WorldWideScience

Sample records for chemical health modeling

  1. Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System

    Energy Technology Data Exchange (ETDEWEB)

    Stenner, Robert D.; Hadley, Donald L.; Armstrong, Peter R.; Buck, John W.; Hoopes, Bonnie L.; Janus, Michael C.

    2001-03-01

    Indoor air quality effects on human health are of increasing concern to public health agencies and building owners. The prevention and treatment of 'sick building' syndrome and the spread of air-borne diseases in hospitals, for example, are well known priorities. However, increasing attention is being directed to the vulnerability of our public buildings/places, public security and national defense facilities to terrorist attack or the accidental release of air-borne biological pathogens, harmful chemicals, or radioactive contaminants. The Indoor Air Nuclear, Biological, and Chemical Health Modeling and Assessment System (IA-NBC-HMAS) was developed to serve as a health impact analysis tool for use in addressing these concerns. The overall goal was to develop a user-friendly fully functional prototype Health Modeling and Assessment system, which will operate under the PNNL FRAMES system for ease of use and to maximize its integration with other modeling and assessment capabilities accessible within the FRAMES system (e.g., ambient air fate and transport models, water borne fate and transport models, Physiologically Based Pharmacokinetic models, etc.). The prototype IA-NBC-HMAS is designed to serve as a functional Health Modeling and Assessment system that can be easily tailored to meet specific building analysis needs of a customer. The prototype system was developed and tested using an actual building (i.e., the Churchville Building located at the Aberdeen Proving Ground) and release scenario (i.e., the release and measurement of tracer materials within the building) to ensure realism and practicality in the design and development of the prototype system. A user-friendly "demo" accompanies this report to allow the reader the opportunity for a "hands on" review of the prototype system's capability.

  2. A model for probabilistic health impact assessment of exposure to food chemicals.

    NARCIS (Netherlands)

    van der Voet, H.; van der Heijden, G.W.; Bos, P.M.J.; Bosgra, S.; Boon, P.E.; Muri, S.D.; Bruschweiler, B.J.

    2010-01-01

    A statistical model is presented extending the integrated probabilistic risk assessment (IPRA) model of van der Voet and Slob [van der Voet, H., Slob, W., 2007. Integration of probabilistic exposure assessment and probabilistic hazard characterisation. Risk Analysis, 27, 351-371]. The aim is to char

  3. A model for probabilistic health impact assessment of exposure to food chemicals

    NARCIS (Netherlands)

    Voet, van der H.; Heijden, van der G.W.A.M.; Bos, P.M.J.; Bosgra, S.; Boon, P.E.; Muri, S.D.; Brüschweiler, B.J.

    2009-01-01

    A statistical model is presented extending the integrated probabilistic risk assessment (IPRA) model of van der Voet and Slob [van der Voet, H., Slob, W., 2007. Integration of probabilistic exposure assessment and probabilistic hazard characterisation. Risk Analysis, 27, 351–371]. The aim is to char

  4. Dose-response modeling : Evaluation, application, and development of procedures for benchmark dose analysis in health risk assessment of chemical substances

    OpenAIRE

    Sand, Salomon

    2005-01-01

    In this thesis, dose-response modeling and procedures for benchmark dose (BMD) analysis in health risk assessment of chemical substances have been investigated. The BMD method has been proposed as an alternative to the NOAEL (no-observedadverse- effect-level) approach in health risk assessment of non-genotoxic agents. According to the BMD concept, a dose-response model is fitted to data and the BMD is defined as the dose causing a predetermined change in response. A lowe...

  5. Modeling chemical kinetics graphically

    NARCIS (Netherlands)

    A. Heck

    2012-01-01

    In literature on chemistry education it has often been suggested that students, at high school level and beyond, can benefit in their studies of chemical kinetics from computer supported activities. Use of system dynamics modeling software is one of the suggested quantitative approaches that could h

  6. Modeling in Chemical Engineering

    Directory of Open Access Journals (Sweden)

    Jaap van Brakel

    2000-10-01

    Full Text Available Models underlying the use of similarity considerations, dimensionless numbers, and dimensional analysis in chemical engineering are discussed. Special attention is given to the many levels at which models and ceteris paribus conditions play a role and to the modeling of initial and boundary conditions. It is shown that both the laws or dimensionless number correlations and the systems to which they apply are models. More generally, no matter which model or description one picks out, what is being modeled is itself a model of something else. Instead of saying that the artifact S models the given B, it is therefore better to say that S and B jointly make up B and S.

  7. Chemical kinetics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C.K.; Pitz, W.J. [Lawrence Livermore National Laboratory, CA (United States)

    1993-12-01

    This project emphasizes numerical modeling of chemical kinetics of combustion, including applications in both practical combustion systems and in controlled laboratory experiments. Elementary reaction rate parameters are combined into mechanisms which then describe the overall reaction of the fuels being studied. Detailed sensitivity analyses are used to identify those reaction rates and product species distributions to which the results are most sensitive and therefore warrant the greatest attention from other experimental and theoretical research programs. Experimental data from a variety of environments are combined together to validate the reaction mechanisms, including results from laminar flames, shock tubes, flow systems, detonations, and even internal combustion engines.

  8. Chemical modeling of waste sludges

    Energy Technology Data Exchange (ETDEWEB)

    Weber, C.F.; Beahm, E.C.

    1996-10-01

    The processing of waste from underground storage tanks at the Oak Ridge National Laboratory (ORNL) and other facilities will require an understanding of the chemical interactions of the waste with process chemicals. Two aspects of sludge treatment should be well delineated and predictable: (1) the distribution of chemical species between aqueous solutions and solids, and (2) potential problems due to chemical interactions that could result in process difficulties or safety concerns. It is likely that the treatment of waste tank sludge will begin with washing, followed by basic or acidic leaching. The dissolved materials will be in a solution that has a high ionic strength where activity coefficients are far from unity. Activity coefficients are needed in order to calculate solubilities. Several techniques are available for calculating these values, and each technique has its advantages and disadvantages. The techniques adopted and described here is the Pitzer method. Like any of the methods, prudent use of this approach requires that it be applied within concentration ranges where the experimental data were fit, and its use in large systems should be preceded by evaluating subsystems. While much attention must be given to the development of activity coefficients, other factors such as coprecipitation of species and Ostwald ripening must also be considered when one aims to interpret results of sludge tests or to predict results of treatment strategies. An understanding of sludge treatment processes begins with the sludge tests themselves and proceeds to a general interpretation with the aid of modeling. One could stop with only data from the sludge tests, in which case the table of data would become an implicit model. However, this would be a perilous approach in situations where processing difficulties could be costly or result in concerns for the environment or health and safety.

  9. Reduction of chemical reaction models

    Science.gov (United States)

    Frenklach, Michael

    1991-01-01

    An attempt is made to reconcile the different terminologies pertaining to reduction of chemical reaction models. The approaches considered include global modeling, response modeling, detailed reduction, chemical lumping, and statistical lumping. The advantages and drawbacks of each of these methods are pointed out.

  10. Environmentally-Induced Malignancies: An In Vivo Model to Evaluate the Health Impact of Chemicals in Mixed Waste

    Energy Technology Data Exchange (ETDEWEB)

    Maria Pallavicini

    2001-05-04

    Occupational and environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls are linked with increased risk of hematologic malignancies. DOE facilities and waste sites in the U.S. are contaminated with mixtures of potentially hazardous chemicals such as metals, organic ligands, solvents, fuel hydrocarbons, polychlorinated biphenyls and radioactive isotopes. A major goal of this project was to establish linkage between chemical/radiation exposure and induction of genomic damage in target populations with the capability to undergo transformation.

  11. Environmentally-Induced Malignancies: An In Vivo Model to Evaluate the Health Impact of Chemicals in Mixed Waste

    International Nuclear Information System (INIS)

    Occupational and environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls are linked with increased risk of hematologic malignancies. DOE facilities and waste sites in the U.S. are contaminated with mixtures of potentially hazardous chemicals such as metals, organic ligands, solvents, fuel hydrocarbons, polychlorinated biphenyls and radioactive isotopes. A major goal of this project was to establish linkage between chemical/radiation exposure and induction of genomic damage in target populations with the capability to undergo transformation

  12. Public health challenges posed by chemical mixtures.

    Science.gov (United States)

    Hansen, H; De Rosa, C T; Pohl, H; Fay, M; Mumtaz, M M

    1998-12-01

    Approximately 40 million people live within a 4-mile radius of waste sites that the Agency for Toxic Substances and Disease Registry (ATSDR) has assessed to date. Human populations living in the vicinity of such sites are often subjected to complex chemical exposures that may contribute to the total body burden of oxogenous chemicals. Apart from the contaminants found at waste sites, exposure may also include environmental, occupational, and personal agents. Concurrent exposure to chemicals such as welding fumes, indoor air pollutants, tobacco smoke, alcohol, and prescription and nonprescription drugs makes the health assessment of exposure to waste site chemicals a more complex task. Voluntary exposures such as these frequently entail exposures to relatively high chemical concentrations and can usually be well defined and quantified. Conversely, involuntary exposures from waste sites may be at low concentrations and hence difficult to characterize and quantify. Of the approximately 1450 waste sites evaluated by the ATSDR, 530 (37%) had either completed or potentially completed exposure pathways. Results of public health assessments conducted at 167 sites during 1993 to 1995 show that about 1.5 million people have been exposed to site-specific contaminants. At 10% or more of the sites that had either completed or potentially completed exposure pathways, 56 substances were identified. Of these, 19 are either known or anticipated human carcinogens, and 9 are associated with reproductive or endocrine-disrupting effects. In this paper we present important concerns regarding hazardous waste sites including the impact on human health, ecology, and quality of life. To address such human-health related issues, the ATSDR has established a mixtures program that consists of three components: trend analysis to identify combinations of chemicals of concern, experimental studies to identify data that would be useful in the development and implementation of predictive decision

  13. Radiation, chemicals, and occupational health research

    International Nuclear Information System (INIS)

    Radiation protection and its interplay with physical research programs are described. Differences and similarities between problems in health protection for chemicals and for radiation are discussed. The importance of dosimetry in radiation work and its relevance to chemicals are cited. A collaborative program between physical and biological scientists on the toxicity of metals is briefly described. It serves as an example of new research directed toward the development of fundamental concepts and principles as a basis for understanding and controlling occupational and population exposures to chemicals. 12 references, 4 figures

  14. Modeling of turbulent chemical reaction

    Science.gov (United States)

    Chen, J.-Y.

    1995-01-01

    Viewgraphs are presented on modeling turbulent reacting flows, regimes of turbulent combustion, regimes of premixed and regimes of non-premixed turbulent combustion, chemical closure models, flamelet model, conditional moment closure (CMC), NO(x) emissions from turbulent H2 jet flames, probability density function (PDF), departures from chemical equilibrium, mixing models for PDF methods, comparison of predicted and measured H2O mass fractions in turbulent nonpremixed jet flames, experimental evidence of preferential diffusion in turbulent jet flames, and computation of turbulent reacting flows.

  15. Occupational health surveillance in the chemical industry.

    Science.gov (United States)

    Flueckiger, A

    2000-08-01

    Health surveillance has its well defined place within occupational health care. Only a few functions are specific to the chemical industry. Occupational health surveillance used to be targeted at the early detection of occupational illnesses (secondary prevention) but other purposes have gained importance in recent years: ensuring the fitness of every worker for his or her job, promoting workers' health in general, contributing to the safety of the plant operation by identifying workers whose behaviour is likely to endanger others, contributing to product quality by assisting in the fulfilment of good manufacturing practice requirements, etc. If the occupational physician wants to maintain his role as key player in protecting workers' health, he must get involved in the important activities of primary prevention contributing directly to workplace improvements. Such improvements can only be based on systematic assessments of the workplaces. These assessments again provide the necessary objective basis to structure health surveillance in a way that takes into account the possible adverse effects coming from the workplace. PMID:11294324

  16. Environmentally-induced malignancies: An in vivo model to evaluate the health impact of chemicals in mixed waste. 1997 annual progress report

    International Nuclear Information System (INIS)

    'Occupational or environmental exposure to organic ligands, solvents, fuel hydrocarbons, and polychlorinated biphenyls is linked to increased risk of developing leukemia, a blood cancer. The long term health effects of exposure to complex mixtures of chemicals and radionuclides are of particular concern because their biologic effects may synergize to increase risk of malignancy. Increased understanding of steps in the progression pathway of a normal cell to a cancer cell is important for biomonitoring, risk assessment and intervention in exposed individuals. Leukemias are characterized by multiple genetic aberrations. Accumulation of multiple genomic changes may reflect genomic instability in the affected ceils. Thus agents that induce DNA damage or genomic instability may increase accumulation of genomic alterations, thereby predisposing cells to transformation. However, not all DNA damaging agents predispose to transformation. Other factors such as genetic susceptibility, cell and tissue response to genotoxicity and cytotoxicity, DNA repair, etc. will impact malignant progression. The author proposed a progression model (Figure 1) of environmentally-induced leukemia that can be evaluated using mouse models.'

  17. Chemical kinetics and combustion modeling

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

  18. Development of regionalized multimedia chemical fate models for China

    OpenAIRE

    Zhu, Ying

    2016-01-01

    To balance the economic development with environmental safety and human health, China has released chemicals management legislation for which chemical prioritization and risk assessment are key issues. To support these ambitions two versions of an environmental fate and behaviour model SESAMe (Sino Evaluative Simplebox-MAMI models), have been developed with different resolutions and structures in this thesis. SESAMe is applied to hypothetical chemicals to investigate the influence of environm...

  19. Chemical Models of Collapsing Envelopes

    CERN Document Server

    Bergin, E A

    1999-01-01

    We discuss recent models of chemical evolution in the developing and collapsing protostellar envelopes associated with low-mass star formation. In particular, the effects of depletion of gas-phase molecules onto grain surfaces is considered. We show that during the middle to late evolutionary stages, prior to the formation of a protostar, various species selectively deplete from the gas phase. The principal pattern of selective depletions is the depletion of sulfur-bearing molecules relative to nitrogen-bearing species: NH3 and N2H+. This pattern is shown to be insensitive to the details of the dynamics and marginally sensitive to whether the grain mantle is dominated by polar or non-polar molecules. Based on these results we suggest that molecular ions are good tracers of collapsing envelopes. The effects of coupling chemistry and dynamics on the resulting physical evolution are also examined. Particular attention is paid to comparisons between models and observations.

  20. Chemical leasing business models: a contribution to the effective risk management of chemical substances.

    Science.gov (United States)

    Ohl, Cornelia; Moser, Frank

    2007-08-01

    Chemicals indisputably contribute greatly to the well-being of modern societies. Apart from such benefits, however, chemicals often pose serious threats to human health and the environment when improperly handled. Therefore, the European Commission has proposed a regulatory framework for the Registration, Evaluation and Authorization of Chemicals (REACH) that requires companies using chemicals to gather pertinent information on the properties of these substances. In this article, we argue that the crucial aspect of this information management may be the honesty and accuracy of the transfer of relevant knowledge from the producer of a chemical to its user. This may be particularly true if the application of potentially hazardous chemicals is not part of the user's core competency. Against this background, we maintain that the traditional sales concept provides no incentives for transferring this knowledge. The reason is that increased user knowledge of a chemical's properties may raise the efficiency of its application. That is, excessive and unnecessary usage will be eliminated. This, in turn, would lower the amount of chemicals sold and in competitive markets directly decrease profits of the producer. Through the introduction of chemical leasing business models, we attempt to present a strategy to overcome the incentive structure of classical sales models, which is counterproductive for the transfer of knowledge. By introducing two models (a Model A that differs least and a Model B that differs most from traditional sales concepts), we demonstrate that chemical leasing business models are capable of accomplishing the goal of Registration, Evaluation and Authorization of Chemicals: to effectively manage the risk of chemicals by reducing the total quantity of chemicals used, either by a transfer of applicable knowledge from the lessor to the lessee (Model A) or by efficient application of the chemical by the lessor him/herself (Model B).

  1. Health effects assessment of chemical exposures: ARIES methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sierra, L; Montero, M.; Rabago, I.; Vidania, R.

    1995-07-01

    In this work, we present ARIES* update: a system designed in order to facilitate the human health effects assessment produced by accidental release of toxic chemicals. The first version of ARIES was developed in relation to 82/501/EEC Directive about mayor accidents in the chemical industry. So, the first aim was the support of the effects assessment derived for the chemicals included into this directive. From this establishment, it was considered acute exposures for high concentrations. In this report, we present the actual methodology for considering other type of exposures, such as environmental and occupational. Likewise other versions, the methodology comprises two approaches: quantitative and qualitative assessments. Quantitative assessment incorporates the mathematical algorithms useful to evaluate the effects produced by the most important routes of exposure: inhalation, ingestion, eye contact and skin absorption, in a short, medium and long term. It has been included models that realizes an accurate quantification of doses, effects,... and so on, such as simple approaches when the available information is not enough. Qualitative assessment, designed in order to complement or replace the previous one, is incorporated into an informatics system, developed in Clipper. It executes and displays outstanding and important toxicological information of about 100 chemicals. This information comes from ECDIN (Environmental Chemicals Data and Information Network) database through a collaboration with JRC-ISPRA working group. (Author) 24 refs.

  2. Health effects assessment of chemical exposures: ARIES methodology

    International Nuclear Information System (INIS)

    In this work, we present ARIES* update: a system designed in order to facilitate the human health effects assessment produced by accidental release of toxic chemicals. The first version of ARIES was developed in relation to 82/501/EEC Directive about mayor accidents in the chemical industry. So, the first aim was the support of the effects assessment derived for the chemicals included into this directive. From this establishment, it was considered acute exposures for high concentrations. In this report, we present the actual methodology for considering other type of exposures, such as environmental and occupational. Likewise other versions, the methodology comprises two approaches: quantitative and qualitative assessments. Quantitative assessment incorporates the mathematical algorithms useful to evaluate the effects produced by the most important routes of exposure: inhalation, ingestion, eye contact and skin absorption, in a short, medium and long term. It has been included models that realizes an accurate quantification of doses, effects,... and so on, such as simple approaches when the available information is not enough. Qualitative assessment, designed in order to complement or replace the previous one, is incorporated into an informatics system, developed in Clipper. It executes and displays outstanding and important toxicological information of about 100 chemicals. This information comes from ECDIN (Environmental Chemicals Data and Information Network) database through a collaboration with JRC-ISPRA working group. (Author) 24 refs

  3. Chemical modeling of exoplanet atmospheres

    CERN Document Server

    Venot, Olivia

    2014-01-01

    The past twenty years have revealed the diversity of planets that exist in the Universe. It turned out that most of exoplanets are different from the planets of our Solar System and thus, everything about them needs to be explored. Thanks to current observational technologies, we are able to determine some information about the atmospheric composition, the thermal structure and the dynamics of these exoplanets, but many questions remain still unanswered. To improve our knowledge about exoplanetary systems, more accurate observations are needed and that is why the Exoplanet Characterisation Observatory (EChO) is an essential space mission. Thanks to its large spectral coverage and high spectral resolution, EChO will provide exoplanetary spectra with an unprecedented accuracy, allowing to improve our understanding of exoplanets. In this work, we review what has been done to date concerning the chemical modeling of exoplanet atmospheres and what are the main characteristics of warm exoplanet atmospheres, which a...

  4. Health Aspects of the Disposal of Waste Chemicals.

    Science.gov (United States)

    Grisham, Joe W., Ed.

    Intended to be a source of information on the nature and significance of health effects related to chemical disposal, this document is the final report of the Executive Scientific Panel on Health Aspects of the Disposal of Waste Chemicals. The panel, which was organized by the Universities Associated for Research and Education in Pathology…

  5. Chemical Leasing business models and corporate social responsibility.

    Science.gov (United States)

    Moser, Frank; Jakl, Thomas; Joas, Reihard; Dondi, Francesco

    2014-11-01

    Chemical Leasing is a service-oriented business model that shifts the focus from increasing sales volume of chemicals towards a value-added approach. Recent pilot projects have shown the economic benefits of introducing Chemical Leasing business models in a broad range of sectors. A decade after its introduction, the promotion of Chemical Leasing is still predominantly done by the public sector and international organizations. We show in this paper that awareness-raising activities to disseminate information on this innovative business model mainly focus on the economic benefits. We argue that selling Chemical Leasing business models solely on the grounds of economic and ecological considerations falls short of branding it as a corporate social responsibility initiative, which, for this paper, is defined as a stakeholder-oriented concept that extends beyond the organization's boundaries and is driven by an ethical understanding of the organization's responsibility for the impact of its business activities. For the analysis of Chemical Leasing business models, we introduce two case studies from the water purification and metal degreasing fields, focusing on employees and local communities as two specific stakeholder groups of the company introducing Chemical Leasing. The paper seeks to demonstrate that Chemical Leasing business models can be branded as a corporate social responsibility initiative by outlining the vast potential of Chemical Leasing to improve occupational health and safety and to strengthen the ability of companies to protect the environment from the adverse effects of the chemicals they apply.

  6. Chemical Leasing business models and corporate social responsibility.

    Science.gov (United States)

    Moser, Frank; Jakl, Thomas; Joas, Reihard; Dondi, Francesco

    2014-11-01

    Chemical Leasing is a service-oriented business model that shifts the focus from increasing sales volume of chemicals towards a value-added approach. Recent pilot projects have shown the economic benefits of introducing Chemical Leasing business models in a broad range of sectors. A decade after its introduction, the promotion of Chemical Leasing is still predominantly done by the public sector and international organizations. We show in this paper that awareness-raising activities to disseminate information on this innovative business model mainly focus on the economic benefits. We argue that selling Chemical Leasing business models solely on the grounds of economic and ecological considerations falls short of branding it as a corporate social responsibility initiative, which, for this paper, is defined as a stakeholder-oriented concept that extends beyond the organization's boundaries and is driven by an ethical understanding of the organization's responsibility for the impact of its business activities. For the analysis of Chemical Leasing business models, we introduce two case studies from the water purification and metal degreasing fields, focusing on employees and local communities as two specific stakeholder groups of the company introducing Chemical Leasing. The paper seeks to demonstrate that Chemical Leasing business models can be branded as a corporate social responsibility initiative by outlining the vast potential of Chemical Leasing to improve occupational health and safety and to strengthen the ability of companies to protect the environment from the adverse effects of the chemicals they apply. PMID:24943884

  7. COSYMA: Health effects models

    International Nuclear Information System (INIS)

    As one of the main objectives of the MARIA project (''Methods for Assessing the Radiological Impact of Accidents'') initiated by the Commission of the European Communities the program package COSYMA (''COde SYstem from MARIA'') for assessing the radiological and economic off-site consequences of accidental releases of radioactive material to the atmosphere has been jointly developed by the Kernforschungszentrum Karlsruhe (KfK), FRG, and the National Radiological Protection Board (NRPB), UK. COSYMA includes models and data for assessing a broad spectrum of accident consequences, and they are implemented in independent modules. The subject of this report are those modules, which incorporate models and data for assessing individual and collective risks for deterministic and stochastic health effects. It describes the models implemented, the mathematical algorithms and the required data. Examples are given and explained for the input and output part of the modules. (orig.)

  8. Chemical composition and health effects of Tartary buckwheat.

    Science.gov (United States)

    Zhu, Fan

    2016-07-15

    Tartary buckwheat (Fagopyrum tataricum) contains a range of nutrients including bioactive carbohydrates and proteins, polyphenols, phytosterols, vitamins, carotenoids, and minerals. The unique composition of Tartary buckwheat contributes to their various health benefits such as anti-oxidative, anti-cancer, anti-hypertension, anti-diabetic, cholesterol-lowering, and cognition-improving. Compared with the more widely cultivated and utilised common buckwheat (F. esculentum), Tartary buckwheat tends to contain higher amounts of certain bioactive components such as rutin, therefore, showing higher efficiency in preventing/treating various disorders. This review summarises the current knowledge of the chemical composition of Tartary buckwheat, and their bio-functions as studied by both in vitro and in vivo models. Tartary buckwheat can be further developed as a sustainable crop for functional food production to improve human health.

  9. Chemical composition and health effects of Tartary buckwheat.

    Science.gov (United States)

    Zhu, Fan

    2016-07-15

    Tartary buckwheat (Fagopyrum tataricum) contains a range of nutrients including bioactive carbohydrates and proteins, polyphenols, phytosterols, vitamins, carotenoids, and minerals. The unique composition of Tartary buckwheat contributes to their various health benefits such as anti-oxidative, anti-cancer, anti-hypertension, anti-diabetic, cholesterol-lowering, and cognition-improving. Compared with the more widely cultivated and utilised common buckwheat (F. esculentum), Tartary buckwheat tends to contain higher amounts of certain bioactive components such as rutin, therefore, showing higher efficiency in preventing/treating various disorders. This review summarises the current knowledge of the chemical composition of Tartary buckwheat, and their bio-functions as studied by both in vitro and in vivo models. Tartary buckwheat can be further developed as a sustainable crop for functional food production to improve human health. PMID:26948610

  10. Environmental influences on reproductive health: the importance of chemical exposures.

    Science.gov (United States)

    Wang, Aolin; Padula, Amy; Sirota, Marina; Woodruff, Tracey J

    2016-09-15

    Chemical exposures during pregnancy can have a profound and life-long impact on human health. Because of the omnipresence of chemicals in our daily life, there is continuous contact with chemicals in food, water, air, and consumer products. Consequently, human biomonitoring studies show that pregnant women around the globe are exposed to a variety of chemicals. In this review we provide a summary of current data on maternal and fetal exposure, as well as health consequences from these exposures. We review several chemical classes, including polychlorinated biphenyls, perfluoroalkyl substances, polybrominated diphenyl ethers, phenols, phthalates, pesticides, and metals. Additionally, we discuss environmental disparities and vulnerable populations, and future research directions. We conclude by providing some recommendations for prevention of chemical exposure and its adverse reproductive health consequences. PMID:27513554

  11. Chemical-based risk assessment and in vitro models of human health effects induced by organic pollutants in soils from the Olona valley

    Energy Technology Data Exchange (ETDEWEB)

    Baderna, Diego, E-mail: diego.baderna@marionegri.it; Colombo, Andrea; Amodei, Giorgia; Cantù, Stefano; Teoldi, Federico; Cambria, Felice; Rotella, Giuseppe; Natolino, Fabrizio; Lodi, Marco; Benfenati, Emilio

    2013-10-01

    Risk assessment of soils is usually based on chemical measurements and assuming accidental soil ingestion and evaluating induced toxic and carcinogenic effects. Recently biological tools have been coupled to chemical-based risk assessment since they integrate the biological effects of all xenobiotics in soils. We employed integrated monitoring of soils based on chemical analyses, risk assessment and in vitro models in the highly urbanized semirural area of the Olona Valley in northern Italy. Chemical characterization of the soils indicated low levels of toxic and carcinogenic pollutants such as PAHs, PCDD/Fs, PCBs and HCB and human risk assessment did not give any significant alerts. HepG2 and BALB/c 3T3 cells were used as a model for the human liver and as a tool for the evaluation of carcinogenic potential. Cells were treated with soil extractable organic matters (EOMs) and the MTS assay, LDH release and morphological transformation were selected as endpoints for toxicity and carcinogenicity. Soil EOMs induced dose-dependent inhibition of cell growth at low doses and cytotoxicity after exposure to higher doses. This might be the result of block of cell cycle progression to repair DNA damage caused by oxidative stress; if this DNA damage cannot be repaired, cells die. No significant inductions of foci were recorded after exposure to EOMs. These results indicate that, although the extracts contain compounds with proven carcinogenic potential, the levels of these pollutants in the analyzed soils were too low to induce carcinogenesis in our experimental conditions. In this proposed case study, HepG2 cells were found an appropriate tool to assess the potential harm caused by the ingestion of contaminated soil as they were able to detect differences in the toxicity of soil EOMs. Moreover, the cell transformation assay strengthened the combined approach giving useful information on carcinogenic potential of mixtures. Highlights: • A combined approach for risk

  12. Mathematical Modeling of Chemical Stoichiometry

    Science.gov (United States)

    Croteau, Joshua; Fox, William P.; Varazo, Kristofoland

    2007-01-01

    In beginning chemistry classes, students are taught a variety of techniques for balancing chemical equations. The most common method is inspection. This paper addresses using a system of linear mathematical equations to solve for the stoichiometric coefficients. Many linear algebra books carry the standard balancing of chemical equations as an…

  13. Chemical reactor modeling multiphase reactive flows

    CERN Document Server

    Jakobsen, Hugo A

    2014-01-01

    Chemical Reactor Modeling closes the gap between Chemical Reaction Engineering and Fluid Mechanics.  The second edition consists of two volumes: Volume 1: Fundamentals. Volume 2: Chemical Engineering Applications In volume 1 most of the fundamental theory is presented. A few numerical model simulation application examples are given to elucidate the link between theory and applications. In volume 2 the chemical reactor equipment to be modeled are described. Several engineering models are introduced and discussed. A survey of the frequently used numerical methods, algorithms and schemes is provided. A few practical engineering applications of the modeling tools are presented and discussed. The working principles of several experimental techniques employed in order to get data for model validation are outlined. The monograph is based on lectures regularly taught in the fourth and fifth years graduate courses in transport phenomena and chemical reactor modeling, and in a post graduate course in modern reactor m...

  14. Modeling Microscopic Chemical Sensors in Capillaries

    CERN Document Server

    Hogg, Tad

    2008-01-01

    Nanotechnology-based microscopic robots could provide accurate in vivo measurement of chemicals in the bloodstream for detailed biological research and as an aid to medical treatment. Quantitative performance estimates of such devices require models of how chemicals in the blood diffuse to the devices. This paper models microscopic robots and red blood cells (erythrocytes) in capillaries using realistic distorted cell shapes. The models evaluate two sensing scenarios: robots moving with the cells past a chemical source on the vessel wall, and robots attached to the wall for longer-term chemical monitoring. Using axial symmetric geometry with realistic flow speeds and diffusion coefficients, we compare detection performance with a simpler model that does not include the cells. The average chemical absorption is quantitatively similar in both models, indicating the simpler model is an adequate design guide to sensor performance in capillaries. However, determining the variation in forces and absorption as cells...

  15. A chemical evolution model for galaxy clusters

    OpenAIRE

    Portinari, L.; A. Moretti(Fermilab, Batavia, IL, USA); Chiosi, C.

    2001-01-01

    We develop a toy-model for the chemical evolution of the intracluster medium, polluted by the galactic winds from elliptical galaxies. The model follows the "galaxy formation history" of cluster galaxies, constrained by the observed luminosity function.

  16. Toxikological and health aspects of nonlethal chemical weapons.

    OpenAIRE

    HAMERNÍKOVÁ, Magdalena

    2010-01-01

    ABSTRACT Toxicology and Health Aspects of Non-lethal Chemical Weapons. Non-lethal chemical weapons, which belong among the mass destruction weapons, have been one of the most frequently discussed topics recently. These weapons are able to disbar manpower or combat technology and weapons smartly and temporarily with minimum costs. The range of possible application of chemical weapons as non-lethal is probably wider compared to any other type, and there are a lot of means capable of immediate w...

  17. Towards consensus in chemical characterization modeling for LCA:

    DEFF Research Database (Denmark)

    Rosenbaum, Ralf; Hauschild, Michael Zwicky; Bachmann, Till;

    2006-01-01

    components are and if there can be a consensus model built from them, leading towards recommended practice in chemical characterization for LCIA. The models were selected in an open process inviting all models identified to be capable of characterizing a chemical in terms of environmental fate, human...... exposure, human toxicity and ecotoxicity. The invitation was accepted by the developers of CalTOX, IMPACT 2002, USES-LCA, EDIP, WATSON, and EcoSense. A consistent chemical test set comprising 66 organic (generic, amphiphilic and dissociating) and inorganic (metals, salts) compounds was selected...... representing a wide range of substance property combinations. All compared models showed correlation for human health endpoints for generic organics, with high variations on individual chemicals, typically with high Kow. For the other organics and inorganics, less agreement was observed. Influential processes...

  18. ANIMALS AS SENTINELS OF HUMAN HEALTH HAZARDS OF ENVIRONMENTAL CHEMICALS

    Science.gov (United States)

    A workshop titled "Using Sentinel Species Data to Address the Potential Human Health Effects of Chemicals in the Environmnet," sponsored by the U.S. Army Center for Environmental Health Research, the National Center for Environmental Assessment of the EPA, and the Agency for Toxi...

  19. Coulombic Models in Chemical Bonding.

    Science.gov (United States)

    Sacks, Lawrence J.

    1986-01-01

    Compares the coulumbic point charge model for hydrogen chloride with the valence bond model. It is not possible to assign either a nonpolar or ionic canonical form of the valence bond model, while the covalent-ionic bond distribution does conform to the point charge model. (JM)

  20. Chemical equilibrium modeling of detonation

    Energy Technology Data Exchange (ETDEWEB)

    Fried, Laurence E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bastea, Sorin [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2010-05-19

    Energetic materials are unique for having a strong exothermic reactivity, which has made them desirable for both military and commercial applications. Energetic materials are commonly divided into high explosives, propellants, and pyrotechnics. We will focus on high explosive (HE) materials here, although there is a great deal of commonality between the classes of energetic materials. Furthermore the history of HE materials is long, their condensed-phase chemical properties are poorly understood.

  1. Chemical Kinetic Modeling of Biofuel Combustion

    Science.gov (United States)

    Sarathy, Subram Maniam

    Bioalcohols, such as bioethanol and biobutanol, are suitable replacements for gasoline, while biodiesel can replace petroleum diesel. Improving biofuel engine performance requires understanding its fundamental combustion properties and the pathways of combustion. This study's contribution is experimentally validated chemical kinetic combustion mechanisms for biobutanol and biodiesel. Fundamental combustion data and chemical kinetic mechanisms are presented and discussed to improve our understanding of biofuel combustion. The net environmental impact of biobutanol (i.e., n-butanol) has not been studied extensively, so this study first assesses the sustainability of n-butanol derived from corn. The results indicate that technical advances in fuel production are required before commercializing biobutanol. The primary contribution of this research is new experimental data and a novel chemical kinetic mechanism for n-butanol combustion. The results indicate that under the given experimental conditions, n-butanol is consumed primarily via abstraction of hydrogen atoms to produce fuel radical molecules, which subsequently decompose to smaller hydrocarbon and oxygenated species. The hydroxyl moiety in n-butanol results in the direct production of the oxygenated species such as butanal, acetaldehyde, and formaldehyde. The formation of these compounds sequesters carbon from forming soot precursors, but they may introduce other adverse environmental and health effects. Biodiesel is a mixture of long chain fatty acid methyl esters derived from fats and oils. This research study presents high quality experimental data for one large fatty acid methyl ester, methyl decanoate, and models its combustion using an improved skeletal mechanism. The results indicate that methyl decanoate is consumed via abstraction of hydrogen atoms to produce fuel radicals, which ultimately lead to the production of alkenes. The ester moiety in methyl decanoate leads to the formation of low molecular

  2. Chemical Kinetic Modeling of Advanced Transportation Fuels

    Energy Technology Data Exchange (ETDEWEB)

    PItz, W J; Westbrook, C K; Herbinet, O

    2009-01-20

    Development of detailed chemical kinetic models for advanced petroleum-based and nonpetroleum based fuels is a difficult challenge because of the hundreds to thousands of different components in these fuels and because some of these fuels contain components that have not been considered in the past. It is important to develop detailed chemical kinetic models for these fuels since the models can be put into engine simulation codes used for optimizing engine design for maximum efficiency and minimal pollutant emissions. For example, these chemistry-enabled engine codes can be used to optimize combustion chamber shape and fuel injection timing. They also allow insight into how the composition of advanced petroleum-based and non-petroleum based fuels affect engine performance characteristics. Additionally, chemical kinetic models can be used separately to interpret important in-cylinder experimental data and gain insight into advanced engine combustion processes such as HCCI and lean burn engines. The objectives are: (1) Develop detailed chemical kinetic reaction models for components of advanced petroleum-based and non-petroleum based fuels. These fuels models include components from vegetable-oil-derived biodiesel, oil-sand derived fuel, alcohol fuels and other advanced bio-based and alternative fuels. (2) Develop detailed chemical kinetic reaction models for mixtures of non-petroleum and petroleum-based components to represent real fuels and lead to efficient reduced combustion models needed for engine modeling codes. (3) Characterize the role of fuel composition on efficiency and pollutant emissions from practical automotive engines.

  3. Safety, health and environmental committee (JKSHE): Establishing chemical hazard management

    International Nuclear Information System (INIS)

    Most of the laboratories in Malaysian Nuclear Agency are using chemicals in their research activities. However, it is known that using of chemicals without proper knowledge especially on the material characteristics as well as safe handling procedure may cause great harm to the workers. Therefore, Safety, Health and Environmental Committee (JKSHE) sees the need to establish a good chemical hazard management to ensure that a safe and healthy workplace and environment is provided. One of the elements in chemical hazard management is to carry out Chemical Hazard Risk Assessment (CHRA). The assessment was done so that decision can be made on suitable control measures upon use of such chemicals, such as induction and training courses to be given to the workers and health surveillance activities that may be needed to protect the workers. For this, JKSHE has recommended to conduct CHRA for one of the laboratories at Secondary Standard Dosimetry Laboratory (SSDL) namely Film Dosimeter Processing Room (dark room) as the initial effort towards a better chemical hazard management. This paper presents the case study where CHRA was conducted to identify the chemical hazards at the selected laboratory, the adequacy of existing control measures and finally the recommendation for more effective control measures. (author)

  4. Health and environmental effects of complex chemical mixtures: proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1985-01-01

    The Office of Health and Environmental Research (OHER) of the Department of Energy supports a broad long-term research program on human health and environmental effects from potential exposure to energy-related complex chemical mixtures. The program seeks basic mechanistic data on the effects of complex mixtures at the cellular, molecular, and whole animal levels to aid in predicting human health effects and seeks ecological data on biological and physical transformations in the mixtures, concentrations of the mixtures in various compartments of the environment, and potential routes for human exposure to these mixtures (e.g., food chain). On June 17-18, 1985, OHER held its First Annual Technical Meeting on the Complex Chemical Mixtures Program in Chicago, IL. The primary purpose of the meeting was to enable principal investigators to report the research status and accomplishments of ongoing complex chemical mixture studies supported by OHER. To help focus future research directions round table discussions were conducted.

  5. Mathematical modeling a chemical engineer's perspective

    CERN Document Server

    Rutherford, Aris

    1999-01-01

    Mathematical modeling is the art and craft of building a system of equations that is both sufficiently complex to do justice to physical reality and sufficiently simple to give real insight into the situation. Mathematical Modeling: A Chemical Engineer's Perspective provides an elementary introduction to the craft by one of the century's most distinguished practitioners.Though the book is written from a chemical engineering viewpoint, the principles and pitfalls are common to all mathematical modeling of physical systems. Seventeen of the author's frequently cited papers are reprinted to illus

  6. Public Health Risk Conditioned by Chemical Composition of Ground Water

    Science.gov (United States)

    Yankovich, E.; Osipova, N.; Yankovich, K.; Matveenko, I.

    2016-03-01

    The article studies the public health potential risk originated from water consumption and estimated on the basis of the groundwater chemical composition. We have processed the results of chemical groundwater analysis in different aquifers of Tomsk district (Tomsk Oblast, Russia). More than 8400 samples of chemical groundwater analyses were taken during long-term observation period. Human health risk assessment of exposure to contaminants in drinking water was performed in accordance with the risk assessment guidance for public health concerning chemical pollution of the environment (Russian reference number: 2.1.10.1920-04-M, 2004). Identified potential risks were estimated for consuming water of each aquifer. The comparative analysis of water quality of different aquifers was performed on the basis of the risk coefficient of the total non-carcinogenic effects. The non-carcinogenic risk for the health of the Tomsk district population due to groundwater consumption without prior sanitary treatment was admitted acceptable. A rather similar picture is observed for all aquifers, although deeper aquifers show lower hazard coefficients.

  7. Exposure to Endocrine Disrupting Chemicals and Male Reproductive Health

    Directory of Open Access Journals (Sweden)

    Hueiwang Anna Jeng

    2014-06-01

    Full Text Available Endocrine disrupting chemicals (EDCs can interfere with normal hormonal balance and may exert adverse consequences on humans. The male reproductive system may be susceptible to the effects of such environmental toxicants. This review discusses the recent progress in scientific data mainly from epidemiology studies on the associations between EDCs and male reproductive health and our understanding of possible mechanisms associated with the effects of EDCs on male reproductive health. Finally, the review provides recommendations on future research to enhance our understanding of EDCs and male reproductive health. The review highlights the need for 1 well-defined longitudinal epidemiology studies, with appropriately designed exposure assessment to determine potential causal relationships; 2 chemical and biochemical approaches aimed at a better understanding of the mechanism of action of xenoestrogens with regard to low-dose effects, and assessment of identify genetic susceptibility factors associated with the risk of adverse effects following exposure to EDCs.

  8. Chemical Evolution models of Local Group galaxies

    CERN Document Server

    Tosi, M P

    2003-01-01

    Status quo and perspectives of standard chemical evolution models of Local Group galaxies are summarized, discussing what we have learnt from them, what we know we have not learnt yet, and what I think we will learn in the near future. It is described how Galactic chemical evolution models have helped showing that: i) stringent constraints on primordial nucleosynthesis can be derived from the observed Galactic abundances of the light elements, ii) the Milky Way has been accreting external gas from early epochs to the present time, iii) the vast majority of Galactic halo stars have formed quite rapidly at early epochs. Chemical evolution models for the closest dwarf galaxies, although still uncertain so far, are expected to become extremely reliable in the nearest future, thanks to the quality of new generation photometric and spectroscopic data which are currently being acquired.

  9. Communication models in environmental health.

    Science.gov (United States)

    Guidotti, Tee L

    2013-01-01

    Communication models common in environmental health are not well represented in the literature on health communication. Risk communication is a systematic approach to conveying essential information about a specific environmental issue and a framework for thinking about community risk and the alternatives for dealing with it. Crisis communication is intended to provide essential information to people facing an emergency in order to mitigate its effects and to enable them to make appropriate decisions, and it is primarily used in emergency management. Corporate communication is intended to achieve a change in attitude or perception of an organization, and its role in environmental health is usually public relations or to rehabilitate a damaged reputation. Environmental health education is a more didactic approach to science education with respect to health and the environment. Social marketing uses conventional marketing methods to achieve a socially desirable purpose but is more heavily used in health promotion generally. Communication models and styles in environmental health are specialized to serve the needs of the field in communicating with the community. They are highly structured and executed in different ways but have in common a relative lack of emphasis on changing personal or lifestyle behavior compared with health promotion and public health in general and a tendency to emphasize content on specific environmental issues and decision frameworks for protecting oneself or the community through collective action. PMID:23898914

  10. Communication models in environmental health.

    Science.gov (United States)

    Guidotti, Tee L

    2013-01-01

    Communication models common in environmental health are not well represented in the literature on health communication. Risk communication is a systematic approach to conveying essential information about a specific environmental issue and a framework for thinking about community risk and the alternatives for dealing with it. Crisis communication is intended to provide essential information to people facing an emergency in order to mitigate its effects and to enable them to make appropriate decisions, and it is primarily used in emergency management. Corporate communication is intended to achieve a change in attitude or perception of an organization, and its role in environmental health is usually public relations or to rehabilitate a damaged reputation. Environmental health education is a more didactic approach to science education with respect to health and the environment. Social marketing uses conventional marketing methods to achieve a socially desirable purpose but is more heavily used in health promotion generally. Communication models and styles in environmental health are specialized to serve the needs of the field in communicating with the community. They are highly structured and executed in different ways but have in common a relative lack of emphasis on changing personal or lifestyle behavior compared with health promotion and public health in general and a tendency to emphasize content on specific environmental issues and decision frameworks for protecting oneself or the community through collective action.

  11. Consequence and Resilience Modeling for Chemical Supply Chains

    Science.gov (United States)

    Stamber, Kevin L.; Vugrin, Eric D.; Ehlen, Mark A.; Sun, Amy C.; Warren, Drake E.; Welk, Margaret E.

    2011-01-01

    The U.S. chemical sector produces more than 70,000 chemicals that are essential material inputs to critical infrastructure systems, such as the energy, public health, and food and agriculture sectors. Disruptions to the chemical sector can potentially cascade to other dependent sectors, resulting in serious national consequences. To address this concern, the U.S. Department of Homeland Security (DHS) tasked Sandia National Laboratories to develop a predictive consequence modeling and simulation capability for global chemical supply chains. This paper describes that capability , which includes a dynamic supply chain simulation platform called N_ABLE(tm). The paper also presents results from a case study that simulates the consequences of a Gulf Coast hurricane on selected segments of the U.S. chemical sector. The case study identified consequences that include impacted chemical facilities, cascading impacts to other parts of the chemical sector. and estimates of the lengths of chemical shortages and recovery . Overall. these simulation results can DHS prepare for and respond to actual disruptions.

  12. Health insurance basic actuarial models

    CERN Document Server

    Pitacco, Ermanno

    2014-01-01

    Health Insurance aims at filling a gap in actuarial literature, attempting to solve the frequent misunderstanding in regards to both the purpose and the contents of health insurance products (and ‘protection products’, more generally) on the one hand, and the relevant actuarial structures on the other. In order to cover the basic principles regarding health insurance techniques, the first few chapters in this book are mainly devoted to the need for health insurance and a description of insurance products in this area (sickness insurance, accident insurance, critical illness covers, income protection, long-term care insurance, health-related benefits as riders to life insurance policies). An introduction to general actuarial and risk-management issues follows. Basic actuarial models are presented for sickness insurance and income protection (i.e. disability annuities). Several numerical examples help the reader understand the main features of pricing and reserving in the health insurance area. A short int...

  13. Radiative transfer modeling of surface chemical deposits

    Science.gov (United States)

    Reichardt, Thomas A.; Kulp, Thomas J.

    2016-05-01

    Remote detection of a surface-bound chemical relies on the recognition of a pattern, or "signature," that is distinct from the background. Such signatures are a function of a chemical's fundamental optical properties, but also depend upon its specific morphology. Importantly, the same chemical can exhibit vastly different signatures depending on the size of particles composing the deposit. We present a parameterized model to account for such morphological effects on surface-deposited chemical signatures. This model leverages computational tools developed within the planetary and atmospheric science communities, beginning with T-matrix and ray-tracing approaches for evaluating the scattering and extinction properties of individual particles based on their size and shape, and the complex refractive index of the material itself. These individual-particle properties then serve as input to the Ambartsumian invariant imbedding solution for the reflectance of a particulate surface composed of these particles. The inputs to the model include parameters associated with a functionalized form of the particle size distribution (PSD) as well as parameters associated with the particle packing density and surface roughness. The model is numerically inverted via Sandia's Dakota package, optimizing agreement between modeled and measured reflectance spectra, which we demonstrate on data acquired on five size-selected silica powders over the 4-16 μm wavelength range. Agreements between modeled and measured reflectance spectra are assessed, while the optimized PSDs resulting from the spectral fitting are then compared to PSD data acquired from independent particle size measurements.

  14. Chemical Kinetic Modeling of 2-Methylhexane Combustion

    KAUST Repository

    Mohamed, Samah Y.

    2015-03-30

    Accurate chemical kinetic combustion models of lightly branched alkanes (e.g., 2-methylalkanes) are important for investigating the combustion behavior of diesel, gasoline, and aviation fuels. Improving the fidelity of existing kinetic models is a necessity, as new experiments and advanced theories show inaccuracy in certain portions of the models. This study focuses on updating thermodynamic data and kinetic model for a gasoline surrogate fuel, 2-methylhexane, with recently published group values and rate rules. These update provides a better agreement with rapid compression machine measurements of ignition delay time, while also strengthening the fundamental basis of the model.

  15. Application of Physiologically Based Pharmacokinetic Models in Chemical Risk Assessment

    Directory of Open Access Journals (Sweden)

    Moiz Mumtaz

    2012-01-01

    Full Text Available Post-exposure risk assessment of chemical and environmental stressors is a public health challenge. Linking exposure to health outcomes is a 4-step process: exposure assessment, hazard identification, dose response assessment, and risk characterization. This process is increasingly adopting “in silico” tools such as physiologically based pharmacokinetic (PBPK models to fine-tune exposure assessments and determine internal doses in target organs/tissues. Many excellent PBPK models have been developed. But most, because of their scientific sophistication, have found limited field application—health assessors rarely use them. Over the years, government agencies, stakeholders/partners, and the scientific community have attempted to use these models or their underlying principles in combination with other practical procedures. During the past two decades, through cooperative agreements and contracts at several research and higher education institutions, ATSDR funded translational research has encouraged the use of various types of models. Such collaborative efforts have led to the development and use of transparent and user-friendly models. The “human PBPK model toolkit” is one such project. While not necessarily state of the art, this toolkit is sufficiently accurate for screening purposes. Highlighted in this paper are some selected examples of environmental and occupational exposure assessments of chemicals and their mixtures.

  16. In-Space Chemical Propulsion System Model

    Science.gov (United States)

    Byers, David C.; Woodcock, Gordon; Benfield, Michael P. J.

    2004-01-01

    Multiple, new technologies for chemical systems are becoming available and include high temperature rockets, very light propellant tanks and structures, new bipropellant and monopropellant options, lower mass propellant control components, and zero boil off subsystems. Such technologies offer promise of increasing the performance of in-space chemical propulsion for energetic space missions. A mass model for pressure-fed, Earth and space-storable, advanced chemical propulsion systems (ACPS) was developed in support of the NASA MSFC In-Space Propulsion Program. Data from flight systems and studies defined baseline system architectures and subsystems and analyses were formulated for parametric scaling relationships for all ACPS subsystem. The paper will first provide summary descriptions of the approaches used for the systems and the subsystems and then present selected analyses to illustrate use of the model for missions with characteristics of current interest.

  17. Modelling Chemical Reasoning to Predict Reactions

    CERN Document Server

    Segler, Marwin H S

    2016-01-01

    The ability to reason beyond established knowledge allows Organic Chemists to solve synthetic problems and to invent novel transformations. Here, we propose a model which mimics chemical reasoning and formalises reaction prediction as finding missing links in a knowledge graph. We have constructed a knowledge graph containing 14.4 million molecules and 8.2 million binary reactions, which represents the bulk of all chemical reactions ever published in the scientific literature. Our model outperforms a rule-based expert system in the reaction prediction task for 180,000 randomly selected binary reactions. We show that our data-driven model generalises even beyond known reaction types, and is thus capable of effectively (re-) discovering novel transformations (even including transition-metal catalysed reactions). Our model enables computers to infer hypotheses about reactivity and reactions by only considering the intrinsic local structure of the graph, and because each single reaction prediction is typically ac...

  18. Using chemical organization theory for model checking

    OpenAIRE

    Kaleta, Christoph; Richter, Stephan; Dittrich, Peter

    2009-01-01

    Motivation: The increasing number and complexity of biomodels makes automatic procedures for checking the models' properties and quality necessary. Approaches like elementary mode analysis, flux balance analysis, deficiency analysis and chemical organization theory (OT) require only the stoichiometric structure of the reaction network for derivation of valuable information. In formalisms like Systems Biology Markup Language (SBML), however, information about the stoichiometric coefficients re...

  19. Chemical and Hydrodynamical Models of Cometary Comae

    Science.gov (United States)

    Charnley, Steven

    2012-01-01

    Multi-fluid modelling of the outflowing gases which sublimate from cometary nuclei as they approach the Sun is necessary for understanding the important physical and chemical processes occurring in this complex plasma. Coma chemistry models can be employed to interpret observational data and to ultimately determine chemical composition and structure of the nuclear ices and dust. We describe a combined chemical and hydrodynamical model [1] in which differential equations for the chemical abundances and the energy balance are solved as a function of distance from the cometary nucleus. The presence of negative ions (anions) in cometary comae is known from Giotto mass spectrometry of 1P/Halley. The anions O(-), OH(-), C(-), CH(-) and CN(-) have been detected, as well as unidentified anions with masses 22-65 and 85-110 amu [2]. Organic molecular anions such as C4H(-) and C6H(-) are known to have a significant impact on the charge balance of interstellar clouds and circumstellar envelopes and have been shown to act as catalysts for the gas-phase synthesis of larger hydrocarbon molecules in the ISM, but their importance in cometary comae has not yet been fully explored. We present details of new models for the chemistry of cometary comae that include atomic and molecular anions and calculate the impact of these anions on the coma physics and chemistry af the coma.

  20. Chemical toxicity and radiological health detriment associated with the inhalation of various enrichments of uranium

    International Nuclear Information System (INIS)

    The occupational risks associated with the chemical toxicity of uranium can be overlooked during the processing, handling and storage of the material, as the radioactivity of the material is often used alone to assess the health consequences of exposure to uranium compounds. This note provides a summary of the current United Kingdom occupational standards for uranium based on radiation dose and/or chemical toxicity with a particular focus on intake via inhalation. A simple model is subsequently presented to allow a comparison to be drawn between the occupational exposure standard for chemical toxicity and radiological dose limit. Using these data a set of suggested limits on occupational exposure to airborne uranium is proposed that indicate where the legal annual radiological dose limit for workers or the Health and Safety Executive occupational exposure standard for chemical toxicity are at risk of being breached. (note)

  1. Modeling heterogeneous chemical processes on aerosol surface

    Institute of Scientific and Technical Information of China (English)

    Junjun Deng; Tijian Wang; Li Liu; Fei Jiang

    2010-01-01

    To explore the possible impact of heterogeneous chemical processes on atmospheric trace components,a coupled box model including gas-phase chemical processes,aerosol thermodynamic equilibrium processes,and heterogeneous chemical processes on the surface of dust,black carbon(BC)and sea salt is set up to simulate the effects of heterogeneous chemistry on the aerosol surface,and analyze the primary factors affecting the heterogeneous processes.Results indicate that heterogeneous chemical processes on the aerosol surface in the atmosphere will affect the concentrations of trace gases such as H2O2,HO2,O3,NO2,NO3,HNO3 and SO2,and aerosols such as SO42-,NO3-and NH4+.Sensitivity tests suggest that the magnitude of the impact of heterogeneous processes strongly depends on aerosol concentration and the surface uptake coefficients used in the box model.However,the impact of temperature on heterogeneous chemical processes is considerably less.The"renoxification"of HNO3 will affect the components of the troposphere such as nitrogen oxide and ozone.

  2. Synergistic health effects between chemical pollutants and electromagnetic fields.

    Science.gov (United States)

    Ledoigt, Gérard; Sta, Chaima; Goujon, Eric; Souguir, Dalila; El Ferjani, Ezzeddine

    2015-01-01

    Humans and ecosystems are exposed to highly variable and unknown cocktail of chemicals and radiations. Although individual chemicals are typically present at low concentrations, they can interact with each other resulting in additive or potentially synergistic mixture effects. This was also observed with products obtained by radiation actions such as sunlight or electromagnetic fields that can change the effects of chemicals, such as pesticides, and metal trace elements on health. Concomitant presence of various pesticides and their transformation products adds further complexity to chemical risk assessment since chronic inflammation is a key step for cancer promotion. Degradation of a parent molecule can produce several by-products which can trigger various toxic effects with different impacts on health and environment. For instance, the cocktail of sunlight irradiated sulcotrione pesticide has a greater cytotoxicity and genotoxicity than parent molecule, sulcotrione, and questions about the impact of photochemical process on environment. Adjuvants were shown to modify the biological features of pesticides. Addition of other elements, metals or biological products, can differently enhance cell toxicity of pesticides or electromagnetic radiations suggesting a synergy in living organisms. Electromagnetic fields spreading, pesticide by-products and mixtures monitoring become greater for environmental contamination evaluations.

  3. Exploring Contextual Models in Chemical Patent Search

    Science.gov (United States)

    Urbain, Jay; Frieder, Ophir

    We explore the development of probabilistic retrieval models for integrating term statistics with entity search using multiple levels of document context to improve the performance of chemical patent search. A distributed indexing model was developed to enable efficient named entity search and aggregation of term statistics at multiple levels of patent structure including individual words, sentences, claims, descriptions, abstracts, and titles. The system can be scaled to an arbitrary number of compute instances in a cloud computing environment to support concurrent indexing and query processing operations on large patent collections.

  4. 75 FR 4402 - Notice of National Conversation on Public Health and Chemical Exposures Leadership Council...

    Science.gov (United States)

    2010-01-27

    ... Health and Chemical Exposures Leadership Council Conference Call Time and Date: 1 p.m.-3 p.m., Friday... National Conversation on Public Health and Chemical Exposures Leadership Council. The National Conversation... protecting the public's health from harmful chemical exposures. The Leadership Council provides...

  5. New trajectory driven aerosol and chemical process model: chemical and aerosol Lagrangian model (CALM)

    OpenAIRE

    Tunved, P.; D. G. Partridge; Korhonen, H.

    2010-01-01

    A new Chemical and Aerosol Lagrangian Model (CALM) have been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61°51' N, 24°17' E) over a time period of two years, 2000–2001. The model shows good agreement with measurements thro...

  6. Impact of environmental chemicals, sociodemographic variables, depression, and clinical indicators of health and nutrition on self-reported health status

    Science.gov (United States)

    Public health researchers ideally integrate social, environmental, and clinical measures to identify predictors of poor health. Chemicals measured in human tissues are often evaluated in relation to intangible or rare health outcomes, or are studied one chemical at a time. Using ...

  7. International issues on human health effects of exposure to chemical mixtures.

    OpenAIRE

    Feron, Victor J; Cassee, Flemming R; Groten, John P.; van Vliet, Petronella W; van Zorge, Job A

    2002-01-01

    In this article, we highlight new developments and recent studies concerning adverse human health effects related to chemical mixtures. One group of activities comprises the development of a new computer program for analyzing mixture studies and a mathematical model as a basis for combination rules that predict the toxicity of mixtures. Other new activities in the area of experimental studies are the application of gene expression technologies in mixture research, and pattern recognition as a...

  8. "Human Health Impact Characterization of Toxic Chemicals for Sustainable Design and Manufacturing

    OpenAIRE

    Yuan, Chris; Dornfeld, David

    2009-01-01

    A schematic method to characterize the human health impact of toxic chemicals is presented. This schematic method uses a streamlined three-tiered hierarchy process which includes intake, toxicity and persistence of a chemical release for its impact characterization. The human health impact of a chemical is represented by its position in a two-dimensional characterization plot, which enables the benchmarking of chemicals to be easily made by comparing the relative positions of the chemicals in...

  9. Pool chemical-associated health events in public and residential settings - United States, 2003-2012, and Minnesota, 2013.

    Science.gov (United States)

    Hlavsa, Michele C; Robinson, Trisha J; Collier, Sarah A; Beach, Michael J

    2014-05-16

    Pool chemicals are added to treated recreational water venues (e.g., pools, hot tubs/spas, and interactive fountains) primarily to protect public health by inactivating pathogens and maximizing the effectiveness of disinfection by controlling pH. However, pool chemicals also can cause injuries when handled or stored improperly. To estimate the number of emergency department (ED) visits for injuries associated with pool chemicals in the United States per year during 2003-2012, CDC analyzed data from the U.S. Consumer Product Safety Commission's National Electronic Injury Surveillance System (NEISS). This report summarizes the results of that analysis. In 2012 alone, an estimated 4,876 persons (95% confidence interval [CI] = 2,821-6,930) visited an ED for injuries associated with pool chemicals. Almost half of the patients were aged pool chemical-associated health event that occurred in Minnesota in 2013, which sent seven children and one adult to an ED. An investigation by the Minnesota Department of Health (MDH) determined the cause to be poor monitoring of or response to pool chemistry. Pool chemical-associated health events are preventable. CDC's Model Aquatic Health Code (MAHC) (1) is a resource that state and local agencies can use to optimize prevention of injuries and illnesses associated with public treated recreational water venues, including pool chemical-associated health events.

  10. Cleaner combustion developing detailed chemical kinetic models

    CERN Document Server

    Battin-Leclerc, Frédérique; Blurock, Edward

    2013-01-01

    This overview compiles the on-going research in Europe to enlarge and deepen the understanding of the reaction mechanisms and pathways associated with the combustion of an increased range of fuels. Focus is given to the formation of a large number of hazardous minor pollutants and the inability of current combustion models to predict the  formation of minor products such as alkenes, dienes, aromatics, aldehydes and soot nano-particles which have a deleterious impact on both the environment and on human health. Cleaner Combustion describes, at a fundamental level, the reactive chemistry of min

  11. Uncertainties in Galactic Chemical Evolution Models

    Science.gov (United States)

    Côté, Benoit; Ritter, Christian; O’Shea, Brian W.; Herwig, Falk; Pignatari, Marco; Jones, Samuel; Fryer, Chris L.

