[Electronic cigarettes - effects on health. Previous reports].
Napierała, Marta; Kulza, Maksymilian; Wachowiak, Anna; Jabłecka, Katarzyna; Florek, Ewa
2014-01-01
Currently very popular in the market of tobacco products have gained electronic cigarettes (ang. E-cigarettes). These products are considered to be potentially less harmful in compared to traditional tobacco products. However, current reports indicate that the statements of the producers regarding to the composition of the e- liquids not always are sufficient, and consumers often do not have reliable information on the quality of the product used by them. This paper contain a review of previous reports on the composition of e-cigarettes and their impact on health. Most of the observed health effects was related to symptoms of the respiratory tract, mouth, throat, neurological complications and sensory organs. Particularly hazardous effects of the e-cigarettes were: pneumonia, congestive heart failure, confusion, convulsions, hypotension, aspiration pneumonia, face second-degree burns, blindness, chest pain and rapid heartbeat. In the literature there is no information relating to passive exposure by the aerosols released during e-cigarette smoking. Furthermore, the information regarding to the use of these products in the long term are not also available.
Renaissance Learning Equating Study. Report
Sewell, Julie; Sainsbury, Marian; Pyle, Katie; Keogh, Nikki; Styles, Ben
2007-01-01
An equating study was carried out in autumn 2006 by the National Foundation for Educational Research (NFER) on behalf of Renaissance Learning, to provide validation evidence for the use of the Renaissance Star Reading and Star Mathematics tests in English schools. The study investigated the correlation between the Star tests and established tests.…
Cui, Zhaohui; Stevens, June; Truesdale, Kimberly P.; Zeng, Donglin; French, Simone; Gordon-Larsen, Penny
2016-01-01
Objective To compare alternative models for the imputation of BMIM (measured weight in kilograms/measured height in meters squared) in a longitudinal study. Methods We used data from 11,008 adults examined at wave III (2001–2002) and wave IV (2007–2008) in the National Longitudinal Study of Adolescent to Adult Health. Participants were asked their height and weight before being measured. Equations to predict wave IV BMIM were developed in an 80% random subsample and evaluated in the remaining participants. The validity of models that included BMI constructed from previously measured height and weight (BMIPM) was compared to the validity of models that used BMI calculated from concurrently self-reported height and weight (BMISR). The usefulness of including demographics and perceived weight category in those models was also examined. Results The model that used BMISR, compared to BMIPM, as the only variable produced a larger R2 (0.913 vs. 0.693), a smaller root mean square error (2.07 vs. 3.90 kg/m2) and a lower bias between normal-weight participants and those with obesity (0.98 vs. 4.24 kg/m2). The performance of the model containing BMISR alone was not substantially improved by the addition of demographics, perceived weight category or BMIPM. Conclusions Our work is the first to show that concurrent self-reports of height and weight may be more useful than previously measured height and weight for imputation of missing BMIM when the time interval between measures is relatively long. Other time frames and alternatives to in-person collection of self-reported data need to be examined. PMID:27898706
Prolonged asthma after smoke inhalation: A report of three cases and a review of previous reports
Moisan, T.C. (Department of Preventive Medicine, Loyola University-Stritch School of Medicine, Maywood, IL (USA))
1991-04-01
The development of prolonged obstructive airways disease after smoke inhalation is of concern to fire victims and fire fighters. Three cases of asthma that developed following the inhalation of pyrolysis products are presented along with a review of previous reports of airway injury from smoke inhalation. Polyvinyl chloride pyrolysis products seem to pose a high risk, but other toxic inhalants are also implicated. There is substantial evidence that prolonged airway hyper-responsiveness and asthma may follow numerous inflammatory insults including smoke inhalation. Studies to identify specific individual risk factors and asthmagenic pyrolysis products are needed. Early, postexposure anti-inflammatory treatment may modify the outcome. 42 refs.
BRIEF REPORT: The colour relaxation equation
Xiaofei, Zhang; Jiarong, Li
1996-03-01
Colour diffusion in quark - gluon plasma (QGP) is investigated from the transport equations of QGP. The pure non-Abelian collision term describing the colour diffusion in QGP is obtained, the expression for colour relaxation time is derived and the physical picture of the colour diffusion in QGP is shown.
Cannabinoid hyperemesis syndrome. A report of six new cases and a summary of previous reports.
Contreras Narváez, Carla; Mola Gilbert, Montserrat; Batlle de Santiago, Enric; Bigas Farreres, Jordi; Giné Serven, Eloy; Cañete Crespillo, Josep
2016-03-02
Cannabinoid hyperemesis syndrome (CHS) is a medical condition which was identified for the first time in 2004 and affects chronic users of cannabis. It is characterized by cyclic episodes of uncontrollable vomiting as well as compulsive bathing in hot water. The episodes have a duration of two to four days. The vomiting is recognizable by a lack of response to regular antiemetic treatment, and subsides only with cannabis abstinence, reappearing in periods of consumption of this substance. The etiology of this syndrome is unknown. Up until June 2014, 83 cases of CHS were published worldwide, four of them in Spain.The first patient of CHS at Mataró Hospital was diagnosed in 2012. Since then, five new cases have been identified. The average duration between the onset of acute CHS episodes and diagnosis is 6.1 years, similar to that observed in previously published cases, an average of 3.1 years. This "delay" of CHS diagnosis demonstrates a lack of awareness with respect to this medical condition in the healthcare profession.With the objective of providing information concerning CHS and facilitating its timely diagnosis, a series of six new cases of CHS diagnosed in Mataró Hospital is presented along with a summary of cases published between 2004 and June 2014.
Reporting Monte Carlo Studies in Structural Equation Modeling
Boomsma, Anne
2013-01-01
In structural equation modeling, Monte Carlo simulations have been used increasingly over the last two decades, as an inventory from the journal Structural Equation Modeling illustrates. Reaching out to a broad audience, this article provides guidelines for reporting Monte Carlo studies in that fiel
Oster, M W; Park, Y
1983-01-15
Fifteen patients with metastatic breast cancer previously treated with chemotherapy were treated with a regimen consisting of vincristine, Adriamycin, and mitomycin. Eleven patients (73%) responded with three complete and eight partial responses. The median duration of response was eight months. While all four nonresponders died within five months, the median duration of survival of responders was 18 months. Toxicity was significant but tolerable. Thus, this preliminary report suggests that this regimen is active in advanced previously treated breast cancer, providing meaningful remissions with acceptable toxicity.
Reduced processing speed in rugby union players reporting three or more previous concussions.
Gardner, Andrew; Shores, E Arthur; Batchelor, Jennifer
2010-05-01
The issue pertaining to the effect of multiple self-reported sports-related concussions on cognitive function is controversial. Although this topic has received increased attention in the literature recently, the issue remains unresolved. Evidence supporting a detrimental cognitive effect has been reported at a sub-concussive level and following one, two, and three or more previous concussions. However, numerous studies have been unable to replicate these findings. Additionally, discrepancies between neuropsychological testing formats have been identified, where studies utilizing traditional tests tend to support the notion of detrimental cognitive effects whereas studies with computerized tests have tended to demonstrate no effect. The present study sought to examine possible detrimental cognitive effects in a sample of adult male rugby union players who reported a history of three or more concussions (n = 34) compared with those who reported no previous concussions (n = 39). A computerized neuropsychological battery and a traditional neuropsychological measure of processing speed were administered for this purpose. Findings revealed that there were differences between groups on two processing speed measures from both traditional and computerized tests. Athletes with a history of multiple concussions performed significantly lower on these measures than those with no history of concussion. These results provide further evidence to suggest that a history of three or more self-reported concussions in active athletes may have a detrimental effect on cognitive function. Future research may focus on identifying moderating factors in an attempt to resolve some of the conflicting findings and identify potential athletes at risk for sustaining cognitive deficits.
Bevan, Steve; Traylor, Matthew; Adib-Samii, Poneh; Malik, Rainer; Paul, Nicola L M; Jackson, Caroline; Farrall, Martin; Rothwell, Peter M; Sudlow, Cathie; Dichgans, Martin; Markus, Hugh S
2012-12-01
The contribution of genetics to stroke risk, and whether this differs for different stroke subtypes, remainsuncertain. Genomewide complex trait analysis allows heritability to be assessed from genomewide association study (GWAS) data. Previous candidate gene studies have identified many associations with stoke but whether these are important requires replication in large independent data sets. GWAS data sets provide a powerful resource to perform replication studies. We applied genomewide complex trait analysis to a GWAS data set of 3752 ischemic strokes and 5972 controls and determined heritability for all ischemic stroke and the most common subtypes: large-vessel disease, small-vessel disease, and cardioembolic stroke. By systematic review we identified previous candidate gene and GWAS associations with stroke and previous GWAS associations with related cardiovascular phenotypes (myocardial infarction, atrial fibrillation, and carotid intima-media thickness). Fifty associations were identified. For all ischemic stroke, heritability was 37.9%. Heritability varied markedly by stroke subtype being 40.3% for large-vessel disease and 32.6% for cardioembolic but lower for small-vessel disease (16.1%). No previously reported candidate gene was significant after rigorous correction for multiple testing. In contrast, 3 loci from related cardiovascular GWAS studies were significant: PHACTR1 in large-vessel disease (P=2.63e(-6)), PITX2 in cardioembolic stroke (P=4.78e(-8)), and ZFHX3 in cardioembolic stroke (P=5.50e(-7)). There is substantial heritability for ischemic stroke, but this varies for different stroke subtypes. Previous candidate gene associations contribute little to this heritability, but GWAS studies in related cardiovascular phenotypes are identifying robust associations. The heritability data, and data from GWAS, suggest detecting additional associations will depend on careful stroke subtyping.
Sekhon, Lali
2005-01-01
This is the first reported case of cervical arthroplasty using the Bryan Cervical Disc Prosthesis System (Medtronic Sofamor Danek, Inc., Memphis, TN) in the management of adjacent segment degeneration associated with previous fusion surgery and surgery at the cervicothoracic junction. This case report describes a 25-year-old woman who initially underwent a two-level anterior cervical fusion in 1998, 2 years after being involved in a motor vehicle accident. She was well until 18 months before presentation, when she developed bilateral shoulder pain, mechanical neck pain worse on flexion, and bilateral C8 distribution arm pain and paresthesia. On clinical examination, no focal deficits were found, although the range of motion was reduced. Preoperative cervical spine x-rays and magnetic resonance scanning confirmed accelerated degeneration of the C4-C5 and C7-T1 disc spaces, with evidence of neural compression at those levels. After careful consideration of various treatment options and failure of all conservative measures, the patient underwent an anterior C4-C5 and C7-T1 decompression with removal of the anterior cervical plate and placement of two artificial disc prostheses. After surgery, her course was uncomplicated and she was discharged from hospital well. There was complete resolution of the arm symptoms and reduction of the neck pain, with a reduction in the amount of analgesia she was taking. Seven months after surgery, she remains well with repeat x-rays confirming motion at the operated levels. This case demonstrates that cervical arthroplasty is a reasonable treatment option for patients who have had previous surgery in which interbody fusion has been performed and who have developed degeneration of adjacent levels. Despite the altered biomechanics at the cervicothoracic junction, no adverse features were noted with arthroplasty at this level.
Update to Core reporting practices in structural equation modeling.
Schreiber, James B
2016-07-21
This paper is a technical update to "Core Reporting Practices in Structural Equation Modeling."(1) As such, the content covered in this paper includes, sample size, missing data, specification and identification of models, estimation method choices, fit and residual concerns, nested, alternative, and equivalent models, and unique issues within the SEM family of techniques.
Structural Equation Modeling Reporting Practices for Language Assessment
Ockey, Gary J.; Choi, Ikkyu
2015-01-01
Studies that use structural equation modeling (SEM) techniques are increasingly encountered in the language assessment literature. This popularity has created the need for a set of guidelines that can indicate what should be included in a research report and make it possible for research consumers to judge the appropriateness of the…
Are all the previously reported genetic variants in limb girdle muscular dystrophy genes pathogenic?
Di Fruscio, Giuseppina; Garofalo, Arcomaria; Mutarelli, Margherita; Savarese, Marco; Nigro, Vincenzo
2016-01-01
Hundreds of variants in autosomal genes associated with the limb girdle muscular dystrophies (LGMDs) have been reported as being causative. However, in most cases the proof of pathogenicity derives from their non-occurrence in hundreds of healthy controls and/or from segregation studies in small families. The limited statistics of the genetic variations in the general population may hamper a correct interpretation of the effect of variants on the protein. To clarify the meaning of low-frequency variants in LGMD genes, we have selected all variants described as causative in the Leiden Open Variation Database and the Human Gene Mutation Database. We have systematically searched for their frequency in the NHLBI GO Exome Sequencing Project (ESP) and in our internal database. Surprisingly, the ESP contains about 4% of the variants previously associated with a dominant inheritance and about 9% of those associated with a recessive inheritance. The putative disease alleles are much more frequent than those estimated considering the disease prevalence. In conclusion, we hypothesize that a number of disease-associated variants are non-pathogenic and that other variations are not fully penetrant, even if they affect the protein function, suggesting a more complex genetic mechanisms for such heterogeneous disorders.
Adenylosuccinate lyase (ADSL) and infantile autism: Absence of previously reported point mutation
Fon, E.A.; Sarrazin, J.; Rouleau, G.A. [Montreal General Hospital (Canada)] [and others
1995-12-18
Autism is a heterogeneous neuropsychiatric syndrome of unknown etiology. There is evidence that a deficiency in the enzyme adenylosuccinate lyase (ADSL), essential for de novo purine biosynthesis, could be involved in the pathogenesis of certain cases. A point mutation in the ADSL gene, resulting in a predicted serine-to-proline substitution and conferring structural instability to the mutant enzyme, has been reported previously in 3 affected siblings. In order to determine the prevalence of the mutation, we PCR-amplified the exon spanning the site of this mutation from the genomic DNA of patients fulfilling DSM-III-R criteria for autistic disorder. None of the 119 patients tested were found to have this mutation. Furthermore, on preliminary screening using single-strand conformation polymorphism (SSCP), no novel mutations were detected in the coding sequence of four ADSL exons, spanning approximately 50% of the cDNA. In light of these findings, it appears that mutations in the ADSL gene represent a distinctly uncommon cause of autism. 12 refs., 2 figs.
Infantile onset spinocerebellar ataxia 2 (SCA2): a clinical report with review of previous cases.
Singh, Ankur; Faruq, Mohammed; Mukerji, Mitali; Dwivedi, Manish Kumar; Pruthi, Sumit; Kapoor, Seema
2014-01-01
Autosomal dominant cerebellar ataxia type I is a heterogeneous group of spinocerebellar ataxias with variable neurologic presentations, with age of onset varying from infancy to adulthood. Autosomal dominant cerebellar ataxia type I is composed mainly of 3 prevalent spinocerebellar ataxia types with different pathogenic loci, specifically spinocerebellar ataxia 1 (6p24-p23), spinocerebellar ataxia 2 (12q24.1), and spinocerebellar ataxia 3 (14q32.1). The shared pathogenic mutational event is the expansion of the CAG repeat that results in polyglutamine extended stretches in the encoded proteins. CAG repeat disorders generally show the phenomenon of anticipation, which is more often associated with paternal transmission. In this report, we describe a patient with infantile-onset spinocerebellar ataxia type 2 (~320 CAG repeat) who inherited the disease from his father (47 CAG repeats). We have summarized the clinical, neuroimaging, electroencephalographic (EEG), and molecular data of previous cases and attempt to highlight the most consistent findings. Our intent is to help treating clinicians to suspect this disorder and to offer timely genetic counseling for a currently potentially untreatable disorder.
Xinzhi Liu
1998-01-01
Full Text Available This paper studies a class of high order delay partial differential equations. Employing high order delay differential inequalities, several oscillation criteria are established for such equations subject to two different boundary conditions. Two examples are also given.
Clausen, M B; Tang, L; Zebis, M K;
2015-01-01
Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study...... was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15–18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS...... questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (
Stijve, T.; Kuyper, Th.W.
1988-01-01
Seven taxa of agarics reported in literature to contain psilocybin (viz. Psathyrella candolleana, Gymnopilus spectabilis, G. fulgens, Hygrocybe psittacina var. psittacina and var. californica, Rickenella fibula, R. swartzii) have been analysed for psilocybin and related tryptamines with negative
Stijve, T.; Kuyper, Th.W.
1988-01-01
Seven taxa of agarics reported in literature to contain psilocybin (viz. Psathyrella candolleana, Gymnopilus spectabilis, G. fulgens, Hygrocybe psittacina var. psittacina and var. californica, Rickenella fibula, R. swartzii) have been analysed for psilocybin and related tryptamines with negative res
Wroclawski, Marcelo Langer; Carneiro, Ariê; Tristão, Rodrigo Alves; Sakuramoto, Paulo Kouiti; Youssef, Jorg Daoud Merched; Lopes Neto, Antonio Correa; Santiago, Lucila Heloísa Simardi; Pompeo, Antonio Carlos Lima
2015-01-01
Giant prostatic hyperplasia is a rare condition characterized by very high volume benign prostatic enlargement (>500g). Few cases have been reported so far and most of them are associated with severe lower urinary symptoms. We report the first case of asymptomatic giant prostatic hyperplasia in an elderly man who had a 720g prostate adenoma, sudden gross hematuria and hypovolemic shock. The patient was successfully treated with open transvesical prostatectomy and had an uneventful postoperative recovery.
Tyrosinemia type II in two cases previously reported as Richner-Hanhart syndrome.
Balato, N; Cusano, F; Lembo, G; Santoianni, P
1986-01-01
Two sibs with palmo-plantar keratosis and dendritic corneal opacities, previously described as suffering from Richner-Hanhart syndrome by other authors, about 25 years ago, showed increased plasma and urine tyrosine levels. Their neurological and mental features were within normal limits. A comprehensive review of the literature showed a total of 47 cases of fully documented tyrosinemia type II; 8 more patients also had the clinical features of the disease, but aminoacidemia had never been observed. The importance of early diagnosis is stressed, since a low tyrosine-phenylalanine diet dramatically improves the symptoms and may prevent mental retardation.
Non-detection of Previously Reported Transits of HD 97658b with MOST Photometry
Dragomir, Diana; Matthews, Jaymie M.; Howard, Andrew W.
2012-01-01
The radial velocity-discovered exoplanet HD 97658b was recently announced to transit, with a derived planetary radius of 2.93 ± 0.28 R ⊕. As a transiting super-Earth orbiting a bright star, this planet would make an attractive candidate for additional observations, including studies of its...... out transits for a planet with radius larger than 2.09 R ⊕, corresponding to the reported 3σ lower limit. We also report new radial velocity measurements which continue to support the existence of an exoplanet with a period of 9.5 days, and obtain improved orbital parameters....
Venesmaa, Sari; Juvonen, Petri; Kettunen, Hannu-Pekka
2013-01-01
We describe a rare case of a pancreaticobronchial fistula caused by pancreatic pseudocysts due to previous trauma. A 54-year-old man with a history of traumatic hemothorax was referred to central hospital for investigations due to cough, dyspnea, vertigo and fever. An ultrasound scan and abdominal computed tomography scan showed huge pancreatic pseudocysts around the pancreas extending to the right side of the mediastinum with gas. The etiology for the pseudocysts was unconfirmed. First, the patient recovered with antibiotics and external pseudocyst drainage. After five months the patient started to suffer from respiratory symptoms again, such as coughing with sputum, dyspnea and mild fever. The computer tomography scan confirmed the pancreaticobronchial fistula as a diagnosis and the patient was referred to the university hospital for further treatment.
Tsagris, Vasileios; Vliora, Christianna; Mihelarakis, Ioannis; Syridou, Garyfallia; Pasparakis, Dimitrios; Lebessi, Evangelia; Tsolia, Maria
2016-01-01
Salmonella osteomyelitis in children is an uncommon condition, typically associated with hemoglobinopathies or other underlying disorders. Only few cases have been reported in children without predisposing factors. We describe 4 cases of Salmonella osteomyelitis in otherwise healthy children. Since treatment duration is expected to be prolonged, the practice of direct inoculation of aspirates into blood culture bottles appears to be essential for diagnosis and targeted therapy.
Manoj Kumar Roy
2015-05-01
Full Text Available The association of Neurofibromatosis 1 (NF 1, an autosomal dominant genetic disease with autoimmune diseases like systemic lupus erythematosus is rare, five case reports are there in medical literature showing such association. Here we have documented a case of Lupus nephritis associated with Neurofibromatosis 1 diagnosed in the same setting, in a 24 years old female patient presented with oliguria, hypertension, anasarca, cafe-au-lait spots, palmer freckling, subcutaneous nodules, alopecia areata and positive family history for NF 1. [Int J Res Med Sci 2015; 3(5.000: 1277-1280
[Lessons from abroad. Current and previous crisis in other countries. SESPAS report 2014].
Rivadeneyra-Sicilia, Ana; Minué Lorenzo, Sergio; Artundo Purroy, Carlos; Márquez Calderón, Soledad
2014-06-01
The evidence available on the impact of previous crises on health reveals different patterns attributable to study designs, the characteristics of each crisis, and other factors related to the socioeconomic and political context. There is greater consensus on the mediating role of government policy responses to financial crises. These responses may magnify or mitigate the adverse effects of crises on population health. Some studies have shown a significant deterioration in some health indicators in the context of the current crisis, mainly in relation to mental health and communicable diseases. Alcohol and tobacco use have also declined in some European countries. In addition, this crisis is being used by some governments to push reforms aimed at privatizing health services, thereby restricting the right to health and healthcare. Specifically, action is being taken on the three axes that determine health system financing: the population covered, the scope of services, and the share of the costs covered. These measures are often arbitrarily implemented based on ideological decisions rather than on the available evidence and therefore adverse consequences are to be expected in terms of financial protection, efficiency, and equity. Copyright © 2013 SESPAS. Published by Elsevier Espana. All rights reserved.
Angiosarcoma in previously irradiated breast in patient with Li-Fraumeni syndrome. A case report
Oséias Vargas Barbosa
Full Text Available CONTEXT: Li-Fraumeni syndrome is a rare disease with an autosomal dominant inheritance pattern and high penetrance that defines a 50% chance of developing cancer before the age of 30 years, including cases of breast sarcoma. Patients with this syndrome who require radiotherapy have an increased risk of developing secondary malignancies including angiosarcomas. CASE REPORT: This was a case report on a female patient with Li-Fraumeni syndrome. In October 2005, she was diagnosed with invasive ductal carcinoma of the right breast and underwent sectorectomy. She then received chemotherapy and adjuvant radiotherapy. Trastuzumab and tamoxifen were also part of the treatment. She recently sought care at our hospital, complaining of hyperemia and nodulation in the right breast, and underwent surgical resection that revealed epithelioid angiosarcoma. CONCLUSIONS: When genetic predisposition due to Li-Fraumeni syndrome is documented, the therapy should be adapted so as to minimize the risk. Thus, conservative surgical treatments should be avoided and mastectomy without radiation should be prioritized. In cases in which use of radiotherapy is justified, patients should be followed up intensively.
Cals, Jochen W L; Mallen, Christian D; Glynn, Liam G; Kotz, Daniel
2013-01-01
Publishing research can be time consuming, as papers are often submitted and reviewed by multiple journals before final acceptance. We hypothesized that attaching previous peer-review reports to the next submission of the paper to a different journal (possibly with point-to-point responses and amendments) could decrease the workload for both reviewers and editors and could shorten the time from final draft to actual publication. We therefore performed an online survey to assess the views of the editors-in-chief of all 100 general medical journals from the citation impact factor report category "internal & general medicine" (ISI Web of Knowledge). Of contacted editors, 61% responded. One of 4 journals do currently receive peer-review reports on occasion. Editors recognized potential advantages but also concerns on using previous peer-review reports across 3 themes: scientific community, quality of papers, and the publication process. The use of previous peer-review reports has the potential to facilitate authors, reviewers, and editors in optimizing peer review in general medical science.
Jesse Papenburg
2009-01-01
Full Text Available A case of near-fatal oseltamivir-resistant seasonal influenza A infection in a previously healthy four-year-old boy is reported. This case highlights three important points for physicians: oseltamivir-resistant influenza A (H1N1 has recently emerged in North America; contrary to previously held beliefs, such strains are capable of causing severe disease in healthy children; and given this change in epidemiology, clinicians caring for children with severe seasonal influenza A infection should consider empiric dual therapy with oseltamivir and amantadine.
Final Report: Symposium on Adaptive Methods for Partial Differential Equations
Pernice, M.; Johnson, C.R.; Smith, P.J.; Fogelson, A.
1998-12-10
OAK-B135 Final Report: Symposium on Adaptive Methods for Partial Differential Equations. Complex physical phenomena often include features that span a wide range of spatial and temporal scales. Accurate simulation of such phenomena can be difficult to obtain, and computations that are under-resolved can even exhibit spurious features. While it is possible to resolve small scale features by increasing the number of grid points, global grid refinement can quickly lead to problems that are intractable, even on the largest available computing facilities. These constraints are particularly severe for three dimensional problems that involve complex physics. One way to achieve the needed resolution is to refine the computational mesh locally, in only those regions where enhanced resolution is required. Adaptive solution methods concentrate computational effort in regions where it is most needed. These methods have been successfully applied to a wide variety of problems in computational science and engineering. Adaptive methods can be difficult to implement, prompting the development of tools and environments to facilitate their use. To ensure that the results of their efforts are useful, algorithm and tool developers must maintain close communication with application specialists. Conversely it remains difficult for application specialists who are unfamiliar with the methods to evaluate the trade-offs between the benefits of enhanced local resolution and the effort needed to implement an adaptive solution method.
Williams, Winfred W.; Salem, Rany M.; McKnight, Amy Jayne; Sandholm, Niina; Forsblom, Carol; Taylor, Andrew; Guiducci, Candace; McAteer, Jarred B.; McKay, Gareth J.; Isakova, Tamara; Brennan, Eoin P.; Sadlier, Denise M.; Palmer, Cameron; Söderlund, Jenny; Fagerholm, Emma; Harjutsalo, Valma; Lithovius, Raija; Gordin, Daniel; Hietala, Kustaa; Kytö, Janne; Parkkonen, Maija; Rosengård-Bärlund, Milla; Thorn, Lena; Syreeni, Anna; Tolonen, Nina; Saraheimo, Markku; Wadén, Johan; Pitkäniemi, Janne; Sarti, Cinzia; Tuomilehto, Jaakko; Tryggvason, Karl; Österholm, Anne-May; He, Bing; Bain, Steve; Martin, Finian; Godson, Catherine; Hirschhorn, Joel N.; Maxwell, Alexander P.; Groop, Per-Henrik; Florez, Jose C.
2012-01-01
We formed the GEnetics of Nephropathy–an International Effort (GENIE) consortium to examine previously reported genetic associations with diabetic nephropathy (DN) in type 1 diabetes. GENIE consists of 6,366 similarly ascertained participants of European ancestry with type 1 diabetes, with and without DN, from the All Ireland-Warren 3-Genetics of Kidneys in Diabetes U.K. and Republic of Ireland (U.K.-R.O.I.) collection and the Finnish Diabetic Nephropathy Study (FinnDiane), combined with reanalyzed data from the Genetics of Kidneys in Diabetes U.S. Study (U.S. GoKinD). We found little evidence for the association of the EPO promoter polymorphism, rs161740, with the combined phenotype of proliferative retinopathy and end-stage renal disease in U.K.-R.O.I. (odds ratio [OR] 1.14, P = 0.19) or FinnDiane (OR 1.06, P = 0.60). However, a fixed-effects meta-analysis that included the previously reported cohorts retained a genome-wide significant association with that phenotype (OR 1.31, P = 2 × 10−9). An expanded investigation of the ELMO1 locus and genetic regions reported to be associated with DN in the U.S. GoKinD yielded only nominal statistical significance for these loci. Finally, top candidates identified in a recent meta-analysis failed to reach genome-wide significance. In conclusion, we were unable to replicate most of the previously reported genetic associations for DN, and significance for the EPO promoter association was attenuated. PMID:22721967
Colvin Hugh Shunsuke
2009-07-01
Full Text Available Abstract Introduction Perforations of jejunal diverticula are uncommon and repeated symptomatic perforations have been reported only twice before in the literature. This is the first case report of recurrent perforation of a jejunal diverticulum to be successfully managed non-operatively. Case presentation We report a recurrent perforation of a jejunal diverticulum in an 87-year-old Caucasian man who presented with a 1-week history of epigastric pain. The diagnosis of a perforated jejunal diverticulum was made from the appearances of the abdominal computed tomography scan together with the presence of jejunal diverticula noted at the time of a previous laparotomy for the first perforation of a jejunal diverticulum. Conclusion Whilst this case report by itself does not add to the knowledge we already have of jejunal diverticula, it is one report of a rare condition and more reports are required in the future to establish the recurrence rate of jejunal diverticula perforation and how perforated jejunal diverticula are best managed.
Boundary regularity for some nonlinear elliptic degenerate equations. Technical summary report
Brezis, H.; Lions, P.
1979-08-01
Special solutions of the Yang-Mills field equations of theoretical physics may be obtained by solving a boundary value problem for a nonlinear elliptic equation in a two dimensional half space. This equation degenerates at the boundary of the region and this degeneracy makes it a delicate matter to study how the solutions behave near the boundary. In this work it is proved that the weak solutions previously known to exist are in fact smooth up to the boundary.
Espinal, Mariana; DeStephano, Christopher C; Guha, Paulami; Gajarawala, Shilpa P; Chen, Anita H; Pettit, Paul D
2017-07-17
Fecal incontinence (FI) is a disabling problem affecting women. Conservative treatment includes dietary modification, antimotility agents, and pelvic floor physical therapy. If conservative medical management is unsuccessful, surgical intervention may be required. Surgical options include rectal sphincteroplasty, bulking agent injection, radiofrequency anal sphincter remodeling, and sacral nerve stimulation therapy. Recently, a new therapy for FI, the FENIX Continence Restoration System (Torax Medical, Inc., Shoreview, MN), has become available. The FENIX device is placed through a perineal incision; however, pelvic radiation and previous anal carcinoma are both contraindications. We report the case of a 62-year-old woman with FI after anal carcinoma. Treatment included surgery, chemotherapy, and pelvic radiation. Initially, she was treated with conservative therapy and sacral nerve stimulation, which were only partially effective. A physical examination showed perineal skin changes consistent with previous radiation, which increased the patient's risk of infection and a nonhealing wound. Therefore, a robotic approach was used to place the FENIX device and improve the patient's quality of life. Our case sets a precedent for expanding the treatment options of FI in patients with previous pelvic radiation and using a robotic approach for the placement of the FENIX device. Copyright © 2017 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.
McGregor, Douglas H; Liu, Xiaoying; Ulusarac, Ozlem; Ponnuru, Kimberly D; Schnepp, Stephanie L
2011-02-18
An 86 year old male with a four-day history of nonspecific gastrointestinal symptoms was found on colonoscopy to have evidence of sigmoid colon obstruction and possible perforation. Emergent operative exploration revealed diffuse peritonitis, sigmoid perforation, adjacent dense adhesions, and a foreign body protruding through the perforated area. Pathologic examination showed the foreign body to be a sliver of bone consistent with chicken bone and the sigmoid subacute perforation to be associated distally with a circumferential ulcerated obstructing mass, microscopically seen to be transmurally infiltrating adenocarcinoma, signet-ring cell type. There was extensive acute and organizing peritonitis, 100% Escherichia coli was cultured from peritoneal fluid, and the patient died two days postoperatively with sepsis and hypotension. This appears to be the fifth reported case of colonic perforation resulting from foreign body perforation due to previously undiagnosed adenocarcinoma. The four previously reported cases were all deeply invasive adenocarcinoma of sigmoid colon, and the foreign bodies included three chicken/poultry bones and a metallic staple. These five cases are highly unusual examples of a potentially lethal malignant neoplasm being clinically revealed by a usually (but not always) innocuous event, the ingestion of a small foreign body.
Ulusarac Ozlem
2011-02-01
Full Text Available Abstract An 86 year old male with a four-day history of nonspecific gastrointestinal symptoms was found on colonoscopy to have evidence of sigmoid colon obstruction and possible perforation. Emergent operative exploration revealed diffuse peritonitis, sigmoid perforation, adjacent dense adhesions, and a foreign body protruding through the perforated area. Pathologic examination showed the foreign body to be a sliver of bone consistent with chicken bone and the sigmoid subacute perforation to be associated distally with a circumferential ulcerated obstructing mass, microscopically seen to be transmurally infiltrating adenocarcinoma, signet-ring cell type. There was extensive acute and organizing peritonitis, 100% Escherichia coli was cultured from peritoneal fluid, and the patient died two days postoperatively with sepsis and hypotension. This appears to be the fifth reported case of colonic perforation resulting from foreign body perforation due to previously undiagnosed adenocarcinoma. The four previously reported cases were all deeply invasive adenocarcinoma of sigmoid colon, and the foreign bodies included three chicken/poultry bones and a metallic staple. These five cases are highly unusual examples of a potentially lethal malignant neoplasm being clinically revealed by a usually (but not always innocuous event, the ingestion of a small foreign body.
Thomson, Cynthia A; Flatt, Shirley W; Rock, Cheryl L; Ritenbaugh, Cheryl; Newman, Vicky; Pierce, John P
2002-06-01
To describe the dietary intake patterns of women before and after breast cancer diagnosis. 3,084 women (age range 27 to 70 years) who had been treated for early-stage breast cancer, who were free of recurrent disease, and who were willing to complete study questionnaires. A descriptive analysis of baseline demographic and lifestyle questionnaire data, including reported dietary intake data from women who have had breast cancer participating in a randomized, controlled dietary intervention trial. Outcomes include dietary intakes of high- and low-fat foods, fruits and vegetables, and whole grains. Analyses included frequency of intake of selected food items, chi2 analysis to determine associations between reported intakes and demographic and personal characteristics, and logistic regression to assess odds of making more healthful changes. Women who have had breast cancer reported higher fruit, vegetable, and fiber-rich food intakes (58%, 60%, 38% more, respectively) and lower intakes of high-fat foods, including fast foods, after diagnosis. Those older than age 60 years were more likely to report no change in intake, including red meat (41%), vegetables (51%), and whole grains (62%). Odds ratios (OR) for more healthful diet choices varied by age and time since diagnosis. The longer the time since diagnosis the more likely women selected low-fat (vs high-fat) foods (OR 1.56, 95% confidence interval [CI] 1.16-2.09 for 3 to 4 years vs dietetics professionals may be able to promote healthful and evidence-based eating habits among women previously treated for breast cancer.
AlSaad D
2017-05-01
Full Text Available Doua AlSaad,1,2 Sawsan Alobaidly,3 Palli Abdulrouf,1 Binny Thomas,4,5 Afif Ahmed,1 Moza AlHail1 1Department of Pharmacy, Women’s Hospital, Hamad Medical Corporation, Doha, Qatar; 2Public Health Program, London School of Hygiene and Tropical Medicine, University of London, UK; 3Department of Obstetrics and Gynecology, Women’s Hospital, 4Clinical Support Service Unit, Hamad Medical Corporation, Doha, Qatar; 5Pharmacy and Life Sciences Research Institute, Robert Gordon University, Aberdeen, Scotland Background: Misoprostol is an effective medical method for the management of pregnancy loss. However, data on its efficacy and safety in women with previous cesarean deliveries are limited.Case presentation: We report a 36-year-old patient, gravida 11 para 6, with a diagnosis of missed miscarriage at 15 weeks of gestation. The patient had a significant obstetric history of previous five cesarean deliveries and uterine rupture. Following patient counseling about the medical and surgical options of managing her miscarriage, the patient opted for medical method. Low-dose misoprostol of 100 µg was inserted vaginally and repeated again after 6 hours. The patient had an uneventful complete miscarriage following the second dose of misoprostol. No uterine rupture, no extra vaginal bleeding, and no blood transfusion were observed.Conclusion: We conclude that adopting a low-dose misoprostol protocol could be potentially safe and effective in managing second trimester missed miscarriage in women with repeated cesarean deliveries and/or uterine rupture history. Further studies are needed to confirm these results. Keywords: cesarean section, uterine rupture, prostaglandin E1, misoprostol, second trimester, miscarriage, abortion
Chen, Haiwen; Holland, Paul
2009-01-01
In this paper, we develop a new chained equipercentile equating procedure for the nonequivalent groups with anchor test (NEAT) design under the assumptions of the classical test theory model. This new equating is named chained true score equipercentile equating. We also apply the kernel equating framework to this equating design, resulting in a…
Hefer, David Václav Fred; Munir, Aman; Khouli, Hassan
2007-10-01
The case of a 29 year-old man who suffered a cardiac arrest due to a massive pulmonary embolism while he was undergoing surgical repair of a complex tibial plateau fracture is presented. After 70 min of unsuccessful cardiopulmonary resuscitation a bolus of 20 mg tenecteplase was given, with a return of spontaneous circulation 2 min after administration of the drug. Pulmonary embolism was subsequently demonstrated on a pulmonary angiogram. To our knowledge this is the first report to show that the use of a low dose of tenecteplase might be useful to achieve the return of spontaneous circulation in the resuscitation of patients with cardiac arrest secondary to massive pulmonary embolism. Previously reported cases are reviewed.
Holguin, Francia; Rubió-Casadevall, Jordi; Saigi, Maria; Marruecos, Jordi; Taberna, Miren; Tobed, Marc; Maños, Manuel; Mesía, Ricard
2016-07-05
Cetuximab is a monoclonal antibody against epidermal growth factor receptor useful in the treatment of patients with Head and Neck Squamous Cell Carcinoma combined with radiotherapy or chemotherapy. Its pharmacokinetics are not influenced by hepatic status and there are no specific warnings concerning its indication in patients with impaired hepatic function. Patients with a previous liver transplant are at risk for hepatic toxicity and use immunosupressants to avoid rejection that can interact with other drugs. We present two cases of patients with a previous liver transplant in which cetuximab was administered to treat head and neck cancer.
Maegawa, Gustavo H. B.; Stockley, Tracy; Tropak, Michael; Banwell, Brenda; Blaser, Susan; Kok, Fernando; Giugliani, Roberto; Mahuran, Don; Clarke, Joe T. R.
2010-01-01
OBJECTIVE Juvenile GM2 gangliosidosis is a group of inherited neurodegenerative diseases caused by deficiency of lysosomal β-hexosaminidase resulting in GM2 ganglioside accumulation in brain. The purpose of this study was to delineate the natural history of the condition and identify genotype-phenotype correlations that might be helpful in predicting the course of the disease in individual patients. METHODS A cohort of 21 patients with juvenile GM2 gangliosidosis, 15 with the Tay-Sachs variant and 6 with the Sandhoff variant, was studied prospectively in 2 centers. Our experience was compared with previously published reports on 134 patients. Information about clinical features, β-hexosaminidase enzyme activity, and mutation analysis was collected. RESULTS In our cohort of patients, the mean (±SD) age of onset of symptoms was 5.3 ± 4.1 years, with a mean follow-up time of 8.4 years. The most common symptoms at onset were gait disturbances (66.7%), incoordination (52.4%), speech problems (28.6%), and developmental delay (28.6%). The age of onset of gait disturbances was 7.1 ± 5.6 years. The mean time for progression to becoming wheelchair-bound was 6.2 ± 5.5 years. The mean age of onset of speech problems was 7.0 ± 5.6 years, with a mean time of progression to anarthria of 5.6 ± 5.3 years. Muscle wasting (10.6 ± 7.4 years), proximal weakness (11.1 ± 7.7 years), and incontinence of sphincters (14.6 ± 9.7 years) appeared later in the course of the disease. Psychiatric disturbances and neuropathy were more prevalent in patients with the Sandhoff variant than in those with the Tay-Sachs variant. However, dysphagia, sphincter incontinence, and sleep problems occurred earlier in those with the Tay-Sachs variant. Cerebellar atrophy was the most common finding on brain MRI (52.9%). The median survival time among the studied and reviewed patients was 14.5 years. The genotype-phenotype correlation revealed that in patients with the Tay-Sachs variant, the presence
Jean-François Roussy; Catherine Allard; Guy St-Germain; Jacques Pépin
2012-01-01
Mucormycosis is an uncommon opportunistic infection and the gastrointestinal form is the rarest. Rhizopus sp. is the most frequent pathogen and infection occurs almost exclusively in immunocompromised patients. We describe the first case of intestinal mucormycosis occurring after a Streptococcus pyogenes toxic shock syndrome in a previously healthy patient caused by Rhizopus microsporus var. azygosporus.
Roussy, Jean-François; Allard, Catherine; St-Germain, Guy; Pépin, Jacques
2012-01-01
Mucormycosis is an uncommon opportunistic infection and the gastrointestinal form is the rarest. Rhizopus sp. is the most frequent pathogen and infection occurs almost exclusively in immunocompromised patients. We describe the first case of intestinal mucormycosis occurring after a Streptococcus pyogenes toxic shock syndrome in a previously healthy patient caused by Rhizopus microsporus var. azygosporus.
Jean-François Roussy
2012-01-01
Full Text Available Mucormycosis is an uncommon opportunistic infection and the gastrointestinal form is the rarest. Rhizopus sp. is the most frequent pathogen and infection occurs almost exclusively in immunocompromised patients. We describe the first case of intestinal mucormycosis occurring after a Streptococcus pyogenes toxic shock syndrome in a previously healthy patient caused by Rhizopus microsporus var. azygosporus.
White, Kristin L; Vierkant, Robert A; Fogarty, Zachary C
2013-01-01
Ovarian cancer is a leading cause of cancer-related death among women. In an effort to understand contributors to disease outcome, we evaluated single-nucleotide polymorphisms (SNP) previously associated with ovarian cancer recurrence or survival, specifically in angiogenesis, inflammation, mitosis...
Mori, Yoshimasa; Hashizume, Chisa; Shibamoto, Yuta; Kobayashi, Tatsuya; Nakazawa, Hisato; Hagiwara, Masahiro; Tsugawa, Takahiko
2013-08-01
Results of stereotactic radiotherapy (SRT) for spinal intradural metastases developing inside or adjacent to the previous external-beam radiation therapy (EBRT) field are shown in 3 cases. One case of spinal intramedullary metastasis and two cases of intradural extramedullary metastases were treated using a Novalis shaped-beam SRT. Case 1 developed an intramedullary metastatic tumor in the C1 spinal medulla inside the previous whole brain EBRT field and another lesion adjacent to the field in the C2 spinal medulla. Case 2 developed intradural extramedullary metastasis around C6-8 inside the previous EBRT field for the primary lung adenocarcinoma. Case 3 developed multiple spinal intradural extramedullary metastatic deposits after surgical resection and following whole brain EBRT for brain metastasis. We delivered 24 to 36 Gy in 5 to 12 fractions. The treated tumors were stable or decreased in size until the patients' death from the primary cancer (10, 22, and 5 months). Neurological symptoms were stable or improved in all 3 patients. Palliative SRT using Novalis is expected to be safe and effective even if the patient develops spinal intradural metastases within or adjacent to the previous irradiation field.
Usui Rie
2011-10-01
Full Text Available Abstract Introduction Uterine rupture is a life-threatening condition both to mothers and fetuses. Its early diagnosis and treatment may save their lives. Previous myomectomy is a high risk factor for uterine rupture. Intestinal adhesion due to previous myomectomy may also prevent early diagnosis of uterine rupture. Case presentation A 38-year-old primiparous non-laboring Japanese woman with a history of myomectomy was admitted in her 34th week due to lower abdominal pain. Although the pain was slight and her vital signs were stable, computed tomography revealed massive fluid collection in her abdominal cavity, which led us to perform a laparotomy. Uterine rupture had occurred at the site of the previous myomectomy; however, the small intestine was adhered tightly to the rupture, thus masking it. The baby was delivered through a low uterine segment transverse incision. The ruptured uterine wall was reconstructed. Conclusion Intestinal adhesion due to a prior myomectomy occluded a uterine rupture, possibly masking its symptoms and signs, which may have prevented early diagnosis.
Ioannidis, Konstantinos; Serfontein, Jaco; Müller, Ulrich
2014-05-01
There is increasing literature suggesting a link between attention-deficit hyperactivity disorder (ADHD) and eating disorders (EDs), especially bulimia nervosa. ADHD is under-diagnosed in girls and children of high intelligence are typically missed. We identified a case of a 23-year-old woman suffering from severe bulimia nervosa and previously unsuspected ADHD in adulthood; we diagnosed and treated her with extended-release methylphenidate. We performed a literature review on the ADHD and bulimia nervosa comorbidity. We discuss the reasons why her ADHD remained undiagnosed and the difficulties in diagnosing ADHD in patients with EDs. We suggest that identifying comorbid ADHD is crucial for these patients and argue for the use of a structured interview, collateral history and investigation of onset of symptoms to establish a diagnosis of ADHD in adults with bulimia nervosa. Comorbidities and overlap of symptomatology need to be taken into account. Copyright © 2013 Wiley Periodicals, Inc.
