAs on complex genetic networks. Mathematically, the presentation is based primarily on temporal mean-field kinetic equations. The stochastic and spatio-temporal effects are also briefly discussed.

Magnitude Knowledge: The Common Core of Numerical Development

Science.gov (United States)

Siegler, Robert S.

2016-01-01

The integrated theory of numerical development posits that a central theme of numerical development from infancy to adulthood is progressive broadening of the types and ranges of numbers whose magnitudes are accurately represented. The process includes four overlapping trends: (1) representing increasingly precisely the magnitudes of non-symbolic…

A review of numerical techniques approaching microstructures of crystalline rocks

Science.gov (United States)

Zhang, Yahui; Wong, Louis Ngai Yuen

2018-06-01

The macro-mechanical behavior of crystalline rocks including strength, deformability and failure pattern are dominantly influenced by their grain-scale structures. Numerical technique is commonly used to assist understanding the complicated mechanisms from a microscopic perspective. Each numerical method has its respective strengths and limitations. This review paper elucidates how numerical techniques take geometrical aspects of the grain into consideration. Four categories of numerical methods are examined: particle-based methods, block-based methods, grain-based methods, and node-based methods. Focusing on the grain-scale characters, specific relevant issues including increasing complexity of micro-structure, deformation and breakage of model elements, fracturing and fragmentation process are described in more detail. Therefore, the intrinsic capabilities and limitations of different numerical approaches in terms of accounting for the micro-mechanics of crystalline rocks and their phenomenal mechanical behavior are explicitly presented.

Reliability and limitation of various diagnostic methods including nuclear medicine in myocardial disease

International Nuclear Information System (INIS)

Tokuyasu, Yoshiki; Kusakabe, Kiyoko; Yamazaki, Toshio

1981-01-01

Electrocardiography (ECG), echocardiography, nuclear method, cardiac catheterization, left ventriculography and endomyocardial biopsy (biopsy) were performed in 40 cases of cardiomyopathy (CM), 9 of endocardial fibroelastosis and 19 of specific heart muscle disease, and the usefulness and limitation of each method was comparatively estimated. In CM, various methods including biopsy were performed. The 40 patients were classified into 3 groups, i.e., hypertrophic (17), dilated (20) and non-hypertrophic.non-dilated (3) on the basis of left ventricular ejection fraction and hypertrophy of the ventricular wall. The hypertrophic group was divided into 4 subgroups: 9 septal, 4 apical, 2 posterior and 2 anterior. The nuclear study is useful in assessing the site of the abnormal ventricular thickening, perfusion defect and ventricular function. Echocardiography is most useful in detecting asymmetric septal hypertrophy. The biopsy gives the sole diagnostic clue, especially in non-hypertrophic.non-dilated cardiomyopathy. ECG is useful in all cases but correlation with the site of disproportional hypertrophy was not obtained. (J.P.N.)

Stochastic numerical methods an introduction for students and scientists

CERN Document Server

Toral, Raul

2014-01-01

Stochastic Numerical Methods introduces at Master level the numerical methods that use probability or stochastic concepts to analyze random processes. The book aims at being rather general and is addressed at students of natural sciences (Physics, Chemistry, Mathematics, Biology, etc.) and Engineering, but also social sciences (Economy, Sociology, etc.) where some of the techniques have been used recently to numerically simulate different agent-based models. Examples included in the book range from phase-transitions and critical phenomena, including details of data analysis (extraction of critical exponents, finite-size effects, etc.), to population dynamics, interfacial growth, chemical reactions, etc. Program listings are integrated in the discussion of numerical algorithms to facilitate their understanding. From the contents: Review of Probability ConceptsMonte Carlo IntegrationGeneration of Uniform and Non-uniformRandom Numbers: Non-correlated ValuesDynamical MethodsApplications to Statistical MechanicsIn...

The Role of High-Density Lipoproteins in Reducing the Risk of Vascular Diseases, Neurogenerative Disorders, and Cancer

Directory of Open Access Journals (Sweden)

Donovan McGrowder

2011-01-01

Full Text Available High-density lipoprotein (HDL is one of the major carriers of cholesterol in the blood. It attracts particular attention because, in contrast with other lipoproteins, as many physiological functions of HDL influence the cardiovascular system in favourable ways unless HDL is modified pathologically. The functions of HDL that have recently attracted attention include anti-inflammatory and anti-oxidant activities. High anti-oxidant and anti-inflammatory activities of HDL are associated with protection from cardiovascular disease. Atheroprotective activities, as well as a functional deficiency of HDL, ultimately depend on the protein and lipid composition of HDL. Further, numerous epidemiological studies have shown a protective association between HDL-cholesterol and cognitive impairment. Oxidative stress, including lipid peroxidation, has been shown to be the mediator of the pathologic effects of numerous risk factors of Alzheimer's disease. Lifestyle interventions proven to increase HDL- cholesterol levels including “healthy” diet, regular exercise, weight control, and smoking cessation have also been shown to provide neuro-protective effects. This review will focus on current knowledge of the beneficial effects of HDL-cholesterol as it relates to cardiovascular diseases, breast and lung cancers, non-Hodgkin's lymphoma, as well as its neuroprotective potential in reducing the risk of Alzheimer's disease and dementia.

Numerical Modelling of Flow and Settling in Secondary Settling Tanks

DEFF Research Database (Denmark)

Dahl, Claus Poulsen

This thesis discusses the development of a numerical model for the simulation of secondary settling tanks. In the first part, the status on the development of numerical models for settling tanks and a discussion of the current design practice are presented. A study of the existing numerical models...... and design practice proved a demand for further development to include numerical models in the design of settling tanks, thus improving the future settling tanks....

Are Humans too Numerous to Become Extinct?

OpenAIRE

Cairns, John

2009-01-01

Some claim that humans are too numerous to become extinct. However, passenger pigeon, once the most numerous birds on the planet, are now extinct. For years, humankind has been damaging its habitat, discharging toxic chemicals into the environment, and having harmful effects on agricultural productivity due to climate change. Humankind s extinction depends on the continuation of various human activities including economic growth, addiction to fossil fuel, over consumption, overpopulation, oc...

CHIRON: a package for ChPT numerical results at two loops

Energy Technology Data Exchange (ETDEWEB)

Bijnens, Johan [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden)

2015-01-01

This document describes the package CHIRON which includes two libraries, chiron itself and jbnumlib.chiron is a set of routines useful for two-loop numerical results in chiral perturbation theory (ChPT). It includes programs for the needed one- and two-loop integrals as well as routines to deal with the ChPT parameters. The present version includes everything needed for the masses, decay constants and quark-antiquark vacuum-expectation-values. An added routine calculates consistent values for the masses and decay constants when the pion and kaon masses are varied. In addition a number of finite volume results are included: one-loop tadpole integrals, two-loop sunset integrals and the results for masses and decay constants. The numerical routine library jbnumlib contains the numerical routines used in chiron. Many are to a large extent simple C++ versions of routines in the CERNLIB numerical library. Notable exceptions are the dilogarithm and the Jacobi theta function implementations. This paper describes what is included in CHIRON v0.50. (orig.)

Numerical methods in simulation of resistance welding

DEFF Research Database (Denmark)

Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi

2015-01-01

Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...... thecontact area and the distribution of contact pressure. The numerical simulation of resistancewelding is illustrated by a spot welding example that includes subsequent tensile shear testing...

Numerical studies of the linear theta pinch

International Nuclear Information System (INIS)

Brackbill, J.U.; Menzel, M.T.; Barnes, D.C.

1975-01-01

Aspects of several physical problems associated with linear theta pinches were studied using recently developed numerical methods for the solution of the nonlinear equations for time-dependent magnetohydrodynamic flow in two- and three-dimensions. The problems studied include the propagation of end-loss produced rarefaction waves, the flow produced in a proposed injection experiment geometry, and the linear growth and nonlinear saturation of instabilities in rotating plasmas, all in linear geometries. The studies illustrate how numerical computations aid in flow visualization, and how the small amplitude behavior and nonlinear fate of plasmas in unstable equilibria can be connected through the numerical solution of the dynamical equations. (auth)

Coincidental match of numerical simulation and physics

Science.gov (United States)

Pierre, B.; Gudmundsson, J. S.

2010-08-01

Consequences of rapid pressure transients in pipelines range from increased fatigue to leakages and to complete ruptures of pipeline. Therefore, accurate predictions of rapid pressure transients in pipelines using numerical simulations are critical. State of the art modelling of pressure transient in general, and water hammer in particular include unsteady friction in addition to the steady frictional pressure drop, and numerical simulations rely on the method of characteristics. Comparison of rapid pressure transient calculations by the method of characteristics and a selected high resolution finite volume method highlights issues related to modelling of pressure waves and illustrates that matches between numerical simulations and physics are purely coincidental.

Towards standard testbeds for numerical relativity

International Nuclear Information System (INIS)

Alcubierre, Miguel; Allen, Gabrielle; Bona, Carles; Fiske, David; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Hawley, Scott H; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David; Salgado, Marcelo; Schnetter, Erik; Seidel, Edward; Shinkai, Hisa-aki; Shoemaker, Deirdre; Szilagyi, Bela; Takahashi, Ryoji; Winicour, Jeff

2004-01-01

In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community

Towards standard testbeds for numerical relativity

Energy Technology Data Exchange (ETDEWEB)

Alcubierre, Miguel [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Allen, Gabrielle; Goodale, Tom; Guzman, F Siddhartha; Hawke, Ian; Husa, Sascha; Koppitz, Michael; Lechner, Christiane; Pollney, Denis; Rideout, David [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany); Bona, Carles [Departament de Fisica, Universitat de les Illes Balears, Ctra de Valldemossa km 7.5, 07122 Palma de Mallorca (Spain); Fiske, David [Dept. of Physics, Univ. of Maryland, College Park, MD 20742-4111 (United States); Hawley, Scott H [Center for Relativity, Univ. of Texas at Austin, Austin, Texas 78712 (United States); Salgado, Marcelo [Inst. de Ciencias Nucleares, Univ. Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico); Schnetter, Erik [Inst. fuer Astronomie und Astrophysik, Universitaet Tuebingen, 72076 Tuebingen (Germany); Seidel, Edward [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Inst., 14476 Golm (Germany); Shinkai, Hisa-aki [Computational Science Div., Inst. of Physical and Chemical Research (RIKEN), Hirosawa 2-1, Wako, Saitama 351-0198 (Japan); Shoemaker, Deirdre [Center for Radiophysics and Space Research, Cornell Univ., Ithaca, NY 14853 (United States); Szilagyi, Bela [Dept. of Physics and Astronomy, Univ. of Pittsburgh, Pittsburgh, PA 15260 (United States); Takahashi, Ryoji [Theoretical Astrophysics Center, Juliane Maries Vej 30, 2100 Copenhagen, (Denmark); Winicour, Jeff [Max-Planck-Inst. fuer Gravitationsphysik, Albert-Einstein-Institut, 14476 Golm (Germany)

2004-01-21

In recent years, many different numerical evolution schemes for Einstein's equations have been proposed to address stability and accuracy problems that have plagued the numerical relativity community for decades. Some of these approaches have been tested on different spacetimes, and conclusions have been drawn based on these tests. However, differences in results originate from many sources, including not only formulations of the equations, but also gauges, boundary conditions, numerical methods and so on. We propose to build up a suite of standardized testbeds for comparing approaches to the numerical evolution of Einstein's equations that are designed to both probe their strengths and weaknesses and to separate out different effects, and their causes, seen in the results. We discuss general design principles of suitable testbeds, and we present an initial round of simple tests with periodic boundary conditions. This is a pivotal first step towards building a suite of testbeds to serve the numerical relativists and researchers from related fields who wish to assess the capabilities of numerical relativity codes. We present some examples of how these tests can be quite effective in revealing various limitations of different approaches, and illustrating their differences. The tests are presently limited to vacuum spacetimes, can be run on modest computational resources and can be used with many different approaches used in the relativity community.

Potential Applications and Limitations of Electronic Nose Devices for Plant Disease Diagnosis

Directory of Open Access Journals (Sweden)

Antonio Cellini

2017-11-01

Full Text Available Electronic nose technology has recently been applied to the detection of several plant diseases and pests, with promising results. However, in spite of its numerous advantages, including operational simplicity, non-destructivity, and bulk sampling, drawbacks include a low sensitivity and specificity in comparison with microbiological and molecular methods. A critical review of the use of an electronic nose for plant disease diagnosis and pest detection is presented, describing the instrumental and procedural advances of sensorial analysis, for the improvement of discrimination between healthy and infected or infested plants. In conclusion, the use of electronic nose technology is suggested to assist, direct, and optimise traditionally adopted diagnostic techniques.

Numerical analysis of electromagnetic fields

CERN Document Server

Zhou Pei Bai

1993-01-01

Numerical methods for solving boundary value problems have developed rapidly. Knowledge of these methods is important both for engineers and scientists. There are many books published that deal with various approximate methods such as the finite element method, the boundary element method and so on. However, there is no textbook that includes all of these methods. This book is intended to fill this gap. The book is designed to be suitable for graduate students in engineering science, for senior undergraduate students as well as for scientists and engineers who are interested in electromagnetic fields. Objective Numerical calculation is the combination of mathematical methods and field theory. A great number of mathematical concepts, principles and techniques are discussed and many computational techniques are considered in dealing with practical problems. The purpose of this book is to provide students with a solid background in numerical analysis of the field problems. The book emphasizes the basic theories ...

Numerical Modelling Of Pumpkin Balloon Instability

Science.gov (United States)

Wakefield, D.

Tensys have been involved in the numerical formfinding and load analysis of architectural stressed membrane structures for 15 years. They have recently broadened this range of activities into the `lighter than air' field with significant involvement in aerostat and heavy-lift hybrid airship design. Since early 2004 they have been investigating pumpkin balloon instability on behalf of the NASA ULDB programme. These studies are undertaken using inTENS, an in-house finite element program suite based upon the Dynamic Relaxation solution method and developed especially for the non-linear analysis and patterning of membrane structures. The paper describes the current state of an investigation that started with a numerical simulation of the lobed cylinder problem first studied by Calladine. The influence of material properties and local geometric deformation on stability is demonstrated. A number of models of complete pumpkin balloons have then been established, including a 64-gore balloon with geometry based upon Julian Nott's Endeavour. This latter clefted dramatically upon initial inflation, a phenomenon that has been reproduced in the numerical model. Ongoing investigations include the introduction of membrane contact modelling into inTENS and correlation studies with the series of large-scale ULDB models currently in preparation.

Efficacy of a Multimodal Cognitive Rehabilitation Including Psychomotor and Endurance Training in Parkinson's Disease

Directory of Open Access Journals (Sweden)

I. Reuter

2012-01-01

Full Text Available Mild cognitive impairment, especially executive dysfunction might occur early in the course of Parkinson's disease. Cognitive training is thought to improve cognitive performance. However, transfer of improvements achieved in paper and pencil tests into daily life has been difficult. The aim of the current study was to investigate whether a multimodal cognitive rehabilitation programme including physical exercises might be more successful than cognitive training programmes without motor training. 240 PD-patients were included in the study and randomly allocated to three treatment arms, group A cognitive training, group B cognitive training and transfer training and group C cognitive training, transfer training and psychomotor and endurance training. The primary outcome measure was the ADAS-Cog. The secondary outcome measure was the SCOPA-Cog. Training was conducted for 4 weeks on a rehabilitation unit, followed by 6 months training at home. Caregivers received an education programme. The combination of cognitive training using paper and pencil and the computer, transfer training and physical training seems to have the greatest effect on cognitive function. Thus, patients of group C showed the greatest improvement on the ADAS-Cog and SCOPA-COG and were more likely to continue with the training programme after the study.

Mucosal-associated invariant T cells are numerically and functionally deficient in patients with mycobacterial infection and reflect disease activity.

Science.gov (United States)

Kwon, Yong-Soo; Cho, Young-Nan; Kim, Moon-Ju; Jin, Hye-Mi; Jung, Hyun-Ju; Kang, Jeong-Hwa; Park, Ki-Jeong; Kim, Tae-Jong; Kee, Hae Jin; Kim, Nacksung; Kee, Seung-Jung; Park, Yong-Wook

2015-05-01

Mucosal-associated invariant T (MAIT) cells contribute to protection against certain microorganism infections. The aims of this study were to examine the levels of MAIT cells in pulmonary tuberculosis (TB) and nontuberculous mycobacteria (NTM) lung disease patients, to evaluate the clinical relevance of MAIT cell levels, and to investigate the functions of MAIT cells. Patients with pulmonary TB (n = 35), NTM (n = 29), and healthy controls (n = 75) were enrolled in the study. MAIT cell levels and functions were measured by flow cytometry. Circluating MAIT cell levels were found to be reduced in TB and NTM patients. MAIT cell deficiency reflects a variety of clinical conditions. In particular, MAIT cell numbers were significantly correlated with sputum AFB positivity, extent of disease, hemoglobin levels, lymphocyte counts, CRP and ESR levels. MAIT cells in TB patients failed to produce interferon-γ irrespective of the mode of stimulation, whereas NTM patients displayed a defect in MR1-dependent signaling pathway. Notably, an elevated expression of programmed death-1 was also associated with MAIT cell deficiency in TB. This study shows that MAIT cells are numerically and functionally deficient in TB and NTM patients and these deficiencies could contribute to immune system dysreguation in mycobacterial infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

Numerical analysis

CERN Document Server

Rao, G Shanker

2006-01-01

About the Book: This book provides an introduction to Numerical Analysis for the students of Mathematics and Engineering. The book is designed in accordance with the common core syllabus of Numerical Analysis of Universities of Andhra Pradesh and also the syllabus prescribed in most of the Indian Universities. Salient features: Approximate and Numerical Solutions of Algebraic and Transcendental Equation Interpolation of Functions Numerical Differentiation and Integration and Numerical Solution of Ordinary Differential Equations The last three chapters deal with Curve Fitting, Eigen Values and Eigen Vectors of a Matrix and Regression Analysis. Each chapter is supplemented with a number of worked-out examples as well as number of problems to be solved by the students. This would help in the better understanding of the subject. Contents: Errors Solution of Algebraic and Transcendental Equations Finite Differences Interpolation with Equal Intervals Interpolation with Unequal Int...

[Venous thromboembolic disease: presentation of a case].

Science.gov (United States)

Mirpuri-Mirpuri, P G; Álvarez-Cordovés, M M; Pérez-Monje, A

2013-01-01

Venous thromboembolic disease in its clinical spectrum includes both deep vein thrombosis and pulmonary thromboembolism, which is usually a complication of deep vein thrombosis. It is a relatively common disease with significant morbidity and requires an accurate diagnosis. They are numerous risk factors for venous thromboembolism, and there is evidence that the risk of thromboembolic disease increases proportionally to the number of predisposing risk factors present. The primary care physician should know the risk factors and suspect the presence of venous thromboembolic disease when there is a compatible clnical picture. The treatment for this pathology is anticoagulation. We report a patient with cardiovascular risk factors who was seen with pain in the right leg and shortness of breath and referred to the hospital with suspected venous thromboembolism, atrial fibrillation and pleural effusion. Copyright © 2012 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España. All rights reserved.

On Numerical Methods for Including the Effect of Capillary Pressure Forces on Two-phase, Immiscible Flow in a Layered Porous Medium

Energy Technology Data Exchange (ETDEWEB)

Ersland, B.G.

1996-05-01

This mathematical doctoral thesis contains the theory, algorithms and numerical simulations for a heterogeneous oil reservoir. It presents the equations, which apply to immiscible and incompressible two-phase fluid flow in the reservoir, including the effect of capillary pressure forces, and emphasises in particular the interior boundary conditions at the interface between two sediments. Two different approaches are discussed. The first approach is to decompose the computational domain along the interior boundary and iterate between the subdomains until mass balance is achieved. The second approach accounts for the interior boundary conditions in the basis in which the solution is expanded, the basis being discontinuous over the interior boundaries. An overview of the construction of iterative solvers for partial differential equations by means of Schwartz methods is given, and the algorithm for local refinement with Schwartz iterations as iterative solver is described. The theory is then applied to a core plug problem in one and two space dimensions and the results of different methods compared. A general description is given of the computer simulation model, which is implemented in C++. 64 refs., 49 figs., 7 tabs.

Upper aerodigestive tract disorders and gastro-oesophageal reflux disease.

Science.gov (United States)

Ciorba, Andrea; Bianchini, Chiara; Zuolo, Michele; Feo, Carlo Vittorio

2015-02-16

A wide variety of symptoms and diseases of the upper aerodigestive tract are associated to gastro-oesophageal reflux disease (GORD). These disorders comprise a large variety of conditions such as asthma, chronic otitis media and sinusitis, chronic cough, and laryngeal disorders including paroxysmal laryngospasm. Laryngo-pharyngeal reflux disease is an extraoesophageal variant of GORD that can affect the larynx and pharynx. Despite numerous research efforts, the diagnosis of laryngopharyngeal reflux often remains elusive, unproven and controversial, and its treatment is then still empiric. Aim of this paper is to review the current literature on upper aerodigestive tract disorders in relation to pathologic gastro-oesophageal reflux, focusing in particular on the pathophysiology base and results of the surgical treatment of GORD.

Numerical Analysis of Dusty-Gas Flows

Science.gov (United States)

Saito, T.

2002-02-01

This paper presents the development of a numerical code for simulating unsteady dusty-gas flows including shock and rarefaction waves. The numerical results obtained for a shock tube problem are used for validating the accuracy and performance of the code. The code is then extended for simulating two-dimensional problems. Since the interactions between the gas and particle phases are calculated with the operator splitting technique, we can choose numerical schemes independently for the different phases. A semi-analytical method is developed for the dust phase, while the TVD scheme of Harten and Yee is chosen for the gas phase. Throughout this study, computations are carried out on SGI Origin2000, a parallel computer with multiple of RISC based processors. The efficient use of the parallel computer system is an important issue and the code implementation on Origin2000 is also described. Flow profiles of both the gas and solid particles behind the steady shock wave are calculated by integrating the steady conservation equations. The good agreement between the pseudo-stationary solutions and those from the current numerical code validates the numerical approach and the actual coding. The pseudo-stationary shock profiles can also be used as initial conditions of unsteady multidimensional simulations.

Balloon angioplasty in acute and chronic coronary artery disease

International Nuclear Information System (INIS)

Holmes, D.R. Jr.; Vlietstra, R.E.

1989-01-01

Percutaneous transluminal coronary angioplasty has grown exponentially since its introduction. Currently, selection criteria include single-vessel and multivessel disease, stable and unstable angina, and acute infarction. The outcome depends on specific patient and antiographic characteristics. In ideal lesions, success rates should be greater than 90%, with low morbidity and mortality. With more severe and diffuse multivessel disease, success rates are lower and complication rates are higher. In these cases, percutaneous transluminal coronary angioplasty still offers a reasonable option, provided complete revascularization can be achieved or the angina-producing lesion dilated. Numerous issues remain unresolved, including (1) the role of percutaneous transluminal coronary angioplasty vs coronary surgery (currently being tested), (2) restenosis, which occurs in approximately 30% of treated lesions, and (3) organizational adjustments such as training and certification to maintain high standards of care

A delta-rule model of numerical and non-numerical order processing.

Science.gov (United States)

Verguts, Tom; Van Opstal, Filip

2014-06-01

Numerical and non-numerical order processing share empirical characteristics (distance effect and semantic congruity), but there are also important differences (in size effect and end effect). At the same time, models and theories of numerical and non-numerical order processing developed largely separately. Currently, we combine insights from 2 earlier models to integrate them in a common framework. We argue that the same learning principle underlies numerical and non-numerical orders, but that environmental features determine the empirical differences. Implications for current theories on order processing are pointed out. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Numerical differential protection

CERN Document Server

Ziegler, Gerhard

2012-01-01

Differential protection is a fast and selective method of protection against short-circuits. It is applied in many variants for electrical machines, trans?formers, busbars, and electric lines.Initially this book covers the theory and fundamentals of analog and numerical differential protection. Current transformers are treated in detail including transient behaviour, impact on protection performance, and practical dimensioning. An extended chapter is dedicated to signal transmission for line protection, in particular, modern digital communication and GPS timing.The emphasis is then pla

Fluid Dynamics Theory, Computation, and Numerical Simulation

CERN Document Server

Pozrikidis, Constantine

2009-01-01

Fluid Dynamics: Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner. The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming. This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice. There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes. Two distinguishing features of the discourse are: solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty. Matlab codes are presented and discussed for ...

Molecular dynamics with deterministic and stochastic numerical methods

CERN Document Server

Leimkuhler, Ben

2015-01-01

This book describes the mathematical underpinnings of algorithms used for molecular dynamics simulation, including both deterministic and stochastic numerical methods. Molecular dynamics is one of the most versatile and powerful methods of modern computational science and engineering and is used widely in chemistry, physics, materials science and biology. Understanding the foundations of numerical methods means knowing how to select the best one for a given problem (from the wide range of techniques on offer) and how to create new, efficient methods to address particular challenges as they arise in complex applications.  Aimed at a broad audience, this book presents the basic theory of Hamiltonian mechanics and stochastic differential equations, as well as topics including symplectic numerical methods, the handling of constraints and rigid bodies, the efficient treatment of Langevin dynamics, thermostats to control the molecular ensemble, multiple time-stepping, and the dissipative particle dynamics method...

Potential of chromatin modifying compounds for the treatment of Alzheimer's disease.

Science.gov (United States)

Karagiannis, Tom C; Ververis, Katherine

2012-01-01

Alzheimer's disease is a very common progressive neurodegenerative disorder affecting the learning and memory centers in the brain. The hallmarks of disease are the accumulation of β-amyloid neuritic plaques and neurofibrillary tangles formed by abnormally phosphorylated tau protein. Alzheimer's disease is currently incurable and there is an intense interest in the development of new potential therapies. Chromatin modifying compounds such as sirtuin modulators and histone deacetylase inhibitors have been evaluated in models of Alzheimer's disease with some promising results. For example, the natural antioxidant and sirtuin 1 activator resveratrol has been shown to have beneficial effects in animal models of disease. Similarly, numerous histone deacetylase inhibitors including Trichostatin A, suberoylanilide hydroxamic acid, valproic acid and phenylbutyrate reduction have shown promising results in models of Alzheimer's disease. These beneficial effects include a reduction of β-amyloid production and stabilization of tau protein. In this review we provide an overview of the histone deacetylase enzymes, with a focus on enzymes that have been identified to have an important role in the pathobiology of Alzheimer's disease. Further, we discuss the potential for pharmacological intervention with chromatin modifying compounds that modulate histone deacetylase enzymes.

Potential of chromatin modifying compounds for the treatment of Alzheimer's disease

Directory of Open Access Journals (Sweden)

Tom C. Karagiannis

2012-02-01

Full Text Available Alzheimer's disease is a very common progressive neurodegenerative disorder affecting the learning and memory centers in the brain. The hallmarks of disease are the accumulation of β-amyloid neuritic plaques and neurofibrillary tangles formed by abnormally phosphorylated tau protein. Alzheimer's disease is currently incurable and there is an intense interest in the development of new potential therapies. Chromatin modifying compounds such as sirtuin modulators and histone deacetylase inhibitors have been evaluated in models of Alzheimer's disease with some promising results. For example, the natural antioxidant and sirtuin 1 activator resveratrol has been shown to have beneficial effects in animal models of disease. Similarly, numerous histone deacetylase inhibitors including Trichostatin A, suberoylanilide hydroxamic acid, valproic acid and phenylbutyrate reduction have shown promising results in models of Alzheimer's disease. These beneficial effects include a reduction of β-amyloid production and stabilization of tau protein. In this review we provide an overview of the histone deacetylase enzymes, with a focus on enzymes that have been identified to have an important role in the pathobiology of Alzheimer's disease. Further, we discuss the potential for pharmacological intervention with chromatin modifying compounds that modulate histone deacetylase enzymes.

Playing Linear Numerical Board Games Promotes Low-Income Children's Numerical Development

Science.gov (United States)

Siegler, Robert S.; Ramani, Geetha B.

2008-01-01

The numerical knowledge of children from low-income backgrounds trails behind that of peers from middle-income backgrounds even before the children enter school. This gap may reflect differing prior experience with informal numerical activities, such as numerical board games. Experiment 1 indicated that the numerical magnitude knowledge of…

Numerical issues for liquid-metal boiling transient analysis

International Nuclear Information System (INIS)

Rowe, D.S.

1986-01-01

The large liquid-to-vapor density ratio of a boiling liquid-metal leads to a very abrupt change of the two-phase mixture density at the inception of boiling. Unfortunately, the strong dependence of mixture density on pressure leads to a key numerical issue that adversely affects the behavior of numerical solutions. The difficulties can be reduced by using techniques that acknowledge this functional behavior at the start of boiling. Some of the methods used include a spatially averaged density function, mathematical smoothing, and under relaxation. Nonequilibrium two-fluid models also seem to offer aid in obtaining reliable numerical solutions. (author)

Neuroproteases in peptide neurotransmission and neurodegenerative diseases: applications to drug discovery research.

Science.gov (United States)

Hook, Vivian Y H

2006-01-01

The nervous system represents a key area for development of novel therapeutic agents for the treatment of neurological and neurodegenerative diseases. Recent research has demonstrated the critical importance of neuroproteases for the production of specific peptide neurotransmitters and for the production of toxic peptides in major neurodegenerative diseases that include Alzheimer, Huntington, and Parkinson diseases. This review illustrates the successful criteria that have allowed identification of proteases responsible for converting protein precursors into active peptide neurotransmitters, consisting of dual cysteine protease and subtilisin-like protease pathways in neuroendocrine cells. These peptide neurotransmitters are critical regulators of neurologic conditions, including analgesia and cognition, and numerous behaviors. Importantly, protease pathways also represent prominent mechanisms in neurodegenerative diseases, especially Alzheimer, Huntington, and Parkinson diseases. Recent studies have identified secretory vesicle cathepsin B as a novel beta-secretase for production of the neurotoxic beta-amyloid (Abeta) peptide of Alzheimer disease. Moreover, inhibition of cathepsin B reduces Abeta peptide levels in brain. These neuroproteases potentially represent new drug targets that should be explored in future pharmaceutical research endeavors for drug discovery.

Central nervous system infectious diseases mimicking multiple sclerosis: recognizing distinguishable features using MRI

Directory of Open Access Journals (Sweden)

Antonio Jose da Rocha

2013-09-01

Full Text Available The current diagnostic criteria for multiple sclerosis (MS confirm the relevant role of magnetic resonance imaging (MRI, supporting the possibility of characterizing the dissemination in space (DIS and the dissemination in time (DIT in a single scan. To maintain the specificity of these criteria, it is necessary to determine whether T2/FLAIR visible lesions and the gadolinium enhancement can be attributed to diseases that mimic MS. Several diseases are included in the MS differential diagnosis list, including diseases with exacerbation, remitting periods and numerous treatable infectious diseases, which can mimic the MRI features of MS. We discuss the most relevant imaging features in several infectious diseases that resemble MS and examine the primary spatial distributions of lesions and the gadolinium enhancement patterns related to MS. Recognizing imaging "red flags" can be useful for the proper diagnostic evaluation of suspected cases of MS, facilitating the correct differential diagnosis by assessing the combined clinical, laboratory and MR imaging information.

Modeling Electric Double-Layers Including Chemical Reaction Effects

DEFF Research Database (Denmark)

Paz-Garcia, Juan Manuel; Johannesson, Björn; Ottosen, Lisbeth M.

2014-01-01

A physicochemical and numerical model for the transient formation of an electric double-layer between an electrolyte and a chemically-active flat surface is presented, based on a finite elements integration of the nonlinear Nernst-Planck-Poisson model including chemical reactions. The model works...... for symmetric and asymmetric multi-species electrolytes and is not limited to a range of surface potentials. Numerical simulations are presented, for the case of a CaCO3 electrolyte solution in contact with a surface with rate-controlled protonation/deprotonation reactions. The surface charge and potential...... are determined by the surface reactions, and therefore they depends on the bulk solution composition and concentration...

Lecture notes in numerical analysis with Mathematica

CERN Document Server

Styś, Tadeusz

2014-01-01

The contents of this book include chapters on floating point computer arithmetic, natural and generalized interpolating polynomials, uniform approximation, numerical integration, polynomial splines and many more.This book is intended for undergraduate and graduate students in institutes, colleges, universities and academies who want to specialize in this field. The readers will develop a solid understanding of the concepts of numerical methods and their application. The inclusion of Lagrane and Hermite approximation by polynomials, Trapezian rule, Simpsons rule, Gauss methods and Romberg`s met

Classical mechanics including an introduction to the theory of elasticity

CERN Document Server

Hentschke, Reinhard

2017-01-01

This textbook teaches classical mechanics as one of the foundations of physics. It describes the mechanical stability and motion in physical systems ranging from the molecular to the galactic scale. Aside from the standard topics of mechanics in the physics curriculum, this book includes an introduction to the theory of elasticity and its use in selected modern engineering applications, e.g. dynamic mechanical analysis of viscoelastic materials. The text also covers many aspects of numerical mechanics, ranging from the solution of ordinary differential equations, including molecular dynamics simulation of many particle systems, to the finite element method. Attendant Mathematica programs or parts thereof are provided in conjunction with selected examples. Numerous links allow the reader to connect to related subjects and research topics. Among others this includes statistical mechanics (separate chapter), quantum mechanics, space flight, galactic dynamics, friction, and vibration spectroscopy. An introductory...

Silicone breast implants and connective tissue disease

DEFF Research Database (Denmark)

Lipworth, Loren; Holmich, Lisbet R; McLaughlin, Joseph K

2011-01-01

The association of silicone breast implants with connective tissue diseases (CTDs), including systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, and fibromyalgia, as well as a hypothesized new "atypical" disease, which does not meet established diagnostic criteria for any known...... CTD, has been extensively studied. We have reviewed the epidemiologic literature regarding an association between cosmetic breast implants and CTDs, with particular emphasis on results drawn from the most recent investigations, many of which are large cohort studies with long-term follow-up, as well...... as on those studies that address some of the misinformation and historically widespread claims regarding an association between breast implants and CTDs. These claims have been unequivocally refuted by the remarkably consistent evidence from published studies, as well as numerous independent meta...

Effect of changes in human ecology and behavior on patterns of sexually transmitted diseases, including human immunodeficiency virus infection.

Science.gov (United States)

Wasserheit, J N

1994-01-01

The last 20 years have witnessed six striking changes in patterns of sexually transmitted diseases (STDs): emergence of new STD organisms and etiologies, reemergence of old STDs, shifts in the populations in which STDs are concentrated, shifts in the etiological spectra of STD syndromes, alterations in the incidence of STD complications, and increases in antimicrobial resistance. For example, human immunodeficiency virus (HIV) emerged to devastate the United States with a fatal pandemic involving at least 1 million people. The incidence of syphilis rose progressively after 1956 to reach a 40-year peak by 1990. In both cases, disease patterns shifted from homosexual men to include minority heterosexuals. Over the last decade, gonorrhea became increasingly concentrated among adolescents, and several new types of antimicrobial resistance appeared. Three interrelated types of environments affect STD patterns. The microbiologic, hormonal, and immunologic microenvironments most directly influence susceptibility, infectiousness, and development of sequelae. These microenvironments are shaped, in part, by the personal environments created by an individual's sexual, substance-use, and health-related behaviors. The personal environments are also important determinants of acquisition of infection and development of sequelae but, in addition, they mediate risk of exposure to infection. These are, therefore, the environments that most directly affect changing disease patterns. Finally, individuals' personal environments are, in turn, molded by powerful macroenvironmental forces, including socioeconomic, demographic, geographic, political, epidemiologic, and technological factors. Over the past 20 years, the profound changes that have occurred in many aspects of the personal environment and the macroenvironment have been reflected in new STD patterns. PMID:8146135

Fluid dynamics theory, computation, and numerical simulation

CERN Document Server

Pozrikidis, C

2001-01-01

Fluid Dynamics Theory, Computation, and Numerical Simulation is the only available book that extends the classical field of fluid dynamics into the realm of scientific computing in a way that is both comprehensive and accessible to the beginner The theory of fluid dynamics, and the implementation of solution procedures into numerical algorithms, are discussed hand-in-hand and with reference to computer programming This book is an accessible introduction to theoretical and computational fluid dynamics (CFD), written from a modern perspective that unifies theory and numerical practice There are several additions and subject expansions in the Second Edition of Fluid Dynamics, including new Matlab and FORTRAN codes Two distinguishing features of the discourse are solution procedures and algorithms are developed immediately after problem formulations are presented, and numerical methods are introduced on a need-to-know basis and in increasing order of difficulty Matlab codes are presented and discussed for a broad...

Summary of research in applied mathematics, numerical analysis, and computer sciences

Science.gov (United States)

1986-01-01

The major categories of current ICASE research programs addressed include: numerical methods, with particular emphasis on the development and analysis of basic numerical algorithms; control and parameter identification problems, with emphasis on effective numerical methods; computational problems in engineering and physical sciences, particularly fluid dynamics, acoustics, and structural analysis; and computer systems and software, especially vector and parallel computers.

Numerical investigations of gravitational collapse

Energy Technology Data Exchange (ETDEWEB)

Csizmadia, Peter; Racz, Istvan, E-mail: iracz@rmki.kfki.h [RMKI, Budapest, Konkoly Thege Miklos ut 29-33, H-1121 (Hungary)

2010-03-01

Some properties of a new framework for simulating generic 4-dimensional spherically symmetric gravitating systems are discussed. The framework can be used to investigate spacetimes that undergo complete gravitational collapse. The analytic setup is chosen to ensure that our numerical method is capable to follow the time evolution everywhere, including the black hole region.

DISEASES

DEFF Research Database (Denmark)

Pletscher-Frankild, Sune; Pallejà, Albert; Tsafou, Kalliopi

2015-01-01

Text mining is a flexible technology that can be applied to numerous different tasks in biology and medicine. We present a system for extracting disease-gene associations from biomedical abstracts. The system consists of a highly efficient dictionary-based tagger for named entity recognition...... of human genes and diseases, which we combine with a scoring scheme that takes into account co-occurrences both within and between sentences. We show that this approach is able to extract half of all manually curated associations with a false positive rate of only 0.16%. Nonetheless, text mining should...... not stand alone, but be combined with other types of evidence. For this reason, we have developed the DISEASES resource, which integrates the results from text mining with manually curated disease-gene associations, cancer mutation data, and genome-wide association studies from existing databases...

Numerical Modeling of Ablation Heat Transfer

Science.gov (United States)

Ewing, Mark E.; Laker, Travis S.; Walker, David T.

2013-01-01

A unique numerical method has been developed for solving one-dimensional ablation heat transfer problems. This paper provides a comprehensive description of the method, along with detailed derivations of the governing equations. This methodology supports solutions for traditional ablation modeling including such effects as heat transfer, material decomposition, pyrolysis gas permeation and heat exchange, and thermochemical surface erosion. The numerical scheme utilizes a control-volume approach with a variable grid to account for surface movement. This method directly supports implementation of nontraditional models such as material swelling and mechanical erosion, extending capabilities for modeling complex ablation phenomena. Verifications of the numerical implementation are provided using analytical solutions, code comparisons, and the method of manufactured solutions. These verifications are used to demonstrate solution accuracy and proper error convergence rates. A simple demonstration of a mechanical erosion (spallation) model is also provided to illustrate the unique capabilities of the method.

Evaluation of wave runup predictions from numerical and parametric models

Science.gov (United States)

Stockdon, Hilary F.; Thompson, David M.; Plant, Nathaniel G.; Long, Joseph W.

2014-01-01

Wave runup during storms is a primary driver of coastal evolution, including shoreline and dune erosion and barrier island overwash. Runup and its components, setup and swash, can be predicted from a parameterized model that was developed by comparing runup observations to offshore wave height, wave period, and local beach slope. Because observations during extreme storms are often unavailable, a numerical model is used to simulate the storm-driven runup to compare to the parameterized model and then develop an approach to improve the accuracy of the parameterization. Numerically simulated and parameterized runup were compared to observations to evaluate model accuracies. The analysis demonstrated that setup was accurately predicted by both the parameterized model and numerical simulations. Infragravity swash heights were most accurately predicted by the parameterized model. The numerical model suffered from bias and gain errors that depended on whether a one-dimensional or two-dimensional spatial domain was used. Nonetheless, all of the predictions were significantly correlated to the observations, implying that the systematic errors can be corrected. The numerical simulations did not resolve the incident-band swash motions, as expected, and the parameterized model performed best at predicting incident-band swash heights. An assimilated prediction using a weighted average of the parameterized model and the numerical simulations resulted in a reduction in prediction error variance. Finally, the numerical simulations were extended to include storm conditions that have not been previously observed. These results indicated that the parameterized predictions of setup may need modification for extreme conditions; numerical simulations can be used to extend the validity of the parameterized predictions of infragravity swash; and numerical simulations systematically underpredict incident swash, which is relatively unimportant under extreme conditions.

Susceptibility based upon Chemical Interaction with Disease ...