    2016-06-01

    We use a simple one-zone galactic chemical evolution model to quantify the uncertainties generated by the input parameters in numerical predictions for a galaxy with properties similar to those of the Milky Way. We compiled several studies from the literature to gather the current constraints for our simulations regarding the typical value and uncertainty of the following seven basic parameters: the lower and upper mass limits of the stellar initial mass function (IMF), the slope of the high-mass end of the stellar IMF, the slope of the delay-time distribution function of Type Ia supernovae (SNe Ia), the number of SNe Ia per M ⊙ formed, the total stellar mass formed, and the final mass of gas. We derived a probability distribution function to express the range of likely values for every parameter, which were then included in a Monte Carlo code to run several hundred simulations with randomly selected input parameters. This approach enables us to analyze the predicted chemical evolution of 16 elements in a statistical manner by identifying the most probable solutions, along with their 68% and 95% confidence levels. Our results show that the overall uncertainties are shaped by several input parameters that individually contribute at different metallicities, and thus at different galactic ages. The level of uncertainty then depends on the metallicity and is different from one element to another. Among the seven input parameters considered in this work, the slope of the IMF and the number of SNe Ia are currently the two main sources of uncertainty. The thicknesses of the uncertainty bands bounded by the 68% and 95% confidence levels are generally within 0.3 and 0.6 dex, respectively. When looking at the evolution of individual elements as a function of galactic age instead of metallicity, those same thicknesses range from 0.1 to 0.6 dex for the 68% confidence levels and from 0.3 to 1.0 dex for the 95% confidence levels. The uncertainty in our chemical evolution model

  12. Status of dental health in chemical warfare victims: The case of Isfahan, Iran

    Directory of Open Access Journals (Sweden)

    Ahmad Mottaghi

    2012-01-01

    Conclusion: Chemical warfare victims have relatively poor dental/oral health. Chemical injury might cause a dysfunction in saliva secretion, with decrease in saliva secretion increasing the risk for tooth decay and periodontal disorders. Further research is required to find out the exact underlying mechanisms and the factors associated with poor dental/oral health in chemical warfare victims.

  13. New trajectory-driven aerosol and chemical process model Chemical and Aerosol Lagrangian Model (CALM)

    OpenAIRE

    Tunved, P.; D. G. Partridge; Korhonen, H.

    2010-01-01

    A new Chemical and Aerosol Lagrangian Model (CALM) has been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61° 51' N, 24° 17' E) over a time period of two years, 2000–2001. The model shows good agreement with measurements throughout mos...

  14. The Impact of Modeling Assumptions in Galactic Chemical Evolution Models

    CERN Document Server

    Côté, Benoit; Ritter, Christian; Herwig, Falk; Venn, Kim A

    2016-01-01

    We use the OMEGA galactic chemical evolution code to investigate how the assumptions used for the treatment of galactic inflows and outflows impact numerical predictions. The goal is to determine how our capacity to reproduce the chemical evolution trends of a galaxy is affected by the choice of implementation used to include those physical processes. In pursuit of this goal, we experiment with three different prescriptions for galactic inflows and outflows and use OMEGA within a Markov Chain Monte Carlo code to recover the set of input parameters that best reproduces the chemical evolution of nine elements in the dwarf spheroidal galaxy Sculptor. Despite their different degrees of intended physical realism, we found that all three prescriptions can reproduce in an almost identical way the stellar abundance trends observed in Sculptor. While the three models have the same capacity to fit the data, the best values recovered for the parameters controlling the number of Type Ia supernovae and the strength of gal...

  15. A kinetic model for chemical neurotransmission

    Science.gov (United States)

    Ramirez-Santiago, Guillermo; Martinez-Valencia, Alejandro; Fernandez de Miguel, Francisco

    Recent experimental observations in presynaptic terminals at the neuromuscular junction indicate that there are stereotyped patterns of cooperativeness in the fusion of adjacent vesicles. That is, a vesicle in hemifusion process appears on the side of a fused vesicle and which is followed by another vesicle in a priming state while the next one is in a docking state. In this talk we present a kinetic model for this morphological pattern in which each vesicle state previous to the exocytosis is represented by a kinetic state. This chain states kinetic model can be analyzed by means of a Master equation whose solution is simulated with the stochastic Gillespie algorithm. With this approach we have reproduced the responses to the basal release in the absence of stimulation evoked by the electrical activity and the phenomena of facilitation and depression of neuromuscular synapses. This model offers new perspectives to understand the underlying phenomena in chemical neurotransmission based on molecular interactions that result in the cooperativity between vesicles during neurotransmitter release. DGAPA Grants IN118410 and IN200914 and Conacyt Grant 130031.

  16. Chemical cleaning specification: few tube test model

    International Nuclear Information System (INIS)

    The specification is for the waterside chemical cleaning of the 2 1/4 Cr - 1 Mo steel steam generator tubes. It describes the reagents and conditions for post-chemical cleaning passivation of the evaporator tubes

  17. A mesoscale chemical transport model (MEDIUM) nested in a global chemical transport model (MEDIANTE)

    Energy Technology Data Exchange (ETDEWEB)

    Claveau, J.; Ramaroson, R. [Office National d`Etudes et de Recherches Aerospatiales (ONERA), 92 - Chatillon (France)

    1997-12-31

    The lower stratosphere and upper troposphere (UT-LS) are frequently subject to mesoscale or local scale exchange of air masses occurring along discontinuities. This exchange (e.g. downward) can constitute one of the most important source of ozone from the stratosphere down to the middle troposphere where strong mixing dilutes the air mass and competing the non-linear chemistry. The distribution of the chemical species in the troposphere and the lower stratosphere depends upon various source emissions, e.g. from polluted boundary layer or from aircraft emissions. Global models, as well as chemical transport models describe the climatological state of the atmosphere and are not able to describe correctly the stratosphere and troposphere exchange. Mesoscale models go further in the description of smaller scales and can reasonably include a rather detailed chemistry. They can be used to assess the budget of NO{sub x} from aircraft emissions in a mesoscale domain. (author) 4 refs.

  18. Epigenome: A Biomarker or Screening Tool to Evaluate Health Impact of Cumulative Exposure to Chemical and Non-Chemical Stressors.

    Science.gov (United States)

    Olden, Kenneth; Lin, Yu-Sheng; Bussard, David

    2016-06-01

    Current risk assessment practices and toxicity information are hard to utilize for assessing the health impact of combined or cumulative exposure to multiple chemical and non-chemical stressors encountered in the "real world" environment. Non-chemical stressors such as heat, radiation, noise, humidity, bacterial and viral agents, and social factors, like stress related to violence and socioeconomic position generally cannot be currently incorporated into the risk assessment paradigm. The Science and Decisions report released by the National Research Council (NRC) in 2009 emphasized the need to characterize the effects of multiple stressors, both chemical and non-chemical exposures. One impediment to developing information relating such non-chemical stressors to health effects and incorporating them into cumulative assessment has been the lack of analytical tools to easily and quantitatively monitor the cumulative exposure to combined effects of stressors over the life course.

  19. Epigenome: A Biomarker or Screening Tool to Evaluate Health Impact of Cumulative Exposure to Chemical and Non-Chemical Stressors.

    Science.gov (United States)

    Olden, Kenneth; Lin, Yu-Sheng; Bussard, David

    2016-06-01

    Current risk assessment practices and toxicity information are hard to utilize for assessing the health impact of combined or cumulative exposure to multiple chemical and non-chemical stressors encountered in the "real world" environment. Non-chemical stressors such as heat, radiation, noise, humidity, bacterial and viral agents, and social factors, like stress related to violence and socioeconomic position generally cannot be currently incorporated into the risk assessment paradigm. The Science and Decisions report released by the National Research Council (NRC) in 2009 emphasized the need to characterize the effects of multiple stressors, both chemical and non-chemical exposures. One impediment to developing information relating such non-chemical stressors to health effects and incorporating them into cumulative assessment has been the lack of analytical tools to easily and quantitatively monitor the cumulative exposure to combined effects of stressors over the life course. PMID:27534725

  20. A proposed health model: a step before model confirmation.

    Science.gov (United States)

    Gauff, J F

    1992-01-01

    Health marketers have devoted extensive conceptual and empirical effort toward explaining and predicting individuals' health-related decisions. This paper proposes a health behavior model by combining the health belief model and the theory of planned behavior model. Recent modifications of the Fishbein and Ajzen (1975) model are discussed and an extension is introduced to better explain goal pursuit. These revisions (Bagozzi and Warshaw 1990) are incorporated in the proposed model. PMID:10124784

  1. THE USE OF CHEMICALS IN THE FIELD OF FARM ANIMAL HEALTH (NUTRITION, ENTOMOLOGY, PATHOLOGY). AGRICULTURAL CHEMICALS TECHNOLOGY, NUMBER 7.

    Science.gov (United States)

    Ohio State Univ., Columbus. Center for Vocational and Technical Education.

    DEVELOPED BY A NATIONAL TASK FORCE ON THE BASIS OF STATE STUDIES, THIS MODULE IS ONE OF A SERIES DESIGNED TO ASSIST TEACHERS IN PREPARING POST-SECONDARY STUDENTS FOR AGRICULTURAL CHEMICAL OCCUPATIONS. THE SPECIFIC OBJECTIVE OF THIS MODULE IS TO PREPARE TECHNICIANS IN THE FIELD OF THE USE OF CHEMICALS FOR ANIMAL HEALTH. SECTIONS INCLUDE -- (1)…

  2. Comparative dynamics in a health investment model.

    Science.gov (United States)

    Eisenring, C

    1999-10-01

    The method of comparative dynamics fully exploits the inter-temporal structure of optimal control models. I derive comparative dynamic results in a simplified demand for health model. The effect of a change in the depreciation rate on the optimal paths for health capital and investment in health is studied by use of a phase diagram.

  3. A generalized physiologically-based toxicokinetic modeling system for chemical mixtures containing metals

    Directory of Open Access Journals (Sweden)

    Isukapalli Sastry S

    2010-06-01

    -to-dose-to-effect" framework for modeling population health risks from environmental contaminants. As new data become available on interactions of multiple chemicals, the GTMM can be iteratively parameterized to improve mechanistic understanding of human health risks from exposures to complex mixtures of chemicals.

  4. Modeling Per Capita State Health Expenditure Variat...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Modeling Per Capita State Health Expenditure Variation State-Level Characteristics Matter, published in Volume 3, Issue 4, of the Medicare and Medicaid Research...

  5. Chemical Mechanism Solvers in Air Quality Models

    OpenAIRE

    Linford, John C.; Adrian Sandu; Rolf Sander; Hong Zhang

    2011-01-01

    The solution of chemical kinetics is one of the most computationally intensive tasks in atmospheric chemical transport simulations. Due to the stiff nature of the system, implicit time stepping algorithms which repeatedly solve linear systems of equations are necessary. This paper reviews the issues and challenges associated with the construction of efficient chemical solvers, discusses several families of algorithms, presents strategies for increasing computational efficiency, and gives insi...

  6. Contamination weeping: A chemical ion exchange model

    International Nuclear Information System (INIS)

    Experiments have been conducted to determine the applicability of a chemical ion-exchange model to characterize the problem of nuclear fuel transportation cask contamination and release (''weeping''). Surface charge characteristics of Cr2O3 and stainless steel (304) powders have been measured to determine the potential for ion exchange at metal oxide -- aqueous interfaces. The solubility of pool contaminant Co and Cs electrolytes at varying pH and the adsorption characteristics of these ions on Cr2O3 and stainless steel powders in aqueous slurries have been studied. Experiments show that Co ions do reversibly adsorb on these powder surfaces and, more specifically, that adsorption occurs in the nominal pH range (pH = 4--6) of a boric acid-moderated spent fuel pool. Desorption has been demonstrated to occur at pH ≤ 3. Cs ions also have been shown to have an affinity for these surfaces although the reversibility of Cs+ bonding by H+ ion exchange has not been fully demonstrated. These results have significant implications for effective decontamination and coating processes used on nuclear fuel transportation casks. 9 refs., 5 figs., 1 tab

  7. The chemical transport model Oslo CTM3

    Directory of Open Access Journals (Sweden)

    O. A. Søvde

    2012-06-01

    Full Text Available We present here the global chemical transport model Oslo CTM3, an update of the Oslo CTM2. The update comprises a faster transport scheme, an improved wet scavenging scheme for large scale rain, updated photolysis rates and a new lightning parameterization. Oslo CTM3 is better parallelized and allows for stable, large time steps for advection, enabling more complex or high resolution simulations. Thorough comparisons between the Oslo CTM3, Oslo CTM2 and measurements are performed, and in general the Oslo CTM3 is found to reproduce measurements well. Inclusion of tropospheric sulfur chemistry and nitrate aerosols in CTM3 is shown to be important to reproduce tropospheric O3, OH and the CH4 lifetime well. Using the same meteorology to drive the two models, shows that some features related to transport are better resolved by the CTM3, such as polar cap transport, while features like transport close to the vortex edge are resolved better in the Oslo CTM2 due to its required shorter transport time step. The longer transport time steps in CTM3 result in larger errors e.g. near the jets, and when necessary, this can be remedied by using a shorter time step. An additional, more accurate and time consuming, treatment of polar cap transport is presented, however, both perform acceptably. A new treatment of the horizontal distribution of lightning is presented and found to compare well with measurements. Vertical distributions of lighting are updated, and tested against the old vertical distribution. The new profiles are found to produce more NOx in the tropical middle troposphere, and less at the surface and at high altitudes.

  8. Chemical analysis and potential health risks of hookah charcoal.

    Science.gov (United States)

    Elsayed, Yehya; Dalibalta, Sarah; Abu-Farha, Nedal

    2016-11-01

    Hookah (waterpipe) smoking is a very common practice that has spread globally. There is growing evidence on the hazardous consequences of smoking hookah, with studies indicating that its harmful effects are comparable to cigarette smoking if not worse. Charcoal is commonly used as a heating source for hookah smoke. Although charcoal briquettes are thought to be one of the major contributors to toxicity, their composition and impact on the smoke generated remains largely unidentified. This study aims to analyze the elemental composition of five different raw synthetic and natural charcoals by using Carbon-Hydrogen-Nitrogen (CHN) analysis, inductively coupled plasma (ICP), and scanning electron microscopy coupled with energy dispersive X-Ray spectrometry (SEM-EDS). Elemental analysis showed that the raw charcoals contain heavy metals such as zinc, iron, cadmium, vanadium, aluminum, lead, chromium, manganese and cobalt at concentrations similar, if not higher than, cigarettes. In addition, thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS) was used to analyze the chemical composition of the smoke produced from burning the charcoal samples. The smoke emitted from charcoal was found to be the source of numerous compounds which could be hazardous to health. A total of seven carcinogens, 39 central nervous system depressants and 31 respiratory irritants were identified. PMID:27343945

  9. Modeling Electric Double-Layers Including Chemical Reaction Effects

    DEFF Research Database (Denmark)

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

    2014-01-01

    A physicochemical and numerical model for the transient formation of an electric double-layer between an electrolyte and a chemically-active flat surface is presented, based on a finite elements integration of the nonlinear Nernst-Planck-Poisson model including chemical reactions. The model works...

  10. Modeling release of chemicals from multilayer materials into food

    Directory of Open Access Journals (Sweden)

    Huang Xiu-Ling

    2016-01-01

    Full Text Available The migration of chemicals from materials into food is predictable by various mathematical models. In this article, a general mathematical model is developed to quantify the release of chemicals through multilayer packaging films based on Fick's diffusion. The model is solved numerically to elucidate the effects of different diffusivity values of different layers, distribution of chemical between two adjacent layers and between material and food, mass transfer at the interface of material and food on the migration process.

  11. Monks' Health: Holistic Health Care Model by Community Participation

    OpenAIRE

    Decha Buates; Songkoon Chantachon; Kosit Paengsoi; Anongrit Kangrang

    2010-01-01

    Problem statement: Monks health tended to be a continuous increased problem. They were groups who had limitations to access health services due to their monastic disciplines and their most importance for Buddhist institution. Without urgent solution, their normal way of life would have been affected. Approach: This research aimed to study current conditions and to develop monks holistic health care models by community participation in central region of Thailand. The study ...

  12. A chemical model of meteoric ablation

    Directory of Open Access Journals (Sweden)

    T. Vondrak

    2008-12-01

    Full Text Available Most of the extraterrestrial dust entering the Earth's atmosphere ablates to produce metal vapours, which have significant effects on the aeronomy of the upper mesosphere and lower thermosphere. A new Chemical Ablation Model (CAMOD is described which treats the physics and chemistry of ablation, by including the following processes: sputtering by inelastic collisions with air molecules before the meteoroid melts; evaporation of atoms and oxides from the molten particle; diffusion-controlled migration of the volatile constituents (Na and K through the molten particle; and impact ionization of the ablated fragments by hyperthermal collisions with air molecules. Evaporation is based on thermodynamic equilibrium in the molten meteoroid (treated as a melt of metal oxides, and between the particle and surrounding vapour phase. The loss rate of each element is then determined assuming Langmuir evaporation. CAMOD successfully predicts the meteor head echo appearance heights, observed from incoherent scatter radars, over a wide range of meteoroid velocities. The model also confirms that differential ablation explains common-volume lidar observations of K, Ca and Ca+ in fresh meteor trails. CAMOD is then used to calculate the injection rates into the atmosphere of a variety of elements as a function of altitude, integrated over the meteoroid mass and velocity distributions. The most abundant elements (Fe, Mg and Si have peak injection rates around 85 km, with Na and K about 8 km higher. The more refractory element Ca ablates around 82 km with a Na:Ca ratio of 4:1, which does therefore not explain the depletion of atomic Ca to Na, by more than 2 orders of magnitude, in the upper mesosphere. Diffusion of the most volatile elements (Na and K does not appear to be rate-limiting except in the fastest meteoroids. Non-thermal sputtering causes ~35% mass loss from the fastest (~60–70 km s−1 and smallest (10−17–10

  13. A chemical model of meteoric ablation

    Directory of Open Access Journals (Sweden)

    T. Vondrak

    2008-07-01

    Full Text Available Most of the extraterrestrial dust entering the Earth's atmosphere ablates to produce metal vapours, which have significant effects on the aeronomy of the upper mesosphere and lower thermosphere. A new Chemical Ablation Model (CAMOD is described which treats the physics and chemistry of ablation, by including the following processes: sputtering by inelastic collisions with air molecules before the meteoroid melts; evaporation of atoms and oxides from the molten particle; diffusion-controlled migration of the volatile constituents (Na and K through the molten particle; and impact ionization of the ablated fragments by hyperthermal collisions with air molecules. Evaporation is based on thermodynamic equilibrium in the molten meteoroid (treated as a melt of metal oxides, and between the particle and surrounding vapour phase. The loss rate of each element is then determined assuming Langmuir evaporation. CAMOD successfully predicts the meteor head echo appearance heights, observed from incoherent scatter radars, over a wide range of meteoroid velocities. The model also confirms that differential ablation explains common-volume lidar observations of K, Ca and Ca+ in fresh meteor trails. CAMOD is then used to calculate the injection rates into the atmosphere of a variety of elements as a function of altitude, integrated over the meteoroid mass and velocity distributions. The most abundant elements (Fe, Mg and Si have peak injection rates around 85 km, with Na and K about 8 km higher. The more refractory element Ca ablates around 82 km with a Na:Ca ratio of 4:1, which does therefore not explain the depletion of atomic Ca to Na, by more than 2 orders of magnitude, in the upper mesosphere. Diffusion of the most volatile elements (Na and K does not appear to be rate-limiting except in the fastest meteoroids. Non-thermal sputtering causes ~35% mass loss from the fastest (~60–70 km s−1 and smallest (10−17–10

  14. Human health issues for combined exposures to plutonium and chemicals - an experimental toxicology approach

    International Nuclear Information System (INIS)

    Workers throughout the U.S. Department of Energy (DOE) complex may be exposed to combinations of various agents. The possibility that chemicals and/or radiation may interact in producing deleterious effects in exposed individuals has been recognized for some time. Although there is a substantial body of knowledge on how specific interactions influence various biological endpoints, no comprehensive framework exists that allows one to reliably predict health effect outcomes from combined exposures. As a result, regulators have relied on simple additive models for setting exposure standards

  15. Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter

    OpenAIRE

    Oyewale Mayowa Morakinyo; Matlou Ingrid Mokgobu; Murembiwa Stanley Mukhola; Raymond Paul Hunter

    2016-01-01

    Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease...

  16. Incorporating Health Impacts from Exposure to Chemicals in Food Packaging in LCA

    OpenAIRE

    Ernstoff, Alexi; Trier, Xenia; Jolliet, Oliver; Fantke, Peter

    2014-01-01

    Life cycle assessments (LCA) on the environmental and public health impacts of food and beverage packaging materials have found some advantages to plastic over glass. Entirely missing from these evaluations are the health impacts of possible chemical, e.g. endocrine dis-ruptor, exposure through migration of chemicals from the packaging into the food product. We build a framework based on a life cycle perspective to predict which chemicals may be in a package that are not intentionally added i...

  17. Voltammetry as a Model for Teaching Chemical Instrumentation.

    Science.gov (United States)

    Gunasingham, H.; Ang, K. P.

    1985-01-01

    Voltammetry is used as a model for teaching chemical instrumentation to chemistry undergraduates at the National University of Singapore. Lists six criteria used to select a successful teaching model and shows how voltammetry satisfies each criterion. (JN)

  18. Using Physiologically-Based Pharmacokinetic Models to Incorporate Chemical and Non-Chemical Stressors into Cumulative Risk Assessment: A Case Study of Pesticide Exposures

    Directory of Open Access Journals (Sweden)

    Jonathan I. Levy

    2012-05-01

    Full Text Available Cumulative risk assessment has been proposed as an approach to evaluate the health risks associated with simultaneous exposure to multiple chemical and non-chemical stressors. Physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD models can allow for the inclusion and evaluation of multiple stressors, including non-chemical stressors, but studies have not leveraged PBPK/PD models to jointly consider these disparate exposures in a cumulative risk context. In this study, we focused on exposures to organophosphate (OP pesticides for children in urban low-income environments, where these children would be simultaneously exposed to other pesticides (including pyrethroids and non-chemical stressors that may modify the effects of these exposures (including diet. We developed a methodological framework to evaluate chemical and non-chemical stressor impacts on OPs, utilizing an existing PBPK/PD model for chlorpyrifos. We evaluated population-specific stressors that would influence OP doses or acetylcholinesterase (AChE inhibition, the relevant PD outcome. We incorporated the impact of simultaneous exposure to pyrethroids and dietary factors on OP dose through the compartments of metabolism and PD outcome within the PBPK model, and simulated combinations of stressors across multiple exposure ranges and potential body weights. Our analyses demonstrated that both chemical and non-chemical stressors can influence the health implications of OP exposures, with up to 5-fold variability in AChE inhibition across combinations of stressor values for a given OP dose. We demonstrate an approach for modeling OP risks in the presence of other population-specific environmental stressors, providing insight about co-exposures and variability factors that most impact OP health risks and contribute to children’s cumulative health risk from pesticides. More generally, this framework can be used to inform cumulative risk assessment for any compound impacted by

  19. Property Modelling for Applications in Chemical Product and Process Design

    DEFF Research Database (Denmark)

    Gani, Rafiqul

    is missing, the atom connectivity based model is employed to predict the missing group interaction. In this way, a wide application range of the property modeling tool is ensured. Based on the property models, targeted computer-aided techniques have been developed for design and analysis of organic chemicals......, polymers, mixtures as well as separation processes. The presentation will highlight the framework (ICAS software) for property modeling, the property models and issues such as prediction accuracy, flexibility, maintenance and updating of the database. Also, application issues related to the use of property......Physical-chemical properties of pure chemicals and their mixtures play an important role in the design of chemicals based products and the processes that manufacture them. Although, the use of experimental data in design and analysis of chemicals based products and their processes is desirable...

  20. Fate modelling of chemical compounds with incomplete data sets

    DEFF Research Database (Denmark)

    Birkved, Morten; Heijungs, Reinout

    2011-01-01

    and other indicators. ERA typically addresses one specific chemical, but in an LCIA, the number of chemicals encountered may be quite high, up to hundreds or thousands. This study explores the development of meta-models, which are supposed to reflect the “true”multi-media fate and exposure model......, and to provide simplified proxies for the more complicated “real”model relationships. In the presented study two approaches for the reduction of the data demand associated with characterization of chemical emissions in USEtoxTM are tested: The first approach yields a simplified set of mode of entry specific meta-models......Impact assessment of chemical compounds in Life Cycle Impact Assessment (LCIA) and Environmental Risk Assessment (ERA) requires a vast amount of data on the properties of the chemical compounds being assessed. These data are used in multi-media fate and exposure models, to calculate risk levels...

  1. Global Health Innovation Technology Models

    OpenAIRE

    Kimberly Harding

    2016-01-01

    Chronic technology and business process disparities between High Income, Low Middle Income and Low Income (HIC, LMIC, LIC) research collaborators directly prevent the growth of sustainable Global Health innova‐ tion for infectious and rare diseases. There is a need for an Open Source-Open Science Architecture Framework to bridge this divide. We are proposing such a framework for consideration by the Global Health community, by utiliz‐ ing a hybrid approach of integrating agnostic Open Source ...

  2. The Implications of Death for Health: A Terror Management Health Model for Behavioral Health Promotion

    Science.gov (United States)

    Goldenberg, Jamie L.; Arndt, Jamie

    2008-01-01

    This article introduces a terror management health model (TMHM). The model integrates disparate health and social psychology literatures to elucidate how the conscious and nonconscious awareness of death can influence the motivational orientation that is most operative in the context of health decisions. Three formal propositions are presented.…

  3. A grand model for chemical product design

    DEFF Research Database (Denmark)

    Fung, Ka Y.; Ng, Ka M.; Zhang, Lei;

    2016-01-01

    Chemical engineering has been expanding its focus from primarily business-to-business products (B2B) to business-to-consumer (B2C) products. The production of B2B products generally emphasizes on process design and optimization, whereas the production of B2C products focuses on product quality, i...

  4. Modelling Human Exposure to Chemicals in Food

    NARCIS (Netherlands)

    Slob W

    1993-01-01

    Exposure to foodborne chemicals is often estimated using the average consumption pattern in the human population. To protect the human population instead of the average individual, however, interindividual variability in consumption behaviour must be taken into account. This report shows how food

  5. Chemical-specific health consultation for chromated copper arsenate chemical mixture: port of Djibouti.

    Science.gov (United States)

    Chou, Selene; Colman, Joan; Tylenda, Carolyn; De Rosa, Christopher

    2007-05-01

    The Agency for Toxic Substances and Disease Registry (ATSDR) prepared this health consultation to provide support for assessing the public health implications of hazardous chemical exposure, primarily through drinking water, related to releases of chromated copper arsenate (CCA) in the port of Djibouti. CCA from a shipment, apparently intended for treating electric poles, is leaking into the soil in the port area. CCA is a pesticide used to protect wood against decay-causing organisms. This mixture commonly contains chromium(VI) (hexavalent chromium) as chromic acid, arsenic(V) (pentavalent arsenic) as arsenic pentoxide and copper (II) (divalent copper) as cupric oxide, often in an aqueous solution or concentrate. Experimental studies of the fate of CCA in soil and monitoring studies of wood-preserving sites where CCA was spilled on the soil indicate that the chromium(VI), arsenic and copper components of CCA can leach from soil into groundwater and surface water. In addition, at CCA wood-preserving sites, substantial concentrations of chromium(VI), arsenic and copper remained in the soil and were leachable into water four years after the use of CCA was discontinued, suggesting prolonged persistence in soil, with continued potential for leaching. The degree of leaching depended on soil composition and the extent of soil contamination with CCA. In general, leaching was highest for chromium(VI), intermediate for arsenic and lowest for copper. Thus, the potential for contamination of sources of drinking water exists. Although arsenic that is leached from CCA-contaminated soil into surface water may accumulate in the tissues of fish and shellfish, most of the arsenic in these animals will be in a form (often called fish arsenic) that is less harmful. Copper, which leaches less readily than the other components, can accumulate in tissues of mussels and oysters. Chromium is not likely to accumulate in the tissues of fish and shellfish. Limited studies of air

  6. [Evaluation model for municipal health planning management].

    Science.gov (United States)

    Berretta, Isabel Quint; Lacerda, Josimari Telino de; Calvo, Maria Cristina Marino

    2011-11-01

    This article presents an evaluation model for municipal health planning management. The basis was a methodological study using the health planning theoretical framework to construct the evaluation matrix, in addition to an understanding of the organization and functioning designed by the Planning System of the Unified National Health System (PlanejaSUS) and definition of responsibilities for the municipal level under the Health Management Pact. The indicators and measures were validated using the consensus technique with specialists in planning and evaluation. The applicability was tested in 271 municipalities (counties) in the State of Santa Catarina, Brazil, based on population size. The proposed model features two evaluative dimensions which reflect the municipal health administrator's commitment to planning: the guarantee of resources and the internal and external relations needed for developing the activities. The data were analyzed using indicators, sub-dimensions, and dimensions. The study concludes that the model is feasible and appropriate for evaluating municipal performance in health planning management.

  7. Engineered Barrier System: Physical and Chemical Environment Model

    International Nuclear Information System (INIS)

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports

  8. Global Health Innovation Technology Models

    Directory of Open Access Journals (Sweden)

    Kimberly Harding

    2016-04-01

    Full Text Available Chronic technology and business process disparities between High Income, Low Middle Income and Low Income (HIC, LMIC, LIC research collaborators directly prevent the growth of sustainable Global Health innova‐ tion for infectious and rare diseases. There is a need for an Open Source-Open Science Architecture Framework to bridge this divide. We are proposing such a framework for consideration by the Global Health community, by utiliz‐ ing a hybrid approach of integrating agnostic Open Source technology and healthcare interoperability standards and Total Quality Management principles. We will validate this architecture framework through our programme called Project Orchid. Project Orchid is a conceptual Clinical Intelligence Exchange and Virtual Innovation platform utilizing this approach to support clinical innovation efforts for multi-national collaboration that can be locally sustainable for LIC and LMIC research cohorts. The goal is to enable LIC and LMIC research organizations to acceler‐ ate their clinical trial process maturity in the field of drug discovery, population health innovation initiatives and public domain knowledge networks. When sponsored, this concept will be tested by 12 confirmed clinical research and public health organizations in six countries. The potential impact of this platform is reduced drug discovery and public health innovation lag time and improved clinical trial interventions, due to reliable clinical intelligence and bio-surveillance across all phases of the clinical innovation process.

  9. Detailed Chemical Kinetic Modeling of Cyclohexane Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Silke, E J; Pitz, W J; Westbrook, C K; Ribaucour, M

    2006-11-10

    A detailed chemical kinetic mechanism has been developed and used to study the oxidation of cyclohexane at both low and high temperatures. Reaction rate constant rules are developed for the low temperature combustion of cyclohexane. These rules can be used for in chemical kinetic mechanisms for other cycloalkanes. Since cyclohexane produces only one type of cyclohexyl radical, much of the low temperature chemistry of cyclohexane is described in terms of one potential energy diagram showing the reaction of cyclohexyl radical + O{sub 2} through five, six and seven membered ring transition states. The direct elimination of cyclohexene and HO{sub 2} from RO{sub 2} is included in the treatment using a modified rate constant of Cavallotti et al. Published and unpublished data from the Lille rapid compression machine, as well as jet-stirred reactor data are used to validate the mechanism. The effect of heat loss is included in the simulations, an improvement on previous studies on cyclohexane. Calculations indicated that the production of 1,2-epoxycyclohexane observed in the experiments can not be simulated based on the current understanding of low temperature chemistry. Possible 'alternative' H-atom isomerizations leading to different products from the parent O{sub 2}QOOH radical were included in the low temperature chemical kinetic mechanism and were found to play a significant role.

  10. Environmental and health hazard ranking and assessment of plastic polymers based on chemical composition

    International Nuclear Information System (INIS)

    Plastics constitute a large material group with a global annual production that has doubled in 15 years (245 million tonnes in 2008). Plastics are present everywhere in society and the environment, especially the marine environment, where large amounts of plastic waste accumulate. The knowledge of human and environmental hazards and risks from chemicals associated with the diversity of plastic products is very limited. Most chemicals used for producing plastic polymers are derived from non-renewable crude oil, and several are hazardous. These may be released during the production, use and disposal of the plastic product. In this study the environmental and health hazards of chemicals used in 55 thermoplastic and thermosetting polymers were identified and compiled. A hazard ranking model was developed for the hazard classes and categories in the EU classification and labelling (CLP) regulation which is based on the UN Globally Harmonized System. The polymers were ranked based on monomer hazard classifications, and initial assessments were made. The polymers that ranked as most hazardous are made of monomers classified as mutagenic and/or carcinogenic (category 1A or 1B). These belong to the polymer families of polyurethanes, polyacrylonitriles, polyvinyl chloride, epoxy resins, and styrenic copolymers. All have a large global annual production (1-37 million tonnes). A considerable number of polymers (31 out of 55) are made of monomers that belong to the two worst of the ranking model's five hazard levels, i.e. levels IV-V. The polymers that are made of level IV monomers and have a large global annual production (1-5 million tonnes) are phenol formaldehyde resins, unsaturated polyesters, polycarbonate, polymethyl methacrylate, and urea-formaldehyde resins. This study has identified hazardous substances used in polymer production for which the risks should be evaluated for decisions on the need for risk reduction measures, substitution, or even phase out. - Research

  11. Parameter Estimates in Differential Equation Models for Chemical Kinetics

    Science.gov (United States)

    Winkel, Brian

    2011-01-01

    We discuss the need for devoting time in differential equations courses to modelling and the completion of the modelling process with efforts to estimate the parameters in the models using data. We estimate the parameters present in several differential equation models of chemical reactions of order n, where n = 0, 1, 2, and apply more general…

  12. Learning of Chemical Equilibrium through Modelling-Based Teaching

    Science.gov (United States)

    Maia, Poliana Flavia; Justi, Rosaria

    2009-01-01

    This paper presents and discusses students' learning process of chemical equilibrium from a modelling-based approach developed from the use of the "Model of Modelling" diagram. The investigation was conducted in a regular classroom (students 14-15 years old) and aimed at discussing how modelling-based teaching can contribute to students learning…

  13. Occupational safety and health guidelines for chemical hazards. Supplement IV-OHG

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    This document is the fourth in a seris of supplements to the 1981 Publication NIOSH/OSHA Occupational Health Guidelines for Chemical Hazards. The 62 guidelines presented here in the fourth supplement include 11 revisions of previously issued guidelines and 51 new guidelines. The 62 occupational safety and health guidelines presented here are being published to disseminate technical information about chemical hazards to workers, employers, and occupational safety and health professionals. Each guideline includes (1) data on the chemical name and synonyms, cemnical and physical properties, exposure limits, and signs and symptoms of exposure, personal protective equipment, and control procedures.

  14. New trajectory-driven aerosol and chemical process model Chemical and Aerosol Lagrangian Model (CALM

    Directory of Open Access Journals (Sweden)

    P. Tunved

    2010-11-01

    Full Text Available A new Chemical and Aerosol Lagrangian Model (CALM has been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61° 51' N, 24° 17' E over a time period of two years, 2000–2001. The model shows good agreement with measurements throughout most of the year, but fails in reproducing the aerosol properties during the winter season, resulting in poor agreement between model and measurements especially during December–January. Nevertheless, through the rest of the year both trends and magnitude of modal concentrations show good agreement with observation, as do the monthly average size distribution properties. The model is also shown to capture individual nucleation events to a certain degree. This indicates that nucleation largely is controlled by the availability of nucleating material (as prescribed by the [H2SO4], availability of condensing material (in this model 15% of primary reactions of monoterpenes (MT are assumed to produce low volatile species and the properties of the size distribution (more specifically, the condensation sink. This is further demonstrated by the fact that the model captures the annual trend in nuclei mode concentration. The model is also used, alongside sensitivity tests, to examine which processes dominate the aerosol size distribution physical properties. It is shown, in agreement with previous studies, that nucleation governs the number concentration during transport from clean areas. It is also shown that primary number emissions almost exclusively govern the CN concentration when air from Central Europe is advected north over Scandinavia. We also show that biogenic emissions have a large influence on the amount of potential CCN observed

  15. New trajectory driven aerosol and chemical process model: chemical and aerosol Lagrangian model (CALM

    Directory of Open Access Journals (Sweden)

    P. Tunved

    2010-06-01

    Full Text Available A new Chemical and Aerosol Lagrangian Model (CALM have been developed and tested. The model incorporates all central aerosol dynamical processes, from nucleation, condensation, coagulation and deposition to cloud formation and in-cloud processing. The model is tested and evaluated against observations performed at the SMEAR II station located at Hyytiälä (61°51' N, 24°17' E over a time period of two years, 2000–2001. The model shows good agreement with measurements throughout most of the year, but fails in reproducing the aerosol properties during the winter season, resulting in poor agreement between model and measurements especially during December–January. Nevertheless, through the rest of the year both trends and magnitude of modal concentrations show good agreement with observation, as do the monthly average size distribution properties. The model is also shown to capture individual nucleation events to a certain degree. This indicates that nucleation largely is controlled by the availability of nucleating material (as prescribed by the [H2SO4], availability of condensing material (in this model 15% of primary reactions of monoterpenes (MT are assumed to produce low volatile species and the properties of the size distribution (more specifically, the condensation sink. This is further demonstrated by the fact that the model captures the annual trend in nuclei mode concentration. The model is also used, alongside sensitivity tests, to examine which processes dominate the aerosol size distribution physical properties. It is shown, in agreement with previous studies, that nucleation governs the number concentration while transport from clean areas takes place. It is also shown that primary number emissions almost exclusively govern the CN concentration when air from Central Europe is advected north over Scandinavia. We also show that biogenic emissions have a large influence on the amount of potential CCN observed

  16. Chemically induced intestinal damage models in zebrafish larvae.

    Science.gov (United States)

    Oehlers, Stefan H; Flores, Maria Vega; Hall, Christopher J; Okuda, Kazuhide S; Sison, John Oliver; Crosier, Kathryn E; Crosier, Philip S

    2013-06-01

    Several intestinal damage models have been developed using zebrafish, with the aim of recapitulating aspects of human inflammatory bowel disease (IBD). These experimentally induced inflammation models have utilized immersion exposure to an array of colitogenic agents (including live bacteria, bacterial products, and chemicals) to induce varying severity of inflammation. This technical report describes methods used to generate two chemically induced intestinal damage models using either dextran sodium sulfate (DSS) or trinitrobenzene sulfonic acid (TNBS). Methods to monitor intestinal damage and inflammatory processes, and chemical-genetic methods to manipulate the host response to injury are also described.

  17. A methodology for overall consequence modeling in chemical industry

    International Nuclear Information System (INIS)

    Risk assessment in chemical process industry is a very important issue for safeguarding human and the ecosystem from damages caused to them. Consequence assessment is an integral part of risk assessment. However, the commonly used consequence estimation methods involve time-consuming complex mathematical models and simple assimilation of losses without considering all the consequence factors. This lead to the deterioration of quality of estimated risk value. So, the consequence modeling has to be performed in detail considering all major losses with optimal time to improve the decisive value of risk. The losses can be broadly categorized into production loss, assets loss, human health and safety loss, and environment loss. In this paper, a conceptual framework is developed to assess the overall consequence considering all the important components of major losses. Secondly, a methodology is developed for the calculation of all the major losses, which are normalized to yield the overall consequence. Finally, as an illustration, the proposed methodology is applied to a case study plant involving benzene extraction. The case study result using the proposed consequence assessment scheme is compared with that from the existing methodologies.

  18. A Chemical Properties Simulator to Support Integrated Environmental Modeling (proceeding)

    Science.gov (United States)

    Users of Integrated Environmental Modeling (IEM) systems are responsible for defining individual chemicals and their properties, a process that is time-consuming at best and overwhelming at worst, especially for new chemicals with new structures. A software tool is needed to allo...

  19. Upper Secondary Teachers' Knowledge for Teaching Chemical Bonding Models

    Science.gov (United States)

    Bergqvist, Anna; Drechsler, Michal; Chang Rundgren, Shu-Nu

    2016-01-01

    Researchers have shown a growing interest in science teachers' professional knowledge in recent decades. The article focuses on how chemistry teachers impart chemical bonding, one of the most important topics covered in upper secondary school chemistry courses. Chemical bonding is primarily taught using models, which are key for understanding…

  20. THEORETICAL CHEMICAL ENGINEERING - Modeling and Simulation by Christo Boyadjiev

    Directory of Open Access Journals (Sweden)

    Simeon Oka

    2010-01-01

    Full Text Available Book Title: THEORETICAL CHEMICAL ENGINEERING - Modeling and Simulation Author(s: Christo Boyadjiev Institute of Chemical Engineering, Bulgarian Academy of Science, Sofia Publisher: Springer, 2010 ISBN: 978-3-642-10777-1 Review by: Prof. Simeon Oka, Ph. D., Scientific advisor - retired

  1. Psychosocial environment: a health promotion model.

    Science.gov (United States)

    Kar, S B

    1983-01-01

    This article presents a multidimensional model of psychosocial determinants of health behavior for health promotion research and policy analysis. Frequently, health promotion focuses almost exclusively on intrapsychic determinants and on individual level behavior. Based upon Field Theory and attitude theories, this proposed model holds that in populations with comparable sociodemographic and biological status (exogenous variables) a health behavior is a function of direct and interaction effects of five key intrapsychic and external variables. These are: behavioral intentions, social support, accessibility of means for action, personal autonomy, and action situation. Empirical tests with cross-cultural studies in Venezuela, Kenya, and the Philippines provide substantial support for the model. The findings suggest that while health promotion strategies should deal with intrapsychic determinants of behavior, key extrapsychic factors (such as social support, quality and accessibility of health care measures, and situational factors) all have direct and independent effects on health behavior as well. Health promotion research and interventions which aim exclusively at intrapsychic determinants would thus have rather limited overall value. The article discusses key research and policy implications of the model presented.

  2. Endocrine-disrupting chemicals and public health protection

    DEFF Research Database (Denmark)

    Zoeller, R Thomas; Brown, T R; Doan, L L;

    2012-01-01

    in regulation of these events across the life cycle. The developmental age at which EDC exposures occur is a critical consideration in understanding their effects. Because endocrine systems exhibit tissue-, cell-, and receptor-specific actions during the life cycle, EDC can produce complex, mosaic effects......An endocrine-disrupting chemical (EDC) is an exogenous chemical, or mixture of chemicals, that can interfere with any aspect of hormone action. The potential for deleterious effects of EDC must be considered relative to the regulation of hormone synthesis, secretion, and actions and the variability....... This complexity causes difficulty when a static approach to toxicity through endocrine mechanisms driven by rigid guidelines is used to identify EDC and manage risk to human and wildlife populations. We propose that principles taken from fundamental endocrinology be employed to identify EDC and manage their risk...

  3. Extension of association models to complex chemicals

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard

    Summary of “Extension of association models to complex chemicals”. Ph.D. thesis by Ane Søgaard Avlund The subject of this thesis is application of SAFT type equations of state (EoS). Accurate and predictive thermodynamic models are important in many industries including the petroleum industry. Th...

  4. Incorporating Health Impacts from Exposure to Chemicals in Food Packaging in LCA

    DEFF Research Database (Denmark)

    Ernstoff, Alexi; Trier, Xenia; Jolliet, Oliver;

    2014-01-01

    Life cycle assessments (LCA) on the environmental and public health impacts of food and beverage packaging materials have found some advantages to plastic over glass. Entirely missing from these evaluations are the health impacts of possible chemical, e.g. endocrine dis-ruptor, exposure through...... migration of chemicals from the packaging into the food product. We build a framework based on a life cycle perspective to predict which chemicals may be in a package that are not intentionally added ingredients, and we apply this approach to the US EPA’s CPCAT database. In total we find 1,154 chemicals...... within the CPCAT database related to food-contact materials; out of these 107 are potential endocrine disruptors according to the TEDX list of endocrine disruptors. We also build a framework in an effort to begin harmonizing LCA to include health impacts of chemical exposure related to food packaging...

  5. NONLINEAR MODEL PREDICTIVE CONTROL OF CHEMICAL PROCESSES

    Directory of Open Access Journals (Sweden)

    SILVA R. G.

    1999-01-01

    Full Text Available A new algorithm for model predictive control is presented. The algorithm utilizes a simultaneous solution and optimization strategy to solve the model's differential equations. The equations are discretized by equidistant collocation, and along with the algebraic model equations are included as constraints in a nonlinear programming (NLP problem. This algorithm is compared with the algorithm that uses orthogonal collocation on finite elements. The equidistant collocation algorithm results in simpler equations, providing a decrease in computation time for the control moves. Simulation results are presented and show a satisfactory performance of this algorithm.

  6. Sustainable Material Selection of Toxic Chemicals in Design and Manufacturing From Human Health Impact Perspective

    OpenAIRE

    Yuan, Chris; Dornfeld, David

    2009-01-01

    Toxic chemicals used in product design and manufacturing are grave concerns due to their significant impact on human health. Sustainable material selections are needed by industry to reduce the overall impact of toxic chemicals in both design and manufacturing. In this paper, we integrate the human health impact assessment into standard material selection process for developing a sustainable material selection metric for decision support in design and manufacturing. A schematic method is pres...

  7. Comparison of Family Clinic Community Health Service Model with State-owned Community Health Service Model

    Institute of Scientific and Technical Information of China (English)

    万方荣; 卢祖洵; 张金隆

    2002-01-01

    Summary: Based on a survey of community health service organization in several cities, communi-ty health service model based on the family clinic was compared with state-owned communityhealth service model, and status quo, advantages and problems of family community health serviceorganization were analyzed. Furthermore, policies for the management of community health ser-vice organization based on the family clinic were put forward.

  8. Reevaluation of 1999 Health-Based Environmental Screening Levels (HBESLs) for Chemical Warfare Agents

    Energy Technology Data Exchange (ETDEWEB)

    Watson, Annetta Paule [ORNL; Dolislager, Fredrick G [ORNL

    2007-05-01

    This report evaluates whether new information and updated scientific models require that changes be made to previously published health-based environmental soil screening levels (HBESLs) and associated environmental fate/breakdown information for chemical warfare agents (USACHPPM 1999). Specifically, the present evaluation describes and compares changes that have been made since 1999 to U.S. Environmental Protection Agency (EPA) risk assessment models, EPA exposure assumptions, as well as to specific chemical warfare agent parameters (e.g., toxicity values). Comparison was made between screening value estimates recalculated with current assumptions and earlier health-based environmental screening levels presented in 1999. The chemical warfare agents evaluated include the G-series and VX nerve agents and the vesicants sulfur mustard (agent HD) and Lewisite (agent L). In addition, key degradation products of these agents were also evaluated. Study findings indicate that the combined effect of updates and/or changes to EPA risk models, EPA default exposure parameters, and certain chemical warfare agent toxicity criteria does not result in significant alteration to the USACHPPM (1999) health-based environmental screening level estimates for the G-series and VX nerve agents or the vesicant agents HD and L. Given that EPA's final position on separate Tier 1 screening levels for indoor and outdoor worker screening assessments has not yet been released as of May 2007, the study authors find that the 1999 screening level estimates (see Table ES.1) are still appropriate and protective for screening residential as well as nonresidential sites. As such, risk management decisions made on the basis of USACHPPM (1999) recommendations do not require reconsideration. While the 1999 HBESL values are appropriate for continued use as general screening criteria, the updated '2007' estimates (presented below) that follow the new EPA protocols currently under development

  9. Thermodynamically consistent model calibration in chemical kinetics

    Directory of Open Access Journals (Sweden)

    Goutsias John

    2011-05-01

    Full Text Available Abstract Background The dynamics of biochemical reaction systems are constrained by the fundamental laws of thermodynamics, which impose well-defined relationships among the reaction rate constants characterizing these systems. Constructing biochemical reaction systems from experimental observations often leads to parameter values that do not satisfy the necessary thermodynamic constraints. This can result in models that are not physically realizable and may lead to inaccurate, or even erroneous, descriptions of cellular function. Results We introduce a thermodynamically consistent model calibration (TCMC method that can be effectively used to provide thermodynamically feasible values for the parameters of an open biochemical reaction system. The proposed method formulates the model calibration problem as a constrained optimization problem that takes thermodynamic constraints (and, if desired, additional non-thermodynamic constraints into account. By calculating thermodynamically feasible values for the kinetic parameters of a well-known model of the EGF/ERK signaling cascade, we demonstrate the qualitative and quantitative significance of imposing thermodynamic constraints on these parameters and the effectiveness of our method for accomplishing this important task. MATLAB software, using the Systems Biology Toolbox 2.1, can be accessed from http://www.cis.jhu.edu/~goutsias/CSS lab/software.html. An SBML file containing the thermodynamically feasible EGF/ERK signaling cascade model can be found in the BioModels database. Conclusions TCMC is a simple and flexible method for obtaining physically plausible values for the kinetic parameters of open biochemical reaction systems. It can be effectively used to recalculate a thermodynamically consistent set of parameter values for existing thermodynamically infeasible biochemical reaction models of cellular function as well as to estimate thermodynamically feasible values for the parameters of new

  10. Potts Flux Tube Model at Nonzero Chemical Potential

    CERN Document Server

    Condella, J; Condella, Jac; Tar, Carleton De

    2000-01-01

    We model the deconfinement phase transition in quantum chromodynamics at nonzero baryon number density and large quark mass by extending the flux tube model (three-state, three-dimensional Potts model) to nonzero chemical potential. In a direct numerical simulation we confirm mean-field-theory predictions that the deconfinement transition does not occur in a baryon-rich environment.

  11. Chemical Kinetic Models for HCCI and Diesel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Westbrook, C K; Mehl, M; Sarathy, S M

    2010-11-15

    Predictive engine simulation models are needed to make rapid progress towards DOE's goals of increasing combustion engine efficiency and reducing pollutant emissions. These engine simulation models require chemical kinetic submodels to allow the prediction of the effect of fuel composition on engine performance and emissions. Chemical kinetic models for conventional and next-generation transportation fuels need to be developed so that engine simulation tools can predict fuel effects. The objectives are to: (1) Develop detailed chemical kinetic models for fuel components used in surrogate fuels for diesel and HCCI engines; (2) Develop surrogate fuel models to represent real fuels and model low temperature combustion strategies in HCCI and diesel engines that lead to low emissions and high efficiency; and (3) Characterize the role of fuel composition on low temperature combustion modes of advanced combustion engines.

  12. Chemically-induced Mouse Lung Tumors: Applications to Human Health Assessments

    Science.gov (United States)

    A state-of-the-science workshop on chemically-induced mouse lung tumors was conducted by U.S. Environmental Protection Agency to better understand the mouse lung tumor data’s role in human health assessments. Three environmental chemicals - naphthalene, styrene, and ethylbe...

  13. Environmental chemicals in human milk: a review of levels, infant exposures and health, and guidance for future research

    International Nuclear Information System (INIS)

    The aim of this review is to introduce the reader to various science and policy aspects of the topic of environmental chemicals in human milk. Although information on environmental chemicals in human milk has been available since the 1950s, it is only relatively recently that public awareness of the issue has grown. This review on environmental chemicals in human milk provides a resource summarizing what is currently known about levels and trends of environmental chemicals in human milk, potential infant exposures, and benefits of breast-feeding relative to the risks of exposures to environmental chemicals. The term 'environmental chemicals', as it pertains to human milk, refers to many classes of exogenous chemicals that may be detected in human milk. For example, pharmaceutical agents and alcohol are environmental chemicals that have been found in human milk. Other chemicals, such as heavy metals and volatile organic compounds, have also been detected in human milk. Most research on environmental chemicals in human milk has concentrated on persistent, bioaccumulative, and toxic (PBT) chemicals. In this review, a description of human milk is provided, including a brief review of endogenous substances in human milk. Determinants of levels of PBTs are discussed, as are models that have been developed to predict levels of PBTs in human milk and associated body burdens in breast-feeding infants. Methodologies for human milk sampling and analysis, and concepts for consideration in interpretation and communication of study results, as developed by the Technical Workshop on Human Milk Surveillance and Research for Environmental Chemicals in the United States are described. Studies which have compared the health risks and benefits associated with breast-feeding and formula-feeding are discussed

  14. Engineered Barrier System: Physical and Chemical Environment Model

    Energy Technology Data Exchange (ETDEWEB)

    D. M. Jolley; R. Jarek; P. Mariner

    2004-02-09

    The conceptual and predictive models documented in this Engineered Barrier System: Physical and Chemical Environment Model report describe the evolution of the physical and chemical conditions within the waste emplacement drifts of the repository. The modeling approaches and model output data will be used in the total system performance assessment (TSPA-LA) to assess the performance of the engineered barrier system and the waste form. These models evaluate the range of potential water compositions within the emplacement drifts, resulting from the interaction of introduced materials and minerals in dust with water seeping into the drifts and with aqueous solutions forming by deliquescence of dust (as influenced by atmospheric conditions), and from thermal-hydrological-chemical (THC) processes in the drift. These models also consider the uncertainty and variability in water chemistry inside the drift and the compositions of introduced materials within the drift. This report develops and documents a set of process- and abstraction-level models that constitute the engineered barrier system: physical and chemical environment model. Where possible, these models use information directly from other process model reports as input, which promotes integration among process models used for total system performance assessment. Specific tasks and activities of modeling the physical and chemical environment are included in the technical work plan ''Technical Work Plan for: In-Drift Geochemistry Modeling'' (BSC 2004 [DIRS 166519]). As described in the technical work plan, the development of this report is coordinated with the development of other engineered barrier system analysis model reports.

  15. Free Energy Transduction in a Chemical Motor Model

    CERN Document Server

    Baker, J E

    2003-01-01

    Motor enzymes catalyze chemical reactions, like the hydrolysis of ATP, and in the process they also perform work. Recent studies indicate that motor enzymes perform work with specific intermediate steps in their catalyzed reactions, challenging the classic view (in Brownian motor models) that work can only be performed within biochemical states. An alternative class of models (chemical motor models) has emerged in which motors perform work with biochemical transitions, but many of these models lack a solid physicochemical foundation. In this paper, I develop a self consistent framework for chemical motor models. This novel framework accommodates multiple pathways for free energy transfer, predicts rich behaviors from the simplest multi motor systems, and provides important new insights into muscle and motor function.

  16. Implementation and evaluation of an array of chemical solvers in a global chemical transport model

    Directory of Open Access Journals (Sweden)

    M. Lee

    2009-03-01

    Full Text Available This paper discusses the implementation and performance of an array of gas-phase chemistry solvers for the state-of-the-science GEOS-Chem global chemical transport model. The implementation is based on the Kinetic PreProcessor (KPP. Two perl parsers automatically generate the needed interfaces between GEOS-Chem and KPP, and allow access to the chemical simulation code without any additional programming effort. This work illustrates the potential of KPP to positively impact global chemical transport modeling by providing additional functionality as follows. (1 The user can select a highly efficient numerical integration method from an array of solvers available in the KPP library. (2 KPP offers extreme flexibility for studies that involve changing the chemical mechanism (e.g., a set of additional reactions is automatically translated into efficient code and incorporated into a modified global model. (3 This work provides immediate access to tangent linear, continuous adjoint, and discrete adjoint chemical models, with applications to sensitivity analysis and data assimilation.

  17. Public Health Action Model for Cancer Survivorship.

    Science.gov (United States)

    Moore, Angela R; Buchanan, Natasha D; Fairley, Temeika L; Lee Smith, Judith

    2015-12-01

    Long-term objectives associated with cancer survivors have been suggested by Healthy People 2020, including increasing the proportion of survivors living beyond 5 years after diagnosis and improving survivors' mental and physical health-related quality of life. Prior to reaching these objectives, several intermediate steps must be taken to improve the physical, social, emotional, and financial well-being of cancer survivors. Public health has a role in developing strategic, actionable, and measurable approaches to facilitate change at multiple levels to improve the lives of survivors and their families. The social ecological model has been used by the public health community as the foundation of multilevel intervention design and implementation, encouraging researchers and practitioners to explore methods that promote internal and external changes at the individual, interpersonal, organizational, community, and policy levels. The survivorship community, including public health professionals, providers, policymakers, survivors, advocates, and caregivers, must work collaboratively to identify, develop, and implement interventions that benefit cancer survivors. The National Action Plan for Cancer Survivorship highlights public health domains and associated strategies that can be the impetus for collaboration between and among the levels in the social ecological model and are integral to improving survivor outcomes. This paper describes the Public Health Action Model for Cancer Survivorship, an integrative framework that combines the National Action Plan for Cancer Survivorship with the social ecological model to demonstrate how interaction among the various levels may promote better outcomes for survivors. PMID:26590641

  18. [Health for refugees - the Bremen model].

    Science.gov (United States)

    Mohammadzadeh, Zahra; Jung, Felicitas; Lelgemann, Monika

    2016-05-01

    The Bremen model recognizes that refugee health care has to go beyond merely checking for the prevalence of contagious diseases. Elementary health care offered in the reception centre and transitory facilities is based on voluntary acceptance by the refugees. At the same time, legal requirements for the medical reception of refugees are observed. In addition, doctors performing the initial medical examination are enabled to cover acute care on the spot. During the preliminary phase of immigration refugees are allowed to see a doctor in their facility repeatedly. After a certain time, they are provided with a health card permitting limited access to regular care outside of their facility. The current rise of refugee numbers affects the situation of Bremen health care for adult as well as juvenile refugees. In spite of the increase, health care standards are maintained by means of the health card. From 2011 to 2014, "Factors influencing health status and contact with health services" averaged 29.6 % in the health check data. Diseases of the respiratory system (18.1 %) and "symptoms, signs and abnormal findings not elsewhere classified" (16.9 %) ranked second and third, respectively. Diseases of the digestive system (6.1 %) of the musculoskeletal system (6 %) and of the skin and subcutaneous tissue (3.6 %) followed. Infectious diseases such as HIV infections, hepatitis or tuberculosis were seldom. PMID:27098974

  19. Grape Seed Oil Compounds: Biological and Chemical Actions for Health

    Science.gov (United States)

    Garavaglia, Juliano; Markoski, Melissa M.; Oliveira, Aline; Marcadenti, Aline

    2016-01-01

    Grape seed oil is rich in phenolic compounds, fatty acids, and vitamins, with economic importance to pharmaceutical, cosmetic, and food industry. Its use as an edible oil has also been suggested, especially due to its pleasant sensory characteristics. Grape seed oil has beneficial properties for health that are mainly detected by in vitro studies, such as anti-inflammatory, cardioprotective, antimicrobial, and anticancer properties, and may interact with cellular and molecular pathways. These effects have been related to grape seed oil constituents, mainly tocopherol, linolenic acid, resveratrol, quercetin, procyanidins, carotenoids, and phytosterols. The aim of this article was to briefly review the composition and nutritional aspects of grape seed oil, the interactions of its compounds with molecular and cellular pathways, and its possible beneficial effects on health. PMID:27559299

  20. Grape Seed Oil Compounds: Biological and Chemical Actions for Health.

    Science.gov (United States)

    Garavaglia, Juliano; Markoski, Melissa M; Oliveira, Aline; Marcadenti, Aline

    2016-01-01

    Grape seed oil is rich in phenolic compounds, fatty acids, and vitamins, with economic importance to pharmaceutical, cosmetic, and food industry. Its use as an edible oil has also been suggested, especially due to its pleasant sensory characteristics. Grape seed oil has beneficial properties for health that are mainly detected by in vitro studies, such as anti-inflammatory, cardioprotective, antimicrobial, and anticancer properties, and may interact with cellular and molecular pathways. These effects have been related to grape seed oil constituents, mainly tocopherol, linolenic acid, resveratrol, quercetin, procyanidins, carotenoids, and phytosterols. The aim of this article was to briefly review the composition and nutritional aspects of grape seed oil, the interactions of its compounds with molecular and cellular pathways, and its possible beneficial effects on health. PMID:27559299

  1. Walnuts (Juglans regia) Chemical Composition and Research in Human Health.

    Science.gov (United States)

    Hayes, David; Angove, Michael J; Tucci, Joe; Dennis, Christina

    2016-06-10

    Walnuts are among the most widely consumed commercially grown tree nuts in the world. Many health benefits have been claimed for the consumption of these, including reduced risk of cardiovascular disease, coronary heart disease, type II diabetes treatment, and prevention and treatment of certain cancers, and the lessening of symptoms attributed to age-related and other neurological disorders. The health-promoting benefits of walnut consumption are ascribed to its fatty acid profile, which is rich in polyunsaturated fatty acids with a particularly high ω3:ω6 ratio-the highest among all the tree nuts. The content of polyphenols and other phytochemicals in walnuts, with their claimed cytotoxic properties, also make them an attractive candidate for research for the prevention of free radical-induced nucleic acid damage. Research of walnut consumption in humans and animals employing a range of data sets and statistical methods suggest that walnuts may be considered a safe potential nutraceutical or possibly pharmaceutical substance. Nevertheless, few reviews of scientific research on the proposed benefits of these nuts exist, in spite of the numerous claims attributed to them in the lay media. This brief review article attempts to disseminate much of the information surrounding walnut consumption, and human health benefits, to other scientists and the interested general reader. PMID:25747270

  2. Walnuts (Juglans regia) Chemical Composition and Research in Human Health.

    Science.gov (United States)

    Hayes, David; Angove, Michael J; Tucci, Joe; Dennis, Christina

    2016-06-10

    Walnuts are among the most widely consumed commercially grown tree nuts in the world. Many health benefits have been claimed for the consumption of these, including reduced risk of cardiovascular disease, coronary heart disease, type II diabetes treatment, and prevention and treatment of certain cancers, and the lessening of symptoms attributed to age-related and other neurological disorders. The health-promoting benefits of walnut consumption are ascribed to its fatty acid profile, which is rich in polyunsaturated fatty acids with a particularly high ω3:ω6 ratio-the highest among all the tree nuts. The content of polyphenols and other phytochemicals in walnuts, with their claimed cytotoxic properties, also make them an attractive candidate for research for the prevention of free radical-induced nucleic acid damage. Research of walnut consumption in humans and animals employing a range of data sets and statistical methods suggest that walnuts may be considered a safe potential nutraceutical or possibly pharmaceutical substance. Nevertheless, few reviews of scientific research on the proposed benefits of these nuts exist, in spite of the numerous claims attributed to them in the lay media. This brief review article attempts to disseminate much of the information surrounding walnut consumption, and human health benefits, to other scientists and the interested general reader.