Poulin, Frédéric; Lamarche, Yoan; Le, Van Hoai Viet; Doucet, Michel; Roméo, Philippe; Généreux, Philippe
2016-02-01
We report on a man with bioprosthetic mitral valve perforation who presented late after transcatheter aortic valve replacement with a balloon-expandable transcatheter heart valve (THV). The protrusion of the commissural strut of the bioprosthetic mitral valve coupled with the low implanted THV resulted in repetitive trauma leading to rupture of a mitral leaflet. Potential preventive strategies are discussed. This case illustrates the importance of preprocedural imaging screening and cautious THV deployment in patients with a bioprosthetic mitral valve.
Wilkens, Alisha; Liu, Hongbin; Park, Kristen; Campbell, Lindsey B; Jackson, Marie; Kostanecka, Anna; Pipan, Mary; Izumi, Kosuke; Pallister, Phillip; Krantz, Ian D
2012-12-01
Pallister-Killian syndrome is a rare, multi-system developmental diagnosis typically caused by tetrasomy of chromosome 12p that exhibits tissue-limited mosaicism. The spectrum of clinical manifestations in Pallister-Killian syndrome is wide and includes craniofacial anomalies, clefts, ophthalmologic, audiologic, cardiac, musculoskeletal, diaphragmatic, gastrointestinal, genitourinary, and cutaneous anomalies in association with intellectual disability and seizures. Growth parameters are often normal to elevated at birth with deceleration of growth postnatally. No formal estimate of the prevalence of Pallister-Killian syndrome has been made. Here, we report the clinical findings in 59 individuals with Pallister-Killian syndrome who were ascertained at Pallister-Killian syndrome Foundation family meetings held in the summers of 2006, 2008, 2009, and 2010. In addition, the clinical findings of 152 cases reported in the medical literature were reviewed and compared to the cohort examined here. Several novel clinical characteristics were identified through detailed dysmorphology examinations of this cohort and reassertion of a mild developmental variant is described. This report expands the clinical manifestations of Pallister-Killian syndrome and highlights the variable expressivity of this diagnosis with important implications for diagnosis and counseling.
Danae Campos-Melo
2014-09-01
Full Text Available MicroRNAs (miRNAs are small non-coding RNAs that regulate the majority of the transcriptome at a post-transcriptional level. Because of this critical role, it is important to ensure that the assays used to determine their functionality are robust and reproducible. Typically, the reporter gene assay in cell-based systems has been the first-line method to study miRNA functionality. In order to overcome some of the potential errors in interpretation that can be associated with this assay, we have developed a detailed protocol for the luciferase reporter gene assay that has been modified for miRNAs. We demonstrate that normalization against the effect of the miRNA and cellular factors on the luciferase coding sequence is essential to obtain the specific impact of the miRNA on the 3'UTR (untranslated region target. Our findings suggest that there is a real possibility that the roles for miRNA in transcriptome regulation may be misreported due to inaccurate normalization of experimental data and also that up-regulatory effects of miRNAs are not uncommon in cells. We propose to establish this comprehensive method as standard for miRNA luciferase reporter assays to avoid errors and misinterpretations in the functionality of miRNAs.
Schulz Kenneth F
2010-04-01
Full Text Available Abstract Although current electronic methods of scientific publishing offer increased opportunities for publishing all research studies and describing them in sufficient detail, health research literature still suffers from many shortcomings. These shortcomings seriously undermine the value and utility of the literature and waste scarce resources invested in the research. In recent years there have been several positive steps aimed at improving this situation, such as a strengthening of journals' policies on research publication and the wide requirement to register clinical trials. The EQUATOR (Enhancing the QUAlity and Transparency Of health Research Network is an international initiative set up to advance high quality reporting of health research studies; it promotes good reporting practices including the wider implementation of reporting guidelines. EQUATOR provides free online resources http://www.equator-network.org supported by education and training activities and assists in the development of robust reporting guidelines. This paper outlines EQUATOR's goals and activities and offers suggestions for organizations and individuals involved in health research on how to strengthen research reporting.
2010-12-27
... abbreviations are used in this document. CAA Clean Air Act CBI confidential business information CEMS continuous... monitoring systems (CEMS). Several reporters wrote that they would have installed CEMS or otherwise changed... emissions with CEMS as an alternative to calculation with emission equations but that, by the time...
Ikeda, Shu-Ichi
2012-01-01
Leukoencephalopathy or leukodystrophy is characterized pathologically by extensive degenerative and/or demyelinating lesions in cerebral white matter and produces various clinical manifestations such as behavioral and/or mood changes, dementia, motor impairment and epilepsy. The hereditary form of this disease is rare, but recent advances in diagnostic techniques have made it possible to make a correct pre-mortem diagnosis for some diseases including CADASIL and CARASIL. Recently, another unique form of the disease, hereditary diffuse leukoencephalopathy with axonal spheroids (HDLS) has been noted. The clinical picture of HDLS is as follows: age of onset ranging from 8 to 78 years (average: 39 years), autosomal dominant inheritance, and dementia. The presence of numerous neuroaxonal spheroid in cerebral white matter is one of the pathologic hallmarks of HDLS. Another term "familial pigmentary orthochromatic leukodystrophy (POLD)" has been also used for the patients showing similar clinical pictures and pathologic findings of the patients. Both disorders are now regarded as a single disease entity. Rademakers et al have just reported that HDLS is caused by mutation in the colony stimulating factor 1 receptor gene (CSF1R) and HDLS should be included in the differential diagnosis of familial occurrence of pre-senile dementia.
Scherrer, Martin C; Dobson, Keith S; Quigley, Leanne
2014-09-01
This study identified and examined a set of potential predictors of self-reported negative mood following a depressive mood induction procedure (MIP) in a sample of previously depressed, clinically anxious, and control participants. The examined predictor variables were selected on the basis of previous research and theories of depression, and included symptoms of depression and anxiety, negative and positive affect, negative and positive automatic thoughts, dysfunctional beliefs, rumination, self-concept, and occurrence and perceived unpleasantness of recent negative events. The sample consisted of 33 previously depressed, 22 currently anxious, and 26 non-clinical control participants, recruited from community sources. Participant group status was confirmed through structured diagnostic interviews. Participants completed the Velten negative self-statement MIP as well as self-report questionnaires of affective, cognitive, and psychosocial variables selected as potential predictors of mood change. Symptoms of anxiety were associated with increased self-reported negative mood shift following the MIP in previously depressed participants, but not clinically anxious or control participants. Increased occurrence of recent negative events was a marginally significant predictor of negative mood shift for the previously depressed participants only. None of the other examined variables was significant predictors of MIP response for any of the participant groups. These results identify factors that may increase susceptibility to negative mood states in previously depressed individuals, with implications for theory and prevention of relapse to depression. The findings also identify a number of affective, cognitive, and psychosocial variables that do not appear to influence mood change following a depressive MIP in previously depressed, currently anxious, and control individuals. Limitations of the study and directions for future research are discussed. Current anxiety
Forcen, Fernando Espi; Martinez, Fernando Luis Espi; Moya, Amparo Martinez
2012-01-01
Varenicline is gaining popularity for the treatment of nicotine dependence. General treatment guidelines recommend monitoring for behavioral changes in patients with a mental illness. There are very few cases reported on patients developing psychiatric symptoms with no previous history. We are reporting the case of a Spanish patient who had developed a first-psychotic episode after he was started on varenicline. He was ultimately diagnosed with a paranoid personality disorder. Therefore, prior to starting a patient on varenicline, the clinician must identify possible paranoid and other cluster A personality traits. It is essential to monitor for new onset of psychotic symptoms during the treatment with this drug.
Gong, Hyun Sik; Jeon, Su Ha; Baek, Goo Hyun
2009-01-01
Scaphoid excision and four-corner fusion is one of the treatment choices for patients who have stage II or III SLAC (scapholunate advanced collapse)/SNAC (scaphoid non-union advanced collapse) wrist arthritis. We report a case of ulnar-sided wrist pain which occurred after four-corner fusion for stage II SNAC wrist with a previously-asymptomatic ulnar positive variance, and was successfully treated by ulnar shortening osteotomy. This case highlights a possible coincidental pathology of the ulnocarpal joint in the setting of post-traumatic radiocarpal arthrosis.
Ehemann, N R; González-González, L V; Trites, A W
2017-03-01
Three rays opportunistically obtained near Margarita Island, Venezuela, were identified as lesser devil rays Mobula cf. hypostoma, but their disc widths were between 207 and 230 cm, which is almost double the reported maximum disc width of 120 cm for this species. These morphometric data suggest that lesser devil rays are either larger than previously recognized or that these specimens belong to an unknown sub-species of Mobula in the Caribbean Sea. Better data are needed to describe the distribution, phenotypic variation and population structure of this poorly known species.
Seung Eun Bae
2013-10-01
Full Text Available A single specimen of the genus Sillago, collected from Gwangyang, Korea, in May 2009, is characterized by XI first dorsal fin spines, 3 or 4 rows of melanophore pattern along the second dorsal fin membrane, and a darkish posterior margin of the caudal fin. Our specimen was identified as Sillago sinica reported as a new species; this identification is confirmed by mitochondrial DNA cytochrome oxidase subunit I sequences, which show that our specimen corresponds to S. sinica (d=0.000 and differs from the congeneric species Sillago parvisquamis (d=0.170. Comparisons of Korean specimens previously reported as S. parvisquamis with specimens of S. sinica show that the S. parvisquamis specimens are actually S. sinica. We propose the new Korean name “buk-bang-jeom-bo-ri-myeol” for S. sinica.
Reporting Results from Structural Equation Modeling Analyses in Archives of Scientific Psychology.
Hoyle, Rick H; Isherwood, Jennifer C
2013-02-01
Psychological research typically involves the analysis of data (e.g., questionnaire responses, records of behavior) using statistical methods. The description of how those methods are used and the results they produce is a key component of scholarly publications. Despite their importance, these descriptions are not always complete and clear. In order to ensure the completeness and clarity of these descriptions, the Archives of Scientific Psychology requires that authors of manuscripts to be considered for publication adhere to a set of publication standards. Although the current standards cover most of the statistical methods commonly used in psychological research, they do not cover them all. In this manuscript, we propose adjustments to the current standards and the addition of additional standards for a statistical method not adequately covered in the current standards-structural equation modeling (SEM). Adherence to the standards we propose would ensure that scholarly publications that report results of data analyzed using SEM are complete and clear.
S. Guerriero
2011-01-01
Full Text Available Hepatocellular carcinoma rarely metastasizes to the orbit. We report a 45-year-old male, HBV+, HIV+, with a past history of a liver transplant for ELSD (end-stage liver disease with hepatocellular carcinoma and recurrent HCC, who presented with proptosis and diplopia of the left eye. CT scans of the head revealed a large, irregular mass in the left orbit causing superior and lateral destruction of the orbital bone. Biopsy specimens of the orbital tumor showed features of metastatic foci of hepatocellular carcinoma. Only 16 other cases of HCC metastasis to the orbit have been described in literature, and this is the first case in a previously transplanted HIV+, HBV+ patient.
Buchner, Amos; Vered, Marilena
2013-11-01
To analyze neoplastic and hamartomatous variants of ameloblastic fibromas (AFs). Analysis of 172 cases (162 previously reported, 10 new). AF emerged as a lesion primarily of children and adolescents (mean age, 14.9 years), with about 80% diagnosed when odontogenesis is completed (age, 22 years are considered true neoplasms, while those in younger patients may be either true neoplasms or odontomas in early stages of development. Although the histopathology of hamartomatous and neoplastic variants of AF are indistinguishable, clinical and radiologic features can be of some help to distinguish between them. Asymptomatic small unilocular lesions with no or minimal bone expansion in young individuals are likely to be developing odontomas, and large, expansile lesions with extensive bone destruction are neoplasms. Copyright © 2013 Elsevier Inc. All rights reserved.
Tang, Fang; Yang, Shengming; Liu, Jinge; Zhu, Hongyan
2016-01-01
Rj4 is a dominant gene in soybeans (Glycine max) that restricts nodulation by many strains of Bradyrhizobium elkanii. The soybean-B. elkanii symbiosis has a low nitrogen-fixation efficiency, but B. elkanii strains are highly competitive for nodulation; thus, cultivars harboring an Rj4 allele are considered favorable. Cloning the Rj4 gene is the first step in understanding the molecular basis of Rj4-mediated nodulation restriction and facilitates the development of molecular tools for genetic improvement of nitrogen fixation in soybeans. We finely mapped the Rj4 locus within a small genomic region on soybean chromosome 1, and validated one of the candidate genes as Rj4 using both complementation tests and CRISPR/Cas9-based gene knockout experiments. We demonstrated that Rj4 encodes a thaumatin-like protein, for which a corresponding allele is not present in the surveyed rj4 genotypes, including the reference genome Williams 82. Our conclusion disagrees with the previous report that Rj4 is the Glyma.01G165800 gene (previously annotated as Glyma01g37060). Instead, we provide convincing evidence that Rj4 is Glyma.01g165800-D, a duplicated and unique version of Glyma.01g165800, that has evolved the ability to control symbiotic specificity. © 2016 American Society of Plant Biologists. All Rights Reserved.
Tang, Fang; Yang, Shengming; Liu, Jinge
2016-01-01
Rj4 is a dominant gene in soybeans (Glycine max) that restricts nodulation by many strains of Bradyrhizobium elkanii. The soybean-B. elkanii symbiosis has a low nitrogen-fixation efficiency, but B. elkanii strains are highly competitive for nodulation; thus, cultivars harboring an Rj4 allele are considered favorable. Cloning the Rj4 gene is the first step in understanding the molecular basis of Rj4-mediated nodulation restriction and facilitates the development of molecular tools for genetic improvement of nitrogen fixation in soybeans. We finely mapped the Rj4 locus within a small genomic region on soybean chromosome 1, and validated one of the candidate genes as Rj4 using both complementation tests and CRISPR/Cas9-based gene knockout experiments. We demonstrated that Rj4 encodes a thaumatin-like protein, for which a corresponding allele is not present in the surveyed rj4 genotypes, including the reference genome Williams 82. Our conclusion disagrees with the previous report that Rj4 is the Glyma.01G165800 gene (previously annotated as Glyma01g37060). Instead, we provide convincing evidence that Rj4 is Glyma.01g165800-D, a duplicated and unique version of Glyma.01g165800, that has evolved the ability to control symbiotic specificity. PMID:26582727
Moses, Tim; Holland, Paul
2007-01-01
The purpose of this study was to empirically evaluate the impact of loglinear presmoothing accuracy on equating bias and variability across chained and post-stratification equating methods, kernel and percentile-rank continuization methods, and sample sizes. The results of evaluating presmoothing on equating accuracy generally agreed with those of…
control theory to systems described by partial differential equations. The intent is not to advance the theory of partial differential equations per se. Thus all considerations will be restricted to the more familiar equations of the type which often occur in mathematical physics. Specifically, the distributed parameter systems under consideration are represented by a set of field
Hörnell, Agneta; Winkvist, Anna; Hallmans, Göran; Weinehall, Lars; Johansson, Ingegerd
2010-10-30
Food pattern analyses are popular tools in the study of associations between diet and health. However, there is a need for further evaluation of this methodology. The aim of the present cross-sectional study was to evaluate the relationship between food pattern groups (FPG) and existing health, and to identify factors influencing this relationship. The inhabitants of Västerbotten County in northern Sweden are invited to health check-ups when they turn 30, 40, 50, and 60 years of age. The present study includes data collected from almost 60,000 individuals between 1992 and 2005. Associations between FPG (established using K-means cluster analyses) and health were analyzed separately in men and women. The health status of the participants and their close family and reporting accuracy differed significantly between men and women and among FPG. Crude regression analyses, with the high fat FPG as reference, showed increased risks for several health outcomes for all other FPGs in both sexes. However, when limiting analysis to individuals without previous ill-health and with adequate energy intake reports, most of the risks instead showed a trend towards protective effects. Food pattern classifications reflect both eating habits and other own and family health related factors, a finding important to remember and to adjust for before singling out the diet as a primary cause for present and future health problems. Appropriate exclusions are suggested to avoid biases and attenuated associations in nutrition epidemiology.
Li, Xigong; Lou, Xianfeng; Lin, Xiangjin; Du, Junhua
2014-05-01
Kyphoplasty has been shown to provide symptomatic relief of vertebral compression fractures refractory to medical therapy. However, few reports have focused on refracture of cemented vertebrae after kyphoplasty. The presence of cemented vertebrae refracture concurrent with cement fragmentation is an extremely rare condition. We reported an 86-year-old man with a T12 osteoporotic compression fracture undergoing the kyphoplasty treatment. The patient postoperatively continued to have back pain at the same level. The solid lumped polymethylmethacrylate (PMMA) mass and inadequate use and insufficient filling of PMMA cement were observed in postoperative radiographs and magnetic resonance image (MRI) examination. He refused to receive the surgical intervention, but had not strict compliance with oral anti-osteoporotic medications. Ten months postoperatively, refracture of osteoporotic vertebral body concurrent with cement fragmentation occurred at the previously kyphoplasty-treated vertebral level. Bone mineral analysis showed severe osteoporosis with a T-score of -4.0. The patient finally obtained therapeutic benefit of pain relief and bony union of T12 vertebral body by consistently adhering to anti-osteoporotic medication treatment. This case illustrated that patients who underwent kyphoplasty to treat osteoporotic vertebral compression fractures with intravertebral fracture should be strictly followed up and supervised in their anti-osteoporotic medication treatment. The interdigitation injection pattern of PMMA and sufficient PMMA filling with trabeculae in the kyphoplasty procedure also might prevent refracture of the cemented vertebrae concurrent with PMMA fragmentation.
Weinehall Lars
2010-10-01
Full Text Available Abstract Background Food pattern analyses are popular tools in the study of associations between diet and health. However, there is a need for further evaluation of this methodology. The aim of the present cross-sectional study was to evaluate the relationship between food pattern groups (FPG and existing health, and to identify factors influencing this relationship. Methods The inhabitants of Västerbotten County in northern Sweden are invited to health check-ups when they turn 30, 40, 50, and 60 years of age. The present study includes data collected from almost 60,000 individuals between 1992 and 2005. Associations between FPG (established using K-means cluster analyses and health were analyzed separately in men and women. Results The health status of the participants and their close family and reporting accuracy differed significantly between men and women and among FPG. Crude regression analyses, with the high fat FPG as reference, showed increased risks for several health outcomes for all other FPGs in both sexes. However, when limiting analysis to individuals without previous ill-health and with adequate energy intake reports, most of the risks instead showed a trend towards protective effects. Conclusions Food pattern classifications reflect both eating habits and other own and family health related factors, a finding important to remember and to adjust for before singling out the diet as a primary cause for present and future health problems. Appropriate exclusions are suggested to avoid biases and attenuated associations in nutrition epidemiology.
Kroos, Marian; Hoogeveen-Westerveld, Marianne; Michelakakis, Helen; Pomponio, Robert; Van der Ploeg, Ans; Halley, Dicky; Reuser, Arnold
2012-08-01
Pompe disease is an autosomal recessive lysosomal glycogen storage disorder, characterized by progressive muscle weakness. Deficiency of acid α-glucosidase (EC; 3.2.1.20/3) can be caused by numerous pathogenic variants in the GAA gene. The Pompe Disease Mutation Database at http://www.pompecenter.nl aims to list all variants and their effect. This update reports on 94 variants. We examined 35 novel and 34 known mutations by site-directed mutagenesis and transient expression in COS-7 cells or HEK293T cells. Each of these mutations was given a severity rating using a previously published system, based on the level of acid α-glucosidase activity in medium and transfected cells and on the quantity and quality of the different molecular mass species in the posttranslational modification and transport of acid α-glucosidase. This approach enabled to classify 55 missense mutations as pathogenic and 13 as likely nonpathogenic. Based on their nature and the use of in silico analysis (Alamut® software), 12 of the additional 25 novel mutations were predicted to be pathogenic including 4 splicing mutations, 6 mutations leading to frameshift, and 2 point mutations causing stop codons. Seven of the additional mutations were considered nonpathogenic (4 silent and 3 occurring in intron regions), and 6 are still under investigation.
Norton Sandra
2006-10-01
Full Text Available Abstract Background Hamate hook fracture is a common fracture in golfers and others who play sports that involve rackets or sticks such as tennis or hockey. This patient had a previous hamate fracture in the opposing wrist along with potential features of hamate bipartite. Case presentation A 19 year old male presented with a complaint of right wrist pain on the ulnar side of the wrist with no apparent mechanism of injury. The pain came on gradually one week before being seen in the office and he reported no prior care for the complaint. His history includes traumatic left hamate hook fracture with surgical excision. Conclusion The patient was found to have marked tenderness over the hamate and with a prior fracture to the other wrist, computed tomography of the wrist was ordered revealing a fracture to the hamate hook in the right wrist. He was referred for surgical evaluation and the hook of the hamate was excised. Post-surgically, the patient was able to return to normal activity within eight weeks. This case is indicative of fracture rather than hamate bipartite. This fracture should be considered in a case of ulnar sided wrist pain where marked tenderness is noted over the hamate, especially after participation in club or racket sports.
Warth, Lucian C; Callaghan, John J; Liu, Steve S; Klaassen, Alison L; Goetz, Devon D; Johnston, Richard C
2014-11-05
We report the updated results for a previously described cohort of patients who were less than fifty years old at the time of the index Charnley total hip arthroplasty with cement. The original cohort consisted of ninety-three consecutive hips in sixty-nine patients. The patients were followed for a minimum of thirty-five years after surgery or until death. At the latest follow-up evaluation, there were forty-one total hip replacements (44%) in thirty-two living patients. Thirty-four (37%) of the ninety-three total hip replacements in the original cohort had been revised or removed. Twenty acetabular (22%) and seven femoral (8%) components had been revised for aseptic loosening. Since the twenty-five-year follow-up, the average six-minute-walk distance decreased from 395 m to 171 m, and this decrease correlated with increasing comorbidity. This study demonstrates the durability of cemented total hip replacements in a young patient population. Although 63% (fifty-nine) of the ninety-three original hip replacements were functioning at the latest follow-up or at the time of death, a significant decrease in activity level was seen over time (p < 0.001). Of the forty-one original implants in the patients who were alive at the time of the thirty-five-year follow-up, only 46% (nineteen) were retained. Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.
Grant, Mary C.; Zhang, Lilly; Damiano, Michele
2009-01-01
This study investigated kernel equating methods by comparing these methods to operational equatings for two tests in the SAT Subject Tests[TM] program. GENASYS (ETS, 2007) was used for all equating methods and scaled score kernel equating results were compared to Tucker, Levine observed score, chained linear, and chained equipercentile equating…
Impact of Local Item Dependence on True-Score Equating. LSAC Research Report Series.
Reese, Lynda M.; Pashley, Peter J.
This study investigated the practical effects of local item dependence (LID) on item response theory (IRT) true-score equating. A scenario was defined that emulated the Law School Admission Test (LSAT) preequating model, and data were generated to assess the impact of different degrees of LID on final equating outcomes. An extreme amount of LID…
The Kernel Levine Equipercentile Observed-Score Equating Function. Research Report. ETS RR-13-38
von Davier, Alina A.; Chen, Haiwen
2013-01-01
In the framework of the observed-score equating methods for the nonequivalent groups with anchor test design, there are 3 fundamentally different ways of using the information provided by the anchor scores to equate the scores of a new form to those of an old form. One method uses the anchor scores as a conditioning variable, such as the Tucker…
Sampling of Common Items: An Unrecognized Source of Error in Test Equating. CSE Report 636
Michaelides, Michalis P.; Haertel, Edward H.
2004-01-01
There is variability in the estimation of an equating transformation because common-item parameters are obtained from responses of samples of examinees. The most commonly used standard error of equating quantifies this source of sampling error, which decreases as the sample size of examinees used to derive the transformation increases. In a…
Lattice Boltzmann model for nonlinear convection-diffusion equations.
Shi, Baochang; Guo, Zhaoli
2009-01-01
A lattice Boltzmann model for convection-diffusion equation with nonlinear convection and isotropic-diffusion terms is proposed through selecting equilibrium distribution function properly. The model can be applied to the common real and complex-valued nonlinear evolutionary equations, such as the nonlinear Schrödinger equation, complex Ginzburg-Landau equation, Burgers-Fisher equation, nonlinear heat conduction equation, and sine-Gordon equation, by using a real and complex-valued distribution function and relaxation time. Detailed simulations of these equations are performed, and it is found that the numerical results agree well with the analytical solutions and the numerical solutions reported in previous studies.
Callaghan, John J; Wells, Christopher W; Liu, Steve S; Goetz, Devon D; Johnston, Richard C
2010-07-07
We previously evaluated 119 consecutive total knee arthroplasties performed by a single surgeon in eighty-six patients with use of the cemented LCS (low contact stress) mobile-bearing, rotating-platform system and an all-polyethylene patellar component. The average age of the patients at the time of surgery was seventy years. The patients were contacted as part of their routine follow-up and were asked to participate in this study. The purpose of the present study was to report the updated results at a minimum follow-up of twenty years. Twenty patients (twenty-six knees) were living, and one was lost to follow-up. Three knees required a reoperation (two for periprosthetic fractures and one for infection). No component was revised as a part of the reoperations. No knee required revision since the fifteen-year follow-up evaluation. Osteolysis was present in six knees compared with only three knees at the time of the fifteen-year follow-up. One knee had radiographic signs of femoral component loosening, which was associated with osteolysis. It occurred after the fifteen-year follow-up study. The average range of motion was from 1 degrees of extension to 105 degrees of flexion. The average clinical and functional Knee Society scores were 43 and 49 points, respectively, at the preoperative evaluation and 89 and 67 points at the time of the final follow-up. We concluded that the cemented LCS rotating-platform knee performed well, with durable clinical and radiographic results at a minimum follow-up of twenty years. However, the prevalence of osteolysis continues to increase with a longer duration of follow-up in these patients.
Pingenot, J; Jandhyala, V
2007-03-01
This report summarizes the work performed for Lawrence Livermore National Laboratory (LLNL) at the University of Washington between September 2004 and May 2006. This project studied fast solvers and stability for time domain integral equations (TDIE), especially as applied to radiating boundary for a massively parallel FEM solver.
Repeater Effects on Score Equating for a Graduate Admissions Exam. Research Report. ETS RR-11-17
Yang, Wen-Ling; Bontya, Andrea M.; Moses, Tim P.
2011-01-01
Using self-reported but empirically verified repeater groups, we analyzed vast amounts of real test data across a wide range of administrations from a graduate admissions examination that was administered in a non-English language to investigate repeater effects on score equating using the nonequivalent groups with anchor test (NEAT) design. Both…
Andrea Prosperetti
2006-03-24
The report briefly describes the activities carried out in the course of the project. A first line of research was the development of systematic closure relations for averaged equations for disperse multiphase flow. A second line was the development of efficient numerical methods for the simulation of Navier-Stokes flows with many suspended particles. The report also lists the 21 journal articles in which this work is more fully decsribed.
The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...
Young, C.W. [Applied Research Associates, Inc., Albuquerque, NM (United States)
1997-10-01
In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.
Numerical solution of systems of simultaneous polynomial equations. Technical report SOL 83-10
Rosenberg, A.N.
1983-07-01
A program for finding all real and complex solutions to a system of simultaneous polynomial equations is developed and tested. The program uses a homotopy method to follow paths from solutions of an easy system of equations to solutions of the system of equations being solved. A continuous path-following method takes advantage of the differential information available and does not require the structure of a subdivision to be superimposed on the structure of the problem, as would be the case with a piecewise-linear method. The numerical methods used in the program are chosen empirically. The way an algorithm misbehaves tells about the problem being solved and suggests computational techniques. Problems synthesized by random number generators and problems from other sources are solved by the program. It finds all but a few roots for most systems the size of three quartics in three unknowns or five quadratics in five unknowns. Isolated roots are accurate to machine precision.
Okech, David
2012-01-01
Objectives: Using baseline and second wave data, the study evaluated the measurement and structural properties of parenting stress, personal mastery, and economic strain with N = 381 lower income parents who decided to join and those who did not join in a child development savings account program. Methods: Structural equation modeling mean and…
NSGIC GIS Inventory (aka Ramona) — This Parcels and Land Ownership dataset as of 2008. It is described as 'reported in previous surveys to have parcel GIS capability; however no website or evidence...
Lindgren, Natalie K; Sisson, Melissa S; Archambeault, Alan D; Rahlwes, Brent C; Willett, James R; Bucheli, Sibyl R
2015-03-01
A yearlong survey of insect taxa associated with human decomposition was conducted at the Southeast Texas Applied Forensic Science (STAFS) facility located in the Center for Biological Field Studies of Sam Houston State University in Huntsville, TX. During this study, four insect-cadaver interactions were observed that represent previously poorly documented yet forensically significant interactions: Syrphidae maggots colonized a corpse in an aquatic situation; Psychodidae adults mated and oviposited on an algal film that was present on a corpse that had been recently removed from water; several Panorpidae were the first insects to feed upon a freshly placed corpse in the autumn; and a noctuid caterpillar was found chewing and ingesting dried human skin. Baseline knowledge of insect-cadaver interactions is the foundation of forensic entomology, and unique observations have the potential to expand our understanding of decomposition ecology.
Callaghan, John J; Bracha, Peter; Liu, Steve S; Piyaworakhun, Somyot; Goetz, Devon D; Johnston, Richard C
2009-11-01
The purpose of this study was to update the results, at a minimum of thirty-five years, in a single-surgeon series of primary Charnley total hip arthroplasties performed with cement. Twelve patients (fifteen hips) were alive, 249 patients (314 hips) had died, and one patient (one hip) had been lost to follow-up. Seven of the hips in the living patients had required at least one revision; 290 (88%) of the original group of total hip prostheses either continued to function or were in patients who had died. Since the time of a thirty-year study of this cohort, one hip that had previously been revised because of acetabular loosening required an additional revision because of acetabular loosening and two additional hips had evidence of radiographic loosening (of one acetabular and one femoral component). The survival rate with revision for any reason as the end point was 78%. This end result study should provide a benchmark for subsequent procedures and designs with the caveat that patient life expectancy will likely continue to increase and modern-design implants are being used in younger patients.
O'Brien, Carolyn R; Malik, Richard; Globan, Maria; Reppas, George; McCowan, Christina; Fyfe, Janet A
2017-09-01
This paper, the last in a series of three on 'feline leprosy', provides a detailed description of disease referable to the previously unnamed species, Candidatus 'Mycobacterium lepraefelis', a close relative of the human pathogens Mycobacterium leprae and Mycobacterium lepromatosis. Cases were sourced retrospectively and prospectively for this observational study, describing clinical, geographical and molecular microbiological data for cats definitively diagnosed with Candidatus 'M lepraefelis' infection. A total of 145 cases of feline leprosy were scrutinised; 114 'new' cases were sourced from the Victorian Infectious Diseases Reference Laboratory (VIDRL) records, veterinary pathology laboratories or veterinarians, and 31 cases were derived from six published studies. Thirty-eight cats were definitively diagnosed with Candidatus 'M lepraefelis' infection. Typically, cats tended to be middle-aged or older when first infected, with a male predilection. Affected cats typically had widespread cutaneous lesions, in some cases after initially localised disease. Advanced cases were often systemically unwell. All cats had outdoor access. The histological picture was lepromatous in the majority of patients, although two cases had tuberculoid disease. In one case that underwent necropsy, lesions were evident in the liver, spleen and lungs. Treatment was varied, although most cats received a combination of oral clarithromycin and rifampicin. Prognosis for recovery was variable, but typically poor. Candidatus 'M lepraefelis' typically causes high bacterial index (lepromatous) feline leprosy that in some cases progresses to systemic mycobacteriosis. The disease has a variable clinical course and prognosis. Many cases either died or were euthanased due to the infection. Multilocus sequence analysis reveals a heterogeneous picture and further analysis of draft genome sequencing may give clues to the taxonomy and epidemiology of this organism. Prospective treatment trials and
Brian Spencer Hoyt
2014-01-01
Full Text Available Radiation therapy is associated with a variety of complications, including the development of primary skin cancers in the radiated region. However, it is rare for patients with visceral cancers who are treated with radiation therapy to subsequently develop cutaneous metastasis within the radiation port. We describe two patients with internal malignancies who developed cutaneous metastases within their radiation ports following radiotherapy. In addition, we used PubMed to perform an extensive literature review and identify additional reports of cutaneous metastasis within a radiation port. We excluded patients who developed melanoma or primary skin cancers in the radiation port. We also excluded patients with non-solid organ malignancies. Herein, we summarize the characteristics of 23 additional patients who experienced radiation port cutaneous metastases and explore possible mechanisms for the occurrence of radiation port cutaneous metastases.
Piane, Maria; Della Monica, Matteo; Piatelli, Gianluca; Lulli, Patrizia; Lonardo, Fortunato; Chessa, Luciana; Scarano, Gioacchino
2009-11-01
We report on a 3-year-old boy with prenatal onset of proportionate dwarfism, postnatal severe microcephaly, high forehead with receded hairline, sparse scalp hair, beaked nose, mild retrognathia and hypotonia diagnosed at birth as Seckel syndrome. At age 3 years, he became paralyzed due to a cerebrovascular malformation. Based on the clinical and radiological features showing evidence of skeletal dysplasia, the diagnosis was revised to Majewski osteodysplastic primordial dwarfism type II (MOPD II) syndrome. Western blot analysis of the patient's lymphoblastoid cell line lysate showed the absence of the protein pericentrin. Subsequent molecular analysis identified a novel homozygous single base insertion (c.1527_1528insA) in exon 10 of the PCNT gene, which leads to a frameshift (Treo510fs) and to premature protein truncation. PCNT mutations must be considered diagnostic of MOPD II syndrome. A possible role of pericentrin in the development of cerebral vessels is suggested. Copyright 2009 Wiley-Liss, Inc.
The Development of a Numerical Solution to the Transport Equation. Report 1. Methodology,
1983-09-01
0 h] 5y h ] Consider now the right hand side of (2.2). As previously men - tioned, the turbulent dispersion coefficients are developed from time...HuP) + a( HvP ) a HD - - y a HS =0 (8.1).at- ax ay ax x x ayA A. 2 2 1/2 au au u(u +v) 1 s-+ u - +v--fv+ g +g (8.2) at ax ay a x c2H pH x 2 2 1/2 av av
Qian, Jiahe; Jiang, Yanming; von Davier, Alina A.
2013-01-01
Several factors could cause variability in item response theory (IRT) linking and equating procedures, such as the variability across examinee samples and/or test items, seasonality, regional differences, native language diversity, gender, and other demographic variables. Hence, the following question arises: Is it possible to select optimal…
Glimm, James; Deng, Yuefan; Lindquist, W. Brent; Tangerman, Folkert
2001-08-30
The objectives of this research remain as stated in our proposal of November 1997. We report on progress in the quantification of uncertainty and prediction, with applications to flow in porous media and to shock wave physics. The main strength of this work is an innovative theory for the quantification of uncertainty based on models for solution errors in numerical simulations. We also emphasize a deep connection to application communities, including those in DOE Laboratories.
The Modified Magnetohydrodynamical Equations
EvangelosChaliasos
2003-01-01
After finding the really self-consistent electromagnetic equations for a plasma, we proceed in a similar fashion to find how the magnetohydrodynamical equations have to be modified accordingly. Substantially this is done by replacing the "Lorentz" force equation by the correct (in our case) force equation. Formally we have to use the vector potential instead of the magnetic field intensity. The appearance of the formulae presented is the one of classical vector analysis. We thus find a set of eight equations in eight unknowns, as previously known concerning the traditional MHD equations.
The Modified Magnetohydrodynamical Equations
Evangelos Chaliasos
2003-01-01
After finding the really self-consistent electromagnetic equations for a plasma, we proceed in a similarfashion to find how the magnetohydrodynamical equations have to be modified accordingly. Substantially this is doneby replacing the "Lorentz" force equation by the correct (in our case) force equation. Formally we have to use the vectorpotential instead of the magnetic field intensity. The appearance of the formulae presented is the one of classical vectoranalysis. We thus find a set of eight equations in eight unknowns, as previously known concerning the traditional MHDequations.
Sakata, Junichi; Saito, Tatsuya; Fujii, Akira; Tsukamoto, Masaru; Date, Osamu; Yokoyama, Hideo; Abe, Tomio; Nakase, Atsunobu; Ohori, Katsumi
2014-08-01
Performing a redo-sternotomy when a mammary artery graft is patent can be rather difficult. We previously reported a redo-sternotomy technique involving direct visualization with a retrosternal dissection (DR) method using a Kent's retractor. The DR method in detail is as follows: 1) A midline skin incision is extended to the abdomen about 5 cm. 2) The bilateral costal arches are divided from the rectal muscle. 3). A pair of retractors is placed under the costal arch. 4) A stainless steel wire is applied to the previous sternal wire at the center of the sternum. 5) The retractor and sternal wire are lifted up using the Kent's retractor to widen the retrosternal space. 6) The sternum and sub-sternal tissue are carefully divided using an electronic scalpel or metal retractor with an entirely sternal length. 7) Routine sternotomy is performed using a Stryker. Herein, we report a patient who had undergone cardiac surgery, coronary artery bypass grafting (CABG), using a left internal mammary artery and mitral annuloplasty 2 years previously, and then developed mitral regurgitation caused by infectious endocarditis. He successfully underwent redo-sternotomy and mitral valve replacement using the DR method. In a patient with a patent internal mammary artery, the DR method greatly reduces the risk of graft injury.
A Bayesian Nonparametric Approach to Test Equating
Karabatsos, George; Walker, Stephen G.
2009-01-01
A Bayesian nonparametric model is introduced for score equating. It is applicable to all major equating designs, and has advantages over previous equating models. Unlike the previous models, the Bayesian model accounts for positive dependence between distributions of scores from two tests. The Bayesian model and the previous equating models are…
Kusakari, Yoshiyuki; Yamasaki, Kenshi; Takahashi, Toshiya; Tsuchiyama, Kenichiro; Shimada-Omori, Ryoko; Nasu-Tamabuchi, Mei; Aiba, Setsuya
2015-07-01
The efficacy and safety of biologic treatments have been established in patients with moderate to severe psoriasis, but there are few reports on biologic therapy for patients with psoriasis complicated by end-stage renal failure on hemodialysis (HD). In this report, we demonstrated the efficacy and safety of adalimumab for patients with severe psoriasis on HD. A 46-year-old Japanese man with a 14-year history of psoriasis was referred to our clinic in September 2009. He had developed hypertension and renal failure during a 7-year history of cyclosporin treatment. With the infliximab treatment, he achieved 75% improvement of the Psoriasis Area and Severity Index (PASI) score within 3 months from the PASI of 42.3 before the treatment. However, his renal failure gradually deteriorated, and HD was initiated at 1 year after the introduction of infliximab. Because of hydration during the i.v. injection of infliximab, he developed pulmonary edema with every infliximab treatment after starting HD. We switched to ustekinumab treatment, but his psoriasis was not improved. Then, we switched to adalimumab and achieved a PASI-100 response within 2 months. The patient received adalimumab treatment for more than a year without any adverse effects. In addition to our case, five articles reported cases of psoriasis patients with renal failure on HD who were treated with biologics. The psoriatic lesions were improved by biologics in these cases, and no severe adverse effects on the renal function were reported. Thus, biologics are a reasonable treatment option for patients with severe psoriasis with renal failure on HD.
Ammar H Hakim
2011-10-20
In this Phase I project we have extended the BOUT++ code to solve edge fluid equations. We added a simple neutral fluid model, created a mesh generator as well as collected a set of difficult test problems for benchmarking edge codes. The work in this project should be useful as a starting point to build a complete set of edge fluid equations in BOUT++ that would enhance its ability to not only perform edge turbulence calculations, but also allow the coupled transport-turbulence equations evolved in an efficient manner.
Clarke Philip M
2011-09-01
Full Text Available Abstract Background Many studies have documented the bias in body mass index (BMI determined from self-reported data on height and weight, but few have examined the change in bias over time. Methods Using data from large, nationally-representative population health surveys, we examined change in bias in height and weight reporting among Australian adults between 1995 and 2008. Our study dataset included 9,635 men and women in 1995 and 9,141 in 2007-2008. We investigated the determinants of the bias and derived correction equations using 2007-2008 data, which can be applied when only self-reported anthropometric data are available. Results In 1995, self-reported BMI (derived from height and weight was 1.2 units (men and 1.4 units (women lower than measured BMI. In 2007-2008, there was still underreporting, but the amount had declined to 0.6 units (men and 0.7 units (women below measured BMI. The major determinants of reporting error in 2007-2008 were age, sex, measured BMI, and education of the respondent. Correction equations for height and weight derived from 2007-2008 data and applied to self-reported data were able to adjust for the bias and were accurate across all age and sex strata. Conclusions The diminishing reporting bias in BMI in Australia means that correction equations derived from 2007-2008 data may not be transferable to earlier self-reported data. Second, predictions of future overweight and obesity in Australia based on trends in self-reported information are likely to be inaccurate, as the change in reporting bias will affect the apparent increase in self-reported obesity prevalence.
Xu, Yan; Lei, Huo; Dong, Hong; Zhang, Liping; Qin, Qionglian; Gao, Jianmei; Zou, Yunlian; Yan, Xinmin
2009-09-01
Previous studies found that the forkhead transcription factor 2 (FOXL2) gene mutations are responsible for both types of blepharophimosis-ptosis-epicanthus inversus syndrome (BPES) but have not established any systematic statistic model for the complex and even contradictory results about genotype-phenotype correlations between them. This study is aimed to find possible mutations of FOXL2 gene in a Chinese family with type II BPES by using DNA sequencing and to further clarify genotype-phenotype correlations between FOXL2 mutations and BPES by using a systematic statistical method, namely Multifactor Dimensionality Reduction (MDR). A novel mutation (g.933_965dup) which could result in an expansion of the polyalanine (polyAla) tract was detected in all patients of this family. MDR analysis for intragenic mutations of FOXL2 gene reported in previous BPES studies indicated that the mutations which led to much stronger disturbance of amino acid sequence were responsible for more type I BPES, while other kinds of mutation were responsible for more type II BPES. In conclusion, the present study found a novel FOXL2 gene mutation in a Chinese BPES family and a new general genotype-phenotype correlation tendency between FOXL2 intragenic mutations and BPES, both of which expanded the knowledge about FOXL2 gene and BPES.
Abstract methods in partial differential equations
Carroll, Robert W
2012-01-01
Detailed, self-contained treatment examines modern abstract methods in partial differential equations, especially abstract evolution equations. Suitable for graduate students with some previous exposure to classical partial differential equations. 1969 edition.
Wei Khim Ng
2009-02-01
Full Text Available We construct nonlinear extensions of Dirac's relativistic electron equation that preserve its other desirable properties such as locality, separability, conservation of probability and Poincaré invariance. We determine the constraints that the nonlinear term must obey and classify the resultant non-polynomial nonlinearities in a double expansion in the degree of nonlinearity and number of derivatives. We give explicit examples of such nonlinear equations, studying their discrete symmetries and other properties. Motivated by some previously suggested applications we then consider nonlinear terms that simultaneously violate Lorentz covariance and again study various explicit examples. We contrast our equations and construction procedure with others in the literature and also show that our equations are not gauge equivalent to the linear Dirac equation. Finally we outline various physical applications for these equations.
Savović, Svetislav; Djordjevich, Alexandar
2002-05-20
The power-flow equation is approximated by the Fokker-Planck equation that is further transformed into a stochastic differential (Langevin) equation, resulting in an efficient method for the estimation of the state of mode coupling along step-index optical fibers caused by their intrinsic perturbation effects. The inherently stochastic nature of these effects is thus fully recognized mathematically. The numerical integration is based on the computer-simulated Langevin force. The solution matches the solution of the power-flow equation reported previously. Conceptually important steps of this work include (i) the expression of the power-flow equation in a form of the diffusion equation that is known to represent the solution of the stochastic differential equation describing processes with random perturbations and (ii) the recognition that mode coupling in multimode optical fibers is caused by random perturbations.
Magnus, Wilhelm
2004-01-01
The hundreds of applications of Hill's equation in engineering and physics range from mechanics and astronomy to electric circuits, electric conductivity of metals, and the theory of the cyclotron. New applications are continually being discovered and theoretical advances made since Liapounoff established the equation's fundamental importance for stability problems in 1907. Brief but thorough, this volume offers engineers and mathematicians a complete orientation to the subject.""Hill's equation"" connotes the class of homogeneous, linear, second order differential equations with real, period
Studies on Microwave Heated Drying-rate Equations of Foods
1990-01-01
In order to design various microwave heated drying apparatuses, we must take drying-rate equations which are based on simple drying-rate models. In a previous paper (KUBOTA, et al., 1990), we have studied a convenient microwave heated drying instrument, and studied the simple drying-rate equations of potato and so on by using the simple empirical rate equations that have been reported in previous papers (KUBOTA, 1979-1, 1979-2). In this paper, we studied the microwave drying rate of the const...
No Previous Public Services Required
Taylor, Kelley R.