Science.gov (United States)

One of the challenges facing toxicology and risk assessment is that numerous host and environmental factors may modulate vulnerability and risk. An area of increasing interest is the potential for chemicals to interact with background aging and disease processes, an interaction that may yield cumulative damage, altered chemical potency, and increased disease incidence. This review outlines the interactions possible between chemicals and background disease and identifies the type of information needed to evaluate such interactions. Key among these is the existence of a clinically relevant and easy to measure biomarker of disease risk which allows the identification of vulnerable individuals based upon the level of risk biomarker. The impact of toxic chemicals on this biomarker can then be used to predict how the chemical modifies disease risk as long as related mechanistic and toxicological data are consistent with toxicant effect on the disease process. Several case studies are briefly presented which describe the toxic chemical, the clinical biomarker and the impacted disease including: fine particulate matter/decreased heart rate variability/increased cardiopulmonary events; cadmium/decreased glomerular filtration rate/increased chronic kidney disease; methyl mercury/decreased paraoxonase-1/increased cardiovascular risk; trichloroethylene/increased anti-nuclear antibody/autoimmunity; dioxin/increased CYP1A1/hypertension. These case studies point o

Multisystem Disease, Including Eosinophilia and Progressive Hyper-Creatine-Kinase-emia over 10 Years, Suggests Mitochondrial Disorder

Directory of Open Access Journals (Sweden)

Josef Finsterer

2017-04-01

Full Text Available Background: Eosinophilia has not been reported as a manifestation of a mitochondrial disorder (MID. Here, we report a patient with clinical features suggesting a MID and permanent eosinophilia, multisystem disease, and progressive hyper-creatine-kinase (CK-emia for at least 10 years. Materials and Methods: Methods applied included a clinical exam, blood chemical investigations, electrophysiological investigations, imaging, and invasive cardiological investigations. The patient was repeatedly followed up over several years. He required replacement cardiac surgery. Results: In a 57-year-old male, eosinophilia was first detected at the age of 44 years and has remained almost constantly present until today. In addition to eosinophilia, he developed progressive hyper-CK-emia at the age of 47 years. His history was further positive for hepatopathy, hyperlipidemia, hypothyroidism, renal insufficiency, spontaneous Achilles tendon rupture, double vision, exercise intolerance, muscle aching, mild hypoacusis, sensory neuropathy, seizures, and mitral insufficiency/stenosis requiring valve replacement therapy, oral anticoagulation, and pacemaker implantation. Based on the multisystem nature of his abnormalities and permanent hyper-CK-emia, a MID was suspected. Conclusion: Eosinophilia can be associated with a MID with myopathy, possibly as a reaction to myofiber necrosis. If eosinophilia is associated with progressive hyper-CK-emia and multisystem disease, a MID should be suspected.

Crohn's disease of the vulva.

Science.gov (United States)

Barret, Maximilien; de Parades, Vincent; Battistella, Maxime; Sokol, Harry; Lemarchand, Nicolas; Marteau, Philippe

2014-07-01

Crohn's disease (CD) of the vulva is a rare, yet under recognized condition. Fistulae arising from the digestive tract account for the greater part of genital lesions in CD. However, cutaneous so-called metastatic lesions of the vulva have been reported in the literature. They are clinically challenging for gastroenterologists as well as for gynecologists, with numerous differential diagnoses, especially among venereal diseases, and require a multidisciplinary approach. The most frequently observed features of the disease are labial swelling, vulvar ulcers, and hypertrophic lesions. Biopsy samples for histological study are mandatory, in order to establish the diagnosis of vulvar CD. Treatment options include oral prolonged courses of metronidazole and systemic immunosuppressive therapy such as corticosteroids and azathioprine, with promising data published on the efficacy of infliximab. Surgery remains restricted to medical treatment failures or resection of unsightly lesions. Prospective studies or case series with long follow-up data are still missing to guide the treatment of this condition. © 2013. Published by Elsevier B.V. All rights reserved.

The contributions of numerical acuity and non-numerical stimulus features to the development of the number sense and symbolic math achievement.

Science.gov (United States)

Starr, Ariel; DeWind, Nicholas K; Brannon, Elizabeth M

2017-11-01

Numerical acuity, frequently measured by a Weber fraction derived from nonsymbolic numerical comparison judgments, has been shown to be predictive of mathematical ability. However, recent findings suggest that stimulus controls in these tasks are often insufficiently implemented, and the proposal has been made that alternative visual features or inhibitory control capacities may actually explain this relation. Here, we use a novel mathematical algorithm to parse the relative influence of numerosity from other visual features in nonsymbolic numerical discrimination and to examine the strength of the relations between each of these variables, including inhibitory control, and mathematical ability. We examined these questions developmentally by testing 4-year-old children, 6-year-old children, and adults with a nonsymbolic numerical comparison task, a symbolic math assessment, and a test of inhibitory control. We found that the influence of non-numerical features decreased significantly over development but that numerosity was a primary determinate of decision making at all ages. In addition, numerical acuity was a stronger predictor of math achievement than either non-numerical bias or inhibitory control in children. These results suggest that the ability to selectively attend to number contributes to the maturation of the number sense and that numerical acuity, independent of inhibitory control, contributes to math achievement in early childhood. Copyright © 2017 Elsevier B.V. All rights reserved.

Network-level reproduction number and extinction threshold for vector-borne diseases.

Science.gov (United States)

Xue, Ling; Scoglio, Caterina

2015-06-01

The basic reproduction number of deterministic models is an essential quantity to predict whether an epidemic will spread or not. Thresholds for disease extinction contribute crucial knowledge of disease control, elimination, and mitigation of infectious diseases. Relationships between basic reproduction numbers of two deterministic network-based ordinary differential equation vector-host models, and extinction thresholds of corresponding stochastic continuous-time Markov chain models are derived under some assumptions. Numerical simulation results for malaria and Rift Valley fever transmission on heterogeneous networks are in agreement with analytical results without any assumptions, reinforcing that the relationships may always exist and proposing a mathematical problem for proving existence of the relationships in general. Moreover, numerical simulations show that the basic reproduction number does not monotonically increase or decrease with the extinction threshold. Consistent trends of extinction probability observed through numerical simulations provide novel insights into mitigation strategies to increase the disease extinction probability. Research findings may improve understandings of thresholds for disease persistence in order to control vector-borne diseases.

A New Language Design for Prototyping Numerical Computation

Directory of Open Access Journals (Sweden)

Thomas Derby

1996-01-01

Full Text Available To naturally and conveniently express numerical algorithms, considerable expressive power is needed in the languages in which they are implemented. The language Matlab is widely used by numerical analysts for this reason. Expressiveness or ease-of-use can also result in a loss of efficiency, as is the case with Matlab. In particular, because numerical analysts are highly interested in the performance of their algorithms, prototypes are still often implemented in languages such as Fortran. In this article we describe a language design that is intended to both provide expressiveness for numerical computation, and at the same time provide performance guarantees. In our language, EQ, we attempt to include both syntactic and semantic features that correspond closely to the programmer's model of the problem, including unordered equations, large-granularity state transitions, and matrix notation. The resulting language does not fit into standard language categories such as functional or imperative but has features of both paradigms. We also introduce the notion of language dependability, which is the idea that a language should guarantee that certain program transformations are performed by all implementations. We first describe the interesting features of EQ, and then present three examples of algorithms written using it. We also provide encouraging performance results from an initial implementation of our language.

Farber's Disease

Science.gov (United States)

... management, and therapy of rare diseases, including the lipid storage diseases. Research on lipid storage diseases within the Network includes ... management, and therapy of rare diseases, including the lipid storage diseases. Research on lipid storage diseases within the Network includes ...

Aerosol simulation including chemical and nuclear reactions

International Nuclear Information System (INIS)

Marwil, E.S.; Lemmon, E.C.

1985-01-01

The numerical simulation of aerosol transport, including the effects of chemical and nuclear reactions presents a challenging dynamic accounting problem. Particles of different sizes agglomerate and settle out due to various mechanisms, such as diffusion, diffusiophoresis, thermophoresis, gravitational settling, turbulent acceleration, and centrifugal acceleration. Particles also change size, due to the condensation and evaporation of materials on the particle. Heterogeneous chemical reactions occur at the interface between a particle and the suspending medium, or a surface and the gas in the aerosol. Homogeneous chemical reactions occur within the aersol suspending medium, within a particle, and on a surface. These reactions may include a phase change. Nuclear reactions occur in all locations. These spontaneous transmutations from one element form to another occur at greatly varying rates and may result in phase or chemical changes which complicate the accounting process. This paper presents an approach for inclusion of these effects on the transport of aerosols. The accounting system is very complex and results in a large set of stiff ordinary differential equations (ODEs). The techniques for numerical solution of these ODEs require special attention to achieve their solution in an efficient and affordable manner. 4 refs

Numerical study of effect of oxygen fraction on local entropy ...

Indian Academy of Sciences (India)

This study considers numerical simulation of the combustion of methane with air, including oxygen and nitrogen, in a burner and the numerical solution of local entropy generation rate due to high temperature and velocity gradients in the combustion chamber. The effects of equivalence ratio () and oxygen percentage () ...

Curcumin, the golden nutraceutical: multitargeting for multiple chronic diseases.

Science.gov (United States)

Kunnumakkara, Ajaikumar B; Bordoloi, Devivasha; Padmavathi, Ganesan; Monisha, Javadi; Roy, Nand Kishor; Prasad, Sahdeo; Aggarwal, Bharat B

2017-06-01

Curcumin, a yellow pigment in the Indian spice Turmeric (Curcuma longa), which is chemically known as diferuloylmethane, was first isolated exactly two centuries ago in 1815 by two German Scientists, Vogel and Pelletier. However, according to the pubmed database, the first study on its biological activity as an antibacterial agent was published in 1949 in Nature and the first clinical trial was reported in The Lancet in 1937. Although the current database indicates almost 9000 publications on curcumin, until 1990 there were less than 100 papers published on this nutraceutical. At the molecular level, this multitargeted agent has been shown to exhibit anti-inflammatory activity through the suppression of numerous cell signalling pathways including NF-κB, STAT3, Nrf2, ROS and COX-2. Numerous studies have indicated that curcumin is a highly potent antimicrobial agent and has been shown to be active against various chronic diseases including various types of cancers, diabetes, obesity, cardiovascular, pulmonary, neurological and autoimmune diseases. Furthermore, this compound has also been shown to be synergistic with other nutraceuticals such as resveratrol, piperine, catechins, quercetin and genistein. To date, over 100 different clinical trials have been completed with curcumin, which clearly show its safety, tolerability and its effectiveness against various chronic diseases in humans. However, more clinical trials in different populations are necessary to prove its potential against different chronic diseases in humans. This review's primary focus is on lessons learnt about curcumin from clinical trials. This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc. © 2016 The British Pharmacological Society.

Curcumin, the golden nutraceutical: multitargeting for multiple chronic diseases

Science.gov (United States)

Bordoloi, Devivasha; Padmavathi, Ganesan; Monisha, Javadi; Roy, Nand Kishor; Prasad, Sahdeo

2016-01-01

Curcumin, a yellow pigment in the Indian spice Turmeric (Curcuma longa), which is chemically known as diferuloylmethane, was first isolated exactly two centuries ago in 1815 by two German Scientists, Vogel and Pelletier. However, according to the pubmed database, the first study on its biological activity as an antibacterial agent was published in 1949 in Nature and the first clinical trial was reported in The Lancet in 1937. Although the current database indicates almost 9000 publications on curcumin, until 1990 there were less than 100 papers published on this nutraceutical. At the molecular level, this multitargeted agent has been shown to exhibit anti‐inflammatory activity through the suppression of numerous cell signalling pathways including NF‐κB, STAT3, Nrf2, ROS and COX‐2. Numerous studies have indicated that curcumin is a highly potent antimicrobial agent and has been shown to be active against various chronic diseases including various types of cancers, diabetes, obesity, cardiovascular, pulmonary, neurological and autoimmune diseases. Furthermore, this compound has also been shown to be synergistic with other nutraceuticals such as resveratrol, piperine, catechins, quercetin and genistein. To date, over 100 different clinical trials have been completed with curcumin, which clearly show its safety, tolerability and its effectiveness against various chronic diseases in humans. However, more clinical trials in different populations are necessary to prove its potential against different chronic diseases in humans. This review's primary focus is on lessons learnt about curcumin from clinical trials. Linked Articles This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc PMID:27638428

Numerical analysis in electromagnetics the TLM method

CERN Document Server

Saguet, Pierre

2013-01-01

The aim of this book is to give a broad overview of the TLM (Transmission Line Matrix) method, which is one of the "time-domain numerical methods". These methods are reputed for their significant reliance on computer resources. However, they have the advantage of being highly general.The TLM method has acquired a reputation for being a powerful and effective tool by numerous teams and still benefits today from significant theoretical developments. In particular, in recent years, its ability to simulate various situations with excellent precision, including complex materials, has been

Numerical orbit generators of artificial earth satellites

Science.gov (United States)

Kugar, H. K.; Dasilva, W. C. C.

1984-04-01

A numerical orbit integrator containing updatings and improvements relative to the previous ones that are being utilized by the Departmento de Mecanica Espacial e Controle (DMC), of INPE, besides incorporating newer modellings resulting from the skill acquired along the time is presented. Flexibility and modularity were taken into account in order to allow future extensions and modifications. Characteristics of numerical accuracy, processing quickness, memory saving as well as utilization aspects were also considered. User's handbook, whole program listing and qualitative analysis of accuracy, processing time and orbit perturbation effects were included as well.

Numerical analysis of the performance prediction for a thermoelectric generator

Energy Technology Data Exchange (ETDEWEB)

Kim, Chang Nyung [Kyung Hee University, Yongin (Korea, Republic of)

2015-09-15

The present study develops a two-dimensional numerical code that can predict the performance of a thermoelectric generator module including a p-leg/n-leg pair and top and bottom electrodes. The present code can simulate the detailed thermoelectric phenomena including the heat flow, electric current, Joule heating, Peltier heating, and Thomson heating, together with the efficiency of the modules whose properties depend on the temperature. The present numerical code can be used for the design optimization of a thermoelectric power generator.

Should Cost-Effectiveness Analysis Include the Cost of Consumption Activities? AN Empirical Investigation.

Science.gov (United States)

Adarkwah, Charles Christian; Sadoghi, Amirhossein; Gandjour, Afschin

2016-02-01

There has been a debate on whether cost-effectiveness analysis should consider the cost of consumption and leisure time activities when using the quality-adjusted life year as a measure of health outcome under a societal perspective. The purpose of this study was to investigate whether the effects of ill health on consumptive activities are spontaneously considered in a health state valuation exercise and how much this matters. The survey enrolled patients with inflammatory bowel disease in Germany (n = 104). Patients were randomized to explicit and no explicit instruction for the consideration of consumption and leisure effects in a time trade-off (TTO) exercise. Explicit instruction to consider non-health-related utility in TTO exercises did not influence TTO scores. However, spontaneous consideration of non-health-related utility in patients without explicit instruction (60% of respondents) led to significantly lower TTO scores. Results suggest an inclusion of consumption costs in the numerator of the cost-effectiveness ratio, at least for those respondents who spontaneously consider non-health-related utility from treatment. Results also suggest that exercises eliciting health valuations from the general public may include a description of the impact of disease on consumptive activities. Copyright © 2015 John Wiley & Sons, Ltd.

Theoretical and applied aerodynamics and related numerical methods

CERN Document Server

Chattot, J J

2015-01-01

This book covers classical and modern aerodynamics, theories and related numerical methods, for senior and first-year graduate engineering students, including: -The classical potential (incompressible) flow theories for low speed aerodynamics of thin airfoils and high and low aspect ratio wings. - The linearized theories for compressible subsonic and supersonic aerodynamics. - The nonlinear transonic small disturbance potential flow theory, including supercritical wing sections, the extended transonic area rule with lift effect, transonic lifting line and swept or oblique wings to minimize wave drag. Unsteady flow is also briefly discussed. Numerical simulations based on relaxation mixed-finite difference methods are presented and explained. - Boundary layer theory for all Mach number regimes and viscous/inviscid interaction procedures used in practical aerodynamics calculations. There are also four chapters covering special topics, including wind turbines and propellers, airplane design, flow analogies and h...

Genotator: A disease-agnostic tool for genetic annotation of disease

Directory of Open Access Journals (Sweden)

Jung Jae-Yoon

2010-10-01

Full Text Available Abstract Background Disease-specific genetic information has been increasing at rapid rates as a consequence of recent improvements and massive cost reductions in sequencing technologies. Numerous systems designed to capture and organize this mounting sea of genetic data have emerged, but these resources differ dramatically in their disease coverage and genetic depth. With few exceptions, researchers must manually search a variety of sites to assemble a complete set of genetic evidence for a particular disease of interest, a process that is both time-consuming and error-prone. Methods We designed a real-time aggregation tool that provides both comprehensive coverage and reliable gene-to-disease rankings for any disease. Our tool, called Genotator, automatically integrates data from 11 externally accessible clinical genetics resources and uses these data in a straightforward formula to rank genes in order of disease relevance. We tested the accuracy of coverage of Genotator in three separate diseases for which there exist specialty curated databases, Autism Spectrum Disorder, Parkinson's Disease, and Alzheimer Disease. Genotator is freely available at http://genotator.hms.harvard.edu. Results Genotator demonstrated that most of the 11 selected databases contain unique information about the genetic composition of disease, with 2514 genes found in only one of the 11 databases. These findings confirm that the integration of these databases provides a more complete picture than would be possible from any one database alone. Genotator successfully identified at least 75% of the top ranked genes for all three of our use cases, including a 90% concordance with the top 40 ranked candidates for Alzheimer Disease. Conclusions As a meta-query engine, Genotator provides high coverage of both historical genetic research as well as recent advances in the genetic understanding of specific diseases. As such, Genotator provides a real-time aggregation of ranked

Genotator: a disease-agnostic tool for genetic annotation of disease.

Science.gov (United States)

Wall, Dennis P; Pivovarov, Rimma; Tong, Mark; Jung, Jae-Yoon; Fusaro, Vincent A; DeLuca, Todd F; Tonellato, Peter J

2010-10-29

Disease-specific genetic information has been increasing at rapid rates as a consequence of recent improvements and massive cost reductions in sequencing technologies. Numerous systems designed to capture and organize this mounting sea of genetic data have emerged, but these resources differ dramatically in their disease coverage and genetic depth. With few exceptions, researchers must manually search a variety of sites to assemble a complete set of genetic evidence for a particular disease of interest, a process that is both time-consuming and error-prone. We designed a real-time aggregation tool that provides both comprehensive coverage and reliable gene-to-disease rankings for any disease. Our tool, called Genotator, automatically integrates data from 11 externally accessible clinical genetics resources and uses these data in a straightforward formula to rank genes in order of disease relevance. We tested the accuracy of coverage of Genotator in three separate diseases for which there exist specialty curated databases, Autism Spectrum Disorder, Parkinson's Disease, and Alzheimer Disease. Genotator is freely available at http://genotator.hms.harvard.edu. Genotator demonstrated that most of the 11 selected databases contain unique information about the genetic composition of disease, with 2514 genes found in only one of the 11 databases. These findings confirm that the integration of these databases provides a more complete picture than would be possible from any one database alone. Genotator successfully identified at least 75% of the top ranked genes for all three of our use cases, including a 90% concordance with the top 40 ranked candidates for Alzheimer Disease. As a meta-query engine, Genotator provides high coverage of both historical genetic research as well as recent advances in the genetic understanding of specific diseases. As such, Genotator provides a real-time aggregation of ranked data that remains current with the pace of research in the disease

Numerical simulations of progressive hardening by using ABAQUS FEA software

Directory of Open Access Journals (Sweden)

Domański Tomasz

2018-01-01

Full Text Available The paper concerns numerical simulations of progressive hardening include phase transformations in solid state of steel. Abaqus FEA software is used for numerical analysis of temperature field and phase transformations. Numerical subroutines, written in fortran programming language are used in computer simulations where models of the distribution of movable heat source, kinetics of phase transformations in solid state as well as thermal and structural strain are implemented. Model for evaluation of fractions of phases and their kinetics is based on continuous heating diagram and continuous cooling diagram. The numerical analysis of thermal fields, phase fractions and strain associated progressive hardening of elements made of steel were done.

Progress toward an integrated understanding of Parkinson's disease [version 1; referees: 2 approved

Directory of Open Access Journals (Sweden)

Maxime W.C. Rousseaux

2017-07-01

Full Text Available Parkinson's disease (PD is the second most common neurodegenerative disorder after Alzheimer's disease, affecting over 10 million individuals worldwide. While numerous effective symptomatic treatments are currently available, no curative or disease-modifying therapies exist. An integrated, comprehensive understanding of PD pathogenic mechanisms will likely address this unmet clinical need. Here, we highlight recent progress in PD research with an emphasis on promising translational findings, including (i advances in our understanding of disease susceptibility, (ii improved knowledge of cellular dysfunction, and (iii insights into mechanisms of spread and propagation of PD pathology. We emphasize connections between these previously disparate strands of PD research and the development of an emerging systems-level understanding that will enable the next generation of PD therapeutics.

The role of EMMPRIN in T cell biology and immunological diseases.

Science.gov (United States)

Hahn, Jennifer Nancy; Kaushik, Deepak Kumar; Yong, V Wee

2015-07-01

EMMPRIN (CD147), originally described as an inducer of the expression of MMPs, has gained attention in its involvement in various immunologic diseases, such that anti-EMMPRIN antibodies are considered as potential therapeutic medications. Given that MMPs are involved in the pathogenesis of various disease states, it is relevant that targeting an upstream inducer would make for an effective therapeutic strategy. Additionally, EMMPRIN is now appreciated to have multiple roles apart from MMP induction, including in cellular functions, such as migration, adhesion, invasion, energy metabolism, as well as T cell activation and proliferation. Here, we review what is known about EMMPRIN in numerous immunologic/inflammatory disease conditions with a particular focus on its complex roles in T cell biology. © Society for Leukocyte Biology.

Uncertainty Quantification in Numerical Aerodynamics

KAUST Repository

Litvinenko, Alexander

2017-05-16

We consider uncertainty quantification problem in aerodynamic simulations. We identify input uncertainties, classify them, suggest an appropriate statistical model and, finally, estimate propagation of these uncertainties into the solution (pressure, velocity and density fields as well as the lift and drag coefficients). The deterministic problem under consideration is a compressible transonic Reynolds-averaged Navier-Strokes flow around an airfoil with random/uncertain data. Input uncertainties include: uncertain angle of attack, the Mach number, random perturbations in the airfoil geometry, mesh, shock location, turbulence model and parameters of this turbulence model. This problem requires efficient numerical/statistical methods since it is computationally expensive, especially for the uncertainties caused by random geometry variations which involve a large number of variables. In numerical section we compares five methods, including quasi-Monte Carlo quadrature, polynomial chaos with coefficients determined by sparse quadrature and gradient-enhanced version of Kriging, radial basis functions and point collocation polynomial chaos, in their efficiency in estimating statistics of aerodynamic performance upon random perturbation to the airfoil geometry [D.Liu et al \\'17]. For modeling we used the TAU code, developed in DLR, Germany.

Numerical Development

Science.gov (United States)

Siegler, Robert S.; Braithwaite, David W.

2016-01-01

In this review, we attempt to integrate two crucial aspects of numerical development: learning the magnitudes of individual numbers and learning arithmetic. Numerical magnitude development involves gaining increasingly precise knowledge of increasing ranges and types of numbers: from non-symbolic to small symbolic numbers, from smaller to larger…

Numerical Optimization in Microfluidics

DEFF Research Database (Denmark)

Jensen, Kristian Ejlebjærg

2017-01-01

Numerical modelling can illuminate the working mechanism and limitations of microfluidic devices. Such insights are useful in their own right, but one can take advantage of numerical modelling in a systematic way using numerical optimization. In this chapter we will discuss when and how numerical...... optimization is best used....

Hindi Numerals.

Science.gov (United States)

Bright, William

In most languages encountered by linguists, the numerals, considered as a paradigmatic set, constitute a morpho-syntactic problem of only moderate complexity. The Indo-Aryan language family of North India, however, presents a curious contrast. The relatively regular numeral system of Sanskrit, as it has developed historically into the modern…

Uncertainty Quantification in Numerical Aerodynamics

KAUST Repository

Litvinenko, Alexander; Matthies, Hermann G.; Liu, Dishi; Schillings, Claudia; Schulz, Volker

2017-01-01

In numerical section we compares five methods, including quasi-Monte Carlo quadrature, polynomial chaos with coefficients determined by sparse quadrature and gradient-enhanced version of Kriging, radial basis functions and point collocation polynomial chaos, in their efficiency in estimating statistics of aerodynamic performance upon random perturbation to the airfoil geometry [D.Liu et al '17]. For modeling we used the TAU code, developed in DLR, Germany.

Methods of numerical relativity

International Nuclear Information System (INIS)

Piran, T.

1983-01-01

Numerical Relativity is an alternative to analytical methods for obtaining solutions for Einstein equations. Numerical methods are particularly useful for studying generation of gravitational radiation by potential strong sources. The author reviews the analytical background, the numerical analysis aspects and techniques and some of the difficulties involved in numerical relativity. (Auth.)

Force-controlled absorption in a fully-nonlinear numerical wave tank

International Nuclear Information System (INIS)

Spinneken, Johannes; Christou, Marios; Swan, Chris

2014-01-01

An active control methodology for the absorption of water waves in a numerical wave tank is introduced. This methodology is based upon a force-feedback technique which has previously been shown to be very effective in physical wave tanks. Unlike other methods, an a-priori knowledge of the wave conditions in the tank is not required; the absorption controller being designed to automatically respond to a wide range of wave conditions. In comparison to numerical sponge layers, effective wave absorption is achieved on the boundary, thereby minimising the spatial extent of the numerical wave tank. In contrast to the imposition of radiation conditions, the scheme is inherently capable of absorbing irregular waves. Most importantly, simultaneous generation and absorption can be achieved. This is an important advance when considering inclusion of reflective bodies within the numerical wave tank. In designing the absorption controller, an infinite impulse response filter is adopted, thereby eliminating the problem of non-causality in the controller optimisation. Two alternative controllers are considered, both implemented in a fully-nonlinear wave tank based on a multiple-flux boundary element scheme. To simplify the problem under consideration, the present analysis is limited to water waves propagating in a two-dimensional domain. The paper presents an extensive numerical validation which demonstrates the success of the method for a wide range of wave conditions including regular, focused and random waves. The numerical investigation also highlights some of the limitations of the method, particularly in simultaneously generating and absorbing large amplitude or highly-nonlinear waves. The findings of the present numerical study are directly applicable to related fields where optimum absorption is sought; these include physical wavemaking, wave power absorption and a wide range of numerical wave tank schemes

Handbook of numerical analysis

CERN Document Server

Ciarlet, Philippe G

Mathematical finance is a prolific scientific domain in which there exists a particular characteristic of developing both advanced theories and practical techniques simultaneously. Mathematical Modelling and Numerical Methods in Finance addresses the three most important aspects in the field: mathematical models, computational methods, and applications, and provides a solid overview of major new ideas and results in the three domains. Coverage of all aspects of quantitative finance including models, computational methods and applications Provides an overview of new ideas an

[Clinical scores for the venous thromboembolic disease: an aid for the diagnosis and the treatment?].

Science.gov (United States)

Junod, A

2015-03-04

The venous thromboembolic disease includes a wide range of conditions from well defined medical entities (pulmonary embolism, deep venous thrombosis), their diagnosis and prognosis, as well as the risk of developping a venous thromboembolic disease in association with hospitalisation for acute medical illness and with cancer. The assessment of the risk of treatment with anticoagulants is also itaken into account. For all these medical situations, numerous (approximately 50) clinical scores have been reported. They will be presented and critically analysed in the next series of 6 articles.

Numerical and field tests of hydraulic transients at Piva power plant

International Nuclear Information System (INIS)

Giljen, Z

2014-01-01

In 2009, a sophisticated field investigation was undertaken and later, in 2011, numerical tests were completed, on all three turbine units at the Piva hydroelectric power plant. These tests were made in order to assist in making decisions about the necessary scope of the reconstruction and modernisation of the Piva hydroelectric power plant, a plant originally constructed in the mid-1970s. More specifically, the investigation included several hydraulic conditions including both the start-up and stopping of each unit, load rejection under governor control from different initial powers, as well as emergency shut-down. Numerical results were obtained using the method of characteristics in a representation that included the full flow system and the characteristics of each associated Francis turbine. The impact of load rejection and emergency shut-down on the penstock pressure and turbine speed changes are reported and numerical and experimental results are compared, showing close agreement

Effect of human movement on airborne disease transmission in an airplane cabin: study using numerical modeling and quantitative risk analysis.

Science.gov (United States)

Han, Zhuyang; To, Gin Nam Sze; Fu, Sau Chung; Chao, Christopher Yu-Hang; Weng, Wenguo; Huang, Quanyi

2014-08-06

Airborne transmission of respiratory infectious disease in indoor environment (e.g. airplane cabin, conference room, hospital, isolated room and inpatient ward) may cause outbreaks of infectious diseases, which may lead to many infection cases and significantly influences on the public health. This issue has received more and more attentions from academics. This work investigates the influence of human movement on the airborne transmission of respiratory infectious diseases in an airplane cabin by using an accurate human model in numerical simulation and comparing the influences of different human movement behaviors on disease transmission. The Eulerian-Lagrangian approach is adopted to simulate the dispersion and deposition of the expiratory aerosols. The dose-response model is used to assess the infection risks of the occupants. The likelihood analysis is performed as a hypothesis test on the input parameters and different human movement pattern assumptions. An in-flight SARS outbreak case is used for investigation. A moving person with different moving speeds is simulated to represent the movement behaviors. A digital human model was used to represent the detailed profile of the occupants, which was obtained by scanning a real thermal manikin using the 3D laser scanning system. The analysis results indicate that human movement can strengthen the downward transport of the aerosols, significantly reduce the overall deposition and removal rate of the suspended aerosols and increase the average infection risk in the cabin. The likelihood estimation result shows that the risk assessment results better fit the outcome of the outbreak case when the movements of the seated passengers are considered. The intake fraction of the moving person is significantly higher than most of the seated passengers. The infection risk distribution in the airplane cabin highly depends on the movement behaviors of the passengers and the index patient. The walking activities of the crew

Teaching numerical methods with IPython notebooks and inquiry-based learning

KAUST Repository

Ketcheson, David I.

2014-01-01

A course in numerical methods should teach both the mathematical theory of numerical analysis and the craft of implementing numerical algorithms. The IPython notebook provides a single medium in which mathematics, explanations, executable code, and visualizations can be combined, and with which the student can interact in order to learn both the theory and the craft of numerical methods. The use of notebooks also lends itself naturally to inquiry-based learning methods. I discuss the motivation and practice of teaching a course based on the use of IPython notebooks and inquiry-based learning, including some specific practical aspects. The discussion is based on my experience teaching a Masters-level course in numerical analysis at King Abdullah University of Science and Technology (KAUST), but is intended to be useful for those who teach at other levels or in industry.

Numerical stability in problems of linear algebra.

Science.gov (United States)

Babuska, I.

1972-01-01

Mathematical problems are introduced as mappings from the space of input data to that of the desired output information. Then a numerical process is defined as a prescribed recurrence of elementary operations creating the mapping of the underlying mathematical problem. The ratio of the error committed by executing the operations of the numerical process (the roundoff errors) to the error introduced by perturbations of the input data (initial error) gives rise to the concept of lambda-stability. As examples, several processes are analyzed from this point of view, including, especially, old and new processes for solving systems of linear algebraic equations with tridiagonal matrices. In particular, it is shown how such a priori information can be utilized as, for instance, a knowledge of the row sums of the matrix. Information of this type is frequently available where the system arises in connection with the numerical solution of differential equations.

Finger-Based Numerical Skills Link Fine Motor Skills to Numerical Development in Preschoolers.

Science.gov (United States)

Suggate, Sebastian; Stoeger, Heidrun; Fischer, Ursula

2017-12-01

Previous studies investigating the association between fine-motor skills (FMS) and mathematical skills have lacked specificity. In this study, we test whether an FMS link to numerical skills is due to the involvement of finger representations in early mathematics. We gave 81 pre-schoolers (mean age of 4 years, 9 months) a set of FMS measures and numerical tasks with and without a specific finger focus. Additionally, we used receptive vocabulary and chronological age as control measures. FMS linked more closely to finger-based than to nonfinger-based numerical skills even after accounting for the control variables. Moreover, the relationship between FMS and numerical skill was entirely mediated by finger-based numerical skills. We concluded that FMS are closely related to early numerical skill development through finger-based numerical counting that aids the acquisition of mathematical mental representations.

Numerical methods design, analysis, and computer implementation of algorithms

CERN Document Server

Greenbaum, Anne

2012-01-01

Numerical Methods provides a clear and concise exploration of standard numerical analysis topics, as well as nontraditional ones, including mathematical modeling, Monte Carlo methods, Markov chains, and fractals. Filled with appealing examples that will motivate students, the textbook considers modern application areas, such as information retrieval and animation, and classical topics from physics and engineering. Exercises use MATLAB and promote understanding of computational results. The book gives instructors the flexibility to emphasize different aspects--design, analysis, or computer implementation--of numerical algorithms, depending on the background and interests of students. Designed for upper-division undergraduates in mathematics or computer science classes, the textbook assumes that students have prior knowledge of linear algebra and calculus, although these topics are reviewed in the text. Short discussions of the history of numerical methods are interspersed throughout the chapters. The book a...

Mathematica with a Numerical Methods Course

Science.gov (United States)

Varley, Rodney

2003-04-01

An interdisciplinary "Numerical Methods" course has been shared between physics, mathematics and computer science since 1992 at Hunter C. Recently, the lectures and workshops for this course have become formalized and placed on the internet at http://www.ph.hunter.cuny.edu (follow the links "Course Listings and Websites" >> "PHYS385 (Numerical Methods)". Mathematica notebooks for the lectures are available for automatic download (by "double clicking" the lecture icon) for student use in the classroom or at home. AOL (or Netscape/Explorer) can be used provided Mathematica (or the "free" MathReader) has been made a "helper application". Using Mathematica has the virtue that mathematical equations (no LaTex required) can easily be included with the text and Mathematica's graphing is easy to use. Computational cells can be included within the notebook and students may easily modify the calculation to see the result of "what if..." questions. Homework is sent as Mathematica notebooks to the instructor via the internet and the corrected workshops are returned in the same manner. Most exam questions require computational solutions.

Representation of Numerical and Non-Numerical Order in Children

Science.gov (United States)

Berteletti, Ilaria; Lucangeli, Daniela; Zorzi, Marco

2012-01-01

The representation of numerical and non-numerical ordered sequences was investigated in children from preschool to grade 3. The child's conception of how sequence items map onto a spatial scale was tested using the Number-to-Position task (Siegler & Opfer, 2003) and new variants of the task designed to probe the representation of the alphabet…

Splicing regulatory factors, ageing and age-related disease.

Science.gov (United States)

Latorre, Eva; Harries, Lorna W

2017-07-01

Alternative splicing is a co-transcriptional process, which allows for the production of multiple transcripts from a single gene and is emerging as an important control point for gene expression. Alternatively expressed isoforms often have antagonistic function and differential temporal or spatial expression patterns, yielding enormous plasticity and adaptability to cells and increasing their ability to respond to environmental challenge. The regulation of alternative splicing is critical for numerous cellular functions in both pathological and physiological conditions, and deregulated alternative splicing is a key feature of common chronic diseases. Isoform choice is controlled by a battery of splicing regulatory proteins, which include the serine arginine rich (SRSF) proteins and the heterogeneous ribonucleoprotein (hnRNP) classes of genes. These important splicing regulators have been implicated in age-related disease, and in the ageing process itself. This review will outline the important contribution of splicing regulator proteins to ageing and age-related disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Simple Numerical Simulation of Strain Measurement

Science.gov (United States)

Tai, H.

2002-01-01

By adopting the basic principle of the reflection (and transmission) of a plane polarized electromagnetic wave incident normal to a stack of films of alternating refractive index, a simple numerical code was written to simulate the maximum reflectivity (transmittivity) of a fiber optic Bragg grating corresponding to various non-uniform strain conditions including photo-elastic effect in certain cases.

Practical design of magnetostatic structure using numerical simulation

CERN Document Server

Wang, Qiuliang

2013-01-01

Covers the practical numerical method for the analysis and design of magnets Extensively covers the magnet design and computation aspects from theories to practical applications, emphasizing design methods of practical structures such as superconducting, electromagnetic and permanent magnet for use in various scientific instruments, industrial processing, biomedicine and special electrical equipments. The computations cover a wide range of numerical techniques and analytical derivation to efficiently provide solutions to complicated problems that are often encountered in practice, where simple analytical calculations are no longer adequate. Chapters include: Introduction of Magnet Technology, Magnetostatic Equation for the Magnet Structure, Finite Element Analysis for Magnetostatic Field, Integral Method for Magnetostatic Field, Numerical Method of Solenoid Coils Design, Series Analysis of Axially Symmetric Magnetic Field, Magnets with High Magnetic Field and High Homogeneity, Permanent Magnet and its App...

Numerical Modelling and Measurement in a Test Secondary Settling Tank

DEFF Research Database (Denmark)

Dahl, C.; Larsen, Torben; Petersen, O.

1994-01-01

sludge. Phenomena as free and hindered settling and the Bingham plastic characteristic of activated sludge suspensions are included in the numerical model. Further characterisation and test tank experiments are described. The characterisation experiments were designed to measure calibration parameters...... for model description of settling and density differences. In the test tank experiments, flow velocities and suspended sludge concentrations were measured with different tank inlet geomotry and hydraulic and sludge loads. The test tank experiments provided results for the calibration of the numerical model......A numerical model and measurements of flow and settling in activated sludge suspension is presented. The numerical model is an attempt to describe the complex and interrelated hydraulic and sedimentation phenomena by describing the turbulent flow field and the transport/dispersion of suspended...

Numerical Analysis of Fractional Order Epidemic Model of Childhood Diseases

Directory of Open Access Journals (Sweden)

Fazal Haq

2017-01-01

Full Text Available The fractional order Susceptible-Infected-Recovered (SIR epidemic model of childhood disease is considered. Laplace–Adomian Decomposition Method is used to compute an approximate solution of the system of nonlinear fractional differential equations. We obtain the solutions of fractional differential equations in the form of infinite series. The series solution of the proposed model converges rapidly to its exact value. The obtained results are compared with the classical case.

Ultrasonography for diagnosis of alcoholic cirrhosis in people with alcoholic liver disease

DEFF Research Database (Denmark)

Pavlov, Chavdar S; Casazza, Giovanni; Semenistaia, Marianna

2016-01-01

, but people in whom hepatocellular carcinoma has developed are often co-infected with hepatitis B or C virus.Abstinence from alcohol may help people with alcoholic disease in improving their prognosis of survival at any stage of their disease; however, the more advanced the stage, the higher the risk...... with alcoholic liver disease; however, besides the difficulties of finding a suitable liver transplant organ, there are many other factors that may influence a person's survival.Ultrasound is an inexpensive method that has been used for years in clinical practice to diagnose alcoholic cirrhosis. Ultrasound...... Handbook for Systematic Reviews of Diagnostic Test Accuracy. MAIN RESULTS: The review included two studies that provided numerical data regarding alcoholic cirrhosis in 205 men and women with alcoholic liver disease. Although there were no applicability concerns in terms of participant selection, index...

Pervasive Sharing of Genetic Effects in Autoimmune Disease

DEFF Research Database (Denmark)

Cotsapas, Chris; Voight, Benjamin F.; Rossin, Elizabeth

2011-01-01

Genome-wide association (GWA) studies have identified numerous, replicable, genetic associations between common single nucleotide polymorphisms (SNPs) and risk of common autoimmune and inflammatory (immune-mediated) diseases, some of which are shared between two diseases. Along with epidemiologic...

Numerical methods in finance and economics a MATLAB-based introduction

CERN Document Server

Brandimarte, Paolo

2006-01-01

A state-of-the-art introduction to the powerful mathematical and statistical tools used in the field of financeThe use of mathematical models and numerical techniques is a practice employed by a growing number of applied mathematicians working on applications in finance. Reflecting this development, Numerical Methods in Finance and Economics: A MATLAB?-Based Introduction, Second Edition bridges the gap between financial theory and computational practice while showing readers how to utilize MATLAB?--the powerful numerical computing environment--for financial applications.The author provides an essential foundation in finance and numerical analysis in addition to background material for students from both engineering and economics perspectives. A wide range of topics is covered, including standard numerical analysis methods, Monte Carlo methods to simulate systems affected by significant uncertainty, and optimization methods to find an optimal set of decisions.Among this book''s most outstanding features is the...

The application of lipidomics to biomarker research and pathomechanisms in Alzheimer's disease.

Science.gov (United States)

Wong, Matthew W; Braidy, Nady; Poljak, Anne; Sachdev, Perminder S

2017-03-01

Alzheimer's disease is the most common cause of dementia. There are still no disease modifying treatments that can cure or slow disease progression. Recently, Alzheimer's disease researchers have attempted to improve early detection and diagnostic criteria for Alzheimer's disease, with the rationale that treatment of disease, or even prevention, may be more successful during the early preclinical stages of Alzheimer's disease when neurodegenerative damage is not as widespread. As the brain has a high lipid content, lipidomics may offer novel insights into the underlying pathogenesis of Alzheimer's disease. This review reports on recent developments in the relatively unexplored field of lipidomics in Alzheimer's disease, including novel biomarkers and pathomechanisms of Alzheimer's disease. Numerous biomarker panels involving phospholipids and sphingolipids have been proposed, indicating perturbed lipid metabolism in early stages of Alzheimer's disease. Future strategies targeting these metabolic changes through dietary supplementation could have therapeutic benefits in at-risk individuals. Dysregulated lipid metabolism could reflect pathological changes in synaptic function and neuronal membranes, leading to cognitive decline. However, extensive validation in large independent cohorts is required before lipid biomarkers can be used clinically to assess Alzheimer's disease risk and progression.

LEBER'S DISEASE. CLINICAL CASE

Directory of Open Access Journals (Sweden)

N. N. Maslova

2013-01-01

Full Text Available Violation of visual functions and oculomotor frustration develop at 90% of patients with MS. More than a half of patients are transferred by the numerous recurrence of an optical neuritis which is coming to an end with a partial atrophy of optic nerve. For well-timed purpose of pathogenetic treatment differential diagnostics with other diseases, being accompanied an atrophy of an optic nerve, in particular with Leber's disease. 

Inhaled Pollutants: The Molecular Scene behind Respiratory and Systemic Diseases Associated with Ultrafine Particulate Matter

Directory of Open Access Journals (Sweden)

Hussein Traboulsi

2017-01-01

Full Text Available Air pollution of anthropogenic origin is largely from the combustion of biomass (e.g., wood, fossil fuels (e.g., cars and trucks, incinerators, landfills, agricultural activities and tobacco smoke. Air pollution is a complex mixture that varies in space and time, and contains hundreds of compounds including volatile organic compounds (e.g., benzene, metals, sulphur and nitrogen oxides, ozone and particulate matter (PM. PM0.1 (ultrafine particles (UFP, those particles with a diameter less than 100 nm (includes nanoparticles (NP are considered especially dangerous to human health and may contribute significantly to the development of numerous respiratory and cardiovascular diseases such as chronic obstructive pulmonary disease (COPD and atherosclerosis. Some of the pathogenic mechanisms through which PM0.1 may contribute to chronic disease is their ability to induce inflammation, oxidative stress and cell death by molecular mechanisms that include transcription factors such as nuclear factor κB (NF-κB and nuclear factor (erythroid-derived 2-like 2 (Nrf2. Epigenetic mechanisms including non-coding RNA (ncRNA may also contribute towards the development of chronic disease associated with exposure to PM0.1. This paper highlights emerging molecular concepts associated with inhalational exposure to PM0.1 and their ability to contribute to chronic respiratory and systemic disease.

