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Sample records for drugs methods problems

  1. Methods for population size estimation of problem drug users using a single registration.

    PubMed

    van der Heijden, Peter G M; Cruts, Guus; Cruyff, Maarten

    2013-11-01

    The number of problem drug users is used as a key indicator to monitor the drug situation in the European Union. An alternative approach to estimate the number of problem drug users is given by 'the one-source capture-recapture analysis' that uses a single registration. Two variants of the one-source capture-recapture analysis were applied to a single registration: the truncated Poisson regression model (TPR) and the Zelterman regression model. These models were applied to data about clinical drug-related hospital admissions derived from the Dutch Hospital Registration (LMR). The TPR accounts for heterogeneity in capture probabilities by allowing for covariates and the Zelterman regression model relies on the problem drug users that were seen only once or twice in the hospital; the latter model is known to be robust against unobserved heterogeneity. The TPR model was found to have a bad fit due to unobserved heterogeneity. The Zelterman regression model estimated the population size at 10,415 problem drug users (95% CI is 8400-12,429). This figure is an estimate of the number of problem drug users who are at risk of a clinical hospital admission due to the medical consequences of their drug use. The model can also provide estimates of different subgroups of problematic drug users. The method presented here offers a promising alternative for estimating the number of problem drug users, including different subgroups of drug users. In addition, observed and unobserved heterogeneity can be accounted for in these estimates. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Structure-based methods for predicting target mutation-induced drug resistance and rational drug design to overcome the problem.

    PubMed

    Hao, Ge-Fei; Yang, Guang-Fu; Zhan, Chang-Guo

    2012-10-01

    Drug resistance has become one of the biggest challenges in drug discovery and/or development and has attracted great research interests worldwide. During the past decade, computational strategies have been developed to predict target mutation-induced drug resistance. Meanwhile, various molecular design strategies, including targeting protein backbone, targeting highly conserved residues and dual/multiple targeting, have been used to design novel inhibitors for combating the drug resistance. In this article we review recent advances in development of computational methods for target mutation-induced drug resistance prediction and strategies for rational design of novel inhibitors that could be effective against the possible drug-resistant mutants of the target.

  3. A breakthrough novel method to resolve the drug and target interference problem in immunogenicity assays.

    PubMed

    Zoghbi, Jad; Xu, Yuanxin; Grabert, Ryan; Theobald, Valerie; Richards, Susan

    2015-11-01

    Biological matrix interference in detection and quantitation immunoassays remains a major challenge in the field of bioanalysis. For example, circulating drug may interfere with the detection of anti-drug antibodies (ADA) and drug target, or ADA may interfere with quantitation of drug levels in PK/TK analysis. Monoclonal antibody drug interference, especially for human IgG4 drugs, presents an additional challenge for ADA analysis due to its longer half-life and higher dose. Assay tolerance to such interference may depend on assay platform and reagents. Various approaches have been used to improve drug tolerance in ADA analysis but limited success was observed. We have developed a breakthrough novel method that uses Precipitation and Acid dissociation (PandA) to overcome drug interference in the ADA assay. The method principle is based on four components for detection of total ADA (free ADA and drug bound ADA) in the presence of drug in patient samples: (1) use excess drug to saturate free ADA to form drug bound ADA as drug:ADA complexes, (2) precipitate the complex using an agent such as PEG, (3) acid dissociate ADA from drug and immobilize (capture) free ADA (and free drug) under acidic conditions (without neutralization) onto a large capacity surface, and (4) detect free ADA (not the captured drug) using specific anti-human Ig detection reagent. In this manuscript, we are describing case studies for three humanized monoclonal antibodies (an IgG1 and two IgG4 drugs). The three drug specific PandA ADA assays resulted in complete recovery of ADA in samples containing drug levels in excess of those expected in patients, in contrast to the commonly used acid dissociation approach in ECL bridging assays. This breakthrough novel method shows significant improvement over the current approaches. In fact, the drug interference or under detecting of ADA in all three cases was eliminated. This assay principle could be used not only for ADA assays but also PK and biomarker

  4. Is the Drug Problem Soluble?

    ERIC Educational Resources Information Center

    Jonas, Steven

    1989-01-01

    Concludes that the principle drug problems in the United States arise from the use of cigarette tobacco and alcoholic beverages. Identifies a drug culture as the persistent force in society that promotes drug use. Points out that the influence of the primary drug industries inhibit attempts to deal effectively with drug problems. (KO)

  5. Is the Drug Problem Soluble?

    ERIC Educational Resources Information Center

    Jonas, Steven

    1989-01-01

    Concludes that the principle drug problems in the United States arise from the use of cigarette tobacco and alcoholic beverages. Identifies a drug culture as the persistent force in society that promotes drug use. Points out that the influence of the primary drug industries inhibit attempts to deal effectively with drug problems. (KO)

  6. Preventing Alcohol-Related Problems on Campus: Methods for Assessing Student Use of Alcohol and Other Drugs. A Guide for Program Coordinators.

    ERIC Educational Resources Information Center

    DeJong, William; Wechsler, Henry

    Under the Drug-Free Schools and Campuses Act, institutions of higher education are required to review the effectiveness of their alcohol and drug prevention programs biannually. This guide offers a method for gathering and interpreting student survey data on alcohol-related problems based on the methodology of the College Alcohol Survey developed…

  7. Problems with drugs in Croatia.

    PubMed

    Vrhovac, B

    1997-01-01

    Croatia has 4.8 million inhabitants, 11,800 physicians, 2000 pharmacists, two now shareholding, pharmaceutical companies (about 6500 employees, total sales of about 350 million US dollars). There are a number of problems due to the war (GNP fell from 3800 to about 1500 US dollars), occupation of 25% of its territory, 0.5 million refugees and lack of resources (139 US dollars/capita for health, about 40 US dollars i.e. 30%!! for drugs)--about three times less than before the aggression. The drug situation is controlled with the help of: (1) donations (approximate value of 600 million US dollars since 1991 from Europe and US), (2) (essential) drug formularies--250 for outpatients, and 580 generic names for various levels of hospital use, (3) special efforts to purchase drugs of good quality at a reasonable price (a kind of tender), (4) control of prescribing (prescriptions, specialists referral) especially by GPs. A new Medicines Act is in preparation and about 1000 generic names are on the market. DRUG EDUCATION: Pharmaca: the Croatian journal of pharmacotherapy has been published since 1962, there are several Drug bulletins (one published since 1975); special chapters on clinical pharmacology in textbooks, translation of three editions of Laurence's textbook with special commentary and adaptation to local needs; ADR spontaneous and intensive monitoring (WHO programme) with a personal feedback to the reporters and regular articles on drug use in a number of periodicals. Data on drug consumption indicates that there is room for improvement of prescribing. There is an enthusiasm for 'vasoactive drugs'--after dipirydamole came oxpentifylline and antimicrobials are always overprescribed. All these problems will hopefully decrease when the war finally stops and when industry (especially tourism) starts being fruitful again. In any case the importance of teaching of pharmacotherapy at the under- and postgraduate level should be recognized.

  8. Illicit Drug Use and Problem Gambling

    PubMed Central

    Wayne Skinner, W. J.; Matheson, Flora I.

    2013-01-01

    Problem gambling, substance use disorders, and their cooccurrence are serious public health concerns. We conducted a comprehensive review of the literature to understand the present state of the evidence on these coaddictions. Our main focus was illicit drug use rather than misuse of legal substances. The review covers issues related to gambling as a hidden problem in the illicit drug use community; prevalence, problem gambling, and substance use disorders as kindred afflictions; problem gambling as an addiction similar to illicit drug use; risk factors and problems associated with comorbidity, and gender issues. We end with some suggestions for future research. PMID:25938114

  9. Drug problems among health professionals.

    PubMed

    Janecek, E; Marshman, J A; Brewster, J M

    1989-03-01

    Available information on patterns of alcohol and drug abuse among health professionals, as well as information on abuse versus impairment, is reviewed. Past and present attitudes and approaches to helping the alcohol- or drug-impaired health professional in Ontario are examined.

  10. Time Investment in Drug Supply Problems by Flemish Community Pharmacies.

    PubMed

    De Weerdt, Elfi; Simoens, Steven; Casteels, Minne; Huys, Isabelle

    2017-01-01

    Introduction: Drug supply problems are a known problem for pharmacies. Community and hospital pharmacies do everything they can to minimize impact on patients. This study aims to quantify the time spent by Flemish community pharmacies on drug supply problems. Materials and Methods: During 18 weeks, employees of 25 community pharmacies filled in a template with the total time spent on drug supply problems. The template stated all the steps community pharmacies could undertake to manage drug supply problems. Results: Considering the median over the study period, the median time spent on drug supply problems was 25 min per week, with a minimum of 14 min per week and a maximum of 38 min per week. After calculating the median of each pharmacy, large differences were observed between pharmacies: about 25% spent less than 15 min per week and one-fifth spent more than 1 h per week. The steps on which community pharmacists spent most time are: (i) "check missing products from orders," (ii) "contact wholesaler/manufacturers regarding potential drug shortages," and (iii) "communicating to patients." These three steps account for about 50% of the total time spent on drug supply problems during the study period. Conclusion: Community pharmacies spend about half an hour per week on drug supply problems. Although 25 min per week does not seem that much, the time spent is not delineated and community pharmacists are constantly confronted with drug supply problems.

  11. Time Investment in Drug Supply Problems by Flemish Community Pharmacies

    PubMed Central

    De Weerdt, Elfi; Simoens, Steven; Casteels, Minne; Huys, Isabelle

    2017-01-01

    Introduction: Drug supply problems are a known problem for pharmacies. Community and hospital pharmacies do everything they can to minimize impact on patients. This study aims to quantify the time spent by Flemish community pharmacies on drug supply problems. Materials and Methods: During 18 weeks, employees of 25 community pharmacies filled in a template with the total time spent on drug supply problems. The template stated all the steps community pharmacies could undertake to manage drug supply problems. Results: Considering the median over the study period, the median time spent on drug supply problems was 25 min per week, with a minimum of 14 min per week and a maximum of 38 min per week. After calculating the median of each pharmacy, large differences were observed between pharmacies: about 25% spent less than 15 min per week and one-fifth spent more than 1 h per week. The steps on which community pharmacists spent most time are: (i) “check missing products from orders,” (ii) “contact wholesaler/manufacturers regarding potential drug shortages,” and (iii) “communicating to patients.” These three steps account for about 50% of the total time spent on drug supply problems during the study period. Conclusion: Community pharmacies spend about half an hour per week on drug supply problems. Although 25 min per week does not seem that much, the time spent is not delineated and community pharmacists are constantly confronted with drug supply problems. PMID:28878679

  12. Prescription drug abuse: problem, policies, and implications.

    PubMed

    Phillips, Janice

    2013-01-01

    This article provides an overview on prescription drug abuse and highlights a number of related legislative bills introduced during the 112th Congress in response to this growing epidemic. Prescription drug abuse has emerged as the nation's fastest growing drug problem. Although prescription drugs have been used effectively and appropriately for decades, deaths from prescription pain medicine in particular have reached epidemic proportions. Bills related to prescription drug abuse introduced during the 112th Congress focus on strengthening provider and consumer education, tracking and monitoring prescription drug abuse, improving data collection on drug overdose fatalities, combating fraud and abuse in Medicare and Medicaid programs, reclassifying drugs to make them more difficult to prescribe and obtain, and enforcing stricter penalties for individuals who operate scam pain clinics and sell pain pills illegitimately. This article underscores the importance of a multifaceted approach to combating prescription drug abuse and concludes with implications for nursing. Copyright © 2013. Published by Mosby, Inc.

  13. Social Problems of Drug Use and Drug Policies.

    ERIC Educational Resources Information Center

    Fort, Joel

    The social and legal policies that control or prevent the use of mind-altering drugs are the main cause of the social problems arising from their use. The existing policies are ineffective; the wrong drugs receive the most attention and laws are directed at the wrong phase of the cycle of promotion, distribution and use. The following reforms are…

  14. Addressing the clinical needs of problem drug user patients

    PubMed Central

    Krupski, Antoinette; West, Imara I.; Graves, Meredith C.; Atkins, David C.; Maynard, Charles; Bumgardner, Kristin; Donovan, Dennis; Ries, Richard; Roy-Byrne, Peter

    2016-01-01

    Introduction Illicit drug use is a serious public health problem associated with significant co-occurring medical disorders, mental disorders, and social problems. Yet most individuals with drug use disorders have never been treated, though they often seek medical treatment in primary care. The purpose of the present study was to examine baseline characteristics of persons presenting in primary care across a range of problem drug use severity to identify their clinical needs. Methods We examined socio-demographic characteristics, medical and psychiatric comorbidities, drug use severity, social and legal problems, and service utilization for 868 patients with drug problems recruited from primary care clinics in a safety-net medical setting. Based on Drug Abuse Screening Test (DAST-10) results, individuals were categorized as having low, intermediate, or substantial/severe drug use severity. Results Patients with substantial/severe drug use severity had serious drug use (opiates, stimulants, sedatives, intravenous drug use), high levels of homelessness (50%), psychiatric comorbidity (69%), arrests for serious crimes (24%), and frequent use of expensive emergency department and inpatient hospitals. Patients with low drug use severity were primarily users of marijuana with little reported use of other drugs, less psychiatric co-morbidity, and more stable lifestyles. Patients with intermediate drug use severity fell in-between the substantial/severe and low drug use severity subgroups on most variables. Conclusions Patients with highest drug use severity are likely to require specialized psychiatric and substance abuse care in addition to ongoing medical care that is equipped to address the consequences of severe/substantial drug use including intravenous drug use. Because of their milder symptoms, patients with low drug use severity may benefit from a collaborative care model that integrates psychiatric and substance abuse care in the primary care setting. Patients

  15. Drug problem in southeast and southwest Asia.

    PubMed

    Kulsudjarit, Kongpetch

    2004-10-01

    In 2002, the drug problem in Southeast and Southwest Asia was serious, particularly in the production of opium and heroin in Afghanistan, Myanmar, and Laos, the three largest producers of illicit opium in the world. The increasing illicit manufacture of ATS, particularly methamphetamine, in Southeast Asia, mainly in China and Myanmar, was also a major concern. Some reports indicated that ephedrine, used for illicitly producing methamphetamine in Southeast Asia, is diverted and smuggled out of China and India, whereas caffeine, the adulterant used for producing methamphetamine tablets, is mainly smuggled into Myanmar through its border with Thailand. Seizure data showed a dramatic increase in trafficking in MDMA through Southeast Asia. In terms of the drug epidemic, in 2002, cannabis remained overall the main drug of abuse in all of the countries of Southeast and Southwest Asia. Opiates, mainly opium and heroin, were also the drugs of choice except in Thailand, where opiate abuse declined, but ATS was the main drug of abuse due to its low cost and availability. A significant increase in ATS abuse, amphetamine, methamphetamine, and MDMA among the youth who smoked, sniffed, and inhaled them was reported in Cambodia, China, Indonesia, Laos, Myanmar, the Philippines, and Thailand. Injecting drug use among opiate abusers has been identified as the prime cause of the rapid spread of HIV/AIDS in Southeast and Southwest Asia.

  16. Spectral methods for discontinuous problems

    NASA Technical Reports Server (NTRS)

    Abarbanel, S.; Gottlieb, D.; Tadmor, E.

    1985-01-01

    Spectral methods yield high-order accuracy even when applied to problems with discontinuities, though not in the sense of pointwise accuracy. Two different procedures are presented which recover pointwise accurate approximations from the spectral calculations.

  17. Multigrid method for stability problems

    NASA Technical Reports Server (NTRS)

    Taasan, Shlomo

    1988-01-01

    The problem of calculating the stability of steady state solutions of differential equations is treated. Leading eigenvalues (i.e., having maximal real part) of large matrices that arise from discretization are to be calculated. An efficient multigrid method for solving these problems is presented. The method begins by obtaining an initial approximation for the dominant subspace on a coarse level using a damped Jacobi relaxation. This proceeds until enough accuracy for the dominant subspace has been obtained. The resulting grid functions are then used as an initial approximation for appropriate eigenvalue problems. These problems are being solved first on coarse levels, followed by refinement until a desired accuracy for the eigenvalues has been achieved. The method employs local relaxation on all levels together with a global change on the coarsest level only, which is designed to separate the different eigenfunctions as well as to update their corresponding eigenvalues. Coarsening is done using the FAS formulation in a non-standard way in which the right hand side of the coarse grid equations involves unknown parameters to be solved for on the coarse grid. This in particular leads to a new multigrid method for calculating the eigenvalues of symmetric problems. Numerical experiments with a model problem demonstrate the effectiveness of the method proposed. Using an FMG algorithm a solution to the level of discretization errors is obtained in just a few work units (less than 10), where a work unit is the work involved in one Jacobi relization on the finest level.

  18. Prenatal drug exposure, behavioral problems and drug experimentation among African American urban adolescents

    PubMed Central

    Wang, Yan; Buckingham-Howes, Stacy; Nair, Prasanna; Zhu, Shijun; Magder, Larry; Black, Maureen M.

    2014-01-01

    Purpose To examine how prenatal heroin/cocaine exposure (PDE) and behavioral problems relate to adolescent drug experimentation. Methods The sample included African American adolescents (mean age=14.2 yr, SD=1.2) with PDE (n=73) and a non-exposed community comparison (n=61). PDE status was determined at delivery through toxicology analysis and maternal-report. Internalizing/externalizing problems were assessed during adolescence with the Behavior Assessment System for Children, Second Edition. Drug experimentation was assessed by adolescent-report and urine analysis. Logistic regression evaluated the likelihood of drug experimentation related to PDE and behavioral problems, adjusting for age, gender, prenatal tobacco/alcohol exposure, perceived peer drug use and caregiver drug use. Interaction terms examined gender modification. Results 67 (50%) used drugs. 25 (19%) used tobacco/alcohol only and 42 (31%) used marijuana/illegal drugs. 94 (70%) perceived peer drug use. PDE significantly increased the risk of tobacco/alcohol experimentation (OR=3.07, 95% CI: 1.09–8.66, p=0.034), but not after covariate adjustment (aOR=1.31, 95% CI: 0.39–4.36, p>0.05). PDE was not related to overall or marijuana/illegal drug experimentation. The likelihood of overall drug experimentation was doubled per Standard Deviation (SD) increase in externalizing problems (aOR=2.28, 95% CI: 1.33–3.91, p=0.003) and, among girls, 2.82 times greater (aOR=2.82, 95% CI: 1.34–5.94, p=0.006) per SD increase in internalizing problems. Age and perceived peer drug use were significant covariates. Conclusions Drug experimentation was relatively common (50%), especially in the context of externalizing problems, internalizing problems (girls only), age, and perceived peer drug use. Findings support Problem Behavior Theory and suggest that adolescent drug prevention address behavioral problems and promote prosocial peer groups. PMID:24768161

  19. Revisiting sub-Saharan African countries' drug problems: health, social, economic costs, and drug control policy.

    PubMed

    Affinnih, Yahya H

    2002-02-01

    This article takes an international perspective on the drug problem in sub-Saharan Africa. This analysis borrows ideas from physical and economic geography as a heuristic device to conceptualize the global narcoscapes in which drug trafficking occurs. Both the legitimate and the illegal drug trade operate within the same global capitalist system and draw on the same technological innovations and business processes. Central to the paper's argument is evidence that sub-Saharan African countries are now integrated into the political economy of drug consumption due to the spill-over effect. These countries are now minor markets for "hard drugs" as the result of the activities of organizations and individual traffickers that use Africa as a staging point in their trade with Europe and the United States. As a result, sub-Saharan African countries have drug consumption problems that were essentially absent prior to 1980, along with associated health, social, and economic costs. The emerging drug problem has forced African countries to develop their own drug control policy. The sub-Saharan African countries mentioned below vary to some extent in the level of drug use and misuse problems: Burundi, Comoros, Djibouti, Eritrea, Ethiopia, Kenya, Madagascar, Malawi, Mauritius, Mozambique, Reunion, Rwanda, Seychelles, Somalia, Tanzania, Uganda, Zambia, Angola, Cameroon, Central African Republic, Chad, Congo, Congo (Zaire), Equatorial Guinea, Gabon, Sao Tome and Principe, Botswana, Lesotho, Namibia, South Africa, Swaziland, Benin, Burkina Faso, Cape Verde, Cote d'Ivoire, Gambia, Ghana, Guinea, Guinea Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, and Togo. As part of this effort, African countries are assessing the health, social, and economic costs of drug-use-related problems to pinpoint methods which are both effective and inexpensive, since their budgets for social programs are severely constrained. Many have progressed to the point of adopting anti-drug

  20. Computational methods in drug discovery

    PubMed Central

    Leelananda, Sumudu P

    2016-01-01

    The process for drug discovery and development is challenging, time consuming and expensive. Computer-aided drug discovery (CADD) tools can act as a virtual shortcut, assisting in the expedition of this long process and potentially reducing the cost of research and development. Today CADD has become an effective and indispensable tool in therapeutic development. The human genome project has made available a substantial amount of sequence data that can be used in various drug discovery projects. Additionally, increasing knowledge of biological structures, as well as increasing computer power have made it possible to use computational methods effectively in various phases of the drug discovery and development pipeline. The importance of in silico tools is greater than ever before and has advanced pharmaceutical research. Here we present an overview of computational methods used in different facets of drug discovery and highlight some of the recent successes. In this review, both structure-based and ligand-based drug discovery methods are discussed. Advances in virtual high-throughput screening, protein structure prediction methods, protein–ligand docking, pharmacophore modeling and QSAR techniques are reviewed. PMID:28144341

  1. Computational methods in drug discovery.

    PubMed

    Leelananda, Sumudu P; Lindert, Steffen

    2016-01-01

    The process for drug discovery and development is challenging, time consuming and expensive. Computer-aided drug discovery (CADD) tools can act as a virtual shortcut, assisting in the expedition of this long process and potentially reducing the cost of research and development. Today CADD has become an effective and indispensable tool in therapeutic development. The human genome project has made available a substantial amount of sequence data that can be used in various drug discovery projects. Additionally, increasing knowledge of biological structures, as well as increasing computer power have made it possible to use computational methods effectively in various phases of the drug discovery and development pipeline. The importance of in silico tools is greater than ever before and has advanced pharmaceutical research. Here we present an overview of computational methods used in different facets of drug discovery and highlight some of the recent successes. In this review, both structure-based and ligand-based drug discovery methods are discussed. Advances in virtual high-throughput screening, protein structure prediction methods, protein-ligand docking, pharmacophore modeling and QSAR techniques are reviewed.

  2. Computational Methods in Drug Discovery

    PubMed Central

    Sliwoski, Gregory; Kothiwale, Sandeepkumar; Meiler, Jens

    2014-01-01

    Computer-aided drug discovery/design methods have played a major role in the development of therapeutically important small molecules for over three decades. These methods are broadly classified as either structure-based or ligand-based methods. Structure-based methods are in principle analogous to high-throughput screening in that both target and ligand structure information is imperative. Structure-based approaches include ligand docking, pharmacophore, and ligand design methods. The article discusses theory behind the most important methods and recent successful applications. Ligand-based methods use only ligand information for predicting activity depending on its similarity/dissimilarity to previously known active ligands. We review widely used ligand-based methods such as ligand-based pharmacophores, molecular descriptors, and quantitative structure-activity relationships. In addition, important tools such as target/ligand data bases, homology modeling, ligand fingerprint methods, etc., necessary for successful implementation of various computer-aided drug discovery/design methods in a drug discovery campaign are discussed. Finally, computational methods for toxicity prediction and optimization for favorable physiologic properties are discussed with successful examples from literature. PMID:24381236

  3. Multigrid Methods for EHL Problems

    NASA Technical Reports Server (NTRS)

    Nurgat, Elyas; Berzins, Martin

    1996-01-01

    In many bearings and contacts, forces are transmitted through thin continuous fluid films which separate two contacting elements. Objects in contact are normally subjected to friction and wear which can be reduced effectively by using lubricants. If the lubricant film is sufficiently thin to prevent the opposing solids from coming into contact and carries the entire load, then we have hydrodynamic lubrication, where the lubricant film is determined by the motion and geometry of the solids. However, for loaded contacts of low geometrical conformity, such as gears, rolling contact bearings and cams, this is not the case due to high pressures and this is referred to as Elasto-Hydrodynamic Lubrication (EHL) In EHL, elastic deformation of the contacting elements and the increase in fluid viscosity with pressure are very significant and cannot be ignored. Since the deformation results in changing the geometry of the lubricating film, which in turn determines the pressure distribution, an EHL mathematical model must simultaneously satisfy the complex elasticity (integral) and the Reynolds lubrication (differential) equations. The nonlinear and coupled nature of the two equations makes numerical calculations computationally intensive. This is especially true for highly loaded problems found in practice. One novel feature of these problems is that the solution may exhibit sharp pressure spikes in the outlet region. To this date both finite element and finite difference methods have been used to solve EHL problems with perhaps greater emphasis on the use of the finite difference approach. In both cases, a major computational difficulty is ensuring convergence of the nonlinear equations solver to a steady state solution. Two successful methods for achieving this are direct iteration and multigrid methods. Direct iteration methods (e.g Gauss Seidel) have long been used in conjunction with finite difference discretizations on regular meshes. Perhaps one of the best examples of

  4. Multigrid Methods for EHL Problems

    NASA Technical Reports Server (NTRS)

    Nurgat, Elyas; Berzins, Martin

    1996-01-01

    In many bearings and contacts, forces are transmitted through thin continuous fluid films which separate two contacting elements. Objects in contact are normally subjected to friction and wear which can be reduced effectively by using lubricants. If the lubricant film is sufficiently thin to prevent the opposing solids from coming into contact and carries the entire load, then we have hydrodynamic lubrication, where the lubricant film is determined by the motion and geometry of the solids. However, for loaded contacts of low geometrical conformity, such as gears, rolling contact bearings and cams, this is not the case due to high pressures and this is referred to as Elasto-Hydrodynamic Lubrication (EHL) In EHL, elastic deformation of the contacting elements and the increase in fluid viscosity with pressure are very significant and cannot be ignored. Since the deformation results in changing the geometry of the lubricating film, which in turn determines the pressure distribution, an EHL mathematical model must simultaneously satisfy the complex elasticity (integral) and the Reynolds lubrication (differential) equations. The nonlinear and coupled nature of the two equations makes numerical calculations computationally intensive. This is especially true for highly loaded problems found in practice. One novel feature of these problems is that the solution may exhibit sharp pressure spikes in the outlet region. To this date both finite element and finite difference methods have been used to solve EHL problems with perhaps greater emphasis on the use of the finite difference approach. In both cases, a major computational difficulty is ensuring convergence of the nonlinear equations solver to a steady state solution. Two successful methods for achieving this are direct iteration and multigrid methods. Direct iteration methods (e.g Gauss Seidel) have long been used in conjunction with finite difference discretizations on regular meshes. Perhaps one of the best examples of

  5. Operational analysis for the drug detection problem

    NASA Astrophysics Data System (ADS)

    Hoopengardner, Roger L.; Smith, Michael C.

    1994-10-01

    New techniques and sensors to identify the molecular, chemical, or elemental structures unique to drugs are being developed under several national programs. However, the challenge faced by U.S. drug enforcement and Customs officials goes far beyond the simple technical capability to detect an illegal drug. Entry points into the U.S. include ports, border crossings, and airports where cargo ships, vehicles, and aircraft move huge volumes of freight. Current technology and personnel are able to physically inspect only a small fraction of the entering cargo containers. The complexities of how to best utilize new technology to aid the detection process and yet not adversely affect the processing of vehicles and time-sensitive cargo is the challenge faced by these officials. This paper describes an ARPA sponsored initiative to develop a simple, yet useful, method for examining the operational consequences of utilizing various procedures and technologies in combination to achieve an `acceptable' level of detection probability. Since Customs entry points into the U.S. vary from huge seaports to a one lane highway checkpoint between the U.S. and Canadian or Mexico border, no one system can possibly be right for all points. This approach can examine alternative concepts for using different techniques/systems for different types of entry points. Operational measures reported include the average time to process vehicles and containers, the average and maximum numbers in the system at any time, and the utilization of inspection teams. The method is implemented via a PC-based simulation written in GPSS-PC language. Input to the simulation model is (1) the individual detection probabilities and false positive rates for each detection technology or procedure, (2) the inspection time for each procedure, (3) the system configuration, and (4) the physical distance between inspection stations. The model offers on- line graphics to examine effects as the model runs.

  6. Methods of assessment of antiepileptic drugs.

    PubMed Central

    Milligan, N; Richens, A

    1981-01-01

    Epilepsy is a symptom with protean manifestations and as such it is a difficult disease in which to carry out a therapeutic trial. The methods available to research workers for the assessment of new antiepileptic drugs are hampered by the fact that epilepsy is a fluctuant condition. Although it is a chronic disorder open to study using cross-over trials and within-patient comparisons, accurate assessment cannot be easily made at any one point in time. Research workers are therefore automatically placed at a time factor disadvantage and this is especially so for those searching for quick methods of evaluating new compounds. The need for a quick and reliable method of assessing a new antiepileptic drug has long been appreciated. This article will discuss the methods currently available and we will begin by considering the most commonly used method of assessment with particular reference to some of the problems involved in conducting a controlled clinical trial in epilepsy. PMID:7272157

  7. The Problem-Drinking Drug Addict. Services Research Report.

    ERIC Educational Resources Information Center

    Barr, Harriet L.; Cohen, Arie

    An increasingly important consideration in drug abuse policy and programming is the growing number of multiple substance abusers, i.e., problem-drinking drug addicts. A longitudinal study of two drug addict populations examined drug and alcohol usage, psychological variables, and criminal justice and employment indicators. Findings indicated that…

  8. Influences of Motivational Contexts on Prescription Drug Misuse and Related Drug Problems

    PubMed Central

    Kelly, Brian C.; Rendina, H. Jonathon; Vuolo, Mike; Wells, Brooke E.; Parsons, Jeffrey T.

    2014-01-01

    Prescription drug misuse has emerged as a significant problem among young adults. While the effects of motivational contexts have been demonstrated for illicit drugs, the role of motivational contexts in prescription drug misuse remains understudied. Using data from 400 young adults recruited via time-space sampling, we examined the role of motivational contexts in the frequency of misuse of three prescription drug types as well as drug-related problems and symptoms of dependency. Both negative and positive motivations to use drugs are associated with increases in prescription drug misuse frequency. Only negative motivations are associated directly with drug problems and drug dependence, as well as indirectly via prescription pain killer misuse. Addressing positive and negative motivational contexts of prescription drug misuse may not only provide a means to reduce misuse and implement harm reduction measures, but may also inform the content of treatment plans for young adults with prescription drug misuse problems. PMID:25115134

  9. Influences of motivational contexts on prescription drug misuse and related drug problems.

    PubMed

    Kelly, Brian C; Rendina, H Jonathon; Vuolo, Mike; Wells, Brooke E; Parsons, Jeffrey T

    2015-01-01

    Prescription drug misuse has emerged as a significant problem among young adults. While the effects of motivational contexts have been demonstrated for illicit drugs, the role of motivational contexts in prescription drug misuse remains understudied. Using data from 400 young adults recruited via time-space sampling, we examined the role of motivational contexts in the frequency of misuse of three prescription drug types as well as drug-related problems and symptoms of dependency. Both negative and positive motivations to use drugs are associated with increases in prescription drug misuse frequency. Only negative motivations are associated directly with drug problems and drug dependence, as well as indirectly via prescription pain killer misuse. Addressing positive and negative motivational contexts of prescription drug misuse may not only provide a means to reduce misuse and implement harm reduction measures, but may also inform the content of treatment plans for young adults with prescription drug misuse problems.

  10. The Social Construction of the Minority Drug Problem.

    ERIC Educational Resources Information Center

    Covington, Jeanette

    1997-01-01

    Examines how the minority drug problem is framed in terms of anomie and underclass models suggesting that drug subcultures in urban black areas are formed as an adaptation to aggregate community conditions. The article considers how researchers use ecological and ethnographic data to back up claims that drug subcultures are a response to inner…

  11. The Social Construction of the Minority Drug Problem.

    ERIC Educational Resources Information Center

    Covington, Jeanette

    1997-01-01

    Examines how the minority drug problem is framed in terms of anomie and underclass models suggesting that drug subcultures in urban black areas are formed as an adaptation to aggregate community conditions. The article considers how researchers use ecological and ethnographic data to back up claims that drug subcultures are a response to inner…

  12. Selective Prevention: Addressing Vulnerability to Problem Drug Use in Europe

    ERIC Educational Resources Information Center

    Burkhart, Gregor; Gyarmathy, V. Anna; Bo, Alessandra

    2011-01-01

    Following the 2003 publication of the European Union (EU) Council Recommendations and the 2005-2008 and 2009-2012 EU Drugs Action Plans, increasing attention has been given in EU member states' drug policies to populations that are vulnerable to problem drug use (PDU). Monitoring data reported to the EMCDDA by designated agencies from 30 countries…

  13. Selective Prevention: Addressing Vulnerability to Problem Drug Use in Europe

    ERIC Educational Resources Information Center

    Burkhart, Gregor; Gyarmathy, V. Anna; Bo, Alessandra

    2011-01-01

    Following the 2003 publication of the European Union (EU) Council Recommendations and the 2005-2008 and 2009-2012 EU Drugs Action Plans, increasing attention has been given in EU member states' drug policies to populations that are vulnerable to problem drug use (PDU). Monitoring data reported to the EMCDDA by designated agencies from 30 countries…

  14. Early Twentieth Century Responses to the Drug Problem.

    ERIC Educational Resources Information Center

    Pfennig, Dennis Joseph

    1991-01-01

    Describes early twentieth-century responses to the drug problem in the United States. Discusses pressure from the media and reformers to control the availability of drugs such as opium and cocaine that were widely available in over-the-counter medications. Focuses on New York State, which took the lead in enacting drug control legislation. (DK)

  15. Early Twentieth Century Responses to the Drug Problem.

    ERIC Educational Resources Information Center

    Pfennig, Dennis Joseph

    1991-01-01

    Describes early twentieth-century responses to the drug problem in the United States. Discusses pressure from the media and reformers to control the availability of drugs such as opium and cocaine that were widely available in over-the-counter medications. Focuses on New York State, which took the lead in enacting drug control legislation. (DK)

  16. NARCOTIC DRUG ADDICTION: A PUBLIC HEALTH PROBLEM

    PubMed Central

    Bishop, Ernest S.

    1919-01-01

    Dr. Bishop tells us that drug addicts are sick men and not criminals. They ought to receive treatment instead of being sent to jail. Medical, legislative and popular ideas are all in error. He calls for a revolution to wake up the doctors and educate the people. PMID:18010126

  17. Drug laws and the 'derivative' problem.

    PubMed

    King, Leslie A; Ujváry, István; Brandt, Simon D

    2014-01-01

    The concept of a 'derivative' is used widely in chemistry, where its precise meaning depends on the circumstances. However, numerous examples of derivative also occur in domestic drugs legislation, some of which stem from the 1961 United Nations Single Convention on Narcotic Drugs. There is a commonly held view that only 'first-order' derivatives should be considered: substances that can be created from a parent structure in a single chemical reaction. In other words, 'derivatives of derivatives' are excluded. However, some substances related to ecgonine (e.g. 2-carbomethoxytropinone) are clearly convertible to cocaine, even though this may require more than one reaction step. It follows that 2-carbomethoxytropinone is a controlled drug, a situation that most chemists would regard as perverse. A more extreme example of the complexity of 'derivative' is shown by the conversion of thebaine to buprenorphine. Even though this requires six or more stages, the US Drug Enforcement Administration successfully argued in a 1986 case that for the purposes of the Controlled Substances Act, the number of steps required was irrelevant; buprenorphine was a derivative of thebaine. Because the term derivative is rarely defined in statutes, the legal status of some substances, such as 2-bromo-LSD, is uncertain. Although a number of definitions of derivative can be found in the chemical literature, no single definition is adequate to describe all situations where it occurs in legislation. Unless qualified, it is suggested that the term derivative should be avoided in any future legislation.

  18. [Drugs, a current problem: difficulties in handling drug addictions].

    PubMed

    Amigo Tadín, Montserrat

    2005-12-01

    A patient suffering a drug addiction usually presents some characteristic demands and necessities. A professional's attitude must be clear and firm, showing empathy and being an active listener offering assistance, but not expressing either rebuke or threats. The professional attending such a patient takes advantage of a consultation to motivate the patient to begin, or continue, treatment in a corresponding specialized center and will process the necessary paperwork to contact such a center.

  19. 2010 drug packaging review: identifying problems to prevent errors.

    PubMed

    2011-06-01

    Prescrire's analyses showed that the quality of drug packaging in 2010 still left much to be desired. Potentially dangerous packaging remains a significant problem: unclear labelling is source of medication errors; dosing devices for some psychotropic drugs create a risk of overdose; child-proof caps are often lacking; and too many patient information leaflets are misleading or difficult to understand. Everything that is needed for safe drug packaging is available; it is now up to regulatory agencies and drug companies to act responsibly. In the meantime, health professionals can help their patients by learning to identify the pitfalls of drug packaging and providing safe information to help prevent medication errors.

  20. Parent Drug Education Programs: Reasons, Problems, and Implications.

    ERIC Educational Resources Information Center

    Fox, Tricia A.

    1991-01-01

    Presents an overview of parent drug education programs together with information regarding those problems, concerns, and needs faced by parents who are dealing with an offspring drug user/abuser. Emphasizes the unique, individual characteristics of parents and suggests that these influences may be the main determinants of the effectiveness of…

  1. Computer-Assisted Instruction; How to Solve Drug Formulation Problems.

    ERIC Educational Resources Information Center

    Mezei, Janos; And Others

    1990-01-01

    Computer simulation of drug formulation problems involves a database of pharmacological properties, chemical stability, and compatibility data on 20 active ingredients, physiological factors and requirements for parenteral solutions, and additives. The user gathers data from the database, formulates a stable and effective solution, and the drug is…

  2. Preventing Alcohol and Other Drug Problems through Drug Education. Policy Bulletin No. 3.

    ERIC Educational Resources Information Center

    Bailey, William J.

    Public schools have a responsibility to educate students about drug abuse, and states have a responsibility to assist schools in their efforts. Properly designed and implemented drug education programs are the most cost-effective means of preventing alcohol and other drug problems. Poorly designed and implemented programs, on the other hand, can…

  3. Drug Response Prediction as a Link Prediction Problem

    PubMed Central

    Stanfield, Zachary; Coşkun, Mustafa; Koyutürk, Mehmet

    2017-01-01

    Drug response prediction is a well-studied problem in which the molecular profile of a given sample is used to predict the effect of a given drug on that sample. Effective solutions to this problem hold the key for precision medicine. In cancer research, genomic data from cell lines are often utilized as features to develop machine learning models predictive of drug response. Molecular networks provide a functional context for the integration of genomic features, thereby resulting in robust and reproducible predictive models. However, inclusion of network data increases dimensionality and poses additional challenges for common machine learning tasks. To overcome these challenges, we here formulate drug response prediction as a link prediction problem. For this purpose, we represent drug response data for a large cohort of cell lines as a heterogeneous network. Using this network, we compute “network profiles” for cell lines and drugs. We then use the associations between these profiles to predict links between drugs and cell lines. Through leave-one-out cross validation and cross-classification on independent datasets, we show that this approach leads to accurate and reproducible classification of sensitive and resistant cell line-drug pairs, with 85% accuracy. We also examine the biological relevance of the network profiles. PMID:28067293

  4. Drug permeability prediction using PMF method.

    PubMed

    Meng, Fancui; Xu, Weiren

    2013-03-01

    Drug permeability determines the oral availability of drugs via cellular membranes. Poor permeability makes a drug unsuitable for further development. The permeability may be estimated as the free energy change that the drug should overcome through crossing membrane. In this paper the drug permeability was simulated using molecular dynamics method and the potential energy profile was calculated with potential of mean force (PMF) method. The membrane was simulated using DPPC bilayer and three drugs with different permeability were tested. PMF studies on these three drugs show that doxorubicin (low permeability) should pass higher free energy barrier from water to DPPC bilayer center while ibuprofen (high permeability) has a lower energy barrier. Our calculation indicates that the simulation model we built is suitable to predict drug permeability.

  5. Outcome Trajectories in Drug Court: Do All Participants Have Drug Problems?

    PubMed Central

    DeMatteo, David; Marlowe, Douglas B.; Festinger, David S.; Arabia, Patricia L.

    2011-01-01

    Graduation rates in drug courts average 50% to 70%, but it is unclear what proportion of graduates responded to the drug court services and what proportion might not have had serious drug problems upon entry. This study cluster-analyzed urine drug screen results during the first 14 weeks of treatment on 284 participants from three misdemeanor drug courts. A four-cluster solution (R2 > .75) produced distinct subgroups characterized by (1) consistently drug-negative urine specimens (34% of the sample), (2) consistently drug-positive specimens (21%), (3) consistently missed urine specimens (26%), and (4) urine specimens that began as drug-positive but became progressively drug-negative over time (19%). These data suggest that approximately one-third of the participants might not have had serious drug problems upon entry. Approximately one-fifth appeared to respond to drug court services, and nearly one-half continued to exhibit problems after 14 weeks. Implications for adaptive programming in drug courts are discussed. PMID:22081732

  6. Outcome Trajectories in Drug Court: Do All Participants Have Drug Problems?

    PubMed

    Dematteo, David; Marlowe, Douglas B; Festinger, David S; Arabia, Patricia L

    2009-04-01

    Graduation rates in drug courts average 50% to 70%, but it is unclear what proportion of graduates responded to the drug court services and what proportion might not have had serious drug problems upon entry. This study cluster-analyzed urine drug screen results during the first 14 weeks of treatment on 284 participants from three misdemeanor drug courts. A four-cluster solution (R(2) > .75) produced distinct subgroups characterized by (1) consistently drug-negative urine specimens (34% of the sample), (2) consistently drug-positive specimens (21%), (3) consistently missed urine specimens (26%), and (4) urine specimens that began as drug-positive but became progressively drug-negative over time (19%). These data suggest that approximately one-third of the participants might not have had serious drug problems upon entry. Approximately one-fifth appeared to respond to drug court services, and nearly one-half continued to exhibit problems after 14 weeks. Implications for adaptive programming in drug courts are discussed.

  7. Inverse problems using reduced basis method

    NASA Astrophysics Data System (ADS)

    Gralla, Phil

    Inverse Problems is a field of great interest for many applications, such as parameter identification and image reconstruction. The underlying models of inverse problems in many applications often involve Partial Differential Equations (PDEs). A Reduced Basis (RB) method for solving PDE based inverse problems is introduced in this thesis. The RB has been rigorously established as an efficient approach for solving PDEs in recent years. In this work, we investigate whether the RB method can be used as a regularization for solving ill-posed and nonlinear inverse problems using iterative methods. We rigorously analyze the RB method and prove convergence of the RB approximation to the exact solution. Furthermore, an iterative algorithm is proposed based on gradient method with RB regularization. We also implement the proposed method numerically and apply the algorithm to the inverse problem of Electrical Impedance Tomography (EIT) which is known to be a notoriously ill-posed and nonlinear. For the EIT example, we provide all necessary details and carefully explain each step of the RB method. We also investigate the limitations of the RB method for solving nonlinear inverse problems in general. We conclude that the RB method can be used to solve nonlinear inverse problems with appropriate assumptions however the assumptions are somewhat restrictive and may not be applicable for a wide range of problems.

  8. A Guided Interview Process to Improve Student Pharmacists' Identification of Drug Therapy Problems

    PubMed Central

    Miller, Michael J.; Koenigsfeld, Carrie; Haack, Sally; Hegge, Karly; McCleeary, Erin

    2011-01-01

    Objective To measure agreement between advanced pharmacy practice experience students using a guided interview process and experienced clinical pharmacists using standard practices to identify drug therapy problems. Methods Student pharmacists enrolled in an advanced pharmacy practice experience (APPE) and clinical pharmacists conducted medication therapy management interviews to identify drug therapy problems in elderly patients recruited from the community. Student pharmacists used a guided interview tool, while clinical pharmacists' interviews were conducted using their usual and customary practices. Student pharmacists also were surveyed to determine their perceptions of the interview tool. Results Fair to moderate agreement was observed on student and clinical pharmacists' identification of 4 of 7 drug therapy problems. Of those, agreement was significantly higher than chance for 3 drug therapy problems (adverse drug reaction, dosage too high, and needs additional drug therapy) and not significant for 1 (unnecessary drug therapy). Students strongly agreed that the interview tool was useful but agreed less strongly on recommending its use in practice. Conclusions The guided interview process served as a useful teaching aid to assist student pharmacists to identify drug therapy problems. PMID:21451770

  9. Self-Reported Alcohol and Drug Problems Among Internal Medicine Outpatients: Relationships With Criminal Behavior

    PubMed Central

    Lam, Charlene; Wiederman, Michael W.

    2011-01-01

    Objective: Previous research indicates relationships between alcohol/substance misuse and criminal behavior, but past studies have restricted investigations to atypical samples and/or utilized limited assessments of illegal behavior. In the present study, we explored relationships between alcohol/drug problems and charges for 27 criminal behaviors in a primary care sample. Method: Participants were a cross-sectional sample of 376 consecutive men and women, aged 18 years or older, being seen for nonemergent medical care at an outpatient internal medicine clinic staffed predominantly by residents and located in a midsized, midwestern city in October 2010. Using a self-report survey methodology, we examined relationships between alcohol and drug problems (“Have you ever had a problem with alcohol?” and “Have you ever had a problem with drugs?”) and 27 illegal behaviors as delineated by the categories used by the US Federal Bureau of Investigation. Results: Men with alcohol or drug problems statistically exhibited the greatest number of charges for different forms of illegal behavior (P < .001). These charges were directly related to alcohol/drug misuse (eg, driving under the influence of alcohol or drugs) and otherwise (eg, aggravated assault, simple assault, gambling, larceny-theft). Conclusions: In primary care settings, men with alcohol/drug problems may also have a history of illegal behaviors—a finding that is relevant in terms of social and legal implications. PMID:22454803

  10. Spectral methods for time dependent problems

    NASA Technical Reports Server (NTRS)

    Tadmor, Eitan

    1990-01-01

    Spectral approximations are reviewed for time dependent problems. Some basic ingredients from the spectral Fourier and Chebyshev approximations theory are discussed. A brief survey was made of hyperbolic and parabolic time dependent problems which are dealt with by both the energy method and the related Fourier analysis. The ideas presented above are combined in the study of accuracy stability and convergence of the spectral Fourier approximation to time dependent problems.

  11. Multi-objective optimization methods in drug design.

    PubMed

    Nicolaou, Christos A; Brown, Nathan

    2013-09-01

    Drug discovery is a challenging multi-objective problem where numerous pharmaceutically important objectives need to be adequately satisfied for a solution to be found. The problem is characterized by vast, complex solution spaces further perplexed by the presence of conflicting objectives. Multi-objective optimization methods, designed specifically to address such problems, have been introduced to the drug discovery field over a decade ago and have steadily gained in acceptance ever since. This paper reviews the latest multi-objective methods and applications reported in the literature, specifically in quantitative structure–activity modeling, docking, de novo design and library design. Further, the paper reports on related developments in drug discovery research and advances in the multi-objective optimization field.

  12. Random Walk Method for Potential Problems

    NASA Technical Reports Server (NTRS)

    Krishnamurthy, T.; Raju, I. S.

    2002-01-01

    A local Random Walk Method (RWM) for potential problems governed by Lapalace's and Paragon's equations is developed for two- and three-dimensional problems. The RWM is implemented and demonstrated in a multiprocessor parallel environment on a Beowulf cluster of computers. A speed gain of 16 is achieved as the number of processors is increased from 1 to 23.

  13. Drug-related problems among medical ward patients in Jimma university specialized hospital, Southwest Ethiopia

    PubMed Central

    Tigabu, Bereket Molla; Daba, Daniel; Habte, Belete

    2014-01-01

    Objective: The increasing number of available drugs and drug users, as well as more complex drug regimens led to more side effects and drug interactions and complicates follow-up. The objective of this study was to assess drug-related problems (DRPs) and associated factors in hospitalized patients. Methods: A hospital-based cross-sectional study design was employed. The study was conducted in Jimma University Specialized Hospital, Jimma, located in the south west of Addis Ababa. All patients who were admitted to the medical ward from February 2011 to March 2011 were included in the study. Data on sociodemographic variables, past medical history, drug history, current diagnosis, current medications, vital signs, and relevant laboratory data were collected using semi-structured questionnaire and data collection forms which were filling through patient interview and card review. Data were analyzed using SPSS version 16 for windows. Descriptive statistics, cross-tabs, Chi-square, and logistic regression were utilized. Findings: Out of 257 study participants, 189 (73.5%) had DRPs and a total of 316 DRPs were identified. From the six classes of DRPs studied, 103 (32.6%) cases related to untreated indication or need additional drug therapy, and 49 (15.5%) cases related to high medication dosage. Unnecessary drug therapy in 49 (15.5%) cases, low medication dosage in 44 (13.9%) cases, and ineffective drug therapy in 42 (13.3%) cases were the other classes of problems identified. Noncompliance in 31 (9.8%) cases was the least prevalent DRP. Independent factors which predicted the occurrence of DRPs in the study population were sex, age, polypharmacy, and clinically significant potential drug-drug interactions. The prevalence of DRPs was substantially high (73.5%). Conclusion: Drug-related problems are common among medical ward patients. Indication-related problems, untreated indication and unnecessary drug therapy were the most common types of DRPs among patients of our

  14. Community Development Strategies To Prevent Alcohol and Other Drug Problems.

    ERIC Educational Resources Information Center

    Strategy Alert, 1992

    1992-01-01

    How community-based groups are confronting and preventing alcohol and other drug problems and related crime in their communities is the focus of this publication. A wide range of approaches and strategies, used by 10 nonprofit, community-based organizations representative of urban and rural areas, are presented. Case studies describe two community…

  15. Helping someone with problem drug use: a delphi consensus study of consumers, carers, and clinicians

    PubMed Central

    2011-01-01

    Background Problem use of illicit drugs (i.e. drug abuse or dependence) is associated with considerable health and social harms, highlighting the need for early intervention and engagement with health services. Family members, friends and colleagues play an important role in supporting and assisting individuals with problem drug use to seek professional help, however there are conflicting views about how and when such support should be offered. This paper reports on the development of mental health first aid guidelines for problem drug use in adults, to help inform community members on how to assist someone developing problem drug use or experiencing a drug-related crisis. Methods A systematic review of the scientific and lay literature was conducted to develop a 228-item survey containing potential first-aid strategies to help someone developing a drug problem or experiencing a drug-related crisis. Three panels of experts (29 consumers, 31 carers and 27 clinicians) were recruited from Australia, Canada, New Zealand, the United Kingdom, and the United States. Panel members independently rated the items over three rounds, with strategies reaching consensus on importance written into the guidelines. Results The overall response rate across three rounds was 80% (86% consumers, 81% carers, 74% clinicians). 140 first aid strategies were endorsed as essential or important by 80% or more of panel members. The endorsed strategies provide information and advice on what is problem drug use and its consequences, how to approach a person about their problem drug use, tips for effective communication, what to do if the person is unwilling to change their drug use, what to do if the person does (or does not) want professional help, what are drug-affected states and how to deal with them, how to deal with adverse reactions leading to a medical emergency, and what to do if the person is aggressive. Conclusions The guidelines provide a consensus-based resource for community members

  16. Automated method for study of drug metabolism

    NASA Technical Reports Server (NTRS)

    Furner, R. L.; Feller, D. D.

    1973-01-01

    Commercially available equipment can be modified to provide automated system for assaying drug metabolism by continuous flow-through. System includes steps and devices for mixing drug with enzyme and cofactor in the presence of pure oxygen, dialyzing resulting metabolite against buffer, and determining amount of metabolite by colorimetric method.

  17. Crystallization Methods for Preparation of Nanocrystals for Drug Delivery System.

    PubMed

    Gao, Yuan; Wang, Jingkang; Wang, Yongli; Yin, Qiuxiang; Glennon, Brian; Zhong, Jian; Ouyang, Jinbo; Huang, Xin; Hao, Hongxun

    2015-01-01

    Low water solubility of drug products causes delivery problems such as low bioavailability. The reduced particle size and increased surface area of nanocrystals lead to the increasing of the dissolution rate. The formulation of drug nanocrystals is a robust approach and has been widely applied to drug delivery system (DDS) due to the significant development of nanoscience and nanotechnology. It can be used to improve drug efficacy, provide targeted delivery and minimize side-effects. Crystallization is the main and efficient unit operation to produce nanocrystals. Both traditional crystallization methods such as reactive crystallization, anti-solvent crystallization and new crystallization methods such as supercritical fluid crystallization, high-gravity controlled precipitation can be used to produce nanocrystals. The current mini-review outlines the main crystallization methods addressed in literature. The advantages and disadvantages of each method were summarized and compared.

  18. Potential and problems in ultrasound-responsive drug delivery systems

    PubMed Central

    Zhao, Ying-Zheng; Du, Li-Na; Lu, Cui-Tao; Jin, Yi-Guang; Ge, Shu-Ping

    2013-01-01

    Ultrasound is an important local stimulus for triggering drug release at the target tissue. Ultrasound-responsive drug delivery systems (URDDS) have become an important research focus in targeted therapy. URDDS include many different formulations, such as microbubbles, nanobubbles, nanodroplets, liposomes, emulsions, and micelles. Drugs that can be loaded into URDDS include small molecules, biomacromolecules, and inorganic substances. Fields of clinical application include anticancer therapy, treatment of ischemic myocardium, induction of an immune response, cartilage tissue engineering, transdermal drug delivery, treatment of Huntington’s disease, thrombolysis, and disruption of the blood–brain barrier. This review focuses on recent advances in URDDS, and discusses their formulations, clinical application, and problems, as well as a perspective on their potential use in the future. PMID:23637531

  19. Policy Issues and the Drug Abuse Problem in America: Overview, Critique, and Recommendations.

    ERIC Educational Resources Information Center

    Johnston, Lloyd D.

    The so-called "drug abuse problem" in America is really a constellation of separate but related problems; since a variety of drugs are illicitly used, and drug abuse leads to many derivative problems, both within and outside the United States. This monograph begins by assessing the current state of the drug abuse problem in America, and analyzing…

  20. Regulatory Solutions to the Problem of High Generic Drug Costs

    PubMed Central

    Luo, Jing; Sarpatwari, Ameet; Kesselheim, Aaron S.

    2015-01-01

    Recent reports have highlighted dramatic price increases for several older generic drugs, including a number of essential products used to treat deadly infectious diseases. Although most of these medicines have been widely available at reasonable prices for decades, some manufacturers have seized on unique features of the pharmaceutical marketplace to seek substantial profits. In this Perspective, we examine limitations in current price regulation among public and private payors and consider several reforms that could address the problem of expensive generic drugs through improved competition. PMID:26693494

  1. The averaging method in applied problems

    NASA Astrophysics Data System (ADS)

    Grebenikov, E. A.

    1986-04-01

    The totality of methods, allowing to research complicated non-linear oscillating systems, named in the literature "averaging method" has been given. THe author is describing the constructive part of this method, or a concrete form and corresponding algorithms, on mathematical models, sufficiently general , but built on concrete problems. The style of the book is that the reader interested in the Technics and algorithms of the asymptotic theory of the ordinary differential equations, could solve individually such problems. For specialists in the area of applied mathematics and mechanics.

  2. Collaborative Problem Solving Methods towards Critical Thinking

    ERIC Educational Resources Information Center

    Yin, Khoo Yin; Abdullah, Abdul Ghani Kanesan; Alazidiyeen, Naser Jamil

    2011-01-01

    This research attempts to examine the collaborative problem solving methods towards critical thinking based on economy (AE) and non economy (TE) in the SPM level among students in the lower sixth form. The quasi experiment method that uses the modal of 3X2 factorial is applied. 294 lower sixth form students from ten schools are distributed…

  3. Computer-Aided Drug Design Methods.

    PubMed

    Yu, Wenbo; MacKerell, Alexander D

    2017-01-01

    Computational approaches are useful tools to interpret and guide experiments to expedite the antibiotic drug design process. Structure-based drug design (SBDD) and ligand-based drug design (LBDD) are the two general types of computer-aided drug design (CADD) approaches in existence. SBDD methods analyze macromolecular target 3-dimensional structural information, typically of proteins or RNA, to identify key sites and interactions that are important for their respective biological functions. Such information can then be utilized to design antibiotic drugs that can compete with essential interactions involving the target and thus interrupt the biological pathways essential for survival of the microorganism(s). LBDD methods focus on known antibiotic ligands for a target to establish a relationship between their physiochemical properties and antibiotic activities, referred to as a structure-activity relationship (SAR), information that can be used for optimization of known drugs or guide the design of new drugs with improved activity. In this chapter, standard CADD protocols for both SBDD and LBDD will be presented with a special focus on methodologies and targets routinely studied in our laboratory for antibiotic drug discoveries.

  4. Spectral methods for exterior elliptic problems

    NASA Technical Reports Server (NTRS)

    Canuto, C.; Hariharan, S. I.; Lustman, L.

    1984-01-01

    Spectral approximations for exterior elliptic problems in two dimensions are discussed. As in the conventional finite difference or finite element methods, the accuracy of the numerical solutions is limited by the order of the numerical farfield conditions. A spectral boundary treatment is introduced at infinity which is compatible with the infinite order interior spectral scheme. Computational results are presented to demonstrate the spectral accuracy attainable. Although a simple Laplace problem is examined, the analysis covers more complex and general cases.

  5. Childhood Sleep Problems, Response Inhibition, and Alcohol and Drug Outcomes in Adolescence and Young Adulthood

    PubMed Central

    Wong, Maria M.; Brower, Kirk J.; Nigg, Joel T.; Zucker, Robert A.

    2014-01-01

    Background To our knowledge, no prospective studies examine the relationships among childhood sleep problems, adolescent executive functioning, and substance outcomes (i.e., substance use and substance-related problems). In this study, we examined whether childhood sleep problems predicted adolescent sleep problems and response inhibition. We also tested whether adolescent sleep problems and poor response inhibition mediated the relationship between childhood sleep problems and substance (alcohol and drug) outcomes in young adulthood. Methods Study participants were 292 boys and 94 girls (M = 4.85, SD = 1.47) from a community sample of high-risk families and controls. Results When compared to their counterparts, those with trouble sleeping in childhood were twice as likely to have the same problem in adolescence. Childhood overtiredness predicted poor response inhibition in adolescence. Persistent trouble sleeping from childhood to adolescence and response inhibition in adolescence mediated the relationship between childhood sleep problems and drug outcomes in young adulthood, whereas overtiredness in childhood directly predicted alcohol use outcomes and alcohol-related problems in young adulthood. Conclusions This is the first study showing a long-term relationship between childhood sleep measures and subsequent alcohol and drug outcomes. The developmental and clinical implications of these findings were discussed. Prevention and intervention programs may want to consider the role of sleep problems and response inhibition on substance use and abuse. PMID:20374209

  6. Post-marketing drug withdrawals: Pharmacovigilance success, regulatory problems.

    PubMed

    Aronson, Jeffrey K

    2017-03-30

    Modern pharmacovigilance began in the 1960s, since when the subject has grown markedly, interest having particularly increased since 2010. One index of its success is the increasing speed with which serious adverse drug reactions are discovered after marketing of a medicinal product. However, the speed with which products have subsequently been withdrawn as a result of the discovery of serious adverse reactions has not consistently changed. This highlights problems that regulators and manufacturers face when serious reactions are discovered, with difficulties in deciding which of several consequent actions to take: to add specific warnings (cautions) or contraindications to the product label; to issue a Direct Healthcare Professional Communication; to allow informed patients to decide whether they will take the drug; or, in the most serious cases, to withdraw the product or revoke the licence. Conflicts of interest may inhibit decision-making. Recommendations that arise from these observations are that: health professionals and patients should be more vigorously encouraged to report suspected adverse drug reactions; regulatory authorities and drug manufacturers should take quicker confirmatory action when serious suspected adverse drug reactions are reported, even anecdotally, with formal studies to test for causality conducted sooner rather than later, applying lower than usual thresholds for suspicion; temporary suspensions or restrictions could be considered during such assessments; universal guidelines are needed for determining when a drug should be withdrawn if serious adverse drug reactions are suspected; there should be more rigorous monitoring and verification of deaths and reporting of reasons for drop-outs during clinical trials, with more transparency in reporting adverse events and ready access to premarketing clinical study reports; post-marketing drug monitoring systems and medicines regulation in low-to-middle income economies, especially in Africa

  7. Teens and the Misuse of Prescription Drugs: Evidence-Based Recommendations to Curb a Growing Societal Problem

    ERIC Educational Resources Information Center

    Twombly, Eric C.; Holtz, Kristen D.