  3. Monks' Health: Holistic Health Care Model by Community Participation

    Directory of Open Access Journals (Sweden)

    Decha Buates

    2010-01-01

    Full Text Available Problem statement: Monks’ health tended to be a continuous increased problem. They were groups who had limitations to access health services due to their monastic disciplines and their most importance for Buddhist institution. Without urgent solution, their normal way of life would have been affected. Approach: This research aimed to study current conditions and to develop monks’ holistic health care models by community participation in central region of Thailand. The study was a qualitative research conducted in 9 temples; 3 temples in urban area, 3 in semi-urban area and 3 in rural area. Samples were 224 persons; consisted of monks, public health officers from Department of Religious Affairs, local administrative organizations and people; selected by purposive sampling method. Observation form, survey form, interview form, focus group discussion and workshop were used as research tools while data was analyzed by descriptive research. Results: The result founded that in former time culture of monks’ health care was leaned on community, social, culture and tradition. People spoke in style of central Thai language and were in agricultural sector as well as had their belief in merit, sin and elder respect. Relation in communities was in form of generosity and living as similar as relatives. When some monk got sick, they would visit, take care and give foods and medicines. Most of medicines were household remedy and Thai herbal medicine that bought from drug stores in local market or grocery stores in village and monks were sent to hospital in case of severe illness. Temple was a part of community, so they had close relation. Nowadays people increasingly worked in manufactories that caused conflicts and alienations among them. Monks leaned on local markets for receiving foods offering and most of foods were cooked from flour, sugar, coconut milk and fat. These caused three-fourth of monks having chronic disease as diabetes

  4. A Coupled Chemical and Mass Transport Model for Concrete Durability

    DEFF Research Database (Denmark)

    Jensen, Mads Mønster; Johannesson, Björn; Geiker, Mette Rica

    2012-01-01

    In this paper a general continuum theory is used to evaluate the service life of cement based materials, in terms of mass transport processes and chemical degradation of the solid matrix. The model established is a reactive mass transport model, based on an extended version of the Poisson...... curves which is established from a set of mathematical criteria. The chemical degradation is modelled with the geochemical code iphreeqc, which provides a general tool for evaluating different paste compositions. The governing system of equations is solved by the finite element method with a Newton...... simulation. The relative simple test cases show that sorption hysteresis cannot be neglected in a mass transport model for cement based materials and a description of the chemical degradation is crucial for long term simulation of service life prediction....

  5. Intervention Model in Pre-School Health

    OpenAIRE

    Almeida, I.; Corte, A; Rato, C.; Silvestre, A.; Grande, M.; Gil, G; Martins, C.

    2014-01-01

    The authors develop in this work, a model for intervention in school health, and reinforce the benefits of a global medical examination at the end of pre-school.They had done a research of pedagogic general objectives defined to pre-school education and the objectives of education for a pre-school health. They also reflect about an intervention in children with special needs of education.

  6. Two-Compartment Pharmacokinetic Models for Chemical Engineers

    Science.gov (United States)

    Kanneganti, Kumud; Simon, Laurent

    2011-01-01

    The transport of potassium permanganate between two continuous-stirred vessels was investigated to help chemical and biomedical engineering students understand two-compartment pharmacokinetic models. Concepts of modeling, mass balance, parameter estimation and Laplace transform were applied to the two-unit process. A good agreement was achieved…

  7. Towards consensus in comparative chemical characterization modeling for LCIA

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Bachmann, Till; Huijbregts, Mark;

    2006-01-01

    work within, for instance, the OECD, and guidance from a series of expert workshops held between 2002 and 2005, preliminary guidelines focusing on chemical fate, and human and ecotoxic effects were established. For further elaboration of the fate-, exposure- and effect-sides of the modeling, six models...

  8. Hydration of Portoguese cements, measurement and modelling of chemical shrinkage

    DEFF Research Database (Denmark)

    Maia, Lino; Geiker, Mette Rica; Figueiras, Joaquim A.

    2008-01-01

    Development of cement hydration was studied by measuring the chemical shrinkage of pastes. Five types of Portuguese Portland cement were used in cement pastes with . Chemical shrinkage was measured by gravimetry and dilatometry. In gravimeters results were recorded automatically during at least...... seven days, dilatometers were manually recorded during at least 56 days. The dispersion model was applied to fit chemical shrinkage results and to estimate the maximum (or ultimate) value for calculation of degree of hydration. Except for a pure Portland cement best fits were obtained by the general...

  9. Aesthetics of Chemical Products: Materials, Molecules, and Molecular Models

    OpenAIRE

    Joachim Schummer

    2003-01-01

    By comparing chemistry to art, chemists have recently made claims to the aesthetic value, even beauty, of some of their products. This paper takes these claims seriously and turns them into a systematic investigation of the aesthetics of chemical products. I distinguish three types of chemical products - materials, molecules, and molecular models - and use a wide variety of aesthetic theories suitable for an investigation of the corresponding sorts of objects. These include aesthetics of mate...

  10. Hydrogeochemical modeling of groundwater chemical environmental evolution in Hebei Plain

    Institute of Scientific and Technical Information of China (English)

    郭永海; 沈照理; 钟佐燊

    1997-01-01

    Using the hydrogeochemical modeling method, the groundwater chemical environmental problems of the Hebei Plain which involve increasing of hardness and total dissolved solids in piedmont area and mixing of saline water with fresh water in middle-eastern area are studied. The water-rock interactions and mass transfer along a ground-water flow path and in mixing processes are calculated. Thus the evolution mechanisms of the groundwater chemical environment are brought to light.

  11. Identification of Chemical Reactor Plant’s Mathematical Model

    Directory of Open Access Journals (Sweden)

    Pyakillya Boris

    2015-01-01

    Full Text Available This work presents a solution of the identification problem of chemical reactor plant’s mathematical model. The main goal is to obtain a mathematical description of a chemical reactor plant from experimental data, which based on plant’s time response measurements. This data consists sequence of measurements for water jacket temperature and information about control input signal, which is used to govern plant’s behavior.

  12. Quantum-chemical modeling of smectite clays

    Science.gov (United States)

    Aronowitz, S.; Coyne, L.; Lawless, J.; Rishpon, J.

    1982-01-01

    A self-consistent charge extended Hueckel program is used in modeling isomorphic substitution of Al(3+) by Na(+), K(+), Mg(2+), Fe(2+), and Fe(3+) in the octahedral layer of a dioctahedral smectite clay, such as montmorillonite. Upon comparison of the energies involved in the isomorphic substitution, it is found that the order for successful substitution is as follows: Al(3+), Fe(3+), Mg(2+), Fe(2+), Na(+), which is equivalent to Ca(2+), and then K(+). This ordering is found to be consistent with experimental observation. The calculations also make it possible to determine the possible penetration of metal ions into the clay's 2:1 crystalline layer. For the cases studied, this type of penetration can occur at elevated temperatures into regions where isomorphic substitution has occurred with metal ions that bear a formal charge of less than 3+. The computed behavior of the electronic structure in the presence of isomorphic substitution is found to be similar to behavior associated with semiconductors.

  13. A multimedia fate and chemical transport modeling system for pesticides: II. Model evaluation

    Science.gov (United States)

    Li, Rong; Scholtz, M. Trevor; Yang, Fuquan; Sloan, James J.

    2011-07-01

    Pesticides have adverse health effects and can be transported over long distances to contaminate sensitive ecosystems. To address problems caused by environmental pesticides we developed a multimedia multi-pollutant modeling system, and here we present an evaluation of the model by comparing modeled results against measurements. The modeled toxaphene air concentrations for two sites, in Louisiana (LA) and Michigan (MI), are in good agreement with measurements (average concentrations agree to within a factor of 2). Because the residue inventory showed no soil residues at these two sites, resulting in no emissions, the concentrations must be caused by transport; the good agreement between the modeled and measured concentrations suggests that the model simulates atmospheric transport accurately. Compared to the LA and MI sites, the measured air concentrations at two other sites having toxaphene soil residues leading to emissions, in Indiana and Arkansas, showed more pronounced seasonal variability (higher in warmer months); this pattern was also captured by the model. The model-predicted toxaphene concentration fraction on particles (0.5-5%) agrees well with measurement-based estimates (3% or 6%). There is also good agreement between modeled and measured dry (1:1) and wet (within a factor of less than 2) depositions in Lake Ontario. Additionally this study identified erroneous soil residue data around a site in Texas in a published US toxaphene residue inventory, which led to very low modeled air concentrations at this site. Except for the erroneous soil residue data around this site, the good agreement between the modeled and observed results implies that both the US and Mexican toxaphene soil residue inventories are reasonably good. This agreement also suggests that the modeling system is capable of simulating the important physical and chemical processes in the multimedia compartments.

  14. Progress in Chemical Kinetic Modeling for Surrogate Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Pitz, W J; Westbrook, C K; Herbinet, O; Silke, E J

    2008-06-06

    Gasoline, diesel, and other alternative transportation fuels contain hundreds to thousands of compounds. It is currently not possible to represent all these compounds in detailed chemical kinetic models. Instead, these fuels are represented by surrogate fuel models which contain a limited number of representative compounds. We have been extending the list of compounds for detailed chemical models that are available for use in fuel surrogate models. Detailed models for components with larger and more complicated fuel molecular structures are now available. These advancements are allowing a more accurate representation of practical and alternative fuels. We have developed detailed chemical kinetic models for fuels with higher molecular weight fuel molecules such as n-hexadecane (C16). Also, we can consider more complicated fuel molecular structures like cyclic alkanes and aromatics that are found in practical fuels. For alternative fuels, the capability to model large biodiesel fuels that have ester structures is becoming available. These newly addressed cyclic and ester structures in fuels profoundly affect the reaction rate of the fuel predicted by the model. Finally, these surrogate fuel models contain large numbers of species and reactions and must be reduced for use in multi-dimensional models for spark-ignition, HCCI and diesel engines.

  15. Multi-scale modeling for sustainable chemical production

    DEFF Research Database (Denmark)

    Zhuang, Kai; Bakshi, Bhavik R.; Herrgard, Markus

    2013-01-01

    , chemical industry, economy, and ecosystem. In addition, we propose a multi-scale approach for integrating the existing models into a cohesive framework. The major benefit of this proposed framework is that the design and decision-making at each scale can be informed, guided, and constrained by simulations...... associated with the development and implementation of a su stainable biochemical industry. The temporal and spatial scales of modeling approaches for sustainable chemical production vary greatly, ranging from metabolic models that aid the design of fermentative microbial strains to material and monetary flow...... models that explore the ecological impacts of all economic activities. Research efforts that attempt to connect the models at different scales have been limited. Here, we review a number of existing modeling approaches and their applications at the scales of metabolism, bioreactor, overall process...

  16. Understanding Business Models in Health Care.

    Science.gov (United States)

    Sharan, Alok D; Schroeder, Gregory D; West, Michael E; Vaccaro, Alexander R

    2016-05-01

    The increasing focus on the costs of care is forcing health care organizations to critically look at their basic set of processes and activities, to determine what type of value they can deliver. A business model describes the resources, processes, and cost assumptions that an organization makes that will lead to the delivery of a unique value proposition to a customer. As health care organizations are beginning to transform their structure in preparation for a value-based delivery system, understanding business model theory can help in the redesign process. PMID:27018909

  17. CHEMICAL REACTIONS SIMULATED BY GROUND-WATER-QUALITY MODELS.

    Science.gov (United States)

    Grove, David B.; Stollenwerk, Kenneth G.

    1987-01-01

    Recent literature concerning the modeling of chemical reactions during transport in ground water is examined with emphasis on sorption reactions. The theory of transport and reactions in porous media has been well documented. Numerous equations have been developed from this theory, to provide both continuous and sequential or multistep models, with the water phase considered for both mobile and immobile phases. Chemical reactions can be either equilibrium or non-equilibrium, and can be quantified in linear or non-linear mathematical forms. Non-equilibrium reactions can be separated into kinetic and diffusional rate-limiting mechanisms. Solutions to the equations are available by either analytical expressions or numerical techniques. Saturated and unsaturated batch, column, and field studies are discussed with one-dimensional, laboratory-column experiments predominating. A summary table is presented that references the various kinds of models studied and their applications in predicting chemical concentrations in ground waters.

  18. Model National Implementing Legislation for the Chemical Weapons Convention

    Energy Technology Data Exchange (ETDEWEB)

    Tanzman, E.A. [Argonne National Lab., IL (United States); Kellman, B. [DePaul University, Chicago, IL (United States)

    1997-12-31

    It is an honor to address this distinguished audience. We are grateful to the Republique Gabonaise for hosting this important gathering and to the staff of the Organization for the Prohibition of Chemical Weapons (OPCW) for supporting it. This seminar is another excellent opportunity for all of us to learn from each other about how the Chemical Weapons Convention (CWC) can become a foundation of arms control in Africa and around the world. At this meeting we speak only for ourselves, neither for the government of the United States of America nor for any other institution. This paper discusses model national implementing legislation under the CWC. Every State Party likely must enact implementing legislation - not only the few States Parties that will declare and destroy chemical weapons, but also the many States Parties that have never had a chemical weapons programme.

  19. Degradation Modelling for Health Monitoring Systems

    Science.gov (United States)

    Stetter, R.; Witczak, M.

    2014-12-01

    Condition-monitoring plays an increasingly important role for technical processes in order to improve reliability, availability, maintenance and lifetime of equipment. With increasing demands for efficiency and product quality, plus progress in the integration of automatic control systems in high-cost mechatronic and critical safety processes, the field of health monitoring is gaining interest. A similar research field is concerned with an estimation of the remaining useful life. A central question in these fields is the modelling of degradation; degradation is a process of a gradual and irreversible accumulation of damage which will finally result in a failure of the system. This paper is based on a current research project and explores various degradation modelling techniques. These results are explained on the basis of an industrial product - a system for the generation of health status information for pump systems. The result of this fuzzy-logic based system is a single number indicating the current health of a pump system.

  20. Multi-scale modeling for sustainable chemical production.

    Science.gov (United States)

    Zhuang, Kai; Bakshi, Bhavik R; Herrgård, Markus J

    2013-09-01

    With recent advances in metabolic engineering, it is now technically possible to produce a wide portfolio of existing petrochemical products from biomass feedstock. In recent years, a number of modeling approaches have been developed to support the engineering and decision-making processes associated with the development and implementation of a sustainable biochemical industry. The temporal and spatial scales of modeling approaches for sustainable chemical production vary greatly, ranging from metabolic models that aid the design of fermentative microbial strains to material and monetary flow models that explore the ecological impacts of all economic activities. Research efforts that attempt to connect the models at different scales have been limited. Here, we review a number of existing modeling approaches and their applications at the scales of metabolism, bioreactor, overall process, chemical industry, economy, and ecosystem. In addition, we propose a multi-scale approach for integrating the existing models into a cohesive framework. The major benefit of this proposed framework is that the design and decision-making at each scale can be informed, guided, and constrained by simulations and predictions at every other scale. In addition, the development of this multi-scale framework would promote cohesive collaborations across multiple traditionally disconnected modeling disciplines to achieve sustainable chemical production. PMID:23520143

  1. Upper Secondary Teachers' Knowledge for Teaching Chemical Bonding Models

    Science.gov (United States)

    Bergqvist, Anna; Drechsler, Michal; Rundgren, Shu-Nu Chang

    2016-01-01

    Researchers have shown a growing interest in science teachers' professional knowledge in recent decades. The article focuses on how chemistry teachers impart chemical bonding, one of the most important topics covered in upper secondary school chemistry courses. Chemical bonding is primarily taught using models, which are key for understanding science. However, many studies have determined that the use of models in science education can contribute to students' difficulties understanding the topic, and that students generally find chemical bonding a challenging topic. The aim of this study is to investigate teachers' knowledge of teaching chemical bonding. The study focuses on three essential components of pedagogical content knowledge (PCK): (1) the students' understanding, (2) representations, and (3) instructional strategies. We analyzed lesson plans about chemical bonding generated by 10 chemistry teachers with whom we also conducted semi-structured interviews about their teaching. Our results revealed that the teachers were generally unaware of how the representations of models they used affected student comprehension. The teachers had trouble specifying students' difficulties in understanding. Moreover, most of the instructional strategies described were generic and insufficient for promoting student understanding. Additionally, the teachers' rationale for choosing a specific representation or activity was seldom directed at addressing students' understanding. Our results indicate that both PCK components require improvement, and suggest that the two components should be connected. Implications for the professional development of pre-service and in-service teachers are discussed.

  2. ATMOSPHERIC HEALTH EFFECTS FRAMEWORK (AHEF) MODEL

    Science.gov (United States)

    The Atmospheric and Health Effects Framework (AHEF) is used to assess theglobal impacts of substitutes for ozone-depleting substances (ODS). The AHEF is a series of FORTRAN modeling modules that collectively form a simulation framework for (a) translating ODS production into emi...

  3. Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

    2008-11-01

    Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application

  4. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    OpenAIRE

    Centeno, José A.; Duane A. Rogers; Gijsbert B. van der Voet; Elisa Fornero; Lingsu Zhang; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Alexander Stojadinovic; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions rega...

  5. Most Plastic Products Release Estrogenic Chemicals: A Potential Health Problem That Can Be Solved

    OpenAIRE

    Yang, Chun Z.; Yaniger, Stuart I.; Jordan, V. Craig; Klein, Daniel J.; Bittner, George D

    2011-01-01

    Background: Chemicals having estrogenic activity (EA) reportedly cause many adverse health effects, especially at low (picomolar to nanomolar) doses in fetal and juvenile mammals. Objectives: We sought to determine whether commercially available plastic resins and products, including baby bottles and other products advertised as bisphenol A (BPA) free, release chemicals having EA. Methods: We used a roboticized MCF-7 cell proliferation assay, which is very sensitive, accurate, and repeatable,...

  6. Bayesian inference of chemical kinetic models from proposed reactions

    KAUST Repository

    Galagali, Nikhil

    2015-02-01

    © 2014 Elsevier Ltd. Bayesian inference provides a natural framework for combining experimental data with prior knowledge to develop chemical kinetic models and quantify the associated uncertainties, not only in parameter values but also in model structure. Most existing applications of Bayesian model selection methods to chemical kinetics have been limited to comparisons among a small set of models, however. The significant computational cost of evaluating posterior model probabilities renders traditional Bayesian methods infeasible when the model space becomes large. We present a new framework for tractable Bayesian model inference and uncertainty quantification using a large number of systematically generated model hypotheses. The approach involves imposing point-mass mixture priors over rate constants and exploring the resulting posterior distribution using an adaptive Markov chain Monte Carlo method. The posterior samples are used to identify plausible models, to quantify rate constant uncertainties, and to extract key diagnostic information about model structure-such as the reactions and operating pathways most strongly supported by the data. We provide numerical demonstrations of the proposed framework by inferring kinetic models for catalytic steam and dry reforming of methane using available experimental data.

  7. Towards validating use of self reported health (SRH) for community-based studies: Impact of environmental chemicals, sociodemographic variables, depression, and clinical indicators of health and nutrition

    Science.gov (United States)

    Environmental health impact assessment (HIA) studies, should consider social, behavioral, nutritional, dietary, environmental exposure and health risk factors at both the individual and community levels. Chemicals measured in blood or urine are often evaluated in relation to one ...

  8. Implications of imaginary chemical potential for model building of QCD

    CERN Document Server

    Kashiwa, Kouji

    2016-01-01

    Properties of QCD at finite imaginary chemical potential are revisited to utilize for the model building of QCD in low energy regimes. For example, the electric holonomy which is closely related to the Polyakov-loop drastically affects thermodynamic quantities beside the Roberge-Weiss transition line. To incorporate several properties at finite imaginary chemical potential, it is important to introduce the holonomy effects to the coupling constant of effective models. This extension is possible by considering the entanglement vertex. We show justifications of the entanglement vertex based on the derivation of the effective four-fermi interaction in the Nambu--Jona-Lasinio model and present its general form with the local approximation. To discuss how to remove model ambiguities in the entanglement vertex, we calculate the chiral condensate with different $\\mathbb{Z}_3$ sectors and the dual quark condensate.

  9. The Multicultural Model in Chemical Abuse Prevention and Intervention.

    Science.gov (United States)

    Griswold-Ezekoye, Stephanie

    1985-01-01

    Applies the concept of multiculturalism to chemical abuse prevention and intervention programs. Provides a model for implementation and describes projects with a similar conceptual basis. Acknowledges the cultural foundations for developing positive self-understanding. Promotes the development of culture-specific prevention strategies. (Author/LHW)

  10. A model for chemically-induced mechanical loading on MEMS

    DEFF Research Database (Denmark)

    Amiot, Fabien

    2007-01-01

    The development of full displacement field measurements as an alternative to the optical lever technique to measure the mechanical response for microelectro-mechanical systems components in their environment calls for a modeling of chemically-induced mechanical fields (stress, strain, and displac...

  11. Chiral and chemical oscillations in a simple dimerization model

    CERN Document Server

    Stich, Michael; Hochberg, David

    2012-01-01

    We consider the APED model (activation-polymerization-epimerization-depolymerization) for describing the emergence of chiral solutions within a non-catalytic framework for chiral polymerization. The minimal APED model for dimerization can lead to the spontaneous appearance of chiral oscillations and we describe in detail the nature of these oscillations in the enantiomeric excess, and which are the consequence of oscillations of the concentrations of the associated chemical species.

  12. Computer-Aided Multiscale Modelling for Chemical Process Engineering

    DEFF Research Database (Denmark)

    Morales Rodriguez, Ricardo; Gani, Rafiqul

    2007-01-01

    Chemical processes are generally modeled through monoscale approaches, which, while not adequate, satisfy a useful role in product-process design. In this case, use of a multi-dimensional and multi-scale model-based approach has importance in product-process development. A computer-aided framework......T) for model translation, analysis and solution. The integration of ModDev, MoT and ICAS or any other external software or process simulator (using COM-Objects) permits the generation of different models and/or process configurations for purposes of simulation, design and analysis. Consequently, it is possible...... for model generation, analysis, solution and implementation is necessary for the development and application of the desired model-based approach for product-centric process design/analysis. This goal is achieved through the combination of a system for model development (ModDev), and a modelling tool (Mo...

  13. Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction

    Directory of Open Access Journals (Sweden)

    Aleksandar Sabljic

    2004-12-01

    Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  14. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals

    Science.gov (United States)

    Hong, Huixiao; Shen, Jie; Ng, Hui Wen; Sakkiah, Sugunadevi; Ye, Hao; Ge, Weigong; Gong, Ping; Xiao, Wenming; Tong, Weida

    2016-01-01

    Endocrine disruptors such as polychlorinated biphenyls (PCBs), diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT) are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest) and the molecular descriptors calculated from two-dimensional structures by Mold2 software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69%) and external validations using 22 chemicals (balanced accuracy of 71%). Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence) in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed. PMID:27023588

  15. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals

    Directory of Open Access Journals (Sweden)

    Huixiao Hong

    2016-03-01

    Full Text Available Endocrine disruptors such as polychlorinated biphenyls (PCBs, diethylstilbestrol (DES and dichlorodiphenyltrichloroethane (DDT are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest and the molecular descriptors calculated from two-dimensional structures by Mold2 software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69% and external validations using 22 chemicals (balanced accuracy of 71%. Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed.

  16. A Rat α-Fetoprotein Binding Activity Prediction Model to Facilitate Assessment of the Endocrine Disruption Potential of Environmental Chemicals.

    Science.gov (United States)

    Hong, Huixiao; Shen, Jie; Ng, Hui Wen; Sakkiah, Sugunadevi; Ye, Hao; Ge, Weigong; Gong, Ping; Xiao, Wenming; Tong, Weida

    2016-04-01

    Endocrine disruptors such as polychlorinated biphenyls (PCBs), diethylstilbestrol (DES) and dichlorodiphenyltrichloroethane (DDT) are agents that interfere with the endocrine system and cause adverse health effects. Huge public health concern about endocrine disruptors has arisen. One of the mechanisms of endocrine disruption is through binding of endocrine disruptors with the hormone receptors in the target cells. Entrance of endocrine disruptors into target cells is the precondition of endocrine disruption. The binding capability of a chemical with proteins in the blood affects its entrance into the target cells and, thus, is very informative for the assessment of potential endocrine disruption of chemicals. α-fetoprotein is one of the major serum proteins that binds to a variety of chemicals such as estrogens. To better facilitate assessment of endocrine disruption of environmental chemicals, we developed a model for α-fetoprotein binding activity prediction using the novel pattern recognition method (Decision Forest) and the molecular descriptors calculated from two-dimensional structures by Mold² software. The predictive capability of the model has been evaluated through internal validation using 125 training chemicals (average balanced accuracy of 69%) and external validations using 22 chemicals (balanced accuracy of 71%). Prediction confidence analysis revealed the model performed much better at high prediction confidence. Our results indicate that the model is useful (when predictions are in high confidence) in endocrine disruption risk assessment of environmental chemicals though improvement by increasing number of training chemicals is needed. PMID:27023588

  17. Thermal-chemical Mantle Convection Models With Adaptive Mesh Refinement

    Science.gov (United States)

    Leng, W.; Zhong, S.

    2008-12-01

    In numerical modeling of mantle convection, resolution is often crucial for resolving small-scale features. New techniques, adaptive mesh refinement (AMR), allow local mesh refinement wherever high resolution is needed, while leaving other regions with relatively low resolution. Both computational efficiency for large- scale simulation and accuracy for small-scale features can thus be achieved with AMR. Based on the octree data structure [Tu et al. 2005], we implement the AMR techniques into the 2-D mantle convection models. For pure thermal convection models, benchmark tests show that our code can achieve high accuracy with relatively small number of elements both for isoviscous cases (i.e. 7492 AMR elements v.s. 65536 uniform elements) and for temperature-dependent viscosity cases (i.e. 14620 AMR elements v.s. 65536 uniform elements). We further implement tracer-method into the models for simulating thermal-chemical convection. By appropriately adding and removing tracers according to the refinement of the meshes, our code successfully reproduces the benchmark results in van Keken et al. [1997] with much fewer elements and tracers compared with uniform-mesh models (i.e. 7552 AMR elements v.s. 16384 uniform elements, and ~83000 tracers v.s. ~410000 tracers). The boundaries of the chemical piles in our AMR code can be easily refined to the scales of a few kilometers for the Earth's mantle and the tracers are concentrated near the chemical boundaries to precisely trace the evolvement of the boundaries. It is thus very suitable for our AMR code to study the thermal-chemical convection problems which need high resolution to resolve the evolvement of chemical boundaries, such as the entrainment problems [Sleep, 1988].

  18. A Logic Model for the Integration of Mental Health Into Chronic Disease Prevention and Health Promotion

    Directory of Open Access Journals (Sweden)

    James Lando, MD, MPH

    2006-03-01

    Full Text Available Mental illnesses such as depression or anxiety affect an individual’s ability to undertake health-promoting behaviors. Chronic diseases can have a profound impact on an individual’s mental health; in turn, mental health status affects an individual’s ability to participate in treatment and recovery. A group of mental health and public health professionals convened to develop a logic model for addressing mental health as it relates to chronic disease prevention and health promotion. The model provides details on inputs, activities, and desired outcomes, and the designers of the model welcome input from other mental health and public health practitioners.

  19. Iceland as a Model for Chemical Alteration on Mars

    Science.gov (United States)

    Bishop, Janice L.; Schiffman, P.; Murad, E.; Southard, R.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Subglacial volcanic activity on Iceland has led to the formation of a variety of silicate and iron oxide-rich alteration products that may serve as a model for chemical alteration on Mars. Multiple palagonitic tuffs, altered pillow lavas, hydrothermal springs and alteration at glacial run-off streams were observed during a recent field trip in Iceland. Formation of alteration products and ferrihydrite in similar environments on Mars may have contributed to the ferric oxide-rich surface material there. The spectral and chemical properties of Icelandic alteration products and ferrihydrites are presented here.

  20. Modelling Amperometric Biosensors Based on Chemically Modified Electrodes

    Science.gov (United States)

    Baronas, Romas; Kulys, Juozas

    2008-01-01

    The response of an amperometric biosensor based on a chemically modified electrode was modelled numerically. A mathematical model of the biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments: an enzyme layer and an outer diffusion layer. In order to define the main governing parameters the corresponding dimensionless mathematical model was derived. The digital simulation was carried out using the finite difference technique. The adequacy of the model was evaluated using analytical solutions known for very specific cases of the model parameters. By changing model parameters the output results were numerically analyzed at transition and steady state conditions. The influence of the substrate and mediator concentrations as well as of the thicknesses of the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially when the biosensor acts under a mixed limitation of the diffusion and the enzyme interaction with the substrate.

  1. SDG-based Model Validation in Chemical Process Simulation

    Institute of Scientific and Technical Information of China (English)

    张贝克; 许欣; 马昕; 吴重光

    2013-01-01

    Signed direct graph (SDG) theory provides algorithms and methods that can be applied directly to chemical process modeling and analysis to validate simulation models, and is a basis for the development of a soft-ware environment that can automate the validation activity. This paper is concentrated on the pretreatment of the model validation. We use the validation scenarios and standard sequences generated by well-established SDG model to validate the trends fitted from the simulation model. The results are helpful to find potential problems, as-sess possible bugs in the simulation model and solve the problem effectively. A case study on a simulation model of boiler is presented to demonstrate the effectiveness of this method.

  2. Chemically-induced mouse lung tumors: applications to human health assessments [Poster 2014

    Science.gov (United States)

    A state-of-the-science workshop on chemically-induced mouse lung tumors was conducted by U.S. Environmental Protection Agency to discuss issues related to the use of mouse lung tumor data in human health assessments. Naphthalene, styrene, and ethylbenzene were chosen for the anal...

  3. Influence of environmental chemicals on epigenetic programming and its applicability in human health risk assessment.

    Science.gov (United States)

    The field of epigenetics is rapidly evolving in response to the growing concern that heritable changes in gene expression may be involved in chemically-mediated adverse health outcomes, such as cancer. Although human and animal studies have shown a strong involvement of epigeneti...

  4. Aesthetics of Chemical Products: Materials, Molecules, and Molecular Models

    Directory of Open Access Journals (Sweden)

    Joachim Schummer

    2003-03-01

    Full Text Available By comparing chemistry to art, chemists have recently made claims to the aesthetic value, even beauty, of some of their products. This paper takes these claims seriously and turns them into a systematic investigation of the aesthetics of chemical products. I distinguish three types of chemical products - materials, molecules, and molecular models - and use a wide variety of aesthetic theories suitable for an investigation of the corresponding sorts of objects. These include aesthetics of materials, idealistic aesthetics from Plato to Kant and Schopenhauer, psychological approaches of Ernst Gombrich and Rudolf Arnheim, and semiotic aesthetics of Nelson Goodman and Umberto Eco. Although the investigation does not support recent claims, I point out where aesthetics does and can play an import role in chemistry. Particularly, Eco's approach helps us understand that and how aesthetic experience can be a driving force in chemical research.

  5. Co-exposure with fullerene may strengthen health effects of organic industrial chemicals.

    Directory of Open Access Journals (Sweden)

    Maili Lehto

    Full Text Available In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene which can be used with fullerene as reagents or solvents in industrial processes. Potential co-exposure scenarios include a fullerene dust and organic chemical vapor, or a fullerene solution aerosolized in workplace air. Unfiltered and filtered mixtures of C60 and organic chemicals represent different co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C60 that is more cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1β and TNF-α is considered. Complementary atomistic molecular dynamics simulations reveal that C60 co-aggregates with all chemicals in aqueous environment. Stable aggregates have a fullerene-rich core and a chemical-rich surface layer, and while essentially all C60 molecules aggregate together, a portion of organic molecules remains in water.

  6. [Research in Mexico on the health impact of environmental chemical pollutants].

    Science.gov (United States)

    Ortega-Ceseña, J; Carreón-Valencia, T; López-Carrillo, L; Chávez-Ayala, R; Hernández-Avila, M

    1993-01-01

    This paper is intended to offer a qualitative and quantitative diagnosis on publications concerned with human health impact of exposure to environmental chemical pollutants in Mexico. The review of these subjects included scientific papers on studies carried out in Mexico, published both in Mexican and international journals. The articles were analyzed according to the following criteria: chemical pollutants, type of study and institution that conducted it, study population, design, and analysis of data. The article concludes that publications in this field are scarce. Moreover, this review showed that there is little diversity, limited methodology and an unequal distribution of the human and material resources for research. All this indicates a rudimentary level of scientific knowledge in Mexico regarding public health implications of chemical pollutants. PMID:8128296

  7. Use of genotoxicity tests in a TIE to identify chemicals potentially affecting human health

    International Nuclear Information System (INIS)

    Imperial Oil operates a sour gas processing plant in southern Alberta that has, for the past several years, been the focus of considerable public and regulatory concern over perceived contamination of soils and groundwater on a nearby ranch. Elevated concentrations of DOC (∼140 mg/L) have been received in groundwater underlying the plant site. Two process-related chemicals, sulfolane and diisopropanolamine (DIPA), had been previously identified as the primary components of the DOC plume, although the chemicals associated with 30% of the DOC could not be identified. A risk assessment was initiated in 1994 to determine whether off-site migration of sulfolane and DIPA or of other unidentified contaminants poses a risks to human health and/or ecological receptors. One component of the risk assessment included conducting a TIE to help identify the chemical(s) in contaminated groundwater underlying the gas plant that might adversely affect human health. Three endpoints were utilized in the TIE: MicroTox, SOS-Chromotest and the Ames test. MicroTox was used since it exhibited a response to whole groundwater from the site, while the genotoxicity tests were used because DIPA reportedly causes a response in the Ames test and because of the concern over potential human health affects arising from other unidentified contaminants. Results of the TIE indicated that the chemicals causing the toxicity in the groundwater sample were water soluble compounds, with similar characteristics to the process chemicals used at the gas plant and detected at high concentrations in groundwater from the plant site. These results provided additional evidence to help focus the risk assessment on the chemicals sulfolane and diisopropanolamine

  8. 2-D Chemical-Dynamical Modeling of Venus's Sulfur Variability

    Science.gov (United States)

    Bierson, Carver J.; Zhang, Xi

    2016-10-01

    Over the last decade a combination of ground based and Venus Express observations have been made of the concentration of sulfur species in Venus's atmosphere, both above [1, 2] and below the clouds [3, 4]. These observations put constraints on both the vertical and meridional variations of the major sulfur species in Venus's atmosphere.. It has also been observed that SO2 concentrations varies on both timescales of hours and years [1,4]. The spatial and temporal distribution of tracer species is owing to two possibilities: mutual chemical interaction and dynamical tracer transport.Previous Chemical modeling of Venus's middle atmosphere has only been explored in 1-D. We will present the first 2-D (altitude and latitude) chemical-dynamical model for Venus's middle atmosphere. The sulfur chemistry is based on of the 1D model of Zhang et al. 2012 [5]. We do model runs over multiple Venus decades testing two scenarios: first one with varying sulfur fluxes from below, and second with secular dynamical perturbations in the atmosphere [6]. By comparing to Venus Express and ground based observations, we put constraints on the dynamics of Venus's middle atmosphere.References: [1] Belyaev et al. Icarus 2012 [2] Marcq et al. Nature geoscience, 2013 [3] Marcq et al. JGR:Planets, 2008 [4] Arney et al. JGR:Planets, 2014 [5] Zhang et al. Icarus 2012 [6] Parish et al. Icarus 2012

  9. Co-Exposure with Fullerene May Strengthen Health Effects of Organic Industrial Chemicals

    DEFF Research Database (Denmark)

    Lehto, M.; Karilainen, T.; Rog, T.;

    2014-01-01

    In vitro toxicological studies together with atomistic molecular dynamics simulations show that occupational co-exposure with C-60 fullerene may strengthen the health effects of organic industrial chemicals. The chemicals studied are acetophenone, benzaldehyde, benzyl alcohol, m-cresol, and toluene...... co-exposure scenarios in in vitro studies where acute cytotoxicity and immunotoxicity of C-60 and organic chemicals are tested together and alone by using human THP-1-derived macrophages. Statistically significant co-effects are observed for an unfiltered mixture of benzaldehyde and C-60 that is more...... cytotoxic than benzaldehyde alone, and for a filtered mixture of m-cresol and C-60 that is slightly less cytotoxic than m-cresol. Hydrophobicity of chemicals correlates with co-effects when secretion of pro-inflammatory cytokines IL-1 beta and TNF-alpha is considered. Complementary atomistic molecular...

  10. Computer-Aided Construction of Chemical Kinetic Models

    Energy Technology Data Exchange (ETDEWEB)

    Green, William H. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    2014-12-31

    The combustion chemistry of even simple fuels can be extremely complex, involving hundreds or thousands of kinetically significant species. The most reasonable way to deal with this complexity is to use a computer not only to numerically solve the kinetic model, but also to construct the kinetic model in the first place. Because these large models contain so many numerical parameters (e.g. rate coefficients, thermochemistry) one never has sufficient data to uniquely determine them all experimentally. Instead one must work in “predictive” mode, using theoretical rather than experimental values for many of the numbers in the model, and as appropriate refining the most sensitive numbers through experiments. Predictive chemical kinetics is exactly what is needed for computer-aided design of combustion systems based on proposed alternative fuels, particularly for early assessment of the value and viability of proposed new fuels before those fuels are commercially available. This project was aimed at making accurate predictive chemical kinetics practical; this is a challenging goal which requires a range of science advances. The project spanned a wide range from quantum chemical calculations on individual molecules and elementary-step reactions, through the development of improved rate/thermo calculation procedures, the creation of algorithms and software for constructing and solving kinetic simulations, the invention of methods for model-reduction while maintaining error control, and finally comparisons with experiment. Many of the parameters in the models were derived from quantum chemistry calculations, and the models were compared with experimental data measured in our lab or in collaboration with others.

  11. [Indoor air and human health--sick house syndrome and multiple chemical sensitivity].

    Science.gov (United States)

    Ando, Masanori

    2002-01-01

    The number of complaints about the quality of indoor air has increased during the past two decades. These complaints have been frequent enough that the term "Sick House Syndrome or Sick Building Syndrome" and "Multiple Chemical Sensitivity" has been coined. Complaints are likely related to the increased use of synthetic organic materials in house, furnishing, and consumer products; and the buildings, furnishings, and consumer products; and the decreased ventilation for energy conservation in homes. Approximately thousand volatile chemicals have been identified in indoor air. The main sources of these chemicals are house materials, combustion fumes, cleaning compounds, and paints or stains. Exposure to high levels of these emissions and to others, coupled with the fact that most people spend more time indoors than outdoors, raises the possibility that the risk to human health from indoor air pollution may be potentially greater than the risk posed from outdoor pollutants. The complaints most frequently voiced with respect to Sick House Syndrome are irritations of the eye, nose, and throat; cough and hoarseness of voice; headache and mental fatigue. The syndrome of multiple chemical sensitivities is controversial subject with increasing impact on the field of indoor air quality. The controversy surrounding Multiple Chemical Sensitivity includes its definition, theories of etiology and pathogenesis, diagnostic, and life style. Multiple Chemical Sensitivity is considered the hypothesis that is a disease caused by exposure to many chemically distinct environmental substances at very low.

  12. Chemical speciation of trace metals emitted from Indonesian peat fires for health risk assessment

    Science.gov (United States)

    Betha, Raghu; Pradani, Maharani; Lestari, Puji; Joshi, Umid Man; Reid, Jeffrey S.; Balasubramanian, Rajasekhar

    2013-03-01

    Regional smoke-induced haze in Southeast Asia, caused by uncontrolled forest and peat fires in Indonesia, is of major environmental and health concern. In this study, we estimated carcinogenic and non-carcinogenic health risk due to exposure to fine particles (PM2.5) as emitted from peat fires at Kalimantan, Indonesia. For the health risk analysis, chemical speciation (exchangeable, reducible, oxidizable, and residual fractions) of 12 trace metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn) in PM2.5 was studied. Results indicate that Al, Fe and Ti together accounted for a major fraction of total metal concentrations (~ 83%) in PM2.5 emissions in the immediate vicinity of peat fires. Chemical speciation reveals that a major proportion of most of the metals, with the exception of Cr, Mn, Fe, Ni and Cd, was present in the residual fraction. The exchangeable fraction of metals, which represents their bioavailability, could play a major role in inducing human health effects of PM2.5. This fraction contained carcinogenic metals such as Cd (39.2 ng m- 3) and Ni (249.3 ng m- 3) that exceeded their WHO guideline values by several factors. Health risk estimates suggest that exposure to PM2.5 emissions in the vicinity of peat fires poses serious health threats.

  13. Studies on modelling of bubble driven flows in chemical reactors

    Energy Technology Data Exchange (ETDEWEB)

    Grevskott, Sverre

    1997-12-31

    Multiphase reactors are widely used in the process industry, especially in the petrochemical industry. They very often are characterized by very good thermal control and high heat transfer coefficients against heating and cooling surfaces. This thesis first reviews recent advances in bubble column modelling, focusing on the fundamental flow equations, drag forces, transversal forces and added mass forces. The mathematical equations for the bubble column reactor are developed, using an Eulerian description for the continuous and dispersed phase in tensor notation. Conservation equations for mass, momentum, energy and chemical species are given, and the k-{epsilon} and Rice-Geary models for turbulence are described. The different algebraic solvers used in the model are described, as are relaxation procedures. Simulation results are presented and compared with experimental values. Attention is focused on the modelling of void fractions and gas velocities in the column. The energy conservation equation has been included in the bubble column model in order to model temperature distributions in a heated reactor. The conservation equation of chemical species has been included to simulate absorption of CO{sub 2}. Simulated axial and radial mass fraction profiles for CO{sub 2} in the gas phase are compared with measured values. Simulations of the dynamic behaviour of the column are also presented. 189 refs., 124 figs., 1 tab.

  14. Probabilistic consequence model of accidenal or intentional chemical releases.

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.-S.; Samsa, M. E.; Folga, S. M.; Hartmann, H. M.

    2008-06-02

    In this work, general methodologies for evaluating the impacts of large-scale toxic chemical releases are proposed. The potential numbers of injuries and fatalities, the numbers of hospital beds, and the geographical areas rendered unusable during and some time after the occurrence and passage of a toxic plume are estimated on a probabilistic basis. To arrive at these estimates, historical accidental release data, maximum stored volumes, and meteorological data were used as inputs into the SLAB accidental chemical release model. Toxic gas footprints from the model were overlaid onto detailed population and hospital distribution data for a given region to estimate potential impacts. Output results are in the form of a generic statistical distribution of injuries and fatalities associated with specific toxic chemicals and regions of the United States. In addition, indoor hazards were estimated, so the model can provide contingency plans for either shelter-in-place or evacuation when an accident occurs. The stochastic distributions of injuries and fatalities are being used in a U.S. Department of Homeland Security-sponsored decision support system as source terms for a Monte Carlo simulation that evaluates potential measures for mitigating terrorist threats. This information can also be used to support the formulation of evacuation plans and to estimate damage and cleanup costs.

  15. Chemical modeling of water deuteration in IRAS16293-2422

    CERN Document Server

    Wakelam, V; Aikawa, Y; Coutens, A; Bottinelli, S; Caux, E

    2014-01-01

    IRAS 16293-2422 is a well studied low-mass protostar characterized by a strong level of deuterium fractionation. In the line of sight of the protostellar envelope, an additional absorption layer, rich in singly and doubly deuterated water has been discovered by a detailed multiline analysis of HDO. To model the chemistry in this source, the gas-grain chemical code Nautilus has been used with an extended deuterium network. For the protostellar envelope, we solve the chemical reaction network in infalling fluid parcels in a protostellar core model. For the foreground cloud, we explored several physical conditions (density, cosmic ionization rate, C/O ratio). The main results of the paper are that gas-phase abundances of H2O, HDO and D2O observed in the inner regions of IRAS16293-2422 are lower than those predicted by a 1D dynamical/chemical (hot corino) model in which the ices are fully evaporated. The abundance in the outer part of the envelope present chaotic profiles due to adsorption/evaporation competition...

  16. Coupled Thermal-Chemical-Mechanical Modeling of Validation Cookoff Experiments

    Energy Technology Data Exchange (ETDEWEB)

    ERIKSON,WILLIAM W.; SCHMITT,ROBERT G.; ATWOOD,A.I.; CURRAN,P.D.

    2000-11-27

    The cookoff of energetic materials involves the combined effects of several physical and chemical processes. These processes include heat transfer, chemical decomposition, and mechanical response. The interaction and coupling between these processes influence both the time-to-event and the violence of reaction. The prediction of the behavior of explosives during cookoff, particularly with respect to reaction violence, is a challenging task. To this end, a joint DoD/DOE program has been initiated to develop models for cookoff, and to perform experiments to validate those models. In this paper, a series of cookoff analyses are presented and compared with data from a number of experiments for the aluminized, RDX-based, Navy explosive PBXN-109. The traditional thermal-chemical analysis is used to calculate time-to-event and characterize the heat transfer and boundary conditions. A reaction mechanism based on Tarver and McGuire's work on RDX{sup 2} was adjusted to match the spherical one-dimensional time-to-explosion data. The predicted time-to-event using this reaction mechanism compares favorably with the validation tests. Coupled thermal-chemical-mechanical analysis is used to calculate the mechanical response of the confinement and the energetic material state prior to ignition. The predicted state of the material includes the temperature, stress-field, porosity, and extent of reaction. There is little experimental data for comparison to these calculations. The hoop strain in the confining steel tube gives an estimation of the radial stress in the explosive. The inferred pressure from the measured hoop strain and calculated radial stress agree qualitatively. However, validation of the mechanical response model and the chemical reaction mechanism requires more data. A post-ignition burn dynamics model was applied to calculate the confinement dynamics. The burn dynamics calculations suffer from a lack of characterization of the confinement for the flaw

  17. The Instanton-Dyon Liquid Model III: Finite Chemical Potential

    CERN Document Server

    Liu, Yizhuang; Zahed, Ismail

    2016-01-01

    We discuss an extension of the instanton-dyon liquid model that includes light quarks at finite chemical potential in the center symmetric phase. We develop the model in details for the case of SU_c(2)\\times SU_f(2) by mapping the theory on a 3-dimensional quantum effective theory. We analyze the different phases in the mean-field approximation. We extend this analysis to the general case of SU_c(N_c)\\times SU_f(N_f) and note that the chiral and diquark pairings are always comparable.

  18. Aerosols and clouds in chemical transport models and climate models.

    Energy Technology Data Exchange (ETDEWEB)

    Lohmann,U.; Schwartz, S. E.

    2008-03-02

    Clouds exert major influences on both shortwave and longwave radiation as well as on the hydrological cycle. Accurate representation of clouds in climate models is a major unsolved problem because of high sensitivity of radiation and hydrology to cloud properties and processes, incomplete understanding of these processes, and the wide range of length scales over which these processes occur. Small changes in the amount, altitude, physical thickness, and/or microphysical properties of clouds due to human influences can exert changes in Earth's radiation budget that are comparable to the radiative forcing by anthropogenic greenhouse gases, thus either partly offsetting or enhancing the warming due to these gases. Because clouds form on aerosol particles, changes in the amount and/or composition of aerosols affect clouds in a variety of ways. The forcing of the radiation balance due to aerosol-cloud interactions (indirect aerosol effect) has large uncertainties because a variety of important processes are not well understood precluding their accurate representation in models.

  19. Health assessment for Agrico Chemical Company, Pensacola, Florida, Region 4. CERCLIS No. FLD980221857. Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    1990-05-31

    The site of the former Agrico Chemical Company covers an area of approximately 30 acres. Based on the available information, it has been concluded this site is of potential public health concern because of the risk to human health from exposure to hazardous substances at concentrations that may result in adverse health effects. As noted in the Environmental Contamination and Physical Hazards sections, human exposure to arsenic, chromium, fluoride, nitrate, and benzene may occur through contact with contaminated ground water; human exposure to fluoride may occur through contact with sediments and surface water in on-site impoundments. Air and edible plant and animal exposure pathways were not addressed in the information reviewed for this Preliminary Health Assessment.

  20. Modeling turbulence structure. Chemical kinetics interaction in turbulent reactive flows

    Energy Technology Data Exchange (ETDEWEB)

    Magnussen, B.F. [The Norwegian Univ. of Science and Technology, Trondheim (Norway)

    1997-12-31

    The challenge of the mathematical modelling is to transfer basic physical knowledge into a mathematical formulation such that this knowledge can be utilized in computational simulation of practical problems. The combustion phenomena can be subdivided into a large set of interconnected phenomena like flow, turbulence, thermodynamics, chemical kinetics, radiation, extinction, ignition etc. Combustion in one application differs from combustion in another area by the relative importance of the various phenomena. The difference in fuel, geometry and operational conditions often causes the differences. The computer offers the opportunity to treat the individual phenomena and their interactions by models with wide operational domains. The relative magnitude of the various phenomena therefore becomes the consequence of operational conditions and geometry and need not to be specified on the basis of experience for the given problem. In mathematical modelling of turbulent combustion, one of the big challenges is how to treat the interaction between the chemical reactions and the fluid flow i.e. the turbulence. Different scientists adhere to different concepts like the laminar flamelet approach, the pdf approach of the Eddy Dissipation Concept. Each of these approaches offers different opportunities and problems. All these models are based on a sound physical basis, however none of these have general validity in taking into consideration all detail of the physical chemical interaction. The merits of the models can only be judged by their ability to reproduce physical reality and consequences of operational and geometric conditions in a combustion system. The presentation demonstrates and discusses the development of a coherent combustion technology for energy conversion and safety based on the Eddy Dissipation Concept by Magnussen. (author) 30 refs.

  1. Modeling the chemical evolution of nitrogen oxides near roadways

    Science.gov (United States)

    Wang, Yan Jason; DenBleyker, Allison; McDonald-Buller, Elena; Allen, David; Zhang, K. Max

    2011-01-01

    The chemical evolution of nitrogen dioxide (NO 2) and nitrogen monoxide (NO) in the vicinity of roadways is numerically investigated using a computational fluid dynamics model, CFD-VIT-RIT and a Gaussian-based model, CALINE4. CFD-VIT-RIT couples a standard k- ɛ turbulence model for turbulent mixing and the Finite-Rate model for chemical reactions. CALINE4 employs a discrete parcel method, assuming that chemical reactions are independent of the dilution process. The modeling results are compared to the field measurement data collected near two roadways in Austin, Texas, State Highway 71 (SH-71) and Farm to Market Road 973 (FM-973), under parallel and perpendicular wind conditions during the summer of 2007. In addition to ozone (O 3), other oxidants and reactive species including hydroperoxyl radical (HO 2), organic peroxyl radical (RO 2), formaldehyde (HCHO) and acetaldehyde (CH 3CHO) are considered in the transformation from NO to NO 2. CFD-VIT-RIT is shown to be capable of predicting both NO x and NO 2 profiles downwind. CALINE4 is able to capture the NO x profiles, but underpredicts NO 2 concentrations under high wind velocity. Our study suggests that the initial NO 2/NO x ratios have to be carefully selected based on traffic conditions in order to assess NO 2 concentrations near roadways. The commonly assumed NO 2/NO x ratio by volume of 5% may not be suitable for most roadways, especially those with a high fraction of heavy-duty truck traffic. In addition, high O 3 concentrations and high traffic volumes would lead to the peak NO 2 concentration occurring near roadways with elevated concentrations persistent over a long distance downwind.

  2. Health Insurance, Medical Care, and Health Outcomes: A Model of Elderly Health Dynamics

    Science.gov (United States)

    Yang, Zhou; Gilleskie, Donna B.; Norton, Edward C.

    2009-01-01

    Prescription drug coverage creates a change in medical care consumption, beyond standard moral hazard, arising both from the differential cost-sharing and the relative effectiveness of different types of care. We model the dynamic supplemental health insurance decisions of Medicare beneficiaries, their medical care demand, and subsequent health…

  3. Ensuring Adequate Health and Safety Information for Decision Makers during Large-Scale Chemical Releases

    Science.gov (United States)

    Petropoulos, Z.; Clavin, C.; Zuckerman, B.

    2015-12-01

    The 2014 4-Methylcyclohexanemethanol (MCHM) spill in the Elk River of West Virginia highlighted existing gaps in emergency planning for, and response to, large-scale chemical releases in the United States. The Emergency Planning and Community Right-to-Know Act requires that facilities with hazardous substances provide Material Safety Data Sheets (MSDSs), which contain health and safety information on the hazardous substances. The MSDS produced by Eastman Chemical Company, the manufacturer of MCHM, listed "no data available" for various human toxicity subcategories, such as reproductive toxicity and carcinogenicity. As a result of incomplete toxicity data, the public and media received conflicting messages on the safety of the contaminated water from government officials, industry, and the public health community. Two days after the governor lifted the ban on water use, the health department partially retracted the ban by warning pregnant women to continue avoiding the contaminated water, which the Centers for Disease Control and Prevention deemed safe three weeks later. The response in West Virginia represents a failure in risk communication and calls to question if government officials have sufficient information to support evidence-based decisions during future incidents. Research capabilities, like the National Science Foundation RAPID funding, can provide a solution to some of the data gaps, such as information on environmental fate in the case of the MCHM spill. In order to inform policy discussions on this issue, a methodology for assessing the outcomes of RAPID and similar National Institutes of Health grants in the context of emergency response is employed to examine the efficacy of research-based capabilities in enhancing public health decision making capacity. The results of this assessment highlight potential roles rapid scientific research can fill in ensuring adequate health and safety data is readily available for decision makers during large

  4. GENE ARRAYS FOR ELUCIDATING MECHANISTIC DATA FROM MODELS OF MALE INFERTILITY AND CHEMICAL EXPOSURE IN MICE, RATS AND HUMANS

    Science.gov (United States)

    Gene arrays for elucidating mechanistic data from models of male infertility and chemical exposure in mice, rats and humansJohn C. Rockett and David J. Dix Gamete and Early Embryo Biology Branch, Reproductive Toxicology Division, National Health and Environmental Effects ...

  5. Exploring models for the roles of health systems’ responsiveness and social determinants in explaining universal health coverage and health outcomes

    OpenAIRE

    Valentine, Nicole Britt; Bonsel, Gouke J.

    2016-01-01

    Background: Intersectoral perspectives of health are present in the rhetoric of the sustainable development goals. Yet its descriptions of systematic approaches for an intersectoral monitoring vision, joining determinants of health, and barriers or facilitators to accessing healthcare services are lacking.Objective: To explore models of associations between health outcomes and health service coverage, and health determinants and health systems responsiveness, and thereby to contribute to moni...

  6. Incorporation of chemical kinetic models into process control

    International Nuclear Information System (INIS)

    An important consideration in chemical process control is to determine the precise rationing of reactant streams, particularly when a large time delay exists between the mixing of the reactants and the measurement of the product. In this paper, a method is described for incorporating chemical kinetic models into the control strategy in order to achieve optimum operating conditions. The system is first characterized by determining a reaction rate surface as a function of all input reactant concentrations over a feasible range. A nonlinear constrained optimization program is then used to determine the combination of reactants which produces the specified yield at minimum cost. This operating condition is then used to establish the nominal concentrations of the reactants. The actual operation is determined through a feedback control system employing a Smith predictor. The method is demonstrated on a laboratory bench scale enzyme reactor

  7. Cellular automaton model of mass transport with chemical reactions

    International Nuclear Information System (INIS)

    The transport and chemical reactions of solutes are modelled as a cellular automaton in which molecules of different species perform a random walk on a regular lattice and react according to a local probabilistic rule. The model describes advection and diffusion in a simple way, and as no restriction is placed on the number of particles at a lattice site, it is also able to describe a wide variety of chemical reactions. Assuming molecular chaos and a smooth density function, we obtain the standard reaction-transport equations in the continuum limit. Simulations on one-and two-dimensional lattices show that the discrete model can be used to approximate the solutions of the continuum equations. We discuss discrepancies which arise from correlations between molecules and how these discrepancies disappear as the continuum limit is approached. Of particular interest are simulations displaying long-time behaviour which depends on long-wavelength statistical fluctuations not accounted for by the standard equations. The model is applied to the reactions a + b ↔ c and a + b → c with homogeneous and inhomogeneous initial conditions as well as to systems subject to autocatalytic reactions and displaying spontaneous formation of spatial concentration patterns. (author) 9 figs., 34 refs

  8. Gompertz kinetics model of fast chemical neurotransmission currents.

    Science.gov (United States)

    Easton, Dexter M

    2005-10-01

    At a chemical synapse, transmitter molecules ejected from presynaptic terminal(s) bind reversibly with postsynaptic receptors and trigger an increase in channel conductance to specific ions. This paper describes a simple but accurate predictive model for the time course of the synaptic conductance transient, based on Gompertz kinetics. In the model, two simple exponential decay terms set the rates of development and decline of transmitter action. The first, r, triggering conductance activation, is surrogate for the decelerated rate of growth of conductance, G. The second, r', responsible for Y, deactivation of the conductance, is surrogate for the decelerated rate of decline of transmitter action. Therefore, the differential equation for the net conductance change, g, triggered by the transmitter is dg/dt=g(r-r'). The solution of that equation yields the product of G(t), representing activation, and Y(t), which defines the proportional decline (deactivation) of the current. The model fits, over their full-time course, published records of macroscopic ionic current associated with fast chemical transmission. The Gompertz model is a convenient and accurate method for routine analysis and comparison of records of synaptic current and putative transmitter time course. A Gompertz fit requiring only three independent rate constants plus initial current appears indistinguishable from a Markov fit using seven rate constants.