2009-01-01
In 2007, the Supreme Court heard a case that involved the question of whether a school district could be required to reimburse parents who unilaterally placed their child in private school when the child had not previously received special education and related services in a public institution ("Board of Education v. Tom F."). The…
Relativistic Guiding Center Equations
White, R. B. [PPPL; Gobbin, M. [Euratom-ENEA Association
2014-10-01
In toroidal fusion devices it is relatively easy that electrons achieve relativistic velocities, so to simulate runaway electrons and other high energy phenomena a nonrelativistic guiding center formalism is not sufficient. Relativistic guiding center equations including flute mode time dependent field perturbations are derived. The same variables as used in a previous nonrelativistic guiding center code are adopted, so that a straightforward modifications of those equations can produce a relativistic version.
Moiseiwitsch, B L
2005-01-01
Two distinct but related approaches hold the solutions to many mathematical problems--the forms of expression known as differential and integral equations. The method employed by the integral equation approach specifically includes the boundary conditions, which confers a valuable advantage. In addition, the integral equation approach leads naturally to the solution of the problem--under suitable conditions--in the form of an infinite series.Geared toward upper-level undergraduate students, this text focuses chiefly upon linear integral equations. It begins with a straightforward account, acco
Covariant equations for the NN-πNN system
Phillips, D. R.; Afnan, I. R.
1995-05-01
We explain the deficiencies of the current NN-πNN equations, sketch the derivation of a set of covariant NN-πNN equations and describe the ways in which these equations differ from previous sets of covariant equations.
刘丽; 衡伟
2015-01-01
近年来随着分子生物学研究的不断深入，靶向治疗成为当前肺癌治疗的趋势。目前肺癌个体化的最佳治疗效果日益受到重视，棘皮动物微管相关蛋白4-间变型淋巴瘤激酶（echinoderm microtubule associated protein like 4 anaplastic lymphoma kinase, EML4-ALK）融合基因作为新兴生物标记物是当前肺癌治疗领域研究热点。与此同时，随着抗肿瘤治疗水平的不断提高，生存期明显延长，发生多原发癌（multiple primary carcinomas, MPC）的机会增多。EML4-ALK融合基因阳性的肺腺癌合并淋巴瘤发生于同一患者文献报道罕见。本文报道1例ALK融合基因阳性的非小细胞肺癌（non-small cell lung cancer, NSCLC）合并淋巴瘤病例，同时对异时性肺癌合并淋巴瘤的文献进行复习。%In recent years, with the deepening of the research of molecular biology, targeted therapy has become one of the trend of lung cancer treatment. hTe individualized treatment of lung cancer is attached great importance at present. Echinoderm microtubule associated protein like 4 anaplastic lymphoma kinase (EML4-ALK) as a new biological marker is a hot topic in the ifeld of lung cancer treatment. Meanwhile, with the improvement of anticancer treatment and survival, the inci-dence of multiple primary carcinomas (MPC) has become increasingly. But the report that malignant lymphoma complicated with lung adenocarcinoma harboring EML4-ALK fusion gene in one individual is rare. Here, we report an EML4-ALK positive non-small cell lung cancer (NSCLC) in a patient previously diagnosed with T cell lymphoma and review literature on meta-chronous lung cancer complicating with lymphoma.
Lloyd K. Williams
1987-01-01
Full Text Available In this paper we find closed form solutions of some Riccati equations. Attention is restricted to the scalar as opposed to the matrix case. However, the ones considered have important applications to mathematics and the sciences, mostly in the form of the linear second-order ordinary differential equations which are solved herewith.
Prentis, Jeffrey J.
1996-05-01
One of the most challenging goals of a physics teacher is to help students see that the equations of physics are connected to each other, and that they logically unfold from a small number of basic ideas. Derivations contain the vital information on this connective structure. In a traditional physics course, there are many problem-solving exercises, but few, if any, derivation exercises. Creating an equation poem is an exercise to help students see the unity of the equations of physics, rather than their diversity. An equation poem is a highly refined and eloquent set of symbolic statements that captures the essence of the derivation of an equation. Such a poetic derivation is uncluttered by the extraneous details that tend to distract a student from understanding the essential physics of the long, formal derivation.
Molnar, Denes [Purdue Univ., West Lafayette, IN (United States)
2014-04-14
The Section below summarizes research activities and achievements during the first four years of the PI’s Early Career Research Project (ECRP). Two main areas have been advanced: i) radiative 3 ↔ 2 radiative transport, via development of a new computer code MPC/Grid that solves the Boltzmann transport equation in full 6+1D (3X+3V+time) on both single-CPU and parallel computers; ii) development of a self-consistent framework to convert viscous fluids to particles, and application of this framework to relativistic heavy-ion collisions, in particular, determination of the shear viscosity. Year 5 of the ECRP is under a separate award number, and therefore it has its own report document ’Final Technical Report for Year 5 of the Early Career Research Project “Viscosity and equation of state of hot and dense QCDmatter”’ (award DE-SC0008028). The PI’s group was also part of the DOE JET Topical Collaboration, a multi-institution project that overlapped in time significantly with the ECRP. Purdue achievements as part of the JET Topical Collaboration are in a separate report “Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration” (award DE-SC0004077).
Sacripanti, A. [ENEA, Rome (Italy). Direzione Sicurezza Nazionale e Protezione Sanitaria; Dal Monte, A. [CONI, Rome (Italy). Ist. di Scienza dello Sport; Rossi, L.; Fabbri, M. [ENEA, Casaccia (Italy)
1993-12-31
The foundation, evolution and related improvements of the new heat and mass transfer equation, used in the joint research of CONI-ENEA (the Italian National Agency for Energy, New Technologies and the Environment) - FILPJ are shown in this report. Emphasis is given to the experimental history and the changes that are justified in a more formal approach on the basis of theoretical thermodynamics or similarity and dimensional theory. The new form of the equation in the computer code actually utilized in the research is given in the appendix.
Tricomi, FG
2013-01-01
Based on his extensive experience as an educator, F. G. Tricomi wrote this practical and concise teaching text to offer a clear idea of the problems and methods of the theory of differential equations. The treatment is geared toward advanced undergraduates and graduate students and addresses only questions that can be resolved with rigor and simplicity.Starting with a consideration of the existence and uniqueness theorem, the text advances to the behavior of the characteristics of a first-order equation, boundary problems for second-order linear equations, asymptotic methods, and diff
Davidowitz, Bette; Chittleborough, Gail; Murray, Eileen
2010-01-01
This paper reports on a pedagogical approach to the teaching of chemical equations introduced to first year university students with little previous chemical knowledge. During the instruction period students had to interpret and construct diagrams of reactions at the submicro level, and relate them to chemical equations at the symbolic level with…
Davidowitz, Bette; Chittleborough, Gail; Murray, Eileen
2010-01-01
This paper reports on a pedagogical approach to the teaching of chemical equations introduced to first year university students with little previous chemical knowledge. During the instruction period students had to interpret and construct diagrams of reactions at the submicro level, and relate them to chemical equations at the symbolic level with…
Barbu, Viorel
2016-01-01
This textbook is a comprehensive treatment of ordinary differential equations, concisely presenting basic and essential results in a rigorous manner. Including various examples from physics, mechanics, natural sciences, engineering and automatic theory, Differential Equations is a bridge between the abstract theory of differential equations and applied systems theory. Particular attention is given to the existence and uniqueness of the Cauchy problem, linear differential systems, stability theory and applications to first-order partial differential equations. Upper undergraduate students and researchers in applied mathematics and systems theory with a background in advanced calculus will find this book particularly useful. Supplementary topics are covered in an appendix enabling the book to be completely self-contained.
Wang, Z J
2012-12-06
The overriding objective for this project is to develop an efficient and accurate method for capturing strong discontinuities and fine smooth flow structures of disparate length scales with unstructured grids, and demonstrate its potentials for problems relevant to DOE. More specifically, we plan to achieve the following objectives: 1. Extend the SV method to three dimensions, and develop a fourth-order accurate SV scheme for tetrahedral grids. Optimize the SV partition by minimizing a form of the Lebesgue constant. Verify the order of accuracy using the scalar conservation laws with an analytical solution; 2. Extend the SV method to Navier-Stokes equations for the simulation of viscous flow problems. Two promising approaches to compute the viscous fluxes will be tested and analyzed; 3. Parallelize the 3D viscous SV flow solver using domain decomposition and message passing. Optimize the cache performance of the flow solver by designing data structures minimizing data access times; 4. Demonstrate the SV method with a wide range of flow problems including both discontinuities and complex smooth structures. The objectives remain the same as those outlines in the original proposal. We anticipate no technical obstacles in meeting these objectives.
Cynthia L. Murray
2013-01-01
Full Text Available Objective. Researchers have established a preponderance of height overestimation among men and weight underestimation among women in self-reported anthropometric data, which skews obesity prevalence data and obscures obesity-chronic disease relationships. The objective of this study was to reevaluate associations between obesity and chronic diseases using body mass index (BMI correction equations derived from measured data. Methods. Measured height and weight (MHW data were collected on a subsample of the 17,126 Atlantic Canadians who participated in the 2007-2008 Canadian Community Health Survey (CCHS. To obtain corrected BMI estimates for the 17,126 adults, correction equations were developed in the MHW subsample and multiple regression procedures were used to model BMI. To test obesity-chronic disease relationships, logistic regression models were utilized. Results. The correction procedure eliminated statistically significant relations (P<0.05 between obesity and chronic bronchitis and obesity and stroke. Also, correction attenuated many relationships between adiposity and chronic disease. For example, among obese adults, there was a 13%, 12%, and 7% reduction in the adjusted odds ratios for asthma, urinary incontinence, and cardiovascular disease, respectively. Conclusion. Further research is needed to fully understand how the usage of self-reported data alters our understanding of the relationships between overweight or obesity and chronic diseases.
Sinharay, Sandip; Holland, Paul W.
2008-01-01
The nonequivalent groups with anchor test (NEAT) design involves missing data that are missing by design. Three popular equating methods that can be used with a NEAT design are the poststratification equating method, the chain equipercentile equating method, and the item-response-theory observed-score-equating method. These three methods each…
Dirac and Maxwell equations in Split Octonions
Beradze, Revaz
2016-01-01
The split octonionic form of Dirac and Maxwell equations are found. In contrast with the previous attempts these equations are derived from the octonionic analyticity condition and also we use different basis of the 8-dimensional space of split octonions.
All General Solutions of Post Equations
Dragi(c) BANKOVI(C)
2007-01-01
In a previous paper, we have described all reproductive general solutions of a Post equation, supposing that a general solution is known. In this paper we describe all general solutions of Post equation, supposing that a general solution of this equation is known (Theorem 6). As a special case we get the previous characterization of reproductive solutions and a similar result for Boolean equations (Theorem 9).
2002-03-01
Full Text Available According to models estimated separately for second-, third-, and fourth-birth rates in Norway, an increase took place from the mid-1970s to about 1990, given age and duration since last previous birth. A similar rise in the birth rates was seen in Sweden, except that the upturn at short durations was sharper. It is shown in this study, using Norwegian register data, that the increase partly reflects earlier changes in lower-order parity transitions. When models for each parity transition are estimated jointly, with a common unobserved factor included, there is no longer an upward trend in Norwegian second-birth rates, but a very weak decline, and the increase in the higher-order birth rates is strongly reduced compared to that found in the simpler approach.
Lee, Yi-Hsuan; von Davier, Alina A.
2008-01-01
The kernel equating method (von Davier, Holland, & Thayer, 2004) is based on a flexible family of equipercentile-like equating functions that use a Gaussian kernel to continuize the discrete score distributions. While the classical equipercentile, or percentile-rank, equating method carries out the continuization step by linear interpolation,…
Jaiswal, Neeshma; Upadhyay, S K; Malhotra, Anshu; Blend, Charles K; Dronen, Norman O; Malhotra, Sandeep K
2014-05-23
Neolebouria capoori n. sp. (Opecoelidae: Plagioporinae) is described from the whitecheek monocle bream, Scolopsis vosmeri (Bloch) (Perciformes: Nemipteridae) from the Panjim coast on the central west coast of India at Goa. The new species differs from both Neolebouria cantherhini (Li, Qiu & Zhang, 1988) as originally described from Thamnaconus modestus (Günther) (syn. Cantherines modestus Günther ) and Neolebouria confusum (Overstreet, 1969) as originally described from Ocyurus chrysurus (Bloch) by having the cirrus sac surpassing the ventral sucker posteriorly in N. cantherhini and being entirely preacetabular in N. confusum compared to terminating near the midlevel of the ventral sucker in N. capoori n. sp. The new species is most similar to N. confusum, but it further differs from this species by having the vitelline fields terminating near the level of the esophageal bifurcation compared to terminating near the level of the posterior margin of the pharynx, a larger sucker ratio (1:1.7-1:2.0 compared to 1:1.4-1:1.7), a somewhat shorter cirrus sac relative to body length (160-448, representing 9-18% of the body length compared to about 367, representing 22%), and the egg of the new species has a boss at the anopercular end that is not present in N. confusum. This study represents the first report on an opecoelid from S. vosmeri. A review of the parasites reported from S. vosmeri is included.
Molnar, Denes [Purdue Univ., West Lafayette, IN (United States)
2016-05-25
The Section below summarizes research activities and achievements during the fifth (last) year of the PI’s Early Career Research Project (ECRP). Unlike the first four years of the project, the last year was not funded under the American Recovery and Reinvestment Act (ARRA). The ECRP advanced two main areas: i) radiative 3 ↔ 2 radiative transport, via development of a new computer code MPC/Grid that solves the Boltzmann transport equation in full 6+1D (3X+3V+time); and ii) application of relativistic hydrodynamics, via development of a self-consistent framework to convert viscous fluids to particles. In Year 5 we finalized thermalization studies with radiative gg ↔ ggg transport (Sec. 1.1.1) and used nonlinear covariant transport to assess the accuracy of fluid-to-particle conversion models (Sec. 1.1.2), calculated observables with self-consistent fluid-to-particle conversion from realistic viscous hydrodynamic evolution (Secs. 1.2.1 and 1.2.2), extended the covariant energy loss formulation to heavy quarks (Sec. 1.4.1) and studied energy loss in small systems (Sec. 1.4.2), and also investigated how much of the elliptic flow could have non-hydrodynamic origin (Sec 1.3). Years 1-4 of the ECRP were ARRA-funded and, therefore, they have their own report document ’Final Technical Report for Years 1-4 of the Early Career Research Project “Viscosity and equation of state of hot and dense QCD matter”’ (same award number DE-SC0004035). The PI’s group was also part of the DOE JET Topical Collaboration, a multi-institution project that overlapped in time significantly with the ECRP. Purdue achievements as part of the JET Top- ical Collaboration are in a separate report “Final Technical Report summarizing Purdue research activities as part of the DOE JET Topical Collaboration” (award DE-SC0004077).
Tricomi, Francesco Giacomo
1957-01-01
This classic text on integral equations by the late Professor F. G. Tricomi, of the Mathematics Faculty of the University of Turin, Italy, presents an authoritative, well-written treatment of the subject at the graduate or advanced undergraduate level. To render the book accessible to as wide an audience as possible, the author has kept the mathematical knowledge required on the part of the reader to a minimum; a solid foundation in differential and integral calculus, together with some knowledge of the theory of functions is sufficient. The book is divided into four chapters, with two useful
On symmetry groups of a 2D nonlinear diffusion equation with source
Radica Cimpoiasu
2015-04-01
Symmetry analysis of a 2D nonlinear evolutionary equation with mixed spatial derivative and general source term involving the dependent variable and its spatial derivatives is performed. The source terms for which the equation admits nontrivial Lie symmetries are identified for two different forms of the symmetry operator. In one of these cases, the symmetries do not depend on the form of nonlinearities and in the other case, nonlinearities of power, exponential and trigonometric forms are considered. There are no supplementary nonclassical symmetries for the investigated equation. The results reported here generalize the previous results on the 2D heat equation and the 2D Ricci model.
Stochastic partial differential equations
Chow, Pao-Liu
2014-01-01
Preliminaries Introduction Some Examples Brownian Motions and Martingales Stochastic Integrals Stochastic Differential Equations of Itô Type Lévy Processes and Stochastic IntegralsStochastic Differential Equations of Lévy Type Comments Scalar Equations of First Order Introduction Generalized Itô's Formula Linear Stochastic Equations Quasilinear Equations General Remarks Stochastic Parabolic Equations Introduction Preliminaries Solution of Stochastic Heat EquationLinear Equations with Additive Noise Some Regularity Properties Stochastic Reaction-Diffusion Equations Parabolic Equations with Grad
XIE Fu-Ding; CHEN Jing; L(U) Zhuo-Sheng
2005-01-01
The extended tanh method is further improved by generalizing the Riccati equation and introducing its twenty seven new solutions. As its application, the (2+ 1)-dimensional Broer-Kaup equation is investigated and then its fifty four non-travelling wave solutions have been obtained. The results reported in this paper show that this method is more powerful than those, such as tanh method, extended tanh method, modified extended tanh method and Riccati equation expansion method introduced in previous literatures.
The Effect of Repeaters on Equating
Kim, HeeKyoung; Kolen, Michael J.
2010-01-01
Test equating might be affected by including in the equating analyses examinees who have taken the test previously. This study evaluated the effect of including such repeaters on Medical College Admission Test (MCAT) equating using a population invariance approach. Three-parameter logistic (3-PL) item response theory (IRT) true score and…
77 FR 70176 - Previous Participation Certification
2012-11-23
... URBAN DEVELOPMENT Previous Participation Certification AGENCY: Office of the Chief Information Officer... digital submission of all data and certifications is available via HUD's secure Internet systems. However...: Previous Participation Certification. OMB Approval Number: 2502-0118. Form Numbers: HUD-2530 ....
Herpes zoster recurrences more frequent than previously reported.
Yawn, Barbara P; Wollan, Peter C; Kurland, Marge J; St Sauver, Jennifer L; Saddier, Patricia
2011-02-01
To present population-based estimates of herpes zoster (HZ) recurrence rates among adults. To identify recurrent cases of HZ, we reviewed the medical records (through December 31, 2007) of all Olmsted County, Minnesota, residents aged 22 years or older who had an incident case of HZ between January 1, 1996, and December 31, 2001. Kaplan-Meier curves and Cox regression models were used to describe recurrences by age, immune status, and presence of prolonged pain at the time of the incident HZ episode. Of the 1669 persons with a medically documented episode of HZ, 95 had 105 recurrences (8 persons with >1 recurrence) by December 31, 2007, an average follow-up of 7.3 years. The Kaplan-Meier estimate of the recurrence rate at 8 years was 6.2%. With a maximum follow-up of 12 years, the time between HZ episodes in the same person varied from 96 days to 10 years. Recurrences were significantly more likely in persons with zoster-associated pain of 30 days or longer at the initial episode (hazard ratio, 2.80; 95% confidence interval, 1.84-4.27; P<.001) and in immunocompromised individuals (hazard ratio, 2.35; 95% confidence interval, 1.35-4.08; P=.006). Women and anyone aged 50 years or older at the index episode also had a greater likelihood of recurrence. Rates of HZ recurrence appear to be comparable to rates of first HZ occurrence in immunocompetent individuals, suggesting that recurrence is sufficiently common to warrant investigation of vaccine prevention in this group.
Uncomplicated pregnancy and delivery after previous severe postpartum cerebral angiopathy.
Rémi, Jan; Pfefferkorn, Thomas; Fesl, Gunther; Rogenhofer, Nina; Straube, Andreas; Klein, Matthias
2011-09-01
Postpartum cerebral angiopathy (PCA) is a cerebral vasoconstriction syndrome developing shortly after delivery, without signs of preceding eclampsia. The risk for recurrence of PCA is unknown. Here, we report on a closely monitored, uneventful pregnancy of a woman with a previous severe episode of PCA. In summary, this case report demonstrates that PCA does not necessarily recur in following pregnancies, even after previous severe episodes.
Uncomplicated Pregnancy and Delivery after Previous Severe Postpartum Cerebral Angiopathy
Jan Rémi
2011-10-01
Full Text Available Postpartum cerebral angiopathy (PCA is a cerebral vasoconstriction syndrome developing shortly after delivery, without signs of preceding eclampsia. The risk for recurrence of PCA is unknown. Here, we report on a closely monitored, uneventful pregnancy of a woman with a previous severe episode of PCA. In summary, this case report demonstrates that PCA does not necessarily recur in following pregnancies, even after previous severe episodes.
The Statistical Drake Equation
Maccone, Claudio
2010-12-01
function, apparently previously unknown and dubbed "Maccone distribution" by Paul Davies. DATA ENRICHMENT PRINCIPLE. It should be noticed that ANY positive number of random variables in the Statistical Drake Equation is compatible with the CLT. So, our generalization allows for many more factors to be added in the future as long as more refined scientific knowledge about each factor will be known to the scientists. This capability to make room for more future factors in the statistical Drake equation, we call the "Data Enrichment Principle," and we regard it as the key to more profound future results in the fields of Astrobiology and SETI. Finally, a practical example is given of how our statistical Drake equation works numerically. We work out in detail the case, where each of the seven random variables is uniformly distributed around its own mean value and has a given standard deviation. For instance, the number of stars in the Galaxy is assumed to be uniformly distributed around (say) 350 billions with a standard deviation of (say) 1 billion. Then, the resulting lognormal distribution of N is computed numerically by virtue of a MathCad file that the author has written. This shows that the mean value of the lognormal random variable N is actually of the same order as the classical N given by the ordinary Drake equation, as one might expect from a good statistical generalization.
Generalized estimating equations
Hardin, James W
2013-01-01
Generalized Estimating Equations, Second Edition updates the best-selling previous edition, which has been the standard text on the subject since it was published a decade ago. Combining theory and application, the text provides readers with a comprehensive discussion of GEE and related models. Numerous examples are employed throughout the text, along with the software code used to create, run, and evaluate the models being examined. Stata is used as the primary software for running and displaying modeling output; associated R code is also given to allow R users to replicat
Mei Symmetry and New Conserved Quantity of Tzénoff Equations for Holonomic Systems
ZHENG Shi-Wang; XIE Jia-Fang; ZHANG Qing-Hua
2007-01-01
@@ A new conserved quantity is deduced from Mei symmetry of Tzénoff equations for holonomic systems. The expression of this new conserved quantity is given, and the determining equation to induce this new conserved quantity is presented. The results exhibit that this new method is easier to find more conserved quantities than the previously reported ones. Finally, application of this new result is presented by a practical example.
Sarkar, Tanmay
2015-06-01
In this paper, we demonstrate that previously reported traveling wave solutions for the fifth order KdV type equations with time dependent coefficients (Triki and Wazwaz, 2014) are incorrect. We present the corrected traveling wave solutions for fifth order KdV type equations using sine-cosine method. In addition, we provide traveling wave solutions for the Kawahara equation and Kaup-Kupershmidt equation as an application.
Higher derivative gravity: Field equation as the equation of state
Dey, Ramit; Liberati, Stefano; Mohd, Arif
2016-08-01
One of the striking features of general relativity is that the Einstein equation is implied by the Clausius relation imposed on a small patch of locally constructed causal horizon. The extension of this thermodynamic derivation of the field equation to more general theories of gravity has been attempted many times in the last two decades. In particular, equations of motion for minimally coupled higher-curvature theories of gravity, but without the derivatives of curvature, have previously been derived using a thermodynamic reasoning. In that derivation the horizon slices were endowed with an entropy density whose form resembles that of the Noether charge for diffeomorphisms, and was dubbed the Noetheresque entropy. In this paper, we propose a new entropy density, closely related to the Noetheresque form, such that the field equation of any diffeomorphism-invariant metric theory of gravity can be derived by imposing the Clausius relation on a small patch of local causal horizon.
Higher derivative gravity: field equation as the equation of state
Dey, Ramit; Mohd, Arif
2016-01-01
One of the striking features of general relativity is that the Einstein equation is implied by the Clausius relation imposed on a small patch of locally constructed causal horizon. Extension of this thermodynamic derivation of the field equation to more general theories of gravity has been attempted many times in the last two decades. In particular, equations of motion for minimally coupled higher curvature theories of gravity, but without the derivatives of curvature, have previously been derived using a thermodynamic reasoning. In that derivation the horizon slices were endowed with an entropy density whose form resembles that of the Noether charge for diffeomorphisms, and was dubbed the Noetheresque entropy. In this paper, we propose a new entropy density, closely related to the Noetheresque form, such that the field equation of any diffeomorphism invariant metric theory of gravity can be derived by imposing the Clausius relation on a small patch of local causal horizon.
Generalized Set of Boussinesq equations for Surf Zone Region
Dutta, R
2005-01-01
In this report, generalized wave breaking equations are developed using three dimensional fully nonlinear extended Boussinesq equations to encompass rotational dynamics in wave breaking zone. The derivation for vorticity distributions are developed from Reynold based stress equations.
Partial Differential Equations
1988-01-01
The volume contains a selection of papers presented at the 7th Symposium on differential geometry and differential equations (DD7) held at the Nankai Institute of Mathematics, Tianjin, China, in 1986. Most of the contributions are original research papers on topics including elliptic equations, hyperbolic equations, evolution equations, non-linear equations from differential geometry and mechanics, micro-local analysis.
Multi-Order Exact Solutions for a generalized shallow water wave equation and other nonlinear PDEs
Bagchi, Bijan; Ganguly, Asish
2011-01-01
We seek multi-order exact solutions of a generalized shallow water wave equation along with those corresponding to a class of nonlinear systems described by the KdV, modified KdV, Boussinesq, Klein-Gordon and modified Benjamin-Bona-Mahony equation. We employ a modified version of a generalized Lame equation and subject it to a perturbative treatment identifying the solutions order by order in terms of Jacobi elliptic functions. Our solutions are new and hold the key feature that they are expressible in terms of an auxiliary function f in a generic way. For appropriate choices of f we recover the previous results reported in the literature.
Topczewski, Anna; Cui, Zhongmin; Woodruff, David; Chen, Hanwei; Fang, Yu
2013-01-01
This paper investigates four methods of linear equating under the common item nonequivalent groups design. Three of the methods are well known: Tucker, Angoff-Levine, and Congeneric-Levine. A fourth method is presented as a variant of the Congeneric-Levine method. Using simulation data generated from the three-parameter logistic IRT model we…
Subsequent pregnancy outcome after previous foetal death
Nijkamp, J. W.; Korteweg, F. J.; Holm, J. P.; Timmer, A.; Erwich, J. J. H. M.; van Pampus, M. G.
2013-01-01
Objective: A history of foetal death is a risk factor for complications and foetal death in subsequent pregnancies as most previous risk factors remain present and an underlying cause of death may recur. The purpose of this study was to evaluate subsequent pregnancy outcome after foetal death and to
Partial differential equations of parabolic type
Friedman, Avner
2008-01-01
This accessible and self-contained treatment provides even readers previously unacquainted with parabolic and elliptic equations with sufficient background to understand research literature. Author Avner Friedman - Director of the Mathematical Biosciences Institute at The Ohio State University - offers a systematic and thorough approach that begins with the main facts of the general theory of second order linear parabolic equations. Subsequent chapters explore asymptotic behavior of solutions, semi-linear equations and free boundary problems, and the extension of results concerning fundamenta
Solutions to the Optical Cascading Equations
Lafortune, S; Menyuk, C R
1998-01-01
Group theoretical methods are used to study the equations describing by inverse scattering techniques. On the other hand, these equations do share some of the nice properties of soliton equations. Large families of explicit analytical solutions are obtained in terms of elliptic functions. In special cases, these periodic solutions reduce to localized ones, i.e., solitary waves. All previously known explicit solutions are recovered, and many additional ones are obtained
Induced vaginal birth after previous caesarean section
Akylbek Tussupkaliyev; Andrey Gayday; Bibigul Karimsakova; Saule Bermagambetova; Lunara Uteniyazova; Guldana Iztleuova; Gulkhanym Kusherbayeva; Meruyert Konakbayeva; Assylzada Merekeyeva; Zamira Imangaliyeva
2016-01-01
Introduction The rate of operative birth by Caesarean section is constantly rising. In Kazakhstan, it reaches 27 per cent. Research data confirm that the percentage of successful vaginal births after previous Caesarean section is 50–70 per cent. How safe the induction of vaginal birth after Caesarean (VBAC) remains unclear. Methodology The studied techniques of labour induction were amniotomy of the foetal bladder with the vulsellum ramus, intravaginal administra...
Previously undiagnosed hemophilia patient with intracerebral hemorrhage
Eray Atalay
2015-09-01
Full Text Available Intracranial bleeding in hemophilia patients is a rare but a mortal complication. Diagnosis of hemophilia in adulthood is an uncommon occurrence. In this case report an adult patient with intracranial hemorrhage is presented.
Stability theory of differential equations
Bellman, Richard
2008-01-01
Suitable for advanced undergraduates and graduate students, this was the first English-language text to offer detailed coverage of boundedness, stability, and asymptotic behavior of linear and nonlinear differential equations. It remains a classic guide, featuring material from original research papers, including the author's own studies.The linear equation with constant and almost-constant coefficients receives in-depth attention that includes aspects of matrix theory. No previous acquaintance with the theory is necessary, since author Richard Bellman derives the results in matrix theory from
Improving the Bandwidth Selection in Kernel Equating
Andersson, Björn; von Davier, Alina A.
2014-01-01
We investigate the current bandwidth selection methods in kernel equating and propose a method based on Silverman's rule of thumb for selecting the bandwidth parameters. In kernel equating, the bandwidth parameters have previously been obtained by minimizing a penalty function. This minimization process has been criticized by practitioners…
"Battered Women" and Previous Victimization: Is the Question Relevant?
Gudim, Laurie, Comp.; And Others
This report discusses battered women and the role of their previous victimization. After a literature review on family violence in general, these topics are discussed: (1) family violence and the patriarchy; (2) the historical background of family violence; (3) intergenerational cycle of violence; and (4) psychological literature's four ways…
Haemophilus influenzae type f meningitis in a previously healthy boy
Ronit, Andreas; Berg, Ronan M G; Bruunsgaard, Helle;
2013-01-01
Non-serotype b strains of Haemophilus influenzae are extremely rare causes of acute bacterial meningitis in immunocompetent individuals. We report a case of acute bacterial meningitis in a 14-year-old boy, who was previously healthy and had been immunised against H influenzae serotype b (Hib...
"Battered Women" and Previous Victimization: Is the Question Relevant?
Gudim, Laurie, Comp.; And Others
This report discusses battered women and the role of their previous victimization. After a literature review on family violence in general, these topics are discussed: (1) family violence and the patriarchy; (2) the historical background of family violence; (3) intergenerational cycle of violence; and (4) psychological literature's four ways…
Nonlinear Electrostatic Wave Equations for Magnetized Plasmas
Dysthe, K.B.; Mjølhus, E.; Pécseli, Hans
1984-01-01
The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed.......The lowest order kinetic effects are included in the equations for nonlinear electrostatic electron waves in a magnetized plasma. The modifications of the authors' previous analysis based on a fluid model are discussed....
Cataract surgery in previously vitrectomized eyes.
Akinci, A; Batman, C; Zilelioglu, O
2008-05-01
To evaluate the results of extracapsular cataract extraction (ECCE) and phacoemulsification (PHACO) performed in previously vitrectomized eyes. In this retrospective study, 56 vitrectomized eyes that had ECCE and 60 vitrectomized eyes that had PHACO were included in the study group while 65 eyes that had PHACO in the control group. The evaluated parameters were the incidence of intra-operative and postoperative complications (IPC) and visual outcomes. Chi-squared, independent samples and paired samples tests were used for comparing the results. Deep anterior chamber (AC) was significantly more common in the PHACO group of vitrectomized eyes (PGVE) and observed in eyes that had undergone extensive vitreous removal (p ECCE group and the PGVE (p > 0.05). Some of the intra-operative conditions such as posterior synechiae, primary posterior capsular opacification (PCO) and postoperative complications such as retinal detachment (RD), PCO were significantly more common in vitrectomized eyes than the controls (p ECCE group and the PGVE (p > 0.05). Deep AC is more common in eyes with extensive vitreous removal during PHACO than ECCE. Decreasing the bottle height is advised in this case. Except for this, the results of ECCE and PHACO are similar in previously vitrectomized eyes. Posterior synechiaes, primary and postoperative PCO and RD are more common in vitrectomized eyes than the controls.
Kinetic energy equations for the average-passage equation system
Johnson, Richard W.; Adamczyk, John J.
1989-01-01
Important kinetic energy equations derived from the average-passage equation sets are documented, with a view to their interrelationships. These kinetic equations may be used for closing the average-passage equations. The turbulent kinetic energy transport equation used is formed by subtracting the mean kinetic energy equation from the averaged total instantaneous kinetic energy equation. The aperiodic kinetic energy equation, averaged steady kinetic energy equation, averaged unsteady kinetic energy equation, and periodic kinetic energy equation, are also treated.
Kinetic energy equations for the average-passage equation system
Johnson, Richard W.; Adamczyk, John J.
1989-01-01
Important kinetic energy equations derived from the average-passage equation sets are documented, with a view to their interrelationships. These kinetic equations may be used for closing the average-passage equations. The turbulent kinetic energy transport equation used is formed by subtracting the mean kinetic energy equation from the averaged total instantaneous kinetic energy equation. The aperiodic kinetic energy equation, averaged steady kinetic energy equation, averaged unsteady kinetic energy equation, and periodic kinetic energy equation, are also treated.
2013-01-01
Background The extent to which psychosocial and diet behavior factors affect dietary self-report remains unclear. We examine the contribution of these factors to measurement error of self-report. Methods In 450 postmenopausal women in the Women’s Health Initiative Observational Study doubly labeled water and urinary nitrogen were used as biomarkers of objective measures of total energy expenditure and protein. Self-report was captured from food frequency questionnaire (FFQ), four day food record (4DFR) and 24 hr. dietary recall (24HR). Using regression calibration we estimated bias of self-reported dietary instruments including psychosocial factors from the Stunkard-Sorenson Body Silhouettes for body image perception, the Crowne-Marlowe Social Desirability Scale, and the Three Factor Eating Questionnaire (R-18) for cognitive restraint for eating, uncontrolled eating, and emotional eating. We included a diet behavior factor on number of meals eaten at home using the 4DFR. Results Three categories were defined for each of the six psychosocial and diet behavior variables (low, medium, high). Participants with high social desirability scores were more likely to under-report on the FFQ for energy (β = -0.174, SE = 0.054, p social desirability scores. Participants consuming a high percentage of meals at home were less likely to under-report on the FFQ for energy (β = 0.181, SE = 0.053, p < 0.05) and protein (β = 0.127, SE = 0.06, p < 0.05) compared to participants consuming a low percentage of meals at home. In the calibration equations combining FFQ, 4DFR, 24HR with age, body mass index, race, and the psychosocial and diet behavior variables, the six psychosocial and diet variables explained 1.98%, 2.24%, and 2.15% of biomarker variation for energy, protein, and protein density respectively. The variations explained are significantly different between the calibration equations with or without the six psychosocial and diet variables
Mossavar-Rahmani, Yasmin; Tinker, Lesley F; Huang, Ying; Neuhouser, Marian L; McCann, Susan E; Seguin, Rebecca A; Vitolins, Mara Z; Curb, J David; Prentice, Ross L
2013-05-16
The extent to which psychosocial and diet behavior factors affect dietary self-report remains unclear. We examine the contribution of these factors to measurement error of self-report. In 450 postmenopausal women in the Women's Health Initiative Observational Study doubly labeled water and urinary nitrogen were used as biomarkers of objective measures of total energy expenditure and protein. Self-report was captured from food frequency questionnaire (FFQ), four day food record (4DFR) and 24 hr. dietary recall (24HR). Using regression calibration we estimated bias of self-reported dietary instruments including psychosocial factors from the Stunkard-Sorenson Body Silhouettes for body image perception, the Crowne-Marlowe Social Desirability Scale, and the Three Factor Eating Questionnaire (R-18) for cognitive restraint for eating, uncontrolled eating, and emotional eating. We included a diet behavior factor on number of meals eaten at home using the 4DFR. Three categories were defined for each of the six psychosocial and diet behavior variables (low, medium, high). Participants with high social desirability scores were more likely to under-report on the FFQ for energy (β = -0.174, SE = 0.054, p social desirability scores. Participants consuming a high percentage of meals at home were less likely to under-report on the FFQ for energy (β = 0.181, SE = 0.053, p < 0.05) and protein (β = 0.127, SE = 0.06, p < 0.05) compared to participants consuming a low percentage of meals at home. In the calibration equations combining FFQ, 4DFR, 24HR with age, body mass index, race, and the psychosocial and diet behavior variables, the six psychosocial and diet variables explained 1.98%, 2.24%, and 2.15% of biomarker variation for energy, protein, and protein density respectively. The variations explained are significantly different between the calibration equations with or without the six psychosocial and diet variables for protein density (p
The Dirac equation as one fourth-order equation for one function -- a general form
Akhmeteli, Andrey
2015-01-01
Previously (A. Akhmeteli, J. Math. Phys., v. 52, p. 082303 (2011)), the Dirac equation in an arbitrary electromagnetic field was shown to be generally equivalent to a fourth-order equation for just one component of the four-component Dirac spinor function. This was done for a specific (chiral) representation of gamma-matrices and for a specific component. In the current work, the result is generalized for a general representation of gamma-matrices and a general component (satisfying some conditions). The resulting equivalent of the Dirac equation is also much more symmetric than that of the previous work and should be useful in applications of the Dirac equation.
Solving Nonlinear Wave Equations by Elliptic Equation
FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo
2003-01-01
The elliptic equation is taken as a transformation and applied to solve nonlinear wave equations. It is shown that this method is more powerful to give more kinds of solutions, such as rational solutions, solitary wave solutions,periodic wave solutions and so on, so it can be taken as a generalized method.
Sachin Kumar; K Singh; R K Gupta
2012-07-01
In this paper, coupled Higgs field equation are studied using the Lie classical method. Symmetry reductions and exact solutions are reported for Higgs equation and Hamiltonian amplitude equation. We also establish the travelling wave solutions involving parameters of the coupled Higgs equation and Hamiltonian amplitude equation using (′/)-expansion methodc, where = () satisfies a second-order linear ordinary differential equation (ODE). The travelling wave solutions expressed by hyperbolic, trigonometric and the rational functions are obtained.
Books average previous decade of economic misery.
R Alexander Bentley
Full Text Available For the 20(th century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.
Obinutuzumab for previously untreated chronic lymphocytic leukemia.
Abraham, Jame; Stegner, Mark
2014-04-01
Obinutuzumab was approved by the Food and Drug Administration in late 2013 for use in combination with chlorambucil for the treatment of patients with previously untreated chronic lymphocytic leukemia (CLL). The approval was based on results of an open-label phase 3 trial that showed improved progression-free survival (PFS) with the combination of obinutuzumab plus chlorambucil compared with chlorambucil alone. Obinutuzumab is a monoclonal antibody that targets CD20 antigen expressed on the surface of pre B- and mature B-lymphocytes. After binding to CD20, obinutuzumab mediates B-cell lysis by engaging immune effector cells, directly activating intracellular death signaling pathways, and activating the complement cascade. Immune effector cell activities include antibody-dependent cellular cytotoxicity and antibody-dependent cellular phagocytosis.
Can previous learning alter future plasticity mechanisms?
Crestani, Ana Paula; Quillfeldt, Jorge Alberto
2016-02-01
The dynamic processes related to mnemonic plasticity have been extensively researched in the last decades. More recently, studies have attracted attention because they show an unusual plasticity mechanism that is independent of the receptor most usually related to first-time learning--that is, memory acquisition-the NMDA receptor. An interesting feature of this type of learning is that a previous experience may cause modifications in the plasticity mechanism of a subsequent learning, suggesting that prior experience in a very similar task triggers a memory acquisition process that does not depend on NMDARs. The intracellular molecular cascades necessary to assist the learning process seem to depend on the activation of hippocampal CP-AMPARs. Moreover, most of these studies were performed on hippocampus-dependent tasks, even though other brain areas, such as the basolateral amygdala, also display NMDAR-independent learning.
Books average previous decade of economic misery.
Bentley, R Alexander; Acerbi, Alberto; Ormerod, Paul; Lampos, Vasileios
2014-01-01
For the 20(th) century since the Depression, we find a strong correlation between a 'literary misery index' derived from English language books and a moving average of the previous decade of the annual U.S. economic misery index, which is the sum of inflation and unemployment rates. We find a peak in the goodness of fit at 11 years for the moving average. The fit between the two misery indices holds when using different techniques to measure the literary misery index, and this fit is significantly better than other possible correlations with different emotion indices. To check the robustness of the results, we also analysed books written in German language and obtained very similar correlations with the German economic misery index. The results suggest that millions of books published every year average the authors' shared economic experiences over the past decade.
Induced vaginal birth after previous caesarean section
Akylbek Tussupkaliyev
2016-11-01
Full Text Available Introduction The rate of operative birth by Caesarean section is constantly rising. In Kazakhstan, it reaches 27 per cent. Research data confirm that the percentage of successful vaginal births after previous Caesarean section is 50–70 per cent. How safe the induction of vaginal birth after Caesarean (VBAC remains unclear. Methodology The studied techniques of labour induction were amniotomy of the foetal bladder with the vulsellum ramus, intravaginal administration of E1 prostaglandin (Misoprostol, and intravenous infusion of Oxytocin-Richter. The assessment of rediness of parturient canals was conducted by Bishop’s score; the labour course was assessed by a partogram. The effectiveness of labour induction techniques was assessed by the number of administered doses, the time of onset of regular labour, the course of labour and the postpartum period and the presence of complications, and the course of the early neonatal period, which implied the assessment of the child’s condition, described in the newborn development record. The foetus was assessed by medical ultrasound and antenatal and intranatal cardiotocography (CTG. Obtained results were analysed with SAS statistical processing software. Results The overall percentage of successful births with intravaginal administration of Misoprostol was 93 per cent (83 of cases. This percentage was higher than in the amniotomy group (relative risk (RR 11.7 and was similar to the oxytocin group (RR 0.83. Amniotomy was effective in 54 per cent (39 of cases, when it induced regular labour. Intravenous oxytocin infusion was effective in 94 per cent (89 of cases. This percentage was higher than that with amniotomy (RR 12.5. Conclusions The success of vaginal delivery after previous Caesarean section can be achieved in almost 70 per cent of cases. At that, labour induction does not decrease this indicator and remains within population boundaries.
Elimination of redundancy in superspace equations of supergravity. [Field equation minimal list
Gell-Mann, M.; Ramond, P.; Schwarz, J.H.
1978-01-01
The equations of N = 1 supergravity in superspace, with e not equal to 0 and with external vector--spinor matter, were derived previously, but in redundant form (420 equations for 112 potentials V/sub A//sup ..lambda../ and h/sub ..lambda..//sup rs/). There are many possible minimal lists of 112 equations from which the other equations can be obtained by means of Bianchi identities for the field strengths. Such a minimal list is exhibited, and the full set of equations derived. The procedure can easily be generalized to extended supergravity (N > 1).
Introduction to differential equations
Taylor, Michael E
2011-01-01
The mathematical formulations of problems in physics, economics, biology, and other sciences are usually embodied in differential equations. The analysis of the resulting equations then provides new insight into the original problems. This book describes the tools for performing that analysis. The first chapter treats single differential equations, emphasizing linear and nonlinear first order equations, linear second order equations, and a class of nonlinear second order equations arising from Newton's laws. The first order linear theory starts with a self-contained presentation of the exponen
Defendants previous history and mock sentencing.
Wear, D A; Pasewark, R A
1984-05-01
Six hundred forty-four undergraduates served as mock judges in sentencing male or female defendants convicted of homicide, child molestation, embezzlement, fraudulent issuance of checks, heroin possession, and consensual homosexuality. Defendants had a reported history of psychiatric hospitalization, imprisonment, or neither hospitalization nor incarceration. Results indicated: (1) those defendants with a mental health history were more likely to be accorded a disposition that involved mandatory health treatment; (2) dispositions of persons with a mental health history tended to be more restrictive than those of defendants with neither a mental health nor criminal history; and (3) sex of defendant of mock judge influenced sentencing disposition only in child molestation cases.
Previous gastric bypass surgery complicating total thyroidectomy.
Alfonso, Bianca; Jacobson, Adam S; Alon, Eran E; Via, Michael A
2015-03-01
Hypocalcemia is a well-known complication of total thyroidectomy. Patients who have previously undergone gastric bypass surgery may be at increased risk of hypocalcemia due to gastrointestinal malabsorption, secondary hyperparathyroidism, and an underlying vitamin D deficiency. We present the case of a 58-year-old woman who underwent a total thyroidectomy for the follicular variant of papillary thyroid carcinoma. Her history included Roux-en-Y gastric bypass surgery. Following the thyroid surgery, she developed postoperative hypocalcemia that required large doses of oral calcium carbonate (7.5 g/day), oral calcitriol (up to 4 μg/day), intravenous calcium gluconate (2.0 g/day), calcium citrate (2.0 g/day), and ergocalciferol (50,000 IU/day). Her serum calcium levels remained normal on this regimen after hospital discharge despite persistent hypoparathyroidism. Bariatric surgery patients who undergo thyroid surgery require aggressive supplementation to maintain normal serum calcium levels. Preoperative supplementation with calcium and vitamin D is strongly recommended.