    2008-01-01

    The misuse of prescription drugs by teens in the United States is a growing public health problem. This article provides a systematic synthesis of multiple strands of literature to recommend effective prevention methods. Using a social-ecological framework, we review the scope of the problem of prescription drug use among teens. Then, we analyze…

  8. [Alcohol and drug problems in the Third World].

    PubMed

    Mork, T

    1991-06-10

    The paper reviews recent development in abuse of alcohol, narcotics and psychotropic substances in developing countries. There has been a marked increase in production and sale of alcoholic beverages, and alcohol abuse has spread to new groups of the population. This has led to serious social and health problems in many developing countries. There has also been a substantial increase in abuse of narcotic drugs and psychotropic substances in some developing countries. The illicit production and traffic in narcotic drugs have resulted in more crime and corruption, and in some countries to terrorism and economic and political destabilization. The paper also summarizes activities undertaken within the UN-system in the field of alcohol and drug abuse.

  9. An efficient method for inverse problems

    NASA Technical Reports Server (NTRS)

    Daripa, Prabir

    1987-01-01

    A new inverse method for aerodynamic design of subcritical airfoils is presented. The pressure distribution in this method can be prescribed in a natural way, i.e. as a function of arclength of the as yet unknown body. This inverse problem is shown to be mathematically equivalent to solving a single nonlinear boundary value problem subject to known Dirichlet data on the boundary. The solution to this problem determines the airfoil, the free stream Mach number M(sub x) and the upstream flow direction theta(sub x). The existence of a solution for any given pressure distribution is discussed. The method is easy to implement and extremely efficient. We present a series of results for which comparisons are made with the known airfoils.

  10. Annual Report on the State of the Drugs Problem in the European Union, 2000.

    ERIC Educational Resources Information Center

    European Monitoring Centre for Drugs and Drug Addiction, Lisbon (Portugal).

    This report presents an overview of the drug phenomenon in Europe at the start of the new millennium. The first chapter begins with a discussion of overall drug trends. Specifically, it examines trends in drug use and the consequences including multiple drug use; problem drug use and demand for treatment; drug-related deaths; drug-related…

  11. Problems in the regulatory policy of the drug market

    PubMed Central

    Miziara, Nathália Molleis; Coutinho, Diogo Rosenthal

    2015-01-01

    OBJECTIVE Analyze the implementation of drug price regulation policy by the Drug Market Regulation Chamber. METHODS This is an interview-based study, which was undertaken in 2012, using semi-structured questionnaires with social actors from the pharmaceutical market, the pharmaceuticals industry, consumers and the regulatory agency. In addition, drug prices were compiled based on surveys conducted in the state of Sao Paulo, at the point of sale, between February 2009 and May 2012. RESULTS The mean drug prices charged at the point of sale (pharmacies) were well below the maximum price to the consumer, compared with many drugs sold in Brazil. Between 2009 and 2012, 44 of the 129 prices, corresponding to 99 drugs listed in the database of compiled prices, showed a variation of more than 20.0% in the mean prices at the point of sale and the maximum price to the consumer. In addition, many laboratories have refused to apply the price adequacy coefficient in their sales to government agencies. CONCLUSIONS The regulation implemented by the pharmaceutical market regulator was unable to significantly control prices of marketed drugs, without succeeding to push them to levels lower than those determined by the pharmaceutical industry and failing, therefore, in its objective to promote pharmaceutical support for the public. It is necessary reconstruct the regulatory law to allow market prices to be reduced by the regulator as well as institutional strengthen this government body. PMID:26083945

  12. How the US Food and Drug Administration Can Solve the Prescription Drug Shortage Problem

    PubMed Central

    2013-01-01

    Drug shortages are threatening care quality and cost-containment efforts. I describe the pharmaceutical marketplace changes that have caused the problem, and propose new policies to solve it, through changing incentives for producers and purchasers. I propose a grading scheme for the Food and Drug Administration when it inspects manufacturing facilities in the United States and abroad. The inspections’ focus would change from closing unsafe plants to improving production process quality, reducing the likelihood that plants will be closed—the most frequent cause of drug shortages. PMID:23488502

  13. How the US Food and Drug Administration can solve the prescription drug shortage problem.

    PubMed

    Schweitzer, Stuart O

    2013-05-01

    Drug shortages are threatening care quality and cost-containment efforts. I describe the pharmaceutical marketplace changes that have caused the problem, and propose new policies to solve it, through changing incentives for producers and purchasers. I propose a grading scheme for the Food and Drug Administration when it inspects manufacturing facilities in the United States and abroad. The inspections' focus would change from closing unsafe plants to improving production process quality, reducing the likelihood that plants will be closed-the most frequent cause of drug shortages.

  14. [The Swiss population and drug problems: perception of the problems and proposals for solutions].

    PubMed

    Leuthold, A; Cattaneo, M; Dubois-Arber, F

    1993-01-01

    The aim of this study is to investigate which problems in relation with drug abuse are considered to be the most important by the Swiss population and which measures do they support to reduce them. Base for this study are the results of a representative telephone survey realized in october 1991 with 1004 Swiss residents. People are mostly concerned with problems related to the danger for youth and those concerning public order but also with the human condition of addicts. Drug addicts are considered as people who have lost the sense of live, as sick but also as dangerous and less truthful. Supported are overall prevention, offers for therapies, the repression of trafficking and money-laundering but not of drug users as well as measures going in the direction of harm-minimisation (shooting rooms, medical prescription of drugs). Younger people, those with higher education and the german-speaking population have a more positive view of drug addicts and support measures in the sense of harm-minimisation. Elder people and the french-speaking population have a rather negative view of drug addicts and don't favour measures for harm-minimisation.

  15. Analysis of adverse drug reactions using drug and drug target interactions and graph-based methods.

    PubMed

    Lin, Shih-Fang; Xiao, Ke-Ting; Huang, Yu-Ting; Chiu, Chung-Cheng; Soo, Von-Wun

    2010-01-01

    The purpose of this study was to integrate knowledge about drugs, drug targets, and topological methods. The goals were to build a system facilitating the study of adverse drug events, to make it easier to find possible explanations, and to group similar drug-drug interaction cases in the adverse drug reaction reports from the US Food and Drug Administration (FDA). We developed a system that analyses adverse drug reaction (ADR) cases reported by the FDA. The system contains four modules. First, we integrate drug and drug target databases that provide information related to adverse drug reactions. Second, we classify drug and drug targets according to anatomical therapeutic chemical classification (ATC) and drug target ontology (DTO). Third, we build drug target networks based on drug and drug target databases. Finally, we apply topological analysis to reveal drug interaction complexity for each ADR case reported by the FDA. We picked 1952 ADR cases from the years 2005-2006. Our dataset consisted of 1952 cases, of which 1471 cases involved ADR targets, 845 cases involved absorption, distribution, metabolism, and excretion (ADME) targets, and 507 cases involved some drugs acting on the same targets, namely, common targets (CTs). We then investigated the cases involving ADR targets, ADME targets, and CTs using the ATC system and DTO. In the cases that led to death, the average number of common targets (NCTs) was 0.879 and the average of average clustering coefficient (ACC) was 0.067. In cases that did not lead to death, the average NCTs was 0.551, and the average of ACC was 0.039. We implemented a system that can find possible explanations and cluster similar ADR cases reported by the FDA. We found that the average of ACC and the average NCTs in cases leading to death are higher than in cases not leading to death, suggesting that the interactions in cases leading to death are generally more complicated than in cases not leading to death. This indicates that our system

  16. Transport Test Problems for Hybrid Methods Development

    SciTech Connect

    Shaver, Mark W.; Miller, Erin A.; Wittman, Richard S.; McDonald, Benjamin S.

    2011-12-28

    This report presents 9 test problems to guide testing and development of hybrid calculations for the ADVANTG code at ORNL. These test cases can be used for comparing different types of radiation transport calculations, as well as for guiding the development of variance reduction methods. Cases are drawn primarily from existing or previous calculations with a preference for cases which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22.

  17. Adjoint variational methods in nonconservative stability problems.

    NASA Technical Reports Server (NTRS)

    Prasad, S. N.; Herrmann, G.

    1972-01-01

    A general nonself-adjoint eigenvalue problem is examined and it is shown that the commonly employed approximate methods, such as the Galerkin procedure, the method of weighted residuals and the least square technique lack variational descriptions. When used in their previously known forms they do not yield stationary eigenvalues and eigenfunctions. With the help of an adjoint system, however, several analogous variational descriptions may be developed and it is shown in the present study that by properly restating the method of least squares, stationary eigenvalues may be obtained. Several properties of the adjoint eigenvalue problem, known only for a restricted group, are shown to exist for the more general class selected for study.

  18. Schools and Drugs: Educational Partnership as a Remedy for the School Drug Problem.

    ERIC Educational Resources Information Center

    Seeley, David S.

    This paper applies the concept of educational partnership to the problem of drug use among students. The present structure of public education in the United States is critiqued, and a new structure based on shared responsibility of home, school, and community, and on the voice, educational choice, and loyalty of participants, is proposed. The…

  19. The linear separability problem: some testing methods.

    PubMed

    Elizondo, D

    2006-03-01

    The notion of linear separability is used widely in machine learning research. Learning algorithms that use this concept to learn include neural networks (single layer perceptron and recursive deterministic perceptron), and kernel machines (support vector machines). This paper presents an overview of several of the methods for testing linear separability between two classes. The methods are divided into four groups: Those based on linear programming, those based on computational geometry, one based on neural networks, and one based on quadratic programming. The Fisher linear discriminant method is also presented. A section on the quantification of the complexity of classification problems is included.

  20. Doctors' willingness to intervene in patients' drug and alcohol problems.

    PubMed

    Roche, A M; Richard, G P

    1991-01-01

    A telephone survey of 103 Sydney general practitioners (GPs) was conducted to assess the extent of agreement or disagreement with 15 statements originating from an earlier, focus groups study, concerning patients' drug and alcohol problems. Another aim of the present study was to determine whether the results provided evidence for a typology of general practitioners. A cluster analysis indicated the presence of three groups: Interactive Problem Solvers; Traditionalist Healers and; Distant Technologists. However, a subsequent principal components analysis and re-examination of the distributions of scores lead to the preferred explanation that the survey was measuring a continuous dimension--"Willingness To Intervene" (WTI). Overall, the GPs' responses suggested high levels of willingness to intervene, although older doctors showed less willingness to intervene than younger doctors. Implications of these findings for medical educators are discussed in relation to evidence that, in practice, doctors often fail to intervene in patients' drug and alcohol problems. Willingness to intervene is viewed as one of several necessary factors, such as knowledge, clinical skills and self efficacy, none of which are sufficient alone to guarantee intervention. Arising from consideration of the willingness to intervene dimension, a general model of probability of medical intervention is outlined.

  1. Researching the spiritual dimensions of alcohol and other drug problems.

    PubMed

    Miller, W R

    1998-07-01

    Although religions have been far from silent on the use of psychoactive drugs, and spirituality has long been emphasized as an important factor in recovery from addiction, surprisingly little research has explored the relationships between these two phenomena. Current findings indicate that spiritual/religious involvement may be an important protective factor against alcohol/drug abuse. Individuals currently suffering from these problems are found to have a low level of religious involvement, and spiritual (re)engagement appears to be correlated with recovery. Reasons are explored for the lack of studies testing spiritual hypotheses, and promising avenues for future research are discussed. Comprehensive addictions research should include not only biomedical, psychological and socio-cultural factors but spiritual aspects of the individual as well.

  2. An inverse problem by boundary element method

    SciTech Connect

    Tran-Cong, T.; Nguyen-Thien, T.; Graham, A.L.

    1996-02-01

    Boundary Element Methods (BEM) have been established as useful and powerful tools in a wide range of engineering applications, e.g. Brebbia et al. In this paper, we report a particular three dimensional implementation of a direct boundary integral equation (BIE) formulation and its application to numerical simulations of practical polymer processing operations. In particular, we will focus on the application of the present boundary element technology to simulate an inverse problem in plastics processing.by extrusion. The task is to design profile extrusion dies for plastics. The problem is highly non-linear due to material viscoelastic behaviours as well as unknown free surface conditions. As an example, the technique is shown to be effective in obtaining the die profiles corresponding to a square viscoelastic extrudate under different processing conditions. To further illustrate the capability of the method, examples of other non-trivial extrudate profiles and processing conditions are also given.

  3. An alternative method on quadratic programming problems

    NASA Astrophysics Data System (ADS)

    Dasril, Y.; Mohd, I. B.; Mustaffa, I.; Aminuddin, MMM.

    2015-05-01

    In this paper we proposed an alternative approach to find the optimum solution of quadratic programming problems (QPP) in its original form without additional information such as slack variable, surplus variable or artificial variable as done in other favourite methods. This approached is based on the violated constraints by the unconstrained optimum. The optimal solution of QPP obtained by searching from initial point to another point alongside of feasible region.

  4. Variational Bayesian Approximation methods for inverse problems

    NASA Astrophysics Data System (ADS)

    Mohammad-Djafari, Ali

    2012-09-01

    Variational Bayesian Approximation (VBA) methods are recent tools for effective Bayesian computations. In this paper, these tools are used for inverse problems where the prior models include hidden variables and where where the estimation of the hyper parameters has also to be addressed. In particular two specific prior models (Student-t and mixture of Gaussian models) are considered and details of the algorithms are given.

  5. New drug treatments for alcohol problems: a critical appraisal.

    PubMed

    Moncrieff, J; Drummond, D C

    1997-08-01

    This review considers the novel drug treatments that have been suggested to help prevent relapse or attenuate drinking in people with alcohol problems. The evidence from randomized controlled trials for the efficacy of some of the main candidates: acamprosate, naltrexone, bromocriptine, selective serotonin re-uptake inhibitors and buspirone, was examined. Important methodological problems which may have introduced bias were detected in many of the trials. These included failure to test the integrity of the double blind, excluding or estimating outcome in early withdrawals and the comparison of groups on multiple outcome measures with selective reporting of results. In addition, the generalizability of some studies was limited by the procedures used for sample selection. In view of the potential adverse effects of drug treatment it is concluded that the evidence is not strong enough to support the introduction of any of these substances into routine clinical practice at present. The review also emphasizes the importance of methodological rigour to maximize objectivity in treatment evaluation research.

  6. [Drug-facilitated crime: a public health problem?].

    PubMed

    Goullé, Jean-Pierre; Saussereau, Elodie; Guerbet, Michel; Lacroix, Christian

    2010-02-01

    Drug-facilitated crime (DFC) is well known to the public, yet general practitioners and other physicians are unfamiliar with this issue, largely because toxicology is not part of the medical curriculum. This often leads to diagnostic errors. The frequency of DFC is underestimated, often owing to late examination and analytical problems. On 24 December 2002 the French authorities issued a circular defining DFC as "the administration of a psychoactive drug without the victim's knowledge, as a means of aggression"; and listing places where victims can be managed On 19 July 2005, the French Agency for Health Product Safety (Afssaps) sent a letter to all professionals potentially concerned by this issue, offering guidelines for both medical personnel and laboratory staff conducting toxicological investigations. One difficulty in drug identification is that the doses administered are often low. Toxicology laboratories need sophisticated equipment and expertise to ensure that the perpetrator is prosecuted or, alternatively, to rule out DFC. More information is needed, not only for the public but also for physicians and toxicologists. Benzodiazepines and related compounds are identified in about 75% of DFC cases.

  7. A meshless method for unbounded acoustic problems.

    PubMed

    Shojaei, Arman; Boroomand, Bijan; Soleimanifar, Ehsan

    2016-05-01

    In this paper an effective meshless method is proposed to solve time-harmonic acoustic problems defined on unbounded domains. To this end, the near field is discretized by a set of nodes and the far field effect is taken into account by considering radiative boundary conditions. The approximation within the near field is performed using a set of local residual-free basis functions defined on a series of finite clouds. For considering the far field effect, a series of infinite clouds are defined on which another set of residual-free bases, satisfying the radiation conditions, are considered for the approximation. Validation of the results is performed through solving some acoustic problems.

  8. Drugs-nutrient interactions: a potential problem during adolescence.

    PubMed

    Alonso-Aperte, E; Varela-Moreiras, G

    2000-03-01

    The concept of drug-nutrient interactions is not new, but it has only recently gained currency in medicine. Although the elderly are normally considered to be at particular risk, other groups may also be at risk: infants, adolescents, pregnant women, alcohol and tobacco users, etc. In infants and adolescents there are several factors that may influence the possible interactions: firstly, nutrient needs are usually higher, mainly micronutrients; systems for detoxification of anutrients are not complete; the tendency to restricted diets (especially girls) that are unable to cover the actual recommended intakes for a number of micronutrients (i.e. vitamins); and the dangerous increase in alcohol consumption either in males or females. Administration of drugs in population with adequate vitamin intake is usually not a problem, but administration of drugs in those with borderline intake of vitamins or in patients with low nutritional status can result in symptomatic vitamin deficiency states. The groups at risk of poor vitamin status are smokers (a high proportion of adolescents are active smokers); dieters (skipping meals and dieting to lose weight frequently compromise micronutrient intake, and it should be considered that it is extremely difficult to meet all the requirements at intakes of less than 1,200 calories per day), oral contraceptive users, and pregnant and lactating women, excessive alcohol users, etc. The chapter also focuses on the case of folate: rapidly dividing tissues during the adolescent growth spurt increase requirements for folate. Because of this increased need, folate status appears to be of concern during the age of this rapid growth. A variety of drugs are known to interfere with vitamin utilization by blocking or altering transformation of the vitamin to its metabolically active form. Serum folate levels are known to be low in a high percentage of patients with rheumatoid arthritis, suggesting that aspirin alters the transport of folate by

  9. Implicit Extrapolation Methods for Variable Coefficient Problems

    NASA Technical Reports Server (NTRS)

    Jung, M.; Ruede, U.

    1996-01-01

    Implicit extrapolation methods for the solution of partial differential equations are based on applying the extrapolation principle indirectly. Multigrid tau-extrapolation is a special case of this idea. In the context of multilevel finite element methods, an algorithm of this type can be used to raise the approximation order, even when the meshes are nonuniform or locally refined. Here previous results are generalized to the variable coefficient case and thus become applicable for nonlinear problems. The implicit extrapolation multigrid algorithm converges to the solution of a higher order finite element system. This is obtained without explicitly constructing higher order stiffness matrices but by applying extrapolation in a natural form within the algorithm. The algorithm requires only a small change of a basic low order multigrid method.

  10. Numerical methods for problems in computational aeroacoustics

    NASA Astrophysics Data System (ADS)

    Mead, Jodi Lorraine

    1998-12-01

    A goal of computational aeroacoustics is the accurate calculation of noise from a jet in the far field. This work concerns the numerical aspects of accurately calculating acoustic waves over large distances and long time. More specifically, the stability, efficiency, accuracy, dispersion and dissipation in spatial discretizations, time stepping schemes, and absorbing boundaries for the direct solution of wave propagation problems are determined. Efficient finite difference methods developed by Tam and Webb, which minimize dispersion and dissipation, are commonly used for the spatial and temporal discretization. Alternatively, high order pseudospectral methods can be made more efficient by using the grid transformation introduced by Kosloff and Tal-Ezer. Work in this dissertation confirms that the grid transformation introduced by Kosloff and Tal-Ezer is not spectrally accurate because, in the limit, the grid transformation forces zero derivatives at the boundaries. If a small number of grid points are used, it is shown that approximations with the Chebyshev pseudospectral method with the Kosloff and Tal-Ezer grid transformation are as accurate as with the Chebyshev pseudospectral method. This result is based on the analysis of the phase and amplitude errors of these methods, and their use for the solution of a benchmark problem in computational aeroacoustics. For the grid transformed Chebyshev method with a small number of grid points it is, however, more appropriate to compare its accuracy with that of high- order finite difference methods. This comparison, for an order of accuracy 10-3 for a benchmark problem in computational aeroacoustics, is performed for the grid transformed Chebyshev method and the fourth order finite difference method of Tam. Solutions with the finite difference method are as accurate. and the finite difference method is more efficient than, the Chebyshev pseudospectral method with the grid transformation. The efficiency of the Chebyshev

  11. Prevalence of skin problems and leg ulceration in a sample of young injecting drug users

    PubMed Central

    2014-01-01

    Background Drug users suffer harm from the injecting process, and clinical services are reporting increasing numbers presenting with skin-related problems such as abscesses and leg ulcers. Skin breakdown can lead to long-term health problems and increased service costs and is often the first indication of serious systemic ill health. The extent of skin problems in injecting drug users has not previously been quantified empirically, and there is a dearth of robust topical literature. Where skin problems have been reported, this is often without clear definition and generic terms such as ‘soft tissue infection’ are used which lack specificity. The aim of this study was to identify the range and extent of skin problems including leg ulceration in a sample of injecting drug users. Definitions of skin problems were developed and applied to descriptions from drug users to improve rigour. Methods Data were collected in needle exchanges and methadone clinics across Glasgow, Scotland, from both current and former drug injectors using face-to-face interviews. Results Two hundred participants were recruited, of which 74% (n = 148) were males and 26% (n = 52) were females. The age range was 21–44 years (mean 35 years). Just under two thirds (64%, n = 127) were currently injecting or had injected within the last 6 months, and 36% (n = 73) had previously injected and had not injected for more than 6 months. Sixty per cent (n = 120) of the sample had experienced a skin problem, and the majority reported more than one problem. Most common were abscesses, lumps, track marks and leg ulcers. Fifteen per cent (n = 30) of all participants reported having had a leg ulcer. Conclusions This is an original empirical study which demonstrated unique findings of a high prevalence of skin disease (60%) and surprisingly high rates of leg ulceration (15%). Skin disease in injecting drug users is clearly widespread. Leg ulceration in particular is a chronic recurring

  12. Methods for Anticipating Problems with Electrical Wiring

    NASA Technical Reports Server (NTRS)

    Yost, William T. (Inventor); Cramer, K. Elliott (Inventor); Perey, Daniel F. (Inventor)

    2005-01-01

    Passive and active methods for anticipating problems with electrical wiring are provided. An insulative material in contact with an electrical conductor has at least one impurity that is impregnated in the insulative material and/or disposed thereon. An environment around the electrical conductor is monitored for the presence or the level of the impurity(ies) emanating from the insulative material in the form of a gaseous effluent. An alarm signal is generated when a predetermined level of the gaseous effluent is detected.

  13. Kinetics methods for clinical epidemiology problems

    PubMed Central

    Corlan, Alexandru Dan; Ross, John

    2015-01-01

    Calculating the probability of each possible outcome for a patient at any time in the future is currently possible only in the simplest cases: short-term prediction in acute diseases of otherwise healthy persons. This problem is to some extent analogous to predicting the concentrations of species in a reactor when knowing initial concentrations and after examining reaction rates at the individual molecule level. The existing theoretical framework behind predicting contagion and the immediate outcome of acute diseases in previously healthy individuals is largely analogous to deterministic kinetics of chemical systems consisting of one or a few reactions. We show that current statistical models commonly used in chronic disease epidemiology correspond to simple stochastic treatment of single reaction systems. The general problem corresponds to stochastic kinetics of complex reaction systems. We attempt to formulate epidemiologic problems related to chronic diseases in chemical kinetics terms. We review methods that may be adapted for use in epidemiology. We show that some reactions cannot fit into the mass-action law paradigm and solutions to these systems would frequently exhibit an antiportfolio effect. We provide a complete example application of stochastic kinetics modeling for a deductive meta-analysis of two papers on atrial fibrillation incidence, prevalence, and mortality. PMID:26578757

  14. Kinetics methods for clinical epidemiology problems.

    PubMed

    Corlan, Alexandru Dan; Ross, John

    2015-11-17

    Calculating the probability of each possible outcome for a patient at any time in the future is currently possible only in the simplest cases: short-term prediction in acute diseases of otherwise healthy persons. This problem is to some extent analogous to predicting the concentrations of species in a reactor when knowing initial concentrations and after examining reaction rates at the individual molecule level. The existing theoretical framework behind predicting contagion and the immediate outcome of acute diseases in previously healthy individuals is largely analogous to deterministic kinetics of chemical systems consisting of one or a few reactions. We show that current statistical models commonly used in chronic disease epidemiology correspond to simple stochastic treatment of single reaction systems. The general problem corresponds to stochastic kinetics of complex reaction systems. We attempt to formulate epidemiologic problems related to chronic diseases in chemical kinetics terms. We review methods that may be adapted for use in epidemiology. We show that some reactions cannot fit into the mass-action law paradigm and solutions to these systems would frequently exhibit an antiportfolio effect. We provide a complete example application of stochastic kinetics modeling for a deductive meta-analysis of two papers on atrial fibrillation incidence, prevalence, and mortality.

  15. Potential new methods for antiepileptic drug delivery.

    PubMed

    Fisher, Robert S; Ho, Jet

    2002-01-01

    Use of novel drug delivery methods could enhance the efficacy and reduce the toxicity of antiepileptic drugs (AEDs). Slow-release oral forms of medication or depot drugs such as skin patches might improve compliance and therefore seizure control. In emergency situations, administration via rectal, nasal or buccal mucosa can deliver the drug more quickly than can oral administration. Slow-release oral forms and rectal forms of AEDs are already approved for use, nasal and buccal administration is currently off-label and skin patches for AEDs are an attractive but currently hypothetical option. Therapies under development may result in the delivery of AEDs directly to the regions of the brain involved in seizures. Experimental protocols are underway to allow continuous infusion of potent excitatory amino acid antagonists into the CSF. In experiments with animal models of epilepsy, AEDs have been delivered successfully to seizure foci in the brain by programmed infusion pumps, acting in response to computerised EEG seizure detection. Inactive prodrugs can be given systemically and activated at the site of the seizure focus by locally released compounds. One such drug under development is DP-VPA (or DP16), which is cleaved to valproic acid (sodium valproate) by phospholipases at the seizure focus. Liposomes and nanoparticles are engineered micro-reservoirs of a drug, with attached antibodies or receptor-specific binding agents designed to target the particles to a specific region of the body. Liposomes in theory could deliver a high concentration of an AED to a seizure focus. Penetration of the blood-brain barrier can be accomplished by linking large particles to iron transferrin or biological toxins that can cross the barrier. In the near future, it is likely that cell transplants that generate neurotransmitters and neuromodulators will accomplish renewable endogenous drug delivery. However, the survival and viability of transplanted cells have yet to be demonstrated

  16. Drug susceptibility testing by dilution methods.

    PubMed

    Jeannot, Katy; Plésiat, Patrick

    2014-01-01

    Serial twofold dilution methods are widely used to assess the bacteriostatic activities of antibiotics. This can be achieved by dilution of considered drugs in agar medium or in culture broth, and inoculation by calibrated inoculums. Although seemingly simple, these methods are greatly influenced by the experimental conditions used and may lead to discrepant results, in particular with untrained investigators. The present step-by-step protocol has been validated for Pseudomonas species, including P. aeruginosa. Introduction of appropriate control strains is crucial to ascertain minimal inhibitory concentration values and compare the results of independent experiments.

  17. Hybrid intelligent optimization methods for engineering problems

    NASA Astrophysics Data System (ADS)

    Pehlivanoglu, Yasin Volkan

    The purpose of optimization is to obtain the best solution under certain conditions. There are numerous optimization methods because different problems need different solution methodologies; therefore, it is difficult to construct patterns. Also mathematical modeling of a natural phenomenon is almost based on differentials. Differential equations are constructed with relative increments among the factors related to yield. Therefore, the gradients of these increments are essential to search the yield space. However, the landscape of yield is not a simple one and mostly multi-modal. Another issue is differentiability. Engineering design problems are usually nonlinear and they sometimes exhibit discontinuous derivatives for the objective and constraint functions. Due to these difficulties, non-gradient-based algorithms have become more popular in recent decades. Genetic algorithms (GA) and particle swarm optimization (PSO) algorithms are popular, non-gradient based algorithms. Both are population-based search algorithms and have multiple points for initiation. A significant difference from a gradient-based method is the nature of the search methodologies. For example, randomness is essential for the search in GA or PSO. Hence, they are also called stochastic optimization methods. These algorithms are simple, robust, and have high fidelity. However, they suffer from similar defects, such as, premature convergence, less accuracy, or large computational time. The premature convergence is sometimes inevitable due to the lack of diversity. As the generations of particles or individuals in the population evolve, they may lose their diversity and become similar to each other. To overcome this issue, we studied the diversity concept in GA and PSO algorithms. Diversity is essential for a healthy search, and mutations are the basic operators to provide the necessary variety within a population. After having a close scrutiny of the diversity concept based on qualification and

  18. [A proposal for the prevention of ethical problems related to drug promotion: a national network for drug information].

    PubMed

    Civaner, Murat

    2008-01-01

    The promotional activities of pharmaceutical companies are becoming an increasingly hot topic among healthcare workers and the general public. There are many studies in the literature claiming that drug promotion may lead to ethical problems, irrational use of medication, and increased costs, as well as negative effects on the patient-physician relationship and the medical profession. When considering that healthcare workers generally acquire their knowledge from the pharmaceutical industry, the problems mentioned, which are indeed of paramount importance, and the need for effective and sustainable interventions are clearly revealed. Many kinds of interventions have been recommended by various authorities and studies in order to prevent the kinds of problems mentioned above, including training healthcare workers, publishing professional codes to serve as guidelines about which professional values should be protected and how to cope with different situations in relationship to the pharmaceutical industry, or applying the business ethics codes of the pharmaceutical companies. Studies that assessed the effectiveness of different interventions, however, revealed that educating healthcare workers about marketing methods and state regulations are the only effective interventions. In this article, after defining the problem, a proposed national network for drug information is to decrease the negative effects of drug promotion and to promote the rational choice of medicines is described. According to the World Health Organization, rational use of medicine is the most effective, safe, applicable/suitable, and, lastly, the most cost effective option. A national network that will gather drug information by compiling evidence-based knowledge and taking rational use of medicine measures into account should be established. It should transmit information to all healthcare workers in a fast, equal, up to date, easily accessible, and free way. The network should also support

  19. College Students' Perceptions of Severity and Willingness to Seek Psychological Help For Drug and Alcohol Problems

    ERIC Educational Resources Information Center

    Lowinger, Robert Jay

    2012-01-01

    A sample of 201 college students were surveyed with respect to their perceptions of severity and willingness to seek psychological help for drug and alcohol problems. Results indicated that students perceive alcohol problems as significantly less serious than drug problems and are significantly less willing to seek help for alcohol problems. Males…

  20. College Students' Perceptions of Severity and Willingness to Seek Psychological Help For Drug and Alcohol Problems

    ERIC Educational Resources Information Center

    Lowinger, Robert Jay

    2012-01-01

    A sample of 201 college students were surveyed with respect to their perceptions of severity and willingness to seek psychological help for drug and alcohol problems. Results indicated that students perceive alcohol problems as significantly less serious than drug problems and are significantly less willing to seek help for alcohol problems. Males…

  1. The Commissioning and Provision of Advocacy for Problem Drug Users in English DATS: A Cross-Sectional Survey

    ERIC Educational Resources Information Center

    Cargill, Tamsin; Weaver, Tim D.; Patterson, Sue

    2012-01-01

    Aims: This study investigated the commissioning and delivery of advocacy for problem drug users. We aimed to quantify provision, describe the commissioning of advocacy services in Drug Action Teams (DATs) and to identify factors influencing advocacy provision. Methods: A cross-sectional survey of a randomly selected sample of 50 English DATs. The…

  2. The Commissioning and Provision of Advocacy for Problem Drug Users in English DATS: A Cross-Sectional Survey

    ERIC Educational Resources Information Center

    Cargill, Tamsin; Weaver, Tim D.; Patterson, Sue

    2012-01-01

    Aims: This study investigated the commissioning and delivery of advocacy for problem drug users. We aimed to quantify provision, describe the commissioning of advocacy services in Drug Action Teams (DATs) and to identify factors influencing advocacy provision. Methods: A cross-sectional survey of a randomly selected sample of 50 English DATs. The…

  3. Drug-related problems in medical wards of Tikur Anbessa specialized hospital, Ethiopia

    PubMed Central

    Ayalew, Mohammed Biset; Megersa, Teshome Nedi; Mengistu, Yewondwossen Taddese

    2015-01-01

    Objective: This study was aimed to determine the prevalence of drug-related problems (DRPs), identify the most common drugs, and drug classes involved in DRPs as well as associated factors with the occurrence of DRPs. Methods: A prospective cross-sectional study was conducted on 225 patients admitted to medical wards of Tikur Anbessa Specialized Hospital, Addis Ababa from March to June 2014. Data regarding patient characteristics, medications, diagnosis, length of hospitalization, investigation, and laboratory results were collected using data abstraction forms through review of patients’ medical card and medication charts. Identified DRPs were recorded and classified using DRP registration forms. The possible intervention measures for the identified DRPs were proposed and communicated to either the physician or the patient. Data were entered into Epi Info 7 and analyzed using SPSS version 21 (IBM Corp. Released 2012, Armonk, NY: IBM Corp). Findings: DRPs were found in 52% of study subjects. A drug-drug interaction (48% of all DRPs) was the most common DRP followed by adverse drug reaction (23%). Anti-infectives and gastrointestinal medicines were commonly involved in DRPs. Drugs with the highest drug risk ratio were gentamycin, warfarin, nifedipine, and cimetidine. The number of drugs taken by the patient per day is an important risk factor for DRPs. Conclusion: DRPs are common among medical ward patients. Polypharmacy has a significant association with the occurrence of DRP. Drugs such as gentamycin, warfarin, nifedipine, and cimetidine have the highest probability of causing DRP. So, patients who are taking either of these drugs or polypharmacy should be closely assessed for identification and timely correction of DRPs. PMID:26645029

  4. Incompatible numerical manifold method for fracture problems

    NASA Astrophysics Data System (ADS)

    Wei, Gaofeng; Li, Kaitai; Jiang, Haihui

    2010-05-01

    The incompatible numerical manifold method (INMM) is based on the finite cover approximation theory, which provides a unified framework for problems dealing with continuum and discontinuities. The incompatible numerical manifold method employs two cover systems as follows. The mathematical cover system provides the nodes for forming finite covers of the solution domain and the weighted functions, and the physical cover system describes geometry of the domain and the discontinuous surfaces therein. In INMM, the mathematical finite cover approximation theory is used to model cracks that lead to interior discontinuities in the process of displacement. Therefore, the discontinuity is treated mathematically instead of empirically by the existing methods. However, one cover of a node is divided into two irregular sub-covers when the INMM is used to model the discontinuity. As a result, the method sometimes causes numerical errors at the tip of a crack. To improve the precision of the INMM, the analytical solution is used at the tip of a crack, and thus the cover displacement functions are extended with higher precision and computational efficiency. Some numerical examples are given.

  5. [Effects of the new comprehensive system for designating illegal drug components on the abuse of designer drugs and future problems based on an online questionnaire].

    PubMed

    Morino, Taichi; Okazaki, Mitsuhiro; Toda, Takaki; Yokoyama, Takashi

    2015-12-01

    Recently, the abuse of designer drugs has become a social problem. Designer drugs are created by modifying part of the chemical structure of drugs that have already been categorized as illegal, thereby creating a different chemical compound in order to evade Pharmaceutical Affairs Law regulations. The new comprehensive system for designating illegal drug components has been in effect since March 2013, and many designer drugs can now be regulated. We conducted an online questionnaire survey of people with a history of designer drug use to elucidate the effects of the new system on the abuse of designer drugs and to identify potential future problems. Over half the subjects obtained designer drugs only before the new system was implemented. Awareness of the system was significantly lower among subjects who obtained designer drugs for the first time after its introduction than those who obtained the drugs only before its implementation. Due to the new system, all methods of acquiring designer drugs saw decreases in activity. However, the ratio of the acquisition of designer drugs via the Internet increased. Since over 50% of the subjects never obtained designer drugs after the new system was introduced, goals that aimed to make drug procurement more difficult were achieved. However, awareness of the new system among subjects who obtained designer drugs after the new system was introduced was significantly low. Therefore, fostering greater public awareness of the new system is necessary. The results of the questionnaire also suggested that acquiring designer drugs through the Internet has hardly been affected by the new system. We strongly hope that there will be a greater push to restrict the sale of designer drugs on the Internet in the near future.

  6. MIB Galerkin method for elliptic interface problems

    PubMed Central

    Xia, Kelin; Zhan, Meng; Wei, Guo-Wei

    2014-01-01

    Summary Material interfaces are omnipresent in the real-world structures and devices. Mathematical modeling of material interfaces often leads to elliptic partial differential equations (PDEs) with discontinuous coefficients and singular sources, which are commonly called elliptic interface problems. The development of high-order numerical schemes for elliptic interface problems has become a well defined field in applied and computational mathematics and attracted much attention in the past decades. Despite of significant advances, challenges remain in the construction of high-order schemes for nonsmooth interfaces, i.e., interfaces with geometric singularities, such as tips, cusps and sharp edges. The challenge of geometric singularities is amplified when they are associated with low solution regularities, e.g., tip-geometry effects in many fields. The present work introduces a matched interface and boundary (MIB) Galerkin method for solving two-dimensional (2D) elliptic PDEs with complex interfaces, geometric singularities and low solution regularities. The Cartesian grid based triangular elements are employed to avoid the time consuming mesh generation procedure. Consequently, the interface cuts through elements. To ensure the continuity of classic basis functions across the interface, two sets of overlapping elements, called MIB elements, are defined near the interface. As a result, differentiation can be computed near the interface as if there is no interface. Interpolation functions are constructed on MIB element spaces to smoothly extend function values across the interface. A set of lowest order interface jump conditions is enforced on the interface, which in turn, determines the interpolation functions. The performance of the proposed MIB Galerkin finite element method is validated by numerical experiments with a wide range of interface geometries, geometric singularities, low regularity solutions and grid resolutions. Extensive numerical studies confirm

  7. MIB Galerkin method for elliptic interface problems.

    PubMed

    Xia, Kelin; Zhan, Meng; Wei, Guo-Wei

    2014-12-15

    Material interfaces are omnipresent in the real-world structures and devices. Mathematical modeling of material interfaces often leads to elliptic partial differential equations (PDEs) with discontinuous coefficients and singular sources, which are commonly called elliptic interface problems. The development of high-order numerical schemes for elliptic interface problems has become a well defined field in applied and computational mathematics and attracted much attention in the past decades. Despite of significant advances, challenges remain in the construction of high-order schemes for nonsmooth interfaces, i.e., interfaces with geometric singularities, such as tips, cusps and sharp edges. The challenge of geometric singularities is amplified when they are associated with low solution regularities, e.g., tip-geometry effects in many fields. The present work introduces a matched interface and boundary (MIB) Galerkin method for solving two-dimensional (2D) elliptic PDEs with complex interfaces, geometric singularities and low solution regularities. The Cartesian grid based triangular elements are employed to avoid the time consuming mesh generation procedure. Consequently, the interface cuts through elements. To ensure the continuity of classic basis functions across the interface, two sets of overlapping elements, called MIB elements, are defined near the interface. As a result, differentiation can be computed near the interface as if there is no interface. Interpolation functions are constructed on MIB element spaces to smoothly extend function values across the interface. A set of lowest order interface jump conditions is enforced on the interface, which in turn, determines the interpolation functions. The performance of the proposed MIB Galerkin finite element method is validated by numerical experiments with a wide range of interface geometries, geometric singularities, low regularity solutions and grid resolutions. Extensive numerical studies confirm the

  8. The Long-term Effects of Childhood Maltreatment Experiences on Subsequent Illicit Drug Use and Drug-related Problems in Young Adulthood

    PubMed Central

    Huang, Shi; Trapido, Edward; Fleming, Lora; Arheart, Kristopher; Crandall, Lee; French, Michael; Malcolm, Shandey; Prado, Guillermo

    2010-01-01

    OBJECTIVES The objective of this study was to examine the associations between (a) childhood maltreatment (i.e., physical abuse, sexual abuse, and neglect) and subsequent illicit drug use and (b) childhood maltreatment and drug-related problems in young adulthood. METHODS Wave 1 and Wave 3 public-use data from the National Longitudinal Study of Adolescent Health were used. Logistic regressions, controlling for adolescent drug use and other important family and peer contextual processes, were estimated to determine the associations between (a) childhood maltreatment experiences and subsequent illicit drug use and (b) childhood maltreatment and drug-related problems in young adulthood. RESULTS Among the participants, 31.9% reported some form of childhood maltreatment. Childhood physical abuse was associated with a 37% (OR=1.37; 95% CI=1.04, 1.80) increase in illicit drug use during the 30 days prior to the Wave 3 survey, a 48% (OR=1.48; 95% CI=1.16, 1.89) increase in illicit drug use during the year prior to the Wave 3 survey, and a 96% (OR=1.96; 95% CI=1.40, 2.76) increase in drug-related problems in young adulthood. The latter two associations persisted even after controlling for illicit drug use in adolescence. Neglect among females was associated with a higher likelihood of past year illicit drug use in young adulthood (OR=1.31; 95% CI=1.002, 1.71). However, this association was not significant once the effect of illicit drug use in adolescence was statistically controlled for. CONCLUSIONS The present findings suggest that childhood maltreatment is related to subsequent illicit drug use and drug-related problems in young adulthood and that some of these associations differ by gender. Implications for preventive intervention are discussed. PMID:20947260

  9. Problem drinking and the dimension of involvement with drugs: a Guttman scalogram analysis of adolescent drug use.

    PubMed Central

    Donovan, J E; Jessor, R

    1983-01-01

    Analyses of data from two nationwide surveys of high school students, one carried out in 1974 and the other in 1978, suggest that problem drinking may be seen as yet another step along an underlying dimension of involvement with both licit and illicit drugs. The dimension of involvement with drugs consists of the following levels: nonuse of alcohol or illicit drugs; nonproblem use of alcohol; marijuana use; problem drinking; use of pills (amphetamines, barbiturates, hallucinogenic drugs); and the use of "hard drugs" such as cocaine or heroin. The dimension possesses excellent Guttman-scale properties in both national samples as well as in subsamples differing in gender and ethnic background. The ordering of the levels of involvement was confirmed by the ordering of the alcohol-drug involvement groups based on their mean scores on measures of psychosocial proneness for involvement in problem behavior. The excessive use of a licit drug, i.e., problem drinking, appears to indicate greater involvement in drug use than does the use of an illicit drug, marijuana. This finding points to the importance of distinguishing between use and problem use of drugs in efforts to understand adolescent drug involvement. PMID:6837819

  10. Tuberculosis in London: the importance of homelessness, problem drug use and prison

    PubMed Central

    Story, A; Murad, S; Roberts, W; Verheyen, M; Hayward, A C

    2007-01-01

    Background The control of tuberculosis (TB) is founded on early case detection and complete treatment of disease. In the UK, TB is concentrated in subgroups of the population in large urban centres. The impact of homelessness, imprisonment and problem drug use on TB control in London is reviewed. Methods A cohort study was undertaken of all patients with TB in Greater London to determine the point prevalence of disease in different groups and to examine risk factors for smear positivity, drug resistance, treatment adherence, loss to follow‐up and use of directly observed therapy (DOT). Results Data were collected on 97% (1941/1995) of eligible patients. The overall prevalence of TB was 27 per 100 000. An extremely high prevalence of TB was seen in homeless people (788/100 000), problem drug users (354/100 000) and prisoners (208/100 000). Multivariate analysis showed that problem drug use was associated with smear positive disease (OR 2.2, p<0.001), being part of a known outbreak of drug resistant TB (OR 3.5, p = 0.001) and loss to follow‐up (OR 2.7, p<0.001). Imprisonment was associated with being part of the outbreak (OR 10.3, p<0.001) and poor adherence (OR 3.9, p<0.001). Homelessness was associated with infectious TB (OR 1.6, p = 0.05), multidrug resistance (OR 2.1, p = 0.03), poor adherence (OR 2.5, p<0.001) and loss to follow‐up (OR 3.8, p<0.001). In London, homeless people, prisoners and problem drug users collectively comprise 17% of TB cases, 44% of smear positive drug resistant cases, 38% of poorly compliant cases and 44% of cases lost to follow‐up. 15% of these patients start treatment on DOT but 46% end up on DOT. Conclusions High levels of infectious and drug resistant disease, poor adherence and loss to follow‐up care indicate that TB is not effectively controlled among homeless people, prisoners and problem drug users in London. PMID:17289861

  11. Racial discrimination, post-traumatic stress and prescription drug problems among Aboriginal Canadians.

    PubMed

    Currie, Cheryl; Wild, T Cameron; Schopflocher, Donald; Laing, Lory

    2015-06-24

    1) To examine associations between racial discrimination and drug problems among urban-based Aboriginal adults; and 2) to determine whether these associations are best explained by symptoms of psychological stress, distress or post-traumatic stress disorder (PTSD). Data were collected through in-person surveys with a community-based sample of Aboriginal adults (N = 372) living in a mid-sized city in western Canada in 2010. Associations were examined using bootstrapped linear regression models adjusted for confounders, with continuous prescription and illicit drug problem scores as outcomes. Mediation was examined using the cross-products of coefficients method. More than 80% of Aboriginal adults had experienced racial discrimination in the past year, with the majority reporting high levels in that period. Past-year discrimination was a risk factor for PTSD symptoms and prescription drug problems in models adjusted for confounders and other forms of psychological trauma. In mediation models, PTSD symptoms explained the association between discrimination and prescription drug problems; psychological stress and distress did not. PTSD symptoms also explained this association when the covariance between mediators was controlled. The results also indicate that participation in Aboriginal cultural traditions was associated with increased discrimination. Most efforts to address Aboriginal health inequities in Canada have focused on the role Aboriginal people play in these disparities. The current findings combine with others to call for an expanded focus. Non-Aboriginal Canadians may also play a role in the health inequities observed. The findings of this study suggest efforts to reduce discrimination experienced by Aboriginal adults in cities may reduce PTSD symptomology and prescription drug problems in these populations.

  12. Alcohol and Drugs in Schools: Teachers' Reactions to the Problem

    ERIC Educational Resources Information Center

    Finn, Kristin V.; Willert, H. Jeannette

    2006-01-01

    Although schools are places for learning and growth, they are also places where students engage in alcohol and drug use. This study showed that most teachers were aware of drugs in their schools, but did not regard drug use as an interference in their own classrooms. Many teachers were knowledgeable about their schools' drug policy, but did not…

  13. Do You or a Loved One Have a Drug Use Problem?

    MedlinePlus

    ... Have a Drug Use Problem? Do You or a Loved One Have a Drug Use Problem? Listen PDF: EasyToRead_WhatIsAddiction_Final_ ... treatment centers in your area. Do you think a lot about drugs? Did you ever try to ...

  14. Optimization methods for activities selection problems

    NASA Astrophysics Data System (ADS)

    Mahad, Nor Faradilah; Alias, Suriana; Yaakop, Siti Zulaika; Arshad, Norul Amanina Mohd; Mazni, Elis Sofia

    2017-08-01

    Co-curriculum activities must be joined by every student in Malaysia and these activities bring a lot of benefits to the students. By joining these activities, the students can learn about the time management and they can developing many useful skills. This project focuses on the selection of co-curriculum activities in secondary school using the optimization methods which are the Analytic Hierarchy Process (AHP) and Zero-One Goal Programming (ZOGP). A secondary school in Negeri Sembilan, Malaysia was chosen as a case study. A set of questionnaires were distributed randomly to calculate the weighted for each activity based on the 3 chosen criteria which are soft skills, interesting activities and performances. The weighted was calculated by using AHP and the results showed that the most important criteria is soft skills. Then, the ZOGP model will be analyzed by using LINGO Software version 15.0. There are two priorities to be considered. The first priority which is to minimize the budget for the activities is achieved since the total budget can be reduced by RM233.00. Therefore, the total budget to implement the selected activities is RM11,195.00. The second priority which is to select the co-curriculum activities is also achieved. The results showed that 9 out of 15 activities were selected. Thus, it can concluded that AHP and ZOGP approach can be used as the optimization methods for activities selection problem.

  15. Problem gambling and comorbid psychiatric and substance use disorders among drug users recruited from drug treatment and community settings.

    PubMed

    Cunningham-Williams, R M; Cottler, L B; Compton, W M; Spitznagel, E L; Ben-Abdallah, A

    2000-01-01

    Little is known about gambling rates of drug users recruited from drug treatment compared with those recruited from the community. We use the Diagnostic Interview Schedule (DIS) to provide lifetime prevalence estimates of problem gambling (i.e., at least one gambling problem) and DSM-III-R pathological gambling (i.e., at least four gambling problems) and describe the association between gambling and psychiatric disorders for drug users recruited from drug treatment settings (n = 512) and from the community (n = 478). We also report the relative risk of being a recreational and problem gambler in this sample. The sample was first interviewed in 1989-90 as a part of two NIDA-funded St. Louis-based studies. The prevalence of problem gambling in the overall sample was 22% and the prevalence of pathological gambling was 11%. There were no statistically significant differences in problem and pathological gambling rates for subjects recruited from drug treatment and those recruited from the community. The conditional prevalence rates, that is, the rate of problem and pathological gambling only among gamblers were 27% and 13.5%, respectively. Major findings indicate that problem gambling was associated with Antisocial Personality Disorder (ASPD), even after controlling for recruitment source and socio-demographic characteristics. In fact, when examining the temporal order of these disorders, we found that pathological gambling was always secondary to ASPD, occurring on average 11.4 years after the onset of ASPD. Problem gamblers, compared with everyone else, were more likely to be male, African-American, recruited from drug treatment, have ASPD and be dependent on illicit drugs. Multinomial logistic regression analysis predicted the relative risk of being a recreational and problem gambler (compared with a nongambler) in this sample according to socio-demographics, ASPD, and dependence on illicit drugs. Results imply that screening for gambling problems will need to be

  16. Problems and Solutions in Click Chemistry Applied to Drug Probes

    PubMed Central

    Zhong, Weilong; Sun, Bo; Lu, Cheng; Yu, Hengheng; Wang, Changhua; He, Lingfei; Gu, Ju; Chen, Shuang; Liu, Yanrong; Jing, Xiangyan; Bi, Zhun; Yang, Guang; Zhou, Honggang; Sun, Tao; Yang, Cheng

    2016-01-01

    Small-molecule fluorescent probes have been widely used in target identification, but this method has many disadvantages. For example, the identified proteins are usually complex, and additional biochemical studies are needed to distinguish real targets from interference results. To address this problem, we propose a series of strategies for improving the efficiency of target identification. First, pretreatment with a lower concentration of hydrogen peroxide can shield against thiol interference. Second, the use of benzophenone as a photo-affinity group is not appropriate, and diazirines are preferred. Third, if cytoskeleton proteins or stress proteins are captured, the interference must be carefully eliminated. The specificity of target identification can be improved by optimizing these three strategies. In this paper, we discuss the problems associated with the use of the click reaction in living cells and provide important complementary techniques for photo-affinity probes based on the click chemistry reaction. PMID:27782133

  17. Problems of applicability of statistical methods in cosmology

    SciTech Connect

    Levin, S. F.

    2015-12-15

    The problems arising from the incorrect formulation of measuring problems of identification for cosmological models and violations of conditions of applicability of statistical methods are considered.

  18. Drug use, mental health and problems related to crime and violence: cross-sectional study1

    PubMed Central

    Claro, Heloísa Garcia; de Oliveira, Márcia Aparecida Ferreira; Bourdreaux, Janet Titus; Fernandes, Ivan Filipe de Almeida Lopes; Pinho, Paula Hayasi; Tarifa, Rosana Ribeiro

    2015-01-01

    Objective: to investigate the correlation between disorders related to the use of alcohol and other drugs and symptoms of mental disorders, problems related to crime and violence and to age and gender. Methods: cross-sectional descriptive study carried out with 128 users of a Psychosocial Care Center for Alcohol and other Drugs, in the city of São Paulo, interviewed by means of the instrument entitled Global Appraisal of Individual Needs - Short Screener. Univariate and multiple linear regression models were used to verify the correlation between the variables. Results: using univariate regression models, internalizing and externalizing symptoms and problems related to crime/violence proved significant and were included in the multiple model, in which only the internalizing symptoms and problems related to crime and violence remained significant. Conclusions: there is a correlation between the severity of problems related to alcohol use and severity of mental health symptoms and crime and violence in the study sample. The results emphasize the need for an interdisciplinary and intersectional character of attention to users of alcohol and other drugs, since they live in a socially vulnerable environment. PMID:26626010

  19. Differential Effects of Parent and Grandparent Drug Use on Behavior Problems of Male and Female Children.

    ERIC Educational Resources Information Center

    Stein, Judith A.; And Others

    1993-01-01

    Grandparents' and mothers' drug use predicted hyperactivity, psychosomatic complaints, and social problems for boys, and acting-out behaviors for boys and girls. Maternal drug use predicted fearfulness, hyperactivity, and social problems for boys, and developmental problems for boys and girls. (BC)

  20. Drug-related problems in type 2 diabetes mellitus patients with dyslipidemia

    PubMed Central

    2013-01-01

    Background Drug-Related Problems (DRPs) commonly occur among type 2 diabetes mellitus (T2DM) patients. However, few studies have been performed on T2DM patients with dyslipidemia. This purpose of this study was to assess drug-related problems (DRPs) and factors associated with its occurrence. Methods The retrospective study involved 208 T2DM in-patients and out-patients with dyslipidemia, and was conducted at a tertiary hospital in Malaysia from January 2009 to December 2011. The identification and assessment of DRPs were based on the Pharmaceutical Care Network Europe (PCNE) tool version 5.01. The potentially inappropriate medication use in older adults was assessed based on the American Geriatrics Society updated Beers Criteria. Results A total of 406 DRPs were identified. Among these patients, 91.8% had at least one DRP, averaging 1.94 ± 1.10 problems per patient. The majority of T2DM patients with dyslipidemia (91.8%) had at least one DRP. The most frequent types of DRP were potential drug-drug interaction (18.0%), drug not taken or administered (14.3%) and insufficient awareness of health and diseases (11.8%). Anti-hypertensive, lipid-modifying and anti-diabetic agents were the drug classes that were most likely to be associated with DRPs. Male gender, renal impairment, polypharmacy and poor lipid control were factors that were significantly associated with DRP in diabetic dyslipidemia patients. Conclusion Early identification of DRPs and factors associated with them are essential to prevent and resolve DRPs in T2DM patients with dyslipidemia. PMID:24341672

  1. Drug Abuse: Methadone Becomes the Solution and the Problem

    ERIC Educational Resources Information Center

    Bazell, Robert J.

    1973-01-01

    Methadone is used to divert heroin addicts from using stronger drugs. Rate of crimes committed by drug addicts has fallen considerably after putting them on methadone. Despite criticisms, methadone use seems to be encouraging for the future. (PS)

  2. Youth Reporters Discuss "Problem" Drugs. Youth Reports Number 2.

    ERIC Educational Resources Information Center

    Herzog, Elizabeth; And Others

    This report on drugs is based on mail responses received from urban and suburban high school students enrolled in college preparatory courses. The questions asked of these students included: (1) how do teenagers feel about the use of the various kinds of drugs by people their age? (2) what makes some teenagers use such drugs? (3) what keeps some…

  3. Nonlinear Multidimensional Assignment Problems Efficient Conic Optimization Methods and Applications

    DTIC Science & Technology

    2015-06-24

    AFRL-AFOSR-VA-TR-2015-0281 Nonlinear Multidimensional Assignment Problems Efficient Conic Optimization Methods and Applications Hans Mittelmann...2012 - March 2015 4. TITLE AND SUBTITLE Nonlinear Multidimensional Assignment Problems Efficient Conic Optimization Methods and Applications 5a...problems. The size 16 three-dimensional quadratic assignment problem Q3AP from wireless communications was solved using a sophisticated approach

  4. Pattern of drug therapy problems and interventions in ambulatory patients receiving antiretroviral therapy in Nigeria

    PubMed Central

    Ojeh, Victor B.; Naima, Nasir; Abah, Isaac O.; Falang, Kakjing D.; Lucy, Ogwuche; London, Ibrahim; Dady, Christiana; Agaba, Patricia; Agbaji, Oche

    2015-01-01

    Objectives: We describe the frequency and types of drug therapy problems (DTPs), and interventions carried out to resolve them, among a cohort of HIV-infected patients on ART in Jos, Nigeria. Methods: A prospective pharmacists’ intervention study was conducted between January and August 2012 at the outpatient HIV clinic of the Jos University Teaching Hospital (JUTH). Pharmacists identified DTPs and made recommendations to resolve them. The main outcome measures were number of DTPs encountered, interventions proposed and acceptance rate of recommendations. Results: A total of 42,416 prescriptions were dispensed to 9339 patients during the eight months study. A total of 420 interventions (Intervention rate of 1 per 100 prescriptions) were made to resolve DTPs in 401 (4.3%) patients with a mean age of 41 (SD=10) years, and made up of 73% females. DTPs encountered were drug omission (n=89, 21.2%), unnecessary drug (n=55, 13.1%) and wrong drug indication (n=55, 13.1%). Recommendations offered included; Addition of another drug to the therapy (n=87, 20.7%), rectification of incomplete prescriptions (n=85, 20.2%), change of drug or dosage (n=67, 16.0%), and discontinuation of the offending drug (n=59, 14.0%). A total of 389 (93%) out of 420 of the recommendations were accepted. In all, 50.4% (212) of the problematic prescriptions were changed and dispensed, 22.2% (89) were clarified and dispensed, while wrong identities were corrected in 11.7% (49). However, 7.5% (30) prescriptions were dispensed as prescribed, 5.2% (21) were not dispensed, and 3% (12) were unresolved. Conclusion: Our findings suggest that pharmacists-initiated interventions can ameliorate DTPs in patients receiving ART given the high intervention acceptance rate recorded. The implication of this finding is that pharmacists with requisite training in HIV pharmacotherapy are an excellent resource in detecting and minimizing the effect of antiretroviral drug-related errors. PMID:26131046

  5. Nearly 1 in 5 U.S. Adults Has Mental Illness or Drug Problem

    MedlinePlus

    ... html Nearly 1 in 5 U.S. Adults Has Mental Illness or Drug Problem New Jersey is the mentally ... 1 in 5 American adults deals with a mental illness or substance abuse problem each year, a U.S. ...

  6. Developing natural product drugs: Supply problems and how they have been overcome.

    PubMed

    Newman, David J

    2016-06-01

    The development of natural product-derived drugs has some unique problems associated with the process, which can be best described as the "problem of supply". In this short review, four examples are given demonstrating how the "supply problem" was overcome using as examples the development of Picato® from a plant, Kyprolis® modified from a microbial metabolite, Halaven® a totally synthetic compound based on a marine sponge metabolite and Yondelis® isolated from a marine tunicate and now known to be from an as yet uncultured microbe in the tunicate. The methods used are described in each case and show how all scientific disciplines are necessary to succeed. All of these are antitumor agents and the time involved ranged from a low of 13years to greater than 29years from the initial identification of an active compound. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Matrix iteration method for nonlinear eigenvalue problems with applications

    NASA Astrophysics Data System (ADS)

    Ram, Y. M.

    2016-12-01

    A simple and intuitive matrix iteration method for solving nonlinear eigenvalue problems is described and demonstrated in detail by two problems: (i) the boundary value problem associated with large deflection of a flexible rod, and (ii) the initial value problem associated with normal mode motion of a double pendulum. The two problems are solved by two approaches, the finite difference approach and a continuous realization approach which is similar in spirit to the Rayleigh-Ritz method.

  8. Program Administrator's Handbook. Strategies for Preventing Alcohol and Other Drug Problems. The College Series.

    ERIC Educational Resources Information Center

    CSR, Inc., Washington, DC.

