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

Smith, Jeremy C.; Cheng, Xiaolin; Nickels, Jonathan D.

Understanding of cell membrane organization has evolved significantly from the classic fluid mosaic model. It is now recognized that biological membranes are highly organized structures, with differences in lipid compositions between inner and outer leaflets and in lateral structures within the bilayer plane, known as lipid rafts. These organizing principles are important for protein localization and function as well as cellular signaling. However, the mechanisms and biophysical basis of lipid raft formation, structure, dynamics and function are not clearly understood. One key question, which we focus on in this review, is how lateral organization and leaflet compositional asymmetry are coupled.more » Detailed information elucidating this question has been sparse because of the small size and transient nature of rafts and the experimental challenges in constructing asymmetric bilayers. Resolving this mystery will require advances in both experimentation and modeling. We discuss here the preparation of model systems along with experimental and computational approaches that have been applied in efforts to address this key question in membrane biology. Furthermore, we seek to place recent and future advances in experimental and computational techniques in context, providing insight into in-plane and transverse organization of biological membranes.« less

Action Learning for Strategic Innovation in Mature Organizations: Key Cognitive, Design and Contextual Considerations

ERIC Educational Resources Information Center

Kuhn, Jeffrey S.; Marsick, Victoria J.

2005-01-01

This article lays out a model of action learning for catalyzing strategic innovation in mature organizations that are faced with a new competitive playing field. Central to this model is the development of a set of sophisticated cognitive capabilities--sensemaking, strategic thinking, critical thinking, divergent thinking, conceptual capacity and…

Lateral organization, bilayer asymmetry, and inter-leaflet coupling of biological membranes

DOE PAGES

Smith, Jeremy C.; Cheng, Xiaolin; Nickels, Jonathan D.

2015-07-29

Understanding of cell membrane organization has evolved significantly from the classic fluid mosaic model. It is now recognized that biological membranes are highly organized structures, with differences in lipid compositions between inner and outer leaflets and in lateral structures within the bilayer plane, known as lipid rafts. These organizing principles are important for protein localization and function as well as cellular signaling. However, the mechanisms and biophysical basis of lipid raft formation, structure, dynamics and function are not clearly understood. One key question, which we focus on in this review, is how lateral organization and leaflet compositional asymmetry are coupled.more » Detailed information elucidating this question has been sparse because of the small size and transient nature of rafts and the experimental challenges in constructing asymmetric bilayers. Resolving this mystery will require advances in both experimentation and modeling. We discuss here the preparation of model systems along with experimental and computational approaches that have been applied in efforts to address this key question in membrane biology. Furthermore, we seek to place recent and future advances in experimental and computational techniques in context, providing insight into in-plane and transverse organization of biological membranes.« less

A Dynamic Energy Budget (DEB) model to describe Laternula elliptica (King, 1832) seasonal feeding and metabolism

PubMed Central

Ahn, In-Young; Guillaumot, Charlène; Danis, Bruno

2017-01-01

Antarctic marine organisms are adapted to an extreme environment, characterized by a very low but stable temperature and a strong seasonality in food availability arousing from variations in day length. Ocean organisms are particularly vulnerable to global climate change with some regions being impacted by temperature increase and changes in primary production. Climate change also affects the biotic components of marine ecosystems and has an impact on the distribution and seasonal physiology of Antarctic marine organisms. Knowledge on the impact of climate change in key species is highly important because their performance affects ecosystem functioning. To predict the effects of climate change on marine ecosystems, a holistic understanding of the life history and physiology of Antarctic key species is urgently needed. DEB (Dynamic Energy Budget) theory captures the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model is a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. In this study, we estimate the DEB model parameters for the bivalve Laternula elliptica using literature-extracted and field data. The DEB model we present here aims at better understanding the biology of L. elliptica and its levels of adaptation to its habitat with a special focus on food seasonality. The model parameters describe a metabolism specifically adapted to low temperatures, with a low maintenance cost and a high capacity to uptake and mobilise energy, providing this organism with a level of energetic performance matching that of related species from temperate regions. It was also found that L. elliptica has a large energy reserve that allows enduring long periods of starvation. Additionally, we applied DEB parameters to time-series data on biological traits (organism condition, gonad growth) to describe the effect of a varying environment in food and temperature on the organism condition and energy use. The DEB model developed here for L. elliptica allowed us to improve benchmark knowledge on the ecophysiology of this key species, providing new insights in the role of food availability and temperature on its life cycle and reproduction strategy. PMID:28850607

A Dynamic Energy Budget (DEB) model to describe Laternula elliptica (King, 1832) seasonal feeding and metabolism.

PubMed

Agüera, Antonio; Ahn, In-Young; Guillaumot, Charlène; Danis, Bruno

2017-01-01

Antarctic marine organisms are adapted to an extreme environment, characterized by a very low but stable temperature and a strong seasonality in food availability arousing from variations in day length. Ocean organisms are particularly vulnerable to global climate change with some regions being impacted by temperature increase and changes in primary production. Climate change also affects the biotic components of marine ecosystems and has an impact on the distribution and seasonal physiology of Antarctic marine organisms. Knowledge on the impact of climate change in key species is highly important because their performance affects ecosystem functioning. To predict the effects of climate change on marine ecosystems, a holistic understanding of the life history and physiology of Antarctic key species is urgently needed. DEB (Dynamic Energy Budget) theory captures the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model is a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. In this study, we estimate the DEB model parameters for the bivalve Laternula elliptica using literature-extracted and field data. The DEB model we present here aims at better understanding the biology of L. elliptica and its levels of adaptation to its habitat with a special focus on food seasonality. The model parameters describe a metabolism specifically adapted to low temperatures, with a low maintenance cost and a high capacity to uptake and mobilise energy, providing this organism with a level of energetic performance matching that of related species from temperate regions. It was also found that L. elliptica has a large energy reserve that allows enduring long periods of starvation. Additionally, we applied DEB parameters to time-series data on biological traits (organism condition, gonad growth) to describe the effect of a varying environment in food and temperature on the organism condition and energy use. The DEB model developed here for L. elliptica allowed us to improve benchmark knowledge on the ecophysiology of this key species, providing new insights in the role of food availability and temperature on its life cycle and reproduction strategy.

Wood phenology: from organ-scale processes to terrestrial ecosystem models

NASA Astrophysics Data System (ADS)

Delpierre, Nicolas; Guillemot, Joannès

2016-04-01

In temperate and boreal trees, a dormancy period prevents organ development during adverse climatic conditions. Whereas the phenology of leaves and flowers has received considerable attention, to date, little is known regarding the phenology of other tree organs such as wood, fine roots, fruits and reserve compounds. In this presentation, we review both the role of environmental drivers in determining the phenology of wood and the models used to predict its phenology in temperate and boreal forest trees. Temperature is a key driver of the resumption of wood activity in spring. There is no such clear dominant environmental cue involved in the cessation of wood formation in autumn, but temperature and water stress appear as prominent factors. We show that wood phenology is a key driver of the interannual variability of wood growth in temperate tree species. Incorporating representations of wood phenology in a terrestrial ecosystem model substantially improved the simulation of wood growth under current climate.