Mathematical and numerical foundations of turbulence models and applications

CERN Document Server

Chacón Rebollo, Tomás

2014-01-01

With applications to climate, technology, and industry, the modeling and numerical simulation of turbulent flows are rich with history and modern relevance. The complexity of the problems that arise in the study of turbulence requires tools from various scientific disciplines, including mathematics, physics, engineering, and computer science. Authored by two experts in the area with a long history of collaboration, this monograph provides a current, detailed look at several turbulence models from both the theoretical and numerical perspectives. The k-epsilon, large-eddy simulation, and other models are rigorously derived and their performance is analyzed using benchmark simulations for real-world turbulent flows. Mathematical and Numerical Foundations of Turbulence Models and Applications is an ideal reference for students in applied mathematics and engineering, as well as researchers in mathematical and numerical fluid dynamics. It is also a valuable resource for advanced graduate students in fluid dynamics,...

Numerical Simulation of Particle Motion in a Curved Channel

Science.gov (United States)

Liu, Yi; Nie, Deming

2018-01-01

In this work the lattice Boltzmann method (LBM) is used to numerically study the motion of a circular particle in a curved channel at intermediate Reynolds numbers (Re). The effects of the Reynolds number and the initial particle position are taken into account. Numerical results include the streamlines, particle trajectories and final equilibrium positions. It has been found that the particle is likely to migrate to a similar equilibrium position irrespective of its initial position when Re is large.

On the theories, techniques, and computer codes used in numerical reactor criticality and burnup calculations

International Nuclear Information System (INIS)

El-Osery, I.A.

1981-01-01

The purpose of this paper is to discuss the theories, techniques and computer codes that are frequently used in numerical reactor criticality and burnup calculations. It is a part of an integrated nuclear reactor calculation scheme conducted by the Reactors Department, Inshas Nuclear Research Centre. The crude part in numerical reactor criticality and burnup calculations includes the determination of neutron flux distribution which can be obtained in principle as a solution of Boltzmann transport equation. Numerical methods used for solving transport equations are discussed. Emphasis are made on numerical techniques based on multigroup diffusion theory. These numerical techniques include nodal, modal, and finite difference ones. The most commonly known computer codes utilizing these techniques are reviewed. Some of the main computer codes that have been already developed at the Reactors Department and related to numerical reactor criticality and burnup calculations have been presented

Modern Perspectives on Numerical Modeling of Cardiac Pacemaker Cell

Science.gov (United States)

Maltsev, Victor A.; Yaniv, Yael; Maltsev, Anna V.; Stern, Michael D.; Lakatta, Edward G.

2015-01-01

Cardiac pacemaking is a complex phenomenon that is still not completely understood. Together with experimental studies, numerical modeling has been traditionally used to acquire mechanistic insights in this research area. This review summarizes the present state of numerical modeling of the cardiac pacemaker, including approaches to resolve present paradoxes and controversies. Specifically we discuss the requirement for realistic modeling to consider symmetrical importance of both intracellular and cell membrane processes (within a recent “coupled-clock” theory). Promising future developments of the complex pacemaker system models include the introduction of local calcium control, mitochondria function, and biochemical regulation of protein phosphorylation and cAMP production. Modern numerical and theoretical methods such as multi-parameter sensitivity analyses within extended populations of models and bifurcation analyses are also important for the definition of the most realistic parameters that describe a robust, yet simultaneously flexible operation of the coupled-clock pacemaker cell system. The systems approach to exploring cardiac pacemaker function will guide development of new therapies, such as biological pacemakers for treating insufficient cardiac pacemaker function that becomes especially prevalent with advancing age. PMID:24748434

Cut points on 0-10 numeric rating scales for symptoms included in the edmonton symptom assessment scale in cancer patients: A systematic review

NARCIS (Netherlands)

W.H. Oldenmenger (Wendy); P.J. de Raaf (Pleun); C. de Klerk (Cora); C.C.D. van der Rijt (Carin)

2013-01-01

textabstractContext: To improve the management of cancer-related symptoms, systematic screening is necessary, often performed by using 0-10 numeric rating scales. Cut points are used to determine if scores represent clinically relevant burden. Objectives: The aim of this systematic review was to

Double-gate junctionless transistor model including short-channel effects

International Nuclear Information System (INIS)

Paz, B C; Pavanello, M A; Ávila-Herrera, F; Cerdeira, A

2015-01-01

This work presents a physically based model for double-gate junctionless transistors (JLTs), continuous in all operation regimes. To describe short-channel transistors, short-channel effects (SCEs), such as increase of the channel potential due to drain bias, carrier velocity saturation and mobility degradation due to vertical and longitudinal electric fields, are included in a previous model developed for long-channel double-gate JLTs. To validate the model, an analysis is made by using three-dimensional numerical simulations performed in a Sentaurus Device Simulator from Synopsys. Different doping concentrations, channel widths and channel lengths are considered in this work. Besides that, the series resistance influence is numerically included and validated for a wide range of source and drain extensions. In order to check if the SCEs are appropriately described, besides drain current, transconductance and output conductance characteristics, the following parameters are analyzed to demonstrate the good agreement between model and simulation and the SCEs occurrence in this technology: threshold voltage (V TH ), subthreshold slope (S) and drain induced barrier lowering. (paper)

Numerical and adaptive grid methods for ideal magnetohydrodynamics

Science.gov (United States)

Loring, Burlen

2008-02-01

In this thesis numerical finite difference methods for ideal magnetohydrodynamics(MHD) are investigated. A review of the relevant physics, essential for interpreting the results of numerical solutions and constructing validation cases, is presented. This review includes a discusion of the propagation of small amplitude waves in the MHD system as well as a thorough discussion of MHD shocks, contacts and rarefactions and how they can be piece together to obtain a solutions to the MHD Riemann problem. Numerical issues relevant to the MHD system such as: the loss of nonlinear numerical stability in the presence of discontinuous solutions, the introduction of spurious forces due to the growth of the divergence of the magnetic flux density, the loss of pressure positivity, and the effects of non-conservative numerical methods are discussed, along with the practical approaches which can be used to remedy or minimize the negative consequences of each. The use of block structured adaptive mesh refinement is investigated in the context of a divergence free MHD code. A new method for conserving magnetic flux across AMR grid interfaces is developed and a detailed discussion of our implementation of this method using the CHOMBO AMR framework is given. A preliminary validation of the new method for conserving magnetic flux density across AMR grid interfaces illustrates that the method works. Finally a number of code validation cases are examined spurring a discussion of the strengths and weaknesses of the numerics employed.

Summary of Numerical Modeling for Underground Nuclear Test Monitoring Symposium

International Nuclear Information System (INIS)

Taylor, S.R.; Kamm, J.R.

1993-01-01

This document contains the Proceedings of the Numerical Modeling for Underground Nuclear Test Monitoring Symposium held in Durango, Colorado on March 23-25, 1993. The symposium was sponsored by the Office of Arms Control and Nonproliferation of the United States Department of Energy and hosted by the Source Region Program of Los Alamos National Laboratory. The purpose of the meeting was to discuss state-of-the-art advances in numerical simulations of nuclear explosion phenomenology for the purpose of test ban monitoring. Another goal of the symposium was to promote discussion between seismologists and explosion source-code calculators. Presentation topics include the following: numerical model fits to data, measurement and characterization of material response models, applications of modeling to monitoring problems, explosion source phenomenology, numerical simulations and seismic sources

Solutions manual to accompany An introduction to numerical methods and analysis

CERN Document Server

Epperson, James F

2014-01-01

A solutions manual to accompany An Introduction to Numerical Methods and Analysis, Second Edition An Introduction to Numerical Methods and Analysis, Second Edition reflects the latest trends in the field, includes new material and revised exercises, and offers a unique emphasis on applications. The author clearly explains how to both construct and evaluate approximations for accuracy and performance, which are key skills in a variety of fields. A wide range of higher-level methods and solutions, including new topics such as the roots of polynomials, sp

Viral respiratory diseases: vaccines and antivirals.

Science.gov (United States)

Lennette, E H

1981-01-01

Acute respiratory diseases, most of which are generally attributed to viruses, account for about 6% of all deaths and for about 60% of the deaths associated with all respiratory disease. The huge cost attributable to viral respiratory infections as a result of absenteeism and the disruption of business and the burden of medical care makes control of these diseases an important objective. The viruses that infect the respiratory tract fall taxonomically into five viral families. Although immunoprophylaxis would appear to be the logical approach, the development of suitable vaccines has been confronted with numerous obstacles, including antigenic drift and shift in the influenzaviruses, the large number of antigenically distinct immunotypes among rhinoviruses, the occurrence after immunization of rare cases of a severe form of the disease following subsequent natural infection with respiratory syncytial virus, and the risk of oncogenicity of adenoviruses for man. Considerable expenditure on the development of new antiviral drugs has so far resulted in only three compounds that are at present officially approved and licensed for use in the USA. Efforts to improve the tools available for control should continue and imaginative and inventive approaches are called for. However, creativity and ingenuity must operate within the constraints imposed by economic, political, ethical, and legal considerations.

Genetics Home Reference: Darier disease

Science.gov (United States)

... when they are exposed to heat and humidity. UV light; minor injury or friction, such as rubbing or ... the social stigma experienced by people with numerous skin blemishes. A form of Darier disease known as ...

Discerning Primary and Secondary Factors Responsible for Clinical Fatigue in Multisystem Diseases

Directory of Open Access Journals (Sweden)

David Maughan

2014-09-01

Full Text Available Fatigue is a common symptom of numerous acute and chronic diseases, including myalgic encephalomyelitis/chronic fatigue syndrome, multiple sclerosis, heart failure, cancer, and many others. In these multi-system diseases the physiological determinants of enhanced fatigue encompass a combination of metabolic, neurological, and myofibrillar adaptations. Previous research studies have focused on adaptations specific to skeletal muscle and their role in fatigue. However, most have neglected the contribution of physical inactivity in assessing disease syndromes, which, through deconditioning, likely contributes to symptomatic fatigue. In this commentary, we briefly review disease-related muscle phenotypes in the context of whether they relate to the primary disease or whether they develop secondary to reduced physical activity. Knowledge of the etiology of the skeletal muscle adaptations in these conditions and their contribution to fatigue symptoms is important for understanding the utility of exercise rehabilitation as an intervention to alleviate the physiological precipitants of fatigue.

The effect of Chernobyl accident on the development of non malignant diseases

International Nuclear Information System (INIS)

Zonenberg, A.; Leoniak, M.; Zarzycki, W.

2006-01-01

The early medical complications of Chernobyl accident include post radiation disease, which were diagnosed in 134 subjects affected by ionizing radiation. 28 persons died during the first 100 days after the event. The increase occurrence of coronary heart disease, endocrine, haematological, dermatological and other diseases were observed after disaster in the contaminated territories. We also discussed the impact of ionizing radiation from Chernobyl accident on pregnancy and congenital defects occurrence. Changes following the Chernobyl accident, as the inhabitants migration from contaminated regions, political and economic conversions, led to depression, anxiety, and even to '' epidemic '' of mental diseases. Increased suicide rate, car accidents, alcohol and drug abuse have been observed in this population. Nowadays vegetative neurosis is more often diagnosed in Ukrainian children. Epidemiological studies were conducted on the ionising radiation effect on the health and on the dose of received radiation after Chernobyl accident face numerous problems as the absence of reliable data regarding diseases in the contaminated territories.(authors)

Fasting and rheumatic diseases

OpenAIRE

Mohammad Hassan Jokar

2015-01-01

Fasting is one of the important religious practices of Muslims, in which the individuals abstain from eating and drinking from dawn to sunset. Fasting is not obligatory or even not allowed, in case it causes health problems to the fasting individual. Rheumatic diseases are a major group of chronic diseases which can bring about numerous problems while fasting. The aim of this article is to review the impact of Islamic fasting on rheumatic patients, based on the scientific evidences.

Endo-lysosomal and autophagic dysfunction: a driving factor in Alzheimer's disease?

Science.gov (United States)

Whyte, Lauren S; Lau, Adeline A; Hemsley, Kim M; Hopwood, John J; Sargeant, Timothy J

2017-03-01

Alzheimer's disease (AD) is the most common cause of dementia, and its prevalence will increase significantly in the coming decades. Although important progress has been made, fundamental pathogenic mechanisms as well as most hereditary contributions to the sporadic form of the disease remain unknown. In this review, we examine the now substantial links between AD pathogenesis and lysosomal biology. The lysosome hydrolyses and processes cargo delivered by multiple pathways, including endocytosis and autophagy. The endo-lysosomal and autophagic networks are central to clearance of cellular macromolecules, which is important given there is a deficit in clearance of amyloid-β in AD. Numerous studies show prominent lysosomal dysfunction in AD, including perturbed trafficking of lysosomal enzymes and accumulation of the same substrates that accumulate in lysosomal storage disorders. Examination of the brain in lysosomal storage disorders shows the accumulation of amyloid precursor protein metabolites, which further links lysosomal dysfunction with AD. This and other evidence leads us to hypothesise that genetic variation in lysosomal genes modifies the disease course of sporadic AD. © 2016 International Society for Neurochemistry.

Numerical simulation of GEW equation using RBF collocation method

Directory of Open Access Journals (Sweden)

Hamid Panahipour

2012-08-01

Full Text Available The generalized equal width (GEW equation is solved numerically by a meshless method based on a global collocation with standard types of radial basis functions (RBFs. Test problems including propagation of single solitons, interaction of two and three solitons, development of the Maxwellian initial condition pulses, wave undulation and wave generation are used to indicate the efficiency and accuracy of the method. Comparisons are made between the results of the proposed method and some other published numerical methods.

Domain-General Factors Influencing Numerical and Arithmetic Processing

Directory of Open Access Journals (Sweden)

André Knops

2017-12-01

Full Text Available This special issue contains 18 articles that address the question how numerical processes interact with domain-general factors. We start the editorial with a discussion of how to define domain-general versus domain-specific factors and then discuss the contributions to this special issue grouped into two core numerical domains that are subject to domain-general influences (see Figure 1. The first group of contributions addresses the question how numbers interact with spatial factors. The second group of contributions is concerned with factors that determine and predict arithmetic understanding, performance and development. This special issue shows that domain-general (Table 1a as well as domain-specific (Table 1b abilities influence numerical and arithmetic performance virtually at all levels and make it clear that for the field of numerical cognition a sole focus on one or several domain-specific factors like the approximate number system or spatial-numerical associations is not sufficient. Vice versa, in most studies that included domain-general and domain-specific variables, domain-specific numerical variables predicted arithmetic performance above and beyond domain-general variables. Therefore, a sole focus on domain-general aspects such as, for example, working memory, to explain, predict and foster arithmetic learning is also not sufficient. Based on the articles in this special issue we conclude that both domain-general and domain-specific factors contribute to numerical cognition. But the how, why and when of their contribution still needs to be better understood. We hope that this special issue may be helpful to readers in constraining future theory and model building about the interplay of domain-specific and domain-general factors.

Numerical distance protection

CERN Document Server

Ziegler, Gerhard

2011-01-01

Distance protection provides the basis for network protection in transmission systems and meshed distribution systems. This book covers the fundamentals of distance protection and the special features of numerical technology. The emphasis is placed on the application of numerical distance relays in distribution and transmission systems.This book is aimed at students and engineers who wish to familiarise themselves with the subject of power system protection, as well as the experienced user, entering the area of numerical distance protection. Furthermore it serves as a reference guide for s

Numerical methods using Matlab

CERN Document Server

Lindfield, George

2012-01-01

Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of useful and important numerical algorithms that can be implemented into MATLAB for a graphical interpretation to help researchers analyze a particular outcome. Many worked examples are given together with exercises and solutions to illustrate how numerical methods can be used to study problems that have applications in the biosciences, chaos, optimization, engineering and science across the board. Numerical Methods using MATLAB, 3e, is an extensive reference offering hundreds of use

[Autoimmune thyroid disease and other non-endocrine autoimmune diseases].

Science.gov (United States)

Dilas, Ljiljana Todorović; Icin, Tijana; Paro, Jovanka Novaković; Bajkin, Ivana

2011-01-01

Autoimmune diseases are chronic conditions initiated by the loss of immunological tolerance to self-antigens. They constitute heterogeneous group of disorders, in which multiple alterations in the immune system result in a spectrum of syndromes that either target specific organs or affect the body systematically. Recent epidemiological studies have shown a possible shift of one autoimmune disease to another or the fact that more than one autoimmune disease may coexist in a single patient or in the same family. Numerous autoimmune diseases have been shown to coexist frequently with thyroid autoimmune diseases. AUTOIMMNUNE THYROID DISEASE AND OTHER ORGAN SPECIFIC NON-ENDOCRINE AUTOIMMUNE DISEASES: This part of the study reviews the prevalence of autoimmune thyroid disease coexisting with: pernicious anaemia, vitiligo, celiac disease, autoimmune liver disease, miastenia gravis, alopecia areata and sclerosis multiplex, and several recommendations for screening have been given. AUTOIMMUNE THYROID DISEASE AND OTHER ORGAN NON-SPECIFIC NON-ENDOCRINE AUTOIMMUNE DISEASES: Special attention is given to the correlation between autoimmune thyroid disease and rheumatoid arthritis, systemic lupus erythematosus, syndrome Sjögren, systemic sclerosis and mixed connective tissue disease. Screening for autoimmune thyroid diseases should be recommended in everyday clinical practice, in patients with primary organ-specific or organ non-specific autoimmune disease. Otherwise, in patients with primary thyroid autoimmune disease, there is no good reason of seeking for all other autoimmune diseases, although these patients have a greater risk of developing other autoimmune disease. Economic aspects of medicine require further analyzing of these data, from cost/benefit point of view to justified either mandatory screening or medical practitioner judgment.

The numerical solution of ICRF fields in axisymmetric mirrors

International Nuclear Information System (INIS)

Phillips, M.W.; Todd, A.M.M.

1986-01-01

The numerics of a numerical code called GARFIELD (Grumman Aerospace RF fIELD code) designed to calculate the three-dimensional structure of ICRF fields in axisymmetric mirrors is presented. The code solves the electromagnetic wave equation for the electric field using a cold plasma dispersion relation with a small collision term to simulate absorption. The full wave solution including E.B is computed. The fields are Fourier analyzed in the poloidal direction and solved on a grid in the axial and radial directions. A two-dimensional equilibrium can be used as the source of equilibrium data. This allows us to extend previous studies of ICRF wave propagation and absorption in mirrors to include the effect of axial variation of the magnetic field and density. (orig.)

The pathogenomics of McArdle disease--genes, enzymes, models, and therapeutic implications.

Science.gov (United States)

Nogales-Gadea, Gisela; Santalla, Alfredo; Brull, Astrid; de Luna, Noemi; Lucia, Alejandro; Pinós, Tomàs

2015-03-01

Numerous biomedical advances have been made since Carl and Gerty Cori discovered the enzyme phosphorylase in the 1940s and the Scottish physician Brian McArdle reported in 1951 a previously 'undescribed disorder characterized by a gross failure of the breakdown in muscle of glycogen'. Today we know that this disorder, commonly known as 'McArdle disease', is caused by inherited deficiency of the muscle isoform of glycogen phosphorylase (GP). Here we review the main aspects of the 'pathogenomics' of this disease including, among others: the spectrum of mutations in the gene (PYGM) encoding muscle GP; the interplay between the different tissue GP isoforms in cellular cultures and in patients; what can we learn from naturally occurring and recently laboratory-generated animal models of the disease; and potential therapies.

A numerical library in Java for scientists and engineers

CERN Document Server

Lau, Hang T

2003-01-01

At last researchers have an inexpensive library of Java-based numeric procedures for use in scientific computation. The first and only book of its kind, A Numeric Library in Java for Scientists and Engineers is a translation into Java of the library NUMAL (NUMerical procedures in ALgol 60). This groundbreaking text presents procedural descriptions for linear algebra, ordinary and partial differential equations, optimization, parameter estimation, mathematical physics, and other tools that are indispensable to any dynamic research group. The book offers test programs that allow researchers to execute the examples provided; users are free to construct their own tests and apply the numeric procedures to them in order to observe a successful computation or simulate failure. The entry for each procedure is logically presented, with name, usage parameters, and Java code included. This handbook serves as a powerful research tool, enabling the performance of critical computations in Java. It stands as a cost-effi...

Experimental and numerical investigations of plasma turbulence

International Nuclear Information System (INIS)

Huld, T.

1990-07-01

Turbulence in plasmas has been investigated experimentally and numerically. The work described here is divided into four parts: - experiments on edge turbulence in a single-ended Q-machine. Convective cells are investigated in detail together with the anomalous transport caused by them. - Numerical simulation of the edge turbulence in the Q-machine. This simulation uses spectral methods to solve Euler's equation in a cylindrical geometry. - Measurements on wave propagation and the ion beam instability in an unmagnetized plasma with an ion beam with a finite diameter. - Development of software for the automated acquisition of data. This program can control an experiment as well as make measurements. It also include a graphics part. (author) 66 ills., 47 refs

Including refugees in disease elimination: challenges observed from a sleeping sickness programme in Uganda.

Science.gov (United States)

Palmer, Jennifer J; Robert, Okello; Kansiime, Freddie

2017-01-01

Ensuring equity between forcibly-displaced and host area populations is a key challenge for global elimination programmes. We studied Uganda's response to the recent refugee influx from South Sudan to identify key governance and operational lessons for national sleeping sickness programmes working with displaced populations today. A refugee policy which favours integration of primary healthcare services for refugee and host populations and the availability of rapid diagnostic tests (RDTs) to detect sleeping sickness at this health system level makes Uganda well-placed to include refugees in sleeping sickness surveillance. Using ethnographic observations of coordination meetings, review of programme data, interviews with sleeping sickness and refugee authorities and group discussions with health staff and refugees (2013-2016), we nevertheless identified some key challenges to equitably integrating refugees into government sleeping sickness surveillance. Despite fears that refugees were at risk of disease and posed a threat to elimination, six months into the response, programme coordinators progressed to a sentinel surveillance strategy in districts hosting the highest concentrations of refugees. This meant that RDTs, the programme's primary surveillance tool, were removed from most refugee-serving facilities, exacerbating existing inequitable access to surveillance and leading refugees to claim that their access to sleeping sickness tests had been better in South Sudan. This was not intentionally done to exclude refugees from care, rather, four key governance challenges made it difficult for the programme to recognise and correct inequities affecting refugees: (a) perceived donor pressure to reduce the sleeping sickness programme's scope without clear international elimination guidance on surveillance quality; (b) a problematic history of programme relations with refugee-hosting districts which strained supervision of surveillance quality; (c) difficulties that

Shorter height is related to lower cardiovascular disease risk – A narrative review

Directory of Open Access Journals (Sweden)

Thomas T. Samaras

2013-01-01

Full Text Available Numerous Western studies have shown a negative correlation between height and cardiovascular disease. However, these correlations do not prove causation. This review provides a variety of studies showing short people have little to no cardiovascular disease. When shorter people are compared to taller people, a number of biological mechanisms evolve favoring shorter people, including reduced telomere shortening, lower atrial fibrillation, higher heart pumping efficiency, lower DNA damage, lower risk of blood clots, lower left ventricular hypertrophy and superior blood parameters. The causes of increased heart disease among shorter people in the developed world are related to lower income, excessive weight, poor diet, lifestyle factors, catch-up growth, childhood illness and poor environmental conditions. For short people in developed countries, the data indicate that a plant-based diet, leanness and regular exercise can substantially reduce the risk of cardiovascular disease.

Numerical prediction of green water loads on ships

DEFF Research Database (Denmark)

Nielsen, Kristian Bendix

2003-01-01

The main objective of the present study has been to investigate problems related to shipping green water on deck of a floating vessel by use of numerical methods. A Navier-Stokes solver with a free surface capturing scheme, similar to the VOF method (Hirt and Nichols, 1981) has been applied...... green water problem with relative ship motion included. Great effoort has been made to validate and verify the numerical method and all computations have been verified by use of several computational grids with increasing resolution and validated by comparison to experimental data. Results from the dam...

Multiple factors, including non-motor impairments, influence decision making with regard to exercise participation in Parkinson's disease: a qualitative enquiry.

Science.gov (United States)

O'Brien, Christine; Clemson, Lindy; Canning, Colleen G

2016-01-01

To explore how the meaning of exercise and other factors interact and influence the exercise behaviour of individuals with Parkinson's disease (PD) enrolled in a 6-month minimally supervised exercise program to prevent falls, regardless of whether they completed the prescribed exercise or not. This qualitative study utilised in-depth semi-structured interviews analysed using grounded theory methodology. Four main themes were constructed from the data: adapting to change and loss, the influence of others, making sense of the exercise experience and hope for a more active future. Participation in the PD-specific physiotherapy program involving group exercise provided an opportunity for participants to reframe their identity of their "active" self. Three new influences on exercise participation were identified and explored: non-motor impairments of apathy and fatigue, the belief in a finite energy quota, and the importance of feedback. A model was developed incorporating the themes and influences to explain decision-making for exercise participation in this group. Complex and interacting issues, including non-motor impairments, need to be considered in order to enhance the development and ongoing implementation of effective exercise programmes for people with PD. Exercise participation can assist individuals to reframe their identity as they are faced with losses associated with Parkinson's disease and ageing. Non-motor impairments of apathy and fatigue may influence exercise participation in people with Parkinson's disease. Particular attention needs to be paid to the provision of feedback in exercise programs for people with Parkinson's disease as it important for their decision-making about continuing exercise.

Numerical implementation of multiple peeling theory and its application to spider web anchorages.

Science.gov (United States)

Brely, Lucas; Bosia, Federico; Pugno, Nicola M

2015-02-06

Adhesion of spider web anchorages has been studied in recent years, including the specific functionalities achieved through different architectures. To better understand the delamination mechanisms of these and other biological or artificial fibrillar adhesives, and how their adhesion can be optimized, we develop a novel numerical model to simulate the multiple peeling of structures with arbitrary branching and adhesion angles, including complex architectures. The numerical model is based on a recently developed multiple peeling theory, which extends the energy-based single peeling theory of Kendall, and can be applied to arbitrarily complex structures. In particular, we numerically show that a multiple peeling problem can be treated as the superposition of single peeling configurations even for complex structures. Finally, we apply the developed numerical approach to study spider web anchorages, showing how their function is achieved through optimal geometrical configurations.

Assessing the influence of consanguinity on congenital heart disease

Directory of Open Access Journals (Sweden)

Alan H Bittles

2011-01-01

Full Text Available Numerous articles have been published linking consanguineous marriage to an elevated prevalence of congenital heart disease, with ventricular septal defects and atrial septal defects the most commonly cited disorders. While initially persuasive, on closer examination many of these studies have fundamental shortcomings in their design and in the recruitment of study subjects and controls. Improved matching of cases and controls, to include recognition of the long-established community boundaries within which most marriages are contracted, and the assessment of consanguinity within specific levels and types of marital union would improve and help to focus the study outcomes. At the same time, major discrepancies between studies in their reported prevalence and types of congenital heart disease suggest an urgent need for greater standardization in the classification and reporting of these disorders.

Assessing the influence of consanguinity on congenital heart disease

International Nuclear Information System (INIS)

Bittles, Alan H.

2011-01-01

Numerous articles have been published linking consanguineous marriage to an elevated prevalence of congenital heart disease, with ventricular septal defects and atrial septal defects the most commonly cited disorders. While initially persuasive, on closer examination many of these studies have fundamental shortcomings in their design and in the recruitment of study subjects and controls. Improved matching of cases and controls, to include recognition of the long-established community boundaries within which most marriages are contracted, and the assessment of consanguinity within specific levels and types of marital union would improve and help to focus the study outcomes. At the same time, major discrepancies between studies in their reported prevalence and types of congenital heart disease suggest an urgent need for greater standardization in the classification and reporting of these disorders

Orphan drugs in development for Huntington's disease: challenges and progress

Directory of Open Access Journals (Sweden)

Burgunder JM

2015-02-01

Full Text Available Jean-Marc Burgunder1–4 1Swiss Huntington’s Disease Centre, Department of Neurology, University of Bern, Bern, Switzerland; 2Department of Neurology, West China Hospital, Sichuan University, Chengdu, 3Department of Neurology, Xiangya Hospital, Central South University, Changsha, 4Department of Neurology, Sun Yat-sen University, Guangzhou, People’s Republic of China Abstract: Huntington’s disease is a monogenic disorder encompassing a variable phenotype with progressive cognitive, psychiatric, and movement disorders. Knowledge of the mechanisms involved in this disorder has made substantial advances since the discovery of the gene mutation. The dynamic mutation is the expansion of a CAG (cytosine-adenine-guanine repeat in the huntingtin (HTT gene, which is transcribed into an abnormal protein with an elongated polyglutamine tract. Polyglutamine HTT accumulates and is changed in its function in multifaceted ways related to the numerous roles of the normal protein. The protein is expressed in numerous areas of the brain and also in other organs. The major brain region involved in the disease process is the striatum, but it is clear that other systems are involved as well. This accumulated knowledge has now led to the development of treatment strategies based on specific molecular pathways for symptomatic and disease course-modifying treatment. The most proximal way to handle the disturbed protein is to hinder the gene transcription, translation, and/or to increase protein clearance. Other mechanisms now being approached include modulation of energy and intracellular signaling, induction of factors potentially leading to neuroprotection, as well as modulation of glial function. Several clinical trials based on these approaches are now under way, and it is becoming clear that a future disease-modifying therapy will be a combination of several approaches harmonized with symptomatic treatments. In this review, some of the most promising and

Bioactive Components in Moringa Oleifera Leaves Protect against Chronic Disease

Science.gov (United States)

Vergara-Jimenez, Marcela; Almatrafi, Manal Mused

2017-01-01

Moringa Oleifera (MO), a plant from the family Moringacea is a major crop in Asia and Africa. MO has been studied for its health properties, attributed to the numerous bioactive components, including vitamins, phenolic acids, flavonoids, isothiocyanates, tannins and saponins, which are present in significant amounts in various components of the plant. Moringa Oleifera leaves are the most widely studied and they have shown to be beneficial in several chronic conditions, including hypercholesterolemia, high blood pressure, diabetes, insulin resistance, non-alcoholic liver disease, cancer and overall inflammation. In this review, we present information on the beneficial results that have been reported on the prevention and alleviation of these chronic conditions in various animal models and in cell studies. The existing limited information on human studies and Moringa Oleifera leaves is also presented. Overall, it has been well documented that Moringa Oleifera leaves are a good strategic for various conditions associated with heart disease, diabetes, cancer and fatty liver. PMID:29144438

Bioactive Components in Moringa Oleifera Leaves Protect against Chronic Disease

Directory of Open Access Journals (Sweden)

Marcela Vergara-Jimenez

2017-11-01

Full Text Available Moringa Oleifera (MO, a plant from the family Moringacea is a major crop in Asia and Africa. MO has been studied for its health properties, attributed to the numerous bioactive components, including vitamins, phenolic acids, flavonoids, isothiocyanates, tannins and saponins, which are present in significant amounts in various components of the plant. Moringa Oleifera leaves are the most widely studied and they have shown to be beneficial in several chronic conditions, including hypercholesterolemia, high blood pressure, diabetes, insulin resistance, non-alcoholic liver disease, cancer and overall inflammation. In this review, we present information on the beneficial results that have been reported on the prevention and alleviation of these chronic conditions in various animal models and in cell studies. The existing limited information on human studies and Moringa Oleifera leaves is also presented. Overall, it has been well documented that Moringa Oleifera leaves are a good strategic for various conditions associated with heart disease, diabetes, cancer and fatty liver.

Bioactive Components in Moringa Oleifera Leaves Protect against Chronic Disease.

Science.gov (United States)

Vergara-Jimenez, Marcela; Almatrafi, Manal Mused; Fernandez, Maria Luz

2017-11-16

Moringa Oleifera ( MO ), a plant from the family Moringacea is a major crop in Asia and Africa. MO has been studied for its health properties, attributed to the numerous bioactive components, including vitamins, phenolic acids, flavonoids, isothiocyanates, tannins and saponins, which are present in significant amounts in various components of the plant. Moringa Oleifera leaves are the most widely studied and they have shown to be beneficial in several chronic conditions, including hypercholesterolemia, high blood pressure, diabetes, insulin resistance, non-alcoholic liver disease, cancer and overall inflammation. In this review, we present information on the beneficial results that have been reported on the prevention and alleviation of these chronic conditions in various animal models and in cell studies. The existing limited information on human studies and Moringa Oleifera leaves is also presented. Overall, it has been well documented that Moringa Oleifera leaves are a good strategic for various conditions associated with heart disease, diabetes, cancer and fatty liver.

A bibliography on parallel and vector numerical algorithms

Science.gov (United States)

Ortega, James M.; Voigt, Robert G.; Romine, Charles H.

1988-01-01

This is a bibliography on numerical methods. It also includes a number of other references on machine architecture, programming language, and other topics of interest to scientific computing. Certain conference proceedings and anthologies which have been published in book form are also listed.

Cosmic-ray propagation with DRAGON2: I. numerical solver and astrophysical ingredients

Energy Technology Data Exchange (ETDEWEB)

Evoli, Carmelo [Gran Sasso Science Institute, viale Francesco Crispi 7, 67100 L' Aquila (AQ) (Italy); Gaggero, Daniele [GRAPPA Institute, University of Amsterdam, Science Park 904, 1090 GL Amsterdam (Netherlands); Vittino, Andrea [Physik-Department T30d, Technische Universität München, James-Franck-Straße 1, D-85748 Garching (Germany); Bernardo, Giuseppe Di [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, 85740 Garching bei München (Germany); Mauro, Mattia Di [W.W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Ligorini, Arianna [Instytut Fizyki J\\cadrowej—PAN, ul. Radzikowskiego 152, 31-342 Kraków (Poland); Ullio, Piero [Scuola Internazionale di Studi Superiori Avanzati, via Bonomea 265, 34136 Trieste (Italy); Grasso, Dario, E-mail: carmelo.evoli@gssi.infn.it, E-mail: d.gaggero@uva.nl, E-mail: andrea.vittino@tum.de, E-mail: bernardo@mpa-garching.mpg.de, E-mail: mdimauro@slac.stanford.edu, E-mail: arianna.ligorini@ifj.edu.pl, E-mail: piero.ullio@sissa.it, E-mail: dario.grasso@pi.infn.it [INFN and Dipartimento di Fisica ' ' E. Fermi' ' , Pisa University, Largo B. Pontecorvo 3, I-56127 Pisa (Italy)

2017-02-01

We present version 2 of the DRAGON code designed for computing realistic predictions of the CR densities in the Galaxy. The code numerically solves the interstellar CR transport equation (including inhomogeneous and anisotropic diffusion, either in space and momentum, advective transport and energy losses), under realistic conditions. The new version includes an updated numerical solver and several models for the astrophysical ingredients involved in the transport equation. Improvements in the accuracy of the numerical solution are proved against analytical solutions and in reference diffusion scenarios. The novel features implemented in the code allow to simulate the diverse scenarios proposed to reproduce the most recent measurements of local and diffuse CR fluxes, going beyond the limitations of the homogeneous galactic transport paradigm. To this end, several applications using DRAGON2 are presented as well. This new version facilitates the users to include their own physical models by means of a modular C++ structure.

DISEASES: text mining and data integration of disease-gene associations.

Science.gov (United States)

Pletscher-Frankild, Sune; Pallejà, Albert; Tsafou, Kalliopi; Binder, Janos X; Jensen, Lars Juhl

2015-03-01

Text mining is a flexible technology that can be applied to numerous different tasks in biology and medicine. We present a system for extracting disease-gene associations from biomedical abstracts. The system consists of a highly efficient dictionary-based tagger for named entity recognition of human genes and diseases, which we combine with a scoring scheme that takes into account co-occurrences both within and between sentences. We show that this approach is able to extract half of all manually curated associations with a false positive rate of only 0.16%. Nonetheless, text mining should not stand alone, but be combined with other types of evidence. For this reason, we have developed the DISEASES resource, which integrates the results from text mining with manually curated disease-gene associations, cancer mutation data, and genome-wide association studies from existing databases. The DISEASES resource is accessible through a web interface at http://diseases.jensenlab.org/, where the text-mining software and all associations are also freely available for download. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Polyphenols and Oxidative Stress in Atherosclerosis-Related Ischemic Heart Disease and Stroke

Directory of Open Access Journals (Sweden)

Yu-Chen Cheng

2017-01-01

Full Text Available Good nutrition could maintain health and life. Polyphenols are common nutrient mainly derived from fruits, vegetables, tea, coffee, cocoa, mushrooms, beverages, and traditional medicinal herbs. They are potential substances against oxidative-related diseases, for example, cardiovascular disease, specifically, atherosclerosis-related ischemic heart disease and stroke, which are health and economic problems recognized worldwide. In this study, we reviewed the risk factors for atherosclerosis, including hypertension, diabetes mellitus, hyperlipidemia, obesity, and cigarette smoking as well as the antioxidative activity of polyphenols, which could prevent the pathology of atherosclerosis, including endothelial dysfunction, low-density lipoprotein oxidation, vascular smooth muscle cell proliferation, inflammatory process by monocytes, macrophages or T lymphocytes, and platelet aggregation. The strong radical-scavenging properties of polyphenols would exhibit antioxidative and anti-inflammation effects. Polyphenols reduce ROS production by inhibiting oxidases, reducing the production of superoxide, inhibiting OxLDL formation, suppressing VSMC proliferation and migration, reducing platelet aggregation, and improving mitochondrial oxidative stress. Polyphenol consumption also inhibits the development of hypertension, diabetes mellitus, hyperlipidemia, and obesity. Despite the numerous in vivo and in vitro studies, more advanced clinical trials are necessary to confirm the efficacy of polyphenols in the treatment of atherosclerosis-related vascular diseases.

Renal disease in patients with celiac disease.

Science.gov (United States)

Boonpheng, Boonphiphop; Cheungpasitporn, Wisit; Wijarnpreecha, Karn

2018-04-01

Celiac disease, an inflammatory disease of small bowel caused by sensitivity to dietary gluten and related protein, affects approximately 0.5-1% of the population in the Western world. Extra-intestinal symptoms and associated diseases are increasingly recognized including diabetes mellitus type 1, thyroid disease, dermatitis herpetiformis and ataxia. There have also been a number of reports of various types of renal involvement in patients with celiac disease including diabetes nephropathy, IgA nephropathy, membranous nephropathy, membranoproliferative glomerulonephritis, nephrotic syndrome related to malabsorption, oxalate nephropathy, and associations of celiac disease with chronic kidney disease and end-stage kidney disease. This review aims to present the current literature on possible pathologic mechanisms underlying renal disease in patients with celiac disease.

Fluid-structure interaction including volumetric coupling with homogenised subdomains for modeling respiratory mechanics.

Science.gov (United States)

Yoshihara, Lena; Roth, Christian J; Wall, Wolfgang A

2017-04-01

In this article, a novel approach is presented for combining standard fluid-structure interaction with additional volumetric constraints to model fluid flow into and from homogenised solid domains. The proposed algorithm is particularly interesting for investigations in the field of respiratory mechanics as it enables the mutual coupling of airflow in the conducting part and local tissue deformation in the respiratory part of the lung by means of a volume constraint. In combination with a classical monolithic fluid-structure interaction approach, a comprehensive model of the human lung can be established that will be useful to gain new insights into respiratory mechanics in health and disease. To illustrate the validity and versatility of the novel approach, three numerical examples including a patient-specific lung model are presented. The proposed algorithm proves its capability of computing clinically relevant airflow distribution and tissue strain data at a level of detail that is not yet achievable, neither with current imaging techniques nor with existing computational models. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Hybrid RANS-LES using high order numerical methods

Science.gov (United States)

Henry de Frahan, Marc; Yellapantula, Shashank; Vijayakumar, Ganesh; Knaus, Robert; Sprague, Michael

2017-11-01

Understanding the impact of wind turbine wake dynamics on downstream turbines is particularly important for the design of efficient wind farms. Due to their tractable computational cost, hybrid RANS/LES models are an attractive framework for simulating separation flows such as the wake dynamics behind a wind turbine. High-order numerical methods can be computationally efficient and provide increased accuracy in simulating complex flows. In the context of LES, high-order numerical methods have shown some success in predictions of turbulent flows. However, the specifics of hybrid RANS-LES models, including the transition region between both modeling frameworks, pose unique challenges for high-order numerical methods. In this work, we study the effect of increasing the order of accuracy of the numerical scheme in simulations of canonical turbulent flows using RANS, LES, and hybrid RANS-LES models. We describe the interactions between filtering, model transition, and order of accuracy and their effect on turbulence quantities such as kinetic energy spectra, boundary layer evolution, and dissipation rate. This work was funded by the U.S. Department of Energy, Exascale Computing Project, under Contract No. DE-AC36-08-GO28308 with the National Renewable Energy Laboratory.

Unprotected Left Main Coronary Artery Disease: Management in the Post NOBLE and EXCEL Era.

Science.gov (United States)

Borges, Nyal; Kapadia, Samir R; Ellis, Stephen G

2017-09-01

The optimal management of unprotected left main coronary artery (ULMCA) disease is currently a debated topic. Percutaneous coronary intervention (PCI) has seen an increased adoption for the management of ULMCA disease after numerous small-scale randomised trials and cohort studies showed equipoise with coronary artery bypass grafting (CABG) for low complexity lesions. The recently published NOBLE and EXCEL trials are two of the largest international randomised clinical trials comparing PCI and CABG in patients with ULMCA disease. In lieu of all the available evidence, PCI appears to be equivalent to CABG in regard to mortality in patients with ULMCA disease. In non-diabetic patients with low complexity coronary disease (SYNTAX score ≤32), PCI appears to be a reasonable alternative to CABG, especially for ostial and midshaft left main coronary lesions. CABG is preferable in the presence of diabetes, multivessel coronary disease in addition to ULMCA or complex coronary lesions (SYNTAX score >33) including distal left main lesions.