  9. Chemical kinetic modeling of H{sub 2} applications

    Energy Technology Data Exchange (ETDEWEB)

    Marinov, N.M.; Westbrook, C.K.; Cloutman, L.D. [Lawrence Livermore National Lab., CA (United States)] [and others

    1995-09-01

    Work being carried out at LLNL has concentrated on studies of the role of chemical kinetics in a variety of problems related to hydrogen combustion in practical combustion systems, with an emphasis on vehicle propulsion. Use of hydrogen offers significant advantages over fossil fuels, and computer modeling provides advantages when used in concert with experimental studies. Many numerical {open_quotes}experiments{close_quotes} can be carried out quickly and efficiently, reducing the cost and time of system development, and many new and speculative concepts can be screened to identify those with sufficient promise to pursue experimentally. This project uses chemical kinetic and fluid dynamic computational modeling to examine the combustion characteristics of systems burning hydrogen, either as the only fuel or mixed with natural gas. Oxidation kinetics are combined with pollutant formation kinetics, including formation of oxides of nitrogen but also including air toxics in natural gas combustion. We have refined many of the elementary kinetic reaction steps in the detailed reaction mechanism for hydrogen oxidation. To extend the model to pressures characteristic of internal combustion engines, it was necessary to apply theoretical pressure falloff formalisms for several key steps in the reaction mechanism. We have continued development of simplified reaction mechanisms for hydrogen oxidation, we have implemented those mechanisms into multidimensional computational fluid dynamics models, and we have used models of chemistry and fluid dynamics to address selected application problems. At the present time, we are using computed high pressure flame, and auto-ignition data to further refine the simplified kinetics models that are then to be used in multidimensional fluid mechanics models. Detailed kinetics studies have investigated hydrogen flames and ignition of hydrogen behind shock waves, intended to refine the detailed reactions mechanisms.

  10. Health literacy and public health: A systematic review and integration of definitions and models

    LENUS (Irish Health Repository)

    Sorensen, Kristine

    2012-01-25

    Abstract Background Health literacy concerns the knowledge and competences of persons to meet the complex demands of health in modern society. Although its importance is increasingly recognised, there is no consensus about the definition of health literacy or about its conceptual dimensions, which limits the possibilities for measurement and comparison. The aim of the study is to review definitions and models on health literacy to develop an integrated definition and conceptual model capturing the most comprehensive evidence-based dimensions of health literacy. Methods A systematic literature review was performed to identify definitions and conceptual frameworks of health literacy. A content analysis of the definitions and conceptual frameworks was carried out to identify the central dimensions of health literacy and develop an integrated model. Results The review resulted in 17 definitions of health literacy and 12 conceptual models. Based on the content analysis, an integrative conceptual model was developed containing 12 dimensions referring to the knowledge, motivation and competencies of accessing, understanding, appraising and applying health-related information within the healthcare, disease prevention and health promotion setting, respectively. Conclusions Based upon this review, a model is proposed integrating medical and public health views of health literacy. The model can serve as a basis for developing health literacy enhancing interventions and provide a conceptual basis for the development and validation of measurement tools, capturing the different dimensions of health literacy within the healthcare, disease prevention and health promotion settings.

  11. Health literacy and public health: A systematic review and integration of definitions and models

    Directory of Open Access Journals (Sweden)

    Sørensen Kristine

    2012-01-01

    Full Text Available Abstract Background Health literacy concerns the knowledge and competences of persons to meet the complex demands of health in modern society. Although its importance is increasingly recognised, there is no consensus about the definition of health literacy or about its conceptual dimensions, which limits the possibilities for measurement and comparison. The aim of the study is to review definitions and models on health literacy to develop an integrated definition and conceptual model capturing the most comprehensive evidence-based dimensions of health literacy. Methods A systematic literature review was performed to identify definitions and conceptual frameworks of health literacy. A content analysis of the definitions and conceptual frameworks was carried out to identify the central dimensions of health literacy and develop an integrated model. Results The review resulted in 17 definitions of health literacy and 12 conceptual models. Based on the content analysis, an integrative conceptual model was developed containing 12 dimensions referring to the knowledge, motivation and competencies of accessing, understanding, appraising and applying health-related information within the healthcare, disease prevention and health promotion setting, respectively. Conclusions Based upon this review, a model is proposed integrating medical and public health views of health literacy. The model can serve as a basis for developing health literacy enhancing interventions and provide a conceptual basis for the development and validation of measurement tools, capturing the different dimensions of health literacy within the healthcare, disease prevention and health promotion settings.

  12. The Problem of Assessment for Radionuclide and Chemical Hazard to People Heredity and Health

    International Nuclear Information System (INIS)

    In the 21th century the assessment of the hazard to human heredity and health from the radionuclide and chemical environmental pollution becomes of prime social importance since it is related to the problems of utilization of great amounts of radioactive and chemical wastes, spent nuclear fuel, weapon plutonium, nuclear reactors and emergency discharges of isotopes which in total is higher than 1 billion Ci. Long-term cytogenetic monitoring of nuclear and chemical plant workers, local human populations of radioactive waste areas and radionuclide polluted territories has revealed that the level and spectrum of induced chromosome aberrations in blood lymphocytes correlate with the type, dose and duration of exposure. There is very strong evidence that the yield of chromosome aberrations (Y) is related to the dose (D) by the equation: Y=Ao+aD+bD2. Therefore the radiation/radionuclide risk (R(D) ) will correspond to a absorbed dose and its aberrational/mutational consequences ('doubling dose' coefficient). Increased levels of chromosome aberrations in the human body very often precede the development of several syndromes: chronic fatigue, secondary immune deficiency, early aging, reproductive dysfunction, oncological diseases and etc. The increased levels of chromosome aberrations in blood lymphocytes can serve as objective bio indicators of radiation and chemical risk to human heredity and health. Thus, monitoring of chromosome and genome aberrations must be of strategical importance in the system of governmental service for minimization of radionuclide and chemical hazard to human heredity and health the necessity of organization of which has already matured. The above mentioned confirms the necessity of founding a European network for ecological-genetic monitoring with 'Internet' translation of information on radionuclide composition and chromosome aberration levels in people, inhabiting polluted areas

  13. Gastrointestinal tract modelling in health and disease

    Institute of Scientific and Technical Information of China (English)

    Dong-Hua Liao; Jing-Bo Zhao; Hans Gregersen

    2009-01-01

    The gastrointestinal (GI) tract is the system of organs within multi-cellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. The various patterns of GI tract function are generated by the integrated behaviour of multiple tissues and cell types. A thorough study of the GI tract requires understanding of the interactions between cells, tissues and gastrointestinal organs in health and disease. This depends on knowledge, not only of numerous cellular ionic current mechanisms and signal transduction pathways, but also of large scale GI tissue structures and the special distribution of the nervous network. A unique way of coping with this explosion in complexity is mathematical and computational modelling; providing a computational framework for the multilevel modelling and simulation of the human gastrointestinal anatomy and physiology. The aim of this review is to describe the current status of biomechanical modelling work of the GI tract in humans and animals, which can be further used to integrate the physiological, anatomical and medical knowledge of the GI system. Such modelling will aid research and ensure that medical professionals benefit, through the provision of relevant and precise information about the patient's condition and GI remodelling in animal disease models. It will also improve the accuracy and efficiency of medical procedures, which could result in reduced cost for diagnosis and treatment.

  14. [Antecedents of the Catalan health model].

    Science.gov (United States)

    Sabaté i Casellas, Ferran

    2015-11-01

    The Catalan healthcare model is a particular way of addressing public health contingencies of the population as a whole, based on an organizational tradition that brings together stakeholders, such as the civil society, local government, the church, mutual care societies, public and private foundations, which for centuries have worked in coordination and complemented each other to provide quality public healthcare, far and beyond merely catering to the poor or those passing through. This model is based on a selfless, public spirited concept of society, achieved through a vocation to form social agreements, preserved in Catalan civil law. During the 3 periods of self-government Catalonia has enjoyed throughout the twentieth century, it has adapted to the economic, social, and scientific conditions, which define modern society, without sacrificing its fundamental features, thereby achieving a remarkable level of efficiency together with significant social consensus. PMID:26711054

  15. Determinants of health literacy and health behavior regarding infectious respiratory diseases: a pathway model

    OpenAIRE

    Sun, Xinying; Shi, Yuhui; Zeng, Qingqi; Wang, Yanling; Du, Weijing; Wei, Nanfang; Xie, Ruiqian; Chang, Chun

    2013-01-01

    Background Health literacy has been defined as the degree to which individuals have the capacity to obtain, process, and understand the basic health information and services needed to make appropriate health decisions. Currently, few studies have validated the causal pathways of determinants of health literacy through the use of statistical modeling. The purpose of the present study was to develop and validate a health literacy model at an individual level that could best explain the determin...

  16. Model Organisms Fact Sheet: Using Model Organisms to Study Health and Disease

    Science.gov (United States)

    ... Model Organisms to Study Health and Disease Using Model Organisms to Study Health and Disease Tagline (Optional) ... and treating disease in humans. What is a model? The word model has many meanings, but in ...

  17. Modeling Health Insurance Choice Using the Heterogeneous Logit Model

    OpenAIRE

    Keane, Michael

    2004-01-01

    Recent advances in "simulation based inference" have made it feasible to estimate discrete choice models with several alternatives and rich patterns of consumer taste heterogeneity. These new methods have important potential application in health economics. One important application is the analysis of consumer choice behavior in insurance markets characterized by competition among several alternative insurance plans. Analysis of consumer choice behavior in insurance markets is of great intere...

  18. Modelling Amperometric Biosensors Based on Chemically Modified Electrodes

    Directory of Open Access Journals (Sweden)

    Juozas Kulys

    2008-08-01

    Full Text Available The response of an amperometric biosensor based on a chemically modified electrode was modelled numerically. A mathematical model of the biosensor is based on a system of non-linear reaction-diffusion equations. The modelling biosensor comprises two compartments: an enzyme layer and an outer diffusion layer. In order to define the main governing parameters the corresponding dimensionless mathematical model was derived. The digital simulation was carried out using the finite difference technique. The adequacy of the model was evaluated using analytical solutions known for very specific cases of the model parameters. By changing model parameters the output results were numerically analyzed at transition and steady state conditions. The influence of the substrate and mediator concentrations as well as of the thicknesses of the enzyme and diffusion layers on the biosensor response was investigated. Calculations showed complex kinetics of the biosensor response, especially when the biosensor acts under a mixed limitation of the diffusion and the enzyme interaction with the substrate.

  19. Screening chemicals for thyroid-disrupting activity: A critical comparison of mammalian and amphibian models.

    Science.gov (United States)

    Pickford, Daniel B

    2010-11-01

    In order to minimize risks to human and environmental health, chemical safety assessment programs are being reinforced with toxicity tests more specifically designed for detecting endocrine disrupters. This includes the necessity to detect thyroid-disrupting chemicals, which may operate through a variety of modes of action, and have potential to impair neurological development in humans, with resulting deficits of individual and social potential. Mindful of these concerns, the consensus favors in vivo models for both hazard characterization (testing) and hazard identification (screening) steps, in order to minimize false negatives. Owing to its obligate dependence on thyroid hormones, it has been proposed that amphibian metamorphosis be used as a generalized vertebrate model for thyroid function in screening batteries for detection of thyroid disrupters. However, it seems unlikely that such an assay would ever fully replace in vivo mammalian assays currently being validated for human health risk assessment: in its current form the amphibian metamorphosis screening assay would not provide capacity for reliably detecting other modes of endocrine-disrupting activity. Conversely, several candidate mammalian screening assays appear to offer robust capacity to detect a variety of modes of endocrine-disrupting activity, including thyroid activity. To assess whether omission of an amphibian metamorphosis assay from an in vivo screening battery would generate false negatives, the response of amphibian and mammalian assays to a variety known thyroid disrupters, as reported in peer-reviewed literature or government agency reports, was critically reviewed. Of the chemicals investigated from the literature selected (41), more had been tested in mammalian studies with thyroid-relevant endpoints (32) than in amphibian assays with appropriate windows of exposure and developmental endpoints (27). One chemical (methoxychlor) was reported to exhibit thyroid activity in an appropriate

  20. Assimilation of stratospheric ozone in the chemical transport model STRATAQ

    Directory of Open Access Journals (Sweden)

    B. Grassi

    2004-09-01

    Full Text Available We describe a sequential assimilation approach useful for assimilating tracer measurements into a three-dimensional chemical transport model (CTM of the stratosphere. The numerical code, developed largely according to Kha00, uses parameterizations and simplifications allowing assimilation of sparse observations and the simultaneous evaluation of analysis errors, with reasonable computational requirements. Assimilation parameters are set by using χ2 and OmF (Observation minus Forecast statistics. The CTM used here is a high resolution three-dimensional model. It includes a detailed chemical package and is driven by UKMO (United Kingdom Meteorological Office analyses. We illustrate the method using assimilation of Upper Atmosphere Research Satellite/Microwave Limb Sounder (UARS/MLS ozone observations for three weeks during the 1996 antarctic spring. The comparison of results from the simulations with TOMS (Total Ozone Mapping Spectrometer measurements shows improved total ozone fields due to assimilation of MLS observations. Moreover, the assimilation gives indications on a possible model weakness in reproducing polar ozone values during springtime.

  1. Chemical modeling of cementitious grout materials alteration in HLW repositories

    International Nuclear Information System (INIS)

    This paper reports on an investigation initiated into the nature of the chemical alteration of cementitious grout in HLW repository seals, and the implications for long-term seal performance. The equilibrium chemical reaction of two simplified portland cement-based grout models with natural Canadian Shield groundwater compositions was modeled with the computer codes PHREEQE and EQ3NR/EQ6. Increases in porosity and permeability of the grout resulting from dissolution of grout phases and precipitation of secondary phases were estimated. Two bounding hydrologic scenarios were evaluated, one approximating a high gradient, high flow regime, the other a low-gradient, sluggish flow regime. Seal longevity depends in part upon the amount of groundwater coming into intimate contact with, and dissolving, the grout per unit time. Results of the analyses indicate that, given the assumptions and simplifications inherent in the models, acceptable seal performance (i.e., acceptable increases in hydraulic conductivity of the seals) may be expected for at least thousands of years in the worst cases analyzed, and possibly much longer

  2. To Model Chemical Reactivity in Heterogeneous Emulsions, Think Homogeneous Microemulsions.

    Science.gov (United States)

    Bravo-Díaz, Carlos; Romsted, Laurence Stuart; Liu, Changyao; Losada-Barreiro, Sonia; Pastoriza-Gallego, Maria José; Gao, Xiang; Gu, Qing; Krishnan, Gunaseelan; Sánchez-Paz, Verónica; Zhang, Yongliang; Dar, Aijaz Ahmad

    2015-08-25

    Two important and unsolved problems in the food industry and also fundamental questions in colloid chemistry are how to measure molecular distributions, especially antioxidants (AOs), and how to model chemical reactivity, including AO efficiency in opaque emulsions. The key to understanding reactivity in organized surfactant media is that reaction mechanisms are consistent with a discrete structures-separate continuous regions duality. Aggregate structures in emulsions are determined by highly cooperative but weak organizing forces that allow reactants to diffuse at rates approaching their diffusion-controlled limit. Reactant distributions for slow thermal bimolecular reactions are in dynamic equilibrium, and their distributions are proportional to their relative solubilities in the oil, interfacial, and aqueous regions. Our chemical kinetic method is grounded in thermodynamics and combines a pseudophase model with methods for monitoring the reactions of AOs with a hydrophobic arenediazonium ion probe in opaque emulsions. We introduce (a) the logic and basic assumptions of the pseudophase model used to define the distributions of AOs among the oil, interfacial, and aqueous regions in microemulsions and emulsions and (b) the dye derivatization and linear sweep voltammetry methods for monitoring the rates of reaction in opaque emulsions. Our results show that this approach provides a unique, versatile, and robust method for obtaining quantitative estimates of AO partition coefficients or partition constants and distributions and interfacial rate constants in emulsions. The examples provided illustrate the effects of various emulsion properties on AO distributions such as oil hydrophobicity, emulsifier structure and HLB, temperature, droplet size, surfactant charge, and acidity on reactant distributions. Finally, we show that the chemical kinetic method provides a natural explanation for the cut-off effect, a maximum followed by a sharp reduction in AO efficiency with

  3. Chemical kinetics and combustion modelling with CFX 4

    Energy Technology Data Exchange (ETDEWEB)

    Stopford, P. [AEA Technology, Computational Fluid Dynamics Services Harwell, Oxfordshire (United Kingdom)

    1997-12-31

    The presentation describes some recent developments in combustion and kinetics models used in the CFX software of AEA Technology. Three topics are highlighted: the development of coupled solvers in a traditional `SIMPLE`-based CFD code, the use of detailed chemical kinetics mechanism via `look-up` tables and the application of CFD to large-scale multi-burner combustion plant. The aim is identify those physical approximations and numerical methods that are likely to be most useful in the future and those areas where further developments are required. (author) 6 refs.

  4. Analytical model of plasma-chemical etching in planar reactor

    Science.gov (United States)

    Veselov, D. S.; Bakun, A. D.; Voronov, Yu A.; Kireev, V. Yu; Vasileva, O. V.

    2016-09-01

    The paper discusses an analytical model of plasma-chemical etching in planar diode- type reactor. Analytical expressions of etch rate and etch anisotropy were obtained. It is shown that etch anisotropy increases with increasing the ion current and ion energy. At the same time, etch selectivity of processed material decreases as compared with the mask. Etch rate decreases with the distance from the centre axis of the reactor. To decrease the loading effect, it is necessary to reduce the wafer temperature and pressure in the reactor, as well as increase the gas flow rate through the reactor.

  5. Risk-based high-throughput chemical screening and prioritization using exposure models and in vitro bioactivity assays

    International Nuclear Information System (INIS)

    We present a risk-based high-throughput screening (HTS) method to identify chemicals for potential health concerns or for which additional information is needed. The method is applied to 180 organic chemicals as a case study. We first obtain information on how the chemical is used and identify relevant use scenarios (e.g., dermal application, indoor emissions). For each chemical and use scenario, exposure models are then used to calculate a chemical intake fraction, or a product intake fraction, accounting for chemical properties and the exposed population. We then combine these intake fractions with use scenario-specific estimates of chemical quantity to calculate daily intake rates (iR; mg/kg/day). These intake rates are compared to oral equivalent doses (OED; mg/kg/day), calculated from a suite of ToxCast in vitro bioactivity assays using in vitro-to-in vivo extrapolation and reverse dosimetry. Bioactivity quotients (BQs) are calculated as iR/OED to obtain estimates of potential impact associated with each relevant use scenario. Of the 180 chemicals considered, 38 had maximum iRs exceeding minimum OEDs (i.e., BQs > 1). For most of these compounds, exposures are associated with direct intake, food/oral contact, or dermal exposure. The method provides high-throughput estimates of exposure and important input for decision makers to identify chemicals of concern for further evaluation with additional information or more refined models

  6. Chemical composition and potential health risks of raw Arabian incense (Bakhour

    Directory of Open Access Journals (Sweden)

    Yehya Elsayed

    2016-07-01

    Full Text Available Burning Arabian incense (Bakhour is a common indoor practice in the Middle East and the Arabian Gulf region. However, the chemical composition of this substance has never been studied. Three different Bakhour brands were selected for this study. A complete chemical profile for the raw samples was determined using carbon, hydrogen, and nitrogen elemental analysis, inductively coupled plasma optical emission spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy and gas chromatography mass spectrometry techniques. A wide range of elements and compounds were identified, many of which are hazardous to health. Nitrogen was found in all samples which should raise concerns due to the known health implications of amines, nitrogen oxides and nitrites. In addition toxic metals such as cobalt, copper, iron, nickel, lead, and zinc were also determined in all samples. The amounts of these metals are equivalent to those in raw tobacco, where they are known to pose health risks. Three types of solvents (acetone, dichloromethane and toluene were used for the extraction of organic compounds. Carcinogens, toxins and irritants were found along others of different health implications. Isolation of these compounds provides preliminary evidence on the harmful consequences of being exposed to Bakhour.

  7. Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture.

    Science.gov (United States)

    Nicolopoulou-Stamati, Polyxeni; Maipas, Sotirios; Kotampasi, Chrysanthi; Stamatis, Panagiotis; Hens, Luc

    2016-01-01

    The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs, and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production, which is safer for man and the environment, and to this end, steps such as the declaration of Nyéléni have been taken. PMID:27486573

  8. Biological effects of anthropogenic chemical stress: Tools for the assessment of ecosystem health (BEAST)

    DEFF Research Database (Denmark)

    Lehtonen, Kari K.; Sundelin, Brita; Lang, Thomas;

    In the Baltic Sea Action Plan the urgent need to develop biological effects monitoring of hazardous substances and the assessment of ecosystem health has been clearly indicated. These goals will be tackled in the newly launched BEAST project (Biological Effects of Anthropogenic Chemical Stress......: Tools for the Assessment of Ecosystem Health, 2009-2011), which is part of the Baltic Sea BONUS+ Programme funded jointly by national funding agencies and FP7 ERA-NET+ of the European Commission. The BEAST project consists of three workpackages (WP) with the following main tasks: WP1- Field studies and...... experiments in selected sub-regions of the Baltic Sea, WP2 - Application and validation of methods in monitoring and assessment in the Baltic Sea, and WP3 - Developing tools for ecosystem health assessment in the Baltic Sea. BEAST research activities are focused in the sub-regions of Gulf of Bothnia, Gulf of...

  9. Chemical Weapons Exposures in Iraq: Challenges of a Public Health Response a Decade Later.

    Science.gov (United States)

    Baird, Coleen; Mirza, Raul; Sharkey, Jessica M; Teichman, Ron; Longmire, Romarius; Harkins, Deanna; Llanos, Joseph; Abraham, Joseph; McCannon, Charles; Heller, Jack; Tinklepaugh, Carole; Rice, William

    2016-01-01

    An October 14, 2014 article in The New York Times reported that the US Department of Defense (DoD) concealed, for nearly a decade, circumstances surrounding service members' exposure to chemical warfare agents (CWA) while deployed to Iraq in support of Operations Iraqi Freedom and New Dawn from March 13, 2003, to December 31, 2011, and alleged failure of the DoD to provide expedient and adequate medical care. This report prompted the DoD to devise a public health investigation, with the Army Public Health Center (Provisional) as the lead agency to identify, evaluate, document, and track CWA casualties of the Iraq war. Further, the DoD revisited and revised clinical guidelines and health policies concerning CWA exposure based on current evidence-based guidelines and best practices. PMID:27613213

  10. Chemical Pesticides and Human Health: The Urgent Need for a New Concept in Agriculture

    Science.gov (United States)

    Nicolopoulou-Stamati, Polyxeni; Maipas, Sotirios; Kotampasi, Chrysanthi; Stamatis, Panagiotis; Hens, Luc

    2016-01-01

    The industrialization of the agricultural sector has increased the chemical burden on natural ecosystems. Pesticides are agrochemicals used in agricultural lands, public health programs, and urban green areas in order to protect plants and humans from various diseases. However, due to their known ability to cause a large number of negative health and environmental effects, their side effects can be an important environmental health risk factor. The urgent need for a more sustainable and ecological approach has produced many innovative ideas, among them agriculture reforms and food production implementing sustainable practice evolving to food sovereignty. It is more obvious than ever that the society needs the implementation of a new agricultural concept regarding food production, which is safer for man and the environment, and to this end, steps such as the declaration of Nyéléni have been taken. PMID:27486573

  11. Modeling drug- and chemical- induced hepatotoxicity with systems biology approaches

    Directory of Open Access Journals (Sweden)

    Sudin eBhattacharya

    2012-12-01

    Full Text Available We provide an overview of computational systems biology approaches as applied to the study of chemical- and drug-induced toxicity. The concept of ‘toxicity pathways’ is described in the context of the 2007 US National Academies of Science report, Toxicity testing in the 21st Century: A Vision and A Strategy. Pathway mapping and modeling based on network biology concepts are a key component of the vision laid out in this report for a more biologically-based analysis of dose-response behavior and the safety of chemicals and drugs. We focus on toxicity of the liver (hepatotoxicity – a complex phenotypic response with contributions from a number of different cell types and biological processes. We describe three case studies of complementary multi-scale computational modeling approaches to understand perturbation of toxicity pathways in the human liver as a result of exposure to environmental contaminants and specific drugs. One approach involves development of a spatial, multicellular virtual tissue model of the liver lobule that combines molecular circuits in individual hepatocytes with cell-cell interactions and blood-mediated transport of toxicants through hepatic sinusoids, to enable quantitative, mechanistic prediction of hepatic dose-response for activation of the AhR toxicity pathway. Simultaneously, methods are being developing to extract quantitative maps of intracellular signaling and transcriptional regulatory networks perturbed by environmental contaminants, using a combination of gene expression and genome-wide protein-DNA interaction data. A predictive physiological model (DILIsymTM to understand drug-induced liver injury (DILI, the most common adverse event leading to termination of clinical development programs and regulatory actions on drugs, is also described. The model initially focuses on reactive metabolite-induced DILI in response to administration of acetaminophen, and spans multiple biological scales.

  12. Integration Strategies for Efficient Multizone Chemical Kinetics Models

    Energy Technology Data Exchange (ETDEWEB)

    McNenly, M J; Havstad, M A; Aceves, S M; Pitz, W J

    2009-10-15

    Three integration strategies are developed and tested for the stiff, ordinary differential equation (ODE) integrators used to solve the fully coupled multizone chemical kinetics model. Two of the strategies tested are found to provide more than an order of magnitude of improvement over the original, basic level of usage for the stiff ODE solver. One of the faster strategies uses a decoupled, or segregated, multizone model to generate an approximate Jacobian. This approach yields a 35-fold reduction in the computational cost for a 20 zone model. Using the same approximate Jacobian as a preconditioner for an iterative Krylov-type linear system solver, the second improved strategy achieves a 75-fold reduction in the computational cost for a 20 zone model. The faster strategies achieve their cost savings with no significant loss of accuracy. The pressure, temperature and major species mass fractions agree with the solution from the original integration approach to within six significant digits; and the radical mass fractions agree with the original solution to within four significant digits. The faster strategies effectively change the cost scaling of the multizone model from cubic to quadratic, with respect to the number of zones. As a consequence of the improved scaling, the 40 zone model offers more than a 250-fold cost savings over the basic calculation.

  13. Two-dimensional numerical and eco-toxicological modeling of chemical spills

    Institute of Scientific and Technical Information of China (English)

    Suiliang HUANG; Yafei JIA; Sam S. Y. WANG

    2009-01-01

    The effects of chemical spills on aquatic nontarget organisms were evaluated in this study. Based on a review of three types of current eco-toxicological models of chemicals, i.e., ACQUATOX model of the US-EPA, Hudson River Model of PCBs, and critical body residual (CBR) model and dynamic energy budget (DEBtox)model, this paper presents an uncoupled numerical ecotoxicological model. The transport and transformation of spilled chemicals were simulated by a chemical transport model (including flow and sediment transport), and the mortalities of an organism caused by the chemicals were simulated by the extended threshold damage model,separately. Due to extreme scarcity of data, this model was applied to two hypothetical cases of chemical spills happening upstream of a lake. Theoretical analysis and simulated results indicated that this model is capable of reasonably predicting the acute effects of chemical spills on aquatic ecosystems or organism killings.

  14. Toward a New U.S. Chemicals Policy: Rebuilding the Foundation to Advance New Science, Green Chemistry, and Environmental Health

    Science.gov (United States)

    Wilson, Michael P.; Schwarzman, Megan R.

    2009-01-01

    Objective We describe fundamental weaknesses in U.S. chemicals policy, present principles of chemicals policy reform, and articulate interdisciplinary research questions that should be addressed. With global chemical production projected to double over the next 24 years, federal policies that shape the priorities of the U.S. chemical enterprise will be a cornerstone of sustainability. To date, these policies have largely failed to adequately protect public health or the environment or motivate investment in or scientific exploration of cleaner chemical technologies, known collectively as green chemistry. On this trajectory, the United States will face growing health, environmental, and economic problems related to chemical exposures and pollution. Conclusions Existing policies have produced a U.S. chemicals market in which the safety of chemicals for human health and the environment is undervalued relative to chemical function, price, and performance. This market barrier to green chemistry is primarily a consequence of weaknesses in the Toxic Substances Control Act. These weaknesses have produced a chemical data gap, because producers are not required to investigate and disclose sufficient information on chemicals’ hazard traits to government, businesses that use chemicals, or the public; a safety gap, because government lacks the legal tools it needs to efficiently identify, prioritize, and take action to mitigate the potential health and environmental effects of hazardous chemicals; and a technology gap, because industry and government have invested only marginally in green chemistry research, development, and education. Policy reforms that close the three gaps—creating transparency and accountability in the market—are crucial for improving public and environmental health and reducing the barriers to green chemistry. The European Union’s REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) regulation has opened an opportunity for

  15. High Temperature Chemical Kinetic Combustion Modeling of Lightly Methylated Alkanes

    Energy Technology Data Exchange (ETDEWEB)

    Sarathy, S M; Westbrook, C K; Pitz, W J; Mehl, M

    2011-03-01

    Conventional petroleum jet and diesel fuels, as well as alternative Fischer-Tropsch (FT) fuels and hydrotreated renewable jet (HRJ) fuels, contain high molecular weight lightly branched alkanes (i.e., methylalkanes) and straight chain alkanes (n-alkanes). Improving the combustion of these fuels in practical applications requires a fundamental understanding of large hydrocarbon combustion chemistry. This research project presents a detailed high temperature chemical kinetic mechanism for n-octane and three lightly branched isomers octane (i.e., 2-methylheptane, 3-methylheptane, and 2,5-dimethylhexane). The model is validated against experimental data from a variety of fundamental combustion devices. This new model is used to show how the location and number of methyl branches affects fuel reactivity including laminar flame speed and species formation.

  16. A cell dynamical system model of chemical turbulence

    Science.gov (United States)

    Oono, Y.; Yeung, C.

    1987-08-01

    A cellular-automaton-like caricature of chemical turbulence on an infinite one-dimensional lattice is studied. The model exhibits apparently "turbulent" space-time patterns. To make this statement precise, the following problems or points are discussed: (1) The infinite-system-size limit of such cell-dynamical systems and its observability is defined. (2) It is proved that the invariant state in the large-system-size limit of the "turbulent" phase exhibits spatial patterns governed by a Gibbs random field. (3) Potential characteristics of "turbulent" space-time patterns are critically surveyed and a working definition of (weak) turbulence is proposed. (4) It is proved that the invariant state of the `turbulent" phase is actually (weak) turbulent. Furthermore, we conjecture that the turbulent phase of our model is an example of a K system that is not Bernoulli.

  17. Mass transport measurements and modeling for chemical vapor infiltration

    Energy Technology Data Exchange (ETDEWEB)

    Starr, T.L.; Chiang, D.Y.; Fiadzo, O.G.; Hablutzel, N. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Materials Science and Engineering

    1997-12-01

    This project involves experimental and modeling investigation of densification behavior and mass transport in fiber preforms and partially densified composites, and application of these results to chemical vapor infiltration (CVI) process modeling. This supports work on-going at ORNL in process development for fabrication of ceramic matrix composite (CMC) tubes. Tube-shaped composite preforms are fabricated at ORNL with Nextel{trademark} 312 fiber (3M Corporation, St. Paul, MN) by placing and compressing several layers of braided sleeve on a tubular mandrel. In terms of fiber architecture these preforms are significantly different than those made previously with Nicalon{trademark} fiber (Nippon Carbon Corp., Tokyo, Japan) square weave cloth. The authors have made microstructure and permeability measurements on several of these preforms and a few partially densified composites so as to better understand their densification behavior during CVI.

  18. Reaction Networks For Interstellar Chemical Modelling: Improvements and Challenges

    CERN Document Server

    Wakelam, V; Herbst, E; Troe, J; Geppert, W; Linnartz, H; Oberg, K; Roueff, E; Agundez, M; Pernot, P; Cuppen, H M; Loison, J C; Talbi, D

    2010-01-01

    We survey the current situation regarding chemical modelling of the synthesis of molecules in the interstellar medium. The present state of knowledge concerning the rate coefficients and their uncertainties for the major gas-phase processes -- ion-neutral reactions, neutral-neutral reactions, radiative association, and dissociative recombination -- is reviewed. Emphasis is placed on those reactions that have been identified, by sensitivity analyses, as 'crucial' in determining the predicted abundances of the species observed in the interstellar medium. These sensitivity analyses have been carried out for gas-phase models of three representative, molecule-rich, astronomical sources: the cold dense molecular clouds TMC-1 and L134N, and the expanding circumstellar envelope IRC +10216. Our review has led to the proposal of new values and uncertainties for the rate coefficients of many of the key reactions. The impact of these new data on the predicted abundances in TMC-1 and L134N is reported. Interstellar dust p...

  19. Modelling the chemical evolution in galaxies with KROME

    CERN Document Server

    Bovino, Stefano; Capelo, Pedro R; Schleicher, Dominik R G; Banerjee, R

    2015-01-01

    In this paper we present and test chemical models for three-dimensional hydrodynamical simulations of galaxy evolution. The microphysics is modelled by employing the public chemistry package KROME and the chemical networks have been tested to work in a wide range of densities and temperatures. We describe a simple H/He network following the formation of H2, and a more sophisticated network which includes metals. Photochemistry, thermal processes, and different prescriptions for the H2 catalysis on dust are presented and tested within a simple one-zone framework. We explore the effect of changing some of the key parameters such as metallicity, radiation and non-equilibrium versus equilibrium metal cooling approximations on the transition between the different gas phases. We find that employing an accurate treatment of the dust-related processes induces a faster HI-H2 transition. In addition, we show when the equilibrium assumption for metal cooling holds, and how a non-equilibrium approach affects the thermal ...

  20. Probabilistic human health risk assessment of degradation-related chemical mixtures in heterogeneous aquifers: Risk statistics, hot spots, and preferential channels

    Science.gov (United States)

    Henri, Christopher V.; Fernández-Garcia, Daniel; Barros, Felipe P. J.

    2015-06-01

    The increasing presence of toxic chemicals released in the subsurface has led to a rapid growth of social concerns and the need to develop and employ models that can predict the impact of groundwater contamination on human health risk under uncertainty. Monitored natural attenuation is a common remediation action in many contamination cases. However, natural attenuation can lead to the production of daughter species of distinct toxicity that may pose challenges in pollution management strategies. The actual threat that these contaminants pose to human health depends on the interplay between the complex structure of the geological media and the toxicity of each pollutant byproduct. This work addresses human health risk for chemical mixtures resulting from the sequential degradation of a contaminant (such as a chlorinated solvent) under uncertainty through high-resolution three-dimensional numerical simulations. We systematically investigate the interaction between aquifer heterogeneity, flow connectivity, contaminant injection model, and chemical toxicity in the probabilistic characterization of health risk. We illustrate how chemical-specific travel times control the regime of the expected risk and its corresponding uncertainties. Results indicate conditions where preferential flow paths can favor the reduction of the overall risk of the chemical mixture. The overall human risk response to aquifer connectivity is shown to be nontrivial for multispecies transport. This nontriviality is a result of the interaction between aquifer heterogeneity and chemical toxicity. To quantify the joint effect of connectivity and toxicity in health risk, we propose a toxicity-based Damköhler number. Furthermore, we provide a statistical characterization in terms of low-order moments and the probability density function of the individual and total risks.

  1. The Healthy Ageing Model: health behaviour change for older adults.

    Science.gov (United States)

    Potempa, Kathleen M; Butterworth, Susan W; Flaherty-Robb, Marna K; Gaynor, William L

    2010-01-01

    Proposed is a model of primary care for older adults with chronic health conditions that focuses on active engagement in health care. The Healthy Ageing Model is anchored in established theory on motivation and health behaviour change. The model draws on empirical and applied clinical underpinnings in such diverse areas as health promotion and education, treatment of addictions or obesity, management of chronic diseases, goal-setting, and coaching techniques. The conceptual foundation for the Healthy Ageing Model is described first, followed by a brief description of the key characteristics of the model. In conclusion, suggestions are offered for the clinical application and for further developing the model.

  2. A chemical model for the interstellar medium in galaxies

    Science.gov (United States)

    Bovino, S.; Grassi, T.; Capelo, Pedro R.; Schleicher, D. R. G.; Banerjee, R.

    2016-05-01

    Aims: We present and test chemical models for three-dimensional hydrodynamical simulations of galaxies. We explore the effect of changing key parameters such as metallicity, radiation, and non-equilibrium versus equilibrium metal cooling approximations on the transition between the gas phases in the interstellar medium. Methods: The microphysics was modelled by employing the public chemistry package KROME, and the chemical networks were tested to work in a wide range of densities and temperatures. We describe a simple H/He network following the formation of H2 and a more sophisticated network that includes metals. Photochemistry, thermal processes, and different prescriptions for the H2 catalysis on dust are presented and tested within a one-zone framework. The resulting network is made publicly available on the KROME webpage. Results: We find that employing an accurate treatment of the dust-related processes induces a faster HI-H2 transition. In addition, we show when the equilibrium assumption for metal cooling holds and how a non-equilibrium approach affects the thermal evolution of the gas and the HII-HI transition. Conclusions: These models can be employed in any hydrodynamical code via an interface to KROME and can be applied to different problems including isolated galaxies, cosmological simulations of galaxy formation and evolution, supernova explosions in molecular clouds, and the modelling of star-forming regions. The metal network can be used for a comparison with observational data of CII 158 μm emission both for high-redshift and for local galaxies.

  3. CHEMICALS

    CERN Multimedia

    Medical Service

    2002-01-01

    It is reminded that all persons who use chemicals must inform CERN's Chemistry Service (TIS-GS-GC) and the CERN Medical Service (TIS-ME). Information concerning their toxicity or other hazards as well as the necessary individual and collective protection measures will be provided by these two services. Users must be in possession of a material safety data sheet (MSDS) for each chemical used. These can be obtained by one of several means : the manufacturer of the chemical (legally obliged to supply an MSDS for each chemical delivered) ; CERN's Chemistry Service of the General Safety Group of TIS ; for chemicals and gases available in the CERN Stores the MSDS has been made available via EDH either in pdf format or else via a link to the supplier's web site. Training courses in chemical safety are available for registration via HR-TD. CERN Medical Service : TIS-ME :73186 or service.medical@cern.ch Chemistry Service : TIS-GS-GC : 78546

  4. Models of cortical malformation--Chemical and physical.

    Science.gov (United States)

    Luhmann, Heiko J

    2016-02-15

    Pharmaco-resistant epilepsies, and also some neuropsychiatric disorders, are often associated with malformations in hippocampal and neocortical structures. The mechanisms leading to these cortical malformations causing an imbalance between the excitatory and inhibitory system are largely unknown. Animal models using chemical or physical manipulations reproduce different human pathologies by interfering with cell generation and neuronal migration. The model of in utero injection of methylazoxymethanol (MAM) acetate mimics periventricular nodular heterotopia. The freeze lesion model reproduces (poly)microgyria, focal heterotopia and schizencephaly. The in utero irradiation model causes microgyria and heterotopia. Intraperitoneal injections of carmustine 1-3-bis-chloroethyl-nitrosurea (BCNU) to pregnant rats produces laminar disorganization, heterotopias and cytomegalic neurons. The ibotenic acid model induces focal cortical malformations, which resemble human microgyria and ulegyria. Cortical dysplasia can be also observed following prenatal exposure to ethanol, cocaine or antiepileptic drugs. All these models of cortical malformations are characterized by a pronounced hyperexcitability, few of them also produce spontaneous epileptic seizures. This dysfunction results from an impairment in GABAergic inhibition and/or an increase in glutamatergic synaptic transmission. The cortical region initiating or contributing to this hyperexcitability may not necessarily correspond to the site of the focal malformation. In some models wide-spread molecular and functional changes can be observed in remote regions of the brain, where they cause pathophysiological activities. This paper gives an overview on different animal models of cortical malformations, which are mostly used in rodents and which mimic the pathology and to some extent the pathophysiology of neuronal migration disorders associated with epilepsy in humans.

  5. Process Modelling of Chemical Reactors: Zero- versus Multi-dimensional Models

    Directory of Open Access Journals (Sweden)

    Bjørn H. Hjertager

    1997-01-01

    Full Text Available Trends in modelling of flow processes in the chemical reactors are presented. Particular emphasis is given to models that use the multi-dimensional multi-fluid techniques. Examples are given for both gas/liquid as well as gas/particle reators.

  6. Coupled thermo-hydro-chemical models of swelling bentonites

    Science.gov (United States)

    Samper, Javier; Mon, Alba; Zheng, Liange; Montenegro, Luis; Naves, Acacia; Pisani, Bruno

    2014-05-01

    The disposal of radioactive waste in deep geological repositories is based on the multibarrier concept of retention of the waste by a combination of engineered and geological barriers. The engineered barrier system (EBS) includes the solid conditioned waste-form, the waste container, the buffer made of materials such as clay, grout or crushed rock that separate the waste package from the host rock and the tunnel linings and supports. The geological barrier supports the engineered system and provides stability over the long term during which time radioactive decay reduces the levels of radioactivity. The strong interplays among thermal (T), hydrodynamic (H), mechanical (M) and chemical (C) processes during the hydration, thermal and solute transport stages of the engineered barrier system (EBS) of a radioactive waste repository call for coupled THMC models for the metallic overpack, the unsaturated compacted bentonite and the concrete liner. Conceptual and numerical coupled THMC models of the EBS have been developed, which have been implemented in INVERSE-FADES-CORE. Chemical reactions are coupled to the hydrodynamic processes through chemical osmosis (C-H coupling) while bentonite swelling affects solute transport via changes in bentonite porosity changes (M-H coupling). Here we present THMC models of heating and hydration laboratory experiments performed by CIEMAT (Madrid, Spain) on compacted FEBEX bentonite and numerical models for the long-term evolution of the EBS for 1 Ma. The changes in porosity caused by swelling are more important than those produced by the chemical reactions during the early evolution of the EBS (t < 100 years). For longer times, however, the changes in porosity induced by the dissolution/precipitation reactions are more relevant due to: 1) The effect of iron mineral phases (corrosion products) released by the corrosion of the carbon steel canister; and 2) The hyper alkaline plume produced by the concrete liner. Numerical results show that

  7. Chemically induced skin carcinogenesis: Updates in experimental models (Review).

    Science.gov (United States)

    Neagu, Monica; Caruntu, Constantin; Constantin, Carolina; Boda, Daniel; Zurac, Sabina; Spandidos, Demetrios A; Tsatsakis, Aristidis M

    2016-05-01

    Skin cancer is one of the most common malignancies affecting humans worldwide, and its incidence is rapidly increasing. The study of skin carcinogenesis is of major interest for both scientific research and clinical practice and the use of in vivo systems may facilitate the investigation of early alterations in the skin and of the mechanisms involved, and may also lead to the development of novel therapeutic strategies for skin cancer. This review outlines several aspects regarding the skin toxicity testing domain in mouse models of chemically induced skin carcinogenesis. There are important strain differences in view of the histological type, development and clinical evolution of the skin tumor, differences reported decades ago and confirmed by our hands‑on experience. Using mouse models in preclinical testing is important due to the fact that, at the molecular level, common mechanisms with human cutaneous tumorigenesis are depicted. These animal models resemble human skin cancer development, in that genetic changes caused by carcinogens and pro‑inflammatory cytokines, and simultaneous inflammation sustained by pro‑inflammatory cytokines and chemokines favor tumor progression. Drugs and environmental conditions can be tested using these animal models. keeping in mind the differences between human and rodent skin physiology. PMID:26986013

  8. A microscopic model for chemically-powered Janus motors.

    Science.gov (United States)

    Huang, Mu-Jie; Schofield, Jeremy; Kapral, Raymond

    2016-07-01

    Very small synthetic motors that make use of chemical reactions to propel themselves in solution hold promise for new applications in the development of new materials, science and medicine. The prospect of such potential applications, along with the fact that systems with many motors or active elements display interesting cooperative phenomena of fundamental interest, has made the study of synthetic motors an active research area. Janus motors, comprising catalytic and noncatalytic hemispheres, figure prominently in experimental and theoretical studies of these systems. While continuum models of Janus motor systems are often used to describe motor dynamics, microscopic models that are able to account for intermolecular interactions, many-body concentration gradients, fluid flows and thermal fluctuations provide a way to explore the dynamical behavior of these complex out-of-equilibrium systems that does not rely on approximations that are often made in continuum theories. The analysis of microscopic models from first principles provides a foundation from which the range of validity and limitations of approximate theories of the dynamics may be assessed. In this paper, a microscopic model for the diffusiophoretic propulsion of Janus motors, where motor interactions with the environment occur only through hard collisions, is constructed, analyzed and compared to theoretical predictions. Microscopic simulations of both single-motor and many-motor systems are carried out to illustrate the results. PMID:27241052

  9. The application of computer modeling to health effect research

    Energy Technology Data Exchange (ETDEWEB)

    Yang, R.S.H. [Colorado State Univ., Ft. Collins, CO (United States)

    1996-12-31

    In the United States, estimates show that more than 30,000 hazardous waste disposal sites exist, not including military installations, U.S. Department of Energy nuclear facilities, and hundreds and thousands of underground fuel storage tanks; these sites undoubtedly have their own respective hazardous waste chemical problems. When so many sites contain hazardous chemicals, how does one study the health effects of the chemicals at these sites? There could be many different answers, but none would be perfect. For an area as complex and difficult as the study of chemical mixtures associated with hazardous waste disposal sites, there are no perfect approaches and protocols. Human exposure to chemicals, be it environmental or occupational, is rarely, if ever, limited to a single chemical. Therefore, it is essential that we consider multiple chemical effects and interactions in our risk assessment process. Systematic toxicity testing of chemical mixtures in the environment or workplace that uses conventional toxicology methodologies is highly impractical because of the immense numbers of mixtures involved. For example, about 600,000 chemicals are being used in our society. Just considering binary chemical mixtures, this means that there could be 600,000 x 599,999/2 = 359,999,400,000 pairs of chemicals. Assuming that only one in a million of these pairs of chemicals acts synergistically or has other toxicologic interactions, there would still be 359,999 binary chemical mixtures possessing toxicologic interactions. Moreover, toxicologic interactions undoubtedly exist among chemical mixtures with three or more component chemicals; the number of possible combinations for these latter mixtures is almost infinite. These are astronomically large numbers with respect to systematic toxicity testing. 22 refs., 5 figs., 1 tab.

  10. Modelling and implementing electronic health records in Denmark

    DEFF Research Database (Denmark)

    Bernstein, Knut; Rasmussen, Morten Bruun; Vingtoft, Søren;

    2003-01-01

    The Danish Health IT strategy points out that integration between electronic health records (EHR) systems has a high priority. This paper reporst reports new tendencies in modelling and integration platforms globally and how this is reflected in the natinal development.......The Danish Health IT strategy points out that integration between electronic health records (EHR) systems has a high priority. This paper reporst reports new tendencies in modelling and integration platforms globally and how this is reflected in the natinal development....

  11. Chemical Emergencies

    Science.gov (United States)

    When a hazardous chemical has been released, it may harm people's health. Chemical releases can be unintentional, as in the case of an ... the case of a terrorist attack with a chemical weapon. Some hazardous chemicals have been developed by ...

  12. Health care models guiding mental health policy in Kenya 1965 - 1997

    Directory of Open Access Journals (Sweden)

    Jenkins Rachel

    2010-04-01

    Full Text Available Abstract Background Mental health policy is needed to set the strategy and direction for the provision of mental health services in a country. Policy formulation does not occur in a vacuum, however, but is influenced by local and international factors in the health sector and other sectors. Methods This study was carried out in 1997 to examine the evolution of mental health policy in Kenya between 1965 and 1997 in the context of changing international concepts of health and development. Qualitative content analysis of policy documents was combined with interviews of key policy makers. Results The study showed that during the period 1965-1997 the generic health policy in Kenya changed from one based on the Medical Model in the 1960s and 1970s to one based on the Primary Health Care Model in the late 1970s and the 1980s and finally to one based on the Market Model of health care in the 1990s. The mental health policy, on the other hand, evolved from one based on the Medical Model in the 1960s to one based on the Primary Health Care Model in the 1990s, but did not embrace the Market Model of health care. This resulted in a situation in the 1990s where the mental health policy was rooted in a different conceptual model from that of the generic health policy under which it was supposed to be implemented. This "Model Muddlement" may have impeded the implementation of the mental health policy in Kenya. Conclusions Integration of the national mental health policy with the general health policy and other sector policies would be appropriate and is now underway.

  13. Health Education approaches in school textbooks of 14 countries : biomedical model versus health promotion

    OpenAIRE

    Carvalho, Graça Simões; Dantas, Catarina; Rauma, Anna-Liisa; Luzi, Daniela; Geier, Christine; Caussidier, Claude; Berger, Dominique; Clément, Pierre, 1809-1870.

    2007-01-01

    Classically, Health Education has been based in the Biomedical Model (BM) of Health, where the pathologic, Curative and Preventive conceptions are its main pillars. The more recent approach of Health Promotion (HP) looks for identification of Healthy habits, develop empowerment for healthy decision-making towards environmental challenges. The aim of the present study was to compare the emphases on either model (BM or HP) given by textbooks on the topic of Health Education of 14 countries. ...

  14. Patterns of chemical use and exposure control in the Semiconductor Health Study.

    Science.gov (United States)

    Hallock, M F; Hammond, S K; Hines, C J; Woskie, S R; Schenker, M B

    1995-12-01

    Information on chemical use and exposure control between 1986 and 1990 was collected from 14 companies participating in the Semiconductor Health Study. Questionnaires and site visits provided data used to develop exposure categories for three epidemiological studies: prospective, historical, and cross-sectional. Patterns of use of target chemicals were compiled for 82 silicon-wafer fabrication rooms (fabs), including 47 from which subjects were selected for study. Chemical use was examined by operation, year, and epidemiological component. Target agents for epidemiological analyses were present in more than 50% of fabs. Use of these agents was fairly constant from 1986 to 1990, except for a moderate increase in use of propylene glycol monomethyl ether acetate, a solvent being substituted for ethylene-based glycol ethers (EGE) in photoresists. The distribution of personal protective equipment, engineering controls, and other factors potentially affecting employee exposure was also examined. Controls designed to manage processes or high acute toxicity were present in most fabs; their prevalence remained unchanged from 1986 through 1990. Controls designed to reduce exposures to chemicals with low acute toxicity were less widely distributed; their prevalence increased moderately from 1986 to 1990. PMID:8588557

  15. Latent class models for utilisation of health care

    OpenAIRE

    Teresa Bago d’Uva

    2005-01-01

    This paper explores different approaches to econometric modelling of count measures of health care utilisation, with an emphasis on latent class models. A new model is proposed that combines the features of the two most common approaches- the hurdle model and the finite mixture Negative Binomial. Additionally, the panel structure of the data is taken into account. The proposed model is shown to perform better than the existing models for a particular application with data from the RAND Health...

  16. Modulation of Estrogen Chemical Carcinogenesis by Botanical Supplements used for Postmenopausal Women's Health.

    Science.gov (United States)

    Snelten, Courtney S; Dietz, Birgit; Bolton, Judy L

    2012-06-01

    Breast cancer risk has been associated with long-term estrogen exposure including traditional hormone therapy (HT, formally hormone replacement therapy). To avoid traditional HT and associated risks, women have been turning to botanical supplements such as black cohosh, red clover, licorice, hops, dong gui, and ginger to relieve menopausal symptoms despite a lack of efficacy evidence. The mechanisms of estrogen carcinogenesis involve both hormonal and chemical pathways. Botanical supplements could protect women from estrogen carcinogenesis by modulating key enzymatic steps [aromatase, P4501B1, P4501A1, catechol-O-methyltransferase (COMT), NAD(P)H quinone oxidoreductase 1 (NQO1), and reactive oxygen species (ROS) scavenging] in estradiol metabolism leading to estrogen carcinogenesis as outlined in Figure 1. This review summarizes the influence of popular botanical supplements used for women's health on these key steps in the estrogen chemical carcinogenesis pathway, and suggests that botanical supplements may have added chemopreventive benefits by modulating estrogen metabolism. PMID:24223609

  17. Overview of human health and chemical mixtures: problems facing developing countries.

    Science.gov (United States)

    Yáñ ez, Leticia; Ortiz, Deogracias; Calderón, Jaqueline; Batres, Lilia; Carrizales, Leticia; Mejía, Jesús; Martínez, Lourdes; García-Nieto, Edelmira; Díaz-Barriga, Fernando

    2002-01-01

    In developing countries, chemical mixtures within the vicinity of small-scale enterprises, smelters, mines, agricultural areas, toxic waste disposal sites, etc., often present a health hazard to the populations within those vicinities. Therefore, in these countries, there is a need to study the toxicological effects of mixtures of metals, pesticides, and organic compounds. However, the study of mixtures containing substances such as DDT (dichlorodiphenyltrichloroethane, an insecticide banned in developed nations), and mixtures containing contaminants such as fluoride (of concern only in developing countries) merit special attention. Although the studies may have to take into account simultaneous exposures to metals and organic compounds, there is also a need to consider the interaction between chemicals and other specific factors such as nutritional conditions, alcoholism, smoking, infectious diseases, and ethnicity. PMID:12634117

  18. Upper D region chemical kinetic modeling of LORE relaxation times

    Science.gov (United States)

    Gordillo-Vázquez, F. J.; Luque, A.; Haldoupis, C.

    2016-04-01

    The recovery times of upper D region electron density elevations, caused by lightning-induced electromagnetic pulses (EMP), are modeled. The work was motivated from the need to understand a recently identified narrowband VLF perturbation named LOREs, an acronym for LOng Recovery Early VLF events. LOREs associate with long-living electron density perturbations in the upper D region ionosphere; they are generated by strong EMP radiated from large peak current intensities of ±CG (cloud to ground) lightning discharges, known also to be capable of producing elves. Relaxation model scenarios are considered first for a weak enhancement in electron density and then for a much stronger one caused by an intense lightning EMP acting as an impulsive ionization source. The full nonequilibrium kinetic modeling of the perturbed mesosphere in the 76 to 92 km range during LORE-occurring conditions predicts that the electron density relaxation time is controlled by electron attachment at lower altitudes, whereas above 79 km attachment is balanced totally by associative electron detachment so that electron loss at these higher altitudes is controlled mainly by electron recombination with hydrated positive clusters H+(H2O)n and secondarily by dissociative recombination with NO+ ions, a process which gradually dominates at altitudes >88 km. The calculated recovery times agree fairly well with LORE observations. In addition, a simplified (quasi-analytic) model build for the key charged species and chemical reactions is applied, which arrives at similar results with those of the full kinetic model. Finally, the modeled recovery estimates for lower altitudes, that is <79 km, are in good agreement with the observed short recovery times of typical early VLF events, which are known to be associated with sprites.

  19. Reduced Models in Chemical Kinetics via Nonlinear Data-Mining

    Directory of Open Access Journals (Sweden)

    Eliodoro Chiavazzo

    2014-01-01

    Full Text Available The adoption of detailed mechanisms for chemical kinetics often poses two types of severe challenges: First, the number of degrees of freedom is large; and second, the dynamics is characterized by widely disparate time scales. As a result, reactive flow solvers with detailed chemistry often become intractable even for large clusters of CPUs, especially when dealing with direct numerical simulation (DNS of turbulent combustion problems. This has motivated the development of several techniques for reducing the complexity of such kinetics models, where, eventually, only a few variables are considered in the development of the simplified model. Unfortunately, no generally applicable a priori recipe for selecting suitable parameterizations of the reduced model is available, and the choice of slow variables often relies upon intuition and experience. We present an automated approach to this task, consisting of three main steps. First, the low dimensional manifold of slow motions is (approximately sampled by brief simulations of the detailed model, starting from a rich enough ensemble of admissible initial conditions. Second, a global parametrization of the manifold is obtained through the Diffusion Map (DMAP approach, which has recently emerged as a powerful tool in data analysis/machine learning. Finally, a simplified model is constructed and solved on the fly in terms of the above reduced (slow variables. Clearly, closing this latter model requires nontrivial interpolation calculations, enabling restriction (mapping from the full ambient space to the reduced one and lifting (mapping from the reduced space to the ambient one. This is a key step in our approach, and a variety of interpolation schemes are reported and compared. The scope of the proposed procedure is presented and discussed by means of an illustrative combustion example.

  20. Preparedness activities regarding the protection of public health in case of a major oil or chemical spill on the St-Lawrence River

    International Nuclear Information System (INIS)

    A project was initiated to protect the health of people living in the St-Lawrence basin from contaminants associated with an oil or chemical spill. Between 1980 and 1990, more than 240 chemical spills and 300 oil spills were recorded in the region which has prompted concerns regarding the possible contamination of drinking water sources. 45% of Quebec's population relies on the St-Lawrence River as a source of drinking water. Thus far, the project has identified the major chemical and oil products transported on the St-Lawrence River, and the main health risks associated with these products. Computerized dispersion models which can determine the migration of the contaminants in water, are available. Simulation exercises have been carried out to train personnel in the event of an actual spill. 1 ref

  1. Towards an improved modeling of chemical weathering in the SoilGen soil evolution model

    Science.gov (United States)

    Opolot, Emmanuel; Finke, Peter

    2014-05-01

    As the need for soil information particularly in the fields of agriculture, land evaluation, hydrology, biogeochemistry and climate change keeps increasing, models for soil evolution are increasingly becoming valuable tools to provide such soil information. Although still limited, such models are progressively being developed. The SoilGen model is one of such models with capabilities to provide soil information such as soil texture, pH, base saturation, organic carbon, CEC, etc over multi-millennia time scale. SoilGen is a mechanistic water flow driven pedogenetic model describing soil forming processes such as carbon cycling, clay migration, decalcification, bioturbation, physical weathering and chemical weathering. The model has been calibrated and confronted with field measurements in a number of case studies, giving plausible results. Discrepancies between measured and simulated soil properties as concluded from case studies have been mainly attributed to (i) the simple chemical weathering system (ii) poor estimates of initial data inputs such as bulk density and element fluxes, and (iii) incorrect values of variables that describe boundary conditions such as precipitation and potential evapotranspiration. This study focuses on extending the chemical weathering system, such that it can deal with a more heterogeneous composition of primary minerals and includes more elements such as Fe and Si. We propose and discuss here an extended description of chemical weathering in the model that is based on more primary minerals, taking into account the role of the specific area of these minerals, and the effect of physical weathering on these specific areas over time. In the initial stage, the proposed chemical weathering mechanism is also implemented in PHREEQC (a widely applied geochemical code with capabilities to simulate equilibrium reactions involving water and minerals, surface complexes and ion exchangers, etc.) to facilitate comparison with the model results

  2. Modeling Chemical Mechanical Polishing with Couple Stress Fluids

    Institute of Scientific and Technical Information of China (English)

    张朝辉; 雒建斌; 温诗铸

    2004-01-01

    Chemical mechanical polishing (CMP) is a manufacturing process used to achieve high levels of global and local planarity.Currently, the slurries used in CMP usually contain nanoscale particles to accelerate the removal ratio and to optimize the planarity, whose rheological properties can no longer be accurately modeled with Newtonian fluids.The Reynolds equation, including the couple stress effects, was derived in this paper.The equation describes the mechanism to solve the CMP lubrication equation with the couple stress effects.The effects on load and moments resulting from the various parameters, such as pivot height, roll angle, and pitch angle, were subsequently simulated.The results show that the couple stress can provide higher load and angular moments.This study sheds some lights into the mechanism of the CMP process.

  3. Climate change and health modeling: horses for courses

    Directory of Open Access Journals (Sweden)

    Kristie L. Ebi

    2014-05-01

    Full Text Available Mathematical and statistical models are needed to understand the extent to which weather, climate variability, and climate change are affecting current and may affect future health burdens in the context of other risk factors and a range of possible development pathways, and the temporal and spatial patterns of any changes. Such understanding is needed to guide the design and the implementation of adaptation and mitigation measures. Because each model projection captures only a narrow range of possible futures, and because models serve different purposes, multiple models are needed for each health outcome (‘horses for courses’. Multiple modeling results can be used to bracket the ranges of when, where, and with what intensity negative health consequences could arise. This commentary explores some climate change and health modeling issues, particularly modeling exposure-response relationships, developing early warning systems, projecting health risks over coming decades, and modeling to inform decision-making. Research needs are also suggested.