Development of an Integrated Performance Measurement (PM) Model for Pharmaceutical Industry

PubMed Central

Shabaninejad, Hosein; Mirsalehian, Mohammad Hossein; Mehralian, Gholamhossein

2014-01-01

With respect to special characteristics of pharmaceutical industry and lack of reported performance measure, this study tries to design an integrated PM model for pharmaceutical companies. For generating this model; we first identified the key performance indicators (KPIs) and the key result indicators (KRIs) of a typical pharmaceutical company. Then, based on experts᾽ opinions, the identified indicators were ranked with respect to their importance, and the most important of them were selected to be used in the proposed model; In this model, we identified 25 KPIs and 12 KRIs. Although, this model is mostly appropriate to measure the performances of pharmaceutical companies, it can be also used to measure the performances of other industries with some modifications. We strongly recommend pharmaceutical managers to link these indicators with their payment and reward system, which can dramatically affect the performance of employees, and consequently their organization`s success. PMID:24711848

Linking Adverse Outcome Pathways to Dynamic Energy Budgets: A Conceptual Model

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

Murphy, Cheryl; Nisbet, Roger; Antczak, Philipp

Ecological risk assessment quantifies the likelihood of undesirable impacts of stressors, primarily at high levels of biological organization. Data used to inform ecological risk assessments come primarily from tests on individual organisms or from suborganismal studies, indicating a disconnect between primary data and protection goals. We know how to relate individual responses to population dynamics using individual-based models, and there are emerging ideas on how to make connections to ecosystem services. However, there is no established methodology to connect effects seen at higher levels of biological organization with suborganismal dynamics, despite progress made in identifying Adverse Outcome Pathways (AOPs) thatmore » link molecular initiating events to ecologically relevant key events. This chapter is a product of a working group at the National Center for Mathematical and Biological Synthesis (NIMBioS) that assessed the feasibility of using dynamic energy budget (DEB) models of individual organisms as a “pivot” connecting suborganismal processes to higher level ecological processes. AOP models quantify explicit molecular, cellular or organ-level processes, but do not offer a route to linking sub-organismal damage to adverse effects on individual growth, reproduction, and survival, which can be propagated to the population level through individual-based models. DEB models describe these processes, but use abstract variables with undetermined connections to suborganismal biology. We propose linking DEB and quantitative AOP models by interpreting AOP key events as measures of damage-inducing processes in a DEB model. Here, we present a conceptual model for linking AOPs to DEB models and review existing modeling tools available for both AOP and DEB.« less

Soil fauna: key to new carbon models

NASA Astrophysics Data System (ADS)

Filser, Juliane; Faber, Jack H.; Tiunov, Alexei V.; Brussaard, Lijbert; Frouz, Jan; De Deyn, Gerlinde; Uvarov, Alexei V.; Berg, Matty P.; Lavelle, Patrick; Loreau, Michel; Wall, Diana H.; Querner, Pascal; Eijsackers, Herman; José Jiménez, Juan

2016-11-01

Soil organic matter (SOM) is key to maintaining soil fertility, mitigating climate change, combatting land degradation, and conserving above- and below-ground biodiversity and associated soil processes and ecosystem services. In order to derive management options for maintaining these essential services provided by soils, policy makers depend on robust, predictive models identifying key drivers of SOM dynamics. Existing SOM models and suggested guidelines for future SOM modelling are defined mostly in terms of plant residue quality and input and microbial decomposition, overlooking the significant regulation provided by soil fauna. The fauna controls almost any aspect of organic matter turnover, foremost by regulating the activity and functional composition of soil microorganisms and their physical-chemical connectivity with soil organic matter. We demonstrate a very strong impact of soil animals on carbon turnover, increasing or decreasing it by several dozen percent, sometimes even turning C sinks into C sources or vice versa. This is demonstrated not only for earthworms and other larger invertebrates but also for smaller fauna such as Collembola. We suggest that inclusion of soil animal activities (plant residue consumption and bioturbation altering the formation, depth, hydraulic properties and physical heterogeneity of soils) can fundamentally affect the predictive outcome of SOM models. Understanding direct and indirect impacts of soil fauna on nutrient availability, carbon sequestration, greenhouse gas emissions and plant growth is key to the understanding of SOM dynamics in the context of global carbon cycling models. We argue that explicit consideration of soil fauna is essential to make realistic modelling predictions on SOM dynamics and to detect expected non-linear responses of SOM dynamics to global change. We present a decision framework, to be further developed through the activities of KEYSOM, a European COST Action, for when mechanistic SOM models include soil fauna. The research activities of KEYSOM, such as field experiments and literature reviews, together with dialogue between empiricists and modellers, will inform how this is to be done.

Key Elements of a Successful Drive toward Marketing Strategy Making

ERIC Educational Resources Information Center

Cann, Cynthia W.; George, Marie A.

2003-01-01

A conceptual model is presented that depicts the relationship between an internal marketing function and an organization's readiness to learn. Learning and marketing orientations are identified as components to marketing strategy making. Key organizational functions, including communication and decision-making, are utilized in a framework for…

Status of Standards Implementation in Anchorage Secondary Schools: A Concerns Based Acceptance Model (CBAM) Review, 2001-2002.

ERIC Educational Resources Information Center

Fenton, Ray

The Concerns Based Acceptance Model (CBAM) has been a key element in developing and assessing the implementation of science and mathematics programs over the past 20 years. CBAM provides an organized approach to assessing where people stand as they learn about, and accept, changes in organizations. This study examined the status of the adoption of…

Manipulating the dipole layer of polar organic molecules on metal surfaces via different charge-transfer channels

NASA Astrophysics Data System (ADS)

Lin, Meng-Kai; Nakayama, Yasuo; Zhuang, Ying-Jie; Wang, Chin-Yung; Pi, Tun-Wen; Ishii, Hisao; Tang, S.-J.

The key properties of organic films such as energy level alignment (ELA), work functions, and injection barriers are closely linked to this dipole layer. Using angle resolved photoemission spectroscopy (ARPES), we systemically investigate the coverage-dependent work functions and spectra line shapes of occupied molecular orbital states of a polar molecule, chloroaluminium phthalocyanine (ClAlPc), grown on Ag(111) to show that the orientations of the first ClAlPc layer can be manipulated via the molecule deposition rate and post annealing, causing ELA at organic-metal interface to differ for about 0.3 eV between Cl-up and Cl-down configuration. Moreover, by comparing the experimental results with the calculations based on both gas-phase model and realistic model of ClAlPc on Ag(111) , we evidence that the different orientations of ClAlPc dipole layers lead to different charge-transfer channels between ClAlPc and Ag, a key factor that controls the ELA at organic-metal interface.

Parameter Estimations of Dynamic Energy Budget (DEB) Model over the Life History of a Key Antarctic Species: The Antarctic Sea Star Odontaster validus Koehler, 1906.

PubMed

Agüera, Antonio; Collard, Marie; Jossart, Quentin; Moreau, Camille; Danis, Bruno

2015-01-01

Marine organisms in Antarctica are adapted to an extreme ecosystem including extremely stable temperatures and strong seasonality due to changes in day length. It is now largely accepted that Southern Ocean organisms are particularly vulnerable to global warming with some regions already being challenged by a rapid increase of temperature. Climate change affects both the physical and biotic components of marine ecosystems and will have an impact on the distribution and population dynamics of Antarctic marine organisms. To predict and assess the effect of climate change on marine ecosystems a more comprehensive knowledge of the life history and physiology of key species is urgently needed. In this study we estimate the Dynamic Energy Budget (DEB) model parameters for key benthic Antarctic species the sea star Odontaster validus using available information from literature and experiments. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle as a function of temperature and food availability. The DEB model allows for the inclusion of the different life history stages, and thus, becomes a tool that can be used to model lifetime feeding, growth, reproduction, and their responses to changes in biotic and abiotic conditions. The DEB model presented here includes the estimation of reproduction handling rules for the development of simultaneous oocyte cohorts within the gonad. Additionally it links the DEB model reserves to the pyloric caeca an organ whose function has long been ascribed to energy storage. Model parameters described a slowed down metabolism of long living animals that mature slowly. O. validus has a large reserve that-matching low maintenance costs- allow withstanding long periods of starvation. Gonad development is continuous and individual cohorts developed within the gonads grow in biomass following a power function of the age of the cohort. The DEB model developed here for O. validus allowed us to increase our knowledge on the ecophysiology of this species, providing new insights on the role of food availability and temperature on its life cycle and reproduction strategy.

Reference Model for Performance Management in Service-Oriented Virtual Organization Breeding Environments

NASA Astrophysics Data System (ADS)

Paszkiewicz, Zbigniew; Picard, Willy

Performance management (PM) is a key function of virtual organization (VO) management. A large set of PM indicators has been proposed and evaluated within the context of virtual breeding environments (VBEs). However, it is currently difficult to describe and select suitable PM indicators because of the lack of a common vocabulary and taxonomies of PM indicators. Therefore, there is a need for a framework unifying concepts in the domain of VO PM. In this paper, a reference model for VO PM is presented in the context of service-oriented VBEs. In the proposed reference model, both a set of terms that could be used to describe key performance indicators, and a set of taxonomies reflecting various aspects of PM are proposed. The proposed reference model is a first attempt and a work in progress that should not be supposed exhaustive.