Sebacinales everywhere: previously overlooked ubiquitous fungal endophytes.
Weiss, Michael; Sýkorová, Zuzana; Garnica, Sigisfredo; Riess, Kai; Martos, Florent; Krause, Cornelia; Oberwinkler, Franz; Bauer, Robert; Redecker, Dirk
2011-02-15
Inconspicuous basidiomycetes from the order Sebacinales are known to be involved in a puzzling variety of mutualistic plant-fungal symbioses (mycorrhizae), which presumably involve transport of mineral nutrients. Recently a few members of this fungal order not fitting this definition and commonly referred to as 'endophytes' have raised considerable interest by their ability to enhance plant growth and to increase resistance of their host plants against abiotic stress factors and fungal pathogens. Using DNA-based detection and electron microscopy, we show that Sebacinales are not only extremely versatile in their mycorrhizal associations, but are also almost universally present as symptomless endophytes. They occurred in field specimens of bryophytes, pteridophytes and all families of herbaceous angiosperms we investigated, including liverworts, wheat, maize, and the non-mycorrhizal model plant Arabidopsis thaliana. They were present in all habitats we studied on four continents. We even detected these fungi in herbarium specimens originating from pioneering field trips to North Africa in the 1830s/40s. No geographical or host patterns were detected. Our data suggest that the multitude of mycorrhizal interactions in Sebacinales may have arisen from an ancestral endophytic habit by specialization. Considering their proven beneficial influence on plant growth and their ubiquity, endophytic Sebacinales may be a previously unrecognized universal hidden force in plant ecosystems.
Surgery of intracranial aneurysms previously treated endovascularly.
Tirakotai, Wuttipong; Sure, Ulrich; Yin, Yuhua; Benes, Ludwig; Schulte, Dirk Michael; Bien, Siegfried; Bertalanffy, Helmut
2007-11-01
To perform a retrospective study on the patients who underwent aneurysmal surgery following endovascular treatment. We performed a retrospective study on eight patients who underwent aneurysmal surgery following endovascular treatment (-attempts) with gugliemi detachable coils (GDCs). The indications for surgery, surgical techniques and clinical outcomes were analyzed. The indications for surgical treatment after GDC coiling of aneurysm were classified into three groups. First group: surgery of incompletely coiled aneurysms (n=4). Second group: surgery of mass effect on the neural structures due to coil compaction or rebleeding (n=2). Third group: surgery of vascular complications after endovascular procedure due to parent artery occlusion or thrombus propagation from aneurysm (n=2). Aneurysm obliterations could be performed in all cases confirmed by postoperative angiography. Six patients had an excellent outcome and returned to their profession. Patient's visual acuity was improved. One individual experienced right hemiparesis (grade IV/V) and hemihypesthesia. Microsurgical clipping is rarely necessary for previously coiled aneurysms. Surgical treatment is uncommonly required when an acute complication arises during endovascular treatment, or when there is a dynamic change of a residual aneurysm configuration over time that is considered to be insecure.
Sebacinales everywhere: previously overlooked ubiquitous fungal endophytes.
Michael Weiss
Full Text Available Inconspicuous basidiomycetes from the order Sebacinales are known to be involved in a puzzling variety of mutualistic plant-fungal symbioses (mycorrhizae, which presumably involve transport of mineral nutrients. Recently a few members of this fungal order not fitting this definition and commonly referred to as 'endophytes' have raised considerable interest by their ability to enhance plant growth and to increase resistance of their host plants against abiotic stress factors and fungal pathogens. Using DNA-based detection and electron microscopy, we show that Sebacinales are not only extremely versatile in their mycorrhizal associations, but are also almost universally present as symptomless endophytes. They occurred in field specimens of bryophytes, pteridophytes and all families of herbaceous angiosperms we investigated, including liverworts, wheat, maize, and the non-mycorrhizal model plant Arabidopsis thaliana. They were present in all habitats we studied on four continents. We even detected these fungi in herbarium specimens originating from pioneering field trips to North Africa in the 1830s/40s. No geographical or host patterns were detected. Our data suggest that the multitude of mycorrhizal interactions in Sebacinales may have arisen from an ancestral endophytic habit by specialization. Considering their proven beneficial influence on plant growth and their ubiquity, endophytic Sebacinales may be a previously unrecognized universal hidden force in plant ecosystems.
A previously undescribed pathway for pyrimidine catabolism.
Loh, Kevin D; Gyaneshwar, Prasad; Markenscoff Papadimitriou, Eirene; Fong, Rebecca; Kim, Kwang-Seo; Parales, Rebecca; Zhou, Zhongrui; Inwood, William; Kustu, Sydney
2006-03-28
The b1012 operon of Escherichia coli K-12, which is composed of seven unidentified ORFs, is one of the most highly expressed operons under control of nitrogen regulatory protein C. Examination of strains with lesions in this operon on Biolog Phenotype MicroArray (PM3) plates and subsequent growth tests indicated that they failed to use uridine or uracil as the sole nitrogen source and that the parental strain could use them at room temperature but not at 37 degrees C. A strain carrying an ntrB(Con) mutation, which elevates transcription of genes under nitrogen regulatory protein C control, could also grow on thymidine as the sole nitrogen source, whereas strains with lesions in the b1012 operon could not. Growth-yield experiments indicated that both nitrogens of uridine and thymidine were available. Studies with [(14)C]uridine indicated that a three-carbon waste product from the pyrimidine ring was excreted. After trimethylsilylation and gas chromatography, the waste product was identified by mass spectrometry as 3-hydroxypropionic acid. In agreement with this finding, 2-methyl-3-hydroxypropionic acid was released from thymidine. Both the number of available nitrogens and the waste products distinguished the pathway encoded by the b1012 operon from pyrimidine catabolic pathways described previously. We propose that the genes of this operon be named rutA-G for pyrimidine utilization. The product of the divergently transcribed gene, b1013, is a tetracycline repressor family regulator that controls transcription of the b1012 operon negatively.
Clarke, R.; Lintereur, L.; Bahm, C.
2016-01-01
A desire for more complete documentation of the National Aeronautics and Space Administration (NASA) Armstrong Flight Research Center (AFRC), Edwards, California legacy code used in the core simulation has led to this e ort to fully document the oblate Earth six-degree-of-freedom equations of motion and integration algorithm. The authors of this report have taken much of the earlier work of the simulation engineering group and used it as a jumping-o point for this report. The largest addition this report makes is that each element of the equations of motion is traced back to first principles and at no point is the reader forced to take an equation on faith alone. There are no discoveries of previously unknown principles contained in this report; this report is a collection and presentation of textbook principles. The value of this report is that those textbook principles are herein documented in standard nomenclature that matches the form of the computer code DERIVC. Previous handwritten notes are much of the backbone of this work, however, in almost every area, derivations are explicitly shown to assure the reader that the equations which make up the oblate Earth version of the computer routine, DERIVC, are correct.
George F R Ellis
2007-07-01
The Raychaudhuri equation is central to the understanding of gravitational attraction in astrophysics and cosmology, and in particular underlies the famous singularity theorems of general relativity theory. This paper reviews the derivation of the equation, and its significance in cosmology.
Beginning partial differential equations
O'Neil, Peter V
2014-01-01
A broad introduction to PDEs with an emphasis on specialized topics and applications occurring in a variety of fields Featuring a thoroughly revised presentation of topics, Beginning Partial Differential Equations, Third Edition provides a challenging, yet accessible,combination of techniques, applications, and introductory theory on the subjectof partial differential equations. The new edition offers nonstandard coverageon material including Burger's equation, the telegraph equation, damped wavemotion, and the use of characteristics to solve nonhomogeneous problems. The Third Edition is or
Renormalizing Partial Differential Equations
Bricmont, J.; Kupiainen, A.
1994-01-01
In this review paper, we explain how to apply Renormalization Group ideas to the analysis of the long-time asymptotics of solutions of partial differential equations. We illustrate the method on several examples of nonlinear parabolic equations. We discuss many applications, including the stability of profiles and fronts in the Ginzburg-Landau equation, anomalous scaling laws in reaction-diffusion equations, and the shape of a solution near a blow-up point.
Ordinary differential equations
Greenberg, Michael D
2014-01-01
Features a balance between theory, proofs, and examples and provides applications across diverse fields of study Ordinary Differential Equations presents a thorough discussion of first-order differential equations and progresses to equations of higher order. The book transitions smoothly from first-order to higher-order equations, allowing readers to develop a complete understanding of the related theory. Featuring diverse and interesting applications from engineering, bioengineering, ecology, and biology, the book anticipates potential difficulties in understanding the various solution steps
Antenatal diagnosis of Patau syndrome with previous anomalous baby
Keerthi Kocherla; Vasantha Kocherla
2014-01-01
Patau syndrome is the least common and most severe of the viable autosomal trisomies with median survival of fewer than 3 days was first identified as a cytogenetic syndrome in 1960. Patau syndrome is caused by an extra copy of chromosome 13. In this case report, we present antenatal imaging findings and gross foetal specimen correlation of foetus with Patau syndrome confirmed by karyotyping in third gravida who had significant previous obstetric history of gastrochisis in monochorionic and...
Pleuritis due to Brevundimonas diminuta in a previously healthy man.
Lu, Binghuai; Shi, Yanli; Zhu, Fengxia; Xu, Xiaolin
2013-03-01
Brevundimonas diminuta is rarely associated with invasive infections. We report the case of a previously healthy young man with pleural effusion, in which B. diminuta was recovered but incorrectly identified as Kingella kingae when it was freshly isolated. Consequently, the misidentification resulted in initial treatment failure. The correct identification was achieved through further incubation, sequencing of the 16S rRNA gene and MS.
Antenatal diagnosis of Patau syndrome with previous anomalous baby
Keerthi Kocherla; Vasantha Kocherla
2014-01-01
Patau syndrome is the least common and most severe of the viable autosomal trisomies with median survival of fewer than 3 days was first identified as a cytogenetic syndrome in 1960. Patau syndrome is caused by an extra copy of chromosome 13. In this case report, we present antenatal imaging findings and gross foetal specimen correlation of foetus with Patau syndrome confirmed by karyotyping in third gravida who had significant previous obstetric history of gastrochisis in monochorionic and...
Renormalization group and linear integral equations
Klein, W.
1983-04-01
We develop a position-space renormalization-group transformation which can be employed to study general linear integral equations. In this Brief Report we employ our method to study one class of such equations pertinent to the equilibrium properties of fluids. The results of applying our method are in excellent agreement with known numerical calculations where they can be compared. We also obtain information about the singular behavior of this type of equation which could not be obtained numerically.
Ying, Michael; Yung, Dennis M C; Ho, Karen K L
2008-01-01
This study aimed to develop a new two-dimensional (2-D) ultrasound thyroid volume estimation equation using three-dimensional (3-D) ultrasound as the standard of reference, and to compare the thyroid volume estimation accuracy of the new equation with three previously reported equations. 2-D and 3-D ultrasound examinations of the thyroid gland were performed in 150 subjects with normal serum thyrotropin (TSH, thyroid-stimulating hormone) and free thyroxine (fT4) levels (63 men and 87 women, age range: 17 to 71 y). In each subject, the volume of both thyroid lobes was measured by 3-D ultrasound. On 2-D ultrasound, the craniocaudal (CC), lateromedial (LM) and anteroposterior (AP) dimensions of the thyroid lobes were measured. The equation was derived by correlating the volume of the thyroid lobes measured with 3-D ultrasound and the product of the three dimensions measured with 2-D ultrasound using linear regression analysis, in 75 subjects without thyroid nodule. The accuracy of thyroid volume estimation of the new equation and the three previously reported equations was evaluated and compared in another 75 subjects (without thyroid nodule, n = 30; with thyroid nodule, n = 45). It is suggested that volume of thyroid lobe may be estimated as: volume of thyroid lobe = 0.38.(CC.LM.AP) + 1.76. Result showed that the new equation (16.9% to 36.1%) had a significantly smaller thyroid volume estimation error than the previously reported equations (20.8% to 54.9%) (p thyroid volume estimation error when thyroid glands with nodules were examined (p thyroid volume equation, 2-D ultrasound can be a useful alternative in thyroid volume measurement when 3-D ultrasound is not available.
Mahillo-Isla, R; Gonźalez-Morales, M J; Dehesa-Martínez, C
2011-06-01
The slowly varying envelope approximation is applied to the radiation problems of the Helmholtz equation with a planar single-layer and dipolar sources. The analyses of such problems provide procedures to recover solutions of the Helmholtz equation based on the evaluation of solutions of the parabolic wave equation at a given plane. Furthermore, the conditions that must be fulfilled to apply each procedure are also discussed. The relations to previous work are given as well.
Secondary recurrent miscarriage is associated with previous male birth.
Ooi, Poh Veh
2011-01-01
Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.
Secondary recurrent miscarriage is associated with previous male birth.
Ooi, Poh Veh
2012-01-31
Secondary recurrent miscarriage (RM) is defined as three or more consecutive pregnancy losses after delivery of a viable infant. Previous reports suggest that a firstborn male child is associated with less favourable subsequent reproductive potential, possibly due to maternal immunisation against male-specific minor histocompatibility antigens. In a retrospective cohort study of 85 cases of secondary RM we aimed to determine if secondary RM was associated with (i) gender of previous child, maternal age, or duration of miscarriage history, and (ii) increased risk of pregnancy complications. Fifty-three women (62.0%; 53\\/85) gave birth to a male child prior to RM compared to 32 (38.0%; 32\\/85) who gave birth to a female child (p=0.002). The majority (91.7%; 78\\/85) had uncomplicated, term deliveries and normal birth weight neonates, with one quarter of the women previously delivered by Caesarean section. All had routine RM investigations and 19.0% (16\\/85) had an abnormal result. Fifty-seven women conceived again and 33.3% (19\\/57) miscarried, but there was no significant difference in failure rates between those with a previous male or female child (13\\/32 vs. 6\\/25, p=0.2). When patients with abnormal results were excluded, or when women with only one previous child were considered, there was still no difference in these rates. A previous male birth may be associated with an increased risk of secondary RM but numbers preclude concluding whether this increases recurrence risk. The suggested association with previous male birth provides a basis for further investigations at a molecular level.
Integration of quantum hydrodynamical equation
Ulyanova, Vera G.; Sanin, Andrey L.
2007-04-01
Quantum hydrodynamics equations describing the dynamics of quantum fluid are a subject of this report (QFD).These equations can be used to decide the wide class of problem. But there are the calculated difficulties for the equations, which take place for nonlinear hyperbolic systems. In this connection, It is necessary to impose the additional restrictions which assure the existence and unique of solutions. As test sample, we use the free wave packet and study its behavior at the different initial and boundary conditions. The calculations of wave packet propagation cause in numerical algorithm the division. In numerical algorithm at the calculations of wave packet propagation, there arises the problem of division by zero. To overcome this problem we have to sew together discrete numerical and analytical continuous solutions on the boundary. We demonstrate here for the free wave packet that the numerical solution corresponds to the analytical solution.
Singular stochastic differential equations
Cherny, Alexander S
2005-01-01
The authors introduce, in this research monograph on stochastic differential equations, a class of points termed isolated singular points. Stochastic differential equations possessing such points (called singular stochastic differential equations here) arise often in theory and in applications. However, known conditions for the existence and uniqueness of a solution typically fail for such equations. The book concentrates on the study of the existence, the uniqueness, and, what is most important, on the qualitative behaviour of solutions of singular stochastic differential equations. This is done by providing a qualitative classification of isolated singular points, into 48 possible types.
Fractional Differential Equations
Jianping Zhao
2012-01-01
Full Text Available An extended fractional subequation method is proposed for solving fractional differential equations by introducing a new general ansätz and Bäcklund transformation of the fractional Riccati equation with known solutions. Being concise and straightforward, this method is applied to the space-time fractional coupled Burgers’ equations and coupled MKdV equations. As a result, many exact solutions are obtained. It is shown that the considered method provides a very effective, convenient, and powerful mathematical tool for solving fractional differential equations.
Markovich, L. A.; Grimaudo, R.; Messina, A.; Nakazato, H.
2017-10-01
A novel recipe for exactly solving in finite terms a class of special differential Riccati equations is reported. Our procedure is entirely based on a successful resolution strategy quite recently applied to quantum dynamical time-dependent SU(2) problems. The general integral of exemplary differential Riccati equations, not previously considered in the specialized literature, is explicitly determined to illustrate both mathematical usefulness and easiness of applicability of our proposed treatment. The possibility of exploiting the general integral of a given differential Riccati equation to solve an SU(2) quantum dynamical problem, is succinctly pointed out.
Das, Sonali; Chen, Ming-Hui; Warren, Nicholas; Hodgson, Michael
2011-12-01
This paper evaluates relationships between healthcare employees' perceptions of three hospital organizational constructs (Leadership, Support and Resources), and their assessment of two employee-related outcomes (employee satisfaction and retention) and two patient-related outcomes (patient satisfaction and quality of care). Using four all-employee surveys conducted by the Veterans Health Administration in the United States between 1997 and 2006, we examine the strength of these relationships and their changes over time. Exposure and outcome measures are employee-assessed in all the surveys. Because it can accommodate both latent and measured variables into the model, Structural Equation Modelling (SEM) is used to capture and quantify the relationship structure. The aim of the project is to identify possible intervention foci. The analyses revealed that employee-related outcomes are improved by increases in Leadership and Support, and, not surprisingly, the outcome variable of employee satisfaction reduced turnover intention. The employee assessed patient-related outcomes of satisfaction and quality of care were most improved by increases in Resources. Results also indicate that the three organizational constructs and the web of associations characterized by SEM underwent changes over the study period, perhaps in relation to changes in VHA policy emphases, changes in survey wording and other possible unmeasured factors.
Solving Cubic Equations by Polynomial Decomposition
Kulkarni, Raghavendra G.
2011-01-01
Several mathematicians struggled to solve cubic equations, and in 1515 Scipione del Ferro reportedly solved the cubic while participating in a local mathematical contest, but did not bother to publish his method. Then it was Cardano (1539) who first published the solution to the general cubic equation in his book "The Great Art, or, The Rules of…
Operational equations for data in common arrays
Silver, G.L.
2000-10-01
A new method for interpolating experimental data by means of the shifting operator was introduced in 1985. This report illustrates new interpolating equations for data in the five-point rectangle and diamond configurations, new measures of central tendency, and new equations for data at the vertices of a cube.
Rates of induced abortion in Denmark according to age, previous births and previous abortions
Marie-Louise H. Hansen
2009-11-01
Full Text Available Background: Whereas the effects of various socio-demographic determinants on a woman's risk of having an abortion are relatively well-documented, less attention has been given to the effect of previous abortions and births. Objective: To study the effect of previous abortions and births on Danish women's risk of an abortion, in addition to a number of demographic and personal characteristics. Data and methods: From the Fertility of Women and Couples Dataset we obtained data on the number of live births and induced abortions by year (1981-2001, age (16-39, county of residence and marital status. Logistic regression analysis was used to estimate the influence of the explanatory variables on the probability of having an abortion in a relevant year. Main findings and conclusion: A woman's risk of having an abortion increases with the number of previous births and previous abortions. Some interactions were was found in the way a woman's risk of abortion varies with calendar year, age and parity. The risk of an abortion for women with no children decreases while the risk of an abortion for women with children increases over time. Furthermore, the risk of an abortion decreases with age, but relatively more so for women with children compared to childless women. Trends for teenagers are discussed in a separate section.
Andersen, Erling B.
A computer program for solving the conditional likelihood equations arising in the Rasch model for questionnaires is described. The estimation method and the computational problems involved are described in a previous research report by Andersen, but a summary of those results are given in two sections of this paper. A working example is also…
Equation of state measurements in liquid deuterium to 100 GPa
Knudson, M D; Bailey, J E; Lemke, R W; Hall, C A; Deeney, C; Asay, J R
2003-01-01
Using intense magnetic pressure, a method was developed to launch flyer plates to velocities in excess of 20 km s sup - sup 1. This technique was used to perform plate-impact, shock wave experiments on cryogenic liquid deuterium (LD sub 2) to examine its high-pressure equation of state (EOS). Using an impedance matching method, Hugoniot measurements were obtained in the pressure range of 22-100 GPa. The results of these experiments disagree with the previously reported Hugoniot measurements of LD sub 2 in the pressure range above approx 40 GPa, but are in good agreement with first principles, ab initio models for hydrogen and its isotopes.
Asquith, William H.; Thompson, David B.
2008-01-01
The U.S. Geological Survey, in cooperation with the Texas Department of Transportation and in partnership with Texas Tech University, investigated a refinement of the regional regression method and developed alternative equations for estimation of peak-streamflow frequency for undeveloped watersheds in Texas. A common model for estimation of peak-streamflow frequency is based on the regional regression method. The current (2008) regional regression equations for 11 regions of Texas are based on log10 transformations of all regression variables (drainage area, main-channel slope, and watershed shape). Exclusive use of log10-transformation does not fully linearize the relations between the variables. As a result, some systematic bias remains in the current equations. The bias results in overestimation of peak streamflow for both the smallest and largest watersheds. The bias increases with increasing recurrence interval. The primary source of the bias is the discernible curvilinear relation in log10 space between peak streamflow and drainage area. Bias is demonstrated by selected residual plots with superimposed LOWESS trend lines. To address the bias, a statistical framework based on minimization of the PRESS statistic through power transformation of drainage area is described and implemented, and the resulting regression equations are reported. Compared to log10-exclusive equations, the equations derived from PRESS minimization have PRESS statistics and residual standard errors less than the log10 exclusive equations. Selected residual plots for the PRESS-minimized equations are presented to demonstrate that systematic bias in regional regression equations for peak-streamflow frequency estimation in Texas can be reduced. Because the overall error is similar to the error associated with previous equations and because the bias is reduced, the PRESS-minimized equations reported here provide alternative equations for peak-streamflow frequency estimation.
A fifth order differential equation for charged perfect fluids
Kweyama, M C; Maharaj, S D
2013-01-01
We investigate the master nonlinear partial differential equation that governs the evolution of shear-free spherically symmetric charged fluids. We use an approach which has not been considered previously for the underlying equation in shear-free spherically symmetric spacetimes. We derive a fifth order purely differential equation that must be satisfied for the underlying equation to admit a Lie point symmetry. We then perform a comprehensive analysis of this equation utilising the Lie symmetry analysis and direct integration. This enables us to reduce the fifth order equation to quadratures. Earlier results are shown to be contained in our general treatment.
Multi-symplectic method for generalized Boussinesq equation
HU Wei-peng; DENG Zi-chen
2008-01-01
The generalized Boussinesq equation that represents a group of important nonlinear equations possesses many interesting properties. Multi-symplectic formulations of the generalized Boussinesq equation in the Hamilton space are introduced in this paper. And then an implicit multi-symplectic scheme equivalent to the multi-symplectic Box scheme is constructed to solve the partial differential equations (PDEs) derived from the generalized Boussinesq equation. Finally, the numerical experiments on the soliton solutions of the generalized Boussinesq equation are reported. The results show that the multi-symplectic method is an efficient algorithm with excellent long-time numerical behaviors for nonlinear partial differential equations.
Differential equations for dummies
Holzner, Steven
2008-01-01
The fun and easy way to understand and solve complex equations Many of the fundamental laws of physics, chemistry, biology, and economics can be formulated as differential equations. This plain-English guide explores the many applications of this mathematical tool and shows how differential equations can help us understand the world around us. Differential Equations For Dummies is the perfect companion for a college differential equations course and is an ideal supplemental resource for other calculus classes as well as science and engineering courses. It offers step-by-step techniques, practical tips, numerous exercises, and clear, concise examples to help readers improve their differential equation-solving skills and boost their test scores.
Partial differential equations
Evans, Lawrence C
2010-01-01
This text gives a comprehensive survey of modern techniques in the theoretical study of partial differential equations (PDEs) with particular emphasis on nonlinear equations. The exposition is divided into three parts: representation formulas for solutions; theory for linear partial differential equations; and theory for nonlinear partial differential equations. Included are complete treatments of the method of characteristics; energy methods within Sobolev spaces; regularity for second-order elliptic, parabolic, and hyperbolic equations; maximum principles; the multidimensional calculus of variations; viscosity solutions of Hamilton-Jacobi equations; shock waves and entropy criteria for conservation laws; and, much more.The author summarizes the relevant mathematics required to understand current research in PDEs, especially nonlinear PDEs. While he has reworked and simplified much of the classical theory (particularly the method of characteristics), he primarily emphasizes the modern interplay between funct...
Fractional Chemotaxis Diffusion Equations
Langlands, T A M
2010-01-01
We introduce mesoscopic and macroscopic model equations of chemotaxis with anomalous subdiffusion for modelling chemically directed transport of biological organisms in changing chemical environments with diffusion hindered by traps or macro-molecular crowding. The mesoscopic models are formulated using Continuous Time Random Walk master equations and the macroscopic models are formulated with fractional order differential equations. Different models are proposed depending on the timing of the chemotactic forcing. Generalizations of the models to include linear reaction dynamics are also derived. Finally a Monte Carlo method for simulating anomalous subdiffusion with chemotaxis is introduced and simulation results are compared with numerical solutions of the model equations. The model equations developed here could be used to replace Keller-Segel type equations in biological systems with transport hindered by traps, macro-molecular crowding or other obstacles.
2011-08-01
NASA Report TM 109112, NASA Langley Research Center, Hampton, VA [4] Chapra SC, Canale RP (2006) Numerical Methods for Engineers, 5th edn. McGraw-Hill...covariances or deterministic modes, and schemes to maintain orthonormal modes at the numerical level are relevant to any system solved using the DO method ...heat transfers [49, 52]. However, the DO method has not yet been applied to Boussinesq flows, and the numerical challenges of the DO decomposition for
Asymptotic problems for stochastic partial differential equations
Salins, Michael
Stochastic partial differential equations (SPDEs) can be used to model systems in a wide variety of fields including physics, chemistry, and engineering. The main SPDEs of interest in this dissertation are the semilinear stochastic wave equations which model the movement of a material with constant mass density that is exposed to both determinstic and random forcing. Cerrai and Freidlin have shown that on fixed time intervals, as the mass density of the material approaches zero, the solutions of the stochastic wave equation converge uniformly to the solutions of a stochastic heat equation, in probability. This is called the Smoluchowski-Kramers approximation. In Chapter 2, we investigate some of the multi-scale behaviors that these wave equations exhibit. In particular, we show that the Freidlin-Wentzell exit place and exit time asymptotics for the stochastic wave equation in the small noise regime can be approximated by the exit place and exit time asymptotics for the stochastic heat equation. We prove that the exit time and exit place asymptotics are characterized by quantities called quasipotentials and we prove that the quasipotentials converge. We then investigate the special case where the equation has a gradient structure and show that we can explicitly solve for the quasipotentials, and that the quasipotentials for the heat equation and wave equation are equal. In Chapter 3, we study the Smoluchowski-Kramers approximation in the case where the material is electrically charged and exposed to a magnetic field. Interestingly, if the system is frictionless, then the Smoluchowski-Kramers approximation does not hold. We prove that the Smoluchowski-Kramers approximation is valid for systems exposed to both a magnetic field and friction. Notably, we prove that the solutions to the second-order equations converge to the solutions of the first-order equation in an Lp sense. This strengthens previous results where convergence was proved in probability.
Turbulence kinetic energy equation for dilute suspensions
Abou-Arab, T. W.; Roco, M. C.
1989-01-01
A multiphase turbulence closure model is presented which employs one transport equation, namely the turbulence kinetic energy equation. The proposed form of this equation is different from the earlier formulations in some aspects. The power spectrum of the carrier fluid is divided into two regions, which interact in different ways and at different rates with the suspended particles as a function of the particle-eddy size ratio and density ratio. The length scale is described algebraically. A mass/time averaging procedure for the momentum and kinetic energy equations is adopted. The resulting turbulence correlations are modeled under less retrictive assumptions comparative to previous work. The closures for the momentum and kinetic energy equations are given. Comparisons of the predictions with experimental results on liquid-solid jet and gas-solid pipe flow show satisfactory agreement.
Discrete and Continuous Linearizable Equations
Lafortune, S; Ramani, A
1998-01-01
We study the projective systems in both continuous and discrete settings. These systems are linearizable by construction and thus, obviously, integrable. We show that in the continuous case it is possible to eliminate all variables but one and reduce the system to a single differential equation. This equation is of the form of those singled-out by Painlevé in his quest for integrable forms. In the discrete case, we extend previous results of ours showing that, again by elimination of variables, the general projective system can be written as a mapping for a single variable. We show that this mapping is a member of the family of multilinear systems (which is not integrable in general). The continuous limit of multilinear mappings is also discussed.
Quantum lattice gas algorithm for the telegraph equation.
Coffey, Mark W; Colburn, Gabriel G
2009-06-01
The telegraph equation combines features of both the diffusion and wave equations and has many applications to heat propagation, transport in disordered media, and elsewhere. We describe a quantum lattice gas algorithm (QLGA) for this partial differential equation with one spatial dimension. This algorithm generalizes one previously known for the diffusion equation. We present an analysis of the algorithm and accompanying simulation results. The QLGA is suitable for simulation on combined classical-quantum computers.
Construction of alternative Hamiltonian structures for field equations
Herrera, Mauricio [Departamento de Fisica, Facultad de Ciencias Fisicas y Matematicas, Universidad de Chile, Santiago (Chile); Hojman, Sergio A. [Departamento de Fisica, Facultad de Ciencias, Universidad de Chile, Santiago (Chile); Facultad de Educacion, Universidad Nacional Andres Bello, Santiago (Chile); Centro de Recursos Educativos Avanzados, CREA, Santiago (Chile)
2001-08-10
We use symmetry vectors of nonlinear field equations to build alternative Hamiltonian structures. We construct such structures even for equations which are usually believed to be non-Hamiltonian such as heat, Burger and potential Burger equations. We improve on a previous version of the approach using recursion operators to increase the rank of the Poisson bracket matrices. Cole-Hopf and Miura-type transformations allow the mapping of these structures from one equation to another. (author)
K. Banoo
1998-01-01
equation in the discrete momentum space. This is shown to be similar to the conventional drift-diffusion equation except that it is a more rigorous solution to the Boltzmann equation because the current and carrier densities are resolved into M×1 vectors, where M is the number of modes in the discrete momentum space. The mobility and diffusion coefficient become M×M matrices which connect the M momentum space modes. This approach is demonstrated by simulating electron transport in bulk silicon.
Developmental Partial Differential Equations
Duteil, Nastassia Pouradier; Rossi, Francesco; Boscain, Ugo; Piccoli, Benedetto
2015-01-01
In this paper, we introduce the concept of Developmental Partial Differential Equation (DPDE), which consists of a Partial Differential Equation (PDE) on a time-varying manifold with complete coupling between the PDE and the manifold's evolution. In other words, the manifold's evolution depends on the solution to the PDE, and vice versa the differential operator of the PDE depends on the manifold's geometry. DPDE is used to study a diffusion equation with source on a growing surface whose gro...
Differential equations I essentials
REA, Editors of
2012-01-01
REA's Essentials provide quick and easy access to critical information in a variety of different fields, ranging from the most basic to the most advanced. As its name implies, these concise, comprehensive study guides summarize the essentials of the field covered. Essentials are helpful when preparing for exams, doing homework and will remain a lasting reference source for students, teachers, and professionals. Differential Equations I covers first- and second-order equations, series solutions, higher-order linear equations, and the Laplace transform.
Ordinary differential equations
Pontryagin, Lev Semenovich
1962-01-01
Ordinary Differential Equations presents the study of the system of ordinary differential equations and its applications to engineering. The book is designed to serve as a first course in differential equations. Importance is given to the linear equation with constant coefficients; stability theory; use of matrices and linear algebra; and the introduction to the Lyapunov theory. Engineering problems such as the Watt regulator for a steam engine and the vacuum-tube circuit are also presented. Engineers, mathematicians, and engineering students will find the book invaluable.
Minimal relativistic three-particle equations
Lindesay, J.
1981-07-01
A minimal self-consistent set of covariant and unitary three-particle equations is presented. Numerical results are obtained for three-particle bound states, elastic scattering and rearrangement of bound pairs with a third particle, and amplitudes for breakup into states of three free particles. The mathematical form of the three-particle bound state equations is explored; constraints are set upon the range of eigenvalues and number of eigenstates of these one parameter equations. The behavior of the number of eigenstates as the two-body binding energy decreases to zero in a covariant context generalizes results previously obtained non-relativistically by V. Efimov.
A Riccati equation in radiative stellar collapse
Rajah, S S
2008-01-01
We model the behaviour of a relativistic spherically symmetric shearing fluid undergoing gravitational collapse with heat flux. It is demonstrated that the governing equation for the gravitational behaviour is a Riccati equation. We show that the Riccati equation admits two classes of new solutions in closed form. We regain particular models, obtained in previous investigations, as special cases. A significant feature of our solutions is the general spatial dependence in the metric functions which allows for a wider study of the physical features of the model, such as the behaviour of the causal temperature in inhomogeneous spacetimes.
Antenatal diagnosis of Patau syndrome with previous anomalous baby
Keerthi Kocherla
2014-06-01
Full Text Available Patau syndrome is the least common and most severe of the viable autosomal trisomies with median survival of fewer than 3 days was first identified as a cytogenetic syndrome in 1960. Patau syndrome is caused by an extra copy of chromosome 13. In this case report, we present antenatal imaging findings and gross foetal specimen correlation of foetus with Patau syndrome confirmed by karyotyping in third gravida who had significant previous obstetric history of gastrochisis in monochorionic and monoamniotic twins who died at 14 weeks of gestation. [Int J Res Med Sci 2014; 2(3.000: 1172-1175
Handbook of structural equation modeling
Hoyle, Rick H
2012-01-01
The first comprehensive structural equation modeling (SEM) handbook, this accessible volume presents both the mechanics of SEM and specific SEM strategies and applications. The editor, contributors, and editorial advisory board are leading methodologists who have organized the book to move from simpler material to more statistically complex modeling approaches. Sections cover the foundations of SEM; statistical underpinnings, from assumptions to model modifications; steps in implementation, from data preparation through writing the SEM report; and basic and advanced applications, inclu
Numerical Inversion of Integral Equations for Medical Imaging and Geophysics
1988-12-13
Equations for Medical Imaging and Geophysics (Unclassified) 12 PERSONAL AUTHOR(S) Frank Stenger 13a. TYPE OF REPORT 13b TIME COVERED 14. DATE OF REPORT...9r~S NUMERICAL INVERSION OF INTEGRAL EQUATIONS FOR MEDICAL IMAGING AND GEOPHYSICS FINAL REPORT AUTHOR OF REPORT: Frank Stenger December 13, 1988
Anisotropic spheres with Van derWaals-type equation of state
S Thirukkanesh; F C Ragel
2014-07-01
We study static spherically symmetric space-time to describe relativistic compact objects with anisotropic matter distribution and derive two classes of exact models to the Einstein–Maxwell system with a modified Van derWaals equation of state. We motivate a Van derWaals-type equation of state to physically signify a high-density domain of quark matter, and the generated exact solutions are shown to contain several classes of exact models reported previously that correspond to various physical scenarios. Geometrical analysis shows that the physical quantities are well behaved so that these models may be used to describe anisotropic charged compact spheres.
Caicedo-Eraso, J. C.; González-Correa, C. H.; González-Correa, C. A.
2013-04-01
A previous study showed that reported BIA equations for body composition are not suitable for Colombian population. The purpose of this study was to develop and validate a preliminary BIA equation for body composition assessment in young females from Colombia, using hydrodensitometry as reference method. A sample of 30 young females was evaluated. Inclusion and exclusion criteria were defined to minimize the variability of BIA. Height, weight, BIA, residual lung volume (RV) and underwater weight (UWW) were measured. A preliminary BIA equation was developed (r2 = 0.72, SEE = 2.48 kg) by stepwise multiple regression with fat-free mass (FFM) as dependent variable and weight, height and impedance measurements as independent variables. The quality of regression was evaluated and a cross-validation against 50% of sample confirmed that results obtained with the preliminary BIA equation is interchangeable with results obtained with hydrodensitometry (r2 = 0.84, SEE = 2.62 kg). The preliminary BIA equation can be used for body composition assessment in young females from Colombia until a definitive equation is developed. The next step will be increasing the sample, including a second reference method, as deuterium oxide dilution (D2O), and using multi-frequency BIA (MF-BIA). It would also be desirable to develop equations for males and other ethnic groups in Colombia.
Primary papillary thyroid carcinoma previously treated incompletely with radiofrequency ablation.
Kim, Hoon Yub; Ryu, Woo Sang; Woo, Sang Uk; Son, Gil Soo; Lee, Eun Sook; Lee, Jae Bok; Bae, Jeoung Won
2010-01-01
Radiofrequency ablation (RFA) recently has been applied to benign thyroid nodules, mainly for the cosmetic reasons, and limited cases of local recurrences or focal distant metastases of well-differentiated thyroid cancer, in the high-risk reoperative condition or for the palliative purpose. But no report has been made on the RFA for primary thyroid cancer to date. We report on a patient with primary papillary carcinoma of thyroid gland who had undergone RFA before the cytological diagnosis of malignancy, later referred and treated with robotic surgery successfully. We can learn the following lessons from our case; (1) the RFA for operable primary thyroid malignancy should be avoided, because of the possibility of remnant viable cancer and undetectable nodal metastasis, and (2) robotic or endoscopic thyroid surgery may be a feasible operative method for benign or malignant thyroid nodules previously treated with RFA.
Primary papillary thyroid carcinoma previously treated incompletely with radiofrequency ablation
Kim Hoon
2010-01-01
Full Text Available Radiofrequency ablation (RFA recently has been applied to benign thyroid nodules, mainly for the cosmetic reasons, and limited cases of local recurrences or focal distant metastases of well-differentiated thyroid cancer, in the high-risk reoperative condition or for the palliative purpose. But no report has been made on the RFA for primary thyroid cancer to date. We report on a patient with primary papillary carcinoma of thyroid gland who had undergone RFA before the cytological diagnosis of malignancy, later referred and treated with robotic surgery successfully. We can learn the following lessons from our case; (1 the RFA for operable primary thyroid malignancy should be avoided, because of the possibility of remnant viable cancer and undetectable nodal metastasis, and (2 robotic or endoscopic thyroid surgery may be a feasible operative method for benign or malignant thyroid nodules previously treated with RFA.
Hazewinkel, M.
1995-01-01
Dedication: I dedicate this paper to Prof. P.C. Baayen, at the occasion of his retirement on 20 December 1994. The beautiful equation which forms the subject matter of this paper was invented by Wouthuysen after he retired. The four complex variable Wouthuysen equation arises from an original space-
Shabat, A. B.
2016-12-01
We consider the class of entire functions of exponential type in relation to the scattering theory for the Schrödinger equation with a finite potential that is a finite Borel measure. These functions have a special self-similarity and satisfy q-difference functional equations. We study their asymptotic behavior and the distribution of zeros.
Dissipative Boussinesq equations
Dutykh, D; Dias, Fr\\'{e}d\\'{e}ric; Dutykh, Denys
2007-01-01
The classical theory of water waves is based on the theory of inviscid flows. However it is important to include viscous effects in some applications. Two models are proposed to add dissipative effects in the context of the Boussinesq equations, which include the effects of weak dispersion and nonlinearity in a shallow water framework. The dissipative Boussinesq equations are then integrated numerically.
Hannelore Breckner
2000-01-01
Full Text Available We consider a stochastic equation of Navier-Stokes type containing a noise part given by a stochastic integral with respect to a Wiener process. The purpose of this paper is to approximate the solution of this nonlinear equation by the Galerkin method. We prove the convergence in mean square.
Differential Equation of Equilibrium
user
than the classical method in the solution of the aforementioned differential equation. Keywords: ... present a successful approximation of shell ... displacement function. .... only applicable to cylindrical shell subject to ..... (cos. 4. 4. 4. 3 β. + β. + β. -. = β. - β x x e ex. AL. xA w. Substituting equations (29); (30) and (31) into.
Subtalar Fusion Rate in Patients With Previous Ipsilateral Ankle Arthrodesis.
Zanolli, Diego H; Nunley, James A; Easley, Mark E
2015-09-01
Isolated subtalar arthrodesis is generally successful, with reported fusion rates of 84% to 100%. However, alteration of subtalar joint mechanics and talar body vasculature after ankle fusion may negatively influence subsequent ipsilateral subtalar joint fusion. Because there is very limited information on the subtalar fusion rate in patients with previous ipsilateral ankle fusion, the purpose of this study was to describe fusion rates in subtalar joint arthrodesis with and without preexisting ankle fusion in a large consecutive series of primary subtalar arthrodesis cases. All primary subtalar fusions performed between January 2000 and December 2010 were reviewed. Thirteen of 151 consecutive cases were in patients with existing ipsilateral ankle fusions. All patients were evaluated for clinical and radiographic evidence of nonunion at follow-up, and fusion rates in the groups with and without previous ipsilateral ankle fusion were compared. Five nonunions occurred in the 13 cases with prior ipsilateral ankle arthrodesis, a 61.5% fusion rate. Twelve nonunions were identified in the 138 cases without prior ankle arthrodesis, a significantly higher fusion rate of 91.3% (P = .007). In our series, the subtalar fusion rate in patients with previous ipsilateral ankle arthrodesis was significantly lower than that for subtalar arthrodesis in the absence of ipsilateral ankle arthrodesis. Level III, retrospective comparative study. © The Author(s) 2015.
Explicit Integration of Friedmann's Equation with Nonlinear Equations of State
Chen, Shouxin; Yang, Yisong
2015-01-01
This paper is a continuation of our earlier study on the integrability of the Friedmann equations in the light of the Chebyshev theorem. Our main focus will be on a series of important, yet not previously touched, problems when the equation of state for the perfect-fluid universe is nonlinear. These include the generalized Chaplygin gas, two-term energy density, trinomial Friedmann, Born--Infeld, and two-fluid models. We show that some of these may be integrated using Chebyshev's result while other are out of reach by the theorem but may be integrated explicitly by other methods. With the explicit integration, we are able to understand exactly the roles of the physical parameters in various models play in the cosmological evolution. For example, in the Chaplygin gas universe, it is seen that, as far as there is a tiny presence of nonlinear matter, linear matter makes contribution to the dark matter, which becomes significant near the phantom divide line. The Friedmann equations also arise in areas of physics ...
Applied partial differential equations
Logan, J David
2004-01-01
This primer on elementary partial differential equations presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs. What makes this book unique is that it is a brief treatment, yet it covers all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. Mathematical ideas are motivated from physical problems, and the exposition is presented in a concise style accessible to science and engineering students; emphasis is on motivation, concepts, methods, and interpretation, rather than formal theory. This second edition contains new and additional exercises, and it includes a new chapter on the applications of PDEs to biology: age structured models, pattern formation; epidemic wave fronts, and advection-diffusion processes. The student who reads through this book and solves many of t...
Geometric Implications of Maxwell's Equations
Smith, Felix T.
2015-03-01
Maxwell's synthesis of the varied results of the accumulated knowledge of electricity and magnetism, based largely on the searching insights of Faraday, still provide new issues to explore. A case in point is a well recognized anomaly in the Maxwell equations: The laws of electricity and magnetism require two 3-vector and two scalar equations, but only six dependent variables are available to be their solutions, the 3-vectors E and B. This leaves an apparent redundancy of two degrees of freedom (J. Rosen, AJP 48, 1071 (1980); Jiang, Wu, Povinelli, J. Comp. Phys. 125, 104 (1996)). The observed self-consistency of the eight equations suggests that they contain additional information. This can be sought as a previously unnoticed constraint connecting the space and time variables, r and t. This constraint can be identified. It distorts the otherwise Euclidean 3-space of r with the extremely slight, time dependent curvature k (t) =Rcurv-2 (t) of the 3-space of a hypersphere whose radius has the time dependence dRcurv / dt = +/- c nonrelativistically, or dRcurvLor / dt = +/- ic relativistically. The time dependence is exactly that of the Hubble expansion. Implications of this identification will be explored.
Kuksin, Sergei; Maiocchi, Alberto
In this chapter we present a general method of constructing the effective equation which describes the behavior of small-amplitude solutions for a nonlinear PDE in finite volume, provided that the linear part of the equation is a hamiltonian system with a pure imaginary discrete spectrum. The effective equation is obtained by retaining only the resonant terms of the nonlinearity (which may be hamiltonian, or may be not); the assertion that it describes the limiting behavior of small-amplitude solutions is a rigorous mathematical theorem. In particular, the method applies to the three- and four-wave systems. We demonstrate that different possible types of energy transport are covered by this method, depending on whether the set of resonances splits into finite clusters (this happens, e.g. in case of the Charney-Hasegawa-Mima equation), or is connected (this happens, e.g. in the case of the NLS equation if the space-dimension is at least two). For equations of the first type the energy transition to high frequencies does not hold, while for equations of the second type it may take place. Our method applies to various weakly nonlinear wave systems, appearing in plasma, meteorology and oceanography.