  4. How subchronic and chronic health effects can be neglected for GMOs, pesticides or chemicals.

    Science.gov (United States)

    Séralini, Gilles-Eric; de Vendômois, Joël Spiroux; Cellier, Dominique; Sultan, Charles; Buiatti, Marcello; Gallagher, Lou; Antoniou, Michael; Dronamraju, Krishna R

    2009-01-01

    Chronic health effects are increasing in the world such as cancers, hormonal, reproductive, nervous, or immune diseases, even in young people. During regulatory toxicological subchronic tests to prevent these on mammalian health, prior commercialization of chemicals, including pesticides and drugs, or GMOs, some statistically significant findings may be revealed. This discussion is about the need to investigate the relevant criteria to consider those as biologically significant. The sex differences and the non linear dose or time related effects should be considered in contrast to the claims of a Monsanto-supported expert panel about a GMO, the MON 863 Bt maize, but also for pesticides or drugs, in particular to reveal hormone-dependent diseases and first signs of toxicities. PMID:19584953

  5. How Subchronic and Chronic Health Effects can be Neglected for GMOs, Pesticides or Chemicals

    Directory of Open Access Journals (Sweden)

    Gilles-Eric Séralini, Joël Spiroux de Vendômois, Dominique Cellier, Charles Sultan, Marcello Buiatti, Lou Gallagher, Michael Antoniou, Krishna R. Dronamraju

    2009-01-01

    Full Text Available Chronic health effects are increasing in the world such as cancers, hormonal, reproductive, nervous, or immune diseases, even in young people. During regulatory toxicological subchronic tests to prevent these on mammalian health, prior commercialization of chemicals, including pesticides and drugs, or GMOs, some statistically significant findings may be revealed. This discussion is about the need to investigate the relevant criteria to consider those as biologically significant. The sex differences and the non linear dose or time related effects should be considered in contrast to the claims of a Monsanto-supported expert panel about a GMO, the MON 863 Bt maize, but also for pesticides or drugs, in particular to reveal hormone-dependent diseases and first signs of toxicities.

  6. Modelling stratospheric chemistry in a global three-dimensional chemical transport model

    Energy Technology Data Exchange (ETDEWEB)

    Rummukainen, M. [Finnish Meteorological Inst., Sodankylae (Finland). Sodankylae Observatory

    1995-12-31

    Numerical modelling of atmospheric chemistry aims to increase the understanding of the characteristics, the behavior and the evolution of atmospheric composition. These topics are of utmost importance in the study of climate change. The multitude of gases and particulates making up the atmosphere and the complicated interactions between them affect radiation transfer, atmospheric dynamics, and the impacts of anthropogenic and natural emissions. Chemical processes are fundamental factors in global warming, ozone depletion and atmospheric pollution problems in general. Much of the prevailing work on modelling stratospheric chemistry has so far been done with 1- and 2-dimensional models. Carrying an extensive chemistry parameterisation in a model with high spatial and temporal resolution is computationally heavy. Today, computers are becoming powerful enough to allow going over to 3-dimensional models. In order to concentrate on the chemistry, many Chemical Transport Models (CTM) are still run off-line, i.e. with precalculated and archived meteorology and radiation. In chemistry simulations, the archived values drive the model forward in time, without interacting with the chemical evolution. This is an approach that has been adopted in stratospheric chemistry modelling studies at the Finnish Meteorological Institute. In collaboration with the University of Oslo, a development project was initiated in 1993 to prepare a stratospheric chemistry parameterisation, fit for global 3-dimensional modelling. This article presents the parameterisation approach. Selected results are shown from basic photochemical simulations

  7. Towards a Unified Theory of Health-Disease: I. Health as a complex model-object

    Directory of Open Access Journals (Sweden)

    Naomar Almeida-Filho

    2013-06-01

    Full Text Available Theory building is one of the most crucial challenges faced by basic, clinical and population research, which form the scientific foundations of health practices in contemporary societies. The objective of the study is to propose a Unified Theory of Health-Disease as a conceptual tool for modeling health-disease-care in the light of complexity approaches. With this aim, the epistemological basis of theoretical work in the health field and concepts related to complexity theory as concerned to health problems are discussed. Secondly, the concepts of model-object, multi-planes of occurrence, modes of health and disease-illness-sickness complex are introduced and integrated into a unified theoretical framework. Finally, in the light of recent epistemological developments, the concept of Health-Disease-Care Integrals is updated as a complex reference object fit for modeling health-related processes and phenomena.

  8. [HEALTH STATUS OF ELECTROTECHNICAL PERSONNEL EXPOSED TO THE COMBINED IMPACT OF ELECTROMAGNETIC FIELDS OF 50 HZ AND CHEMICALS].

    Science.gov (United States)

    Rusin, M N; Amirov, N Kh; Sibgatullin, A S; Krasnoshchekova, V N

    2015-01-01

    There was performed an analysis of the working conditions and health status of workers of the chemical enterprise. In male electrical staff exposed to electromagnetic fields (EMF) of 50 Hz and chemicals, according to data of periodic medical examinations there was revealed statistically higher incidence of cardiovascular diseases and autonomic disorders. The obtained preliminary results allow to suggest the upsurge of the involvement of the autonomic nervous system in response to the combined effects of EMF of 50 Hz and chemicals.

  9. Chemical Reaction and Flow Modeling in Fullerene and Nanotube Production

    Science.gov (United States)

    Scott, Carl D.; Farhat, Samir; Greendyke, Robert B.

    2004-01-01

    The development of processes to produce fullerenes and carbon nanotubes has largely been empirical. Fullerenes were first discovered in the soot produced by laser ablation of graphite [1]and then in the soot of electric arc evaporated carbon. Techniques and conditions for producing larger and larger quantities of fullerenes depended mainly on trial and error empirical variations of these processes, with attempts to scale them up by using larger electrodes and targets and higher power. Various concepts of how fullerenes and carbon nanotubes were formed were put forth, but very little was done based on chemical kinetics of the reactions. This was mainly due to the complex mixture of species and complex nature of conditions in the reactors. Temperatures in the reactors varied from several thousand degrees Kelvin down to near room temperature. There are hundreds of species possible, ranging from atomic carbon to large clusters of carbonaceous soot, and metallic catalyst atoms to metal clusters, to complexes of metals and carbon. Most of the chemical kinetics of the reactions and the thermodynamic properties of clusters and complexes have only been approximated. In addition, flow conditions in the reactors are transient or unsteady, and three dimensional, with steep spatial gradients of temperature and species concentrations. All these factors make computational simulations of reactors very complex and challenging. This article addresses the development of the chemical reaction involved in fullerene production and extends this to production of carbon nanotubes by the laser ablation/oven process and by the electric arc evaporation process. In addition, the high-pressure carbon monoxide (HiPco) process is discussed. The article is in several parts. The first one addresses the thermochemical aspects of modeling; and considers the development of chemical rate equations, estimates of reaction rates, and thermodynamic properties where they are available. The second part

  10. Man's health through the model of salutogenetic: theory and practice

    OpenAIRE

    Lukjanchenko M.I.

    2010-01-01

    In the article the salutogenetic model of famous medical sociologist A. Antonovsky has been studied. The criteria of researched model concerning to the definition of man's health has been analyzed. The sense of such definitions as "generalized resistance resources" and "sense of coherence" which are prominent in the problem of the formation of health life has been revealed. Conception of the salutogenetic model of health must be a theoretical bases for healthy life style forming of people of ...

  11. A fugacity approach for modeling the transport of airborne organic chemicals in an air/plant/soil system

    International Nuclear Information System (INIS)

    An important issue facing both public and private agencies is the identification and quantification of exposures by indirect pathways to toxic chemicals released to the atmosphere. With recent public concerns over pesticides such as malathion and alar in foods, greater attention is being given to the process of chemical uptake by plants. Whether chemicals taken up by plants can accumulate and ultimately enter the human food chain are important questions for determining health risks and safe levels of toxic air-pollutant emissions and pesticide application. A number of plant-toxicokinetic, or ''botanicokinetic,'' models have been developed to give estimates of how chemicals are partitioned and transported within plants. In this paper, we provide a brief review of these models, describing their main features and listing some of their advantages and disadvantages. We then describe and demonstrate a five-compartment air/plant/soil model, which builds on and extends the features included in previous models. We apply this model to the steady-state chemical partitioning of perchloroethylene, hexachlorobenzene, and 2,3,7,8-tetrachlorodibenzo-p-dioxin in grass as test cases. We conclude with a discussion of the advantages and limitations of the model

  12. Guidance on health effects of toxic chemicals. Safety Analysis Report Update Program

    Energy Technology Data Exchange (ETDEWEB)

    Foust, C.B.; Griffin, G.D.; Munro, N.B.; Socolof, M.L.

    1994-02-01

    Martin Marietta Energy Systems, Inc. (MMES), and Martin Marietta Utility Services, Inc. (MMUS), are engaged in phased programs to update the safety documentation for the existing US Department of Energy (DOE)-owned facilities. The safety analysis of potential toxic hazards requires a methodology for evaluating human health effects of predicted toxic exposures. This report provides a consistent set of health effects and documents toxicity estimates corresponding to these health effects for some of the more important chemicals found within MMES and MMUS. The estimates are based on published toxicity information and apply to acute exposures for an ``average`` individual. The health effects (toxicological endpoints) used in this report are (1) the detection threshold; (2) the no-observed adverse effect level; (3) the onset of irritation/reversible effects; (4) the onset of irreversible effects; and (5) a lethal exposure, defined to be the 50% lethal level. An irreversible effect is defined as a significant effect on a person`s quality of life, e.g., serious injury. Predicted consequences are evaluated on the basis of concentration and exposure time.

  13. Dermal permeation data and models for the prioritization and screening-level exposure assessment of organic chemicals.

    Science.gov (United States)

    Brown, Trevor N; Armitage, James M; Egeghy, Peter; Kircanski, Ida; Arnot, Jon A

    2016-09-01

    High-throughput screening (HTS) models are being developed and applied to prioritize chemicals for more comprehensive exposure and risk assessment. Dermal pathways are possible exposure routes to humans for thousands of chemicals found in personal care products and the indoor environment. HTS exposure models rely on skin permeability coefficient (KP; cm/h) models for exposure predictions. An initial database of approximately 1000 entries for empirically-based KP data was compiled from the literature and a subset of 480 data points for 245 organic chemicals derived from testing with human skin only and using only water as a vehicle was selected. The selected dataset includes chemicals with log octanol-water partition coefficients (KOW) ranging from -6.8 to 7.6 (median=1.8; 95% of the data range from -2.5 to 4.6) and molecular weight (MW) ranging from 18 to 765g/mol (median=180); only 3% >500g/mol. Approximately 53% of the chemicals in the database have functional groups which are ionizable in the pH range of 6 to 7.4, with 31% being appreciably ionized. The compiled log KP values ranged from -5.8 to 0.1cm/h (median=-2.6). The selected subset of the KP data was then used to evaluate eight representative KP models that can be readily applied for HTS assessments, i.e., parameterized with KOW and MW. The analysis indicates that a version of the SKINPERM model performs the best against the selected dataset. Comparisons of representative KP models against model input parameter property ranges (sensitivity analysis) and against chemical datasets requiring human health assessment were conducted to identify regions of chemical properties that should be tested to address uncertainty in KP models and HTS exposure assessments. PMID:27282209

  14. Dynamic Processes of Conceptual Change: Analysis of Constructing Mental Models of Chemical Equilibrium.

    Science.gov (United States)

    Chiu, Mei-Hung; Chou, Chin-Cheng; Liu, Chia-Ju

    2002-01-01

    Investigates students' mental models of chemical equilibrium using dynamic science assessments. Reports that students at various levels have misconceptions about chemical equilibrium. Involves 10th grade students (n=30) in the study doing a series of hands-on chemical experiments. Focuses on the process of constructing mental models, dynamic…

  15. Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health

    Directory of Open Access Journals (Sweden)

    J. Marvin Herndon

    2015-08-01

    Full Text Available The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1 Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2 Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1 the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test and identical variances (F-test; and (2 the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.

  16. Evidence of Coal-Fly-Ash Toxic Chemical Geoengineering in the Troposphere: Consequences for Public Health.

    Science.gov (United States)

    Herndon, J Marvin

    2015-08-11

    The widespread, intentional and increasingly frequent chemical emplacement in the troposphere has gone unidentified and unremarked in the scientific literature for years. The author presents evidence that toxic coal combustion fly ash is the most likely aerosolized particulate sprayed by tanker-jets for geoengineering, weather-modification and climate-modification purposes and describes some of the multifold consequences on public health. Two methods are employed: (1) Comparison of 8 elements analyzed in rainwater, leached from aerosolized particulates, with corresponding elements leached into water from coal fly ash in published laboratory experiments, and (2) Comparison of 14 elements analyzed in dust collected outdoors on a high-efficiency particulate air (HEPA) filter with corresponding elements analyzed in un-leached coal fly ash material. The results show: (1) the assemblage of elements in rainwater and in the corresponding experimental leachate are essentially identical. At a 99% confidence interval, they have identical means (T-test) and identical variances (F-test); and (2) the assemblage of elements in the HEPA dust and in the corresponding average un-leached coal fly ash are likewise essentially identical. The consequences on public health are profound, including exposure to a variety of toxic heavy metals, radioactive elements, and neurologically-implicated chemically mobile aluminum released by body moisture in situ after inhalation or through transdermal induction.

  17. Development of a Medicaid Behavioral Health Case-Mix Model

    Science.gov (United States)

    Robst, John

    2009-01-01

    Many Medicaid programs have either fully or partially carved out mental health services. The evaluation of carve-out plans requires a case-mix model that accounts for differing health status across Medicaid managed care plans. This article develops a diagnosis-based case-mix adjustment system specific to Medicaid behavioral health care. Several…

  18. Our Campus, Our Health: A Model for Undergraduate Health Education Research Engagement

    Science.gov (United States)

    Merten, Julie Williams; Johnson, Dana

    2014-01-01

    Research experience prepares undergraduate students for graduate school, a competitive job market, and their future as the next generation of leaders in public health education. This article describes a model, Our Campus, Our Health, to engage undergraduate students in the delivery of a college health behavior assessment. Through this project,…

  19. Implementation of a vibrationally linked chemical reaction model for DSMC

    Science.gov (United States)

    Carlson, A. B.; Bird, Graeme A.

    1994-01-01

    A new procedure closely linking dissociation and exchange reactions in air to the vibrational levels of the diatomic molecules has been implemented in both one- and two-dimensional versions of Direct Simulation Monte Carlo (DSMC) programs. The previous modeling of chemical reactions with DSMC was based on the continuum reaction rates for the various possible reactions. The new method is more closely related to the actual physics of dissociation and is more appropriate to the particle nature of DSMC. Two cases are presented: the relaxation to equilibrium of undissociated air initially at 10,000 K, and the axisymmetric calculation of shuttle forebody heating during reentry at 92.35 km and 7500 m/s. Although reaction rates are not used in determining the dissociations or exchange reactions, the new method produces rates which agree astonishingly well with the published rates derived from experiment. The results for gas properties and surface properties also agree well with the results produced by earlier DSMC models, equilibrium air calculations, and experiment.

  20. A Chemical Evolution Model for the Fornax Dwarf Spheroidal Galaxy

    Directory of Open Access Journals (Sweden)

    Yuan Zhen

    2016-01-01

    Full Text Available Fornax is the brightest Milky Way (MW dwarf spheroidal galaxy and its star formation history (SFH has been derived from observations. We estimate the time evolution of its gas mass and net inflow and outflow rates from the SFH usinga simple star formation law that relates the star formation rate to the gas mass. We present a chemical evolution model on a 2D mass grid with supernovae (SNe as sources of metal enrichment. We find that a key parameter controlling the enrichment is the mass Mx of the gas to mix with the ejecta from each SN. The choice of Mx depends on the evolution of SN remnants and on the global gas dynamics. It differs between the two types of SNe involved and between the periods before and after Fornax became an MW satellite at time t = tsat. Our results indicate that due to the global gas outflow at t > tsat, part of the ejecta from each SN may directly escape from Fornax. Sample results from our model are presented and compared with data.

  1. A Chemical Evolution Model for the Fornax Dwarf Spheroidal Galaxy

    CERN Document Server

    Yuan, Zhen; Jing, Y P

    2015-01-01

    Fornax is the brightest Milky Way (MW) dwarf spheroidal galaxy and its star formation history (SFH) has been derived from observations. We estimate the time evolution of its gas mass and net inflow and outflow rates from the SFH using a simple star formation law that relates the star formation rate to the gas mass. We present a chemical evolution model on a 2D mass grid with supernovae (SNe) as sources of metal enrichment. We find that a key parameter controlling the enrichment is the mass M_x of the gas to mix with the ejecta from each SN. The choice of M_x depends on the evolution of SN remnants and on the global gas dynamics. It differs between the two types of SNe involved and between the periods before and after Fornax became an MW satellite at time t = t_sat . Our results indicate that due to the global gas outflow at t > t_sat , part of the ejecta from each SN may directly escape from Fornax. Sample results from our model are presented and compared with data.

  2. Access and use of information resources in assessing health risks from chemical exposure: Proceedings

    International Nuclear Information System (INIS)

    Health risk assessment is based on access to comprehensive information about potentially hazardous agents in question. Relevant information is scattered throughout the literature, and often is not readily accessible. To be useful in assessment efforts, emerging scientific findings, risk assess parameters, and associated data must be compiled and evaluated systemically. The US Environmental Protection Agency (EPA) and Oak Ridge National Laboratory (ORNL) are among the federal agencies heavily involved in this effort. This symposium was a direct response by EPA and ORNL to the expressed needs of individuals involved in assessing risks from chemical exposure. In an effort to examine the state of the risk assessment process, the availability of toxicological information, and the future development and transfer of this information, the symposium provided an excellent cadre of speakers and participants from state and federal agencies, academia and research laboratories to address these topics. This stimulating and productive gathering discussed concerns associated with (1) environmental contamination by chemicals; (2) laws regulating chemicals; (3) information needs and resources; (4) applications; (5) challenges and priorities; and (6)future issues. Individual reports are processed separately for the data bases

  3. Access and use of information resources in assessing health risks from chemical exposure: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    Health risk assessment is based on access to comprehensive information about potentially hazardous agents in question. Relevant information is scattered throughout the literature, and often is not readily accessible. To be useful in assessment efforts, emerging scientific findings, risk assess parameters, and associated data must be compiled and evaluated systemically. The US Environmental Protection Agency (EPA) and Oak Ridge National Laboratory (ORNL) are among the federal agencies heavily involved in this effort. This symposium was a direct response by EPA and ORNL to the expressed needs of individuals involved in assessing risks from chemical exposure. In an effort to examine the state of the risk assessment process, the availability of toxicological information, and the future development and transfer of this information, the symposium provided an excellent cadre of speakers and participants from state and federal agencies, academia and research laboratories to address these topics. This stimulating and productive gathering discussed concerns associated with (1) environmental contamination by chemicals; (2) laws regulating chemicals; (3) information needs and resources; (4) applications; (5) challenges and priorities; and (6)future issues. Individual reports are processed separately for the data bases.

  4. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  5. Designing a health equity audit model for Iran in 2010

    Directory of Open Access Journals (Sweden)

    Saeed Karimi

    2011-01-01

    Full Text Available Background: Health equity audit, as an alternative solution, is a process by which local partners systematically review inequalities in the patients` health, their access to appropriate services and health system outputs. Then, necessary activities needed in order to have more equitable services are agreed on and these concurrences become the executive scheme and action initiates. Therefore, it is pivotal for health care organizations to pay special attention to this important topic. The objective of the current study was to review the health equity audit model in different countries to gather viewpoints of various involved groups in health sector, particularly health experts, and to offer a practical and appropriate model for health equity audit in Iran. Methods: This study adopted applied research approach in two phases. In the first step, this study conducted theoretical health equity audit models in the texts; the experiences of other countries were studied and the most appropriate model for Iranian health system was selected. In the second step, this study employed the Delphi technique. According to the Delphi technique the questionnaire applied in order to gather data and then, the final model was extracted. Results: Agreeable topics, performing agencies, 6 equity audit stages, and equity indicators under 3 main parts with 16 sub-sections were elaborated and viewpoints of Iranian experts in the above fields were gathered and presented as the proposed health equity audit model for Iran. Conclusions: This study reviewed the model of health equity audit for UK and provided a comparative model for health system of Iran with respect to the opinions of academic experts.

  6. Modelling the interaction of steroid receptors with endocrine disrupting chemicals

    Directory of Open Access Journals (Sweden)

    Milanesi Luciano

    2005-12-01

    Full Text Available Abstract Background The organic polychlorinated compounds like dichlorodiphenyltrichloroethane with its metabolites and polychlorinated biphenyls are a class of highly persistent environmental contaminants. They have been recognized to have detrimental health effects both on wildlife and humans acting as endocrine disrupters due to their ability of mimicking the action of the steroid hormones, and thus interfering with hormone response. There are several experimental evidences that they bind and activate human steroid receptors. However, despite the growing concern about the toxicological activity of endocrine disrupters, molecular data of the interaction of these compounds with biological targets are still lacking. Results We have used a flexible docking approach to characterize the molecular interaction of seven endocrine disrupting chemicals with estrogen, progesterone and androgen receptors in the ligand-binding domain. All ligands docked in the buried hydrophobic cavity corresponding to the hormone steroid pocket. The interaction was characterized by multiple hydrophobic contacts involving a different number of residues facing the binding pocket, depending on ligands orientation. The EDC ligands did not display a unique binding mode, probably due to their lipophilicity and flexibility, which conferred them a great adaptability into the hydrophobic and large binding pocket of steroid receptors. Conclusion Our results are in agreement with toxicological data on binding and allow to describe a pattern of interactions for a group of ECD to steroid receptors suggesting the requirement of a hydrophobic cavity to accommodate these chlorine carrying compounds. Although the affinity is lower than for hormones, their action can be brought about by a possible synergistic effect.

  7. Two models of primary health care training.

    Science.gov (United States)

    Hill, P; Samisoni, J

    1993-01-01

    In 1991, the Fiji School of Medicine restructured the training of its medical students, dividing the 7-year course into two phases. Students now undertake a 3-year community-oriented primary care practitioners course, after which they may elect to continue practice in a primary health care role, or to undertake further hospital-based training to complete their medical degree. The course responds to the health needs of the South Pacific, and the local patterns of morbidity and mortality, rather than measuring itself against the curricular demands of its more developed neighbours, Australia and New Zealand. At the same time, the Tropical Health Program of the University of Queensland Medical School responded to demands from the Aboriginal and Torres Strait Islander community to develop primary health care training at degree level. This was intended to complement other strategies undertaken by the Aboriginal and Torres Strait Islander Studies Unit such as the recruitment and support of indigenous students through mainstream health professional education. There was a need to address health priorities that are very different to those of the Australian population as a whole, as well as the sociopolitical and cultural context as it affects both students themselves and health issues in their communities. Both institutions have chosen problem-based teaching/learning as appropriate to their courses, and content is also similar, though with emphases that reflect the differing contexts. The two courses are examples of innovative responses by centres with university medical faculties to specific issues in health education. PMID:8433664

  8. The use of food consumption data in assessments of exposure to food chemicals including the application of probabilistic modelling.

    Science.gov (United States)

    Lambe, Joyce

    2002-02-01

    Emphasis on public health and consumer protection, in combination with globalisation of the food market, has created a strong demand for exposure assessments of food chemicals. The food chemicals for which exposure assessments are required include food additives, pesticide residues, environmental contaminants, mycotoxins, novel food ingredients, packaging-material migrants, flavouring substances and nutrients. A wide range of methodologies exists for estimating exposure to food chemicals, and the method chosen for a particular exposure assessment is influenced by the nature of the chemical, the purpose of the assessment and the resources available. Sources of food consumption data currently used in exposure assessments range from food balance sheets to detailed food consumption surveys of individuals and duplicate-diet studies. The fitness-for-purpose of the data must be evaluated in the context of data quality and relevance to the assessment objective. Methods to combine the food consumption data with chemical concentration data may be deterministic or probabilistic. Deterministic methods estimate intakes of food chemicals that may occur in a population, but probabilistic methods provide the advantage of estimating the probability with which different levels of intake will occur. Probabilistic analysis permits the exposure assessor to model the variability (true heterogeneity) and uncertainty (lack of knowledge) that may exist in the exposure variables, including food consumption data, and thus to examine the full distribution of possible resulting exposures. Challenges for probabilistic modelling include the selection of appropriate modes of inputting food consumption data into the models. PMID:12002785

  9. Probabilistic human health risk assessment of degradation-related chemical mixtures in heterogeneous aquifers: risk statistics, hot spots, and preferential channels

    OpenAIRE

    Henri, Christopher Vincent; Fernández García, Daniel; Barros, Felipe de

    2015-01-01

    The increasing presence of toxic chemicals released in the subsurface has led to a rapid growth of social concerns and the need to develop and employ models that can predict the impact of groundwater contamination on human health risk under uncertainty. Monitored natural attenuation is a common remediation action in many contamination cases. However, natural attenuation can lead to the production of daughter species of distinct toxicity that may pose challenges in pollution management strateg...

  10. Man's health through the model of salutogenetic: theory and practice

    Directory of Open Access Journals (Sweden)

    Lukjanchenko M.I.

    2010-11-01

    Full Text Available In the article the salutogenetic model of famous medical sociologist A. Antonovsky has been studied. The criteria of researched model concerning to the definition of man's health has been analyzed. The sense of such definitions as "generalized resistance resources" and "sense of coherence" which are prominent in the problem of the formation of health life has been revealed. Conception of the salutogenetic model of health must be a theoretical bases for healthy life style forming of people of different ages. Defined that a sense of coherence has a positive influence of human's health and helps him to cope with stress. Resistance resources are original potential in fight with disease.

  11. Health effects models for nuclear power plant accident consequence analysis

    International Nuclear Information System (INIS)

    The Nuclear Regulatory Commission (NRC) has sponsored several studies to identify and quantify, through the use of models, the potential health effects of accidental releases of radionuclides from nuclear power plants. The Reactor Safety Study provided the basis for most of the earlier estimates related to these health effects. Subsequent efforts by NRC-supported groups resulted in improved health effects models that were published in the report entitled open-quotes Health Effects Models for Nuclear Power Plant Consequence Analysisclose quotes, NUREG/CR-4214, 1985 and revised further in the 1989 report NUREG/CR-4214, Rev. 1, Part 2. The health effects models presented in the 1989 NUREG/CR-4214 report were developed for exposure to low-linear energy transfer (LET) (beta and gamma) radiation based on the best scientific information available at that time. Since the 1989 report was published, two addenda to that report have been prepared to (1) incorporate other scientific information related to low-LET health effects models and (2) extend the models to consider the possible health consequences of the addition of alpha-emitting radionuclides to the exposure source term. The first addendum report, entitled open-quotes Health Effects Models for Nuclear Power Plant Accident Consequence Analysis, Modifications of Models Resulting from Recent Reports on Health Effects of Ionizing Radiation, Low LET Radiation, Part 2: Scientific Bases for Health Effects Models,close quotes was published in 1991 as NUREG/CR-4214, Rev. 1, Part 2, Addendum 1. This second addendum addresses the possibility that some fraction of the accident source term from an operating nuclear power plant comprises alpha-emitting radionuclides. Consideration of chronic high-LET exposure from alpha radiation as well as acute and chronic exposure to low-LET beta and gamma radiations is a reasonable extension of the health effects model

  12. Sri Lanka's Health Unit Program: A Model of "Selective" Primary Health Care

    Directory of Open Access Journals (Sweden)

    Soma Hewa

    2011-12-01

    Full Text Available This paper argues that the health unit program developed in Sri Lanka in the early twentieth century was an earlier model of selective primary health care promoted by the Rockefeller Foundation in the 1980s in opposition to comprehensive primary health care advocated by the Alma-Ata Declaration of the World Health Organization. A key strategy of the health unit program was to identify the most common and serious infectious diseases in each health unit area and control them through improved sanitation, health education, immunization and treatment with the help of local communities. The health unit program was later introduced to other countries in South and Southeast Asia as part of the Rockefeller Foundation's global campaign to promote public health.

  13. A competencies-based mental health training model for health professionals in low and middle income countries

    OpenAIRE

    Kutcher, Stan; Chehil, Sonia; CASH, COLLEEN; MILLAR, JIM

    2005-01-01

    This paper describes a competencies-based training model specifically created to teach needed mental health skills to health professionals in low and middle income countries (LMICs). The model combines a mental health training needs assessment with the delivery of mental health training modules aligned with national/regional mental health priorities and designed to be used by all health professionals at various levels of the health care system. The model also defines a susta...

  14. Simulation Models for Socioeconomic Inequalities in Health: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Niko Speybroeck

    2013-11-01

    Full Text Available Background: The emergence and evolution of socioeconomic inequalities in health involves multiple factors interacting with each other at different levels. Simulation models are suitable for studying such complex and dynamic systems and have the ability to test the impact of policy interventions in silico. Objective: To explore how simulation models were used in the field of socioeconomic inequalities in health. Methods: An electronic search of studies assessing socioeconomic inequalities in health using a simulation model was conducted. Characteristics of the simulation models were extracted and distinct simulation approaches were identified. As an illustration, a simple agent-based model of the emergence of socioeconomic differences in alcohol abuse was developed. Results: We found 61 studies published between 1989 and 2013. Ten different simulation approaches were identified. The agent-based model illustration showed that multilevel, reciprocal and indirect effects of social determinants on health can be modeled flexibly. Discussion and Conclusions: Based on the review, we discuss the utility of using simulation models for studying health inequalities, and refer to good modeling practices for developing such models. The review and the simulation model example suggest that the use of simulation models may enhance the understanding and debate about existing and new socioeconomic inequalities of health frameworks.

  15. Modelling the chemical evolution of star forming filaments

    Science.gov (United States)

    Seifried, D.; Walch, S.

    2016-05-01

    We present simulations of star forming filaments incorporating - to our knowledge - the largest chemical network used to date on-the-fly in a 3D-MHD simulation. The network contains 37 chemical species and about 300 selected reaction rates. For this we use the newly developed package KROME (Grassi et al. [4]). Our results demonstrate the feasibility of using such a complex chemical network in 3D-MHD simulations on modern supercomputers. We perform simulations with different strengths of the interstellar radiation field and the cosmic ray ionisation rate and find chemical and physical results in accordance with observations and other recent numerical work.

  16. Modelling the chemical evolution of star forming filaments

    CERN Document Server

    Seifried, D

    2015-01-01

    We present simulations of star forming filaments incorporating - to our knowledge - the largest chemical network used to date on-the-fly in a 3D-MHD simulation. The network contains 37 chemical species and about 300 selected reaction rates. For this we use the newly developed package KROME (Grassi et al. 2014). Our results demonstrate the feasibility of using such a complex chemical network in 3D-MHD simulations on modern supercomputers. We perform simulations with different strengths of the interstellar radiation field and the cosmic ray ionisation rate and find chemical and physical results in accordance with observations and other recent numerical work.

  17. In situ chemical sensing for hydrothermal plume mapping and modeling

    Science.gov (United States)

    Fukuba, T.; Kusunoki, T.; Maeda, Y.; Shitashima, K.; Kyo, M.; Fujii, T.; Noguchi, T.; Sunamura, M.

    2012-12-01

    Detection, monitoring, and mapping of biogeochemical anomalies in seawater such as temperature, salinity, turbidity, oxidation-reduction potential, and pH are essential missions to explore undiscovered hydrothermal sites and to understand distribution and behavior of hydrothermal plumes. Utilization of reliable and useful in situ sensors has been widely accepted as a promised approach to realize a spatiotemporally resolved mapping of anomalies without water sampling operations. Due to remarkable progresses of sensor technologies and its relatives, a number of highly miniaturized and robust chemical sensors have been proposed and developed. We have been developed, evaluated, and operated a compact ISFET (Ion-Sensitive Field-Effect Transistor)-based chemical sensors for ocean environmental sensing purposes. An ISFET has advantages against conventional glass-based electrodes on its faster response, robustness, and potential on miniaturization, and thus variety of chemical sensors has been already on the market. In this study, ISFET-based standalone pH sensors with a solid-state Cl-ISE as a reference electrode were mounted on various platforms and operated to monitor the pH anomalies in deep-sea environment at the Kairei, Edmond, and surrounding hydrothermal sites in the southern Central Indian Ridge area during KH10-06 scientific cruise (Nov. 2010), supported by project TAIGA (Trans-crustal Advection and In situ biogeochemical processes of Global sub-seafloor Aquifer). Up to three pH sensors were mounted on a wire-lined CTD/RMS (Rosette Multiple Sampler), dredge sampler, a series of MTD plankton nets, and VMPS (Vertical Multiple-operating Plankton Sampler). A standalone temperature sensor was bundled and operated with the pH sensor when they were mounted on the dredge sampler, MTD plankton nets, and VMPS. An AUV equipped with the pH sensor was also operated for hydrothermal activity survey operations. As a result of Tow-Yo intersect operations of the CTD

  18. E-health stakeholders experiences with clinical modelling and standardizations.

    Science.gov (United States)

    Gøeg, Kirstine Rosenbeck; Elberg, Pia Britt; Højen, Anne Randorff

    2015-01-01

    Stakeholders in e-health such as governance officials, health IT-implementers and vendors have to co-operate to achieve the goal of a future-proof interoperable e-health infrastructure. Co-operation requires knowledge on the responsibility and competences of stakeholder groups. To increase awareness on clinical modeling and standardization we conducted a workshop for Danish and a few Norwegian e-health stakeholders' and made them discuss their views on different aspects of clinical modeling using a theoretical model as a point of departure. Based on the model, we traced stakeholders' experiences. Our results showed there was a tendency that stakeholders were more familiar with e-health requirements than with design methods, clinical information models and clinical terminology as they are described in the scientific literature. The workshop made it possible for stakeholders to discuss their roles and expectations to each other.

  19. Thinking Developmentally: The Next Evolution in Models of Health.

    Science.gov (United States)

    Garner, Andrew S

    2016-09-01

    As the basic sciences that inform conceptions of human health advance, so must the models that are used to frame additional research, to teach the next generation of providers, and to inform health policy. This article briefly reviews the evolution from a biomedical model to a biopsychosocial (BPS) model and to an ecobiodevelopmental (EBD) model. Like the BPS model, the EBD model reaffirms the biological significance of psychosocial features within the patient's ecology, but it does so at the molecular and cellular levels. More importantly, the EBD model adds the dimension of time, forcing providers to "think developmentally" and to acknowledge the considerable biological and psychological consequences of previous experiences. For the health care system to move from a reactive "sick care" system to a proactive "well care" system, all providers must begin thinking developmentally by acknowledging the dynamic but cumulative dance between nature and nurture that drives development, behavior, and health, not only in childhood, but across the lifespan. PMID:27429356

  20. Chemical Evolution Models of Local dSph Galaxies

    CERN Document Server

    Carigi, L; Gilmore, G; Carigi, Leticia; Hernandez, Xavier; Gilmore, Gerard

    2002-01-01

    We calculate chemical evolution models for 4 dwarf spheroidal satellites of the Milky Way (Carina, Ursa Minor, Leo I and Leo II) for which reliable non-parametric star formation histories have been derived. In this way, the independently obtained star formation histories are used to constrain the evolution of the systems we are treating. This allows us to obtain robust inferences on the history of such crucial parameters of galactic evolution as gas infall, gas outflows and global metallicities for these systems. We can then trace the metallicity and abundance ratios of the stars formed, the gas present at any time within the systems and the details of gas ejection, of relevance to enrichment of the galaxies environment. We find that galaxies showing one single burst of star formation (Ursa Minor and Leo II) require a dark halo slightly larger that the current estimates for their tidal radii, or the presence of a metal rich selective wind, which might carry away much of the energy output of their supernovae b...

  1. Theoretical Modeling of (99)Tc NMR Chemical Shifts.

    Science.gov (United States)

    Hall, Gabriel B; Andersen, Amity; Washton, Nancy M; Chatterjee, Sayandev; Levitskaia, Tatiana G

    2016-09-01

    Technetium-99 (Tc) displays a rich chemistry due to its wide range of accessible oxidation states (from -I to +VII) and ability to form coordination compounds. Determination of Tc speciation in complex mixtures is a major challenge, and (99)Tc nuclear magnetic resonance (NMR) spectroscopy is widely used to probe chemical environments of Tc in odd oxidation states. However, interpretation of (99)Tc NMR data is hindered by the lack of reference compounds. Density functional theory (DFT) calculations can help to fill this gap, but to date few computational studies have focused on (99)Tc NMR of compounds and complexes. This work evaluates the effectiveness of both pure generalized gradient approximation and their corresponding hybrid functionals, both with and without the inclusion of scalar relativistic effects, to model the (99)Tc NMR spectra of Tc(I) carbonyl compounds. With the exception of BLYP, which performed exceptionally well overall, hybrid functionals with inclusion of scalar relativistic effects are found to be necessary to accurately calculate (99)Tc NMR spectra. The computational method developed was used to tentatively assign an experimentally observed (99)Tc NMR peak at -1204 ppm to fac-Tc(CO)3(OH)3(2-). This study examines the effectiveness of DFT computations for interpretation of the (99)Tc NMR spectra of Tc(I) coordination compounds in high salt alkaline solutions. PMID:27518482

  2. The effect of uncertainties on chemical models of dark clouds

    CERN Document Server

    Wakelam, V; Selsis, F; Herbst, Eric; Selsis, Franck; Wakelam, Valentine

    2006-01-01

    The gas-phase chemistry of dark clouds has been studied with a treatment of uncertainties caused both by errors in individual rate coefficients and uncertainties in physical conditions. Moreover, a sensitivity analysis has been employed to attempt to determine which reactions are most important in the chemistry of individual species. The degree of overlap between calculated errors in abundances and estimated observational errors has been used as an initial criterion for the goodness of the model and the determination of a best 'chemical' age of the source. For the well-studied sources L134N and TMC-1CP, best agreement is achieved at so-called "early times" ~10$^{5}$ yr, in agreement with previous calculations but here put on a firmer statistical foundation. A more detailed criterion for agreement, which takes into account the degree of disagreement, is also proposed. Poorly understood but critical classes of reactions are delineated, especially reactions between ions and polar neutrals. Such reactions will ha...

  3. Modeling Social Influences on Human Health

    OpenAIRE

    Karelina, Kate; DeVries, A. Courtney

    2010-01-01

    Social interactions have long-term physiological, psychological and behavioral consequences. Social isolation is a well recognized but little understood risk factor and prognostic marker of disease, and can have profoundly detrimental effects on both mental and physical well-being, particularly during states of compromised health. In contrast, the health benefits associated with social support (both reduced risk and improved recovery) are evident in a variety of illnesses and injury states; h...

  4. Modelling of chemical reaction in foods: a multiresponse approach.

    NARCIS (Netherlands)

    Boekel, van M.A.J.S.

    1998-01-01

    The quality of foods depends on several factors. One of these factors is the occurrence of (bio)chemical changes taking place during the post-harvest period and during processing, storage and distribution. In order to optimise quality it is of utmost importance to control (bio)chemical changes as mu

  5. Models for risk assessment of reactive chemicals in aquatic toxicology

    NARCIS (Netherlands)

    Freidig, Andreas Peter

    2001-01-01

    A quantitative structure property relationship (QSPR) for a,b-unsaturated carboxylates (mainly acrylates and methacrylates) was established in chapter 2. Chemical reaction rate constants were measured for 12 different chemicals with three different nucleophiles, namely H 2 O, OH - and glutathione (G

  6. [Depression and the complete state model of health].

    Science.gov (United States)

    Díaz, Darío; Blanco, Amalio; Horcajo, Javier; Valle, Carmen

    2007-05-01

    Health is a state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity. In order to specify the contents of this positive state, the Complete State Model of Health (CSMH) considers mental health as a series of symptoms of hedonia and positive functioning, operationalized by measures of subjective, psychological, and social well-being. This model has empirically confirmed two new axioms: (a) rather than forming a single bipolar dimension, health and illness are correlated unipolar dimensions, and (b) the presence of mental health implies positive personal and social functioning. In the present article, we have taken the CSMH as the theoretical framework for the study of depression. Confirmatory factor analyses did not support the first axiom. In fact, the model that posits that measures of mental illness and health form a single bipolar dimension provided the best fit to the data. PMID:17425901

  7. The Relationship between Spiritual Health and other Dimensions of Health: Presentation of a Model

    Directory of Open Access Journals (Sweden)

    Akram Heidari

    2016-06-01

    Full Text Available Attitudes to humankind will have different effects on health service delivery. Health might used to be intended to provide physical health in the past; today, however, many researchers and clinicians consider the concept health to be beyond physical health. In support of this claim, it is enough to indicate that the bio-psycho-social model has for years been held by scientific communities to be a fully admitted model. However, the missing ring in this model, as suggested by many, is the spiritual health. In recent years, the relationship between spirituality and clinical interventions with a comprehensive focus on health has been under increasing scrutiny. Although different models have been presented for investigation of the relationship between spiritual health and other dimensions, the fundamental challenge in this regard is the actual place of spiritual health compared with other dimensions. In this article, attempts are made to address the position and weight of spiritual health from the Islam’s point of view.

  8. Sustainable Organic Farming For Environmental Health A Social Development Model

    Directory of Open Access Journals (Sweden)

    Ijun Rijwan Susanto

    2015-05-01

    Full Text Available ABSTRACT In this study the researcher attempted 1 to understand the basic features of organic farming in The Paguyuban Pasundans Cianjur 2 to describe and understand how the stakeholders were are able to internalize the challenges of organic farming on their lived experiences in the community 3 to describe and understand how the stakeholders were are able to internalize and applied the values of benefits of organic farming in support of environmental health on their lived experiences in the community 4 The purpose was to describe and understand how the stakeholders who are able to articulate their ideas regarding the model of sustainable organic farming 5 The Policy Recommendation for Organic Farming. The researcher employed triangulation thorough finding that provides breadth and depth to an investigation offering researchers a more accurate picture of the phenomenon. In the implementation of triangulation researchers conducted several interviews to get saturation. After completion of the interview results are written compiled and shown to the participants to check every statement by every participant. In addition researchers also checked the relevant documents and direct observation in the field The participants of this study were the stakeholders namely 1 The leader of Paguyuban Pasundans Organic Farmer Cianjur PPOFC 2 Members of Paguyuban Pasundans Organic FarmersCianjur 3 Leader of NGO 4 Government officials of agriculture 5 Business of organic food 6 and Consumer of organic food. Generally the findings of the study revealed the following 1 PPOFC began to see the reality as the impact of modern agriculture showed in fertility problems due to contaminated soil by residues of agricultural chemicals such as chemical fertilizers and chemical pesticides. So he wants to restore the soil fertility through environmentally friendly of farming practices 2 the challenges of organic farming on their lived experiences in the community farmers did not

  9. Leadership models in health care - a case for servant leadership.

    Science.gov (United States)

    Trastek, Victor F; Hamilton, Neil W; Niles, Emily E

    2014-03-01

    Our current health care system is broken and unsustainable. Patients desire the highest quality care, and it needs to cost less. To regain public trust, the health care system must change and adapt to the current needs of patients. The diverse group of stakeholders in the health care system creates challenges for improving the value of care. Health care providers are in the best position to determine effective ways of improving the value of care. To create change, health care providers must learn how to effectively lead patients, those within health care organizations, and other stakeholders. This article presents servant leadership as the best model for health care organizations because it focuses on the strength of the team, developing trust and serving the needs of patients. As servant leaders, health care providers may be best equipped to make changes in the organization and in the provider-patient relationship to improve the value of care for patients.

  10. Information resources for assessing health effects from chemical exposure: Challenges, priorities, and future issues

    Energy Technology Data Exchange (ETDEWEB)

    Seigel, S. [National Library of Medicine, Bethesda, MD (United States)

    1990-12-31

    Issues related to developing information resources for assessing the health effects from chemical exposure include the question of how to address the individual political issues relevant to identifying and determining the timeliness, scientific credibility, and completeness of such kinds of information resources. One of the important ways for agencies to share information is through connection tables. This type of software is presently being used to build information products for some DHHS agencies. One of the challenges will be to convince vendors of data of the importance of trying to make data files available to communities that need them. In the future, information processing will be conducted with neural networks, object-oriented database management systems, and fuzzy-set technologies, and meta analysis techniques.

  11. Florida county health department, environmental health 2006 survey: do rural counties know "what to do' in a chemical or all-hazards event?

    Science.gov (United States)

    Becker, Alan; Suther, Sandra; Dutton, Matthew; Kearney, Gregory D; Xu, Xiaohui

    2015-01-01

    The objective of the study described here was to determine basic plans and collaboration with first responder stakeholders and to identify perceived roles and responsibilities in preparing for and responding to a chemical disaster. A survey was developed and provided to environmental health personnel at county health departments (CHDs) in Florida. Most of the counties had good collaborative relationships with first responder stakeholders. A little more than half of the respondents had access to a resource manual with contact information and had developed and maintained a chemical plan. Rural counties were less likely to know "what to do" or their responsibility in a chemical disaster; however, both rural and nonrural counties were equally likely not to have a written plan. Public health agencies at the local CHD must be the communicators of public health messages in coordination with the incident commander and the state communications office in a chemical disaster, so it is important to strengthen collaboration and cooperation with chemical response stakeholders. PMID:25619031

  12. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Directory of Open Access Journals (Sweden)

    José A. Centeno

    2014-01-01

    Full Text Available Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU, tungsten (W, lead (Pb, and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF, scanning electron microscopy (SEM, laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS, and confocal laser Raman

  13. Embedded Fragments from U.S. Military Personnel—Chemical Analysis and Potential Health Implications

    Science.gov (United States)

    Centeno, José A.; Rogers, Duane A.; van der Voet, Gijsbert B.; Fornero, Elisa; Zhang, Lingsu; Mullick, Florabel G.; Chapman, Gail D.; Olabisi, Ayodele O.; Wagner, Dean J.; Stojadinovic, Alexander; Potter, Benjamin K.

    2014-01-01

    Background: The majority of modern war wounds are characterized by high-energy blast injuries containing a wide range of retained foreign materials of a metallic or composite nature. Health effects of retained fragments range from local or systemic toxicities to foreign body reactions or malignancies, and dependent on the chemical composition and corrosiveness of the fragments in vivo. Information obtained by chemical analysis of excised fragments can be used to guide clinical decisions regarding the need for fragment removal, to develop therapeutic interventions, and to better anticipate future medical problems from retained fragment related injuries. In response to this need, a new U.S Department of Defense (DoD) directive has been issued requiring characterization of all removed fragments to provide a database of fragment types occurring in combat injuries. Objectives: The objective of this study is to determine the chemical composition of retained embedded fragments removed from injured military personnel, and to relate results to histological findings in tissue adjacent to fragment material. Methods: We describe an approach for the chemical analysis and characterization of retained fragments and adjacent tissues, and include case examples describing fragments containing depleted uranium (DU), tungsten (W), lead (Pb), and non-metal foreign bodies composed of natural and composite materials. Fragments obtained from four patients with penetrating blast wounds to the limbs were studied employing a wide range of chemical and microscopy techniques. Available adjacent tissues from three of the cases were histologically, microscopically, and chemically examined. The physical and compositional properties of the removed foreign material surfaces were examined with energy dispersive x-ray fluorescence spectrometry (EDXRF), scanning electron microscopy (SEM), laser ablation inductively-coupled plasma mass-spectrometry (LA-ICP-MS), and confocal laser Raman

  14. Human and animal health risk assessments of chemicals in the food chain: Comparative aspects and future perspectives

    Energy Technology Data Exchange (ETDEWEB)

    Dorne, J.L.C.M., E-mail: jean-lou.dorne@efsa.europa.eu [Emerging Risk Unit, Via Carlo Magno 1A, 43126 Parma (Italy); Fink-Gremmels, J. [Utrecht University, Faculty of Veterinary Medicine, Institute for Risk Assessment Sciences, Yalelaan 104, 3584 CM Utrecht (Netherlands)

    2013-08-01

    Chemicals from anthropogenic and natural origins enter animal feed, human food and water either as undesirable contaminants or as part of the components of a diet. Over the last five decades, considerable efforts and progress to develop methodologies to protect humans and animals against potential risks associated with exposure to such potentially toxic chemicals have been made. This special issue presents relevant methodological developments and examples of risk assessments of undesirable substances in the food chain integrating the animal health and the human health perspective and refers to recent Opinions of the Scientific Panel on Contaminants in the Food Chain (CONTAM) of the European Food Safety Authority (EFSA). This introductory review aims to give a comparative account of the risk assessment steps used in human health and animal health risk assessments for chemicals in the food chain and provides a critical view of the data gaps and future perspectives for this cross-disciplinary field. - Highlights: ► Principles of human and animal health risk assessment. ► Data gaps for each step of animal health risk assessment. ► Implications of animal risk assessment on human risk assessment. ► Future perspectives on chemical risk assessment.

  15. eHealth literacy issues, constructs, models, and methods for health information technology design and evaluation

    Directory of Open Access Journals (Sweden)

    Helen Monkman

    2015-12-01

    Full Text Available The concept of eHealth literacy is beginning to be recognized as a being of key importance in the design and adoption of effective and efficient health information systems and applications targeted to lay people and patients. Indeed, many systems such as patient portals and personal health records have not been adopted due to a mismatch between the level of eHealth literacy demanded by a system and the level of eHealth literacy possessed by end users. The purpose of this paper is to present an overview of important concepts related to eHealth literacy, as well as how the notion of eHealth literacy can be applied to improve the design and adoption of consumer health information systems. This paper begins with describing the importance of eHealth literacy with respect to design of health applications for the general public paired with examples of consumer health information systems whose limited success and adoption has been attributed to the lack of consideration for eHealth literacy. This is followed by definitions of what eHealth literacy is and how it emerged from the related concept of health literacy. A model for conceptualizing the importance of aligning consumers’ eHealth literacy skills and the demands systems place on their skills is then described. Next, current tools for assessing consumers’ eHealth literacy levels are outlined, followed by an approach to systematically incorporating eHealth literacy in the deriving requirements for new systems is presented. Finally, a discussion of evolving approaches for incorporating eHealth literacy into usability engineering methods is presented.

  16. Evidence for the credibility of health economic models for health policy decision-making

    DEFF Research Database (Denmark)

    Søgaard, Rikke; Lindholt, Jes S.

    2012-01-01

    OBJECTIVE: To investigate whether the credibility of health economic models of screening for abdominal aortic aneurysms for health policy decision-making has improved since 2005 when a systematic review by Campbell et al. concluded that reporting standards were poor and there was divergence between...... the findings of studies that was hard to explain. METHODS: A systematic literature review was carried out following PRISMA reporting principles. Health economic models of the cost-effectiveness of screening for abdominal aortic aneurysms published between 2005-2010 were included. Key characteristics were...... benefited from general advances in health economic modelling and some improvements in reporting were noted. However, the low level of agreement between studies in model structures and assumptions, and difficulty in justifying these (convergent validity), remain a threat to the credibility of health economic...

  17. Modelling the optical properties of aerosols in a chemical transport model

    Science.gov (United States)

    Andersson, E.; Kahnert, M.

    2015-12-01

    According to the IPCC fifth assessment report (2013), clouds and aerosols still contribute to the largest uncertainty when estimating and interpreting changes to the Earth's energy budget. Therefore, understanding the interaction between radiation and aerosols is both crucial for remote sensing observations and modelling the climate forcing arising from aerosols. Carbon particles are the largest contributor to the aerosol absorption of solar radiation, thereby enhancing the warming of the planet. Modelling the radiative properties of carbon particles is a hard task and involves many uncertainties arising from the difficulties of accounting for the morphologies and heterogeneous chemical composition of the particles. This study aims to compare two ways of modelling the optical properties of aerosols simulated by a chemical transport model. The first method models particle optical properties as homogeneous spheres and are externally mixed. This is a simple model that is particularly easy to use in data assimilation methods, since the optics model is linear. The second method involves a core-shell internal mixture of soot, where sulphate, nitrate, ammonia, organic carbon, sea salt, and water are contained in the shell. However, by contrast to previously used core-shell models, only part of the carbon is concentrated in the core, while the remaining part is homogeneously mixed with the shell. The chemical transport model (CTM) simulations are done regionally over Europe with the Multiple-scale Atmospheric Transport and CHemistry (MATCH) model, developed by the Swedish Meteorological and Hydrological Institute (SMHI). The MATCH model was run with both an aerosol dynamics module, called SALSA, and with a regular "bulk" approach, i.e., a mass transport model without aerosol dynamics. Two events from 2007 are used in the analysis, one with high (22/12-2007) and one with low (22/6-2007) levels of elemental carbon (EC) over Europe. The results of the study help to assess the

  18. Evaluation of a Three-Dimensional Chemical Transport Model (PMCAMx) in the Mexico City Metropolitan Area

    Science.gov (United States)

    Tsimpidi, A. P.; Karydis, V. A.; Zavala, M.; Lei, W.; Molina, L. T.; Pandis, S. N.

    2007-05-01

    Atmospheric aerosols have adverse effects on human health, contribute to the visibility reduction and influence the energy balance of the planet. A three-dimensional chemical transport model (PMCAMx) (Gaydos et al., 2007) is used to simulate the particular matter (PM) mass composition distribution in the Mexico City Metropolitan Area (MCMA). PMCAMx uses the framework of CAMx (ENVIRON, 2002) modelling the processes of horizontal and vertical advection, horizontal and vertical dispersion, wet and dry deposition, and gas-phase chemistry. In addition to the above, PMCAMx includes three detailed aerosol modules: inorganic aerosol growth (Gaydos et al., 2003; Koo et al., 2003a), aqueous-phase chemistry (Fahey and Pandis, 2001), and secondary organic aerosol formation and growth (Koo et al., 2004). The aerosol thermodynamic model ISORROPIA has been improved as it now simulates explicitly the chemistry of Ca, Mg, and K salts and is linked to PMCAMx. The hybrid approach (Koo et al., 2003b) for modelling aerosol dynamics is applied in order to accurately simulate the inorganic components in coarse mode. This approach assumes that the smallest particles are in equilibrium while the condensation/evaporation equation is solved for the larger ones. The new CMU organic aerosol model, which is based on the splitting of the organic aerosol volatility range in discrete bins, is also used. The model predictions are evaluated against the PM and vapour concentration measurements from the MCMA-2003 Campaign (Molina et al., 2007). References Gaydos, T., Pinder, R., Koo, B., Fahey, Κ., Yarwood, G., and Pandis, S. N., (2007). Development and application of a three-dimensional Chemical Transport Model, PMCAMx. Atmospheric Environment, in press. ENVIRON (2002). User's guide to the comprehensive air quality model with extensions (CAMx). Version 3.10. Report prepared by ENVIRON International corporation, Novato, CA Gaydos, T., Koo, B., and Pandis, S. N., (2003). Development and application of

  19. Health effects of the London bicycle sharing system: health impact modelling study

    OpenAIRE

    Woodcock, James; Tainio, Marko; Cheshire, James; O’Brien, Oliver; Goodman, Anna

    2014-01-01

    Objective To model the impacts of the bicycle sharing system in London on the health of its users. Design Health impact modelling and evaluation, using a stochastic simulation model. Setting Central and inner London, England. Data sources Total population operational registration and usage data for the London cycle hire scheme (collected April 2011-March 2012), surveys of cycle hire users (collected 2011), and London data on travel, physical activity, road traffic collisions, and particulate ...

  20. Health assessment for Crystal Chemical Company, Houston, Harris County, Texas, Region 6. CERCLIS No. TXD990707010. Addendum. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-27

    The Crystal Chemical Company, a National Priorities List site, is located on a 5-acre tract off Westpark Drive in Houston, Texas. The company was in operation from 1968 to 1981 and manufactured arsenic-based herbicides. In 1988, the Agency for Toxic Substances and Disease Registry (ATSDR) prepared and released a Health Assessment for the site. ATSDR concluded that soil, surface water, and ground water at the Crystal Chemical site were contaminated with arsenic both on and off site. They also concluded that children playing in the area and workers involved in remediation on and off site could be exposed to site arsenic through oral, skin, and inhalation exposures. The Public Health Assessment Addendum evaluates the public health implications of new environmental sampling information from the Supplemental Feasibility Study (SFS), reviews the Crystal Chemical Company Exposure Study findings, and comments on the proposed clean-up levels for arsenic with remediation of the site.

  1. Children’s Oral Health: The Opportunity for Improvement Using the WHO Health Promoting School Model

    Directory of Open Access Journals (Sweden)

    Andrew J. Macnab

    2015-01-01

    Full Text Available The health and quality of life of a large proportion of the world’s children are compromised by dental caries and periodontal disease. Those in developing countries and from disadvantaged populations suffer disproportionately from these forms of poor oral health; however, much of the primary disease and secondary pathology is preventable by simple and inexpensive measures that children can readily learn. WHO health promoting schools (HPS are an established model for addressing public health issues through education of children in a manner that achieves acquisition of knowledge and health practices that promote behaviours that positively impact determinants of health. HPS programs that address poor oral health have achieved improvement in oral health practices and reduction in caries rates among disadvantaged populations of children. WHO has called for more programs to address the “epidemic” of poor oral health worldwide, and the WHO HPS model appears to be a relevant and applicable way forward. Health care professionals and educators who want to improve the health and quality of life of children related to caries and periodontal disease now have an opportunity to collaborate to initiate, deliver, and evaluate community-based HPS interventions using proven concepts, content, and process.

  2. Cluster model of chemical modification of sapropelitic coals

    Energy Technology Data Exchange (ETDEWEB)

    Bodoev, N.V.; Kozlov, A.P.; Gruber, R.; Kucherenko, V.A.; Guet, J.-M. [Buryat State University, Ulan-Ude (Russian Federation)

    1999-07-01

    The possibility of active carbon preparation from sapropelitic coals was investigated. Chemical modification and structural alteration as well as thermolysis of modified sapropelite are described. 2 refs., 2 tabs.

  3. Model reduction for stochastic chemical systems with abundant species

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon [School of Biological Sciences, University of Edinburgh, Mayfield Road, Edinburgh EH93JR, Scotland (United Kingdom)

    2015-12-07

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  4. Model reduction for stochastic chemical systems with abundant species

    Science.gov (United States)

    Smith, Stephen; Cianci, Claudia; Grima, Ramon

    2015-12-01

    Biochemical processes typically involve many chemical species, some in abundance and some in low molecule numbers. We first identify the rate constant limits under which the concentrations of a given set of species will tend to infinity (the abundant species) while the concentrations of all other species remains constant (the non-abundant species). Subsequently, we prove that, in this limit, the fluctuations in the molecule numbers of non-abundant species are accurately described by a hybrid stochastic description consisting of a chemical master equation coupled to deterministic rate equations. This is a reduced description when compared to the conventional chemical master equation which describes the fluctuations in both abundant and non-abundant species. We show that the reduced master equation can be solved exactly for a number of biochemical networks involving gene expression and enzyme catalysis, whose conventional chemical master equation description is analytically impenetrable. We use the linear noise approximation to obtain approximate expressions for the difference between the variance of fluctuations in the non-abundant species as predicted by the hybrid approach and by the conventional chemical master equation. Furthermore, we show that surprisingly, irrespective of any separation in the mean molecule numbers of various species, the conventional and hybrid master equations exactly agree for a class of chemical systems.

  5. A gandhian model of health: Looking at Alzheimer's disease.

    Science.gov (United States)

    Weaver, R C

    1987-03-01

    Mahatma Gandhi was often criticized for mixing religion, politics, economics, and health. However, it was his very insistence on the fundamental interrelationship of all aspects of life that gives his ideas such relevance for today's problems. This paper focuses on his views on health and attempts to develop a Gandhian model of health that has relevance for us today. This model is then specifically applied to the vexing problem of Alzheimer's disease, and an ongoing therapeutic trial that is based on this model is described.

  6. A review of operational, regional-scale, chemical weather forecasting models in Europe

    Directory of Open Access Journals (Sweden)

    J. Kukkonen

    2012-01-01

    Full Text Available Numerical models that combine weather forecasting and atmospheric chemistry are here referred to as chemical weather forecasting models. Eighteen operational chemical weather forecasting models on regional and continental scales in Europe are described and compared in this article. Topics discussed in this article include how weather forecasting and atmospheric chemistry models are integrated into chemical weather forecasting systems, how physical processes are incorporated into the models through parameterization schemes, how the model architecture affects the predicted variables, and how air chemistry and aerosol processes are formulated. In addition, we discuss sensitivity analysis and evaluation of the models, user operational requirements, such as model availability and documentation, and output availability and dissemination. In this manner, this article allows for the evaluation of the relative strengths and weaknesses of the various modelling systems and modelling approaches. Finally, this article highlights the most prominent gaps of knowledge for chemical weather forecasting models and suggests potential priorities for future research directions, for the following selected focus areas: emission inventories, the integration of numerical weather prediction and atmospheric chemical transport models, boundary conditions and nesting of models, data assimilation of the various chemical species, improved understanding and parameterization of physical processes, better evaluation of models against data and the construction of model ensembles.