Integrated multiscale biomaterials experiment and modelling: a perspective

PubMed Central

Buehler, Markus J.; Genin, Guy M.

2016-01-01

Advances in multiscale models and computational power have enabled a broad toolset to predict how molecules, cells, tissues and organs behave and develop. A key theme in biological systems is the emergence of macroscale behaviour from collective behaviours across a range of length and timescales, and a key element of these models is therefore hierarchical simulation. However, this predictive capacity has far outstripped our ability to validate predictions experimentally, particularly when multiple hierarchical levels are involved. The state of the art represents careful integration of multiscale experiment and modelling, and yields not only validation, but also insights into deformation and relaxation mechanisms across scales. We present here a sampling of key results that highlight both challenges and opportunities for integrated multiscale experiment and modelling in biological systems. PMID:28981126

Spatially organizing biochemistry: choosing a strategy to translate synthetic biology to the factory.

PubMed

Jakobson, Christopher M; Tullman-Ercek, Danielle; Mangan, Niall M

2018-05-29

Natural biochemical systems are ubiquitously organized both in space and time. Engineering the spatial organization of biochemistry has emerged as a key theme of synthetic biology, with numerous technologies promising improved biosynthetic pathway performance. One strategy, however, may produce disparate results for different biosynthetic pathways. We use a spatially resolved kinetic model to explore this fundamental design choice in systems and synthetic biology. We predict that two example biosynthetic pathways have distinct optimal organization strategies that vary based on pathway-dependent and cell-extrinsic factors. Moreover, we demonstrate that the optimal design varies as a function of kinetic and biophysical properties, as well as culture conditions. Our results suggest that organizing biosynthesis has the potential to substantially improve performance, but that choosing the appropriate strategy is key. The flexible design-space analysis we propose can be adapted to diverse biosynthetic pathways, and lays a foundation to rationally choose organization strategies for biosynthesis.

Springtails in the Classroom: Collembola as Model Organisms for Inquiry-based Laboratories.

ERIC Educational Resources Information Center

Moore, John C.; Tripp, Bradley B.; Simpson, Rod T.; Coleman, David C.

2000-01-01

Advocates the use of springtails (Collembola) in the K-12 classroom as a model invertebrate that can easily be reared and manipulated to demonstrate key concepts in biology. Describes experimental procedures using springtails. (SAH)

Managing professional work: three models of control for health organizations.

PubMed Central

Scott, W R

1982-01-01

Three arrangements for structuring the work of professional participants in professional organizations are described, contrasted and evaluated. Arguments are illustrated by application to the organization of physicians within hospitals. The primary rationale, the support structures that have fostered its development, the key structural features and the advantages and disadvantages of each arrangement are described. The effect on these arrangements of structures and forces external to any particular professional organization is emphasized. PMID:6749761

Public health departments and accountable care organizations: finding common ground in population health.

PubMed

Ingram, Richard; Scutchfield, F Douglas; Costich, Julia F

2015-05-01

We examined areas of potential collaboration between accountable care organizations and public health agencies, as well as perceived barriers and facilitators. We interviewed 9 key informants on 4 topics: advantages of public health agency involvement in accountable care organizations; services public health agencies could provide; practical, cultural, and legal barriers to accountable care organization-public health agency involvement; and business models that facilitate accountable care organization-public health agency collaboration. Public health agencies could help accountable care organizations partner with community organizations and reach vulnerable patients, provide population-based services and surveillance data, and promote policies that improve member health. Barriers include accountable care organizations' need for short-term financial yield, limited public health agency technical and financial capacity, and the absence of a financial model.

SCIENCE VERSION OF PM CHEMISTRY MODEL

EPA Science Inventory

PM chemistry models containing detailed treatments of key chemical processes controlling ambient concentrations of inorganic and organic compounds in PM2.5 are needed to develop strategies for reducing PM2.5 concentrations. This task, that builds on previous research conducted i...

A Primer on Mathematical Modeling in the Study of Organisms and Their Parts.

PubMed

Montévil, Maël

2018-01-01

Mathematical modeling is a very powerful tool for understanding natural phenomena. Such a tool carries its own assumptions and should always be used critically. In this chapter, we highlight the key ingredients and steps of modeling and focus on their biological interpretation. In particular, we discuss the role of theoretical principles in writing models. We also highlight the meaning and interpretation of equations. The main aim of this chapter is to facilitate the interaction between biologists and mathematical modelers. We focus on the case of cell proliferation and motility in the context of multicellular organisms.

Evaluation and application of site-specific data to revise the first-order decay model for estimating landfill gas generation and emissions at Danish landfills.

PubMed

Mou, Zishen; Scheutz, Charlotte; Kjeldsen, Peter

2015-06-01

Methane (CH₄) generated from low-organic waste degradation at four Danish landfills was estimated by three first-order decay (FOD) landfill gas (LFG) generation models (LandGEM, IPCC, and Afvalzorg). Actual waste data from Danish landfills were applied to fit model (IPCC and Afvalzorg) required categories. In general, the single-phase model, LandGEM, significantly overestimated CH₄generation, because it applied too high default values for key parameters to handle low-organic waste scenarios. The key parameters were biochemical CH₄potential (BMP) and CH₄generation rate constant (k-value). In comparison to the IPCC model, the Afvalzorg model was more suitable for estimating CH₄generation at Danish landfills, because it defined more proper waste categories rather than traditional municipal solid waste (MSW) fractions. Moreover, the Afvalzorg model could better show the influence of not only the total disposed waste amount, but also various waste categories. By using laboratory-determined BMPs and k-values for shredder, sludge, mixed bulky waste, and street-cleaning waste, the Afvalzorg model was revised. The revised model estimated smaller cumulative CH₄generation results at the four Danish landfills (from the start of disposal until 2020 and until 2100). Through a CH₄mass balance approach, fugitive CH₄emissions from whole sites and a specific cell for shredder waste were aggregated based on the revised Afvalzorg model outcomes. Aggregated results were in good agreement with field measurements, indicating that the revised Afvalzorg model could provide practical and accurate estimation for Danish LFG emissions. This study is valuable for both researchers and engineers aiming to predict, control, and mitigate fugitive CH₄emissions from landfills receiving low-organic waste. Landfill operators use the first-order decay (FOD) models to estimate methane (CH₄) generation. A single-phase model (LandGEM) and a traditional model (IPCC) could result in overestimation when handling a low-organic waste scenario. Site-specific data were important and capable of calibrating key parameter values in FOD models. The comparison study of the revised Afvalzorg model outcomes and field measurements at four Danish landfills provided a guideline for revising the Pollutants Release and Transfer Registers (PRTR) model, as well as indicating noteworthy waste fractions that could emit CH₄at modern landfills.

Using open source computational tools for predicting human metabolic stability and additional absorption, distribution, metabolism, excretion, and toxicity properties.

PubMed

Gupta, Rishi R; Gifford, Eric M; Liston, Ted; Waller, Chris L; Hohman, Moses; Bunin, Barry A; Ekins, Sean

2010-11-01

Ligand-based computational models could be more readily shared between researchers and organizations if they were generated with open source molecular descriptors [e.g., chemistry development kit (CDK)] and modeling algorithms, because this would negate the requirement for proprietary commercial software. We initially evaluated open source descriptors and model building algorithms using a training set of approximately 50,000 molecules and a test set of approximately 25,000 molecules with human liver microsomal metabolic stability data. A C5.0 decision tree model demonstrated that CDK descriptors together with a set of Smiles Arbitrary Target Specification (SMARTS) keys had good statistics [κ = 0.43, sensitivity = 0.57, specificity = 0.91, and positive predicted value (PPV) = 0.64], equivalent to those of models built with commercial Molecular Operating Environment 2D (MOE2D) and the same set of SMARTS keys (κ = 0.43, sensitivity = 0.58, specificity = 0.91, and PPV = 0.63). Extending the dataset to ∼193,000 molecules and generating a continuous model using Cubist with a combination of CDK and SMARTS keys or MOE2D and SMARTS keys confirmed this observation. When the continuous predictions and actual values were binned to get a categorical score we observed a similar κ statistic (0.42). The same combination of descriptor set and modeling method was applied to passive permeability and P-glycoprotein efflux data with similar model testing statistics. In summary, open source tools demonstrated predictive results comparable to those of commercial software with attendant cost savings. We discuss the advantages and disadvantages of open source descriptors and the opportunity for their use as a tool for organizations to share data precompetitively, avoiding repetition and assisting drug discovery.