Numerical analysis

CERN Document Server

Brezinski, C

2012-01-01

Numerical analysis has witnessed many significant developments in the 20th century. This book brings together 16 papers dealing with historical developments, survey papers and papers on recent trends in selected areas of numerical analysis, such as: approximation and interpolation, solution of linear systems and eigenvalue problems, iterative methods, quadrature rules, solution of ordinary-, partial- and integral equations. The papers are reprinted from the 7-volume project of the Journal of Computational and Applied Mathematics on '/homepage/sac/cam/na2000/index.html<

Numerical and symbolic scientific computing

CERN Document Server

Langer, Ulrich

2011-01-01

The book presents the state of the art and results and also includes articles pointing to future developments. Most of the articles center around the theme of linear partial differential equations. Major aspects are fast solvers in elastoplasticity, symbolic analysis for boundary problems, symbolic treatment of operators, computer algebra, and finite element methods, a symbolic approach to finite difference schemes, cylindrical algebraic decomposition and local Fourier analysis, and white noise analysis for stochastic partial differential equations. Further numerical-symbolic topics range from

Transfer RNA and human disease

Directory of Open Access Journals (Sweden)

Jamie A Abbott

2014-06-01

Full Text Available Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA genes are hotspots for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase, mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers, and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes. Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing. Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.

Transfer RNA and human disease.

Science.gov (United States)

Abbott, Jamie A; Francklyn, Christopher S; Robey-Bond, Susan M

2014-01-01

Pathological mutations in tRNA genes and tRNA processing enzymes are numerous and result in very complicated clinical phenotypes. Mitochondrial tRNA (mt-tRNA) genes are "hotspots" for pathological mutations and over 200 mt-tRNA mutations have been linked to various disease states. Often these mutations prevent tRNA aminoacylation. Disrupting this primary function affects protein synthesis and the expression, folding, and function of oxidative phosphorylation enzymes. Mitochondrial tRNA mutations manifest in a wide panoply of diseases related to cellular energetics, including COX deficiency (cytochrome C oxidase), mitochondrial myopathy, MERRF (Myoclonic Epilepsy with Ragged Red Fibers), and MELAS (mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes). Diseases caused by mt-tRNA mutations can also affect very specific tissue types, as in the case of neurosensory non-syndromic hearing loss and pigmentary retinopathy, diabetes mellitus, and hypertrophic cardiomyopathy. Importantly, mitochondrial heteroplasmy plays a role in disease severity and age of onset as well. Not surprisingly, mutations in enzymes that modify cytoplasmic and mitochondrial tRNAs are also linked to a diverse range of clinical phenotypes. In addition to compromised aminoacylation of the tRNAs, mutated modifying enzymes can also impact tRNA expression and abundance, tRNA modifications, tRNA folding, and even tRNA maturation (e.g., splicing). Some of these pathological mutations in tRNAs and processing enzymes are likely to affect non-canonical tRNA functions, and contribute to the diseases without significantly impacting on translation. This chapter will review recent literature on the relation of mitochondrial and cytoplasmic tRNA, and enzymes that process tRNAs, to human disease. We explore the mechanisms involved in the clinical presentation of these various diseases with an emphasis on neurological disease.

Numerical Method for Darcy Flow Derived Using Discrete Exterior Calculus

Science.gov (United States)

Hirani, A. N.; Nakshatrala, K. B.; Chaudhry, J. H.

2015-05-01

We derive a numerical method for Darcy flow, and also for Poisson's equation in mixed (first order) form, based on discrete exterior calculus (DEC). Exterior calculus is a generalization of vector calculus to smooth manifolds and DEC is one of its discretizations on simplicial complexes such as triangle and tetrahedral meshes. DEC is a coordinate invariant discretization, in that it does not depend on the embedding of the simplices or the whole mesh. We start by rewriting the governing equations of Darcy flow using the language of exterior calculus. This yields a formulation in terms of flux differential form and pressure. The numerical method is then derived by using the framework provided by DEC for discretizing differential forms and operators that act on forms. We also develop a discretization for a spatially dependent Hodge star that varies with the permeability of the medium. This also allows us to address discontinuous permeability. The matrix representation for our discrete non-homogeneous Hodge star is diagonal, with positive diagonal entries. The resulting linear system of equations for flux and pressure are saddle type, with a diagonal matrix as the top left block. The performance of the proposed numerical method is illustrated on many standard test problems. These include patch tests in two and three dimensions, comparison with analytically known solutions in two dimensions, layered medium with alternating permeability values, and a test with a change in permeability along the flow direction. We also show numerical evidence of convergence of the flux and the pressure. A convergence experiment is included for Darcy flow on a surface. A short introduction to the relevant parts of smooth and discrete exterior calculus is included in this article. We also include a discussion of the boundary condition in terms of exterior calculus.

2nd International Workshop on the Numerical Solution of Markov Chains

CERN Document Server

1995-01-01

Computations with Markov Chains presents the edited and reviewed proceedings of the Second International Workshop on the Numerical Solution of Markov Chains, held January 16--18, 1995, in Raleigh, North Carolina. New developments of particular interest include recent work on stability and conditioning, Krylov subspace-based methods for transient solutions, quadratic convergent procedures for matrix geometric problems, further analysis of the GTH algorithm, the arrival of stochastic automata networks at the forefront of modelling stratagems, and more. An authoritative overview of the field for applied probabilists, numerical analysts and systems modelers, including computer scientists and engineers.

Numerical study of nonspherical black hole accretion

International Nuclear Information System (INIS)

Hawley, J.F.

1984-01-01

This thesis describes in detail a two-dimensional, axisymmetric computer code for calculating fully relativistic ideal gas hydrodynamics around a Kerr black hole. The aim is to study fully dynamic inviscid fluid accretion onto black holes, as well as to study the evolution and development of nonlinear instabilities in pressure supported accretion disks. In order to fully calibrate and document the code, certain analytic solutions for shock tubes and special accretion flows are derived; these solutions form the basis for code testing. The numerical techniques used are developed and discussed. A variety of alternate differencing schemes are compared on an analytic test bed. Some discussion is devoted to general issues in finite differencing. The working code is calibrated using analytically solvable accretion problems, including the radial accretion of dust and of fluid with pressure (Bondi accretion). Two dimensional test problems include the spiraling infall of low angular momentum fluid, the formation of a pressure supported torus, and the stable evolution of a torus. A series of numerical models are discussed and illustrated with selected plots

Numeral-Incorporating Roots in Numeral Systems: A Comparative Analysis of Two Sign Languages

Science.gov (United States)

Fuentes, Mariana; Massone, Maria Ignacia; Fernandez-Viader, Maria del Pilar; Makotrinsky, Alejandro; Pulgarin, Francisca

2010-01-01

Numeral-incorporating roots in the numeral systems of Argentine Sign Language (LSA) and Catalan Sign Language (LSC), as well as the main features of the number systems of both languages, are described and compared. Informants discussed the use of numerals and roots in both languages (in most cases in natural contexts). Ten informants took part in…

Numerical experimentation on convective coolant flow in Ghana ...

African Journals Online (AJOL)

Numerical experiments on one dimensional convective coolant flow during steady state operation of the Ghana Research Reactor-1 (GHARR-I) were performed to determine the thermal hydraulic parameters of temperature, density and flow rate. The computational domain was the reactor vessel, including the reactor core.

Physical and numerical modeling of Joule-heated melters

Energy Technology Data Exchange (ETDEWEB)

Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

1985-10-01

The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs.

Physical and numerical modeling of Joule-heated melters

International Nuclear Information System (INIS)

Eyler, L.L.; Skarda, R.J.; Crowder, R.S. III; Trent, D.S.; Reid, C.R.; Lessor, D.L.

1985-10-01

The Joule-heated ceramic-lined melter is an integral part of the high level waste immobilization process under development by the US Department of Energy. Scaleup and design of this waste glass melting furnace requires an understanding of the relationships between melting cavity design parameters and the furnace performance characteristics such as mixing, heat transfer, and electrical requirements. Developing empirical models of these relationships through actual melter testing with numerous designs would be a very costly and time consuming task. Additionally, the Pacific Northwest Laboratory (PNL) has been developing numerical models that simulate a Joule-heated melter for analyzing melter performance. This report documents the method used and results of this modeling effort. Numerical modeling results are compared with the more conventional, physical modeling results to validate the approach. Also included are the results of numerically simulating an operating research melter at PNL. Physical Joule-heated melters modeling results used for qualiying the simulation capabilities of the melter code included: (1) a melter with a single pair of electrodes and (2) a melter with a dual pair (two pairs) of electrodes. The physical model of the melter having two electrode pairs utilized a configuration with primary and secondary electrodes. The principal melter parameters (the ratio of power applied to each electrode pair, modeling fluid depth, electrode spacing) were varied in nine tests of the physical model during FY85. Code predictions were made for five of these tests. Voltage drops, temperature field data, and electric field data varied in their agreement with the physical modeling results, but in general were judged acceptable. 14 refs., 79 figs., 17 tabs

Including gauge corrections to thermal leptogenesis

International Nuclear Information System (INIS)

Huetig, Janine

2013-01-01

. Furthermore, we have computed the Majorana neutrino production rate itself in chapter 6 to test our numerical procedure. In this context we have calculated the tree-level result as well as the gauge corrected result for the Majorana neutrino production rate. Finally in chapter 7, we have implemented the Majorana neutrino ladder rung diagram into our setup for leptogenesis: As a first consideration, we have collected all gauge corrected diagrams up to three-loop order for the asymmetry-causing two-loop diagrams. However, the results of chap. 5 showed that it is not sufficient to just include diagrams up to three-loop level. Due to the necessity of resumming all n-loop diagrams, we have constructed a cylindrical diagram that fulfils this condition. This diagram is the link between the Majorana neutrino ladder rung diagram calculated before on the one hand and the lepton asymmetry on the other. Therefore we have been able to derive a complete expression for the integrated lepton number matrix including all leading order corrections. The numerical analysis of this lepton number matrix needs a great computational effort since for the resulting eight-dimensional integral two ordinary differential equations have to be computed for each point the routine evaluates. Thus the result remains yet inaccessible. Research perspectives: Summarising, this thesis provides the basis for a systematic inclusion of gauge interactions in thermal leptogenesis scenarios. As a next step, one should evaluate the expression for the integrated lepton number numerically to gain a value, which can be used for comparison to earlier results such as the solutions of the Boltzmann equations as well as the Kadanoff-Baym ansatz with the implemented Standard Model widths. This numerical result would be the first quantitative number, which contains leading order corrections due to all interactions of the Majorana neutrino with the Standard Model particles. Further corrections by means of including washout effects

Including gauge corrections to thermal leptogenesis

Energy Technology Data Exchange (ETDEWEB)

Huetig, Janine

2013-05-17

. Furthermore, we have computed the Majorana neutrino production rate itself in chapter 6 to test our numerical procedure. In this context we have calculated the tree-level result as well as the gauge corrected result for the Majorana neutrino production rate. Finally in chapter 7, we have implemented the Majorana neutrino ladder rung diagram into our setup for leptogenesis: As a first consideration, we have collected all gauge corrected diagrams up to three-loop order for the asymmetry-causing two-loop diagrams. However, the results of chap. 5 showed that it is not sufficient to just include diagrams up to three-loop level. Due to the necessity of resumming all n-loop diagrams, we have constructed a cylindrical diagram that fulfils this condition. This diagram is the link between the Majorana neutrino ladder rung diagram calculated before on the one hand and the lepton asymmetry on the other. Therefore we have been able to derive a complete expression for the integrated lepton number matrix including all leading order corrections. The numerical analysis of this lepton number matrix needs a great computational effort since for the resulting eight-dimensional integral two ordinary differential equations have to be computed for each point the routine evaluates. Thus the result remains yet inaccessible. Research perspectives: Summarising, this thesis provides the basis for a systematic inclusion of gauge interactions in thermal leptogenesis scenarios. As a next step, one should evaluate the expression for the integrated lepton number numerically to gain a value, which can be used for comparison to earlier results such as the solutions of the Boltzmann equations as well as the Kadanoff-Baym ansatz with the implemented Standard Model widths. This numerical result would be the first quantitative number, which contains leading order corrections due to all interactions of the Majorana neutrino with the Standard Model particles. Further corrections by means of including washout effects

Constrained evolution in numerical relativity

Science.gov (United States)

Anderson, Matthew William

The strongest potential source of gravitational radiation for current and future detectors is the merger of binary black holes. Full numerical simulation of such mergers can provide realistic signal predictions and enhance the probability of detection. Numerical simulation of the Einstein equations, however, is fraught with difficulty. Stability even in static test cases of single black holes has proven elusive. Common to unstable simulations is the growth of constraint violations. This work examines the effect of controlling the growth of constraint violations by solving the constraints periodically during a simulation, an approach called constrained evolution. The effects of constrained evolution are contrasted with the results of unconstrained evolution, evolution where the constraints are not solved during the course of a simulation. Two different formulations of the Einstein equations are examined: the standard ADM formulation and the generalized Frittelli-Reula formulation. In most cases constrained evolution vastly improves the stability of a simulation at minimal computational cost when compared with unconstrained evolution. However, in the more demanding test cases examined, constrained evolution fails to produce simulations with long-term stability in spite of producing improvements in simulation lifetime when compared with unconstrained evolution. Constrained evolution is also examined in conjunction with a wide variety of promising numerical techniques, including mesh refinement and overlapping Cartesian and spherical computational grids. Constrained evolution in boosted black hole spacetimes is investigated using overlapping grids. Constrained evolution proves to be central to the host of innovations required in carrying out such intensive simulations.

Numerical Simulation Of Silicon-Ribbon Growth

Science.gov (United States)

Woda, Ben K.; Kuo, Chin-Po; Utku, Senol; Ray, Sujit Kumar

1987-01-01

Mathematical model includes nonlinear effects. In development simulates growth of silicon ribbon from melt. Takes account of entire temperature and stress history of ribbon. Numerical simulations performed with new model helps in search for temperature distribution, pulling speed, and other conditions favoring growth of wide, flat, relatively defect-free silicon ribbons for solar photovoltaic cells at economically attractive, high production rates. Also applicable to materials other than silicon.

[Infectious diseases research].

Science.gov (United States)

Carratalà, Jordi; Alcamí, José; Cordero, Elisa; Miró, José M; Ramos, José Manuel

2008-12-01

There has been a significant increase in research activity into infectious diseases in Spain in the last few years. The Spanish Society of Infectious Diseases and Clinical Microbiology (SEIMC) currently has ten study groups, with the cooperation of infectious diseases specialists and microbiologists from different centres, with significant research activity. The program of Redes Temáticas de Investigación Cooperativa en Salud (Special Topics Cooperative Health Research Networks) is an appropriate framework for the strategic coordination of research groups from the Spanish autonomous communities. The Spanish Network for Research in Infectious Diseases (REIPI) and the Network for Research in AIDS (RIS) integrate investigators in Infectious Diseases from multiple groups, which continuously perform important research projects. Research using different experimental models in infectious diseases, in numerous institutions, is an important activity in our country. The analysis of the recent scientific production in Infectious Diseases shows that Spain has a good position in the context of the European Union. The research activity in Infectious Diseases carried out in our country is a great opportunity for the training of specialists in this area of knowledge.

Numerical Study on Critical Wedge Angle of Cellular Detonation Reflections

International Nuclear Information System (INIS)

Gang, Wang; Kai-Xin, Liu; De-Liang, Zhang

2010-01-01

The critical wedge angle (CWA) for the transition from regular reflection (RR) to Mach reflection (MR) of a cellular detonation wave is studied numerically by an improved space-time conservation element and solution element method together with a two-step chemical reaction model. The accuracy of that numerical way is verified by simulating cellular detonation reflections at a 19.3° wedge. The planar and cellular detonation reflections over 45°–55° wedges are also simulated. When the cellular detonation wave is over a 50° wedge, numerical results show a new phenomenon that RR and MR occur alternately. The transition process between RR and MR is investigated with the local pressure contours. Numerical analysis shows that the cellular structure is the essential reason for the new phenomenon and the CWA of detonation reflection is not a certain angle but an angle range. (fundamental areas of phenomenology(including applications))

Two numerical methods for mean-field games

KAUST Repository

Gomes, Diogo A.

2016-01-01

Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

Two numerical methods for mean-field games

KAUST Repository

Gomes, Diogo A.

2016-01-09

Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

First-order symmetrizable hyperbolic formulations of Einstein's equations including lapse and shift as dynamical fields

International Nuclear Information System (INIS)

Alvi, Kashif

2002-01-01

First-order hyperbolic systems are promising as a basis for numerical integration of Einstein's equations. In previous work, the lapse and shift have typically not been considered part of the hyperbolic system and have been prescribed independently. This can be expensive computationally, especially if the prescription involves solving elliptic equations. Therefore, including the lapse and shift in the hyperbolic system could be advantageous for numerical work. In this paper, two first-order symmetrizable hyperbolic systems are presented that include the lapse and shift as dynamical fields and have only physical characteristic speeds

A Space-Time Finite Element Approach to the Numerical Simulation of Vascular Fluid-Solid Interaction

NARCIS (Netherlands)

Vlijm, E.J.; Van Brummelen, E.H.

2008-01-01

Numerical studies of cardiovascular diseases like arteriosclerosis have gained increasing attention the last decade. The modeling of blood, blood vessel and their coupling, shows to be a challenging problem. In this thesis a two-dimensional model has been constructed and its behaviour has been

An improved numerical approximation for the first derivative

Indian Academy of Sciences (India)

Administrator

The traditional numerical computation of the first derivative f ′(x) of a given function f (x) of a single argument ... includes the option of user-provided analytic deriva- tives, but its ...... will be in the near future, and back to the present. The macro ...

Practical considerations in developing numerical simulators for thermal recovery

Energy Technology Data Exchange (ETDEWEB)

Abou-Kassem, J.H. [Chemical and Petroleum Engineering Department, UAE University, Al-Ain (United Arab Emirates)

1996-08-15

Numerical simulation of steam injection and in-situ combustion-based oil recovery processes is of great importance in project design. Development of such numerical simulators is an on-going process, with improvements made as the process description becomes more complete, and also as better methods are devised to resolve certain numerical difficulties. This paper addresses some of the latter, and based on the author`s experience gives useful guidelines for developing more efficient numerical simulators of steam injection and in-situ combustion. The paper takes up a series of questions related to simulating thermal processes. Included are: the elimination of constraint equations at the matrix level, phase change, steam injection rate, alternative treatments of heat loss, relative permeabilities and importance of hysteresis effects, improved solutions to the grid orientation problem and other simulation problems such as potential inversion, grid block size, time-step size control and induced fractures. The points discussed in the paper should be of use to both simulator developers and users alike, and will lead to a better understanding of simulation results

Iron deficiency anemia in patients with inflammatory bowel disease

Directory of Open Access Journals (Sweden)

Goldberg ND

2013-06-01

Full Text Available Neil D Goldberg Emeritus Chief of Gastroenterology, University of Maryland St. Joseph Medical Center, Towson, MD, USA Abstract: Iron deficiency anemia is the most common form of anemia worldwide, caused by poor iron intake, chronic blood loss, or impaired absorption. Patients with inflammatory bowel disease (IBD are increasingly likely to have iron deficiency anemia, with an estimated prevalence of 36%–76%. Detection of iron deficiency is problematic as outward signs and symptoms are not always present. Iron deficiency can have a significant impact on a patient's quality of life, necessitating prompt management and treatment. Effective treatment includes identifying and treating the underlying cause and initiating iron replacement therapy with either oral or intravenous iron. Numerous formulations for oral iron are available, with ferrous fumarate, sulfate, and gluconate being the most commonly prescribed. Available intravenous formulations include iron dextran, iron sucrose, ferric gluconate, and ferumoxytol. Low-molecular weight iron dextran and iron sucrose have been shown to be safe, efficacious, and effective in a host of gastrointestinal disorders. Ferumoxytol is the newest US Food and Drug Administration-approved intravenous iron therapy, indicated for iron deficiency anemia in adults with chronic kidney disease. Ferumoxytol is also being investigated in Phase 3 studies for the treatment of iron deficiency anemia in patients without chronic kidney disease, including subgroups with IBD. A review of the efficacy and safety of iron replacement in IBD, therapeutic considerations, and recommendations for the practicing gastroenterologist are presented. Keywords: anemia, inflammatory bowel disease, intravenous iron, iron deficiency, oral iron, therapy

Efficient numerical methods for fluid- and electrodynamics on massively parallel systems

Energy Technology Data Exchange (ETDEWEB)

Zudrop, Jens

2016-07-01

In the last decade, computer technology has evolved rapidly. Modern high performance computing systems offer a tremendous amount of computing power in the range of a few peta floating point operations per second. In contrast, numerical software development is much slower and most existing simulation codes cannot exploit the full computing power of these systems. Partially, this is due to the numerical methods themselves and partially it is related to bottlenecks within the parallelization concept and its data structures. The goal of the thesis is the development of numerical algorithms and corresponding data structures to remedy both kinds of parallelization bottlenecks. The approach is based on a co-design of the numerical schemes (including numerical analysis) and their realizations in algorithms and software. Various kinds of applications, from multicomponent flows (Lattice Boltzmann Method) to electrodynamics (Discontinuous Galerkin Method) to embedded geometries (Octree), are considered and efficiency of the developed approaches is demonstrated for large scale simulations.

Lysosomes, Lysosomal Storage Diseases, and Inflammation

Directory of Open Access Journals (Sweden)

Calogera M. Simonaro PhD

2016-05-01

Full Text Available Lysosomes were originally described in the early 1950s by de Duve who was also the first to recognize the importance of these organelles in human disease. We know now that lysosomes are involved in numerous biological processes, and abnormalities in lysosomal function may result in a broad range of diseases. This review will briefly discuss the role of lysosomes in inflammation and how disruption of normal lysosomal function in the lysosomal storage diseases (LSDs leads to abnormalities in inflammation and immunity.

Therapeutic potential of flavonoids in inflammatory bowel disease: A comprehensive review.

Science.gov (United States)

Salaritabar, Ali; Darvishi, Behrad; Hadjiakhoondi, Farzaneh; Manayi, Azadeh; Sureda, Antoni; Nabavi, Seyed Fazel; Fitzpatrick, Leo R; Nabavi, Seyed Mohammad; Bishayee, Anupam

2017-07-28

The inflammatory process plays a central role in the development and progression of numerous pathological situations, such as inflammatory bowel disease (IBD), autoimmune and neurodegenerative diseases, metabolic syndrome, and cardiovascular disorders. IBDs involve inflammation of the gastrointestinal area and mainly comprise Crohn's disease (CD) and ulcerative colitis (UC). Both pathological situations usually involve recurring or bloody diarrhea, pain, fatigue and weight loss. There is at present no pharmacological cure for CD or UC. However, surgery may be curative for UC patients. The prescribed treatment aims to ameliorate the symptoms and prevent and/or delay new painful episodes. Flavonoid compounds are a large family of hydroxylated polyphenolic molecules abundant in plants, including vegetables and fruits which are the major dietary sources of these compounds for humans, together with wine and tea. Flavonoids are becoming very popular because they have many health-promoting and disease-preventive effects. Most interest has been directed towards the antioxidant activity of flavonoids, evidencing a remarkable free-radical scavenging capacity. However, accumulating evidence suggests that flavonoids have many other biological properties, including anti-inflammatory, antiviral, anticancer, and neuroprotective activities through different mechanisms of action. The present review analyzes the available data about the different types of flavonoids and their potential effectiveness as adjuvant therapy of IBDs.

Merkel Cell Carcinomas Arising in Autoimmune Disease Affected Patients Treated with Biologic Drugs, Including Anti-TNF.

Science.gov (United States)

Rotondo, John Charles; Bononi, Ilaria; Puozzo, Andrea; Govoni, Marcello; Foschi, Valentina; Lanza, Giovanni; Gafà, Roberta; Gaboriaud, Pauline; Touzé, Françoise Antoine; Selvatici, Rita; Martini, Fernanda; Tognon, Mauro

2017-07-15

Purpose: The purpose of this investigation was to characterize Merkel cell carcinomas (MCC) arisen in patients affected by autoimmune diseases and treated with biologic drugs. Experimental Design: Serum samples from patients with MCC were analyzed for the presence and titer of antibodies against antigens of the oncogenic Merkel cell polyomavirus (MCPyV). IgG antibodies against the viral oncoproteins large T (LT) and small T (ST) antigens and the viral capsid protein-1 were analyzed by indirect ELISA. Viral antigens were recombinant LT/ST and virus-like particles (VLP), respectively. MCPyV DNA sequences were studied using PCR methods in MCC tissues and in peripheral blood mononuclear cells (PBMC). Immunohistochemical (IHC) analyses were carried out in MCC tissues to reveal MCPyV LT oncoprotein. Results: MCPyV DNA sequences identified in MCC tissues showed 100% homology with the European MKL-1 strain. PBMCs from patients tested MCPyV-negative. Viral DNA loads in the three MCC tissues were in the 0.1 to 30 copy/cell range. IgG antibodies against LT/ST were detected in patients 1 and 3, whereas patient 2 did not react to the MCPyV LT/ST antigen. Sera from the three patients with MCC contained IgG antibodies against MCPyV VP1. MCC tissues tested MCPyV LT-antigen-positive in IHC assays, with strong LT expression with diffuse nuclear localization. Normal tissues tested MCPyV LT-negative when employed as control. Conclusions: We investigated three new MCCs in patients affected by rheumatologic diseases treated with biologic drugs, including TNF. A possible cause-effect relationship between pharmacologic immunosuppressive treatment and MCC onset is suggested. Indeed, MCC is associated with MCPyV LT oncoprotein activity. Clin Cancer Res; 23(14); 3929-34. ©2017 AACR . ©2017 American Association for Cancer Research.

Newly Diagnosed Meniere's Disease: Clinical Course With Initiation of Noninvasive Treatment Including an Accounting of Vestibular Migraine.

Science.gov (United States)

Sbeih, Firas; Christov, Florian; Gluth, Michael B

2018-05-01

To describe the course of Meniere's disease with noninvasive treatment during the first few years after initial diagnosis. A retrospective review of consecutive patients with newly diagnosed definite Meniere's disease between 2013 and 2016 and a minimum follow-up of 1 year. Patients received a written plan for low sodium, water therapy, and treatment with a diuretic and/or betahistine. Subjects were screened and treated for vestibular migraine as needed. Vertigo control and hearing status at most recent follow-up were assessed. Forty-four subjects had an average follow up of 24.3 months. Thirty-four percent had Meniere's disease and vestibular migraine, and 84% had unilateral Meniere's disease. Seventy-five percent had vertigo well controlled at most recent follow-up, with only noninvasive treatments. Age, gender, body mass index, presence of vestibular migraine, bilateral disease, and duration of follow-up did not predict noninvasive treatment failure. Worse hearing threshold at 250 Hz and lower pure tone average (PTA) at the time of diagnosis did predict failure. Fifty-two percent of ears had improved PTA at most recent visit, 20% had no change, and 28% were worse Conclusions: Encountering excellent vertigo control and stable hearing after a new diagnosis of Meniere's disease is possible with noninvasive treatments. Worse hearing status at diagnosis predicted treatment failure.

PREVALENCE OF CELIAC DISEASE PREDISPOSING GENOTYPES, INCLUDING HLA-DQ2.2 VARIANT, IN BRAZILIAN CHILDREN.

Science.gov (United States)

Selleski, Nicole; Almeida, Lucas Malta; Almeida, Fernanda Coutinho de; Pratesi, Claudia Beatriz; Nóbrega, Yanna Karla de Medeiros; Gandolfi, Lenora

2018-01-01

Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Almost all celiac patients carry immune recognition genes coding for HLA-DQ2.5 and DQ8 heterodimers. Over the last few years, great importance has been given to HLA-DQ2.2 as probable predisposing variant, although controversies still exist regarding its relevance. The aim of our study was to determine the possible existence of an association between HLA-DQ2.2 and celiac disease in Brazilian children by analyzing the prevalence of the predisposing variants for celiac disease in a representative group of children of a population in which this determination is still missing. HLA-DQ typing was performed in samples from a group of celiac (n=100) and non-celiac children (n=110). All samples were tested for the presence of the following variants: DQA1*05-DQB1*02 (DQ2.5), DQA1*03-DQB1*03:02 (DQ8) and DQA1*02:01-DQB1*02:02 (DQ2.2). Fisher`s exact test was used for statistical analysis. In the group of 100 celiac children, 78 (78%) were positive for DQ2, 13 (13 %) were DQ2/DQ8 and 6 (6%) were DQ8 positives. The HLA-DQ pattern in the 110 non-celiac children was as follows: positive for DQ2 in 33 (29.9%) samples, in 2 (1.8 %) was positive for DQ2/DQ8 and in 15 (13.6%) was positive for DQ8. We found significant differences between the distribution of some but not all of the analyzed alleles when comparing celiac and non-celiac children. The genotyping of celiac disease HLA-DQ predisposing alleles showed similarities with HLA-DQ patterns found in both European and non-European populations, which may be a reflection of the miscegenation, which gave origin to the current Brazilian population. No significant association was found between DQ2.2 variant and celiac disease in the studied population.

PREVALENCE OF CELIAC DISEASE PREDISPOSING GENOTYPES, INCLUDING HLA-DQ2.2 VARIANT, IN BRAZILIAN CHILDREN

Directory of Open Access Journals (Sweden)

Nicole SELLESKI

Full Text Available ABSTRACT BACKGROUND: Celiac disease is an autoimmune enteropathy triggered by the ingestion of gluten in genetically susceptible individuals. Almost all celiac patients carry immune recognition genes coding for HLA-DQ2.5 and DQ8 heterodimers. Over the last few years, great importance has been given to HLA-DQ2.2 as probable predisposing variant, although controversies still exist regarding its relevance. OBJECTIVE: The aim of our study was to determine the possible existence of an association between HLA-DQ2.2 and celiac disease in Brazilian children by analyzing the prevalence of the predisposing variants for celiac disease in a representative group of children of a population in which this determination is still missing. METHODS: HLA-DQ typing was performed in samples from a group of celiac (n=100 and non-celiac children (n=110. All samples were tested for the presence of the following variants: DQA1*05-DQB1*02 (DQ2.5, DQA1*03-DQB1*03:02 (DQ8 and DQA1*02:01-DQB1*02:02 (DQ2.2. Fisher`s exact test was used for statistical analysis. RESULTS: In the group of 100 celiac children, 78 (78% were positive for DQ2, 13 (13 % were DQ2/DQ8 and 6 (6% were DQ8 positives. The HLA-DQ pattern in the 110 non-celiac children was as follows: positive for DQ2 in 33 (29.9% samples, in 2 (1.8 % was positive for DQ2/DQ8 and in 15 (13.6% was positive for DQ8. We found significant differences between the distribution of some but not all of the analyzed alleles when comparing celiac and non-celiac children. CONCLUSION: The genotyping of celiac disease HLA-DQ predisposing alleles showed similarities with HLA-DQ patterns found in both European and non-European populations, which may be a reflection of the miscegenation, which gave origin to the current Brazilian population. No significant association was found between DQ2.2 variant and celiac disease in the studied population.

Borna disease virus and its role in the pathology of animals and humans

Directory of Open Access Journals (Sweden)

A. O. Mikheev

2017-12-01

Full Text Available Infectious diseases that are caused by numerous pathogenic microorganisms – bacteria, viruses, protozoa or fungi – can be transmitted from patients or carriers to healthy people or animals. A large group of infectious disease is caused by pathogens of animal infections – zoonoses. The issue of zoonoses is of great significance in human pathology and requires comprehensive study. This is of particular relevance to Ukraine, as the question of prevalence, level within the population and threats to human life and health from zoonoses, though highly important, has remained insufficiently studied. Information about many of these pathogens is absent in the existing scientific literature accessible in Ukraine – both veterinary and medical. This applies, in particular, to a causative agent of viral zoonoses the Borna disease virus or Bornavirus. For this purpose, an analysis of the literature concerning the role of the Bornavirus in the pathology of animals and humans was conducted. It is well known that a large number of pathogens of animal infections (zoonoses, including viral, pose a potential threat to human health. Among these potential threats is the Borna disease virus belonging to the family of Bornaviridae, order Mononegavirales. This order includes representatives of deadly human diseases like rabies (family Rhabdoviridae, Ebola virus (family Filoviridae and Nipah virus (family Paramyxoviridae. Borna virus disease affects mainly mammals, but can infect birds and even reptiles (Aspid bornavirus. It is established that Bornaviruses have a wide range of natural hosts (horses, sheeps, cats, bats and various birds, including domestic animals, which poses a potential threat to human health. This is evidenced by numerous, although contradictory, research into the role of the Borna disease virus in human pathologies such as schizophrenia, depression, prolonged fatigue syndrome, multiple sclerosis and others. Analysis of the literature clearly

Development process of muzzle flows including a gun-launched missile

Directory of Open Access Journals (Sweden)

Zhuo Changfei

2015-04-01

Full Text Available Numerical investigations on the launch process of a gun-launched missile from the muzzle of a cannon to the free-flight stage have been performed in this paper. The dynamic overlapped grids approach are applied to dealing with the problems of a moving gun-launched missile. The high-resolution upwind scheme (AUSMPW+ and the detailed reaction kinetics model are adopted to solve the chemical non-equilibrium Euler equations for dynamic grids. The development process and flow field structure of muzzle flows including a gun-launched missile are discussed in detail. This present numerical study confirms that complicated transient phenomena exist in the shortly launching stages when the gun-launched missile moves from the muzzle of a cannon to the free-flight stage. The propellant gas flows, the initial environmental ambient air flows and the moving missile mutually couple and interact. A complete structure of flow field is formed at the launching stages, including the blast wave, base shock, reflected shock, incident shock, shear layer, primary vortex ring and triple point.

IPM strategies and their dilemmas including an introduction to www.Eurowheat.org

DEFF Research Database (Denmark)

Jørgensen, Lise Nistrup; Hovmøller, Mogens Støvring; Hansen, Jens Grønbech

2014-01-01

Information about disease management in winter wheat (Triticum aestiva) in eight European countries was collated and analysed by scientists and extension workers within a European Network for Durable Exploitation (ENDURE). This included information about specific disease thresholds, decision...... information platformwww.EuroWheat.org was used for dissemination of information and results including information on control thresholds, cultural practices which can influence disease attack, fungicide efficacy, fungicide resistance and pathogen virulence, which are all elements supporting IPM for disease...... control in wheat. The platform is open to all users. The target groups of EuroWheat information are researchers, advisors, breeders and similar partners dealing with disease management in wheat....

Gab Docking Proteins in Cardiovascular Disease, Cancer, and Inflammation

Directory of Open Access Journals (Sweden)

Yoshikazu Nakaoka

2013-01-01

Full Text Available The docking proteins of the Grb2-associated binder (Gab family have emerged as crucial signaling compartments in metazoans. In mammals, the Gab proteins, consisting of Gab1, Gab2, and Gab3, are involved in the amplification and integration of signal transduction evoked by a variety of extracellular stimuli, including growth factors, cytokines, antigens, and other molecules. Gab proteins lack the enzymatic activity themselves; however, when phosphorylated on tyrosine residues, they provide binding sites for multiple Src homology-2 (SH2 domain-containing proteins, such as SH2-containing protein tyrosine phosphatase 2 (SHP2, phosphatidylinositol 3-kinase regulatory subunit p85, phospholipase Cγ, Crk, and GC-GAP. Through these interactions, the Gab proteins transduce signals from activated receptors into pathways with distinct biological functions, thereby contributing to signal diversification. They are known to play crucial roles in numerous physiological processes through their associations with SHP2 and p85. In addition, abnormal Gab protein signaling has been linked to human diseases including cancer, cardiovascular disease, and inflammatory disorders. In this paper, we provide an overview of the structure, effector functions, and regulation of the Gab docking proteins, with a special focus on their associations with cardiovascular disease, cancer, and inflammation.

Numeral Incorporation in Japanese Sign Language

Science.gov (United States)

Ktejik, Mish

2013-01-01

This article explores the morphological process of numeral incorporation in Japanese Sign Language. Numeral incorporation is defined and the available research on numeral incorporation in signed language is discussed. The numeral signs in Japanese Sign Language are then introduced and followed by an explanation of the numeral morphemes which are…

Numerical analysis

CERN Document Server

Jacques, Ian

1987-01-01

This book is primarily intended for undergraduates in mathematics, the physical sciences and engineering. It introduces students to most of the techniques forming the core component of courses in numerical analysis. The text is divided into eight chapters which are largely self-contained. However, with a subject as intricately woven as mathematics, there is inevitably some interdependence between them. The level of difficulty varies and, although emphasis is firmly placed on the methods themselves rather than their analysis, we have not hesitated to include theoretical material when we consider it to be sufficiently interesting. However, it should be possible to omit those parts that do seem daunting while still being able to follow the worked examples and to tackle the exercises accompanying each section. Familiarity with the basic results of analysis and linear algebra is assumed since these are normally taught in first courses on mathematical methods. For reference purposes a list of theorems used in the t...

Numerical evaluation of high energy particle effects in magnetohydrodynamics

International Nuclear Information System (INIS)

White, R.B.; Wu, Y.

1994-03-01

The interaction of high energy ions with magnetohydrodynamic modes is analyzed. A numerical code is developed which evaluates the contribution of the high energy particles to mode stability using orbit averaging of motion in either analytic or numerically generated equilibria through Hamiltonian guiding center equations. A dispersion relation is then used to evaluate the effect of the particles on the linear mode. Generic behavior of the solutions of the dispersion relation is discussed and dominant contributions of different components of the particle distribution function are identified. Numerical convergence of Monte-Carlo simulations is analyzed. The resulting code ORBIT provides an accurate means of comparing experimental results with the predictions of kinetic magnetohydrodynamics. The method can be extended to include self consistent modification of the particle orbits by the mode, and hence the full nonlinear dynamics of the coupled system

Nonlinear ordinary differential equations analytical approximation and numerical methods

CERN Document Server

Hermann, Martin

2016-01-01

The book discusses the solutions to nonlinear ordinary differential equations (ODEs) using analytical and numerical approximation methods. Recently, analytical approximation methods have been largely used in solving linear and nonlinear lower-order ODEs. It also discusses using these methods to solve some strong nonlinear ODEs. There are two chapters devoted to solving nonlinear ODEs using numerical methods, as in practice high-dimensional systems of nonlinear ODEs that cannot be solved by analytical approximate methods are common. Moreover, it studies analytical and numerical techniques for the treatment of parameter-depending ODEs. The book explains various methods for solving nonlinear-oscillator and structural-system problems, including the energy balance method, harmonic balance method, amplitude frequency formulation, variational iteration method, homotopy perturbation method, iteration perturbation method, homotopy analysis method, simple and multiple shooting method, and the nonlinear stabilized march...

Numerical simulation of droplet evaporation between two circular plates

International Nuclear Information System (INIS)

Bam, Hang Jin; Son, Gi Hun

2015-01-01

Numerical simulation is performed for droplet evaporation between two circular plates. The flow and thermal characteristics of the droplet evaporation are numerically investigated by solving the conservation equations of mass, momentum, energy and mass fraction in the liquid and gas phases. The liquid-gas interface is tracked by a sharp-interface level-set method which is modified to include the effects of evaporation at the liquid-gas interface and contact angle hysteresis at the liquid-gas-solid contact line. An analytical model to predict the droplet evaporation is also developed by simplifying the mass and vapor fraction equations in the gas phase. The numerical results demonstrate that the 1-D analytical prediction is not applicable to the high rate evaporation process. The effects of plate gap and receding contact angle on the droplet evaporation are also quantified.

Virus like particle-based vaccines against emerging infectious disease viruses.

Science.gov (United States)

Liu, Jinliang; Dai, Shiyu; Wang, Manli; Hu, Zhihong; Wang, Hualin; Deng, Fei

2016-08-01

Emerging infectious diseases are major threats to human health. Most severe viral disease outbreaks occur in developing regions where health conditions are poor. With increased international travel and business, the possibility of eventually transmitting infectious viruses between different countries is increasing. The most effective approach in preventing viral diseases is vaccination. However, vaccines are not currently available for numerous viral diseases. Virus-like particles (VLPs) are engineered vaccine candidates that have been studied for decades. VLPs are constructed by viral protein expression in various expression systems that promote the selfassembly of proteins into structures resembling virus particles. VLPs have antigenicity similar to that of the native virus, but are non-infectious as they lack key viral genetic material. VLP vaccines have attracted considerable research interest because they offer several advantages over traditional vaccines. Studies have shown that VLP vaccines can stimulate both humoral and cellular immune responses, which may offer effective antiviral protection. Here we review recent developments with VLP-based vaccines for several highly virulent emerging or re-emerging infectious diseases. The infectious agents discussed include RNA viruses from different virus families, such as the Arenaviridae, Bunyaviridae, Caliciviridae, Coronaviridae, Filoviridae, Flaviviridae, Orthomyxoviridae, Paramyxoviridae, and Togaviridae families.

A mathematical and numerical analysis of the Maxwell-Stefan diffusion equations

OpenAIRE

Boudin , Laurent; Grec , Bérénice; Salvarani , Francesco

2012-01-01

International audience; We consider the Maxwell-Stefan model of diffusion in a multicomponent gaseous mixture. After focusing on the main differences with the Fickian diffusion model, we study the equations governing a three-component gas mixture. We provide a qualitative and quantitative mathematical analysis of the model. The main properties of the standard explicit numerical scheme are also analyzed. We eventually include some numerical simulations pointing out the uphill diffusion phenome...

Numerical Model of Air Valve For Computation of One-dimensional Flow

Directory of Open Access Journals (Sweden)

Daniel HIMR

2014-06-01

Full Text Available The paper is focused on a numerical simulation of unsteady flow in a pipeline. The special attention is paid to a numerical model of an air valve, which has to include all possible regimes: critical/subcritical inflow and critical/subcritical outflow of air. Thermodynamic equation of subcritical mass flow was simplified to get more friendly shape of relevant equations, which enables easier solution of the problem.