    This handbook is for administrators of programs in higher education settings which deal with alcohol and other drug (AOD) related problems. Chapter 1, "Defining the Problem, Issues, and Trends" examines the problem from various perspectives and presents the latest statistics on the extent of AOD use on campuses, specific problems affecting…

  9. Interpersonal and Emotional Problem Solving among Narcotic Drug Abusers.

    ERIC Educational Resources Information Center

    Appel, Philip W.; Kaestner, Elisabeth

    1979-01-01

    Measured problem-solving abilities of narcotics abusers using the modified means-ends problem-solving procedure. Good subjects had more total relevent means (RMs) for solving problems, used more introspective and emotional RMs, and were better at RM recognition, but did not have more sufficient narratives than poor subjects. (Author/BEF)

  10. Interpersonal and Emotional Problem Solving among Narcotic Drug Abusers.

    ERIC Educational Resources Information Center

    Appel, Philip W.; Kaestner, Elisabeth

    1979-01-01

    Measured problem-solving abilities of narcotics abusers using the modified means-ends problem-solving procedure. Good subjects had more total relevent means (RMs) for solving problems, used more introspective and emotional RMs, and were better at RM recognition, but did not have more sufficient narratives than poor subjects. (Author/BEF)

  11. Discontinuous Mixed Covolume Methods for Parabolic Problems

    PubMed Central

    Zhu, Ailing

    2014-01-01

    We present the semidiscrete and the backward Euler fully discrete discontinuous mixed covolume schemes for parabolic problems on triangular meshes. We give the error analysis of the discontinuous mixed covolume schemes and obtain optimal order error estimates in discontinuous H(div) and first-order error estimate in L2. PMID:24983008

  12. Optimization Problems: Duality and Multiplier Methods.

    DTIC Science & Technology

    1982-02-19

    provides a new computational handle on many problems in partial differential equations that can be represented as variational inequalities. Much remains...abstract entered in Block 20. If different from Report) DTIC III SUPPLEMENTARY NOTES MARO0 61M8 Nonlinear programming, stochastic programming, subgradient...following headings: (1) nonlinear programming algorithms, (2) multistage gradient analysis and nonsmooth optimization, (5) marginal values and sensitivity

  13. Smoking cessation in people with alcohol and other drug problems.

    PubMed

    Mendelsohn, Colin P; Wodak Am, Alex

    2016-08-01

    People who consume alcohol and other drugs are at particularly high risk of harm from smoking, yet tobacco use is commonly neglected in this patient group. The objectives of this article are to increase awareness of the high risk of tobacco-related harm in people who consume alcohol and other drugs, identify the barriers to quitting and provide practical guidelines to assist quitting. People who are dependent on alcohol and other drugs are far more likely to die from a smoking-related illness than from their other drugs. Most are motivated to quit smoking; however, their quit rates are lower than in the general population. Substance users who also smoke can usually be treated with similar behavioural and pharmacological treatments as others who smoke, but generally require more intensive and longer treatment. Quitting smoking at the same time as undergoing other drug treatment does not undermine drug treatment outcomes and may improve them. Smoking cessation should be integrated into the routine care of patients who consume alcohol and other drugs.

  14. Disease specific problems related to drug therapy in pregnancy.

    PubMed

    Ostensen, M

    2004-01-01

    Rheumatic diseases occur frequently in women of childbearing years necessitating drug treatment also during a concurrent pregnancy in order to control maternal disease activity and to ensure a successful pregnancy outcome. This survey reviews maternal and fetal side effects of nonsteroidal anti-inflammatory drugs (NSAID) and immunosuppressive agents in pregnant patients. The classic nonselective nonsteroidal anti-inflammatory drugs are not teratogenic, but given in late pregnancy they can induce renal and cardiac side effects in the fetus. Similar effects must be expected of the new, selective Cox2-inhibitors. NSAID should therefore be stopped by gestational week 32. Corticosteroids are frequently necessary to control rheumatic disease flares and for prevention of serious organ manifestations. However, due to an increased risk of oral clefts, high doses (1-2 mg/kg) should be avoided in the first trimester. Among disease modifying drugs, sulfasalazine and antimalarials have the safest record. Cyclosporine and azathioprine can be given throughout pregnancy if disease control requires it. Insufficient data exist for treatment of pregnant patients with TNF-inhibitors and mycophenolate mofetil. The severity of the disease under treatment decides if continuation of one of these drugs is justified. Prophylactic withdrawal of drugs before pregnancy is mandatory for leflunomide and the cytotoxic agents methotrexate and cyclophosphamide. Prepregnancy counselling and careful monitoring during pregnancy help to tailor necessary drug treatment for the benefit of mother and child.

  15. Solution of acoustic workshop problems by a spectral multidomain method

    NASA Technical Reports Server (NTRS)

    Kopriva, Davis A.; Kolias, John H.

    1995-01-01

    We use a new staggered grid Chebyshev spectral multidomain method to solve three of the Workshop benchmark problems. The method defines solution unknowns at the nodes of the Chebyshev Gauss quadrature, and the fluxes at the nodes of the Chebyshev Gauss-Lobatto quadrature. The Chebyshev spectral method gives exponentially convergent phase and dissipation errors. The multidomain approximation gives the method flexibility. Using the method, we solve problems in Categories 1 and 5 of the benchmark problems.

  16. An Examination Of Five Difficult Issues Related To School Drug Problems

    ERIC Educational Resources Information Center

    Nickerson, Carl J.

    1972-01-01

    The author identifies such problems as emergency care and profiteering as they relate to the larger issue of drug abuse. His attention is on those problems which usually receive little consideration but which are an integral part of the drug scene. (BY)

  17. Drug Abuse--A School Disaster and A Problem for Guidance.

    ERIC Educational Resources Information Center

    Brayer, Herbert O.

    Drug abuse is an increasingly common problem that must be faced by the school and community. Since counselors have a great deal of responsibility in working with students who abuse drugs, more effective ways of handling this problem need to be considered by them. The first part of this paper is concerned with a plan for working with the secondary…

  18. Understanding and Preventing the Problem of Alcohol and Drug Abuse. Adult Education Series. Discussion Paper One.

    ERIC Educational Resources Information Center

    Lethbridge Univ. (Alberta). Four Worlds Development Project.

    Discussion in Native American communities of problems related to alcoholism and drug abuse is encouraged through reading this paper, working on suggested activities and questions, and applying the information to improve local situations. Alcohol and drug abuse symptoms are described along with statistics illustrating the scope of the problem. The…

  19. Illicit and prescription drug problems among urban Aboriginal adults in Canada: the role of traditional culture in protection and resilience.

    PubMed

    Currie, Cheryl L; Wild, T Cameron; Schopflocher, Donald P; Laing, Lory; Veugelers, Paul

    2013-07-01

    Illicit and prescription drug use disorders are two to four times more prevalent among Aboriginal peoples in North America than the general population. Research suggests Aboriginal cultural participation may be protective against substance use problems in rural and remote Aboriginal communities. As Aboriginal peoples continue to urbanize rapidly around the globe, the role traditional Aboriginal beliefs and practices may play in reducing or even preventing substance use problems in cities is becoming increasingly relevant, and is the focus of the present study. Mainstream acculturation was also examined. Data were collected via in-person surveys with a community-based sample of Aboriginal adults living in a mid-sized city in western Canada (N = 381) in 2010. Associations were analysed using two sets of bootstrapped linear regression models adjusted for confounders with continuous illicit and prescription drug problem scores as outcomes. Psychological mechanisms that may explain why traditional culture is protective for Aboriginal peoples were examined using the cross-products of coefficients mediation method. The extent to which culture served as a resilience factor was examined via interaction testing. Results indicate Aboriginal enculturation was a protective factor associated with reduced 12-month illicit drug problems and 12-month prescription drug problems among Aboriginal adults in an urban setting. Increased self-esteem partially explained why cultural participation was protective. Cultural participation also promoted resilience by reducing the effects of high school incompletion on drug problems. In contrast, mainstream acculturation was not associated with illicit drug problems and served as a risk factor for prescription drug problems in this urban sample. Findings encourage the growth of programs and services that support Aboriginal peoples who strive to maintain their cultural traditions within cities, and further studies that examine how Aboriginal

  20. Inner City Youth and Drug Dealing: A Review of the Problem.

    ERIC Educational Resources Information Center

    Centers, Nathan L.; Weist, Mark D.

    1998-01-01

    Existing literature on drug dealing and inner-city adolescents was reviewed. Around one in six urban adolescents has had some involvement with drug dealing, with rates higher for African-American males males over age 16. For inner-city teenagers, there are many problems associated with drug dealing, and few efforts to prevent it. (SLD)

  1. The Drug Problem and the Schools. ERIC Abstracts Series, Number Sixteen.

    ERIC Educational Resources Information Center

    American Association of School Administrators, Washington, DC.

    ERIC abstracts on the drug problem and the schools, announced in RIE through December 1970, are presented. The key terms used in compiling this collection are "drug abuse" and "drug addiction." The following information is presented for each document: Author, title, place of publication, publisher, publication date, number of pages, ERIC document…

  2. Cell averaging Chebyshev methods for hyperbolic problems

    NASA Technical Reports Server (NTRS)

    Wei, Cai; Gottlieb, David; Harten, Ami

    1990-01-01

    A cell averaging method for the Chebyshev approximations of first order hyperbolic equations in conservation form is described. Formulas are presented for transforming between pointwise data at the collocation points and cell averaged quantities, and vice-versa. This step, trivial for the finite difference and Fourier methods, is nontrivial for the global polynomials used in spectral methods. The cell averaging methods presented are proven stable for linear scalar hyperbolic equations and present numerical simulations of shock-density wave interaction using the new cell averaging Chebyshev methods.

  3. [The therapeutic problem of current drug addiction in Italy].

    PubMed

    De Caro, D

    1980-04-28

    Psicosocial factors which are of main importance for drug-dependences, especially in young people, are examined. Then the most important elements of the therapy of drug-dependences are indicated, which first of all consists in the necessary treatment in the hospital and farmacological therapy (particularly during acute and over-dose states), and also psicotherapeutic--generally speaking--and social approaches. Among those therapeutic Communities seem to be extremely significant, whose most important patterns are described.

  4. Preconditioned Krylov subspace methods for eigenvalue problems

    SciTech Connect

    Wu, Kesheng; Saad, Y.; Stathopoulos, A.

    1996-12-31

    Lanczos algorithm is a commonly used method for finding a few extreme eigenvalues of symmetric matrices. It is effective if the wanted eigenvalues have large relative separations. If separations are small, several alternatives are often used, including the shift-invert Lanczos method, the preconditioned Lanczos method, and Davidson method. The shift-invert Lanczos method requires direct factorization of the matrix, which is often impractical if the matrix is large. In these cases preconditioned schemes are preferred. Many applications require solution of hundreds or thousands of eigenvalues of large sparse matrices, which pose serious challenges for both iterative eigenvalue solver and preconditioner. In this paper we will explore several preconditioned eigenvalue solvers and identify the ones suited for finding large number of eigenvalues. Methods discussed in this paper make up the core of a preconditioned eigenvalue toolkit under construction.

  5. Methods in systems biology of experimental methamphetamine drug abuse.

    PubMed

    Kobeissy, Firas H; Sadasivan, Shankar; Buchanan, Melinda; Zhang, Zhiqun; Gold, Mark S; Wang, Kevin K W

    2010-01-01

    The use of methamphetamine (METH) as recreational drugs is a growing problem worldwide with recent concerns that it might cause long-lasting harmful effects to the human brain. METH is an illicit drug that is known to exert neurotoxic effects on both dopaminergic and serotonergic neural systems. Our laboratory has been studying the biochemical mechanisms underlying METH-induced neurotoxic effects both in vivo and in vitro. Our psychoproteomics METH abuse research focuses on the global alteration of cortical protein expression in rats treated with acute METH. In our analysis, an altered protein expression was identified using a multistep protein separation/proteomic platform. Differential changes of the selected proteins were further confirmed by quantitative immunoblotting. Our study identified 82 differentially expressed proteins, 40 of which were downregulated and 42 of which were upregulated post acute METH treatment. In this chapter, we describe the current protocols for the neuronal cell culture in vitro and the in vivo rat model of acute METH treatment (4 x 10 mg/kg) coupled with the description current bioinformatics analysis utilized to analyze the different implicated interaction protein/gene maps that reflected on the altered functions observed. These methods and protocols are discussed in the paradigm of the acute model of METH drug abuse and neuronal cell culture and can be applied on other models of substance abuse such as on MDMA or cocaine.

  6. Numerical Methods for Initial Value Problems.

    DTIC Science & Technology

    1980-07-01

    of general multistep methods for ordinary differential equations a4 to implement an efficient algorithm for the solution of stiff equations . Still...integral equations II. Roundoff error for variants of Gaussian elimination III. Multistep methods for ordinary differential equations IV. Multi-grid...62 -! Paige III. NUMERICAL SOLUTION OF ORDINARY DIFFERENTIAL EQUATIONS ....... 63 1. Equivalent Forms of Multistep

  7. The stability problem for linear multistep methods

    NASA Astrophysics Data System (ADS)

    Aceto, L.; Trigiante, D.

    2007-12-01

    The paper reviews results on rigorous proofs for stability properties of classes of linear multistep methods (LMMs) used either as IVMs or as BVMs. The considered classes are not only the well-known classical ones (BDF, Adams, ...) along with their BVM correspondent, but also those which were considered unstable as IVMs, but stable as BVMs. Among the latter we find two classes which deserve attention because of their peculiarity: the TOMs (top order methods) which have the highest order allowed to a LMM and the Bs-LMMs which have the property to carry with each method its natural continuous extension.

  8. Implicit Spectral Methods for Wave Propagation Problems

    NASA Astrophysics Data System (ADS)

    Wineberg, Stephen B.; McGrath, Joseph F.; Gabl, Edward F.; Ridgway Scott, L.; Southwell, Charles E.

    1991-12-01

    The numerical solution of a non-linear wave equation can be obtained by using spectral methods to resolve the unknown in space and the standard Crank-Nicolson differencing scheme to advance the solution in time. We have analyzed iterative techniques for solving the non-linear equations that arise from such implicit time-stepping schemes for the K-dV and the KP equations. We derived predictor—corrector method that retain the full accuracy of the implicit method with minimal stability restrictions on the size of the time step. Some numerical examples show the propagation of interacting solitons.

  9. Drug and alcohol problems amongst individuals with severe mental health problems in an inner city area of the UK.

    PubMed

    Graham, H L; Maslin, J; Copello, A; Birchwood, M; Mueser, K; McGovern, D; Georgiou, G

    2001-09-01

    The extent and impact of drug and alcohol use among those with severe mental health problems has been well documented in the US. However, little is known of the nature of this problem in the UK, particularly in community treatment settings. This paper outlines findings from a large-scale survey conducted across community-based Mental Health and Substance Misuse services, which aimed to ascertain the prevalence of drug and alcohol problems among those with severe mental health problems. An assessment instrument was completed by keyworkers for each of their clients, which included mental health diagnosis and an adapted version of the Clinician Rating Scales for Alcohol and Drug Use. From a sample of 3079 clients across services, 1369 clients were identified with a severe mental illness diagnosis. According to their key-workers, 24% of these clients (324/1369) had used alcohol and/or drugs problematically during the past year. These individuals were most likely to have a diagnosis within the schizophrenia cluster, were mainly white males in their mid-30s, and tended to be located within Mental Health services in Assertive Outreach teams and to be higher utilisers of crises/emergency services. It can be concluded that similar to other studies in inner city areas of the UK, problem substance use is common amongst those with severe mental health problems within Northern Birmingham.

  10. Drug delivery systems: polymers and drugs monitored by capillary electromigration methods.

    PubMed

    Simó, Carolina; Cifuentes, Alejandro; Gallardo, Alberto

    2003-11-25

    In this paper, different electromigration methods used to monitor drugs and polymers released from drug delivery systems are reviewed. First, an introduction to the most typical arrangements used as drug delivery systems (e.g., polymer-drug covalent conjugates, membrane or matrix-based devices) is presented. Next, the principles of different capillary electromigration procedures are discussed, followed by a revision on the different procedures employed to monitor the release of drugs and the degradation or solubilization of the polymeric matrices from drug delivery systems during both in vitro and in vivo assays. A critical comparison between these capillary electrophoretic methods and the more common chromatographic methods employed to analyze drugs and polymers from drug delivery systems is presented. Finally, future outlooks of these electromigration procedures in the controlled release field are discussed.

  11. The problems of classification: Method of committees

    NASA Astrophysics Data System (ADS)

    Nikonov, Oleg I.; Chernavin, Fedor P.; Medvedeva, Marina A.

    2016-06-01

    In the paper, we consider a particular case of a neural network - a committee method. The described approach was first introduced by the paper of Ablow and Kaylor (1965). Then further development of the committee machine methods have been carried out by Yekaterinburg pattern recognition school in Institute of Mathematics and Mechanics, Ural Branch of Russian Academy of Sciences Nowadays theory of committee machine structures is based on results of Mazurov and Hachay (1990, 1999).

  12. Meshless Local Petrov-Galerkin Method for Bending Problems

    NASA Technical Reports Server (NTRS)

    Phillips, Dawn R.; Raju, Ivatury S.

    2002-01-01

    Recent literature shows extensive research work on meshless or element-free methods as alternatives to the versatile Finite Element Method. One such meshless method is the Meshless Local Petrov-Galerkin (MLPG) method. In this report, the method is developed for bending of beams - C1 problems. A generalized moving least squares (GMLS) interpolation is used to construct the trial functions, and spline and power weight functions are used as the test functions. The method is applied to problems for which exact solutions are available to evaluate its effectiveness. The accuracy of the method is demonstrated for problems with load discontinuities and continuous beam problems. A Petrov-Galerkin implementation of the method is shown to greatly reduce computational time and effort and is thus preferable over the previously developed Galerkin approach. The MLPG method for beam problems yields very accurate deflections and slopes and continuous moment and shear forces without the need for elaborate post-processing techniques.

  13. Multigrid Methods for Aerodynamic Problems in Complex Geometries

    NASA Technical Reports Server (NTRS)

    Caughey, David A.

    1995-01-01

    Work has been directed at the development of efficient multigrid methods for the solution of aerodynamic problems involving complex geometries, including the development of computational methods for the solution of both inviscid and viscous transonic flow problems. The emphasis is on problems of complex, three-dimensional geometry. The methods developed are based upon finite-volume approximations to both the Euler and the Reynolds-Averaged Navier-Stokes equations. The methods are developed for use on multi-block grids using diagonalized implicit multigrid methods to achieve computational efficiency. The work is focused upon aerodynamic problems involving complex geometries, including advanced engine inlets.

  14. Ending Discrimination against People with Alcohol and Drug Problems.

    ERIC Educational Resources Information Center

    Join Together, Boston, MA.

    People with alcohol or other drug disease face public and private policies that restrict their access to appropriate health care, employment, and public benefits, discouraging them from seeking treatment, robbing them of hope for recovery, and costing society millions of dollars. Join Together, a project of Boston University School of Public…

  15. [Selected Readings for the Professional Working with Drug Related Problems.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison.

    A bibliography of selected readings compiled at the University of Wisconsin for the National Drug Education Training Program. These selected readings include information on narcotics, amphetamines, mescaline, psilogybin, hallucinogens, LSD, barbiturates, alcohol, and other stimulants. The intended user of this bibliography is the professional…

  16. [Selected Readings for the Professional Working with Drug Related Problems.

    ERIC Educational Resources Information Center

    Wisconsin Univ., Madison.

    A bibliography of selected readings compiled at the University of Wisconsin for the National Drug Education Training Program. These selected readings include information on narcotics, amphetamines, mescaline, psilogybin, hallucinogens, LSD, barbiturates, alcohol, and other stimulants. The intended user of this bibliography is the professional…

  17. Drug Education--A Problem In Moral Philosophy

    ERIC Educational Resources Information Center

    Bethell, B. J.; Bellward, G. D.

    1973-01-01

    During the development or assessment of drug education programs, many individuals insist on the avoidance of "moralizing". An awareness of moral principles, rules and values is a necessary criterion to rational thought processes. This paper attempts to clarify these philosophical issues in a manner which can be put into practice in many types of…

  18. Who's to Blame for America's Drug Problem?: The Search for Scapegoats in the "War on Drugs."

    ERIC Educational Resources Information Center

    Mackey-Kallis, Susan; Hahn, Dan

    1994-01-01

    Analyzes six years (from 1986 to 1991) of political debate and social action in the United States' war on drugs. Explores the characteristics of guilt-based, scapegoating drug rhetoric and how scapegoating in the drug war has been problematic. Discusses the desirability and limits of guilt as a rhetorical strategy. (HB)

  19. Who's to Blame for America's Drug Problem?: The Search for Scapegoats in the "War on Drugs."

    ERIC Educational Resources Information Center

    Mackey-Kallis, Susan; Hahn, Dan

    1994-01-01

    Analyzes six years (from 1986 to 1991) of political debate and social action in the United States' war on drugs. Explores the characteristics of guilt-based, scapegoating drug rhetoric and how scapegoating in the drug war has been problematic. Discusses the desirability and limits of guilt as a rhetorical strategy. (HB)

  20. Syringe exchanges: a public health response to problem drug use.

    PubMed

    Cox, G M; Lawless, M C; Cassin, S P; Geoghegan, T W

    2000-01-01

    This paper presents the findings of the first ever Irish follow-up study to establish the effectiveness of syringe exchanges as a harm reduction strategy in the context of public health. The study was conducted in collaboration with 370 injecting drug users who attended the Merchant's Quay Project's Health Promotion Unit between May 1st 1997 and October 31st 1998. Data was collected from respondents by means of a structured interview at first visit and three-months after initial contact. Evidence from the study demonstrates that syringe exchanges play an important contributing role in significantly reducing the numbers reporting both the use of heroin as a primary drug (n=41; McNemar x2=10.1;p<0.01), and its frequency of use (n=70; McNemar x2=4.13;p<0.05) at follow-up. Moreover, there were significant reductions in the reported borrowing (n=60; McNemar x2=10.1;p<0.01) and lending (n=42: McNemar x2=7.9;p<0.01) of used injecting equipment. There was however no significant change in the reported sharing of injecting paraphernalia or in levels of reported condom use. The results of this study illustrate that low threshold services such as the Health Promotion Unit have the ability to attract injecting drug users not in contact with other drug treatment services. Furthermore, this type of service has been shown to be effective in maintaining contact with injecting drug users and promoting safer drug use among attendees. Even though the distribution of sterile injecting equipment reduces the situational sharing, this is hampered by the limited availability of sterile injecting equipment in Dublin. There is a need to continue to develop strategies to prevent HIV and hepatitis C transmission. One such approach would be to develop effective outreach as a means of reaching greater numbers of drug users earlier in their injecting histories. Other areas for future HIV and HCV prevention include discouraging the transition from smoking to injecting, and among those who inject

  1. Highlighting the Scientific Method through Mathematics Problems.

    ERIC Educational Resources Information Center

    McGalliard, William A., Jr.

    This paper argues that the introduction of the scientific method in the very rich environments of the natural sciences or human sciences may disguise the process and create difficulties for students because of the multiplicity of variables involved, whereas the variables present in a mathematical context can be readily manipulated and their…

  2. Alcohol and Other Drugs on Campus: The Scope of the Problem. Infofacts/Resources

    ERIC Educational Resources Information Center

    Kapner, Daniel Ari

    2008-01-01

    The most widespread health problem on college and university campuses in the United States is high-risk alcohol and other drug (AOD) use. Recent reports confirm that the nation's campuses continue to encounter significant consequences as a result of this problem. This "Infofacts/Resources" offers an overview of the problem and highlights effective…

  3. Adaptive implicit-explicit methods for flow problems

    NASA Technical Reports Server (NTRS)

    Liou, J.; Tezduyar, T. E.

    1989-01-01

    Studies on the adaptive implicit-explicit (AIE) method for large-scale problems are presented. The AIE method is based on dynamic grouping of the elements into the implicit and explicit subsets as dictated by the element level stability and accuracy considerations. The method has been applied to various flow problems including the incompressible flow and convection-diffusion problems, and it has been demonstrated that substantial savings in CPU time and memory can be achieved.

  4. Computational Methods Applied to Rational Drug Design.

    PubMed

    Ramírez, David

    2016-01-01

    Due to the synergic relationship between medical chemistry, bioinformatics and molecular simulation, the development of new accurate computational tools for small molecules drug design has been rising over the last years. The main result is the increased number of publications where computational techniques such as molecular docking, de novo design as well as virtual screening have been used to estimate the binding mode, site and energy of novel small molecules. In this work I review some tools, which enable the study of biological systems at the atomistic level, providing relevant information and thereby, enhancing the process of rational drug design.

  5. Computational Methods Applied to Rational Drug Design

    PubMed Central

    Ramírez, David

    2016-01-01

    Due to the synergic relationship between medical chemistry, bioinformatics and molecular simulation, the development of new accurate computational tools for small molecules drug design has been rising over the last years. The main result is the increased number of publications where computational techniques such as molecular docking, de novo design as well as virtual screening have been used to estimate the binding mode, site and energy of novel small molecules. In this work I review some tools, which enable the study of biological systems at the atomistic level, providing relevant information and thereby, enhancing the process of rational drug design. PMID:27708723

  6. Problems with the Baade-Wesselink method

    NASA Technical Reports Server (NTRS)

    Bohm-Vitense, E.; Garnavich, P.; Lawler, M.; Mena-Werth, J.; Morgan, S.

    1989-01-01

    The discrepancy noted in radii obtained by the Baade-Wesselink method when different colors are used to determine the effective temperatures is explored. The discrepancy is found to be due to an inconsistency in the applied temperature-color calibrations. The assumption of the maximum likelihood method that beta (the effective temperature + 0.1 times the bolometric correction) is a linear function of the color is valid for the B-V and V-I colors, but not for the V-R colors. It is suggested that the errors introduced by the nonlinearity in the relation between beta and the V-R colors will produce radii which are too large. The radii derived from the V-B colors appear to be too small.

  7. Problems with the Baade-Wesselink method

    NASA Technical Reports Server (NTRS)

    Bohm-Vitense, E.; Garnavich, P.; Lawler, M.; Mena-Werth, J.; Morgan, S.

    1989-01-01

    The discrepancy noted in radii obtained by the Baade-Wesselink method when different colors are used to determine the effective temperatures is explored. The discrepancy is found to be due to an inconsistency in the applied temperature-color calibrations. The assumption of the maximum likelihood method that beta (the effective temperature + 0.1 times the bolometric correction) is a linear function of the color is valid for the B-V and V-I colors, but not for the V-R colors. It is suggested that the errors introduced by the nonlinearity in the relation between beta and the V-R colors will produce radii which are too large. The radii derived from the V-B colors appear to be too small.

  8. Computational Methods for Probabilistic Target Tracking Problems

    DTIC Science & Technology

    2007-09-01

    Undergraduate Students: Ms. Angela Edwards, Mr. Bryahn Ivery, Mr. Dustin Lupton, Mr. James Pender, Mr. Terrell Felder , Ms. Krystal Knight Under...two more graduate students, Mr. Ricardo Bernal and Ms Alisha Williams, and two more undergraduate students, Ms Krystal Knight and Mr. Terrell Felder ...Technical State University, April 24, 2006 “Using Tree Based Methods to Classify Messages”, Terrell A. Felder , Math Awareness Mini-Conference

  9. Methods and applications of structure based pharmacophores in drug discovery.

    PubMed

    Pirhadi, Somayeh; Shiri, Fereshteh; Ghasemi, Jahan B

    2013-01-01

    A pharmacophore model does not describe a real molecule or a real association of functional groups but illustrates a molecular recognition of a biological target shared by a group of compounds. Pharmacophores also represent the spatial arrangement of essential interactions in a receptor-binding pocket. Structure based pharmacophores (SBPs) can work both with a free (apo) structure or a macromolecule-ligand complex (holo) structure. The SBP methods that derive pharmacophore from protein-ligand complexes use the potential interactions observed between ligand and protein, whereas, the SBP method that aims to derive pharmacophore from ligand free protein, uses only protein active site information. Therefore SBPs do not encounter to challenging problems such as ligand flexibility, molecular alignment as well as proper selection of training set compounds in ligand based pharmacophore modeling. The current review deals with Hot Spot' analysis of binding site to feature generation, several approaches to feature reduction, and considers shape and excluded volumes to SBP model building. This review continues to represent several applications of SBPs in virtual screening especially in parallel screening approach and multi-target drug design. Also it reports the applications of SBPs in QSAR. This review emphasizes that SBPs are valuable tools for hit to lead optimization, virtual screening, scaffold hopping, and multi-target drug design.

  10. Drug-eluting stents: some first-generation problems.

    PubMed

    Murphy, Bruce E

    2004-01-01

    The recent fervor surrounding the introduction of drug-eluting stents into the practice of cardiology has proven to be problematic. The experience with the Cypher Sirolimus-Eluting Coronary Stent (Cordis Corp., Miami Lakes, FL) at Arkansas Heart Hospital progressed from anxious anticipation to complete removal of the stent from inventory in a 6-month period. Several cases involving edge dissection and subacute thrombosis were the catalyst for the decision to cease use of the device. While new products may entice, each new modality must be approached with measured enthusiasm. Drug-eluting stents are first-generation devices that may have unexposed flaws when used as first-line treatment in routine practice. The first-generation Cypher stent, as with many new devices, offers treatment-not a cure-for coronary atherosclerosis and enhances the desire for an evolved product.

  11. Presenting clinical pharmacology and therapeutics: a problem based approach for choosing and prescribing drugs.

    PubMed Central

    De Vries, T P

    1993-01-01

    As a guide to the rational choice and prescribing of drugs a normative (ideal) problem-solving model has been developed. This model combines medical problem solving and decision analysis, practical medical aspects, and pharmacological facts and basic principles. It consists of a set of actions or steps: determine the goal for treatment, choose a (drug) treatment, start drug treatment, monitor the results, draw conclusions, determine further action, and stop, alter or continue treatment. All steps require several kinds of skills. The cognitive skills needed include the correct use of pharmacological facts and basic principles in the framework of the whole problem-solving process. PMID:8329283

  12. Postmarketing surveillance of adverse drug reactions: problems and solutions.

    PubMed Central

    Lortie, F M

    1986-01-01

    The surveillance of adverse drug reactions (ADRs) is an unqualified must. However, the optimal means of surveillance is still unclear. Although anecdotal reports are the backbone of an ADR surveillance system, they are not enough. The pharmaceutical industry, academics and regulatory agencies need to expand their efforts in monitoring ADRs. The author discusses the various techniques for counting and evaluating adverse reactions and suggests ways in which the system could be improved. PMID:3719483

  13. A Bright Future for Evolutionary Methods in Drug Design.

    PubMed

    Le, Tu C; Winkler, David A

    2015-08-01

    Most medicinal chemists understand that chemical space is extremely large, essentially infinite. Although high-throughput experimental methods allow exploration of drug-like space more rapidly, they are still insufficient to fully exploit the opportunities that such large chemical space offers. Evolutionary methods can synergistically blend automated synthesis and characterization methods with computational design to identify promising regions of chemical space more efficiently. We describe how evolutionary methods are implemented, and provide examples of published drug development research in which these methods have generated molecules with increased efficacy. We anticipate that evolutionary methods will play an important role in future drug discovery.

  14. A Focus on Problems of National Interest in the College General Chemistry Laboratory: The Effects of the Problem-Oriented Method Compared with Those of the Traditional Approach.

    ERIC Educational Resources Information Center

    Neman, Robert Lynn

    This study was designed to assess the effects of the problem-oriented method compared to those of the traditional approach in general chemistry at the college level. The problem-oriented course included topics such as air and water pollution, drug addiction and analysis, tetraethyl-lead additives, insecticides in the environment, and recycling of…

  15. A Focus on Problems of National Interest in the College General Chemistry Laboratory: The Effects of the Problem-Oriented Method Compared with Those of the Traditional Approach.

    ERIC Educational Resources Information Center

    Neman, Robert Lynn

    This study was designed to assess the effects of the problem-oriented method compared to those of the traditional approach in general chemistry at the college level. The problem-oriented course included topics such as air and water pollution, drug addiction and analysis, tetraethyl-lead additives, insecticides in the environment, and recycling of…

  16. Helping someone with problem drug use: a Delphi consensus study of consumers, carers, and clinicians.

    PubMed

    Kingston, Anna H; Morgan, Amy J; Jorm, Anthony F; Hall, Kate; Hart, Laura M; Kelly, Claire M; Lubman, Dan I

    2011-01-05

    Problem use of illicit drugs (i.e. drug abuse or dependence) is associated with considerable health and social harms, highlighting the need for early intervention and engagement with health services. Family members, friends and colleagues play an important role in supporting and assisting individuals with problem drug use to seek professional help, however there are conflicting views about how and when such support should be offered. This paper reports on the development of mental health first aid guidelines for problem drug use in adults, to help inform community members on how to assist someone developing problem drug use or experiencing a drug-related crisis. A systematic review of the scientific and lay literature was conducted to develop a 228-item survey containing potential first-aid strategies to help someone developing a drug problem or experiencing a drug-related crisis. Three panels of experts (29 consumers, 31 carers and 27 clinicians) were recruited from Australia, Canada, New Zealand, the United Kingdom, and the United States. Panel members independently rated the items over three rounds, with strategies reaching consensus on importance written into the guidelines. The overall response rate across three rounds was 80% (86% consumers, 81% carers, 74% clinicians). 140 first aid strategies were endorsed as essential or important by 80% or more of panel members. The endorsed strategies provide information and advice on what is problem drug use and its consequences, how to approach a person about their problem drug use, tips for effective communication, what to do if the person is unwilling to change their drug use, what to do if the person does (or does not) want professional help, what are drug-affected states and how to deal with them, how to deal with adverse reactions leading to a medical emergency, and what to do if the person is aggressive. The guidelines provide a consensus-based resource for community members who want to help someone with a drug

  17. Decomposition method for zonal resource allocation problems in telecommunication networks

    NASA Astrophysics Data System (ADS)

    Konnov, I. V.; Kashuba, A. Yu

    2016-11-01

    We consider problems of optimal resource allocation in telecommunication networks. We first give an optimization formulation for the case where the network manager aims to distribute some homogeneous resource (bandwidth) among users of one region with quadratic charge and fee functions and present simple and efficient solution methods. Next, we consider a more general problem for a provider of a wireless communication network divided into zones (clusters) with common capacity constraints. We obtain a convex quadratic optimization problem involving capacity and balance constraints. By using the dual Lagrangian method with respect to the capacity constraint, we suggest to reduce the initial problem to a single-dimensional optimization problem, but calculation of the cost function value leads to independent solution of zonal problems, which coincide with the above single region problem. Some results of computational experiments confirm the applicability of the new methods.

  18. Globally Convergent Numerical Methods for Coefficient Inverse Problems

    DTIC Science & Technology

    2008-09-23

    Problems , 18, 209-219, 2002. 50. A.N. Tikhonov and V. Ya. Arsenin , Solutions of Ill - Posed Problems Winston & Sons. Washington...is because solutions of PDEs depend nonlinearly on their coefficients. The ill - posedness is a well known feature of inverse problems . This means that...ut (x, 0)‖L2(Ω) ≤ CK. Theorem 8.5 enables us to prove convergence of our method. Following the Tikhonov concept for ill - posed problems [50], we

  19. Using Lin's method to solve Bykov's problems

    NASA Astrophysics Data System (ADS)

    Knobloch, Jürgen; Lamb, Jeroen S. W.; Webster, Kevin N.

    2014-10-01

    We consider nonwandering dynamics near heteroclinic cycles between two hyperbolic equilibria. The constituting heteroclinic connections are assumed to be such that one of them is transverse and isolated. Such heteroclinic cycles are associated with the termination of a branch of homoclinic solutions, and called T-points in this context. We study codimension-two T-points and their unfoldings in Rn. In our consideration we distinguish between cases with real and complex leading eigenvalues of the equilibria. In doing so we establish Lin's method as a unified approach to (re)gain and extend results of Bykov's seminal studies and related works. To a large extent our approach reduces the study to the discussion of intersections of lines and spirals in the plane. Case (RR): Under open conditions on the eigenvalues, there exist open sets in parameter space for which there exist periodic orbits close to the heteroclinic cycle. In addition, there exist two one-parameter families of homoclinic orbits to each of the saddle points p1 and p2.See Theorem 2.1 and Proposition 2.2 for precise statements and Fig. 2 for bifurcation diagrams. Cases (RC) and (CC): At the bifurcation point μ=0 and for each N≥2, there exists an invariant set S0N close to the heteroclinic cycle on which the first return map is topologically conjugated to a full shift on N symbols. For any fixed N≥2, the invariant set SμN persists for |μ| sufficiently small.In addition, there exist infinitely many transversal and non-transversal heteroclinic orbits connecting the saddle points p1 and p2 in a neighbourhood of μ=0, as well as infinitely many one-parameter families of homoclinic orbits to each of the saddle points.For full statements of the results see Theorem 2.3 and Propositions 2.4, 2.5 and Fig. 3 for bifurcation diagrams. The dynamics near T-points has been studied previously by Bykov [6-10], Glendinning and Sparrow [20], Kokubu [27,28] and Labouriau and Rodrigues [30,31,38]. See also the surveys

  20. A Modified Alternating Direction Method for Variational Inequality Problems

    SciTech Connect

    Han, D.

    2002-07-01

    The alternating direction method is an attractive method for solving large-scale variational inequality problems whenever the subproblems can be solved efficiently. However, the subproblems are still variational inequality problems, which are as structurally difficult to solve as the original one. To overcome this disadvantage, in this paper we propose a new alternating direction method for solving a class of nonlinear monotone variational inequality problems. In each iteration the method just makes an orthogonal projection to a simple set and some function evaluations. We report some preliminary computational results to illustrate the efficiency of the method.

  1. Numerical methods for solving terminal optimal control problems

    NASA Astrophysics Data System (ADS)

    Gornov, A. Yu.; Tyatyushkin, A. I.; Finkelstein, E. A.

    2016-02-01

    Numerical methods for solving optimal control problems with equality constraints at the right end of the trajectory are discussed. Algorithms for optimal control search are proposed that are based on the multimethod technique for finding an approximate solution of prescribed accuracy that satisfies terminal conditions. High accuracy is achieved by applying a second-order method analogous to Newton's method or Bellman's quasilinearization method. In the solution of problems with direct control constraints, the variation of the control is computed using a finite-dimensional approximation of an auxiliary problem, which is solved by applying linear programming methods.

  2. Solving Fluid Structure Interaction Problems with an Immersed Boundary Method

    NASA Technical Reports Server (NTRS)

    Barad, Michael F.; Brehm, Christoph; Kiris, Cetin C.

    2016-01-01

    An immersed boundary method for the compressible Navier-Stokes equations can be used for moving boundary problems as well as fully coupled fluid-structure interaction is presented. The underlying Cartesian immersed boundary method of the Launch Ascent and Vehicle Aerodynamics (LAVA) framework, based on the locally stabilized immersed boundary method previously presented by the authors, is extended to account for unsteady boundary motion and coupled to linear and geometrically nonlinear structural finite element solvers. The approach is validated for moving boundary problems with prescribed body motion and fully coupled fluid structure interaction problems. Keywords: Immersed Boundary Method, Higher-Order Finite Difference Method, Fluid Structure Interaction.

  3. Preparation of drug nanoparticles by emulsion evaporation method

    NASA Astrophysics Data System (ADS)

    Hoa, Le Thi Mai; Chi, Nguyen Tai; Triet, Nguyen Minh; Thanh Nhan, Le Ngoc; Mau Chien, Dang

    2009-09-01

    Polymeric drug nanoparticles were prepared by emulsion solvent evaporation method. In this study, prepared the polymeric drug nanoparticles consist of ketoprofen and Eudragit E 100. The morphology structure was investigated by scanning electron microscopy (SEM). The interactions between the drug and polymer were investigated by Fourier transform infrared spectroscopy (FTIR). The size distribution was measured by means of Dynamic Light Scattering. The nanoparticles have an average size of about 150 nm. The incorporation ability of drugs in the polymeric nanoparticles depended on the integration between polymer and drug as well as the glass transition temperature of the polymer.

  4. Application of the Discontinuous Galerkin Method to Acoustic Scatter Problems

    NASA Technical Reports Server (NTRS)

    Atkins, H. L.

    1997-01-01

    The application of the quadrature-free form of the discontinuous Galerkin method to two problems from Category 1 of the Second Computational Aeroacoustics Workshop on Benchmark problems is presented. The method and boundary conditions relevant to this work are described followed by two test problems, both of which involve the scattering of an acoustic wave off a cylinder. The numerical test performed to evaluate mesh-resolution requirements and boundary-condition effectiveness are also described.

  5. Application of the Discontinuous Galerkin Method to Acoustic Scatter Problems

    NASA Technical Reports Server (NTRS)

    Atkins, H. L.

    1997-01-01

    The application of the quadrature-free form of the discontinuous Galerkin method to two problems from Category 1 of the Second Computational Aeroacoustics Workshop on Benchmark problems is presented. The method and boundary conditions relevant to this work are described followed by two test problems, both of which involve the scattering of an acoustic wave off a cylinder. The numerical test performed to evaluate mesh-resolution requirements and boundary-condition effectiveness are also described.

  6. Efficient numerical methods for entropy-linear programming problems

    NASA Astrophysics Data System (ADS)

    Gasnikov, A. V.; Gasnikova, E. B.; Nesterov, Yu. E.; Chernov, A. V.

    2016-04-01

    Entropy-linear programming (ELP) problems arise in various applications. They are usually written as the maximization of entropy (minimization of minus entropy) under affine constraints. In this work, new numerical methods for solving ELP problems are proposed. Sharp estimates for the convergence rates of the proposed methods are established. The approach described applies to a broader class of minimization problems for strongly convex functionals with affine constraints.

  7. Drug therapy for Helicobacter pylori infection: problems and pitfalls.

    PubMed

    Glupczynski, Y; Burette, A

    1990-12-01

    Antibacterial chemotherapy against Helicobacter pylori is currently being assessed by open or randomized controlled clinical studies for its efficacy in eradicating this bacterium from the stomach of patients with gastritis or gastroduodenal ulcer. Whereas there is presently no "optimal" agent and treatment scheme, the combination of some antibiotics (metronidazole, tinidazole, amoxicillin) with bismuth salts proves definitely superior in vivo to either of these agents administered alone. Several reasons have been proposed, to explain the clinical failure after treatment: insufficient concentration of active drugs in gastric mucus, instability of some agents at an acidic pH, inappropriate formulation of drug, insufficient duration of treatment, and variable compliance of patients. Recently, it has appeared from several clinical trials that H. pylori may rapidly acquire resistance to some antibiotics, and that this event might also account for clinical failure. A critical review of the literature on H. pylori treatment indicates that association of bismuth and antibiotics or of antibiotics alone both may efficiently reduce the risk of emergence of resistance and improve the therapeutic outcome. Guidelines of treatment are suggested in order to avoid the future misuse of antibiotics that would increase selection of antibiotic-resistant H. pylori and negatively affect the ecology of the gastric microflora. Likewise, an accurate definition of a subset of patients with H. pylori who really will require treatment needs to be rapidly established.

  8. Approved drugs and their problems in patient care: routes of administration and dosing.

    PubMed

    Cook, Stuart D

    2007-08-15

    Problems in patient care with regard to route of administration and dosing of currently approved drugs are reviewed. Dose, frequency and route of administration can make a difference in efficacy, side effects, quality of life, antigenicity, cost, and compliance.

  9. What to Do If You Have a Problem with Drugs: For Teens and Young Adults

    MedlinePlus

    ... tell your doctor about your depression (or other mental health problems) as well as your drug use. There ... medicines that can help with depression or other mental health issues. Sometimes doctors do not talk to each ...

  10. Applications of Genetic Methods to NASA Design and Operations Problems

    NASA Technical Reports Server (NTRS)

    Laird, Philip D.

    1996-01-01

    We review four recent NASA-funded applications in which evolutionary/genetic methods are important. In the process we survey: the kinds of problems being solved today with these methods; techniques and tools used; problems encountered; and areas where research is needed. The presentation slides are annotated briefly at the top of each page.

  11. Alcohol and Illicit Drug Use Are Important Factors for School-Related Problems among Adolescents

    PubMed Central

    Heradstveit, Ove; Skogen, Jens C.; Hetland, Jørn; Hysing, Mari

    2017-01-01

    The aim of this study was to investigate the association between alcohol and drug use, and school-related problems measured by low grade point average (GPA) and high school attendance. We also examined potential confounding effects from mental health problems. Although the issue is not new within current literature, the present study has its strengths in a large number of participants and the utilization of registry-based data on school-related functioning. A cross-sectional design is employed in this study using data from a large population-based sample of adolescents, youth@hordaland, in a linkage to official school registry data, and the current study presents data from N = 7,874. The main independent variables were alcohol use and drug use, as well as potential alcohol- and drug-related problems. The dependent variables were registry-based school attendance and grades. All the alcohol- and drug measures included were consistently associated with low GPA (Odds ratios (OR) ranging 1.82–2.21, all p < 0.001) and high levels of missed days from school (ORs ranging 1.79–3.04, all p < 0.001) and high levels of hours missed from school (ORs ranging 2.17–3.44, all p < 0.001). Even after adjusting for gender, age, socioeconomic status and mental health problems all the associations between alcohol and illicit drug use and the school-related outcomes remained statistically significant. Increasing number of indications on alcohol/drug-related problems and increasing levels of alcohol consumption were associated with more negative school-related outcomes. The results suggest that alcohol- and drug use, and particularly alcohol/drug-related problems, are important factors for school-related problems independently of mental health problems. PMID:28676779

  12. Alcohol and Illicit Drug Use Are Important Factors for School-Related Problems among Adolescents.

    PubMed

    Heradstveit, Ove; Skogen, Jens C; Hetland, Jørn; Hysing, Mari

    2017-01-01

    The aim of this study was to investigate the association between alcohol and drug use, and school-related problems measured by low grade point average (GPA) and high school attendance. We also examined potential confounding effects from mental health problems. Although the issue is not new within current literature, the present study has its strengths in a large number of participants and the utilization of registry-based data on school-related functioning. A cross-sectional design is employed in this study using data from a large population-based sample of adolescents, youth@hordaland, in a linkage to official school registry data, and the current study presents data from N = 7,874. The main independent variables were alcohol use and drug use, as well as potential alcohol- and drug-related problems. The dependent variables were registry-based school attendance and grades. All the alcohol- and drug measures included were consistently associated with low GPA (Odds ratios (OR) ranging 1.82-2.21, all p < 0.001) and high levels of missed days from school (ORs ranging 1.79-3.04, all p < 0.001) and high levels of hours missed from school (ORs ranging 2.17-3.44, all p < 0.001). Even after adjusting for gender, age, socioeconomic status and mental health problems all the associations between alcohol and illicit drug use and the school-related outcomes remained statistically significant. Increasing number of indications on alcohol/drug-related problems and increasing levels of alcohol consumption were associated with more negative school-related outcomes. The results suggest that alcohol- and drug use, and particularly alcohol/drug-related problems, are important factors for school-related problems independently of mental health problems.

  13. Coexisting social conditions and health problems among clients seeking treatment for illicit drug use in Finland: The HUUTI study

    PubMed Central

    2013-01-01

    Background Illicit drug use is an important public health problem. Identifying conditions that coexist with illicit drug use is necessary for planning health services. This study described the prevalence and factors associated with social and health problems among clients seeking treatment for illicit drug use. Methods We carried out cross-sectional analyses of baseline data of 2526 clients who sought treatment for illicit drug use at Helsinki Deaconess Institute between 2001 and 2008. At the clients’ first visit, trained clinicians conducted face-to-face interviews using a structured questionnaire. Logistic regression was used to compute adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for factors associated with social and health problems. Results The mean age of the clients was 25 years, 21% (n = 519) were homeless, 54% (n = 1363) were unemployed and 7% (n = 183) had experienced threats of violence. Half of the clients (50%, n = 1258) were self-referred and 31% (n = 788) used opiates as their primary drugs of abuse. Hepatitis C (25%, n = 630) was more prevalent than other infectious diseases and depressive symptoms (59%, n = 1490) were the most prevalent psychological problems. Clients who were self-referred to treatment were most likely than others to report social problems (AOR = 1.86; 95% CI = 1.50–2.30) and psychological problems (AOR = 1.51; 95% CI = 1.23–1.85). Using opiates as primary drugs of abuse was the strongest factor associated with infectious diseases (AOR = 3.89; 95% CI = 1.32–11.46) and for reporting a combination of social and health problems (AOR = 3.24; 95% CI = 1.58–6.65). Conclusion The existence of illicit drug use with other social and health problems could lead to increased utilisation and cost of healthcare services. Coexisting social and health problems may interfere with clients’ treatment response. Our findings support the call for integration of

  14. Levenberg-Marquardt method for the eigenvalue complementarity problem.

    PubMed

    Chen, Yuan-yuan; Gao, Yan

    2014-01-01

    The eigenvalue complementarity problem (EiCP) is a kind of very useful model, which is widely used in the study of many problems in mechanics, engineering, and economics. The EiCP was shown to be equivalent to a special nonlinear complementarity problem or a mathematical programming problem with complementarity constraints. The existing methods for solving the EiCP are all nonsmooth methods, including nonsmooth or semismooth Newton type methods. In this paper, we reformulate the EiCP as a system of continuously differentiable equations and give the Levenberg-Marquardt method to solve them. Under mild assumptions, the method is proved globally convergent. Finally, some numerical results and the extensions of the method are also given. The numerical experiments highlight the efficiency of the method.

  15. Recovery from Problem Drug Use: What Can We Learn from the Dociologist Erving Goffman?

    ERIC Educational Resources Information Center

    Neale, Joanne; Nettleton, Sarah; Pickering, Lucy

    2011-01-01

    In this commentary, we critically review the contribution of the sociologist Erving Goffman (1922-1982) to understanding recovery from problem drug use. Previous research has indicated that drug users have a "spoiled identity" and must restore a "normal" or "unspoiled" identity in order to recover. This argument has been linked to Goffman's…

  16. Lessons from the Field: Profiling State Alcohol, Tobacco & Other Drug Problems.

    ERIC Educational Resources Information Center

    Drug Strategies, Washington, DC.

    This document is a step-by-step guide to profiling statewide alcohol, tobacco, and other drug problems and policies. Profiles of this sort capture the complexity of alcohol, tobacco, and other drug abuse indicators at the local level, incorporating data from a range of disciplines and making it possible to design data-driven interventions. The…

  17. Identifying and Preventing Health Problems among Young Drug-Misusing Offenders

    ERIC Educational Resources Information Center

    Bennett, Trevor; Holloway, Katy

    2008-01-01

    Purpose: The purpose of this paper is to identify the health problems and treatment needs of drug-misusing offenders and to draw out the implications of the findings for health education and prevention. Design/methodology/approach: This analysis is based on data collected as part of the New English and Welsh Arrestee Drug Abuse Monitoring…

  18. Recovery from Problem Drug Use: What Can We Learn from the Dociologist Erving Goffman?

    ERIC Educational Resources Information Center

    Neale, Joanne; Nettleton, Sarah; Pickering, Lucy

    2011-01-01

    In this commentary, we critically review the contribution of the sociologist Erving Goffman (1922-1982) to understanding recovery from problem drug use. Previous research has indicated that drug users have a "spoiled identity" and must restore a "normal" or "unspoiled" identity in order to recover. This argument has been linked to Goffman's…

  19. Identifying and Preventing Health Problems among Young Drug-Misusing Offenders

    ERIC Educational Resources Information Center

    Bennett, Trevor; Holloway, Katy

    2008-01-01

    Purpose: The purpose of this paper is to identify the health problems and treatment needs of drug-misusing offenders and to draw out the implications of the findings for health education and prevention. Design/methodology/approach: This analysis is based on data collected as part of the New English and Welsh Arrestee Drug Abuse Monitoring…

  20. Solving Sturm-Liouville problems by piecewise perturbation methods, revisited

    NASA Astrophysics Data System (ADS)

    Ledoux, V.; Van Daele, M.

    2010-08-01

    We present the extension of the successful Constant Perturbation Method (CPM) for Schrödinger problems to the more general class of Sturm-Liouville eigenvalue problems. Whereas the original CPM can only be applied to Sturm-Liouville problems after a Liouville transformation, the more general CPM presented here solves the Sturm-Liouville problem directly. This enlarges the range of applicability of the CPM to a wider variety of problems and allows a more efficient solution of many problems. The CPMs are closely related to the second-order coefficient approximation method underlying the SLEDGE software package, but provide for higher order approximations. These higher order approximations can also be obtained by applying a modified Neumann method. The CPM approach, however, leads to simpler formulae in a more convenient form.

  1. Finite element method for eigenvalue problems in electromagnetics

    NASA Technical Reports Server (NTRS)

    Reddy, C. J.; Deshpande, Manohar D.; Cockrell, C. R.; Beck, Fred B.

    1994-01-01

    Finite element method (FEM) has been a very powerful tool to solve many complex problems in electromagnetics. The goal of the current research at the Langley Research Center is to develop a combined FEM/method of moments approach to three-dimensional scattering/radiation problem for objects with arbitrary shape and filled with complex materials. As a first step toward that goal, an exercise is taken to establish the power of FEM, through closed boundary problems. This paper demonstrates the developed of FEM tools for two- and three-dimensional eigenvalue problems in electromagnetics. In section 2, both the scalar and vector finite elements have been used for various waveguide problems to demonstrate the flexibility of FEM. In section 3, vector finite element method has been extended to three-dimensional eigenvalue problems.

  2. Alzheimer’s Disease Drug Development in 2008 and Beyond: Problems and Opportunities

    PubMed Central

    Becker, Robert E.; Greig, Nigel H.

    2008-01-01

    Recently, a number of Alzheimer’s disease (AD) multi-center clinical trials (CT) have failed to provide statistically significant evidence of drug efficacy. To test for possible design or execution flaws we analyzed in detail CTs for two failed drugs that were strongly supported by preclinical evidence and by proven CT AD efficacy for other drugs in their class. Studies of the failed commercial trials suggest that methodological flaws may contribute to the failures and that these flaws lurk within current drug development practices ready to impact other AD drug development [1]. To identify and counter risks we considered the relevance to AD drug development of the following factors: (1) effective dosing of the drug product, (2) reliable evaluations of research subjects, (3) effective implementation of quality controls over data at research sites, (4) resources for practitioners to effectively use CT results in patient care, (5) effective disease modeling, (6) effective research designs. New drugs currently under development for AD address a variety of specific mechanistic targets. Mechanistic targets provide AD drug development opportunities to escape from many of the factors that currently undermine AD clinical pharmacology, especially the problems of inaccuracy and imprecision associated with using rated outcomes. In this paper we conclude that many of the current problems encountered in AD drug development can be avoided by changing practices. Current problems with human errors in clinical trials make it difficult to differentiate drugs that fail to evidence efficacy from apparent failures due to Type II errors. This uncertainty and the lack of publication of negative data impede researchers’ abilities to improve methodologies in clinical pharmacology and to develop a sound body of knowledge about drug actions. We consider the identification of molecular targets as offering further opportunities for overcoming current failures in drug development. PMID

  3. Current HPLC Methods for Assay of Nano Drug Delivery Systems.

    PubMed

    Tekkeli, Serife Evrim Kepekci; Kiziltas, Mustafa Volkan

    2017-01-01

    In nano drug formulations the mechanism of release is a critical process to recognize controlled and targeted drug delivery systems. In order to gain high bioavailability and specificity from the drug to reach its therapeutic goal, the active substance must be loaded into the nanoparticles efficiently. Therefore, the amount in biological fluids or tissues and the remaining amount in nano carriers are very important parameters to understand the potential of the nano drug delivery systems. For this aim, suitable and validated quantitation methods are required to determine released drug concentrations from nano pharmaceutical formulations. HPLC (High Performance Liquid Chromatography) is one of the most common techniques used for determination of released drug content out of nano drug formulations, in different physical conditions, over different periods of time. Since there are many types of HPLC methods depending on detector and column types, it is a challenge for the researchers to choose a suitable method that is simple, fast and validated HPLC techniques for their nano drug delivery systems. This review's goal is to compare HPLC methods that are currently used in different nano drug delivery systems in order to provide detailed and useful information for researchers. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Novel Methods of Lipidic Nanoparticle Preparation and Drug Loading

    NASA Astrophysics Data System (ADS)

    Maitani, Y.

    2013-09-01

    In improving cancer chemotherapy, lipidic nanoparticle systems for drug delivery, such as liposomes and emulsions, have received much attention because they are capable of delivering their drug payload selectively to cancer cells and of circulating for a long period in the bloodstream. In addition, lipidic nanoparticles have been examined for use in gene delivery as a non-viral vector. Preparation methods of particles and drug loading methods are crucial for the physicochemical properties of nanoparticles, which are the key aspects for pharmaceutical applications. This review describes new preparation methods for nanoparticles and a loading method for drugs using nanotechnology, including an evaluation of nanoparticles from the point of drug release for applications in cancer therapy and gene delivery.

  5. Pediatric drug-related problems: a multicenter study in four French-speaking countries.

    PubMed

    Prot-Labarthe, Sonia; Di Paolo, Ermindo R; Lavoie, Annie; Quennery, Stefanie; Bussières, Jean-François; Brion, Françoise; Bourdon, Olivier

    2013-04-01

    Pediatric intensive care patients represent a population at high risk for drug-related problems. There are few studies that compare the activity of clinical pharmacists between countries. To describe the drug-related problems identified and interventions by four pharmacists in a pediatric cardiac and intensive care unit. Four pediatric centers in France, Quebec, Switzerland and Belgium. This was a six-month multicenter, descriptive and prospective study conducted from August 1, 2009 to January 31, 2010. Drug-related problems and clinical interventions were compiled from four pediatric centers in France, Quebec, Switzerland and Belgium. Data on patients, drugs, intervention, documentation, approval and estimated impact were compiled. Number and type of drug-related problems encountered in a large pediatric inpatient population. A total of 996 interventions were recorded: 238 (24 %) in France, 278 (28 %) in Quebec, 351 (35 %) in Switzerland and 129 (13 %) in Belgium. These interventions targeted 270 patients (median 21 months old, 53 % male): 88 (33 %) in France, 56 (21 %) in Quebec, 57 (21 %) in Switzerland and 69 (26 %) in Belgium. The main drug-related problems were inappropriate administration technique (29 %), untreated indication (25 %) and supra-therapeutic dose (11 %). The pharmacists' interventions were mostly optimizing the mode of administration (22 %), dose adjustment (20 %) and therapeutic monitoring (16 %). The two major drug classes that led to interventions were anti-infectives for systemic use (23 %) and digestive system and metabolism drugs (22 %). Interventions mainly involved residents and all clinical staff (21 %). Among the 878 (88 %) proposed interventions requiring physician approval, 860 (98 %) were accepted. This descriptive study illustrates drug-related problems and the ability of clinical pharmacists to identify and resolve them in pediatric intensive care units in four French-speaking countries.

  6. Optimization based inversion method for the inverse heat conduction problems

    NASA Astrophysics Data System (ADS)

    Mu, Huaiping; Li, Jingtao; Wang, Xueyao; Liu, Shi

    2017-05-01

    Precise estimation of the thermal physical properties of materials, boundary conditions, heat flux distributions, heat sources and initial conditions is highly desired for real-world applications. The inverse heat conduction problem (IHCP) analysis method provides an alternative approach for acquiring such parameters. The effectiveness of the inversion algorithm plays an important role in practical applications of the IHCP method. Different from traditional inversion models, in this paper a new inversion model that simultaneously highlights the measurement errors and the inaccurate properties of the forward problem is proposed to improve the inversion accuracy and robustness. A generalized cost function is constructed to convert the original IHCP into an optimization problem. An iterative scheme that splits a complicated optimization problem into several simpler sub-problems and integrates the superiorities of the alternative optimization method and the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm is developed for solving the proposed cost function. Numerical experiment results validate the effectiveness of the proposed inversion method.

  7. Extension of modified power method to two-dimensional problems

    SciTech Connect

    Zhang, Peng; Lee, Hyunsuk; Lee, Deokjung

    2016-09-01

    In this study, the generalized modified power method was extended to two-dimensional problems. A direct application of the method to two-dimensional problems was shown to be unstable when the number of requested eigenmodes is larger than a certain problem dependent number. The root cause of this instability has been identified as the degeneracy of the transfer matrix. In order to resolve this instability, the number of sub-regions for the transfer matrix was increased to be larger than the number of requested eigenmodes; and a new transfer matrix was introduced accordingly which can be calculated by the least square method. The stability of the new method has been successfully demonstrated with a neutron diffusion eigenvalue problem and the 2D C5G7 benchmark problem. - Graphical abstract:.