Evolving Ideas on the Origin and Evolution of Flowers: New Perspectives in the Genomic Era

PubMed Central

Chanderbali, Andre S.; Berger, Brent A.; Howarth, Dianella G.; Soltis, Pamela S.; Soltis, Douglas E.

2016-01-01

The origin of the flower was a key innovation in the history of complex organisms, dramatically altering Earth’s biota. Advances in phylogenetics, developmental genetics, and genomics during the past 25 years have substantially advanced our understanding of the evolution of flowers, yet crucial aspects of floral evolution remain, such as the series of genetic and morphological changes that gave rise to the first flowers; the factors enabling the origin of the pentamerous eudicot flower, which characterizes ∼70% of all extant angiosperm species; and the role of gene and genome duplications in facilitating floral innovations. A key early concept was the ABC model of floral organ specification, developed by Elliott Meyerowitz and Enrico Coen and based on two model systems, Arabidopsis thaliana and Antirrhinum majus. Yet it is now clear that these model systems are highly derived species, whose molecular genetic-developmental organization must be very different from that of ancestral, as well as early, angiosperms. In this article, we will discuss how new research approaches are illuminating the early events in floral evolution and the prospects for further progress. In particular, advancing the next generation of research in floral evolution will require the development of one or more functional model systems from among the basal angiosperms and basal eudicots. More broadly, we urge the development of “model clades” for genomic and evolutionary-developmental analyses, instead of the primary use of single “model organisms.” We predict that new evolutionary models will soon emerge as genetic/genomic models, providing unprecedented new insights into floral evolution. PMID:27053123

Experimentally validated computational modeling of organic binder burnout from green ceramic compacts

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

Ewsuk, K.G.; Cochran, R.J.; Blackwell, B.F.

The properties and performance of a ceramic component is determined by a combination of the materials from which it was fabricated and how it was processed. Most ceramic components are manufactured by dry pressing a powder/binder system in which the organic binder provides formability and green compact strength. A key step in this manufacturing process is the removal of the binder from the powder compact after pressing. The organic binder is typically removed by a thermal decomposition process in which heating rate, temperature, and time are the key process parameters. Empirical approaches are generally used to design the burnout time-temperaturemore » cycle, often resulting in excessive processing times and energy usage, and higher overall manufacturing costs. Ideally, binder burnout should be completed as quickly as possible without damaging the compact, while using a minimum of energy. Process and computational modeling offer one means to achieve this end. The objective of this study is to develop an experimentally validated computer model that can be used to better understand, control, and optimize binder burnout from green ceramic compacts.« less

Effective Segmentation of University Alumni: Mining Contribution Data with Finite-Mixture Models

ERIC Educational Resources Information Center

Durango-Cohen, Elizabeth J.; Balasubramanian, Siva K.

2015-01-01

Having an effective segmentation strategy is key to the viability of any organization. This is particularly true for colleges, universities, and other nonprofit organizations--who have seen sharp declines in private contributions, endowment income, and government grants in the past few years, and face fierce competition for donor dollars…

Biocuration at the Saccharomyces genome database.

PubMed

Skrzypek, Marek S; Nash, Robert S

2015-08-01

Saccharomyces Genome Database is an online resource dedicated to managing information about the biology and genetics of the model organism, yeast (Saccharomyces cerevisiae). This information is derived primarily from scientific publications through a process of human curation that involves manual extraction of data and their organization into a comprehensive system of knowledge. This system provides a foundation for further analysis of experimental data coming from research on yeast as well as other organisms. In this review we will demonstrate how biocuration and biocurators add a key component, the biological context, to our understanding of how genes, proteins, genomes and cells function and interact. We will explain the role biocurators play in sifting through the wealth of biological data to incorporate and connect key information. We will also discuss the many ways we assist researchers with their various research needs. We hope to convince the reader that manual curation is vital in converting the flood of data into organized and interconnected knowledge, and that biocurators play an essential role in the integration of scientific information into a coherent model of the cell. © 2015 Wiley Periodicals, Inc.

Biocuration at the Saccharomyces Genome Database

PubMed Central

Skrzypek, Marek S.; Nash, Robert S.

2015-01-01

Saccharomyces Genome Database is an online resource dedicated to managing information about the biology and genetics of the model organism, yeast (Saccharomyces cerevisiae). This information is derived primarily from scientific publications through a process of human curation that involves manual extraction of data and their organization into a comprehensive system of knowledge. This system provides a foundation for further analysis of experimental data coming from research on yeast as well as other organisms. In this review we will demonstrate how biocuration and biocurators add a key component, the biological context, to our understanding of how genes, proteins, genomes and cells function and interact. We will explain the role biocurators play in sifting through the wealth of biological data to incorporate and connect key information. We will also discuss the many ways we assist researchers with their various research needs. We hope to convince the reader that manual curation is vital in converting the flood of data into organized and interconnected knowledge, and that biocurators play an essential role in the integration of scientific information into a coherent model of the cell. PMID:25997651

Physiologically based pharmacokinetic modeling of polyethylene glycol-coated polyacrylamide nanoparticles in rats.

PubMed

Li, Dingsheng; Johanson, Gunnar; Emond, Claude; Carlander, Ulrika; Philbert, Martin; Jolliet, Olivier

2014-08-01

Nanoparticles' health risks depend on their biodistribution in the body. Phagocytosis may greatly affect this distribution but has not yet explicitly accounted for in whole body pharmacokinetic models. Here, we present a physiologically based pharmacokinetic model that includes phagocytosis of nanoparticles to explore the biodistribution of intravenously injected polyethylene glycol-coated polyacrylamide nanoparticles in rats. The model explains 97% of the observed variation in nanoparticles amounts across organs. According to the model, phagocytizing cells quickly capture nanoparticles until their saturation and thereby constitute a major reservoir in richly perfused organs (spleen, liver, bone marrow, lungs, heart and kidneys), storing 83% of the nanoparticles found in these organs 120 h after injection. Key determinants of the nanoparticles biodistribution are the uptake capacities of phagocytizing cells in organs, the partitioning between tissue and blood, and the permeability between capillary blood and tissues. This framework can be extended to other types of nanoparticles by adapting these determinants.

Organic matter diagenesis as the key to a unifying theory for the genesis of tabular uranium-vanadium deposits in the Morrison Formation, Colorado Plateau

USGS Publications Warehouse

Hansley, P.L.; Spirakis, C.S.

1992-01-01

Interstitial, epigenetic amorphous organic matter is intimately associated with uranium in the Grants uranium region and is considered essential to genetic models for these deposits. In contrast, uranium minerals are intimately associated with authigenic vanadium chlorite and vanadium oxides in amorphous organic matter-poor ores of the Slick Rock and Henry Mountains mining districts and therefore, in some genetic models amorphous organic matter is not considered crucial to the formation of these deposits. Differences in organic matter content can be explained by recognizing that amorphous organic matter-poor deposits have been subjected to more advanced stages of diagenesis than amorphous organic matter-rich deposits. Evidence that amorphous organic matter was involved in the genesis of organic matter-poor, as well as organic matter-rich, deposits is described. -from Authors

The key technique study of a kind of personal navigation oriented LBS system

NASA Astrophysics Data System (ADS)

Yan, Lei; Zheng, Jianghua; Zhang, Xin; Peng, Chunhua; He, Lina

2005-11-01

With the integration of GIS, IT technology and wireless communication techniques, LBS is fast developing and caused wide concern. Personal navigation is the critical application of LBS. It has higher requirement of data quality, positioning accuracy and multi-model services. The study discusses the key techniques of a personal navigation oriented LBS system. As an example for service platform of China Unicom, NAVISTAR especially emphasizes the importance of spatial data organization. Based-on CDMA1X network, it adopts gpsOne\\MS-Assisted dynamic positioning technique, and puts forward a data organization solution to realize multi-scale representation.