XFEL OSCILLATOR SIMULATION INCLUDING ANGLE-DEPENDENT CRYSTAL REFLECTIVITY

International Nuclear Information System (INIS)

Fawley, William; Lindberg, Ryan; Kim, K.-J.; Shvyd'ko, Yuri

2010-01-01

The oscillator package within the GINGER FEL simulation code has now been extended to include angle-dependent reflectivity properties of Bragg crystals. Previously, the package was modified to include frequencydependent reflectivity in order to model x-ray FEL oscillators from start-up from shot noise through to saturation. We present a summary of the algorithms used for modeling the crystal reflectivity and radiation propagation outside the undulator, discussing various numerical issues relevant to the domain of high Fresnel number and efficient Hankel transforms. We give some sample XFEL-O simulation results obtained with the angle-dependent reflectivity model, with particular attention directed to the longitudinal and transverse coherence of the radiation output.

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

Science.gov (United States)

Mermelstein, Joseph; Chait Mermelstein, Alanna; Chait, Maxwell M

2018-01-01

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist. PMID:29606884

A cubic B-spline Galerkin approach for the numerical simulation of the GEW equation

Directory of Open Access Journals (Sweden)

S. Battal Gazi Karakoç

2016-02-01

Full Text Available The generalized equal width (GEW wave equation is solved numerically by using lumped Galerkin approach with cubic B-spline functions. The proposed numerical scheme is tested by applying two test problems including single solitary wave and interaction of two solitary waves. In order to determine the performance of the algorithm, the error norms L2 and L∞ and the invariants I1, I2 and I3 are calculated. For the linear stability analysis of the numerical algorithm, von Neumann approach is used. As a result, the obtained findings show that the presented numerical scheme is preferable to some recent numerical methods.  

Numerical Modeling and Mechanical Analysis of Flexible Risers

Directory of Open Access Journals (Sweden)

J. Y. Li

2015-01-01

Full Text Available ABAQUS is used to create a detailed finite element model for a 10-layer unbonded flexible riser to simulate the riser’s mechanical behavior under three load conditions: tension force and internal and external pressure. It presents a technique to create detailed finite element model and to analyze flexible risers. In FEM model, all layers are modeled separately with contact interfaces; interaction between steel trips in certain layers has been considered as well. FEM model considering contact interaction, geometric nonlinearity, and friction has been employed to accurately simulate the structural behavior of riser. The model includes the main features of the riser geometry with very little simplifying assumptions. The model was solved using a fully explicit time-integration scheme implemented in a parallel environment on an eight-processor cluster and 24 G memory computer. There is a very good agreement obtained from numerical and analytical comparisons, which validates the use of numerical model here. The results from the numerical simulation show that the numerical model takes into account various details of the riser. It has been shown that the detailed finite element model can be used to predict riser’s mechanics behavior under various load cases and bound conditions.

Numerical study of emergency cryogenics gas relief into confined spaces

CERN Multimedia

CERN. Geneva

2016-01-01

The presented work focuses on the risk analysis and the consequences of the unexpected leak to the tunnel of cryogenics gases. Formation of the gas mixture and its propagation along tunnels is an important issue for the safe operation of cryogenic machines, including superconducting accelerators or free electron lasers. As the cryogenics gas the helium and argon will be considered. A minimal numerical model will be presented and discussed. Series of numerical results related to emergency helium relief to the CERN tunnel and related to unexpected leak of the argon to an underground tunnel, will be shown. The numerical results will show temperature distribution, oxygen deficiency and gas cloud propagation in function of intensity of the leak and intensity of the ventilation.

Combustion Behaviour of Pulverised Wood - Numerical and Experimental Studies. Part 1 Numerical Study

Energy Technology Data Exchange (ETDEWEB)

Elfasakhany, A.; Xue-Song Bai [Lund Inst. of Tech. (Sweden). Dept. of Heat and Power Engineering

2002-12-01

This report describes a theoretical/numerical investigation of the particle motion and the particle drying, pyrolysis, oxidation of volatile and char in a pulverised biofuel (wood) flame. This work, along with the experimental measurement of a pulverised wood flame in a vertical furnace at TPS, is supported by the Swedish Energy Agency, STEM. The fundamental combustion process of a pulverised wood flame with determined size distribution and anisotropy character is studied. Comprehensive submodels are studied and some models not available in the literature are developed. The submodels are integrated to a CFD code, previously developed at LTH. The numerical code is used to simulate the experimental flame carried out at TPS (as sub-task 2 within the project). The sub-models describe the drying, devolatilization, char formation of wood particles, and the oxidation reaction of char and the gas phase volatile. At the present stage, the attention is focused on the understanding and modelling of non-spherical particle dynamics and the drying, pyrolysis, and oxidation of volatile and char. Validation of the sub-models against the experimental data is presented and discussed in this study. The influence of different factors on the pulverised wood flame in the TPS vertical furnace is investigated. This includes shape of the particles, the effect of volatile release, as well as the orientation of the particles on the motion of the particles. The effect of particle size on the flame structure (distribution of species and temperature along the axis of the furnace) is also studied. The numerical simulation is in close agreement with the TPS experimental data in the concentrations of species O{sub 2}, CO{sub 2} as well as temperature. Some discrepancy between the model simulations and measurements is observed, which suggests that further improvement in our understanding and modeling the pulverised wood flame is needed.

Histologic scoring indices for evaluation of disease activity in Crohn's disease.

Science.gov (United States)

Novak, Gregor; Parker, Claire E; Pai, Rish K; MacDonald, John K; Feagan, Brian G; Sandborn, William J; D'Haens, Geert; Jairath, Vipul; Khanna, Reena

2017-07-21

Histologic assessment of mucosal disease activity has been increasingly used in clinical trials of treatment for Crohn's disease. However, the operating properties of the currently existing histologic scoring indices remain unclear. A systematic review was undertaken to evaluate the development and operating characteristics of available histologic disease activity indices in Crohn's disease. Electronic searches of MEDLINE, EMBASE, PubMed, and the Cochrane Library (CENTRAL) databases from inception to 20 July 2016 were supplemented by manual reviews of bibliographies and abstracts submitted to major gastroenterology meetings (Digestive Disease Week, United European Gastroenterology Week, European Crohn's and Colitis Organisation). Any study design (e.g. randomised controlled trial, cohort study, case series) that evaluated a histologic disease activity index in patients with Crohn's disease was considered for inclusion. Study participants included adult patients (> 16 years), diagnosed with Crohn's disease using conventional clinical, radiographic or endoscopic criteria. Two authors independently reviewed the titles and abstracts of the studies identified from the literature search. The full text of potentially relevant citations were reviewed for inclusion and the study investigators were contacted as needed for clarification. Any disagreements regarding study eligibility were resolved by discussion and consensus with a third author.Two authors independently extracted and recorded data using a standard form. The following data were recorded from each eligible study: number of patients enrolled; number of patients per treatment arm; patient characteristics: age and gender distribution; description of histologic disease activity index utilized; and outcomes such as content validity, construct validity, criterion validity, responsiveness, intra-rater reliability, inter-rater reliability, and feasibility. Sixteen reports of 14 studies describing 14 different numerical

High resolution CT in diffuse lung disease

International Nuclear Information System (INIS)

Webb, W.R.

1995-01-01

High resolution CT (computerized tomography) was discussed in detail. The conclusions were HRCT is able to define lung anatomy at the secondary lobular level and define a variety of abnormalities in patients with diffuse lung diseases. Evidence from numerous studies indicates that HRCT can play a major role in the assessment of diffuse infiltrative lung disease and is indicate clinically (95 refs.)

High resolution CT in diffuse lung disease

Energy Technology Data Exchange (ETDEWEB)

Webb, W R [California Univ., San Francisco, CA (United States). Dept. of Radiology

1996-12-31

High resolution CT (computerized tomography) was discussed in detail. The conclusions were HRCT is able to define lung anatomy at the secondary lobular level and define a variety of abnormalities in patients with diffuse lung diseases. Evidence from numerous studies indicates that HRCT can play a major role in the assessment of diffuse infiltrative lung disease and is indicate clinically (95 refs.).

Cannabinoids for treatment of Alzheimer’s disease: moving towards the clinic

Directory of Open Access Journals (Sweden)

Isidro eFerrer

2014-03-01

Full Text Available The limited effectiveness of current therapies against Alzheimer’s disease highlights the need for intensifying research efforts devoted to developing new agents for preventing or retarding the disease process. During the last few years, targeting the endogenous cannabinoid system has emerged as a potential therapeutic approach to treat Alzheimer. The endocannabinoid system is composed by a number of cannabinoid receptors, including the well-characterized CB1 and CB2 receptors, with their endogenous ligands and the enzymes related to the synthesis and degradation of these endocannabinoid compounds. Several findings indicate that the activation of both CB1 and CB2 receptors by natural or synthetic agonists, at non-psychoactive doses, have beneficial effects in Alzheimer experimental models by reducing the harmful A peptide action and tau phosphorylation, as well as by promoting the brain’s intrinsic repair mechanisms. Moreover, endocannabinoid signaling has been demonstrated to modulate numerous concomitant pathological processes, including neuroinflammation, excitotoxicity, mitochondrial dysfunction, and oxidative stress. The present paper summarizes the main experimental studies demonstrating the polyvalent properties of cannabinoid compounds for the treatment of Alzheimer’s disease, which together encourage progress towards a clinical trial.

Nutraceuticals and their preventive or potential therapeutic value in Parkinson's disease.

Science.gov (United States)

Chao, Jianfei; Leung, Yen; Wang, Mingfu; Chang, Raymond Chuen-Chung

2012-07-01

Parkinson's disease (PD) is the second most common aging-related disorder in the world, after Alzheimer's disease. It is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta and other parts of the brain, leading to motor impairment, cognitive impairment, and dementia. Current treatment methods, such as L-dopa therapy, are focused only on relieving symptoms and delaying progression of the disease. To date, there is no known cure for PD, making prevention of PD as important as ever. More than a decade of research has revealed a number of major risk factors, including oxidative stress and mitochondrial dysfunction. Moreover, numerous nutraceuticals have been found to target and attenuate these risk factors, thereby preventing or delaying the progression of PD. These nutraceuticals include vitamins C, D, E, coenzyme Q10, creatine, unsaturated fatty acids, sulfur-containing compounds, polyphenols, stilbenes, and phytoestrogens. This review examines the role of nutraceuticals in the prevention or delay of PD as well as the mechanisms of action of nutraceuticals and their potential applications as therapeutic agents, either alone or in combination with current treatment methods. © 2012 International Life Sciences Institute.

A deterministic combination of numerical and physical models for coastal waves

DEFF Research Database (Denmark)

Zhang, Haiwen

2006-01-01

of numerical and physical modelling hence provides an attractive alternative to the use of either tool on it's own. The goal of this project has been to develop a deterministically combined numerical/physical model where the physical wave tank is enclosed in a much larger computational domain, and the two......Numerical and physical modelling are the two main tools available for predicting the influence of water waves on coastlines and structures placed in the near-shore environment. Numerical models can cover large areas at the correct scale, but are limited in their ability to capture strong...... nonlinearities, wave breaking, splash, mixing, and other such complicated physics. Physical models naturally include the real physics (at the model scale), but are limited by the physical size of the facility and must contend with the fact that different physical effects scale differently. An integrated use...

Utility of dynamic computed tomography in diffuse liver diseases

International Nuclear Information System (INIS)

Fujikawa, Koichi; Inagawa, Akira; Yokoyama, Tatsushi; Iwamoto, Toshiyuki; Katayama, Hiroshi; Mori, Masaki; Ito, Katsuhide; Katsuta, Shizutomo.

1985-01-01

We tested the diagnostic abilities of dynamic CT in diffuse liver diseases. The material includes 23 cases of chronic active hepatitis (CAH), 32 cases of liver cirrhosis (LC) and 15 cases with normal liver. For each case, time-density curve was obtained from the right lobe of the liver. To allow numerical evaluation of the curve, gamma variate fit techniques were employed. Changes in the curves were analyzed by comparing three parameters-rise time (RT), decay time (DT) and corrected first moment (MC)-derived from two coefficients of the fitting equation. Values of three parameters increased with the severity of the diseases reflecting prolonged curves with delayed peak and gradual downslope in damaged livers. MC values showed most significant correlation with the degree of the diseases. High MC value (>95) were associated with 30 cases of LC and 3 cases of CHA, and moderate MC value (70< MC<=95) with 19 cases of CAH and 2 controls, and low MC value (<=70) with 15 controls and a case of CAH. We conclude that dynamic CT time-density study with gamma variate fitting is useful in the differential diagnosis of the diffuse liver diseases. (author)

Adult Onset Still's Disease and Rocky Mountain Spotted Fever

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Paul Persad

2010-01-01

Full Text Available Adult Still's Disease was first described in 1971 by Bywaters in fourteen adult female patients who presented with symptoms indistinguishable from that of classic childhood Still's Disease (Bywaters, 1971. George Still in 1896 first recognized this triad of quotidian (daily fevers, evanescent rash, and arthritis in children with what later became known as juvenile inflammatory arthritis (Still, 1990. Adult Onset Still's Disease (AOSD is an inflammatory condition of unknown etiology characterized by an evanescent rash, quotidian fevers, and arthralgias. Numerous infectious agents have been associated with its presentation. This case is to our knowledge the first presentation of AOSD in the setting of Rocky Mountain Spotted Fever. Although numerous infectious agents have been suggested, the etiology of this disorder remains elusive. Nevertheless, infection may in fact play a role in triggering the onset of symptoms in those with this disorder. Our case presentation is, to our knowledge, the first case of Adult Onset Still's Disease associated with Rocky Mountain spotted fever (RMSF.

Efficacy of in-feed medication with chlortetracycline in a farrow-to-finish herd against a clinical outbreak of respiratory disease in fattening pigs.

Science.gov (United States)

Del Pozo Sacristán, R; Rodríguez, A L; Sierens, A; Vranckx, K; Boyen, F; Dereu, A; Haesebrouck, F; Maes, D G D

The efficacy of chlortetracycline (CTC) in-feed medication to treat pigs with clinical respiratory disease was investigated in a farrow-to-finish pig herd infected with Mycoplasma hyopneumoniae, and with clinical respiratory disease in growing pigs. In total, 533 pigs were included. The animals were vaccinated against M hyopneumoniae and porcine circovirus type 2 at weaning. At onset of clinical respiratory disease, they were randomly allocated to one of the following treatment groups: chlortetracycline 1 (CTC1) (two consecutive weeks, 500 ppm), chlortetracycline 2 (CTC2) (two non-consecutive weeks, with a non-medicated week interval in between, 500 ppm) or tylosin (T) (three consecutive weeks, 100 ppm). Performance (daily weight gain, feed conversion ratio), pneumonia lesions at slaughter and clinical parameters (respiratory disease score) were assessed. Only numeric differences in favour of the CTC2 group were obtained for the performance and the clinical parameters. The prevalence of pneumonia lesions was 20.5, 13.1 and 23.0 per cent (Ppneumonia lesions, and numerically reduce performance losses and clinical signs.

Numerical methods for engine-airframe integration

International Nuclear Information System (INIS)

Murthy, S.N.B.; Paynter, G.C.

1986-01-01

Various papers on numerical methods for engine-airframe integration are presented. The individual topics considered include: scientific computing environment for the 1980s, overview of prediction of complex turbulent flows, numerical solutions of the compressible Navier-Stokes equations, elements of computational engine/airframe integrations, computational requirements for efficient engine installation, application of CAE and CFD techniques to complete tactical missile design, CFD applications to engine/airframe integration, and application of a second-generation low-order panel methods to powerplant installation studies. Also addressed are: three-dimensional flow analysis of turboprop inlet and nacelle configurations, application of computational methods to the design of large turbofan engine nacelles, comparison of full potential and Euler solution algorithms for aeropropulsive flow field computations, subsonic/transonic, supersonic nozzle flows and nozzle integration, subsonic/transonic prediction capabilities for nozzle/afterbody configurations, three-dimensional viscous design methodology of supersonic inlet systems for advanced technology aircraft, and a user's technology assessment

Abstract numerical discrimination learning in rats.

Science.gov (United States)

Taniuchi, Tohru; Sugihara, Junko; Wakashima, Mariko; Kamijo, Makiko

2016-06-01

In this study, we examined rats' discrimination learning of the numerical ordering positions of objects. In Experiments 1 and 2, five out of seven rats successfully learned to respond to the third of six identical objects in a row and showed reliable transfer of this discrimination to novel stimuli after being trained with three different training stimuli. In Experiment 3, the three rats from Experiment 2 continued to be trained to respond to the third object in an object array, which included an odd object that needed to be excluded when identifying the target third object. All three rats acquired this selective-counting task of specific stimuli, and two rats showed reliable transfer of this selective-counting performance to test sets of novel stimuli. In Experiment 4, the three rats from Experiment 3 quickly learned to respond to the third stimulus in object rows consisting of either six identical or six different objects. These results offer strong evidence for abstract numerical discrimination learning in rats.

Numerical calculation of two-phase flows

International Nuclear Information System (INIS)

Travis, J.R.; Harlow, F.H.; Amsden, A.A.

1975-06-01

The theoretical study of time-varying two-phase flow problems in several space dimensions introduces such a complicated set of coupled nonlinear partial differential equations that numerical solution procedures for high-speed computers are required in almost all but the simplest examples. Efficient attainment of realistic solutions for practical problems requires a finite- difference formulation that is simultaneously implicit in the treatment of mass convection, equations of state, and the momentum coupling between phases. Such a method is described, the equations on which it is based are discussed, and its properties are illustrated by means of examples. In particular, the capability for calculating physical instabilities and other time-varying dynamics, at the same time avoiding numerical instability is emphasized. The computer code is applicable to problems in reactor safety analysis, the dynamics of fluidized dust beds, raindrops or aerosol transport, and a variety of similar circumstances, including the effects of phase transitions and the release of latent heat or chemical energy. (U.S.)

Difficulties in diagnosis and treatment of Paget’s disease

Directory of Open Access Journals (Sweden)

Aleksandra Kawalec

2016-12-01

Full Text Available Paget’s disease is a rare finding in Poland. It is a disorder of the osteoarticular system, which, in adults, mostly affects people over 55 years of age. The clinical picture varies, depending on the location of the lesions, making the diagnosis difficult, sometimes taking many years for a correct diagnosis to be made. In etiopathogenesis, genetic predispositions as well as viral infections play an important role. From the genetic point of view, Paget’s disease is heterogeneous, as numerous mutations are known, and the genotype to phenotype relationship is unclear. The first phase of the disease is characterized by an increased osteocytes activity, due to morphologically changed and RANKL overstimulated osteocytes. This leads to an intensification of ossification processes that occur in a chaotic manner. Therefore, the resulting bone is weak, extensively vascularized and there is an increased risk of fracture or deformity. Clinical manifestations of Paget’s disease might include pain, excessive warmth, bone deformations, degenerative lesions in the adjacent joints, compression of the neural structures, hearing loss, and dilated cardiomiopathy. Other possible complications include the development of benign and malignant bone tumors and hypercalcaemia in the case of immobilization. An elevated level of serum alkaline phosphatase, bone x-ray and bone scintigraphy are crucial in making the diagnosis. The disease should be distinguished from osteomalacia, osteoporosis, hyperparathyroidism and multiple myeloma. Bisphosphonates at doses higher than those applied for osteoporosis are an effective treatment. The occurrence of orthopedic, neurological and laryngological complications is often a reason for surgical intervention.

Tumor cell anaplasia and multinucleation are predictors of disease recurrence in oropharyngeal squamous cell carcinoma, including among just the human papillomavirus-related cancers.

Science.gov (United States)

Lewis, James S; Scantlebury, Juliette B; Luo, Jingqin; Thorstad, Wade L

2012-07-01

Oropharyngeal squamous cell carcinoma (SCC) is frequently related to high risk human papillomavirus. This tumor expresses p16, frequently has a nonkeratinizing morphology, and has improved outcomes. Despite having a good prognosis, tumors can have focal or diffuse nuclear anaplasia or multinucleation, the significance of which is unknown. From a database of 270 oropharyngeal SCCs with known histologic typing (using our established system) and p16 immunohistochemistry, all surgically resected cases (149) were reviewed. Anaplasia was defined as any × 40 field with ≥ 3 tumor nuclei with diameters ≥ 5 lymphocyte nuclei (~25 μm), and multinucleation was defined as any × 40 field with ≥ 3 tumor cells with multiple nuclei. p16 was positive in 128 cases (85.9%), 64 cases (43.0%) showed anaplasia, and 71 (47.7%) showed multinucleation. Anaplasia and multinucleation were highly related (Panaplasia or multinucleation had worse overall, disease-specific, and disease-free survival (Panaplasia and multinucleation both predicted worse disease-specific survival (hazard ratio 9.9, P=0.04; and hazard ratio 11.9, P=0.02, respectively) independent of the other variables. In summary, among surgically resectable oropharyngeal SCC (including among just the p16-positive cohort), tumor cell anaplasia and multinucleation independently correlated with disease recurrence and poorer survival.

Acid-Base and Electrolyte Disorders in Patients with and without Chronic Kidney Disease: An Update.

Science.gov (United States)

Dhondup, Tsering; Qian, Qi

2017-12-01

Kidneys play a pivotal role in the maintenance and regulation of acid-base and electrolyte homeostasis, which is the prerequisite for numerous metabolic processes and organ functions in the human body. Chronic kidney diseases compromise the regulatory functions, resulting in alterations in electrolyte and acid-base balance that can be life-threatening. In this review, we discuss the renal regulations of electrolyte and acid-base balance and several common disorders including metabolic acidosis, alkalosis, dysnatremia, dyskalemia, and dysmagnesemia. Common disorders in chronic kidney disease are also discussed. The most recent and relevant advances on pathophysiology, clinical characteristics, diagnosis, and management of these conditions have been incorporated.

New Insights from Rodent Models of Fatty Liver Disease

Science.gov (United States)

2011-01-01

Abstract Rodent models of fatty liver disease are essential research tools that provide a window into disease pathogenesis and a testing ground for prevention and treatment. Models come in many varieties involving dietary and genetic manipulations, and sometimes both. High-energy diets that induce obesity do not uniformly cause fatty liver disease; this has prompted close scrutiny of specific macronutrients and nutrient combinations to determine which have the greatest potential for hepatotoxicity. At the same time, diets that do not cause obesity or the metabolic syndrome but do cause severe steatohepatitis have been exploited to study factors important to progressive liver injury, including cell death, oxidative stress, and immune activation. Rodents with a genetic predisposition to overeating offer yet another model in which to explore the evolution of fatty liver disease. In some animals that overeat, steatohepatitis can develop even without resorting to a high-energy diet. Importantly, these models and others have been used to document that aerobic exercise can prevent or reduce fatty liver disease. This review focuses primarily on lessons learned about steatohepatitis from manipulations of diet and eating behavior. Numerous additional insights about hepatic lipid metabolism, which have been gained from genetically engineered mice, are also mentioned. Antioxid. Redox Signal. 15, 535–550. PMID:21126212

The SIR model of Zika virus disease outbreak in Brazil at year 2015

Science.gov (United States)

Aik, Lim Eng; Kiang, Lam Chee; Hong, Tan Wei; Abu, Mohd Syafarudy

2017-05-01

This research study demonstrates a numerical model intended for comprehension the spread of the year 2015 Zika virus disease utilizing the standard SIR framework. In modeling virulent disease dynamics, it is important to explore whether the illness spread could accomplish a pandemic level or it could be eradicated. Information from the year 2015 Zika virus disease event is utilized and Brazil where the event began is considered in this research study. A three dimensional nonlinear differential equation is formulated and solved numerically utilizing the Euler's method in MS excel. It is appeared from the research study that, with health intercessions of public, the viable regenerative number can be decreased making it feasible for the event to cease to exist. It is additionally indicated numerically that the pandemic can just cease to exist when there are no new infected people in the populace.

Numerical relativity in spherical coordinates with the Einstein Toolkit

Science.gov (United States)

Mewes, Vassilios; Zlochower, Yosef; Campanelli, Manuela; Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

2018-04-01

Numerical relativity codes that do not make assumptions on spatial symmetries most commonly adopt Cartesian coordinates. While these coordinates have many attractive features, spherical coordinates are much better suited to take advantage of approximate symmetries in a number of astrophysical objects, including single stars, black holes, and accretion disks. While the appearance of coordinate singularities often spoils numerical relativity simulations in spherical coordinates, especially in the absence of any symmetry assumptions, it has recently been demonstrated that these problems can be avoided if the coordinate singularities are handled analytically. This is possible with the help of a reference-metric version of the Baumgarte-Shapiro-Shibata-Nakamura formulation together with a proper rescaling of tensorial quantities. In this paper we report on an implementation of this formalism in the Einstein Toolkit. We adapt the Einstein Toolkit infrastructure, originally designed for Cartesian coordinates, to handle spherical coordinates, by providing appropriate boundary conditions at both inner and outer boundaries. We perform numerical simulations for a disturbed Kerr black hole, extract the gravitational wave signal, and demonstrate that the noise in these signals is orders of magnitude smaller when computed on spherical grids rather than Cartesian grids. With the public release of our new Einstein Toolkit thorns, our methods for numerical relativity in spherical coordinates will become available to the entire numerical relativity community.

Numerical computation of gravitational field for general axisymmetric objects

Science.gov (United States)

Fukushima, Toshio

2016-10-01

We developed a numerical method to compute the gravitational field of a general axisymmetric object. The method (I) numerically evaluates a double integral of the ring potential by the split quadrature method using the double exponential rules, and (II) derives the acceleration vector by numerically differentiating the numerically integrated potential by Ridder's algorithm. Numerical comparison with the analytical solutions for a finite uniform spheroid and an infinitely extended object of the Miyamoto-Nagai density distribution confirmed the 13- and 11-digit accuracy of the potential and the acceleration vector computed by the method, respectively. By using the method, we present the gravitational potential contour map and/or the rotation curve of various axisymmetric objects: (I) finite uniform objects covering rhombic spindles and circular toroids, (II) infinitely extended spheroids including Sérsic and Navarro-Frenk-White spheroids, and (III) other axisymmetric objects such as an X/peanut-shaped object like NGC 128, a power-law disc with a central hole like the protoplanetary disc of TW Hya, and a tear-drop-shaped toroid like an axisymmetric equilibrium solution of plasma charge distribution in an International Thermonuclear Experimental Reactor-like tokamak. The method is directly applicable to the electrostatic field and will be easily extended for the magnetostatic field. The FORTRAN 90 programs of the new method and some test results are electronically available.

Advanced numerical methods for three dimensional two-phase flow calculations

Energy Technology Data Exchange (ETDEWEB)

Toumi, I. [Laboratoire d`Etudes Thermiques des Reacteurs, Gif sur Yvette (France); Caruge, D. [Institut de Protection et de Surete Nucleaire, Fontenay aux Roses (France)

1997-07-01

This paper is devoted to new numerical methods developed for both one and three dimensional two-phase flow calculations. These methods are finite volume numerical methods and are based on the use of Approximate Riemann Solvers concepts to define convective fluxes versus mean cell quantities. The first part of the paper presents the numerical method for a one dimensional hyperbolic two-fluid model including differential terms as added mass and interface pressure. This numerical solution scheme makes use of the Riemann problem solution to define backward and forward differencing to approximate spatial derivatives. The construction of this approximate Riemann solver uses an extension of Roe`s method that has been successfully used to solve gas dynamic equations. As far as the two-fluid model is hyperbolic, this numerical method seems very efficient for the numerical solution of two-phase flow problems. The scheme was applied both to shock tube problems and to standard tests for two-fluid computer codes. The second part describes the numerical method in the three dimensional case. The authors discuss also some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. Such a scheme is not implemented in a thermal-hydraulic computer code devoted to 3-D steady-state and transient computations. Some results obtained for Pressurised Water Reactors concerning upper plenum calculations and a steady state flow in the core with rod bow effect evaluation are presented. In practice these new numerical methods have proved to be stable on non staggered grids and capable of generating accurate non oscillating solutions for two-phase flow calculations.

Advanced numerical methods for three dimensional two-phase flow calculations

International Nuclear Information System (INIS)

Toumi, I.; Caruge, D.

1997-01-01

This paper is devoted to new numerical methods developed for both one and three dimensional two-phase flow calculations. These methods are finite volume numerical methods and are based on the use of Approximate Riemann Solvers concepts to define convective fluxes versus mean cell quantities. The first part of the paper presents the numerical method for a one dimensional hyperbolic two-fluid model including differential terms as added mass and interface pressure. This numerical solution scheme makes use of the Riemann problem solution to define backward and forward differencing to approximate spatial derivatives. The construction of this approximate Riemann solver uses an extension of Roe's method that has been successfully used to solve gas dynamic equations. As far as the two-fluid model is hyperbolic, this numerical method seems very efficient for the numerical solution of two-phase flow problems. The scheme was applied both to shock tube problems and to standard tests for two-fluid computer codes. The second part describes the numerical method in the three dimensional case. The authors discuss also some improvements performed to obtain a fully implicit solution method that provides fast running steady state calculations. Such a scheme is not implemented in a thermal-hydraulic computer code devoted to 3-D steady-state and transient computations. Some results obtained for Pressurised Water Reactors concerning upper plenum calculations and a steady state flow in the core with rod bow effect evaluation are presented. In practice these new numerical methods have proved to be stable on non staggered grids and capable of generating accurate non oscillating solutions for two-phase flow calculations

The effect of saturation on resin flow in injection pultrusion: a preliminary numerical study

DEFF Research Database (Denmark)

Spangenberg, Jon; Larsen, Martin; R. Rodríguez, Rosa

. The implemented saturation and relative permeability curves are adopted from relationships presented in the literature. The results of the numerical model highlights the importance of accurately determining thesaturation curve when included in a numerical solver that is used to predict the resin flow in injection...

Evaluation of diffuse hepatic diseases by integrated image, SPECT and numerical taxonomic analysis

Energy Technology Data Exchange (ETDEWEB)

Kobayashi, Shin

1987-02-01

In 135 patients with various hepatic diseases, cardiopulmonary circulation and hepatic accumulation of the activity were collected for 100 sec after bolus injection of 111-222 MBq (3 - 6 mci) of /sup 99m/Tc-phytate, and then integrated as a single image. Anterior, right lateral and posterior planar images, and hepatosplenic SPECT images were obtained thereafter. Lung to liver count ratio (P/L) was estimated by the integrated image. Liver volume (HV), spleen volume (SV) and liver to spleen count ratio (MHC/MSC) were calculated using the data obtained by SPECT. P/L was useful as an index of effective hepatic blood flow. MHC/MSC was closely correlated with the grade of portal hypertension. HV or SV alone shows low clinical value in discriminating liver diseases. Principal component analysis was applied to the 4 above-mentioned radinuclide data and the following 11 laboratory data ; total serum protein, serum albumine, glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), lactic dehydrogenase (LDH), alkaline phosphatase (AL-P), zink sulfateturbidity test (ZTT), thymol turbidity test (TTT), r-glutamyl transpeptidase (r-GTP), cholinesterase (Ch-E), and total bilirubin (T-Bil). These fifteen data were condensed to 5 principal components. And then cluster analysis was carried out among 135 patients. The subjects were classified in 7 small groups. In group (G) I to GIII, frequency of liver cirrhosis was high, while on the contrary in GIV to GVII, the frequency of normal cases increased gradually. From the above results, cluster analysis seemed to reflect the pathophysiological state and the grade of the disease. This method might be useful for estimation of the grade of damage in diffuse hepatic disease and a good objective evaluation method in follow-up studies. (J.P.N.).

Monograph - The Numerical Integration of Ordinary Differential Equations.

Science.gov (United States)

Hull, T. E.

The materials presented in this monograph are intended to be included in a course on ordinary differential equations at the upper division level in a college mathematics program. These materials provide an introduction to the numerical integration of ordinary differential equations, and they can be used to supplement a regular text on this…

Genetic Modification of the Lung Directed Toward Treatment of Human Disease.

Science.gov (United States)

Sondhi, Dolan; Stiles, Katie M; De, Bishnu P; Crystal, Ronald G

2017-01-01

Genetic modification therapy is a promising therapeutic strategy for many diseases of the lung intractable to other treatments. Lung gene therapy has been the subject of numerous preclinical animal experiments and human clinical trials, for targets including genetic diseases such as cystic fibrosis and α1-antitrypsin deficiency, complex disorders such as asthma, allergy, and lung cancer, infections such as respiratory syncytial virus (RSV) and Pseudomonas, as well as pulmonary arterial hypertension, transplant rejection, and lung injury. A variety of viral and non-viral vectors have been employed to overcome the many physical barriers to gene transfer imposed by lung anatomy and natural defenses. Beyond the treatment of lung diseases, the lung has the potential to be used as a metabolic factory for generating proteins for delivery to the circulation for treatment of systemic diseases. Although much has been learned through a myriad of experiments about the development of genetic modification of the lung, more work is still needed to improve the delivery vehicles and to overcome challenges such as entry barriers, persistent expression, specific cell targeting, and circumventing host anti-vector responses.

Numerical heating in Particle-In-Cell simulations with Monte Carlo binary collisions

Science.gov (United States)

Alves, E. Paulo; Mori, Warren; Fiuza, Frederico

2017-10-01

The binary Monte Carlo collision (BMCC) algorithm is a robust and popular method to include Coulomb collision effects in Particle-in-Cell (PIC) simulations of plasmas. While a number of works have focused on extending the validity of the model to different physical regimes of temperature and density, little attention has been given to the fundamental coupling between PIC and BMCC algorithms. Here, we show that the coupling between PIC and BMCC algorithms can give rise to (nonphysical) numerical heating of the system, that can be far greater than that observed when these algorithms operate independently. This deleterious numerical heating effect can significantly impact the evolution of the simulated system particularly for long simulation times. In this work, we describe the source of this numerical heating, and derive scaling laws for the numerical heating rates based on the numerical parameters of PIC-BMCC simulations. We compare our theoretical scalings with PIC-BMCC numerical experiments, and discuss strategies to minimize this parasitic effect. This work is supported by DOE FES under FWP 100237 and 100182.

Numerical modeling of turbulent combustion and flame spread

Energy Technology Data Exchange (ETDEWEB)

Yan Zhenghua

1999-01-01

Theoretical models have been developed to address several important aspects of numerical modeling of turbulent combustion and flame spread. The developed models include a pyrolysis model for charring and non-charring solid materials, a fast narrow band radiation property evaluation model (FASTNB) and a turbulence model for buoyant flow and flame. In the pyrolysis model, a completely new algorithm has been proposed, where a moving dual mesh concept was developed and implemented. With this new concept, it provides proper spatial resolution for both temperature and density and automatically considers the regression of the surface of the non-charring solid material during its pyrolysis. It is simple, very efficient and applicable to both charring and non-charring materials. FASTNB speeds up significantly the evaluation of narrow band spectral radiation properties and thus provides a potential of applying narrow band model in numerical simulations of practical turbulent combustion. The turbulence model was developed to improve the consideration of buoyancy effect on turbulence and turbulent transport. It was found to be simple, promising and numerically stable. It has been tested against both plane and axisymmetric thermal plumes and an axisymmetric buoyant diffusion flame. When compared with the widely used standard buoyancy-modified {kappa} - {epsilon} model, it gives significant improvement on numerical results. These developed models have been fully incorporated into CFD (Computational Fluid Dynamics) code and coupled with other CFD sub-models, including the DT (Discrete Transfer) radiation model, EDC (Eddy Dissipation Concept) combustion model, flamelet combustion model, various soot models and transpired wall function. Comprehensive numerical simulations have been carried out to study soot formation and oxidation in turbulent buoyant diffusion flames, flame heat transfer and flame spread in fires. The gas temperature and velocity, soot volume fraction, wall

Neural correlates of the numerical distance effect in children

Directory of Open Access Journals (Sweden)

Christophe eMussolin

2013-10-01

Full Text Available In number comparison tasks, the performance is better when the distance between the two numbers to compare increases. During development this so-called numerical distance effect decreases with age and the neuroanatomical correlates of these age-related changes are poorly known. Using functional magnetic resonance imaging, we recorded the brain activity changes in children aged from 8 to 14 years while they performed a number comparison task on pairs of Arabic digits and a control colour comparison task on non-numerical symbols. On the one hand, we observed developmental changes in the recruitment of frontal regions and the left intraparietal sulcus, with lower activation as the age increased. On the other hand, we found that a behavioural index of selective sensitivity to the numerical distance effect was positively correlated with higher brain activity in a right lateralized occipito-temporo-parietal network including the intraparietal sulcus. This leads us to propose that the left intraparietal sulcus would be engaged in the refinement of cognitive processes involved in number comparison during development, while the right intraparietal sulcus would underlie the semantic representation of numbers and its activation would be mainly affected by the numerical proximity between them.

Data regarding association between serum osteoprotegerin level, numerous of circulating endothelial-derived and mononuclear-derived progenitor cells in patients with metabolic syndrome

Directory of Open Access Journals (Sweden)

Alexander E. Berezin

2016-09-01

Full Text Available Metabolic syndrome (MetS is defined as cluster of multiple metabolic and cardiovascular (CV abnormalities included abdominal obesity, high-normal blood pressure, dyslipidaemia, and impaired fasting glucose tolerance that exhibits has a growing prevalence worldwide. We investigated whether an elevated level of osteoprotegerin (OPG predicts imbalance between different phenotypes of circulating endothelial (EPCs and mononuclear (MPCs progenitor cells in MetS patients. We have analyzed data regarding dysmetabolic disorder subjects without known CV disease, as well as with known type two diabetes mellitus. All patients have given their informed written consent for participation in the study. This article contains data on the independent predictors of depletion in numerous of circulating EPCs and MPCs in MetS patients. The data are supplemental to our original research article describing detailed associations of elevated OPG level in MetS patients with numerous of EPCs and MPCs beyond traditional CV risk factors. Keywords: Metabolic syndrome, Osteoprotegerin, Circulating endothelial derived progenitor cells, Mononuclear-derived progenitor cells

A 2-d classification of diseases based on age-specific death rates

Science.gov (United States)

Richmond, Peter; Roehner, Bertrand M.

2018-02-01

Age specific mortality curves exhibit an age tc (about 10 years) which plays a crucial role in that the mortality curve decreases hyperbolically in the age interval A before tc and increases exponentially in the interval B following tc. For those familiar with reliability theory, region A is called the "burn in" phase and B is the "wear out" phase. Using the exponents of the hyperbolic and exponential phases, we introduce a new 2 dimensional map of diseases. This permits the classification of diseases into three broad classes: AS1, AS2 and S. Class AS1 includes all diseases arising from congenital malformations which dominate infant and child mortality; class AS2 includes degenerative diseases such as dementia and Alzheimer's which dominate old age mortality. In class S, which includes most infectious and metabolic diseases, the exponents from both aging phases contribute to positions on the map. Cancer is one of these mixed cases but is closer to class AS2 than AS1. A second line classification is needed to resolve S cases and to this end we introduce a 3rd dimension, namely (calendar) time. Using historical data we show that in their response to treatment (particularly vaccination), S diseases fall into three sub-classes. (i) Class E diseases (e.g. measles or meningococcal disease) which have been almost eliminated at all ages (ii) class C diseases (e.g. tuberculosis) which can be cured but whose cure becomes less effective at old age. (iii) Class U diseases for which radical cures are still unknown. Regarding the future, the fact that the wear-out process of numerous diseases already starts around the age of 25 means that a major extension of the human lifespan beyond 120 certainly also requires to uncover the secret of the "elixir of eternal youth" which has driven timeless human efforts and still seems unlikely in the foreseeable future.

Mast cells are important modifiers of autoimmune disease: With so much evidence, why is there controversy?

Directory of Open Access Journals (Sweden)

Melissa Ann Brown

2012-06-01

Full Text Available There is abundant evidence that mast cells are active participants in events that mediate tissue damage in autoimmune disease. Disease-associated increases in mast cell numbers accompanied by mast cell degranulation and elaboration of numerous mast cell mediators at sites of inflammation are commonly observed in many human autoimmune diseases including multiple sclerosis, rheumatoid arthritis and bullous pemphigoid. In animal models, treatment with mast cell stabilizing drugs or mast cell ablation can result in diminished disease. A variety of receptors including those engaged by antibody, complement, pathogens and intrinsic danger signals are implicated in mast cell activation in disease. Similar to their role as first responders in infection settings, mast cells likely orchestrate early recruitment of immune cells, including neutrophils, to the sites of autoimmune destruction. This co-localization promotes cellular crosstalk and activation and results in the amplification of the local inflammatory response thereby promoting and sustaining tissue damage. Despite the evidence, there is still a debate regarding the relative role of mast cells in these processes. However, by definition, mast cells can only act as accessory cells to the self-reactive T and/or antibody driven autoimmune responses. Thus, when evaluating mast cell involvement using existing and somewhat imperfect animal models of disease, their importance is sometimes obscured. However, these potent immune cells are undoubtedly major contributors to autoimmunity and should be considered as important targets for therapeutic disease intervention.

Endocrine disorders in mitochondrial disease.

Science.gov (United States)

Schaefer, Andrew M; Walker, Mark; Turnbull, Douglass M; Taylor, Robert W

2013-10-15

Endocrine dysfunction in mitochondrial disease is commonplace, but predominantly restricted to disease of the endocrine pancreas resulting in diabetes mellitus. Other endocrine manifestations occur, but are relatively rare by comparison. In mitochondrial disease, neuromuscular symptoms often dominate the clinical phenotype, but it is of paramount importance to appreciate the multi-system nature of the disease, of which endocrine dysfunction may be a part. The numerous phenotypes attributable to pathogenic mutations in both the mitochondrial (mtDNA) and nuclear DNA creates a complex and heterogeneous catalogue of disease which can be difficult to navigate for novices and experts alike. In this article we provide an overview of the endocrine disorders associated with mitochondrial disease, the way in which the underlying mitochondrial disorder influences the clinical presentation, and how these factors influence subsequent management. Copyright © 2013 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Research in progress in applied mathematics, numerical analysis, fluid mechanics, and computer science

Science.gov (United States)

1994-01-01

This report summarizes research conducted at the Institute for Computer Applications in Science and Engineering in applied mathematics, fluid mechanics, and computer science during the period October 1, 1993 through March 31, 1994. The major categories of the current ICASE research program are: (1) applied and numerical mathematics, including numerical analysis and algorithm development; (2) theoretical and computational research in fluid mechanics in selected areas of interest to LaRC, including acoustics and combustion; (3) experimental research in transition and turbulence and aerodynamics involving LaRC facilities and scientists; and (4) computer science.