Differential equations problem solver
Arterburn, David R
2012-01-01
REA's Problem Solvers is a series of useful, practical, and informative study guides. Each title in the series is complete step-by-step solution guide. The Differential Equations Problem Solver enables students to solve difficult problems by showing them step-by-step solutions to Differential Equations problems. The Problem Solvers cover material ranging from the elementary to the advanced and make excellent review books and textbook companions. They're perfect for undergraduate and graduate studies.The Differential Equations Problem Solver is the perfect resource for any class, any exam, and
Ordinary differential equations
Miller, Richard K
1982-01-01
Ordinary Differential Equations is an outgrowth of courses taught for a number of years at Iowa State University in the mathematics and the electrical engineering departments. It is intended as a text for a first graduate course in differential equations for students in mathematics, engineering, and the sciences. Although differential equations is an old, traditional, and well-established subject, the diverse backgrounds and interests of the students in a typical modern-day course cause problems in the selection and method of presentation of material. In order to compensate for this diversity,
Pierret, Frédéric
2016-02-01
We derived the equations of Celestial Mechanics governing the variation of the orbital elements under a stochastic perturbation, thereby generalizing the classical Gauss equations. Explicit formulas are given for the semimajor axis, the eccentricity, the inclination, the longitude of the ascending node, the pericenter angle, and the mean anomaly, which are expressed in term of the angular momentum vector H per unit of mass and the energy E per unit of mass. Together, these formulas are called the stochastic Gauss equations, and they are illustrated numerically on an example from satellite dynamics.
Beginning partial differential equations
O'Neil, Peter V
2011-01-01
A rigorous, yet accessible, introduction to partial differential equations-updated in a valuable new edition Beginning Partial Differential Equations, Second Edition provides a comprehensive introduction to partial differential equations (PDEs) with a special focus on the significance of characteristics, solutions by Fourier series, integrals and transforms, properties and physical interpretations of solutions, and a transition to the modern function space approach to PDEs. With its breadth of coverage, this new edition continues to present a broad introduction to the field, while also addres
Hyperbolic partial differential equations
Witten, Matthew
1986-01-01
Hyperbolic Partial Differential Equations III is a refereed journal issue that explores the applications, theory, and/or applied methods related to hyperbolic partial differential equations, or problems arising out of hyperbolic partial differential equations, in any area of research. This journal issue is interested in all types of articles in terms of review, mini-monograph, standard study, or short communication. Some studies presented in this journal include discretization of ideal fluid dynamics in the Eulerian representation; a Riemann problem in gas dynamics with bifurcation; periodic M
Wu Zhuo Qun; Li Hui Lai; Zhao Jun Ning
2001-01-01
Nonlinear diffusion equations, an important class of parabolic equations, come from a variety of diffusion phenomena which appear widely in nature. They are suggested as mathematical models of physical problems in many fields, such as filtration, phase transition, biochemistry and dynamics of biological groups. In many cases, the equations possess degeneracy or singularity. The appearance of degeneracy or singularity makes the study more involved and challenging. Many new ideas and methods have been developed to overcome the special difficulties caused by the degeneracy and singularity, which
Partial differential equations
Friedman, Avner
2008-01-01
This three-part treatment of partial differential equations focuses on elliptic and evolution equations. Largely self-contained, it concludes with a series of independent topics directly related to the methods and results of the preceding sections that helps introduce readers to advanced topics for further study. Geared toward graduate and postgraduate students of mathematics, this volume also constitutes a valuable reference for mathematicians and mathematical theorists.Starting with the theory of elliptic equations and the solution of the Dirichlet problem, the text develops the theory of we
Introduction to functional equations
Sahoo, Prasanna K
2011-01-01
Introduction to Functional Equations grew out of a set of class notes from an introductory graduate level course at the University of Louisville. This introductory text communicates an elementary exposition of valued functional equations where the unknown functions take on real or complex values. In order to make the presentation as manageable as possible for students from a variety of disciplines, the book chooses not to focus on functional equations where the unknown functions take on values on algebraic structures such as groups, rings, or fields. However, each chapter includes sections hig
Uncertain differential equations
Yao, Kai
2016-01-01
This book introduces readers to the basic concepts of and latest findings in the area of differential equations with uncertain factors. It covers the analytic method and numerical method for solving uncertain differential equations, as well as their applications in the field of finance. Furthermore, the book provides a number of new potential research directions for uncertain differential equation. It will be of interest to researchers, engineers and students in the fields of mathematics, information science, operations research, industrial engineering, computer science, artificial intelligence, automation, economics, and management science.
A Comparison of IRT Equating and Beta 4 Equating.
Kim, Dong-In; Brennan, Robert; Kolen, Michael
Four equating methods were compared using four equating criteria: first-order equity (FOE), second-order equity (SOE), conditional mean squared error (CMSE) difference, and the equipercentile equating property. The four methods were: (1) three parameter logistic (3PL) model true score equating; (2) 3PL observed score equating; (3) beta 4 true…
Mindikoglu, Ayse L.; Dowling, Thomas C.; Weir, Matthew R.; Seliger, Stephen L.; Christenson, Robert H.; Magder, Laurence S.
2013-01-01
Conventional creatinine-based glomerular filtration rate (GFR) equations are insufficiently accurate for estimating GFR in cirrhosis. The Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) recently proposed an equation to estimate GFR in subjects without cirrhosis using both serum creatinine and cystatin C levels. Performance of the new CKD-EPI creatinine-cystatin C equation (2012) was superior to previous creatinine- or cystatin C-based GFR equations. To evaluate the performance of the CKD-EPI creatinine-cystatin C equation in subjects with cirrhosis, we compared it to GFR measured by non-radiolabeled iothalamate plasma clearance (mGFR) in 72 subjects with cirrhosis. We compared the “bias”, “precision” and “accuracy” of the new CKD-EPI creatinine-cystatin C equation to that of 24-hour urinary creatinine clearance (CrCl), Cockcroft-Gault (CG) and previously reported creatinine- and/or cystatin C-based GFR-estimating equations. Accuracy of CKD-EPI creatinine-cystatin C equation as quantified by root mean squared error of difference scores [differences between mGFR and estimated GFR (eGFR) or between mGFR and CrCl, or between mGFR and CG equation for each subject] (RMSE=23.56) was significantly better than that of CrCl (37.69, P=0.001), CG (RMSE=36.12, P=0.002) and GFR-estimating equations based on cystatin C only. Its accuracy as quantified by percentage of eGFRs that differed by greater than 30% with respect to mGFR was significantly better compared to CrCl (P=0.024), CG (P=0.0001), 4-variable MDRD (P=0.027) and CKD-EPI creatinine 2009 (P=0.012) equations. However, for 23.61% of the subjects, GFR estimated by CKD-EPI creatinine-cystatin C equation differed from the mGFR by more than 30%. CONCLUSIONS The diagnostic performance of CKD-EPI creatinine-cystatin C equation (2012) in patients with cirrhosis was superior to conventional equations in clinical practice for estimating GFR. However, its diagnostic performance was substantially worse than
Static trace free Einstein equations and stellar distributions
Hansraj, Sudan; Goswami, Rituparno; Mkhize, Njabulo; Ellis, George
2017-08-01
We construct models of static spherical distributions of the perfect fluid in trace free Einstein gravity theory. The equations governing the gravitational field are equivalent to standard Einstein's equations; however, their presentation is manifestly different, which motivates the question whether new information would emerge due to the nonlinearity of the field equations. The incompressible fluid assumption does not lead to the well known Schwarzschild interior metric of Einstein gravity, and a term denoting the presence of a cosmological constant is present on account of the integration process. The Schwarzschild interior is regained as a special case of a richer geometry. On the other hand, when the Schwarzschild geometry is prescribed, a constant density fluid emerges consistent with the standard equations. A complete model of an isothermal fluid sphere with pressure and density obeying the inverse square law is obtained. Corrections to the model previously presented in the literature by Saslaw et al. are exhibited. The isothermal ansatz does not yield a constant gravitational potential in general, but both potentials are position dependent. Conversely, it is shown that assuming a constant gr r gravitational potential does not yield an isothermal fluid in general as is the case in standard general relativity. The results of the standard Einstein equations are special cases of the models reported here. Noteworthy is the fact that whereas the previously reported isothermal solution was only of cosmological interest, the solution reported herein admits compact objects by virtue of the fact that a pressure free hypersurface exists. Finally we analyze the consequences of selecting the Finch-Skea metric as the seed solution. The density profiles match; however, there is a deviation between the pressure profiles with the Einstein case although the qualitative behavior is the same. It is shown in detail that the model satisfies elementary requirements for physical
Recurrent arthralgias in a patient with previous Mayaro fever infection.
Taylor, Shawn F; Patel, Paresh R; Herold, Thomas J S
2005-04-01
Mayaro fever is an acute, self-limited, febrile, mosquito-borne viral disease manifested by fever, chills, headache, myalgias, and arthralgias. The virus belongs to the family Togaviridae and the genus Alphavirus. Five other mosquito-borne viruses have been described as causing a similar dengue-like illness. The virus was first isolated in 1954, and the first epidemics were described in 1955 in Brazil and Bolivia. Other cases have been reported in Suriname, Brazil, Peru, French Guiana, and Trinidad. Up to 10 to 15% of febrile illnesses in endemic areas have been attributed to Mayaro virus. The exact pathogenesis and pathophysiology among humans is unknown. Animal models have demonstrated necrosis of skeletal muscle, periosteum, perichondrial tissues, and evidence of meningitis and encephalitis. All previous cases of Mayaro fever describe a self-limited illness. No reports of recurrent symptoms exist in the literature. This report describes a case of recurrent arthralgias in a military service member presenting to the emergency department.
High-Grade Leiomyosarcoma Arising in a Previously Replanted Limb
Tiffany J. Pan
2015-01-01
Full Text Available Sarcoma development has been associated with genetics, irradiation, viral infections, and immunodeficiency. Reports of sarcomas arising in the setting of prior trauma, as in burn scars or fracture sites, are rare. We report a case of a leiomyosarcoma arising in an arm that had previously been replanted at the level of the elbow joint following traumatic amputation when the patient was eight years old. He presented twenty-four years later with a 10.8 cm mass in the replanted arm located on the volar forearm. The tumor was completely resected and pathology examination showed a high-grade, subfascial spindle cell sarcoma diagnosed as a grade 3 leiomyosarcoma with stage pT2bNxMx. The patient underwent treatment with brachytherapy, reconstruction with a free flap, and subsequently chemotherapy. To the best of our knowledge, this is the first case report of leiomyosarcoma developing in a replanted extremity. Development of leiomyosarcoma in this case could be related to revascularization, scar formation, or chronic injury after replantation. The patient remains healthy without signs of recurrence at three-year follow-up.
Elbridge Gerry Puckett
2008-05-13
this he had been a Deputy Section Head at the National Center for Atmospheric Research in Colorado. My understanding is that Chris Algieri is the first person that Bill hired after coming to LBNL. The plan is that Chris Algieri will finish his PhD thesis while employed as a staff scientist in Bill's group. Both Sarah and Chris were supported in part with funds from DE-FC02-01ER25473. In Sarah's case she received support both while at U.C. Davis (UCD) taking classes and writing an MS thesis and during some of the time she was living in Berkeley, working at LBNL and finishing her PhD thesis. In Chris' case he was at U.C. Davis during the entire time he received support from DE-FC02-01ER25473. More specific details of their work are included in the report below. Finally my own research conducted under the auspices of DE-FC02-01ER25473 either involved direct collaboration with researchers at LBNL - Phil Colella and Peter Schwartz who is a member of Phil's Applied Numerical Algorithms Group - or was on problems that are closely related to research that has been and continues to be conducted by researchers at LBNL. Specific details of this work can be found below. Finally, I would like to note that the work conducted by my students and me under the auspices of this contract is closely related to work that I have performed with funding from my DOE MICS contract DE-FC02-03ER25579 'Development of High-Order Accurate Interface Tracking Algorithms and Improved Constitutive Models for Problems in Continuum Mechanics with Applications to Jetting' and with my CoPI on that grant Professor Greg Miller of the Department of Applied Science at UCD. In theory I tried to use funds from the SciDAC grant DE-FC02-01ER25473 to support work that directly involved implementing algorithms developed by my research group at U.C. Davis in software that was developed and is maintained by my SciDAC CoPI's at LBNL.
Iju, T; Fujiki, K
2014-01-01
We report kinematic properties of slow interplanetary coronal mass ejections (ICMEs) identified by SOHO/LASCO, interplanetary scintillation, and in-situ observations, and propose a modified equation for the ICME motion. We identify seven ICMEs between 2010 and 2011, and examine them with 39 events reported in our previous work. We examine 15 fast (V_SOHO - V_bg > 500 km/s), 25 moderate (0 km/s 2300 km/s.
Applied partial differential equations
Logan, J David
2015-01-01
This text presents the standard material usually covered in a one-semester, undergraduate course on boundary value problems and PDEs. Emphasis is placed on motivation, concepts, methods, and interpretation, rather than on formal theory. The concise treatment of the subject is maintained in this third edition covering all the major ideas: the wave equation, the diffusion equation, the Laplace equation, and the advection equation on bounded and unbounded domains. Methods include eigenfunction expansions, integral transforms, and characteristics. In this third edition, text remains intimately tied to applications in heat transfer, wave motion, biological systems, and a variety other topics in pure and applied science. The text offers flexibility to instructors who, for example, may wish to insert topics from biology or numerical methods at any time in the course. The exposition is presented in a friendly, easy-to-read, style, with mathematical ideas motivated from physical problems. Many exercises and worked e...
Frédéric, Pierret
2014-01-01
The equations of celestial mechanics that govern the variation of the orbital elements are completely derived for stochastic perturbation which generalized the classic perturbation equations which are used since Gauss, starting from Newton's equation and it's solution. The six most understandable orbital element, the semi-major axis, the eccentricity, the inclination, the longitude of the ascending node, the pericenter angle and the mean motion are express in term of the angular momentum vector $\\textbf{H}$ per unit of mass and the energy $E$ per unit of mass. We differentiate those expressions using It\\^o's theory of differential equations due to the stochastic nature of the perturbing force. The result is applied to the two-body problem perturbed by a stochastic dust cloud and also perturbed by a stochastic dynamical oblateness of the central body.
Kinetic equations: computation
Pareschi, Lorenzo
2013-01-01
Kinetic equations bridge the gap between a microscopic description and a macroscopic description of the physical reality. Due to the high dimensionality the construction of numerical methods represents a challenge and requires a careful balance between accuracy and computational complexity.
Saaty, Thomas L
1981-01-01
Covers major types of classical equations: operator, functional, difference, integro-differential, and more. Suitable for graduate students as well as scientists, technologists, and mathematicians. "A welcome contribution." - Math Reviews. 1964 edition.
Geometry of differential equations
Khovanskiĭ, A; Vassiliev, V
1998-01-01
This volume contains articles written by V. I. Arnold's colleagues on the occasion of his 60th birthday. The articles are mostly devoted to various aspects of geometry of differential equations and relations to global analysis and Hamiltonian mechanics.
Regularized Structural Equation Modeling.
Jacobucci, Ross; Grimm, Kevin J; McArdle, John J
A new method is proposed that extends the use of regularization in both lasso and ridge regression to structural equation models. The method is termed regularized structural equation modeling (RegSEM). RegSEM penalizes specific parameters in structural equation models, with the goal of creating easier to understand and simpler models. Although regularization has gained wide adoption in regression, very little has transferred to models with latent variables. By adding penalties to specific parameters in a structural equation model, researchers have a high level of flexibility in reducing model complexity, overcoming poor fitting models, and the creation of models that are more likely to generalize to new samples. The proposed method was evaluated through a simulation study, two illustrative examples involving a measurement model, and one empirical example involving the structural part of the model to demonstrate RegSEM's utility.
A.I.Arbab
2013-01-01
A unified complex model of Maxwell's equations is presented.The wave nature of the electromagnetic field vector is related to the temporal and spatial distributions and the circulation of charge and current densities.A new vacuum solution is obtained,and a new transformation under which Maxwell's equations are invariant is proposed.This transformation extends ordinary gauge transformation to include charge-current as well as scalar-vector potential.An electric dipole moment is found to be related to the magnetic charges,and Dirac's quantization is found to determine an uncertainty relation expressing the indeterminacy of electric and magnetic charges.We generalize Maxwell's equations to include longitudinal waves.A formal analogy between this formulation and Dirac's equation is also discussed.
Applied partial differential equations
DuChateau, Paul
2012-01-01
Book focuses mainly on boundary-value and initial-boundary-value problems on spatially bounded and on unbounded domains; integral transforms; uniqueness and continuous dependence on data, first-order equations, and more. Numerous exercises included.
Singular Renormalization Group Equations
Minoru, HIRAYAMA; Department of Physics, Toyama University
1984-01-01
The possible behaviour of the effective charge is discussed in Oehme and Zimmermann's scheme of the renormalization group equation. The effective charge in an example considered oscillates so violently in the ultraviolet limit that the bare charge becomes indefinable.
Problems in differential equations
Brenner, J L
2013-01-01
More than 900 problems and answers explore applications of differential equations to vibrations, electrical engineering, mechanics, and physics. Problem types include both routine and nonroutine, and stars indicate advanced problems. 1963 edition.
Generalizing the Boltzmann equation in complex phase space.
Zadehgol, Abed
2016-08-01
In this work, a generalized form of the BGK-Boltzmann equation is proposed, where the velocity, position, and time can be represented by real or complex variables. The real representation leads to the conventional BGK-Boltzmann equation, which can recover the continuity and Navier-Stokes equations. We show that the complex representation yields a different set of equations, and it can also recover the conservation and Navier-Stokes equations, at low Mach numbers, provided that the imaginary component of the macroscopic mass can be neglected. We briefly review the Constant Speed Kinetic Model (CSKM), which was introduced in Zadehgol and Ashrafizaadeh [J. Comp. Phys. 274, 803 (2014)JCTPAH0021-999110.1016/j.jcp.2014.06.053] and Zadehgol [Phys. Rev. E 91, 063311 (2015)PLEEE81539-375510.1103/PhysRevE.91.063311]. The CSKM is then used as a basis to show that the complex-valued equilibrium distribution function of the present model can be identified with a simple singularity in the complex phase space. The virtual particles, in the present work, are concentrated on virtual "branes" which surround the computational nodes. Employing the Cauchy integral formula, it is shown that certain variations of the "branes," in the complex phase space, do not affect the local kinetic states. This property of the new model, which is referred to as the "apparent jumps" in the present work, is used to construct new models. The theoretical findings have been tested by simulating three benchmark flows. The results of the present simulations are in excellent agreement with the previous results reported by others.
Generalizing the Boltzmann equation in complex phase space
Zadehgol, Abed
2016-08-01
In this work, a generalized form of the BGK-Boltzmann equation is proposed, where the velocity, position, and time can be represented by real or complex variables. The real representation leads to the conventional BGK-Boltzmann equation, which can recover the continuity and Navier-Stokes equations. We show that the complex representation yields a different set of equations, and it can also recover the conservation and Navier-Stokes equations, at low Mach numbers, provided that the imaginary component of the macroscopic mass can be neglected. We briefly review the Constant Speed Kinetic Model (CSKM), which was introduced in Zadehgol and Ashrafizaadeh [J. Comp. Phys. 274, 803 (2014), 10.1016/j.jcp.2014.06.053] and Zadehgol [Phys. Rev. E 91, 063311 (2015), 10.1103/PhysRevE.91.063311]. The CSKM is then used as a basis to show that the complex-valued equilibrium distribution function of the present model can be identified with a simple singularity in the complex phase space. The virtual particles, in the present work, are concentrated on virtual "branes" which surround the computational nodes. Employing the Cauchy integral formula, it is shown that certain variations of the "branes," in the complex phase space, do not affect the local kinetic states. This property of the new model, which is referred to as the "apparent jumps" in the present work, is used to construct new models. The theoretical findings have been tested by simulating three benchmark flows. The results of the present simulations are in excellent agreement with the previous results reported by others.
On solving equations of algebraic sum of equal powers
WANG Xinghua; YANG Shijun
2006-01-01
It is well known that a system of equations of sum of equal powers can be converted to an algebraic equation of higher degree via Newton's identities. This is the Viete-Newton theorem. This work reports the generalizations of the Viete-Newton theorem to a system of equations of algebraic sum of equal powers. By exploiting some facts from algebra and combinatorics,it is shown that a system of equations of algebraic sum of equal powers can be converted in a closed form to two algebraic equations, whose degree sum equals the number of unknowns of the system of equations of algebraic sum of equal powers.
Stewart, Benjamin James; Majoni, Sandawana William
2014-01-01
We describe a haemodialysis patient who presented with an exacerbation of previously undiagnosed chronic focal myositis during a hospital admission for missed dialysis and chronic foot osteomyelitis. The association of focal myositis with haemodialysis has been reported once previously, but we report the third case in our experience and argue that it is probably more common than previously appreciated. We consider a focused differential diagnosis for a diabetic dialysis patient with leg pain and discuss important features of this rare condition. PMID:25342033
Asymptotics for dissipative nonlinear equations
Hayashi, Nakao; Kaikina, Elena I; Shishmarev, Ilya A
2006-01-01
Many of problems of the natural sciences lead to nonlinear partial differential equations. However, only a few of them have succeeded in being solved explicitly. Therefore different methods of qualitative analysis such as the asymptotic methods play a very important role. This is the first book in the world literature giving a systematic development of a general asymptotic theory for nonlinear partial differential equations with dissipation. Many typical well-known equations are considered as examples, such as: nonlinear heat equation, KdVB equation, nonlinear damped wave equation, Landau-Ginzburg equation, Sobolev type equations, systems of equations of Boussinesq, Navier-Stokes and others.
Functional Equations and Fourier Analysis
2010-01-01
By exploring the relations among functional equations, harmonic analysis and representation theory, we give a unified and very accessible approach to solve three important functional equations -- the d'Alembert equation, the Wilson equation, and the d'Alembert long equation, on compact groups.
Melanoma diagnosed in lesions previously treated by laser therapy.
Delker, Sarah; Livingstone, Elisabeth; Schimming, Tobias; Schadendorf, Dirk; Griewank, Klaus G
2017-01-01
Laser therapy has become a routine procedure in dermatological practice and is frequently also used for pigmented lesions. Few reports exist of melanomas diagnosed in lesions previously treated by laser therapy. Between 2007 and 2014, we identified 11 patients who presented to our department with a melanoma diagnosed in a region previously treated by laser therapy. The course of events until the diagnosis of melanoma was assessed as well as patient outcome including treatment for disease progression. No histological assessment had been performed prior to laser therapy in nine of 11 (82%) cases. Benign melanocytic lesions had been diagnosed by biopsy prior to laser therapy in the other two cases. Time from laser therapy to diagnosis of melanoma ranged from less than 1 to 10 years. Stage of disease at diagnosis varied from stage IA to IIIC. Four patients progressed to stage IV disease, of whom at least one died of melanoma. We conclude that laser treatment of pigmented lesions can complicate the diagnosis of melanoma and lead to diagnosis delay with potentially fatal consequences. Considering this risk, we believe laser therapy for pigmented lesions should either be avoided entirely or at a minimum performed only after prior histological assessment. © 2016 Japanese Dermatological Association.
Reanalysis of the equation for simple action
Warren-Boulton, Frederick R.; Silberberg, Alan; Gray, Michael; Ollom, Randolph
1985-01-01
De Villiers and Herrnstein (1976) have shown that the equation for simple action, derived from the matching law, predicts change in behavioral output for some 40 experiments in which the value of a single source of reinforcement has been varied. Using only the positive-reinforcement studies they cite that used five or more different reinforcement values, we found the high percentage of variance they report accommodated by this equation (94%) is predicated on instances of averaging rates of be...
Transfer equation of exergy cost and its application
无
2003-01-01
This report reviews the development of the theoretical framework for exergoeconomics, and proposes a time and space-dependent exergy cost transfer equation. The exergy cost transfer equation, together with the exergy transfer equation, constitutes the theoretical fundament for exergy analysis, exergoeconomic analysis and optimization. With these transfer equations, three theorems regarding to exergoeconomics are therefore derived, expounded and proved, which could be utilized to solve problems in esti-mating exergy, exergy fluxes and exergy destruction costing.
The stability of locus equation slopes across stop consonant voicing/aspiration
Sussman, Harvey M.; Modarresi, Golnaz
2001-05-01
The consistency of locus equation slopes as phonetic descriptors of stop place in CV sequences across voiced and voiceless aspirated stops was explored in the speech of five male speakers of American English and two male speakers of Persian. Using traditional locus equation measurement sites for F2 onsets, voiceless labial and coronal stops had significantly lower locus equation slopes relative to their voiced counterparts, whereas velars failed to show voicing differences. When locus equations were derived using F2 onsets for voiced stops that were measured closer to the stop release burst, comparable to the protocol for measuring voiceless aspirated stops, no significant effects of voicing/aspiration on locus equation slopes were observed. This methodological factor, rather than an underlying phonetic-based explanation, provides a reasonable account for the observed flatter locus equation slopes of voiceless labial and coronal stops relative to voiced cognates reported in previous studies [Molis et al., J. Acoust. Soc. Am. 95, 2925 (1994); O. Engstrand and B. Lindblom, PHONUM 4, 101-104]. [Work supported by NIH.
Covariant equations for the {ital NN}{minus}{pi}{ital NN} system
Phillips, D.R.; Afnan, I.R. [School of Physical Sciences, Flinders University of South Australia, GPO Box 2100, Adelaide 5001 (Australia)
1995-05-10
We explain the deficiencies of the current {ital NN}{minus}{pi}{ital NN} equations, sketch the derivation of a set of covariant {ital NN}{minus}{pi}{ital NN} equations and describe the ways in which these equations differ from previous sets of covariant equations. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.
Scaling Equation for Invariant Measure
LIU Shi-Kuo; FU Zun-Tao; LIU Shi-Da; REN Kui
2003-01-01
An iterated function system (IFS) is constructed. It is shown that the invariant measure of IFS satisfies the same equation as scaling equation for wavelet transform (WT). Obviously, IFS and scaling equation of WT both have contraction mapping principle.
Feshchenko, R M
2016-01-01
In this paper exact 1D transparent boundary conditions (TBC) for the 2D parabolic wave equation with a linear or a quadratic dependence of the dielectric permittivity on the transversal coordinate are reported. Unlike the previously derived TBCs they contain only elementary functions. The obtained boundary conditions can be used to numerically solve the 2D parabolic equation describing the propagation of light in weakly bent optical waveguides and fibers including waveguides with variable curvature. They also are useful when solving the equivalent 1D Schr\\"odinger equation with a potential depending linearly or quadratically on the coordinate. The prospects and problems of discretization of the derived transparent boundary conditions are discussed.
Measles Outbreak among Previously Immunized Adult Healthcare Workers, China, 2015
Zhengyi Zhang
2016-01-01
Full Text Available Measles is caused by measles virus belonging to genus Morbillivirus of the family Paramyxoviridae. Vaccination has played a critical role in controlling measles infection worldwide. However, in the recent years, outbreaks of measles infection still occur in many developing countries. Here, we report an outbreak of measles among healthcare workers and among the 60 measles infected patients 50 were healthcare workers including doctors, nurses, staff, and medics. Fifty-one patients (85% tested positive for IgM antibodies against the measles virus and 50 patients (83.3% tested positive for measles virus RNA. Surprisingly, 73.3% of the infected individuals had been previously immunized against measles. Since there is no infection division in our hospital, the fever clinics are located in the Emergency Division. In addition, the fever and rash were not recognized as measles symptoms at the beginning of the outbreak. These factors result in delay in isolation and early confirmation of the suspected patients and eventually a measles outbreak in the hospital. Our report highlights the importance of following a two-dose measles vaccine program in people including the healthcare workers. In addition, vigilant attention should be paid to medical staff with clinical fever and rash symptoms to avoid a possible nosocomial transmission of measles infection.
Cerebral Metastasis from a Previously Undiagnosed Appendiceal Adenocarcinoma
Antonio Biroli
2012-01-01
Full Text Available Brain metastases arise in 10%–40% of all cancer patients. Up to one third of the patients do not have previous cancer history. We report a case of a 67-years-old male patient who presented with confusion, tremor, and apraxia. A brain MRI revealed an isolated right temporal lobe lesion. A thorax-abdomen-pelvis CT scan showed no primary lesion. The patient underwent a craniotomy with gross-total resection. Histopathology revealed an intestinal-type adenocarcinoma. A colonoscopy found no primary lesion, but a PET-CT scan showed elevated FDG uptake in the appendiceal nodule. A right hemicolectomy was performed, and the specimen showed a moderately differentiated mucinous appendiceal adenocarcinoma. Whole brain radiotherapy was administrated. A subsequent thorax-abdomen CT scan revealed multiple lung and hepatic metastasis. Seven months later, the patient died of disease progression. In cases of undiagnosed primary lesions, patients present in better general condition, but overall survival does not change. Eventual identification of the primary tumor does not affect survival. PET/CT might be a helpful tool in detecting lesions of the appendiceal region. To the best of our knowledge, such a case was never reported in the literature, and an appendiceal malignancy should be suspected in patients with brain metastasis from an undiagnosed primary tumor.
Measles Outbreak among Previously Immunized Adult Healthcare Workers, China, 2015
Zhang, Zhengyi; Zhao, Yuan; Yang, Lili; Lu, Changhong; Meng, Ying; Guan, Xiaoli; An, Hongjin; Zhang, Meizhong; Guo, Wenqin; Shang, Bo; Yu, Jing
2016-01-01
Measles is caused by measles virus belonging to genus Morbillivirus of the family Paramyxoviridae. Vaccination has played a critical role in controlling measles infection worldwide. However, in the recent years, outbreaks of measles infection still occur in many developing countries. Here, we report an outbreak of measles among healthcare workers and among the 60 measles infected patients 50 were healthcare workers including doctors, nurses, staff, and medics. Fifty-one patients (85%) tested positive for IgM antibodies against the measles virus and 50 patients (83.3%) tested positive for measles virus RNA. Surprisingly, 73.3% of the infected individuals had been previously immunized against measles. Since there is no infection division in our hospital, the fever clinics are located in the Emergency Division. In addition, the fever and rash were not recognized as measles symptoms at the beginning of the outbreak. These factors result in delay in isolation and early confirmation of the suspected patients and eventually a measles outbreak in the hospital. Our report highlights the importance of following a two-dose measles vaccine program in people including the healthcare workers. In addition, vigilant attention should be paid to medical staff with clinical fever and rash symptoms to avoid a possible nosocomial transmission of measles infection. PMID:27366157
Handbook of differential equations evolutionary equations
Dafermos, CM
2008-01-01
The material collected in this volume discusses the present as well as expected future directions of development of the field with particular emphasis on applications. The seven survey articles present different topics in Evolutionary PDE's, written by leading experts.- Review of new results in the area- Continuation of previous volumes in the handbook series covering Evolutionary PDEs- Written by leading experts
Florian Ion Tiberiu Petrescu
2015-09-01
Full Text Available This paper presents the dynamic, original, machine motion equations. The equation of motion of the machine that generates angular speed of the shaft (which varies with position and rotation speed is deduced by conservation kinetic energy of the machine. An additional variation of angular speed is added by multiplying by the coefficient dynamic D (generated by the forces out of mechanism and or by the forces generated by the elasticity of the system. Kinetic energy conservation shows angular speed variation (from the shaft with inertial masses, while the dynamic coefficient introduces the variation of w with forces acting in the mechanism. Deriving the first equation of motion of the machine one can obtain the second equation of motion dynamic. From the second equation of motion of the machine it determines the angular acceleration of the shaft. It shows the distribution of the forces on the mechanism to the internal combustion heat engines. Dynamic, the velocities can be distributed in the same way as forces. Practically, in the dynamic regimes, the velocities have the same timing as the forces. Calculations should be made for an engine with a single cylinder. Originally exemplification is done for a classic distribution mechanism, and then even the module B distribution mechanism of an Otto engine type.
Introduction to partial differential equations
Greenspan, Donald
2000-01-01
Designed for use in a one-semester course by seniors and beginning graduate students, this rigorous presentation explores practical methods of solving differential equations, plus the unifying theory underlying the mathematical superstructure. Topics include basic concepts, Fourier series, second-order partial differential equations, wave equation, potential equation, heat equation, approximate solution of partial differential equations, and more. Exercises appear at the ends of most chapters. 1961 edition.
Model equation for strongly focused finite-amplitude sound beams
Kamakura; Ishiwata; Matsuda
2000-06-01
A model equation that describes the propagation of sound beams in a fluid is developed using the oblate spheroidal coordinate system. This spheroidal beam equation (SBE) is a parabolic equation and has a specific application to a theoretical prediction on focused, high-frequency beams from a circular aperture. The aperture angle does not have to be small. The theoretical background is basically along the same analytical lines as the composite method (CM) reported previously [B. Ystad and J. Berntsen, Acustica 82, 698-706 (1996)]. Numerical examples are displayed for the amplitudes of sound pressure along and across the beam axis when sinusoidal waves are radiated from the source with uniform amplitude distribution. The primitive approach to linear field analysis is readily extended to the case where harmonic generation in finite-amplitude sound beams becomes significant due to the inherent nonlinearity of the medium. The theory provides the propagation and beam pattern profiles that differ from the CM solution for each harmonic component.
Self-consistent generalized Langevin equation for colloidal mixtures.
Chávez-Rojo, Marco Antonio; Medina-Noyola, Magdaleno
2005-09-01
A self-consistent theory of collective and tracer diffusion in colloidal mixtures is presented. This theory is based on exact results for the partial intermediate scattering functions derived within the framework of the generalized Langevin equation formalism, plus a number of conceptually simple and sensible approximations. The first of these consists of a Vineyard-like approximation between collective and tracer diffusion, which writes the collective dynamics in terms of the memory function related to tracer diffusion. The second consists of interpolating this only unknown memory function between its two exact limits at small and large wave vectors; for this, a phenomenologically determined, but not arbitrary, interpolating function is introduced: a Lorentzian with its inflection point located at the first minimum of the partial static structure factor. The small wave-vector exact limit involves a time-dependent friction function, for which we take a general approximate result, previously derived within the generalized Langevin equation formalism. This general result expresses the time-dependent friction function in terms of the partial intermediate scattering functions, thus closing the system of equations into a fully self-consistent scheme. This extends to mixtures a recently proposed self-consistent theory developed for monodisperse suspensions [Yeomans-Reyna and Medina-Noyola, Phys. Rev. E 64, 066114 (2001)]. As an illustration of its quantitative accuracy, its application to a simple model of a binary dispersion in the absence of hydrodynamic interactions is reported.
Generalization of Hopf Functional Equation
无
2002-01-01
This paper generalizes the Hopf functional equation in order to apply it to a wider class of not necessarily incompressible fluid flows. We start by defining characteristic functionals of the velocity field, the density field and the temperature field of a compressible field. Using the continuity equation, the Navier-Stokes equations and the equation of energy we derive a functional equation governing the motion of an ideal gas flow and a van der Waals gas flow, and then give some general methods of deriving a functional equation governing the motion of any compressible fluid flow. These functional equations can be considered as the generalization of the Hopf functional equation.
Gastrointestinal tolerability with ibandronate after previous weekly bisphosphonate treatment
Richard Derman
2009-09-01
Full Text Available Richard Derman1, Joseph D Kohles2, Ann Babbitt31Department of Obstetrics and Gynecology, Christiana Hospital, Newark, DE, USA; 2Roche, Nutley, NJ, USA; 3Greater Portland Bone and Joint Specialists, Portland, ME, USAAbstract: Data from two open-label trials (PRIOR and CURRENT of women with postmenopausal osteoporosis or osteopenia were evaluated to assess whether monthly oral and quarterly intravenous (IV ibandronate dosing improved self-reported gastrointestinal (GI tolerability for patients who had previously experienced GI irritation with bisphosphonate (BP use. In PRIOR, women who had discontinued daily or weekly BP treatment due to GI intolerance received monthly oral or quarterly IV ibandronate for 12 months. The CURRENT subanalysis included women receiving weekly BP treatment who switched to monthly oral ibandronate for six months. GI symptom severity and frequency were assessed using the Osteoporosis Patient Satisfaction Questionnaire™. In PRIOR, mean GI tolerability scores increased significantly at month 1 from screening for both treatment groups (oral: 79.3 versus 54.1; IV: 84.4 versus 51.0; p < 0.001 for both. Most patients reported improvement in GI symptom severity and frequency from baseline at all post-screening assessments (>90% at Month 10. In the CURRENT subanalysis >60% of patients reported improvements in heartburn or acid reflux and >70% indicated improvement in other stomach upset at month 6. Postmenopausal women with GI irritability with daily or weekly BPs experienced improvement in symptoms with extended dosing monthly or quarterly ibandronate compared with baseline.Keywords: ibandronate, osteoporosis, bisphosphonate, gastrointestinal
Stochastic porous media equations
Barbu, Viorel; Röckner, Michael
2016-01-01
Focusing on stochastic porous media equations, this book places an emphasis on existence theorems, asymptotic behavior and ergodic properties of the associated transition semigroup. Stochastic perturbations of the porous media equation have reviously been considered by physicists, but rigorous mathematical existence results have only recently been found. The porous media equation models a number of different physical phenomena, including the flow of an ideal gas and the diffusion of a compressible fluid through porous media, and also thermal propagation in plasma and plasma radiation. Another important application is to a model of the standard self-organized criticality process, called the "sand-pile model" or the "Bak-Tang-Wiesenfeld model". The book will be of interest to PhD students and researchers in mathematics, physics and biology.
Quasirelativistic Langevin equation.
Plyukhin, A V
2013-11-01
We address the problem of a microscopic derivation of the Langevin equation for a weakly relativistic Brownian particle. A noncovariant Hamiltonian model is adopted, in which the free motion of particles is described relativistically while their interaction is treated classically, i.e., by means of action-to-a-distance interaction potentials. Relativistic corrections to the classical Langevin equation emerge as nonlinear dissipation terms and originate from the nonlinear dependence of the relativistic velocity on momentum. On the other hand, similar nonlinear dissipation forces also appear as classical (nonrelativistic) corrections to the weak-coupling approximation. It is shown that these classical corrections, which are usually ignored in phenomenological models, may be of the same order of magnitude, if not larger than, relativistic ones. The interplay of relativistic corrections and classical beyond-the-weak-coupling contributions determines the sign of the leading nonlinear dissipation term in the Langevin equation and thus is qualitatively important.
Boussinesq evolution equations
Bredmose, Henrik; Schaffer, H.; Madsen, Per A.
2004-01-01
This paper deals with the possibility of using methods and ideas from time domain Boussinesq formulations in the corresponding frequency domain formulations. We term such frequency domain models "evolution equations". First, we demonstrate that the numerical efficiency of the deterministic...... Boussinesq evolution equations of Madsen and Sorensen [Madsen, P.A., Sorensen, O.R., 1993. Bound waves and triad interactions in shallow water. Ocean Eng. 20 359-388] can be improved by using Fast Fourier Transforms to evaluate the nonlinear terms. For a practical example of irregular waves propagating over...... a submerged bar, it is demonstrated that evolution equations utilising FFT can be solved around 100 times faster than the corresponding time domain model. Use of FFT provides an efficient bridge between the frequency domain and the time domain. We utilise this by adapting the surface roller model for wave...
On the full Boltzmann equations for Leptogenesis
Garayoa, J; Pinto, T; Rius, N; Vives, O
2009-01-01
We consider the full Boltzmann equations for standard and soft leptogenesis, instead of the usual integrated Boltzmann equations which assume kinetic equilibrium for all species. Decays and inverse decays may be inefficient for thermalising the heavy-(s)neutrino distribution function, leading to significant deviations from kinetic equilibrium. We analyse the impact of using the full kinetic equations in the case of a previously generated lepton asymmetry, and find that the washout of this initial asymmetry due to the interactions of the right-handed neutrino is larger than when calculated via the integrated equations. We also solve the full Boltzmann equations for soft leptogenesis, where the lepton asymmetry induced by the soft SUSY-breaking terms in sneutrino decays is a purely thermal effect, since at T=0 the asymmetry in leptons cancels the one in sleptons. In this case, we obtain that in the weak washout regime (K ~< 1) the final lepton asymmetry can change up to a factor four with respect to previous...
On the full Boltzmann equations for leptogenesis
Garayoa, J.; Pastor, S.; Pinto, T.; Rius, N.; Vives, O., E-mail: garayoa@ific.uv.es, E-mail: pastor@ific.uv.es, E-mail: teguayco@gmail.com, E-mail: nuria@ific.uv.es, E-mail: vives@ific.uv.es [Depto. de Física Teórica and IFIC, Universidad de Valencia-CSIC, Edificio de Institutos de Paterna, Apt. 22085, 46071 Valencia (Spain)
2009-09-01
We consider the full Boltzmann equations for standard and soft leptogenesis, instead of the usual integrated Boltzmann equations which assume kinetic equilibrium for all species. Decays and inverse decays may be inefficient for thermalising the heavy-(s)neutrino distribution function, leading to significant deviations from kinetic equilibrium. We analyse the impact of using the full kinetic equations in the case of a previously generated lepton asymmetry, and find that the washout of this initial asymmetry due to the interactions of the right-handed neutrino is larger than when calculated via the integrated equations. We also solve the full Boltzmann equations for soft leptogenesis, where the lepton asymmetry induced by the soft SUSY-breaking terms in sneutrino decays is a purely thermal effect, since at T = 0 the asymmetry in leptons cancels the one in sleptons. In this case, we obtain that in the weak washout regime (K ∼< 1) the final lepton asymmetry can change up to a factor four with respect to previous estimates.
Nonlocal electrical diffusion equation
Gómez-Aguilar, J. F.; Escobar-Jiménez, R. F.; Olivares-Peregrino, V. H.; Benavides-Cruz, M.; Calderón-Ramón, C.
2016-07-01
In this paper, we present an analysis and modeling of the electrical diffusion equation using the fractional calculus approach. This alternative representation for the current density is expressed in terms of the Caputo derivatives, the order for the space domain is 0numerical methods based on Fourier variable separation. The case with spatial fractional derivatives leads to Levy flight type phenomena, while the time fractional equation is related to sub- or super diffusion. We show that the mathematical concept of fractional derivatives can be useful to understand the behavior of semiconductors, the design of solar panels, electrochemical phenomena and the description of anomalous complex processes.
Equations of mathematical physics
Tikhonov, A N
2011-01-01
Mathematical physics plays an important role in the study of many physical processes - hydrodynamics, elasticity, and electrodynamics, to name just a few. Because of the enormous range and variety of problems dealt with by mathematical physics, this thorough advanced-undergraduate or graduate-level text considers only those problems leading to partial differential equations. The authors - two well-known Russian mathematicians - have focused on typical physical processes and the principal types of equations deailing with them. Special attention is paid throughout to mathematical formulation, ri
Gas Dynamics Equations: Computation
Chen, Gui-Qiang G
2012-01-01
Shock waves, vorticity waves, and entropy waves are fundamental discontinuity waves in nature and arise in supersonic or transonic gas flow, or from a very sudden release (explosion) of chemical, nuclear, electrical, radiation, or mechanical energy in a limited space. Tracking these discontinuities and their interactions, especially when and where new waves arise and interact in the motion of gases, is one of the main motivations for numerical computation for the gas dynamics equations. In this paper, we discuss some historic and recent developments, as well as mathematical challenges, in designing and formulating efficient numerical methods and algorithms to compute weak entropy solutions for the Euler equations for gas dynamics.
Theory of differential equations
Gel'fand, I M
1967-01-01
Generalized Functions, Volume 3: Theory of Differential Equations focuses on the application of generalized functions to problems of the theory of partial differential equations.This book discusses the problems of determining uniqueness and correctness classes for solutions of the Cauchy problem for systems with constant coefficients and eigenfunction expansions for self-adjoint differential operators. The topics covered include the bounded operators in spaces of type W, Cauchy problem in a topological vector space, and theorem of the Phragmén-Lindelöf type. The correctness classes for the Cau
Systematic Equation Formulation
Lindberg, Erik
2007-01-01
A tutorial giving a very simple introduction to the set-up of the equations used as a model for an electrical/electronic circuit. The aim is to find a method which is as simple and general as possible with respect to implementation in a computer program. The “Modified Nodal Approach”, MNA, and th......, and the “Controlled Source Approach”, CSA, for systematic equation formulation are investigated. It is suggested that the kernel of the P Spice program based on MNA is reprogrammed....
Generalized estimating equations
Hardin, James W
2002-01-01
Although powerful and flexible, the method of generalized linear models (GLM) is limited in its ability to accurately deal with longitudinal and clustered data. Developed specifically to accommodate these data types, the method of Generalized Estimating Equations (GEE) extends the GLM algorithm to accommodate the correlated data encountered in health research, social science, biology, and other related fields.Generalized Estimating Equations provides the first complete treatment of GEE methodology in all of its variations. After introducing the subject and reviewing GLM, the authors examine th
Ding Yi
2009-01-01
In this article, the author derives a functional equation η(s)=［(π/4)s-1/2√2/πг(1-s)sin(πs/2)]η(1-s) of the analytic function η(s) which is defined by η(s)=1-s-3-s-5-s+7-s…for complex variable s with Re s>1, and is defined by analytic continuation for other values of s. The author proves (1) by Ramanujan identity (see [1], [3]). Her method provides a new derivation of the functional equation of Riemann zeta function by using Poisson summation formula.