Lean Information Management: Criteria For Selecting Key Performance Indicators At Shop Floor

NASA Astrophysics Data System (ADS)

Iuga, Maria Virginia; Kifor, Claudiu Vasile; Rosca, Liviu-Ion

2015-07-01

Most successful organizations worldwide use key performance indicators as an important part of their corporate strategy in order to forecast, measure and plan their businesses. Performance metrics vary in their purpose, definition and content. Therefore, the way organizations select what they think are the optimal indicators for their businesses varies from company to company, sometimes even from department to department. This study aims to answer the question of what is the most suitable way to define and select key performance indicators. More than that, it identifies the right criteria to select key performance indicators at shop floor level. This paper contributes to prior research by analysing and comparing previously researched selection criteria and proposes an original six-criteria-model, which caters towards choosing the most adequate KPIs. Furthermore, the authors take the research a step further by further steps to closed research gaps within this field of study.

Simulating natural selection in landscape genetics

Treesearch

E. L. Landguth; S. A. Cushman; N. Johnson

2012-01-01

Linking landscape effects to key evolutionary processes through individual organism movement and natural selection is essential to provide a foundation for evolutionary landscape genetics. Of particular importance is determining how spatially- explicit, individual-based models differ from classic population genetics and evolutionary ecology models based on ideal...

[Scale of organizational learning in schools. Organizational learning is a key element for the development of organizations].

PubMed

López, Verónica; Ahumada, Luis; Olivares, Rodrigo; González, Alvaro

2012-05-01

Organizational learning is a key element for the development of organizations. School organizations are not exempt from this challenge and they currently face a highly dynamic and demanding context of education policies that emphasize the school's ability to learn. Thus, research on organizational learning in educational contexts requires valid instruments that are sensitive to the specifics of schools as organizations. In this study, we adapted and validated a scale of organizational learning in a sample of 119 Chilean municipal schools (N= 1,545). The results suggest a structural model made up of three factors: culture of learning, strategic clarity, and group learning. These factors predicted dimensions of educational achievement, as measured through the National Assessment System of Educational Achievement (SNED). Results are discussed in view of the literature on school improvement.

Reflections on experiential learning in evaluation capacity building with a community organization, Dancing With Parkinson's.

PubMed

Nakaima, April; Sridharan, Sanjeev

2017-05-08

This paper discusses what was learned about evaluation capacity building with community organizations who deliver services to individuals with neurological disorders. Evaluation specialists engaged by the Ontario Brain Institute Evaluation Support Program were paired with community organizations, such as Dancing With Parkinson's. Some of the learning included: relationship building is key for this model of capacity building; community organizations often have had negative experiences with evaluation and the idea that evaluations can be friendly tools in implementing meaningful programs is one key mechanism by which such an initiative can work; community organizations often need evaluation most to be able to demonstrate their value; a strength of this initiative was that the focus was not just on creating products but mostly on developing a learning process in which capacities would remain; evaluation tools and skills that organizations found useful were developing a theory of change and the concept of heterogeneous mechanisms (informed by a realist evaluation lens). Copyright © 2017. Published by Elsevier Ltd.

Studies on Mathematical Models of Wet Adhesion and Lifetime Prediction of Organic Coating/Steel by Grey System Theory.

PubMed

Meng, Fandi; Liu, Ying; Liu, Li; Li, Ying; Wang, Fuhui

2017-06-28

A rapid degradation of wet adhesion is the key factor controlling coating lifetime, for the organic coatings under marine hydrostatic pressure. The mathematical models of wet adhesion have been studied by Grey System Theory (GST). Grey models (GM) (1, 1) of epoxy varnish (EV) coating/steel and epoxy glass flake (EGF) coating/steel have been established, and a lifetime prediction formula has been proposed on the basis of these models. The precision assessments indicate that the established models are accurate, and the prediction formula is capable of making precise lifetime forecasting of the coatings.

Studies on Mathematical Models of Wet Adhesion and Lifetime Prediction of Organic Coating/Steel by Grey System Theory

PubMed Central

Meng, Fandi; Liu, Ying; Liu, Li; Li, Ying; Wang, Fuhui

2017-01-01

A rapid degradation of wet adhesion is the key factor controlling coating lifetime, for the organic coatings under marine hydrostatic pressure. The mathematical models of wet adhesion have been studied by Grey System Theory (GST). Grey models (GM) (1, 1) of epoxy varnish (EV) coating/steel and epoxy glass flake (EGF) coating/steel have been established, and a lifetime prediction formula has been proposed on the basis of these models. The precision assessments indicate that the established models are accurate, and the prediction formula is capable of making precise lifetime forecasting of the coatings. PMID:28773073

Assessment of Important SPECIATE Profiles in EPA’s Emissions Modeling Platform and Current Data Gaps

EPA Science Inventory

The US Environmental Protection Agency (EPA)’s SPECIATE database contains speciation profiles for both particulate matter (PM) and volatile organic compounds (VOCs) that are key inputs for creating speciated emission inventories for air quality modeling. The objective of th...

Epoxide pathways improve model predictions of isoprene markers and reveal key role of acidity in aerosol formation

EPA Science Inventory

Isoprene significantly contributes to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, the Community Multiscale Air Quality model is updated to predict isoprene aerosol from epoxides produced under both ...

The short-lived African turquoise killifish: an emerging experimental model for ageing

PubMed Central

Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo

2016-01-01

ABSTRACT Human ageing is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human ageing are shared with other organisms; thus, animal models have been invaluable in providing key mechanistic and molecular insights into the common bases of biological ageing. In this Review, we briefly summarise the major applications of the most commonly used model organisms adopted in ageing research and highlight their relevance in understanding human ageing. We compare the strengths and limitations of different model organisms and discuss in detail an emerging ageing model, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of ageing and discuss potential future applications of this promising animal model. PMID:26839399

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory.

PubMed

Ng, Tse Nga; Schwartz, David E; Lavery, Leah L; Whiting, Gregory L; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-01-01

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic.

Key parameters for behaviour related to source separation of household organic waste: A case study in Hanoi, Vietnam.

PubMed

Kawai, Kosuke; Huong, Luong Thi Mai

2017-03-01

Proper management of food waste, a major component of municipal solid waste (MSW), is needed, especially in developing Asian countries where most MSW is disposed of in landfill sites without any pretreatment. Source separation can contribute to solving problems derived from the disposal of food waste. An organic waste source separation and collection programme has been operated in model areas in Hanoi, Vietnam, since 2007. This study proposed three key parameters (participation rate, proper separation rate and proper discharge rate) for behaviour related to source separation of household organic waste, and monitored the progress of the programme based on the physical composition of household waste sampled from 558 households in model programme areas of Hanoi. The results showed that 13.8% of 558 households separated organic waste, and 33.0% discharged mixed (unseparated) waste improperly. About 41.5% (by weight) of the waste collected as organic waste was contaminated by inorganic waste, and one-third of the waste disposed of as organic waste by separators was inorganic waste. We proposed six hypothetical future household behaviour scenarios to help local officials identify a final or midterm goal for the programme. We also suggested that the city government take further actions to increase the number of people participating in separating organic waste, improve the accuracy of separation and prevent non-separators from discharging mixed waste improperly.

Evaluating filterability of different types of sludge by statistical analysis: The role of key organic compounds in extracellular polymeric substances.