Emerging Animal Parasitic Diseases: A Global Overview and Appropriate Strategies for their Monitoring and Surveillance in Nigeria.

Science.gov (United States)

Atehmengo, Ngongeh L; Nnagbo, Chiejina S

2014-01-01

Emerging animal parasitic diseases are reviewed and appropriate strategies for efficient monitoring and surveillance in Nigeria are outlined. Animal and human parasitic infections are distinguished. Emerging diseases have been described as those diseases that are being recognised for the first time or diseases that are already recorded but their frequency and/or geographic range is being increased tremendously. Emergence of new diseases may be due to a number of factors such as the spread of a new infectious agent, recognition of an infection that has been in existence but undiagnosed, or when it is realised that an established disease has an infectious origin. The terms could also be used to describe the resurgence of a known infection after its incidence had been known to have declined. Emerging infections are compounding the control of infectious diseases and huge resources are being channeled to alleviate the rising challenge. The diseases are numerous and include helminth, protozoal / rickettsial and entomological. A list of parasitic emerging diseases in Nigeria is included. Globally occurring emerging parasitic diseases are also outlined. Emerging and re-emerging infections can be brought about by many factors including climate change and global warming, changes in biodiversity, population mobility, movement of animals, globalisation of commerce/trade and food supply, social and cultural factors such as food eating habits, religious beliefs, farming practices, trade of infected healthy animals, reduction in the available land for animals, immune-suppressed host and host density and misuse or over use of some drugs leading to drug resistance.

Emerging Animal Parasitic Diseases: A Global Overview and Appropriate Strategies for their Monitoring and Surveillance in Nigeria

Science.gov (United States)

Atehmengo, Ngongeh L; Nnagbo, Chiejina S

2014-01-01

Emerging animal parasitic diseases are reviewed and appropriate strategies for efficient monitoring and surveillance in Nigeria are outlined. Animal and human parasitic infections are distinguished. Emerging diseases have been described as those diseases that are being recognised for the first time or diseases that are already recorded but their frequency and/or geographic range is being increased tremendously. Emergence of new diseases may be due to a number of factors such as the spread of a new infectious agent, recognition of an infection that has been in existence but undiagnosed, or when it is realised that an established disease has an infectious origin. The terms could also be used to describe the resurgence of a known infection after its incidence had been known to have declined. Emerging infections are compounding the control of infectious diseases and huge resources are being channeled to alleviate the rising challenge. The diseases are numerous and include helminth, protozoal / rickettsial and entomological. A list of parasitic emerging diseases in Nigeria is included. Globally occurring emerging parasitic diseases are also outlined. Emerging and re-emerging infections can be brought about by many factors including climate change and global warming, changes in biodiversity, population mobility, movement of animals, globalisation of commerce/trade and food supply, social and cultural factors such as food eating habits, religious beliefs, farming practices, trade of infected healthy animals, reduction in the available land for animals, immune-suppressed host and host density and misuse or over use of some drugs leading to drug resistance. PMID:25328553

Including pathogen risk in life cycle assessment of wastewater management. 1. Estimating the burden of disease associated with pathogens.

Science.gov (United States)

Harder, Robin; Heimersson, Sara; Svanström, Magdalena; Peters, Gregory M

2014-08-19

The environmental performance of wastewater and sewage sludge management is commonly assessed using life cycle assessment (LCA), whereas pathogen risk is evaluated with quantitative microbial risk assessment (QMRA). This study explored the application of QMRA methodology with intent to include pathogen risk in LCA and facilitate a comparison with other potential impacts on human health considered in LCA. Pathogen risk was estimated for a model wastewater treatment system (WWTS) located in an industrialized country and consisting of primary, secondary, and tertiary wastewater treatment, anaerobic sludge digestion, and land application of sewage sludge. The estimation was based on eight previous QMRA studies as well as parameter values taken from the literature. A total pathogen risk (expressed as burden of disease) on the order of 0.2-9 disability-adjusted life years (DALY) per year of operation was estimated for the model WWTS serving 28,600 persons and for the pathogens and exposure pathways included in this study. The comparison of pathogen risk with other potential impacts on human health considered in LCA is detailed in part 2 of this article series.

A numerical method for solving singular De`s

Energy Technology Data Exchange (ETDEWEB)

Mahaver, W.T.

1996-12-31

A numerical method is developed for solving singular differential equations using steepest descent based on weighted Sobolev gradients. The method is demonstrated on a variety of first and second order problems, including linear constrained, unconstrained, and partially constrained first order problems, a nonlinear first order problem with irregular singularity, and two second order variational problems.

Potential application of lithium in Parkinson’s and other neurodegenerative diseases

Directory of Open Access Journals (Sweden)

Carol A Lazzara

2015-10-01

Full Text Available Lithium, the long-standing hallmark treatment for bipolar disorder, has recently been identified as a potential neuroprotective agent in neurodegeneration. Here we focus on introducing numerous in vitro and in vivo studies that have shown lithium treatment to be efficacious in reducing oxidative stress and inflammation, increasing autophagy, inhibiting apoptosis, and decreasing the accumulation of α-synulcein, with an emphasis on Parkinson’s disease. A number of biological pathways have been shown to be involved in causing these neuroprotective effects. The inhibition of GSK-3β has been the mechanism most studied; however, other modes of action include the regulation of apoptotic proteins and glutamate excitotoxicity as well as down-regulation of Calpain-1. This review provides a framework of the neuroprotective effects of lithium in neurodegenerative diseases and the putative mechanisms by which lithium provides the protection. Lithium-only treatment may not be a suitable therapeutic option for neurodegenerative diseases due to inconsistent efficacy and potential side-effects, however, the use of low dose lithium in combination with other potential or existing therapeutic compounds may be a promising approach to reduce symptoms and disease progression in neurodegenerative diseases.

The Role of Unfolded Protein Response and Mitogen-Activated Protein Kinase Signaling in Neurodegenerative Diseases with Special Focus on Prion Diseases

Directory of Open Access Journals (Sweden)

Lifeng Yang

2017-05-01

Full Text Available Prion diseases are neurodegenerative pathologies characterized by the accumulation of a protease-resistant form of the cellular prion protein named prion protein scrapie (PrPSc in the brain. PrPSc accumulation in the endoplasmic reticulum (ER result in a dysregulated calcium (Ca2+ homeostasis and subsequent initiation of unfolded protein response (UPR leading to neuronal dysfunction and apoptosis. The molecular mechanisms for the transition between adaptation to ER stress and ER stress-induced apoptosis are still unclear. Mitogen-activated protein kinases (MAPKs are serine/threonine protein kinases that rule the signaling of many extracellular stimuli from plasma membrane to the nucleus. However the identification of numerous points of cross talk between the UPR and MAPK signaling pathways may contribute to our understanding of the consequences of ER stress in prion diseases. Indeed the MAPK signaling network is known to regulate cell cycle progression and cell survival or death responses following a variety of stresses including misfolded protein response stress. In this article, we review the UPR signaling in prion diseases and discuss the triad of MAPK signaling pathways. We also describe the role played by MAPK signaling cascades in Alzheimer’s (AD and Parkinson’s disease (PD. We will also overview the mechanisms of cell death and the role of MAPK signaling in prion disease progression and highlight potential avenues for therapeutic intervention.

Advanced Parkinson's disease: clinical characteristics and treatment. Part II.

Science.gov (United States)

Kulisevsky, J; Luquin, M R; Arbelo, J M; Burguera, J A; Carrillo, F; Castro, A; Chacón, J; García-Ruiz, P J; Lezcano, E; Mir, P; Martinez-Castrillo, J C; Martínez-Torres, I; Puente, V; Sesar, A; Valldeoriola-Serra, F; Yañez, R

2013-01-01

Many patients who have had Parkinson's disease (PD) for several years will present severe motor fluctuations and dyskinesias which require more aggressive therapies. The different approaches which are now available include deep brain stimulation of the subthalamic nucleus or medial globus pallidus, subcutaneous infusion of apomorphine, and intestinal infusion of levodopa-carbidopa. To define the indications and results for the 3 available therapies for advanced PD. Exhaustive review of the literature concerning the indications and results of deep brain stimulation, subcutaneous apomorphine infusion and duodenal infusion of levodopa/carbidopa gel to treat patients with advanced Parkinson disease. Although numerous studies have confirmed the efficacy of the 3 different therapies in advanced PD, there are no comparative studies that would allow us to define the best candidate for each technique. Copyright © 2013 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.

Approximate Analytic and Numerical Solutions to Lane-Emden Equation via Fuzzy Modeling Method

Directory of Open Access Journals (Sweden)

De-Gang Wang

2012-01-01

Full Text Available A novel algorithm, called variable weight fuzzy marginal linearization (VWFML method, is proposed. This method can supply approximate analytic and numerical solutions to Lane-Emden equations. And it is easy to be implemented and extended for solving other nonlinear differential equations. Numerical examples are included to demonstrate the validity and applicability of the developed technique.

Current status of regional hydrogeological studies and numerical simulations on geological disposal

International Nuclear Information System (INIS)

Nakao, Shinsuke; Kikuchi, Tsuneo; Ishido, Tsuneo

2004-01-01

Current status of regional hydrogeological studies on geological disposal including hydrogeological modeling using numerical simulators is reviewed in this report. A regional scale and boundary conditions of numerical models are summarized mainly from the results of the RHS (regional hydrogeological study) project conducted by Japan Nuclear Cycle Development Institute (JNC) in the Tono area. We also refer to the current conceptual modes of hydrology and numerical models of unsaturated zone flow at Yucca Mountain, Nevada, which is the arid site proposed for consideration as the United States' first underground high-level radioactive waste repository. Understanding behavior of a freshwater-saltwater transition zone seems to play a key role in the hydrogeological modeling in a coastal region. Technical features of a numerical simulator as a tool for geothermal reservoir modeling is also briefly described. (author)

Composite body movements modulate numerical cognition: Evidence from the motion–numerical compatibility effect

Directory of Open Access Journals (Sweden)

Xiaorong eCheng

2015-11-01

Full Text Available A recent hierarchical model of numerical processing, initiated by Fischer and Brugger (2011 and Fisher (2012, suggested that situated factors, such as different body postures and body movements, can influence the magnitude representation and bias numerical processing. Indeed, Loetscher and colleagues (2008 found that participants’ behavior in a random number generation (RNG task was biased by head rotations. More small numbers were reported after leftward than rightward head turns, i.e. a motion–numerical compatibility effect. Here, by carrying out two experiments, we explored whether similar motion–numerical compatibility effects exist for movements of other important body components, e.g. arms, and for composite body movements as well, which are basis for complex human activities in many ecologically meaningful situations. In Experiment 1, a motion-numerical compatibility effect was observed for lateral rotations of two body components, i.e., the head and arms. Relatively large numbers were reported after making rightward compared to leftward movements for both lateral head and arm turns. The motion-numerical compatibility effect was observed again in Experiment 2 when participants were asked to perform composite body movements of congruent movement directions, e.g., simultaneous head left turns and arm left turns. However, it disappeared when the movement directions were incongruent, e.g., simultaneous head left turns and arm right turns. Taken together, our results extended Loetscher et al.'s (2008 finding by demonstrating that their effect is effector-general and exists for arm movements. Moreover, our study reveals for the first time that the impact of spatial information on numerical processing induced by each of the two sensorimotor-based situated factors, e.g., a lateral head turn and a lateral arm turn, can cancel each other out.

Uralic numerals : is the evolution of numeral system reconstructable? : (Reading new Václav Balzhek's book on numerals in Eurasia) / Vladimir Napolskich

Index Scriptorium Estoniae

Napolskich, Vladimir

2003-01-01

Rmt.: Balzhek, Václav. Numerals. Comparative-etymological analyses of numeral systems and their implications (saharan, nubian, egyptian, berber, kartvelian, ralic, altaic and indo-european languages). Brno, 1999. (Spisy Masarykovy Univerzity v Brné. Filozofická fakulta; 322). Ülevaade uurali keelte arvsõnu käsitlevast osast

Numerical methods for the Lévy LIBOR model

DEFF Research Database (Denmark)

Papapantoleon, Antonis; Skovmand, David

2010-01-01

but the methods are generally slow. We propose an alternative approximation scheme based on Picard iterations. Our approach is similar in accuracy to the full numerical solution, but with the feature that each rate is, unlike the standard method, evolved independently of the other rates in the term structure....... This enables simultaneous calculation of derivative prices of different maturities using parallel computing. We include numerical illustrations of the accuracy and speed of our method pricing caplets.......The aim of this work is to provide fast and accurate approximation schemes for the Monte-Carlo pricing of derivatives in the L\\'evy LIBOR model of Eberlein and \\"Ozkan (2005). Standard methods can be applied to solve the stochastic differential equations of the successive LIBOR rates...

Numerical Methods for the Lévy LIBOR Model

DEFF Research Database (Denmark)

Papapantoleon, Antonis; Skovmand, David

are generally slow. We propose an alternative approximation scheme based on Picard iterations. Our approach is similar in accuracy to the full numerical solution, but with the feature that each rate is, unlike the standard method, evolved independently of the other rates in the term structure. This enables...... simultaneous calculation of derivative prices of different maturities using parallel computing. We include numerical illustrations of the accuracy and speed of our method pricing caplets.......The aim of this work is to provide fast and accurate approximation schemes for the Monte-Carlo pricing of derivatives in the Lévy LIBOR model of Eberlein and Özkan (2005). Standard methods can be applied to solve the stochastic differential equations of the successive LIBOR rates but the methods...

Numerical Relativity Simulations for Black Hole Merger Astrophysics

Science.gov (United States)

Baker, John G.

2010-01-01

Massive black hole mergers are perhaps the most energetic astronomical events, establishing their importance as gravitational wave sources for LISA, and also possibly leading to observable influences on their local environments. Advances in numerical relativity over the last five years have fueled the development of a rich physical understanding of general relativity's predictions for these events. Z will overview the understanding of these event emerging from numerical simulation studies. These simulations elucidate the pre-merger dynamics of the black hole binaries, the consequent gravitational waveform signatures ' and the resulting state, including its kick velocity, for the final black hole produced by the merger. Scenarios are now being considered for observing each of these aspects of the merger, involving both gravitational-wave and electromagnetic astronomy.

Wind conditions in urban layout - Numerical and experimental research

Science.gov (United States)

Poćwierz, Marta; Zielonko-Jung, Katarzyna

2018-01-01

This paper presents research which compares the numerical and the experimental results for different cases of airflow around a few urban layouts. The study is concerned mostly with the analysis of parameters, such as pressure and velocity fields, which are essential in the building industry. Numerical simulations have been performed by the commercial software Fluent, with the use of a few different turbulence models, including popular k-ɛ, k-ɛ realizable or k-ω. A particular attention has been paid to accurate description of the conditions on the inlet and the selection of suitable computing grid. The pressure measurement near buildings and oil visualization were undertaken and described accordingly.

Java technology for implementing efficient numerical analysis in intranet

International Nuclear Information System (INIS)

Song, Hee Yong; Ko, Sung Ho

2001-01-01

This paper introduces some useful Java technologies for utilizing the internet in numerical analysis, and suggests one architecture performing efficient numerical analysis in the intranet by using them. The present work has verified it's possibility by implementing some parts of this architecture with two easy examples. One is based on Servlet-Applet communication, JDBC and swing. The other is adding multi-threads, file transfer and Java remote method invocation to the former. Through this work it has been intended to make the base for the later advanced and practical research that will include efficiency estimates of this architecture and deal with advanced load balancing

Numerical semigroups and applications

CERN Document Server

Assi, Abdallah

2016-01-01

This work presents applications of numerical semigroups in Algebraic Geometry, Number Theory, and Coding Theory. Background on numerical semigroups is presented in the first two chapters, which introduce basic notation and fundamental concepts and irreducible numerical semigroups. The focus is in particular on free semigroups, which are irreducible; semigroups associated with planar curves are of this kind. The authors also introduce semigroups associated with irreducible meromorphic series, and show how these are used in order to present the properties of planar curves. Invariants of non-unique factorizations for numerical semigroups are also studied. These invariants are computationally accessible in this setting, and thus this monograph can be used as an introduction to Factorization Theory. Since factorizations and divisibility are strongly connected, the authors show some applications to AG Codes in the final section. The book will be of value for undergraduate students (especially those at a higher leve...

Time's arrow: A numerical experiment

Science.gov (United States)

Fowles, G. Richard

1994-04-01

The dependence of time's arrow on initial conditions is illustrated by a numerical example in which plane waves produced by an initial pressure pulse are followed as they are multiply reflected at internal interfaces of a layered medium. Wave interactions at interfaces are shown to be analogous to the retarded and advanced waves of point sources. The model is linear and the calculation is exact and demonstrably time reversible; nevertheless the results show most of the features expected of a macroscopically irreversible system, including the approach to the Maxwell-Boltzmann distribution, ergodicity, and concomitant entropy increase.

Foot-and-mouth disease: past, present and future

DEFF Research Database (Denmark)

Jamal, Syed Muhammad; Belsham, Graham

2013-01-01

within countries where the disease is endemic due to reduced animal productivity and the restrictions on international trade in animal products. The disease is caused by infection with foot-and-mouth disease virus (FMDV), a picornavirus. Seven different serotypes (and numerous variants) of FMDV have been...... it is important to characterize the viruses that are circulating if vaccination is being used for disease control. This review describes current methods for the detection and characterization of FMDVs. Sequence information is increasingly being used for identifying the source of outbreaks. In addition...

Can numerical simulations accurately predict hydrodynamic instabilities in liquid films?

Science.gov (United States)

Denner, Fabian; Charogiannis, Alexandros; Pradas, Marc; van Wachem, Berend G. M.; Markides, Christos N.; Kalliadasis, Serafim

2014-11-01

Understanding the dynamics of hydrodynamic instabilities in liquid film flows is an active field of research in fluid dynamics and non-linear science in general. Numerical simulations offer a powerful tool to study hydrodynamic instabilities in film flows and can provide deep insights into the underlying physical phenomena. However, the direct comparison of numerical results and experimental results is often hampered by several reasons. For instance, in numerical simulations the interface representation is problematic and the governing equations and boundary conditions may be oversimplified, whereas in experiments it is often difficult to extract accurate information on the fluid and its behavior, e.g. determine the fluid properties when the liquid contains particles for PIV measurements. In this contribution we present the latest results of our on-going, extensive study on hydrodynamic instabilities in liquid film flows, which includes direct numerical simulations, low-dimensional modelling as well as experiments. The major focus is on wave regimes, wave height and wave celerity as a function of Reynolds number and forcing frequency of a falling liquid film. Specific attention is paid to the differences in numerical and experimental results and the reasons for these differences. The authors are grateful to the EPSRC for their financial support (Grant EP/K008595/1).

The Navier-Stokes Equations Theory and Numerical Methods

CERN Document Server

Masuda, Kyûya; Rautmann, Reimund; Solonnikov, Vsevolod

1990-01-01

These proceedings contain original (refereed) research articles by specialists from many countries, on a wide variety of aspects of Navier-Stokes equations. Additionally, 2 survey articles intended for a general readership are included: one surveys the present state of the subject via open problems, and the other deals with the interplay between theory and numerical analysis.

Two Numerical Approaches to Stationary Mean-Field Games

KAUST Repository

Almulla, Noha; Ferreira, Rita; Gomes, Diogo A.

2016-01-01

Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

Two Numerical Approaches to Stationary Mean-Field Games

KAUST Repository

Almulla, Noha

2016-10-04

Here, we consider numerical methods for stationary mean-field games (MFG) and investigate two classes of algorithms. The first one is a gradient-flow method based on the variational characterization of certain MFG. The second one uses monotonicity properties of MFG. We illustrate our methods with various examples, including one-dimensional periodic MFG, congestion problems, and higher-dimensional models.

How to Overcome Numerical Challenges to Modeling Stirling Engines

Science.gov (United States)

Dyson, Rodger W.; Wilson, Scott D.; Tew, Roy C.

2004-01-01

Nuclear thermal to electric power conversion carries the promise of longer duration missions and higher scientific data transmission rates back to Earth for a range of missions, including both Mars rovers and deep space missions. A free-piston Stirling convertor is a candidate technology that is considered an efficient and reliable power conversion device for such purposes. While already very efficient, it is believed that better Stirling engines can be developed if the losses inherent in current designs could be better understood. However, they are difficult to instrument and so efforts are underway to simulate a complete Stirling engine numerically. This has only recently been attempted and a review of the methods leading up to and including such computational analysis is presented. And finally it is proposed that the quality and depth of Stirling loss understanding may be improved by utilizing the higher fidelity and efficiency of recently developed numerical methods. One such method, the Ultra HI-FI technique is presented in detail.

Numerical electromagnetic frequency domain analysis with discrete exterior calculus

Science.gov (United States)

Chen, Shu C.; Chew, Weng Cho

2017-12-01

In this paper, we perform a numerical analysis in frequency domain for various electromagnetic problems based on discrete exterior calculus (DEC) with an arbitrary 2-D triangular or 3-D tetrahedral mesh. We formulate the governing equations in terms of DEC for 3-D and 2-D inhomogeneous structures, and also show that the charge continuity relation is naturally satisfied. Then we introduce a general construction for signed dual volume to incorporate material information and take into account the case when circumcenters fall outside triangles or tetrahedrons, which may lead to negative dual volume without Delaunay triangulation. Then we examine the boundary terms induced by the dual mesh and provide a systematical treatment of various boundary conditions, including perfect magnetic conductor (PMC), perfect electric conductor (PEC), Dirichlet, periodic, and absorbing boundary conditions (ABC) within this method. An excellent agreement is achieved through the numerical calculation of several problems, including homogeneous waveguides, microstructured fibers, photonic crystals, scattering by a 2-D PEC, and resonant cavities.

Curcumin as a potential protective compound against cardiac diseases.

Science.gov (United States)

Jiang, Shuai; Han, Jing; Li, Tian; Xin, Zhenlong; Ma, Zhiqiang; Di, Wencheng; Hu, Wei; Gong, Bing; Di, Shouyin; Wang, Dongjin; Yang, Yang

2017-05-01

Curcumin, which was first used 3000 years ago as an anti-inflammatory agent, is a well-known bioactive compound derived from the active ingredient of turmeric (Curcuma longa). Previous research has demonstrated that curcumin has immense therapeutic potential in a variety of diseases via anti-oxidative, anti-apoptotic, and anti-inflammatory pathways. Cardiac diseases are the leading cause of mortality worldwide and cause considerable harm to human beings. Numerous studies have suggested that curcumin exerts a protective role in the human body whereas its actions in cardiac diseases remain elusive and poorly understood. On the basis of the current evidence, we first give a brief introduction of cardiac diseases and curcumin, especially regarding the effects of curcumin in embryonic heart development. Secondly, we analyze the basic roles of curcumin in pathways that are dysregulated in cardiac diseases, including oxidative stress, apoptosis, and inflammation. Thirdly, actions of curcumin in different cardiac diseases will be discussed, as will relevant clinical trials. Eventually, we would like to discuss the existing controversial opinions and provide a detailed analysis followed by the remaining obstacles, advancement, and further prospects of the clinical application of curcumin. The information compiled here may serve as a comprehensive reference of the protective effects of curcumin in the heart, which is significant to the further research and design of curcumin analogs as therapeutic options for cardiac diseases. Copyright © 2017 Elsevier Ltd. All rights reserved.

Protection against neurodegenerative disease on Earth and in space

Science.gov (United States)

Takamatsu, Yoshiki; Koike, Wakako; Takenouchi, Takato; Sugama, Shuei; Wei, Jianshe; Waragai, Masaaki; Sekiyama, Kazunari; Hashimoto, Makoto

2016-01-01

All living organisms have evolutionarily adapted themselves to the Earth’s gravity, and failure to adapt to gravity changes may lead to pathological conditions. This perspective may also apply to abnormal aging observed in bedridden elderly patients with aging-associated diseases such as osteoporosis and sarcopenia. Given that bedridden elderly patients are partially analogous to astronauts in that both cannot experience the beneficial effects of gravity on the skeletal system and may suffer from bone loss and muscle weakness, one may wonder whether there are gravity-related mechanisms underlying diseases among the elderly. In contrast to numerous studies of the relevance of microgravity in skeletal disorders, little attention has been paid to neurodegenerative diseases. Therefore, the objective of this paper is to discuss the possible relevance of microgravity in these diseases. We particularly noted a proteomics paper showing that levels of hippocampal proteins, including β-synuclein and carboxyl-terminal ubiquitin hydrolase L1, which have been linked to familial neurodegenerative diseases, were significantly decreased in the hippocampus of mice subjected to hindlimb suspension, a model of microgravity. We suggest that microgravity-induced neurodegeneration may be further exacerbated by diabetes and other factors. On the basis of this view, prevention of neurodegenerative diseases through ‘anti-diabetes’ and ‘hypergravity’ approaches may be important as a common therapeutic approach on Earth and in space. Collectively, neurodegenerative diseases and space medicine may be linked to each other more strongly than previously thought. PMID:28725728

Foundations of children's numerical and mathematical skills: the roles of symbolic and nonsymbolic representations of numerical magnitude.

Science.gov (United States)

Lyons, Ian M; Ansari, Daniel

2015-01-01

Numerical and mathematical skills are critical predictors of academic success. The last three decades have seen a substantial growth in our understanding of how the human mind and brain represent and process numbers. In particular, research has shown that we share with animals the ability to represent numerical magnitude (the total number of items in a set) and that preverbal infants can process numerical magnitude. Further research has shown that similar processing signatures characterize numerical magnitude processing across species and developmental time. These findings suggest that an approximate system for nonsymbolic (e.g., dot arrays) numerical magnitude representation serves as the basis for the acquisition of cultural, symbolic (e.g., Arabic numerals) representations of numerical magnitude. This chapter explores this hypothesis by reviewing studies that have examined the relation between individual differences in nonsymbolic numerical magnitude processing and symbolic math abilities (e.g., arithmetic). Furthermore, we examine the extent to which the available literature provides strong evidence for a link between symbolic and nonsymbolic representations of numerical magnitude at the behavioral and neural levels of analysis. We conclude that claims that symbolic number abilities are grounded in the approximate system for the nonsymbolic representation of numerical magnitude are not strongly supported by the available evidence. Alternative models and future research directions are discussed. © 2015 Elsevier Inc. All rights reserved.

Numerical simulation of gas metal arc welding parametrical study

International Nuclear Information System (INIS)

Szanto, M.; Gilad, I.; Shai, I.; Quinn, T.P.

2002-01-01

The Gas Metal Arc Welding (GMAW) is a widely used welding process in the industry. The process variables are usually determined through extensive experiments. Numerical simulation, reduce the cost and extends the understanding of the process. In the present work, a versatile model for numerical simulation of GMAW is presented. The model provides the basis for fundamental understanding of the process. The model solves the magneto-hydrodynamic equations for the flow and temperature fields of the molten electrode and the plasma simultaneously, to form a fully coupled model. A commercial CFD code was extended to include the effects of radiation, Lorentz forces, Joule heating and thermoelectric effects. The geometry of the numerical model assembled to fit an experimental apparatus. To demonstrate the method, an aluminum electrode was modeled in a pure argon arc. Material properties and welding parameters are the input variables in the numerical model. In a typical process, the temperature distribution of the plasma is over 15000 K, resulting high non-linearity of the material properties. Moreover, there is high uncertainty in the available property data, at that range of temperatures. Therefore, correction factors were derived for the material properties to adjust between the numerical and the experimental results. Using the compensated properties, parametric study was performed. The effects of the welding parameters on the process, such the working voltage, electrode feed rate and shielding gas flow, were derived. The principal result of the present work is the ability to predict, by numerical simulation, the mode, size and frequency of the metal transferred from the electrode, which is the main material and energy source for the welding pool in GMAW

Third-order-accurate numerical methods for efficient, large time-step solutions of mixed linear and nonlinear problems

Energy Technology Data Exchange (ETDEWEB)

Cobb, J.W.

1995-02-01

There is an increasing need for more accurate numerical methods for large-scale nonlinear magneto-fluid turbulence calculations. These methods should not only increase the current state of the art in terms of accuracy, but should also continue to optimize other desired properties such as simplicity, minimized computation, minimized memory requirements, and robust stability. This includes the ability to stably solve stiff problems with long time-steps. This work discusses a general methodology for deriving higher-order numerical methods. It also discusses how the selection of various choices can affect the desired properties. The explicit discussion focuses on third-order Runge-Kutta methods, including general solutions and five examples. The study investigates the linear numerical analysis of these methods, including their accuracy, general stability, and stiff stability. Additional appendices discuss linear multistep methods, discuss directions for further work, and exhibit numerical analysis results for some other commonly used lower-order methods.

Numerical Asymptotic Solutions Of Differential Equations

Science.gov (United States)

Thurston, Gaylen A.

1992-01-01

Numerical algorithms derived and compared with classical analytical methods. In method, expansions replaced with integrals evaluated numerically. Resulting numerical solutions retain linear independence, main advantage of asymptotic solutions.

Propagation of steel corrosion in concrete: Experimental and numerical investigations

DEFF Research Database (Denmark)

Michel, Alexander; Otieno, M.; Stang, Henrik

2016-01-01

This paper focuses on experimental and numerical investigations of the propagation phase of reinforcement corrosion to determine anodic and cathodic Tafel constants and exchange current densities, from corrosion current density and corrosion potential measurements. The experimental program includ...

A rat model system to study complex disease risks, fitness, aging, and longevity.

Science.gov (United States)

Koch, Lauren Gerard; Britton, Steven L; Wisløff, Ulrik

2012-02-01

The association between low exercise capacity and all-cause morbidity and mortality is statistically strong yet mechanistically unresolved. By connecting clinical observation with a theoretical base, we developed a working hypothesis that variation in capacity for oxygen metabolism is the central mechanistic determinant between disease and health (aerobic hypothesis). As an unbiased test, we show that two-way artificial selective breeding of rats for low and high intrinsic endurance exercise capacity also produces rats that differ for numerous disease risks, including the metabolic syndrome, cardiovascular complications, premature aging, and reduced longevity. This contrasting animal model system may prove to be translationally superior relative to more widely used simplistic models for understanding geriatric biology and medicine. Copyright © 2012 Elsevier Inc. All rights reserved.

Numerical analysis using Sage

CERN Document Server

Anastassiou, George A

2015-01-01

This is the first numerical analysis text to use Sage for the implementation of algorithms and can be used in a one-semester course for undergraduates in mathematics, math education, computer science/information technology, engineering, and physical sciences. The primary aim of this text is to simplify understanding of the theories and ideas from a numerical analysis/numerical methods course via a modern programming language like Sage. Aside from the presentation of fundamental theoretical notions of numerical analysis throughout the text, each chapter concludes with several exercises that are oriented to real-world application.  Answers may be verified using Sage.  The presented code, written in core components of Sage, are backward compatible, i.e., easily applicable to other software systems such as Mathematica®.  Sage is  open source software and uses Python-like syntax. Previous Python programming experience is not a requirement for the reader, though familiarity with any programming language is a p...

Numerical simulation of DPF filter for selected regimes with deposited soot particles

Science.gov (United States)

Lávička, David; Kovařík, Petr

2012-04-01

For the purpose of accumulation of particulate matter from Diesel engine exhaust gas, particle filters are used (referred to as DPF or FAP filters in the automotive industry). However, the cost of these filters is quite high. As the emission limits become stricter, the requirements for PM collection are rising accordingly. Particulate matters are very dangerous for human health and these are not invisible for human eye. They can often cause various diseases of the respiratory tract, even what can cause lung cancer. Performed numerical simulations were used to analyze particle filter behavior under various operating modes. The simulations were especially focused on selected critical states of particle filter, when engine is switched to emergency regime. The aim was to prevent and avoid critical situations due the filter behavior understanding. The numerical simulations were based on experimental analysis of used diesel particle filters.

Clinical Uses of Melatonin in Neurological Diseases and Mental and Behavioural Disorders.

Science.gov (United States)

Sanchez-Barcelo, Emilio J; Rueda, Noemi; Mediavilla, María D; Martinez-Cue, Carmen; Reiter, Russel J

2017-11-20

Melatonin is a molecule with numerous properties applicable to the treatment of neurological diseases. Among these properties are the following: potent scavenger of oxygen and nitrogen reactive species, anti-inflammatory features, immuno-enhancing nature, and modulation of circadian rhythmicity. Furthermore, low concentrations of melatonin are usually found in patients with neurological diseases and mental disorders. The positive results obtained in experimental models of diverse pathologies, including diseases of the nervous system (e.g., Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, Huntington's disease, epilepsy, headaches, etc.) as well as mental and behavioural disordes (e.g., autism spectrum disorders, attention-deficit hyperactivity disorders, etc.), have served as a basis for the design of clinical trials to study melatonin's possible usefulness in human pathology, although the satisfactory results obtained from the laboratory "bench" are not always applicable to the patient's "bedside". In this article, we review those papers describing the results of the administration of melatonin to humans for various therapeutic purposes in the field of neuropathology. Clinical trials with strong methodologies and appropriate doses of melatonin are necessary to support or reject the usefulness of melatonin in neurological diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Numerical simulation of laser resonators

International Nuclear Information System (INIS)

Yoo, J. G.; Jeong, Y. U.; Lee, B. C.; Rhee, Y. J.; Cho, S. O.

2004-01-01

We developed numerical simulation packages for laser resonators on the bases of a pair of integral equations. Two numerical schemes, a matrix formalism and an iterative method, were programmed for finding numeric solutions to the pair of integral equations. The iterative method was tried by Fox and Li, but it was not applicable for high Fresnel numbers since the numerical errors involved propagate and accumulate uncontrollably. In this paper, we implement the matrix method to extend the computational limit further. A great number of case studies are carried out with various configurations of stable and unstable r;esonators to compute diffraction losses, phase shifts, intensity distributions and phases of the radiation fields on mirrors. Our results presented in this paper show not only a good agreement with the results previously obtained by Fox and Li, but also the legitimacy of our numerical procedures for high Fresnel numbers.

Model Selection and Evaluation Based on Emerging Infectious Disease Data Sets including A/H1N1 and Ebola

Directory of Open Access Journals (Sweden)

Wendi Liu

2015-01-01

Full Text Available The aim of the present study is to apply simple ODE models in the area of modeling the spread of emerging infectious diseases and show the importance of model selection in estimating parameters, the basic reproduction number, turning point, and final size. To quantify the plausibility of each model, given the data and the set of four models including Logistic, Gompertz, Rosenzweg, and Richards models, the Bayes factors are calculated and the precise estimates of the best fitted model parameters and key epidemic characteristics have been obtained. In particular, for Ebola the basic reproduction numbers are 1.3522 (95% CI (1.3506, 1.3537, 1.2101 (95% CI (1.2084, 1.2119, 3.0234 (95% CI (2.6063, 3.4881, and 1.9018 (95% CI (1.8565, 1.9478, the turning points are November 7,November 17, October 2, and November 3, 2014, and the final sizes until December 2015 are 25794 (95% CI (25630, 25958, 3916 (95% CI (3865, 3967, 9886 (95% CI (9740, 10031, and 12633 (95% CI (12515, 12750 for West Africa, Guinea, Liberia, and Sierra Leone, respectively. The main results confirm that model selection is crucial in evaluating and predicting the important quantities describing the emerging infectious diseases, and arbitrarily picking a model without any consideration of alternatives is problematic.

NUMERICAL SIMULATION OF POLLUTION DISPERSION IN URBAN STREET

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M. M. Biliaiev

2017-08-01

Full Text Available Purpose. The scientific paper solves the question of 2D numerical model development, which allows quick computation of air pollution in streets from vehicles. The aim of the work is numerical model development that would enable to predict the level of air pollution by using protective barriers along the road. Methodology. The developed model is based on the equation of inviscid flow and equation of pollutant transfer. Potential equation is used to compute velocity field of air flow near road in the case of protection barriers application. To solve equation for potential flow implicit difference scheme of «conditional approximation« is used. The implicit change – triangle difference scheme is used to solve equation of convective – diffusive dispersion. Numerical integration is carried out using the rectangular difference grid. Method of porosity technique («markers method» is used to create the form of comprehensive computational region. Emission of toxic gases from vehicle is modeled using Delta function for point source.Findings. Authors developed 2D numerical model. It takes into account the main physical factors affecting the process of dispersion of pollutants in the atmosphere when emissions of vehicle including protection barriers near the road. On the basis of the developed numerical models a computational experiment was performed to estimate the level of air pollution in the street. Originality. A numerical model has been created. It makes it possible to calculate 2D aerodynamics of the wind flow in the presence of noises and the process of mass transfer of toxic gas emissions from the motorway. The model allows taking into account the presence of the car on the road, the form of a protective barrier, the presence of a curb. Calculations have been performed to determine the contamination zone formed at the protective barrier that is located at the motorway. Practical value. An effective numerical model that can be applied in the

Numerical

Directory of Open Access Journals (Sweden)

M. Boumaza

2015-07-01

Full Text Available Transient convection heat transfer is of fundamental interest in many industrial and environmental situations, as well as in electronic devices and security of energy systems. Transient fluid flow problems are among the more difficult to analyze and yet are very often encountered in modern day technology. The main objective of this research project is to carry out a theoretical and numerical analysis of transient convective heat transfer in vertical flows, when the thermal field is due to different kinds of variation, in time and space of some boundary conditions, such as wall temperature or wall heat flux. This is achieved by the development of a mathematical model and its resolution by suitable numerical methods, as well as performing various sensitivity analyses. These objectives are achieved through a theoretical investigation of the effects of wall and fluid axial conduction, physical properties and heat capacity of the pipe wall on the transient downward mixed convection in a circular duct experiencing a sudden change in the applied heat flux on the outside surface of a central zone.

Systematic review with meta-analysis: online psychological interventions for mental and physical health outcomes in gastrointestinal disorders including irritable bowel syndrome and inflammatory bowel disease.

Science.gov (United States)

Hanlon, I; Hewitt, C; Bell, K; Phillips, A; Mikocka-Walus, A

2018-06-14

Online psychotherapy has been successfully used as supportive treatment in many chronic illnesses. However, there is a lack of evidence on its role in the management of gastrointestinal (GI) diseases. To examine whether online psychological interventions improve mental and physical outcomes in gastrointestinal diseases. We searched CINAHL Plus, MEDLINE, EMBASE, Health Management Information Consortium, PsycINFO, British Nursing Index, Cochrane Library, a specialised register of the IBD/FBD Cochrane Group, MEDLINE (PubMed) WHO International Clinical Trial Registry, ClinicalTrials.gov, and reference lists of all papers included in the review. The Cochrane Risk of Bias Tool was used to assess internal validity. Where possible, data were pooled using random-effects meta-analysis. We identified 11 publications (encompassing nine studies) meeting inclusion criteria. One study had a high risk of selection bias (allocation concealment), all studies had a high risk of performance and detection bias. Eight studies were included in the meta-analyses (6 on irritable bowel syndrome [IBS] and two on inflammatory bowel disease [IBD]). Online cognitive behavioural therapy (CBT) was shown to significantly improve gastrointestinal symptom-specific anxiety (MD: -8.51, 95% CI -12.99 to -4.04, P = 0.0002) and lessen symptom-induced disability (MD: -2.78, 95% CI -5.43 to -0.12, P = 0.04) in IBS post intervention. There was no significant effect of online CBT on any other outcomes in IBS. No significant effect of online psychotherapy was demonstrated in IBD. There is insufficient evidence to demonstrate the effectiveness of online CBT to manage mental and physical outcomes in gastrointestinal diseases. © 2018 John Wiley & Sons Ltd.

Numerical Methods for Free Boundary Problems

CERN Document Server

1991-01-01

About 80 participants from 16 countries attended the Conference on Numerical Methods for Free Boundary Problems, held at the University of Jyviiskylii, Finland, July 23-27, 1990. The main purpose of this conference was to provide up-to-date information on important directions of research in the field of free boundary problems and their numerical solutions. The contributions contained in this volume cover the lectures given in the conference. The invited lectures were given by H.W. Alt, V. Barbu, K-H. Hoffmann, H. Mittelmann and V. Rivkind. In his lecture H.W. Alt considered a mathematical model and existence theory for non-isothermal phase separations in binary systems. The lecture of V. Barbu was on the approximate solvability of the inverse one phase Stefan problem. K-H. Hoff­ mann gave an up-to-date survey of several directions in free boundary problems and listed several applications, but the material of his lecture is not included in this proceedings. H.D. Mittelmann handled the stability of thermo capi...

Innovative measures to combat rare diseases in China: The national rare diseases registry system, larger-scale clinical cohort studies, and studies in combination with precision medicine research.

Science.gov (United States)

Song, Peipei; He, Jiangjiang; Li, Fen; Jin, Chunlin

2017-02-01

China is facing the great challenge of treating the world's largest rare disease population, an estimated 16 million patients with rare diseases. One effort offering promise has been a pilot national project that was launched in 2013 and that focused on 20 representative rare diseases. Another government-supported special research program on rare diseases - the "Rare Diseases Clinical Cohort Study" - was launched in December 2016. According to the plan for this research project, the unified National Rare Diseases Registry System of China will be established as of 2020, and a large-scale cohort study will be conducted from 2016 to 2020. The project plans to develop 109 technical standards, to establish and improve 2 national databases of rare diseases - a multi-center clinical database and a biological sample library, and to conduct studies on more than 50,000 registered cases of 50 different rare diseases. More importantly, this study will be combined with the concept of precision medicine. Chinese population-specific basic information on rare diseases, clinical information, and genomic information will be integrated to create a comprehensive predictive model with a follow-up database system and a model to evaluate prognosis. This will provide the evidence for accurate classification, diagnosis, treatment, and estimation of prognosis for rare diseases in China. Numerous challenges including data standardization, protecting patient privacy, big data processing, and interpretation of genetic information still need to be overcome, but research prospects offer great promise.

Emerging and Reemerging Neglected Tropical Diseases: a Review of Key Characteristics, Risk Factors, and the Policy and Innovation Environment

Science.gov (United States)

Liang, Bryan A.; Cuomo, Raphael; Hafen, Ryan; Brouwer, Kimberly C.; Lee, Daniel E.