Comparison of Kernel Equating and Item Response Theory Equating Methods
Meng, Yu
2012-01-01
The kernel method of test equating is a unified approach to test equating with some advantages over traditional equating methods. Therefore, it is important to evaluate in a comprehensive way the usefulness and appropriateness of the Kernel equating (KE) method, as well as its advantages and disadvantages compared with several popular item…
Test equating methods and practices
Kolen, Michael J
1995-01-01
In recent years, many researchers in the psychology and statistical communities have paid increasing attention to test equating as issues of using multiple test forms have arisen and in response to criticisms of traditional testing techniques This book provides a practically oriented introduction to test equating which both discusses the most frequently used equating methodologies and covers many of the practical issues involved The main themes are - the purpose of equating - distinguishing between equating and related methodologies - the importance of test equating to test development and quality control - the differences between equating properties, equating designs, and equating methods - equating error, and the underlying statistical assumptions for equating The authors are acknowledged experts in the field, and the book is based on numerous courses and seminars they have presented As a result, educators, psychometricians, professionals in measurement, statisticians, and students coming to the subject for...
Single antiplatelet therapy for patients with previous gastrointestinal bleeds.
Gellatly, Rochelle M; Ackman, Margaret L
2008-06-01
To determine whether aspirin plus a proton pump inhibitor (PPI) is preferable, from a gastrointestinal bleed (GIB) risk perspective, to clopidogrel in patients who have experienced a GIB while on aspirin and who require single antiplatelet therapy for secondary prevention of cardiovascular disease. A literature search was conducted using EMBASE (1980-January 2008), PubMed (1966-January 2008), Google, and a manual search of the reference lists using the search terms gastrointestinal bleed, gastrointestinal hemorrhage, peptic ulcer hemorrhage, ASA, aspirin, Plavix, clopidogrel, and PPI. The search, limited to human and English studies, yielded 110 returns. Randomized trials that compared aspirin with clopidogrel, involved patients who had previously experienced a GIB, and provided detailed information on the type and dose of drugs used were included. Studies were required to provide information on the recurrence of GIB. Two randomized trials were reviewed to assess the safety of secondary prevention of cardiovascular disease with respect to previous GIB. These noninferiority trials compared aspirin plus a PPI with clopidogrel over 12 months following confirmed healing of an aspirin-induced ulcer. In both trials, the majority of the GIB recurrences were in the clopidogrel group (8.6% vs 0.7%; difference 7.9%; 95% CI 3.4 to 12.4; p = 0.001 and 13.6% vs 0%; difference 13.6%; 95% CI 6.3 to 20.9; p = 0.0019) and the difference in recurrence rates exceeded the a priori selected upper boundary. Findings reported in the limited literature available support that clopidogrel is not equivalent to the combination of aspirin plus a PPI in the patient population studied. Aspirin plus a PPI would be considered clinically superior and should be used in medically managed patients who require single antiplatelet therapy but have had a prior GIB while on aspirin. Further research regarding dual antiplatelet therapy and a PPI is required.
Combat modeling with partial differential equations
Protopopescu, V.; Santoro, R.T.; Dockery, J.; Cox, R.L.; Barnes, J.M.
1987-11-01
A new analytic model based on coupled nonlinear partial differential equations is proposed to describe the temporal and spatial evolution of opposing forces in combat. Analytic descriptions of combat have been developed previously using relatively simpler models based on ordinary differential equations (.e.g, Lanchester's equations of combat) that capture only the global temporal variation of the forces, but not their spatial movement (advance, retreat, flanking maneuver, etc.). The rationale for analytic models and, particularly, the motivation for the present model are reviewed. A detailed description of this model in terms of the mathematical equations together with the possible and plausible military interpretation are presented. Numerical solutions of the nonlinear differential equation model for a large variety of parameters (battlefield length, initial force ratios, initial spatial distribution of forces, boundary conditions, type of interaction, etc.) are implemented. The computational methods and computer programs are described and the results are given in tabular and graphic form. Where possible, the results are compared with the predictions given by the traditional Lanchester equations. Finally, a PC program is described that uses data downloaded from the mainframe computer for rapid analysis of the various combat scenarios. 11 refs., 10 figs., 5 tabs.
Variation principle of piezothermoelastic bodies, canonical equation and homogeneous equation
LIU Yan-hong; ZHANG Hui-ming
2007-01-01
Combining the symplectic variations theory, the homogeneous control equation and isoparametric element homogeneous formulations for piezothermoelastic hybrid laminates problems were deduced. Firstly, based on the generalized Hamilton variation principle, the non-homogeneous Hamilton canonical equation for piezothermoelastic bodies was derived. Then the symplectic relationship of variations in the thermal equilibrium formulations and gradient equations was considered, and the non-homogeneous canonical equation was transformed to homogeneous control equation for solving independently the coupling problem of piezothermoelastic bodies by the incensement of dimensions of the canonical equation. For the convenience of deriving Hamilton isoparametric element formulations with four nodes, one can consider the temperature gradient equation as constitutive relation and reconstruct new variation principle. The homogeneous equation simplifies greatly the solution programs which are often performed to solve nonhomogeneous equation and second order differential equation on the thermal equilibrium and gradient relationship.
Lyapunov functionals and stability of stochastic functional differential equations
Shaikhet, Leonid
2013-01-01
Stability conditions for functional differential equations can be obtained using Lyapunov functionals. Lyapunov Functionals and Stability of Stochastic Functional Differential Equations describes the general method of construction of Lyapunov functionals to investigate the stability of differential equations with delays. This work continues and complements the author’s previous book Lyapunov Functionals and Stability of Stochastic Difference Equations, where this method is described for discrete- and continuous-time difference equations. The text begins with a description of the peculiarities of deterministic and stochastic functional differential equations. There follow basic definitions for stability theory of stochastic hereditary systems, and a formal procedure of Lyapunov functionals construction is presented. Stability investigation is conducted for stochastic linear and nonlinear differential equations with constant and distributed delays. The proposed method is used for stability investigation of di...
Integrability of Lie Systems Through Riccati Equations
Cariñena, José F.; de Lucas, Javier
Integrability conditions for Lie systems are related to reduction or transformation processes. We here analyse a geometric method to construct integrability conditions for Riccati equations following these approaches. This approach provides us with a unified geometrical viewpoint that allows us to analyse some previous works on the topic and explain new properties. Moreover, this new approach can be straightforwardly generalised to describe integrability conditions for any Lie system. Finally, we show the usefulness of our treatment in order to study the problem of the linearisability of Riccati equations.
Integrability of Lie systems through Riccati equations
Cariñena, José F
2010-01-01
Integrability conditions for Lie systems are related to reduction or transformation processes. We here analyse a geometric method to construct integrability conditions for Riccati equations following these approaches. This approach provides us with a unified geometrical viewpoint that allows us to analyse some previous works on the topic and explain new properties. Moreover, this new approach can be straightforwardly generalised to describe integrability conditions for any Lie system. Finally, we show the usefulness of our treatment in order to study the problem of the linearisability of Riccati equations.
Time integration of the shallow water equations in spherical geometry
D. Lanser; J.G. Blom (Joke); J.G. Verwer (Jan)
2000-01-01
textabstractThe shallow water equations in spherical geometry provide a prototype for developing and testing numerical algorithms for atmospheric circulation models. In a previous paper we have studied a spatial discretization of these equations based on an Osher-type finite-volume method on stereog
Time integration of the shallow water equations in spherical geometry
Lanser, D.; Blom, J.G.; Verwer, J.G.
2000-01-01
The shallow water equations in spherical geometry provide a prototype for developing and testing numerical algorithms for atmospheric circulation models. In a previous paper we have studied a spatial discretization of these equations based on an Osher-type finite-volume method on stereographic and l
Updated generalized biomass equations for North American tree species
David C. Chojnacky; Linda S. Heath; Jennifer C. Jenkins
2014-01-01
Historically, tree biomass at large scales has been estimated by applying dimensional analysis techniques and field measurements such as diameter at breast height (dbh) in allometric regression equations. Equations often have been developed using differing methods and applied only to certain species or isolated areas. We previously had compiled and combined (in meta-...
Solving Fractional Partial Differential Equations with Corrected Fourier Series Method
Nor Hafizah Zainal
2014-01-01
Full Text Available The corrected Fourier series (CFS is proposed for solving partial differential equations (PDEs with fractional time derivative on a finite domain. In the previous work, we have been solving partial differential equations by using corrected Fourier series. The fractional derivatives are described in Riemann sense. Some numerical examples are presented to show the solutions.
Calculus & ordinary differential equations
Pearson, David
1995-01-01
Professor Pearson's book starts with an introduction to the area and an explanation of the most commonly used functions. It then moves on through differentiation, special functions, derivatives, integrals and onto full differential equations. As with other books in the series the emphasis is on using worked examples and tutorial-based problem solving to gain the confidence of students.
Standardized Referente Evapotranspiration Equation
M.D. Mundo–Molina
2009-04-01
Full Text Available In this paper is presented a discussion on the necessity to standardize the Penman–Monteith equations in order to estimate ETo. The proposal is to define an accuracy and standarize equation based in Penman–Monteith. The automated weather station named CIANO (27° 22 ' 144 North latitude and 109" 55' west longitude it was selected tomake comparisons. The compared equations we re: a CIANO weat her station, b Penman–Monteith ASCE (PMA, Penman–Monteith FAO 56 (PM FAO 56, Penman–Monteith estandarizado ASCE (PM Std. ASCE. The results were: a There are important differences between PMA and CIANO weather station. The differences are attributed to the nonstandardization of the equation CIANO weather station, b The coefficient of correlation between both methods was of 0,92, with a standard deviation of 1,63 mm, an average quadratic error of 0,60 mm and one efficiency in the estimation of ETo with respect to the method pattern of 87%.
Modified differential equations
Chartier, Philippe; Hairer, Ernst; Vilmart, Gilles
2007-01-01
Motivated by the theory of modified differential equations (backward error analysis) an approach for the construction of high order numerical integrators that preserve geometric properties of the exact flow is developed. This summarises a talk presented in honour of Michel Crouzeix.
Equational binary decision diagrams
Groote, J.F.; Pol, J.C. van de
2000-01-01
We incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tautology checkin
Garkavenko A. S.
2011-08-01
Full Text Available The rate equations of the exciton laser in the system of interacting excitons have been obtained and the inverted population conditions and generation have been derived. The possibility of creating radically new gamma-ray laser has been shown.
Equational binary decision diagrams
J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)
2000-01-01
textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and
Structural Equation Model Trees
Brandmaier, Andreas M.; von Oertzen, Timo; McArdle, John J.; Lindenberger, Ulman
2013-01-01
In the behavioral and social sciences, structural equation models (SEMs) have become widely accepted as a modeling tool for the relation between latent and observed variables. SEMs can be seen as a unification of several multivariate analysis techniques. SEM Trees combine the strengths of SEMs and the decision tree paradigm by building tree…
Generalized reduced magnetohydrodynamic equations
Kruger, S.E.
1999-02-01
A new derivation of reduced magnetohydrodynamic (MHD) equations is presented. A multiple-time-scale expansion is employed. It has the advantage of clearly separating the three time scales of the problem associated with (1) MHD equilibrium, (2) fluctuations whose wave vector is aligned perpendicular to the magnetic field, and (3) those aligned parallel to the magnetic field. The derivation is carried out without relying on a large aspect ratio assumption; therefore this model can be applied to any general configuration. By accounting for the MHD equilibrium and constraints to eliminate the fast perpendicular waves, equations are derived to evolve scalar potential quantities on a time scale associated with the parallel wave vector (shear-Alfven wave time scale), which is the time scale of interest for MHD instability studies. Careful attention is given in the derivation to satisfy energy conservation and to have manifestly divergence-free magnetic fields to all orders in the expansion parameter. Additionally, neoclassical closures and equilibrium shear flow effects are easily accounted for in this model. Equations for the inner resistive layer are derived which reproduce the linear ideal and resistive stability criterion of Glasser, Greene, and Johnson. The equations have been programmed into a spectral initial value code and run with shear flow that is consistent with the equilibrium input into the code. Linear results of tearing modes with shear flow are presented which differentiate the effects of shear flow gradients in the layer with the effects of the shear flow decoupling multiple harmonics.
Hatem Mejjaoli
2008-12-01
Full Text Available We introduce and study the Dunkl symmetric systems. We prove the well-posedness results for the Cauchy problem for these systems. Eventually we describe the finite speed of it. Next the semi-linear Dunkl-wave equations are also studied.
Equational binary decision diagrams
J.F. Groote (Jan Friso); J.C. van de Pol (Jaco)
2000-01-01
textabstractWe incorporate equations in binary decision diagrams (BDD). The resulting objects are called EQ-BDDs. A straightforward notion of ordered EQ-BDDs (EQ-OBDD) is defined, and it is proved that each EQ-BDD is logically equivalent to an EQ-OBDD. Moreover, on EQ-OBDDs satisfiability and tauto
A simple and accurate model for Love wave based sensors: Dispersion equation and mass sensitivity
Jiansheng Liu
2014-07-01
Full Text Available Dispersion equation is an important tool for analyzing propagation properties of acoustic waves in layered structures. For Love wave (LW sensors, the dispersion equation with an isotropic-considered substrate is too rough to get accurate solutions; the full dispersion equation with a piezoelectric-considered substrate is too complicated to get simple and practical expressions for optimizing LW-based sensors. In this work, a dispersion equation is introduced for Love waves in a layered structure with an anisotropic-considered substrate and an isotropic guiding layer; an intuitive expression for mass sensitivity is also derived based on the dispersion equation. The new equations are in simple forms similar to the previously reported simplified model with an isotropic substrate. By introducing the Maxwell-Weichert model, these equations are also applicable to the LW device incorporating a viscoelastic guiding layer; the mass velocity sensitivity and the mass propagation loss sensitivity are obtained from the real part and the imaginary part of the complex mass sensitivity, respectively. With Love waves in an elastic SiO2 layer on an ST-90°X quartz structure, for example, comparisons are carried out between the velocities and normalized sensitivities calculated by using different dispersion equations and corresponding mass sensitivities. Numerical results of the method presented in this work are very close to those of the method with a piezoelectric-considered substrate. Another numerical calculation is carried out for the case of a LW sensor with a viscoelastic guiding layer. If the viscosity of the layer is not too big, the effect on the real part of the velocity and the mass velocity sensitivity is relatively small; the propagation loss and the mass loss sensitivity are proportional to the viscosity of the guiding layer.
OSCILLATION THEOREMS FOR SECOND ORDER QUASILINEAR PERTURBED DIFFERENTIAL EQUATIONS
无
2001-01-01
New oscillation criteria for the second order perturbed differential equation are presented. The special case of the results includes the corresponding results in previous papers,extends and unifies a number of known results.
A geometric approach to integrability conditions for Riccati equations
Arturo Ramos
2007-09-01
Full Text Available Several instances of integrable Riccati equations are analyzed from the geometric perspective of the theory of Lie systems. This provides us a unifying viewpoint for previous approaches.
IDENTIFICATION OF PARAMETERS IN PARABOLIC EQUATIONS WITH NONLINEARITY
无
2010-01-01
In this paper, we consider the identification of parameters in parabolic equations with nonlinearity. Some approximation processes for the identification problem are given. Our results improve and generalize the previous results.
22 CFR 40.91 - Certain aliens previously removed.
2010-04-01
... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Certain aliens previously removed. 40.91... IMMIGRANTS UNDER THE IMMIGRATION AND NATIONALITY ACT, AS AMENDED Aliens Previously Removed § 40.91 Certain aliens previously removed. (a) 5-year bar. An alien who has been found inadmissible, whether as a result...
Lie Symmetries of Ishimori Equation
SONG Xu-Xia
2013-01-01
The Ishimori equation is one of the most important (2+1)-dimensional integrable models,which is an integrable generalization of (1+1)-dimensional classical continuous Heisenberg ferromagnetic spin equations.Based on importance of Lie symmetries in analysis of differential equations,in this paper,we derive Lie symmetries for the Ishimori equation by Hirota's direct method.
Lectures on partial differential equations
Petrovsky, I G
1992-01-01
Graduate-level exposition by noted Russian mathematician offers rigorous, transparent, highly readable coverage of classification of equations, hyperbolic equations, elliptic equations and parabolic equations. Wealth of commentary and insight invaluable for deepening understanding of problems considered in text. Translated from the Russian by A. Shenitzer.
Note on Nonlinear Schr\\"odinger Equation, KdV Equation and 2D Topological Yang-Mills-Higgs Theory
Nian, Jun
2016-01-01
In this paper we discuss the relation between the (1+1)D nonlinear Schr\\"odinger equation and the KdV equation. By applying the boson/vortex duality, we can map the classical nonlinear Schr\\"odinger equation into the classical KdV equation in the small coupling limit, which corresponds to the UV regime of the theory. At quantum level, the two theories satisfy the Bethe Ansatz equations of the spin-$\\frac{1}{2}$ XXX chain and the XXZ chain in the continuous limit respectively. Combining these relations with the dualities discussed previously in the literature, we propose a duality web in the UV regime among the nonlinear Schr\\"odinger equation, the KdV equation and the 2D $\\mathcal{N}=(2,2)^*$ topological Yang-Mills-Higgs theory.
Kondo, Kenichi
2013-11-01
Ultradiscretization with negative values is a long-standing problem and several attempts have been made to solve it. Among others, we focus on the symmetrized max-plus algebra, with which we ultradiscretize the discrete sine-Gordon equation. Another ultradiscretization of the discrete sine-Gordon equation has already been proposed by previous studies, but the equation and the solutions obtained here are considered to directly correspond to the discrete counterpart. We also propose a noncommutative discrete analogue of the sine-Gordon equation, reveal its relations to other integrable systems including the noncommutative discrete KP equation, and construct multisoliton solutions by a repeated application of Darboux transformations. Moreover, we derive a noncommutative ultradiscrete analogue of the sine-Gordon equation and its 1-soliton and 2-soliton solutions, using the symmetrized max-plus algebra. As a result, we have a complete set of commutative and noncommutative versions of continuous, discrete, and ultradiscrete sine-Gordon equations.
Kenichi Kondo
2013-11-01
Full Text Available Ultradiscretization with negative values is a long-standing problem and several attempts have been made to solve it. Among others, we focus on the symmetrized max-plus algebra, with which we ultradiscretize the discrete sine-Gordon equation. Another ultradiscretization of the discrete sine-Gordon equation has already been proposed by previous studies, but the equation and the solutions obtained here are considered to directly correspond to the discrete counterpart. We also propose a noncommutative discrete analogue of the sine-Gordon equation, reveal its relations to other integrable systems including the noncommutative discrete KP equation, and construct multisoliton solutions by a repeated application of Darboux transformations. Moreover, we derive a noncommutative ultradiscrete analogue of the sine-Gordon equation and its 1-soliton and 2-soliton solutions, using the symmetrized max-plus algebra. As a result, we have a complete set of commutative and noncommutative versions of continuous, discrete, and ultradiscrete sine-Gordon equations.
Elements of partial differential equations
Sneddon, Ian N
2006-01-01
Geared toward students of applied rather than pure mathematics, this volume introduces elements of partial differential equations. Its focus is primarily upon finding solutions to particular equations rather than general theory.Topics include ordinary differential equations in more than two variables, partial differential equations of the first and second orders, Laplace's equation, the wave equation, and the diffusion equation. A helpful Appendix offers information on systems of surfaces, and solutions to the odd-numbered problems appear at the end of the book. Readers pursuing independent st
Previously unknown class of metalorganic compounds revealed in meteorites
Ruf, Alexander; Kanawati, Basem; Hertkorn, Norbert; Yin, Qing-Zhu; Moritz, Franco; Harir, Mourad; Lucio, Marianna; Michalke, Bernhard; Wimpenny, Joshua; Shilobreeva, Svetlana; Bronsky, Basil; Saraykin, Vladimir; Gabelica, Zelimir; Gougeon, Régis D.; Quirico, Eric; Ralew, Stefan; Jakubowski, Tomasz; Haack, Henning; Gonsior, Michael; Jenniskens, Peter; Hinman, Nancy W.; Schmitt-Kopplin, Philippe
2017-01-01
The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR]−, in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies. PMID:28242686
Previously unknown class of metalorganic compounds revealed in meteorites.
Ruf, Alexander; Kanawati, Basem; Hertkorn, Norbert; Yin, Qing-Zhu; Moritz, Franco; Harir, Mourad; Lucio, Marianna; Michalke, Bernhard; Wimpenny, Joshua; Shilobreeva, Svetlana; Bronsky, Basil; Saraykin, Vladimir; Gabelica, Zelimir; Gougeon, Régis D; Quirico, Eric; Ralew, Stefan; Jakubowski, Tomasz; Haack, Henning; Gonsior, Michael; Jenniskens, Peter; Hinman, Nancy W; Schmitt-Kopplin, Philippe
2017-03-14
The rich diversity and complexity of organic matter found in meteorites is rapidly expanding our knowledge and understanding of extreme environments from which the early solar system emerged and evolved. Here, we report the discovery of a hitherto unknown chemical class, dihydroxymagnesium carboxylates [(OH)2MgO2CR](-), in meteoritic soluble organic matter. High collision energies, which are required for fragmentation, suggest substantial thermal stability of these Mg-metalorganics (CHOMg compounds). This was corroborated by their higher abundance in thermally processed meteorites. CHOMg compounds were found to be present in a set of 61 meteorites of diverse petrological classes. The appearance of this CHOMg chemical class extends the previously investigated, diverse set of CHNOS molecules. A connection between the evolution of organic compounds and minerals is made, as Mg released from minerals gets trapped into organic compounds. These CHOMg metalorganic compounds and their relation to thermal processing in meteorites might shed new light on our understanding of carbon speciation at a molecular level in meteorite parent bodies.
Exploration of POD-Galerkin Techniques for Developing Reduced Order Models of the Euler Equations
2015-07-01
Models of the Euler Equations 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Mundis, N., Edoh, A. and Sankaran...for describing combustion response to specific excitations using Euler equations as a continued work from a previous studies using a reaction...eigen-bases. For purposes of this study, a linearized version of the Euler equations is employed. The knowledge obtained from previous scalar equation
Methods for Equating Mental Tests.
1984-11-01
1983) compared conventional and IRT methods for equating the Test of English as a Foreign Language ( TOEFL ) after chaining. Three conventional and...three IRT equating methods were examined in this study; two sections of TOEFL were each (separately) equated. The IRT methods included the following: (a...group. A separate base form was established for each of the six equating methods. Instead of equating the base-form TOEFL to itself, the last (eighth
Differential Equations with Linear Algebra
Boelkins, Matthew R; Potter, Merle C
2009-01-01
Linearity plays a critical role in the study of elementary differential equations; linear differential equations, especially systems thereof, demonstrate a fundamental application of linear algebra. In Differential Equations with Linear Algebra, we explore this interplay between linear algebra and differential equations and examine introductory and important ideas in each, usually through the lens of important problems that involve differential equations. Written at a sophomore level, the text is accessible to students who have completed multivariable calculus. With a systems-first approach, t
SPECIFIC SOLUTIONS GROUNDWATER FLOW EQUATION
Syahruddin, Muhammad Hamzah
2014-01-01
Geophysic publication Groundwater flow under surface, its usually slow moving, so that in laminer flow condition can find analisys using the Darcy???s law. The combination between Darcy law and continuity equation can find differential Laplace equation as general equation groundwater flow in sub surface. Based on Differential Laplace Equation is the equation that can be used to describe hydraulic head and velocity flow distribution in porous media as groundwater. In the modeling Laplace e...
Stochastic differential equations and applications
Friedman, Avner
2006-01-01
This text develops the theory of systems of stochastic differential equations, and it presents applications in probability, partial differential equations, and stochastic control problems. Originally published in two volumes, it combines a book of basic theory and selected topics with a book of applications.The first part explores Markov processes and Brownian motion; the stochastic integral and stochastic differential equations; elliptic and parabolic partial differential equations and their relations to stochastic differential equations; the Cameron-Martin-Girsanov theorem; and asymptotic es
2012-05-31
...) highlights activities such as counseling, marketing, meetings/conferences, and services to businesses as... Requests for Renewal of a Previously Approved Information Collection: Small Business Transportation... Quarterly Report Form (DOT F 4502) AGENCY: Office of Small and Disadvantaged Business Utilization...
Kaw Bing Chua; Gary Crameri; Alex Hyatt; Meng Yu; Mohd Rosli Tompang; Juliana Rosli; Jennifer McEachern; Sandra Crameri; Verasingam Kumarasamy; Bryan T. Eaton; Lin-Fa Wang
2007-01-01
.... Here, we report a previously unknown reovirus (named "Melaka virus") isolated from a 39-year-old male patient in Melaka, Malaysia, who was suffering from high fever and acute respiratory disease at the time of virus isolation...
New Conditions for Obtaining the Exact Solutions of the General Riccati Equation
Lazhar Bougoffa
2014-01-01
Full Text Available We propose a direct method for solving the general Riccati equation y′=f(x+g(xy+h(xy2. We first reduce it into an equivalent equation, and then we formulate the relations between the coefficients functions f(x,g(x, and h(x of the equation to obtain an equivalent separable equation from which the previous equation can be solved in closed form. Several examples are presented to demonstrate the efficiency of this method.
New conditions for obtaining the exact solutions of the general Riccati equation.
Bougoffa, Lazhar
2014-01-01
We propose a direct method for solving the general Riccati equation y' = f(x) + g(x)y + h(x)y(2). We first reduce it into an equivalent equation, and then we formulate the relations between the coefficients functions f(x), g(x), and h(x) of the equation to obtain an equivalent separable equation from which the previous equation can be solved in closed form. Several examples are presented to demonstrate the efficiency of this method.
Propagating Qualitative Values Through Quantitative Equations
Kulkarni, Deepak
1992-01-01
In most practical problems where traditional numeric simulation is not adequate, one need to reason about a system with both qualitative and quantitative equations. In this paper, we address the problem of propagating qualitative values represented as interval values through quantitative equations. Previous research has produced exponential-time algorithms for approximate solution of the problem. These may not meet the stringent requirements of many real time applications. This paper advances the state of art by producing a linear-time algorithm that can propagate a qualitative value through a class of complex quantitative equations exactly and through arbitrary algebraic expressions approximately. The algorithm was found applicable to Space Shuttle Reaction Control System model.
Singularities of Type-Q ABS Equations
James Atkinson
2011-07-01
Full Text Available The type-Q equations lie on the top level of the hierarchy introduced by Adler, Bobenko and Suris (ABS in their classification of discrete counterparts of KdV-type integrable partial differential equations. We ask what singularities are possible in the solutions of these equations, and examine the relationship between the singularities and the principal integrability feature of multidimensional consistency. These questions are considered in the global setting and therefore extend previous considerations of singularities which have been local. What emerges are some simple geometric criteria that determine the allowed singularities, and the interesting discovery that generically the presence of singularities leads to a breakdown in the global consistency of such systems despite their local consistency property. This failure to be globally consistent is quantified by introducing a natural notion of monodromy for isolated singularities.
Dyre, Jeppe
1995-01-01
energies chosen randomly according to a Gaussian. The random-walk model is here derived from Newton's laws by making a number of simplifying assumptions. In the second part of the paper an approximate low-temperature description of energy fluctuations in the random-walk modelthe energy master equation...... (EME)is arrived at. The EME is one dimensional and involves only energy; it is derived by arguing that percolation dominates the relaxational properties of the random-walk model at low temperatures. The approximate EME description of the random-walk model is expected to be valid at low temperatures...... of the random-walk model. The EME allows a calculation of the energy probability distribution at realistic laboratory time scales for an arbitrarily varying temperature as function of time. The EME is probably the only realistic equation available today with this property that is also explicitly consistent...
Classical Diophantine equations
1993-01-01
The author had initiated a revision and translation of "Classical Diophantine Equations" prior to his death. Given the rapid advances in transcendence theory and diophantine approximation over recent years, one might fear that the present work, originally published in Russian in 1982, is mostly superseded. That is not so. A certain amount of updating had been prepared by the author himself before his untimely death. Some further revision was prepared by close colleagues. The first seven chapters provide a detailed, virtually exhaustive, discussion of the theory of lower bounds for linear forms in the logarithms of algebraic numbers and its applications to obtaining upper bounds for solutions to the eponymous classical diophantine equations. The detail may seem stark--- the author fears that the reader may react much as does the tourist on first seeing the centre Pompidou; notwithstanding that, Sprind zuk maintainsa pleasant and chatty approach, full of wise and interesting remarks. His emphases well warrant, ...
Numerical Solution of Heun Equation Via Linear Stochastic Differential Equation
Hamidreza Rezazadeh
2014-05-01
Full Text Available In this paper, we intend to solve special kind of ordinary differential equations which is called Heun equations, by converting to a corresponding stochastic differential equation(S.D.E.. So, we construct a stochastic linear equation system from this equation which its solution is based on computing fundamental matrix of this system and then, this S.D.E. is solved by numerically methods. Moreover, its asymptotic stability and statistical concepts like expectation and variance of solutions are discussed. Finally, the attained solutions of these S.D.E.s compared with exact solution of corresponding differential equations.
Dissipative Boussinesq equations
2007-01-01
40 pages, 15 figures, published in C. R. Mecanique 335 (2007) Other author's papers can be downloaded at http://www.cmla.ens-cachan.fr/~dutykh; International audience; The classical theory of water waves is based on the theory of inviscid flows. However it is important to include viscous effects in some applications. Two models are proposed to add dissipative effects in the context of the Boussinesq equations, which include the effects of weak dispersion and nonlinearity in a shallow water fr...
Differential equations with Mathematica
Abell, Martha L
2004-01-01
The Third Edition of the Differential Equations with Mathematica integrates new applications from a variety of fields,especially biology, physics, and engineering. The new handbook is also completely compatible with recent versions of Mathematica and is a perfect introduction for Mathematica beginners.* Focuses on the most often used features of Mathematica for the beginning Mathematica user* New applications from a variety of fields, including engineering, biology, and physics* All applications were completed using recent versions of Mathematica
Arithmetic partial differential equations
Buium, Alexandru; Simanca, Santiago R.
2006-01-01
We develop an arithmetic analogue of linear partial differential equations in two independent ``space-time'' variables. The spatial derivative is a Fermat quotient operator, while the time derivative is the usual derivation. This allows us to ``flow'' integers or, more generally, points on algebraic groups with coordinates in rings with arithmetic flavor. In particular, we show that elliptic curves have certain canonical ``flows'' on them that are the arithmetic analogues of the heat and wave...
Stability in Neutral Equations
1976-02-04
Martinez-Amores Division of Applied Mathematics Brown University Providence, Rhode Island 02912 and Universidad de Granada, Seccion de Matematicas , Spain S...XG w)1- 0 ~t)- >~~~ 0 suc ht j~<kIp, Ii 2 ~ o ~~~ X~ G (t) , y’ip X= 0 y 20 since equation (3.16) is satisfied. Since F = col(f,0), only the col
Trzetrzelewski, Maciej
2016-11-01
Starting with a Nambu-Goto action, a Dirac-like equation can be constructed by taking the square-root of the momentum constraint. The eigenvalues of the resulting Hamiltonian are real and correspond to masses of the excited string. In particular there are no tachyons. A special case of radial oscillations of a closed string in Minkowski space-time admits exact solutions in terms of wave functions of the harmonic oscillator.
D. Diederen
2015-06-01
Full Text Available We present a new equation describing the hydrodynamics in infinitely long tidal channels (i.e., no reflection under the influence of oceanic forcing. The proposed equation is a simple relationship between partial derivatives of water level and velocity. It is formally derived for a progressive wave in a frictionless, prismatic, tidal channel with a horizontal bed. Assessment of a large number of numerical simulations, where an open boundary condition is posed at a certain distance landward, suggests that it can also be considered accurate in the more natural case of converging estuaries with nonlinear friction and a bed slope. The equation follows from the open boundary condition and is therefore a part of the problem formulation for an infinite tidal channel. This finding provides a practical tool for evaluating tidal wave dynamics, by reconstructing the temporal variation of the velocity based on local observations of the water level, providing a fully local open boundary condition and allowing for local friction calibration.
Quantum molecular master equations
Brechet, Sylvain D.; Reuse, Francois A.; Maschke, Klaus; Ansermet, Jean-Philippe
2016-10-01
We present the quantum master equations for midsize molecules in the presence of an external magnetic field. The Hamiltonian describing the dynamics of a molecule accounts for the molecular deformation and orientation properties, as well as for the electronic properties. In order to establish the master equations governing the relaxation of free-standing molecules, we have to split the molecule into two weakly interacting parts, a bath and a bathed system. The adequate choice of these systems depends on the specific physical system under consideration. Here we consider a first system consisting of the molecular deformation and orientation properties and the electronic spin properties and a second system composed of the remaining electronic spatial properties. If the characteristic time scale associated with the second system is small with respect to that of the first, the second may be considered as a bath for the first. Assuming that both systems are weakly coupled and initially weakly correlated, we obtain the corresponding master equations. They describe notably the relaxation of magnetic properties of midsize molecules, where the change of the statistical properties of the electronic orbitals is expected to be slow with respect to the evolution time scale of the bathed system.
M. Paul Gough
2008-07-01
Full Text Available LandauerÃ¢Â€Â™s principle is applied to information in the universe. Once stars began forming there was a constant information energy density as the increasing proportion of matter at high stellar temperatures exactly compensated for the expanding universe. The information equation of state was close to the dark energy value, w = -1, for a wide range of redshifts, 10 > z > 0.8, over one half of cosmic time. A reasonable universe information bit content of only 1087 bits is sufficient for information energy to account for all dark energy. A time varying equation of state with a direct link between dark energy and matter, and linked to star formation in particular, is clearly relevant to the cosmic coincidence problem. In answering the Ã¢Â€Â˜Why now?Ã¢Â€Â™ question we wonder Ã¢Â€Â˜What next?Ã¢Â€Â™ as we expect the information equation of state to tend towards w = 0 in the future.c
On the Well-Posedness of the Vacuum Einstein's Equations
Karp, Lavi
2009-01-01
The Cauchy problem of the vacuum Einstein's equations aims to find a semi-metric $g_{\\alpha\\beta}$ of a spacetime with vanishing Ricci curvature $R_{\\alpha,\\beta}$ and prescribed initial data. Under the harmonic gauge condition, the equations $R_{\\alpha,\\beta}=0$ are transferred into a system of quasi-linear wave equations which are called the reduced Einstein equations. The initial data for Einstein's equations are a proper Riemannian metric $h_{ab}$ and a second fundamental form $K_{ab}$. A necessary condition for the reduced Einstein equation to satisfy the vacuum equations is that the initial data satisfy Einstein constraint equations. Hence the data $(h_{ab},K_{ab})$ cannot serve as initial data for the reduced Einstein equations. Previous results in the case of asymptotically flat spacetimes provide a solution to the constraint equations in one type of Sobolev spaces, while initial data for the evolution equations belong to a different type of Sobolev spaces. The goal of our work is to resolve this inco...
Identification of magnetosheath mirror modes in Equator-S magnetic field data
E. A. Lucek
Full Text Available Between December 1997 and March 1998 Equator-S made a number of excursions into the dawn-side magnetosheath, over a range of local times between 6:00 and 10:40 LT. Clear mirror-like structures, characterised by compressive fluctuations in |B| on occasion lasting for up to 5 h, were observed during a significant fraction of these orbits. During most of these passes the satellite appeared to remain close to the magnetopause (within 1–2 Re, during sustained compressions of the magnetosphere, and so the characteristics of the mirror structures are used as a diagnostic of magnetosheath structure close to the magnetopause during these orbits. It is found that in the majority of cases mirror-like activity persists, undamped, to within a few minutes of the magnetopause, with no observable ramp in |B|, irrespective of the magnetic shear across the boundary. This suggests that any plasma depletion layer is typically of narrow extent or absent at the location of the satellite, at least during the subset of orbits containing strong magnetosheath mirror-mode signatures. Power spectra for the mirror signatures show predominately field aligned power, a well defined shoulder at around 3–10 x 10 ^{–2} Hz and decreasing power at higher frequencies. On occasions the fluctuations are more sinusoidal, leading to peaked spectra instead of a shoulder. In all cases mirror structures are found to lie approximately parallel to the observed magnetopause boundary. There is some indication that the amplitude of the compressional fluctuations tends to be greater closer to the magnetopause. This has not been previously reported in the Earth's magnetosphere, but has been suggested in the case of other planets.
Key words. Magnetospheric physics (magnetosheath; plasma waves and instabilities; magnetopause, cusp and boundary layers
Nishioka, A. [Hitachi, Ltd., Tokyo (Japan)
1998-07-25
There are many types of acoustic noise from flow fields, for example, jet noise, boundary layer noise, tone due to Karman vortex, singing flame, and Rijke tube. This paper proposes an equation of acoustic energy conservation in open systems, which explains various types of oscillating phenomena excited by fields. This equation is from perturbation of the Navier-Storkes` equation. From this analysis it became clear that the generation and dissipation of acoustic energy are caused by the following: work by pressure, viscous loss, interaction between pressure variation and heating rate variation, stable heating, and work by vortex. A simplified model is used to describe these unstable factors by wave equation. Also, a one-dimensional analysis for a duct with a large temperature gradient and a large sectional area gradient was done by the transfer matrix method. Those factors have an effect on the phase velocity. 13 refs., 2 figs.
Two-parameter Rankine Heat Pumps’ COP Equations
Samuel Sunday Adefila
2012-05-01
Full Text Available Equations for ideal vapour compression heat pump coefficient of performance (COPR which contain two fit-parameters are reported in this work. These equations contain either temperature term alone or temperature and pressure terms as the only thermodynamic variable(s. The best equation gave error ≥5% over wide range of temperature-lift and for different working fluid types that include fluorocarbons, hydrocarbons and inorganic fluids. In these respects the equation performs better than the one-parameter models reported earlier.
Utilizing Probabilistic Linear Equations in Cube Attacks
Yuan Yao; Bin Zhang; Wen-Ling Wu
2016-01-01
Cube attacks, proposed by Dinur and Shamir at EUROCRYPT 2009, have shown huge power against stream ciphers. In the original cube attacks, a linear system of secret key bits is exploited for key recovery attacks. However, we find a number of equations claimed linear in previous literature actually nonlinear and not fit into the theoretical framework of cube attacks. Moreover, cube attacks are hard to apply if linear equations are rare. Therefore, it is of significance to make use of probabilistic linear equations, namely nonlinear superpolys that can be approximated by linear expressions effectively. In this paper, we suggest a way to test out and utilize these probabilistic linear equations, thus extending cube attacks to a wider scope. Concretely, we employ the standard parameter estimation approach and the sequential probability ratio test (SPRT) for linearity test in the preprocessing phase, and use maximum likelihood decoding (MLD) for solving the probabilistic linear equations in the online phase. As an application, we exhibit our new attack against 672 rounds of Trivium and reduce the number of key bits to search by 7.
Gravitationally Coupled Dirac Equation for Antimatter
Jentschura, U D
2013-01-01
The coupling of antimatter to gravity is of general interest because of conceivable cosmological consequences ("surprises") related to dark energy and the cosmological constant. Here, we revisit the derivation of the gravitationally coupled Dirac equation and find that the prefactor of a result given previously in [D.R. Brill and J.A. Wheeler, Rev. Mod. Phys., vol. 29, p. 465 (1957)] for the affine connection matrix is in need of a correction. We also discuss the conversion the curved-space Dirac equation from East-Coast to West-Coast conventions, in order to bring the gravitationally coupled Dirac equation to a form where it can easily be unified with the electromagnetic coupling as it is commonly used in modern particle physics calculations. The Dirac equation describes anti-particles as negative-energy states. We find a symmetry of the gravitationally coupled Dirac equation, which connects particle and antiparticle solutions for a general space-time metric of the Schwarzschild type and implies that particl...
Reduction operators of Burgers equation.
Pocheketa, Oleksandr A; Popovych, Roman O
2013-02-01
The solution of the problem on reduction operators and nonclassical reductions of the Burgers equation is systematically treated and completed. A new proof of the theorem on the special "no-go" case of regular reduction operators is presented, and the representation of the coefficients of operators in terms of solutions of the initial equation is constructed for this case. All possible nonclassical reductions of the Burgers equation to single ordinary differential equations are exhaustively described. Any Lie reduction of the Burgers equation proves to be equivalent via the Hopf-Cole transformation to a parameterized family of Lie reductions of the linear heat equation.
Bitsadze, A V
1963-01-01
Equations of the Mixed Type compiles a series of lectures on certain fundamental questions in the theory of equations of mixed type. This book investigates the series of problems concerning linear partial differential equations of the second order in two variables, and possessing the property that the type of the equation changes either on the boundary of or inside the considered domain. Topics covered include general remarks on linear partial differential equations of mixed type; study of the solutions of second order hyperbolic equations with initial conditions given along the lines of parab
New application to Riccati equation
Taogetusang; Sirendaoerji; Li, Shu-Min
2010-08-01
To seek new infinite sequence of exact solutions to nonlinear evolution equations, this paper gives the formula of nonlinear superposition of the solutions and Bäcklund transformation of Riccati equation. Based on the tanh-function expansion method and homogenous balance method, new infinite sequence of exact solutions to Zakharov-Kuznetsov equation, Karamoto-Sivashinsky equation and the set of (2+1)-dimensional asymmetric Nizhnik-Novikov-Veselov equations are obtained with the aid of symbolic computation system Mathematica. The method is of significance to construct infinite sequence exact solutions to other nonlinear evolution equations.
On averaging methods for partial differential equations
Verhulst, F.
2001-01-01
The analysis of weakly nonlinear partial differential equations both qualitatively and quantitatively is emerging as an exciting eld of investigation In this report we consider specic results related to averaging but we do not aim at completeness The sections and contain important material which
Evaluating Equating Results: Percent Relative Error for Chained Kernel Equating
Jiang, Yanlin; von Davier, Alina A.; Chen, Haiwen
2012-01-01
This article presents a method for evaluating equating results. Within the kernel equating framework, the percent relative error (PRE) for chained equipercentile equating was computed under the nonequivalent groups with anchor test (NEAT) design. The method was applied to two data sets to obtain the PRE, which can be used to measure equating…
Auxiliary equation method for solving nonlinear partial differential equations
Sirendaoreji,; Jiong, Sun
2003-03-31
By using the solutions of an auxiliary ordinary differential equation, a direct algebraic method is described to construct several kinds of exact travelling wave solutions for some nonlinear partial differential equations. By this method some physically important nonlinear equations are investigated and new exact travelling wave solutions are explicitly obtained with the aid of symbolic computation.
New Exact Solutions to NLS Equation and Coupled NLS Equations
FU Zun-Tao; LIU Shi-Da; LIU Shi-Kuo
2004-01-01
A transformation is introduced on the basis of the projective Riccati equations, and it is applied as an intermediate in expansion method to solve nonlinear Schrodinger (NLS) equation and coupled NLS equations. Many kinds of envelope travelling wave solutions including envelope solitary wave solution are obtained, in which some are found for the first time.
The compressible adjoint equations in geodynamics: equations and numerical assessment
Ghelichkhan, Siavash; Bunge, Hans-Peter
2016-04-01
The adjoint method is a powerful means to obtain gradient information in a mantle convection model relative to past flow structure. While the adjoint equations in geodynamics have been derived for the conservation equations of mantle flow in their incompressible form, the applicability of this approximation to Earth is limited, because density increases by almost a factor of two from the surface to the Core Mantle Boundary. Here we introduce the compressible adjoint equations for the conservation equations in the anelastic-liquid approximation. Our derivation applies an operator formulation in Hilbert spaces, to connect to recent work in seismology (Fichtner et al (2006)) and geodynamics (Horbach et al (2014)), where the approach was used to derive the adjoint equations for the wave equation and incompressible mantle flow. We present numerical tests of the newly derived equations based on twin experiments, focusing on three simulations. A first, termed Compressible, assumes the compressible forward and adjoint equations, and represents the consistent means of including compressibility effects. A second, termed Mixed, applies the compressible forward equation, but ignores compressibility effects in the adjoint equations, where the incompressible equations are used instead. A third simulation, termed Incompressible, neglects compressibility effects entirely in the forward and adjoint equations relative to the reference twin. The compressible and mixed formulations successfully restore earlier mantle flow structure, while the incompressible formulation yields noticeable artifacts. Our results suggest the use of a compressible formulation, when applying the adjoint method to seismically derived mantle heterogeneity structure.
Elliptic Equation and New Solutions to Nonlinear Wave Equations
FU Zun-Tao; LIU Shi-Kuo; LIU Shi-Da
2004-01-01
The new solutions to elliptic equation are shown, and then the elliptic equation is taken as a transformationand is applied to solve nonlinear wave equations. It is shown that more kinds of solutions are derived, such as periodicsolutions of rational form, solitary wave solutions of rational form, and so on.
28 CFR 10.5 - Incorporation of papers previously filed.
2010-07-01
... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Incorporation of papers previously filed... CARRYING ON ACTIVITIES WITHIN THE UNITED STATES Registration Statement § 10.5 Incorporation of papers previously filed. Papers and documents already filed with the Attorney General pursuant to the said act...