PubMed

Xiao, Keke; Chen, Yun; Jiang, Xie; Zhou, Yan

2017-03-01

An investigation was conducted for 20 different types of sludge in order to identify the key organic compounds in extracellular polymeric substances (EPS) that are important in assessing variations of sludge filterability. The different types of sludge varied in initial total solids (TS) content, organic composition and pre-treatment methods. For instance, some of the sludges were pre-treated by acid, ultrasonic, thermal, alkaline, or advanced oxidation technique. The Pearson's correlation results showed significant correlations between sludge filterability and zeta potential, pH, dissolved organic carbon, protein and polysaccharide in soluble EPS (SB EPS), loosely bound EPS (LB EPS) and tightly bound EPS (TB EPS). The principal component analysis (PCA) method was used to further explore correlations between variables and similarities among EPS fractions of different types of sludge. Two principal components were extracted: principal component 1 accounted for 59.24% of total EPS variations, while principal component 2 accounted for 25.46% of total EPS variations. Dissolved organic carbon, protein and polysaccharide in LB EPS showed higher eigenvector projection values than the corresponding compounds in SB EPS and TB EPS in principal component 1. Further characterization of fractionized key organic compounds in LB EPS was conducted with size-exclusion chromatography-organic carbon detection-organic nitrogen detection (LC-OCD-OND). A numerical multiple linear regression model was established to describe relationship between organic compounds in LB EPS and sludge filterability. Copyright © 2016 Elsevier Ltd. All rights reserved.

The "Organization" as an Interdisciplinary Learning Zone: Using a Strategic Game to Integrate Learning about Supply Chain Management and Advertising

ERIC Educational Resources Information Center

Arora, Anshu Saxena

2012-01-01

Purpose: The research study seeks to explore the relationship among strategic gaming, the learning organization model and approach, and transfer of learning as key success strategies for improved individual and organizational performance and sustainable competitive advantage. This research aims to identify and elaborate on the strategic…

Modeling of DNA and Protein Organization Levels with Cn3D Software

ERIC Educational Resources Information Center

Stasinakis, Panagiotis K.; Nicolaou, Despoina

2017-01-01

The molecular structure of living organisms and the complex interactions amongst its components are the basis for the diversity observed at the macroscopic level. Proteins and nucleic acids are some of the major molecular components, and play a key role in several biological functions, such as those of development and evolution. This article…

Statistics of certain models of evolution

NASA Astrophysics Data System (ADS)

Standish, Russell K.

1999-02-01

In a recent paper, Newman [J. Theo. Bio. 189, 235 (1997)] surveys the literature on power law spectra in evolution, self-organized criticality and presents a model of his own to arrive at a conclusion that self-organized criticality is not necessary for evolution. Not only did he miss a key model (Ecolab) that has a clear self-organized critical mechanism, but also Newman's model exhibits the same mechanism that gives rise to power law behavior, as does Ecolab. Newman's model is, in fact, a ``mean field'' approximation of a self-organized critical system. In this paper, I have also implemented Newman's model using the Ecolab software, removing the restriction that the number of species must remain constant. It turns out that the requirement of constant species number is nontrivial, leading to a global coupling between species that is similar in effect to the species interactions seen in Ecolab. In fact, the model must self-organize to a state where the long time average of speciations balances that of the extinctions; otherwise, the system either collapses or explodes. In view of this, Newman's model does not provide the hoped-for counterexample to the presence of self-organized criticality in evolution, but does provide a simple, almost analytic model that can be used to understand more intricate models such as Ecolab.

A devolved model for public involvement in the field of mental health research: case study learning.

PubMed

Moule, Pam; Davies, Rosie

2016-12-01

Patient and public involvement in all aspects of research is espoused and there is a continued interest in understanding its wider impact. Existing investigations have identified both beneficial outcomes and remaining issues. This paper presents the impact of public involvement in one case study led by a mental health charity conducted as part of a larger research project. The case study used a devolved model of working, contracting with service user-led organizations to maximize the benefits of local knowledge on the implementation of personalized budgets, support recruitment and local user-led organizations. To understand the processes and impact of public involvement in a devolved model of working with user-led organizations. Multiple data collection methods were employed throughout 2012. These included interviews with the researchers (n = 10) and research partners (n = 5), observation of two case study meetings and the review of key case study documentation. Analysis was conducted in NVivo10 using a coding framework developed following a literature review. Five key themes emerged from the data; Devolved model, Nature of involvement, Enabling factors, Implementation challenges and Impact. While there were some challenges of implementing the devolved model it is clear that our findings add to the growing understanding of the positive benefits research partners can bring to complex research. A devolved model can support the involvement of user-led organizations in research if there is a clear understanding of the underpinning philosophy and support mechanisms are in place. © 2015 The Authors. Health Expectations Published by John Wiley & Sons Ltd.

Molecular simulations of self-assembly processes in metal-organic frameworks: Model dependence

NASA Astrophysics Data System (ADS)

Biswal, Debasmita; Kusalik, Peter G.

2017-07-01

Molecular simulation is a powerful tool for investigating microscopic behavior in various chemical systems, where the use of suitable models is critical to successfully reproduce the structural and dynamic properties of the real systems of interest. In this context, molecular dynamics simulation studies of self-assembly processes in metal-organic frameworks (MOFs), a well-known class of porous materials with interesting chemical and physical properties, are relatively challenging, where a reasonably accurate representation of metal-ligand interactions is anticipated to play an important role. In the current study, we both investigate the performance of some existing models and introduce and test new models to help explore the self-assembly in an archetypal Zn-carboxylate MOF system. To this end, the behavior of six different Zn-ion models, three solvent models, and two ligand models was examined and validated against key experimental structural parameters. To explore longer time scale ordering events during MOF self-assembly via explicit solvent simulations, it is necessary to identify a suitable combination of simplified model components representing metal ions, organic ligands, and solvent molecules. It was observed that an extended cationic dummy atom (ECDA) Zn-ion model combined with an all-atom carboxylate ligand model and a simple dipolar solvent model can reproduce characteristic experimental structures for the archetypal MOF system. The successful use of these models in extensive sets of molecular simulations, which provide key insights into the self-assembly mechanism of this archetypal MOF system occurring during the early stages of this process, has been very recently reported.

Anthropology and International Business Research Methods in DBA Teaching: Frameworks for Cultural Awareness.

ERIC Educational Resources Information Center

Whiteley, Alma

2001-01-01

Discusses the rationale for introducing anthropology into a doctoral-level international business research methods course. Describes three anthropological frameworks designed for the course: a cultural awareness model adapted from G. Morgan's (1980) idea of paradigmatic orthodoxy; key organizing principles; and a mapping model allowing researchers…

Healing models for organizations: description, measurement, and outcomes.

PubMed

Malloch, K

2000-01-01

Healthcare leaders are continually searching for ways to improve their ability to provide optimal healthcare services, be financially viable, and retain quality caregivers, often feeling like such goals are impossible to achieve in today's intensely competitive environment. Many healthcare leaders intuitively recognize the need for more humanistic models and the probable connection with positive patient outcomes and financial success but are hesitant to make significant changes in their organizations because of the lack of model descriptions or documented recognition of the clinical and financial advantages of humanistic models. This article describes a study that was developed in response to the increasing work in humanistic or healing environment models and the need for validation of the advantages of such models. The healthy organization model, a framework for healthcare organizations that incorporates humanistic healing values within the traditional structure, is presented as a result of the study. This model addresses the importance of optimal clinical services, financial performance, and staff satisfaction. The five research-based organizational components that form the framework are described, and key indicators of organizational effectiveness over a five-year period are presented. The resulting empirical data are strongly supportive of the healing model and reflect positive outcomes for the organization.

Core-oscillator model of Caulobacter crescentus

NASA Astrophysics Data System (ADS)

Vandecan, Yves; Biondi, Emanuele; Blossey, Ralf

2016-06-01

The gram-negative bacterium Caulobacter crescentus is a powerful model organism for studies of bacterial cell cycle regulation. Although the major regulators and their connections in Caulobacter have been identified, it still is a challenge to properly understand the dynamics of its circuitry which accounts for both cell cycle progression and arrest. We show that the key decision module in Caulobacter is built from a limit cycle oscillator which controls the DNA replication program. The effect of an induced cell cycle arrest is demonstrated to be a key feature to classify the underlying dynamics.

Neurotransmitter release mechanisms studied in Caenorhabditis elegans.