  8. Comparisons of numerical methods with respect to convectively dominated problems

    NASA Astrophysics Data System (ADS)

    Wang, Yongqi; Hutter, Kolumban

    2001-11-01

    A series of numerical schemes: first-order upstream, Lax-Friedrichs; second-order upstream, central difference, Lax-Wendroff, Beam-Warming, Fromm; third-order QUICK, QUICKEST and high resolution flux-corrected transport and total variation diminishing (TVD) methods are compared for one-dimensional convection-diffusion problems. Numerical results show that the modified TVD Lax-Friedrichs method is the most competent method for convectively dominated problems with a steep spatial gradient of the variables. Copyright

  9. Solving a Class of Nonlinear Eigenvalue Problems by Newton's Method

    SciTech Connect

    Gao, Weiguo; Yang, Chao; Meza, Juan C.

    2009-07-02

    We examine the possibility of using the standard Newton's method for solving a class of nonlinear eigenvalue problems arising from electronic structure calculation. We show that the Jacobian matrix associated with this nonlinear system has a special structure that can be exploited to reduce the computational complexity of the Newton's method. Preliminary numerical experiments indicate that the Newton's method can be more efficient for small problems in which a few smallest eigenpairs are needed.

  10. [Procedural aspects and interpretation problems in the analysis of drugs of abuse].

    PubMed

    Mancinelli, Rosanna; Guiducci, Maria Soccorsa

    2002-01-01

    Addiction scene is showing rapid changes about substances and patterns of use/abuse. Increasing requirements from clinical and forensic fields to identify drugs of abuse and to find them at ever decreasing levels in biological samples, have led to a great improvement in the state of the art of analytical toxicology. This paper discusses various aspects of these developments highlighting possibilities and problems that make the toxicological determination to be evaluated with prudence, keeping in mind that these results involve legal aspects too. Special attention is focused to the so-called "designer drugs", to the outside laboratory assays and to the problems due to poly-drugs assumption.

  11. Do emergency physicians attribute drug-related emergency department visits to medication-related problems?

    PubMed

    Hohl, Corinne M; Zed, Peter J; Brubacher, Jeffrey R; Abu-Laban, Riyad B; Loewen, Peter S; Purssell, Roy A

    2010-06-01

    Adverse drug events represent the most common cause of preventable nonsurgical adverse events in medicine but may remain undetected. Our objective is to determine the proportion of drug-related visits emergency physicians attribute to medication-related problems. This prospective observational study enrolled adults presenting to a tertiary care emergency department (ED) during 12 weeks. Drug-related visits were defined as ED visits caused by adverse drug events. The definition of adverse drug event was varied to examine both narrow and broad adverse drug event classification systems. Clinical pharmacists evaluated all patients for drug-related visits, using standardized assessment algorithms, and then followed patients until hospital discharge. Interrater agreement for the clinical pharmacist diagnosis of drug-related visit was assessed. Emergency physicians, blinded to the clinical pharmacist opinion, were interviewed at the end of each shift to determine whether they attributed the visit to a medication-related problem. An independent committee reviewed and adjudicated all cases in which the emergency physicians' and clinical pharmacists' assessments were discordant, or either the emergency physician or clinical pharmacist was uncertain. The primary outcome was the proportion of drug-related visits attributed to a medication-related problem by emergency physicians. Nine hundred forty-four patients were enrolled, of whom 44 patients received a diagnosis of the narrowest definition of an adverse drug event, an adverse drug reaction (4.7%; 95% confidence interval [CI] 3.5% to 6.2%). Twenty-seven of these were categorized as medication-related by emergency physicians (61.4%; 95% CI 46.5% to 74.3%), 10 were categorized as uncertain (22.7%; 95% CI 12.9% to 37.1%), and 7 categorized as a non-medication-related problem (15.9%; 95% CI 8.0% to 29.5%). Seventy-eight patients (8.3%; 95% CI 6.7% to 10.2%) received a diagnosis of an adverse drug event caused by an adverse drug

  12. Characteristics of individuals presenting to treatment for primary alcohol problems versus other drug problems in the Australian patient pathways study.

    PubMed

    Lubman, Dan I; Garfield, Joshua B B; Manning, Victoria; Berends, Lynda; Best, David; Mugavin, Janette M; Lam, Tina; Buykx, Penny; Larner, Andrew; Lloyd, Belinda; Room, Robin; Allsop, Steve

    2016-07-19

    People seeking treatment for substance use disorders often have additional health and social issues. Although individuals presenting with alcohol as the primary drug of concern (PDOC) account for nearly half of all treatment episodes to the Australian alcohol and other drug (AOD) service system, previous treatment cohort studies have focused only on the profile of Australian heroin or methamphetamine users. While studies overseas indicate that clients seeking treatment primarily for their drinking are less likely to experience social and economic marginalisation than those seeking treatment primarily for illicit or pharmaceutical drug use, very little research has directly compared individuals presenting with alcohol as the PDOC to those primarily presenting with other drugs as their PDOC. Seven hundred and ninety-six participants were recruited at entry to specialist AOD treatment in Victoria and Western Australia, and completed measures of demographic and social factors, substance use, quality of life, service use, and criminal justice involvement. We compared those with alcohol as their PDOC to those with other drugs as their PDOC using Pearson chi-square and Mann-Whitney U tests. Rates of social disadvantage, poor quality of life, high severity of substance dependence, and past-year AOD, mental health, acute health, and social service use were high in all groups. However, participants with alcohol as the PDOC were older; more likely to have an educational qualification; less likely to report criminal justice involvement, housing/homelessness service use, tobacco smoking, or problems with multiple substances; and reported better environmental quality of life; but were more likely to have used ambulance services, than those with other drugs as their PDOC. While those seeking treatment primarily for alcohol problems appear less likely to suffer some forms of social and economic disadvantage or to use multiple substances than those with a primary drug problem, they

  13. Polymeric drug nanoparticles prepared by an aerosol flow reactor method.

    PubMed

    Eerikäinen, Hannele; Kauppinen, Esko I; Kansikas, Jarno

    2004-01-01

    Our purpose was to study the possibility of using a novel method, namely, aerosol flow reactor method, for the preparation of drug-containing nanoparticles with varying amounts of drug and polymer. The physical properties of the prepared nanoparticles were analyzed. The nanoparticle size distributions were measured using differential mobility analyzer. The structure of the prepared nanoparticles was assessed by x-ray diffraction, differential scanning calorimetry, and electron microscopy. Drug release from the nanoparticles was analyzed. The spherical particles produced showed a unimodal and lognormal size distribution, and the geometric number mean size of the nanoparticles could be varied between 90 and 200 nm. When the amount of drug in the polymeric matrix was small, the nanoparticles had a homogeneous, amorphous structure. Drug crystals were formed when the amount of drug was increased over the solubility limit of the drug into the polymer. The amounts of drug and polymer controlled the drug release from the nanoparticles. The aerosol flow reactor method was found to be able to produce homogeneous amorphous matrix-type nanoparticles that can directly be collected as dry powder.

  14. Educational Policy and the Drug Problem--A Redistributive Politics Issue

    ERIC Educational Resources Information Center

    Caliguri, Joseph P.

    1975-01-01

    The drug problem exists as a cluster of problems affecting broad interests or groups. The issues are redistributive in that everything relates to everything else. It seems apparent that a cluster of policies and programs need development as well as genuine citizen participation in the formulation of these policies. (Author)

  15. Educational Policy and the Drug Problem--A Redistributive Politics Issue

    ERIC Educational Resources Information Center

    Caliguri, Joseph P.

    1975-01-01

    The drug problem exists as a cluster of problems affecting broad interests or groups. The issues are redistributive in that everything relates to everything else. It seems apparent that a cluster of policies and programs need development as well as genuine citizen participation in the formulation of these policies. (Author)

  16. Addiction as an occupational hazard: 144 doctors with drug and alcohol problems.

    PubMed

    Brooke, D; Edwards, G; Taylor, C

    1991-08-01

    Information was abstracted from the hospital notes of 144 doctors who had received treatment for drug and alcohol dependency. These problems affect those in every specialty, and at all degrees of seniority. Over half came into treatment following medical referral. Social morbidity was an important contributory reason for seeking help. The mean age at presentation was 43.1 years; the mean duration of problematic use prior to this was 6.4 years for drug misusers and 6.7 years for alcohol misusers. Alcohol was the current problem for 41.6% and drug misuse for 26.4%; 31.3% were misusing both alcohol and drugs at presentation. Of the 83 subjects who were misusing drugs, only four had ever used blackmarket supplies. Psychotropic agents are readily available to doctors, but the consequences of this are not addressed. Those who develop dependency suffer a delay of years before reaching help.

  17. Schwarz alternating methods for anisotropic problems with prolate spheroid boundaries.

    PubMed

    Dai, Zhenlong; Du, Qikui; Liu, Baoqing

    2016-01-01

    The Schwarz alternating algorithm, which is based on natural boundary element method, is constructed for solving the exterior anisotropic problem in the three-dimension domain. The anisotropic problem is transformed into harmonic problem by using the coordinate transformation. Correspondingly, the algorithm is also changed. Continually, we analysis the convergence and the error estimate of the algorithm. Meanwhile, we give the contraction factor for the convergence. Finally, some numerical examples are computed to show the efficiency of this algorithm.

  18. Newton's method for large bound-constrained optimization problems.

    SciTech Connect

    Lin, C.-J.; More, J. J.; Mathematics and Computer Science

    1999-01-01

    We analyze a trust region version of Newton's method for bound-constrained problems. Our approach relies on the geometry of the feasible set, not on the particular representation in terms of constraints. The convergence theory holds for linearly constrained problems and yields global and superlinear convergence without assuming either strict complementarity or linear independence of the active constraints. We also show that the convergence theory leads to an efficient implementation for large bound-constrained problems.

  19. Methods for reduction of cohesive forces between carrier and drug in DPI formulation.

    PubMed

    Desai, Swapnil S; Aher, Abhijeet A; Kadaskar, Preeti T

    2013-11-01

    Dry powder inhaler (DPI) has become a well accepted drug delivery for pulmonary system to treat many related diseases including symptomatic and life threatening diseases. Successful delivery of dry powder to the lung requires careful consideration of powder production process, formulation and inhaler device. The formulation of DPI mostly comprises of lactose as a carrier for drug delivery. In DPI formulation, particulate interactions within the formulation govern both the drug dissociation from carrier particles and the disaggregation of drug into primary particles with a capacity to penetrate deep into lung. Two contradictory requirements must be fulfilled for this type of dry powder formulation. On one hand, adhesion between carrier and drug must be sufficient for the blend drug/carrier to be stable. On the other hand, adhesion drug/carrier has to be weak enough to enable the release of drug from carrier during patient inhalation. Thus the carrier use restricted due to detachment problem. Different methods are proposed to reduce the cohesive forces between drug and carrier to desired level. Various studies conducted for understanding the mechanism of deposition into lungs and making formulation with optimum carrier drug cohesive force. This review provides information on various processes involved in reducing the cohesive forces between drug and carrier, to a required level.

  20. A numerical method for phase-change problems

    NASA Technical Reports Server (NTRS)

    Kim, Charn-Jung; Kaviany, Massoud

    1990-01-01

    A highly accurate and efficient finite-difference method for phase-change problems with multiple moving boundaries of irregular shape is developed by employing a coordinate transformation that immobilizes moving boundaries and preserves the conservative forms of the original governing equations. The numerical method is first presented for one-dimensional phase-change problems (involving large density variation between phases, heat generation, and multiple moving boundaries) and then extended to solve two-dimensional problems (without change of densities between phases). Numerical solutions are obtained non-iteratively using an explicit treatment of the interfacial mass and energy balances and an implicit treatment of the temperature field equations. The accuracy and flexibility of the present numerical method are verified by solving some phase-change problems and comparing the results with existing analytical, semi-analytical and numerical solutions. Results indicate that one- and two-dimensional phase-change problems can be handled easily with excellent accuracies.

  1. Overview of Krylov subspace methods with applications to control problems

    NASA Technical Reports Server (NTRS)

    Saad, Youcef

    1989-01-01

    An overview of projection methods based on Krylov subspaces are given with emphasis on their application to solving matrix equations that arise in control problems. The main idea of Krylov subspace methods is to generate a basis of the Krylov subspace Span and seek an approximate solution the the original problem from this subspace. Thus, the original matrix problem of size N is approximated by one of dimension m typically much smaller than N. Krylov subspace methods have been very successful in solving linear systems and eigenvalue problems and are now just becoming popular for solving nonlinear equations. It is shown how they can be used to solve partial pole placement problems, Sylvester's equation, and Lyapunov's equation.

  2. A numerical method for phase-change problems

    NASA Technical Reports Server (NTRS)

    Kim, Charn-Jung; Kaviany, Massoud

    1990-01-01

    A highly accurate and efficient finite-difference method for phase-change problems with multiple moving boundaries of irregular shape is developed by employing a coordinate transformation that immobilizes moving boundaries and preserves the conservative forms of the original governing equations. The numerical method is first presented for one-dimensional phase-change problems (involving large density variation between phases, heat generation, and multiple moving boundaries) and then extended to solve two-dimensional problems (without change of densities between phases). Numerical solutions are obtained non-iteratively using an explicit treatment of the interfacial mass and energy balances and an implicit treatment of the temperature field equations. The accuracy and flexibility of the present numerical method are verified by solving some phase-change problems and comparing the results with existing analytical, semi-analytical and numerical solutions. Results indicate that one- and two-dimensional phase-change problems can be handled easily with excellent accuracies.

  3. Written consent to use the drug in children: the problem of off-label drugs.

    PubMed

    Maid, Gustavo; Guerchicoff, Marianna; Falconi, Mariano; de Arenaza, Diego Perez

    2008-01-01

    Cardiac arrhythmias in pediatric patients have different mechanisms and frequencies compared to adult patients. There are many physiological differences between children and adults that may affect the pharmacodynamic and pharmacokinetic of the antiarrhythmic drugs in pediatric population. Children, and specially breast feeding children, cannot be considered low weighted adults to select antiarrhythmic drug doses. Although radiofrequency ablation has experienced great technological advances, it is performed in selected pediatric patients. Therefore, the main therapeutic strategy is the use of antiarrhythmic drugs in children. The medical management of arrhythmias in pediatric patients is challenging and complex. There are few clinical guidelines. There is scarce and incomplete information about the efficacy and safety of antiarrhythmic drugs in pediatric population. Most of the doses and drug administration intervals are extrapolated from adult population and applied to children. Antiarrhythmic drug doses have been extensively studied in adult population. However, in pediatric population, there are very few clinical trials and the safety of these drugs is not well known. In general, dose regimens are based on small uncontrolled studies, extrapolation of drug doses from studies performed in the adult population or physician experience. As a consequence, there is a need for further studies to assess the most effective antiarrhythmic drug regimens in children reducing the risk of side effects. Evidence suggests that medical research in pediatric population is necessary and morally valuable. But investigators involved must take care of moral and ethical values, including the respect for the child-subject and his parents or legal representatives, and this respect compels them to consider the patient and family in the decision making process. The participation request and the informed consent must be obtained according to the competitions the patient exhibits, trying to

  4. Application of AN Asymptotic Method to Transient Dynamic Problems

    NASA Astrophysics Data System (ADS)

    Fafard, M.; Henchi, K.; Gendron, G.; Ammar, S.

    1997-11-01

    A new method to solve linear dynamics problems using an asymptotic method is presented. Asymptotic methods have been efficiently used for many decades to solve non-linear quasistatic structural problems. Generally, structural dynamics problems are solved using finite elements for the discretization of the space domain of the differential equations, and explicit or implicit schemes for the time domain. With the asymptotic method, time schemes are not necessary to solve the discretized (space) equations. Using the analytical solution of a single degree of freedom (DOF) problem, it is demonstrated, that the Dynamic Asymptotic Method (DAM) converges to the exact solution when an infinite series expansion is used. The stability of the method has been studied. DAM is conditionally stable for a finite series expansion and unconditionally stable for an infinite series expansion. This method is similar to the analytical method of undetermined coefficients or to power series method being used to solve ordinary differential equations. For a multi-degree-of-freedom (MDOF) problem with a lumped mass matrix, no factorization or explicit inversion of global matrices is necessary. It is shown that this conditionally stable method is more efficient than other conditionally stable explicit central difference integration techniques. The solution is continuous irrespective of the time segment (step) and the derivatives are continuous up to orderN-1 whereNis the order of the series expansion.

  5. In silico methods to predict drug toxicity.

    PubMed

    Roncaglioni, Alessandra; Toropov, Andrey A; Toropova, Alla P; Benfenati, Emilio

    2013-10-01

    This review describes in silico methods to characterize the toxicity of pharmaceuticals, including tools which predict toxicity endpoints such as genotoxicity or organ-specific models, tools addressing ADME processes, and methods focusing on protein-ligand docking binding. These in silico tools are rapidly evolving. Nowadays, the interest has shifted from classical studies to support toxicity screening of candidates, toward the use of in silico methods to support the expert. These methods, previously considered useful only to provide a rough, initial estimation, currently have attracted interest as they can assist the expert in investigating toxic potential. They provide the expert with safety perspectives and insights within a weight-of-evidence strategy. This represents a shift of the general philosophy of in silico methodology, and it is likely to further evolve especially exploiting links with system biology. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Methods to Design and Synthesize Antibody-Drug Conjugates (ADCs)

    PubMed Central

    Yao, Houzong; Jiang, Feng; Lu, Aiping; Zhang, Ge

    2016-01-01

    Antibody-drug conjugates (ADCs) have become a promising targeted therapy strategy that combines the specificity, favorable pharmacokinetics and biodistributions of antibodies with the destructive potential of highly potent drugs. One of the biggest challenges in the development of ADCs is the application of suitable linkers for conjugating drugs to antibodies. Recently, the design and synthesis of linkers are making great progress. In this review, we present the methods that are currently used to synthesize antibody-drug conjugates by using thiols, amines, alcohols, aldehydes and azides. PMID:26848651

  7. Analyzing HIV/AIDS and Alcohol and Other Drug Use as a Social Problem

    PubMed Central

    PATTERSON, DAVID A.; Wolf (Adelv unegv Waya), Silver

    2012-01-01

    Most prevention and intervention activities directed toward HIV/AIDS and alcohol and other drug use separately as well as the combining of the two (e.g., those who are both HIV/AIDS and using alcohol and other drugs) comes in the form of specific, individualized therapies without consideration of social influences that may have a greater impact on this population. Approaching this social problem from the narrowed view of individualized, mi-cro solutions disregards the larger social conditions that affect or perhaps even are at the root of the problem. This paper analyzes the social problem of HIV/AIDS and alcohol and other drug abuse using three sociological perspectives—social construction theory, ethnomethodology, and conflict theory—informing the reader of the broader influences accompanying this problem. PMID:23264724

  8. Biomarker method validation in anticancer drug development.

    PubMed

    Cummings, J; Ward, T H; Greystoke, A; Ranson, M; Dive, C

    2008-02-01

    Over recent years the role of biomarkers in anticancer drug development has expanded across a spectrum of applications ranging from research tool during early discovery to surrogate endpoint in the clinic. However, in Europe when biomarker measurements are performed on samples collected from subjects entered into clinical trials of new investigational agents, laboratories conducting these analyses become subject to the Clinical Trials Regulations. While these regulations are not specific in their requirements of research laboratories, quality assurance and in particular assay validation are essential. This review, therefore, focuses on a discussion of current thinking in biomarker assay validation. Five categories define the majority of biomarker assays from 'absolute quantitation' to 'categorical'. Validation must therefore take account of both the position of the biomarker in the spectrum towards clinical end point and the level of quantitation inherent in the methodology. Biomarker assay validation should be performed ideally in stages on 'a fit for purpose' basis avoiding unnecessarily dogmatic adherence to rigid guidelines but with careful monitoring of progress at the end of each stage. These principles are illustrated with two specific examples: (a) absolute quantitation of protein biomarkers by mass spectrometry and (b) the M30 and M65 ELISA assays as surrogate end points of cell death.

  9. A Semantic-Linguistic Method of Solving Verbal Problems.

    ERIC Educational Resources Information Center

    Hoggard, Franklin R.

    1987-01-01

    Suggests a method for solving verbal problems in chemistry using a linguistic algorithm that is partly adapted from two artificial intelligence languages. Provides examples of problems solved using the mental concepts of translation, rotation, mirror image symmetry, superpositioning, disjoininng, and conjoining. (TW)

  10. Meshless method for solving fixed boundary problem of plasma equilibrium

    NASA Astrophysics Data System (ADS)

    Imazawa, Ryota; Kawano, Yasunori; Itami, Kiyoshi

    2015-07-01

    This study solves the Grad-Shafranov equation with a fixed plasma boundary by utilizing a meshless method for the first time. Previous studies have utilized a finite element method (FEM) to solve an equilibrium inside the fixed separatrix. In order to avoid difficulties of FEM (such as mesh problem, difficulty of coding, expensive calculation cost), this study focuses on the meshless methods, especially RBF-MFS and KANSA's method to solve the fixed boundary problem. The results showed that CPU time of the meshless methods was ten to one hundred times shorter than that of FEM to obtain the same accuracy.

  11. Materials and methods for delivery of biological drugs

    NASA Astrophysics Data System (ADS)

    Zelikin, Alexander N.; Ehrhardt, Carsten; Healy, Anne Marie

    2016-11-01

    Biological drugs generated via recombinant techniques are uniquely positioned due to their high potency and high selectivity of action. The major drawback of this class of therapeutics, however, is their poor stability upon oral administration and during subsequent circulation. As a result, biological drugs have very low bioavailability and short therapeutic half-lives. Fortunately, tools of chemistry and biotechnology have been developed into an elaborate arsenal, which can be applied to improve the pharmacokinetics of biological drugs. Depot-type release systems are available to achieve sustained release of drugs over time. Conjugation to synthetic or biological polymers affords long circulating formulations. Administration of biological drugs through non-parenteral routes shows excellent performance and the first products have reached the market. This Review presents the main accomplishments in this field and illustrates the materials and methods behind existing and upcoming successful formulations and delivery strategies for biological drugs.

  12. Diffuse interface methods for inverse problems: case study for an elliptic Cauchy problem

    NASA Astrophysics Data System (ADS)

    Burger, Martin; Løseth Elvetun, Ole; Schlottbom, Matthias

    2015-12-01

    Many inverse problems have to deal with complex, evolving and often not exactly known geometries, e.g. as domains of forward problems modeled by partial differential equations. This makes it desirable to use methods which are robust with respect to perturbed or not well resolved domains, and which allow for efficient discretizations not resolving any fine detail of those geometries. For forward problems in partial differential equations methods based on diffuse interface representations have gained strong attention in the last years, but so far they have not been considered systematically for inverse problems. In this work we introduce a diffuse domain method as a tool for the solution of variational inverse problems. As a particular example we study ECG inversion in further detail. ECG inversion is a linear inverse source problem with boundary measurements governed by an anisotropic diffusion equation, which naturally cries for solutions under changing geometries, namely the beating heart. We formulate a regularization strategy using Tikhonov regularization and, using standard source conditions, we prove convergence rates. A special property of our approach is that not only operator perturbations are introduced by the diffuse domain method, but more important we have to deal with topologies which depend on a parameter \\varepsilon in the diffuse domain method, i.e. we have to deal with \\varepsilon -dependent forward operators and \\varepsilon -dependent norms. In particular the appropriate function spaces for the unknown and the data depend on \\varepsilon . This prevents the application of some standard convergence techniques for inverse problems, in particular interpreting the perturbations as data errors in the original problem does not yield suitable results. We consequently develop a novel approach based on saddle-point problems. The numerical solution of the problem is discussed as well and results for several computational experiments are reported. In

  13. Methods and problems in heat and mass transfer

    NASA Astrophysics Data System (ADS)

    Kotliar, Iakov Mikhailovich; Sovershennyi, Viacheslav Dmitrievich; Strizhenov, Dmitrii Sergeevich

    The book focuses on the mathematical methods used in heat and mass transfer problems. The theory, statement, and solution of some problems of practical importance in heat and mass transfer are presented, and methods are proposed for solving algebraic, transcendental, and differential equations. Examples of exact solutions to heat and mass transfer equations are given. The discussion also covers some aspects of the development of a mathematical model of turbulent flows.

  14. Parallel decomposition methods for the solution of electromagnetic scattering problems

    NASA Technical Reports Server (NTRS)

    Cwik, Tom

    1992-01-01

    This paper contains a overview of the methods used in decomposing solutions to scattering problems onto coarse-grained parallel processors. Initially, a short summary of relevant computer architecture is presented as background to the subsequent discussion. After the introduction of a programming model for problem decomposition, specific decompositions of finite difference time domain, finite element, and integral equation solutions to Maxwell's equations are presented. The paper concludes with an outline of possible software-assisted decomposition methods and a summary.

  15. A reduced basis Landweber method for nonlinear inverse problems

    NASA Astrophysics Data System (ADS)

    Garmatter, Dominik; Haasdonk, Bernard; Harrach, Bastian

    2016-03-01

    We consider parameter identification problems in parametrized partial differential equations (PDEs). These lead to nonlinear ill-posed inverse problems. One way of solving them is using iterative regularization methods, which typically require numerous amounts of forward solutions during the solution process. In this article we consider the nonlinear Landweber method and couple it with the reduced basis method as a model order reduction technique in order to reduce the overall computational time. In particular, we consider PDEs with a high-dimensional parameter space, which are known to pose difficulties in the context of reduced basis methods. We present a new method that is able to handle such high-dimensional parameter spaces by combining the nonlinear Landweber method with adaptive online reduced basis updates. It is then applied to the inverse problem of reconstructing the conductivity in the stationary heat equation.

  16. Methods for Managing Variation in Clinical Drug Names

    PubMed Central

    Peters, Lee; Kapusnik-Uner, Joan E.; Bodenreider, Olivier

    2010-01-01

    Objectives: To develop normalization methods for managing the variation in clinical drug names. Methods: Manual examination of drug names from RxNorm and local variants collected from formularies led to the identification of three types of drug-specific normalization rules: expansion of abbreviations (e.g., tab to tablet);reformatting of specific elements (e.g., space between number and unit); and removal of salt variants (e.g., succinate from metoprolol succinate). Results: After drug-specific normalization, recall of 3397 previously non-matching names from formularies reaches 45% overall (70% of some subsets), compared to 10–20% after generic normalization. Ambiguity has not increased significantly in the RxNorm dataset. Conclusions: A limited number of drug-specific normalization operations provide significant improvement over general language normalization. PMID:21347056

  17. Predicting new indications for approved drugs using a proteochemometric method.

    PubMed

    Dakshanamurthy, Sivanesan; Issa, Naiem T; Assefnia, Shahin; Seshasayee, Ashwini; Peters, Oakland J; Madhavan, Subha; Uren, Aykut; Brown, Milton L; Byers, Stephen W

    2012-08-09

    The most effective way to move from target identification to the clinic is to identify already approved drugs with the potential for activating or inhibiting unintended targets (repurposing or repositioning). This is usually achieved by high throughput chemical screening, transcriptome matching, or simple in silico ligand docking. We now describe a novel rapid computational proteochemometric method called "train, match, fit, streamline" (TMFS) to map new drug-target interaction space and predict new uses. The TMFS method combines shape, topology, and chemical signatures, including docking score and functional contact points of the ligand, to predict potential drug-target interactions with remarkable accuracy. Using the TMFS method, we performed extensive molecular fit computations on 3671 FDA approved drugs across 2335 human protein crystal structures. The TMFS method predicts drug-target associations with 91% accuracy for the majority of drugs. Over 58% of the known best ligands for each target were correctly predicted as top ranked, followed by 66%, 76%, 84%, and 91% for agents ranked in the top 10, 20, 30, and 40, respectively, out of all 3671 drugs. Drugs ranked in the top 1-40 that have not been experimentally validated for a particular target now become candidates for repositioning. Furthermore, we used the TMFS method to discover that mebendazole, an antiparasitic with recently discovered and unexpected anticancer properties, has the structural potential to inhibit VEGFR2. We confirmed experimentally that mebendazole inhibits VEGFR2 kinase activity and angiogenesis at doses comparable with its known effects on hookworm. TMFS also predicted, and was confirmed with surface plasmon resonance, that dimethyl celecoxib and the anti-inflammatory agent celecoxib can bind cadherin-11, an adhesion molecule important in rheumatoid arthritis and poor prognosis malignancies for which no targeted therapies exist. We anticipate that expanding our TMFS method to the >27

  18. Data sources and methods for ascertaining human exposure to drugs.

    PubMed

    Jones, J K; Kennedy, D L

    Estimates of population exposure based on drug use data are critical elements in the post marketing surveillance of drugs and provide a context for assessing the various risks and benefits associated with drug treatment. Such information is important in predicting morbidity and planning public health protection strategies, indepth studies, and regulatory actions. Knowledge that a population of one thousand instead of one million may potentially be exposed to a drug can help determine how a particular regulatory problem will be handled and would obviously be a major determinant in designing a case-control or cohort study. National estimates of drug use give an overview of the most commonly used drug therapies in current practice. They also furnish valuable comparison data for specific studies of drug use limited to one group of drugs, one geographic region, or one medical care setting. The FDA has access to several different national drug use data bases, each measuring a different point in the drug distribution channels. None covers the entire spectrum of drug exposures. The major "holes" in this patchwork of data bases are the inability to measure OTC drug use with any accuracy and the lack of qualitative information on drug use in hospitals. In addition, there is no patient linkage with the data. The data can only show trends in drug use. They impart no sense of the longitudinal use of drugs for individual patients. There is no direct connection between the different data bases, all of which have their own sampling frames and their own projection methodologies. The market research companies have complete control over these methodologies and they are subject to periodic changes, a situation not entirely satisfactory for epidemiologic research. Sometimes it is a struggle to keep up with these changes. Over the past two years, every one of these data bases has undergone some type of sampling or projection methodology change. One important limitation to the use of all

  19. Efficiency of Runge-Kutta methods in solving Kepler problem

    NASA Astrophysics Data System (ADS)

    Gorgey, Annie; Muhammad, Hafizul

    2017-05-01

    The aim of this research is to study the efficiency of symplectic and non-symplectic Runge-Kutta methods in solving Kepler problem. The numerical behavior of the Runge-Kutta (RK) methods that are symmetric such as the implicit midpoint rule (IMR), implicit trapezoidal rule (ITR), 2-stage and 2-stage Gauss (G2) method are compared with the non-symmetric Runge-Kutta methods such as the explicit and implicit Euler (EE and IE), explicit midpoint rule (EIMR), explicit trapezoidal rules (EITR), explicit 4-stage Runge-Kutta (RK4) method and 2-stage Radau IIA method (R2A). Kepler problem is one type of nonlinear Hamiltonian problem that describes the motion in a plane of a material point that is attracted towards the origin with a force inversely proportional to the distance squared. The exact solutions phase diagram produces a unit circle. The non-symplectic methods only reproduce a unit circle at certain time intervals while the symplectic methods do produce a unit circle at any time intervals. Some phase diagram show spiral in or spiral out patterns which means the solutions are running away from the unit circle. This also means that the absolute error will be increasing in long time integration. The numerical experiments for the Kepler problem are given for many time intervals and the results show that the most efficient method is G2 of order-4 and surprisingly RK4 seems to be efficient too although it is not a symplectic nor a symmetric method. The numerical results on Kepler problem concluded that, the higher the order of the method, the most efficient the method can be in solving Kepler problem despite whether they are explicit or implicit or symmetric and symplectic.

  20. Undocumented Immigration, Drug Problems, and Driving Under the Influence in the United States, 1990-2014.

    PubMed

    Light, Michael T; Miller, Ty; Kelly, Brian C

    2017-09-01

    To examine the influence of undocumented immigration in the United States on 4 different metrics of drug and alcohol problems: drug arrests, drug overdose fatalities, driving under the influence (DUI) arrests, and DUI deaths. We combined newly developed state-level estimates of the undocumented population between 1990 and 2014 from the Center for Migration Studies with arrest data from the Federal Bureau of Investigation Uniform Crime Reports and fatality information from the Fatality Analysis Reporting System and the Centers for Disease Control and Prevention Underlying Cause of Death database. We used fixed-effects regression models to examine the longitudinal association between increased undocumented immigration and drug problems and drunk driving. Increased undocumented immigration was significantly associated with reductions in drug arrests, drug overdose deaths, and DUI arrests, net of other factors. There was no significant relationship between increased undocumented immigration and DUI deaths. This study provides evidence that undocumented immigration has not increased the prevalence of drug or alcohol problems, but may be associated with reductions in these public health concerns.

  1. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1989-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  2. A weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1990-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  3. Weak Hamiltonian finite element method for optimal control problems

    NASA Technical Reports Server (NTRS)

    Hodges, Dewey H.; Bless, Robert R.

    1991-01-01

    A temporal finite element method based on a mixed form of the Hamiltonian weak principle is developed for dynamics and optimal control problems. The mixed form of Hamilton's weak principle contains both displacements and momenta as primary variables that are expanded in terms of nodal values and simple polynomial shape functions. Unlike other forms of Hamilton's principle, however, time derivatives of the momenta and displacements do not appear therein; instead, only the virtual momenta and virtual displacements are differentiated with respect to time. Based on the duality that is observed to exist between the mixed form of Hamilton's weak principle and variational principles governing classical optimal control problems, a temporal finite element formulation of the latter can be developed in a rather straightforward manner. Several well-known problems in dynamics and optimal control are illustrated. The example dynamics problem involves a time-marching problem. As optimal control examples, elementary trajectory optimization problems are treated.

  4. Spectral finite-element methods for parametric constrained optimization problems.

    SciTech Connect

    Anitescu, M.; Mathematics and Computer Science

    2009-01-01

    We present a method to approximate the solution mapping of parametric constrained optimization problems. The approximation, which is of the spectral finite element type, is represented as a linear combination of orthogonal polynomials. Its coefficients are determined by solving an appropriate finite-dimensional constrained optimization problem. We show that, under certain conditions, the latter problem is solvable because it is feasible for a sufficiently large degree of the polynomial approximation and has an objective function with bounded level sets. In addition, the solutions of the finite-dimensional problems converge for an increasing degree of the polynomials considered, provided that the solutions exhibit a sufficiently large and uniform degree of smoothness. Our approach solves, in the case of optimization problems with uncertain parameters, the most computationally intensive part of stochastic finite-element approaches. We demonstrate that our framework is applicable to parametric eigenvalue problems.

  5. International drug control system and the United Nations General Assembly Special Session (UNGASS) on the world drug problem: an overview.

    PubMed

    Niaz, Kamran

    2017-05-01

    The international drug control system is one of the oldest consensus-based multilateral systems in existence. It provides the basis for the international community and the individual Member States to effectively put in place the mechanisms to address the problem of drug production trafficking and use of illicit substances at different levels. Currently, the international drug control conventions enjoy near universal adherence, with over 180 states party to the three international drug control conventions. This level of consensus is impressive given the highly contentious nature of the subject matter. Since the global drug situation remains very dynamic, the multilateral system has the ability to adjust and respond to the changing situation over the years. This report summarizes for healthcare managers those developments and their implications post UNGASS for the development of policies and in identifying the challenges and priorities for their responses to address the drug situation in order to achieve the targets set for 2019 and the 2030 agenda for sustainable development.

  6. Child abuse, drug addiction and mental health problems of incarcerated women in Israel.

    PubMed

    Chen, Gila; Gueta, Keren

    2015-01-01

    The mental health problems and pathways to drug addiction and crime among female inmates have long been of interest to researchers and practitioners. The purpose of the current study was to examine the possible association between multiple types of childhood abuse, mental health problems, and drug addiction and the incarceration of 50 Israeli women in prison. The findings indicated that female inmates come from risky families with a high prevalence of family mental health problems, parental drug addiction and crime, and sibling drug addiction and crime. Furthermore, they revealed that incarcerated women from risky families were victims of multiple types of childhood abuse and neglect by their parents, as well as their siblings. Overall, the results suggest that the adverse consequences of a family's mental health problems are much more dramatic than we assumed to date, and that women are more likely than men to be the victims of multiple types of childhood abuse and neglect, as well as suffering more severe psychiatric problems, depression, and drug addiction. The implications of these findings are discussed.

  7. A method of designing clinical trials for combination drugs.

    PubMed

    Pigeon, J G; Copenhaver, M D; Whipple, J P

    1992-06-15

    Many pharmaceutical companies are now exploring combination drug therapies as an alternative to monotherapy. Consequently, it is of interest to investigate the simultaneous dose response relationship of two active drugs to select the lowest effective combination. In this paper, we propose a method for designing clinical trials for drug combinations that seems to offer several advantages over the 4 x 3 or even larger factorial studies that have been used to date. In addition, our proposed method provides a convenient formula for calculating the required sample size.

  8. Finite element methods for nonlinear elastostatic problems in rubber elasticity

    NASA Technical Reports Server (NTRS)

    Oden, J. T.; Becker, E. B.; Miller, T. H.; Endo, T.; Pires, E. B.

    1983-01-01

    A number of finite element methods for the analysis of nonlinear problems in rubber elasticity are outlined. Several different finite element schemes are discussed. These include the augmented Lagrangian method, continuation or incremental loading methods, and associated Riks-type methods which have the capability of incorporating limit point behavior and bifurcations. Algorithms for the analysis of limit point behavior and bifurcations are described and the results of several numerical experiments are presented. In addition, a brief survey of some recent work on modelling contact and friction in elasticity problems is given. These results pertain to the use of new nonlocal and nonlinear friction laws.

  9. Solution of exterior acoustic problems by the boundary element method

    NASA Astrophysics Data System (ADS)

    Kirkup, Stephen Martin

    The boundary element method is described and investigated, especially in respect of its application to exterior two-dimensional Laplace problems. Both empirical and algebraic analyses (including the effects of approximation of the boundary and boundary functions and the precision of the evaluation of the discrete forms) are developed. Methods for the automatic evaluation of the discrete forms of the Laplace and Helmholtz integral operators are reviewed and extended. Boundary element methods for the solution of exterior Helmholtz problems with general (but most importantly Neumann) boundary conditions are reviewed and some are explicitly stated using a new notation. Boundary element methods based on the boundary integral equations introduced by Brakhage and Werner/Leis/Panich/Kussmaul (indirect) and Burton and Miller (direct) are given prime consideration and implemented for three-dimensional problems. The influence of the choice of weighting parameter on the performance of the methods is explored and further guidance is given. The application of boundary element methods and methods based on the Rayleigh integral to acoustic radiation problems are considered. Methods for speeding up their solution via the boundary element method are developed. Library subroutines for the solution of acoustic radiation problems are described and demonstrated. Computational techniques for the problem of predicting the noise produced by a running engine are reviewed and appraised. The application of the boundary element method to low-noise engine design and in the design of noise shields is considered. The boundary element method is applied to the Ricardo crankcase simulation rig, which is an engine-like structure. A comparison of predicted and measured sound power spectra is given.

  10. Solution of Exterior Acoustic Problems by the Boundary Element Method.

    NASA Astrophysics Data System (ADS)

    Kirkup, Stephen Martin

    Available from UMI in association with The British Library. The boundary element method is described and investigated, especially in respect of its application to exterior two -dimensional Laplace problems. Both empirical and algebraic analyses (including the effects of approximation of the boundary and boundary functions and the precision of the evaluation of the discrete forms) are developed. Methods for the automatic evaluation of the discrete forms of the Laplace and Helmholtz integral operators are reviewed and extended. Boundary element methods for the solution of exterior Helmholtz problems with general (but most importantly Neumann) boundary conditions are reviewed and some are explicitly stated using a new notation. Boundary element methods based on the boundary integral equations introduced by Brakhage & Werner/ Leis/ Panich/ Kussmaul (indirect) and Burton & Miller (direct) are given prime consideration and implemented for three -dimensional problems. The influence of the choice of weighting parameter on the performance of the methods is explored and further guidance is given. The application of boundary element methods and methods based on the Rayleigh integral to acoustic radiation problems are considered. Methods for speeding up their solution via the boundary element method are developed. Library subroutines for the solution of acoustic radiation problems are described and demonstrated. Computational techniques for the problem of predicting the noise produced by a running engine are reviewed and appraised. The application of the boundary element method to low-noise engine design and in the design of noise shields is considered. The boundary element method is applied to the Ricardo crankcase simulation rig, which is an engine -like structure. A comparison of predicted and measured sound power spectra is given.

  11. Computerized pharmacy surveillance and alert system for drug-related problems.

    PubMed

    Ferrández, O; Urbina, O; Grau, S; Mateu-de-Antonio, J; Marin-Casino, M; Portabella, J; Mojal, S; Riu, M; Salas, E

    2017-04-01

    Because of the impact of drug-related problems (DRPs) on morbidity and mortality, there is a need for computerized strategies to increase drug safety. The detection and identification of the causes of potential DRPs can be facilitated by the incorporation of a pharmacy warning system (PWS) in the computerized prescriber order entry (CPOE) and its application in the routine validation of inpatient drug therapy. A limited number of studies have evaluated a clinical decision support system to monitor drug treatment. Most of these applications have utilized a small range of drugs with alerts and/or types of alert. The objective of this study was to describe the implementation of a PWS integrated in the electronic medical record (EMR). The PWS was developed in 2003-2004. Pharmacological information to generate drug alerts was entered on demographic data, drug dosage, laboratory tests related to the prescribed drug and drug combinations (interactions, duplications and necessary combinations). The PWS was applied in the prescription reviews conducted in patients admitted to the hospital in 2012. Information on 83% of the drugs included in the pharmacopeia was introduced into the PWS, allowing detection of 2808 potential DRPs, representing 79·1% of all potential DRPs detected during the study period. Twenty per cent of PWS DRPs were clinically relevant, requiring pharmacist intervention. The PWS detected most potential DRPs, thus increasing inpatient safety. The detection ability of the PWS was higher than that reported for other tools described in the literature. © 2017 John Wiley & Sons Ltd.

  12. Domain decomposition methods for solving an image problem

    SciTech Connect

    Tsui, W.K.; Tong, C.S.

    1994-12-31

    The domain decomposition method is a technique to break up a problem so that ensuing sub-problems can be solved on a parallel computer. In order to improve the convergence rate of the capacitance systems, pre-conditioned conjugate gradient methods are commonly used. In the last decade, most of the efficient preconditioners are based on elliptic partial differential equations which are particularly useful for solving elliptic partial differential equations. In this paper, the authors apply the so called covering preconditioner, which is based on the information of the operator under investigation. Therefore, it is good for various kinds of applications, specifically, they shall apply the preconditioned domain decomposition method for solving an image restoration problem. The image restoration problem is to extract an original image which has been degraded by a known convolution process and additive Gaussian noise.

  13. Drugs.

    ERIC Educational Resources Information Center

    Hurst, Hunter, Ed.; And Others

    1984-01-01

    This document contains the third volume of "Today's Delinquent," an annual publication of the National Center for Juvenile Justice. This volume deals with the issue of drugs and includes articles by leading authorities in delinquency and substance abuse who share their views on causes and cures for the drug problem among youth in this country.…

  14. Advanced systems biology methods in drug discovery and translational biomedicine.

    PubMed

    Zou, Jun; Zheng, Ming-Wu; Li, Gen; Su, Zhi-Guang

    2013-01-01

    Systems biology is in an exponential development stage in recent years and has been widely utilized in biomedicine to better understand the molecular basis of human disease and the mechanism of drug action. Here, we discuss the fundamental concept of systems biology and its two computational methods that have been commonly used, that is, network analysis and dynamical modeling. The applications of systems biology in elucidating human disease are highlighted, consisting of human disease networks, treatment response prediction, investigation of disease mechanisms, and disease-associated gene prediction. In addition, important advances in drug discovery, to which systems biology makes significant contributions, are discussed, including drug-target networks, prediction of drug-target interactions, investigation of drug adverse effects, drug repositioning, and drug combination prediction. The systems biology methods and applications covered in this review provide a framework for addressing disease mechanism and approaching drug discovery, which will facilitate the translation of research findings into clinical benefits such as novel biomarkers and promising therapies.

  15. Methods to sustain drug efficacy in helminth control programmes.

    PubMed

    Albonico, M

    2003-05-01

    Assessment of the efficacy of anthelminthic treatment in public health is a broad concept, which goes beyond parasitological methods and should be clearly defined according to several indicators of morbidity. Several factors may influence the efficacy of anthelminthic drugs. The quality of drug is an issue of great importance, especially when produced locally as a generic product and used in large-scale chemotherapy-based control programmes. Other factors include the drug-patient interaction, the host-parasite relationship, the diagnostic method used, genetic variations between parasite strains and induced drug resistance. Veterinary scientists have warned that drug resistance can be selected through frequent mass treatment of sheep and goats and have developed a body of knowledge on evaluation of efficacy and detection of resistance in nematodes of veterinary importance. In soil-transmitted nematodes infections of humans, the egg reduction rate (ERR), the egg hatch assay (EHA) and novel molecular biological techniques may be used to monitor drug efficacy in helminth control programmes and to detect early occurrence of resistance. Evidence of reduced drug efficacy of some anthelminthics has been suggested by recent studies and strategies to prevent or delay the emergence of drug resistance in human soil-transmitted nematodes.

  16. Self-help organizations for alcohol and drug problems: toward evidence-based practice and policy.

    PubMed

    Humphreys, Keith; Wing, Stephen; McCarty, Dennis; Chappel, John; Gallant, Lewi; Haberle, Beverly; Horvath, A Thomas; Kaskutas, Lee Ann; Kirk, Thomas; Kivlahan, Daniel; Laudet, Alexandre; McCrady, Barbara S; McLellan, A Thomas; Morgenstern, Jon; Townsend, Mike; Weiss, Roger

    2004-04-01

    This expert consensus statement reviews evidence on the effectiveness of drug and alcohol self-help groups and presents potential implications for clinicians, treatment program managers and policymakers. Because longitudinal studies associate self-help group involvement with reduced substance use, improved psychosocial functioning, and lessened health care costs, there are humane and practical reasons to develop self-help group supportive policies. Policies described here that could be implemented by clinicians and program managers include making greater use of empirically-validated self-help group referral methods in both specialty and non-specialty treatment settings and developing a menu of locally available self-help group options that are responsive to client's needs, preferences, and cultural background. The workgroup also offered possible self-help supportive policy options (e.g., supporting self-help clearinghouses) for state and federal decision makers. Implementing such policies could strengthen alcohol and drug self-help organizations, and thereby enhance the national response to the serious public health problem of substance abuse.

  17. Boundary data completion: the method of boundary value problem factorization

    NASA Astrophysics Data System (ADS)

    Ben Abda, Amel; Henry, Jacques; Jday, Fadhel

    2011-05-01

    We consider the following data completion problem for the Laplace equation in the cylindrical domain: \\Omega =\\left]0,a\\right[\\times { O},{ O}\\subset {R}^{n-1} ({ O} is a smooth bounded open set and a > 0), limited by the faces \\Gamma _{0}=\\lbrace 0\\rbrace \\times { O} and \\Gamma _{a}=\\lbrace a\\rbrace \\times { O}. The Neumann and Dirichlet boundary conditions are given on Γ0 while no condition is given on Γa. The completion data problem consists in recovering a boundary condition on Γa. This problem has been known to be ill-posed since Hadamard [12]. The problem is set as an optimal control problem with a regularized cost function. To obtain directly an approximation of the missing data on Γa we use the method of factorization of elliptic boundary value problems. This method allows us to factorize a boundary value problem in the product of two parabolic problems. Here it is applied to the optimality system (i.e. jointly on the state and adjoint state equations).

  18. Methods of centers and methods of feasible directions for the solution of optimal control problems.

    NASA Technical Reports Server (NTRS)

    Polak, E.; Mukai, H.; Pironneau, O.

    1971-01-01

    Demonstration of the applicability of methods of centers and of methods of feasible directions to optimal control problems. Presented experimental results show that extensions of Frank-Wolfe (1956), Zoutendijk (1960), and Pironneau-Polak (1971) algorithms for nonlinear programming problems can be quite efficient in solving optimal control problems.

  19. Drug use problems with self-injected low-molecular-weight heparins in primary care.

    PubMed

    Mengiardi, Seraina; Tsakiris, Dimitrios A; Lampert, Markus L; Hersberger, Kurt E

    2011-02-01

    Outpatient subcutaneous therapies are becoming increasingly common. A literature search failed to find produced any studies on application problems pertaining to the self-injection of low-molecular-weight heparins (LMWH) in a heterogeneous outpatient population under daily-life conditions. We therefore designed a study with the aim of recording drug use problems, patient satisfaction, compliance, problems arising from the injection site (abdomen vs. thigh), and residual drug volumes in pre-filled syringes used in self-injection therapy. Patients were recruited in community pharmacies by 95 trained Master's students in pharmacy. Data were collected during recruitment and by means of structured questionnaire-based telephone interviews that were carried out at the beginning and the end of the LMWH treatment. The median age of the 213 patients enrolled in the study was 54 years [interquartile range (IQR) 39-70 years]; of these, 15.5% had their injections administered by a third person. The rate of self-reported non-compliance was 17.1%. At least one relevant problem was recorded in 85.0% of the cases. At the end of the treatment, 38.9% of the patients stated self-administration of the injections required some effort. The preferred injection site was the thigh (68.5%). An overall mean residual drug volume ≥ 10.0% was detected for 3.9% of the patients. If residual drug was present, a median of 11.2% (IQR 8.6-17.6%) of the total drug volume had not been injected. Patients injecting into the thigh showed a higher risk of leaving residual medication (odds ratio 2.16, 95% confidence interval 1.04-4.51). Most patients had drug use problems, whereas no clear factors were associated with non-compliance, the injection site (apart from residual drug), and discomfort or effort required (apart from prior injection use).

  20. A Novel Drug-Mouse Phenotypic Similarity Method Detects Molecular Determinants of Drug Effects.

    PubMed

    Prinz, Jeanette; Vogt, Ingo; Adornetto, Gianluca; Campillos, Mónica

    2016-09-01

    The molecular mechanisms that translate drug treatment into beneficial and unwanted effects are largely unknown. We present here a novel approach to detect gene-drug and gene-side effect associations based on the phenotypic similarity of drugs and single gene perturbations in mice that account for the polypharmacological property of drugs. We scored the phenotypic similarity of human side effect profiles of 1,667 small molecules and biologicals to profiles of phenotypic traits of 5,384 mouse genes. The benchmarking with known relationships revealed a strong enrichment of physical and indirect drug-target connections, causative drug target-side effect links as well as gene-drug links involved in pharmacogenetic associations among phenotypically similar gene-drug pairs. The validation by in vitro assays and the experimental verification of an unknown connection between oxandrolone and prokineticin receptor 2 reinforces the ability of this method to provide new molecular insights underlying drug treatment. Thus, this approach may aid in the proposal of novel and personalized treatments.

  1. A Novel Drug-Mouse Phenotypic Similarity Method Detects Molecular Determinants of Drug Effects

    PubMed Central

    Prinz, Jeanette; Vogt, Ingo; Adornetto, Gianluca; Campillos, Mónica

    2016-01-01

    The molecular mechanisms that translate drug treatment into beneficial and unwanted effects are largely unknown. We present here a novel approach to detect gene-drug and gene-side effect associations based on the phenotypic similarity of drugs and single gene perturbations in mice that account for the polypharmacological property of drugs. We scored the phenotypic similarity of human side effect profiles of 1,667 small molecules and biologicals to profiles of phenotypic traits of 5,384 mouse genes. The benchmarking with known relationships revealed a strong enrichment of physical and indirect drug-target connections, causative drug target-side effect links as well as gene-drug links involved in pharmacogenetic associations among phenotypically similar gene-drug pairs. The validation by in vitro assays and the experimental verification of an unknown connection between oxandrolone and prokineticin receptor 2 reinforces the ability of this method to provide new molecular insights underlying drug treatment. Thus, this approach may aid in the proposal of novel and personalized treatments. PMID:27673331

  2. Application of essentially nonoscillatory methods to aeroacoustic flow problems

    NASA Technical Reports Server (NTRS)

    Atkins, Harold L.

    1995-01-01

    A finite-difference essentially nonoscillatory (ENO) method has been applied to several of the problems prescribed for the workshop sponsored jointly by the Institute for Computer Applications in Science and Engineering and by NASA Langley Research Center entitled 'Benchmark Problems in Computational Aeroacoustics'. The workshop focused on computational challenges specific to aeroacoustics. Among these are long-distance propagation of a short-wavelength disturbance, propagation of small-amplitude disturbances, and nonreflective boundary conditions. The shock capturing-capability inherent to the ENO method effectively eliminates oscillations near shock waves without the need to add and tune dissipation or filter terms. The method-of-lines approach allows the temporal and spatial operators to be chosen separately in accordance with the demands of a particular problem. The ENO method was robust and accurate for all problems in which the propagating wave was resolved with 8 or more points per wavelength. The finite-wave-model boundary condition, a local nonlinear acoustic boundary condition, performed well for the one-dimensional problems. The buffer-domain approach performed well for the two-dimensional test problem. The amplitude of nonphysical reflections were less than 1 percent of the exiting wave's amplitude.

  3. Application of essentially nonoscillatory methods to aeroacoustic flow problems

    NASA Technical Reports Server (NTRS)

    Atkins, Harold L.

    1995-01-01

    A finite-difference essentially nonoscillatory (ENO) method has been applied to several of the problems prescribed for the workshop sponsored jointly by the Institute for Computer Applications in Science and Engineering and by NASA Langley Research Center entitled 'Benchmark Problems in Computational Aeroacoustics'. The workshop focused on computational challenges specific to aeroacoustics. Among these are long-distance propagation of a short-wavelength disturbance, propagation of small-amplitude disturbances, and nonreflective boundary conditions. The shock capturing-capability inherent to the ENO method effectively eliminates oscillations near shock waves without the need to add and tune dissipation or filter terms. The method-of-lines approach allows the temporal and spatial operators to be chosen separately in accordance with the demands of a particular problem. The ENO method was robust and accurate for all problems in which the propagating wave was resolved with 8 or more points per wavelength. The finite-wave-model boundary condition, a local nonlinear acoustic boundary condition, performed well for the one-dimensional problems. The buffer-domain approach performed well for the two-dimensional test problem. The amplitude of nonphysical reflections were less than 1 percent of the exiting wave's amplitude.

  4. A meshless method for solving the EEG forward problem.

    PubMed

    von Ellenrieder, Nicolas; Muravchik, Carlos H; Nehorai, Arye

    2005-02-01

    We present a numerical method to solve the quasistatic Maxwell equations and compute the electroencephalography (EEG) forward problem solution. More generally, we develop a computationally efficient method to obtain the electric potential distribution generated by a source of electric activity inside a three-dimensional body of arbitrary shape and layers of different electric conductivities. The method needs only a set of nodes on the surface and inside the head, but not a mesh connecting the nodes. This represents an advantage over traditional methods like boundary elements or finite elements since the generation of the mesh is typically computationally intensive. The performance of the proposed method is compared with the boundary element method (BEM) by numerically solving some EEG forward problems examples. For a large number of nodes and the same precision, our method has lower computational load than BEM due to a faster convergence rate and to the sparsity of the linear system to be solved.

  5. Proposal of Evolutionary Simplex Method for Global Optimization Problem

    NASA Astrophysics Data System (ADS)

    Shimizu, Yoshiaki

    To make an agile decision in a rational manner, role of optimization engineering has been notified increasingly under diversified customer demand. With this point of view, in this paper, we have proposed a new evolutionary method serving as an optimization technique in the paradigm of optimization engineering. The developed method has prospects to solve globally various complicated problem appearing in real world applications. It is evolved from the conventional method known as Nelder and Mead’s Simplex method by virtue of idea borrowed from recent meta-heuristic method such as PSO. Mentioning an algorithm to handle linear inequality constraints effectively, we have validated effectiveness of the proposed method through comparison with other methods using several benchmark problems.

  6. Fluorescence And Alternative Methods In Urine Drug Testing

    NASA Astrophysics Data System (ADS)

    Jain, Naresh C.

    1988-04-01

    Drug abuse has become-one of the most compelling realities _ ot contemporary society. It has penetrated every segment ot our population: trom schools to sports and trom organized crime to board rooms . Drugs in tie w9rkplace allegedly cost government agencies and business millions ot dollars each year in increased absenteeism,. poor work performance, thefts,accidents andwastedtime. The President's Commission on Organized Crime and the federal government are in tavor ot urine drug testing. In fact many employers are now resorting to urine drug testing on current and prospective employees. This presep.tation discusses different laboratory methods used in urine drug.testing, including immunoassays, fluorescence polarization, thin layer chromatography, high pressure liquid chromatography, gas chromatography and gas-chromatography-mass spectrometry.

  7. Application of supercritical antisolvent method in drug encapsulation: a review

    PubMed Central

    Kalani, Mahshid; Yunus, Robiah

    2011-01-01

    The review focuses on the application of supercritical fluids as antisolvents in the pharmaceutical field and demonstrates the supercritical antisolvent method in the use of drug encapsulation. The main factors for choosing the solvent and biodegradable polymer to produce fine particles to ensure effective drug delivery are emphasized and the effect of polymer structure on drug encapsulation is illustrated. The review also demonstrates the drug release mechanism and polymeric controlled release system, and discusses the effects of the various conditions in the process, such as pressure, temperature, concentration, chemical compositions (organic solvents, drug, and biodegradable polymer), nozzle geometry, CO2 flow rate, and the liquid phase flow rate on particle size and its distribution. PMID:21796245

  8. Application of supercritical antisolvent method in drug encapsulation: a review.

    PubMed

    Kalani, Mahshid; Yunus, Robiah

    2011-01-01

    The review focuses on the application of supercritical fluids as antisolvents in the pharmaceutical field and demonstrates the supercritical antisolvent method in the use of drug encapsulation. The main factors for choosing the solvent and biodegradable polymer to produce fine particles to ensure effective drug delivery are emphasized and the effect of polymer structure on drug encapsulation is illustrated. The review also demonstrates the drug release mechanism and polymeric controlled release system, and discusses the effects of the various conditions in the process, such as pressure, temperature, concentration, chemical compositions (organic solvents, drug, and biodegradable polymer), nozzle geometry, CO(2) flow rate, and the liquid phase flow rate on particle size and its distribution.

  9. Formalization of a synthesis problem and methods for its solution

    NASA Astrophysics Data System (ADS)

    Dokukin, A. A.

    2014-06-01

    A formal formulation is proposed for the synthesis problem of finding objects with certain properties described only by a collection of precedents. A key feature of this formalization is that it is closely related to the pattern recognition theory. A general approach to solving the synthesis problem is described, and particular solution methods are presented in two important cases. For this purpose, a new recognition method is proposed that exhibits a high speed as applied to the data of the structure under study. The performance of the methods is demonstrated on actual data.

  10. Clinical pragmatism: a method of moral problem solving.

    PubMed

    Fins, Joseph J; Bacchetta, Matthew D; Miller, Franklin G

    1997-06-01

    This paper presents a method of moral problem solving in clinical practice that is inspired by the philosophy of John Dewey. This method, called "clinical pragmatism," integrates clinical and ethical decision making. Clinical pragmatism focuses on the interpersonal processes of assessment and consensus formation as well as the ethical analysis of relevant moral considerations. The steps in this method are delineated and then illustrated through a detailed case study. The implications of clinical pragmatism for the use of principles in moral problem solving are discussed.

  11. Preconditioned Mixed Spectral Element Methods for Elasticity and Stokes Problems

    NASA Technical Reports Server (NTRS)

    Pavarino, Luca F.

    1996-01-01

    Preconditioned iterative methods for the indefinite systems obtained by discretizing the linear elasticity and Stokes problems with mixed spectral elements in three dimensions are introduced and analyzed. The resulting stiffness matrices have the structure of saddle point problems with a penalty term, which is associated with the Poisson ratio for elasticity problems or with stabilization techniques for Stokes problems. The main results of this paper show that the convergence rate of the resulting algorithms is independent of the penalty parameter, the number of spectral elements Nu and mildly dependent on the spectral degree eta via the inf-sup constant. The preconditioners proposed for the whole indefinite system are block-diagonal and block-triangular. Numerical experiments presented in the final section show that these algorithms are a practical and efficient strategy for the iterative solution of the indefinite problems arising from mixed spectral element discretizations of elliptic systems.