2014-01-01

SUMMARY In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern. PMID:25278579

Bone Marrow-Derived Cells as a Therapeutic Approach to Optic Nerve Diseases

Directory of Open Access Journals (Sweden)

Louise A. Mesentier-Louro

2016-01-01

Full Text Available Following optic nerve injury associated with acute or progressive diseases, retinal ganglion cells (RGCs of adult mammals degenerate and undergo apoptosis. These diseases have limited therapeutic options, due to the low inherent capacity of RGCs to regenerate and due to the inhibitory milieu of the central nervous system. Among the numerous treatment approaches investigated to stimulate neuronal survival and axonal extension, cell transplantation emerges as a promising option. This review focuses on cell therapies with bone marrow mononuclear cells and bone marrow-derived mesenchymal stem cells, which have shown positive therapeutic effects in animal models of optic neuropathies. Different aspects of available preclinical studies are analyzed, including cell distribution, potential doses, routes of administration, and mechanisms of action. Finally, published and ongoing clinical trials are summarized.

A review of laboratory and numerical modelling in volcanology

Directory of Open Access Journals (Sweden)

J. L. Kavanagh

2018-04-01

Full Text Available Modelling has been used in the study of volcanic systems for more than 100 years, building upon the approach first applied by Sir James Hall in 1815. Informed by observations of volcanological phenomena in nature, including eye-witness accounts of eruptions, geophysical or geodetic monitoring of active volcanoes, and geological analysis of ancient deposits, laboratory and numerical models have been used to describe and quantify volcanic and magmatic processes that span orders of magnitudes of time and space. We review the use of laboratory and numerical modelling in volcanological research, focussing on sub-surface and eruptive processes including the accretion and evolution of magma chambers, the propagation of sheet intrusions, the development of volcanic flows (lava flows, pyroclastic density currents, and lahars, volcanic plume formation, and ash dispersal. When first introduced into volcanology, laboratory experiments and numerical simulations marked a transition in approach from broadly qualitative to increasingly quantitative research. These methods are now widely used in volcanology to describe the physical and chemical behaviours that govern volcanic and magmatic systems. Creating simplified models of highly dynamical systems enables volcanologists to simulate and potentially predict the nature and impact of future eruptions. These tools have provided significant insights into many aspects of the volcanic plumbing system and eruptive processes. The largest scientific advances in volcanology have come from a multidisciplinary approach, applying developments in diverse fields such as engineering and computer science to study magmatic and volcanic phenomena. A global effort in the integration of laboratory and numerical volcano modelling is now required to tackle key problems in volcanology and points towards the importance of benchmarking exercises and the need for protocols to be developed so that models are routinely tested against real

A review of laboratory and numerical modelling in volcanology

Science.gov (United States)

Kavanagh, Janine L.; Engwell, Samantha L.; Martin, Simon A.

2018-04-01

Modelling has been used in the study of volcanic systems for more than 100 years, building upon the approach first applied by Sir James Hall in 1815. Informed by observations of volcanological phenomena in nature, including eye-witness accounts of eruptions, geophysical or geodetic monitoring of active volcanoes, and geological analysis of ancient deposits, laboratory and numerical models have been used to describe and quantify volcanic and magmatic processes that span orders of magnitudes of time and space. We review the use of laboratory and numerical modelling in volcanological research, focussing on sub-surface and eruptive processes including the accretion and evolution of magma chambers, the propagation of sheet intrusions, the development of volcanic flows (lava flows, pyroclastic density currents, and lahars), volcanic plume formation, and ash dispersal. When first introduced into volcanology, laboratory experiments and numerical simulations marked a transition in approach from broadly qualitative to increasingly quantitative research. These methods are now widely used in volcanology to describe the physical and chemical behaviours that govern volcanic and magmatic systems. Creating simplified models of highly dynamical systems enables volcanologists to simulate and potentially predict the nature and impact of future eruptions. These tools have provided significant insights into many aspects of the volcanic plumbing system and eruptive processes. The largest scientific advances in volcanology have come from a multidisciplinary approach, applying developments in diverse fields such as engineering and computer science to study magmatic and volcanic phenomena. A global effort in the integration of laboratory and numerical volcano modelling is now required to tackle key problems in volcanology and points towards the importance of benchmarking exercises and the need for protocols to be developed so that models are routinely tested against real world data.

A primer on stochastic epidemic models: Formulation, numerical simulation, and analysis

Directory of Open Access Journals (Sweden)

Linda J.S. Allen

2017-05-01

Full Text Available Some mathematical methods for formulation and numerical simulation of stochastic epidemic models are presented. Specifically, models are formulated for continuous-time Markov chains and stochastic differential equations. Some well-known examples are used for illustration such as an SIR epidemic model and a host-vector malaria model. Analytical methods for approximating the probability of a disease outbreak are also discussed. Keywords: Branching process, Continuous-time Markov chain, Minor outbreak, Stochastic differential equation, 2000 MSC: 60H10, 60J28, 92D30

Is cytomegalovirus infection related to inflammatory bowel disease, especially steroid-resistant inflammatory bowel disease? A meta-analysis

Directory of Open Access Journals (Sweden)

Lv Y

2017-12-01

Full Text Available Ya-li Lv, Fei-fei Han, Yang-jie Jia, Zi-rui Wan, Li-li Gong, He Liu, Li-hong Liu Department of Pharmacy, Beijing Chao-Yang Hospital, Capital Medical University, Beijing, People’s Republic of China Background: Human cytomegalovirus (HCMV infection has been associated with inflammatory bowel disease (IBD. Numerous studies have been conducted to analyze the association between HCMV infection and risk of IBD and steroid-resistant IBD, but no clear consensus had been reached. Objectives: The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis. Study design: We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they 1 evaluated the association between HCMV infection and IBD disease; 2 evaluated the association between HCMV infection and steroid-resistant IBD disease; 3 were case–control studies or nested case–control studies; 4 provided the numbers (or percentage of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators. Results and conclusion: A total of 18 studies including 1,168 patients and 951 health groups was identified, and HCMV infection was distinctly confirmed as a risk factor for the occurrence and development of IBD. When involving 17 studies including 1,306 IBD patients, a total of 52.9% of patients in the cytomegalovirus (CMV-positive groups were observed to have steroid resistance, compared with 30.2% of patients in the CMV-negative groups. There was a significant difference in the risk of steroid resistance between people exposed to HCMV infection and those not exposed HCMV infection in IBD patients. This meta-analysis suggested that HCMV infection is associated with an increased risk for IBD and steroid-resistant IBD. Keywords: cytomegalovirus, infection, inflammatory bowel disease, Crohn’s disease, ulcerative colitis, meta-analysis

DSP30 and interleukin-2 as a mitotic stimulant in B-cell disorders including those with a low disease burden.

Science.gov (United States)

Dun, Karen A; Riley, Louise A; Diano, Giuseppe; Adams, Leanne B; Chiu, Eleanor; Sharma, Archna

2018-05-01

Chromosome abnormalities detected during cytogenetic investigations for B-cell malignancy offer prognostic information that can have wide ranging clinical impacts on patients. These impacts may include monitoring frequency, treatment type, and disease staging level. The use of the synthetic oligonucleotide DSP30 combined with interleukin 2 (IL2) has been described as an effective mitotic stimulant in B-cell disorders, not only in chronic lymphocytic leukemia (CLL) but also in a range of other B-cell malignancies. Here, we describe the comparison of two B-cell mitogens, lipopolysaccharide (LPS), and DSP30 combined with IL2 as mitogens in a range of common B-cell disorders excluding CLL. The results showed that DSP30/IL2 was an effective mitogen in mature B-cell disorders, revealing abnormal cytogenetic results in a range of B-cell malignancies. The abnormality rate increased when compared to the use of LPS to 64% (DSP30/IL2) from 14% (LPS). In a number of cases the disease burden was proportionally very low, less than 10% of white cells. In 37% of these cases, the DSP30 culture revealed abnormal results. Importantly, we also obtained abnormal conventional cytogenetics results in 3 bone marrow cases in which immunophenotyping showed an absence of an abnormal B-cell clone. In these cases, the cytogenetics results correlated with the provisional diagnosis and altered their staging level. The use of DSP30 and IL2 is recommended for use in many B-cell malignancies as an effective mitogen and their use has been shown to enable successful culture of the malignant clone, even at very low levels of disease. © 2018 Wiley Periodicals, Inc.

Entomologic index for human risk of Lyme disease.

Science.gov (United States)

Mather, T N; Nicholson, M C; Donnelly, E F; Matyas, B T

1996-12-01

An entomologic index based on density estimates of Lyme disease spirochete-infected nymphal deer ticks (lxodes scapularis) was developed to assess human risk of Lyme disease. The authors used a standardized protocol to determine tick density and infection in numerous forested sites in six Rhode Island towns. An entomologic risk index calculated for each town was compared with the number of human Lyme disease cases reported to the Rhode Island State Health Department for the same year. A strong positive relation between entomologic risk index and the Lyme disease case rate for each town suggested that the entomologic index was predictive of Lyme disease risk.

Hodgkin's disease part 1: pathology, staging, and management of early stage disease

International Nuclear Information System (INIS)

Mauch, Peter; Yahalom, Joachim

1995-01-01

Over the past 25 years there have been dramatic improvements in our understanding of the epidemiology, biology, natural history, and treatment of Hodgkins disease. Hodgkin's disease is one of the few cancers where both chemotherapy and radiation therapy have provided dramatic improvements in cure of this once uniformly fatal disease. Part 1 of the refresher course on Hodgkin's disease will include a review of: 1) New Findings in epidemiology, immunohistochemistry and molecular biology of the Reed-Sternberg cell including association with Epstein-Barr virus; 2) Review of pathology including discussions of NS 1 vs NS2, and nodular LP subclassifications; 3) Recommendations for staging including the role of staging laparotomy in Hodgkin's disease; 4) Standard techniques for commonly used radiation therapy fields for Hodgkin's disease and 5) Treatment of early stage Hodgkin's disease including an overview on recent and current clinical trials

Including an ocean carbon cycle model into iLOVECLIM (v1.0)

NARCIS (Netherlands)

Bouttes, N.; Roche, D.M.V.A.P.; Mariotti, V.; Bopp, L.

2015-01-01

The atmospheric carbon dioxide concentration plays a crucial role in the radiative balance and as such has a strong influence on the evolution of climate. Because of the numerous interactions between climate and the carbon cycle, it is necessary to include a model of the carbon cycle within a

International Winter Workshop on Differential Equations and Numerical Analysis

CERN Document Server

Miller, John; Narasimhan, Ramanujam; Mathiazhagan, Paramasivam; Victor, Franklin

2016-01-01

This book offers an ideal introduction to singular perturbation problems, and a valuable guide for researchers in the field of differential equations. It also includes chapters on new contributions to both fields: differential equations and singular perturbation problems. Written by experts who are active researchers in the related fields, the book serves as a comprehensive source of information on the underlying ideas in the construction of numerical methods to address different classes of problems with solutions of different behaviors, which will ultimately help researchers to design and assess numerical methods for solving new problems. All the chapters presented in the volume are complemented by illustrations in the form of tables and graphs.

A numerical study of bulk evaporation and condensation problem

International Nuclear Information System (INIS)

Ding, Z.; Anghaie, S.

1996-01-01

A numerical model is developed to simulate the dynamic behavior of bulk evaporation and condensation process in an encapsulated container with internal heat generation at micro-gravity level. Thermal performance of a multi-phase system with internal heat generation is investigated. The numerical simulation yields the evolution of the bulk liquid-vapor phase change process. This includes the evolution of the liquid-vapor interface, the formation and development of the liquid film covering the side wall surface, the temperature distribution and the convection flow field. An example of such systems is a phase change nuclear fuel element which was first introduced by Ding and Anghaie with application in high temperature space nuclear power and propulsion systems

Numerical Gram-Schmidt orthonormalization

International Nuclear Information System (INIS)

Werneth, Charles M; Dhar, Mallika; Maung, Khin Maung; Sirola, Christopher; Norbury, John W

2010-01-01

A numerical Gram-Schmidt orthonormalization procedure is presented for constructing an orthonormal basis function set from a non-orthonormal set, when the number of basis functions is large. This method will provide a pedagogical illustration of the Gram-Schmidt procedure and can be presented in classes on numerical methods or computational physics.

Numerical Transducer Modeling

DEFF Research Database (Denmark)

Henriquez, Vicente Cutanda

This thesis describes the development of a numerical model of the propagation of sound waves in fluids with viscous and thermal losses, with application to the simulation of acoustic transducers, in particular condenser microphones for measurement. The theoretical basis is presented, numerical...... manipulations are developed to satisfy the more complicated boundary conditions, and a model of a condenser microphone with a coupled membrane is developed. The model is tested against measurements of ¼ inch condenser microphones and analytical calculations. A detailed discussion of the results is given....

Fast numerical algorithm for the linear canonical transform.

Science.gov (United States)

Hennelly, Bryan M; Sheridan, John T

2005-05-01

The linear canonical transform (LCT) describes the effect of any quadratic phase system (QPS) on an input optical wave field. Special cases of the LCT include the fractional Fourier transform (FRT), the Fourier transform (FT), and the Fresnel transform (FST) describing free-space propagation. Currently there are numerous efficient algorithms used (for purposes of numerical simulation in the area of optical signal processing) to calculate the discrete FT, FRT, and FST. All of these algorithms are based on the use of the fast Fourier transform (FFT). In this paper we develop theory for the discrete linear canonical transform (DLCT), which is to the LCT what the discrete Fourier transform (DFT) is to the FT. We then derive the fast linear canonical transform (FLCT), an N log N algorithm for its numerical implementation by an approach similar to that used in deriving the FFT from the DFT. Our algorithm is significantly different from the FFT, is based purely on the properties of the LCT, and can be used for FFT, FRT, and FST calculations and, in the most general case, for the rapid calculation of the effect of any QPS.

Numerical simulation of real-world flows

Energy Technology Data Exchange (ETDEWEB)

Hayase, Toshiyuki, E-mail: hayase@ifs.tohoku.ac.jp [Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577 (Japan)

2015-10-15

Obtaining real flow information is important in various fields, but is a difficult issue because measurement data are usually limited in time and space, and computational results usually do not represent the exact state of real flows. Problems inherent in the realization of numerical simulation of real-world flows include the difficulty in representing exact initial and boundary conditions and the difficulty in representing unstable flow characteristics. This article reviews studies dealing with these problems. First, an overview of basic flow measurement methodologies and measurement data interpolation/approximation techniques is presented. Then, studies on methods of integrating numerical simulation and measurement, namely, four-dimensional variational data assimilation (4D-Var), Kalman filters (KFs), state observers, etc are discussed. The first problem is properly solved by these integration methodologies. The second problem can be partially solved with 4D-Var in which only initial and boundary conditions are control parameters. If an appropriate control parameter capable of modifying the dynamical structure of the model is included in the formulation of 4D-Var, unstable modes are properly suppressed and the second problem is solved. The state observer and KFs also solve the second problem by modifying mathematical models to stabilize the unstable modes of the original dynamical system by applying feedback signals. These integration methodologies are now applied in simulation of real-world flows in a wide variety of research fields. Examples are presented for basic fluid dynamics and applications in meteorology, aerospace, medicine, etc. (topical review)

Development of Numerical Grids for UZ Flow and Transport Modeling

International Nuclear Information System (INIS)

Hinds, J.

2001-01-01

This Analysis/Model Report (AMR) describes the methods used to develop numerical grids of the unsaturated hydrogeologic system beneath Yucca Mountain. Numerical grid generation is an integral part of the development of a complex, three-dimensional (3-D) model, such as the Unsaturated-Zone Flow and Transport Model (UZ Model) of Yucca Mountain. The resulting numerical grids, developed using current geologic, hydrogeologic, and mineralogic data, provide the necessary framework to: (1) develop calibrated hydrogeologic property sets and flow fields, (2) test conceptual hypotheses of flow and transport, and (3) predict flow and transport behavior under a variety of climatic and thermal loading conditions. Revision 00 of the work described herein follows the planning and work direction outlined in the ''Development of Numerical Grids for UZ Flow and Transport Modeling'' (CRWMS M and O 1999c). The technical scope, content, and management of ICN 01 of this AMR is currently controlled by the planning document, ''Technical Work Plan for Unsaturated Zone (UZ) Flow and Transport Process Model Report'' (BSC 2001a). The scope for the TBV resolution actions in this ICN is described in the ''Technical Work Plan for: Integrated Management of Technical Product Input Department'' (BSC 2001 b, Addendum B, Section 4.1). The steps involved in numerical grid development include: (1) defining the location of important calibration features, (2) determining model grid layers and fault geometry based on the Geologic Framework Model (GFM), the Integrated Site Model (ISM), and definition of hydrogeologic units (HGUs), (3) analyzing and extracting GFM and ISM data pertaining to layer contacts and property distributions, (4) discretizing and refining the two-dimensional (2-D), plan-view numerical grid, (5) generating the 3-D grid with finer resolution at the repository horizon and within the Calico Hills nonwelded (CHn) hydrogeologic unit, and (6) formulating the dual-permeability mesh. The

Four emerging arboviral diseases in North America: Jamestown Canyon, Powassan, chikungunya, and Zika virus diseases.

Science.gov (United States)

Pastula, Daniel M; Smith, Daniel E; Beckham, J David; Tyler, Kenneth L

2016-06-01

Arthropod-borne viruses, or arboviruses, are viruses that are transmitted through the bites of mosquitoes, ticks, or sandflies. There are numerous arboviruses throughout the world capable of causing human disease spanning different viral families and genera. Recently, Jamestown Canyon, Powassan, chikungunya, and Zika viruses have emerged as increasingly important arboviruses that can cause human disease in North America. Unfortunately, there are currently no proven disease-modifying therapies for these arboviral diseases, so treatment is largely supportive. Given there are also no commercially available vaccines for these four arboviral infections, prevention is the key. To prevent mosquito or tick bites that might result in one of these arboviral diseases, people should wear long-sleeved shirts and pants while outside if feasible, apply insect repellant when going outdoors, using window screens or air conditioning to keep mosquitoes outside, and perform tick checks after being in wooded or brushy outdoor areas.

The gut microbiota in internal medicine: implications for health and disease

NARCIS (Netherlands)

Lankelma, J. M.; Nieuwdorp, M.; de Vos, W. M.; Wiersinga, W. J.

2015-01-01

The human gut microbiota may be viewed as an organ, executing numerous functions in metabolism, development of the immune system and host defence against pathogens. It may therefore be involved in the development of a range of diseases such as gastrointestinal infections, inflammatory bowel disease,

Function and modulation of premotor brainstem parasympathetic cardiac neurons that control heart rate by hypoxia-, sleep-, and sleep-related diseases including obstructive sleep apnea.

Science.gov (United States)

Dergacheva, Olga; Weigand, Letitia A; Dyavanapalli, Jhansi; Mares, Jacquelyn; Wang, Xin; Mendelowitz, David

2014-01-01

Parasympathetic cardiac vagal neurons (CVNs) in the brainstem dominate the control of heart rate. Previous work has determined that these neurons are inherently silent, and their activity is largely determined by synaptic inputs to CVNs that include four major types of synapses that release glutamate, GABA, glycine, or serotonin. Whereas prior reviews have focused on glutamatergic, GABAergic and glycinergic pathways, and the receptors in CVNs activated by these neurotransmitters, this review focuses on the alterations in CVN activity with hypoxia-, sleep-, and sleep-related cardiovascular diseases including obstructive sleep apnea. © 2014 Elsevier B.V. All rights reserved.

Clinical Prediction Models for Cardiovascular Disease: Tufts Predictive Analytics and Comparative Effectiveness Clinical Prediction Model Database.

Science.gov (United States)

Wessler, Benjamin S; Lai Yh, Lana; Kramer, Whitney; Cangelosi, Michael; Raman, Gowri; Lutz, Jennifer S; Kent, David M

2015-07-01

Clinical prediction models (CPMs) estimate the probability of clinical outcomes and hold the potential to improve decision making and individualize care. For patients with cardiovascular disease, there are numerous CPMs available although the extent of this literature is not well described. We conducted a systematic review for articles containing CPMs for cardiovascular disease published between January 1990 and May 2012. Cardiovascular disease includes coronary heart disease, heart failure, arrhythmias, stroke, venous thromboembolism, and peripheral vascular disease. We created a novel database and characterized CPMs based on the stage of development, population under study, performance, covariates, and predicted outcomes. There are 796 models included in this database. The number of CPMs published each year is increasing steadily over time. Seven hundred seventeen (90%) are de novo CPMs, 21 (3%) are CPM recalibrations, and 58 (7%) are CPM adaptations. This database contains CPMs for 31 index conditions, including 215 CPMs for patients with coronary artery disease, 168 CPMs for population samples, and 79 models for patients with heart failure. There are 77 distinct index/outcome pairings. Of the de novo models in this database, 450 (63%) report a c-statistic and 259 (36%) report some information on calibration. There is an abundance of CPMs available for a wide assortment of cardiovascular disease conditions, with substantial redundancy in the literature. The comparative performance of these models, the consistency of effects and risk estimates across models and the actual and potential clinical impact of this body of literature is poorly understood. © 2015 American Heart Association, Inc.

Resveratrol and Ophthalmic Diseases

Science.gov (United States)

Abu-Amero, Khaled K.; Kondkar, Altaf A.; Chalam, Kakarla V.

2016-01-01

Resveratrol, a naturally occurring plant polyphenol found in grapes, is the principal biologically active component in red wine. Clinical studies have shown that resveratrol due to its potent anti-oxidant and anti-inflammatory properties are cardio-protective, chemotherapeutic, neuroprotective, and display anti-aging effects. Oxidative stress and inflammation play a critical role in the initiation and progression of age-related ocular diseases (glaucoma, cataract, diabetic retinopathy and macular degeneration) that lead to progressive loss of vision and blindness. In vitro and in vivo (animal model) experimental studies performed so far have provided evidence for the biological effects of resveratrol on numerous pathways including oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, pro-survival or angiogenesis that are implicated in the pathogenesis of these age-related ocular disorders. In this review, we provide a brief overview of current scientific literature on resveratrol, its plausible mechanism(s) of action, its potential use and current limitations as a nutritional therapeutic intervention in the eye and its related disorders. PMID:27058553

Numerical taxonomic studies of some tribes of Brassicaceae from Egypt

NARCIS (Netherlands)

Abdel Khalik, K.; Maesen, van der L.J.G.; Koopman, W.J.M.; Berg, van den R.G.

2002-01-01

A systematic study of 45 taxa belonging to 23 genera of tribes Arabideae, Euclidieae, Hesperideae, Lunarieae, Matthioleae and Sisymbrieae of Brassicaceae from Egypt was conducted by means of numerical analysis based on sixty two morphological characters, including vegetative parts, pollen grains and

Epidemiologic Study of Bacteria Zoonotic Diseases in South Dakota: 2010-2014.

Science.gov (United States)

Ludvik, Jessica L; Anderson, Susan M; Huntington, Mark K

2017-06-01

Although the burden of infectious diseases has decreased dramatically due to advances in health care, disease prevention and numerous public health efforts and innovations, zoonotic diseases continue to pose a problem in terms of both existing and emerging diseases. These risks are of particular concern in rural areas, in which there is more contact with animals for occupational and recreational purposes. As a rural and agricultural state, South Dakota has a large percentage of its population at risk of exposure to zoonotic diseases through their substantial contact time with animals. De-identified data from the South Dakota Department of Health containing the variables and diseases of interest from the time period of 2010-2014 was obtained. From this data were calculated the incidence rates by county, and seasonal and demographic patterns of the diseases were plotted. The incidence of disease in South Dakota were higher than the national rates for campylobacteriosis (threefold), cryptosporidiosis (sixfold), enterohemorrhagic E. coli (fourfold), Q fever (tenfold), salmonellosis (1.2-fold), and tularemia (14-fold). Only listeriosis had a lower incidence than the national rate among zoonoses included in this study. Seasonality of campylobacteriosis in the state was earlier in the year than is reported for the disease nationally. Zoonotic infections are a substantial threat to health in South Dakota. There is a need to develop collaboration between healthcare providers, public health professionals, livestock producers, veterinarians, and sportsmen to develop a strategy to address this issue.

Determination of adsorption parameters in numerical simulation for polymer flooding

Science.gov (United States)

Bao, Pengyu; Li, Aifen; Luo, Shuai; Dang, Xu

2018-02-01

A study on the determination of adsorption parameters for polymer flooding simulation was carried out. The study mainly includes polymer static adsorption and dynamic adsorption. The law of adsorption amount changing with polymer concentration and core permeability was presented, and the one-dimensional numerical model of CMG was established under the support of a large number of experimental data. The adsorption laws of adsorption experiments were applied to the one-dimensional numerical model to compare the influence of two adsorption laws on the historical matching results. The results show that the static adsorption and dynamic adsorption abide by different rules, and differ greatly in adsorption. If the static adsorption results were directly applied to the numerical model, the difficulty of the historical matching will increase. Therefore, dynamic adsorption tests in the porous medium are necessary before the process of parameter adjustment in order to achieve the ideal history matching result.

Development of numerical concepts

Directory of Open Access Journals (Sweden)

Sabine Peucker

2013-06-01

Full Text Available The development of numerical concepts is described from infancy to preschool age. Infants a few days old exhibit an early sensitivity for numerosities. In the course of development, nonverbal mental models allow for the exact representation of small quantities as well as changes in these quantities. Subitising, as the accurate recognition of small numerosities (without counting, plays an important role. It can be assumed that numerical concepts and procedures start with insights about small numerosities. Protoquantitative schemata comprise fundamental knowledge about quantities. One-to-one-correspondence connects elements and numbers, and, for this reason, both quantitative and numerical knowledge. If children understand that they can determine the numerosity of a collection of elements by enumerating the elements, they have acquired the concept of cardinality. Protoquantitative knowledge becomes quantitative if it can be applied to numerosities and sequential numbers. The concepts of cardinality and part-part-whole are key to numerical development. Developmentally appropriate learning and teaching should focus on cardinality and part-part-whole concepts.

Australian mineral industry annual review 1977 (including information to June 1978)

Energy Technology Data Exchange (ETDEWEB)

Ward, J

1979-01-01

This article records growth of the Australian mineral industry and reports production, consumption, treatment, trade, prices, new developments, exploration, and resources for all mineral commodities including fuels. Equivalent development abroad is summarized. Appendices include principal mineral producers, associations, etc. and royalties. Black coal is described under the headings: production, ex-mine value of output, employment, wages and salaries, production per manshift, interstate trade, port facilities, consumption, stock, prices, new developments, exploration, resources, world review, and coke. There are numerous tables of data and a flow chart of the Australian black coal industry, 1977. Brown coal includes production, consumption, new developments, exploration, resources, and world review.

Discussion on calculation of disease severity index values from scales with unequal intervals

Science.gov (United States)

When estimating severity of disease, a disease interval (or category) scale comprises a number of categories of known numeric values – with plant disease this is generally the percent area with symptoms (e.g., the Horsfall-Barratt (H-B) scale). Studies in plant pathology and plant breeding often use...

Interstitial Lung Disease in a 70-Year-Old Man with Ulcerative Colitis.

Science.gov (United States)

Collins, Hampton W; Frye, Jeanetta W

2018-01-01

Interstitial lung disease is a rare but increasingly recognized extraintestinal manifestation of inflammatory bowel disease that can have devastating consequences if left untreated. We report a case of ulcerative colitis-associated interstitial lung disease presenting with acute hypoxic respiratory failure during an ulcerative colitis flare. Gastroenterologists and pulmonologists should be aware of the numerous bronchopulmonary signs and symptoms that can suggest systemic illness in inflammatory bowel disease.

3rd International Conference on Numerical Analysis and Optimization : Theory, Methods, Applications and Technology Transfer

CERN Document Server

Grandinetti, Lucio; Purnama, Anton

2015-01-01

Presenting the latest findings in the field of numerical analysis and optimization, this volume balances pure research with practical applications of the subject. Accompanied by detailed tables, figures, and examinations of useful software tools, this volume will equip the reader to perform detailed and layered analysis of complex datasets. Many real-world complex problems can be formulated as optimization tasks. Such problems can be characterized as large scale, unconstrained, constrained, non-convex, non-differentiable, and discontinuous, and therefore require adequate computational methods, algorithms, and software tools. These same tools are often employed by researchers working in current IT hot topics such as big data, optimization and other complex numerical algorithms on the cloud, devising special techniques for supercomputing systems. The list of topics covered include, but are not limited to: numerical analysis, numerical optimization, numerical linear algebra, numerical differential equations, opt...

Direct Numerical Simulations of Rayleigh-Taylor instability

International Nuclear Information System (INIS)

Livescu, D; Wei, T; Petersen, M R

2011-01-01

The development of the Rayleigh-Taylor mixing layer is studied using data from an extensive new set of Direct Numerical Simulations (DNS), performed on the 0.5 Petaflops, 150k compute cores BG/L Dawn supercomputer at Lawrence Livermore National Laboratory. This includes a suite of simulations with grid size of 1024 2 × 4608 and Atwood number ranging from 0.04 to 0.9, in order to examine small departures from the Boussinesq approximation as well as large Atwood number effects, and a high resolution simulation of grid size 4096 2 × 4032 and Atwood number of 0.75. After the layer width had developed substantially, additional branched simulations have been run under reversed and zero gravity conditions. While the bulk of the results will be published elsewhere, here we present preliminary results on: 1) the long-standing open question regarding the discrepancy between the numerically and experimentally measured mixing layer growth rates and 2) mixing characteristics.

Numerical study of the impact of a drop containing a bubble

Science.gov (United States)

Wei, Yu; Thoraval, Marie-Jean

2017-11-01

The impact of a drop has many applications from inkjet printing to the spreading of crops diseases. This fundamental phenomenon has therefore attracted a lot of interest from different fields. However, they have mostly focused on the simplest case of a drop containing a single fluid. In inkjet printing and in the deposition process of thermal barrier coatings, some bubbles can be present in the drop when it impacts on the solid surface. The presence of the bubble can produce some additional splashing, and affect the quality of the deposited material. Only a few studies have looked at this problem, and many questions still need to be investigated. Generally, there are three possibilities when a drop containing a bubble impacts onto a solid surface, namely the bubble stays in drop, the bubble bursts and a counter jet forms. We have performed axisymmetric numerical simulations with the open source code Gerris to study this vertical jet. We have systematically varied several parameters, including the impact velocity, the bubble size, the vertical position of the bubble, and the liquid properties. We were thus able to characterize under which condition the bubble leads to splashing and the velocity of the produced jet.

[Diverticular disease of the large bowel - surgical treatment].

Science.gov (United States)

Levý, M; Herdegen, P; Sutoris, K; Simša, J

2013-07-01

Surgical treatment, despite the rapid development of the numerous modern miniinvasive intervention techniques, remains essential in the treatment of complicated diverticular disease. The aim of this work is to summarize indications for surgical treatment in both acute and elective patients suffering from diverticular disease of the large bowel. Review of the literature and recent findings concerning indications for surgical intervention in patients with diverticulosis of the colon. The article describes indications, types of procedures, techniques and postoperative care in patients undergoing surgical intervention for diverticular disease.

JDiffraction: A GPGPU-accelerated JAVA library for numerical propagation of scalar wave fields

Science.gov (United States)

Piedrahita-Quintero, Pablo; Trujillo, Carlos; Garcia-Sucerquia, Jorge

2017-05-01

JDiffraction, a GPGPU-accelerated JAVA library for numerical propagation of scalar wave fields, is presented. Angular spectrum, Fresnel transform, and Fresnel-Bluestein transform are the numerical algorithms implemented in the methods and functions of the library to compute the scalar propagation of the complex wavefield. The functionality of the library is tested with the modeling of easy to forecast numerical experiments and also with the numerical reconstruction of a digitally recorded hologram. The performance of JDiffraction is contrasted with a library written for C++, showing great competitiveness in the apparently less complex environment of JAVA language. JDiffraction also includes JAVA easy-to-use methods and functions that take advantage of the computation power of the graphic processing units to accelerate the processing times of 2048×2048 pixel images up to 74 frames per second.

Numerical study of damage evolution and failure in an electromagnetic corner fill operation

International Nuclear Information System (INIS)

Imbert, J.M.; Winkler, S.L.; Worswick, M.J.; Oliveira, D.A.; Golovashchenko, S.

2004-01-01

A numerical study of an electromagnetic corner fill operation using AA5754 aluminum alloy sheet was performed. Conical parts with side angles of 40 and 45 deg. (included angles of 100 and 90 deg.) were modeled. The numerical calculations were performed with an explicit dynamic finite element structural code, using an analytical electromagnetic pressure distribution. Damage evolution was predicted using a damage subroutine based on the Gurson-Tvergaard-Needleman constitutive model. Experiments were performed to validate the numerical results. Damage measurements were made using optical microscopy to determine the actual damage produced by the forming operations. Predicted final shape, failure and damage levels are presented and compared with experimental results. The numerical models were able to accurately predict damage trends. Failure was predicted in general agreement with the experiments

Numerical modelling of solidification of thin walled hypereutectic ductile cast iron

DEFF Research Database (Denmark)

Pedersen, Karl Martin; Hattel, Jesper; Tiedje, Niels

2006-01-01

Numerical simulation of solidification of ductile cast iron is normally based on a model where graphite nodules are surrounded by an austenite shell. The two phases are then growing as two concentric spheres governed by diffusion of carbon through the austenite shell. Experiments have however shown...... simulation of thin-walled ductile iron castings. Simulations have been performed with a 1-D numerical solidi¬fication model that includes the precipitation of non-eutectic austenite during the eutectic stage. Results from the simulations have been compared with experimental castings with wall thick...

Cognitive Strategy Use and Measured Numeric Ability in Immediate- and Long-Term Recall of Everyday Numeric Information

Science.gov (United States)

Bermingham, Douglas; Hill, Robert D.; Woltz, Dan; Gardner, Michael K.

2013-01-01

The goals of this study were to assess the primary effects of the use of cognitive strategy and a combined measure of numeric ability on recall of every-day numeric information (i.e. prices). Additionally, numeric ability was assessed as a moderator in the relationship between strategy use and memory for prices. One hundred participants memorized twelve prices that varied from 1 to 6 digits; they recalled these immediately and after 7 days. The use of strategies, assessed through self-report, was associated with better overall recall, but not forgetting. Numeric ability was not associated with either better overall recall or forgetting. A small moderating interaction was found, in which higher levels of numeric ability enhanced the beneficial effects of strategy use on overall recall. Exploratory analyses found two further small moderating interactions: simple strategy use enhanced overall recall at higher levels of numeric ability, compared to complex strategy use; and complex strategy use was associated with lower levels of forgetting, but only at higher levels of numeric ability, compared to the simple strategy use. These results provide support for an objective measure of numeric ability, as well as adding to the literature on memory and the benefits of cognitive strategy use. PMID:23483964

Testing gravitational-wave searches with numerical relativity waveforms: results from the first Numerical INJection Analysis (NINJA) project

International Nuclear Information System (INIS)

Aylott, Benjamin; Baker, John G; Camp, Jordan; Centrella, Joan; Boggs, William D; Buonanno, Alessandra; Boyle, Michael; Buchman, Luisa T; Chu, Tony; Brady, Patrick R; Brown, Duncan A; Bruegmann, Bernd; Cadonati, Laura; Campanelli, Manuela; Faber, Joshua; Chatterji, Shourov; Christensen, Nelson; Diener, Peter; Dorband, Nils; Etienne, Zachariah B

2009-01-01

The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave data analysis communities. The purpose of NINJA is to study the sensitivity of existing gravitational-wave search algorithms using numerically generated waveforms and to foster closer collaboration between the numerical relativity and data analysis communities. We describe the results of the first NINJA analysis which focused on gravitational waveforms from binary black hole coalescence. Ten numerical relativity groups contributed numerical data which were used to generate a set of gravitational-wave signals. These signals were injected into a simulated data set, designed to mimic the response of the initial LIGO and Virgo gravitational-wave detectors. Nine groups analysed this data using search and parameter-estimation pipelines. Matched filter algorithms, un-modelled-burst searches and Bayesian parameter estimation and model-selection algorithms were applied to the data. We report the efficiency of these search methods in detecting the numerical waveforms and measuring their parameters. We describe preliminary comparisons between the different search methods and suggest improvements for future NINJA analyses.

Why industry propaganda and political interference cannot disguise the inevitable role played by human exposure to aluminum in neurodegenerative diseases, including Alzheimer's disease.

Science.gov (United States)

Exley, Christopher

2014-01-01

In the aluminum age, it is clearly unpalatable for aluminum, the globe's most successful metal, to be implicated in human disease. It is unpalatable because for approximately 100 years human beings have reaped the rewards of the most abundant metal of the Earth's crust without seriously considering the potential consequences for human health. The aluminum industry is a pillar of the developed and developing world and irrespective of the tyranny of human exposure to aluminum it cannot be challenged without significant consequences for businesses, economies, and governments. However, no matter how deep the dependency or unthinkable the withdrawal, science continues to document, if not too slowly, a burgeoning body burden of aluminum in human beings. Herein, I will make the case that it is inevitable both today and in the future that an individual's exposure to aluminum is impacting upon their health and is already contributing to, if not causing, chronic diseases such as Alzheimer's disease. This is the logical, if uncomfortable, consequence of living in the aluminum age.

Numerical modeling of fires on gas pipelines

International Nuclear Information System (INIS)

Zhao Yang; Jianbo Lai; Lu Liu

2011-01-01

When natural gas is released through a hole on a high-pressure pipeline, it disperses in the atmosphere as a jet. A jet fire will occur when the leaked gas meets an ignition source. To estimate the dangerous area, the shape and size of the fire must be known. The evolution of the jet fire in air is predicted by using a finite-volume procedure to solve the flow equations. The model is three-dimensional, elliptic and calculated by using a compressibility corrected version of the k - ξ turbulence model, and also includes a probability density function/laminar flamelet model of turbulent non-premixed combustion process. Radiation heat transfer is described using an adaptive version of the discrete transfer method. The model is compared with the experiments about a horizontal jet fire in a wind tunnel in the literature with success. The influence of wind and jet velocity on the fire shape has been investigated. And a correlation based on numerical results for predicting the stoichiometric flame length is proposed. - Research highlights: → We developed a model to predict the evolution of turbulent jet diffusion flames. → Measurements of temperature distributions match well with the numerical predictions. → A correlation has been proposed to predict the stoichiometric flame length. → Buoyancy effects are higher in the numerical results. → The radiative heat loss is bigger in the experimental results.

Numerical abilities in fish: A methodological review.

Science.gov (United States)

Agrillo, Christian; Miletto Petrazzini, Maria Elena; Bisazza, Angelo

2017-08-01

The ability to utilize numerical information can be adaptive in a number of ecological contexts including foraging, mating, parental care, and anti-predator strategies. Numerical abilities of mammals and birds have been studied both in natural conditions and in controlled laboratory conditions using a variety of approaches. During the last decade this ability was also investigated in some fish species. Here we reviewed the main methods used to study this group, highlighting the strengths and weaknesses of each of the methods used. Fish have only been studied under laboratory conditions and among the methods used with other species, only two have been systematically used in fish-spontaneous choice tests and discrimination learning procedures. In the former case, the choice between two options is observed in a biologically relevant situation and the degree of preference for the larger/smaller group is taken as a measure of the capacity to discriminate the two quantities (e.g., two shoals differing in number). In discrimination learning tasks, fish are trained to select the larger or the smaller of two sets of abstract objects, typically two-dimensional geometric figures, using food or social companions as reward. Beyond methodological differences, what emerges from the literature is a substantial similarity of the numerical abilities of fish with those of other vertebrates studied. Copyright © 2017 Elsevier B.V. All rights reserved.

Health and economic benefits of reducing sugar intake in the USA, including effects via non-alcoholic fatty liver disease: a microsimulation model

Science.gov (United States)

Vreman, Rick A; Goodell, Alex J; Rodriguez, Luis A; Porco, Travis C; Lustig, Robert H; Kahn, James G

2017-01-01

Objectives Excessive consumption of added sugars in the human diet has been associated with obesity, type 2 diabetes (T2D), coronary heart disease (CHD) and other elements of the metabolic syndrome. Recent studies have shown that non-alcoholic fatty liver disease (NAFLD) is a critical pathway to metabolic syndrome. This model assesses the health and economic benefits of interventions aimed at reducing intake of added sugars. Methods Using data from US National Health Surveys and current literature, we simulated an open cohort, for the period 2015–2035. We constructed a microsimulation model with Markov chains for NAFLD (including steatosis, non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma (HCC)), body mass index, T2D and CHD. We assessed reductions in population disease prevalence, disease-attributable disability-adjusted life years (DALYs) and costs, with interventions that reduce added sugars consumption by either 20% or 50%. Findings The model estimated that a 20% reduction in added sugars intake will reduce prevalence of hepatic steatosis, NASH, cirrhosis, HCC, obesity, T2D and CHD. Incidence of T2D and CHD would be expected to decrease by 19.9 (95% CI 12.8 to 27.0) and 9.4 (95% CI 3.1 to 15.8) cases per 100 000 people after 20 years, respectively. A 20% reduction in consumption is also projected to annually avert 0.767 million (M) DALYs (95% CI 0.757M to 0.777M) and a total of US$10.3 billion (B) (95% CI 10.2B to 10.4B) in discounted direct medical costs by 2035. These effects increased proportionally when added sugars intake were reduced by 50%. Conclusions The decrease in incidence and prevalence of disease is similar to results in other models, but averted costs and DALYs were higher, mainly due to inclusion of NAFLD and CHD. The model suggests that efforts to reduce consumption of added sugars may result in significant public health and economic benefits. PMID:28775179

Self-management interventions including action plans for exacerbations versus usual care in patients with chronic obstructive pulmonary disease

NARCIS (Netherlands)

Lenferink, Anke; Brusse-Keizer, Marjolein; van der Valk, Paul D.L.P.M.; Frith, Peter A.; Zwerink, Marlies; Monninkhof, Evelyn M.; van der Palen, Job; Effing-Tijdhof, Tanja W

2017-01-01

Background: Chronic Obstructive Pulmonary Disease (COPD) self-management interventions should be structured but personalised and often multi-component, with goals of motivating, engaging and supporting the patients to positively adapt their behaviour(s) and develop skills to better manage disease.