PubMed

Barclay, Jeff W; Morgan, Alan; Burgoyne, Robert D

2012-01-01

The process of regulated exocytosis has received considerable interest as a key component of synaptic transmission. Fusion of presynaptic vesicles and the subsequent release of their neurotransmitter contents is driven by a series of interactions between evolutionarily conserved proteins. Key insights into the molecular mechanisms of vesicle fusion have come from research using genetic model systems such as the nematode worm Caenorhabditis elegans. We review here the current knowledge regarding regulated exocytosis at the C. elegans synapse and future research directions involving this model organism. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genome-based analysis of heme biosynthesis and uptake in prokaryotic systems.

PubMed

Cavallaro, Gabriele; Decaria, Leonardo; Rosato, Antonio

2008-11-01

Heme is the prosthetic group of many proteins that carry out a variety of key biological functions. In addition, for many pathogenic organisms, heme (acquired from the host) may constitute a very important source of iron. Organisms can meet their heme demands by taking it up from external sources, by producing the cofactor through a dedicated biosynthetic pathway, or both. Here we analyzed the distribution of proteins specifically involved in the processes of heme biosynthesis and heme uptake in 474 prokaryotic organisms. These data allowed us to identify which organisms are capable of performing none, one, or both processes, based on the similarity to known systems. Some specific instances where one or more proteins along the pathways had unusual modifications were singled out. For two key protein domains involved in heme uptake, we could build a series of structural models, which suggested possible alternative modes of heme binding. Future directions for experimental work are given.

Impact of spatial organization on a novel auxotrophic interaction among soil microbes

DOE PAGES

Jiang, Xue; ZerfaB, Christian; Feng, Song; ...

2018-03-23

Here, a key prerequisite to achieve a deeper understanding of microbial communities and to engineer synthetic ones is to identify the individual metabolic interactions among key species and how these interactions are affected by different environmental factors. Deciphering the physiological basis of species–species and species–environment interactions in spatially organized environments requires reductionist approaches using ecologically and functionally relevant species. To this end, we focus here on a defined system to study the metabolic interactions in a spatial context among the plant-beneficial endophytic fungus Serendipita indica, and the soil-dwelling model bacterium Bacillus subtilis. Focusing on the growth dynamics of S. indicamore » under defined conditions, we identified an auxotrophy in this organism for thiamine, which is a key co-factor for essential reactions in the central carbon metabolism. We found that S. indica growth is restored in thiamine-free media, when co-cultured with B. subtilis. The success of this auxotrophic interaction, however, was dependent on the spatial and temporal organization of the system; the beneficial impact of B. subtilis was only visible when its inoculation was separated from that of S. indica either in time or space. These findings describe a key auxotrophic interaction in the soil among organisms that are shown to be important for plant ecosystem functioning, and point to the potential importance of spatial and temporal organization for the success of auxotrophic interactions. These points can be particularly important for engineering of minimal functional synthetic communities as plant seed treatments and for vertical farming under defined conditions.« less

Impact of spatial organization on a novel auxotrophic interaction among soil microbes.

PubMed

Jiang, Xue; Zerfaß, Christian; Feng, Song; Eichmann, Ruth; Asally, Munehiro; Schäfer, Patrick; Soyer, Orkun S

2018-06-01

A key prerequisite to achieve a deeper understanding of microbial communities and to engineer synthetic ones is to identify the individual metabolic interactions among key species and how these interactions are affected by different environmental factors. Deciphering the physiological basis of species-species and species-environment interactions in spatially organized environments requires reductionist approaches using ecologically and functionally relevant species. To this end, we focus here on a defined system to study the metabolic interactions in a spatial context among the plant-beneficial endophytic fungus Serendipita indica, and the soil-dwelling model bacterium Bacillus subtilis. Focusing on the growth dynamics of S. indica under defined conditions, we identified an auxotrophy in this organism for thiamine, which is a key co-factor for essential reactions in the central carbon metabolism. We found that S. indica growth is restored in thiamine-free media, when co-cultured with B. subtilis. The success of this auxotrophic interaction, however, was dependent on the spatial and temporal organization of the system; the beneficial impact of B. subtilis was only visible when its inoculation was separated from that of S. indica either in time or space. These findings describe a key auxotrophic interaction in the soil among organisms that are shown to be important for plant ecosystem functioning, and point to the potential importance of spatial and temporal organization for the success of auxotrophic interactions. These points can be particularly important for engineering of minimal functional synthetic communities as plant seed treatments and for vertical farming under defined conditions.

Impact of spatial organization on a novel auxotrophic interaction among soil microbes

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

Jiang, Xue; ZerfaB, Christian; Feng, Song

Here, a key prerequisite to achieve a deeper understanding of microbial communities and to engineer synthetic ones is to identify the individual metabolic interactions among key species and how these interactions are affected by different environmental factors. Deciphering the physiological basis of species–species and species–environment interactions in spatially organized environments requires reductionist approaches using ecologically and functionally relevant species. To this end, we focus here on a defined system to study the metabolic interactions in a spatial context among the plant-beneficial endophytic fungus Serendipita indica, and the soil-dwelling model bacterium Bacillus subtilis. Focusing on the growth dynamics of S. indicamore » under defined conditions, we identified an auxotrophy in this organism for thiamine, which is a key co-factor for essential reactions in the central carbon metabolism. We found that S. indica growth is restored in thiamine-free media, when co-cultured with B. subtilis. The success of this auxotrophic interaction, however, was dependent on the spatial and temporal organization of the system; the beneficial impact of B. subtilis was only visible when its inoculation was separated from that of S. indica either in time or space. These findings describe a key auxotrophic interaction in the soil among organisms that are shown to be important for plant ecosystem functioning, and point to the potential importance of spatial and temporal organization for the success of auxotrophic interactions. These points can be particularly important for engineering of minimal functional synthetic communities as plant seed treatments and for vertical farming under defined conditions.« less

Definition and automatic anatomy recognition of lymph node zones in the pelvis on CT images

NASA Astrophysics Data System (ADS)

Liu, Yu; Udupa, Jayaram K.; Odhner, Dewey; Tong, Yubing; Guo, Shuxu; Attor, Rosemary; Reinicke, Danica; Torigian, Drew A.

2016-03-01

Currently, unlike IALSC-defined thoracic lymph node zones, no explicitly provided definitions for lymph nodes in other body regions are available. Yet, definitions are critical for standardizing the recognition, delineation, quantification, and reporting of lymphadenopathy in other body regions. Continuing from our previous work in the thorax, this paper proposes a standardized definition of the grouping of pelvic lymph nodes into 10 zones. We subsequently employ our earlier Automatic Anatomy Recognition (AAR) framework designed for body-wide organ modeling, recognition, and delineation to actually implement these zonal definitions where the zones are treated as anatomic objects. First, all 10 zones and key anatomic organs used as anchors are manually delineated under expert supervision for constructing fuzzy anatomy models of the assembly of organs together with the zones. Then, optimal hierarchical arrangement of these objects is constructed for the purpose of achieving the best zonal recognition. For actual localization of the objects, two strategies are used -- optimal thresholded search for organs and one-shot method for the zones where the known relationship of the zones to key organs is exploited. Based on 50 computed tomography (CT) image data sets for the pelvic body region and an equal division into training and test subsets, automatic zonal localization within 1-3 voxels is achieved.

XFEM-based modeling of successive resections for preoperative image updating

NASA Astrophysics Data System (ADS)

Vigneron, Lara M.; Robe, Pierre A.; Warfield, Simon K.; Verly, Jacques G.

2006-03-01

We present a new method for modeling organ deformations due to successive resections. We use a biomechanical model of the organ, compute its volume-displacement solution based on the eXtended Finite Element Method (XFEM). The key feature of XFEM is that material discontinuities induced by every new resection can be handled without remeshing or mesh adaptation, as would be required by the conventional Finite Element Method (FEM). We focus on the application of preoperative image updating for image-guided surgery. Proof-of-concept demonstrations are shown for synthetic and real data in the context of neurosurgery.