  12. The menu-setting problem and subsidized prices: drug formulary illustration.

    PubMed

    Olmstead, T; Zeckhauser, R

    1999-10-01

    The menu-setting problem (MSP) determines the goods and services an institution offers and the prices charged. It appears widely in health care, from choosing the services an insurance arrangement offers, to selecting the health plans an employer proffers. The challenge arises because purchases are subsidized, and consumers (or their physician agents) may make cost-ineffective choices. The intuitively comprehensible MSP model--readily solved by computer using actual data--helps structure thinking and support decision making about such problems. The analysis uses drug formularies--lists of approved drugs in a plan or institution--to illustrate the framework.

  13. Error Analysis for Discontinuous Galerkin Method for Parabolic Problems

    NASA Technical Reports Server (NTRS)

    Kaneko, Hideaki

    2004-01-01

    In the proposal, the following three objectives are stated: (1) A p-version of the discontinuous Galerkin method for a one dimensional parabolic problem will be established. It should be recalled that the h-version in space was used for the discontinuous Galerkin method. An a priori error estimate as well as a posteriori estimate of this p-finite element discontinuous Galerkin method will be given. (2) The parameter alpha that describes the behavior double vertical line u(sub t)(t) double vertical line 2 was computed exactly. This was made feasible because of the explicitly specified initial condition. For practical heat transfer problems, the initial condition may have to be approximated. Also, if the parabolic problem is proposed on a multi-dimensional region, the parameter alpha, for most cases, would be difficult to compute exactly even in the case that the initial condition is known exactly. The second objective of this proposed research is to establish a method to estimate this parameter. This will be done by computing two discontinuous Galerkin approximate solutions at two different time steps starting from the initial time and use them to derive alpha. (3) The third objective is to consider the heat transfer problem over a two dimensional thin plate. The technique developed by Vogelius and Babuska will be used to establish a discontinuous Galerkin method in which the p-element will be used for through thickness approximation. This h-p finite element approach, that results in a dimensional reduction method, was used for elliptic problems, but the application appears new for the parabolic problem. The dimension reduction method will be discussed together with the time discretization method.

  14. TWO-GRID METHODS FOR MAXWELL EIGENVALUE PROBLEMS

    PubMed Central

    ZHOU, J.; HU, X.; ZHONG, L.; SHU, S.; CHEN, L.

    2015-01-01

    Two new two-grid algorithms are proposed for solving the Maxwell eigenvalue problem. The new methods are based on the two-grid methodology recently proposed by Xu and Zhou [Math. Comp., 70 (2001), pp. 17–25] and further developed by Hu and Cheng [Math. Comp., 80 (2011), pp. 1287–1301] for elliptic eigenvalue problems. The new two-grid schemes reduce the solution of the Maxwell eigenvalue problem on a fine grid to one linear indefinite Maxwell equation on the same fine grid and an original eigenvalue problem on a much coarser grid. The new schemes, therefore, save total computational cost. The error estimates reveals that the two-grid methods maintain asymptotically optimal accuracy, and the numerical experiments presented confirm the theoretical results. PMID:26190866

  15. Are therapeutic vaccines an answer to the global problem of drug and alcohol abuse?

    PubMed

    Brashier, Dick B S; Sharma, Ashok Kumar; Akhoon, Neha

    2016-01-01

    Drug Abuse has become a major challenging problem for the society. It effects people of all countries economical strata's and all ages. According. Monetary loss all over the world regarding drug abuse is in million dollars, it not only has an impact on human productivity and healthcare cost but also on cost of crimes conducted by these drugs and alcohol abuse. Therapeutic vaccine has come as new approach to deal with this problem, after failures in search for a pharmaceutical agent to deal with drug of abuse and alcohol. Research in field of nicotine abuse has gone a way ahead with number of vaccines being tried clinically followed by cocaine, opioids, methamphetamine, phencyclidine and alcohol. All of them have a common mechanism of action by antibody production whereas alcohol acts by genetic intervention. None have being approved yet due to poor results in phase II trials, possibly due to not able to trigger an adequate immunological response. But still quest is on for cracking the ice by developing first successful vaccine against drug of abuse, that would follow for other drugs too. It would be great step in field of therapeutic vaccines for drug abuse after similar successful vaccines being approved for other diseases like cancer.

  16. Drug trajectories among youth undergoing treatment: the influence of psychological problems and delinquency.

    PubMed

    Brunelle, Natacha; Bertrand, Karine; Beaudoin, Isabelle; Ledoux, Cinthia; Gendron, Annie; Arseneault, Catherine

    2013-08-01

    Previous research has documented associations of addiction with delinquency and psychological problems. However, few studies have evaluated their influence on adolescent's drug use trajectories. The current study aims to examine the influence of these factors on the recovery trajectories of 199 youths aged 15.6 years on average admitted to inpatient and outpatient addiction treatment centers, followed up three and six months later. Results indicate that youth who show higher severity of drug abuse exhibit greater improvement than youth with a lower severity of drug abuse at the onset of treatment. Although psychological problems were associated with baseline drug use, they did not influence drug use trajectory over time. Only delinquency influenced the recovery trajectories of these youth. Results suggest that a high level of delinquency can have a significant effect on the drug recovery process of adolescents and that interventions should attempt to reduce both drug use and delinquency. Copyright © 2013 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  17. Are therapeutic vaccines an answer to the global problem of drug and alcohol abuse?

    PubMed Central

    Brashier, Dick B. S.; Sharma, Ashok Kumar; Akhoon, Neha

    2016-01-01

    Drug Abuse has become a major challenging problem for the society. It effects people of all countries economical strata's and all ages. According. Monetary loss all over the world regarding drug abuse is in million dollars, it not only has an impact on human productivity and healthcare cost but also on cost of crimes conducted by these drugs and alcohol abuse. Therapeutic vaccine has come as new approach to deal with this problem, after failures in search for a pharmaceutical agent to deal with drug of abuse and alcohol. Research in field of nicotine abuse has gone a way ahead with number of vaccines being tried clinically followed by cocaine, opioids, methamphetamine, phencyclidine and alcohol. All of them have a common mechanism of action by antibody production whereas alcohol acts by genetic intervention. None have being approved yet due to poor results in phase II trials, possibly due to not able to trigger an adequate immunological response. But still quest is on for cracking the ice by developing first successful vaccine against drug of abuse, that would follow for other drugs too. It would be great step in field of therapeutic vaccines for drug abuse after similar successful vaccines being approved for other diseases like cancer. PMID:27721531

  18. Space-time adaptive wavelet methods for parabolic evolution problems

    NASA Astrophysics Data System (ADS)

    Schwab, Christoph; Stevenson, Rob

    2009-09-01

    With respect to space-time tensor-product wavelet bases, parabolic initial boundary value problems are equivalently formulated as bi-infinite matrix problems. Adaptive wavelet methods are shown to yield sequences of approximate solutions which converge at the optimal rate. In case the spatial domain is of product type, the use of spatial tensor product wavelet bases is proved to overcome the so-called curse of dimensionality, i.e., the reduction of the convergence rate with increasing spatial dimension.

  19. Aerosol flow reactor method for synthesis of drug nanoparticles.

    PubMed

    Eerikäinen, Hannele; Watanabe, Wiwik; Kauppinen, Esko I; Ahonen, P Petri

    2003-05-01

    An aerosol flow reactor method, a one-step continuous process to produce nanometer-sized drug particles with unimodal size distribution, was developed. This method involves first dissolving the drug material in question into a suitable solvent, which is then followed by atomising the solution as fine droplets into carrier gas. A heated laminar flow reactor tube is used to evaporate the solvent, and solid drug nanoparticles are formed. In this study, the effect of drying temperature on the particle size and morphology was examined. A glucocorticosteroid used for asthma therapy, beclomethasone dipropionate, was selected as an experimental model drug. The geometric number mean particle diameter increases significantly with increasing reactor temperatures due to formation of hollow nanoparticles. Above 160 degrees C, however, further increase in temperature results in decreasing particle size. The produced nanoparticles are spherical and show smooth surfaces at all studied experimental conditions.

  20. Solving inverse problems of identification type by optimal control methods

    SciTech Connect

    Lenhart, S.; Protopopescu, V.; Jiongmin Yong

    1997-06-01

    Inverse problems of identification type for nonlinear equations are considered within the framework of optimal control theory. The rigorous solution of any particular problem depends on the functional setting, type of equation, and unknown quantity (or quantities) to be determined. Here the authors present only the general articulations of the formalism. Compared to classical regularization methods (e.g. Tikhonov coupled with optimization schemes), their approach presents several advantages, namely: (i) a systematic procedure to solve inverse problems of identification type; (ii) an explicit expression for the approximations of the solution; and (iii) a convenient numerical solution of these approximations.

  1. Hybrid Monte Carlo/deterministic methods for radiation shielding problems

    NASA Astrophysics Data System (ADS)

    Becker, Troy L.

    For the past few decades, the most common type of deep-penetration (shielding) problem simulated using Monte Carlo methods has been the source-detector problem, in which a response is calculated at a single location in space. Traditionally, the nonanalog Monte Carlo methods used to solve these problems have required significant user input to generate and sufficiently optimize the biasing parameters necessary to obtain a statistically reliable solution. It has been demonstrated that this laborious task can be replaced by automated processes that rely on a deterministic adjoint solution to set the biasing parameters---the so-called hybrid methods. The increase in computational power over recent years has also led to interest in obtaining the solution in a region of space much larger than a point detector. In this thesis, we propose two methods for solving problems ranging from source-detector problems to more global calculations---weight windows and the Transform approach. These techniques employ sonic of the same biasing elements that have been used previously; however, the fundamental difference is that here the biasing techniques are used as elements of a comprehensive tool set to distribute Monte Carlo particles in a user-specified way. The weight window achieves the user-specified Monte Carlo particle distribution by imposing a particular weight window on the system, without altering the particle physics. The Transform approach introduces a transform into the neutron transport equation, which results in a complete modification of the particle physics to produce the user-specified Monte Carlo distribution. These methods are tested in a three-dimensional multigroup Monte Carlo code. For a basic shielding problem and a more realistic one, these methods adequately solved source-detector problems and more global calculations. Furthermore, they confirmed that theoretical Monte Carlo particle distributions correspond to the simulated ones, implying that these methods

  2. Iterated preconditioned LSQR method for inverse problems on unstructured grids

    NASA Astrophysics Data System (ADS)

    Arridge, S. R.; Betcke, M. M.; Harhanen, L.

    2014-06-01

    This article presents a method for solving large-scale linear inverse imaging problems regularized with a nonlinear, edge-preserving penalty term such as total variation or the Perona-Malik technique. Our method is aimed at problems defined on unstructured meshes, where such regularizers naturally arise in unfactorized form as a stiffness matrix of an anisotropic diffusion operator and factorization is prohibitively expensive. In the proposed scheme, the nonlinearity is handled with lagged diffusivity fixed point iteration, which involves solving a large-scale linear least squares problem in each iteration. Because the convergence of Krylov methods for problems with discontinuities is notoriously slow, we propose to accelerate it by means of priorconditioning (Bayesian preconditioning). priorconditioning is a technique that, through transformation to the standard form, embeds the information contained in the prior (Bayesian interpretation of a regularizer) directly into the forward operator and thence into the solution space. We derive a factorization-free preconditioned LSQR algorithm (MLSQR), allowing implicit application of the preconditioner through efficient schemes such as multigrid. The resulting method is also matrix-free i.e. the forward map can be defined through its action on a vector. We illustrate the performance of the method on two numerical examples. Simple 1D-deblurring problem serves to visualize the discussion throughout the paper. The effectiveness of the proposed numerical scheme is demonstrated on a three-dimensional problem in fluorescence diffuse optical tomography with total variation regularization derived algebraic multigrid preconditioner, which is the type of large scale, unstructured mesh problem, requiring matrix-free and factorization-free approaches that motivated the work here.

  3. Computational methods for drug design and discovery: focus on China.

    PubMed

    Zheng, Mingyue; Liu, Xian; Xu, Yuan; Li, Honglin; Luo, Cheng; Jiang, Hualiang

    2013-10-01

    In the past decades, China's computational drug design and discovery research has experienced fast development through various novel methodologies. Application of these methods spans a wide range, from drug target identification to hit discovery and lead optimization. In this review, we firstly provide an overview of China's status in this field and briefly analyze the possible reasons for this rapid advancement. The methodology development is then outlined. For each selected method, a short background precedes an assessment of the method with respect to the needs of drug discovery, and, in particular, work from China is highlighted. Furthermore, several successful applications of these methods are illustrated. Finally, we conclude with a discussion of current major challenges and future directions of the field.

  4. Solution of prey-predator problem by multistage decomposition method

    NASA Astrophysics Data System (ADS)

    Chowdhury, M. S. H.; Hashim, I.; Mawa, S.

    2008-01-01

    The prey-predator problem is simulated by an adaptation of the classical Adomian decomposition method (ADM). The classical ADM is converted into a hybrid numeric-analytic method called the multistage ADM (MADM). The decomposition solutions presented by previous authors are corrected. The numerical results obtained from the MADM and the classical fourth-order Rungge-Kutta (RK4) method are in complete agreement.

  5. A Review of Computational Methods for Predicting Drug Targets.

    PubMed

    Huang, Guohua; Yan, Fengxia; Tan, Duoduo

    2016-11-14

    Drug discovery and development is not only a time-consuming and labor-intensive process but also full of risk. Identifying targets of small molecules helps evaluate safety of drugs and find new therapeutic applications. The biotechnology measures a wide variety of properties related to drug and targets from different perspectives, thus generating a large body of data. This undoubtedly provides a solid foundation to explore relationships between drugs and targets. A large number of computational techniques have recently been developed for drug target prediction. In this paper, we summarize these computational methods and classify them into structure-based, molecular activity-based, side-effect-based and multi-omics-based predictions according to the used data for inference. The multi-omics-based methods are further grouped into two types: classifier-based and network-based predictions. Furthermore,the advantages and limitations of each type of methods are discussed. Finally, we point out the future directions of computational predictions for drug targets.

  6. Application of the boundary integral method to immiscible displacement problems

    SciTech Connect

    Masukawa, J.; Horne, R.N.

    1988-08-01

    This paper presents an application of the boundary integral method (BIM) to fluid displacement problems to demonstrate its usefulness in reservoir simulation. A method for solving two-dimensional (2D), piston-like displacement for incompressible fluids with good accuracy has been developed. Several typical example problems with repeated five-spot patterns were solved for various mobility ratios. The solutions were compared with the analytical solutions to demonstrate accuracy. Singularity programming was found to be a major advantage in handling flow in the vicinity of wells. The BIM was found to be an excellent way to solve immiscible displacement problems. Unlike analytic methods, it can accommodate complex boundary shapes and does not suffer from numerical dispersion at the front.

  7. Integrated Force Method Solution to Indeterminate Structural Mechanics Problems

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Hopkins, Dale A.; Halford, Gary R.

    2004-01-01

    Strength of materials problems have been classified into determinate and indeterminate problems. Determinate analysis primarily based on the equilibrium concept is well understood. Solutions of indeterminate problems required additional compatibility conditions, and its comprehension was not exclusive. A solution to indeterminate problem is generated by manipulating the equilibrium concept, either by rewriting in the displacement variables or through the cutting and closing gap technique of the redundant force method. Compatibility improvisation has made analysis cumbersome. The authors have researched and understood the compatibility theory. Solutions can be generated with equal emphasis on the equilibrium and compatibility concepts. This technique is called the Integrated Force Method (IFM). Forces are the primary unknowns of IFM. Displacements are back-calculated from forces. IFM equations are manipulated to obtain the Dual Integrated Force Method (IFMD). Displacement is the primary variable of IFMD and force is back-calculated. The subject is introduced through response variables: force, deformation, displacement; and underlying concepts: equilibrium equation, force deformation relation, deformation displacement relation, and compatibility condition. Mechanical load, temperature variation, and support settling are equally emphasized. The basic theory is discussed. A set of examples illustrate the new concepts. IFM and IFMD based finite element methods are introduced for simple problems.

  8. Method for Solving Physical Problems Described by Linear Differential Equations

    NASA Astrophysics Data System (ADS)

    Belyaev, B. A.; Tyurnev, V. V.

    2017-01-01

    A method for solving physical problems is suggested in which the general solution of a differential equation in partial derivatives is written in the form of decomposition in spherical harmonics with indefinite coefficients. Values of these coefficients are determined from a comparison of the decomposition with a solution obtained for any simplest particular case of the examined problem. The efficiency of the method is demonstrated on an example of calculation of electromagnetic fields generated by a current-carrying circular wire. The formulas obtained can be used to analyze paths in the near-field magnetic (magnetically inductive) communication systems working in moderately conductive media, for example, in sea water.

  9. The pre-image problem in kernel methods.

    PubMed

    Kwok, James Tin-yau; Tsang, Ivor Wai-hung

    2004-11-01

    In this paper, we address the problem of finding the pre-image of a feature vector in the feature space induced by a kernel. This is of central importance in some kernel applications, such as on using kernel principal component analysis (PCA) for image denoising. Unlike the traditional method which relies on nonlinear optimization, our proposed method directly finds the location of the pre-image based on distance constraints in the feature space. It is noniterative, involves only linear algebra and does not suffer from numerical instability or local minimum problems. Evaluations on performing kernel PCA and kernel clustering on the USPS data set show much improved performance.

  10. The caustics method in the contact problems of anisotropic materials

    NASA Astrophysics Data System (ADS)

    Bakić, A.; Semenski, D.; Jecić, S.

    2010-06-01

    Regions with high stress gradients represent critical zones of engineering structures such as crack tip or vicinity of the contact zone. The optical method of caustics is one of the few experimental methods which provide applicable results in these locations. This method was originally developed for crack-tip measurements of stress intensity factors and J-integral for isotropic and then for anisotropic materials. Subsequently, it was extended to contact problems where the size and shape of caustics on the screen are related to the amount and the inclination of loading force. Here, the method of caustics is extended to the analysis of contact problems for mechanically anisotropic materials. This makes the caustics method widely applicable to the analysis of any high stress gradient locations in a structure.

  11. Dose Equivalents for Antipsychotic Drugs: The DDD Method.

    PubMed

    Leucht, Stefan; Samara, Myrto; Heres, Stephan; Davis, John M

    2016-07-01

    Dose equivalents of antipsychotics are an important but difficult to define concept, because all methods have weaknesses and strongholds. We calculated dose equivalents based on defined daily doses (DDDs) presented by the World Health Organisation's Collaborative Center for Drug Statistics Methodology. Doses equivalent to 1mg olanzapine, 1mg risperidone, 1mg haloperidol, and 100mg chlorpromazine were presented and compared with the results of 3 other methods to define dose equivalence (the "minimum effective dose method," the "classical mean dose method," and an international consensus statement). We presented dose equivalents for 57 first-generation and second-generation antipsychotic drugs, available as oral, parenteral, or depot formulations. Overall, the identified equivalent doses were comparable with those of the other methods, but there were also outliers. The major strength of this method to define dose response is that DDDs are available for most drugs, including old antipsychotics, that they are based on a variety of sources, and that DDDs are an internationally accepted measure. The major limitations are that the information used to estimate DDDS is likely to differ between the drugs. Moreover, this information is not publicly available, so that it cannot be reviewed. The WHO stresses that DDDs are mainly a standardized measure of drug consumption, and their use as a measure of dose equivalence can therefore be misleading. We, therefore, recommend that if alternative, more "scientific" dose equivalence methods are available for a drug they should be preferred to DDDs. Moreover, our summary can be a useful resource for pharmacovigilance studies. © The Author 2016. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  12. Problems of drug abuse, HIV and AIDS: the burden of care in one general practice.

    PubMed Central

    Ronald, P J; Witcomb, J C; Robertson, J R; Roberts, J J; Shishodia, P C; Whittaker, A

    1992-01-01

    Responsibility for many of the problems of intravenous drug abuse and human immunodeficiency virus (HIV) infection lies with community care agencies, such as general practitioners, community psychiatric and district nurses and drug agencies. It is in general practice that this burden is most clearly observed, given that general practitioners are in charge of the day-to-day care of patients. In an attempt to quantify this workload in an inner city practice with 11,200 patients, data were gathered from several sources relating to drug use and HIV infection. The study identified 432 patients who had consulted with problems of drug abuse and/or HIV infection over the period 1981-90. Among this group of patients 161 (37%) were HIV antibody positive. Among 191 drug abusers who were still registered with the practice in 1990 dihydrocodeine was the most commonly prescribed substitute treatment (130 patients) and only nine patients were prescribed methadone. Forty seven per cent of drug users continued to inject drugs occasionally. However, analysis of urine samples revealed that there was a shift away from injecting mainly heroin to multiple drug use, including benzodiazepines, usually originating from prescribed sources. Drug abusers who were HIV positive consulted their general practitioner significantly more often over one year than those who were not (mean 24.9 versus 15.8 consultations, P < 0.01). However, there was no significant difference between these two groups in terms of days spent in hospital. A total of 61 patients were referred to a community psychiatric nurse over an eight month period.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1419244

  13. Multigrid methods for bifurcation problems: The self adjoint case

    NASA Technical Reports Server (NTRS)

    Taasan, Shlomo

    1987-01-01

    This paper deals with multigrid methods for computational problems that arise in the theory of bifurcation and is restricted to the self adjoint case. The basic problem is to solve for arcs of solutions, a task that is done successfully with an arc length continuation method. Other important issues are, for example, detecting and locating singular points as part of the continuation process, switching branches at bifurcation points, etc. Multigrid methods have been applied to continuation problems. These methods work well at regular points and at limit points, while they may encounter difficulties in the vicinity of bifurcation points. A new continuation method that is very efficient also near bifurcation points is presented here. The other issues mentioned above are also treated very efficiently with appropriate multigrid algorithms. For example, it is shown that limit points and bifurcation points can be solved for directly by a multigrid algorithm. Moreover, the algorithms presented here solve the corresponding problems in just a few work units (about 10 or less), where a work unit is the work involved in one local relaxation on the finest grid.

  14. College Health and the Responsibility for Solving Problems of Alcohol, Tobacco, and Other Drug Use.

    ERIC Educational Resources Information Center

    Charney, Merle H.

    1994-01-01

    The problems presented by alcohol, tobacco, and other drug use and abuse among college students are varied and sometimes complex. College student health services should continue to take a leadership role in addressing substance abuse issues on campus, through efforts to change both behavior and environment. (MSE)

  15. Tuberculosis in London: the importance of homelessness, problem drug use and prison.

    PubMed

    Story, A; Murad, S; Roberts, W; Verheyen, M; Hayward, A C

    2007-08-01

    The control of tuberculosis (TB) is founded on early case detection and complete treatment of disease. In the UK, TB is concentrated in subgroups of the population in large urban centres. The impact of homelessness, imprisonment and problem drug use on TB control in London is reviewed. A cohort study was undertaken of all patients with TB in Greater London to determine the point prevalence of disease in different groups and to examine risk factors for smear positivity, drug resistance, treatment adherence, loss to follow-up and use of directly observed therapy (DOT). Data were collected on 97% (1941/1995) of eligible patients. The overall prevalence of TB was 27 per 100,000. An extremely high prevalence of TB was seen in homeless people (788/100,000), problem drug users (354/100,000) and prisoners (208/100,000). Multivariate analysis showed that problem drug use was associated with smear positive disease (OR 2.2, p<0.001), being part of a known outbreak of drug resistant TB (OR 3.5, p = 0.001) and loss to follow-up (OR 2.7, p<0.001). Imprisonment was associated with being part of the outbreak (OR 10.3, p<0.001) and poor adherence (OR 3.9, p<0.001). Homelessness was associated with infectious TB (OR 1.6, p = 0.05), multidrug resistance (OR 2.1, p = 0.03), poor adherence (OR 2.5, p<0.001) and loss to follow-up (OR 3.8, p<0.001). In London, homeless people, prisoners and problem drug users collectively comprise 17% of TB cases, 44% of smear positive drug resistant cases, 38% of poorly compliant cases and 44% of cases lost to follow-up. 15% of these patients start treatment on DOT but 46% end up on DOT. High levels of infectious and drug resistant disease, poor adherence and loss to follow-up care indicate that TB is not effectively controlled among homeless people, prisoners and problem drug users in London.

  16. Medicine-taking behaviour and drug-related problems in adolescents of a Swedish high school.

    PubMed

    Westerlund, Michael; Brånstad, Jan-Olof; Westerlund, Tommy

    2008-06-01

    To examine (1) which over-the-counter (OTC) and prescription drugs adolescents most frequently use and for which ailments or diseases, and (2) which DRPs adolescents have experienced, as well as if and by whom these problems were resolved. Setting A high school in Helsingborg, Sweden. A self-completion questionnaire was designed and used in students with a median age of 17 in late 2005 and early 2006. To enable students to identify DRPs they may have experienced, the questionnaire contained a list of DRPs in lay language. The questionnaires were distributed by the teachers to be completed by the students in the classroom. Self-reported prevalence of OTC and prescription drug use and experienced drug-related problems. A total of 245 students (99%) took part, 138 females and 107 males. OTCs had been used occasionally by 37.7% of the girls and 62.6% of the boys, while 10.9% and 6.5% respectively were daily users. Analgesics were the most frequently used OTCs. DRPs had been experienced by 31.1% of the female and 19.6% of the male students, the most common of which was therapy failure (too little or no effect), accounting for 46.5% of the girls' and 38.1% of the boys' OTC DRPs. Eighty-five percent of the problems with OTCs had been resolved, half of them by the teenagers themselves. Prescription drugs had been used occasionally by 31.9% of the female and 29.0% of the male students, while 28.3% and 26.2% respectively reported using such drugs on a daily basis. Antibiotics were the most frequently taken prescription drugs. DRPs related to prescribed drugs were reported by 32.6% of the girls and 10.3% of the boys. The most common DRPs were side effects, accounting for 34.8% of the girls' problems, and therapy failure, experienced by 28.6% of the boys. All the boys' DRPs were reported to be resolved, but only 75% of those of the girls. Physicians were stated to have resolved the problems in 41.4% of the cases. There is a need to develop the interface between pharmacy

  17. Off-label drug use in paediatrics: a world-wide problem.

    PubMed

    Lenk, Christian

    2012-06-01

    Since more than 35 years, the international medical scientific community tries to solve the problem of the off-label use of paediatric drugs. The aim is simple, but ambitious: to supply children and adolescents with effective drugs, as safe as possible, with known and well-documented side effects, and with accurate and up-to-date information on dosage and administration form. However, despite the significant efforts of paediatricians, researchers and international health politics, a number of severe obstacles for the optimal supply of children and adolescents with safe drugs remain. The detailed analysis of the problem shows not only a still remaining lack of medical knowledge, but also persistent weaknesses in the ethical, legal, medical, pharmacological, and political practices that surround the phenomenon of off-label use in paediatrics. The article gives an overview about the remaining difficulties in the field of paediatric off-label medication with special consideration to ethical and regulatory questions.

  18. [Applications of the Fragment Molecular Orbital Method in Drug Discovery].

    PubMed

    Ishikawa, Takeshi

    2016-01-01

      Recently, ab initio quantum mechanical calculations have been applied to large molecules, including biomolecular systems. The fragment molecular orbital (FMO) method is one of the most efficient approaches for the quantum mechanical investigation of such molecules. In the FMO method, dividing a target molecule into small fragments reduces computational effort. The clear definition of inter-fragment interaction energy (IFIE) as an expression of total energy is another valuable feature of the FMO method because it provides the ability to analyze interactions in biomolecules. Thus, the FMO method is expected to be useful for drug discovery. This study demonstrates applications of the FMO method related to drug discovery. First, IFIE, according to FMO calculations, was used in the optimization of drug candidates for the development of anti-prion compounds. The second example involved interaction analysis of the human immunodeficiency virus type 1 (HIV-1) protease and a drug compound that used a novel analytical method for dispersion interaction, i.e., fragment interaction analysis based on LMP2 (FILM).

  19. Characterization and Developmental History of Problem Solving Methods in Medicine

    PubMed Central

    Harbort, Robert A.

    1980-01-01

    The central thesis of this paper is the importance of the framework in which information is structured. It is technically important in the design of systems; it is also important in guaranteeing that systems are usable by clinicians. Progress in medical computing depends on our ability to develop a more quantitative understanding of the role of context in our choice of problem solving techniques. This in turn will help us to design more flexible and responsive computer systems. The paper contains an overview of some models of knowledge and problem solving methods, a characterization of modern diagnostic techniques, and a discussion of skill development in medical practice. Diagnostic techniques are examined in terms of how they are taught, what problem solving methods they use, and how they fit together into an overall theory of interpretation of the medical status of a patient.

  20. Finite element methods on supercomputers - The scatter-problem

    NASA Technical Reports Server (NTRS)

    Loehner, R.; Morgan, K.

    1985-01-01

    Certain problems arise in connection with the use of supercomputers for the implementation of finite-element methods. These problems are related to the desirability of utilizing the power of the supercomputer as fully as possible for the rapid execution of the required computations, taking into account the gain in speed possible with the aid of pipelining operations. For the finite-element method, the time-consuming operations may be divided into three categories. The first two present no problems, while the third type of operation can be a reason for the inefficient performance of finite-element programs. Two possibilities for overcoming certain difficulties are proposed, giving attention to a scatter-process.

  1. Problems of Mathematical Finance by Stochastic Control Methods

    NASA Astrophysics Data System (ADS)

    Stettner, Łukasz

    The purpose of this paper is to present main ideas of mathematics of finance using the stochastic control methods. There is an interplay between stochastic control and mathematics of finance. On the one hand stochastic control is a powerful tool to study financial problems. On the other hand financial applications have stimulated development in several research subareas of stochastic control in the last two decades. We start with pricing of financial derivatives and modeling of asset prices, studying the conditions for the absence of arbitrage. Then we consider pricing of defaultable contingent claims. Investments in bonds lead us to the term structure modeling problems. Special attention is devoted to historical static portfolio analysis called Markowitz theory. We also briefly sketch dynamic portfolio problems using viscosity solutions to Hamilton-Jacobi-Bellman equation, martingale-convex analysis method or stochastic maximum principle together with backward stochastic differential equation. Finally, long time portfolio analysis for both risk neutral and risk sensitive functionals is introduced.

  2. Extrapolation techniques applied to matrix methods in neutron diffusion problems

    NASA Technical Reports Server (NTRS)

    Mccready, Robert R

    1956-01-01

    A general matrix method is developed for the solution of characteristic-value problems of the type arising in many physical applications. The scheme employed is essentially that of Gauss and Seidel with appropriate modifications needed to make it applicable to characteristic-value problems. An iterative procedure produces a sequence of estimates to the answer; and extrapolation techniques, based upon previous behavior of iterants, are utilized in speeding convergence. Theoretically sound limits are placed on the magnitude of the extrapolation that may be tolerated. This matrix method is applied to the problem of finding criticality and neutron fluxes in a nuclear reactor with control rods. The two-dimensional finite-difference approximation to the two-group neutron fluxes in a nuclear reactor with control rods. The two-dimensional finite-difference approximation to the two-group neutron-diffusion equations is treated. Results for this example are indicated.

  3. Pain, problem drug use history, and aberrant analgesic use behaviors in persons living with HIV

    PubMed Central

    Tsao, Jennie C. I.; Stein, Judith A.; Dobalian, Aram

    2007-01-01

    Little is known about the relationship between pain and aberrant use of prescription analgesics in persons living with HIV. We examined the predictive and concurrent associations among pain, aberrant use of opioids, and problem drug use history in a nationally representative longitudinal sample of 2267 HIV+ persons. Covariance structure analyses tested a conceptual model wherein HIV+ patients with a history of problematic drug use (n = 870), compared to those without such history (n = 1397), were hypothesized to report more pain and aberrant opioid use, as well as use of opioids specifically for pain at baseline and 6 and 12 month follow-ups, after controlling for key sociodemographic characteristics. In support of the hypothesized model, patients with a history of problematic drug use reported more pain, and were more likely to report aberrant use of prescription analgesics, as well as use of such medications specifically for pain, compared to patients without such history. We also found a trend toward greater stability of aberrant opioid use over time in problem drug users compared with non-problem users suggesting a persistent pattern of inappropriate medication use in the former group. Our findings suggest that even though HIV+ persons with a history of problematic drug use report on-going patterns of using prescription analgesics specifically for pain, these patients continued to experience persistently higher levels of pain, relative to non-problem users. Among non-problem users, pain was not linked to aberrant use of opioids, but was linked to the use of such medications specifically for pain. PMID:17449182

  4. The oral health of street-recruited injecting drug users: prevalence and correlates of problems.

    PubMed

    Laslett, Anne-Marie; Dietze, Paul; Dwyer, Robyn

    2008-11-01

    To examine the effects of a series of injecting drug users' (IDU) characteristics and drug use behaviours upon the self-reported oral health of a sample of IDU. Cross-sectional survey. Melbourne, Australia. A total of 285 IDU recruited through needle and syringe programmes, snowballing and outreach across six sites. Structured survey that collected information on current drug use patterns, self-reported blood-borne virus status and general health factors, including open-ended questions on past-year dental health problems. Sixty-eight per cent of the sample reported dental problems that were commonly severe and caused dental pain. Despite these reported problems, almost half the sample had not visited the dentist in the 12 months prior to the survey. Participants who were older, and reported homelessness, not eating every day and more common injection of amphetamines rather than heroin in the previous month, were more likely to report having a past-year dental problem. Dental problems in IDUs are common but few receive treatment. Further, those using amphetamines, with poor housing, hygiene and poor nutrition, are most at risk. Programmes designed to improve the oral health of IDU need to be developed and implemented in a manner amenable to the varying social circumstances of this marginalized group in the community.

  5. Use of refractometry and colorimetry as field methods to rapidly assess antimalarial drug quality.

    PubMed

    Green, Michael D; Nettey, Henry; Villalva Rojas, Ofelia; Pamanivong, Chansapha; Khounsaknalath, Lamphet; Grande Ortiz, Miguel; Newton, Paul N; Fernández, Facundo M; Vongsack, Latsamy; Manolin, Ot

    2007-01-04

    The proliferation of counterfeit and poor-quality drugs is a major public health problem; especially in developing countries lacking adequate resources to effectively monitor their prevalence. Simple and affordable field methods provide a practical means of rapidly monitoring drug quality in circumstances where more advanced techniques are not available. Therefore, we have evaluated refractometry, colorimetry and a technique combining both processes as simple and accurate field assays to rapidly test the quality of the commonly available antimalarial drugs; artesunate, chloroquine, quinine, and sulfadoxine. Method bias, sensitivity, specificity and accuracy relative to high-performance liquid chromatographic (HPLC) analysis of drugs collected in the Lao PDR were assessed for each technique. The HPLC method for each drug was evaluated in terms of assay variability and accuracy. The accuracy of the combined method ranged from 0.96 to 1.00 for artesunate tablets, chloroquine injectables, quinine capsules, and sulfadoxine tablets while the accuracy was 0.78 for enterically coated chloroquine tablets. These techniques provide a generally accurate, yet simple and affordable means to assess drug quality in resource-poor settings.

  6. Problems in Choosing Tools and Methods for Teaching Programming

    ERIC Educational Resources Information Center

    Vitkute-Adžgauskiene, Davia; Vidžiunas, Antanas

    2012-01-01

    The paper analyses the problems in selecting and integrating tools for delivering basic programming knowledge at the university level. Discussion and analysis of teaching the programming disciplines, the main principles of study programme design, requirements for teaching tools, methods and corresponding languages is presented, based on literature…

  7. Stevens' Direct Scaling Methods and the Uniqueness Problem

    ERIC Educational Resources Information Center

    Augustin, Thomas

    2006-01-01

    Stevens postulated that we can use the responses of a participant in a ratio scaling experiment directly to construct a psychophysical function representing the participant's sensations. Although Stevens' methods of constructing measurement scales are widely used in the behavioral sciences, the problem of which scale type is appropriate to…

  8. Approximate proximal point methods for convex programming problems

    SciTech Connect

    Eggermont, P.

    1994-12-31

    We study proximal point methods for the finite dimensional convex programming problem minimize f(x) such that x {element_of} C, where f : dom f {contained_in} RIR is a proper convex function and C {contained_in} R is a closed convex set.

  9. The lattice Boltzmann method and the problem of turbulence

    SciTech Connect

    Djenidi, L.

    2015-03-10

    This paper reports a brief review of numerical simulations of homogeneous isotopic turbulence (HIT) using the lattice Boltzmann method (LBM). The LBM results shows that the details of HIT are well captured and in agreement with existing data. This clearly indicates that the LBM is as good as current Navier-Stokes solvers and is very much adequate for investigating the problem of turbulence.

  10. Monitoring of air pollution by plants methods and problems

    SciTech Connect

    Steubing, L.; Jager, H.J.

    1985-01-01

    Ecosystem pollution is often discovered too late for preventive measure to be implemented. Papers include the topics of methods and problems of bioindication of air pollution. The participants discussed passive and active biological monitoring, including mapping of natural vegetation (lichens and mosses, for example) and plant exposure. Morphological and microscopical studies, chemical, physiological and biochemical investigations are presented.

  11. MIMD massively parallel methods for engineering and science problems

    SciTech Connect

    Camp, W.J.; Plimpton, S.J.

    1993-08-01

    MIMD massively parallel computers promise unique power and flexibility for engineering and scientific simulations. In this paper we review the development of a number of software methods and algorithms for scientific and engineering problems which are helping to realize that promise. We discuss new domain decomposition, load balancing, data layout and communications methods applicable to simulations in a broad range of technical field including signal processing, multi-dimensional structural and fluid mechanics, materials science, and chemical and biological systems.

  12. Methodes entropiques appliquees au probleme inverse en magnetoencephalographie

    NASA Astrophysics Data System (ADS)

    Lapalme, Ervig

    2005-07-01

    This thesis is devoted to biomagnetic source localization using magnetoencephalography. This problem is known to have an infinite number of solutions. So methods are required to take into account anatomical and functional information on the solution. The work presented in this thesis uses the maximum entropy on the mean method to constrain the solution. This method originates from statistical mechanics and information theory. This thesis is divided into two main parts containing three chapters each. The first part reviews the magnetoencephalographic inverse problem: the theory needed to understand its context and the hypotheses for simplifying the problem. In the last chapter of this first part, the maximum entropy on the mean method is presented: its origins are explained and also how it is applied to our problem. The second part is the original work of this thesis presenting three articles; one of them already published and two others submitted for publication. In the first article, a biomagnetic source model is developed and applied in a theoretical con text but still demonstrating the efficiency of the method. In the second article, we go one step further towards a realistic modelization of the cerebral activation. The main priors are estimated using the magnetoencephalographic data. This method proved to be very efficient in realistic simulations. In the third article, the previous method is extended to deal with time signals thus exploiting the excellent time resolution offered by magnetoencephalography. Compared with our previous work, the temporal method is applied to real magnetoencephalographic data coming from a somatotopy experience and results agree with previous physiological knowledge about this kind of cognitive process.

  13. Discontinuous Galerkin Finite Element Method for Parabolic Problems

    NASA Technical Reports Server (NTRS)

    Kaneko, Hideaki; Bey, Kim S.; Hou, Gene J. W.

    2004-01-01

    In this paper, we develop a time and its corresponding spatial discretization scheme, based upon the assumption of a certain weak singularity of parallel ut(t) parallel Lz(omega) = parallel ut parallel2, for the discontinuous Galerkin finite element method for one-dimensional parabolic problems. Optimal convergence rates in both time and spatial variables are obtained. A discussion of automatic time-step control method is also included.

  14. Sensitivity analysis and approximation methods for general eigenvalue problems

    NASA Technical Reports Server (NTRS)

    Murthy, D. V.; Haftka, R. T.

    1986-01-01

    Optimization of dynamic systems involving complex non-hermitian matrices is often computationally expensive. Major contributors to the computational expense are the sensitivity analysis and reanalysis of a modified design. The present work seeks to alleviate this computational burden by identifying efficient sensitivity analysis and approximate reanalysis methods. For the algebraic eigenvalue problem involving non-hermitian matrices, algorithms for sensitivity analysis and approximate reanalysis are classified, compared and evaluated for efficiency and accuracy. Proper eigenvector normalization is discussed. An improved method for calculating derivatives of eigenvectors is proposed based on a more rational normalization condition and taking advantage of matrix sparsity. Important numerical aspects of this method are also discussed. To alleviate the problem of reanalysis, various approximation methods for eigenvalues are proposed and evaluated. Linear and quadratic approximations are based directly on the Taylor series. Several approximation methods are developed based on the generalized Rayleigh quotient for the eigenvalue problem. Approximation methods based on trace theorem give high accuracy without needing any derivatives. Operation counts for the computation of the approximations are given. General recommendations are made for the selection of appropriate approximation technique as a function of the matrix size, number of design variables, number of eigenvalues of interest and the number of design points at which approximation is sought.

  15. Variational Methods For Sloshing Problems With Surface Tension

    NASA Astrophysics Data System (ADS)

    Tan, Chee Han; Carlson, Max; Hohenegger, Christel; Osting, Braxton

    2016-11-01

    We consider the sloshing problem for an incompressible, inviscid, irrotational fluid in a container, including effects due to surface tension on the free surface. We restrict ourselves to a constant contact angle and we seek time-harmonic solutions of the linearized problem, which describes the time-evolution of the fluid due to a small initial disturbance of the surface at rest. As opposed to the zero surface tension case, where the problem reduces to a partial differential equation for the velocity potential, we obtain a coupled system for the velocity potential and the free surface displacement. We derive a new variational formulation of the coupled problem and establish the existence of solutions using the direct method from the Calculus of Variations. In the limit of zero surface tension, we recover the variational formulation of the classical Steklov eigenvalue problem, as derived by B. A. Troesch. For the particular case of an axially symmetric container, we propose a finite element numerical method for computing the sloshing modes of the coupled system. The scheme is implemented in FEniCS and we obtain a qualitative description of the effect of surface tension on the sloshing modes.

  16. New high throughput screening method for drug release measurements.

    PubMed

    Pelczarska, Aleksandra; Delie, Florence; Domańska, Urszula; Carrupt, Pierre-Alain; Martel, Sophie

    2013-09-01

    In the field of drug delivery systems, microparticles made of polymeric matrix appear as an attractive approach. The in vitro release kinetic profile is crucial information when developing new particulate formulations. These data are essential for batch to batch comparison, quality control as well as for anticipation of in vivo behavior to select the best formulation to go further in preclinical investigations. The methods available present common drawbacks such as the time- and compound-consumption that does not fit with formulation screening requirements in early development stages. In this study, a new microscale high throughput screening (HTS) method has been developed to investigate drug release kinetic from piroxicam-loaded polylactic acid (PLA) and polylactic-co-glycolic acid (PLGA) microparticles. The method is a sample- and separation-based method where separation is performed by filtration using 96-well micro filter plates. 96 experiments can therefore be performed on one plate in one time in a fully automated way and with a very low sample and particle consumption. The influence of different parameters controlling release profiles was also investigated using this technique. The HTS method gave the same release profile than the standard dialysis method. Shaking, particle concentration, and the nature of the release medium were found to be of influence. The HTS method appears as a reliable method to evaluate drug release from particles with smaller standard deviation and less consumption of material.

  17. The Use of Qsar and Computational Methods in Drug Design

    NASA Astrophysics Data System (ADS)

    Bajot, Fania

    The application of quantitative structure-activity relationships (QSARs) has significantly impacted the paradigm of drug discovery. Following the successful utilization of linear solvation free-energy relationships (LSERs), numerous 2D- and 3D-QSAR methods have been developed, most of them based on descriptors for hydrophobicity, polarizability, ionic interactions, and hydrogen bonding. QSAR models allow for the calculation of physicochemical properties (e.g., lipophilicity), the prediction of biological activity (or toxicity), as well as the evaluation of absorption, distribution, metabolism, and excretion (ADME). In pharmaceutical research, QSAR has a particular interest in the preclinical stages of drug discovery to replace tedious and costly experimentation, to filter large chemical databases, and to select drug candidates. However, to be part of drug discovery and development strategies, QSARs need to meet different criteria (e.g., sufficient predictivity). This chapter describes the foundation of modern QSAR in drug discovery and presents some current challenges and applications for the discovery and optimization of drug candidates

  18. An adaptive pseudo-spectral method for reaction diffusion problems

    NASA Technical Reports Server (NTRS)

    Bayliss, A.; Gottlieb, D.; Matkowsky, B. J.; Minkoff, M.

    1987-01-01

    The spectral interpolation error was considered for both the Chebyshev pseudo-spectral and Galerkin approximations. A family of functionals I sub r (u), with the property that the maximum norm of the error is bounded by I sub r (u)/J sub r, where r is an integer and J is the degree of the polynomial approximation, was developed. These functionals are used in the adaptive procedure whereby the problem is dynamically transformed to minimize I sub r (u). The number of collocation points is then chosen to maintain a prescribed error bound. The method is illustrated by various examples from combustion problems in one and two dimensions.

  19. Formulations and computational methods for contact problems in solid mechanics

    NASA Astrophysics Data System (ADS)

    Mirar, Anand Ramchandra

    2000-11-01

    A study of existing formulations and computational methods for contact problems is conducted. The purpose is to gain insights into the solution procedures and pinpoint their limitations so that alternate procedures can be developed. Three such procedures based on the augmented Lagrangian method (ALM) are proposed. Small-scale benchmark problems are solved analytically as well as numerically to study the existing and proposed methods. The variational inequality formulation for frictionless contact is studied using the two bar truss-wall problem in a closed form. Sub-differential formulation is investigated using the spring-wall contact and the truss-wall friction problems. A two-phase analytical procedure is developed for solving the truss-wall frictional contact benchmark problem. The variational equality formulation for contact problems is studied using the penalty method along with the Newton-Raphson procedure. Limitations of such procedures, mainly due to their dependence on the user defined parameters (i.e., the penalty values and the number of time steps), are identified. Based on the study it is concluded that alternate formulations need to be developed. Frictionless contact formulation is developed using the basic concepts of ALM from optimization theory. A new frictional contact formulation (ALM1) is then developed employing ALM. Automatic penalty update procedure is used to eliminate dependence of the solution on the penalty values. Dependence of the solution on the number of time steps in the existing as well as ALM1 formulations is attributed to a flaw in the return mapping procedure for friction. Another new frictional contact formulation (ALM2) is developed to eliminate the dependence of solution on the number of time steps along with the penalty values. Effectiveness of ALM2 is demonstrated by solving the two bar and five bar truss-wall problems. The solutions are compared with the analytical and existing formulations. Design sensitivity analysis of

  20. Solution of Aeroacoustic Problems by a Nonlinear, Hybrid Method

    NASA Technical Reports Server (NTRS)

    Oezyoeruek, Yusuf; Long, Lyle N.

    1997-01-01

    Category 1, problem 3 (scattering of sound by a sphere) and category 2, problem 1 (spherical source in a cylindrical duct subject to uniform flow) are solved in generalized coordinates using the nonlinear Euler equations together with nonreflecting boundary conditions. A temporally and spatially fourth-order accurate finite-difference, Runge-Kutta time-marching technique is employed for the near-field calculations and a Kirchhoff method is employed for the prediction of far-field sound. Computations are all performed on parallel processors using the data-parallel paradigm.

  1. A time domain sampling method for inverse acoustic scattering problems

    NASA Astrophysics Data System (ADS)

    Guo, Yukun; Hömberg, Dietmar; Hu, Guanghui; Li, Jingzhi; Liu, Hongyu

    2016-06-01

    This work concerns the inverse scattering problems of imaging unknown/inaccessible scatterers by transient acoustic near-field measurements. Based on the analysis of the migration method, we propose efficient and effective sampling schemes for imaging small and extended scatterers from knowledge of time-dependent scattered data due to incident impulsive point sources. Though the inverse scattering problems are known to be nonlinear and ill-posed, the proposed imaging algorithms are totally ;direct; involving only integral calculations on the measurement surface. Theoretical justifications are presented and numerical experiments are conducted to demonstrate the effectiveness and robustness of our methods. In particular, the proposed static imaging functionals enhance the performance of the total focusing method (TFM) and the dynamic imaging functionals show analogous behavior to the time reversal inversion but without solving time-dependent wave equations.

  2. [The problem of post-marketing surveillance planning on drugs for infectious disease].

    PubMed

    Sato, J

    2001-12-01

    In principle, a new drug is approved via the assessments of safety and efficacy by the Ministry of Health, Labor and Welfare (MHLW). After approval, conduct of post-marketing surveillance is requested by law in order to assess the safety and efficacy of the drug in a large number of patients. Before initiating a surveillance, submission to MHLW of a document on the plan of survey is necessary in the purpose of inspection if it includes any ethical or regulatory problem or not. Through the inspections of the plans submitted during the period of April 1998 and March 2000, many problems have been pointed out. In this report, the author introduces some of the concrete problems noted in the plans on drugs for infectious diseases and shows some of the guidance made by the authority how to improve them. It is expected that such practical analyses of cases may be useful for future planning of post-marketing surveillance on drugs for infectious diseases.

  3. Problem solving styles among people who use alcohol and other drugs in South Africa.

    PubMed

    Sorsdahl, Katherine; Stein, Dan J; Carrara, Henri; Myers, Bronwyn

    2014-01-01

    The present study examines the relationship between problem-solving styles, socio-demographic variables and risk of alcohol and other drug (AOD)-related problems among a South African population. The Social Problem-Solving Inventory-Revised, Center for Epidemiologic Studies Depression Scale (CES-D) and the Alcohol, Smoking and Substance Involvement Screening Test (ASSIST) were administered to a convenience sample of 1000 respondents. According to the ASSIST, 32% and 49% of respondents met criteria for moderate to high risk of alcohol use and illicit drug use respectively. After adjusting for the effects of other variables in the model, respondents who were of "Coloured" ancestry (PR=1.20, 95% CI 1.0-1.4), male (PR=1.19, 95% CI 1.04-1.37), older (PR=1.01, 95% CI 1.00-1.02), who adopted an avoidance style of coping with problems (PR=1.03, 95% CI 1.01-1.05) and who met criteria for depression (PR=1.42, 95% CI 1.12-1.79) were more likely to be classified as having risky AOD use. This suggests that interventions to improve problem solving and provide people with cognitive strategies to cope better with their problems may hold promise for reducing risky AOD use.

  4. Do adolescent drug use consequences predict externalizing and internalizing problems in emerging adulthood as well as traditional drug use measures in a Hispanic sample?

    PubMed Central

    Grigsby, Timothy J.; Forster, Myriam; Baezconde-Garbanati, Lourdes; Soto, Daniel W.; Unger, Jennifer B.

    2014-01-01

    The present study compares statistical models for three conceptualizations of drug use in 11th grade (past 30 day ever/never use, past 30 day frequency of drug use and past 30 day drug use consequences) with externalizing and internalizing problems in emerging adulthood when controlling for age, academic achievement and socioeconomic status in a Hispanic sample. Multivariate logistic regression models for the different drug use variables were compared when modeling weapon carrying, arrest, multiple lifetime sex partners, drug/alcohol use before sex and condom use in emerging adulthood. A multivariate linear regression model was used to model depression in emerging adulthood as a function of drug use measurement controlling for other covariates and depression in adolescence. Our findings suggest that any conceptualization of drug use will produce equitable results and model fit statistics when examining externalizing problems. However, when investigating internalizing problems, such as depression, lower frequency drug use—and not high frequency—was more strongly associated with depression whereas experiencing high levels of drug use consequences—and not low levels of consequences—was associated with depression in emerging adulthood despite similar model fit values. Variation between drug use and the experience of drug use consequences may lead to misspecification of “at-risk” subgroups of drug users. Implications and future directions are discussed. PMID:24345310

  5. Do adolescent drug use consequences predict externalizing and internalizing problems in emerging adulthood as well as traditional drug use measures in a Hispanic sample?

    PubMed

    Grigsby, Timothy J; Forster, Myriam; Baezconde-Garbanati, Lourdes; Soto, Daniel W; Unger, Jennifer B

    2014-03-01

    The present study compares statistical models for three conceptualizations of drug use in 11th grade (past 30 day ever/never use, past 30 day frequency of drug use and past 30 day drug use consequences) with externalizing and internalizing problems in emerging adulthood when controlling for age, academic achievement and socioeconomic status in a Hispanic sample. Multivariate logistic regression models for the different drug use variables were compared when modeling weapon carrying, arrest, multiple lifetime sex partners, drug/alcohol use before sex and condom use in emerging adulthood. A multivariate linear regression model was used to model depression in emerging adulthood as a function of drug use measurement controlling for other covariates and depression in adolescence. Our findings suggest that any conceptualization of drug use will produce equitable results and model fit statistics when examining externalizing problems. However, when investigating internalizing problems, such as depression, lower frequency drug use-and not high frequency-was more strongly associated with depression whereas experiencing high levels of drug use consequences-and not low levels of consequences-was associated with depression in emerging adulthood despite similar model fit values. Variation between drug use and the experience of drug use consequences may lead to misspecification of "at-risk" subgroups of drug users. Implications and future directions are discussed.

  6. Joint medicine-information and pharmacovigilance services could improve detection and communication about drug-safety problems

    PubMed Central

    Schjøtt, Jan; Bergman, Jenny

    2014-01-01

    Background RELIS is a Norwegian network of four regional medicine-information and pharmacovigilance centers where pharmacists and clinical pharmacologists provide feedback to health care professionals in spontaneous drug-related questions and adverse drug-reaction (ADR) reports published in a question–answer pair (QAP) database (the RELIS database) and the Norwegian ADR database, respectively. Objective To describe the potential of RELIS’s dual service to improve detection and communication of drug-safety problems. Materials and methods We searched the RELIS database for QAPs about ADRs with use of the Norwegian ADR database as a reference. We also searched the Norwegian ADR database for reports that used the RELIS database as a reference. Both searches were limited to the years 2003–2012. We then selected the example of pregabalin and drug abuse after the marketing of Lyrica in Norway in September 2004 to illustrate RELIS’s potential to detect new drug-safety information through a limited number of QAPs and ADR reports. Results A total of 5,427 (26%) of 21,071 QAPs in the RELIS database concerned ADRs. QAPs from this database were used as references in 791 (4%) of a total of 22,090 reports in the Norwegian ADR database. The Norwegian ADR database was used as a reference in 363 (7%) of 5,427 QAPs that concerned ADRs. Between September 2004 and September 2008, RELIS received eleven questions and 13 ADR reports about suspicion of Lyrica (pregabalin) and different aspects of abuse. Conclusion RELIS processes data through two databases that facilitate communication about ADRs. Our service also has the potential to detect new drug-safety problems with a limited number of questions and ADR reports. PMID:25061339

  7. A new method for transonic static aeroelasticity problems

    NASA Technical Reports Server (NTRS)

    Felker, Fort F.

    1992-01-01

    A new method has been developed to calculate the steady flow and structural deformations for fluid/structure interaction problems. The discretized fluid dynamic and structural equations are regarded as a single set of coupled, nonlinear, algebraic equations. The equilibrium solution is directly obtained using Newton's method. The governing equations used for the fluid flow are the two-dimensional Navier-Stokes equations, and a finite-element model is used to represent the structure. This paper describes the analytical method and presents sample calculations demonstrating the technique. The results show rapid convergence and good agreement with experimental data.

  8. Branch and Bound Methods for the Traveling Salesman Problem.

    DTIC Science & Technology

    1983-03-01

    42 318 BRANCH AND ROUND METHODS FOR THE TRAVELING SALESMAN I PRO EM U) CARNEGIE-MELLON UNIV PITSBURGH PA MANAGEMENT SCIENCES RESEARCH GROUP E RU AS...fl 2.2 1 1 6 5 4 .6 MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU Of SIANARDS ) Qh A i . ’i ’V aBRANCH AND BOUND METHODS FOR THE TRAVELING ...06 20 126 a 77 W.P.#45-82-83 Management Science Research Report No. MSRR 488 BRANCH AND BOUND METHODS FOR THE TRAVELING SALESMAN PROBLEM by Egon Balas

  9. A parallel Lanczos method for symmetric generalized eigenvalue problems

    SciTech Connect

    Wu, K.; Simon, H.D.

    1997-12-01

    Lanczos algorithm is a very effective method for finding extreme eigenvalues of symmetric matrices. It requires less arithmetic operations than similar algorithms, such as, the Arnoldi method. In this paper, the authors present their parallel version of the Lanczos method for symmetric generalized eigenvalue problem, PLANSO. PLANSO is based on a sequential package called LANSO which implements the Lanczos algorithm with partial re-orthogonalization. It is portable to all parallel machines that support MPI and easy to interface with most parallel computing packages. Through numerical experiments, they demonstrate that it achieves similar parallel efficiency as PARPACK, but uses considerably less time.

  10. A flux correction method for the conjugate heat transfer problem

    SciTech Connect

    He, M.; Bishop, P.J.; Minardi, A.; Kassab, A.J.

    1995-12-31

    A computational method, the flux correction method, is proposed to deal with the conjugate heat transfer problem, which uses a coupled FDM/BEM iteration scheme. The convective heat transfer in the fluid is solved using the BEM. The two solutions are coupled by enforcing continuity of temperature and heat flux at the solid-fluid interfaces. The proposed method is tested using available experimental data. For the considered cases of flow in a parallel plate channel subjected to constant heat flux or constant temperature, good agreements are observed.

  11. Projected discrete ordinates methods for numerical transport problems

    SciTech Connect

    Larsen, E.W.

    1985-01-01

    A class of Projected Discrete-Ordinates (PDO) methods is described for obtaining iterative solutions of discrete-ordinates problems with convergence rates comparable to those observed using Diffusion Synthetic Acceleration (DSA). The spatially discretized PDO solutions are generally not equal to the DSA solutions, but unlike DSA, which requires great care in the use of spatial discretizations to preserve stability, the PDO solutions remain stable and rapidly convergent with essentially arbitrary spatial discretizations. Numerical results are presented which illustrate the rapid convergence and the accuracy of solutions obtained using PDO methods with commonplace differencing methods.

  12. Biophysical methods in drug discovery from small molecule to pharmaceutical.

    PubMed

    Holdgate, Geoffrey; Geschwindner, Stefan; Breeze, Alex; Davies, Gareth; Colclough, Nicola; Temesi, David; Ward, Lara

    2013-01-01

    Biophysical methods have become established in many areas of drug discovery. Application of these methods was once restricted to a relatively small number of scientists using specialized, low throughput technologies and methods. Now, automated high-throughput instruments are to be found in a growing number of laboratories. Many biophysical methods are capable of measuring the equilibrium binding constants between pairs of molecules crucial for molecular recognition processes, encompassing protein-protein, protein-small molecule, and protein-nucleic acid interactions, and several can be used to measure the kinetic or thermodynamic components controlling these biological processes. For a full characterization of a binding process, determinations of stoichiometry, binding mode, and any conformational changes associated with such interactions are also required. The suite of biophysical methods that are now available represents a powerful toolbox of techniques which can effectively deliver this full characterization.The aim of this chapter is to provide the reader with an overview of the drug discovery process and how biophysical methods, such as surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), nuclear magnetic resonance, mass spectrometry (MS), and thermal unfolding methods can answer specific questions in order to influence project progression and outcomes. The selection of these examples is based upon the experiences of the authors at AstraZeneca, and relevant approaches are highlighted where they have utility in a particular drug discovery scenario.

  13. Optimal least-squares finite element method for elliptic problems

    NASA Technical Reports Server (NTRS)

    Jiang, Bo-Nan; Povinelli, Louis A.

    1991-01-01

    An optimal least squares finite element method is proposed for two dimensional and three dimensional elliptic problems and its advantages are discussed over the mixed Galerkin method and the usual least squares finite element method. In the usual least squares finite element method, the second order equation (-Delta x (Delta u) + u = f) is recast as a first order system (-Delta x p + u = f, Delta u - p = 0). The error analysis and numerical experiment show that, in this usual least squares finite element method, the rate of convergence for flux p is one order lower than optimal. In order to get an optimal least squares method, the irrotationality Delta x p = 0 should be included in the first order system.