  7. Discovering health topics in social media using topic models.

    Directory of Open Access Journals (Sweden)

    Michael J Paul

    Full Text Available By aggregating self-reported health statuses across millions of users, we seek to characterize the variety of health information discussed in Twitter. We describe a topic modeling framework for discovering health topics in Twitter, a social media website. This is an exploratory approach with the goal of understanding what health topics are commonly discussed in social media. This paper describes in detail a statistical topic model created for this purpose, the Ailment Topic Aspect Model (ATAM, as well as our system for filtering general Twitter data based on health keywords and supervised classification. We show how ATAM and other topic models can automatically infer health topics in 144 million Twitter messages from 2011 to 2013. ATAM discovered 13 coherent clusters of Twitter messages, some of which correlate with seasonal influenza (r = 0.689 and allergies (r = 0.810 temporal surveillance data, as well as exercise (r =  .534 and obesity (r =  -.631 related geographic survey data in the United States. These results demonstrate that it is possible to automatically discover topics that attain statistically significant correlations with ground truth data, despite using minimal human supervision and no historical data to train the model, in contrast to prior work. Additionally, these results demonstrate that a single general-purpose model can identify many different health topics in social media.

  8. A simple model for the distribution and fate of organic chemicals in a landfill: MOCLA

    DEFF Research Database (Denmark)

    Kjeldsen, Peter; Christensen, Thomas Højlund

    2001-01-01

    -leachate interface. Degradation of the chemicals is expressed as a first order reaction. Annual specific leachate and gas generation data in combination with data on landfill area and volume allow for prediction of main emission routes. Model simulations involving two landfill scenarios for a number of chemicals......A simple mathematical model (MOCLA: Model for Organic Chemicals in Landfills) is presented, describing the distribution of organic chemicals between leachate, gas and solid waste. The model also predicts the fate of the chemicals in terms of emissions with leachate and landfill gas and in terms...... of degradation and transformation in the landfill. Local equilibrium is assumed for the distribution of the chemicals in the landfill as expressed by Henry’s Law for the leachate-gas interface, and by the linear partition coefficient based on the waste solid organic carbon content for the waste...

  9. Fuel reactor modelling in chemical-looping combustion of coal: 1. model formulation

    OpenAIRE

    Abad Secades, Alberto; Gayán Sanz, Pilar; Diego Poza, Luis F. de; García Labiano, Francisco; Adánez Elorza, Juan

    2013-01-01

    A fundamental part of the reliability of the Chemical-Looping Combution system when a 13 solid fuel, such as coal, is fed to the reactor is based on the behaviour of the fuel reactor, which determines the conversion of the solid fuel. The objective of this work is to develop a model describing the fuel reactor in the Chemical–Looping Combustion with coal (CLCC) process. The model is used to simulate the performance of the 1 MWth CLCC rig built in the Technology University of Darmsta...

  10. QSAR modeling of toxicity of diverse organic chemicals to Daphnia magna using 2D and 3D descriptors

    Energy Technology Data Exchange (ETDEWEB)

    Kar, Supratik [Drug Theoretics and Cheminformatics Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Raja S C Mullick Road, Kolkata 700032 (India); Roy, Kunal, E-mail: kunalroy_in@yahoo.com [Drug Theoretics and Cheminformatics Laboratory, Department of Pharmaceutical Technology, Jadavpur University, Raja S C Mullick Road, Kolkata 700032 (India)

    2010-05-15

    One of the major economic alternatives to experimental toxicity testing is the use of quantitative structure-activity relationships (QSARs) which are used in formulating regulatory decisions of environmental protection agencies. In this background, we have modeled a large diverse group of 297 chemicals for their toxicity to Daphnia magna using mechanistically interpretable descriptors. Three-dimensional (3D) (electronic and spatial) and two-dimensional (2D) (topological and information content indices) descriptors along with physicochemical parameter log K{sub o/w} (n-octanol/water partition coefficient) and structural descriptors were used as predictor variables. The QSAR models were developed by stepwise multiple linear regression (MLR), partial least squares (PLS), genetic function approximation (GFA), and genetic PLS (G/PLS). All the models were validated internally and externally. Among several models developed using different chemometric tools, the best model based on both internal and external validation characteristics was a PLS equation with 7 descriptors and three latent variables explaining 67.8% leave-one-out predicted variance and 74.1% external predicted variance. The PLS model suggests that higher lipophilicity and electrophilicity, less negative charge surface area and presence of ether linkage, hydrogen bond donor groups and acetylenic carbons are responsible for greater toxicity of chemicals. The developed model may be used for prediction of toxicity, safety and risk assessment of chemicals to achieve better ecotoxicological management and prevent adverse health consequences.

  11. Mammalian models of chemically induced primary malignancies exploitable for imaging-based preclinical theragnostic research

    OpenAIRE

    Liu, Yewei; YIN Ting; Feng, Yuanbo; Cona, Marlein Miranda; Huang, Gang; Liu, Jianjun; Song, Shaoli; Jiang, Yansheng; Xia, Qian; Swinnen, Johannes V; Bormans, Guy; Himmelreich, Uwe; Oyen, Raymond; Ni, Yicheng

    2015-01-01

    Compared with transplanted tumor models or genetically engineered cancer models, chemically induced primary malignancies in experimental animals can mimic the clinical cancer progress from the early stage on. Cancer caused by chemical carcinogens generally develops through three phases namely initiation, promotion and progression. Based on different mechanisms, chemical carcinogens can be divided into genotoxic and non-genotoxic ones, or complete and incomplete ones, usually with an organ-spe...

  12. Modelling the spectro-photometric and chemical evolution of Low Surface Brightness spiral galaxies

    OpenAIRE

    Hoek, L. B. van den; de Blok, W J G

    1995-01-01

    We investigate the star formation history and chemical evolution of Low Surface Brightness (LSB) spiral galaxies by means of their observed spectro-photometric and chemical properties. We present preliminary results for Johnson-Cousins UBVRI magnitudes and stellar [O/H] abundance ratios using a galactic chemical evolution model incorporating a detailed metallicity dependent set of stellar input data covering all relevant stages of stellar evolution. Comparison of our model results with observ...

  13. Tagged ozone mechanism for MOZART-4, CAM-chem and other chemical transport models

    OpenAIRE

    L. K. Emmons; Hess, P. G.; Lamarque, J. -F.; G. G. Pfister

    2012-01-01

    A procedure for tagging ozone produced from NO sources through updates to an existing chemical mechanism is described, and results from its implementation in the Model for Ozone and Related chemical Tracers (MOZART-4), a global chemical transport model, are presented. Artificial tracers are added to the mechanism, thus, not affecting the standard chemistry. The results are linear in the troposphere, i.e., the sum of ozone from individual tagged sources equals the ...

  14. A new model for health care delivery

    Directory of Open Access Journals (Sweden)

    Kepros John P

    2009-04-01

    Full Text Available Abstract Background The health care delivery system in the United States is facing cost and quality pressures that will require fundamental changes to remain viable. The optimal structures of the relationships between the hospital, medical school, and physicians have not been determined but are likely to have a large impact on the future of healthcare delivery. Because it is generally agreed that academic medical centers will play a role in the sustainability of this future system, a fundamental understanding of the relative contributions of the stakeholders is important as well as creativity in developing novel strategies to achieve a shared vision. Discussion Core competencies of each of the stakeholders (the hospital, the medical school and the physicians must complement the others and should act synergistically. At the same time, the stakeholders should determine the common core values and should be able to make a meaningful contribution to the delivery of health care. Summary Health care needs to achieve higher quality and lower cost. Therefore, in order for physicians, medical schools, and hospitals to serve the needs of society in a gratifying way, there will need to be change. There needs to be more scientific and social advances. It is obvious that there is a real and urgent need for relationship building among the professionals whose duty it is to provide these services.

  15. The Culture-Work-Health Model and Work Stress.

    Science.gov (United States)

    Peterson, Michael; Wilson, John F.

    2002-01-01

    Examines the role of organizational culture in the etiology of workplace stress through the framework of the Culture-Work- Health model. A review of relevant business and health literature indicates that culture is an important component of work stress and may be a key to creating effective organizational stress interventions. (SM)

  16. Six challenges in modelling for public health policy

    Directory of Open Access Journals (Sweden)

    C.J.E. Metcalf

    2015-03-01

    Full Text Available The World Health Organisation's definition of public health refers to all organized measures to prevent disease, promote health, and prolong life among the population as a whole (World Health Organization, 2014. Mathematical modelling plays an increasingly important role in helping to guide the most high impact and cost-effective means of achieving these goals. Public health programmes are usually implemented over a long period of time with broad benefits to many in the community. Clinical trials are seldom large enough to capture these effects. Observational data may be used to evaluate a programme after it is underway, but have limited value in helping to predict the future impact of a proposed policy. Furthermore, public health practitioners are often required to respond to new threats, for which there is little or no previous data on which to assess the threat. Computational and mathematical models can help to assess potential threats and impacts early in the process, and later aid in interpreting data from complex and multifactorial systems. As such, these models can be critical tools in guiding public health action. However, there are a number of challenges in achieving a successful interface between modelling and public health. Here, we discuss some of these challenges.

  17. A multimedia fate and chemical transport modeling system for pesticides: I. Model development and implementation

    Science.gov (United States)

    Li, Rong; Scholtz, M. Trevor; Yang, Fuquan; Sloan, James J.

    2011-07-01

    We have combined the US EPA MM5/MCIP/SMOKE/CMAQ modeling system with a dynamic soil model, the pesticide emission model (PEM), to create a multimedia chemical transport model capable of describing the important physical and chemical processes involving pesticides in the soil, in the atmosphere, and on the surface of vegetation. These processes include: agricultural practices (e.g. soil tilling and pesticide application mode); advection and diffusion of pesticides, moisture, and heat in the soil; partitioning of pesticides between soil organic carbon and interstitial water and air; emissions from the soil to the atmosphere; gas-particle partitioning and transport in the atmosphere; and atmospheric chemistry and dry and wet deposition of pesticides to terrestrial and water surfaces. The modeling system was tested by simulating toxaphene in a domain that covers most of North America for the period from 1 January 2000 to 31 December 2000. The results show obvious transport of the pesticide from the heavily contaminated soils in the southern United States and Mexico to water bodies including the Atlantic Ocean, the Gulf of Mexico and the Great Lakes, leading to significant dry and wet deposition into these ecosystems. The spatial distributions of dry and wet depositions differ because of their different physical mechanisms; the former follows the distribution of air concentrations whereas the latter is more biased to the North East due to the effect of precipitation.

  18. Semi-gas kinetics model for performance modeling of flowing chemical oxygen-iodine lasers (COIL)

    Institute of Scientific and Technical Information of China (English)

    GAO Zhi; HU Limin; SHEN Yiqing

    2004-01-01

    A semi-gas kinetics (SGK) model for performance analyses of flowing chemical oxygen-iodine laser (COIL) is presented. In this model, the oxygen-iodine reaction gas flow is treated as a continuous medium, and the effect of thermal motions of particles of different laser energy levels on the performances of the COIL is included and the velocity distribution function equations are solved by using the double-parameter perturbational method. For a premixed flow, effects of different chemical reaction systems, different gain saturation models and temperature, pressure, yield of excited oxygen, iodine concentration and frequency-shift on the performances of the COIL are computed, and the calculated output power agrees well with the experimental data. The results indicate that the power extraction of the SGK model considering 21 reactions is close to those when only the reversible pumping reaction is considered, while different gain saturation models and adjustable parameters greatly affect the output power, the optimal threshold gain range, and the length of power extraction.

  19. Use of the Chemical Transformation Simulator as a Parameterization Tool for Modeling the Environmental Fate of Organic Chemicals and their Transformation Products

    Science.gov (United States)

    A Chemical Transformation Simulator is a web-based system for predicting transformation pathways and physicochemical properties of organic chemicals. Role in Environmental Modeling • Screening tool for identifying likely transformation products in the environment • Parameteri...

  20. CONSISTENT USE OF THE KALMAN FILTER IN CHEMICAL TRANSPORT MODELS (CTMS) FOR DEDUCING EMISSIONS

    Science.gov (United States)

    Past research has shown that emissions can be deduced using observed concentrations of a chemical, a Chemical Transport Model (CTM), and the Kalman filter in an inverse modeling application. An expression was derived for the relationship between the "observable" (i.e., the con...

  1. Mathematical Modeling of Tin-Free Chemically-Active Antifouling Paint Behavior

    DEFF Research Database (Denmark)

    Yebra, Diego Meseguer; Kiil, Søren; Dam-Johansen, Kim;

    2006-01-01

    Mathematical modeling has been used to characterize and validate the working mechanisms of tin-free, chemically-active antifouling (AF) paints. The model-based analysis of performance data from lab-scale rotary experiments has shown significant differences between antifouling technologies as rega...... of Chemical Engineers....

  2. The Kimball Free-Cloud Model: A Failed Innovation in Chemical Education?

    Science.gov (United States)

    Jensen, William B.

    2014-01-01

    This historical review traces the origins of the Kimball free-cloud model of the chemical bond, otherwise known as the charge-cloud or tangent-sphere model, and the central role it played in attempts to reform the introductory chemical curriculum at both the high school and college levels in the 1960s. It also critically evaluates the limitations…

  3. A standard telemental health evaluation model: the time is now.

    Science.gov (United States)

    Kramer, Greg M; Shore, Jay H; Mishkind, Matt C; Friedl, Karl E; Poropatich, Ronald K; Gahm, Gregory A

    2012-05-01

    The telehealth field has advanced historic promises to improve access, cost, and quality of care. However, the extent to which it is delivering on its promises is unclear as the scientific evidence needed to justify success is still emerging. Many have identified the need to advance the scientific knowledge base to better quantify success. One method for advancing that knowledge base is a standard telemental health evaluation model. Telemental health is defined here as the provision of mental health services using live, interactive video-teleconferencing technology. Evaluation in the telemental health field largely consists of descriptive and small pilot studies, is often defined by the individual goals of the specific programs, and is typically focused on only one outcome. The field should adopt new evaluation methods that consider the co-adaptive interaction between users (patients and providers), healthcare costs and savings, and the rapid evolution in communication technologies. Acceptance of a standard evaluation model will improve perceptions of telemental health as an established field, promote development of a sounder empirical base, promote interagency collaboration, and provide a framework for more multidisciplinary research that integrates measuring the impact of the technology and the overall healthcare aspect. We suggest that consideration of a standard model is timely given where telemental health is at in terms of its stage of scientific progress. We will broadly recommend some elements of what such a standard evaluation model might include for telemental health and suggest a way forward for adopting such a model.

  4. The method of modelling of relationships between hardenability and chemical composition of the constructional alloy steels

    International Nuclear Information System (INIS)

    Basing on the experimental results of the hardenability investigations, which employed Jominy method, the model of the neural networks was developed and fully verified experimentally. The model makes it possible to obtain Jominy hardenability curves basing on the steel chemical composition. The model of neural networks, making it possible to design the steel chemical composition, basing on the known Jominy hardenability curve shape, was developed also and fully verified numerically. The practical usability of the models developed is presented. (author)

  5. Application and Modification of the Integrative Model for Environmental Health

    OpenAIRE

    Polivka, Barbara J.; Chaudry, Rosemary; Mac Crawford, J.; Wilson, Robyn; Galos, Dylan

    2012-01-01

    The Integrative Model for Environmental Health (IMEH) has guided research, literature reviews, and practice initiatives since 2002. This paper presents the Modified IMEH that was developed based on using the IMEH as a guiding conceptual framework in a community-based participatory research environmental health project. Concepts from the Model of Risk Information Seeking and Processing as well as emergent themes from the data analysis were instrumental in this process. The Modified IMEH alters...

  6. A new challenge: Model of positive health and clinical psychology

    OpenAIRE

    Miloseva, Lence; Milosev, Vladimir

    2009-01-01

    The main aim of this paper is to present a new model and approach in Health and Clinical practice – Applied Positive Psychology. Through discussion about the roots of Positive Psychology and interest in what is good about humans and their lives and in optimal human functioning we will try to introduce a new model of Positive Health and Clinical Psychology. From Aristotle’s treatises on eudemonia, through Aquinas’ writings about virtue during the Renaissance, to the inquires of modern psycholo...

  7. A PDF closure model for compressible turbulent chemically reacting flows

    Science.gov (United States)

    Kollmann, W.

    1992-01-01

    The objective of the proposed research project was the analysis of single point closures based on probability density function (pdf) and characteristic functions and the development of a prediction method for the joint velocity-scalar pdf in turbulent reacting flows. Turbulent flows of boundary layer type and stagnation point flows with and without chemical reactions were be calculated as principal applications. Pdf methods for compressible reacting flows were developed and tested in comparison with available experimental data. The research work carried in this project was concentrated on the closure of pdf equations for incompressible and compressible turbulent flows with and without chemical reactions.

  8. Some Sensitivity Studies of Chemical Transport Simulated in Models of the Soil-Plant-Litter System

    Energy Technology Data Exchange (ETDEWEB)

    Begovich, C.L.

    2002-10-28

    Fifteen parameters in a set of five coupled models describing carbon, water, and chemical dynamics in the soil-plant-litter system were varied in a sensitivity analysis of model response. Results are presented for chemical distribution in the components of soil, plants, and litter along with selected responses of biomass, internal chemical transport (xylem and phloem pathways), and chemical uptake. Response and sensitivity coefficients are presented for up to 102 model outputs in an appendix. Two soil properties (chemical distribution coefficient and chemical solubility) and three plant properties (leaf chemical permeability, cuticle thickness, and root chemical conductivity) had the greatest influence on chemical transport in the soil-plant-litter system under the conditions examined. Pollutant gas uptake (SO{sub 2}) increased with change in plant properties that increased plant growth. Heavy metal dynamics in litter responded to plant properties (phloem resistance, respiration characteristics) which induced changes in the chemical cycling to the litter system. Some of the SO{sub 2} and heavy metal responses were not expected but became apparent through the modeling analysis.

  9. Sustaining librarian vitality: embedded librarianship model for health sciences libraries.

    Science.gov (United States)

    Wu, Lin; Mi, Misa

    2013-01-01

    With biomedical information widely accessible from anywhere at any time, health sciences libraries have become less centralized, and they are challenged to stay relevant and vital to the mission and strategic goals of their home institution. One solution is to embed librarians at strategic points in health professions' education, research, and patient care. This article discusses a proposed five-level model of embedded librarianship within the context of health sciences libraries and describes different roles, knowledge, and skills desirable for health sciences librarians working as embedded librarians.

  10. Sustaining librarian vitality: embedded librarianship model for health sciences libraries.

    Science.gov (United States)

    Wu, Lin; Mi, Misa

    2013-01-01

    With biomedical information widely accessible from anywhere at any time, health sciences libraries have become less centralized, and they are challenged to stay relevant and vital to the mission and strategic goals of their home institution. One solution is to embed librarians at strategic points in health professions' education, research, and patient care. This article discusses a proposed five-level model of embedded librarianship within the context of health sciences libraries and describes different roles, knowledge, and skills desirable for health sciences librarians working as embedded librarians. PMID:23869633

  11. Quantum origins of the Iczkowski-Margrave model of chemical potential

    Energy Technology Data Exchange (ETDEWEB)

    Valone, Steven M [Los Alamos National Laboratory

    2010-01-01

    Charge flow in materials is controlled at the atomistic level through some model of the chemical potential, such as the Iczkowski-Margrave (IM) model. This model is built largely on heuristic arguments. Here a model Hamiltonian is constructed at the atomistic level commensurate with the IM model. Essential properties of the model Hamiltonian are presented, including a possible revision of the charge dependence in the IM model. Transitional properties of the model are shown to be central to regulating charge flow.

  12. Probabilistic Health Risk Assessment of Chemical Mixtures: Importance of Travel Times and Connectivity

    Science.gov (United States)

    Henri, Christopher V.; Fernàndez-Garcia, Daniel; de Barros, Felipe P. J.

    2014-05-01

    Subsurface contamination cases giving rise to groundwater pollutions are extensively found in all industrialized countries. Under this pressure, risk assessment methods play an important role in population protection by (1) quantifying the potential impact on human health of an aquifer contamination and (2) helping and driving decisions of groundwater-resource managers. Many reactive components such as chlorinated solvents or nitrates potentially experience attenuation processes under common geochemical conditions. This represents an attractive and extensively used remediation solution but leads often to the production of by-products before to reach a harmless chemical form. This renders mixtures of contaminants a common issue for groundwater resources managers. In this case, the threat posed by these contaminants to human health at a given sensitive location greatly depends on the competition between reactive and advective-dispersive characteristic times. However, hydraulic properties of the aquifer are known to be spatially variable, which can lead to the formation of preferential flow channels and fast contamination pathways. Therefore, the uncertainty on the spatial distribution of the aquifer properties controlling the plume travel time may then play a particular role in the human health risk assessment of chemical mixtures. We investigate here the risk related to a multispecies system in response to different degrees of heterogeneity of the hydraulic conductivity (K or Y =ln(K)). This work focuses on a Perchloroethylene (PCE) contamination problem followed by the sequential first-order production/biodegradation of its daughter species Trichloroethylene (TCE), Dichloroethylene (DCE) and Vinyl Chlorine (VC). For this specific case, VC is known to be a highly toxic contaminant. By performing numerical experiments, we evaluate transport through three-dimensional mildly (σY 2=1.0) and highly (σY 2=4.0) heterogeneous aquifers. Uncertainty on the hydraulic

  13. An analysis of comprehensive health promotion programs' consistency with the systems model of health.

    Science.gov (United States)

    Meek, J

    1993-01-01

    Purpose. The purpose of this article is to report a review and analysis of the concordance between current comprehensive corporate health promotion programs as described in the published literature and the systems model of health and to explore emerging trends in the field of health promotion. Search Methods. MEDLINE, BIOSIS, and PsycINFO searches were conducted from 1985 to 1991, and the bibliographies of articles thus obtained were back searched for additional descriptions of corporate health promotion programs. Inclusive criteria included "comprehensive" corporate programs, published in peer-reviewed journals or books, and descriptions adequate enough to permit coding in the majority of analysis matrix categories. Out of 63 identified programs, 16 met the inclusion criteria; 47 were excluded. A common reason for rejection was the limitation imposed by inadequate program descriptions in the published literature. Major Findings. On average, the comprehensive corporate programs reviewed were initiated between 1984 and 1987 and set in the context of a manufacturing firm with over 10,000 employees. A minority of programs (12.5%) consistently satisfied systems model criteria. The most common category of programs were those which were inconsistent (44%), meeting some of the criteria of a systems model of health promotion, but not all. The mechanistic medical and public health models predominated strongly (63%) with the preeminent goal being individual risk factor modification. Conclusions. The limitations of the published literature do not permit strong conclusions about the number or degree to which current corporate comprehensive programs are concordant with the systems model of health. Although mechanistic models of health predominated, there is evidence that a number of comprehensive programs were inconsistent with the mechanistic model, meeting some of the criteria, but also meeting some systems model criteria. To continue the advancement of health promotion with

  14. A generalized measurement model to quantify health: the multi-attribute preference response model.

    Directory of Open Access Journals (Sweden)

    Paul F M Krabbe

    Full Text Available After 40 years of deriving metric values for health status or health-related quality of life, the effective quantification of subjective health outcomes is still a challenge. Here, two of the best measurement tools, the discrete choice and the Rasch model, are combined to create a new model for deriving health values. First, existing techniques to value health states are briefly discussed followed by a reflection on the recent revival of interest in patients' experience with regard to their possible role in health measurement. Subsequently, three basic principles for valid health measurement are reviewed, namely unidimensionality, interval level, and invariance. In the main section, the basic operation of measurement is then discussed in the framework of probabilistic discrete choice analysis (random utility model and the psychometric Rasch model. It is then shown how combining the main features of these two models yields an integrated measurement model, called the multi-attribute preference response (MAPR model, which is introduced here. This new model transforms subjective individual rank data into a metric scale using responses from patients who have experienced certain health states. Its measurement mechanism largely prevents biases such as adaptation and coping. Several extensions of the MAPR model are presented. The MAPR model can be applied to a wide range of research problems. If extended with the self-selection of relevant health domains for the individual patient, this model will be more valid than existing valuation techniques.

  15. Rethinking schools of public health: a strategic alliance model.

    Science.gov (United States)

    Moloughney, Brent W; Skinner, Harvey A

    2006-01-01

    Canada is in the midst of rejuvenation of public health organizations, mandates and infrastructure. Major planning exercises are underway regarding public health human resources, where academic institutions have a key role to play. To what extent could schools of public health be part of the solution? Many universities across Canada are considering or in the process of implementing MPH programs (some 17 programs planned and/or underway) and possible schools of public health. However, concerns are raised about critical mass, quality and standards. We encourage innovation and debate about ways to enhance collaborative and structural arrangements for education programs. A school of public health model might emerge from this, but so too might other models. Also, novel types of organizational structure need consideration. One example is a "strategic alliance" model that is broad-based, integrative and adaptive--building on the interdisciplinary focus needed for addressing public health concerns in the 21st century. From our perspective, the central question is: what (new) types of organizational structures and, equally important, collaborative networks will enable Canada to strengthen its public health workforce so that it may better address local and global challenges to public health? PMID:16827419

  16. A Model for Risk Assessment in Health Care.

    Science.gov (United States)

    Prijatelj, Vesna; Rajkovič, Vladislav; Šušteršič, Olga

    2016-01-01

    The purpose of our research is to reduce risks and hence prevent errors in the health care process. The aim is to design an organizational information model using error prevention methods for risk assessment in a clinical setting. The model is based on selected indicators of quality nursing care, resulting from the world-known theoretical and practical models combined with experience in the Slovenian health care. The proposed organizational information model and software solution has a significant impact on the professional attention, communication and information, critical thinking, experience and knowledge. PMID:27332383

  17. Approximate modeling of chemically reacting gas mixtures of detonation products

    International Nuclear Information System (INIS)

    Based on the assumption of the existence of the partial chemical equilibrium in the detonation products, an approximate method for calculating composition of the detonation products has been developed. The method uses the assumption of the existence of extremum of Helmholtz free energy for a given density, temperature, and molecular weight of the detonation products mixture

  18. Chemical health risk assessment for hazardous and mixed waste management units at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    The Lawrence Livermore National Laboratory (LLNL) operates three Hazardous Waste Management Facilities with 24 associated waste management units for the treatment and storage of hazardous and mixed wastes. These wastes are generated by research programs and support operations. The storage and treatment units are presently operated under interim status in accordance with the requirements of the US Envirorunental Protection Agency (US EPA) and the Department of Toxic Substances Control (DTSC), a division of the California Envirorunental Protection Agency (Cal/EPA). As required by the California Hazardous Waste Control Act and the Resource Conservation and Recovery Act (RCRA), LLNL ha s applied for a Part B permit to continue operating the storage and waste treatment facilities. As part of this permitting process, LLNL is required to conduct a health risk assessment (HRA) to examine the potential health impacts to the surrounding community from continued storage and treatment of hazardous and mixed wastes. analysis document presents the results of this risk assessment. An analysis of maximum credible chemical accidents is also included in Section 7.0. This HRA was prepared in accordance with procedures set forth by the California Air Pollution Control Officers Association (CAPCOA) ''Air Toxics Assessment Manual,'' CAPCOA guidelines for preparing risk assessments under the Air Toxic ''Hot Spots'' Act (AB 2588) and requirements of the US EPA. By following these procedures, this risk assessment presents a conservative analysis of a hypothetical Maximally Exposed Individual (MEI) using many worst-case assumptions that will not apply to an actual individual. As such, the risk estimates presented should be regarded as a worst-case estimate of any actual risk that may be present

  19. A detailed chemical kinetic model for pyrolysis of the lignin model compound chroman

    Directory of Open Access Journals (Sweden)

    James Bland

    2013-12-01

    Full Text Available The pyrolysis of woody biomass, including the lignin component, is emerging as a potential technology for the production of renewable fuels and commodity chemicals. Here we describe the construction and implementation of an elementary chemical kinetic model for pyrolysis of the lignin model compound chroman and its reaction intermediate ortho-quinone methide (o-QM. The model is developed using both experimental and theoretical data, and represents a hybrid approach to kinetic modeling that has the potential to provide molecular level insight into reaction pathways and intermediates while accurately describing reaction rates and product formation. The kinetic model developed here can replicate all known aspects of chroman pyrolysis, and provides new information on elementary reaction steps. Chroman pyrolysis is found to proceed via an initial retro-Diels–Alder reaction to form o-QM + ethene (C2H4, followed by dissociation of o-QM to the C6H6 isomers benzene and fulvene (+ CO. At temperatures of around 1000–1200 K and above fulvene rapidly isomerizes to benzene, where an activation energy of around 270 kJ mol-1 is required to reproduce experimental observations. A new G3SX level energy surface for the isomerization of fulvene to benzene supports this result. Our modeling also suggests that thermal decomposition of fulvene may be important at around 950 K and above. This study demonstrates that theoretical protocols can provide a significant contribution to the development of kinetic models for biomass pyrolysis by elucidating reaction mechanisms, intermediates, and products, and also by supplying realistic rate coefficients and thermochemical properties.

  20. [Tridimensional evaluation model of health promotion in school -- a proposition].

    Science.gov (United States)

    Kulmatycki, Lesław

    2005-01-01

    A good school health programme can be one of the most cost effective investments for simultaneously improving education and health. The general direction of WHO's European Network of Health Promoting Schools and Global Schools Health Initiative is guided by the holistic approach and the Ottawa Charter for Health Promotion (1986). A health promoting school strives to improve the health and well-being of school pupils as well as school personnel, families and community members; and works with community leaders to help them understand how the community contributes to health and education. Evaluation research is essential to describe the nature and effectiveness of school health promoting activity. The overall aim of this paper is to help school leaders and health promotion coordinators to measure their work well and effectively. The specific aim is to offer a practical three-dimensional evaluation model for health promoting schools. The material is presented in two sections. The first one is a 'theoretical base' for health promotion which was identified from broad based daily health promotion practical activities, strategies and intersectional interventions closely related to the philosophy of the holistic approach. The three dimensions refer to: 1. 'areas' -- according to the mandala of health. 2. 'actions' -- according to Ottawa Charter strategies which should be adapted to the local school networks. 3. 'data'-- according to different groups of evidence (process, changes and progress). The second one, as a result of the mentioned base, represents the three 'core elements': standards, criteria and indicators. In conclusion, this article provides a practical answer to the dilemma of the evaluation model in the network of local school environment. This proposition is addressed to school staff and school health promotion providers to make their work as effective as possible to improve pupils health. Health promoting school can be characterized as a school constantly

  1. A Model for Implementing Integrative Practice in Health Care Agencies

    Directory of Open Access Journals (Sweden)

    Chris Patterson

    2008-01-01

    Full Text Available Over the last few years, there has been increased awareness and use of complementary/alternative therapies (CAM in many countries without the health care infrastructure to support it. The National Centre for Complementary and Alternative Medicine referred to the combining of mainstream medical therapies and CAM as integrative medicine. The creation of integrative health care teams will definitely result in redefining roles, but more importantly in a change in how services are delivered. The purpose of this paper is to describe a model of the necessary health care agency resources to support an integrative practice model. A logic model is used to depict the findings of a review of current evidence. Logic models are designed to show relationships between the goals of a program or initiative, the resources to achieve desired outputs and the activities that lead to outcomes. The four major resource categories necessary for implementing integrative care are within the domains of a professional and research development, b health human resource planning, c regulation and legislation and d practice and management in clinical areas. It was concluded that the system outcomes from activities within these resource categories should lead to freedom of choice in health care; a culturally sensitive health care system and a broader spectrum of services for achieving public health goals.

  2. Health assessment for Maywood Chemical Company, Maywood, Bergen County, New Jersey, Region 2. CERCLIS No. NJD980529762. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1990-07-30

    The Health Assessment for the Maywood Chemical Company Site includes the Maywood Interim Storage Site (MISS), the Ballod property, the Scanel site, residential properties, and the Sears warehouse and its adjacent properties, all of which are located in the towns of Maywood and Rochelle Park of Bergen County, New Jersey. These sites are at different investigative or remediation stages under the auspices of both the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Energy (DOE). The EPA is responsible for chemical characterization and cleanup operations, whereas the DOE is primarily in charge of radiologic analysis and remediation. On the basis of the information reviewed, ATSDR and NJDOH have concluded that the Maywood Chemical site is of public health concern because humans have probably been exposed to hazardous substances at concentrations that may result in adverse health effects. As noted in the Environmental Contamination and Physical Hazards section above, human exposure to chemical and radiological contamination is probably occurring and has probably occurred in the past via the use of contaminated groundwater and contact with contaminated soils. Before suspected areas of contamination are developed, both on-site contamination and the potential off-site migration of contaminants need to be fully evaluated. Developing an area, without characterizing potential contamination could lead to an adverse impact on the public health.

  3. A First Exploration of Health Impact Assessment of Chemical Exposure: Assigning Weights to Subclinical Effects Based on Animal Studies

    NARCIS (Netherlands)

    Burg, W. ter; Bokkers, B.G.H.; Kroese, E.D.; Schuur, A.G.

    2015-01-01

    ABSTRACT: Health impact assessments (HIA) have become an important tool for applying evidence-based policy. Recently, the concept of HIA has been introduced in the field of chemical substances. Two main issues are encountered, i.e., the focus of risk assessment is deriving safe levels and on first s

  4. Endocrine-Disrupting Activity of Hydraulic Fracturing Chemicals and Adverse Health Outcomes After Prenatal Exposure in Male Mice.

    Science.gov (United States)

    Kassotis, Christopher D; Klemp, Kara C; Vu, Danh C; Lin, Chung-Ho; Meng, Chun-Xia; Besch-Williford, Cynthia L; Pinatti, Lisa; Zoeller, R Thomas; Drobnis, Erma Z; Balise, Victoria D; Isiguzo, Chiamaka J; Williams, Michelle A; Tillitt, Donald E; Nagel, Susan C

    2015-12-01

    Oil and natural gas operations have been shown to contaminate surface and ground water with endocrine-disrupting chemicals. In the current study, we fill several gaps in our understanding of the potential environmental impacts related to this process. We measured the endocrine-disrupting activities of 24 chemicals used and/or produced by oil and gas operations for five nuclear receptors using a reporter gene assay in human endometrial cancer cells. We also quantified the concentration of 16 of these chemicals in oil and gas wastewater samples. Finally, we assessed reproductive and developmental outcomes in male C57BL/6J mice after the prenatal exposure to a mixture of these chemicals. We found that 23 commonly used oil and natural gas operation chemicals can activate or inhibit the estrogen, androgen, glucocorticoid, progesterone, and/or thyroid receptors, and mixtures of these chemicals can behave synergistically, additively, or antagonistically in vitro. Prenatal exposure to a mixture of 23 oil and gas operation chemicals at 3, 30, and 300 μg/kg · d caused decreased sperm counts and increased testes, body, heart, and thymus weights and increased serum testosterone in male mice, suggesting multiple organ system impacts. Our results suggest possible adverse developmental and reproductive health outcomes in humans and animals exposed to potential environmentally relevant levels of oil and gas operation chemicals. PMID:26465197

  5. Endocrine-Disrupting Activity of Hydraulic Fracturing Chemicals and Adverse Health Outcomes After Prenatal Exposure in Male Mice.

    Science.gov (United States)

    Kassotis, Christopher D; Klemp, Kara C; Vu, Danh C; Lin, Chung-Ho; Meng, Chun-Xia; Besch-Williford, Cynthia L; Pinatti, Lisa; Zoeller, R Thomas; Drobnis, Erma Z; Balise, Victoria D; Isiguzo, Chiamaka J; Williams, Michelle A; Tillitt, Donald E; Nagel, Susan C

    2015-12-01

    Oil and natural gas operations have been shown to contaminate surface and ground water with endocrine-disrupting chemicals. In the current study, we fill several gaps in our understanding of the potential environmental impacts related to this process. We measured the endocrine-disrupting activities of 24 chemicals used and/or produced by oil and gas operations for five nuclear receptors using a reporter gene assay in human endometrial cancer cells. We also quantified the concentration of 16 of these chemicals in oil and gas wastewater samples. Finally, we assessed reproductive and developmental outcomes in male C57BL/6J mice after the prenatal exposure to a mixture of these chemicals. We found that 23 commonly used oil and natural gas operation chemicals can activate or inhibit the estrogen, androgen, glucocorticoid, progesterone, and/or thyroid receptors, and mixtures of these chemicals can behave synergistically, additively, or antagonistically in vitro. Prenatal exposure to a mixture of 23 oil and gas operation chemicals at 3, 30, and 300 μg/kg · d caused decreased sperm counts and increased testes, body, heart, and thymus weights and increased serum testosterone in male mice, suggesting multiple organ system impacts. Our results suggest possible adverse developmental and reproductive health outcomes in humans and animals exposed to potential environmentally relevant levels of oil and gas operation chemicals.

  6. Public health assessment for Greenwood Chemical Company, Greenwood, Albemarle County, Virginia, Region 3. CERCLIS number VAD003125374; Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The Greenwood Chemical Company, a former chemical manufacturing facility, is located in the village of Newton, Albermarle County, Virginia. Numerous volatile and semi-volatile organic compounds, as well as arsenic and cyanide, have been detected in on-site soils, sediments, ground water, and surface water. Although the site is located in a sparsely populated, rural area, access to the site is located in a sparsely populated, rural area, access to the site by nearby residents currently is unrestricted. Potential human exposure pathways include ingestion of contaminants in ground water and soils; dermal absorption of contaminants in ground water and soils; and inhalation of volatile organic compounds in contaminated ground water. The Virginia Department of Health concludes that the Greenwood Chemical Company presents a public health hazard, based on the current information reviewed.

  7. Development of a global 1-D chemically radiatively coupled model and an introduction to the development of a chemically coupled General Circulation Model

    International Nuclear Information System (INIS)

    A global one-dimensional, chemically and radiatively coupled model has been developed. The basic concept of the coupled model, definition of globally averaged zenith angles, the formulation of the model chemistry, radiation, the coupled processes, and profiles and diurnal variations of temperature and chemical species at a normal steady state are presented. Furthermore, a suddenly doubled CO2 experiment and a Pinatubo aerosol increase experiment were performed with the model. The time scales of variations in ozone and temperature in the lower stratosphere of the coupled system in the doubled CO2 experiment was long, due to a feedback process among ultra violet radiation, O(1D), NOy, NOx, and O3. From the Pinatubo aerosol experiment, a delay of maximum ozone decrease from the maximum aerosol loading is shown and discussed. Developments of 3-D chemical models with coupled processes are briefly described, and the ozone distribution from the first version of the 3-D model are presented. Chemical model development in National Institute for Environmental Studies (NIES) are briefly described. (author)

  8. Contemporary models of change in the health professions.

    Science.gov (United States)

    Schneller, E S; Ott, J B

    1996-01-01

    This article reviews the special position that health professionals have occupied and the ways in which changes threaten the foundations of professional work. The application of modern management principles to health care runs the risk of overriding the "action orientation" that is a defining component of professional work. One goal of health workforce design should be the engineering of opportunities for the preservation of "professional voice" as a countervailing force to ensure high quality health care. Contemporary models of change applied to health care workforce include: (1) the system of professions models in which securing and maintaining jurisdiction are the mechanisms that professions employ to sustain their position, (2) a strategic adaptation model by which professions attempt to adjust to changing environments, (3) a model of redesigning patient care which applies Total Quality Management (TQM) and other "industrial techniques" to the health care workplace, and, (4) model of "consumer sovereignty" in which groups of citizens come together to determine the nature of care services and professional work, with the participation of the organizations and providers.

  9. Chemical composition and potential health effects of prunes: a functional food?

    Science.gov (United States)

    Stacewicz-Sapuntzakis, M; Bowen, P E; Hussain, E A; Damayanti-Wood, B I; Farnsworth, N R

    2001-05-01

    Prunes are dried plums, fruits of Prunus domestica L., cultivated and propagated since ancient times. Most dried prunes are produced from cultivar d'Agen, especially in California and France, where the cultivar originated. After harvest, prune-making plums are dehydrated in hot air at 85 to 90 degrees C for 18 h, then further processed into prune juice, puree, or other prune products. This extensive literature review summarizes the current knowledge of chemical composition of prunes and their biological effects on human health. Because of their sweet flavor and well-known mild laxative effect, prunes are considered to be an epitome of functional foods, but the understanding of their mode of action is still unclear. Dried prunes contain approximately 6.1 g of dietary fiber per 100 g, while prune juice is devoid of fiber due to filtration before bottling. The laxative action of both prune and prune juice could be explained by their high sorbitol content (14.7 and 6.1 g/100 g, respectively). Prunes are good source of energy in the form of simple sugars, but do not mediate a rapid rise in blood sugar concentration, possibly because of high fiber, fructose, and sorbitol content. Prunes contain large amounts of phenolic compounds (184 mg/100 g), mainly as neochlorogenic and chlorogenic acids, which may aid in the laxative action and delay glucose absorption. Phenolic compounds in prunes had been found to inhibit human LDL oxidation in vitro, and thus might serve as preventive agents against chronic diseases, such as heart disease and cancer. Additionally, high potassium content of prunes (745 mg/100 g) might be beneficial for cardiovascular health. Dried prunes are an important source of boron, which is postulated to play a role in prevention of osteoporosis. A serving of prunes (100 g) fulfills the daily requirement for boron (2 to 3 mg). More research is needed to assess the levels of carotenoids and other phytochemicals present in prunes to ensure correct labeling and

  10. Bio-antioxidants - a chemical base of their antioxidant activity and beneficial effect on human health.

    Science.gov (United States)

    Kancheva, V D; Kasaikina, O T

    2013-01-01

    The paradox of aerobic life is that higher eukaryotic organisms cannot exist without oxygen, yet oxygen is inherently dangerous to their existence. Autoxidation of organic substances frequently occurs via free radical mechanism which generates different active radicals and peroxides OH(•), O2 (•-), LO2 (•), HOOH, LOOH, so called reactive oxygen species (ROS), which appear to be responsible for oxygen toxicity. To survive in such an unfriendly oxygen environment, living organisms generate - or obtain from food - a variety of water- and lipid-soluble antioxidant compounds. Biologically active compounds with antioxidant potential, i.e. bio-antioxidants (natural and their synthetic analogues) have a wide range of applications. They are important drugs, antibiotics, agrochemical substitutes, and food preservatives. Many of the drugs today are synthetic modifications of naturally obtained substances. This review presents information about the chemical base of antioxidant activities and beneficial effects on human health of known and new bio-antioxidants. There is abundant literature on the phenolic antioxidants and tocopherols in particular. In this review the following bio-antioxidants are considered: A) Carotenoids, B) Cathecholamines, C) Phospholipids, D) Chalcones, E) Coumarins, F) Phenolic acids, G) Flavonoids, H) Lignans, and I) Tannins.

  11. A model for training public health workers in health policy: the Nebraska Health Policy Academy.

    Science.gov (United States)

    Brandert, Kathleen; McCarthy, Claudine; Grimm, Brandon; Svoboda, Colleen; Palm, David; Stimpson, Jim P

    2014-01-01

    There is growing recognition that health goals are more likely to be achieved and sustained if programs are complemented by appropriate changes in the policies, systems, and environments that shape their communities. However, the knowledge, skills, and abilities needed to create and implement policy are among the major needs identified by practitioners at both the state and local levels. This article describes the structure and content of the Nebraska Health Policy Academy (the Academy), a 9-month program developed to meet the demand for this training. The Academy is a competency-based training program that aims to increase the capacity of Nebraska's state and local public health staff and their community partners to use public health policy and law as a public health tool. Our initiative allows for participation across a large, sparsely populated state; is grounded in adult learning theory; introduces the key principles and practices of policy, systems, and environmental change; and is offered free of charge to the state's public health workforce. Challenges and lessons learned when offering workforce development on public health policy efforts are discussed. PMID:24831286

  12. Social class: concepts and operationalization models in health research.

    Science.gov (United States)

    Barata, Rita Barradas; Ribeiro, Manoel Carlos Sampaio de Almeida; Silva, Zilda Pereira da; Antunes, José Leopoldo Ferreira

    2013-08-01

    This article discusses the use of the concept of class in health research, different sociological approaches to social stratification and class structure, and the explanatory potential of the class concept in studies on social determinants and health inequalities. It also elaborates on the operationalization models that have been developed for use in sociological, demographic, or health research, as well as the limitations and scope of these models. Four main operationalization models were highlighted: the model developed by Singer for studies on income distribution in Brazil and adapted by Barros for use in epidemiological research, the model of Bronfman and Tuirán to study the Mexican demographics census and adapted by Lombardi for epidemiological research, the model proposed by Goldthorpe for socioeconomic studies in the UK and adapted by the Spanish Society of Epidemiology, and the model proposed by Wright for research in sociology and political science, which has also been used in population surveys in health. In conclusion, each of the models presented is consistent with their underlying theoretical concept, precluding the selection of one model over the others. PMID:24346674

  13. Population health improvement: a community health business model that engages partners in all sectors.

    Science.gov (United States)

    Kindig, David A; Isham, George

    2014-01-01

    Because population health improvement requires action on multiple determinants--including medical care, health behaviors, and the social and physical environments--no single entity can be held accountable for achieving improved outcomes. Medical organizations, government, schools, businesses, and community organizations all need to make substantial changes in how they approach health and how they allocate resources. To this end, we suggest the development of multisectoral community health business partnership models. Such collaborative efforts are needed by sectors and actors not accustomed to working together. Healthcare executives can play important leadership roles in fostering or supporting such partnerships in local and national arenas where they have influence. In this article, we develop the following components of this argument: defining a community health business model; defining population health and the Triple Aim concept; reaching beyond core mission to help create the model; discussing the shift for care delivery beyond healthcare organizations to other community sectors; examining who should lead in developing the community business model; discussing where the resources for a community business model might come from; identifying that better evidence is needed to inform where to make cost-effective investments; and proposing some next steps. The approach we have outlined is a departure from much current policy and management practice. But new models are needed as a road map to drive action--not just thinking--to address the enormous challenge of improving population health. While we applaud continuing calls to improve health and reduce disparities, progress will require more robust incentives, strategies, and action than have been in practice to date. Our hope is that ideas presented here will help to catalyze a collective, multisectoral response to this critical social and economic challenge.

  14. MODELING DISPERSION FROM CHEMICALS RELEASED AFTER A TRAIN COLLISION IN GRANITEVILLE, SOUTH CAROLINA

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, R; Chuck Hunter, C; Robert Addis, R; Matt Parker, M

    2006-08-07

    The Savannah River National Laboratory's (SRNL) Weather INformation and Display (WIND) System was used to provide meteorological and atmospheric modeling/consequence assessment support to state and local agencies following the collision of two Norfolk Southern freight trains on the morning of January 6, 2005. This collision resulted in the release of several toxic chemicals to the environment, including chlorine. The dense and highly toxic cloud of chlorine gas that formed in the vicinity of the accident was responsible for nine fatalities, and caused injuries to more than five hundred others. Transport model results depicting the forecast path of the ongoing release were made available to emergency managers in the county's Unified Command Center shortly after SRNL received a request for assistance. Support continued over the ensuing two days of the active response. The SRNL also provided weather briefings and transport/consequence assessment model results to responders from South Carolina Department of Health and Environmental Control (SCDHEC), the Savannah River Site's (SRS) Emergency Operations Center (EOC), Department of Energy Headquarters, and hazmat teams dispatched from the SRS. Although model-generated forecast winds used in consequence assessments conducted during the incident were provided at 2-km horizontal grid spacing during the accident response, a high-resolution Regional Atmospheric Modeling System (RAMS, version 4.3.0) simulation was later performed to examine potential influences of local topography on plume migration. The detailed RAMS simulation was used to determine meteorology using multiple grids with an innermost grid spacing of 125 meters. Results from the two simulations are shown to generally agree with meteorological observations at the time; consequently, local topography did not significantly affect wind in the area. Use of a dense gas dispersion model to simulate localized plume behavior using the higher resolution

  15. Nutritional models for space travel from chemically defined diets

    Science.gov (United States)

    Dufour, P. A.

    1984-01-01

    Human nutritional requirements are summarized, including recommended daily intake and maximum safe chronic intake of nutrients. The biomedical literature on various types of chemically defined diets (CDD's), which are liquid, formulated diets for enteral and total parenteral nutrition, is reviewed. The chemical forms of the nutrients in CDD's are detailed, and the compositions and sources of representative commercial CDD's are tabulated. Reported effects of CDD's in medical patients, healthy volunteers, and laboratory animals are discussed. The effects include gastrointestinal side effects, metabolic imbalances, nutrient deficiencies and excesses, and psychological problems. Dietary factors contributing to the side effects are examined. Certain human nutrient requirements have been specified more precisely as a result of long-term use of CDD's, and related studies are included. CDD's are the most restricted yet nutritionally complete diets available.

  16. Developing a Semi-Quantitative Occupational Risk Prediction Model for Chemical Exposures and Its Application to a National Chemical Exposure Databank

    Directory of Open Access Journals (Sweden)

    Chiu-Ying Chen

    2013-07-01

    Full Text Available In this study, a semi-quantitative occupational chemical exposure risk prediction model, based on the calculation of exposure hazard indexes, was proposed, corrected, and applied to a national chemical exposure databank. The model comprises one factor used to describe toxicity (i.e., the toxicity index, and two factors used to reflect the exposure potential (i.e., the exposure index and protection deficiency index of workers exposed to chemicals. An expert system was used to correct the above proposed model. By applying the corrected model to data obtained from a national occupational chemical hazard survey program, chemical exposure risks of various manufacturing industries were determined and a national control strategy for the abatement of occupational chemical exposures was proposed. The results of the present study would provide useful information for governmental agencies to allocate their limited resources effectively for reducing chemical exposures of workers.

  17. Extending Social Cognition Models of Health Behaviour

    Science.gov (United States)

    Abraham, Charles; Sheeran, Paschal; Henderson, Marion

    2011-01-01

    A cross-sectional study assessed the extent to which indices of social structure, including family socio-economic status (SES), social deprivation, gender and educational/lifestyle aspirations correlated with adolescent condom use and added to the predictive utility of a theory of planned behaviour model. Analyses of survey data from 824 sexually…

  18. Approaches to advancing quantitative human health risk assessment of environmental chemicals in the post-genomic era

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, Weihsueh A., E-mail: chiu.weihsueh@epa.gov [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington DC, 20460 (United States); Euling, Susan Y.; Scott, Cheryl Siegel; Subramaniam, Ravi P. [National Center for Environmental Assessment, U.S. Environmental Protection Agency, Washington DC, 20460 (United States)

    2013-09-15

    The contribution of genomics and associated technologies to human health risk assessment for environmental chemicals has focused largely on elucidating mechanisms of toxicity, as discussed in other articles in this issue. However, there is interest in moving beyond hazard characterization to making more direct impacts on quantitative risk assessment (QRA) — i.e., the determination of toxicity values for setting exposure standards and cleanup values. We propose that the evolution of QRA of environmental chemicals in the post-genomic era will involve three, somewhat overlapping phases in which different types of approaches begin to mature. The initial focus (in Phase I) has been and continues to be on “augmentation” of weight of evidence — using genomic and related technologies qualitatively to increase the confidence in and scientific basis of the results of QRA. Efforts aimed towards “integration” of these data with traditional animal-based approaches, in particular quantitative predictors, or surrogates, for the in vivo toxicity data to which they have been anchored are just beginning to be explored now (in Phase II). In parallel, there is a recognized need for “expansion” of the use of established biomarkers of susceptibility or risk of human diseases and disorders for QRA, particularly for addressing the issues of cumulative assessment and population risk. Ultimately (in Phase III), substantial further advances could be realized by the development of novel molecular and pathway-based biomarkers and statistical and in silico models that build on anticipated progress in understanding the pathways of human diseases and disorders. Such efforts would facilitate a gradual “reorientation” of QRA towards approaches that more directly link environmental exposures to human outcomes.

  19. Business Models for Successfully Maintaining Games for Health.

    Science.gov (United States)

    Baranowski, Moderator Tom; Isaac, Participants Fikry; Ashford, Chris; Goldman, Ron; Lenihan, David J; Poole, Brent; Buday, Richard; van Rijswijk, Jurriaan

    2013-04-01

    Videogames for health provide innovative, exciting, and possibly highly effective new media for helping players change their behaviors or otherwise benefit their health. Getting the right videogames into the hands of players who can benefit most in a way that pays for the continued innovation and creation of such games is a current challenge. Entertainment videogame companies, which create games primarily to enhance players' enjoyment, have used the general business marketplace (e.g., online stores, walk-in stores, app stores) to deliver their products directly to consumers and earn enough capital to invest in making new products. No one believes, however, that enough kids or adults would use the general business marketplace to purchase games for health in sufficient volume to provide the down payment for the innovation and creation of new games for health. A successful business model is critical to the financial future of games for health. We asked members of our Editorial Board who are in health-related companies (Fikry Isaac, MD, MPH), in several game development companies (Chris Ashford, Ron Goldman, David J. Lenihan, Brent Poole, and Richard Buday, FAIA), and the head of the Games for Health Europe Foundation (Jurriaan van Rijswijk, MSc) to address questions in a roundtable about the current and possible future business models for games for health. PMID:26192123

  20. Business Models for Successfully Maintaining Games for Health.

    Science.gov (United States)

    Baranowski, Moderator Tom; Isaac, Participants Fikry; Ashford, Chris; Goldman, Ron; Lenihan, David J; Poole, Brent; Buday, Richard; van Rijswijk, Jurriaan

    2013-04-01

    Videogames for health provide innovative, exciting, and possibly highly effective new media for helping players change their behaviors or otherwise benefit their health. Getting the right videogames into the hands of players who can benefit most in a way that pays for the continued innovation and creation of such games is a current challenge. Entertainment videogame companies, which create games primarily to enhance players' enjoyment, have used the general business marketplace (e.g., online stores, walk-in stores, app stores) to deliver their products directly to consumers and earn enough capital to invest in making new products. No one believes, however, that enough kids or adults would use the general business marketplace to purchase games for health in sufficient volume to provide the down payment for the innovation and creation of new games for health. A successful business model is critical to the financial future of games for health. We asked members of our Editorial Board who are in health-related companies (Fikry Isaac, MD, MPH), in several game development companies (Chris Ashford, Ron Goldman, David J. Lenihan, Brent Poole, and Richard Buday, FAIA), and the head of the Games for Health Europe Foundation (Jurriaan van Rijswijk, MSc) to address questions in a roundtable about the current and possible future business models for games for health.

  1. Exploring the Use of Multiple Analogical Models when Teaching and Learning Chemical Equilibrium

    Science.gov (United States)

    Harrison, Allan G.; De Jong, Onno

    2005-01-01

    This study describes the multiple analogical models used to introduce and teach Grade 12 chemical equilibrium. We examine the teacher's reasons for using models, explain each model's development during the lessons, and analyze the understandings students derived from the models. A case study approach was used and the data were drawn from the…

  2. River Health Assessment Based on Fuzzy Matter-element Model

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The study aimed to assess the health state of rivers by using fuzzy matter-element model.[Method] Based on fuzzy matter-element analysis theory,the assessment model of river health was established,then a modified method to calculate the superior subordinate degree was put forward according to Hamming distance.Afterwards,a multi-level evaluation model,which contained the assessment indicators about hydrological features,ecological characteristics,environmental traits and service function,was set ...

  3. Grouping chemicals for health risk assessment: A text mining-based case study of polychlorinated biphenyls (PCBs).

    Science.gov (United States)

    Ali, Imran; Guo, Yufan; Silins, Ilona; Högberg, Johan; Stenius, Ulla; Korhonen, Anna

    2016-01-22

    As many chemicals act as carcinogens, chemical health risk assessment is critically important. A notoriously time consuming process, risk assessment could be greatly supported by classifying chemicals with similar toxicological profiles so that they can be assessed in groups rather than individually. We have previously developed a text mining (TM)-based tool that can automatically identify the mode of action (MOA) of a carcinogen based on the scientific evidence in literature, and it can measure the MOA similarity between chemicals on the basis of their literature profiles (Korhonen et al., 2009, 2012). A new version of the tool (2.0) was recently released and here we apply this tool for the first time to investigate and identify meaningful groups of chemicals for risk assessment. We used published literature on polychlorinated biphenyls (PCBs)-persistent, widely spread toxic organic compounds comprising of 209 different congeners. Although chemically similar, these compounds are heterogeneous in terms of MOA. We show that our TM tool, when applied to 1648 PubMed abstracts, produces a MOA profile for a subgroup of dioxin-like PCBs (DL-PCBs) which differs clearly from that for the rest of PCBs. This suggests that the tool could be used to effectively identify homogenous groups of chemicals and, when integrated in real-life risk assessment, could help and significantly improve the efficiency of the process.

  4. Grouping chemicals for health risk assessment: A text mining-based case study of polychlorinated biphenyls (PCBs).

    Science.gov (United States)

    Ali, Imran; Guo, Yufan; Silins, Ilona; Högberg, Johan; Stenius, Ulla; Korhonen, Anna

    2016-01-22

    As many chemicals act as carcinogens, chemical health risk assessment is critically important. A notoriously time consuming process, risk assessment could be greatly supported by classifying chemicals with similar toxicological profiles so that they can be assessed in groups rather than individually. We have previously developed a text mining (TM)-based tool that can automatically identify the mode of action (MOA) of a carcinogen based on the scientific evidence in literature, and it can measure the MOA similarity between chemicals on the basis of their literature profiles (Korhonen et al., 2009, 2012). A new version of the tool (2.0) was recently released and here we apply this tool for the first time to investigate and identify meaningful groups of chemicals for risk assessment. We used published literature on polychlorinated biphenyls (PCBs)-persistent, widely spread toxic organic compounds comprising of 209 different congeners. Although chemically similar, these compounds are heterogeneous in terms of MOA. We show that our TM tool, when applied to 1648 PubMed abstracts, produces a MOA profile for a subgroup of dioxin-like PCBs (DL-PCBs) which differs clearly from that for the rest of PCBs. This suggests that the tool could be used to effectively identify homogenous groups of chemicals and, when integrated in real-life risk assessment, could help and significantly improve the efficiency of the process. PMID:26562772

  5. Effect of health belief model and health promotion model on breast cancer early diagnosis behavior: a systematic review.

    Science.gov (United States)

    Ersin, Fatma; Bahar, Zuhal

    2011-01-01

    Breast cancer is an important public health problem on the grounds that it is frequently seen and it is a fatal disease. The objective of this systematic analysis is to indicate the effects of interventions performed by nurses by using the Health Belief Model (HBM) and Health Promotion Model (HPM) on the breast cancer early diagnosis behaviors and on the components of the Health Belief Model and Health Promotion Model. The reveiw was created in line with the Centre for Reviews and Dissemination guide dated 2009 (CRD) and developed by York University National Institute of Health Researches. Review was conducted by using PUBMED, OVID, EBSCO and COCHRANE databases. Six hundred seventy eight studies (PUBMED: 236, OVID: 162, EBSCO: 175, COCHRANE:105) were found in total at the end of the review. Abstracts and full texts of these six hundred seventy eight studies were evaluated in terms of inclusion and exclusion criteria and 9 studies were determined to meet the criteria. Samplings of the studies varied between ninety four and one thousand six hundred fifty five. It was detected in the studies that educations provided by taking the theories as basis became effective on the breast cancer early diagnosis behaviors. When the literature is examined, it is observed that the experimental researches which compare the concepts of Health Belief Model (HBM) and Health Promotion Model (HPM) preoperatively and postoperatively and show the effect of these concepts on education and are conducted by nurses are limited in number. Randomized controlled studies which compare HBM and HPM concepts preoperatively and postoperatively and show the efficiency of the interventions can be useful in evaluating the efficiency of the interventions.