The basic approach to age-structured population dynamics models, methods and numerics

CERN Document Server

Iannelli, Mimmo

2017-01-01

This book provides an introduction to age-structured population modeling which emphasises the connection between mathematical theory and underlying biological assumptions. Through the rigorous development of the linear theory and the nonlinear theory alongside numerics, the authors explore classical equations that describe the dynamics of certain ecological systems. Modeling aspects are discussed to show how relevant problems in the fields of demography, ecology, and epidemiology can be formulated and treated within the theory. In particular, the book presents extensions of age-structured modelling to the spread of diseases and epidemics while also addressing the issue of regularity of solutions, the asymptotic behaviour of solutions, and numerical approximation. With sections on transmission models, non-autonomous models and global dynamics, this book fills a gap in the literature on theoretical population dynamics. The Basic Approach to Age-Structured Population Dynamics will appeal to graduate students an...

Impact of intermittent fasting on health and disease processes.

Science.gov (United States)

Mattson, Mark P; Longo, Valter D; Harvie, Michelle

2017-10-01

Humans in modern societies typically consume food at least three times daily, while laboratory animals are fed ad libitum. Overconsumption of food with such eating patterns often leads to metabolic morbidities (insulin resistance, excessive accumulation of visceral fat, etc.), particularly when associated with a sedentary lifestyle. Because animals, including humans, evolved in environments where food was relatively scarce, they developed numerous adaptations that enabled them to function at a high level, both physically and cognitively, when in a food-deprived/fasted state. Intermittent fasting (IF) encompasses eating patterns in which individuals go extended time periods (e.g., 16-48h) with little or no energy intake, with intervening periods of normal food intake, on a recurring basis. We use the term periodic fasting (PF) to refer to IF with periods of fasting or fasting mimicking diets lasting from 2 to as many as 21 or more days. In laboratory rats and mice IF and PF have profound beneficial effects on many different indices of health and, importantly, can counteract disease processes and improve functional outcome in experimental models of a wide range of age-related disorders including diabetes, cardiovascular disease, cancers and neurological disorders such as Alzheimer's disease Parkinson's disease and stroke. Studies of IF (e.g., 60% energy restriction on 2days per week or every other day), PF (e.g., a 5day diet providing 750-1100kcal) and time-restricted feeding (TRF; limiting the daily period of food intake to 8h or less) in normal and overweight human subjects have demonstrated efficacy for weight loss and improvements in multiple health indicators including insulin resistance and reductions in risk factors for cardiovascular disease. The cellular and molecular mechanisms by which IF improves health and counteracts disease processes involve activation of adaptive cellular stress response signaling pathways that enhance mitochondrial health, DNA repair

Environmental influences on major waterfowl diseases

Science.gov (United States)

Friend, M.

1992-01-01

The decline of North American waterfowl resources since the 1960s is well-known to this audience and need not be detailed to establish that population numbers for several key waterfowl species are at or near their lowest levels since records have been kept. Loss of habitat is an accepted major cause for the decline of waterfowl numbers and the wildlife conservation community is responding with initiatives to prevent further loss of existing wetland acreage, restoration for degraded wetlands and creation of new wetlands. Numerous joint ventures focusing on key waterfowl habitat requirements are being developed under the North American Waterfowl Plan. The importance of habitat loss also is reflected in many of the presentations at this conference on wetland conservation, including one special session devoted solely to that topic. A basic premise of the focus on wetlands is that restoration of waterfowl populations is habitat dependent. This is a tenable thesis if other factors suppressing waterfowl numbers are dealt with and the habitat base being enhanced sustains waterfowl rather than contributes to their death. My presentation addresses disease as a factor suppressing waterfowl numbers and the relation of habitat quantity and quality with waterfowl disease.

Advanced modelling and numerical strategies in nuclear thermal-hydraulics

International Nuclear Information System (INIS)

Staedtke, H.

2001-01-01

The first part of the lecture gives a brief review of the current status of nuclear thermal hydraulics as it forms the basis of established system codes like TRAC, RELAP5, CATHARE or ATHLET. Specific emphasis is given to the capabilities and limitations of the underlying physical modelling and numerical solution strategies with regard to the description of complex transient two-phase flow and heat transfer conditions as expected to occur in PWR reactors during off-normal and accident conditions. The second part of the lecture focuses on new challenges and future needs in nuclear thermal-hydraulics which might arise with regard to re-licensing of old plants using bestestimate methodologies or the design and safety analysis of Advanced Light Water Reactors relying largely on passive safety systems. In order to meet these new requirements various advanced modelling and numerical techniques will be discussed including extended wellposed (hyperbolic) two-fluid models, explicit modelling of interfacial area transport or higher order numerical schemes allowing a high resolution of local multi-dimensional flow processes.(author)

Hybrid numerical calculation method for bend waveguides

OpenAIRE

Garnier , Lucas; Saavedra , C.; Castro-Beltran , Rigoberto; Lucio , José Luis; Bêche , Bruno

2017-01-01

National audience; The knowledge of how the light will behave in a waveguide with a radius of curvature becomes more and more important because of the development of integrated photonics, which include ring micro-resonators, phasars, and other devices with a radius of curvature. This work presents a numerical calculation method to determine the eigenvalues and eigenvectors of curved waveguides. This method is a hybrid method which uses at first conform transformation of the complex plane gene...

Refsum Disease

Science.gov (United States)

... night blindness due to degeneration of the retina (retinitis pigmentosa). If the disease progresses, other symptoms may include ... night blindness due to degeneration of the retina (retinitis pigmentosa). If the disease progresses, other symptoms may include ...

Pre-Ebola virus disease laboratory system and related challenges in Liberia

Directory of Open Access Journals (Sweden)

Stephen B. Kennedy

2016-10-01

Full Text Available Prior to the Ebola virus disease outbreak in Liberia, the laboratory system was duplicativefragmented and minimally coordinated. The National Reference Laboratory was conceptualisedto address the existing challenges by promoting the implementation of effective and sustainablelaboratory services in Liberia. However, in a resource-limited environment such as Liberiaprogress regarding the rebuilding of the health system can be relatively slow, while efforts tosustain the transient gains remain a key challenge for the Ministry of Health. In this paper, wedescribe the pre-Ebola virus disease laboratory system in Liberia and its prevailing efforts toaddress future emerging infectious diseases, as well as current Infectious diseases, all of whichare exacerbated by poverty. We conclude that laboratory and diagnostic services in Liberiahave encountered numerous challenges regarding its efforts to strengthen the healthcaredelivery system. These challenges include limited trained human resource capacity, inadequateinfrastructure, and a lack of coordination. As with most countries in sub-Saharan Africa, whencomparing urban and rural settings, diagnostic and clinical services are generally skewedtoward urban health facilities and private, faith-based health facilities. We recommend thatstructured policy be directed at these challenges for national institutions to develop guidelinesto improve, strengthen and sustain diagnostic and curative laboratory services to effectivelyaddress current infectious diseases and prepare for future emerging and re-emerging infectiousdiseases.

Therapies in Parkinson's disease.

Science.gov (United States)

Jankovic, Joseph; Poewe, Werner

2012-08-01

This review examines currently available therapeutic strategies for Parkinson's disease, emphasizing evidence-based data as well as a patient-centered approach to the treatment of motor and nonmotor symptoms. Although clinical trials of disease-modifying approaches have been thus far disappointing, steady advances are being made in the symptomatic treatment of Parkinson's disease. In this review, we focus on recent studies with monoamine oxidase type B inhibitors (selegiline and rasagiline), coenzyme Q10, creatine, and exercise in early Parkinson's disease. We also discuss the relative merits and disadvantages of delaying the initiation of levodopa therapy, the role of dopamine agonists, particularly ropinirole and pramipexole, and management of motor and behavioral complications, such as fluctuations, dyskinesias and impulse-control disorders. Novel formulations and delivery approaches for conventional and new drugs are also discussed. Finally, we review recent studies of surgical treatments of Parkinson's disease, such as deep brain stimulation. Numerous clinical trials have provided evidence that health-related quality of life can be substantially improved with early diagnosis and institution of exercise and other physical measures, appropriate timing of dopaminergic therapy, and strategies to delay and treat levodopa-related motor complications and nonmotor Parkinson's disease-related symptoms.

Zdeněk Kopal: Numerical Analyst

Science.gov (United States)

Křížek, M.

2015-07-01

We give a brief overview of Zdeněk Kopal's life, his activities in the Czech Astronomical Society, his collaboration with Vladimír Vand, and his studies at Charles University, Cambridge, Harvard, and MIT. Then we survey Kopal's professional life. He published 26 monographs and 20 conference proceedings. We will concentrate on Kopal's extensive monograph Numerical Analysis (1955, 1961) that is widely accepted to be the first comprehensive textbook on numerical methods. It describes, for instance, methods for polynomial interpolation, numerical differentiation and integration, numerical solution of ordinary differential equations with initial or boundary conditions, and numerical solution of integral and integro-differential equations. Special emphasis will be laid on error analysis. Kopal himself applied numerical methods to celestial mechanics, in particular to the N-body problem. He also used Fourier analysis to investigate light curves of close binaries to discover their properties. This is, in fact, a problem from mathematical analysis.

On numerical considerations for modeling reactive astrophysical shocks

International Nuclear Information System (INIS)

Papatheodore, Thomas L.; Messer, O. E. Bronson

2014-01-01

Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds and associated quantities is to prohibit burning inside the numerically broadened shock. We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in models of Type Ia supernovae, including potential impacts on observables.

Analytical and numerical modelling of thermoviscous shocks in their interactions in nonlinear fluids including dissipation

DEFF Research Database (Denmark)

Rasmussen, Anders Rønne; Sørensen, Mads Peter; Gaididei, Yuri Borisovich

2010-01-01

A wave equation, that governs finite amplitude acoustic disturbances in a thermoviscous Newtonian fluid, and includes nonlinear terms up to second order, is proposed. The equation preserves the Hamiltonian structure of the fundamental fluid dynamical equations in the non dissipative limit. An exact...... thermoviscous shock solution is derived. This solution is, in an overall sense, equivalent to the Taylor shock solution of the Burgers equation. However, in contrast to the Burgers equation, the model equation considered here is capable to describe waves propagating in opposite directions. Studies of head...

Numerical method for two phase flow with a unstable interface

International Nuclear Information System (INIS)

Glimm, J.; Marchesin, D.; McBryan, O.

1981-01-01

The random choice method is used to compute the oil-water interface for two dimensional porous media equations. The equations used are a pair of coupled equations; the (elliptic) pressure equation and the (hyperbolic) saturation equation. The equations do not include the dispersive capillary pressure term and the computation does not introduce numerical diffusion. The method resolves saturation discontinuities sharply. The main conclusion of this paper is that the random choice is a correct numerical procedure for this problem even in the highly fingered case. Two methods of inducing fingers are considered: deterministically, through choice of Cauchy data and heterogeneity, through maximizing the randomness of the random choice method

Numerical Experiments Providing New Insights into Plasma Focus Fusion Devices

Directory of Open Access Journals (Sweden)

Sing Lee

2010-04-01

Full Text Available Recent extensive and systematic numerical experiments have uncovered new insights into plasma focus fusion devices including the following: (1 a plasma current limitation effect, as device static inductance is reduced towards very small values; (2 scaling laws of neutron yield and soft x-ray yield as functions of storage energies and currents; (3 a global scaling law for neutron yield as a function of storage energy combining experimental and numerical data showing that scaling deterioration has probably been interpreted as neutron ‘saturation’; and (4 a fundamental cause of neutron ‘saturation’. The ground-breaking insights thus gained may completely change the directions of plasma focus fusion research.

A review on functional and structural brain connectivity in numerical cognition

Directory of Open Access Journals (Sweden)

Korbinian eMoeller

2015-05-01

Full Text Available Only recently has the complex anatomo-functional system underlying numerical cognition become accessible to evaluation in the living brain. We identified 26 studies investigating brain connectivity in numerical cognition. Despite considerable heterogeneity regarding methodological approaches, populations investigated, and assessment procedures implemented, the results provided largely converging evidence regarding the underlying brain connectivity involved in numerical cognition. Analyses of both functional/effective as well as structural connectivity have consistently corroborated the assumption that numerical cognition is subserved by a fronto-parietal network including (intraparietal as well as (prefrontal cortex sites. Evaluation of structural connectivity has indicated the involvement of fronto-parietal association fibers encompassing the superior longitudinal fasciculus dorsally and the external capsule/extreme capsule system ventrally. Additionally, commissural fibers seem to connect the bilateral intraparietal sulci when number magnitude information is processed. Finally, the identification of projection fibers such as the superior corona radiata indicates connections between cortex and basal ganglia as well as the thalamus in numerical cognition. Studies on functional/effective connectivity further indicated a specific role of the hippocampus. These specifications of brain connectivity augment the triple-code model of number processing and calculation with respect to how grey matter areas associated with specific number-related representations may work together.

Advances in vaccine research against economically important viral diseases of food animals: Infectious bursal disease virus.

Science.gov (United States)

Jackwood, Daral J

2017-07-01

Numerous reviews have been published on infectious bursal disease (IBD) and infectious bursal disease virus (IBDV). Many high quality vaccines are commercially available for the control of IBD that, when used correctly, provide solid protection against infection and disease caused by IBDV. Viruses are not static however; they continue to evolve and vaccines need to keep pace with them. The evolution of IBDV has resulted in very virulent strains and new antigenic types of the virus. This review will discuss some of the limitations associated with existing vaccines, potential solutions to these problems and advances in new vaccines for the control of IBD. Copyright © 2016 Elsevier B.V. All rights reserved.

Towards numerical simulations of supersonic liquid jets using ghost fluid method

International Nuclear Information System (INIS)

Majidi, Sahand; Afshari, Asghar

2015-01-01

Highlights: • A ghost fluid method based solver is developed for numerical simulation of compressible multiphase flows. • The performance of the numerical tool is validated via several benchmark problems. • Emergence of supersonic liquid jets in quiescent gaseous environment is simulated using ghost fluid method for the first time. • Bow-shock formation ahead of the liquid jet is clearly observed in the obtained numerical results. • Radiation of mach waves from the phase-interface witnessed experimentally is evidently captured in our numerical simulations. - Abstract: A computational tool based on the ghost fluid method (GFM) is developed to study supersonic liquid jets involving strong shocks and contact discontinuities with high density ratios. The solver utilizes constrained reinitialization method and is capable of switching between the exact and approximate Riemann solvers to increase the robustness. The numerical methodology is validated through several benchmark test problems; these include one-dimensional multiphase shock tube problem, shock–bubble interaction, air cavity collapse in water, and underwater-explosion. A comparison between our results and numerical and experimental observations indicate that the developed solver performs well investigating these problems. The code is then used to simulate the emergence of a supersonic liquid jet into a quiescent gaseous medium, which is the very first time to be studied by a ghost fluid method. The results of simulations are in good agreement with the experimental investigations. Also some of the famous flow characteristics, like the propagation of pressure-waves from the liquid jet interface and dependence of the Mach cone structure on the inlet Mach number, are reproduced numerically. The numerical simulations conducted here suggest that the ghost fluid method is an affordable and reliable scheme to study complicated interfacial evolutions in complex multiphase systems such as supersonic liquid

A nonlocal spatial model for Lyme disease

Science.gov (United States)

Yu, Xiao; Zhao, Xiao-Qiang

2016-07-01

This paper is devoted to the study of a nonlocal and time-delayed reaction-diffusion model for Lyme disease with a spatially heterogeneous structure. In the case of a bounded domain, we first prove the existence of the positive steady state and a threshold type result for the disease-free system, and then establish the global dynamics for the model system in terms of the basic reproduction number. In the case of an unbound domain, we obtain the existence of the disease spreading speed and its coincidence with the minimal wave speed. At last, we use numerical simulations to verify our analytic results and investigate the influence of model parameters and spatial heterogeneity on the disease infection risk.

A mutually profitable alliance - Asymptotic expansions and numerical computations

Science.gov (United States)

Euvrard, D.

Problems including the flow past a wing airfoil at Mach 1, and the two-dimensional flow past a partially immersed body are used to show the advantages of coupling a standard numerical method for the whole domain where everything is of the order of 1, with an appropriate asymptotic expansion in the vicinity of some singular point. Cases more closely linking the two approaches are then considered. In the localized finite element method, the asymptotic expansion at infinity becomes a convergent series and the problem reduces to a variational form. Combined analytical and numerical methods are used in the singularity distribution method and in the various couplings of finite elements and a Green integral representation to design a subroutine to compute the Green function and its derivatives.

Numerical Simulation of Nanofluid Suspensions in a Geothermal Heat Exchanger

Directory of Open Access Journals (Sweden)

Xiao-Hui Sun

2018-04-01

Full Text Available It has been shown that using nanofluids as heat carrier fluids enhances the conductive and convective heat transfer of geothermal heat exchangers. In this paper, we study the stability of nanofluids in a geothermal exchanger by numerically simulating nanoparticle sedimentation during a shut-down process. The nanofluid suspension is modeled as a non-linear complex fluid; the nanoparticle migration is modeled by a particle flux model, which includes the effects of Brownian motion, gravity, turbulent eddy diffusivity, etc. The numerical results indicate that when the fluid is static, the nanoparticle accumulation appears to be near the bottom borehole after many hours of sedimentation. The accumulated particles can be removed by the fluid flow at a relatively high velocity. These observations indicate good suspension stability of the nanofluids, ensuring the operational reliability of the heat exchanger. The numerical results also indicate that a pulsed flow and optimized geometry of the bottom borehole can potentially improve the suspension stability of the nanofluids further.

Industrial numerical analysis

International Nuclear Information System (INIS)

McKee, S.; Elliott, C.M.

1986-01-01

The applications of mathematics to industrial problems involves the formulation of problems which are amenable to mathematical investigation, mathematical modelling, the solution of the mathematical problem and the inter-pretation of the results. There are 12 chapters describing industrial problems where mathematics and numerical analysis can be applied. These range from the numerical assessment of the flatness of engineering surfaces and plates, the design of chain links, control problems in tidal power generation and low thrust satellite trajectory optimization to mathematical models in welding. One chapter, on the ageing of stainless steels, is indexed separately. (UK)

Leveraging electronic health records to support chronic disease management: the need for temporal data views.

Science.gov (United States)

Samal, Lipika; Wright, Adam; Wong, Bang T; Linder, Jeffrey A; Bates, David W

2011-01-01

The ageing population worldwide is increasingly acquiring multiple chronic diseases. The complex management of chronic diseases could be improved with electronic health records (EHRs) tailored to chronic disease care, but most EHRs in use today do not adequately support longitudinal data management. A key aspect of chronic disease management is that it takes place over long periods, but the way that most EHRs display longitudinal data makes it difficult to trend changes over time and slows providers as they review each patient's unique course. We present five clinical scenarios illustrating longitudinal data needs in complex chronic disease management. These scenarios may function as example cases for software development. For each scenario, we describe and illustrate improvements in temporal data views. Two potential solutions are visualisation for numerical data and disease-oriented text summaries for non-numerical data. We believe that development and widespread implementation of improved temporal data views in EHRs will improve the efficiency and quality of chronic disease management in primary care.

Impact of delay on disease outbreak in a spatial epidemic model

Science.gov (United States)

Zhao, Xia-Xia; Wang, Jian-Zhong

2015-04-01

One of the central issues in studying epidemic spreading is the mechanism on disease outbreak. In this paper, we investigate the effects of time delay on disease outbreak in spatial epidemics based on a reaction-diffusion model. By mathematical analysis and numerical simulations, we show that when time delay is more than a critical value, the disease outbreaks. The obtained results show that the time delay is an important factor in the spread of the disease, which may provide new insights on disease control.

Developing Teaching Material Software Assisted for Numerical Methods

Science.gov (United States)

Handayani, A. D.; Herman, T.; Fatimah, S.

2017-09-01

The NCTM vision shows the importance of two things in school mathematics, which is knowing the mathematics of the 21st century and the need to continue to improve mathematics education to answer the challenges of a changing world. One of the competencies associated with the great challenges of the 21st century is the use of help and tools (including IT), such as: knowing the existence of various tools for mathematical activity. One of the significant challenges in mathematical learning is how to teach students about abstract concepts. In this case, technology in the form of mathematics learning software can be used more widely to embed the abstract concept in mathematics. In mathematics learning, the use of mathematical software can make high level math activity become easier accepted by student. Technology can strengthen student learning by delivering numerical, graphic, and symbolic content without spending the time to calculate complex computing problems manually. The purpose of this research is to design and develop teaching materials software assisted for numerical method. The process of developing the teaching material starts from the defining step, the process of designing the learning material developed based on information obtained from the step of early analysis, learners, materials, tasks that support then done the design step or design, then the last step is the development step. The development of teaching materials software assisted for numerical methods is valid in content. While validator assessment for teaching material in numerical methods is good and can be used with little revision.

Numerical analysis of bifurcations

International Nuclear Information System (INIS)

Guckenheimer, J.

1996-01-01

This paper is a brief survey of numerical methods for computing bifurcations of generic families of dynamical systems. Emphasis is placed upon algorithms that reflect the structure of the underlying mathematical theory while retaining numerical efficiency. Significant improvements in the computational analysis of dynamical systems are to be expected from more reliance of geometric insight coming from dynamical systems theory. copyright 1996 American Institute of Physics

QUARTZ: a numerical simulation of an asymmetric electrostatic accelerator

International Nuclear Information System (INIS)

Wooten, J.W.; Drooks, L.J.; McCollough, D.H.; McGaffey, R.W.; Whealton, J.H.

1979-01-01

The physics and numerical aspects of the development of the computer code QUARTZ are given. This code includes the (1) use of a finite element code to obtain solutions of Poisson's equation in an asymmetric, three-dimensional volume; (2) inclusion of space charge neutralization by electrons; and (3) inclusion of ion space charge through an iterative procedure

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

Energy Technology Data Exchange (ETDEWEB)

Yanallah, K; Castellanos, A [Departamento de Electronica y Electromagnetismo, Universidad de Sevilla (Spain); Pontiga, F; Fernandez-Rueda, A [Departamento de FIsica Aplicada II, Universidad de Sevilla (Spain)

2009-03-21

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

International Nuclear Information System (INIS)

Yanallah, K; Castellanos, A; Pontiga, F; Fernandez-Rueda, A

2009-01-01

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

Experimental investigation and numerical modelling of positive corona discharge: ozone generation

Science.gov (United States)

Yanallah, K; Pontiga, F; Fernández-Rueda, A; Castellanos, A

2009-03-01

The spatial distribution of the species generated in a wire-cylinder positive corona discharge in pure oxygen has been computed using a plasma chemistry model that includes the most significant reactions between electrons, ions, atoms and molecules. The plasma chemistry model is included in the continuity equations of each species, which are coupled with Poisson's equation for the electric field and the energy conservation equation for the gas temperature. The current-voltage characteristic measured in the experiments has been used as an input data to the numerical simulation. The numerical model is able to reproduce the basic structure of the positive corona discharge and highlights the importance of Joule heating on ozone generation. The average ozone density has been computed as a function of current intensity and compared with the experimental measurements of ozone concentration determined by UV absorption spectroscopy.

XVI 'Jacques-Louis Lions' Spanish-French School on Numerical Simulation in Physics and Engineering

CERN Document Server

Roldán, Teo; Torrens, Juan

2016-01-01

This book presents lecture notes from the XVI ‘Jacques-Louis Lions’ Spanish-French School on Numerical Simulation in Physics and Engineering, held in Pamplona (Navarra, Spain) in September 2014. The subjects covered include: numerical analysis of isogeometric methods, convolution quadrature for wave simulations, mathematical methods in image processing and computer vision, modeling and optimization techniques in food processes, bio-processes and bio-systems, and GPU computing for numerical simulation. The book is highly recommended to graduate students in Engineering or Science who want to focus on numerical simulation, either as a research topic or in the field of industrial applications. It can also benefit senior researchers and technicians working in industry who are interested in the use of state-of-the-art numerical techniques in the fields addressed here. Moreover, the book can be used as a textbook for master courses in Mathematics, Physics, or Engineering.

Diet-induced obesity, gut microbiota and bone, including alveolar bone loss.

Science.gov (United States)

Eaimworawuthikul, Sathima; Thiennimitr, Parameth; Chattipakorn, Nipon; Chattipakorn, Siriporn C

2017-06-01

Obesity is a major risk factor for several pathologies, including jaw bone resorption. The underlying mechanisms involved in pathological conditions resulting from obesity include chronic systemic inflammation and the development of insulin resistance. Although numerous studies have indicated the importance of the role of gut microbiota in the pathogenesis of inflammation and insulin resistance in obesity, only a few studies have established a relationship between obesity, gut microbiota and status of the jaw bone. This review aims to summarize current findings relating to these issues, focusing on the role of obesity and gut microbiota on jaw bone health, including possible mechanisms which can explain this link. Copyright © 2017 Elsevier Ltd. All rights reserved.

Computing the Alexander Polynomial Numerically

DEFF Research Database (Denmark)

Hansen, Mikael Sonne

2006-01-01

Explains how to construct the Alexander Matrix and how this can be used to compute the Alexander polynomial numerically.......Explains how to construct the Alexander Matrix and how this can be used to compute the Alexander polynomial numerically....

Periodontal disease and anemias associated with Crohn's disease. A case report.

Science.gov (United States)

Nagpal, Swati; Acharya, Anirudh B; Thakur, Srinath L

2012-03-01

Crohn's disease (CD) is an inflammatory bowel disease with oral findings, including periodontal manifestations. Anemias, such as iron deficiency and anemia of chronic disease (ACD), are the most common hematologic complications of CD. Periodontitis has systemic effects, and may tend toward anemia, which can be explained by depressed erythropoiesis. In the report presented here, the authors review a case of Crohn's disease diagnosed 10 years previous to the patient presenting with a changing anemic profile and periodontal disease. A discussion of patient and disease management is included.

Energy utilization of induced pluripotent stem cell-derived cardiomyocyte in Fabry disease.

Science.gov (United States)

Chou, Shih-Jie; Yu, Wen-Chung; Chang, Yuh-Lih; Chen, Wen-Yeh; Chang, Wei-Chao; Chien, Yueh; Yen, Jiin-Cherng; Liu, Yung-Yang; Chen, Shih-Jen; Wang, Chien-Ying; Chen, Yu-Han; Niu, Dau-Ming; Lin, Shing-Jong; Chen, Jaw-Wen; Chiou, Shih-Hwa; Leu, Hsin-Bang

2017-04-01

Fabry disease (FD) is a lysosomal storage disease in which glycosphingolipids (GB3) accumulate in organs of the human body, leading to idiopathic hypertrophic cardiomyopathy and target organ damage. Its pathophysiology is still poorly understood. We aimed to generate patient-specific induced pluripotent stem cells (iPSC) from FD patients presenting cardiomyopathy to determine whether the model could recapitulate key features of the disease phenotype and to investigate the energy metabolism in Fabry disease. Peripheral blood mononuclear cells from a 30-year-old Chinese man with a diagnosis of Fabry disease, GLA gene (IVS4+919G>A) mutation were reprogrammed into iPSCs and differentiated into iPSC-CMs and energy metabolism was analyzed in iPSC-CMs. The FD-iPSC-CMs recapitulated numerous aspects of the FD phenotype including reduced GLA activity, cellular hypertrophy, GB3 accumulation and impaired contractility. Decreased energy metabolism with energy utilization shift to glycolysis was observed, but the decreased energy metabolism was not modified by enzyme rescue replacement (ERT) in FD-iPSCs-CMs. This model provided a promising in vitro model for the investigation of the underlying disease mechanism and development of novel therapeutic strategies for FD. This potential remedy for enhancing the energetic network and utility efficiency warrants further study to identify novel therapies for the disease. Copyright © 2017 Elsevier B.V. All rights reserved.

Paediatric Crohn's disease: a radiological review

International Nuclear Information System (INIS)

Ali, S.I.; Carty, H.M.L.

2000-01-01

Paediatric Crohn's disease can be a serious and complex condition which is not always easy to diagnose if it presents in an atypical manner. Although the pathological processes are the same in adults and children, the clinical presentation and disease distribution can be different in children. The impact of the disease can also be much more significant in a growing and developing child than in an adult. Numerous investigations are available to establish the diagnosis, define the complications and to demonstrate the extra-intestinal manifestations. Close co-operation is required between the clinician and radiologist when investigating a child suspected of having Crohn's disease or its symptoms to minimise the radiation dose and the psychological and physical trauma. We review the clinical and radiological aspects of Crohn's disease and discuss the imaging modalities available in diagnosing Crohn's disease and its complications and suggest an investigation pathway as used in our institution. (orig.)

Numerical Verification Of Equilibrium Chemistry

International Nuclear Information System (INIS)

Piro, Markus; Lewis, Brent; Thompson, William T.; Simunovic, Srdjan; Besmann, Theodore M.

2010-01-01

A numerical tool is in an advanced state of development to compute the equilibrium compositions of phases and their proportions in multi-component systems of importance to the nuclear industry. The resulting software is being conceived for direct integration into large multi-physics fuel performance codes, particularly for providing boundary conditions in heat and mass transport modules. However, any numerical errors produced in equilibrium chemistry computations will be propagated in subsequent heat and mass transport calculations, thus falsely predicting nuclear fuel behaviour. The necessity for a reliable method to numerically verify chemical equilibrium computations is emphasized by the requirement to handle the very large number of elements necessary to capture the entire fission product inventory. A simple, reliable and comprehensive numerical verification method is presented which can be invoked by any equilibrium chemistry solver for quality assurance purposes.

BCJ numerators from reduced Pfaffian

Energy Technology Data Exchange (ETDEWEB)

Du, Yi-Jian [Center for Theoretical Physics, School of Physics and Technology, Wuhan University,No. 299 Bayi Road, Wuhan 430072 (China); Teng, Fei [Department of Physics and Astronomy, University of Utah,115 South 1400 East, Salt Lake City, UT 84112 (United States)

2017-04-07

By expanding the reduced Pfaffian in the tree level Cachazo-He-Yuan (CHY) integrands for Yang-Mills (YM) and nonlinear sigma model (NLSM), we can get the Bern-Carrasco-Johansson (BCJ) numerators in Del Duca-Dixon-Maltoni (DDM) form for arbitrary number of particles in any spacetime dimensions. In this work, we give a set of very straightforward graphic rules based on spanning trees for a direct evaluation of the BCJ numerators for YM and NLSM. Such rules can be derived from the Laplace expansion of the corresponding reduced Pfaffian. For YM, the each one of the (n−2)! DDM form BCJ numerators contains exactly (n−1)! terms, corresponding to the increasing trees with respect to the color order. For NLSM, the number of nonzero numerators is at most (n−2)!−(n−3)!, less than those of several previous constructions.

Wilson’s Disease

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Figen Hanağası

2013-12-01

Full Text Available Wilson’s disease is a autosomal recessive disorder of copper metabolism. Clinical phenotypes include hepatic, haemolytic, neurologic and psychiatric diseases. Wilson’s disease is caused by mutations in the ATP7B gene. ATP7B encodes a hepatic copper-transporting protein, which is important for copper excretion into bile. Neurological symptoms in Wilson’s disease include variable combinations of dysathria, ataxia, parkinsonism, dystonia and tremor. Wilson’s disease is lethal if untreated. This review discusses the epidemiology, genetics, clinical features, etiopathophysiology, diagnostic tests, and treatment of Wilson’s disease

EDTA chelation therapy for cardiovascular disease: a systematic review

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Wu Ping

2005-11-01

Full Text Available Abstract Background Numerous practitioners of both conventional and complementary and alternative medicine throughout North America and Europe claim that chelation therapy with EDTA is an effective means to both control and treat cardiovascular disease. These claims are controversial, and several randomized controlled trials have been completed dealing with this topic. To address this issue we conducted a systematic review to evaluate the best available evidence for the use of EDTA chelation therapy in the treatment of cardiovascular disease. Methods We conducted a systematic review of 7 databases from inception to May 2005. Hand searches were conducted in review articles and in any of the trials found. Experts in the field were contacted and registries of clinical trials were searched for unpublished data. To be included in the final systematic review, the studies had to be randomized controlled clinical trials. Results A total of seven articles were found assessing EDTA chelation for the treatment of cardiovascular disease. Two of these articles were subgroup analyses of one RCT that looked at different clinical outcomes. Of the remaining five studies, two smaller studies found a beneficial effect whereas the other three exhibited no benefit for cardiovascular disease from the use of EDTA chelation therapy. Adverse effects were rare but those of note included a few cases of hypocalcemia and a single case of increased creatinine in a patient on the EDTA intervention. Conclusion The best available evidence does not support the therapeutic use of EDTA chelation therapy in the treatment of cardiovascular disease. Although not considered to be a highly invasive or harmful therapy, it is possible that the use of EDTA chelation therapy in lieu of proven therapy may result in causing indirect harm to the patient.

Numerical linear algebra theory and applications

CERN Document Server

Beilina, Larisa; Karchevskii, Mikhail

2017-01-01

This book combines a solid theoretical background in linear algebra with practical algorithms for numerical solution of linear algebra problems. Developed from a number of courses taught repeatedly by the authors, the material covers topics like matrix algebra, theory for linear systems of equations, spectral theory, vector and matrix norms combined with main direct and iterative numerical methods, least squares problems, and eigen problems. Numerical algorithms illustrated by computer programs written in MATLAB® are also provided as supplementary material on SpringerLink to give the reader a better understanding of professional numerical software for the solution of real-life problems. Perfect for a one- or two-semester course on numerical linear algebra, matrix computation, and large sparse matrices, this text will interest students at the advanced undergraduate or graduate level.

Numerical linear algebra with applications using Matlab

CERN Document Server

Ford, William

2014-01-01

Designed for those who want to gain a practical knowledge of modern computational techniques for the numerical solution of linear algebra problems, Numerical Linear Algebra with Applications contains all the material necessary for a first year graduate or advanced undergraduate course on numerical linear algebra with numerous applications to engineering and science. With a unified presentation of computation, basic algorithm analysis, and numerical methods to compute solutions, this book is ideal for solving real-world problems. It provides necessary mathematical background information for

Finite element modeling of contaminant transport in soils including the effect of chemical reactions.

Science.gov (United States)

Javadi, A A; Al-Najjar, M M

2007-05-17

The movement of chemicals through soils to the groundwater is a major cause of degradation of water resources. In many cases, serious human and stock health implications are associated with this form of pollution. Recent studies have shown that the current models and methods are not able to adequately describe the leaching of nutrients through soils, often underestimating the risk of groundwater contamination by surface-applied chemicals, and overestimating the concentration of resident solutes. Furthermore, the effect of chemical reactions on the fate and transport of contaminants is not included in many of the existing numerical models for contaminant transport. In this paper a numerical model is presented for simulation of the flow of water and air and contaminant transport through unsaturated soils with the main focus being on the effects of chemical reactions. The governing equations of miscible contaminant transport including advection, dispersion-diffusion and adsorption effects together with the effect of chemical reactions are presented. The mathematical framework and the numerical implementation of the model are described in detail. The model is validated by application to a number of test cases from the literature and is then applied to the simulation of a physical model test involving transport of contaminants in a block of soil with particular reference to the effects of chemical reactions. Comparison of the results of the numerical model with the experimental results shows that the model is capable of predicting the effects of chemical reactions with very high accuracy. The importance of consideration of the effects of chemical reactions is highlighted.

Numerical treatment of elliptic BVP with several solutions and of MHD equilibrium problems

International Nuclear Information System (INIS)

Meyer-Spasche, R.

1975-12-01

It is found out empirically that Newton iteration and difference methods are very suitable for the numerical treatment of elliptic boundary value problems (Lu)(x) = f(x,u(x)) in D c R 2 , u/deltaD = g having several solutions. Some convergence theorems for these methods are presented. Some notable numerical examples are given, including bifurcation diagrams, which are interesting in themselves and show also the applicability of the methods developed. (orig./WB) [de

SENR /NRPy + : Numerical relativity in singular curvilinear coordinate systems

Science.gov (United States)

Ruchlin, Ian; Etienne, Zachariah B.; Baumgarte, Thomas W.

2018-03-01

We report on a new open-source, user-friendly numerical relativity code package called SENR /NRPy + . Our code extends previous implementations of the BSSN reference-metric formulation to a much broader class of curvilinear coordinate systems, making it ideally suited to modeling physical configurations with approximate or exact symmetries. In the context of modeling black hole dynamics, it is orders of magnitude more efficient than other widely used open-source numerical relativity codes. NRPy + provides a Python-based interface in which equations are written in natural tensorial form and output at arbitrary finite difference order as highly efficient C code, putting complex tensorial equations at the scientist's fingertips without the need for an expensive software license. SENR provides the algorithmic framework that combines the C codes generated by NRPy + into a functioning numerical relativity code. We validate against two other established, state-of-the-art codes, and achieve excellent agreement. For the first time—in the context of moving puncture black hole evolutions—we demonstrate nearly exponential convergence of constraint violation and gravitational waveform errors to zero as the order of spatial finite difference derivatives is increased, while fixing the numerical grids at moderate resolution in a singular coordinate system. Such behavior outside the horizons is remarkable, as numerical errors do not converge to zero near punctures, and all points along the polar axis are coordinate singularities. The formulation addresses such coordinate singularities via cell-centered grids and a simple change of basis that analytically regularizes tensor components with respect to the coordinates. Future plans include extending this formulation to allow dynamical coordinate grids and bispherical-like distribution of points to efficiently capture orbiting compact binary dynamics.

VSNL1 Co-expression networks in aging include calcium signaling, synaptic plasticity, and Alzheimer’s disease pathways

Directory of Open Access Journals (Sweden)

C W Lin

2015-03-01

Full Text Available The Visinin-like 1 (VSNL1 gene encodes Visinin-like protein 1, a peripheral biomarker for Alzheimer disease (AD. Little is known, however, about normal VSNL1 expression in brain and the biologic networks in which it participates. Frontal cortex gray matter from 209 subjects without neurodegenerative or psychiatric illness, ranging in age from 16–91, were processed on Affymetrix GeneChip 1.1 ST and Human SNP Array 6.0. VSNL1 expression was unaffected by age and sex, and not significantly associated with SNPs in cis or trans. VSNL1 was significantly co-expressed with genes in pathways for Calcium Signaling, AD, Long Term Potentiation, Long Term Depression, and Trafficking of AMPA Receptors. The association with AD was driven, in part, by correlation with amyloid precursor protein (APP expression. These findings provide an unbiased link between VSNL1 and molecular mechanisms of AD, including pathways implicated in synaptic pathology in AD. Whether APP may drive increased VSNL1 expression, VSNL1 drives increased APP expression, or both are downstream of common pathogenic regulators will need to be evaluated in model systems.

The Infectious Diseases Society of America emerging infections network: bridging the gap between clinical infectious diseases and public health.

Science.gov (United States)

Pillai, Satish K; Beekmann, Susan E; Santibanez, Scott; Polgreen, Philip M

2014-04-01

In 1995, the Centers for Disease Control and Prevention granted a Cooperative Agreement Program award to the Infectious Diseases Society of America to develop a provider-based emerging infections sentinel network, the Emerging Infections Network (EIN). Over the past 17 years, the EIN has evolved into a flexible, nationwide network with membership representing a broad cross-section of infectious disease physicians. The EIN has an active electronic mail conference (listserv) that facilitates communication among infectious disease providers and the public health community, and also sends members periodic queries (short surveys on infectious disease topics) that have addressed numerous topics relevant to both clinical infectious diseases and public health practice. The article reviews how the various functions of EIN contribute to clinical care and public health, identifies opportunities to further link clinical medicine and public health, and describes future directions for the EIN.

Phytoplasma and phytoplasma diseases: a review of recent research

Directory of Open Access Journals (Sweden)

A. Bertaccini

2010-01-01

Full Text Available Numerous yellows-type diseases of plants have been associated with wall-less prokaryote pathogens – phytoplasma over the last 40 years. These pathogens cannot be grown in axenic culture so that advances in their study are mainly achieved by molecular techniques. Severe disease epidemics associated with a phytoplasma presence have been described worldwide. These include coconut lethal yellowing in Africa and the Caribbean, grapevine yellows in major viticultural areas and various diseases affecting stone and pome fruit plants. Phytoplasma-infected plants exhibit symptoms suggesting a profound disturbance in the normal balance of growth regulators and also yellows symptoms, but very often the symptomatology is not diagnostic. Detection and characterization of phytoplasmas infecting different plant species are now possible with molecular methods, based on the study of 16S rDNA polymorphisms. Molecular diversity of phytoplasmas is also demonstrated by studying genes coding the ribosomal proteins S3, tuf, SecY, amp, imp and other genes. Four phytoplasma genomes have been fully sequenced, including those of two ‘Candidatus Phytoplasma asteris’ strains, and those of strains of ‘Ca. P. mali’ and ‘Ca. P. australiense’. Three of these genomes contain large amounts of repeated DNA sequence, and the fourth carries multiple copies of almost 100 genes. Considering that phytoplasmas have unusually small genomes, these repeats might be related to their transkingdom habitat and to their pathogenic activity. An outlook of recent findings in the field is also reported.

Chronic glutamate toxicity in neurodegenerative diseases-what is the evidence?

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Pamela eMaher

2015-12-01

Full Text Available Together with aspartate, glutamate is the major excitatory neurotransmitter in the brain. Glutamate binds and activates both ligand-gated ion channels (ionotropic glutamate receptors and a class of G-protein coupled receptors (metabotropic glutamate receptors. Although the intracellular glutamate concentration in the brain is in the millimolar range, the extracellular glutamate concentration is kept in the low micromolar range by the action of excitatory amino acid transporters that import glutamate and aspartate into astrocytes and neurons. Excess extracellular glutamate may lead to excitotoxicity in vitro and in vivo in acute insults like ischemic stroke via the overactivation of ionotropic glutamate receptors. In addition, chronic excitotoxicity has been hypothesized to play a role in numerous neurodegenerative diseases including amyotrophic lateral sclerosis, Alzheimer’s disease and Huntington’s disease. Based on this hypothesis, a good deal of effort has been devoted to develop and test drugs that either inhibit glutamate receptors or decrease extracellular glutamate. In this review, we provide an overview of the different pathways that are thought to lead to an over-activation of the glutamatergic system and glutamate toxicity in neurodegeneration. In addition, we summarize the available experimental evidence for glutamate toxicity in animal models of neurodegenerative diseases.