  14. Illicit drug use, alcohol use and problem drinking among infrequent and frequent road ragers.

    PubMed

    Butters, Jennifer E; Smart, Reginald G; Mann, Robert E; Asbridge, Mark

    2005-11-01

    The purpose of this paper is to investigate the relationships between illicit drug and alcohol use, problem drinking, and road rage. Particular attention is devoted to the association between these behaviors and frequent involvement in road rage activities. The data are taken from the 2002 Centre for Addiction and Mental Health (CAMH) Monitor, a representative telephone survey with a sample of 2421 adults aged 18 and older in Ontario. A cluster analysis was performed and analysis of variance procedures were used to test for group differences. The cluster analysis revealed five distinct groups involved in various types of road rage behavior. Frequent road ragers, accounting for 5.3% of the sample, were involved in the most severe forms of road rage behavior and were most likely (24%) to report problem drinking and past year cannabis (23.8%), cocaine (5.4%), and ecstasy (10%) use. These data indicate that illicit drug use and alcohol problems are significantly greater for those involved in the most serious forms of road rage behavior. Further work is needed to identify the mechanisms by which illicit drug use and problem drinking are linked to road rage.

  15. Meshless Petrov-Galerkin Method Applied to Axisymmetric Problems

    NASA Technical Reports Server (NTRS)

    Raju, I. S.; Chen, T.

    2001-01-01

    An axisymmetric Meshless Local Petrov-Galerkin (MLPG) algorithm is presented for the potential and elasticity problems. In this algorithm the trial and test functions are chosen from different spaces. By a judicious choice of these functions, the integrals involved in the weak form can be restricted to a local neighborhood. This makes the method truly meshless. The MLPG algorithm is used to study various potential and elasticity problems for which exact solutions are available. The sensitivity and effectiveness of the MLPG algorithm to various parameters such as the weight functions, basis functions and support domain radius, etc. was studied. The MLPG algorithm yielded accurate solutions for all weight functions, basis functions and support domain radii considered for all of the problems studied.

  16. Drug therapy problems and medication discrepancies during care transitions in super-utilizers.

    PubMed

    Surbhi, Satya; Munshi, Kiraat D; Bell, Paula C; Bailey, James E

    First, to investigate the prevalence and types of drug therapy problems and medication discrepancies among super-utilizers, and associated patient characteristics. Second, to examine the outcomes of pharmacist recommendations and estimated cost avoidance through care transitions support focused on medication management. Retrospective analysis of the pharmacist-led interventions as part of the SafeMed Program. A large nonprofit health care system serving the major medically underserved areas in Memphis, Tennessee. Three hundred seventy-four super-utilizing SafeMed participants with multiple chronic conditions and polypharmacy. Comprehensive medication review, medication therapy management, enhanced discharge planning, home visits, telephone follow-up, postdischarge medication reconciliation, and care coordination with physicians. Types of drug therapy problems, outcomes of pharmacist recommendations, estimated cost avoided, medication discrepancies, and self-reported medication adherence. Prevalence of drug therapy problems and postdischarge medication discrepancies was 80.7% and 75.4%, respectively. The most frequently occurring drug therapy problems were enrollee not receiving needed medications (33.4%), underuse of medications (16.9%), and insufficient dose or duration (11.2%). Overall 50.8% of the pharmacist recommendations were accepted by physicians and patients, resulting in an estimated cost avoidance of $293.30 per drug therapy problem identified. Multivariate analysis indicated that participants with a higher number of comorbidities were more likely to have medication discrepancies (odds ratio 1.23 [95% CI 1.05-1.44]). Additional contributors to postdischarge medication discrepancies were difficulty picking up and paying for medications and not being given necessary prescriptions before discharge. Drug therapy problems and medication discrepancies are common in super-utilizers with multiple chronic conditions and polypharmacy during transitions of care

  17. An Iterative Method for Problems with Multiscale Conductivity

    PubMed Central

    Kim, Hyea Hyun; Minhas, Atul S.; Woo, Eung Je

    2012-01-01

    A model with its conductivity varying highly across a very thin layer will be considered. It is related to a stable phantom model, which is invented to generate a certain apparent conductivity inside a region surrounded by a thin cylinder with holes. The thin cylinder is an insulator and both inside and outside the thin cylinderare filled with the same saline. The injected current can enter only through the holes adopted to the thin cylinder. The model has a high contrast of conductivity discontinuity across the thin cylinder and the thickness of the layer and the size of holes are very small compared to the domain of the model problem. Numerical methods for such a model require a very fine mesh near the thin layer to resolve the conductivity discontinuity. In this work, an efficient numerical method for such a model problem is proposed by employing a uniform mesh, which need not resolve the conductivity discontinuity. The discrete problem is then solved by an iterative method, where the solution is improved by solving a simple discrete problem with a uniform conductivity. At each iteration, the right-hand side is updated by integrating the previous iterate over the thin cylinder. This process results in a certain smoothing effect on microscopic structures and our discrete model can provide a more practical tool for simulating the apparent conductivity. The convergence of the iterative method is analyzed regarding the contrast in the conductivity and the relative thickness of the layer. In numerical experiments, solutions of our method are compared to reference solutions obtained from COMSOL, where very fine meshes are used to resolve the conductivity discontinuity in the model. Errors of the voltage in L2 norm follow O(h) asymptotically and the current density matches quitewell those from the reference solution for a sufficiently small mesh size h. The experimental results present a promising feature of our approach for simulating the apparent conductivity related

  18. Alchemical free energy methods for drug discovery: Progress and challenges

    PubMed Central

    Chodera, John D.; Mobley, David L.; Shirts, Michael R.; Dixon, Richard W.; Branson, Kim; Pande, Vijay S.

    2011-01-01

    Improved rational drug design methods are needed to lower the cost and increase the success rate of drug discovery and development. Alchemical binding free energy calculations, one potential tool for rational design, have progressed rapidly over the last decade, but still fall short of providing robust tools for pharmaceutical engineering. Recent studies, especially on model receptor systems, have clarified many of the challenges that must be overcome for robust predictions of binding affnity to be useful in rational design. In this review, inspired by a recent joint academic/industry meeting organized by the authors, we discuss these challenges and suggest a number of promising approaches for overcoming them. PMID:21349700

  19. In Vivo Methods for the Assessment of Topical Drug Bioavailability

    PubMed Central

    Herkenne, Christophe; Alberti, Ingo; Naik, Aarti; Kalia, Yogeshvar N.; Mathy, François-Xavier; Préat, Véronique

    2007-01-01

    This paper reviews some current methods for the in vivo assessment of local cutaneous bioavailability in humans after topical drug application. After an introduction discussing the importance of local drug bioavailability assessment and the limitations of model-based predictions, the focus turns to the relevance of experimental studies. The available techniques are then reviewed in detail, with particular emphasis on the tape stripping and microdialysis methodologies. Other less developed techniques, including the skin biopsy, suction blister, follicle removal and confocal Raman spectroscopy techniques are also described. PMID:17985216

  20. In silico machine learning methods in drug development.

    PubMed

    Dobchev, Dimitar A; Pillai, Girinath G; Karelson, Mati

    2014-01-01

    Machine learning (ML) computational methods for predicting compounds with pharmacological activity, specific pharmacodynamic and ADMET (absorption, distribution, metabolism, excretion and toxicity) properties are being increasingly applied in drug discovery and evaluation. Recently, machine learning techniques such as artificial neural networks, support vector machines and genetic programming have been explored for predicting inhibitors, antagonists, blockers, agonists, activators and substrates of proteins related to specific therapeutic targets. These methods are particularly useful for screening compound libraries of diverse chemical structures, "noisy" and high-dimensional data to complement QSAR methods, and in cases of unavailable receptor 3D structure to complement structure-based methods. A variety of studies have demonstrated the potential of machine-learning methods for predicting compounds as potential drug candidates. The present review is intended to give an overview of the strategies and current progress in using machine learning methods for drug design and the potential of the respective model development tools. We also regard a number of applications of the machine learning algorithms based on common classes of diseases.

  1. Is There a Space-Based Technology Solution to Problems with Preclinical Drug Toxicity Testing?

    PubMed

    Hammond, Timothy; Allen, Patricia; Birdsall, Holly

    2016-07-01

    Even the finest state-of-the art preclinical drug testing, usually in primary hepatocytes, remains an imperfect science. Drugs continue to be withdrawn from the market due to unforeseen toxicity, side effects, and drug interactions. The space program may be able to provide a lifeline. Best known for rockets, space shuttles, astronauts and engineering, the space program has also delivered some serious medical science. Optimized suspension culture in NASA's specialized suspension culture devices, known as rotating wall vessels, uniquely maintains Phase I and Phase II drug metabolizing pathways in hepatocytes for weeks in cell culture. Previously prohibitively expensive, new materials and 3D printing techniques have the potential to make the NASA rotating wall vessel available inexpensively on an industrial scale. Here we address the tradeoffs inherent in the rotating wall vessel, limitations of alternative approaches for drug metabolism studies, and the market to be addressed. Better pre-clinical drug testing has the potential to significantly reduce the morbidity and mortality of one of the most common problems in modern medicine: adverse events related to pharmaceuticals.

  2. Emerging Computational Methods for the Rational Discovery of Allosteric Drugs

    PubMed Central

    2016-01-01

    Allosteric drug development holds promise for delivering medicines that are more selective and less toxic than those that target orthosteric sites. To date, the discovery of allosteric binding sites and lead compounds has been mostly serendipitous, achieved through high-throughput screening. Over the past decade, structural data has become more readily available for larger protein systems and more membrane protein classes (e.g., GPCRs and ion channels), which are common allosteric drug targets. In parallel, improved simulation methods now provide better atomistic understanding of the protein dynamics and cooperative motions that are critical to allosteric mechanisms. As a result of these advances, the field of predictive allosteric drug development is now on the cusp of a new era of rational structure-based computational methods. Here, we review algorithms that predict allosteric sites based on sequence data and molecular dynamics simulations, describe tools that assess the druggability of these pockets, and discuss how Markov state models and topology analyses provide insight into the relationship between protein dynamics and allosteric drug binding. In each section, we first provide an overview of the various method classes before describing relevant algorithms and software packages. PMID:27074285

  3. A retrospective analysis of drug-related problems documented in a national database.

    PubMed

    Westerlund, Tommy; Gelin, Ulrika; Pettersson, Elisabeth; Skärlund, Fredrik; Wågström, Kajsa; Ringbom, Carina

    2013-04-01

    Numerous patients are subject to drug-related problems (DRPs) every day, resulting in sub-optimal therapy, suffering and decreased quality of life, as well as in high societal health care costs. Classifying DRPs is important for the development of counselling skills and for pharmaceutical care practice and research, including assessments of the value of pharmacists' clinical interventions. Pharmacy practitioners have also reported to become more attentive to patients' drug-related needs, when requested to document their clinical interventions. Several studies have been conducted on DRPs, but there is still a need for a more thorough knowledge about their nature and the reasons for their occurrence. To examine DRP characteristics and causes by retrospectively analysing data and patient case histories, as documented by pharmacy practitioners in the Swedish national DRP database. Community pharmacy based patient documentation, entered into the Swedish national DRP database. Documented DRPs, clinical interventions and patient data were retrospectively examined and analysed. Particular attention was paid to case history reports in free text fields. Only reports containing adequate information for analysis and actual, correctly categorised DRPs were included. Subdivided DRP characteristics and causes. Both similarities and differences between DRP subclasses of prescription patients (n = 5,571) and OTC drug consumers (n = 2,894) were observed. Most DRP categories could be subdivided into at least three subclasses, according to their characteristics. Causes of DRPs could be extracted from free text field reports in four prescription DRP categories and three OTC DRP categories. Uncertainty about the aim of the drug was commonly characterised by a lack of knowledge about the indication in prescription patients and in an inappropriate drug selection in OTC drug consumers. A switch from a brand-name drug to a generic drug or from one generic to another was the cause in half of

  4. Methods for solving reasoning problems in abstract argumentation - A survey.

    PubMed

    Charwat, Günther; Dvořák, Wolfgang; Gaggl, Sarah A; Wallner, Johannes P; Woltran, Stefan

    2015-03-01

    Within the last decade, abstract argumentation has emerged as a central field in Artificial Intelligence. Besides providing a core formalism for many advanced argumentation systems, abstract argumentation has also served to capture several non-monotonic logics and other AI related principles. Although the idea of abstract argumentation is appealingly simple, several reasoning problems in this formalism exhibit high computational complexity. This calls for advanced techniques when it comes to implementation issues, a challenge which has been recently faced from different angles. In this survey, we give an overview on different methods for solving reasoning problems in abstract argumentation and compare their particular features. Moreover, we highlight available state-of-the-art systems for abstract argumentation, which put these methods to practice.

  5. Fully converged iterative method for coupled channel problems

    NASA Astrophysics Data System (ADS)

    Shu, Di; Simbotin, I.; Côté, R.

    2016-05-01

    We implemented a numerical method using a distorted-wave perturbative approach for coupled-channel scattering problems. Our new method provides a way to avoid costly computations for the propagation of the full solutions in coupled-channel problems to large distances for slowly vanishing couplings. Thus, instead of dealing with large matrices, all computations are performed in a channel by channel fashion. The distorted wavefunction for each channel is initialized with the appropriate solution (which includes the diagonal element of the coupling potential matrix). We then solve single-channel inhomogeneous radial equations which contain the (off-diagonal) couplings as a perturbation, and we iterate until desired accuracy is achieved. We tested for stability by continuing to iterate even after convergence has been achieved, e.g., for a total of 75 iterations. Partial support from the US Army Research Office (ARO-MURI W911NF-14-1-0378), and from NSF (Grant No. PHY-1415560).

  6. Algebraic Methods Applied to Network Reliability Problems. Revision.

    DTIC Science & Technology

    1986-09-01

    RD-RIBs 38? ALGEBRAIC METHODS APPLIED TO NETHORK RELIABILITY 1/1 PROBLEMS REVISIOU(U) CLEMSON UNIV SC DEPT OF MATEMATICAL SCIENCES D R SHIER ET AL...class of directed networks, Oper. Res., 32 (1984), pp. 493-515. -2 " 16 [3] A. AGRAWAL AND A. SATYANARAYANA, Network reliability analysis using 2...Networks, 13 (1983), pp. 107-120. [20] A. SATYANARAYANA AND A. PRABHAKAR, A new topological formula and rapid algorithm for reliability analysis of complex

  7. Conjugate Gradient Methods for Constrained Least Squares Problems

    DTIC Science & Technology

    1990-01-01

    TINO Hi!AGL . edi"o ar m m Conjugate Gradient Methods for Constrained Least Squares Problems by Douglas James A thesis 3ubmitted to the Graduate Faculty...Breakdown of Incomplete QR Factorizations The research which led to this dissertation began with a look at incomplete QR preconditioners for ordinary...AFIT/CI/CIA- 90-013D 6a. NAME OF PERFORMING ORGANIZATION 6b. OFFICE SYMBOL 7&. NAME OF MONITORING ORGANIZATION AFIT STUDENT AT (if applicable) AFIT/CIA

  8. Jacobi-Integral Method For Two-Body Problem

    NASA Technical Reports Server (NTRS)

    Bond, Victor R.; Gottlieb, Robert G.; Fraietta, Michael F.

    1991-01-01

    Jacobi-integral method enables efficient, accurate computation of trajectory of natural satellite or spacecraft perturbed by component of gravitational potential depending explicitly on both position and time. Instead of total energy, Jacobi integral, which is energylike constant of motion in this case, embedded in Newtonian differential equations of motion. Trajectories computed in fewer steps. With modifications, applicable to such terrestrial problems as motions of rotors and of beams of electrically charged particles in changing electrical and magnetic fields.

  9. Solving ODE Initial Value Problems With Implicit Taylor Series Methods

    NASA Technical Reports Server (NTRS)

    Scott, James R.

    2000-01-01

    In this paper we introduce a new class of numerical methods for integrating ODE initial value problems. Specifically, we propose an extension of the Taylor series method which significantly improves its accuracy and stability while also increasing its range of applicability. To advance the solution from t (sub n) to t (sub n+1), we expand a series about the intermediate point t (sub n+mu):=t (sub n) + mu h, where h is the stepsize and mu is an arbitrary parameter called an expansion coefficient. We show that, in general, a Taylor series of degree k has exactly k expansion coefficients which raise its order of accuracy. The accuracy is raised by one order if k is odd, and by two orders if k is even. In addition, if k is three or greater, local extrapolation can be used to raise the accuracy two additional orders. We also examine stability for the problem y'= lambda y, Re (lambda) less than 0, and identify several A-stable schemes. Numerical results are presented for both fixed and variable stepsizes. It is shown that implicit Taylor series methods provide an effective integration tool for most problems, including stiff systems and ODE's with a singular point.

  10. On the Application of the Energy Method to Stability Problems

    NASA Technical Reports Server (NTRS)

    Marguerre, Karl

    1947-01-01

    Since stability problems have come into the field of vision of engineers, energy methods have proved to be one of the most powerful aids in mastering them. For finding the especially interesting critical loads special procedures have evolved that depart somewhat from those customary in the usual elasticity theory. A clarification of the connections seemed desirable,especially with regard to the post-critical region, for the treatment of which these special methods are not suited as they are. The present investigation discusses this question-complex (made important by shell construction in aircraft) especially in the classical example of the Euler strut, because in this case - since the basic features are not hidden by difficulties of a mathematical nature - the problem is especially clear. The present treatment differs from that appearing in the Z.f.a.M.M. (1938) under the title "Uber die Behandlung von Stabilittatsproblemen mit Hilfe der energetischen Methode" in that, in order to work out the basic ideas still more clearly,it dispenses with the investigation of behavior at large deflections and of the elastic foundation;in its place the present version gives an elaboration of the 6th section and (in its 7 th and 8th secs.)a new example that shows the applicability of the general criterion to a stability problem that differs from that of Euler in many respects.

  11. The Newton Modified Barrier Method for QP Problems

    NASA Technical Reports Server (NTRS)

    Melman, A.; Polyak, R.

    1996-01-01

    The Modified Barrier Functions (MBF) have elements of both Classical Lagrangians (CL) and Classical Barrier Functions (CBF). The MBF methods find an unconstrained minimizer of some smooth barrier function in primal space and then update the Lagrange multipliers, while the barrier parameter either remains fixed or can be updated at each step. The numerical realization of the MBF method leads to the Newton MBF method, where the primal minimizer is found by using Newton's method. This minimizer is then used to update the Lagrange multipliers. In this paper, we examine the Newton MBF method for the Quadratic Programming (QP) problem. It will be shown that under standard second-order optimality conditions, there is a ball around the primal solution and a cut cone in the dual space such that for a set of Lagrange multipliers in this cut cone, the method converges quadratically to the primal minimizer from any point in the aforementioned ball, and continues to do so after each Lagrange multiplier update. The Lagrange multipliers remain within the cut cone and converge linearly to their optimal values. Any point in this ball will be called a "hot start". Starting at such a "hot start", at most Omicron(1n 1n epsilon(exp -1)) Newton steps are sufficient to perform the primal minimization which is necessary for the Lagrange multiplier update. Here, epsilon > 0 is the desired accuracy. Because of the linear convergence of the Lagrange multipliers, this means that only Omicron(1n epsilon(exp -1))omicron(ln 1n epsilon(exp-1)) Newton steps are required to reach an epsilon-approximation to the solution from any "hot start". In order to reach the "hot start", one has to perform Omicron(square root(m) 1n C) Newton steps, where m characterizes the size of the problem and C > 0 is the condition number of the QP problem. This condition number will be characterized explicitly in terms of key parameters of the QP problem, which in turn depend on the input data and the size of the problem.

  12. The Newton Modified Barrier Method for QP Problems

    NASA Technical Reports Server (NTRS)

    Melman, A.; Polyak, R.

    1996-01-01

    The Modified Barrier Functions (MBF) have elements of both Classical Lagrangians (CL) and Classical Barrier Functions (CBF). The MBF methods find an unconstrained minimizer of some smooth barrier function in primal space and then update the Lagrange multipliers, while the barrier parameter either remains fixed or can be updated at each step. The numerical realization of the MBF method leads to the Newton MBF method, where the primal minimizer is found by using Newton's method. This minimizer is then used to update the Lagrange multipliers. In this paper, we examine the Newton MBF method for the Quadratic Programming (QP) problem. It will be shown that under standard second-order optimality conditions, there is a ball around the primal solution and a cut cone in the dual space such that for a set of Lagrange multipliers in this cut cone, the method converges quadratically to the primal minimizer from any point in the aforementioned ball, and continues to do so after each Lagrange multiplier update. The Lagrange multipliers remain within the cut cone and converge linearly to their optimal values. Any point in this ball will be called a "hot start". Starting at such a "hot start", at most Omicron(1n 1n epsilon(exp -1)) Newton steps are sufficient to perform the primal minimization which is necessary for the Lagrange multiplier update. Here, epsilon > 0 is the desired accuracy. Because of the linear convergence of the Lagrange multipliers, this means that only Omicron(1n epsilon(exp -1))omicron(ln 1n epsilon(exp-1)) Newton steps are required to reach an epsilon-approximation to the solution from any "hot start". In order to reach the "hot start", one has to perform Omicron(square root(m) 1n C) Newton steps, where m characterizes the size of the problem and C > 0 is the condition number of the QP problem. This condition number will be characterized explicitly in terms of key parameters of the QP problem, which in turn depend on the input data and the size of the problem.

  13. Longitudinal study of maternal report of sleep problems in children with prenatal exposure to cocaine and other drugs.

    PubMed

    Stone, Kristen C; High, Pamela C; Miller-Loncar, Cynthia L; Lagasse, Linda L; Lester, Barry M

    2009-01-01

    Sleep data were collected by maternal report in a prospective longitudinal follow up of cocaine-exposed and unexposed children. There were 139 participants: 23 with no prenatal drug exposure, 55 exposed to cocaine alone or in combination with other drugs, and 61 exposed to drugs other than cocaine. Characteristics differed between exposure groups including birth size, caretaker changes, maternal socioeconomic status, and postnatal drug use. Compared to those with no drug exposure, children with prenatal drug exposure other than cocaine experienced greater sleep problems (p = .026). Prenatal nicotine exposure was a unique predictor of sleep problems (p = .048). Early sleep problems predicted later sleep problems (all ps < .01). Together, these preliminary findings suggest possible neurotoxic sleep effects that persist over time. Larger studies, however, need to be conducted that better control for potential postnatal confounding factors.

  14. Conforming and nonconforming virtual element methods for elliptic problems

    SciTech Connect

    Cangiani, Andrea; Manzini, Gianmarco; Sutton, Oliver J.

    2016-08-03

    Here we present, in a unified framework, new conforming and nonconforming virtual element methods for general second-order elliptic problems in two and three dimensions. The differential operator is split into its symmetric and nonsymmetric parts and conditions for stability and accuracy on their discrete counterparts are established. These conditions are shown to lead to optimal H1- and L2-error estimates, confirmed by numerical experiments on a set of polygonal meshes. The accuracy of the numerical approximation provided by the two methods is shown to be comparable.

  15. An Improved Heuristic Method for Subgraph Isomorphism Problem

    NASA Astrophysics Data System (ADS)

    Xiang, Yingzhuo; Han, Jiesi; Xu, Haijiang; Guo, Xin

    2017-09-01

    This paper focus on the subgraph isomorphism (SI) problem. We present an improved genetic algorithm, a heuristic method to search the optimal solution. The contribution of this paper is that we design a dedicated crossover algorithm and a new fitness function to measure the evolution process. Experiments show our improved genetic algorithm performs better than other heuristic methods. For a large graph, such as a subgraph of 40 nodes, our algorithm outperforms the traditional tree search algorithms. We find that the performance of our improved genetic algorithm does not decrease as the number of nodes in prototype graphs.

  16. Conforming and nonconforming virtual element methods for elliptic problems

    DOE PAGES

    Cangiani, Andrea; Manzini, Gianmarco; Sutton, Oliver J.

    2016-08-03

    Here we present, in a unified framework, new conforming and nonconforming virtual element methods for general second-order elliptic problems in two and three dimensions. The differential operator is split into its symmetric and nonsymmetric parts and conditions for stability and accuracy on their discrete counterparts are established. These conditions are shown to lead to optimal H1- and L2-error estimates, confirmed by numerical experiments on a set of polygonal meshes. The accuracy of the numerical approximation provided by the two methods is shown to be comparable.

  17. Application the particle method in problems of mechanics deformable media

    NASA Astrophysics Data System (ADS)

    Berezhnoi, D. V.; Gabsalikova, N. F.; Miheev, V. V.

    2016-11-01

    The work implemented method of deformation of ground-based particle method, which is a collection of mineral grains, which are linked to some system of forces on the contact areas between the mineral particles. Two-parameter potential Lennard-Jones and it is modified version were selected for describing the behavior of ground. Some model problems of straining layer of ground in the gravity field was decided. The calculations were performed on a heterogeneous computing cluster, on each of the seven components that were installed on three GPU AMD Radeon HD 7970.

  18. Some Comments on Numerical Methods for Chaos Problems

    NASA Astrophysics Data System (ADS)

    Miller, R. H.

    1996-03-01

    Hamiltonian systems with chaotic regions are particularly slippery to treat numerically. Numerical treatments can introduce nonphysical features. Simple examples illustrate some of the pitfalls. Integer, or discrete, arithmetic is a favorite “workaround.” While it does not cure chaos, it clarifies the interaction of computational methods with the underlying mathematical structure. Be forewarned: I won't give any prescription that is guaranteed to give a good and reliable method to handle chaotic problems numerically. Instead, I'll stress a few of the concerns and describe one or two pitfalls.

  19. Conforming and nonconforming virtual element methods for elliptic problems

    SciTech Connect

    Cangiani, Andrea; Manzini, Gianmarco; Sutton, Oliver J.

    2016-08-03

    Here we present, in a unified framework, new conforming and nonconforming virtual element methods for general second-order elliptic problems in two and three dimensions. The differential operator is split into its symmetric and nonsymmetric parts and conditions for stability and accuracy on their discrete counterparts are established. These conditions are shown to lead to optimal H1- and L2-error estimates, confirmed by numerical experiments on a set of polygonal meshes. The accuracy of the numerical approximation provided by the two methods is shown to be comparable.

  20. Determination of risk factors for drug-related problems: a multidisciplinary triangulation process

    PubMed Central

    Kaufmann, Carole P; Stämpfli, Dominik; Hersberger, Kurt E; Lampert, Markus L

    2015-01-01

    Introduction and objectives Drug-related problems (DRPs) constitute a frequent safety issue among hospitalised patients leading to patient harm and increased healthcare costs. Because many DRPs are preventable, the specific risk factors that facilitate their occurrence are of considerable interest. The objective of our study was to assess risk factors for the occurrence of DRPs with the intention to identify patients at risk for DRPs to guide and target preventive measures where they are needed most in patients. Design Triangulation process using a mixed methods approach. Methods We conducted an expert panel, using the nominal group technique (NGT) and a qualitative analysis, to gather risk factors for DRPs. The expert panel consisted of two consultant hospital physicians (internal medicine and geriatrics), one emergency physician, one independent general practitioner, one clinical pharmacologist, one clinical pharmacist, one registered nurse, one home care nurse and two independent community pharmacists. The literature was searched for additional risk factors. Gathered factors from the literature search and the NGT were assembled and validated in a two-round Delphi questionnaire. Results The NGT resulted in the identification of 33 items with 13 additional risk factors from the qualitative analysis of the discussion. The literature search delivered another 39 risk factors. The 85 risk factors were refined to produce 42 statements for the Delphi online questionnaire. Of these, 27 risk factors were judged to be ‘important’ or ‘rather important’. Conclusions The gathered risk factors may help to characterise and identify patients at risk for DRPs and may enable clinical pharmacists to guide and target preventive measures in order to limit the occurrence of DRPs. As a further step, these risk factors will serve as the basis for a screening tool to identify patients at risk for DRPs. PMID:25795686

  1. [Iodine containing drugs and thyroid gland function. A diagnostic and therapeutic problem].

    PubMed

    Weissel, M

    1991-01-01

    Iodine-induced thyroid dysfunction will become more important in Austria in the near future, because of the augmentation of the iodine content in salt in 1990. This review therefore tries to summarize the diagnostic and therapeutic problems that may arise in iodine-induced thyroid disease. After discussion of the physiologic reaction of the normal thyroid to iodine the most frequently used iodine-containing drugs used in Austria are presented. Special emphasis is laid on iodine containing antiseptics and on the antiarrhythmic drug amiodarone. The influence of iodine supplementation on the reaction of diseased thyroid glands to iodine overload is stressed. The diagnosis of iodine induced thyroid dysfunction is relatively simple, once it is thought of. Amiodarone-iodine induced thyroid disease may be an exception, because of the intrinsic effect of this drug on thyroid hormone metabolism. Since high intra-thyroidal iodine content inhibits the action of thyrostatics, therapy of iodine-induced hyperthyroidism may be complicated. Alternative possibilities such as cortisone, perchlorate or surgery in thyroid storm are presented. Substitution with 1-thyroxine in iodine-induced hypothyroidism may be harmful in elderly patients with cardiac problems. In conclusion, this review tries to present the state of the art of the solution of diagnostic and therapeutic problems in thyroid dysfunction due to iodine administration.

  2. Comparison of Optimal Design Methods in Inverse Problems

    PubMed Central

    Banks, H. T.; Holm, Kathleen; Kappel, Franz

    2011-01-01

    Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according to the optimal sampling distribution. Here we formulate the classical optimal design problem in the context of general optimization problems over distributions of sampling times. We present a new Prohorov metric based theoretical framework that permits one to treat succinctly and rigorously any optimal design criteria based on the Fisher Information Matrix (FIM). A fundamental approximation theory is also included in this framework. A new optimal design, SE-optimal design (standard error optimal design), is then introduced in the context of this framework. We compare this new design criteria with the more traditional D-optimal and E-optimal designs. The optimal sampling distributions from each design are used to compute and compare standard errors; the standard errors for parameters are computed using asymptotic theory or bootstrapping and the optimal mesh. We use three examples to illustrate ideas: the Verhulst-Pearl logistic population model [13], the standard harmonic oscillator model [13] and a popular glucose regulation model [16, 19, 29]. PMID:21857762

  3. A Space/Time Dynamically Adaptive Method for Multiscale Problems

    NASA Astrophysics Data System (ADS)

    Grenga, Temistocle; Zikoski, Zachary; Paolucci, Samuel; Valorani, Mauro

    2011-11-01

    Systems of partial differential equations (PDEs) describing problems that are multiscale in space and time are computationally very expensive to solve. In order to overcome the challenges related to both thin spatial layers and temporal stiffness we propose the use of a wavelet adaptive multilevel representation (WAMR) in space and an adaptive model reduction method (G-Scheme) in time. The multilevel structure of the algorithm provides a simple way to adapt computational refinements to local demands of the solution. High resolution computations are performed only in spatial regions where sharp transitions occur, while the G-Scheme is an explicit solver developed for stiff problems which is built upon a local decomposition of the dynamics in three subspaces involving slow, active and fast time scales. Only the modes in the active subspace are integrated numerically, the others are approximated asymptotically. Subsequently, the original problem not only becomes substantially smaller, but more importantly non-stiff. Combining the WAMR technique with the G-Scheme yields a time accurate solution of a prescribed accuracy with a much smaller number of space- time degrees of freedom. While the computational scheme can be used to solve a wide class of stiff PDE problems, we will illustrate its use in the solution of the Navier Stokes equations in reactive flows.

  4. Comparison of Optimal Design Methods in Inverse Problems.

    PubMed

    Banks, H T; Holm, Kathleen; Kappel, Franz

    2011-07-01

    Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according to the optimal sampling distribution. Here we formulate the classical optimal design problem in the context of general optimization problems over distributions of sampling times. We present a new Prohorov metric based theoretical framework that permits one to treat succinctly and rigorously any optimal design criteria based on the Fisher Information Matrix (FIM). A fundamental approximation theory is also included in this framework. A new optimal design, SE-optimal design (standard error optimal design), is then introduced in the context of this framework. We compare this new design criteria with the more traditional D-optimal and E-optimal designs. The optimal sampling distributions from each design are used to compute and compare standard errors; the standard errors for parameters are computed using asymptotic theory or bootstrapping and the optimal mesh. We use three examples to illustrate ideas: the Verhulst-Pearl logistic population model [13], the standard harmonic oscillator model [13] and a popular glucose regulation model [16, 19, 29].

  5. The long-term effects of childhood maltreatment experiences on subsequent illicit drug use and drug-related problems in young adulthood.

    PubMed

    Huang, Shi; Trapido, Edward; Fleming, Lora; Arheart, Kristopher; Crandall, Lee; French, Michael; Malcolm, Shandey; Prado, Guillermo

    2011-01-01

    The objective of this study was to examine the associations between (a) childhood maltreatment (i.e., physical abuse, sexual abuse, and neglect) and subsequent illicit drug use and (b) childhood maltreatment and drug-related problems in young adulthood. Wave 1 and Wave 3 public-use data from the National Longitudinal Study of Adolescent Health were used. Logistic regressions, controlling for adolescent drug use and other important family and peer contextual processes, were estimated to determine the associations between (a) childhood maltreatment experiences and subsequent illicit drug use and (b) childhood maltreatment and drug-related problems in young adulthood. Among the participants, 31.9% reported some form of childhood maltreatment. Childhood physical abuse was associated with a 37% (OR=1.37; 95% CI=1.04, 1.80) increase in illicit drug use during the 30 days prior to the Wave 3 survey, a 48% (OR=1.48; 95% CI=1.16, 1.89) increase in illicit drug use during the year prior to the Wave 3 survey, and a 96% (OR=1.96; 95% CI=1.40, 2.76) increase in drug-related problems in young adulthood. The latter two associations persisted even after controlling for illicit drug use in adolescence. Neglect among females was associated with a higher likelihood of past year illicit drug use in young adulthood (OR=1.31; 95% CI=1.002, 1.71). However, this association was not significant once the effect of illicit drug use in adolescence was statistically controlled for. The present findings suggest that childhood maltreatment is related to subsequent illicit drug use and drug-related problems in young adulthood and that some of these associations differ by gender. Implications for preventive intervention are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Substructure method in high-speed monorail dynamic problems

    NASA Astrophysics Data System (ADS)

    Ivanchenko, I. I.

    2008-12-01

    The study of actions of high-speed moving loads on bridges and elevated tracks remains a topical problem for transport. In the present study, we propose a new method for moving load analysis of elevated tracks (monorail structures or bridges), which permits studying the interaction between two strained objects consisting of rod systems and rigid bodies with viscoelastic links; one of these objects is the moving load (monorail rolling stock), and the other is the carrying structure (monorail elevated track or bridge). The methods for moving load analysis of structures were developed in numerous papers [1-15]. At the first stage, when solving the problem about a beam under the action of the simplest moving load such as a moving weight, two fundamental methods can be used; the same methods are realized for other structures and loads. The first method is based on the use of a generalized coordinate in the expansion of the deflection in the natural shapes of the beam, and the problem is reduced to solving a system of ordinary differential equations with variable coefficients [1-3]. In the second method, after the "beam-weight" system is decomposed, just as in the problem with the weight impact on the beam [4], solving the problem is reduced to solving an integral equation for the dynamic weight reaction [6, 7]. In [1-3], an increase in the number of retained forms leads to an increase in the order of the system of equations; in [6, 7], difficulties arise when solving the integral equations related to the conditional stability of the step procedures. The method proposed in [9, 14] for beams and rod systems combines the above approaches and eliminates their drawbacks, because it permits retaining any necessary number of shapes in the deflection expansion and has a resolving system of equations with an unconditionally stable integration scheme and with a minimum number of unknowns, just as in the method of integral equations [6, 7]. This method is further developed for

  7. On path-following methods for structural failure problems

    NASA Astrophysics Data System (ADS)

    Stanić, Andjelka; Brank, Boštjan; Korelc, Jože

    2016-08-01

    We revisit the consistently linearized path-following method that can be applied in the nonlinear finite element analysis of solids and structures in order to compute a solution path. Within this framework, two constraint equations are considered: a quadratic one (that includes as special cases popular spherical and cylindrical forms of constraint equation), and another one that constrains only one degree-of-freedom (DOF), the critical DOF. In both cases, the constrained DOFs may vary from one solution increment to another. The former constraint equation is successful in analysing geometrically nonlinear and/or standard inelastic problems with snap-throughs, snap-backs and bifurcation points. However, it cannot handle problems with the material softening that are computed e.g. by the embedded-discontinuity finite elements. This kind of problems can be solved by using the latter constraint equation. The plusses and minuses of the both presented constraint equations are discussed and illustrated on a set of numerical examples. Some of the examples also include direct computation of critical points and branch switching. The direct computation of the critical points is performed in the framework of the path-following method by using yet another constraint function, which is eigenvector-free and suited to detect critical points.

  8. Drug and alcohol abuse: The pattern and magnitude of the problem

    SciTech Connect

    Ajayi, P.A.

    1996-12-31

    In the last 12 months, many more cases of alcohol and drug (substance) abuse in the workplace were seen in the Escravos operations of Chevron Nigeria Limited than in previous years. This called the attention to the rising prevalence of drug and alcohol abuse in contradistinction to reports from similar organizations in other parts of the world. Chevron Nigeria has a written Drug and Alcohol Policy which has been dormant for some time because of the apparent rarity of the problem of substance abuse in the workplace. This Policy is being reviewed to broaden its scope and make it more effective. A total of 30 employees were tested for drugs and alcohol .6 exceeded the legal limits of Blood Alcohol Concentration (BAC) and 5 tested positive for drugs. Tests were mainly post-accident, reasonable cause and random. The common substances abused were alcohol, cannabis, cocaine and morphine in that order. The findings are compared with those of similar organizations in UK and USA. Efforts to control substance abuse in the workplace are being put into place.

  9. Don't Flush! Why Your Drug Disposal Method Matters ...

    EPA Pesticide Factsheets

    April 30th is the U.S. Drug Enforcement Administration’s National Drug Take-Back Day. All over the country there will be facilities accepting any unwanted or expired medications from 10:00 AM – 2:00 PM – it is the perfect opportunity to clean out your medicine cabinet while simultaneously helping to protect aquatic animals and their environment from chemical exposure!Have you ever participated in a drug take-back program? If not, what do you typically do with leftover medications after you defeat a bacterial infection or find an old bottle of Tylenol? Many people may flush unwanted or expired pharmaceuticals down the toilet or throw them in the trash, but those methods can actually harm our environment.When flushed or thrown-out, these drugs end up in our coastal ecosystems; and all the chemicals in those little pills that were once working together to make us feel better, are now dissolving in our waterways where they can negatively impact aquatic animals.Scientists throughout EPA continue to evaluate the potential toxicity of different drugs in order to determine what specific effects they have on aquatic wildlife, and to develop new ways to detect if an organism has been exposed to those drugs.I recently spoke with Bushra Khan (NRC post-doc) and Theresa Johnson (ORISE fellow) of the EPA’s Atlantic Ecology Division to learn about some of the specific effects they have observed in their research. Bushra talked to me about the effects beta blockers, m

  10. Don't Flush! Why Your Drug Disposal Method Matters ...

    EPA Pesticide Factsheets

    April 30th is the U.S. Drug Enforcement Administration’s National Drug Take-Back Day. All over the country there will be facilities accepting any unwanted or expired medications from 10:00 AM – 2:00 PM – it is the perfect opportunity to clean out your medicine cabinet while simultaneously helping to protect aquatic animals and their environment from chemical exposure!Have you ever participated in a drug take-back program? If not, what do you typically do with leftover medications after you defeat a bacterial infection or find an old bottle of Tylenol? Many people may flush unwanted or expired pharmaceuticals down the toilet or throw them in the trash, but those methods can actually harm our environment.When flushed or thrown-out, these drugs end up in our coastal ecosystems; and all the chemicals in those little pills that were once working together to make us feel better, are now dissolving in our waterways where they can negatively impact aquatic animals.Scientists throughout EPA continue to evaluate the potential toxicity of different drugs in order to determine what specific effects they have on aquatic wildlife, and to develop new ways to detect if an organism has been exposed to those drugs.I recently spoke with Bushra Khan (NRC post-doc) and Theresa Johnson (ORISE fellow) of the EPA’s Atlantic Ecology Division to learn about some of the specific effects they have observed in their research. Bushra talked to me about the effects beta blockers, m

  11. The Problem Solving Method in Teaching Physics in Elementary School

    NASA Astrophysics Data System (ADS)

    Jandrić, Gordana Hajduković; Obadović, Dušanka Ž.; Stojanović, Maja

    2010-01-01

    The most of the teachers ask if there is a "best" known way to teach. The most effective teaching method depends on the specific goals of the course and the needs of the students. An investigation has been carried out to compare the effect of teaching selected physics topics using problem-solving method on the overall achievements of the acquired knowledge and teaching the same material by traditional teaching method. The investigation was performed as a pedagogical experiment of the type of parallel groups with randomly chosen sample of students attending grades eight. The control and experimental groups were equalized in the relevant pedagogical parameters. The obtained results were treated statistically. The comparison showed a significant difference in respect of the speed of acquiring knowledge, the problem-solving teaching being advantageous over traditional methodDo not replace the word "abstract," but do replace the rest of this text. If you must insert a hard line break, please use Shift+Enter rather than just tapping your "Enter" key. You may want to print this page and refer to it as a style sample before you begin working on your paper.

  12. Galerkin boundary integral equation method for spontaneous rupture propagation problems

    NASA Astrophysics Data System (ADS)

    Goto, H.; Bielak, J.

    2007-12-01

    We develop a Galerkin finite element boundary integral equation method (GaBIEM) for spontaneous rupture propagation problems for a planar fault embedded in a homogeneous full 2D space. A simple 2D anti plane rupture propagation problem, with a slip-weakening friction law, is simulated by the GaBIEM. This method allows one to separate explicitly the kernel into singular static and time-dependent parts, and a nonsingular dynamic component. The simulated results throw light into the performance of the GaBIEM and highlight differences with respect to that of the traditional, collocation, boundary integral equation method (BIEM). The rate of convergence of the GaBIEM, as measured from a root mean square (RMS) analysis of the difference of approximate solutions corresponding to increasingly finer element sizes is of a higher order than that of the BIEM. There is no restriction on the CFL stability number since an implicit, unconditionally stable method is used for the time integration. The error of the approximation increases with the time step, as expected, and it can remain below that of the BIEM.

  13. Validation of analytic methods for biomarkers used in drug development.

    PubMed

    Chau, Cindy H; Rixe, Olivier; McLeod, Howard; Figg, William D

    2008-10-01

    The role of biomarkers in drug discovery and development has gained precedence over the years. As biomarkers become integrated into drug development and clinical trials, quality assurance and, in particular, assay validation become essential with the need to establish standardized guidelines for analytic methods used in biomarker measurements. New biomarkers can revolutionize both the development and use of therapeutics but are contingent on the establishment of a concrete validation process that addresses technology integration and method validation as well as regulatory pathways for efficient biomarker development. This perspective focuses on the general principles of the biomarker validation process with an emphasis on assay validation and the collaborative efforts undertaken by various sectors to promote the standardization of this procedure for efficient biomarker development.

  14. Validation of Analytical Methods for Biomarkers Employed in Drug Development

    PubMed Central

    Chau, Cindy H.; Rixe, Olivier; McLeod, Howard; Figg, William D.

    2008-01-01

    The role of biomarkers in drug discovery and development has gained precedence over the years. As biomarkers become integrated into drug development and clinical trials, quality assurance and in particular assay validation becomes essential with the need to establish standardized guidelines for analytical methods used in biomarker measurements. New biomarkers can revolutionize both the development and use of therapeutics, but is contingent upon the establishment of a concrete validation process that addresses technology integration and method validation as well as regulatory pathways for efficient biomarker development. This perspective focuses on the general principles of the biomarker validation process with an emphasis on assay validation and the collaborative efforts undertaken by various sectors to promote the standardization of this procedure for efficient biomarker development. PMID:18829475

  15. Statistical methods for active pharmacovigilance, with applications to diabetes drugs.

    PubMed

    Zhuo, Lan; Farrell, Patrick J; McNair, Doug; Krewski, Daniel

    2014-01-01

    Pharmacovigilance aims to identify adverse drug reactions using postmarket surveillance data under real-world conditions of use. Unlike passive pharmacovigilance, which is based on largely voluntary (and hence incomplete) spontaneous reports of adverse drug reactions with limited information on patient characteristics, active pharmacovigilance is based on electronic health records containing detailed information about patient populations, thereby allowing consideration of modifying factors such as polypharmacy and comorbidity, as well as sociodemographic characteristics. With the present shift toward active pharmacovigilance, statistical methods capable of addressing the complexities of such data are needed. We describe four such methods here, and demonstrate their application in the analysis of a large retrospective cohort of diabetics taking anti-hyperglycemic medications that may increase the risk of adverse cardiovascular events.

  16. WEAK GALERKIN METHODS FOR SECOND ORDER ELLIPTIC INTERFACE PROBLEMS.

    PubMed

    Mu, Lin; Wang, Junping; Wei, Guowei; Ye, Xiu; Zhao, Shan

    2013-10-01

    Weak Galerkin methods refer to general finite element methods for partial differential equations (PDEs) in which differential operators are approximated by their weak forms as distributions. Such weak forms give rise to desirable flexibilities in enforcing boundary and interface conditions. A weak Galerkin finite element method (WG-FEM) is developed in this paper for solving elliptic PDEs with discontinuous coefficients and interfaces. Theoretically, it is proved that high order numerical schemes can be designed by using the WG-FEM with polynomials of high order on each element. Extensive numerical experiments have been carried to validate the WG-FEM for solving second order elliptic interface problems. High order of convergence is numerically confirmed in both L2 and L∞ norms for the piecewise linear WG-FEM. Special attention is paid to solve many interface problems, in which the solution possesses a certain singularity due to the nonsmoothness of the interface. A challenge in research is to design nearly second order numerical methods that work well for problems with low regularity in the solution. The best known numerical scheme in the literature is of order [Formula: see text] to [Formula: see text] for the solution itself in L∞ norm. It is demonstrated that the WG-FEM of the lowest order, i.e., the piecewise constant WG-FEM, is capable of delivering numerical approximations that are of order [Formula: see text] to [Formula: see text] in the L∞ norm for C(1) or Lipschitz continuous interfaces associated with a C(1) or H(2) continuous solution.

  17. WEAK GALERKIN METHODS FOR SECOND ORDER ELLIPTIC INTERFACE PROBLEMS

    PubMed Central

    MU, LIN; WANG, JUNPING; WEI, GUOWEI; YE, XIU; ZHAO, SHAN

    2013-01-01

    Weak Galerkin methods refer to general finite element methods for partial differential equations (PDEs) in which differential operators are approximated by their weak forms as distributions. Such weak forms give rise to desirable flexibilities in enforcing boundary and interface conditions. A weak Galerkin finite element method (WG-FEM) is developed in this paper for solving elliptic PDEs with discontinuous coefficients and interfaces. Theoretically, it is proved that high order numerical schemes can be designed by using the WG-FEM with polynomials of high order on each element. Extensive numerical experiments have been carried to validate the WG-FEM for solving second order elliptic interface problems. High order of convergence is numerically confirmed in both L2 and L∞ norms for the piecewise linear WG-FEM. Special attention is paid to solve many interface problems, in which the solution possesses a certain singularity due to the nonsmoothness of the interface. A challenge in research is to design nearly second order numerical methods that work well for problems with low regularity in the solution. The best known numerical scheme in the literature is of order O(h) to O(h1.5) for the solution itself in L∞ norm. It is demonstrated that the WG-FEM of the lowest order, i.e., the piecewise constant WG-FEM, is capable of delivering numerical approximations that are of order O(h1.75) to O(h2) in the L∞ norm for C1 or Lipschitz continuous interfaces associated with a C1 or H2 continuous solution. PMID:24072935

  18. [Ambulatory blood pressure: methods, equipment, technical problems, validations].

    PubMed

    Carré, A; Petetin, N; Fouquoire, B; Mounier-Vehier, C; Poncelet, P

    1991-09-01

    The measurement of ambulatory blood pressure provides a discontinuous recording which reflects the pressure load over a 24 hour period. The latest recorders allow the patient a relative autonomy due to discontinuous but programmable recording and the miniaturisation of the recorder and relative silence during inflation of the cuff. The main disadvantage of the technique is the necessity of interruption of the patient's physical activity at the moment of recording indicated by an audible "beep". The concept of "active pressure load" is therefore illusory. The traditional controversy between supporters of the auscultatory versus those for the oscillometric method is far from being settled and these discussions do not resolve the problem. The use of finger plethysmographic techniques (Finapress-Ohmeda) is an interesting approach but limited for the time being by the necessity of confinement to a laboratory and recordings of short durations requiring strict conditions of ambient temperature. Future developments using ultrasonic techniques may provide a solution to these problems.

  19. The Relationship of Social Problem-Solving Skills and Dysfunctional Attitudes with Risk of Drug Abuse among Dormitory Students at Isfahan University of Medical Sciences

    PubMed Central

    Nasrazadani, Ehteram; Maghsoudi, Jahangir; Mahrabi, Tayebeh

    2017-01-01

    Background: Dormitory students encounter multiple social factors which cause pressure, such as new social relationships, fear of the future, and separation from family, which could cause serious problems such as tendency toward drug abuse. This research was conducted with the goal to determine social problem-solving skills, dysfunctional attitudes, and risk of drug abuse among dormitory students of Isfahan University of Medical Sciences, Iran. Materials and Methods: This was a descriptive-analytical, correlational, and cross-sectional research. The research sample consisted of 211 students living in dormitories. The participants were selected using randomized quota sampling method. The data collection tools included the Social Problem-Solving Inventory (SPSI), Dysfunctional Attitude Scale (DAS), and Identifying People at Risk of Addiction Questionnaire. Results: The results indicated an inverse relationship between social problem-solving skills and risk of drug abuse (P = 0.0002), a direct relationship between dysfunctional attitude and risk of drug abuse (P = 0.030), and an inverse relationship between social problem-solving skills and dysfunctional attitude among students (P = 0.0004). Conclusions: Social problem-solving skills have a correlation with dysfunctional attitudes. As a result, teaching these skills and the way to create efficient attitudes should be considered in dormitory students. PMID:28904539

  20. A simple method avoiding non-uniqueness in the boundary element method for acoustic scattering problem.

    PubMed

    Hirosawa, Kunikazu; Ishizuka, Takashi; Fujiwara, Kyoji

    2009-05-01

    The boundary element method (BEM) is widely used for sound field analysis problems; however, it has a non-uniqueness problem in the exterior domain. Various methods to avoid this problem have been developed; however, these are not easily applied to the BEM. In this paper, a simple method called the "ICA-Ring (inner cavity ringing) method" is proposed for avoiding the non-uniqueness problem, and this method is applied to the BEM in both single and plural domains. The concept of the ICA-Ring method is that a scatterer in free space is hollowed as a shell and the volume is smaller; the eigenfrequencies are shifted to a higher range. Next, the mechanism of the non-uniqueness problem in plural domains and a reason of the application of the ICA-Ring method to the case of plural domains are explained. Finally, some results calculated by the BEM using the ICA-Ring method are shown. The calculational condition is that a cylinder with radius 0.125 m floats in two-dimensional free space. In this case, no calculational errors exist in 1-6000 Hz in both single and plural domains, when the thickness of the shell is 20 mm. The ICA-Ring method does not need to modify an existing computer program of conventional BEM.

  1. Brief Intervention for Problem Drug Use in Safety-Net Primary Care Settings

    PubMed Central

    Roy-Byrne, Peter; Bumgardner, Kristin; Krupski, Antoinette; Dunn, Chris; Ries, Richard; Donovan, Dennis; West, Imara I.; Maynard, Charles; Atkins, David C.; Graves, Meredith C.; Joesch, Jutta M.; Zarkin, Gary A.

    2015-01-01

    IMPORTANCE Although brief intervention is effective for reducing problem alcohol use, few data exist on its effectiveness for reducing problem drug use, a common issue in disadvantaged populations seeking care in safety-net medical settings (hospitals and community health clinics serving low-income patients with limited or no insurance). OBJECTIVE To determine whether brief intervention improves drug use outcomes compared with enhanced care as usual. DESIGN, SETTING, AND PARTICIPANTS A randomized clinical trial with blinded assessments at baseline and at 3, 6, 9, and 12 months conducted in 7 safety-net primary care clinics in Washington State. Of 1621 eligible patients reporting any problem drug use in the past 90 days, 868 consented and were randomized between April 2009 and September 2012. Follow-up participation was more than 87% at all points. INTERVENTIONS Participants received a single brief intervention using motivational interviewing, a handout and list of substance abuse resources, and an attempted 10-minute telephone booster within 2 weeks (n = 435) or enhanced care as usual, which included a handout and list of substance abuse resources (n = 433). MAIN OUTCOMES AND MEASURES The primary outcomes were self-reported days of problem drug use in the past 30 days and Addiction Severity Index–Lite (ASI) Drug Use composite score. Secondary outcomes were admission to substance abuse treatment; ASI composite scores for medical, psychiatric, social, and legal domains; emergency department and inpatient hospital admissions, arrests, mortality, and human immunodeficiency virus risk behavior. RESULTS Mean days used of the most common problem drug at baseline were 14.40 (SD, 11.29) (brief intervention) and 13.25 (SD, 10.69) (enhanced care as usual); at 3 months postintervention, means were 11.87 (SD, 12.13) (brief intervention) and 9.84 (SD, 10.64) (enhanced care as usual) and not significantly different (difference in differences, β = 0.89 [95% CI, –0.49 to 2

  2. Multidrug and extensively drug-resistant TB (M/XDR-TB): problems and solutions.

    PubMed

    Prasad, Rajendra

    2010-10-01

    Multi Drug Resistant Tuberculosis (MDR-TB) and Extensively Drug Resistant Tuberculosis (XDR-TB) are posing a threat to the control of tuberculosis. The first WHO-IUATLD antituberculosis drug resistance surveillance carried out in 1994 in 35 countries reported the median prevalence of primary and acquired multi drug resistance as 1.4% and 13% respectively. Subsequently, second, third and fourth WHO-IUATLD global drug resistance surveillances were carried out in 1996-99, 1999-2002 and 2002-2007 respectively. Based on drug resistance information from 114 countries, the proportion of MDR-TB among all cases was estimated for countries with no survey information. It was estimated that 4,89,139 cases of MDR-TB emerged in 2006. China and India carry approximately 50% of the global burden. 35 countries and two Special Administrative Regions (SARs) reported data on XDR-TB for the first time in 2006. Multidrug and extensively drug-resistant TB 2010 Global report on Surveillance and response estimated that 4,40,000 cases of MDR-TB emerged globally in 2008 and caused an estimated 1,50,000 deaths. 5.4% of MDR-TB cases were found to have XDR-TB. To date, a cumulative total of 58 countries have confirmed at least one case of XDR-TB. M/XDR-TB is a man-made problem and its emergence can be prevented by prompt diagnosis and effective use of first line drugs in every new patient. The DOTS Plus proposed by WHO highlights the comprehensive management strategy to control MDR-TB. Laboratory services for adequate and timely diagnosis of M/XDR-TB must be strengthened and programmatic management of M/XDR-TB must be scaled up as per target set by global plan. Proper use of second-line drugs must be ensured to cure existing MDR-TB, to reduce its transmission and to prevent XDR-TB. Sound infection control measures to avoid further transmission of M/XDR-TB and research towards development of new diagnostics, drugs and vaccines should be promoted to control M/XDR-TB.

  3. Fully decoupled monolithic projection method for natural convection problems

    NASA Astrophysics Data System (ADS)

    Pan, Xiaomin; Kim, Kyoungyoun; Lee, Changhoon; Choi, Jung-Il

    2017-04-01

    To solve time-dependent natural convection problems, we propose a fully decoupled monolithic projection method. The proposed method applies the Crank-Nicolson scheme in time and the second-order central finite difference in space. To obtain a non-iterative monolithic method from the fully discretized nonlinear system, we first adopt linearizations of the nonlinear convection terms and the general buoyancy term with incurring second-order errors in time. Approximate block lower-upper decompositions, along with an approximate factorization technique, are additionally employed to a global linearly coupled system, which leads to several decoupled subsystems, i.e., a fully decoupled monolithic procedure. We establish global error estimates to verify the second-order temporal accuracy of the proposed method for velocity, pressure, and temperature in terms of a discrete l2-norm. Moreover, according to the energy evolution, the proposed method is proved to be stable if the time step is less than or equal to a constant. In addition, we provide numerical simulations of two-dimensional Rayleigh-Bénard convection and periodic forced flow. The results demonstrate that the proposed method significantly mitigates the time step limitation, reduces the computational cost because only one Poisson equation is required to be solved, and preserves the second-order temporal accuracy for velocity, pressure, and temperature. Finally, the proposed method reasonably predicts a three-dimensional Rayleigh-Bénard convection for different Rayleigh numbers.

  4. Variance reduction methods applied to deep-penetration problems

    SciTech Connect

    Cramer, S.N.

    1984-01-01

    All deep-penetration Monte Carlo calculations require variance reduction methods. Before beginning with a detailed approach to these methods, several general comments concerning deep-penetration calculations by Monte Carlo, the associated variance reduction, and the similarities and differences of these with regard to non-deep-penetration problems will be addressed. The experienced practitioner of Monte Carlo methods will easily find exceptions to any of these generalities, but it is felt that these comments will aid the novice in understanding some of the basic ideas and nomenclature. Also, from a practical point of view, the discussions and developments presented are oriented toward use of the computer codes which are presented in segments of this Monte Carlo course.

  5. The making of a public health problem: multi-drug resistant tuberculosis in India.

    PubMed

    Engel, Nora C

    2013-07-01

    This paper examines how actors construct the public problem of multi-drug resistant tuberculosis (MDR-TB) in India. MDR-TB has been framed by the World Health Organization as a pressing, global public health problem. The responses to MDR-TB are complicated as treatment takes longer and is more expensive than routine TB treatment. This is particularly problematic in countries, such as India, with high patient loads, a large and unregulated private sector, weak health systems and potentially high numbers of MDR-TB cases. This paper analyses how actors struggle for control over ownership, causal theories and political responsibility of the public problem of MDR-TB in India. It combines Gusfield's theory on the construction of public problems with insights from literature on the social construction of diseases and on medical social control. It highlights that there are flexible definitions of public problems, which are negotiated among actor groups and which shift over time. The Indian government has shifted its policy in recent years and acknowledged that MDR-TB needs to be dealt with within the TB programme. The study results reveal how the policy shift happened, why debates on the construction of MDR-TB as a public problem in India continue, and why actors with alternative theories than the government do not succeed in their lobbying efforts. Two main arguments are put forward. First, the construction of the public problem of MDR-TB in India is a social and political process. The need for representative data, international influence and politics define what is controllable. Second, the government seems to be anxious to control the definition of India's MDR-TB problem. This impedes an open, critical and transparent discussion on the definition of the public problem of MDR-TB, which is important in responding flexibly to emerging public health challenges.

  6. Advances in multiparameter optimization methods for de novo drug design.

    PubMed

    Segall, Matthew

    2014-07-01

    A high-quality drug must achieve a balance of physicochemical and absorption, distribution, metabolism and elimination properties, safety and potency against its therapeutic target(s). Multiparameter optimization (MPO) methods guide the simultaneous optimization of multiple factors to quickly target compounds with the highest chance of downstream success. MPO can be combined with 'de novo design' methods to automatically generate and assess a large number of diverse structures and identify strategies to optimize a compound's overall balance of properties. The article provides a review of MPO methods and recent developments in the methods and opinions in the field. It also provides a description of advances in de novo design that improve the relevance of automatically generated compound structures and integrate MPO. Finally, the article provides discussion of a recent case study of the automatic design of ligands to polypharmacological profiles. Recent developments have reduced the generation of chemically infeasible structures and improved the quality of compounds generated by de novo design methods. There are concerns about the ability of simple drug-like properties and ligand efficiency indices to effectively guide the detailed optimization of compounds. De novo design methods cannot identify a perfect compound for synthesis, but it can identify high-quality ideas for detailed consideration by an expert scientist.

  7. In vitro methods for diagnosing nonimmediate hypersensitivity reactions to drugs.

    PubMed

    Mayorga, C; Sanz, M L; Gamboa, P; Garcia-Aviles, M C; Fernandez, J; Torres, M J

    2013-01-01

    Nonimmediate drug hypersensitivity reactions (DHRs) are difficult to manage in daily clinical practice, mainly owing to their heterogeneous clinical manifestations and the lack of selective biological markers. In vitro methods are necessaryto establish a diagnosis, especially given the low sensitivity of skin tests and the inherent risks of drug provocation testing. In vitro evaluation of nonimmediate DHRs must include approaches that can be applied during the different phases of the reaction. During the acute phase, monitoring markers in both skin and peripheral blood helps to discriminate between immediate and nonimmediate DHRs with cutaneous responses and to distinguish between reactions that, although they present similar clinical symptoms, are produced by different immunological mechanisms and therefore have a different treatment and prognosis. During the resolution phase, in vitro testing is used to detect the response of T cells to drug stimulation; however, this approach has certain limitations, such as the lack of validated studies assessing sensitivity. Moreover, in vitro tests indicate an immune response that is not always related to a DHR. In this review, members of the Immunology and Drug Allergy Committee of the Spanish Society of Allergy and Clinical Immunology (SEAIC) provide an overview of the most widely used in vitro tests for evaluating nonimmediate DHRs.