  6. Chemical modeling of irreversible reactions in nuclear waste-water-rock systems

    International Nuclear Information System (INIS)

    Chemical models of aqueous geochemical systems are usually built on the concept of thermodynamic equilibrium. Though many elementary reactions in a geochemical system may be close to equilibrium, others may not be. Chemical models of aqueous fluids should take into account that many aqueous redox reactions are among the latter. The behavior of redox reactions may critically affect migration of certain radionuclides, especially the actinides. In addition, the progress of reaction in geochemical systems requires thermodynamic driving forces associated with elementary reactions not at equilibrium, which are termed irreversible reactions. Both static chemical models of fluids and dynamic models of reacting systems have been applied to a wide spectrum of problems in water-rock interactions. Potential applications in nuclear waste disposal range from problems in geochemical aspects of site evaluation to those of waste-water-rock interactions. However, much further work in the laboratory and the field will be required to develop and verify such applications of chemical modeling

  7. Memphis Business Group on Health: a model for health care reform and cost containment.

    Science.gov (United States)

    Miller, D

    1994-01-01

    A market-driven, community-based, competitive health care model has effectively assisted Memphis employers to achieve their cost containment and health care reform objectives. Members of the Memphis Business Group on Health joined forces and successfully implemented a variety of programs and services that resulted in dramatic cost savings and reform of health care delivery systems. Programs included development of a purchasing alliance for negotiating contracts for hospital, medical, workers' compensation, psychiatric, and substance abuse care and other service and product options. Utilization management programs focused on appropriate consumption of resources and intensive management of critical cases. While increases in per employee costs averaged 14.7 percent per year for five years nationally, members of the Memphis Business Group on Health held their increases to an average of 6 percent per year. PMID:10132786

  8. Health effects models for nuclear power plant accident consequence analysis

    International Nuclear Information System (INIS)

    This report is a revision of NUREG/CR-4214, Rev. 1, Part 1 (1990), Health Effects Models for Nuclear Power Plant Accident Consequence Analysis. This revision has been made to incorporate changes to the Health Effects Models recommended in two addenda to the NUREG/CR-4214, Rev. 1, Part 11, 1989 report. The first of these addenda provided recommended changes to the health effects models for low-LET radiations based on recent reports from UNSCEAR, ICRP and NAS/NRC (BEIR V). The second addendum presented changes needed to incorporate alpha-emitting radionuclides into the accident exposure source term. As in the earlier version of this report, models are provided for early and continuing effects, cancers and thyroid nodules, and genetic effects. Weibull dose-response functions are recommended for evaluating the risks of early and continuing health effects. Three potentially lethal early effects -- the hematopoietic, pulmonary, and gastrointestinal syndromes are considered. Linear and linear-quadratic models are recommended for estimating the risks of seven types of cancer in adults - leukemia, bone, lung, breast, gastrointestinal, thyroid, and ''other''. For most cancers, both incidence and mortality are addressed. Five classes of genetic diseases -- dominant, x-linked, aneuploidy, unbalanced translocations, and multifactorial diseases are also considered. Data are provided that should enable analysts to consider the timing and severity of each type of health risk

  9. The Application of the Health Belief Model in Oral Health Education

    Directory of Open Access Journals (Sweden)

    M Solhi

    2010-12-01

    Full Text Available "nBackground: The goal of this study was to determine the application of health belief model in oral health education for 12-year-old children and its effect on oral health behaviors and indexes. "nMethods: A quasi- experimental study was carried out on twelve-year-old girl students (n-291 in the first grade of secon­dary school, in the central district of Tehran, Iran. Research sample was selected by a multistage cluster sampling. The data was obtained by using a valid reliable questionnaire for measuring the perceptions, a checklist for observing the quality of brush­ing and dental flossing and health files and clinical observation. First, a descriptive study was applied to individual percep­tions, oral behaviors, Oral Hygiene Index (OHI and Decayed, Missing and Filled Teeth Index (DMFTI. Then an educa­tional planning based on the results and Health Belief Model (HBM was applied. The procedure was repeated after six months. "nResults: After education, based on HBM, all the oral health perceptions increased (P<.05. Correct brushing and flossing are influenced by increased perceptions. A low correlation between the reduction of DMFTI and increased perceived sever­ity and increased perceived barriers are found (r= -0.28, r = 0.43 respectively. In addition, there was a limited correlation be­tween OHI and increased perceived benefits (r = -0.26. "nConclusion: Using health belief model in oral health education for increasing the likelihood of taking preventive oral health be­haviors is applicable.  

  10. Health Impacts Estimation of Mineralogical and Chemical Characterization of Suspended Atmospheric Particles over the East Desert

    Directory of Open Access Journals (Sweden)

    U. A. Rahoma

    2010-01-01

    Full Text Available Problem statement: The small size fraction of aerosols, measured as PM10 and PM2.5, rather than the larger particles, is considered to be responsible for most of the health effects. Such particles have a relatively long residence time in the atmosphere and can therefore travel over long distances. Hence, a large portion of ambient concentrations of PM10 and in particular of particles with an aerodynamic diameter less than 2.5 µm (PM2.5, can be attributed to long range trans boundary air pollution or to other remote sources. The estimates of exposure and of health effects are based on a number of uncertain assumptions and data sets, as described in previous article. Approach: In industrialized Middle East countries, the daily deposition of PM10 particles in the lungs is roughly 250 µg day-1, which represents a small dose in terms of traditional toxicology studies. Studies of PM10 have considered this total material but have not asked how much its chemical or physical characteristics contribute to its total toxicity. Results: This article focuses on the description of the present knowledge on PM10 concentration fields and predominant sources contributing to PM10 from long range transport of pollution. PM10 is a complex mixture of many known and unknown components; therefore, a short introduction on the composition of PM10 is given. The studies denote to the African dust from mean PM10 levels background levels are still 5-10 mg m3 higher in the Eastern Basin (EMB when compared with those in the Western (WMB, mainly due to the higher anthropogenic and sea spray loads. Conclusion: As regards for the seasonal trends, these are largely driven by the occurrence of African dust events, resulting in a spring-early summer maximum over the EMB and a clear summer maximum in the WMB, although in this later region the recirculation of aged air masses play an important role. Furthermore, a marked seasonal trend is still evident when subtracting the African

  11. Chemical Analysis of Whale Breath Volatiles: A Case Study for Non-Invasive Field Health Diagnostics of Marine Mammals

    Directory of Open Access Journals (Sweden)

    Raquel Cumeras

    2014-09-01

    Full Text Available We explored the feasibility of collecting exhaled breath from a moribund gray whale (Eschrichtius robustus for potential non-invasive health monitoring of marine mammals. Biogenic volatile organic compound (VOC profiling is a relatively new field of research, in which the chemical composition of breath is used to non-invasively assess the health and physiological processes on-going within an animal or human. In this study, two telescopic sampling poles were designed and tested with the primary aim of collecting whale breath exhalations (WBEs. Once the WBEs were successfully collected, they were immediately transferred onto a stable matrix sorbent through a custom manifold system. A total of two large volume WBEs were successfully captured and pre-concentrated onto two Tenax®-TA traps (one exhalation per trap. The samples were then returned to the laboratory where they were analyzed using solid phase micro extraction (SPME and gas chromatography/mass spectrometry (GC/MS. A total of 70 chemicals were identified (58 positively identified in the whale breath samples. These chemicals were also matched against a database of VOCs found in humans, and 44% of chemicals found in the whale breath are also released by healthy humans. The exhaled gray whale breath showed a rich diversity of chemicals, indicating the analysis of whale breath exhalations is a promising new field of research.

  12. Numerical modeling of chemical spills and assessment of their environmental impacts

    Science.gov (United States)

    Chemical spills in surface water bodies often occur in modern societies, which cause significant impacts on water quality, eco-environment and drinking water safety. In this paper, chemical spill contamination in water resources was studied using a depth-integrated computational model, CCHE2D, for p...

  13. Analyzing Sexual Health-Related Beliefs Among Couples in Marriage Based on the Health Belief Model

    Directory of Open Access Journals (Sweden)

    Majid Barati

    2014-06-01

    Full Text Available Introduction: Sexual health is the integrity between mind, emotions, and body, and any disorder leading to discoordination, can be associated with sexual dysfunction. The aim of this study was to investigate the beliefs of couples attending marriage counseling centers toward sexual health based on the health belief model. Materials and Methods: This cross sectional descriptive study was performed on 400 couples referring to marriage counseling centers of Hamadan recruited with a random sampling method. The participants completed a self-administered questionnaire including demographic characteristics, knowledge and health belief model constructs. Data analysis was performed using SPSS-16 software, by Pearson’s coefficient correlation, independent T-test, and one-way ANOVA. Results: Couples had a moderate knowledge of sexual health. In addition, perceived susceptibility and severity of the consequences of unsafe sexual behavior among couples were not satisfactory however, perceived benefits and barriers were reported in a relatively good level. Internet and friends were the most important sources for sexual health information. Conclusion: Promoting knowledge and beliefs toward sexual health by preparing training packages based on the needs of couples and removing obstacles to have normal sexual behavior are necessary.

  14. Systematic review of health-related quality of life models

    Directory of Open Access Journals (Sweden)

    Bakas Tamilyn

    2012-11-01

    Full Text Available Abstract Background A systematic literature review was conducted to (a identify the most frequently used health-related quality of life (HRQOL models and (b critique those models. Methods Online search engines were queried using pre-determined inclusion and exclusion criteria. We reviewed titles, abstracts, and then full-text articles for their relevance to this review. Then the most commonly used models were identified, reviewed in tables, and critiqued using published criteria. Results Of 1,602 titles identified, 100 articles from 21 countries met the inclusion criteria. The most frequently used HRQOL models were: Wilson and Cleary (16%, Ferrans and colleagues (4%, or World Health Organization (WHO (5%. Ferrans and colleagues’ model was a revision of Wilson and Cleary’s model and appeared to have the greatest potential to guide future HRQOL research and practice. Conclusions Recommendations are for researchers to use one of the three common HRQOL models unless there are compelling and clearly delineated reasons for creating new models. Disease-specific models can be derived from one of the three commonly used HRQOL models. We recommend Ferrans and colleagues’ model because they added individual and environmental characteristics to the popular Wilson and Cleary model to better explain HRQOL. Using a common HRQOL model across studies will promote a coherent body of evidence that will more quickly advance the science in the area of HRQOL.

  15. Modeling lightning-NOx chemistry at sub-grid scale in a global chemical transport model

    Directory of Open Access Journals (Sweden)

    A. Gressent

    2015-12-01

    Full Text Available For the first time, a plume-in-grid approach is implemented in a chemical transport model (CTM to parameterize the effects of the non-linear reactions occurring within high concentrated NOx plumes from lightning NOx emissions (LNOx in the upper troposphere. It is characterized by a set of parameters including the plume lifetime, the effective reaction rate constant related to NOx-O3 chemical interactions and the fractions of NOx conversion into HNO3 within the plume. Parameter estimates were made using the DSMACC chemical box model, simple plume dispersion simulations and the mesoscale 3-D Meso-NH model. In order to assess the impact of the LNOx plume approach on the NOx and O3 distributions at large scale, simulations for the year 2006 were performed using the GEOS-Chem global model with a horizontal resolution of 2° × 2.5°. The implementation of the LNOx parameterization implies NOx and O3 decrease at large scale over the region characterized by a strong lightning activity (up to 25 and 8 %, respectively, over Central Africa in July and a relative increase downwind of LNOx emissions (up to 18 and 2 % for NOx and O3, respectively, in July are derived. The calculated variability of NOx and O3 mixing ratios around the mean value according to the known uncertainties on the parameter estimates is maximum over continental tropical regions with ΔNOx [−33.1; +29.7] ppt and ΔO3 [−1.56; +2.16] ppb, in January, and ΔNOx [−14.3; +21] ppt and ΔO3 [−1.18; +1.93] ppb, in July, mainly depending on the determination of the diffusion properties of the atmosphere and the initial NO mixing ratio injected by lightning. This approach allows (i to reproduce a more realistic lightning NOx chemistry leading to better NOx and O3 distributions at the large scale and (ii focus on other improvements to reduce remaining uncertainties from processes related to NOx chemistry in CTM.

  16. From exposure to effect: a comparison of modeling approaches to chemical carcinogenesis.

    Science.gov (United States)

    van Leeuwen, I M; Zonneveld, C

    2001-10-01

    Standardized long-term carcinogenicity tests aim to reveal the relationship between exposure to a chemical and occurrence of a carcinogenic response. The analysis of such tests may be facilitated by the use of mathematical models. To what extent current models actually achieve this purpose is difficult to evaluate. Various aspects of chemically induced carcinogenesis are treated by different modeling approaches, which proceed very much in isolation of each other. With this paper we aim to provide for the non-mathematician a comprehensive and critical overview of models dealing with processes involved in chemical carcinogenesis. We cover the entire process of carcinogenesis, from exposure to effect. We succinctly summarize the biology underlying the models and emphasize the relationship between model assumptions and model formulations. The use of mathematics is restricted as far as possible with some additional information relegated to boxes. PMID:11673088

  17. Smart health monitoring systems: an overview of design and modeling.

    Science.gov (United States)

    Baig, Mirza Mansoor; Gholamhosseini, Hamid

    2013-04-01

    Health monitoring systems have rapidly evolved during the past two decades and have the potential to change the way health care is currently delivered. Although smart health monitoring systems automate patient monitoring tasks and, thereby improve the patient workflow management, their efficiency in clinical settings is still debatable. This paper presents a review of smart health monitoring systems and an overview of their design and modeling. Furthermore, a critical analysis of the efficiency, clinical acceptability, strategies and recommendations on improving current health monitoring systems will be presented. The main aim is to review current state of the art monitoring systems and to perform extensive and an in-depth analysis of the findings in the area of smart health monitoring systems. In order to achieve this, over fifty different monitoring systems have been selected, categorized, classified and compared. Finally, major advances in the system design level have been discussed, current issues facing health care providers, as well as the potential challenges to health monitoring field will be identified and compared to other similar systems.

  18. How Iranian women conceptualize mental health: an explanatory model.

    Directory of Open Access Journals (Sweden)

    Arash Mirabzadeh

    2014-03-01

    Full Text Available In Iran, more than 25% of women suffer from mental disorders. Mental disorders and subclinical problems are associated with socioeconomic problem. At the community level, mental health promotion can reduce social damage. The aim of this study as a part of community based mental health promotion intervention was to explore how mental health in Iranian women is viewed.According to a qualitative method in 2012, participants were selected by purposeful sampling from married women 18 to 65 years who are residents in Tehran. Fifteen in depth individual interviews were conducted with regard to the concept of mental health, causal pathway and help-seeking behavior according to explanatory model.Mental health was perceived as the same of emotional well-being. It conceptualized not only lack of mental disorder but also sense of satisfaction and healthy functioning. According to participant's view, the causal pathway of mental health problems were classified to individual, familial and social factors. Physical and behavioral problems were related to individual factor, Lack of marital adjustment was one of the most important issues in familial item and in social factor, cultural context and socio-economic problems were extracted. In help seeking process, all of the participants believed that the religion has important effect in mental health.Marital adjustment is an important stage in process of mental health in women.

  19. CHILDREN'S MENTAL HEALTH SERVICE USE AND MATERNAL MENTAL HEALTH: A PATH ANALYTIC MODEL.

    Science.gov (United States)

    Pfefferle, Susan G; Spitznagel, Edward L

    2009-03-01

    OBJECTIVE: This observational study explores pathways towards any past year use of child mental health services. METHODS: Data from the 2002 National Survey of American Families were used to explore the relationship between past month maternal mental health and past year child mental health services use. Observations were limited to the 8072 most knowledgeable adults who were the mothers of target children aged 6-11. Logistic regressions were performed to determine the odds of any child mental health service use followed by path analyses using Maximum Likelihood estimation with robust standard errors. RESULTS: Multiple factors were associated with odds of any child mental health service use. In the path analytic model poor past month maternal mental health was associated with increased aggravation which in turn was associated with increased use of mental health visits. Negative child behaviors as reported by the mother were also associated with increased maternal aggravation and increased service use. CONCLUSIONS: Parental perception of child behaviors influences treatment seeking, both directly and indirectly through parental aggravation. Parental mental health influences tolerance for child behaviors. Findings are consistent with other studies. Interventions should address the entire family and their psychosocial circumstances through collaboration between multiple service sectors. PMID:20161315

  20. Piecewise linear and Boolean models of chemical reaction networks.

    Science.gov (United States)

    Veliz-Cuba, Alan; Kumar, Ajit; Josić, Krešimir

    2014-12-01

    Models of biochemical networks are frequently complex and high-dimensional. Reduction methods that preserve important dynamical properties are therefore essential for their study. Interactions in biochemical networks are frequently modeled using Hill functions ([Formula: see text]). Reduced ODEs and Boolean approximations of such model networks have been studied extensively when the exponent [Formula: see text] is large. However, while the case of small constant [Formula: see text] appears in practice, it is not well understood. We provide a mathematical analysis of this limit and show that a reduction to a set of piecewise linear ODEs and Boolean networks can be mathematically justified. The piecewise linear systems have closed-form solutions that closely track those of the fully nonlinear model. The simpler, Boolean network can be used to study the qualitative behavior of the original system. We justify the reduction using geometric singular perturbation theory and compact convergence, and illustrate the results in network models of a toggle switch and an oscillator.

  1. A Hierarchical Model Architecture for Enterprise Integration in Chemical Industries

    Institute of Scientific and Technical Information of China (English)

    华贲; 周章玉; 成思危

    2001-01-01

    Towards integration of supply chain, manufacturing/production and investment decision making, this paper presents a hierarchical model architecture which contains six sub-models covering the areas of manufacturing control, production operation, design and revamp, production management, supply chain and investment decision making. Six types of flow, material, energy, information, humanware, partsware and capital are ciasified. These flows connect enterprise components/subsystems to formulate system topology and logical structure. Enterprise components/subsystems are abstracted to generic elementary and composite classes. Finally, the model architecture is applied to a management system of an integrated suply chain, and suggestion are made on the usage of the model architecture and further development of the model as well as imvlementation issues.

  2. High-throughput exposure modeling to support prioritization of chemicals in personal care products

    DEFF Research Database (Denmark)

    Csiszar, Susan A.; Ernstoff, Alexi; Fantke, Peter;

    2016-01-01

    We demonstrate the application of a high-throughput modeling framework to estimate exposure to chemicals used in personal care products (PCPs). As a basis for estimating exposure, we use the product intake fraction (PiF), defined as the mass of chemical taken by an individual or population per mass...... intakes were associated with body lotion. Bioactive doses derived from high-throughput in vitro toxicity data were combined with the estimated PiFs to demonstrate an approach to estimate bioactive equivalent chemical content and to screen chemicals for risk....

  3. Evaluation of the Component Chemical Potentials in Analytical Models for Ordered Alloy Phases

    Directory of Open Access Journals (Sweden)

    W. A. Oates

    2011-01-01

    Full Text Available The component chemical potentials in models of solution phases with a fixed number of sites can be evaluated easily when the Helmholtz energy is known as an analytical function of composition. In the case of ordered phases, however, the situation is less straightforward, because the Helmholtz energy is a functional involving internal order parameters. Because of this, the chemical potentials are usually obtained numerically from the calculated integral Helmholtz energy. In this paper, we show how the component chemical potentials can be obtained analytically in ordered phases via the use of virtual cluster chemical potentials. Some examples are given which illustrate the simplicity of the method.

  4. Personality organization, five-factor model, and mental health.

    Science.gov (United States)

    Laverdière, Olivier; Gamache, Dominick; Diguer, Louis; Hébert, Etienne; Larochelle, Sébastien; Descôteaux, Jean

    2007-10-01

    Otto Kernberg has developed a model of personality and psychological functioning centered on the concept of personality organization. The purpose of this study is to empirically examine the relationships between this model, the five-factor model, and mental health. The Personality Organization Diagnostic Form (Diguer et al., The Personality Organization Diagnostic Form-II (PODF-II), 2001), the NEO Five-Factor Inventory (Costa and McCrae, Revised NEO Personality Inventory (NEO-PI-R) and NEO Five-Factor Inventory (NEO-FFI) Professional Manual. 1992a), and the Health-Sickness Rating Scale (Luborsky, Arch Gen Psychiatry. 1962;7:407-417) were used to assess these constructs. Results show that personality organization and personality factors are distinct but interrelated constructs and that both contribute in similar proportion to mental health. Results also suggest that the integration of personality organization and factors can provide clinicians and researchers with an enriched understanding of psychological functioning. PMID:18043522

  5. Organizational models of emerging academic health science centers in England.

    Science.gov (United States)

    Ovseiko, Pavel V; Davies, Stephen M; Buchan, Alastair M

    2010-08-01

    Recent government policy initiatives to foster medical innovation and high-quality care in England have prompted academic and clinical leaders to develop new organizational models to support the tripartite Flexnerian mission of academic medicine. Medical schools and health care providers have responded by aligning their missions and creating integrated governance structures that strengthen their partnerships. In March 2009, the government officially designated five academic-clinical partnerships as England's first academic health science centers (AHSCs). As academic-clinical integration is likely to continue, future AHSC leaders could benefit from an analysis of models for organizing medical school-clinical enterprise relationships in England's emerging AHSCs. In addition, as the United States ponders health systems reform and universal coverage, U.S. medical leaders may benefit from insight into the workings of academic medicine in England's universal health system. In this article, the authors briefly characterize the organization and financing of the National Health Service and how it supports academic medicine. They review the policy behind the designation of AHSCs. Then, the authors describe contrasting organizational models adopted in two of the newly designated AHSCs and analyze these models using a framework derived from U.S. literature. The authors conclude by outlining the major challenges facing academic medicine in England and offer suggestions for future research collaborations between leaders of AHSCs in the United States and England.

  6. Momentum balance equation for nonelectrolytes in models of coupling between chemical reaction and diffusion in membranes.

    Science.gov (United States)

    Gałdzicki, Z; Miekisz, S

    1984-04-01

    The role of viscosity in coupling between chemical reaction (complex formation) and diffusion in membranes has been investigated. The Fick law was replaced by the momentum balance equation with the viscous term. The irreversible thermodynamics admits coupling of the chemical reaction rate with the gradient of velocity. The proposed model has shown the contrary effect of viscosity and confirmed the experimental results. The chemical reaction rate increases only above the limit value of viscosity. The parameter Q (degree of complex formation) was introduced to investigate coupling. Q equals to the ratio of the chemical contribution into the flux of the complex to the total flux of the substance transported. For different values of the parameters of the model the dependence of Q upon position inside the membrane has been numerically calculated. The assumptions of the model limit it to a specific case and they only roughly model the biological situation. PMID:6537360

  7. A Chemically Relevant Model for Teaching the Second Law of Thermodynamics.

    Science.gov (United States)

    Williamson, Bryce E.; Morikawa, Tetsuo

    2002-01-01

    Introduces a chemical model illustrating the aspects of the second law of thermodynamics which explains concepts such as reversibility, path dependence, and extrapolation in terms of electrochemistry and calorimetry. Presents a thought experiment using an ideal galvanic electrochemical cell. (YDS)

  8. Chemical kinetic modeling of H{sub 2} applications

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, C.K.; Marinov, N.; Pitz, W.J.; Curran, H. [Lawrence Livermore National Lab., CA (United States)

    1996-10-01

    This project is intended to develop detailed and simplified kinetic reaction mechanisms for the combustion of practical systems fueled by hydrogen, and then to use those mechanisms to examine the performance, efficiency, pollutant emissions, and other characteristics of those systems. During the last year, a H2/NOx mechanism has been developed that gives much improved predictions of NOx emissions compared to experimental data. Preliminary chemical kinetic and equilibrium calculations have been performed in support of Br2-H2O experiments to be conducted at NREL. Hydrogen, hydrogen/methane and hydrogen/natural gas mixtures have been investigated in a knock-rating engine to assess their automotive knock characteristics. The authors are currently developing the simplified analog reaction mechanisms that are computationally simple, yet still reproduce many of the macroscopic features of flame propagation.

  9. Global health educational engagement - a tale of two models.

    Science.gov (United States)

    Rassiwala, Jasmine; Vaduganathan, Muthiah; Kupershtok, Mania; Castillo, Frank M; Evert, Jessica

    2013-11-01

    Global health learning experiences for medical students sit at the intersection of capacity building, ethics, and education. As interest in global health programs during medical school continues to rise, Northwestern University Alliance for International Development, a student-led and -run organization at Northwestern University Feinberg School of Medicine, has provided students with the opportunity to engage in two contrasting models of global health educational engagement.Eleven students, accompanied by two Northwestern physicians, participated in a one-week trip to Matagalpa, Nicaragua, in December 2010. This model allowed learning within a familiar Western framework, facilitated high-volume care, and focused on hands-on experiences. This approach aimed to provide basic medical services to the local population.In July 2011, 10 other Feinberg students participated in a four-week program in Puerto Escondido, Mexico, which was coordinated by Child Family Health International, a nonprofit organization that partners with native health care providers. A longer duration, homestays, and daily language classes hallmarked this experience. An intermediary, third-party organization served to bridge the cultural and ethical gap between visiting medical students and the local population. This program focused on providing a holistic cultural experience for rotating students.Establishing comprehensive global health curricula requires finding a balance between providing medical students with a fulfilling educational experience and honoring the integrity of populations that are medically underserved. This article provides a rich comparison between two global health educational models and aims to inform future efforts to standardize global health education curricula. PMID:24072106

  10. Modeling the Cumulative Effects of Social Exposures on Health: Moving beyond Disease-Specific Models

    Directory of Open Access Journals (Sweden)

    Heather L. White

    2013-03-01

    Full Text Available The traditional explanatory models used in epidemiology are “disease specific”, identifying risk factors for specific health conditions. Yet social exposures lead to a generalized, cumulative health impact which may not be specific to one illness. Disease-specific models may therefore misestimate social factors’ effects on health. Using data from the Canadian Community Health Survey and Canada 2001 Census we construct and compare “disease-specific” and “generalized health impact” (GHI models to gauge the negative health effects of one social exposure: socioeconomic position (SEP. We use logistic and multinomial multilevel modeling with neighbourhood-level material deprivation, individual-level education and household income to compare and contrast the two approaches. In disease-specific models, the social determinants under study were each associated with the health conditions of interest. However, larger effect sizes were apparent when outcomes were modeled as compound health problems (0, 1, 2, or 3+ conditions using the GHI approach. To more accurately estimate social exposures’ impacts on population health, researchers should consider a GHI framework.

  11. State of chemical modeling modules for the degradation of concrete and cements

    Energy Technology Data Exchange (ETDEWEB)

    Meike, A.

    1997-04-15

    This report describes the conceptual framework upon which modeling activities will be needed to predict the chemistry of water in contact with concrete and its degradation products cover a broad area, from developing databases for existing abiotic codes, to developing codes that can simulate the chemical impact of microbial activities at a level of sophistication equivalent to that of the abiotic modeling codes, and ultimately, to simulating drift-scale chemical systems in support of hydrological, geochemical,a nd engineering efforts.

  12. Risk-based high-throughput chemical screening and prioritization using exposure models and in vitro bioactivity assays

    DEFF Research Database (Denmark)

    Shin, Hyeong-Moo; Ernstoff, Alexi; Arnot, Jon;

    2015-01-01

    We present a risk-based high-throughput screening (HTS) method to identify chemicals for potential health concerns or for which additional information is needed. The method is applied to 180 organic chemicals as a case study. We first obtain information on how the chemical is used and identify...

  13. Autoregressive Models of Background Errors for Chemical Data Assimilation

    OpenAIRE

    Constantinescu, Emil M.; Chai, Tianfeng; Sandu, Adrian; Gregory R. Carmichael

    2006-01-01

    The task of providing an optimal analysis of the state of the atmosphere requires the development of dynamic data-driven systems that efficiently integrate the observational data and the models. Data assimilation (DA) is the process of adjusting the states or parameters of a model in such a way that its outcome (prediction) is close, in some distance metric, to observed (real) states. It is widely accepted that a key ingredient of successful data assimilation is a realistic estimation of th...

  14. The Competence of Modelling in Learning Chemical Change: A Study with Secondary School Students

    Science.gov (United States)

    Oliva, José Mª; del Mar Aragón, María; Cuesta, Josefa

    2015-01-01

    The competence of modelling as part of learning about chemical change is analysed in a sample of 35 secondary students, ages 14-15 years, during their study of a curricular unit on this topic. The teaching approach followed is model based, with frequent use of analogies and mechanical models (fruits and bowls, Lego pieces, balls of plasticine,…

  15. Oral health in Brazil: the challenges for dental health care models.

    Science.gov (United States)

    Chaves, Sônia Cristina Lima

    2012-01-01

    This paper discusses adult oral health in Brazil according to three perspectives: 1) the available epidemiological evidence about the population's oral-health-related epidemiological situation, especially adults and the elderly population, in relation to two high prevalence oral injuries (dental caries and tooth loss), 2) the main health care models for dealing with this situation, by analyzing the related historical processes in order to reveal the likely social, political and epidemiological implications of the different models, and 3) lastly, the possible challenges to Brazilian dentistry or collective oral health in overcoming these obstacles. The main results of the study indicate that, from an epidemiological point of view, Brazil is undergoing a transition in dental caries and tooth loss, which is not yet reflected in the profile of the elderly, but which is tentatively evidenced in young adults. Tooth loss remains high. Certain aspects of society's economic and political superstructure have an important impact on oral health indicators and existing inequalities. Oral health care models have a relative importance and must not be neglected. Vestiges of ideological movements, like preventive medicine, may explain the current impasse in collective oral health practices, such as the preeminence of Finalized Treatment (FT) in clinics and of preventive care in schools fostered by community-based programs. It is therefore important to develop conceptual, theoretical reflections and to increase the objects of intervention, their purposes and their modus operandi. The practice of dentistry according to these alternative models is still being constructed. New studies related to the different formats of these new practices are recommended.

  16. Innovation in health economic modelling of service improvements for longer-term depression: demonstration in a local health community

    OpenAIRE

    Tosh, J.; Kearns, B; Brennan, A.(School of Physics, University of Melbourne, Victoria, Australia); Parry, G; Ricketts, T.; Saxon, D; Kilgarriff-Foster, A.; Thake, A; Chambers, E.; Hutten, R.

    2013-01-01

    Background The purpose of the analysis was to develop a health economic model to estimate the costs and health benefits of alternative National Health Service (NHS) service configurations for people with longer-term depression. Method Modelling methods were used to develop a conceptual and health economic model of the current configuration of services in Sheffield, England for people with longer-term depression. Data and assumptions were synthesised to estimate cost per Quality Ad...

  17. Quebec mental health services networks: models and implementation

    Directory of Open Access Journals (Sweden)

    Marie-Josée Fleury

    2005-06-01

    Full Text Available Purpose: In the transformation of health care systems, the introduction of integrated service networks is considered to be one of the main solutions for enhancing efficiency. In the last few years, a wealth of literature has emerged on the topic of services integration. However, the question of how integrated service networks should be modelled to suit different implementation contexts has barely been touched. To fill that gap, this article presents four models for the organization of mental health integrated networks. Data sources: The proposed models are drawn from three recently published studies on mental health integrated services in the province of Quebec (Canada with the author as principal investigator. Description: Following an explanation of the concept of integrated service network and a description of the Quebec context for mental health networks, the models, applicable in all settings: rural, urban or semi-urban, and metropolitan, and summarized in four figures, are presented. Discussion and conclusion: To apply the models successfully, the necessity of rallying all the actors of a system, from the strategic, tactical and operational levels, according to the type of integration involved: functional/administrative, clinical and physician-system is highlighted. The importance of formalizing activities among organizations and actors in a network and reinforcing the governing mechanisms at the local level is also underlined. Finally, a number of integration strategies and key conditions of success to operationalize integrated service networks are suggested.

  18. Molecular modeling for the design of novel performance chemicals and materials

    CERN Document Server

    Rai, Beena

    2012-01-01

    Molecular modeling (MM) tools offer significant benefits in the design of industrial chemical plants and material processing operations. While the role of MM in biological fields is well established, in most cases MM works as an accessory in novel products/materials development rather than a tool for direct innovation. As a result, MM engineers and practitioners are often seized with the question: ""How do I leverage these tools to develop novel materials or chemicals in my industry?"" Molecular Modeling for the Design of Novel Performance Chemicals and Materials answers this important questio

  19. Predicting carcinogenicity of diverse chemicals using probabilistic neural network modeling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Kunwar P., E-mail: kpsingh_52@yahoo.com [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India); Gupta, Shikha; Rai, Premanjali [Academy of Scientific and Innovative Research, Council of Scientific and Industrial Research, New Delhi (India); Environmental Chemistry Division, CSIR-Indian Institute of Toxicology Research, Post Box 80, Mahatma Gandhi Marg, Lucknow 226 001 (India)

    2013-10-15

    Robust global models capable of discriminating positive and non-positive carcinogens; and predicting carcinogenic potency of chemicals in rodents were developed. The dataset of 834 structurally diverse chemicals extracted from Carcinogenic Potency Database (CPDB) was used which contained 466 positive and 368 non-positive carcinogens. Twelve non-quantum mechanical molecular descriptors were derived. Structural diversity of the chemicals and nonlinearity in the data were evaluated using Tanimoto similarity index and Brock–Dechert–Scheinkman statistics. Probabilistic neural network (PNN) and generalized regression neural network (GRNN) models were constructed for classification and function optimization problems using the carcinogenicity end point in rat. Validation of the models was performed using the internal and external procedures employing a wide series of statistical checks. PNN constructed using five descriptors rendered classification accuracy of 92.09% in complete rat data. The PNN model rendered classification accuracies of 91.77%, 80.70% and 92.08% in mouse, hamster and pesticide data, respectively. The GRNN constructed with nine descriptors yielded correlation coefficient of 0.896 between the measured and predicted carcinogenic potency with mean squared error (MSE) of 0.44 in complete rat data. The rat carcinogenicity model (GRNN) applied to the mouse and hamster data yielded correlation coefficient and MSE of 0.758, 0.71 and 0.760, 0.46, respectively. The results suggest for wide applicability of the inter-species models in predicting carcinogenic potency of chemicals. Both the PNN and GRNN (inter-species) models constructed here can be useful tools in predicting the carcinogenicity of new chemicals for regulatory purposes. - Graphical abstract: Figure (a) shows classification accuracies (positive and non-positive carcinogens) in rat, mouse, hamster, and pesticide data yielded by optimal PNN model. Figure (b) shows generalization and predictive

  20. A model linking clinical workforce skill mix planning to health and health care dynamics

    Directory of Open Access Journals (Sweden)

    McDonnell Geoff

    2010-04-01

    Full Text Available Abstract Background In an attempt to devise a simpler computable tool to assist workforce planners in determining what might be an appropriate mix of health service skills, our discussion led us to consider the implications of skill mixing and workforce composition beyond the 'stock and flow' approach of much workforce planning activity. Methods Taking a dynamic systems approach, we were able to address the interactions, delays and feedbacks that influence the balance between the major components of health and health care. Results We linked clinical workforce requirements to clinical workforce workload, taking into account the requisite facilities, technologies, other material resources and their funding to support clinical care microsystems; gave recognition to productivity and quality issues; took cognisance of policies, governance and power concerns in the establishment and operation of the health care system; and, going back to the individual, gave due attention to personal behaviour and biology within the socio-political family environment. Conclusion We have produced the broad endogenous systems model of health and health care which will enable human resource planners to operate within real world variables. We are now considering the development of simple, computable national versions of this model.

  1. Public health assessment for public health assessment addendum, Stauffer Chemical Company, Tarpon Springs, Florida, Region 4, CERCLIS number FLD010596013. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-08-06

    From 1947 to 1981, the Stauffer Chemical Company in Tarpon Springs, Florida, made elemental phosphorus from phosphate ore. Residents in the area expressed concern about possible adverse health effects resulting from exposure to radium and heavy metals leaching from phosphate slag that was used in nearby roads and buildings. Besides radium, other contaminants of concern to residents were arsenic, asbestos, uranium, radon, and ionizing radiation. There is elevated background radiation from natural radium in phosphate slag and aggregate, but exposures are not expected to result in any adverse health outcomes. Phosphate slag contains concentrations of metals above background levels. However, based on current epidemiological and medical information the levels are not likely to represent a public health hazard.

  2. The effect of biological and chemical control agents on the health status of the very early potato cultivar Rosara

    OpenAIRE

    Cwalina-Ambroziak Bożena; Damszel Marta Maria; Głosek-Sobieraj Małgorzata

    2015-01-01

    The external appearance and quality of table potatoes are determined, among other factors, by the health status of the plants during the growing season. Chemical control methods are often combined with biocontrol agents to effectively fight potato pathogens. Potatoes of the very early cultivar Rosara were grown in experimental plots. The plots were located in Tomaszkowo (NE Poland, 2007-2009). The experiment involved the following treatments: 1) biological control − mycorrhizal Glomus spp. in...

  3. Medicinal Plants Recommended by the World Health Organization: DNA Barcode Identification Associated with Chemical Analyses Guarantees Their Quality

    OpenAIRE

    Rafael Melo Palhares; Marcela Gonçalves Drummond; Bruno Dos Santos Alves Figueiredo Brasil; Gustavo Pereira Cosenza; Maria das Graças Lins Brandão; Guilherme Oliveira

    2015-01-01

    Medicinal plants are used throughout the world, and the regulations defining their proper use, such as identification of the correct species and verification of the presence, purity and concentration of the required chemical compounds, are widely recognized. Herbal medicines are made from vegetal drugs, the processed products of medicinal species. These processed materials present a number of challenges in terms of botanical identification, and according to the World Health Organization (WHO)...

  4. Public health assessment for Revere Chemical Company, Nockamixon, Bucks County, Pennsylvania, Region 3. Cerclis No. PAD051395499. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1994-01-06

    The Revere Chemical National Priorities List (NPL) site is located on the southeast side of Pennsylvania State Route 611, approximately three quarters of a mile south of the town of Revere in Nockamixon Township, Bucks County, Pennsylvania. Operations at the Revere Chemical site were initiated in 1963 and reportedly involved the recycling of spent chromic acid solutions, the recovery of copper from electric plating solution, and the reclamation of metals from printed circuit boards. The process area soils are contaminated with volatile organic compounds and metals. Soil contamination decreases markedly with distance from the process area. Trichloroethene (TCE) and 1,2,4-trichlorobenzene (TCB) were detected in on-site monitoring well MW-4 at concentrations of 110 micrograms per liter and 41 micrograms/liter, respectively. The Revere Chemical site currently represents an indeterminate public health hazard since groundwater flow direction has not been fully characterized and not all residential wells near the site have been sampled.

  5. Conscientiousness, health, and aging: the life course of personality model.

    Science.gov (United States)

    Shanahan, Michael J; Hill, Patrick L; Roberts, Brent W; Eccles, Jacquelynne; Friedman, Howard S

    2014-05-01

    The Conscientiousness (C) of the self and significant others influences health by way of mediational chains involving socioeconomic attainment, the avoidance and neutralization of stressors, the promotion of health behaviors and the minimization of risk behaviors, and the management of symptoms and diseases. Yet, meta-analyses reveal that these associations are moderated by factors that are not well understood. We propose the Life Course of Personality Model (LCP Model), which comprises a series of hypotheses that suggest how such mediational chains are subject to 2 sources of contingency. First, the mechanisms by which C translates into health and the avoidance of risk change from early childhood to late adulthood, involving processes that are specific to phases of the life course; also, however, C influences health by way of continuous processes extending over many decades of life. Second, C may be more consequential in some social contexts than in others, and when accompanied by some constellations of personality characteristics than by others. That is, the mediational processes by which C translates into health and the avoidance of disease are likely moderated by timing, social context (including the C of others), and other aspects of the individual's personality. We consider methodological implications of the LCP Model. PMID:23244406

  6. Chemical genetics and drug screening in Drosophila cancer models

    Institute of Scientific and Technical Information of China (English)

    Mara Gladstone; Tin Tin Su

    2011-01-01

    Drug candidates often fail in preclinical and clinical testing because of reasons of efficacy and/or safety.It would be time- and cost-efficient to have screening models that reduce the rate of such false positive candidates that appear promising at first but fail later.In this regard,it would be particularly useful to have a rapid and inexpensive whole animal model that can pre-select hits from high-throughput screens but before testing in costly rodent assays.Drosophila melanogaster has emerged as a potential whole animal model for drug screening.Of particular interest have been drugs that must act in the context of multi-cellularity such as those for neurological disorders and cancer.A recent review provides a comprehensive summary of drug screening in Drosophila,but with an emphasis on neurodegenerative disorders.Here,we review Drosophila screens in the literature aimed at cancer therapeutics.

  7. Building a sustainable Academic Health Department: the South Carolina model.

    Science.gov (United States)

    Smith, Lillian Upton; Waddell, Lisa; Kyle, Joseph; Hand, Gregory A

    2014-01-01

    Given the limited resources available to public health, it is critical that university programs complement the development needs of agencies. Unfortunately, academic and practice public health entities have long been challenged in building sustainable collaborations that support practice-based research, teaching, and service. The academic health department concept offers a promising solution. In South Carolina, the partners started their academic health department program with a small grant that expanded into a dynamic infrastructure that supports innovative professional exchange and development programs. This article provides a background and describes the key elements of the South Carolina model: joint leadership, a multicomponent memorandum of agreement, and a shared professional development mission. The combination of these elements allows the partners to leverage resources and deftly respond to challenges and opportunities, ultimately fostering the sustainability of the collaboration.

  8. Chemical modelling as a management tool for water pollution control

    Energy Technology Data Exchange (ETDEWEB)

    Limpitlaw, D. [University of the Witwatersrand, Johannesburg (South Africa). Dept. of Mining Engineering

    1996-12-31

    In a colliery currently being re-mined by opencast methods, the coal seam was originally extracted using bord and pillar mining. Depressions in the seam floor have facilitated the formation of large underground water bodies. This water has become acidic and contaminated by heavy metals. Mine water is treated by a liming plant and then released into evaporation pans. Seepage from the pans enters a natural wetlands. The de-watering of old workings ahead of mining periodically subjects the liming plant to large quantities of low quality water, and a nett export of salts such as sulphate occurs. As the mine is situated in a sensitive river catchment, this pollution is unacceptable. A chemical speciation program developed by the US Environmental Protection Agency was used to analyse effluent from the liming plant and wetland. Liming plant effluent water was found to vary greatly due to the conditions prevalent in the different water bodies. The liming plant and wetland were periodically subjected to pollution loads beyond the wetland`s assimilative capacity, resulting failure of the system. Despite this, the software provided evidence of the wetland`s pollution-ameliorating potential. 8 refs., 12 figs.

  9. Technical Work Plan for: Thermodynamic Databases for Chemical Modeling

    International Nuclear Information System (INIS)

    The objective of the work scope covered by this Technical Work Plan (TWP) is to correct and improve the Yucca Mountain Project (YMP) thermodynamic databases, to update their documentation, and to ensure reasonable consistency among them. In addition, the work scope will continue to generate database revisions, which are organized and named so as to be transparent to internal and external users and reviewers. Regarding consistency among databases, it is noted that aqueous speciation and mineral solubility data for a given system may differ according to how solubility was determined, and the method used for subsequent retrieval of thermodynamic parameter values from measured data. Of particular concern are the details of the determination of ''infinite dilution'' constants, which involve the use of specific methods for activity coefficient corrections. That is, equilibrium constants developed for a given system for one set of conditions may not be consistent with constants developed for other conditions, depending on the species considered in the chemical reactions and the methods used in the reported studies. Hence, there will be some differences (for example in log K values) between the Pitzer and ''B-dot'' database parameters for the same reactions or species

  10. Multidimensional Chemical Modeling. III. Abundance and excitation of diatomic hydrides

    CERN Document Server

    Bruderer, Simon; Stäuber, P; Doty, Steven D

    2010-01-01

    The Herschel Space Observatory opens the sky for observations in the far infrared at high spectral and spatial resolution. A particular class of molecules will be directly observable; light diatomic hydrides and their ions (CH, OH, SH, NH, CH+, OH+, SH+, NH+). These simple constituents are important both for the chemical evolution of the region and as tracers of high-energy radiation. If outflows of a forming star erode cavities in the envelope, protostellar far UV (FUV; 6 100 K) for water ice to evaporate. If the cavity shape allows FUV radiation to penetrate this hot-core region, the abundance of FUV destroyed species (e.g. water) is decreased. In particular, diatomic hydrides and their ions CH$+, OH+ and NH+ are enhanced by many orders of magnitude in the outflow walls due to the combination of high gas temperatures and rapid photodissociation of more saturated species. The enhancement of these diatomic hydrides is sufficient for a detection using the HIFI and PACS instruments onboard Herschel. The effect...

  11. Modeling the elution of organic chemicals from a melting homogeneous snow pack.

    Science.gov (United States)

    Meyer, Torsten; Wania, Frank

    2011-06-01

    Organic chemicals are often released in peak concentrations from melting snow packs. A simple, mechanistic snowmelt model was developed to simulate and predict the elution of organic substances from melting, homogeneous snow, as influenced by chemical properties and snow pack characteristics. The model calculates stepwise the chemical transport along with the melt water flow in a multi-layered snow pack, based on chemical equilibrium partitioning between the individual bulk snow phases. The model succeeds in reproducing the elution behavior of several organic contaminants observed in previously conducted cold room experiments. The model aided in identifying four different types of enrichment of organic substances during snowmelt. Water soluble substances experience peak releases early during a melt period (type 1), whereas chemicals that strongly sorb to particulate matter (PM) or snow grain surfaces elute at the end of melting (type 2). Substances that are somewhat water soluble and at the same time have a high affinity for snow grain surfaces may exhibit increasing concentrations in the melt water (type 3). Finally, elution sequences involving peak loads both at the beginning and the end of melting are simulated for chemicals that are partially dissolved in the aqueous melt water phase and partially sorbed to PM (type 4). The extent of type 1 enrichment mainly depends on the snow depth, whereby deeper snow generates more pronounced concentration peaks. PM influences the elution behavior of organic chemicals strongly because of the very large natural variability in the type and amount of particles present in snow. Urban and road-side snow rich in PM can generate type 2 concentration peaks at the end of the melt period for even relatively water soluble substances. From a clean, melting snow pack typical for remote regions, even fairly hydrophobic chemicals can be released in type 1 mode while being almost completely dissolved in the aqueous melt water phase. The

  12. Information resources for assessing health effects from chemical exposure: Office of pesticides programs

    Energy Technology Data Exchange (ETDEWEB)

    Fenner-Crisp, P. [Environmental Protection Agency, Washington, DC (United States)

    1990-12-31

    The US Environmental Protection Agency (EPA) Office of Pesticide Programs is trying to develop a complete picture of a chemical`s toxicity and exposure profile. It is also important to share information in the office`s files because of pesticides, particularly as a consequence of agricultural use, find their way into places not necessarily intended.

  13. Mass Casualties and Health Care Following the Release of Toxic Chemicals or Radioactive Material—Contribution of Modern Biotechnology

    Directory of Open Access Journals (Sweden)

    Åke Sellström

    2011-12-01

    Full Text Available Catastrophic chemical or radiological events can cause thousands of casualties. Such disasters require triage procedures to identify the development of health consequences requiring medical intervention. Our objective is to analyze recent advancements in biotechnology for triage in mass emergency situations. In addition to identifying persons “at risk” of developing health problems, these technologies can aid in securing the unaffected or “worried well”. We also highlight the need for public/private partnerships to engage in some of the underpinning sciences, such as patho-physiological mechanisms of chemical and radiological hazards, and for the necessary investment in the development of rapid assessment tools through identification of biochemical, molecular, and genetic biomarkers to predict health effects. For chemical agents, biomarkers of neurotoxicity, lung damage, and clinical and epidemiological databases are needed to assess acute and chronic effects of exposures. For radiological exposures, development of rapid, sensitive biomarkers using advanced biotechnologies are needed to sort exposed persons at risk of life-threatening effects from persons with long-term risk or no risk. The final implementation of rapid and portable diagnostics tools suitable for emergency care providers to guide triage and medical countermeasures use will need public support, since commercial incentives are lacking.

  14. Chemical pollution of environment in the cities of Central Siberia: risk for the health of the population

    Directory of Open Access Journals (Sweden)

    Ludmila Klimatskaya

    2015-03-01

    Full Text Available pollution in cities including the problem of risk assessment. The aim of the study is to determine carcinogenic and non-carcinogenic risks for the health of the population due to chemical contamination of air, water and food in the cities of the Krasnoyarsk region. Material and methods. The research was conducted in the Center of Hygiene and Epidemiology in the Krasnoyarsk region. 5122 samples of air, 4863 samples of water and 6915 samples of food stuff have been analyzed. Concentration of chemical substances was the base on which individual carcinogenesis risk (ICR and population carcinogenic conventional risks (PCCR and non carcinogenic risks [1] have been calculated. In the industrial cities chemical pollution of air, water and food stuff including carcinogenic substances creates carcinogenic and non-carcinogenic risks of morbidity of the population with the reinforcement of the complex impact, “with” which greatly exceeds the maximum acceptable risks. Results. Chemical pollution of environmental facilities in cities of the Krasnoyarsk region produce complex carcinogenic and non-carcinogenic risks which exceed maximum limit. The greatest shares in structure of complex carcinogenic risks are made in food stuff and water consumption in structure of complex non-carcinogenic risks as a result of air pollution and food stuff pollution. Conclusions. Obtained data could be used to set priorities in preventive measures to preserve health of the population in industrial cities of the Krasnoyarsk region.

  15. An insight into chemical kinetics and turbulence-chemistry interaction modeling in flameless combustion

    Directory of Open Access Journals (Sweden)

    Amir Azimi, Javad Aminian

    2015-01-01

    Full Text Available Computational Fluid Dynamics (CFD study of flameless combustion condition is carried out by solving the Reynolds-Averaged Navier-Stokes (RANS equations in the open-source CFD package of OpenFOAM 2.1.0. Particular attention is devoted to the comparison of three global and detailed chemical mechanisms using the Partially Stirred Reactor (PaSR combustion model for the turbulence-chemistry interaction treatment. The OpenFOAM simulations are assessed against previously published CFD results using the Eddy Dissipation Concept (EDC combustion model as well as the experimental data available in the literature. Results show that global chemical mechanisms provide acceptable predictions of temperature and major species fields in flameless mode with much lower computational costs comparing with the detailed chemical mechanisms. However, incorporation of detailed chemical mechanisms with proper combustion models is crucial to account for finite-rate chemistry effects and accurately predict net production of minor species.

  16. Climate change and health modeling: horses for courses

    OpenAIRE

    Ebi, Kristie L.; Rocklov, Joacim

    2014-01-01

    Mathematical and statistical models are needed to understand the extent to which weather, climate variability, and climate change are affecting current and may affect future health burdens in the context of other risk factors and a range of possible development pathways, and the temporal and spatial patterns of any changes. Such understanding is needed to guide the design and the implementation of adaptation and mitigation measures. Because each model projection captures only a narrow range o...

  17. Development of chemical kinetic models for lean NOx traps.

    Energy Technology Data Exchange (ETDEWEB)

    Larson, Richard S.

    2010-04-01

    Overall project goal: Obtain the fundamental surface chemistry knowledge needed for the design and optimal utilization of NOx trap catalysts, thereby helping to speed the widespread adoption of this technology. Relevance to VT Program goals: Effective, durable advanced aftertreatment systems for lean-burn engines must be available if the fuel economy advantages of these engines are to be realized. Specific current year objective: Identify and correct any deficiencies in the previously developed reaction mechanism describing normal storage/regeneration cycles, and complete development of a supplementary mechanism accounting for the effects of sulfation. A fundamental understanding of LNT chemistry is needed to realize the full potential of this aftertreatment technology, which could lead to greater use of fuel-efficient lean-burn engines. We have used a multi-tiered approach to developing an elementary chemical mechanism benchmarked against experimental data: (1) Simulate a set of steady flow experiments, with storage effects minimized, to infer a tentative mechanism for chemistry on precious metal sites (completed). (2) Simulate a set of long cycle experiments to infer a mechanism for NOx and oxygen storage sites while simultaneously finalizing precious metal chemistry (completed). (3) Simulate a simplified sulfation/desulfation protocol to obtain a supplementary set of reactions involving sulfur on all three kinds of sites (nearly completed). (4) Investigate the potential role of reductants other than CO and H{sub 2}. While simulation of isothermal experiments is the preferred way to extract kinetic parameters, simulation of realistic storage/regeneration cycles requires that exotherms be considered. Our ultimate goal is to facilitate improved designs for LNT-based aftertreatment systems and to assist in the development of improved catalysts.

  18. An ionic-chemical-mechanical model for muscle contraction.

    Science.gov (United States)

    Manning, Gerald S

    2016-12-01

    The dynamic process underlying muscle contraction is the parallel sliding of thin actin filaments along an immobile thick myosin fiber powered by oar-like movements of protruding myosin cross bridges (myosin heads). The free energy for functioning of the myosin nanomotor comes from the hydrolysis of ATP bound to the myosin heads. The unit step of translational movement is based on a mechanical-chemical cycle involving ATP binding to myosin, hydrolysis of the bound ATP with ultimate release of the hydrolysis products, stress-generating conformational changes in the myosin cross bridge, and relief of built-up stress in the myosin power stroke. The cycle is regulated by a transition between weak and strong actin-myosin binding affinities. The dissociation of the weakly bound complex by addition of salt indicates the electrostatic basis for the weak affinity, while structural studies demonstrate that electrostatic interactions among negatively charged amino acid residues of actin and positively charged residues of myosin are involved in the strong binding interface. We therefore conjecture that intermediate states of increasing actin-myosin engagement during the weak-to-strong binding transition also involve electrostatic interactions. Methods of polymer solution physics have shown that the thin actin filament can be regarded in some of its aspects as a net negatively charged polyelectrolyte. Here we employ polyelectrolyte theory to suggest how actin-myosin electrostatic interactions might be of significance in the intermediate stages of binding, ensuring an engaged power stroke of the myosin motor that transmits force to the actin filament, and preventing the motor from getting stuck in a metastable pre-power stroke state. We provide electrostatic force estimates that are in the pN range known to operate in the cycle. PMID:27603027

  19. Permitted Suicide: Model Roles for Mental Health Counseling.

    Science.gov (United States)

    Cohen, Elliot D.

    2001-01-01

    In mental health practice, no explicit provisions have been made for existing law and codes of ethics to protect freedom and confidences of clients who rationally desire to end their lives. Makes a case for permitting suicide by providing an analysis of permitted suicide, the legal background for applying this concept, and ten model rules for…

  20. Managing Dog Waste: Campaign Insights from the Health Belief Model

    Science.gov (United States)

    Typhina, Eli; Yan, Changmin

    2014-01-01

    Aiming to help municipalities develop effective education and outreach campaigns to reduce stormwater pollutants, such as pet waste, this study applied the Health Belief Model (HBM) to identify perceptions of dog waste and corresponding collection behaviors from dog owners living in a small U.S. city. Results of 455 online survey responses…

  1. Optimization of a Reduced Chemical Kinetic Model for HCCI Engine Simulations by Micro-Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A reduced chemical kinetic model (44 species and 72 reactions) for the homogeneous charge compression ignition (HCCI) combustion of n-heptane was optimized to improve its autoignition predictions under different engine operating conditions. The seven kinetic parameters of the optimized model were determined by using the combination of a micro-genetic algorithm optimization methodology and the SENKIN program of CHEMKIN chemical kinetics software package. The optimization was performed within the range of equivalence ratios 0.2-1.2, initial temperature 310-375 K and initial pressure 0.1-0.3 MPa. The engine simulations show that the optimized model agrees better with the detailed chemical kinetic model (544 species and 2 446 reactions) than the original model does.

  2. A physical and chemical model of early lunar history

    Science.gov (United States)

    Hubbard, N. J.; Minear, J. W.

    1975-01-01

    A 'cool' thermal model of the moon's early history is discussed in terms of lunar petrology. Heat from the totally molten outer half of the moon's volume was, according to the model, lost to space and to the lunar interior, so that, barring additions of heat from external sources, all petrogenesis operating exclusively on material of the initially totally molten zone must have occured in an environment of decreasing temperatures. Mare basalts would result from hybridization by migration, mixing, and reequilibration of a variety of intercumulus liquids. Evidence is considered for the layered structure and a significant structural boundary that should result from differentiation of the approximately 350-km-thick initially totally molten zone. Magnetization of lunar rocks is considered.

  3. A Chemical Containment Model for the General Purpose Work Station

    Science.gov (United States)

    Flippen, Alexis A.; Schmidt, Gregory K.

    1994-01-01

    Contamination control is a critical safety requirement imposed on experiments flying on board the Spacelab. The General Purpose Work Station, a Spacelab support facility used for life sciences space flight experiments, is designed to remove volatile compounds from its internal airpath and thereby minimize contamination of the Spacelab. This is accomplished through the use of a large, multi-stage filter known as the Trace Contaminant Control System. Many experiments planned for the Spacelab require the use of toxic, volatile fixatives in order to preserve specimens prior to postflight analysis. The NASA-Ames Research Center SLS-2 payload, in particular, necessitated the use of several toxic, volatile compounds in order to accomplish the many inflight experiment objectives of this mission. A model was developed based on earlier theories and calculations which provides conservative predictions of the resultant concentrations of these compounds given various spill scenarios. This paper describes the development and application of this model.

  4. Biodegradation of organic chemicals in soil/water microcosms system: Model development

    Science.gov (United States)

    Liu, L.; Tindall, J.A.; Friedel, M.J.; Zhang, W.

    2007-01-01

    The chemical interactions of hydrophobic organic contaminants with soils and sediments may result in strong binding and slow subsequent release rates that significantly affect remediation rates and endpoints. In order to illustrate the recalcitrance of chemical to degradation on sites, a sorption mechanism of intraparticle sequestration was postulated to operate on chemical remediation sites. Pseudo-first order sequestration kinetics is used in the study with the hypothesis that sequestration is an irreversibly surface-mediated process. A mathematical model based on mass balance equations was developed to describe the fate of chemical degradation in soil/water microcosm systems. In the model, diffusion was represented by Fick's second law, local sorption-desorption by a linear isotherm, irreversible sequestration by a pseudo-first order kinetics and biodegradation by Monod kinetics. Solutions were obtained to provide estimates of chemical concentrations. The mathematical model was applied to a benzene biodegradation batch test and simulated model responses correlated well compared to measurements of biodegradation of benzene in the batch soil/water microcosm system. A sensitivity analysis was performed to assess the effects of several parameters on model behavior. Overall chemical removal rate decreased and sequestration increased quickly with an increase in the sorption partition coefficient. When soil particle radius, a, was greater than 1 mm, an increase in radius produced a significant decrease in overall chemical removal rate as well as an increase in sequestration. However, when soil particle radius was less than 0.1 mm, an increase in radius resulted in small changes in the removal rate and sequestration. As pseudo-first order sequestration rate increased, both chemical removal rate and sequestration increased slightly. Model simulation results showed that desorption resistance played an important role in the bioavailability of organic chemicals in porous

  5. Fundamental modeling issues on benchmark structure for structural health monitoring

    Institute of Scientific and Technical Information of China (English)

    LI HuaJun; ZHANG Min; WANG JunRong; HU Sau-Lon James

    2009-01-01

    The IASC-ASCE Structural Health Monitoring Task Group developed a series of benchmark problems,and participants of the benchmark study were charged with using a 12-degree-of-freedom (DOF) shear building as their identification model. The present article addresses improperness, including the parameter and modeling errors, of using this particular model for the intended purpose of damage detection, while the measurements of damaged structures are synthesized from a full-order finite-element model. In addressing parameter errors, a model calibration procedure is utilized to tune the mass and stiffness matrices of the baseline identification model, and a 12-DOF shear building model that preserves the first three modes of the full-order model is obtained. Sequentially, this calibrated model is employed as the baseline model while performing the damage detection under various damage scenarios. Numerical results indicate that the 12-DOF shear building model is an over-simplified identification model, through which only idealized damage situations for the benchmark structure can be detected. It is suggested that a more sophisticated 3-dimensional frame structure model should be adopted as the identification model, if one intends to detect local member damages correctly.