2 CFR 1.215 - Relationship to previous issuances.
2010-01-01
... 2 Grants and Agreements 1 2010-01-01 2010-01-01 false Relationship to previous issuances. 1.215 Section 1.215 Grants and Agreements ABOUT TITLE 2 OF THE CODE OF FEDERAL REGULATIONS AND SUBTITLE A Introduction toSubtitle A § 1.215 Relationship to previous issuances. Although some of the guidance was...
49 CFR 236.1031 - Previously approved PTC systems.
2010-10-01
... 49 Transportation 4 2010-10-01 2010-10-01 false Previously approved PTC systems. 236.1031 Section... Train Control Systems § 236.1031 Previously approved PTC systems. (a) Any PTC system fully implemented and operational prior to March 16, 2010, may receive PTC System Certification if the applicable PTC...
Variational Principles for Constrained Electromagnetic Field and Papapetrou Equation
Muminov, A T
2007-01-01
In our previous article [4] an approach to derive Papapetrou equations for constrained electromagnetic field was demonstrated by use of field variational principles. The aim of current work is to present more universal technique of deduction of the equations which could be applied to another types of non-scalar fields. It is based on Noether theorem formulated in terms of Cartan' formalism of orthonormal frames. Under infinitesimal coordinate transformation the one leads to equation which includes volume force of spin-gravitational interaction. Papapetrou equation for vector of propagation of the wave is derived on base of the equation. Such manner of deduction allows to formulate more accurately the constraints and clarify equations for the potential and for spin.
Comment on "General equilibrium shape equations of polymer chains".
Thamwattana, Ngamta; Hill, James M
2008-07-01
In this Comment, we point out that the Euler-Lagrange equations, which are referred to as the general equilibrium shape equations presented by Zhang et al. [Phys. Rev. E 70, 051902 (2004)] are incorrect, along with equations derived from them. The correct equations are provided here and they are cross-checked using certain energy functions previously presented in the literature. Further, with the use of the correct equations, we present new numerical results, which for the values of the constants given by Zhang et al. do not give rise to the physical behavior observed for DNA by those authors. However, the correct equations can be consistent with sensible behavior for different values of the constants.
Local energy decay for linear wave equations with variable coefficients
Ikehata, Ryo
2005-06-01
A uniform local energy decay result is derived to the linear wave equation with spatial variable coefficients. We deal with this equation in an exterior domain with a star-shaped complement. Our advantage is that we do not assume any compactness of the support on the initial data, and its proof is quite simple. This generalizes a previous famous result due to Morawetz [The decay of solutions of the exterior initial-boundary value problem for the wave equation, Comm. Pure Appl. Math. 14 (1961) 561-568]. In order to prove local energy decay, we mainly apply two types of ideas due to Ikehata-Matsuyama [L2-behaviour of solutions to the linear heat and wave equations in exterior domains, Sci. Math. Japon. 55 (2002) 33-42] and Todorova-Yordanov [Critical exponent for a nonlinear wave equation with damping, J. Differential Equations 174 (2001) 464-489].
Partial differential equations
Sloan, D; Süli, E
2001-01-01
/homepage/sac/cam/na2000/index.html7-Volume Set now available at special set price ! Over the second half of the 20th century the subject area loosely referred to as numerical analysis of partial differential equations (PDEs) has undergone unprecedented development. At its practical end, the vigorous growth and steady diversification of the field were stimulated by the demand for accurate and reliable tools for computational modelling in physical sciences and engineering, and by the rapid development of computer hardware and architecture. At the more theoretical end, the analytical insight in
Hyperbolic partial differential equations
Lax, Peter D
2006-01-01
The theory of hyperbolic equations is a large subject, and its applications are many: fluid dynamics and aerodynamics, the theory of elasticity, optics, electromagnetic waves, direct and inverse scattering, and the general theory of relativity. This book is an introduction to most facets of the theory and is an ideal text for a second-year graduate course on the subject. The first part deals with the basic theory: the relation of hyperbolicity to the finite propagation of signals, the concept and role of characteristic surfaces and rays, energy, and energy inequalities. The structure of soluti
Dimensional Equations of Entropy
Sparavigna, Amelia Carolina
2015-01-01
Entropy is a quantity which is of great importance in physics and chemistry. The concept comes out of thermodynamics, proposed by Rudolf Clausius in his analysis of Carnot cycle and linked by Ludwig Boltzmann to the number of specific ways in which a physical system may be arranged. Any physics classroom, in its task of learning physics, has therefore to face this crucial concept. As we will show in this paper, the lectures can be enriched by discussing dimensional equations linked to the entropy of some physical systems.
Partial differential equations
Levine, Harold
1997-01-01
The subject matter, partial differential equations (PDEs), has a long history (dating from the 18th century) and an active contemporary phase. An early phase (with a separate focus on taut string vibrations and heat flow through solid bodies) stimulated developments of great importance for mathematical analysis, such as a wider concept of functions and integration and the existence of trigonometric or Fourier series representations. The direct relevance of PDEs to all manner of mathematical, physical and technical problems continues. This book presents a reasonably broad introductory account of the subject, with due regard for analytical detail, applications and historical matters.
Ordinary differential equations
Cox, William
1995-01-01
Building on introductory calculus courses, this text provides a sound foundation in the underlying principles of ordinary differential equations. Important concepts, including uniqueness and existence theorems, are worked through in detail and the student is encouraged to develop much of the routine material themselves, thus helping to ensure a solid understanding of the fundamentals required.The wide use of exercises, problems and self-assessment questions helps to promote a deeper understanding of the material and it is developed in such a way that it lays the groundwork for further
Savvidy, G K
1998-01-01
We discuss the basic properties of the gonihedric string and the problem of its formulation in continuum. We propose a generalization of the Dirac equation and of the corresponding gamma matrices in order to describe the gonihedric string. The wave function and the Dirac matrices are infinite-dimensional. The spectrum of the theory consists of particles and antiparticles of increasing half-integer spin lying on quasilinear trajectories of different slope. Explicit formulas for the mass spectrum allow to compute the string tension and thus demonstrate the string character of the theory.
The Arrhenius equation revisited.
Peleg, Micha; Normand, Mark D; Corradini, Maria G
2012-01-01
The Arrhenius equation has been widely used as a model of the temperature effect on the rate of chemical reactions and biological processes in foods. Since the model requires that the rate increase monotonically with temperature, its applicability to enzymatic reactions and microbial growth, which have optimal temperature, is obviously limited. This is also true for microbial inactivation and chemical reactions that only start at an elevated temperature, and for complex processes and reactions that do not follow fixed order kinetics, that is, where the isothermal rate constant, however defined, is a function of both temperature and time. The linearity of the Arrhenius plot, that is, Ln[k(T)] vs. 1/T where T is in °K has been traditionally considered evidence of the model's validity. Consequently, the slope of the plot has been used to calculate the reaction or processes' "energy of activation," usually without independent verification. Many experimental and simulated rate constant vs. temperature relationships that yield linear Arrhenius plots can also be described by the simpler exponential model Ln[k(T)/k(T(reference))] = c(T-T(reference)). The use of the exponential model or similar empirical alternative would eliminate the confusing temperature axis inversion, the unnecessary compression of the temperature scale, and the need for kinetic assumptions that are hard to affirm in food systems. It would also eliminate the reference to the Universal gas constant in systems where a "mole" cannot be clearly identified. Unless proven otherwise by independent experiments, one cannot dismiss the notion that the apparent linearity of the Arrhenius plot in many food systems is due to a mathematical property of the model's equation rather than to the existence of a temperature independent "energy of activation." If T+273.16°C in the Arrhenius model's equation is replaced by T+b, where the numerical value of the arbitrary constant b is substantially larger than T and T
Differential Equations as Actions
Ronkko, Mauno; Ravn, Anders P.
1997-01-01
We extend a conventional action system with a primitive action consisting of a differential equation and an evolution invariant. The semantics is given by a predicate transformer. The weakest liberal precondition is chosen, because it is not always desirable that steps corresponding to differential...... actions shall terminate. It is shown that the proposed differential action has a semantics which corresponds to a discrete approximation when the discrete step size goes to zero. The extension gives action systems the power to model real-time clocks and continuous evolutions within hybrid systems....
Czuczman, Myron S; Hess, Georg; Gadeberg, Ole V
2012-01-01
-up time is needed for analysis of survival end points. The most common Common Terminology Criteria grade 3-4 investigator-reported adverse events were leucopenia (29%) and neutropenia (22%). No deaths have been reported. O-CHOP was safe and efficacious in patients with previously untreated FL, including...
Conservational PDF Equations of Turbulence
Shih, Tsan-Hsing; Liu, Nan-Suey
2010-01-01
Recently we have revisited the traditional probability density function (PDF) equations for the velocity and species in turbulent incompressible flows. They are all unclosed due to the appearance of various conditional means which are modeled empirically. However, we have observed that it is possible to establish a closed velocity PDF equation and a closed joint velocity and species PDF equation through conditions derived from the integral form of the Navier-Stokes equations. Although, in theory, the resulted PDF equations are neither general nor unique, they nevertheless lead to the exact transport equations for the first moment as well as all higher order moments. We refer these PDF equations as the conservational PDF equations. This observation is worth further exploration for its validity and CFD application
Program Transformation by Solving Equations
朱鸿
1991-01-01
Based on the theory of orthogonal program expansion[8-10],the paper proposes a method to transform programs by solving program equations.By the method,transformation goals are expressed in program equations,and achieved by solving these equations.Although such equations are usually too complicated to be solved directly,the orthogonal expansion of programs makes it possible to reduce such equations into systems of equations only containing simple constructors of programs.Then,the solutions of such equations can be derived by a system of solving and simplifying rules,and algebraic laws of programs.The paper discusses the methods to simplify and solve equations and gives some examples.
``Riemann equations'' in bidifferential calculus
Chvartatskyi, O.; Müller-Hoissen, F.; Stoilov, N.
2015-10-01
We consider equations that formally resemble a matrix Riemann (or Hopf) equation in the framework of bidifferential calculus. With different choices of a first-order bidifferential calculus, we obtain a variety of equations, including a semi-discrete and a fully discrete version of the matrix Riemann equation. A corresponding universal solution-generating method then either yields a (continuous or discrete) Cole-Hopf transformation, or leaves us with the problem of solving Riemann equations (hence an application of the hodograph method). If the bidifferential calculus extends to second order, solutions of a system of "Riemann equations" are also solutions of an equation that arises, on the universal level of bidifferential calculus, as an integrability condition. Depending on the choice of bidifferential calculus, the latter can represent a number of prominent integrable equations, like self-dual Yang-Mills, as well as matrix versions of the two-dimensional Toda lattice, Hirota's bilinear difference equation, (2+1)-dimensional Nonlinear Schrödinger (NLS), Kadomtsev-Petviashvili (KP) equation, and Davey-Stewartson equations. For all of them, a recent (non-isospectral) binary Darboux transformation result in bidifferential calculus applies, which can be specialized to generate solutions of the associated "Riemann equations." For the latter, we clarify the relation between these specialized binary Darboux transformations and the aforementioned solution-generating method. From (arbitrary size) matrix versions of the "Riemann equations" associated with an integrable equation, possessing a bidifferential calculus formulation, multi-soliton-type solutions of the latter can be generated. This includes "breaking" multi-soliton-type solutions of the self-dual Yang-Mills and the (2+1)-dimensional NLS equation, which are parametrized by solutions of Riemann equations.
Itoh, Y
2004-01-01
An equation of motion for relativistic compact binaries is derived through the third post-Newtonian (3 PN) approximation of general relativity. The strong field point particle limit and multipole expansion of the stars are used to solve iteratively the harmonically relaxed Einstein equations. We take into account the Lorentz contraction on the multipole moments defined in our previous works. We then derive a 3 PN acceleration of the binary orbital motion of the two spherical compact stars based on a surface integral approach which is a direct consequence of local energy momentum conservation. Our resulting equation of motion admits a conserved energy (neglecting the 2.5 PN radiation reaction effect), is Lorentz invariant and is unambiguous: there exist no undetermined parameter reported in the previous works. We shall show that our 3 PN equation of motion agrees physically with the Blanchet and Faye 3 PN equation of motion if $\\lambda = - 1987/3080$, where $\\lambda$ is the parameter which is undetermined with...
Stochastic fuzzy differential equations of a nonincreasing type
Malinowski, Marek T.
2016-04-01
Stochastic fuzzy differential equations constitute an apparatus in modeling dynamic systems operating in fuzzy environment and governed by stochastic noises. In this paper we introduce a new kind of such the equations. Namely, the stochastic fuzzy differential of nonincreasing type are considered. The fuzzy stochastic processes which are solutions to these equations have trajectories with nonincreasing fuzziness in their values. In our previous papers, as a first natural extension of crisp stochastic differential equations, stochastic fuzzy differential equations of nondecreasing type were studied. In this paper we show that under suitable conditions each of the equations has a unique solution which possesses property of continuous dependence on data of the equation. To prove existence of the solutions we use sequences of successive approximate solutions. An estimation of an error of the approximate solution is established as well. Some examples of equations are solved and their solutions are simulated to illustrate the theory of stochastic fuzzy differential equations. All the achieved results apply to stochastic set-valued differential equations.
Synthetic Aperture Sonar Imaging via One-Way Wave Equations
Huynh, Quyen
2009-01-01
We develop an efficient algorithm for Synthetic Aperture Sonar imaging based on the one-way wave equations. The algorithm utilizes the operator-splitting method to integrate the one-way wave equations. The well-posedness of the one-way wave equations and the proposed algorithm is shown. A computational result against real field data is reported and the resulting image is enhanced by the BV-like regularization.
Techniques in Linear and Nonlinear Partial Differential Equations
1991-10-21
nonlinear partial differential equations , elliptic 15. NUMBER OF PAGES hyperbolic and parabolic. Variational methods. Vibration problems. Ordinary Five...NONLINEAR PARTIAL DIFFERENTIAL EQUATIONS FINAL TECHNICAL REPORT PROFESSOR LOUIS NIRENBERG OCTOBER 21, 1991 NT)S CRA&I D FIC ,- U.S. ARMY RESEARCH OFFICE...Analysis and partial differential equations . ed. C. Sadowsky. Marcel Dekker (1990) 567-619. [7] Lin, Fanghua, Asymptotic behavior of area-minimizing
Equation with the many fathers
Kragh, Helge
1984-01-01
In this essay I discuss the origin and early development of the first relativistic wave equation, known as the Klein-Gordon equation. In 1926 several physicists, among them Klein, Fock, Schrödinger, and de Broglie, announced this equation as a candidate for a relativistic generalization of the us...
An Extented Wave Action Equation
左其华
2003-01-01
Based on the Navier-Stokes equation, an average wave energy equation and a generalized wave action conservation equation are presented in this paper. The turbulence effects on water particle velocity ui and wave surface elavation ξ as well as energy dissipation are included. Some simplified forms are also given.
Successfully Transitioning to Linear Equations
Colton, Connie; Smith, Wendy M.
2014-01-01
The Common Core State Standards for Mathematics (CCSSI 2010) asks students in as early as fourth grade to solve word problems using equations with variables. Equations studied at this level generate a single solution, such as the equation x + 10 = 25. For students in fifth grade, the Common Core standard for algebraic thinking expects them to…
Successfully Transitioning to Linear Equations
Colton, Connie; Smith, Wendy M.
2014-01-01
The Common Core State Standards for Mathematics (CCSSI 2010) asks students in as early as fourth grade to solve word problems using equations with variables. Equations studied at this level generate a single solution, such as the equation x + 10 = 25. For students in fifth grade, the Common Core standard for algebraic thinking expects them to…
Prolongation structures for supersymmetric equations
Roelofs, G.H.M.; Hijligenberg, van den N.W.
1990-01-01
The well known prolongation technique of Wahlquist and Estabrook (1975) for nonlinear evolution equations is generalized for supersymmetric equations and applied to the supersymmetric extension of the KdV equation of Manin-Radul. Using the theory of Kac-Moody Lie superalgebras, the explicit form of
Solution of Finite Element Equations
Krenk, Steen
An important step in solving any problem by the finite element method is the solution of the global equations. Numerical solution of linear equations is a subject covered in most courses in numerical analysis. However, the equations encountered in most finite element applications have some special...
The impact of previous traumatic brain injury on health and functioning: a TRACK-TBI study.
Dams-O'Connor, Kristen; Spielman, Lisa; Singh, Ayushi; Gordon, Wayne A; Lingsma, Hester F; Maas, Andrew I R; Manley, Geoffrey T; Mukherjee, Pratik; Okonkwo, David O; Puccio, Ava M; Schnyer, David M; Valadka, Alex B; Yue, John K; Yuh, Esther L
2013-12-15
The idea that multiple traumatic brain injury (TBI) can have a cumulative detrimental effect on functioning is widely accepted. Most research supporting this idea comes from athlete samples, and it is not known whether remote history of previous TBI affects functioning after subsequent TBI in community-based samples. This study investigates whether a previous history of TBI with loss of consciousness (LOC) is associated with worse health and functioning in a sample of individuals who require emergency department care for current TBI. Twenty-three percent of the 586 individuals with current TBI in the Transforming Research and Clinical Knowledge in Traumatic Brain Injury study reported having sustained a previous TBI with LOC. Individuals with previous TBI were more likely to be unemployed (χ(2)=17.86; p=0.000), report a variety of chronic medical and psychiatric conditions (4.75≤χ(2)≥24.16; pTBI history. Those with a previous TBI had less-severe acute injuries, but experienced worse outcomes at 6-month follow-up. Results of a series of regression analyses controlling for demographics and acute injury severity indicated that individuals with previous TBI reported more mood symptoms, more postconcussive symptoms, lower life satisfaction, and had slower processing speed and poorer verbal learning, compared to those with no previous TBI history. These findings suggest that history of TBI with LOC may have important implications for health and psychological functioning after TBI in community-based samples.
Ideal solar cell equation in the presence of photon recycling
Lan, Dongchen, E-mail: d.lan@unsw.edu.au; Green, Martin A., E-mail: m.green@unsw.edu.au [Australian Centre for Advanced Photovoltaics, School of Photovoltaic and Renewable Energy Engineering, University of New South Wales, Sydney 2052 (Australia)
2014-11-07
Previous derivations of the ideal solar cell equation based on Shockley's p-n junction diode theory implicitly assume negligible effects of photon recycling. This paper derives the equation in the presence of photon recycling that modifies the values of dark saturation and light-generated currents, using an approach applicable to arbitrary three-dimensional geometries with arbitrary doping profile and variable band gap. The work also corrects an error in previous work and proves the validity of the reciprocity theorem for charge collection in such a more general case with the previously neglected junction depletion region included.
Solitary Wave Solutions of KP equation, Cylindrical KP Equation and Spherical KP Equation
Li, Xiang-Zheng; Zhang, Jin-Liang; Wang, Ming-Liang
2017-02-01
Three (2+1)-dimensional equations-KP equation, cylindrical KP equation and spherical KP equation, have been reduced to the same KdV equation by different transformation of variables respectively. Since the single solitary wave solution and 2-solitary wave solution of the KdV equation have been known already, substituting the solutions of the KdV equation into the corresponding transformation of variables respectively, the single and 2-solitary wave solutions of the three (2+1)-dimensional equations can be obtained successfully. Supported by the National Natural Science Foundation of China under Grant No. 11301153 and the Doctoral Foundation of Henan University of Science and Technology under Grant No. 09001562, and the Science and Technology Innovation Platform of Henan University of Science and Technology under Grant No. 2015XPT001
Full-deautonomisation of a lattice equation
Willox, R.; Mase, T.; Ramani, A.; Grammaticos, B.
2016-07-01
In this letter we report on the unexpected possibility of applying the full-deautonomisation approach we recently proposed for predicting the algebraic entropy of second-order birational mappings, to discrete lattice equations. Moreover, we show, on two examples, that the full-deautonomisation technique can in fact also be successfully applied to reductions of these lattice equations to mappings with orders higher than 2. In particular, we apply this technique to a recently discovered lattice equation that has confined singularities while being nonintegrable, and we show that our approach accurately predicts this nonintegrable character. Finally, we demonstrate how our method can even be used to predict the algebraic entropy for some nonconfining higher order mappings.
Quantum simulation of the Dirac equation
Gerritsma, Rene; Kirchmair, Gerhard; Zaehringer, Florian; Blatt, Rainer; Roos, Christian [Institut fuer Quantenoptik und Quanteninformation, 6020 Innsbruck (Austria); Solano, Enrique [Departamento de Quimica Fisica, Universidad del Pais Vasco - Euskal Herriko Unibertsitatea, Bilbao (Spain)
2010-07-01
The Dirac equation is a cornerstone in the history of physics, merging successfully quantum mechanics with special relativity, providing a natural description of the electron spin and predicting the existence of anti-matter. However, the Dirac equation also predicts some peculiar effects such as Klein's paradox and Zitterbewegung, an unexpected quivering motion of a free relativistic quantum particle first examined by Schroedinger. In this talk, we report on a proof-of-principle quantum simulation of the one-dimensional Dirac equation using a single trapped ion, which is set to behave as a free relativistic quantum particle. We measure as a function of time the particle position and study Zitterbewegung for different initial superpositions of positive and negative energy spinor states, as well as the cross-over from relativistic to nonrelativistic dynamics.
Discovering evolution equations with applications
McKibben, Mark
2011-01-01
Most existing books on evolution equations tend either to cover a particular class of equations in too much depth for beginners or focus on a very specific research direction. Thus, the field can be daunting for newcomers to the field who need access to preliminary material and behind-the-scenes detail. Taking an applications-oriented, conversational approach, Discovering Evolution Equations with Applications: Volume 2-Stochastic Equations provides an introductory understanding of stochastic evolution equations. The text begins with hands-on introductions to the essentials of real and stochast
A generalized advection dispersion equation
Abdon Atangana
2014-02-01
This paper examines a possible effect of uncertainties, variability or heterogeneity of any dynamic system when being included in its evolution rule; the notion is illustrated with the advection dispersion equation, which describes the groundwater pollution model. An uncertain derivative is defined; some properties of the operator are presented. The operator is used to generalize the advection dispersion equation. The generalized equation differs from the standard equation in four properties. The generalized equation is solved via the variational iteration technique. Some illustrative figures are presented.
Integral equations and their applications
Rahman, M
2007-01-01
For many years, the subject of functional equations has held a prominent place in the attention of mathematicians. In more recent years this attention has been directed to a particular kind of functional equation, an integral equation, wherein the unknown function occurs under the integral sign. The study of this kind of equation is sometimes referred to as the inversion of a definite integral. While scientists and engineers can already choose from a number of books on integral equations, this new book encompasses recent developments including some preliminary backgrounds of formulations of in
Reduction of infinite dimensional equations
Zhongding Li
2006-02-01
Full Text Available In this paper, we use the general Legendre transformation to show the infinite dimensional integrable equations can be reduced to a finite dimensional integrable Hamiltonian system on an invariant set under the flow of the integrable equations. Then we obtain the periodic or quasi-periodic solution of the equation. This generalizes the results of Lax and Novikov regarding the periodic or quasi-periodic solution of the KdV equation to the general case of isospectral Hamiltonian integrable equation. And finally, we discuss the AKNS hierarchy as a special example.
Differential equations extended to superspace
Torres, J. [Instituto de Fisica, Universidad de Guanajuato, A.P. E-143, Leon, Guanajuato (Mexico); Rosu, H.C. [Instituto Potosino de Investigacion Cientifica y Tecnologica, A.P. 3-74, Tangamanga, San Luis Potosi (Mexico)
2003-07-01
We present a simple SUSY Ns = 2 superspace extension of the differential equations in which the sought solutions are considered to be real superfields but maintaining the common derivative operators and the coefficients of the differential equations unaltered. In this way, we get self consistent systems of coupled differential equations for the components of the superfield. This procedure is applied to the Riccati equation, for which we obtain in addition the system of coupled equations corresponding to the components of the general superfield solution. (Author)
Dust levitation about Itokawa's equator
Hartzell, C.; Zimmerman, M.; Takahashi, Y.
2014-07-01
in radius may be able to levitate about Itokawa's equator, which is significantly larger than had previously been considered. In the future, we plan to improve the fidelity of our grain-charging model by using plasma species densities rather than Nitter et al.'s model. Additionally, we will explore the stability of the numerically identified equilibria for a range of dust grain sizes.
Yehorchenko, Irina
2010-01-01
We study possible Lie and non-classical reductions of multidimensional wave equations and the special classes of possible reduced equations - their symmetries and equivalence classes. Such investigation allows to find many new conditional and hidden symmetries of the original equations.
It should be Einstein-Laub Equations inside Matter
Mahdy, Mahdy Rahman Chowdhury
2012-01-01
In a recent article [1], Mansuripur has claimed that inside the matter, conventional Lorentz Force law should be abandoned in favor of a more general expression of the electromagnetic force density such as the one discovered by A. Einstein and J.Laub in 1908. The main focus of the claim of Mansuripur is based on special theory of relativity. According to [1], Lorentz force law is incompatible with special theory of relativity. In this article, we have focused in favor of Einstein-Laub equations (Force law; associated stress tensor, momentum density, Poynting vector etc) from quite different point of views. Especially we have tried to include previously and recently reported experimental observations, Abraham, Minkowski and Nelson controversy, Quantum Electrodynamics and most importantly the significance of associated stress tensors to judge the problem from a broader and engineering point of view. At the end of the day, considering all the issues, we have found that only Einstein-Laub equations can predict th...
黄虎; 丁平兴; 吕秀红
2001-01-01
The Hamiltonian formalism for surface waves and the mild-slope approximation were empolyed in handling the case of slowly varying three-dimensional currents and an uneven bottom, thus leading to an extended mild-slope equation. The bottom topography consists of two components: the slowly varying component whose horizontal length scale is longer than the surface wave length, and the fast varying component with the amplitude being smaller than that of the surface wave. The frequency of the fast varying depth component is, however, comparable to that of the surface waves. The extended mild- slope equation is more widely applicable and contains as special cases famous mild-slope equations below: the classical mild-slope equation of Berkhoff , Kirby' s mild-slope equation with current, and Dingemans' s mild-slope equation for rippled bed. The extended shallow water equations for ambient currents and rapidly varying topography are also obtained.
Scaling of differential equations
Langtangen, Hans Petter
2016-01-01
The book serves both as a reference for various scaled models with corresponding dimensionless numbers, and as a resource for learning the art of scaling. A special feature of the book is the emphasis on how to create software for scaled models, based on existing software for unscaled models. Scaling (or non-dimensionalization) is a mathematical technique that greatly simplifies the setting of input parameters in numerical simulations. Moreover, scaling enhances the understanding of how different physical processes interact in a differential equation model. Compared to the existing literature, where the topic of scaling is frequently encountered, but very often in only a brief and shallow setting, the present book gives much more thorough explanations of how to reason about finding the right scales. This process is highly problem dependent, and therefore the book features a lot of worked examples, from very simple ODEs to systems of PDEs, especially from fluid mechanics. The text is easily accessible and exam...
Cardona, Carlos [Physics Division, National Center for Theoretical Sciences, National Tsing-Hua University,Hsinchu, Taiwan 30013 (China); Gomez, Humberto [Instituto de Fisica - Universidade de São Paulo,Caixa Postal 66318, 05315-970 São Paulo, SP (Brazil); Facultad de Ciencias Basicas, Universidad Santiago de Cali,Calle 5 62-00 Barrio Pampalinda, Cali, Valle (Colombia)
2016-06-16
Recently the CHY approach has been extended to one loop level using elliptic functions and modular forms over a Jacobian variety. Due to the difficulty in manipulating these kind of functions, we propose an alternative prescription that is totally algebraic. This new proposal is based on an elliptic algebraic curve embedded in a ℂP{sup 2} space. We show that for the simplest integrand, namely the n−gon, our proposal indeed reproduces the expected result. By using the recently formulated Λ−algorithm, we found a novel recurrence relation expansion in terms of tree level off-shell amplitudes. Our results connect nicely with recent results on the one-loop formulation of the scattering equations. In addition, this new proposal can be easily stretched out to hyperelliptic curves in order to compute higher genus.
$\\Lambda$ Scattering Equations
Gomez, Humberto
2016-01-01
The CHY representation of scattering amplitudes is based on integrals over the moduli space of a punctured sphere. We replace the punctured sphere by a double-cover version. The resulting scattering equations depend on a parameter $\\Lambda$ controlling the opening of a branch cut. The new representation of scattering amplitudes possesses an enhanced redundancy which can be used to fix, modulo branches, the location of four punctures while promoting $\\Lambda$ to a variable. Via residue theorems we show how CHY formulas break up into sums of products of smaller (off-shell) ones times a propagator. This leads to a powerful way of evaluating CHY integrals of generic rational functions, which we call the $\\Lambda$ algorithm.
OUTCOME OF PREGNANCY IN WOMEN WITH PREVIOUS CAESAREAN SECTION
Bellad Girija
2016-06-01
Full Text Available BACKGROUND Carefully selected cases of Vaginal Birth after Caesarean Section (VBAC is safe and successful. Even though options of elective caesarean section or a trial of labour are given to women with prior caesarean section, the risk is always present. In successful VBACs, morbidity is less compared to repeat caesarean section. That is why this study is conducted to determine the outcome of pregnancy in women with previous CS. OBJECTIVES 1. To evaluate the clinical course of labour in cases with previous caesarean section. 2. To study the perinatal outcome in cases with previous caesarean section either by vaginal delivery or repeat Caesarean section. 3. To study maternal morbidity in these cases. METHOD A retrospective analysis of medical records of 250 women with a previous caesarean section, who delivered in BIMS Hospital between May 2015 and July 2015 was carried out. Women with recurrent indications for caesarean section and those having nonrecurrent indications with any complicating factors in present pregnancy and women with previous two caesarean sections were not given trial for vaginal delivery. Those women with previous section for the non-recurrent indications were given trial for vaginal delivery. STATISTICAL ANALYSIS Was done by Chi-square test. RESULT In 250 cases, 132 cases were given trial for vaginal delivery. In these, vaginal delivery was 61.3% and repeat section was 38%. There is an association between maternal morbidity and type of delivery. Birth weight was associated with the type of delivery. There is no association between neonatal outcome and type of delivery. CONCLUSION In carefully selected patients, appropriate timing and close supervision, trial of vaginal delivery in previous one caesarean section is safe and successful. Individual approach seems to be the best.
Targut (O)zi(s); Imail Asian
2009-01-01
With the aid of symbolic computation system Mathematica, several explicit solutions for Fisher's equation and CKdV equation are constructed by utilizing an auxiliary equation method, the so called G'/G-expansion method, where the new and more general forms of solutions are also constructed. When the parameters are taken as special values, the previously known solutions are recovered.
Riccati equation-based generalization of Dawson's integral function
Messina, R; Messina, A; Napoli, A
2007-01-01
A new generalization of Dawson's integral function based on the link between a Riccati nonlinear differential equation and a second-order ordinary differential equation is reported. The MacLaurin expansion of this generalized function is built up and to this end an explicit formula for a generic cofactor of a triangular matrix is deduced.
Undergraduate Students' Mental Operations in Systems of Differential Equations
Whitehead, Karen; Rasmussen, Chris
2003-01-01
This paper reports on research conducted to understand undergraduate students' ways of reasoning about systems of differential equations (SDEs). As part of a semester long classroom teaching experiment in a first course in differential equations, we conducted task-based interviews with six students after their study of first order differential…
Itoh, Yousuke
2009-01-01
We report our rederivation of the equations of motion for relativistic compact binaries through the third-and-a-half post-Newtonian (3.5 PN) order approximation to general relativity using the strong field point particle limit to describe self-gravitating stars instead of the Dirac delta functional. The computation is done in harmonic coordinates. Our equations of motion describe the orbital motion of the binary consisting of spherically symmetric non-rotating stars. The resulting equations of motion fully agree with the 3.5 PN equations of motion derived in the previous works. We also show that the locally defined energy of the star has a simple relation with its mass up to the 3.5 PN order.
Primary Malignant Tumours of Bone Following Previous Malignancy
Patton, J. T.; Sommerville, S. M. M.; Grimer, R. J.
2008-01-01
Destructive bone lesions occurring in patients who have previously had a malignancy are generally assumed to be a metastasis from that malignancy. We reviewed 60 patients with a previous history of malignancy, who presented with a solitary bone lesion that was subsequently found to be a new and different primary sarcoma of bone. These second malignancies occurred in three distinct groups of patients: (1) patients with original tumours well known to be associated with second malignancies (5%); (2) patients whose second malignancies were likely to be due to the previous treatment of their primary malignancy (40%); (3) patients in whom there was no clearly defined association between malignancies (55%). The purpose of this study is to emphasise the necessity for caution in assuming the diagnosis of a metastasis when a solitary bone lesion is identified following a prior malignancy. Inappropriate biopsy and treatment of primary bone sarcomas compromises limb salvage surgery and can affect patient mortality. PMID:18414590
Primary Malignant Tumours of Bone Following Previous Malignancy
R. J. Grimer
2008-04-01
Full Text Available Destructive bone lesions occurring in patients who have previously had a malignancy are generally assumed to be a metastasis from that malignancy. We reviewed 60 patients with a previous history of malignancy, who presented with a solitary bone lesion that was subsequently found to be a new and different primary sarcoma of bone. These second malignancies occurred in three distinct groups of patients: (1 patients with original tumours well known to be associated with second malignancies (5%; (2 patients whose second malignancies were likely to be due to the previous treatment of their primary malignancy (40%; (3 patients in whom there was no clearly defined association between malignancies (55%. The purpose of this study is to emphasise the necessity for caution in assuming the diagnosis of a metastasis when a solitary bone lesion is identified following a prior malignancy. Inappropriate biopsy and treatment of primary bone sarcomas compromises limb salvage surgery and can affect patient mortality.
Erlotinib-induced rash spares previously irradiated skin
Lips, Irene M.; Vonk, Ernest J.A. [Radiotherapeutisch Instituut Stedendriehoek en Omstreken (RISO), Deventer (Netherlands). Dept. of Radiation Oncology; Koster, Mariska E.Y. [Deventer Hospital (Netherlands). Dept. of Lung Diseases; Houwing, Ronald H. [Deventer Hospital (Netherlands). Dept. of Dermatology
2011-08-15
Erlotinib is an epidermal growth factor receptor inhibitor prescribed to patients with locally advanced or metastasized non-small cell lung carcinoma after failure of at least one earlier chemotherapy treatment. Approximately 75% of the patients treated with erlotinib develop acneiform skin rashes. A patient treated with erlotinib 3 months after finishing concomitant treatment with chemotherapy and radiotherapy for non-small cell lung cancer is presented. Unexpectedly, the part of the skin that had been included in his previously radiotherapy field was completely spared from the erlotinib-induced acneiform skin rash. The exact mechanism of erlotinib-induced rash sparing in previously irradiated skin is unclear. The underlying mechanism of this phenomenon needs to be explored further, because the number of patients being treated with a combination of both therapeutic modalities is increasing. The therapeutic effect of erlotinib in the area of the previously irradiated lesion should be assessed. (orig.)
The Riccati Differential Equation and a Diffusion-Type Equation
Suazo, Erwin; Vega-Guzman, Jose M
2008-01-01
We construct an explicit solution of the Cauchy initial value problem for certain diffusion-type equation with variable coefficients on the entire real line. The corresponding Green function (heat kernel) is given in terms of elementary functions and certain integrals involving a characteristic function, which should be found as an analytic or numerical solution of the second order linear differential equation with time-dependent coefficients. Some special and limiting cases are outlined. Solution of the corresponding nonhomogeneous equation is also found.
Akin Aydogan
2012-01-01
Full Text Available Introduction. Gossypiboma (GP is a term used to express the mass resulting from forgotten cotton sponge in operations. Rarely, a transmural migration may occur into the gastrointestinal lumen without creating any defect by GP. Laparotomy or endoscopic removal may be required, by the way it can be taken out of the body itself by intestinal ways. In this study, we reported a case of mechanical intestinal obstruction causing GP. Case. The fifty-one-year-old female patient admitted to the emergency department with the complaints of mechanical intestinal obstruction and had a history of open cholecystectomy 20 years ago. There were the findings of intestinal obstruction in abdominal plain radiography and computerized tomography. The sponge that obstructed the lumen completely 40 cm proximal to the ileocecal valve was identified in the laparotomy with the diagnosis of brid ileus. The small intestine was closed over double-fold after removal of sponge. Transmural migration of abdominal-remained sponge was thought to be occurred without creating a defect after cholecystectomy. Postoperatively, the patient was discharged without having any problems at 4th day of hospitalization. Conclusion. Although it is a rare situation in routine clinical practice, GP should be considered as a differential diagnosis in the patients who had a diagnosis of mechanical intestinal obstruction, and laparotomy was applied before. As GP may lead to situations which cause mortality, all precautions should be taken to prevent it.
Gravitating vortices and the Einstein--Bogomol'nyi equations
Álvarez-Cónsul, Luis; García-Prada, Oscar
2016-01-01
In this paper we consider the gravitating vortex equations. These are equations coupling a metric over a compact Riemann surface with a hermitian metric over a holomorphic line bundle equipped with a fixed global section -- the Higgs field. These equations appear as dimensional reduction of the Kahler-Yang-Mills equations on a rank two vector bundle over the product of the complex projective line with the Riemann surface, and have a symplectic interpretation as moment map equations. As a particular case of the gravitating vortex equations on the complex projective line we find the Einstein-Bogomol'nyi equations, previously studied in the theory of cosmic strings in physics. Our main result in this paper is giving a converse to an existence theorem of Yisong Yang for the Einstein-Bogomol'nyi equations, establishing in this way a correspondence with Geometric Invariant Theory for these equations. In particular, we prove a conjecture by Yang about the non-existence of cosmic strings on the complex projective lin...
Comparison between characteristics of mild slope equations and Boussinesq equations
无
2005-01-01
Boussinesq-type equations and mild-slope equations are compared in terms of their basic forms and characteristics. It is concluded that linear mild-slope equations on dispersion relation are better than non-linear Boussinesq equations. In addition, Berkhoff experiments are computed and compared by the two models, and agreement between model results and available experimental data is found to be quite reasonable, which demonstrates the two models' capacity to simulate wave transformation. However they can deal with different physical processes respectively, and they have their own characteristics.
A unified transport equation for both cosmic rays and thermal particles
Williams, L. L.; Schwadron, N.; Jokipii, J. R.; Gombosi, T. I.
1993-01-01
We present a unified transport equation that is valid for particles of all energies if the particle mean free paths are much smaller than macroscopic fluid length scales. If restricted to particles with random speeds much greater than fluid flow speeds, this equation reduces to the previously discussed extended cosmic-ray transport equation. It is significant that this allows one to describe the acceleration of particles from thermal energies to cosmic-ray energies using one transport equation. This is in contrast to previous transport equations (the Parker equation and the extended cosmic-ray transport equation), which were restricted to fast particles. The close connection to the extended cosmic-ray transport equation is demonstrated.
Mode decomposition evolution equations.
Wang, Yang; Wei, Guo-Wei; Yang, Siyang
2012-03-01
Partial differential equation (PDE) based methods have become some of the most powerful tools for exploring the fundamental problems in signal processing, image processing, computer vision, machine vision and artificial intelligence in the past two decades. The advantages of PDE based approaches are that they can be made fully automatic, robust for the analysis of images, videos and high dimensional data. A fundamental question is whether one can use PDEs to perform all the basic tasks in the image processing. If one can devise PDEs to perform full-scale mode decomposition for signals and images, the modes thus generated would be very useful for secondary processing to meet the needs in various types of signal and image processing. Despite of great progress in PDE based image analysis in the past two decades, the basic roles of PDEs in image/signal analysis are only limited to PDE based low-pass filters, and their applications to noise removal, edge detection, segmentation, etc. At present, it is not clear how to construct PDE based methods for full-scale mode decomposition. The above-mentioned limitation of most current PDE based image/signal processing methods is addressed in the proposed work, in which we introduce a family of mode decomposition evolution equations (MoDEEs) for a vast variety of applications. The MoDEEs are constructed as an extension of a PDE based high-pass filter (Europhys. Lett., 59(6): 814, 2002) by using arbitrarily high order PDE based low-pass filters introduced by Wei (IEEE Signal Process. Lett., 6(7): 165, 1999). The use of arbitrarily high order PDEs is essential to the frequency localization in the mode decomposition. Similar to the wavelet transform, the present MoDEEs have a controllable time-frequency localization and allow a perfect reconstruction of the original function. Therefore, the MoDEE operation is also called a PDE transform. However, modes generated from the present approach are in the spatial or time domain and can be
Hybrid solution of the averaged Navier-Stokes equations for turbulent flow
Lima, J. A.; Perez-Guerrero, J. S.; Cotta, R. M.
The Generalized Integral Transform Technique (GITT) is utilized in the hybrid numerical-analytical solution of the Reynolds averaged Navier-Stokes equations, for developing turbulent flow inside a parallel-plates channel. An algebraic turbulence model is employed in modelling the turbulent diffusivity. The automatic global error control feature inherent to this approach, permits the determination of fully converged reference results for the validation of purely numerical methods. Therefore, numerical results for different values of Reynolds number are obtained, both for illustrating the convergence characteristics of the integral transform approach, and for critical comparisons with previously reported results through different models and numerical schemes.
The scattering transform for the Benjamin-Ono equation in the small-dispersion limit
Miller, Peter D.; Wetzel, Alfredo N.
2016-10-01
Using exact formulae for the scattering data of the Benjamin-Ono equation valid for general rational potentials recently obtained in Miller and Wetzel [17], we rigorously analyze the scattering data in the small-dispersion limit. In particular, we deduce precise asymptotic formulae for the reflection coefficient, the location of the eigenvalues and their density, and the asymptotic dependence of the phase constant (associated with each eigenvalue) on the eigenvalue itself. Our results give direct confirmation of conjectures in the literature that have been partly justified by means of inverse scattering, and they also provide new details not previously reported in the literature.
Exact periodic waves and their interactions for the (2+1)-dimensional KdV equation
Yan-Ze Peng
2005-08-01
By means of the singular manifold method we obtain a general solution involving three arbitrary functions for the (2+1)-dimensional KdV equation. Diverse periodic wave solutions may be produced by appropriately selecting these arbitrary functions as the Jacobi elliptic functions. The interaction properties of the periodic waves are investigated numerically and found to be nonelastic. The long wave limit yields some new types of solitary wave solutions. Especially the dromion and the solitoff solutions obtained in this paper possess new types of solution structures which are quite different from the basic dromion and solitoff ones reported previously in the literature.
Algebraic Approaches to Partial Differential Equations
Xu, Xiaoping
2012-01-01
Partial differential equations are fundamental tools in mathematics,sciences and engineering. This book is mainly an exposition of the various algebraic techniques of solving partial differential equations for exact solutions developed by the author in recent years, with emphasis on physical equations such as: the Calogero-Sutherland model of quantum many-body system in one-dimension, the Maxwell equations, the free Dirac equations, the generalized acoustic system, the Kortweg and de Vries (KdV) equation, the Kadomtsev and Petviashvili (KP) equation, the equation of transonic gas flows, the short-wave equation, the Khokhlov and Zabolotskaya equation in nonlinear acoustics, the equation of geopotential forecast, the nonlinear Schrodinger equation and coupled nonlinear Schrodinger equations in optics, the Davey and Stewartson equations of three-dimensional packets of surface waves, the equation of the dynamic convection in a sea, the Boussinesq equations in geophysics, the incompressible Navier-Stokes equations...
Recovery of Previously Uncultured Bacterial Genera from Three Mediterranean Sponges
Versluis, Dennis; McPherson, Kyle; Passel, van Mark W.J.; Smidt, Hauke; Sipkema, Detmer
2017-01-01
Sponges often harbour a dense and diverse microbial community. Presently, a large discrepancy exists between the cultivable bacterial fraction from sponges and the community in its natural environment. Here, we aimed to acquire additional insights into cultivability of (previously uncultured)
49 CFR 173.23 - Previously authorized packaging.
2010-10-01
... permit. Editorial Note: For Federal Register citations affecting § 173.23, see the List of CFR Sections... 49 Transportation 2 2010-10-01 2010-10-01 false Previously authorized packaging. 173.23 Section... REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Preparation of Hazardous Materials for Transportation §...
Time to pregnancy after a previous miscarriage in subfertile couples
T. Cox; J.W. van der Steeg; P. Steures; P.G.A. Hompes; F. van der Veen; M.J.C. Eijkemans; J.H. Schagen van Leeuwen; C. Renckens; P.M.M. Bossuyt; B.W.J. Mol
2010-01-01
Objective: To assess the time to spontaneous ongoing pregnancy after a previous miscarriage in subfertile couples. Design: A prospective cohort study. Setting: The study was conducted in 38 fertility centers in the Netherlands. Patient(s): Subfertile couples who miscarried after completing their bas
Abiraterone in metastatic prostate cancer without previous chemotherapy
Ryan, C.J.; Smith, M.R.; Bono, J. De; Molina, A.; Logothetis, C.J.; Souza, P. de; Fizazi, K.; Mainwaring, P.; Piulats, J.M.; Ng, S.; Carles, J.; Mulders, P.F.A.; Basch, E.; Small, E.J.; Saad, F.; Schrijvers, D.; Poppel, H. van; Mukherjee, S.D.; Suttmann, H.; Gerritsen, W.R.; Flaig, T.W.; George, D.J.; Yu, E.Y.; Efstathiou, E.; Pantuck, A.; Winquist, E.; Higano, C.S.; Taplin, M.E.; Park, Y.; Kheoh, T.; Griffin, T.; Scher, H.I.; Rathkopf, D.E.