  8. Global Regularization Method for Planar Restricted Three-body Problem

    NASA Astrophysics Data System (ADS)

    Sharaf, M. A.; Dwidar, H. R.

    2015-12-01

    In this paper, global regularization method for planar restricted three-body problem is purposed by using the transformation z=x+iy=ν cos n(u+iv), where i=√{-1}, 0 < ν ≤ 1 and n is a positive integer. The method is developed analytically and computationally. For the analytical developments, analytical solutions in power series of the pseudo-time τ are obtained for positions and velocities (u,v,u',v') and (x,y,dot{x},dot{y}) in both regularized and physical planes respectively, the physical time {t} is also obtained as power series in τ. Moreover, relations between the coefficients of the power series are obtained for two consequent values of {n}. Also, we developed analytical solutions in power series form for the inverse problem of finding τ in terms of {t}. As typical examples, three symbolic expressions for the coefficients of the power series were developed in terms of the initial values. As to the computational developments, the global regularized equations of motion are developed together with their initial values in forms suitable for digital computations using any differential equations solver. On the other hand, for the numerical evolutions of power series, an efficient method depending on the continued fraction theory is provided.

  9. Matched Interface and Boundary Method for Elasticity Interface Problems

    PubMed Central

    Wang, Bao; Xia, Kelin; Wei, Guo-Wei

    2015-01-01

    Elasticity theory is an important component of continuum mechanics and has had widely spread applications in science and engineering. Material interfaces are ubiquity in nature and man-made devices, and often give rise to discontinuous coefficients in the governing elasticity equations. In this work, the matched interface and boundary (MIB) method is developed to address elasticity interface problems. Linear elasticity theory for both isotropic homogeneous and inhomogeneous media is employed. In our approach, Lamé’s parameters can have jumps across the interface and are allowed to be position dependent in modeling isotropic inhomogeneous material. Both strong discontinuity, i.e., discontinuous solution, and weak discontinuity, namely, discontinuous derivatives of the solution, are considered in the present study. In the proposed method, fictitious values are utilized so that the standard central finite different schemes can be employed regardless of the interface. Interface jump conditions are enforced on the interface, which in turn, accurately determines fictitious values. We design new MIB schemes to account for complex interface geometries. In particular, the cross derivatives in the elasticity equations are difficult to handle for complex interface geometries. We propose secondary fictitious values and construct geometry based interpolation schemes to overcome this difficulty. Numerous analytical examples are used to validate the accuracy, convergence and robustness of the present MIB method for elasticity interface problems with both small and large curvatures, strong and weak discontinuities, and constant and variable coefficients. Numerical tests indicate second order accuracy in both L∞ and L2 norms. PMID:25914439

  10. Matched Interface and Boundary Method for Elasticity Interface Problems.

    PubMed

    Wang, Bao; Xia, Kelin; Wei, Guo-Wei

    2015-09-01

    Elasticity theory is an important component of continuum mechanics and has had widely spread applications in science and engineering. Material interfaces are ubiquity in nature and man-made devices, and often give rise to discontinuous coefficients in the governing elasticity equations. In this work, the matched interface and boundary (MIB) method is developed to address elasticity interface problems. Linear elasticity theory for both isotropic homogeneous and inhomogeneous media is employed. In our approach, Lamé's parameters can have jumps across the interface and are allowed to be position dependent in modeling isotropic inhomogeneous material. Both strong discontinuity, i.e., discontinuous solution, and weak discontinuity, namely, discontinuous derivatives of the solution, are considered in the present study. In the proposed method, fictitious values are utilized so that the standard central finite different schemes can be employed regardless of the interface. Interface jump conditions are enforced on the interface, which in turn, accurately determines fictitious values. We design new MIB schemes to account for complex interface geometries. In particular, the cross derivatives in the elasticity equations are difficult to handle for complex interface geometries. We propose secondary fictitious values and construct geometry based interpolation schemes to overcome this difficulty. Numerous analytical examples are used to validate the accuracy, convergence and robustness of the present MIB method for elasticity interface problems with both small and large curvatures, strong and weak discontinuities, and constant and variable coefficients. Numerical tests indicate second order accuracy in both L∞ and L2 norms.

  11. Epidemiological methods for research with drug misusers: review of methods for studying prevalence and morbidity.

    PubMed

    Dunn, J; Ferri, C P

    1999-04-01

    Epidemiological studies of drug misusers have until recently relied on two main forms of sampling: probability and convenience. The former has been used when the aim was simply to estimate the prevalence of the condition and the latter when in depth studies of the characteristics, profiles and behaviour of drug users were required, but each method has its limitations. Probability samples become impracticable when the prevalence of the condition is very low, less than 0.5% for example, or when the condition being studied is a clandestine activity such as illicit drug use. When stratified random samples are used, it may be difficult to obtain a truly representative sample, depending on the quality of the information used to develop the stratification strategy. The main limitation of studies using convenience samples is that the results cannot be generalised to the whole population of drug users due to selection bias and a lack of information concerning the sampling frame. New methods have been developed which aim to overcome some of these difficulties, for example, social network analysis, snowball sampling, capture-recapture techniques, privileged access interviewer method and contact tracing. All these methods have been applied to the study of drug misuse. The various methods are described and examples of their use given, drawn from both the Brazilian and international drug misuse literature.

  12. Evaluation of a Community Pharmacy-Based Screening Questionnaire to Identify Patients at Risk for Drug Therapy Problems.

    PubMed

    Pammett, Robert T; Blackburn, David; Taylor, Jeff; Mansell, Kerry; Kwan, Debbie; Papoushek, Christine; Jorgenson, Derek

    2015-09-01

    To determine if a short screening questionnaire can identify patients at risk for drug therapy problems (DTPs) in a community pharmacy setting. Self-administered questionnaire. Three community pharmacies in Saskatoon, Canada. Forty-nine adults who were picking up a refill prescription for a medication that had remained stable over the past 6 months (i.e., no changes to drug, dose, or regimen) during 4 consecutive weeks at each of the three pharmacies between November 2013 and February 2014. All patients completed a self-administered screening questionnaire and underwent a blinded comprehensive medication assessment with a clinical pharmacist. Agreement between the screening questionnaire responses and responses based on information from the medication assessment were assessed with Cohen's κ coefficient. The DTPs identified during the medication assessments were categorized in one of the eight standard DTP categories: unnecessary drug therapy, inappropriate drug, subtherapeutic dose, supratherapeutic dose, drug therapy required, adverse drug reaction, noncompliance, and other or unsure. The DTPs were also assigned a severity-mild, moderate, or severe-using adapted Schneider criteria. The number and severity of DTPs identified were compared among patients categorized as high versus low risk for DTPs as determined by the questionnaire responses. Of the 49 patients who completed the study, 18 (37%) were high risk and 31 (63%) low risk. The agreement between risk categorization based on the screening questionnaire and medication assessment was very good (κ = 0.91, p<0.01). Also, patients identified as high risk on the screening questionnaire had a mean of 3.7 (p<0.01) more DTPs than low-risk patients. Seventeen (94%) of the 18 high-risk patients had at least one moderate or severe DTP compared with 15 (48%) of the 31 low-risk patients. The screening questionnaire was a reliable method for identifying patients in community pharmacies who have a large number of DTPs

  13. Ectoparasites of medical and veterinary importance: drug resistance and the need for alternative control methods.

    PubMed

    McNair, Carol M

    2015-03-01

    Despite multiple attempts at eradication, many ectoparasites of humans and domestic livestock remain a persistent problem in the modern world. For many years, a range of pesticide drugs including organophosphates, organochlorides and synthetic pyrethroids provided effective control of these parasites; but intensive use of these drugs has led to the evolution of resistance in many target species. This paper aims to review the effectiveness of current control methods and discuss potential alternatives for the long term sustainable control of ectoparasites. Important medical ectoparasites such as scabies mites, head lice and bed bugs present a significant public health problem, and so adequate control methods are essential. Ectoparasites of domestic livestock and farmed fish (for example sheep scab mites, poultry mites and sea lice) are also of concern given the increasing strain on the world's food supply. These parasites have become resistant to several classes of pesticide, making control very difficult. Recently, an increasing amount of research has focussed on alternative control methods such as insect growth regulators, biological control using essential oils or fungi, as well as vaccine development against some ectoparasites of medical and veterinary importance. Drug resistance is prevalent in all of the ectoparasites discussed in this review. A wide variety of alternative control methods have been identified, however further research is necessary in order for these to be used to successfully control ectoparasitic diseases in the future. © 2015 Royal Pharmaceutical Society.

  14. A Method for Diagnosing and Planning the Treatment of Adolescent Drug Abusers (The Adolescent Drug Abuse Diagnosis [ADAD] Instrument).

    ERIC Educational Resources Information Center

    Friedman, Alfred S.; Utada, Arlene

    1989-01-01

    Describes development of Adolescent Drug Abuse Diagnosis (ADAD), a 150-item instrument with a structured interview format, which produces a comprehensive evaluation of the life problem areas pertinent to the needs of adolescent drug abuse clients. A series of validity and reliability tests are described, along with characteristics of the…

  15. A Method for Diagnosing and Planning the Treatment of Adolescent Drug Abusers (The Adolescent Drug Abuse Diagnosis [ADAD] Instrument).

    ERIC Educational Resources Information Center

    Friedman, Alfred S.; Utada, Arlene

    1989-01-01

    Describes development of Adolescent Drug Abuse Diagnosis (ADAD), a 150-item instrument with a structured interview format, which produces a comprehensive evaluation of the life problem areas pertinent to the needs of adolescent drug abuse clients. A series of validity and reliability tests are described, along with characteristics of the…

  16. New drugs and methods of doping and manipulation.

    PubMed

    Thevis, Mario; Kohler, Maxie; Schänzer, Wilhelm

    2008-01-01

    The issue of doping in sport is multifaceted. New drugs not only with anabolic properties such as selective androgen receptor modulators, synthetic insulins, blood doping with erythropoietins or homologous and autologous blood transfusions but also with sample manipulation have necessitated sensitive, comprehensive and specific detection assays allowing for the identification of cheats. New methods based on mass spectrometry, flow cytometry and immunological techniques have been introduced and improved in the past years to support and enhance the antidoping fight. Although numerous approaches are successful and promising, these methods still have some shortcomings.

  17. Determination of risk factors for drug-related problems: a multidisciplinary triangulation process.

    PubMed

    Kaufmann, Carole P; Stämpfli, Dominik; Hersberger, Kurt E; Lampert, Markus L

    2015-03-20

    Drug-related problems (DRPs) constitute a frequent safety issue among hospitalised patients leading to patient harm and increased healthcare costs. Because many DRPs are preventable, the specific risk factors that facilitate their occurrence are of considerable interest. The objective of our study was to assess risk factors for the occurrence of DRPs with the intention to identify patients at risk for DRPs to guide and target preventive measures where they are needed most in patients. Triangulation process using a mixed methods approach. We conducted an expert panel, using the nominal group technique (NGT) and a qualitative analysis, to gather risk factors for DRPs. The expert panel consisted of two consultant hospital physicians (internal medicine and geriatrics), one emergency physician, one independent general practitioner, one clinical pharmacologist, one clinical pharmacist, one registered nurse, one home care nurse and two independent community pharmacists. The literature was searched for additional risk factors. Gathered factors from the literature search and the NGT were assembled and validated in a two-round Delphi questionnaire. The NGT resulted in the identification of 33 items with 13 additional risk factors from the qualitative analysis of the discussion. The literature search delivered another 39 risk factors. The 85 risk factors were refined to produce 42 statements for the Delphi online questionnaire. Of these, 27 risk factors were judged to be 'important' or 'rather important'. The gathered risk factors may help to characterise and identify patients at risk for DRPs and may enable clinical pharmacists to guide and target preventive measures in order to limit the occurrence of DRPs. As a further step, these risk factors will serve as the basis for a screening tool to identify patients at risk for DRPs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  18. A high-order staggered meshless method for elliptic problems

    DOE PAGES

    Trask, Nathaniel; Perego, Mauro; Bochev, Pavel Blagoveston

    2017-03-21

    Here, we present a new meshless method for scalar diffusion equations, which is motivated by their compatible discretizations on primal-dual grids. Unlike the latter though, our approach is truly meshless because it only requires the graph of nearby neighbor connectivity of the discretization points. This graph defines a local primal-dual grid complex with a virtual dual grid, in the sense that specification of the dual metric attributes is implicit in the method's construction. Our method combines a topological gradient operator on the local primal grid with a generalized moving least squares approximation of the divergence on the local dual grid. We show that the resulting approximation of the div-grad operator maintains polynomial reproduction to arbitrary orders and yields a meshless method, which attainsmore » $$O(h^{m})$$ convergence in both $L^2$- and $H^1$-norms, similar to mixed finite element methods. We demonstrate this convergence on curvilinear domains using manufactured solutions in two and three dimensions. Application of the new method to problems with discontinuous coefficients reveals solutions that are qualitatively similar to those of compatible mesh-based discretizations.« less

  19. Behavioral problems in children with benign childhood epilepsy with centrotemporal spikes treated and untreated with antiepileptic drugs.

    PubMed

    Samaitienė, Rūta; Norkūnienė, Jolita; Jurkevičienė, Giedrė; Grikinienė, Jurgita

    2012-01-01

    The aim of this study was to investigate behavioral problems in two groups of children with benign childhood epilepsy with centrotemporal spikes (BECTS), i.e., those treated with antiepileptic drugs and those not treated in order to identify the factors associated with behavioral problems. MATERIAL AND METHODS. In total, 20 newly diagnosed untreated, 23 treated patients with BECTS, and 20 patients with acute/subacute peripheral nervous system disorders as a comparison group (aged 6-11 years) were examined. The evaluation was performed using the Lithuanian version of the Child Behavior Checklist (CBCL). Schooling parameters, clinical parameters, EEG parameters, and their relation to the results of the CBCL were also investigated. RESULTS. The treated patients with BECTS had significantly higher scores in the subscales of Social Problems, Anxious/Depressed, Aggressive Behavior, and Attention Problems compared with the scores of the patients with peripheral nervous system disorders. A significant relationship was established between the scores of native language grades and Attention Problems; grades in mathematics and treatment duration; and age when the first seizure occurred and Delinquent Behavior in the group of treated patients. The duration of epilepsy was positively correlated with the scores in the subscales of Withdrawn and Delinquent Behavior. The presence of additional extrarolandic focus and spread of focal specific discharges to the centrofrontotemporal and centroparietotemporal areas were related to higher scores in Social Problems, Attention Problems, and Delinquent Behavior in the group of the treated patients with BECTS. CONCLUSIONS. Children with BECTS, especially those treated and with a longer epilepsy course, were found to be at risk of behavioral problems. Lower grades were associated with a longer disease course and medications. The presence of extrarolandic discharges was related to higher CBCL scores in the group of the treated patients with

  20. Resazurin tube method: rapid, simple, and inexpensive method for detection of drug resistance in the clinical isolates of mycobacterium tuberculosis.

    PubMed

    Patil, Santosh S; Mohite, Shivajirao T; Kulkarni, Sunanda A; Udgaonkar, Usha S

    2014-10-01

    Tuberculosis (TB) remains a serious public health problem worldwide. The emergence of drug resistance and multidrug resistance (MDR) has become the main threat to TB treatment and control programs. Rapid detection is critical for the effective treatment of patients. In recent times, a new method using the colorimetric indicator resazurin has been proposed for drug susceptibility of Mycobacterium tuberculosis. In this study, the resazurin reduction assay was adapted to screw cap tubes. Using the Resazurin Tube Method (RTM), a total of 100 clinical isolates were tested against Rifampicin (RIF) and Isoniazide (INH). By visual reading, the minimum inhibitory concentrations (MICs) were obtained after eight days. The results obtained were compared with the gold standard proportion method. Excellent results were obtained for RTM with a sensitivity of 100% for both RIF and INH, with a specificity of 98.7 and 95.3%, respectively. Kappa is the measure of agreement between the RTM and proportion method (PM) for RIF and INH, which was found to be 0.972 and 0.935 for RIF and INH, respectively. The RTM appears to be a reliable method for the rapid and simultaneous detection of MDR-TB and drug susceptibility testing (DST) of M. tuberculosis. It is simple, inexpensive, and with no biohazard risk involved.

  1. Empirical likelihood method for non-ignorable missing data problems.

    PubMed

    Guan, Zhong; Qin, Jing

    2017-01-01

    Missing response problem is ubiquitous in survey sampling, medical, social science and epidemiology studies. It is well known that non-ignorable missing is the most difficult missing data problem where the missing of a response depends on its own value. In statistical literature, unlike the ignorable missing data problem, not many papers on non-ignorable missing data are available except for the full parametric model based approach. In this paper we study a semiparametric model for non-ignorable missing data in which the missing probability is known up to some parameters, but the underlying distributions are not specified. By employing Owen (1988)'s empirical likelihood method we can obtain the constrained maximum empirical likelihood estimators of the parameters in the missing probability and the mean response which are shown to be asymptotically normal. Moreover the likelihood ratio statistic can be used to test whether the missing of the responses is non-ignorable or completely at random. The theoretical results are confirmed by a simulation study. As an illustration, the analysis of a real AIDS trial data shows that the missing of CD4 counts around two years are non-ignorable and the sample mean based on observed data only is biased.

  2. Substance abuse treatment utilization among adults living with HIV/AIDS and alcohol or drug problems.

    PubMed

    Orwat, John; Saitz, Richard; Tompkins, Christopher P; Cheng, Debbie M; Dentato, Michael P; Samet, Jeffrey H

    2011-10-01

    This is a prospective cohort study to identify factors associated with receipt of substance abuse treatment (SAT) among adults with alcohol problems and HIV/AIDS. Data from the HIV Longitudinal Interrelationships of Viruses and Ethanol study were analyzed. Generalized estimating equation logistic regression models were fit to identify factors associated with any service utilization. An alcohol dependence diagnosis had a negative association with SAT (adjusted odds ratio [AOR] = 0.36, 95% confidence interval [95% CI] = 0.19-0.67), as did identifying sexual orientation other than heterosexual (AOR = 0.46, CI = 0.29-0.72) and having social supports that use alcohol/drugs (AOR = 0.62, CI = 0.45-0.83). Positive associations with SAT include presence of hepatitis C antibody (AOR = 3.37, CI = 2.24-5.06), physical or sexual abuse (AOR = 2.12, CI = 1.22-3.69), social supports that help with sobriety (AOR = 1.92, CI = 1.28-2.87), homelessness (AOR = 2.40, CI = 1.60-3.62), drug dependence diagnosis (AOR = 2.64, CI = 1.88-3.70), and clinically important depressive symptoms (AOR = 1.52, CI = 1.08-2.15). While reassuring that factors indicating need for SAT among people with HIV and alcohol problems (e.g., drug dependence) are associated with receipt, nonneed factors (e.g., sexual orientation, age) that should not decrease likelihood of receipt of treatment were identified.

  3. Drug delivery formulations of ordered and nonordered mesoporous silica: comparison of three drug loading methods.

    PubMed

    Limnell, Tarja; Santos, Hélder A; Mäkilä, Ermei; Heikkilä, Teemu; Salonen, Jarno; Murzin, Dmitry Yu; Kumar, Narendra; Laaksonen, Timo; Peltonen, Leena; Hirvonen, Jouni

    2011-08-01

    A poorly soluble model drug, indomethacin (IMC), was loaded into two types of silica particles using three different loading methods. The loading efficiency and the extent/rate of drug release were evaluated. Widely used equipment in pharmaceutical laboratories, rotavapor and fluid bed, were used in the loading. The porous materials used were ordered mesoporous silica MCM-41 and nonordered silica gel Syloid 244 FP EU. The materials differ both in their pore properties and particle sizes. Tablets were successfully compressed from the IMC-loaded particles. Mechanical stability of the porous structures was studied with XRPD and nitrogen sorption after tableting and drug release was evaluated at pH 5.5 before and after tableting. The release of the poorly soluble IMC was faster from the Syloid than from the MCM-41, presumably due to the larger pore size and smaller particle size. Loading of IMC into the MCM-41 microparticles improved the drug dissolution, and blending the microparticles with pharmaceutical excipients improved the IMC release even further. The fast release was also maintained after tableting. Loading of IMC into the Syloid particles alone was sufficient to produce similar IMC release profiles, as in the case of MCM-41 with the excipients.

  4. Sectional methods for aggregation problems: application to volcanic eruptions

    NASA Astrophysics Data System (ADS)

    Rossi, E.

    2016-12-01

    Particle aggregation is a general problem that is common to several scientific disciplines such as planetary formation, food industry and aerosol sciences. So far the ordinary approach to this class of problems relies on the solution of the Smoluchowski Coagulation Equations (SCE), a set of Ordinary Differential Equations (ODEs) derived from the Population Balance Equations (PBE), which basically describe the change in time of an initial grain-size distribution due to the interaction of "single" particles. The frequency of particles collisions and their sticking efficiencies depend on the specific problem under analysis, but the mathematical framework and the possible solutions to the ODEs seem to be somehow discipline-independent and very general. In this work we will focus on the problem of volcanic ash aggregation, since it represents an extreme case of complexity that can be relevant also to other disciplines. In fact volcanic ash aggregates observed during the fallouts are characterized by relevant porosities and they do not fit with simplified descriptions based on monomer-like structures or fractal geometries. In this work we propose a bidimensional approach to the PBEs which uses additive (mass) and non-additive (volume) internal descriptors in order to better characterize the evolution of volcanic ash aggregation. In particular we used sectional methods (fixed-pivot) to discretize the internal parameters space. This algorithm has been applied to a one dimensional volcanic plume model in order to investigate how the Total Grain Size Distribution (TGSD) changes throughout the erupted column in real scenarios (i.e. Eyjafjallajokull 2010, Sakurajima 2013 and Mt. Saint Helens 1980).

  5. Comparison of optimal design methods in inverse problems

    NASA Astrophysics Data System (ADS)

    Banks, H. T.; Holm, K.; Kappel, F.

    2011-07-01

    Typical optimal design methods for inverse or parameter estimation problems are designed to choose optimal sampling distributions through minimization of a specific cost function related to the resulting error in parameter estimates. It is hoped that the inverse problem will produce parameter estimates with increased accuracy using data collected according to the optimal sampling distribution. Here we formulate the classical optimal design problem in the context of general optimization problems over distributions of sampling times. We present a new Prohorov metric-based theoretical framework that permits one to treat succinctly and rigorously any optimal design criteria based on the Fisher information matrix. A fundamental approximation theory is also included in this framework. A new optimal design, SE-optimal design (standard error optimal design), is then introduced in the context of this framework. We compare this new design criterion with the more traditional D-optimal and E-optimal designs. The optimal sampling distributions from each design are used to compute and compare standard errors; the standard errors for parameters are computed using asymptotic theory or bootstrapping and the optimal mesh. We use three examples to illustrate ideas: the Verhulst-Pearl logistic population model (Banks H T and Tran H T 2009 Mathematical and Experimental Modeling of Physical and Biological Processes (Boca Raton, FL: Chapman and Hall/CRC)), the standard harmonic oscillator model (Banks H T and Tran H T 2009) and a popular glucose regulation model (Bergman R N, Ider Y Z, Bowden C R and Cobelli C 1979 Am. J. Physiol. 236 E667-77 De Gaetano A and Arino O 2000 J. Math. Biol. 40 136-68 Toffolo G, Bergman R N, Finegood D T, Bowden C R and Cobelli C 1980 Diabetes 29 979-90).

  6. Links between Alcohol and Other Drug Problems and Maltreatment among Adolescent Girls: Perceived Discrimination, Ethnic Identity, and Ethnic Orientation as Moderators

    ERIC Educational Resources Information Center

    Gray, Calonie M. K.; Montgomery, Marilyn J.

    2012-01-01

    Objectives: This study examined the links between maltreatment, posttraumatic stress symptoms, ethnicity-specific factors (i.e., perceived discrimination, ethnic identity, and ethnic orientation), and alcohol and/or other drug (AOD) problems among adolescent girls. Methods: These relations were examined using archived data from a community sample…

  7. Poor Response Inhibition as a Predictor of Problem Drinking and Illicit Drug Use in Adolescents at Risk for Alcoholism and Other Substance Use Disorders

    ERIC Educational Resources Information Center

    Nigg, Joel T.; Wong, Maria M.; Martel, Michelle M.; Jester, Jennifer M.; Puttler, Leon I.; Glass, Jennifer M.; Adams, Kenneth M.; Fitzgerald, Hiram E.; Zucker, Robert A.

    2006-01-01

    Objective: To evaluate the predictive power of executive functions, in particular, response inhibition, in relation to alcohol-related problems and illicit drug use in adolescence. Method: A total of 498 children from 275 families from a longitudinal high-risk study completed executive function measures in early and late adolescence and lifetime…

  8. Poor Response Inhibition as a Predictor of Problem Drinking and Illicit Drug Use in Adolescents at Risk for Alcoholism and Other Substance Use Disorders

    ERIC Educational Resources Information Center

    Nigg, Joel T.; Wong, Maria M.; Martel, Michelle M.; Jester, Jennifer M.; Puttler, Leon I.; Glass, Jennifer M.; Adams, Kenneth M.; Fitzgerald, Hiram E.; Zucker, Robert A.

    2006-01-01

    Objective: To evaluate the predictive power of executive functions, in particular, response inhibition, in relation to alcohol-related problems and illicit drug use in adolescence. Method: A total of 498 children from 275 families from a longitudinal high-risk study completed executive function measures in early and late adolescence and lifetime…

  9. Links between Alcohol and Other Drug Problems and Maltreatment among Adolescent Girls: Perceived Discrimination, Ethnic Identity, and Ethnic Orientation as Moderators

    ERIC Educational Resources Information Center

    Gray, Calonie M. K.; Montgomery, Marilyn J.

    2012-01-01

    Objectives: This study examined the links between maltreatment, posttraumatic stress symptoms, ethnicity-specific factors (i.e., perceived discrimination, ethnic identity, and ethnic orientation), and alcohol and/or other drug (AOD) problems among adolescent girls. Methods: These relations were examined using archived data from a community sample…

  10. Diffuse Interface Methods for Modeling Drug-Eluting Stent Coatings.

    PubMed

    Saylor, David M; Forrey, Christopher; Kim, Chang-Soo; Warren, James A

    2016-02-01

    An overview of diffuse interface models specific to drug-eluting stent coatings is presented. Microscale heterogeneities, both in the coating and use environment, dictate the performance of these coatings. Using diffuse interface methods, these heterogeneities can be explicitly incorporated into the model equations with relative ease. This enables one to predict the complex microstructures that evolve during coating fabrication and subsequent impact on drug release. Examples are provided that illustrate the wide range of phenomena that can be addressed with diffuse interface models including: crystallization, constrained phase separation, hydrolytic degradation, and heterogeneous binding. Challenges associated with the lack of material property data and numerical solution of the model equations are also highlighted. Finally, in light of these potential drawbacks, the potential to utilize diffuse interface models to help guide product and process development is discussed.

  11. Finite volume method for geodetic boundary value problem

    NASA Astrophysics Data System (ADS)

    Medľa, Matej; Mikula, Karol; Macák, Marek

    2016-04-01

    We present new finite volume numerical scheme for solving the Geodetic boundary value problem on non-uniform logically rentangular grids together with new second-order upwind treatment of the oblique derivative. First the logically rectangular grid is built above the Earth topography by evolving surface approach. Then the Laplace equation is solved on such grid by using the finite volume method in which the normal derivative on finite volume boundary face is split into derivative in tangential direction and a derivative in direction of the vector connecting representative points of neigbouring finite volumes. The oblique derivative boundary condition is understood as a stationary advection equation and second-order upwind method is developed for its discretization. The numerical experiments will be presented.

  12. Drug-related problems in patients with erectile dysfunctions and multiple comorbidities

    PubMed Central

    Huri, Hasniza Zaman; Ling, Chui Fang; Razack, Azad Hassan Abdul

    2017-01-01

    This study was conducted in a tertiary medical center in Kuala Lumpur, Malaysia. A total of 200 erectile dysfunction (ED) patients with 499 cases who had received pharmacological treatments for their ED participated in this study. Types, causes and factors associated with drug-related problems (DRPs) in ED patients with multiple comorbidities were assessed. A total of 244 DRPs with an average of 1.2±2.1 DRPs per patient were identified. Drug interaction contributed the most to DRPs occurrence. There was a significant higher risk of DRPs in patients with benign prostatic hyperplasia, lower urinary tract infection and elderly and end-stage renal disease. Early identification of types of DRPs and factors associated may enhance their prevention and management. PMID:28408836

  13. Drug-related problems in institutionalized, polymedicated elderly patients: opportunities for pharmacist intervention.

    PubMed

    Silva, Cristina; Ramalho, Célia; Luz, Isabel; Monteiro, Joaquim; Fresco, Paula

    2015-04-01

    An aging population and the increasing prevalence of chronic diseases have led to the increased use of medicines. Portugal is one of the European countries where more medicines are consumed and the associated expense is higher. Medicines are associated with enormous health benefits but also with the potential to cause illness and death. A drug related problem (DRP) is an "an event or circumstance involving drug therapy that actually or potentially interferes with desired health outcomes". In the U.S., they represent the 4th-6th leading cause of death and have an estimated cost of 130 billion dollars. Moreover, many of these DRP can be avoided. Elderly are at increased risk of DRP due to multiple factors: pluripathology and consequent polypharmacy, complex dosing regimens, pharmacokinetic/pharmacodynamic and functional/cognitive changes. Therefore, this population would be the one who would benefit most from the prevention, detection and control of DRP. The role of the pharmacist as an integral element of health care has been recognized by various international and European organizations. Providing pharmaceutical care as a patient-centered activity, focusing on their needs related to pharmacotherapy, contributes to guarantee that drug expenditure is a good investment, with benefits that outweigh potential risks. To evaluate the need for pharmaceutical care implementation in institutionalized, polymedicated elderly. Descriptive observational cross-sectional study carried out in six Portuguese nursing homes, selected by convenience, in November-December 2013. Each institution selected up to six patients, according to the following inclusion criteria: age ≥65 years, number of medications ≥5 and ability to respond to an interview. All participants signed an informed consent form. Pharmacists carried out a structured interview with each patient and consulted patient medical records to gather demographic data and information on health problems and medications used. To

  14. [Drug interaction caused by communication problems. Rhabdomyolysis due to a combination of itraconazole and simvastatin].

    PubMed

    Tiessen, Renger G; Lagerwey, Hendrik Jan G; Jager, Gea J; Sprenger, Herman G

    2010-01-01

    A 58-year-old man, who spoke very little Dutch, had various symptoms and used several drugs including simvastatin. He was prescribed itraconazole for onychomycosis. Simvastatin was concurrently replaced with pravastatin to prevent drug interactions. However, the interaction still occurred when the pravastatin ran out, and the patient resumed taking simvastatin on his own initiative. Myalgia and muscle weakness developed after one week. The general practitioner found a strongly elevated creatine kinase level in the blood. The patient required hospitalisation for severe rhabdomyolysis. He was treated with an infusion of an ample quantity of physiological saline solution and made a full recovery. Due to the elevated risk of toxic interactions, doctors should beware of communication problems in complex patients and avoid new prescriptions not strictly required.

  15. The Relationship of Social Problem-Solving Skills and Dysfunctional Attitudes with Risk of Drug Abuse among Dormitory Students at Isfahan University of Medical Sciences.

    PubMed

    Nasrazadani, Ehteram; Maghsoudi, Jahangir; Mahrabi, Tayebeh

    2017-01-01

    Dormitory students encounter multiple social factors which cause pressure, such as new social relationships, fear of the future, and separation from family, which could cause serious problems such as tendency toward drug abuse. This research was conducted with the goal to determine social problem-solving skills, dysfunctional attitudes, and risk of drug abuse among dormitory students of Isfahan University of Medical Sciences, Iran. This was a descriptive-analytical, correlational, and cross-sectional research. The research sample consisted of 211 students living in dormitories. The participants were selected using randomized quota sampling method. The data collection tools included the Social Problem-Solving Inventory (SPSI), Dysfunctional Attitude Scale (DAS), and Identifying People at Risk of Addiction Questionnaire. The results indicated an inverse relationship between social problem-solving skills and risk of drug abuse (P = 0.0002), a direct relationship between dysfunctional attitude and risk of drug abuse (P = 0.030), and an inverse relationship between social problem-solving skills and dysfunctional attitude among students (P = 0.0004). Social problem-solving skills have a correlation with dysfunctional attitudes. As a result, teaching these skills and the way to create efficient attitudes should be considered in dormitory students.

  16. Methods for the coupled Stokes-Darcy problem

    NASA Astrophysics Data System (ADS)

    Feuillebois, F.; Khabthani, S.; Elasmi, L.; Sellier, A.

    2010-11-01

    The motion of particles in a viscous fluid close to a porous membrane is modelled for the case when particles are large compared with the size of pores of the membrane. The hydrodynamic interactions of one particle with the membrane are detailed here. The model involves Stokes equations for the fluid motion around the particle together with Darcy equations for the flow in the porous membrane and Stokes equations for the flow on the other side of the membrane. Boundary conditions at the fluid-membrane interface are the continuity of pressure and velocity in the normal direction and the Beavers and Joseph slip condition on the fluid side in the tangential directions. The no-slip condition applies on the particle. This problem is solved here by two different methods. The first one is an extended boundary integral method (EBIM). A Green function is derived for the flow close to a porous membrane. This function is non-symmetric, leading to difficulties hindering the application of the classical boundary integral method (BIM). Thus, an extended method is proposed, in which the unknown distribution of singularities on the particle surface is not the stress, like in the classical boundary integral method. Yet, the hydrodynamic force and torque on the particle are obtained by integrals of this distribution on the particle surface. The second method consists in searching the solution as an asymptotic expansion in term of a small parameter that is the ratio of the typical pore size to the particle size. The various boundary conditions are taken into account at successive orders: order (0) simply represents an impermeable wall without slip and order (1) an impermeable wall with a peculiar slip prescribed by order (0); at least the 3rd order is necessary to enforce all boundary conditions. The methods are applied numerically to a spherical particle and comparisons are made with earlier works in particular cases.

  17. 21 CFR 530.24 - Procedure for announcing analytical methods for drug residue quantification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... drug residue quantification. 530.24 Section 530.24 Food and Drugs FOOD AND DRUG ADMINISTRATION...-Producing Animals § 530.24 Procedure for announcing analytical methods for drug residue quantification. (a... extralabel use drug residues above the safe levels established under § 530.22 for extralabel use of an...

  18. The residual method for regularizing ill-posed problems

    PubMed Central

    Grasmair, Markus; Haltmeier, Markus; Scherzer, Otmar

    2011-01-01

    Although the residual method, or constrained regularization, is frequently used in applications, a detailed study of its properties is still missing. This sharply contrasts the progress of the theory of Tikhonov regularization, where a series of new results for regularization in Banach spaces has been published in the recent years. The present paper intends to bridge the gap between the existing theories as far as possible. We develop a stability and convergence theory for the residual method in general topological spaces. In addition, we prove convergence rates in terms of (generalized) Bregman distances, which can also be applied to non-convex regularization functionals. We provide three examples that show the applicability of our theory. The first example is the regularized solution of linear operator equations on Lp-spaces, where we show that the results of Tikhonov regularization generalize unchanged to the residual method. As a second example, we consider the problem of density estimation from a finite number of sampling points, using the Wasserstein distance as a fidelity term and an entropy measure as regularization term. It is shown that the densities obtained in this way depend continuously on the location of the sampled points and that the underlying density can be recovered as the number of sampling points tends to infinity. Finally, we apply our theory to compressed sensing. Here, we show the well-posedness of the method and derive convergence rates both for convex and non-convex regularization under rather weak conditions. PMID:22345828

  19. A Predictive Model for Toxicity Effects Assessment of Biotransformed Hepatic Drugs Using Iterative Sampling Method.

    PubMed

    Tharwat, Alaa; Moemen, Yasmine S; Hassanien, Aboul Ella

    2016-12-09

    Measuring toxicity is one of the main steps in drug development. Hence, there is a high demand for computational models to predict the toxicity effects of the potential drugs. In this study, we used a dataset, which consists of four toxicity effects:mutagenic, tumorigenic, irritant and reproductive effects. The proposed model consists of three phases. In the first phase, rough set-based methods are used to select the most discriminative features for reducing the classification time and improving the classification performance. Due to the imbalanced class distribution, in the second phase, different sampling methods such as Random Under-Sampling, Random Over-Sampling and Synthetic Minority Oversampling Technique are used to solve the problem of imbalanced datasets. ITerative Sampling (ITS) method is proposed to avoid the limitations of those methods. ITS method has two steps. The first step (sampling step) iteratively modifies the prior distribution of the minority and majority classes. In the second step, a data cleaning method is used to remove the overlapping that is produced from the first step. In the third phase, Bagging classifier is used to classify an unknown drug into toxic or non-toxic. The experimental results proved that the proposed model performed well in classifying the unknown samples according to all toxic effects in the imbalanced datasets.

  20. A Predictive Model for Toxicity Effects Assessment of Biotransformed Hepatic Drugs Using Iterative Sampling Method

    PubMed Central

    Tharwat, Alaa; Moemen, Yasmine S.; Hassanien, Aboul Ella

    2016-01-01

    Measuring toxicity is one of the main steps in drug development. Hence, there is a high demand for computational models to predict the toxicity effects of the potential drugs. In this study, we used a dataset, which consists of four toxicity effects:mutagenic, tumorigenic, irritant and reproductive effects. The proposed model consists of three phases. In the first phase, rough set-based methods are used to select the most discriminative features for reducing the classification time and improving the classification performance. Due to the imbalanced class distribution, in the second phase, different sampling methods such as Random Under-Sampling, Random Over-Sampling and Synthetic Minority Oversampling Technique are used to solve the problem of imbalanced datasets. ITerative Sampling (ITS) method is proposed to avoid the limitations of those methods. ITS method has two steps. The first step (sampling step) iteratively modifies the prior distribution of the minority and majority classes. In the second step, a data cleaning method is used to remove the overlapping that is produced from the first step. In the third phase, Bagging classifier is used to classify an unknown drug into toxic or non-toxic. The experimental results proved that the proposed model performed well in classifying the unknown samples according to all toxic effects in the imbalanced datasets. PMID:27934950

  1. [Development of a Drug Discovery Method Targeted to Stromal Tissue].

    PubMed

    Kamada, Haruhiko

    2016-01-01

    Several diseases are characterized by alterations in the molecular distribution of vascular structures, presenting the opportunity to use monoclonal antibodies for clinical therapies. This pharmaceutical strategy, often referred to as "vascular targeting", has promise in promoting the discovery and development of selective biological drugs to regulate angiogenesis-related diseases such as cancer. Various experimental approaches have been utilized to discover accessible vascular markers of health and disease at the protein level. Our group has developed a new chemical proteomics technology to identify and quantify accessible vascular proteins in normal organs and at disease sites. Our developed methodology relies on the perfusion of animal models with suitable ester derivatives of biotin, which react with the primary amine groups of proteins as soon as the molecules are attached. This presentation reports biomedical applications based on vascular targeting strategies, as well as methodologies that have been used to discover new vascular targets. The identification of antigens located in the stromal tissue of pathological blood vessels may provide attractive targets for the development of antibody drugs. This method will also provide an efficient discovery target that could lead to the development of novel antibody drugs.

  2. Greedy and Linear Ensembles of Machine Learning Methods Outperform Single Approaches for QSPR Regression Problems.

    PubMed

    Kew, William; Mitchell, John B O

    2015-09-01

    The application of Machine Learning to cheminformatics is a large and active field of research, but there exist few papers which discuss whether ensembles of different Machine Learning methods can improve upon the performance of their component methodologies. Here we investigated a variety of methods, including kernel-based, tree, linear, neural networks, and both greedy and linear ensemble methods. These were all tested against a standardised methodology for regression with data relevant to the pharmaceutical development process. This investigation focused on QSPR problems within drug-like chemical space. We aimed to investigate which methods perform best, and how the 'wisdom of crowds' principle can be applied to ensemble predictors. It was found that no single method performs best for all problems, but that a dynamic, well-structured ensemble predictor would perform very well across the board, usually providing an improvement in performance over the best single method. Its use of weighting factors allows the greedy ensemble to acquire a bigger contribution from the better performing models, and this helps the greedy ensemble generally to outperform the simpler linear ensemble. Choice of data preprocessing methodology was found to be crucial to performance of each method too. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Drug related problems and pharmacist interventions in a geriatric unit employing electronic prescribing.

    PubMed

    Raimbault-Chupin, Mélina; Spiesser-Robelet, Laurence; Guir, Véronique; Annweiler, Cédric; Beauchet, Olivier; Clerc, Marie-Anne; Moal, Frédéric

    2013-10-01

    Computerised physician order entry (CPOE) and the integration of a pharmacist in clinical wards have been shown to prevent drug related problems (DRPs). The primary objective was to make an inventory of the DRPs and resident pharmacist on-ward interventions (PIs) identified in a geriatric acute care unit using CPOE system. The secondary objective was to evaluate the physicians' acceptance of the proposed interventions. A 26-bed geriatric ward of a 1,300-bed teaching hospital. A 6-month descriptive study with prescription analysis and recommendations to physicians by a resident pharmacist during five half days a week. Patients' characteristics, number of prescribed drugs per patient, nature and frequency of DRPs and PIs, physicians' acceptance and drugs questioned. Resident pharmacist reviewed 311 patients and identified 241 DRPs. One hundred and fifty-two patients (49 %) had at least one DRP (mean ± SD age 87 ± 6 years, mean ± SD number of prescribed drugs 10.7 ± 3.4). Most frequent DRPs were: untreated indication (n = 58, 24.1 %), dose too high (n = 46, 19.1 %), improper administration (n = 31, 12.9 %) and drug interactions (n = 23, 9.5 %). The rate of physicians' acceptance was 90.0 % (7.5 % refusals, 2.5 % not assessable). DRPs related to CPOE system misuse (n = 35, 14.5 %) appeared as a worrying phenomenon (e.g., errors in selecting dosage or unit, or duplication of therapy). A resident pharmacist detected various DRPs. Most PIs were accepted. DRPs related to the misuse of the CPOE system appeared potentially dangerous and need particular attention by healthcare professionals. The description of the DRPs is an essential step for implementation of targeted clinical pharmacy services in order to optimize pharmacists' job time.

  4. Domain Decomposition Methods for Problems in H(curl)

    NASA Astrophysics Data System (ADS)

    Calvo, Juan Gabriel

    Two domain decomposition methods for solving vector field problems posed in H(curl) and discretized with Nedelec finite elements are considered. These finite elements are conforming in H(curl). A two-level overlapping Schwarz algorithm in two dimensions is analyzed, where the subdomains are only assumed to be uniform in the sense of Peter Jones. The coarse space is based on energy minimization and its dimension equals the number of interior subdomain edges. Local direct solvers are based on the overlapping subdomains. The bound for the condition number depends only on a few geometric parameters of the decomposition. This bound is independent of jumps in the coefficients across the interface between the subdomains for most of the different cases considered. A bound is also obtained for the condition number of a balancing domain decomposition by constraints (BDDC) algorithm in two dimensions, with Jones subdomains. For the primal variable space, a continuity constraint for the tangential average over each interior subdomain edge is imposed. For the averaging operator, a new technique named deluxe scaling is used. The optimal bound is independent of jumps in the coefficients across the interface between the subdomains. Furthermore, a new coarse function for problems in three dimensions is introduced, with only one degree of freedom per subdomain edge. In all the cases, it is established that the algorithms are scalable. Numerical results that verify the results are provided, including some with subdomains with fractal edges and others obtained by a mesh partitioner.

  5. Training data selection method for prediction of anticancer drug effects using a genetic algorithm with local search.

    PubMed

    Hiroyasu, Tomoyuki; Miyabe, Yota; Yokouchi, Hisatake

    2011-01-01

    Here, we propose a training data selection method using a Support Vector Machine (SVM) to predict the effects of anticancer drugs. Conventionally, SVM is used for distinguishing between several types of data. However, in the method proposed here, the SVM is used to distinguish areas with only one or two types of data. The proposed method treats training data selection as an optimization problem and involves application of a genetic algorithm (GA). Moreover, GA with local search was applied to find the solution as the target problem was difficult to find. The composition method of GA for proposed method was examined. To determine its effectiveness, the proposed method was applied to an artificial anticancer drug data set. The verification results showed that the proposed method can be used to create a verifiable and predictable discriminant function by training data selection.

  6. A Minimum Variance Method for Problems in Radio Antenna Placement

    NASA Astrophysics Data System (ADS)

    Rao, M. V. P.; Ahuja, A. L.; Iyengar, S.; Iyer, K.; Khade, R.; Lodha, S.; Mehta, D.; Nagy, B.

    2009-09-01

    Aperture synthesis radio telescopes generate images of celestial bodies from data obtained from several radio antennas. Placement of these antennas has always been a source of interesting problems. Often, several potentially contradictory objectives like good image quality and low infra-structural cost have to be satisfied simultaneously. In this paper, we propose a general Minimum Variance method that focuses on obtaining good images in the presence of limiting situations. We show its versatility and goodness in three different situations: (a) placing the antennas on the ground to get a target Gaussian UV distribution (b) staggering the construction of a telescope in the event of staggered budgets and (c) whenever available, using the mobility of antennas to obtain a high degree of fault tolerance.

  7. A numerical method for interface problems in elastodynamics

    NASA Technical Reports Server (NTRS)

    Mcghee, D. S.

    1984-01-01

    The numerical implementation of a formulation for a class of interface problems in elastodynamics is discussed. This formulation combines the use of the finite element and boundary integral methods to represent the interior and the exteriro regions, respectively. In particular, the response of a semicylindrical alluvial valley in a homogeneous halfspace to incident antiplane SH waves is considered to determine the accuracy and convergence of the numerical procedure. Numerical results are obtained from several combinations of the incidence angle, frequency of excitation, and relative stiffness between the inclusion and the surrounding halfspace. The results tend to confirm the theoretical estimates that the convergence is of the order H(2) for the piecewise linear elements used. It was also observed that the accuracy descreases as the frequency of excitation increases or as the relative stiffness of the inclusion decreases.

  8. Multigrid methods for parabolic distributed optimal control problems

    NASA Astrophysics Data System (ADS)

    Borzì, Alfio

    2003-08-01

    Multigrid schemes that solve parabolic distributed optimality systems discretized by finite differences are investigated. Accuracy properties of finite difference approximation are discussed and validated. Two multigrid methods are considered which are based on a robust relaxation technique and use two different coarsening strategies: semicoarsening and standard coarsening. The resulting multigrid algorithms show robustness with respect to changes of the value of [nu], the weight of the cost of the control, is sufficiently small. Fourier mode analysis is used to investigate the dependence of the linear twogrid convergence factor on [nu] and on the discretization parameters. Results of numerical experiments are reported that demonstrate sharpness of Fourier analysis estimates. A multigrid algorithm that solves optimal control problems with box constraints on the control is considered.

  9. Multiresolution subspace-based optimization method for inverse scattering problems.

    PubMed

    Oliveri, Giacomo; Zhong, Yu; Chen, Xudong; Massa, Andrea

    2011-10-01

    This paper investigates an approach to inverse scattering problems based on the integration of the subspace-based optimization method (SOM) within a multifocusing scheme in the framework of the contrast source formulation. The scattering equations are solved by a nested three-step procedure composed of (a) an outer multiresolution loop dealing with the identification of the regions of interest within the investigation domain through an iterative information-acquisition process, (b) a spectrum analysis step devoted to the reconstruction of the deterministic components of the contrast sources, and (c) an inner optimization loop aimed at retrieving the ambiguous components of the contrast sources through a conjugate gradient minimization of a suitable objective function. A set of representative reconstruction results is discussed to provide numerical evidence of the effectiveness of the proposed algorithmic approach as well as to assess the features and potentialities of the multifocusing integration in comparison with the state-of-the-art SOM implementation.

  10. Potential drug interactions and duplicate prescriptions among ambulatory cancer patients: a prevalence study using an advanced screening method.

    PubMed

    van Leeuwen, Roelof W F; Swart, Eleonora L; Boom, Frits A; Schuitenmaker, Martin S; Hugtenburg, Jacqueline G

    2010-12-13

    The pharmacotherapeutic treatment of patients with cancer is generally associated with multiple side-effects. Drug interactions and duplicate prescriptions between anti-cancer drugs or interactions with medication to treat comorbidity can reinforce or intensify side-effects.The aim of the present study is to gain more insight into the prevalence of drug interactions and duplicate prescriptions among patients being treated in the outpatient day care departments for oncology and hematological illnesses. For the first time the prevalence of drug interactions with OTC-drugs in cancer patients will be studied. Possible risk factors for the occurrence of these drug-related problems will also be studied. A multicenter cross-sectional observational study of the epidemiology of drug interactions and duplicate prescriptions is performed among all oncology and hemato-oncology patients treated with systemic anti-cancer drugs at the oncology and hematology outpatient day care department of the VU University medical center and the Zaans Medical Center. In this article the prevalence of potential drug interactions in outpatient day-care patients treated with anti-cancer agents is studied using a novel more extensive screening method. If this study shows a high prevalence of drug interactions clinical pharmacists and oncologists must collaborate to develop a pharmaceutical screening programme, including an automated electronic warning system, to support drug prescribing for ambulatory cancer patient. This programme could minimize the occurrence of drug related problems such as drug interactions and duplicate prescriptions, thereby increasing quality of life. This study is registered, number NTR2238.

  11. Characterization of drug-related problems identified by clinical pharmacy staff at Danish hospitals.

    PubMed

    Kjeldsen, Lene Juel; Birkholm, Trine; Fischer, Hanne; Graabæk, Trine; Kibsdal, Karina Porsborg; Ravn-Nielsen, Lene Vestergaard; Truelshøj, Tania Holtum

    2014-08-01

    In 2010, a database of drug related problems (DRPs) was implemented to assist clinical pharmacy staff in documenting clinical pharmacy activities locally. A study of quality, reliability and generalisability showed that national analyses of the data could be conducted. Analyses at the national level may help identify and prevent DRPs by performing national interventions. The aim of the study was to explore the DRP characteristics as documented by clinical pharmacy staff at hospital pharmacies in the Danish DRP-database during a 3-year period. Danish hospital pharmacies. Data documented in the DRP-database during the initial 3 years after implementation were analyzed retrospectively. The DRP-database contains DRPs reported at hospitals by clinical pharmacy staff. The analyses focused on DRP categories, implementation rates and drugs associated with the DRPs. Characteristics of DRPs. In total, 72,044 DRPs were documented in the DRP-database during the first 3 years of implementation, and the number of documented DRPs increased every year. An overall stable implementation rate of approximately 58 % was identified. The DRPs identified were multi-facetted, however evenly distributed for each of the 3 years. The most frequently identified DRP categories were: "Dose", followed by "Nonadherence to guidelines" and "Supplement to treatment". The highest implementation rates were found for the following DRP categories: "Non-adherence to guidelines" (79 %) followed by "Therapeutic duplication" (73 %) and "Dosing time and interval" (70 %). Even though the top 25 drugs were involved in 58 % of all DRPs, multiple drugs were associated with DRPs. The drugs most frequently involved in DRPs were paracetamol (4.6 % of all DRPs), simvastatin (3.0 %), lansoprazole (2.7 %), morphine (2.6 %) and alendronic acid (2.4 %). The study found that a national database on DRPs contained multi-facetted DRPs, however evenly distributed for each of the 3 years. Even though the top 25 drugs were

  12. Psychosocial interventions to reduce alcohol consumption in concurrent problem alcohol and illicit drug users.

    PubMed

    Klimas, Jan; Tobin, Helen; Field, Catherine-Anne; O'Gorman, Clodagh S M; Glynn, Liam G; Keenan, Eamon; Saunders, Jean; Bury, Gerard; Dunne, Colum; Cullen, Walter

    2014-12-03

    Problem alcohol use is common among illicit drug users and is associated with adverse health outcomes. It is also an important factor contributing to a poor prognosis among drug users with hepatitis C virus (HCV) as it impacts on progression to hepatic cirrhosis or opiate overdose in opioid users. To assess the effects of psychosocial interventions for problem alcohol use in illicit drug users (principally problem drug users of opiates and stimulants). We searched the Cochrane Drugs and Alcohol Group trials register (June 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 11, June 2014), MEDLINE (1966 to June 2014); EMBASE (1974 to June 2014); CINAHL (1982 to June 2014); PsycINFO (1872 to June 2014) and the reference lists of eligible articles. We also searched: 1) conference proceedings (online archives only) of the Society for the Study of Addiction, International Harm Reduction Association, International Conference on Alcohol Harm Reduction and American Association for the Treatment of Opioid Dependence; 2) online registers of clinical trials: Current Controlled Trials, Clinical Trials.org, Center Watch and the World Health Organization International Clinical Trials Registry Platform. Randomised controlled trials comparing psychosocial interventions with another therapy (other psychosocial treatment, including non-pharmacological therapies, or placebo) in adult (over the age of 18 years) illicit drug users with concurrent problem alcohol use. We used the standard methodological procedures expected by The Cochrane Collaboration. Four studies, involving 594 participants, were included. Half of the trials were rated as having a high or unclear risk of bias. The studies considered six different psychosocial interventions grouped into four comparisons: (1) cognitive-behavioural coping skills training versus 12-step facilitation (one study; 41 participants), (2) brief intervention versus treatment as usual (one study; 110

  13. Development and validation of the Slovenian drug-related problem classification system based on the PCNE classification V 6.2.

    PubMed

    Horvat, Nejc; Kos, Mitja

    2016-08-01

    Background Classifying drug-related problems increases pharmacists' awareness of patients' drug-related needs and supports the development of counselling skills through increased awareness of the nature and frequency of drug-related problems. No standardised classification system was used in daily pharmacy practice in Slovenia. Objective To translate, upgrade and validate the Pharmaceutical Care Network Europe (PCNE) classification V 6.2 for use in Slovenian community pharmacies. Setting Expert panel meetings at the Faculty of Pharmacy and home-based classification validation. Methods The PCNE classification V 6.2 was translated to Slovenian language by forward-backward translation procedure. An expert panel consisting of nine practicing pharmacists upgraded the content of the translated version. Thirty-one community pharmacists validated this version with the PCNE set of 18 patient cases by coding problems, risk factors and interventions they believed were present in each case. The expert panel discussed the results and upgraded the classification accordingly. Afterwards, 33 community pharmacists validated the upgraded version with a set of 40 actual Slovenian pharmacy patient cases. Based on the results, the expert panel formed a final version of the classification. Main outcome measure Coding consistency between community pharmacists. Results The expert panel performed some major modifications to the PCNE classification V 6.2: the potential problem was added as a sub domain to problems domain; the term adverse drug event was used instead of adverse drug reaction; the causes domain was renamed to risk factors and its sub domains were organized into prescribing, dispensing and use of drugs; dispensing errors were specified; use of drugs was organized into intentional and unintentional use of drugs; the sub domains in the interventions domain were divided according to the communication and agreement with the prescriber. The average coding consistencies in the first

  14. Canonical finite element method for solving nonconvex variational problems to post buckling beam problem

    NASA Astrophysics Data System (ADS)

    Ali, Elaf Jaafar; Gao, David Yang

    2016-10-01

    The goal of this paper is to solve the post buckling phenomena of a large deformed elastic beam by a canonical dual mixed finite element method (CD-FEM). The total potential energy of this beam is a nonconvex functional which can be used to model both pre-and post-buckling problems. Different types of dual stress interpolations are used in order to verify the triality theory. Applications are illustrated with different boundary conditions and external loads by using semi-definite programming (SDP) algorithm. The results show that the global minimum of the total potential energy is stable buckled configuration, the local maximum solution leads to the unbuckled state, and both of these two solutions are numerically stable. While the local minimum is unstable buckled configuration and very sensitive to both stress interpolations and the external loads.

  15. [Drug-resistant malaria: problems with its definition and technical approaches].

    PubMed

    Basco, L; Ringwald, P

    2000-01-01

    % inhibitory concentration IC50). The in vitro assay not only yields quantitative results, it also determines the phenotype of the parasite independently of the immune and physiopathological conditions of the host. However, this in vitro assay requires highly skilled personnel and laboratory equipment. In addition, parasites isolated from patients who have taken medication on their own initiative a few days before consultation usually do not grow in vitro and the interpretation of assay results for patients with multiple infections may be equivocal. One of the major problems with in vitro tests is the determination of the threshold IC50 values that distinguish susceptible from resistant parasites. There are currently no fully validated cut-off points for assessing in vitro resistance. Despite these shortcomings, in vitro tests are of value, particularly if performed in parallel with the in vivo test. Molecular biology has made a major contribution to our understanding of the mechanisms of drug resistance. Discrete point mutations in the genes encoding dihydrofolate reductase and dihydropteroate synthase are strongly associated with resistance in vitro to pyrimethamine and sulfadoxine, respectively. Preliminary results have also suggested that these mutations are responsible for the failure of sulfadoxine-pyrimethamine combination treatment. No causal relationship between discrete polymorphisms in the candidate genes and in vitro chloroquine resistance has yet been established. High-performance liquid chromatography is being increasingly used to determine the plasma concentrations of antimalarial drugs in patients with prophylactic or therapeutic failure, to check that the failure of the treatment is not due to inadequate levels of the drug in the patient. Taking into account all these aspects of resistance to antimalarial drugs we think that the WHO definition of drug resistance is now inadequate. (ABSTRACT TRUNCATED)

  16. A survey of electronic drug information resources and identification of problems associated with the differing vocabularies used to key them.

    PubMed Central

    Gnassi, J. A.; Barnett, G. O.

    1993-01-01

    Drug information resources are increasingly becoming electronically available. They differ in scope, granularity, and purpose. These considerations have shaped the selection of dissimilar drug name keys, complicating access. An abbreviated and simplified historical context of the development of official controlled vocabularies and their relationships is followed by a review of the kinds of information available in several electronic drug information resources. The key vocabularies used are discussed with examples. Problems using the differing terms of the resource vocabularies are identified. PMID:8130551

  17. Parent Drug-Use Problems and Adult Intimate Relations: Associations among Community Samples of Young Adult Women and Men.

    ERIC Educational Resources Information Center

    Newcomb, Michael D.; Rickards, Shannae

    1995-01-01

    Used community samples to determine the effects of childhood family support or dysfunction and the extent of parent drug-use problems on adult intimacy issues, such as sexual satisfaction. Results showed that parent drug-use predicted poor family support; family support correlated strongly with good adult intimate relations. (RJM)

  18. Child maltreatment, parent alcohol and drug-related problems, polydrug problems, and parenting practices: a test of gender differences and four theoretical perspectives.

    PubMed

    Locke, Thomas F; Newcomb, Michael

    2004-03-01

    The authors tested how adverse childhood experiences (child maltreatment and parent alcohol- and drug-related problems) and adult polydrug use (as a mediator) predict poor parenting in a community sample (237 mothers and 81 fathers). These relationships were framed within several theoretical perspectives, including observational learning, impaired functioning, self-medication, and parentification-pseudomaturity. Structural models revealed that child maltreatment predicted poor parenting practices among mothers. Parent alcohol- and drug-related problems had an indirect detrimental influence on mothers' parenting and practices through self-drug problems. Among fathers, emotional neglect experienced as a child predicted lack of parental warmth more parental neglect, and sexual abuse experienced as a child predicted a rejecting style of parenting.

  19. [Drug design ideas and methods of Chinese herb prescriptions].

    PubMed

    Ren, Jun-guo; Liu, Jian-xun

    2015-09-01

    The new drug of Chinese herbal prescription, which is the best carrier for the syndrome differentiation and treatment of Chinese medicine and is the main form of the new drug research and development, plays a very important role in the new drug research and development. Although there are many sources of the prescriptions, whether it can become a new drug, the necessity, rationality and science of the prescriptions are the key to develop the new drug. In this article, aiming at the key issues in prescriptions design, the source, classification, composition design of new drug of Chinese herbal prescriptions are discussed, and provide a useful reference for research and development of new drugs.