  6. Fundamental modeling issues on benchmark structure for structural health monitoring

    Institute of Scientific and Technical Information of China (English)

    HU; Sau-Lon; James

    2009-01-01

    The IASC-ASCE Structural Health Monitoring Task Group developed a series of benchmark problems, and participants of the benchmark study were charged with using a 12-degree-of-freedom (DOF) shear building as their identification model. The present article addresses improperness, including the parameter and modeling errors, of using this particular model for the intended purpose of damage detec- tion, while the measurements of damaged structures are synthesized from a full-order finite-element model. In addressing parameter errors, a model calibration procedure is utilized to tune the mass and stiffness matrices of the baseline identification model, and a 12-DOF shear building model that preserves the first three modes of the full-order model is obtained. Sequentially, this calibrated model is employed as the baseline model while performing the damage detection under various damage scenarios. Numerical results indicate that the 12-DOF shear building model is an over-simplified identification model, through which only idealized damage situations for the benchmark structure can be detected. It is suggested that a more sophisticated 3-dimensional frame structure model should be adopted as the identification model, if one intends to detect local member damages correctly.

  7. Prediction of aged red wine aroma properties from aroma chemical composition. Partial least squares regression models.

    Science.gov (United States)

    Aznar, Margarita; López, Ricardo; Cacho, Juan; Ferreira, Vicente

    2003-04-23

    Partial least squares regression (PLSR) models able to predict some of the wine aroma nuances from its chemical composition have been developed. The aromatic sensory characteristics of 57 Spanish aged red wines were determined by 51 experts from the wine industry. The individual descriptions given by the experts were recorded, and the frequency with which a sensory term was used to define a given wine was taken as a measurement of its intensity. The aromatic chemical composition of the wines was determined by already published gas chromatography (GC)-flame ionization detector and GC-mass spectrometry methods. In the whole, 69 odorants were analyzed. Both matrixes, the sensory and chemical data, were simplified by grouping and rearranging correlated sensory terms or chemical compounds and by the exclusion of secondary aroma terms or of weak aroma chemicals. Finally, models were developed for 18 sensory terms and 27 chemicals or groups of chemicals. Satisfactory models, explaining more than 45% of the original variance, could be found for nine of the most important sensory terms (wood-vanillin-cinnamon, animal-leather-phenolic, toasted-coffee, old wood-reduction, vegetal-pepper, raisin-flowery, sweet-candy-cacao, fruity, and berry fruit). For this set of terms, the correlation coefficients between the measured and predicted Y (determined by cross-validation) ranged from 0.62 to 0.81. Models confirmed the existence of complex multivariate relationships between chemicals and odors. In general, pleasant descriptors were positively correlated to chemicals with pleasant aroma, such as vanillin, beta damascenone, or (E)-beta-methyl-gamma-octalactone, and negatively correlated to compounds showing less favorable odor properties, such as 4-ethyl and vinyl phenols, 3-(methylthio)-1-propanol, or phenylacetaldehyde.

  8. Multispecies QSAR modeling for predicting the aquatic toxicity of diverse organic chemicals for regulatory toxicology.

    Science.gov (United States)

    Singh, Kunwar P; Gupta, Shikha; Kumar, Anuj; Mohan, Dinesh

    2014-05-19

    The research aims to develop multispecies quantitative structure-activity relationships (QSARs) modeling tools capable of predicting the acute toxicity of diverse chemicals in various Organization for Economic Co-operation and Development (OECD) recommended test species of different trophic levels for regulatory toxicology. Accordingly, the ensemble learning (EL) approach based classification and regression QSAR models, such as decision treeboost (DTB) and decision tree forest (DTF) implementing stochastic gradient boosting and bagging algorithms were developed using the algae (P. subcapitata) experimental toxicity data for chemicals. The EL-QSAR models were successfully applied to predict toxicities of wide groups of chemicals in other test species including algae (S. obliguue), daphnia, fish, and bacteria. Structural diversity of the selected chemicals and those of the end-point toxicity data of five different test species were tested using the Tanimoto similarity index and Kruskal-Wallis (K-W) statistics. Predictive and generalization abilities of the constructed QSAR models were compared using statistical parameters. The developed QSAR models (DTB and DTF) yielded a considerably high classification accuracy in complete data of model building (algae) species (97.82%, 99.01%) and ranged between 92.50%-94.26% and 92.14%-94.12% in four test species, respectively, whereas regression QSAR models (DTB and DTF) rendered high correlation (R(2)) between the measured and model predicted toxicity end-point values and low mean-squared error in model building (algae) species (0.918, 0.15; 0.905, 0.21) and ranged between 0.575 and 0.672, 0.18-0.51 and 0.605-0.689 and 0.20-0.45 in four different test species. The developed QSAR models exhibited good predictive and generalization abilities in different test species of varied trophic levels and can be used for predicting the toxicities of new chemicals for screening and prioritization of chemicals for regulation.

  9. Ecohydrological model parameter selection for stream health evaluation.

    Science.gov (United States)

    Woznicki, Sean A; Nejadhashemi, A Pouyan; Ross, Dennis M; Zhang, Zhen; Wang, Lizhu; Esfahanian, Abdol-Hossein

    2015-04-01

    Variable selection is a critical step in development of empirical stream health prediction models. This study develops a framework for selecting important in-stream variables to predict four measures of biological integrity: total number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa, family index of biotic integrity (FIBI), Hilsenhoff biotic integrity (HBI), and fish index of biotic integrity (IBI). Over 200 flow regime and water quality variables were calculated using the Hydrologic Index Tool (HIT) and Soil and Water Assessment Tool (SWAT). Streams of the River Raisin watershed in Michigan were grouped using the Strahler stream classification system (orders 1-3 and orders 4-6), k-means clustering technique (two clusters: C1 and C2), and all streams (one grouping). For each grouping, variable selection was performed using Bayesian variable selection, principal component analysis, and Spearman's rank correlation. Following selection of best variable sets, models were developed to predict the measures of biological integrity using adaptive-neuro fuzzy inference systems (ANFIS), a technique well-suited to complex, nonlinear ecological problems. Multiple unique variable sets were identified, all which differed by selection method and stream grouping. Final best models were mostly built using the Bayesian variable selection method. The most effective stream grouping method varied by health measure, although k-means clustering and grouping by stream order were always superior to models built without grouping. Commonly selected variables were related to streamflow magnitude, rate of change, and seasonal nitrate concentration. Each best model was effective in simulating stream health observations, with EPT taxa validation R2 ranging from 0.67 to 0.92, FIBI ranging from 0.49 to 0.85, HBI from 0.56 to 0.75, and fish IBI at 0.99 for all best models. The comprehensive variable selection and modeling process proposed here is a robust method that extends our

  10. Different Models Used to Interpret Chemical Changes: Analysis of a Curriculum and Its Impact on French Students' Reasoning

    Science.gov (United States)

    Kermen, Isabelle; Meheut, Martine

    2009-01-01

    We present an analysis of the new French curriculum on chemical changes describing the underlying models and highlighting their relations to the empirical level. The authors of the curriculum introduced a distinction between the chemical change of a chemical system and the chemical reactions that account for it. We specify the different roles of…

  11. A New Wet Deposition Module in SILAM Chemical Transport Model

    Science.gov (United States)

    Kouznetsov, R.; Sofiev, M.

    2013-12-01

    The System for Integrated modeLling of Atmopsheric coMposition SILAM (http://silam.fmi.fi/) is a CTM model of FMI air-quality research unit. SILAM is used for research, operational and emergency-response assessments and forecasting of the atmospheric composition within the scope of European and Finnish national projects. Characteristic scales of the SILAM applications vary from -mesoscale (grid spacing 1 km) up to the globe with characteristic resolution of 1 degree. Till recently, a simple approach based on scavenging coefficients and their species-dependent scaling was used in SILAM. Due to the lack of information on the vertical structure of precipitation in older meteorological datasets, it was prescribed. The new scheme uses a mechanistic description of the scavenging process and utilizes the vertical profiles of cloud water content. A simple model for dissociation of H2SO3 accounts for saturation of SO2 scavenging. As the vertical profiles of precipitation rates are rarely available from meteorological models, they are reconstructed from the profiles of cloud water and surface precipitation fields. The rain/snow increment in a 3D model grid cell is taken as a fraction of surface precipitation intensity equal to the cell's fraction of total cloud water column. The phase of precipitation (liquid/solid) is a function of air temperature. The fall speed is derived from the size of water drops given by a function of rain/snow intensity. In-cloud scavenging is considered as an equilibrium process: . the concentrations in cloud water are assumed to be in equilibrium with ambient air. The sub-cloud scavenging is driven by the precipitation that comes from above the cell. The scavenging by a single droplet is considered as a two-way equilibration process of in-water and in-air concentrations, controlled by the hydrometeors size, cross-section and a time the droplet falls through a cell, effective solubility and amount of already dissolved pollutant. The solubility for

  12. Chemical modeling for precipitation from hypersaline hydrofracturing brines.

    Science.gov (United States)

    Zermeno-Motante, Maria I; Nieto-Delgado, Cesar; Cannon, Fred S; Cash, Colin C; Wunz, Christopher C

    2016-10-15

    Hypersaline hydrofracturing brines host very high salt concentrations, as high as 120,000-330,000 mg/L total dissolved solids (TDS), corresponding to ionic strengths of 2.1-5.7 mol/kg. This is 4-10 times higher than for ocean water. At such high ionic strengths, the conventional equations for computing activity coefficients no longer apply; and the complex ion-interactive Pitzer model must be invoked. The authors herein have used the Pitzer-based PHREEQC computer program to compute the appropriate activity coefficients when forming such precipitates as BaSO4, CaSO4, MgSO4, SrSO4, CaCO3, SrCO3, and BaCO3 in hydrofracturing waters. The divalent cation activity coefficients (γM) were computed in the 0.1 to 0.2 range at 2.1 mol/kg ionic strength, then by 5.7 mol/kg ionic strength, they rose to 0.2 for Ba(2+), 0.6 for Sr(2+), 0.8 for Ca(2+), and 2.1 for Mg(2+). Concurrently, the [Formula: see text] was 0.02-0.03; and [Formula: see text] was 0.01-0.02. While employing these Pitzer-derived activity coefficients, the authors then used the PHREEQC model to characterize precipitation of several of these sulfates and carbonates from actual hydrofracturing waters. Modeled precipitation matched quite well with actual laboratory experiments and full-scale operations. Also, the authors found that SrSO4 effectively co-precipitated radium from hydrofracturing brines, as discerned when monitoring (228)Ra and other beta-emitting species via liquid scintillation; and also when monitoring gamma emissions from (226)Ra. PMID:27470293

  13. Assessing the Physical Activity of Health Volunteers Based on the Pender’s Health Promotion Model

    Directory of Open Access Journals (Sweden)

    Rahimian M.* MSc,

    2015-12-01

    Full Text Available Aims Physical inactivity has been identified as the 4th leading risk factor for global mortality causing an estimated of 3.2million deaths per year. This study aimed to assess the physical activity of health volunteers with Pender’s Health Promotion Model. Instrument & Methods This cross-sectional analytical study was performed on 80 health volunteers in Torbat-e-Jam City, Iran, in 2015. A researcher-made questionnaire with the following sections was used to gather data; perceived benefits, perceived barriers, selfefficacy, interpersonal influences, positive emotion, commitment, modeling and competing preferences. SPSS 16 sofware was used to analyze data by independent T, Pearson’s correlation coefficient and linear regression tests. Findings There was no significant difference between the scores according to educational levels, age groups, BMI score, marital status, habitat and experience as a health volunteer duration. Physical activity had positive correlation with perceived benefits, self-efficacy, commitment, positive emotion and situational influences and a negative correlation with perceived barriers. Situational influences, as the strongest predictor of the physical activity, predicted 35.1% of it and then positive emotions predicted 34.7% and self-efficacy predicted 23.4% of physical activity. Conclusion The level of physical activity in health volunteers of Torbat-e-Jam City, Iran, is not appropriate and is less than moderate.

  14. Thermo-Chemical Modelling Strategies for the Pultrusion Process

    DEFF Research Database (Denmark)

    Baran, Ismet; Hattel, Jesper Henri; Tutum, Cem Celal

    2013-01-01

    In the present study, three dimensional (3D) numerical modeling strategies of a thermosetting pultrusion process are investigated considering both transient and steady state approaches. For the transient solution, an unconditionally stable alternating direction implicit Douglas-Gunn (ADI-DG) scheme...... involves many design evaluations. On the other hand sometimes the transient regime may be of interest and here the proposed ADI-DG method shows to be considerably faster than the transient fully implicit method which is generally used by the general purpose commercial finite element solvers. Finally, using...

  15. Improved Chemical Structure-Activity Modeling Through Data Augmentation.

    Science.gov (United States)

    Cortes-Ciriano, Isidro; Bender, Andreas

    2015-12-28

    Extending the original training data with simulated unobserved data points has proven powerful to increase both the generalization ability of predictive models and their robustness against changes in the structure of data (e.g., systematic drifts in the response variable) in diverse areas such as the analysis of spectroscopic data or the detection of conserved domains in protein sequences. In this contribution, we explore the effect of data augmentation in the predictive power of QSAR models, quantified by the RMSE values on the test set. We collected 8 diverse data sets from the literature and ChEMBL version 19 reporting compound activity as pIC50 values. The original training data were replicated (i.e., augmented) N times (N ∈ 0, 1, 2, 4, 6, 8, 10), and these replications were perturbed with Gaussian noise (μ = 0, σ = σnoise) on either (i) the pIC50 values, (ii) the compound descriptors, (iii) both the compound descriptors and the pIC50 values, or (iv) none of them. The effect of data augmentation was evaluated across three different algorithms (RF, GBM, and SVM radial) and two descriptor types (Morgan fingerprints and physicochemical-property-based descriptors). The influence of all factor levels was analyzed with a balanced fixed-effect full-factorial experiment. Overall, data augmentation constantly led to increased predictive power on the test set by 10-15%. Injecting noise on (i) compound descriptors or on (ii) both compound descriptors and pIC50 values led to the highest drop of RMSEtest values (from 0.67-0.72 to 0.60-0.63 pIC50 units). The maximum increase in predictive power provided by data augmentation is reached when the training data is replicated one time. Therefore, extending the original training data with one perturbed repetition thereof represents a reasonable trade-off between the increased performance of the models and the computational cost of data augmentation, namely increase of (i) model complexity due to the need for optimizing

  16. Personality is of central concern to understand health: towards a theoretical model for health psychology.

    Science.gov (United States)

    Ferguson, Eamonn

    2013-05-01

    This paper sets out the case that personality traits are central to health psychology. To achieve this, three aims need to be addressed. First, it is necessary to show that personality influences a broad range of health outcomes and mechanisms. Second, the simple descriptive account of Aim 1 is not sufficient, and a theoretical specification needs to be developed to explain the personality-health link and allow for future hypothesis generation. Third, once Aims 1 and 2 are met, it is necessary to demonstrate the clinical utility of personality. In this review I make the case that all three Aims are met. I develop a theoretical framework to understand the links between personality and health drawing on current theorising in the biology, evolution, and neuroscience of personality. I identify traits (i.e., alexithymia, Type D, hypochondriasis, and empathy) that are of particular concern to health psychology and set these within evolutionary cost-benefit analysis. The literature is reviewed within a three-level hierarchical model (individual, group, and organisational) and it is argued that health psychology needs to move from its traditional focus on the individual level to engage group and organisational levels.

  17. A priori modeling of chemical reactions on computational grid platforms: Workflows and data models

    International Nuclear Information System (INIS)

    Graphical abstract: The quantum framework of the Grid Empowered Molecular Simulator GEMS assembled on the European Grid allows the ab initio evaluation of the dynamics of small systems starting from the calculation of the electronic properties. Highlights: ► The grid based GEMS simulator accurately models small chemical systems. ► Q5Cost and D5Cost file formats provide interoperability in the workflow. ► Benchmark runs on H + H2 highlight the Grid empowering. ► O + O2 and N + N2 calculated k (T)’s fall within the error bars of the experiment. - Abstract: The quantum framework of the Grid Empowered Molecular Simulator GEMS has been assembled on the segment of the European Grid devoted to the Computational Chemistry Virtual Organization. The related grid based workflow allows the ab initio evaluation of the dynamics of small systems starting from the calculation of the electronic properties. Interoperability between computational codes across the different stages of the workflow was made possible by the use of the common data formats Q5Cost and D5Cost. Illustrative benchmark runs have been performed on the prototype H + H2, N + N2 and O + O2 gas phase exchange reactions and thermal rate coefficients have been calculated for the last two. Results are discussed in terms of the modeling of the interaction and advantages of using the Grid is highlighted.

  18. Modeling a Mobile Health Management Business Model for Chronic Kidney Disease.

    Science.gov (United States)

    Lee, Ying-Li; Chang, Polun

    2016-01-01

    In these decades, chronic kidney disease (CKD) has become a global public health problem. Information technology (IT) tools have been used widely to empower the patients with chronic disease (e.g., diabetes and hypertension). It is also a potential application to advance the CKD care. In this project, we analyzed the requirements of a mobile health management system for healthcare workers, patients and their families to design a health management business model for CKD patients. PMID:27332476

  19. Unnecessary Chemicals

    Science.gov (United States)

    Johnson, Anita

    1978-01-01

    Discusses the health hazards resulting from chemical additions of many common products such as cough syrups, food dyes, and cosmetics. Steps being taken to protect consumers from these health hazards are included. (MDR)

  20. The health belief model and consumer information searches: toward an integrated model.

    Science.gov (United States)

    Risker, D C

    1996-01-01

    Some health data organizations (HDOs) are producing consumer-level health services information. National reform proposals would suggest that competition between health plans will be developed through the use of outcome information. Policy makers have paid little attention to how consumers might use that information or how that information might be most effectively packaged for consumer use. This paper argues that marketing literature developed over the last ten to fifteen years could prove to be an informative resource for policy makers and the health services provider community alike. This paper suggests that combining a consumer decision model (CDM) with the health belief model (HBM) will provide an important step toward an increased understanding of consumer information search behavior. This integrated model could form the basis of future research in this important area.

  1. Phase Characterization of Cucumber Growth: A Chemical Gel Model

    Directory of Open Access Journals (Sweden)

    Bo Li

    2016-01-01

    Full Text Available Cucumber grows with complex phenomena by changing its volume and shape, which is not fully investigated and challenges agriculture and food safety industry. In order to understand the mechanism and to characterize the growth process, the cucumber is modeled as a hydrogel in swelling and its development is studied in both preharvest and postharvest stages. Based on thermodynamics, constitutive equations, incorporating biological quantities, are established. The growth behavior of cucumber follows the classic theory of continuous or discontinuous phase transition. The mechanism of bulged tail in cucumber is interpreted by phase coexistence and characterized by critical conditions. Conclusions are given for advances in food engineering and novel fabrication techniques in mechanical biology.

  2. Computer-Aided Modelling of Short-Path Evaporation for Chemical Product Purification, Analysis and Design

    DEFF Research Database (Denmark)

    Sales-Cruz, Alfonso Mauricio; Gani, Rafiqul

    2006-01-01

    An important stage in the design process for many chemical products is its manufacture where, for a class of chemical products that may be thermally unstable (such as, drugs, insecticides, flavours /fragrances, and so on), the purification step plays a major role. Short-path evaporation is a safe...... through a computer-aided modelling framework, which allows the use of systematic simulation strategies for various types of design/analysis problems. The main features of the model and the modelling framework are highlighted through two case studies: (a) the purification of a reaction mixture containing...

  3. Modeling the Emission of CO from Wood Fires using Detailed Chemical Kinetics

    DEFF Research Database (Denmark)

    Dederichs, Anne

    Carbon monoxide is treated as one of the most common and dangerous of gases evolving in fires. Modeling the formation of the toxic gas CO from in fire enclosures using detailed chemical kinetics is the topic of this manuscript. A semi-empirical model is developed to study the formation of CO from...... birch wood using detailed chemical kinetics on the combustion of pyrolysis gas from birch wood. The composition of the pyrolysis gas is taken from the experiment by Zanzi and coworkers. The numerical model applies a counter flow configuration involving 84 chemical species and 804 reactions. Hence......, the model separately treats the process of pyrolysis and combustion. For under ventilated conditions and at high temperatures during pyrolysis it is found that the process of pyrolysation strongly influences the formation of CO in fire. CO2 follows the same trend....

  4. Modelling of the Absorption and Desorption Process of Chemical Heat Pumps

    Institute of Scientific and Technical Information of China (English)

    Gui-PingLin; Xiu-GanYuan

    1993-01-01

    A simple model for the desorption and absorption process of the chemical heat pump is presented in this paper .It is based on the assumption of a definite reaction front.The results from this model are compared with those obtained by finite difference method and it is observed that there is almost no difference between them.

  5. On modeling of the evaporation of chemical warfare agents on the ground

    NARCIS (Netherlands)

    Westin, S.N.; Winter, S.; Karlsson, E.; Hin, A.; Oeseburg, F.

    1998-01-01

    A model for evaporation of chemical warfare agents on the ground has been developed. The process of evaporation is described in three steps: (1) the immediate drop enlargement due to impact momentum is modeled using an empirical correlation from technical literature; (2) further enlargement caused b

  6. Building a model based on scientific consensus for Life Cycle Impact Assessment of chemicals:

    DEFF Research Database (Denmark)

    Hauschild, Michael Zwicky; Huijbregts, Mark; Jolliet, Olivier;

    2008-01-01

    Achieving consensus among scientists is often a challenge - particularly in model development. In this article we describe a recent scientific consensus-building process for Life Cycle Impact Assessment (LCIA) models applied to chemical emissions - including the strategy, execution, and results...

  7. Chemical reaction model of cathode failure in large prebaked anode aluminum reduction cells

    Institute of Scientific and Technical Information of China (English)

    赵群; 谢雁丽; 高炳亮; 邱竹贤; 赵无畏

    2002-01-01

    By partial and general dissection of large prebaked alumina electrolysis cells, the macro appearance, chemical composition and phase variations were studied employing actual observations and measurements on the cells together with X-ray diffraction phase analysis and scanning electron microscopy of samples from different locations. According to the practical production, a chemical reaction model of aluminum reduction cell failure was set up in order to reduce the incidence of cell failure and extend pot service life.

  8. Precipitation of niobium carbonitrides in ferrite: chemical composition measurements and thermodynamic modelling

    OpenAIRE

    Perez, Michel; Courtois, E.; Acevedo, D.; T. Epicier; Maugis, Philippe

    2007-01-01

    High-resolution transmission electron microscopy and electron-energy loss spectroscopy have been used to characterize the structure and chemical composition of niobium carbonitrides in the ferrite of a Fe–Nb–C–N model alloy at different precipitation stages. Experiments seem to indicate the coexistence of two types of precipitates: pure niobium nitrides and mixed substoichiometric niobium carbonitrides. In order to understand the chemical composition of these precipitates, a thermodynamic for...

  9. Molecular finite-size effects in stochastic models of equilibrium chemical systems

    OpenAIRE

    Cianci, Claudia; Smith, Stephen; Grima, Ramon

    2016-01-01

    The reaction-diffusion master equation (RDME) is a standard modelling approach for understanding stochastic and spatial chemical kinetics. An inherent assumption is that molecules are point-like. Here, we introduce the excluded volume reaction-diffusion master equation (vRDME) which takes into account volume exclusion effects on stochastic kinetics due to a finite molecular radius. We obtain an exact closed form solution of the RDME and of the vRDME for a general chemical system in equilibriu...

  10. Modeling accidental releases to the atmosphere of a dense reactive chemical (Uranium hexafluoride)

    Science.gov (United States)

    Hanna, Steven R.; Chang, Joseph C.; Zhang, Xiaoming J.

    In order to model the atmospheric transport and dispersion of dense reactive chemicals such as uranium hexafluoride (UF 6), it is necessary to include algorithms that account for heat exchanges due to chemical reactions and phase changes. UF 6 may be released accidentally at uranium-enrichment plants as a warm gas from a pipeline rupture, or as a flashing liquid from a pressurized tank or line break. The resulting plume is initially very dense due to the large molecular weight of UF 6, but may become lighter-than-air as the UF 6 reacts with water vapor to form HF, which has a molecular weight less than that of air, and which may cause an increase in plume temperature due to the exothermic reaction. The major chemical and thermodynamic processes related to UF 6 have been incorporated in a modified version of an existing dense gas model, HGSYSTEM. The same general approach could be used to include other reactive chemicals in the modeling system. New modules that are applicable to any type of chemical release have also been added to HGSYSTEM to account for building downwash, lift-off of warm plumes from the ground, and deposition. The revised HGSYSTEM/UF 6 model has been evaluated with field data from UF 6 tests. The sensitivities of the model predictions to variations in input parameters have been assessed.

  11. Developing explanatory models of health inequalities in childhood dental caries

    DEFF Research Database (Denmark)

    Pine, Cynthia M; Adair, Pauline M; Petersen, Poul Erik;

    2004-01-01

    protocol and development of two standardised measures. First, to investigate how parental attitudes may impact on their children's oral health-related behaviours and second, to assess how dentists' attitudes may impact on the provision of dental care. SUBJECTS: Core research team, lead methodologists, 44......OBJECTIVE: Long-term aim is to determine optimum interventions to reduce dental caries in children in disadvantaged communities and minimise the effects of exclusion from health care systems, of ethnic diversity, and health inequalities. DESIGN: Generation of initial explanatory models, study...... consortium members from 18 countries. To complete the development of the questionnaire, the initial set of items was administered to parents (n = 23) with children in nursery schools in Dundee, Scotland and sent to the same parents one week later. A standardised measure examining barriers to providing dental...

  12. Immigration and etnosalud: Possibility of a differential model of health.

    Directory of Open Access Journals (Sweden)

    Ofelia Restrepo V

    2009-05-01

    Full Text Available AbstractSpain is a host of Latin American immigrants; the most prominent in number are ecuadorians, colombians, argentines and bolivians. At present, by their very nature, causes and effects, human migrations are considered as a phenomenon of social catastrophe and public health problem. It is a fact that disturbs the balance of physical, psychological, emotional, social, cultural and ecological people. In this sense the host countries should raise differential models and comprehensive health care and responsive to the needs and articulate the various skills and knowledge of medicine (Western-traditional. This communication presents some results of the survey conducted for this purpose, through the Participatory Action Research and development of a diagnostic Etnosalud.‡ The results are: conceptual changes, values and meaning in the categories of person-family-community, health-disease, time-space, body-mind-spirit in the identity, rootedness, a sense of belonging and the epidemiological profile of immigrant.

  13. A coupled physical-biological-chemical model for the Indian Ocean

    Indian Academy of Sciences (India)

    P S Swathi; M K Sharada; K S Yajnik

    2000-12-01

    A coupled physical-biological-chemical model has been developed at C-MMACS. for studying the time- variation of primary productivity and air-sea carbon-dioxide exchange in the Indian Ocean. The physical model is based on the Modular Ocean Model, Version 2 (MOM2) and the biological model describes the nonlinear dynamics of a 7-component marine ecosystem. The chemical model includes dynamical equation for the evolution of dissolved inorganic carbon and total alkalinity. The interaction between the biological and chemical model is through the Redfield ratio. The partial pressure of carbon dioxide pCO2 of the surface layer is obtained from the chemical equilibrium equations of Peng et al 1987. Transfer coefficients for air-sea exchange of CO2 are computed dynamically based on the wind speeds. The coupled model reproduces the high productivity observed in the Arabian Sea off the Somali and Omani coasts during the Southwest (SW) monsoon. The entire Arabian Sea is an outgassing region for CO2 in spite of high productivity with transfer rates as high as 80 m-mol C/m2/day during SW monsoon near the Somali Coast on account of strong winds.

  14. Towards an Integrated Model of Earth's Thermo-Chemical Evolution and Plate Tectonics

    Science.gov (United States)

    Tackley, P. J.; Xie, S.

    2001-05-01

    It has long been a challenge for geodynamicists, who have typically modeled homogeneous mantles, to explain the geochemical evidence for the existence of several distinct chemical reservoirs, in terms of a dynamically and chemically self-consistent model. While the mixing behavior of generalized tracers has received much attention in the modeling community, a recent trend has been towards mantle convection models that track the evolution of specific chemical species, both major and minor, and can thus be related to geochemical observations. However, obtaining realistic chemical evolution in such models is dependent on their having a reasonable representation of plate tectonic behavior since the recycling of oceanic crust and complementary depleted residuum is a key process in Earth that other terrestrial planets may lack. In general, this has required inserting plate motions by hand in models. In recent years, however, we have learned how to perform numerical simulations of mantle convection in which plate tectonic behavior is introduced self-consistently through plastic yielding of the lithosphere. In this presentation, models of mantle convection that combine a treatment of geochemical evolution with self-consistently generated plate tectonics, will be presented. Preliminary results indicate that the system can self-consistently evolve regions which have a HIMU-like signature as well as regions with a high He3/He4 ratio.

  15. Requirements model for an e-Health awareness portal

    Science.gov (United States)

    Hussain, Azham; Mkpojiogu, Emmanuel O. C.; Nawi, Mohd Nasrun M.

    2016-08-01

    Requirements engineering is at the heart and foundation of software engineering process. Poor quality requirements inevitably lead to poor quality software solutions. Also, poor requirement modeling is tantamount to designing a poor quality product. So, quality assured requirements development collaborates fine with usable products in giving the software product the needed quality it demands. In the light of the foregoing, the requirements for an e-Ebola Awareness Portal were modeled with a good attention given to these software engineering concerns. The requirements for the e-Health Awareness Portal are modeled as a contribution to the fight against Ebola and helps in the fulfillment of the United Nation's Millennium Development Goal No. 6. In this study requirements were modeled using UML 2.0 modeling technique.

  16. Medicinal plants recommended by the world health organization: DNA barcode identification associated with chemical analyses guarantees their quality.

    Directory of Open Access Journals (Sweden)

    Rafael Melo Palhares

    Full Text Available Medicinal plants are used throughout the world, and the regulations defining their proper use, such as identification of the correct species and verification of the presence, purity and concentration of the required chemical compounds, are widely recognized. Herbal medicines are made from vegetal drugs, the processed products of medicinal species. These processed materials present a number of challenges in terms of botanical identification, and according to the World Health Organization (WHO, the use of incorrect species is a threat to consumer safety. The samples used in this study consisted of the dried leaves, flowers and roots of 257 samples from 8 distinct species approved by the WHO for the production of medicinal herbs and sold in Brazilian markets. Identification of the samples in this study using DNA barcoding (matK, rbcL and ITS2 regions revealed that the level of substitutions may be as high as 71%. Using qualitative and quantitative chemical analyses, this study identified situations in which the correct species was being sold, but the chemical compounds were not present. Even more troubling, some samples identified as substitutions using DNA barcoding contained the chemical compounds from the correct species at the minimum required concentration. This last situation may lead to the use of unknown species or species whose safety for human consumption remains unknown. This study concludes that DNA barcoding should be used in a complementary manner for species identification with chemical analyses to detect and quantify the required chemical compounds, thus improving the quality of this class of medicines.

  17. Medicinal plants recommended by the world health organization: DNA barcode identification associated with chemical analyses guarantees their quality.

    Science.gov (United States)

    Palhares, Rafael Melo; Gonçalves Drummond, Marcela; Dos Santos Alves Figueiredo Brasil, Bruno; Pereira Cosenza, Gustavo; das Graças Lins Brandão, Maria; Oliveira, Guilherme

    2015-01-01

    Medicinal plants are used throughout the world, and the regulations defining their proper use, such as identification of the correct species and verification of the presence, purity and concentration of the required chemical compounds, are widely recognized. Herbal medicines are made from vegetal drugs, the processed products of medicinal species. These processed materials present a number of challenges in terms of botanical identification, and according to the World Health Organization (WHO), the use of incorrect species is a threat to consumer safety. The samples used in this study consisted of the dried leaves, flowers and roots of 257 samples from 8 distinct species approved by the WHO for the production of medicinal herbs and sold in Brazilian markets. Identification of the samples in this study using DNA barcoding (matK, rbcL and ITS2 regions) revealed that the level of substitutions may be as high as 71%. Using qualitative and quantitative chemical analyses, this study identified situations in which the correct species was being sold, but the chemical compounds were not present. Even more troubling, some samples identified as substitutions using DNA barcoding contained the chemical compounds from the correct species at the minimum required concentration. This last situation may lead to the use of unknown species or species whose safety for human consumption remains unknown. This study concludes that DNA barcoding should be used in a complementary manner for species identification with chemical analyses to detect and quantify the required chemical compounds, thus improving the quality of this class of medicines. PMID:25978064

  18. Medicinal Plants Recommended by the World Health Organization: DNA Barcode Identification Associated with Chemical Analyses Guarantees Their Quality

    Science.gov (United States)

    Palhares, Rafael Melo; Gonçalves Drummond, Marcela; dos Santos Alves Figueiredo Brasil, Bruno; Pereira Cosenza, Gustavo; das Graças Lins Brandão, Maria; Oliveira, Guilherme

    2015-01-01

    Medicinal plants are used throughout the world, and the regulations defining their proper use, such as identification of the correct species and verification of the presence, purity and concentration of the required chemical compounds, are widely recognized. Herbal medicines are made from vegetal drugs, the processed products of medicinal species. These processed materials present a number of challenges in terms of botanical identification, and according to the World Health Organization (WHO), the use of incorrect species is a threat to consumer safety. The samples used in this study consisted of the dried leaves, flowers and roots of 257 samples from 8 distinct species approved by the WHO for the production of medicinal herbs and sold in Brazilian markets. Identification of the samples in this study using DNA barcoding (matK, rbcL and ITS2 regions) revealed that the level of substitutions may be as high as 71%. Using qualitative and quantitative chemical analyses, this study identified situations in which the correct species was being sold, but the chemical compounds were not present. Even more troubling, some samples identified as substitutions using DNA barcoding contained the chemical compounds from the correct species at the minimum required concentration. This last situation may lead to the use of unknown species or species whose safety for human consumption remains unknown. This study concludes that DNA barcoding should be used in a complementary manner for species identification with chemical analyses to detect and quantify the required chemical compounds, thus improving the quality of this class of medicines. PMID:25978064

  19. Managing the health of the elite athlete: a new integrated performance health management and coaching model.

    Science.gov (United States)

    Dijkstra, H Paul; Pollock, N; Chakraverty, R; Alonso, J M

    2014-04-01

    Elite athletes endeavour to train and compete even when ill or injured. Their motivation may be intrinsic or due to coach and team pressures. The sports medicine physician plays an important role to risk-manage the health of the competing athlete in partnership with the coach and other members of the support team. The sports medicine physician needs to strike the right ethical and operational balance between health management and optimising performance. It is necessary to revisit the popular delivery model of sports medicine and science services to elite athletes based on the current reductionist multispecialist system lacking in practice an integrated approach and effective communication. Athlete and coach in isolation or with a member of the multidisciplinary support team, often not qualified or experienced to do so, decide on the utilisation of services and how to apply the recommendations. We propose a new Integrated Performance Health Management and Coaching model based on the UK Athletics experience in preparation for the London Olympic and Paralympic Games. The Medical and Coaching Teams are managed by qualified and experienced individuals operating in synergy towards a common performance goal, accountable to a Performance Director and ultimately to the Board of Directors. We describe the systems, processes and implementation strategies to assist the athlete, coach and support teams to continuously monitor and manage athlete health and performance. These systems facilitate a balanced approach to training and competing decisions, especially while the athlete is ill or injured. They take into account the best medical advice and athlete preference. This Integrated Performance Health Management and Coaching model underpinned the Track and Field Gold Medal performances at the London Olympic and Paralympic Games. PMID:24620040

  20. Advancing the Selection of Neurodevelopmental Measures in Epidemiological Studies of Environmental Chemical Exposure and Health Effects

    Directory of Open Access Journals (Sweden)

    Laura Gutermuth Anthony

    2010-01-01

    Full Text Available With research suggesting increasing incidence of pediatric neurodevelopmental disorders, questions regarding etiology continue to be raised. Neurodevelopmental function tests have been used in epidemiology studies to evaluate relationships between environmental chemical exposures and neurodevelopmental deficits. Limitations of currently used tests and difficulties with their interpretation have been described, but a comprehensive critical examination of tests commonly used in studies of environmental chemicals and pediatric neurodevelopmental disorders has not been conducted. We provide here a listing and critical evaluation of commonly used neurodevelopmental tests in studies exploring effects from chemical exposures and recommend measures that are not often used, but should be considered. We also discuss important considerations in selecting appropriate tests and provide a case study by reviewing the literature on polychlorinated biphenyls.

  1. The Relationship between Odour Annoyance Scores and Modelled Ambient Air Pollution in Sarnia, “Chemical Valley”, Ontario

    Directory of Open Access Journals (Sweden)

    Dominic Odwa Atari

    2009-10-01

    Full Text Available This study aimed at establishing the relationship between annoyance scores and modelled air pollution in “Chemical Valley”, Sarnia, Ontario (Canada. Annoyance scores were taken from a community health survey (N = 774; and respondents’ exposure to nitrogen dioxide (NO2 and sulphur dioxide (SO2 were estimated using land use regression (LUR models. The associations were examined by univariate analysis while multivariate logistic regression was used to examine the determinants of odour annoyance. The results showed that odour annoyance was significantly correlated to modelled pollutants at the individual (NO2, r = 0.15; SO2, r = 0.13 and census tract (NO2, r = 0.56; SO2, r = 0.67 levels. The exposure-response relationships show that residents of Sarnia react to very low pollution concentrations levels even if they are within the Ontario ambient air quality criteria. The study found that exposure to high NO2 and SO2 concentrations, gender, and perception of health effects were significant determinants of individual odour annoyance reporting. The observed association between odour annoyance and modelled ambient pollution suggest that individual and census tract level annoyance scores may serve as proxies for air quality in exposed communities because they capture the within area spatial variability of pollution. However, questionnaire-based odour annoyance scores need to be validated longitudinally and across different scales if they are to be adopted for use at the national level.

  2. A path forward in the debate over health impacts of endocrine disrupting chemicals

    DEFF Research Database (Denmark)

    Zoeller, Robert T; Bergmann, Åke; Becher, Georg;

    2014-01-01

    and risk assessment reviewed the various aspects of the debate to identify the most significant areas of dispute and to propose a path forward. We identified four areas of debate. The first is about the definitions for terms such as "endocrine disrupting chemical", "adverse effects", and "endocrine system......Several recent publications reflect debate on the issue of "endocrine disrupting chemicals" (EDCs), indicating that two seemingly mutually exclusive perspectives are being articulated separately and independently. Considering this, a group of scientists with expertise in basic science, medicine...

  3. Description and evaluation of the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4

    Directory of Open Access Journals (Sweden)

    L. K. Emmons

    2010-01-01

    Full Text Available The Model for Ozone and Related chemical Tracers, version 4 (MOZART-4 is an offline global chemical transport model particularly suited for studies of the troposphere. The updates of the model from its previous version MOZART-2 are described, including an expansion of the chemical mechanism to include more detailed hydrocarbon chemistry and bulk aerosols. Online calculations of a number of processes, such as dry deposition, emissions of isoprene and monoterpenes and photolysis frequencies, are now included. Results from an eight-year simulation (2000–2007 are presented and evaluated. The MOZART-4 source code and standard input files are available for download from the NCAR Community Data Portal (http://cdp.ucar.edu.

  4. Multi-pathway exposure modeling of chemicals in cosmetics with application to shampoo.

    Science.gov (United States)

    Ernstoff, Alexi S; Fantke, Peter; Csiszar, Susan A; Henderson, Andrew D; Chung, Susie; Jolliet, Olivier

    2016-01-01

    We present a novel multi-pathway, mass balance based, fate and exposure model compatible with life cycle and high-throughput screening assessments of chemicals in cosmetic products. The exposures through product use as well as post-use emissions and environmental media were quantified based on the chemical mass originally applied via a product, multiplied by the product intake fractions (PiF, the fraction of a chemical in a product that is taken in by exposed persons) to yield intake rates. The average PiFs for the evaluated chemicals in shampoo ranged from 3×10(-4) up to 0.3 for rapidly absorbed ingredients. Average intake rates ranged between nano- and micrograms per kilogram bodyweight per day; the order of chemical prioritization was strongly affected by the ingredient concentration in shampoo. Dermal intake and inhalation (for 20% of the evaluated chemicals) during use dominated exposure, while the skin permeation coefficient dominated the estimated uncertainties. The fraction of chemical taken in by a shampoo user often exceeded, by orders of magnitude, the aggregated fraction taken in by the population through post-use environmental emissions. Chemicals with relatively high octanol-water partitioning and/or volatility, and low molecular weight tended to have higher use stage exposure. Chemicals with low intakes during use (<1%) and subsequent high post-use emissions, however, may yield comparable intake for a member of the general population. The presented PiF based framework offers a novel and critical advancement for life cycle assessments and high-throughput exposure screening of chemicals in cosmetic products demonstrating the importance of consistent consideration of near- and far-field multi-pathway exposures. PMID:27062422

  5. Multi-pathway exposure modeling of chemicals in cosmetics with application to shampoo.

    Science.gov (United States)

    Ernstoff, Alexi S; Fantke, Peter; Csiszar, Susan A; Henderson, Andrew D; Chung, Susie; Jolliet, Olivier

    2016-01-01

    We present a novel multi-pathway, mass balance based, fate and exposure model compatible with life cycle and high-throughput screening assessments of chemicals in cosmetic products. The exposures through product use as well as post-use emissions and environmental media were quantified based on the chemical mass originally applied via a product, multiplied by the product intake fractions (PiF, the fraction of a chemical in a product that is taken in by exposed persons) to yield intake rates. The average PiFs for the evaluated chemicals in shampoo ranged from 3×10(-4) up to 0.3 for rapidly absorbed ingredients. Average intake rates ranged between nano- and micrograms per kilogram bodyweight per day; the order of chemical prioritization was strongly affected by the ingredient concentration in shampoo. Dermal intake and inhalation (for 20% of the evaluated chemicals) during use dominated exposure, while the skin permeation coefficient dominated the estimated uncertainties. The fraction of chemical taken in by a shampoo user often exceeded, by orders of magnitude, the aggregated fraction taken in by the population through post-use environmental emissions. Chemicals with relatively high octanol-water partitioning and/or volatility, and low molecular weight tended to have higher use stage exposure. Chemicals with low intakes during use (<1%) and subsequent high post-use emissions, however, may yield comparable intake for a member of the general population. The presented PiF based framework offers a novel and critical advancement for life cycle assessments and high-throughput exposure screening of chemicals in cosmetic products demonstrating the importance of consistent consideration of near- and far-field multi-pathway exposures.

  6. A Lines-of-Defense Model for Managing Health Threats

    Science.gov (United States)

    Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

    2013-01-01

    As older individuals face challenges of progressive disease, increasing disability and approach the end of their lives, their capacity for controlling their environment and own health and functioning declines. The Lines-of-Defense Model is based on the Motivational Theory of Life-Span Development and proposes that individuals can adjust their control striving to the progressive physical decline in distinctly organized cycles of goal engagement and goal disengagement that reflect sequentially organized lines of defense. This organized process allows individuals to hold onto and defend still feasible levels of physical health and functioning in activities of daily living, while adjusting to increasing impairments. As physical constraints become more severe towards the end of life, avoiding psychological suffering becomes the focus of individuals' strivings for control. The lines of defense model can also be applied to the inverse process of growth in functioning during recovery and rehabilitation. PMID:23816691

  7. A priori modeling of chemical reactions on computational grid platforms: Workflows and data models

    Energy Technology Data Exchange (ETDEWEB)

    Rampino, S., E-mail: ser_ram@dyn.unipg.it [Dipartimento di Chimica, Universita degli Studi di Perugia, Via Elce di Sotto 8, 06123 Perugia (Italy); Monari, A. [SRSMC-Equipe de Chimie et Biochimie Theoriques, Nancy-Universite et CNRS, Bp70239 Boulevard des Aiguilettes, 54506 Vandoeuvre-les-Nancy Cedex (France); Rossi, E. [CINECA, Via Manganelli 6/3, 40033 Casalecchio di Reno, Bologna (Italy); Evangelisti, S. [Laboratoire de Chimie et de Physique Quantiques, Universite Paul Sabatier Toulouse III et CNRS, 118 Route de Narbonne, 31062 Toulouse Cedex 4 (France); Lagana, A. [Dipartimento di Chimica, Universita degli Studi di Perugia, Via Elce di Sotto 8, 06123 Perugia (Italy)

    2012-04-04

    Graphical abstract: The quantum framework of the Grid Empowered Molecular Simulator GEMS assembled on the European Grid allows the ab initio evaluation of the dynamics of small systems starting from the calculation of the electronic properties. Highlights: Black-Right-Pointing-Pointer The grid based GEMS simulator accurately models small chemical systems. Black-Right-Pointing-Pointer Q5Cost and D5Cost file formats provide interoperability in the workflow. Black-Right-Pointing-Pointer Benchmark runs on H + H{sub 2} highlight the Grid empowering. Black-Right-Pointing-Pointer O + O{sub 2} and N + N{sub 2} calculated k (T)'s fall within the error bars of the experiment. - Abstract: The quantum framework of the Grid Empowered Molecular Simulator GEMS has been assembled on the segment of the European Grid devoted to the Computational Chemistry Virtual Organization. The related grid based workflow allows the ab initio evaluation of the dynamics of small systems starting from the calculation of the electronic properties. Interoperability between computational codes across the different stages of the workflow was made possible by the use of the common data formats Q5Cost and D5Cost. Illustrative benchmark runs have been performed on the prototype H + H{sub 2}, N + N{sub 2} and O + O{sub 2} gas phase exchange reactions and thermal rate coefficients have been calculated for the last two. Results are discussed in terms of the modeling of the interaction and advantages of using the Grid is highlighted.

  8. Photochemical modeling in California with two chemical mechanisms: model intercomparison and response to emission reductions.

    Science.gov (United States)

    Cai, Chenxia; Kelly, James T; Avise, Jeremy C; Kaduwela, Ajith P; Stockwell, William R

    2011-05-01

    An updated version of the Statewide Air Pollution Research Center (SAPRC) chemical mechanism (SAPRC07C) was implemented into the Community Multiscale Air Quality (CMAQ) version 4.6. CMAQ simulations using SAPRC07C and the previously released version, SAPRC99, were performed and compared for an episode during July-August, 2000. Ozone (O3) predictions of the SAPRC07C simulation are generally lower than those of the SAPRC99 simulation in the key areas of central and southern California, especially in areas where modeled concentrations are greater than the federal 8-hr O3 standard of 75 parts per billion (ppb) and/or when the volatile organic compound (VOC)/nitrogen oxides (NOx) ratio is less than 13. The relative changes of ozone production efficiency (OPE) against the VOC/NOx ratio at 46 sites indicate that the OPE is reduced in SAPRC07C compared with SAPRC99 at most sites by as much as approximately 22%. The SAPRC99 and SAPRC07C mechanisms respond similarly to 20% reductions in anthropogenic VOC emissions. The response of the mechanisms to 20% NOx emissions reductions can be grouped into three cases. In case 1, in which both mechanisms show a decrease in daily maximum 8-hr O3 concentration with decreasing NOx emissions, the O3 decrease in SAPRC07C is smaller. In case 2, in which both mechanisms show an increase in O3 with decreasing NOx emissions, the O3 increase is larger in SAPRC07C. In case 3, SAPRC07C simulates an increase in O3 in response to reduced NOx emissions whereas SAPRC99 simulates a decrease in O3 for the same region. As a result, the areas where NOx controls would be disbeneficial are spatially expanded in SAPRC07C. Although the results presented here are valuable for understanding differences in predictions and model response for SAPRC99 and SAPRC07C, the study did not evaluate the impact of mechanism differences in the context of the U.S. Environmental Protection Agency's guidance for using numerical models in demonstrating air quality attainment

  9. Photochemical modeling in California with two chemical mechanisms: model intercomparison and response to emission reductions.

    Science.gov (United States)

    Cai, Chenxia; Kelly, James T; Avise, Jeremy C; Kaduwela, Ajith P; Stockwell, William R

    2011-05-01

    An updated version of the Statewide Air Pollution Research Center (SAPRC) chemical mechanism (SAPRC07C) was implemented into the Community Multiscale Air Quality (CMAQ) version 4.6. CMAQ simulations using SAPRC07C and the previously released version, SAPRC99, were performed and compared for an episode during July-August, 2000. Ozone (O3) predictions of the SAPRC07C simulation are generally lower than those of the SAPRC99 simulation in the key areas of central and southern California, especially in areas where modeled concentrations are greater than the federal 8-hr O3 standard of 75 parts per billion (ppb) and/or when the volatile organic compound (VOC)/nitrogen oxides (NOx) ratio is less than 13. The relative changes of ozone production efficiency (OPE) against the VOC/NOx ratio at 46 sites indicate that the OPE is reduced in SAPRC07C compared with SAPRC99 at most sites by as much as approximately 22%. The SAPRC99 and SAPRC07C mechanisms respond similarly to 20% reductions in anthropogenic VOC emissions. The response of the mechanisms to 20% NOx emissions reductions can be grouped into three cases. In case 1, in which both mechanisms show a decrease in daily maximum 8-hr O3 concentration with decreasing NOx emissions, the O3 decrease in SAPRC07C is smaller. In case 2, in which both mechanisms show an increase in O3 with decreasing NOx emissions, the O3 increase is larger in SAPRC07C. In case 3, SAPRC07C simulates an increase in O3 in response to reduced NOx emissions whereas SAPRC99 simulates a decrease in O3 for the same region. As a result, the areas where NOx controls would be disbeneficial are spatially expanded in SAPRC07C. Although the results presented here are valuable for understanding differences in predictions and model response for SAPRC99 and SAPRC07C, the study did not evaluate the impact of mechanism differences in the context of the U.S. Environmental Protection Agency's guidance for using numerical models in demonstrating air quality attainment

  10. Modelling chemical composition in electric systems ? implications to the dynamics of dye-sensitised solar cells

    OpenAIRE

    Kovanen, T.; Tarhasaari, T.; Kettunen, L.; Korppi-Tommola, J.

    2010-01-01

    Abstract Classical electromagnetism provides limited means to model electric generators. To extend the classical theory in this respect, additional information on microscopic processes is required. In semiconductor devices and electrochemical generators such information may be obtained by modelling chemical composition. Here we use this approach for the modelling of dye-sensitised solar cells. We simulate the steady-state current-voltage characteristics of such a cell, as well as i...

  11. A Lines-of-Defense Model for Managing Health Threats

    OpenAIRE

    Heckhausen, Jutta; Wrosch, Carsten; Schulz, Richard

    2013-01-01

    As older individuals face challenges of progressive disease, increasing disability and approach the end of their lives, their capacity for controlling their environment and own health and functioning declines. The Lines-of-Defense Model is based on the Motivational Theory of Life-Span Development and proposes that individuals can adjust their control striving to the progressive physical decline in distinctly organized cycles of goal engagement and goal disengagement that reflect sequentially ...

  12. A public health model of Medicaid emergency room use

    OpenAIRE

    de Alteriis, Martin; Fanning, Thomas

    1991-01-01

    This study builds a public health model of Medicaid emergency room use for 57 upstate counties in New York from 1985 to 1987. The principle explanatory variables are primary care use (based in physicians' offices, freestanding clinics, and hospital outpatient departments), the concentration of poverty, and geographic and hospital availability. These factors influence the emergency room use of all Medicaid aid categories apart from the Supplemental Security Income recipients. Inherent in these...

  13. Predictive Modeling of Addiction Lapses in a Mobile Health Application

    OpenAIRE

    Chih, Ming-Yuan; Patton, Timothy; McTavish, Fiona M.; Isham, Andrew; Judkins-Fisher, Chris L.; Atwood, Amy K.; Gustafson, David H.

    2013-01-01

    The chronically relapsing nature of alcoholism leads to substantial personal, family, and societal costs. Addiction-Comprehensive Health Enhancement Support System (A-CHESS) is a smartphone application that aims to reduce relapse. To offer targeted support to patients who are at risk of lapses within the coming week, a Bayesian network model to predict such events was constructed using responses on 2,934 weekly surveys (called the Weekly Check-in) from 152 alcohol-dependent individuals who re...

  14. SYMBIOSE: A modeling and simulation platform for environmental chemical risk assessment

    International Nuclear Information System (INIS)

    Environmental systems are considered among the most complex ones because they involve a large number of diverse components, interactions, scale issues, spatial heterogeneity and significant sources of uncertainty. An Environmental Chemical Risk Assessment (ECRA) require therefore the integration of a wide range of data and modeling approaches, while accounting for sources and propagation of uncertainties in the system. Further, the level of detail to be achieved in an assessment depends mainly on environmental management objectives and the difficulty of adequately describing exposure, toxicity and other properties of the chemicals with site-specific data. This can range from simplistic conservative analyses to more realistic spatiotemporal modeling approaches. As a consequence, there is a pressing need for integrated, flexible (and user-friendly) tools that could adapt to this shifting and expanding assessment context. The SYMBIOSE project aims at developing such a modeling and simulation platform, for assessing the fate, transport and effects of chemicals - radionuclides and heavy metals, mainly - on humans and biota, in a multi-media environment. The various aspects of an environmental chemical risk assessment process, and existing relationships between them, are first revisited in a comprehensive way with emphasis on valuable modeling techniques. The modeling approach that will be implemented in the platform is then described through keystone aspects such as conceptual, mathematical and spatial modeling aspects. Finally, some key ideas about the object-oriented software architecture that is foreseen are presented. (author)

  15. Developing a Total Quality Management Model for Health Care Systems

    Directory of Open Access Journals (Sweden)

    AM Mosadegh Rad

    2005-10-01

    Full Text Available Background: Total quality management (TQM is a managerial practice to improve the effectiveness, efficiency, flexibility, and competitiveness of a business as a whole. However, in practice, these TQM benefits are not easy to achieve. Despite its theoretical promise and the enthusiastic response to TQM, recent evidence suggests that attempts to implement it are often unsuccessful. Many of these TQM programmes have been cancelled, or are in the process of being cancelled, as a result of the negative impact on profits. Therefore, there is a pressing need for a clinical approach to establishing TQM. Method: The aim of this article is therefore: “To identify the strengths and weakness of TQM, the logical steps towards TQM, and to develop a model so that health care organizations aiming at using TQM to achieve excellence can follow through easily”. Based on the research questions proposed in this study, the research strategies of a literature review, a questionnaire survey, semi-structured interviews, and a participatory action research were adopted in this study. For determining the success and barriers of TQM in health care organizations, a questionnaire survey has done in 90 health acre organizations in Isfahan Province, which implement TQM. The results of this survey were used for introducing a new model of TQM. This model will be developed via a semi-structured interview with at minimum 10 health care and quality managers. Then, through a participatory action research, this model will be implemented in 3 sites. At this time, the questionnaire survey has done and the model is introduced. Therefore, developing the model and its implementation will be done later. Results: In this survey, the mean score of TQM success was 3.48±0.68 (medium from 5 credits. Implementation of TQM was very low, low, medium, high and very high successful respectively in 3.6, 10.9, 21.8, 56.4 and 7.3 percent of health care organizations. TQM had the most effect on

  16. Theory and model use in social marketing health interventions.

    Science.gov (United States)

    Luca, Nadina Raluca; Suggs, L Suzanne

    2013-01-01

    The existing literature suggests that theories and models can serve as valuable frameworks for the design and evaluation of health interventions. However, evidence on the use of theories and models in social marketing interventions is sparse. The purpose of this systematic review is to identify to what extent papers about social marketing health interventions report using theory, which theories are most commonly used, and how theory was used. A systematic search was conducted for articles that reported social marketing interventions for the prevention or management of cancer, diabetes, heart disease, HIV, STDs, and tobacco use, and behaviors related to reproductive health, physical activity, nutrition, and smoking cessation. Articles were published in English, after 1990, reported an evaluation, and met the 6 social marketing benchmarks criteria (behavior change, consumer research, segmentation and targeting, exchange, competition and marketing mix). Twenty-four articles, describing 17 interventions, met the inclusion criteria. Of these 17 interventions, 8 reported using theory and 7 stated how it was used. The transtheoretical model/stages of change was used more often than other theories. Findings highlight an ongoing lack of use or underreporting of the use of theory in social marketing campaigns and reinforce the call to action for applying and reporting theory to guide and evaluate interventions. PMID:22934539

  17. Theory and model use in social marketing health interventions.

    Science.gov (United States)

    Luca, Nadina Raluca; Suggs, L Suzanne

    2013-01-01

    The existing literature suggests that theories and models can serve as valuable frameworks for the design and evaluation of health interventions. However, evidence on the use of theories and models in social marketing interventions is sparse. The purpose of this systematic review is to identify to what extent papers about social marketing health interventions report using theory, which theories are most commonly used, and how theory was used. A systematic search was conducted for articles that reported social marketing interventions for the prevention or management of cancer, diabetes, heart disease, HIV, STDs, and tobacco use, and behaviors related to reproductive health, physical activity, nutrition, and smoking cessation. Articles were published in English, after 1990, reported an evaluation, and met the 6 social marketing benchmarks criteria (behavior change, consumer research, segmentation and targeting, exchange, competition and marketing mix). Twenty-four articles, describing 17 interventions, met the inclusion criteria. Of these 17 interventions, 8 reported using theory and 7 stated how it was used. The transtheoretical model/stages of change was used more often than other theories. Findings highlight an ongoing lack of use or underreporting of the use of theory in social marketing campaigns and reinforce the call to action for applying and reporting theory to guide and evaluate interventions.

  18. A model for 'reverse innovation' in health care.

    Science.gov (United States)

    Depasse, Jacqueline W; Lee, Patrick T

    2013-01-01

    'Reverse innovation,' a principle well established in the business world, describes the flow of ideas from emerging to more developed economies. There is strong and growing interest in applying this concept to health care, yet there is currently no framework for describing the stages of reverse innovation or identifying opportunities to accelerate the development process. This paper combines the business concept of reverse innovation with diffusion of innovation theory to propose a model for reverse innovation as a way to innovate in health care. Our model includes the following steps: (1) identifying a problem common to lower- and higher-income countries; (2) innovation and spread in the low-income country (LIC); (3) crossover to the higher-income country (HIC); and (4) innovation and spread in the HIC. The crucial populations in this pathway, drawing from diffusion of innovation theory, are LIC innovators, LIC early adopters, and HIC innovators. We illustrate the model with three examples of current reverse innovations. We then propose four sets of specific actions that forward-looking policymakers, entrepreneurs, health system leaders, and researchers may take to accelerate the movement of promising solutions through the reverse innovation pipeline: (1) identify high-priority problems shared by HICs and LICs; (2) create slack for change, especially for LIC innovators, LIC early adopters, and HIC innovators; (3) create spannable social distances between LIC early adopters and HIC innovators; and (4) measure reverse innovation activity globally. PMID:24001367

  19. A model for 'reverse innovation' in health care.

    Science.gov (United States)

    Depasse, Jacqueline W; Lee, Patrick T

    2013-08-30

    'Reverse innovation,' a principle well established in the business world, describes the flow of ideas from emerging to more developed economies. There is strong and growing interest in applying this concept to health care, yet there is currently no framework for describing the stages of reverse innovation or identifying opportunities to accelerate the development process. This paper combines the business concept of reverse innovation with diffusion of innovation theory to propose a model for reverse innovation as a way to innovate in health care. Our model includes the following steps: (1) identifying a problem common to lower- and higher-income countries; (2) innovation and spread in the low-income country (LIC); (3) crossover to the higher-income country (HIC); and (4) innovation and spread in the HIC. The crucial populations in this pathway, drawing from diffusion of innovation theory, are LIC innovators, LIC early adopters, and HIC innovators. We illustrate the model with three examples of current reverse innovations. We then propose four sets of specific actions that forward-looking policymakers, entrepreneurs, health system leaders, and researchers may take to accelerate the movement of promising solutions through the reverse innovation pipeline: (1) identify high-priority problems shared by HICs and LICs; (2) create slack for change, especially for LIC innovators, LIC early adopters, and HIC innovators; (3) create spannable social distances between LIC early adopters and HIC innovators; and (4) measure reverse innovation activity globally.

  20. 75 FR 29754 - Claims of Confidentiality of Certain Chemical Identities Contained in Health and Safety Studies...

    Science.gov (United States)

    2010-05-27

    ... U.S.C. 2601 et seq.). You may be identified by the North American Industrial Classification System... processes used in the manufacturing or processing of a chemical substance or mixture or, in the case of a..., identified by docket identification (ID) number EPA-HQ-OPPT-2010-0446, by one of the following...