2013-01-01
BACKGROUND: Abiraterone acetate, an androgen biosynthesis inhibitor, improves overall survival in patients with metastatic castration-resistant prostate cancer after chemotherapy. We evaluated this agent in patients who had not received previous chemotherapy. METHODS: In this double-blind study, we
2 CFR 230.45 - Relationship to previous issuance.
2010-01-01
... PRINCIPLES FOR NON-PROFIT ORGANIZATIONS (OMB CIRCULAR A-122) § 230.45 Relationship to previous issuance. (a... contains the information that was in Attachment C (non-profit organizations not subject to the Circular) to... agencies for non-profit organizations....
Study of cystic artery by arteriography. Importance of previous cholecystography
Machado, G.O.
An oral cholecystography previously to celiac and mesenteric arteriography is performed, in order to identify the cystic artery, in 42 patients with pancreatitis, according Seldinger technique. The cystic artery was identified in all the cases, the pattern being the outlet of the cystic artery from the right hepatic artery. Infusion pump and seriography were not used.
Birth after previous cesarean delivery: short-term maternal outcomes.
Lydon-Rochelle, Mona T; Cahill, Alison G; Spong, Catherine Y
2010-08-01
An estimated 40% of the 1.3 million cesarean deliveries performed each year in the United States are repeat procedures. The appropriate clinical management approach for women with previous cesarean delivery remains challenging because options are limited. The risks and benefits of clinical management choices in the woman's health need to be quantified. Thus, we discuss the available published scientific data on (1) the short-term maternal outcomes of trial of labor after cesarean and elective repeat cesarean delivery, (2) the differences between outcomes for both, (3) the important factors that influence these outcomes, and (4) successful vs. unsuccessful vaginal birth after cesarean. For women with a previous cesarean delivery, a successful trial of labor offers several distinct, consistently reproducible advantages compared with elective repeat cesarean delivery, including fewer hysterectomies, fewer thromboembolic events, lower blood transfusion rates, and shorter hospital stay. However, when trial of labor after cesarean fails, emergency cesarean is associated with increased uterine rupture, hysterectomy, operative injury, blood transfusion, endometritis, and longer hospital stay. Care of women with a history of previous cesarean delivery involves a confluence of interactions between medical and nonmedical factors; however, the most important determinants of the short-term outcomes among these women are likely individualized counseling, accurate clinical diagnoses, and careful management during a trial of labor. We recommend a randomized controlled trial among women undergoing a TOLAC and a longitudinal cohort study among women with previous cesarean to evaluate adverse outcomes, with focused attention on both mother and the infant.
An approach to rogue waves through the cnoidal equation
Lechuga, Antonio
2014-05-01
Lately it has been realized the importance of rogue waves in some events happening in open seas. Extreme waves and extreme weather could explain some accidents, but not all of them. Every now and then inflicted damages on ships only can be reported to be caused by anomalous and elusive waves, such as rogue waves. That's one of the reason why they continue attracting considerable interest among researchers. In the frame of the Nonlinear Schrödinger equation(NLS), Witham(1974) and Dingemans and Otta (2001)gave asymptotic solutions in moving coordinates that transformed the NLS equation in a ordinary differential equation that is the Duffing or cnoidal wave equation. Applying the Zakharov equation, Stiassnie and Shemer(2004) and Shemer(2010)got also a similar equation. It's well known that this ordinary equation can be solved in elliptic functions. The main aim of this presentation is to sort out the domains of the solutions of this equation, that, of course, are linked to the corresponding solutions of the partial differential equations(PDEs). That being, Lechuga(2007),a simple way to look for anomalous waves as it's the case with some "chaotic" solutions of the Duffing equation.
Modified extended tanh-function method for solving nonlinear partial differential equations
El-Wakil, S.A. [Department of Physics, Faculty of Science, Theoretical Research Group, Mansoura University, 35516 Mansoura (Egypt); Abdou, M.A. [Department of Physics, Faculty of Science, Theoretical Research Group, Mansoura University, 35516 Mansoura (Egypt)]. E-mail: m_abdou_eg@yahoo.com
2007-03-15
Based on computerized symbolic computation, modified extended tanh-method for constructing multiple travelling wave solutions of nonlinear evolution equations is presented and implemented in a computer algebraic system. Applying this method, with the aid of Maple, we consider some nonlinear evolution equations in mathematical physics such as the nonlinear partial differential equation, nonlinear Fisher-type equation, ZK-BBM equation, generalized Burgers-Fisher equation and Drinfeld-Sokolov system. As a result, we can successfully recover the previously known solitary wave solutions that had been found by the extended tanh-function method and other more sophisticated methods.
Introduction to partial differential equations
Borthwick, David
2016-01-01
This modern take on partial differential equations does not require knowledge beyond vector calculus and linear algebra. The author focuses on the most important classical partial differential equations, including conservation equations and their characteristics, the wave equation, the heat equation, function spaces, and Fourier series, drawing on tools from analysis only as they arise.Within each section the author creates a narrative that answers the five questions: (1) What is the scientific problem we are trying to understand? (2) How do we model that with PDE? (3) What techniques can we use to analyze the PDE? (4) How do those techniques apply to this equation? (5) What information or insight did we obtain by developing and analyzing the PDE? The text stresses the interplay between modeling and mathematical analysis, providing a thorough source of problems and an inspiration for the development of methods.
Differential equations methods and applications
Said-Houari, Belkacem
2015-01-01
This book presents a variety of techniques for solving ordinary differential equations analytically and features a wealth of examples. Focusing on the modeling of real-world phenomena, it begins with a basic introduction to differential equations, followed by linear and nonlinear first order equations and a detailed treatment of the second order linear equations. After presenting solution methods for the Laplace transform and power series, it lastly presents systems of equations and offers an introduction to the stability theory. To help readers practice the theory covered, two types of exercises are provided: those that illustrate the general theory, and others designed to expand on the text material. Detailed solutions to all the exercises are included. The book is excellently suited for use as a textbook for an undergraduate class (of all disciplines) in ordinary differential equations. .
Energy Conservation Equations of Motion
Vinokurov, Nikolay A
2015-01-01
A conventional derivation of motion equations in mechanics and field equations in field theory is based on the principle of least action with a proper Lagrangian. With a time-independent Lagrangian, a function of coordinates and velocities that is called energy is constant. This paper presents an alternative approach, namely derivation of a general form of equations of motion that keep the system energy, expressed as a function of generalized coordinates and corresponding velocities, constant. These are Lagrange equations with addition of gyroscopic forces. The important fact, that the energy is defined as the function on the tangent bundle of configuration manifold, is used explicitly for the derivation. The Lagrangian is derived from a known energy function. A development of generalized Hamilton and Lagrange equations without the use of variational principles is proposed. The use of new technique is applied to derivation of some equations.
In vitro culture of previously uncultured oral bacterial phylotypes.
Thompson, Hayley; Rybalka, Alexandra; Moazzez, Rebecca; Dewhirst, Floyd E; Wade, William G
2015-12-01
Around a third of oral bacteria cannot be grown using conventional bacteriological culture media. Community profiling targeting 16S rRNA and shotgun metagenomics methods have proved valuable in revealing the complexity of the oral bacterial community. Studies investigating the role of oral bacteria in health and disease require phenotypic characterizations that are possible only with live cultures. The aim of this study was to develop novel culture media and use an in vitro biofilm model to culture previously uncultured oral bacteria. Subgingival plaque samples collected from subjects with periodontitis were cultured on complex mucin-containing agar plates supplemented with proteose peptone (PPA), beef extract (BEA), or Gelysate (GA) as well as on fastidious anaerobe agar plus 5% horse blood (FAA). In vitro biofilms inoculated with the subgingival plaque samples and proteose peptone broth (PPB) as the growth medium were established using the Calgary biofilm device. Specific PCR primers were designed and validated for the previously uncultivated oral taxa Bacteroidetes bacteria HOT 365 and HOT 281, Lachnospiraceae bacteria HOT 100 and HOT 500, and Clostridiales bacterium HOT 093. All agar media were able to support the growth of 10 reference strains of oral bacteria. One previously uncultivated phylotype, Actinomyces sp. HOT 525, was cultivated on FAA. Of 93 previously uncultivated phylotypes found in the inocula, 26 were detected in in vitro-cultivated biofilms. Lachnospiraceae bacterium HOT 500 was successfully cultured from biofilm material harvested from PPA plates in coculture with Parvimonas micra or Veillonella dispar/parvula after colony hybridization-directed enrichment. The establishment of in vitro biofilms from oral inocula enables the cultivation of previously uncultured oral bacteria and provides source material for isolation in coculture.
Improved Fokker-Planck Equation for Resonance Line Scattering
Rybicki, G B
2006-01-01
A new Fokker-Planck equation is developed for treating resonance line scattering, especially relevant to the treatment of Lyman alpha in the early universe. It is a "corrected" form of the equation of Rybicki & Dell'Antonio that now obeys detailed balance, so that the approach to thermal equilibrium is properly described. The new equation takes into account the energy changes due to scattering off moving particles, the recoil term of Basko, and stimulated scattering. One result is a surprising unification of the equation for resonance line scattering and the Kompaneets equation. An improved energy exchange formula due to resonance line scattering is derived. This formula is compared to previous formulas of Madau, Meikson, & Rees (1997) and Chen & Miralda-Escud\\'e (2004).
Nonlinear Kramers equation associated with nonextensive statistical mechanics.
Mendes, G A; Ribeiro, M S; Mendes, R S; Lenzi, E K; Nobre, F D
2015-05-01
Stationary and time-dependent solutions of a nonlinear Kramers equation, as well as its associated nonlinear Fokker-Planck equations, are investigated within the context of Tsallis nonextensive statistical mechanics. Since no general analytical time-dependent solutions are found for such a nonlinear Kramers equation, an ansatz is considered and the corresponding asymptotic behavior is studied and compared with those known for the standard linear Kramers equation. The H-theorem is analyzed for this equation and its connection with Tsallis entropy is investigated. An application is discussed, namely the motion of Hydra cells in two-dimensional cellular aggregates, for which previous measurements have verified q-Gaussian distributions for velocity components and superdiffusion. The present analysis is in quantitative agreement with these experimental results.
Differential equations and integrable models the $SU(3)$ case
Dorey, P; Dorey, Patrick; Tateo, Roberto
2000-01-01
We exhibit a relationship between the massless $a_2^{(2)}$ integrable quantum field theory and a certain third-order ordinary differential equation, thereby extending a recent result connecting the massless sine-Gordon model to the Schrödinger equation. This forms part of a more general correspondence involving $A_2$-related Bethe ansatz systems and third-order differential equations. A non-linear integral equation for the generalised spectral problem is derived, and some numerical checks are performed. Duality properties are discussed, and a simple variant of the nonlinear equation is suggested as a candidate to describe the finite volume ground state energies of minimal conformal field theories perturbed by the operators $\\phi_{12}$, $\\phi_{21}$ and $\\phi_{15}$. This is checked against previous results obtained using the thermodynamic Bethe ansatz.
Integrable version of Burgers equation in magnetohydrodynamics.
Olesen, P
2003-07-01
It is pointed out that for the case of (compressible) magnetohydrodynamics (MHD) with the fields v(y)(y,t) and Bx(y,t), one can have equations of the Burgers type which are integrable. We discuss the solutions. It turns out that the propagation of the nonlinear effects is governed by the initial velocity (as in Burgers case) as well as by the initial Alfvén velocity. Many results previously obtained for the Burgers equation can be transferred to the MHD case. We also discuss equipartition v(y)=+/-Bx. It is shown that an initial localized small scale magnetic field will end up in fields moving to the left and the right, thus transporting energy from smaller to larger distances.
Stochastic partial differential equations
Lototsky, Sergey V
2017-01-01
Taking readers with a basic knowledge of probability and real analysis to the frontiers of a very active research discipline, this textbook provides all the necessary background from functional analysis and the theory of PDEs. It covers the main types of equations (elliptic, hyperbolic and parabolic) and discusses different types of random forcing. The objective is to give the reader the necessary tools to understand the proofs of existing theorems about SPDEs (from other sources) and perhaps even to formulate and prove a few new ones. Most of the material could be covered in about 40 hours of lectures, as long as not too much time is spent on the general discussion of stochastic analysis in infinite dimensions. As the subject of SPDEs is currently making the transition from the research level to that of a graduate or even undergraduate course, the book attempts to present enough exercise material to fill potential exams and homework assignments. Exercises appear throughout and are usually directly connected ...
Menikoff, Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2015-12-15
The JWL equation of state (EOS) is frequently used for the products (and sometimes reactants) of a high explosive (HE). Here we review and systematically derive important properties. The JWL EOS is of the Mie-Grueneisen form with a constant Grueneisen coefficient and a constants specific heat. It is thermodynamically consistent to specify the temperature at a reference state. However, increasing the reference state temperature restricts the EOS domain in the (V, e)-plane of phase space. The restrictions are due to the conditions that P ≥ 0, T ≥ 0, and the isothermal bulk modulus is positive. Typically, this limits the low temperature regime in expansion. The domain restrictions can result in the P-T equilibrium EOS of a partly burned HE failing to have a solution in some cases. For application to HE, the heat of detonation is discussed. Example JWL parameters for an HE, both products and reactions, are used to illustrate the restrictions on the domain of the EOS.
Lectures on the practical solution of differential equations
Dresner, L.
1979-11-01
This report comprises lectures on the practical solution of ordinary and partial differential equations given in the In-Hours Continuing Education Program for Scientific and Technical Personnel at Oak Ridge National Laboratory.
Investigating Repeater Effects on Chained Equipercentile Equating with Common Anchor Items
Kim, Sooyeon; Walker, Michael E.
2012-01-01
This study investigated the impact of repeat takers of a licensure test on the equating functions in the context of a nonequivalent groups with anchor test (NEAT) design. Examinees who had taken a new, to-be-equated form of the test were divided into three subgroups according to their previous testing experience: (a) repeaters who previously took…
Confronting the bomber: coping at the site of previous terror attacks.
Strous, Rael D; Mishaeli, Nurit; Ranen, Yaniv; Benatov, Joy; Green, Dovid; Zivotofsky, Ari Z
2007-03-01
Terror exposure has become commonplace in Israel, with civilians needing to develop appropriate coping mechanisms. This study investigated coping mechanisms of those who are able to return to leisure activity at sites of previous terror attacks. A specially designed questionnaire, exploring knowledge of the terror event, previous terror exposure, coping mechanisms, state of anxiety, and mood, was administered to 93 restaurant attendees at sites of well-known recent terror attacks (2001-2005). Most respondents were aware of the previous terror attack (92.3%) and most reported no fear at revisiting (70.3%), with 20.9% reporting some anxiety and 5.5% reporting moderate or severe anxiety. Sixty percent reported that they have no fear that a terror attack will reoccur at the same place. Some (27.7%) reported change in practices or decrease in one or more activity, especially use of public transport (18%). The most helpful reported resource for facilitating stress coping following a suicide bombing was to "call or be in touch with friends or relatives," and least helpful was "medicines." Over half of respondents (53%) reported that the current security climate affected their mood. Older individuals and females were more affected by terror events. Study observations confirm that resilience develops in the general population in response to ongoing terror attacks. Response to terror is heterogeneous with a range of coping mechanisms expressed.
The Nonclassical Diffusion Approximation to the Nonclassical Linear Boltzmann Equation
Vasques, Richard
2015-01-01
We show that, by correctly selecting the probability distribution function $p(s)$ for a particle's distance-to-collision, the nonclassical diffusion equation can be represented exactly by the nonclassical linear Boltzmann equation for an infinite homogeneous medium. This choice of $p(s)$ preserves the $true$ mean-squared free path of the system, which sheds new light on the results obtained in previous work.
Simplified P$_N$ Equations for Nonclassical Transport with Isotropic Scattering
Vasques, R
2016-01-01
A nonclassical diffusion approximation has been previously derived for the the one-speed nonclassical transport equation with isotropic scattering. In this paper we use an asymptotic analysis to derive more accurate diffusion approximations to the nonclassical transport equation. If the free-path distribution is given by an exponential (classical transport), these approximations reduce to the simplified P$_N$ (SP$_N$) equations; therefore, they are labeled nonclassical SP$_N$ equations.
Veysel Hatipoglu
2015-09-01
Full Text Available In this study, we present a practical matrix method to find an approximate solution of higher order linear difference equation with constant coefficients under the initial-boundary conditions in terms of Taylor polynomials. To obtain this goal, we first present time scale extension of previous polynomial approach, then restrict the formula to the Integers with h step. This method converts the difference equation to a matrix equation, which may be considered as a system of linear algebraic equations.
谢自立; 敦坤敏; 吴菊芳; 袁存禾
2003-01-01
The XG equation, which is developed by us previously for describing the adsorption equilibrium of pure vapor on activated carbon, is extended to multi-component system. Verified by experimental data, the extended XG equation was found to be more successful in predicting the adsorption equilibrium of vapor mixture on activated carbon than the extended Langmuir equation, the extended BET equation and the ideal adsorbed solution theory (IAST).
The generalized Airy diffusion equation
Frank M. Cholewinski
2003-08-01
Full Text Available Solutions of a generalized Airy diffusion equation and an associated nonlinear partial differential equation are obtained. Trigonometric type functions are derived for a third order generalized radial Euler type operator. An associated complex variable theory and generalized Cauchy-Euler equations are obtained. Further, it is shown that the Airy expansions can be mapped onto the Bessel Calculus of Bochner, Cholewinski and Haimo.
Hyperbolic Methods for Einstein's Equations
Reula Oscar
1998-01-01
Full Text Available I review evolutionary aspects of general relativity, in particular those related to the hyperbolic character of the field equations and to the applications or consequences that this property entails. I look at several approaches to obtaining symmetric hyperbolic systems of equations out of Einstein's equations by either removing some gauge freedoms from them, or by considering certain linear combinations of a subset of them.
Partial Differential Equations of Physics
Geroch, Robert
1996-01-01
Apparently, all partial differential equations that describe physical phenomena in space-time can be cast into a universal quasilinear, first-order form. In this paper, we do two things. First, we describe some broad features of systems of differential equations so formulated. Examples of such features include hyperbolicity of the equations, constraints and their roles (e.g., in connection with the initial-value formulation), how diffeomorphism freedom is manifest, and how interactions betwee...
Integrable Equations on Time Scales
Gurses, Metin; Guseinov, Gusein Sh.; Silindir, Burcu
2005-01-01
Integrable systems are usually given in terms of functions of continuous variables (on ${\\mathbb R}$), functions of discrete variables (on ${\\mathbb Z}$) and recently in terms of functions of $q$-variables (on ${\\mathbb K}_{q}$). We formulate the Gel'fand-Dikii (GD) formalism on time scales by using the delta differentiation operator and find more general integrable nonlinear evolutionary equations. In particular they yield integrable equations over integers (difference equations) and over $q...
PREFACE: Symmetries and Integrability of Difference Equations
Doliwa, Adam; Korhonen, Risto; Lafortune, Stéphane
2007-10-01
The notion of integrability was first introduced in the 19th century in the context of classical mechanics with the definition of Liouville integrability for Hamiltonian flows. Since then, several notions of integrability have been introduced for partial and ordinary differential equations. Closely related to integrability theory is the symmetry analysis of nonlinear evolution equations. Symmetry analysis takes advantage of the Lie group structure of a given equation to study its properties. Together, integrability theory and symmetry analysis provide the main method by which nonlinear evolution equations can be solved explicitly. Difference equations (DE), like differential equations, are important in numerous fields of science and have a wide variety of applications in such areas as mathematical physics, computer visualization, numerical analysis, mathematical biology, economics, combinatorics, and quantum field theory. It is thus crucial to develop tools to study and solve DEs. While the theory of symmetry and integrability for differential equations is now largely well-established, this is not yet the case for discrete equations. Although over recent years there has been significant progress in the development of a complete analytic theory of difference equations, further tools are still needed to fully understand, for instance, the symmetries, asymptotics and the singularity structure of difference equations. The series of SIDE meetings on Symmetries and Integrability of Difference Equations started in 1994. Its goal is to provide a platform for an international and interdisciplinary communication for researchers working in areas associated with integrable discrete systems, such as classical and quantum physics, computer science and numerical analysis, mathematical biology and economics, discrete geometry and combinatorics, theory of special functions, etc. The previous SIDE meetings took place in Estérel near Montréal, Canada (1994), at the University of
Delay equations and radiation damping
Chicone, C.; Kopeikin, S. M.; Mashhoon, B.; Retzloff, D. G.
2001-06-01
Starting from delay equations that model field retardation effects, we study the origin of runaway modes that appear in the solutions of the classical equations of motion involving the radiation reaction force. When retardation effects are small, we argue that the physically significant solutions belong to the so-called slow manifold of the system and we identify this invariant manifold with the attractor in the state space of the delay equation. We demonstrate via an example that when retardation effects are no longer small, the motion could exhibit bifurcation phenomena that are not contained in the local equations of motion.
Correct Linearization of Einstein's Equations
Rabounski D.
2006-06-01
Full Text Available Regularly Einstein's equations can be reduced to a wave form (linearly dependent from the second derivatives of the space metric in the absence of gravitation, the space rotation and Christoffel's symbols. As shown here, the origin of the problem is that one uses the general covariant theory of measurement. Here the wave form of Einstein's equations is obtained in the terms of Zelmanov's chronometric invariants (physically observable projections on the observer's time line and spatial section. The obtained equations depend on solely the second derivatives even if gravitation, the space rotation and Christoffel's symbols. The correct linearization proves: the Einstein equations are completely compatible with weak waves of the metric.
General-dyne unravelling of a thermal master equation
Genoni, M. G.; Mancini, S.; Serafini, A.
2014-07-01
We analyze the unravelling of the quantum optical master equation at finite temperature due to direct, continuous, general-dyne detection of the environment. We first express the general-dyne Positive Operator Valued Measure (POVM) in terms of the eigenstates of a non-Hermitian operator associated to the general-dyne measurement. Then we derive the stochastic master equation obtained by considering the interaction between the system and a reservoir at thermal equilibrium, which is measured according to the POVM previously determined. Finally, we present a feasible measurement scheme, which reproduces general-dyne detection for any value of the parameter characterizing the stochastic master equation.
A neuro approach to solve fuzzy Riccati differential equations
Shahrir, Mohammad Shazri; Kumaresan, N.; Kamali, M. Z. M.; Ratnavelu, Kurunathan
2015-10-01
There are many applications of optimal control theory especially in the area of control systems in engineering. In this paper, fuzzy quadratic Riccati differential equation is estimated using neural networks (NN). Previous works have shown reliable results using Runge-Kutta 4th order (RK4). The solution can be achieved by solving the 1st Order Non-linear Differential Equation (ODE) that is found commonly in Riccati differential equation. Research has shown improved results relatively to the RK4 method. It can be said that NN approach shows promising results with the advantage of continuous estimation and improved accuracy that can be produced over RK4.
Introduction to Structural Equation Modelling Using SPSS and Amos
Blunch, Niels J
2008-01-01
. Introduction to Structural Equation Modelling using SPSS and AMOS is a complete guide to carrying out your own structural equation modelling project. Assuming no previous experience of the subject, and a minimum of mathematical knowledge, this is the ideal guide for those new to structural equation modelling (SEM). Each chapter begins with learning objectives, and ends with a list of the new concepts introduced and questions to open up further discussion. Exercises for each chapter, incuding the necessary data, can be downloaded from the book's website. Helpful real life examples are include
Dynamic ADI methods for elliptic equations with gradient dependent coefficients
Doss, S.
1977-04-01
The dynamic alternating direction implicit (DADI) methods, previously introduced and applied to elliptic problems with linear and nonlinear coefficients (a(u)), are applied here to elliptic problems with nonlinear gradient-dependent coefficients (a(grad u)), such as the minimal surface equation, the capillary surface equation, and the magnetostatic equation. Certain improvements of these methods are developed, and they are extended to ''3-directional'' or ''3-dimensional'' situations. 28 figures, 6 tables.
A neuro approach to solve fuzzy Riccati differential equations
Shahrir, Mohammad Shazri, E-mail: mshazri@gmail.com [InstitutSainsMatematik, Universiti Malaya 50603 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur (Malaysia); Telekom Malaysia, R& D TM Innovation Centre, LingkaranTeknokrat Timur, 63000 Cyberjaya, Selangor (Malaysia); Kumaresan, N., E-mail: drnk2008@gmail.com; Kamali, M. Z. M.; Ratnavelu, Kurunathan [InstitutSainsMatematik, Universiti Malaya 50603 Kuala Lumpur, Wilayah Persekutuan Kuala Lumpur (Malaysia)
2015-10-22
There are many applications of optimal control theory especially in the area of control systems in engineering. In this paper, fuzzy quadratic Riccati differential equation is estimated using neural networks (NN). Previous works have shown reliable results using Runge-Kutta 4th order (RK4). The solution can be achieved by solving the 1st Order Non-linear Differential Equation (ODE) that is found commonly in Riccati differential equation. Research has shown improved results relatively to the RK4 method. It can be said that NN approach shows promising results with the advantage of continuous estimation and improved accuracy that can be produced over RK4.
Yang, Ren-Qiang; Jabbari, Javad; Cheng, Xiao-Shu
2014-01-01
BACKGROUND: Marfan syndrome (MFS) is a rare autosomal dominantly inherited connective tissue disorder with an estimated prevalence of 1:5,000. More than 1000 variants have been previously reported to be associated with MFS. However, the disease-causing effect of these variants may be questionable...... with regard to disease stratification based on these previously reported MFS-associated variants....
Functional Difference Equations and an Epidemic Model.
1980-06-09
ADDRESS 12. REPORT DATE AIR FORCE OFFICE OF SCIENTIFIC RESEARC 913 June 9, 1980 BOLLING AIR FORCE BASE , WASHINGTON, D.tI,3. NUMBEROFAGS 14. MONITORING...allowed spatial effects in an S - I model to arrive at the equation t S(t,x) = S(t,x).J B(;x, )S(t+6,0) dAdO in some region f cR. If X is the ordered
Solutions of relativistic radial quasipotential equations
Minh, V.X.; Kadyshevskii, V.G.; Zhidkov, E.P.
1985-11-01
A systematic approach to the investigation of relativistic radial quasipotential equations is developed. The quasipotential equations can be interpreted either as linear equations in finite differences of fourth and second orders, respectively, or as differential equations of infinite order.
The generalized Kolmogorov-Petrovskii-Piskunov equation
Adomian, G.
1995-02-01
Nonlinear nonlocal equations of mathematical physics such as the K.P.P. equation, the generalized nonlinear Schrödinger equation, the Witham equation for water waves et al. are solved by decomposition.
Anomalous Fractional Diffusion Equation for Transport Phenomena
QiuhuaZENG; HouqiangLI; 等
1999-01-01
We derive the standard diffusion equation from the continuity equation and by discussing the defectiveness of earlier proposed equations,we get the generalized fractional diffusion equation for anomalous diffusion.
Derivation and internal validation of an equation for albumin-adjusted calcium
Zhang Jianguo
2008-11-01
Full Text Available Abstract Background Previously published equations to adjust calcium for albumin concentration may vary depending on factors such as the type of reagents used. Albumin-adjusted calcium equations derived from laboratories using the bromocresol purple (BCP albumin binding reagent have not been described. Methods The linear regression equation for the binding of calcium and BCP-albumin was derived in a cohort of 4613 outpatients, and the albumin-adjusted calcium equation was internally validated in a separate cohort of 1538 subjects. The performance of this equation was compared with a previously published equation (adjusted [Ca](mmol/L = total [Ca](mmol/L + 0.02 (40 - [albumin] (g/L in 343 subjects with albumin Results The local adjustment equation was expressed by the relationship; adjusted [Ca](mmol/L = total [Ca](mmol/L + 0.012 (39.9 - [albumin](g/L. The equation showed evidence of good internal validity (shrinkage value of adjusted r2 = -0.0059. Classification of calcium status differed between the two equations in 47 of 343 subjects with low serum albumin (weighted κ = 0.46; moderate agreement. Conclusion A locally derived and internally validated albumin-adjusted calcium equation differed from previously published equations and resulted in important differences in classification of calcium status in hypoalbuminemia patients. Individual laboratories should determine their own linear regression equation for calcium on albumin rather than relying on published formulas.
[Fatal amnioinfusion with previous choriocarcinoma in a parturient woman].
Hrgović, Z; Bukovic, D; Mrcela, M; Hrgović, I; Siebzehnrübl, E; Karelovic, D
2004-04-01
The case of 36-year-old tercipare is described who developed choriocharcinoma in a previous pregnancy. During the first term labour the patient developed cardiac arrest, so reanimation and sectio cesarea was performed. A male new-born was delivered in good condition, but even after intensive therapy and reanimation occurred death of parturient woman with picture of disseminate intravascular coagulopathia (DIK). On autopsy and on histology there was no sign of malignant disease, so it was not possible to connect previous choricarcinoma with amniotic fluid embolism. Maybe was place of choriocarcinoma "locus minoris resistentiae" which later resulted with failure in placentation what was hard to prove. On autopsy we found embolia of lung with a microthrombosis of terminal circulation with punctiformis bleeding in mucous, what stands for DIK.
Previous studies underestimate BMAA concentrations in cycad flour.
Cheng, Ran; Banack, Sandra Anne
2009-01-01
The traditional diet of the Chamorro people of Guam has high concentrations of the neurotoxin BMAA, beta-methyl-amino-L-alanine, in cycad tortillas and from animals that feed on cycad seeds. We measured BMAA concentration in washed cycad flour and compared different extraction methods used by previous researchers in order to determine how much BMAA may have been unaccounted for in prior research. Samples were analyzed with AQC precolumn derivatization using HPLC-FD detection and verified with UPLC-UV, UPLC-MS, and triple quadrupole LC/MS/MS. Although previous workers had studied only the free amino acid component of BMAA in washed cycad flour, we detected significant levels of protein-associated BMAA in washed cycad flour. These data support a link between ALS/PDC and exposure to BMAA.
Cutaneous responses to vaccinia in individuals with previous smallpox vaccination.
Simpson, Eric L; Hercher, Michelle; Hammarlund, Erika K; Lewis, Matthew W; Slifka, Mark K; Hanifin, Jon M
2007-09-01
The durability of immune responses to smallpox vaccine is a subject of considerable debate. We compared cutaneous vaccinia responses in patients vaccinated in the distant past with vaccine-naïve individuals using serial close-up photographs. The previously vaccinated group had a significantly reduced time course and milder cutaneous reactions. Vaccinated individuals appear to maintain clinically detectable immunity against vaccinia for at least 20 years after smallpox vaccination.
Robotic Assisted Laparoscopic Prostatectomy Performed after Previous Suprapubic Prostatectomy
Tsui, Johnson F.; Feuerstein, Michael; Jazayeri, Seyed Behzad
2016-01-01
Operative management of prostate cancer in a patient who has undergone previous open suprapubic simple prostatectomy poses a unique surgical challenge. Herein, we describe a case of intermediate risk prostate cancer in a man who had undergone simple prostatectomy ten years prior to presentation. The patient was found to have Gleason 7 prostate cancer on MRI fusion biopsy of the prostate for elevated PSA and underwent an uncomplicated robot assisted laparoscopic radical prostatectomy. PMID:27882057
Fontan completion in a patient with previous liver transplantation.
Haida, Hirofumi; Aeba, Ryo; Hoshino, Ken; Morikawa, Yasuhide
2014-10-01
We present the first case of a successful Fontan completion in a patient with previous liver transplantation. An infant with polysplenia syndrome with a functional single ventricle and biliary atresia had been surgically managed by pulmonary artery banding, Kasai operation and living donor liver transplantation. Subsequently, the patient successfully underwent bidirectional cavopulmonary shunt and total cavopulmonary connection with extracardiac conduit at 3 and 5 years of age, respectively.
Previous violent events and mental health outcomes in Guatemala.
Puac-Polanco, Victor D; Lopez-Soto, Victor A; Kohn, Robert; Xie, Dawei; Richmond, Therese S; Branas, Charles C
2015-04-01
We analyzed a probability sample of Guatemalans to determine if a relationship exists between previous violent events and development of mental health outcomes in various sociodemographic groups, as well as during and after the Guatemalan Civil War. We used regression modeling, an interaction test, and complex survey design adjustments to estimate prevalences and test potential relationships between previous violent events and mental health. Many (20.6%) participants experienced at least 1 previous serious violent event. Witnessing someone severely injured or killed was the most common event. Depression was experienced by 4.2% of participants, with 6.5% experiencing anxiety, 6.4% an alcohol-related disorder, and 1.9% posttraumatic stress disorder (PTSD). Persons who experienced violence during the war had 4.3 times the adjusted odds of alcohol-related disorders (P PTSD (P civil war and continues today has had a significant effect on the mental health of Guatemalans. However, mental health outcomes resulting from violent events decreased in the postwar period, suggesting a nation in recovery.
Previous Violent Events and Mental Health Outcomes in Guatemala
Puac-Polanco, Victor D.; Lopez-Soto, Victor A.; Kohn, Robert; Xie, Dawei; Richmond, Therese S.
2015-01-01
Objectives. We analyzed a probability sample of Guatemalans to determine if a relationship exists between previous violent events and development of mental health outcomes in various sociodemographic groups, as well as during and after the Guatemalan Civil War. Methods. We used regression modeling, an interaction test, and complex survey design adjustments to estimate prevalences and test potential relationships between previous violent events and mental health. Results. Many (20.6%) participants experienced at least 1 previous serious violent event. Witnessing someone severely injured or killed was the most common event. Depression was experienced by 4.2% of participants, with 6.5% experiencing anxiety, 6.4% an alcohol-related disorder, and 1.9% posttraumatic stress disorder (PTSD). Persons who experienced violence during the war had 4.3 times the adjusted odds of alcohol-related disorders (P < .05) and 4.0 times the adjusted odds of PTSD (P < .05) compared with the postwar period. Women, indigenous Maya, and urban dwellers had greater odds of experiencing postviolence mental health outcomes. Conclusions. Violence that began during the civil war and continues today has had a significant effect on the mental health of Guatemalans. However, mental health outcomes resulting from violent events decreased in the postwar period, suggesting a nation in recovery. PMID:25713973
Multicentric spinal cord and brain glioblastoma without previous craniotomy
Sayoa A de Eulate-Beramendi
2016-01-01
Conclusions: This report suggests that GBM is a diffuse disease; the more extended the disease, the worse prognosis it has. The management still remains controversial and further studies are required to understand the prognosis factors of dissemination.
lithopaedon presenting as intestinal obstruction with a previous co ...
2013-11-06
Nov 6, 2013 ... reported worldwide) occurs when a fetus dies during an abdominal ... absorbed instead it calcifies to shield the mother from the ... She was admitted in labour ... gravid patient may signal an abdominal pregnancy. Patients may ...
The impact of previous knowledge and experience on the ...
Erna Kinsey
South African Journal of Education ... According to the 2003 edition of the Global Entrepreneurship Monitor (a report which examines the relation of a ... In this regard the outcome of the learning area, Economic and Management Sciences.
Vinh, P. C.; Anh, V. T. N.; Linh, N. T. K.
2016-04-01
The secular equation of Rayleigh propagating in an orthotropic half-space coated by an orthotropic layer has been obtained by Sotiropolous [Sotiropolous, D. A. (1999), The e®ect of anisotropy on guided elastic waves in a layered half-space, Mechanics of Materials 31, 215-233] and by Sotiropolous & Tougelidis [Sotiropolous, D. A. and Tougelidis, G. (1998), Guided elastic waves in orthotropic surface layer, Ultrasonics 36, 371-374]. However, it is not totally explicit and some misprints have occurred in this secular equation in both papers. This secular equation was derived by expanding directly a six-order determinant originated from the traction-free conditions at the top surface of the layer and the continuity of displacements and stresses through the interface between the layer and the half-space. Since the expansion of this six-order determinant was not shown in both two papers, it has been difficult to readers to recognize these misprints. This paper presents a technique that provides a totally explicit secular equation of the wave. The technique makes clear the way from the traction-free and continuity conditions to the secular equation and enables us to recognize the misprints appearing in the reported secular equation. The technique can be employed to obtain explicit secular equations of Rayleigh waves for many other cases. Moreover, the paper introduces a transfer matrix in explicit form for an orthotropic layer that is much simpler in form than the one obtained previously.
Primary papillary thyroid carcinoma previously treated incompletely with radiofrequency ablation
Kim Hoon; Ryu Woo; Woo Sang; Son Gil; Lee Eun; Lee Jae; Bae Jeoung
2010-01-01
Radiofrequency ablation (RFA) recently has been applied to benign thyroid nodules, mainly for the cosmetic reasons, and limited cases of local recurrences or focal distant metastases of well-differentiated thyroid cancer, in the high-risk reoperative condition or for the palliative purpose. But no report has been made on the RFA for primary thyroid cancer to date. We report on a patient with primary papillary carcinoma of thyroid gland who had undergone RFA before the cytological diagnosis of...
Impact of previous lupus nephritis on maternal and fetal outcomes during pregnancy.
Saavedra, Miguel A; Cruz-Reyes, Claudia; Vera-Lastra, Olga; Romero, Griselda T; Cruz-Cruz, Polita; Arias-Flores, Rafael; Jara, Luis J
2012-05-01
Previous reports suggest that renal involvement before pregnancy or active renal disease during pregnancy may be associated with poor fetal and maternal outcomes in systemic lupus erythematosus (SLE) women. We report our experience of fetal and maternal complications in pregnant lupus women with and without previous lupus nephritis. We analyzed the clinical records of pregnant SLE patients attended in a tertiary reference center during a 5-year period. Patients were allocated into two groups according to the presence or absence of previous lupus nephritis. Women were evaluated monthly during pregnancy and at least 1 month postpartum. Maternal and fetal outcomes of pregnancy were abstracted. We included 95 pregnancies in 92 patients. Compared with pregnant women without lupus nephritis (n = 60), pregnancies with previous lupus nephritis (n = 35) were associated with a higher risk of maternal complications (88.5% vs. 43.3%, p = 0.00001), higher rate of lupus flares (54.2% vs. 25%, p = 0.004), and renal flares (45.7% vs. 6.6%, p = 0.00001), but most of which in most instances were reversible. On the other hand, fetal outcome was similar in both groups. Multivariate analysis showed that previous lupus nephritis and active lupus at conception were predictors of adverse maternal outcome. Pregnancies in women with previous lupus nephritis had a higher rate of maternal complications in comparison with those without. However, fetal prognosis was similar in both groups.
Master equation solutions in the linear regime of characteristic formulation of general relativity
M., C E Cedeño
2015-01-01
From the field equations in the linear regime of the characteristic formulation of general relativity, Bishop, for a Schwarzschild's background, and M\\"adler, for a Minkowski's background, were able to show that it is possible to derive a fourth order ordinary differential equation, called master equation, for the $J$ metric variable of the Bondi-Sachs metric. Once $\\beta$, another Bondi-Sachs potential, is obtained from the field equations, and $J$ is obtained from the master equation, the other metric variables are solved integrating directly the rest of the field equations. In the past, the master equation was solved for the first multipolar terms, for both the Minkowski's and Schwarzschild's backgrounds. Also, M\\"adler recently reported a generalisation of the exact solutions to the linearised field equations when a Minkowski's background is considered, expressing the master equation family of solutions for the vacuum in terms of Bessel's functions of the first and the second kind. Here, we report new sol...
Amount of polyhydramnios attributable to diabetes may be less than previously reported
Moore, Lisa E
2017-01-01
AIM To evaluate the frequency and the quantity of polyhydramnios attributable to diabetes in pregnancy. METHODS The charts of patients with a four-quadrant amniotic fluid index (AFI) ≥ 20 cm and either a diagnosis of diabetes or a diabetes screening test during the index pregnancy were retrospectively reviewed. AFI was stratified into 5 categories and the frequency of diabetes was evaluated for each group. The frequency of polyhydramnios attributable to diabetes was compared to the frequency of polyhydramnios in the setting of fetal anomalies or no known cause. RESULTS One thousand five hundred and forty-five patients were included in the study. Eight point five percent (n = 131) had diabetes and no other cause for polyhydramnios. Eleven point two percent (173) had antenatally diagnosed anomalies. For all categories of AFI except the largest (> 40.9 cm) the most common cause of polyhydramnios was idiopathic. In patients with diabetes the AFI was most likely to be between 26 cm and 35.9 cm. CONCLUSION The rate of polyhydramnios in this study is 8.5%. Patients with diabetes most commonly have mild polyhydramnios between 26 and 35.9 cm of fluid on a four-quadrant AFI. PMID:28138359
Yuki Tateno
2016-12-01
Full Text Available Abstract Background Hereditary spherocytosis is autosomal dominant inherited extravascular hemolytic disorder and is the commonest cause of inherited hemolysis in northern Europe and the United States. The classical clinical features of hereditary spherocytosis are anemia, jaundice, and splenomegaly. However, all of these classical features are not always revealed in the case of mild hemolysis or when hemolysis is well compensated. Patients with hereditary spherocytosis may remain undiagnosed for years if their hemolysis is mild. Case presentation A 42-year-old Asian woman presented to our clinic with a sudden onset of high fever with shaking chills and jaundice, suggesting septicemia; however, following detailed investigation, the patient was diagnosed with pyelonephritis and accelerated hemolysis of hereditary spherocytosis due to infection. Conclusions It is important to note that transient anemia or jaundice can sometimes be the only initial presenting symptoms in cases of undiagnosed latent hereditary spherocytosis. This case also highlights the fact that physicians should consider concomitant hemolytic disease in patients in whom jaundice and infections that rarely cause jaundice coexist.
A Late-onset Psoas Abscess Formation Associated with Previous Appendectomy: A Case Report
Sam Moslemi; Maryam Tahamtan; Seyed Vahid Hosseini
2014-01-01
Psoas abscesses could originate from an adjacent source of infection in the abdominopelvic cavity known as a secondary complication of acute appendicitis. However, it is considered as a very rare event when occurring late after the presentation of appendicitis. Whether it is the source or complication of acute appendicitis following appendectomy remains unclear. A 25-year-old man was admitted to our center with fever and abdominal pain. His past medical history was unremarkable except for hav...
A Late-onset Psoas Abscess Formation Associated with Previous Appendectomy: A Case Report
Sam Moslemi
2014-01-01
Full Text Available Psoas abscesses could originate from an adjacent source of infection in the abdominopelvic cavity known as a secondary complication of acute appendicitis. However, it is considered as a very rare event when occurring late after the presentation of appendicitis. Whether it is the source or complication of acute appendicitis following appendectomy remains unclear. A 25-year-old man was admitted to our center with fever and abdominal pain. His past medical history was unremarkable except for having an acute appendicitis and complicated appendectomy 4 years before presenting illness. On admission, the patient was febrile with right lower quadrant abdominal tenderness and moderate leukocytosis. The Abdominopelvic CT- scan revealed a large right psoas muscle than the opposite site, that contained a hypodense mass measuring 6 cm in diameter with extension into right iliacus and internal oblique muscles..The patient underwent subsequent percutaneous abscess drainage under image guide and concurrent broad-spectrum antibiotic therapy.
A Late-onset Psoas Abscess Formation Associated with Previous Appendectomy: A Case Report.
Moslemi, Sam; Tahamtan, Maryam; Hosseini, Seyed Vahid
2014-01-01
Psoas abscesses could originate from an adjacent source of infection in the abdominopelvic cavity known as a secondary complication of acute appendicitis. However, it is considered as a very rare event when occurring late after the presentation of appendicitis. Whether it is the source or complication of acute appendicitis following appendectomy remains unclear. A 25-year-old man was admitted to our center with fever and abdominal pain. His past medical history was unremarkable except for having an acute appendicitis and complicated appendectomy 4 years before presenting illness. On admission, the patient was febrile with right lower quadrant abdominal tenderness and moderate leukocytosis. The Abdominopelvic CT- scan revealed a large right psoas muscle than the opposite site, that contained a hypodense mass measuring 6 cm in diameter with extension into right iliacus and internal oblique muscles..The patient underwent subsequent percutaneous abscess drainage under image guide and concurrent broad-spectrum antibiotic therapy.
Non-detection of Previously Reported Transits of HD 97658b with MOST Photometry
Dragomir, Diana; Matthews, Jaymie M.; Howard, Andrew W.
2012-01-01
The radial velocity-discovered exoplanet HD 97658b was recently announced to transit, with a derived planetary radius of 2.93 ± 0.28 R ⊕. As a transiting super-Earth orbiting a bright star, this planet would make an attractive candidate for additional observations, including studies of its atmosp...