  20. Radiation methods for decontamination of liquid wastes and ecological problems

    SciTech Connect

    Shubin, V.N.; Brusentseva, S.A.; Vysotskaya, N.A.

    1986-01-01

    The authors discuss several possible approaches to the use of radiation for the purposes of rational use of water resources and protecting them from pollution and depletion. The authors note that radiation decontamination makes it possible to solve a number of important problems in protecting fundamental elements of the biosphere by: reducing the uptake of fresh water from natural sources for industrial and household needs and sharply cutting the release of unpurified waste water by creating circulating water systems based on rapid methods of thorough purification; employing a combination of different physical and chemical methods with a final stage that uses radiation-prolonged adsorption to give the water a high degree of purity; preventing bacterial contamination of soils when liquid and semiliquid wastes from cities and livestock farms are used as fertilizers; utilizing the excess active sludges that accumulate in biological treatment factilities as feed additives and fertilizer; and eliminating the release to the atmosphere of effluents from the incineration of highly polluted waste water which often contains carcinogenic and poisonous substances.

  1. Using Problem Fields as a Method of Change.

    ERIC Educational Resources Information Center

    Pehkonen, Erkki

    1992-01-01

    Discusses the rationale and use of problem fields which are sets of related and/or connected open-ended problem-solving tasks within mathematics instruction. Polygons with matchsticks and the number triangle are two examples of problem fields presented along with variations in conditions that promote other matchstick puzzles. (11 references) (JJK)

  2. Skill Acquisition: Compilation of Weak-Method Problem Solutions.

    ERIC Educational Resources Information Center

    Anderson, John R.

    According to the ACT theory of skill acquisition, cognitive skills are encoded by a set of productions, which are organized according to a hierarchical goal structure. People solve problems in new domains by applying weak problem-solving procedures to declarative knowledge they have about this domain. From these initial problem solutions,…

  3. Validated spectrophotometric methods for determination of some oral hypoglycemic drugs.

    PubMed

    Farouk, M; Abdel-Satar, O; Abdel-Aziz, O; Shaaban, M

    2011-02-01

    Four accurate, precise, rapid, reproducible, and simple spectrophotometric methods were validated for determination of repaglinide (RPG), pioglitazone hydrochloride (PGL) and rosiglitazone maleate (RGL). The first two methods were based on the formation of a charge-transfer purple-colored complex of chloranilic acid with RPG and RGL with a molar absorptivity 1.23 × 103 and 8.67 × 102 l•mol-1•cm-1 and a Sandell's sensitivity of 0.367 and 0.412 μg•cm-2, respectively, and an ion-pair yellow-colored complex of bromophenol blue with RPG, PGL and RGL with molar absorptivity 8.86 × 103, 6.95 × 103, and 7.06 × 103 l•mol-1•cm-1, respectively, and a Sandell's sensitivity of 0.051 μg•cm-2 for all ion-pair complexes. The influence of different parameters on color formation was studied to determine optimum conditions for the visible spectrophotometric methods. The other spectrophotometric methods were adopted for demtermination of the studied drugs in the presence of their acid-, alkaline- and oxidative-degradates by computing derivative and pH-induced difference spectrophotometry, as stability-indicating techniques. All the proposed methods were validated according to the International Conference on Harmonization guidelines and successfully applied for determination of the studied drugs in pure form and in pharmaceutical preparations with good extraction recovery ranges between 98.7-101.4%, 98.2-101.3%, and 99.9-101.4% for RPG, PGL, and RGL, respectively. Results of relative standard deviations did not exceed 1.6%, indicating that the proposed methods having good repeatability and reproducibility. All the obtained results were statistically compared to the official method used for RPG analysis and the manufacturers methods used for PGL and RGL analysis, respectively, where no significant differences were found.

  4. Relationship of drug-addicted patients' personality disorders to social problem-solving changes during the rehabilitation process.

    PubMed

    Kolesnikova, Jelena; Miezitis, Solveiga; Osis, Guntars

    2013-08-01

    Drug-addicted patients exhibit various personality disorders that interfere with their adaptation to society, as well as their ability to participate in the rehabilitation process. The Latvian Rehabilitation Programme for drug addicts includes social problem-solving training to help patients reintegrate into society. However, the role of personality disorders has not been investigated in relation to this process. The aim of the study is to assess whether personality disorders predict changes in dimensions of social problem-solving after 6 months of rehabilitation for drug-addicted patients. The sample of this study consists of 31 drug-addicted patients from the Latvian rehabilitation centres aged 21-35 (females 21%, males 79%). Two inventories are used: the Social Problem-Solving Inventory--Revised (SPSI-R) and Millon(TM) Clinical Multiaxial Inventory--III (MCMI-III) adapted into Russian. Results of the study indicated that some MCMI-III personality disorders (Schizoid and Histrionic) negatively predicted SPSI-R Positive problem orientation, and narcissistic disorder positively predicted SPSI-R Avoidance style after 6 months in the Latvian Rehabilitation Programme. The other personality disorders did not predict social problem-solving dimensions. The results of the study suggest that some personality disorders are related to changes in social problem-solving dimensions for drug-addicted patients. Hence, it is important to consider the implications of particular personality disorders to facilitate the implementation of social problem-solving rehabilitation programmes.

  5. Methodical problems of magnetic field measurements in umbra of sunspots

    NASA Astrophysics Data System (ADS)

    Lozitska, N. I.; Lozitsky, V. G.; Andryeyeva, O. A.; Akhtemov, Z. S.; Malashchuk, V. M.; Perebeynos, V. A.; Stepanyan, N. N.; Shtertser, N. I.

    2015-02-01

    Visual measurements of magnetic field strengths in sunspot umbra provide data on magnetic field strength modulus directly, i.e., irrespective from any solar atmosphere model assumptions. In order to increase the accuracy of calculation of the solar magnetic indexes, such as B ‾ max or Bsp, the inclusion of all available data from different observatories is needed. In such measurements some methodical problems arise, which bring about inconsistency of the data samples combined from different sources; this work describes the problems at hand and proposes solutions on how to eliminate the inconsistencies. Data sets of sunspot magnetic field strength visual measurements from Mt. Wilson, Crimea and Kyiv observatories in 2010-2012 have been processed. It is found that two measurement modes of Zeeman split, σ → σ and σ → π, yield almost the same results, if data rows are long enough (over ∼100 sunspots in central area of Sun, r < 0.7 R). It is generally held that the most reliable measurement results are obtained for magnetic fields that exceed 2400 G. However, the empirical comparison of the internal data consistency of the samples produced by different observers shows that for reliable results this limit can be lowered down to 1100 G. To increase the precision of measurements, empirical calibration of the line-shifter is required by using closely positioned telluric lines. Such calibrations have been performed at Kyiv and Crimea, but as far as we know, it has not been carried out at Mt. Wilson observatory after its diffraction grate was replaced in 1994. Taking into consideration the highest quality and coverage of Mt. Wilson sunspot observational data, the authors are convinced that reliable calibration of its instrument by narrow telluric lines is definitely required.

  6. Multiple-drug resistant enterococci: the nature of the problem and an agenda for the future.

    PubMed Central

    Huycke, M. M.; Sahm, D. F.; Gilmore, M. S.

    1998-01-01

    Enterococci, leading causes of nosocomial bacteremia, surgical wound infection, and urinary tract infection, are becoming resistant to many and sometimes all standard therapies. New rapid surveillance methods are highlighting the importance of examining enterococcal isolates at the species level. Most enterococcal infections are caused by Enterococcus faecalis, which are more likely to express traits related to overt virulence but--for the moment--also more likely to retain sensitivity to at least one effective antibiotic. The remaining infections are mostly caused by E. faecium, a species virtually devoid of known overt pathogenic traits but more likely to be resistant to even antibiotics of last resort. Effective control of multiple-drug resistant enterococci will require 1) better understanding of the interaction between enterococci, the hospital environment, and humans, 2) prudent antibiotic use, 3) better contact isolation in hospitals and other patient care environments, and 4) improved surveillance. Equally important is renewed vigor in the search for additional drugs, accompanied by the evolution of new therapeutic paradigms less vulnerable to the cycle of drug introduction and drug resistance. PMID:9621194

  7. Ophthalmic drug dosage forms: characterisation and research methods.

    PubMed

    Baranowski, Przemysław; Karolewicz, Bożena; Gajda, Maciej; Pluta, Janusz

    2014-01-01

    This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommended in vitro and in vivo studies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient's compliance.

  8. Ophthalmic Drug Dosage Forms: Characterisation and Research Methods

    PubMed Central

    Baranowski, Przemysław; Karolewicz, Bożena; Gajda, Maciej; Pluta, Janusz

    2014-01-01

    This paper describes hitherto developed drug forms for topical ocular administration, that is, eye drops, ointments, in situ gels, inserts, multicompartment drug delivery systems, and ophthalmic drug forms with bioadhesive properties. Heretofore, many studies have demonstrated that new and more complex ophthalmic drug forms exhibit advantage over traditional ones and are able to increase the bioavailability of the active substance by, among others, reducing the susceptibility of drug forms to defense mechanisms of the human eye, extending contact time of drug with the cornea, increasing the penetration through the complex anatomical structure of the eye, and providing controlled release of drugs into the eye tissues, which allows reducing the drug application frequency. The rest of the paper describes recommended in vitro and in vivo studies to be performed for various ophthalmic drugs forms in order to assess whether the form is acceptable from the perspective of desired properties and patient's compliance. PMID:24772038

  9. How online counselling can support partners of individuals with problem alcohol or other drug use.

    PubMed

    Wilson, Samara R; Rodda, Simone; Lubman, Dan I; Manning, Victoria; Yap, Marie B H

    2017-07-01

    Problematic alcohol and other drug (AOD) use impacts partners heavily, with an increased risk of experiencing domestic violence, financial stressors, health problems and relationship challenges. However, partners often do not seek help or support due to a range of barriers (e.g., shame, stigma, practical constraints). Online counselling may facilitate help-seeking by overcoming many of these barriers, however research is needed to explore what motivates partners to contact online counselling services, their experiences and needs, and how partners can be best supported online. One hundred transcripts of partners of individuals with problem AOD use were sampled from a 24-hour national AOD synchronous online chat counselling service. Descriptive content analysis was used to investigate themes related to help-seeking. Three broad themes, with seven sub-themes, were identified: (i) the reason for accessing online counselling (seeking advice, wanting to talk), (ii) discussing help-seeking and coping processes (past/present help-seeking or coping strategies, barriers and facilitators to seeking help and change), and (iii) planning for future assistance (future planning, treatment preferences). Partners wanted to talk about their concerns with a non-judgemental professional. However, the majority of help-seekers wanted advice and assistance in problem-solving, coping and the process of seeking further help. Future studies need to examine the impact of online help-seeking by partners. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Boundary-integral methods in elasticity and plasticity. [solutions of boundary value problems

    NASA Technical Reports Server (NTRS)

    Mendelson, A.

    1973-01-01

    Recently developed methods that use boundary-integral equations applied to elastic and elastoplastic boundary value problems are reviewed. Direct, indirect, and semidirect methods using potential functions, stress functions, and displacement functions are described. Examples of the use of these methods for torsion problems, plane problems, and three-dimensional problems are given. It is concluded that the boundary-integral methods represent a powerful tool for the solution of elastic and elastoplastic problems.

  11. Electrospinning: methods and development of biodegradable nanofibres for drug release.

    PubMed

    Ashammakhi, N; Wimpenny, I; Nikkola, L; Yang, Y

    2009-02-01

    It is clear that nanofibrous structures can be used as tools for many applications. It is already known that electrospinning is a highly versatile method of producing nanofibres and recent developments in the technique of electrospinning have led to the development of aligned nanofibres and biphasic, core-sheath fibres which can be used to encapsulate different materials from molecules to cells. Natural extracellular matrix (ECM) contains fibres in both micro and nano-scales and provides a structural scaffold which allows cells to localize, migrate, proliferate and differentiate. Polymer nanofibres can provide the structural cues of ECM. However, current literature gives new hope to further functionalising polymeric nanofibres by using them for drug delivery devices and improving their design to improve control of delivery. By encapsulating active agents within nanofibres (multifunctional nanofibres), a degree of control can be exerted over the release of encapsulated agents and therefore, the behaviour of cells can be manipulated for developing effective therapies and is extremely encouraging in the tissue engineering field by combining factors like fibre diameter, alignment and chemicals in new ways. Such multifunctional nanofibre-based systems are already being investigated in vivo. Experiments have shown the significant potential for treatments of disease and engineering of neural and bone tissues. Further, phase III clinical trials of nanofibrous patches for applications in wound treatment were encouraging. Hopefully, clinical applications of these drug delivery devices will follow, to enhance regenerative medicine applications.

  12. Neurologist knowledge about interactions between antiepileptic drugs and contraceptive methods.

    PubMed

    Suto, Hilda S; Braga, Giordana C; Scarpellini, Giuliano R; Takeuchi, Leandro I; Martins, Ana P; Leite, João P; Vieira, Carolina S

    2016-09-01

    To evaluate neurologists' knowledge of contraceptive counseling for women receiving antiepileptic drugs (AEDs). An interview-based survey was conducted from February 2 to June 30, 2015, among neurologists working in Ribeirão Preto, Brazil. Direct interviews were conducted using a questionnaire that assessed knowledge of the pharmacological interactions between various contraceptive methods and six AEDs (carbamazepine, phenobarbital, topiramate, phenytoin, lamotrigine, and valproate) on the basis of WHO medical eligibility criteria for contraceptive use. Among 42 neurologists who participated, 32 (76%) stated that they treated women with epilepsy and provided them with counseling for family planning. Overall, 34 (81%) recommended the use of a copper intrauterine device irrespective of the AED used, and 26 (60%) stated that they co-prescribed AEDs and hormonal contraceptives. Although 39 (93%) neurologists had knowledge that AEDs might contraindicate the use of some contraceptives, their knowledge regarding the specific drug interactions was lacking. Furthermore, 34 (81%) had no knowledge of WHO medical eligibility criteria for contraceptive use. Although most neurologists interviewed had knowledge of interactions between AEDs and hormonal contraceptives, they did not know which specific AEDs interacted with these agents. Copyright © 2016 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  13. A Method for Overcoming the Problem of Concept-Scale Interaction in Semantic Differential Research

    ERIC Educational Resources Information Center

    Bynner, John; Romney, David

    1972-01-01

    Data collected in a study of hospital staff attitudes to drug addicts and other types of patients are used to illustrate the problem of concept-scale interaction in semantic differential research. (Authors)

  14. Assessment of the clinical and economic outcomes of pharmacy interventions in drug-related problems.

    PubMed

    Westerlund, Tommy; Marklund, B

    2009-06-01

    Due to drug-related problems (DRPs) that cause both unnecessary suffering and huge costs to society, many patients do not receive the intended beneficial effects of their treatment. Pharmacy practitioners have a key responsibility to respond to these problems, but more knowledge about the expected outcomes of their interventions is needed. The objective of the study was to assess the clinical and economic outcomes of community pharmacy interventions in patient DRPs. Drug-related problems in 13 different patient groups were identified and classified, according to the Westerlund System, by pharmacy practitioners from 89 Swedish pharmacies in 2006. The cases were documented in the pharmacy software and transferred to the national DRP database. An assessment model was developed and applied by the researchers (a pharmacist and a physician). This assessment was used to conduct a retrospective review by analysing the DRP and intervention documentation, in particular case descriptions from free text fields. Expected clinical patient outcomes of pharmacy interventions were judged in terms of improved therapeutic effects and prevented or relieved adverse drug reactions (ADRs). The review also assessed the expected patient outcomes with regard to initiated or avoided primary care contacts or avoided hospitalisations. The resulting hypothetically avoided direct societal costs and the estimated pharmacy personnel costs were calculated for the study and extrapolated to the Swedish nationwide level on an annual basis, to demonstrate the potential of national cost savings by pharmacy DRP-interventions. In 358 cases (68%), the pharmacy interventions were judged to have produced an improved therapeutic effect in the patient, and in 172 cases (32%) to have prevented or relieved ADRs. Primary care contacts were initiated for 151 patients (29%), and pharmacy interventions were assessed to have saved 68 (13%) primary care contacts and 16 (3%) future hospitalisations. The potential

  15. Drug-related problems associated with self-medication and medication guided by prescription: A pharmacy-based survey

    PubMed Central

    Panda, Abinash; Pradhan, Supriya; Mohapatra, Gurukrushna; Mohapatra, Jigyansa

    2016-01-01

    Objectives: The objective of this study is to identify and compare the nature of the drug-related problems (DRPs) associated with self-medication and non-self-medication (drug use guided by a prescription). Materials and Methods: The cross-sectional, observational study was conducted on 1100 adult participants at a convenience sample of six retail private pharmacy counters. The data collection form was based on the Pharmaceutical Care Network Europe version 6.2 classification for DRPs. Descriptive statistics was used to represent the prevalence of DRPs. Chi-square test was used to find out the association between the type of medication and DRPs. Odds ratio (OR) with confidence interval (CI) was computed to find the factors determining the occurrence of DRPs. P < 0.05 was considered to be statistically significant. Data were analyzed using SPSS version 16.0. Results: The prevalence of self-medication was 18.72%. The prevalence of DRPs was 17.36%. In the self-medication group, the prevalence of DRPs was high (40.78%) as compared to the non-self-medication group (11.97%). DRP related to inappropriate drug dosing was observed in 44.83% and 40.45% subjects in self-medication and non-self-medication group, respectively (P < 0.001). The subjects in the self-medication group were about 5 times likely to have a DRP (OR: 5.06, CI: 3.59-7.14, P < 0.001). Conclusions: Self-medication is associated with a higher risk of various DRPs. Since retail pharmacy outlet is often the first point of contact between the patient and the health care system in a developing country, interventions like drug information activities at the retail pharmacy is likely to bring down the DRPs associated with self-medication. PMID:27721536

  16. Suicide attempts by poisoning in Hanoi, Vietnam: methods used, mental problems, and history of mental health care.

    PubMed

    Tuan, Nguyen Van; Dalman, Christina; Thiem, Nguyen Viet; Nghi, Tran Viet; Allebeck, Peter

    2009-01-01

    The objective of this paper was to investigate methods of poisoning, presence of mental problems, and the rate of psychiatric care among suicide attempters in Vietnam. Three hundred and nine suicide attempters by poisoning admitted to Bach Mai Hospital's Poison Control Center were investigated by trained nurses and qualified psychiatrists. Standardized questionnaires were used to assess methods of suicide, presence of mental problems, and psychiatric care. The most common methods were poisoning by psychotropic drugs in urban, and pesticides in rural areas. ICD-10 confirmed disorders were present in 68% of the cases and 73% rated positive on SRQ-20. Most patients were not in contact with psychiatric care. Restrictions on availability and handling of drugs and pesticides should be reinforced. Better infrastructures are needed for identification and treatment of persons with mental disorders.

  17. Characterisation of Drug-Related Problems and Associated Factors at a Clinical Pharmacist Service-Naïve Hospital in Northern Sweden.

    PubMed

    Peterson, Cecilia; Gustafsson, Maria

    2017-06-01

    Polypharmacy and increased sensitivity to side effects cause adverse drug events, drug-drug interactions and medication errors in the elderly. The objective of this study was to investigate the prevalence and type of drug-related problems and associated factors among patients admitted to a clinical pharmacist service-naïve medical ward in an inland hospital in northern Sweden. During September-November 2015 and February-April 2016, clinical pharmacists working as part of a ward team on the medical ward conducted 103 medication reviews. Drug-related problems were identified and classified. Associated factors, drug classes and specific drugs involved were also investigated. The clinical pharmacists identified 133 drug-related problems in 66% [68/103] of the study population. The most common drug-related problems in this study were inappropriate drug use and interactions. Cardiovascular drugs and psychotropic drugs were most commonly involved. Drug-related problems were more frequently observed at higher age, increasing number of drugs prescribed and in patients with reduced renal function. In the multivariate analysis, only the number of prescribed drugs was still significant. Drug-related problems were commonly observed among patients admitted to the medical ward. Medication reviews conducted by clinical pharmacists as part of a ward team resulted in several interventions to improve the patients' drug treatment.

  18. An efficient iterative method for the generalized Stokes problem

    SciTech Connect

    Sameh, A.; Sarin, V.

    1996-12-31

    This paper presents an efficient iterative scheme for the generalized Stokes problem, which arises frequently in the simulation of time-dependent Navier-Stokes equations for incompressible fluid flow. The general form of the linear system is where A = {alpha}M + vT is an n x n symmetric positive definite matrix, in which M is the mass matrix, T is the discrete Laplace operator, {alpha} and {nu} are positive constants proportional to the inverses of the time-step {Delta}t and the Reynolds number Re respectively, and B is the discrete gradient operator of size n x k (k < n). Even though the matrix A is symmetric and positive definite, the system is indefinite due to the incompressibility constraint (B{sup T}u = 0). This causes difficulties both for iterative methods and commonly used preconditioners. Moreover, depending on the ratio {alpha}/{nu}, A behaves like the mass matrix M at one extreme and the Laplace operator T at the other, thus complicating the issue of preconditioning.

  19. Effects of medication review on drug-related problems in patients using automated drug-dispensing systems: a pragmatic randomized controlled study.

    PubMed

    Kwint, Henk Frans; Faber, Adrianne; Gussekloo, Jacobijn; Bouvy, Marcel L

    2011-04-01

    There are concerns that automated drug dispensing may increase inappropriate drug use. Automated dispensing could lead to perpetual repeating of drug therapies without the necessary re-evaluation. The aim of this study was to examine the effect of a pharmacist-led medication review on drug-related problems (DRPs) in older patients receiving their drugs via automated dispensing. This was a pragmatic randomized controlled study conducted in primary care. Patients were recruited from six Dutch community pharmacies. They were eligible if they lived at home, were aged ≥ 65 years, and used five or more different drugs, of which at least one had to be dispensed via an automated system. Patients were randomly allocated to receive a medication review at the start of the study (intervention group) or after 6 months (waiting-list group). Each patient was independently reviewed by two pharmacist reviewers. The results of these medication reviews were sent to the community pharmacist to be discussed with the patient's general practitioner (GP). The primary outcome measure was the number of DRPs leading to a recommendation for drug change. Secondary outcomes were the total number of drug changes and the number of drug changes related to a recommendation. In order to analyse drug changes, medication records were collected 6 months after the medication review or index date in the waiting-list group. Potential DRPs were classified using the DOCUMENT classification. There were no baseline differences between the 63 patients in the intervention group and the 55 patients in the waiting-list group with respect to age, sex, number of drugs per patient and type of drug prescribed. The mean number of DRPs per patient at baseline in the intervention group and waiting list combined was 8.5, with no difference between the groups. At baseline, the mean number of DRPs leading to a recommendation for drug change was 4.5 per patient and did not differ between the two groups. After 6 months

  20. An Application of Wedelin's Method to Railway Crew Scheduling Problem

    NASA Astrophysics Data System (ADS)

    Miura, Rei; Imaizumi, Jun; Fukumura, Naoto; Morito, Susumu

    So many scheduling problems arise in railway industries. One of the typical scheduling problems is Crew Scheduling Problem. Much attention has been paid to this problem by a lot of researchers, but many studies have not been done to the problems in railway industries in Japan. In this paper, we consider a railway crew scheduling problem in Japan. The problem can be formulated into Set Covering Problem (SCP). In SCP, a row corresponds to a trip representing a minimal task and a column corresponds to a pairing representing a sequence of trips performed by a certain crew. Many algorithms have been developed and proposed for it. On the other hand, in practical use, it is important to investigate how these algorithms behave and work on a certain problem. Therefore, we focus on Wedelin's algorithm, which is based on Lagrange relaxation and is known as one of the high performance algorithms for SCP, and mainly examine the basic idea of this algorithm. Furthermore, we show effectiveness of this procedure through computational experiments on instances from Japanese railway.

  1. An immuno-chemo-proteomics method for drug target deconvolution.

    PubMed

    Saxena, Chaitanya; Zhen, Eugene; Higgs, Richard E; Hale, John E

    2008-08-01

    Chemical proteomics is an emerging technique for drug target deconvolution and profiling the toxicity of known drugs. With the use of this technique, the specificity of a small molecule inhibitor toward its potential targets can be characterized and information thus obtained can be used in optimizing lead compounds. Most commonly, small molecules are immobilized on solid supports and used as affinity chromatography resins to bind targets. However, it is difficult to evaluate the effect of immobilization on the affinity of the compounds to their targets. Here, we describe the development and application of a soluble probe where a small molecule was coupled with a peptide epitope which was used to affinity isolate binding proteins from cell lysate. The soluble probe allowed direct verification that the compound after coupling with peptide epitope retained its binding characteristics. The PKC-alpha inhibitor Bisindolylmaleimide-III was coupled with a peptide containing the FLAG epitope. Following incubation with cellular lysates, the compound and associated proteins were affinity isolated using anti-FLAG antibody beads. Using this approach, we identified the known Bisindolylmaleimide-III targets, PKC-alpha, GSK3-beta, CaMKII, adenosine kinase, CDK2, and quinine reductase type 2, as well as previously unidentified targets PKAC-alpha, prohibitin, VDAC and heme binding proteins. This method was directly compared to the solid-phase method (small molecule was immobilized to a solid support) providing an orthogonal strategy to aid in target deconvolution and help to eliminate false positives originating from nonspecific binding of the proteins to the matrix.

  2. The Mimetic Finite Element Method and the Virtual Element Method for elliptic problems with arbitrary regularity.

    SciTech Connect

    Manzini, Gianmarco

    2012-07-13

    We develop and analyze a new family of virtual element methods on unstructured polygonal meshes for the diffusion problem in primal form, that use arbitrarily regular discrete spaces V{sub h} {contained_in} C{sup {alpha}} {element_of} N. The degrees of freedom are (a) solution and derivative values of various degree at suitable nodes and (b) solution moments inside polygons. The convergence of the method is proven theoretically and an optimal error estimate is derived. The connection with the Mimetic Finite Difference method is also discussed. Numerical experiments confirm the convergence rate that is expected from the theory.

  3. Application of the method of maximum entropy in the mean to classification problems

    NASA Astrophysics Data System (ADS)

    Gzyl, Henryk; ter Horst, Enrique; Molina, German

    2015-11-01

    In this note we propose an application of the method of maximum entropy in the mean to solve a class of inverse problems comprising classification problems and feasibility problems appearing in optimization. Such problems may be thought of as linear inverse problems with convex constraints imposed on the solution as well as on the data. The method of maximum entropy in the mean proves to be a very useful tool to deal with this type of problems.

  4. Microbially derived artemisinin: a biotechnology solution to the global problem of access to affordable antimalarial drugs.

    PubMed

    Hale, Victoria; Keasling, Jay D; Renninger, Neil; Diagana, Thierry T

    2007-12-01

    Despite considerable efforts by multiple governmental and nongovernmental organizations to increase access to artemisinin-based combination therapies (ACTs), these life-saving antimalarial drugs remain largely unaffordable to the most vulnerable populations. The cost of artemisinin derivatives, ACTs' crucial active ingredients, contributes significantly to the high price of these therapies. With a grant from the Bill and Melinda Gates Foundation, a partnership between Amyris Biotechnologies, the Institute for OneWorld Health, and the University of California, Berkeley is using synthetic biology to help reduce the cost of artemisinin. This article presents a description of the technological platform the partnership--called the Artemisinin Project--is developing to manufacture a low-cost, semi-synthetic artemisinin through a fermentation process. By making life-saving ACTs affordable to the people who most need them, the Artemisinin Project hopes to show that the power of biotechnology can be harnessed to provide solutions to global health problems.

  5. Self-forgiveness, shame, and guilt in recovery from drug and alcohol problems.

    PubMed

    McGaffin, Breanna J; Lyons, Geoffrey C B; Deane, Frank P

    2013-01-01

    People with drug and/or alcohol problems often experience feelings of shame and guilt, which have been associated with poorer recovery. Self-forgiveness has the potential to reduce these negative experiences. The current study tested theorized mediators (acceptance, conciliatory behavior, empathy) of the relationships between shame and guilt with self-forgiveness. A cross-sectional sample of 133 individuals (74.4% male) receiving residential treatment for substance abuse completed self-report measures of shame, guilt, self-forgiveness, and the mediators. Consistent with previous research, guilt had a positive association with self-forgiveness, whereas shame was negatively associated with self-forgiveness. Acceptance mediated the guilt and self-forgiveness relationship and had an indirect effect on the shame and self-forgiveness relationship. These findings emphasize the importance of targeting acceptance when trying to reduce the effects of shame and guilt on self-forgiveness.

  6. 21 CFR 530.24 - Procedure for announcing analytical methods for drug residue quantification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS EXTRALABEL DRUG USE IN ANIMALS Specific Provisions Relating to Extralabel Use of Animal and Human Drugs in Food-Producing Animals § 530.24 Procedure for announcing analytical methods for drug residue quantification....

  7. Identifying drugs that cause acute thrombocytopenia: an analysis using 3 distinct methods.

    PubMed

    Reese, Jessica A; Li, Xiaoning; Hauben, Manfred; Aster, Richard H; Bougie, Daniel W; Curtis, Brian R; George, James N; Vesely, Sara K

    2010-09-23

    Drug-induced immune thrombocytopenia (DITP) is often suspected in patients with acute thrombocytopenia unexplained by other causes, but documenting that a drug is the cause of thrombocytopenia can be challenging. To provide a resource for diagnosis of DITP and for drug safety surveillance, we analyzed 3 distinct methods for identifying drugs that may cause thrombocytopenia. (1) Published case reports of DITP have described 253 drugs suspected of causing thrombocytopenia; using defined clinical criteria, 87 (34%) were identified with evidence that the drug caused thrombocytopenia. (2) Serum samples from patients with suspected DITP were tested for 202 drugs; drug-dependent, platelet-reactive antibodies were identified for 67 drugs (33%). (3) The Food and Drug Administration's Adverse Event Reporting System database was searched for drugs associated with thrombocytopenia by use of data mining algorithms; 1444 drugs had at least 1 report associated with thrombocytopenia, and 573 (40%) drugs demonstrated a statistically distinctive reporting association with thrombocytopenia. Among 1468 drugs suspected of causing thrombocytopenia, 102 were evaluated by all 3 methods, and 23 of these 102 drugs had evidence for an association with thrombocytopenia by all 3 methods. Multiple methods, each with a distinct perspective, can contribute to the identification of drugs that can cause thrombocytopenia.

  8. Methods for Elucidation of DNA-Anticancer Drug Interactions and their Applications in the Development of New Drugs.

    PubMed

    Misiak, Majus; Mantegazza, Francesco; Beretta, Giovanni L

    2016-01-01

    DNA damaging agents including anthracyclines, camptothecins and platinum drugs are among most frequently used drugs in the chemotherapeutic routine. Due to their relatively low selectivity for cancer cells, administration of these drugs is associated with adverse side effects, inherent genotoxicity with risk of developing secondary cancers. Development of new drugs, which could be spared of these drawbacks and characterize by improved antitumor efficacy, remains challenging yet vitally important task. These properties are in large part dictated by the selectivity of interaction between the drug and DNA and in this way the studies aimed at elucidating the complex interactions between ligand and DNA represent a key step in the drug development. Studies of the drug-DNA interactions encompass determination of DNA sequence specificity and mode of DNA binding as well as kinetic, dynamic and structural parameters of binding. Here, we consider the types of interactions between small molecule ligands and polynucleotides, how they are affected by DNA sequence and structure, and what is their significance for the antitumor activity. Based on this knowledge, we discuss the wide array of experimental techniques available to researchers for studying drug-DNA interactions, which include absorption and emission spectroscopies, NMR, magnetic and optical tweezers or atomic force microscopy. We show, using the clinical and experimental anticancer drugs as examples, how these methods provide various types of information and at the same time complement each other to provide full picture of drug- DNA interaction and aid in the development of new drugs.

  9. Prevention des Toxicomanies Aupres des Filles avec des Problemes de Comportement: Effets a Court Terme (Prevention of Drug Addiction in Girls with Behavior Problems: Short-Term Effects).

    ERIC Educational Resources Information Center

    Vitaro, Frank; And Others

    1992-01-01

    This article, written in French, describes and evaluates the first phase of a program to prevent drug addiction among 110 fifth-grade girls with behavior problems in Montreal (Quebec, Canada). Evaluation of the instructional program showed positive results for student knowledge level, attitudes, and behaviors and supported program continuation…

  10. Prevention des Toxicomanies Aupres des Filles avec des Problemes de Comportement: Effets a Court Terme (Prevention of Drug Addiction in Girls with Behavior Problems: Short-Term Effects).

    ERIC Educational Resources Information Center

    Vitaro, Frank; And Others

    1992-01-01

    This article, written in French, describes and evaluates the first phase of a program to prevent drug addiction among 110 fifth-grade girls with behavior problems in Montreal (Quebec, Canada). Evaluation of the instructional program showed positive results for student knowledge level, attitudes, and behaviors and supported program continuation…

  11. Online and Mobile Interventions for Problem Gambling, Alcohol, and Drugs: A Systematic Review

    PubMed Central

    Giroux, Isabelle; Goulet, Annie; Mercier, Jonathan; Jacques, Christian; Bouchard, Stéphane

    2017-01-01

    Online interventions for gambling, alcohol, and illegal drug related problems have been developing at a fast pace over the past decade. Yet, little is known about the content and efficacy of interventions provided entirely online for reducing drug/alcohol use and gambling, or about the characteristics of those who use these interventions. This systematic review aims to describe the characteristics of online interventions, their efficacy, and the profile of their clientele. Documentation was mainly obtained through four scientific databases in psychology, technology, and medical research (PsychINFO, MedLine, Francis, and INSPEC) using three keywords (substances or gambling, intervention, Internet). Of the 4,708 documents initially identified, 18 studies meeting admissibility criteria were retained and analyzed after exclusion of duplicates and non-relevant documents. No study in the review related to problem gambling. The majority of interventions were based upon motivational or cognitive-behavioral theoretical approaches and called upon well-established therapeutic components in the field of addictions. The participants in these studies were generally adults between 30 and 46 years old with a high school education and presenting a high risk or problematic use. More than three quarters of the studies showed a short-term decrease in use that was maintained 6 months later, but only two studies included a 12 months follow-up. Online interventions seem promising and appear to meet the needs of participants who are in the workforce and seeking help for the first time. Long-term efficacy studies should nonetheless be conducted. PMID:28649211

  12. DOCUMENT: a system for classifying drug-related problems in community pharmacy.

    PubMed

    Williams, Mackenzie; Peterson, Gregory M; Tenni, Peter C; Bindoff, Ivan K; Stafford, Andrew C

    2012-02-01

    Drug-related problems (DRPs) are a major burden on the Australian healthcare system. Community pharmacists are in an ideal position to detect, prevent, and resolve these DRPs. Objective To develop and validate an easy-to-use documentation system for pharmacists to classify and record DRPs, and to investigate the nature and frequency of clinical interventions undertaken by Australian community pharmacists to prevent or resolve them. Setting Australian community pharmacies. The DOCUMENT classification system was developed, validated and refined during two pilot studies. The system was then incorporated into software installed in 185 Australian pharmacies to record DRPs and clinical interventions undertaken by pharmacists during a 12-week trial. The number and nature of DRPs detected within Australian community pharmacies. A total of 5,948 DRPs and clinical interventions were documented from 2,013,923 prescriptions dispensed during the trial (intervention frequency 0.3%). Interventions were commonly related to Drug selection problems (30.7%) or Educational issues (23.7%). Pharmacists made an average of 1.6 recommendations per intervention, commonly relating to A change in therapy (40.1%) and Provision of information (34.7%). Almost half of interventions (42.6%) were classified by recording pharmacists as being at a higher level of clinical significance. The DOCUMENT system provided pharmacists with a useful and easy-to-use tool for recording DRPs and clinical interventions. Results from the trial have provided a better understanding of the frequency and nature of clinical interventions performed in Australian community pharmacies, and lead to a national implementation of the system.

  13. Interview of patients by pharmacists contributes significantly to the identification of drug-related problems (DRPs).

    PubMed

    Viktil, Kirsten K; Blix, Hege Salvesen; Moger, Tron A; Reikvam, Aasmund

    2006-09-01

    To investigate whether pharmacist interviews of hospitalised patients about their medication would result in identification of more drug-related problems (DRPs) than those found by usual care procedures and further to characterise the DRPs revealed at the interviews. Patients from five internal medicine and two rheumatology departments in four hospitals in Norway were prospectively included in the study. Clinical pharmacists assessed DRPs by reviewing medical records and by participating in multidisciplinary team discussions. Drugs used, medical history, laboratory data and clinical/pharmacological risk factors were recorded (usual care procedure). A proportion of patients were randomly selected for interview with pharmacists. A quality team assessed the clinical significance of the DRPs. Seven hundred and twenty seven patients were included. Significantly more DRPs were found in the interview group (96 patients), an average of 4.4 DRPs per patient as compared to 2.4 DRPs in the non-interview group (631 patients) (p < 0.01). Of a total of 431 DRPs recorded in the interview group, 168 DRPs (39.9%) were disclosed through interviews. 'Need for additional drug', 'medical chart error', 'patient adherence' and 'need for patient education' were significantly more often recorded in this group. The quality team assessed 63% of the DRPs revealed in the interviews to be of major clinical significance. Significantly more DRPs were identified among the patients who were interviewed compared to those patients having only usual care examination. A high proportion of the DRPs identified in the interviews were of major clinical significance. The clinical pharmacists, with their way of interviewing, seem to fill a gap, ensuring that significant DRPs do not escape detection.

  14. New Testing Methods to Assess Technical Problem-Solving Ability.

    ERIC Educational Resources Information Center

    Hambleton, Ronald K.; And Others

    Tests to assess problem-solving ability being provided for the Air Force are described, and some details on the development and validation of these computer-administered diagnostic achievement tests are discussed. Three measurement approaches were employed: (1) sequential problem solving; (2) context-free assessment of fundamental skills and…

  15. The Method To Acquire the Strategic Knowledge on Problem Solving.

    ERIC Educational Resources Information Center

    Takaoka, Ryo; Okamoto, Toshio

    As a person learns, his problem solving ability improves and one reason for this is the increased acquisition of "macro-rules" which make problem solving more efficient. An intelligent computer assisted learning (ICAI) system is being developed which automatically acquires the useful knowledge from the domain experts; as experts give the learning…

  16. Methods and Strategies: Modeling Problem-Based Instruction

    ERIC Educational Resources Information Center

    Sterling, Donna R.

    2007-01-01

    Students get excited about science when they investigate real scientific problems in the classroom, especially when the investigation extends over several weeks. This article describes a health-science problem-based learning (PBL) investigation that a group of teachers and teacher educators devised together for a group of fourth- to sixth-grade…

  17. The adapted augmented Lagrangian method: a new method for the resolution of the mechanical frictional contact problem

    NASA Astrophysics Data System (ADS)

    Bussetta, Philippe; Marceau, Daniel; Ponthot, Jean-Philippe

    2012-02-01

    The aim of this work is to propose a new numerical method for solving the mechanical frictional contact problem in the general case of multi-bodies in a three dimensional space. This method is called adapted augmented Lagrangian method (AALM) and can be used in a multi-physical context (like thermo-electro-mechanical fields problems). This paper presents this new method and its advantages over other classical methods such as penalty method (PM), adapted penalty method (APM) and, augmented Lagrangian method (ALM). In addition, the efficiency and the reliability of the AALM are proved with some academic problems and an industrial thermo-electromechanical problem.

  18. Patterns of major depression and drug-related problems amongst heroin users across 36 months.

    PubMed

    Darke, Shane; Mills, Katherine; Teesson, Maree; Ross, Joanne; Williamson, Anna; Havard, Alys

    2009-03-31

    The study aimed to determine patterns of major depression (MD) across 36 months, and the relationship to outcomes for the treatment of heroin dependence. As part of a longitudinal cohort study, 429 heroin users were interviewed at 36 month follow-up. MD declined from 23.8% at baseline to 8.2% at 36 months. Females were more likely to have MD at both baseline (31.1 vs. 19.8) and 36 months (11.9 vs. 6.1%). Those with MD at baseline were significantly more likely to be diagnosed with MD at a follow-up interview (40.2 vs. 15.9%) and at 36 months (14.7 vs. 6.1%). Antidepressant use did not decrease across 36 months amongst either gender. Baseline MD was not related to treatment exposure across 36 months. There were large and significant declines in drug use and drug-related problems, and improvements in physical health with no group differences evident at 36 months. Despite improvements in global mental health, at both baseline and 36 months those with MD at baseline had significantly lower SF12 mental health scores. It was concluded that, with the exception of depression, the prognosis of depressed heroin users is not worse than that of non-depressed users.

  19. Effective method for drug injection into subcutaneous tissue.

    PubMed

    Kim, Hyejeong; Park, Hanwook; Lee, Sang Joon

    2017-08-29

    Subcutaneous injection of drug solution is widely used for continuous and low dose drug treatment. Although the drug injections have been administered for a long time, challenges in the design of injection devices are still needed to minimize the variability, pain, or skin disorder by repeated drug injections. To avoid these adverse effects, systematic study on the effects of injection conditions should be conducted to improve the predictability of drug effect. Here, the effects of injection conditions on the drug permeation in tissues were investigated using X-ray imaging technique which provides real-time images of drug permeation with high spatial resolution. The shape and concentration distribution of the injected drug solution in the porcine subcutaneous and muscle tissues are visualized. Dynamic movements of the wetting front (WF) and temporal variations of water contents in the two tissues are quantitatively analyzed. Based on the quantitative analysis of the experimental data, the permeability of drug solution through the tissues are estimated according to permeation direction, injection speed, and tissue. The present results would be helpful for improving the performance of drug injection devices and for predicting the drug efficacy in tissues using biomedical simulation.

  20. Alzheimer's disease drug development and the problem of the blood-brain barrier

    PubMed Central

    Pardridge, William M.

    2009-01-01

    Alzheimer's disease (AD) drug development is limited by the presence of the blood-brain barrier (BBB). More than 98% of all small molecule drugs, and ∼100% of all large molecule drugs, do not cross the BBB. Despite the fact that the vast majority of AD drug candidates do not cross the BBB, the present-day AD drug development effort is characterized by an imbalance, whereby >99% of the drug development effort is devoted to CNS drug discovery, and <1% of drug development is devoted to CNS drug delivery. Future AD drug development needs a concerted effort to incorporate the BBB sciences early in the CNS drug discovery process. This can be accomplished by a reallocation of resources, and an expansion of the effort in the pure science of BBB biology and the applied science of brain drug targeting technology. PMID:19751922

  1. Producing alcohol and other drugs as a policy 'problem': A critical analysis of South Africa's 'National Drug Master Plan' (2013-2017).

    PubMed

    Pienaar, Kiran; Savic, Michael

    2016-04-01

    The strong symbolic value of illicit drug use makes it a contested issue, which attracts mixed public opinion, intense media attention and close political scrutiny. This means that the formulation of plausible, authoritative policies governing illicit drugs must navigate fraught political terrain. In a country like South Africa with its long unique history of institutionalised oppression of the black majority, the issues confronting drug policy are particularly complex and the need for carefully formulated policy responses especially urgent. Yet despite this, the area of drug policy development in South Africa has received little scholarly attention to date. This paper explores the complexities of policymaking in the South African context by drawing on feminist scholar Carol Bacchi's poststructuralist approach to policy analysis, which focuses on how policy helps to produce the problems it purports to solve. Taking as its empirical focus, South Africa's current drug policy, the third National Drug Master Plan (NDMP), 2013-2017, the paper analyses how the policy constitutes the 'problem of alcohol and other drugs' (AODs). We identify three central policy proposals through which specific problematisations emerge: (1) the proposal that drug use is a global issue requiring a coordinated policy response, (2) appeals to evidence-based policy proposals and (3) the proposal that AOD 'use' and 'abuse' be treated interchangeably. We suggest that these proposals reveal a tendency towards inflating the 'problem of AODs' and thus work to justify punitive policy measures. In an effort to explore the implications of particular problematisations for effecting social change, we clarify the ways in which the policy may work to undermine the interests of those it seeks to aid by reinforcing stigma and marginalisation. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. A MEASURE-THEORETIC COMPUTATIONAL METHOD FOR INVERSE SENSITIVITY PROBLEMS I: METHOD AND ANALYSIS

    PubMed Central

    Breidt, J.; Butler, T.; Estep, D.

    2012-01-01

    We consider the inverse sensitivity analysis problem of quantifying the uncertainty of inputs to a deterministic map given specified uncertainty in a linear functional of the output of the map. This is a version of the model calibration or parameter estimation problem for a deterministic map. We assume that the uncertainty in the quantity of interest is represented by a random variable with a given distribution, and we use the law of total probability to express the inverse problem for the corresponding probability measure on the input space. Assuming that the map from the input space to the quantity of interest is smooth, we solve the generally ill-posed inverse problem by using the implicit function theorem to derive a method for approximating the set-valued inverse that provides an approximate quotient space representation of the input space. We then derive an efficient computational approach to compute a measure theoretic approximation of the probability measure on the input space imparted by the approximate set-valued inverse that solves the inverse problem. PMID:23637467

  3. Drug Monitoring Techniques for the Biological Chemistry Laboratory: Determination of Drug Concentrations by Chromatographic and Immunochemical Methods.

    ERIC Educational Resources Information Center

    Corkill, Jeffrey A.

    1988-01-01

    Proposes a series of experiments that integrate analytical techniques in order that students are able to compare, based on their laboratory results, the relative reliabilities of the most common therapeutic drug monitoring methods. Discusses materials, procedures, and results of three experiments on the determination of drug concentration by…

  4. Drug Monitoring Techniques for the Biological Chemistry Laboratory: Determination of Drug Concentrations by Chromatographic and Immunochemical Methods.

    ERIC Educational Resources Information Center

    Corkill, Jeffrey A.

    1988-01-01

    Proposes a series of experiments that integrate analytical techniques in order that students are able to compare, based on their laboratory results, the relative reliabilities of the most common therapeutic drug monitoring methods. Discusses materials, procedures, and results of three experiments on the determination of drug concentration by…

  5. The Patterns of Drug and Alcohol Use and Associated Problems over 30 Years in 397 Men

    PubMed Central

    Schuckit, Marc A.; Smith, Tom L.; Kalmijn, Jelger A.

    2013-01-01

    Background Alcohol- and drug-use disorders (AUDs and SUDs) and their combination are relatively common, and often occur together. However, the relationships of potential early life correlates of alcohol and drug disorders to the combined diagnoses have rarely been evaluated in long-term prospective studies or in populations at high risk for one of these diagnoses but not the other. Methods Data were analyzed from 397males (half with an alcohol-dependent father) who had no AUDs or SUDs at age 20 and who were followed ~every five years for three decades. Early life correlates and the course of AUDs, SUDs, and combined disorders were evaluated for four groups of subjects based on subsequent alcohol and/or drug diagnoses. Results While the overall rates of the development of AUDs and SUDs were 41% and 21%, respectively, the rates of the second substance-related diagnosis were almost two-fold higher for individuals who had the first condition. Among potential risk factors, scores for externalizing traits were elevated for men with AUDs, SUDs, and their combination, but a low level of response (low LR) to alcohol was associated only with the risk for AUDs, even when observed in the context of SUDs. The same earlier life characteristics that related to AUDs and to SUDs also related to the combination of these diagnoses in the same person. Finally, in this prospective study subjects with both alcohol and drug use disorders had a more severe course than subjects with either condition alone. Conclusions This prospective evaluation of a group at high risk for AUDs confirmed the selective impact of the low LR on the risk for AUDs, the relationship of externalizing characteristics to both AUDs and SUDs, and confirmed the more severe clinical course for both conditions when seen together. PMID:23895676

  6. Using standardized methods for research on HIV and injecting drug use in developing/transitional countries: case study from the WHO Drug Injection Study Phase II

    PubMed Central

    Des Jarlais, Don C; Perlis, Theresa E; Stimson, Gerry V; Poznyak, Vladimir

    2006-01-01

    Background Successful cross-national research requires methods that are both standardized across sites and adaptable to local conditions. We report on the development and implementation of the methodology underlying the survey component of the WHO Drug Injection Study Phase II – a multi-site study of risk behavior and HIV seroprevalence among Injecting Drug Users (IDUs). Methods Standardized operational guidelines were developed by the Survey Coordinating Center in collaboration with the WHO Project Officer and participating site Investigators. Throughout the duration of the study, survey implementation at the local level was monitored by the Coordinating Center. Surveys were conducted in 12 different cities. Prior rapid assessment conducted in 10 cities provided insight into local context and guided survey implementation. Where possible, subjects were recruited both from drug abuse treatment centers and via street outreach. While emphasis was on IDUs, non-injectors were also recruited in cities with substantial non-injecting use of injectable drugs. A structured interview and HIV counseling/testing were administered. Results Over 5,000 subjects were recruited. Subjects were recruited from both drug treatment and street outreach in 10 cities. Non-injectors were recruited in nine cities. Prior rapid assessment identified suitable recruitment areas, reduced drug users' distrust of survey staff, and revealed site-specific risk behaviors. Centralized survey coordination facilitated local questionnaire modification within a core structure, standardized data collection protocols, uniform database structure, and cross-site analyses. Major site-specific problems included: questionnaire translation difficulties; locating affordable HIV-testing facilities; recruitment from drug treatment due to limited/selective treatment infrastructure; access to specific sub-groups of drug users in the community, particularly females or higher income groups; security problems for users

  7. Multi-level adaptive finite element methods. 1: Variation problems

    NASA Technical Reports Server (NTRS)

    Brandt, A.

    1979-01-01

    A general numerical strategy for solving partial differential equations and other functional problems by cycling between coarser and finer levels of discretization is described. Optimal discretization schemes are provided together with very fast general solvers. It is described in terms of finite element discretizations of general nonlinear minimization problems. The basic processes (relaxation sweeps, fine-grid-to-coarse-grid transfers of residuals, coarse-to-fine interpolations of corrections) are directly and naturally determined by the objective functional and the sequence of approximation spaces. The natural processes, however, are not always optimal. Concrete examples are given and some new techniques are reviewed. Including the local truncation extrapolation and a multilevel procedure for inexpensively solving chains of many boundary value problems, such as those arising in the solution of time-dependent problems.

  8. Quasistatic Evolution in Debonding Problems via Capacitary Methods

    NASA Astrophysics Data System (ADS)

    Bucur, Dorin; Buttazzo, Giuseppe; Lux, Anne

    2008-09-01

    We discuss quasistatic evolution processes for capacitary measures and shapes in order to model debonding membranes. Minimizing movements as well as rate-independent processes are investigated and some models are described, together with a series of open problems.

  9. Comparing 4 classification systems for drug-related problems: processes and functions.

    PubMed

    Björkman, Ingeborg K; Sanner, Margareta A; Bernsten, Cecilia B

    2008-12-01

    Counseling patients on drug-related problems (DRPs) is a new enterprise for pharmacists. Accordingly, a variety of classification systems have been created to document DRPs. This aroused our interest in finding out how classification systems differ. The objective is to explore and describe the characteristics of 4 classification systems for DRPs to understand their similarities and differences with regard to processes and functions. Four established classification systems were selected; they were Strand, Granada-II, Pharmaceutical Care Network Europe v5.0, and Apoteket. To gain experience of the use of the systems, an existing database containing documented problems that were identified during patient counseling at community pharmacies was used. The entries in the database were classified using the 4 selected classification systems, one at a time. In the following analysis, focus was set on what issues were classified and how they were classified in each system. Based on similarities and differences, 8 themes were identified and characteristics of the 4 systems were listed according to these themes. Characteristics of each system were thoroughly scrutinized and interpreted. The processes of selecting classification categories were different in all 4 systems, and as a result the contents of categories in systems were different. The systems had different characteristics and a decisive characteristic was whether the patients were involved in the classification of problems or not. Because of the different characteristics the systems had different functions. To understand the usefulness of a classification system, both structure of categories and work process must be considered. The studied systems had different functions that revealed different aims embedded in the systems. To develop the counseling role of pharmacists, a limited number of classification systems would be beneficial. To get there, common aims and common systems must be developed.

  10. An enzymatic deconjugation method for the analysis of small molecule active drugs on antibody-drug conjugates

    PubMed Central

    Li, Yi; Gu, Christine; Gruenhagen, Jason; Yehl, Peter; Chetwyn, Nik P.; Medley, Colin D.

    2016-01-01

    ABSTRACT Antibody-drug conjugates (ADCs) are complex therapeutic agents that use the specific targeting properties of antibodies and the highly potent cytotoxicity of small molecule drugs to selectively eliminate tumor cells while limiting the toxicity to normal healthy tissues. Two critical quality attributes of ADCs are the purity and stability of the active small molecule drug linked to the ADC, but these are difficult to assess once the drug is conjugated to the antibody. In this study, we report a enzyme deconjugation approach to cleave small molecule drugs from ADCs, which allows the drugs to be subsequently characterized by reversed-phase high performance liquid chromatography. The model ADC we used in this study utilizes a valine-citrulline linker that is designed to be sensitive to endoproteases after internalization by tumor cells. We screened several proteases to determine the most effective enzyme. Among the 3 cysteine proteases evaluated, papain had the best efficiency in cleaving the small molecule drug from the model ADC. The deconjugation conditions were further optimized to achieve complete cleavage of the small molecule drug. This papain deconjugation approach demonstrated excellent specificity and precision. The purity and stability of the active drug on an ADC drug product was evaluated and the major degradation products of the active drug were identified. The papain deconjugation method was also applied to several other ADCs, with the results suggesting it could be applied generally to ADCs containing a valine-citrulline linker. Our results indicate that the papain deconjugation method is a powerful tool for characterizing the active small molecule drug conjugated to an ADC, and may be useful in ensuring the product quality, efficacy and the safety of ADCs. PMID:26891281

  11. The Drug Education Gap

    ERIC Educational Resources Information Center

    Reynolds, John C., Jr.

    1976-01-01

    Examines the problems of alcoholism, smoking and drug addiction and their influence on students. Suggests that intermediate and secondary schools can assist in alcohol and tobacco (the two legal drugs) programs through improved educational methods. (Author/RK)

  12. The Drug Education Gap

    ERIC Educational Resources Information Center

    Reynolds, John C., Jr.

    1976-01-01

    Examines the problems of alcoholism, smoking and drug addiction and their influence on students. Suggests that intermediate and secondary schools can assist in alcohol and tobacco (the two legal drugs) programs through improved educational methods. (Author/RK)

  13. Other Drug Use and Abuse on Campus: The Scope of the Problem. Infofacts/Resources

    ERIC Educational Resources Information Center

    Ross, Virginia; DeJong, William

    2009-01-01

    Of all drugs abused on college and university campuses, alcohol causes the greatest harm. Other drugs (the prevention field uses the term "other drugs" to distinguish them from alcohol, which also is a drug) also take a significant toll--diminishing the quality of campus life, undermining academic performance, compromising students' health and…

  14. Solving Fuzzy Optimization Problem Using Hybrid Ls-Sa Method

    NASA Astrophysics Data System (ADS)

    Vasant, Pandian

    2011-06-01

    Fuzzy optimization problem has been one of the most and prominent topics inside the broad area of computational intelligent. It's especially relevant in the filed of fuzzy non-linear programming. It's application as well as practical realization can been seen in all the real world problems. In this paper a large scale non-linear fuzzy programming problem has been solved by hybrid optimization techniques of Line Search (LS), Simulated Annealing (SA) and Pattern Search (PS). As industrial production planning problem with cubic objective function, 8 decision variables and 29 constraints has been solved successfully using LS-SA-PS hybrid optimization techniques. The computational results for the objective function respect to vagueness factor and level of satisfaction has been provided in the form of 2D and 3D plots. The outcome is very promising and strongly suggests that the hybrid LS-SA-PS algorithm is very efficient and productive in solving the large scale non-linear fuzzy programming problem.

  15. The CG-BFGS method for unconstrained optimization problems

    NASA Astrophysics Data System (ADS)

    Ibrahim, Mohd Asrul Hery Bin; Mamat, Mustafa; June, Leong Wah; Sofi, Azfi Zaidi Mohammad

    2014-07-01

    In this paper we present a new search direction known as the CG-BFGS method, which uses the search direction of the conjugate gradient method approach in the quasi-Newton methods. The new algorithm is compared with the quasi-Newton methods in terms of the number of iterations and CPU-time. The Broyden-Fletcher-Goldfarb-Shanno (BFGS) method is used as an updating formula for the approximation of the Hessian for both methods. Our numerical analysis provides strong evidence that our CG-BFGS method is more efficient than the ordinary BFGS method. Besides, we also prove that the new algorithm is globally convergent.

  16. Don’t Flush! Why Your Drug Disposal Method Matters

    EPA Science Inventory

    April 30th is the U.S. Drug Enforcement Administration’s National Drug Take-Back Day. All over the country there will be facilities accepting any unwanted or expired medications from 10:00 AM – 2:00 PM – it is the perfect opportunity to clean out your medicine cabinet while simu...

  17. Don’t Flush! Why Your Drug Disposal Method Matters

    EPA Science Inventory

    April 30th is the U.S. Drug Enforcement Administration’s National Drug Take-Back Day. All over the country there will be facilities accepting any unwanted or expired medications from 10:00 AM – 2:00 PM – it is the perfect opportunity to clean out your medicine cabinet while simu...

  18. Risk Pathways among Traumatic Stress, Posttraumatic Stress Disorder Symptoms, and Alcohol and Drug Problems: A Test of Four Hypotheses

    PubMed Central

    Haller, Moira; Chassin, Laurie

    2014-01-01

    The present study utilized longitudinal data from a community sample (n= 377; 166 trauma-exposed; 54% males; 73% non-Hispanic Caucasian; 22% Hispanic; 5% other ethnicity) to test whether pre-trauma substance use problems increase risk for trauma exposure (high-risk hypothesis) or PTSD symptoms (susceptibility hypothesis), whether PTSD symptoms increase risk for later alcohol/drug problems (self-medication hypothesis), and whether the association between PTSD symptoms and alcohol/drug problems is due to shared risk factors (shared vulnerability hypothesis). Logistic and negative binomial regressions were performed in a path analysis framework. Results provided the strongest support for the self-medication hypothesis, such that PTSD symptoms predicted higher levels of later alcohol and drug problems, over and above the influences of pre-trauma family risk factors, pre-trauma substance use problems, trauma exposure, and demographic variables. Results partially supported the high-risk hypothesis, such that adolescent substance use problems had a marginally significant unique effect on risk for assaultive violence exposure but not on overall risk for trauma exposure. There was no support for the susceptibility hypothesis. Finally, there was little support for the shared vulnerability hypothesis. Neither trauma exposure nor preexisting family adversity accounted for the link between PTSD symptoms and later substance use problems. Rather, PTSD symptoms mediated the effect of pre-trauma family adversity on later alcohol and drug problems, thereby supporting the self-medication hypothesis. These findings make important contributions to better understanding the directions of influence among traumatic stress, PTSD symptoms, and substance use problems. PMID:24933396

  19. Iterative method for elliptic problems on regions partitioned into substructures

    SciTech Connect

    Bramble, J.H.; Pasciak, J.E.; Schatz, A.H.

    1986-04-01

    Some new preconditioners for discretizations of elliptic boundary problems are studied. With these preconditioners, the domain under consideration is broken into subdomains and preconditioners are defined which only require the solution of matrix problems on the subdomains. Analytic estimates are given which guarantee that under appropriate hypotheses, the preconditioned iterative procedure converges to the solution of the discrete equations with a rate per iteration that is independent of the number of unknowns. Numerical examples are presented which illustrate the theoretically predicted iterative convergence rates.

  20. A locally implicit method for fluid flow problems

    NASA Technical Reports Server (NTRS)

    Reddy, K. C.

    1986-01-01

    The fluid flow inside the space shuttle main engine (SSME) traverses through a complex geometrical configuration. The flow is compressible, viscous, and turbulent with pockets of separated regions. Several computer codes are being developed to solve three dimensional Navier-Stokes equations with different turbulence models for analyzing the SSME internal flow. The locally implicit scheme is a computationally efficient scheme which converges rapidly in multi-grid modes for elliptic problems. It has the promise of providing a rapidly converging algorithm for steady-state viscous flow problems.