Public Health Departments and Accountable Care Organizations: Finding Common Ground in Population Health

PubMed Central

Ingram, Richard; Scutchfield, F. Douglas

2015-01-01

We examined areas of potential collaboration between accountable care organizations and public health agencies, as well as perceived barriers and facilitators. We interviewed 9 key informants on 4 topics: advantages of public health agency involvement in accountable care organizations; services public health agencies could provide; practical, cultural, and legal barriers to accountable care organization–public health agency involvement; and business models that facilitate accountable care organization–public health agency collaboration. Public health agencies could help accountable care organizations partner with community organizations and reach vulnerable patients, provide population-based services and surveillance data, and promote policies that improve member health. Barriers include accountable care organizations’ need for short-term financial yield, limited public health agency technical and financial capacity, and the absence of a financial model. PMID:25790392

Community Crowd-Funded Solar Finance

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

Jagerson, Gordon "Ty"

The award supported the demonstration and development of the Village Power Platform, which enables community organizations to more readily develop, finance and operate solar installations on local community organizations. The platform enables partial or complete local ownership of the solar installation. The award specifically supported key features including financial modeling tools, community communications tools, crowdfunding mechanisms, a mobile app, and other critical features.

The short-lived African turquoise killifish: an emerging experimental model for ageing.

PubMed

Kim, Yumi; Nam, Hong Gil; Valenzano, Dario Riccardo

2016-02-01

Human ageing is a fundamental biological process that leads to functional decay, increased risk for various diseases and, ultimately, death. Some of the basic biological mechanisms underlying human ageing are shared with other organisms; thus, animal models have been invaluable in providing key mechanistic and molecular insights into the common bases of biological ageing. In this Review, we briefly summarise the major applications of the most commonly used model organisms adopted in ageing research and highlight their relevance in understanding human ageing. We compare the strengths and limitations of different model organisms and discuss in detail an emerging ageing model, the short-lived African turquoise killifish. We review the recent progress made in using the turquoise killifish to study the biology of ageing and discuss potential future applications of this promising animal model. © 2016. Published by The Company of Biologists Ltd.

Can Microbial Ecology and Mycorrhizal Functioning Inform Climate Change Models?

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

Hofmockel, Kirsten; Hobbie, Erik

Our funded research focused on soil organic matter dynamics and plant-microbe interactions by examining the role of belowground processes and mechanisms across scales, including decomposition of organic molecules, microbial interactions, and plant-microbe interactions associated with a changing climate. Research foci included mycorrhizal mediated priming of soil carbon turnover, organic N use and depolymerization by free-living microbes and mycorrhizal fungi, and the use of isotopes as additional constraints for improved modeling of belowground processes. This work complemented the DOE’s mandate to understand both the consequences of atmospheric and climatic change for key ecosystems and the feedbacks on C cycling.

Computational optimization and biological evolution.

PubMed

Goryanin, Igor

2010-10-01

Modelling and optimization principles become a key concept in many biological areas, especially in biochemistry. Definitions of objective function, fitness and co-evolution, although they differ between biology and mathematics, are similar in a general sense. Although successful in fitting models to experimental data, and some biochemical predictions, optimization and evolutionary computations should be developed further to make more accurate real-life predictions, and deal not only with one organism in isolation, but also with communities of symbiotic and competing organisms. One of the future goals will be to explain and predict evolution not only for organisms in shake flasks or fermenters, but for real competitive multispecies environments.

Organization of Anti-Phase Synchronization Pattern in Neural Networks: What are the Key Factors?

PubMed Central

Li, Dong; Zhou, Changsong

2011-01-01

Anti-phase oscillation has been widely observed in cortical neural network. Elucidating the mechanism underlying the organization of anti-phase pattern is of significance for better understanding more complicated pattern formations in brain networks. In dynamical systems theory, the organization of anti-phase oscillation pattern has usually been considered to relate to time delay in coupling. This is consistent to conduction delays in real neural networks in the brain due to finite propagation velocity of action potentials. However, other structural factors in cortical neural network, such as modular organization (connection density) and the coupling types (excitatory or inhibitory), could also play an important role. In this work, we investigate the anti-phase oscillation pattern organized on a two-module network of either neuronal cell model or neural mass model, and analyze the impact of the conduction delay times, the connection densities, and coupling types. Our results show that delay times and coupling types can play key roles in this organization. The connection densities may have an influence on the stability if an anti-phase pattern exists due to the other factors. Furthermore, we show that anti-phase synchronization of slow oscillations can be achieved with small delay times if there is interaction between slow and fast oscillations. These results are significant for further understanding more realistic spatiotemporal dynamics of cortico-cortical communications. PMID:22232576

Stable isotopes and Digital Elevation Models to study nutrient inputs in high-Arctic lakes

NASA Astrophysics Data System (ADS)

Calizza, Edoardo; Rossi, David; Costantini, Maria Letizia; Careddu, Giulio; Rossi, Loreto

2016-04-01

Ice cover, run-off from the watershed, aquatic and terrestrial primary productivity, guano deposition from birds are key factors controlling nutrient and organic matter inputs in high-Arctic lakes. All these factors are expected to be significantly affected by climate change. Quantifying these controls is a key baseline step to understand what combination of factors subtends the biological productivity in Arctic lakes and will drive their ecological response to environmental change. Basing on Digital Elevation Models, drainage maps, and C and N elemental content and stable isotope analysis in sediments, aquatic vegetation and a dominant macroinvertebrate species (Lepidurus arcticus Pallas 1973) belonging to Tvillingvatnet, Storvatnet and Kolhamna, three lakes located in North Spitsbergen (Svalbard), we propose an integrated approach for the analysis of (i) nutrient and organic matter inputs in lakes; (ii) the role of catchment hydro-geomorphology in determining inter-lake differences in the isotopic composition of sediments; (iii) effects of diverse nutrient inputs on the isotopic niche of Lepidurus arcticus. Given its high run-off and large catchment, organic deposits in Tvillingvatnet where dominated by terrestrial inputs, whereas inputs were mainly of aquatic origin in Storvatnet, a lowland lake with low potential run-off. In Kolhamna, organic deposits seem to be dominated by inputs from birds, which actually colonise the area. Isotopic signatures were similar between samples within each lake, representing precise tracers for studies on the effect of climate change on biogeochemical cycles in lakes. The isotopic niche of L. aricticus reflected differences in sediments between lakes, suggesting a bottom-up effect of hydro-geomorphology characterizing each lake on nutrients assimilated by this species. The presented approach proven to be an effective research pathway for the identification of factors subtending to nutrient and organic matter inputs and transfer within each water body, as well as for the modelling of expected changes in nutrient content associated to changes in isotopic composition of sediments. Key words: nitrogen; carbon, sediment; biogeochemical cycle; climate change; hydro-ecology; isotopic niche; Svalbard

Probing Complex Free-Radical Reaction Pathways of Fuel Model Compounds

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

Buchanan III, A C; Kidder, Michelle; Beste, Ariana

2012-01-01

Fossil (e.g. coal) and renewable (e.g. woody biomass) organic energy resources have received considerable attention as possible sources of liquid transportation fuels and commodity chemicals. Knowledge of the reactivity of these complex materials has been advanced through fundamental studies of organic compounds that model constituent substructures. In particular, an improved understanding of thermochemical reaction pathways involving free-radical intermediates has arisen from detailed experimental kinetic studies and, more recently, advanced computational investigations. In this presentation, we will discuss our recent investigations of the fundamental pyrolysis pathways of model compounds that represent key substructures in the lignin component of woody biomass withmore » a focus on molecules representative of the dominant beta-O-4 aryl ether linkages. Additional mechanistic insights gleaned from DFT calculations on the kinetics of key elementary reaction steps will also be presented, as well as a few thoughts on the significant contributions of Jim Franz to this area of free radical chemistry.« less

3D Miniaturization of Human Organs for Drug Discovery.

PubMed

Park, Joseph; Wetzel, Isaac; Dréau, Didier; Cho, Hansang

2018-01-01

"Engineered human organs" hold promises for predicting the effectiveness and accuracy of drug responses while reducing cost, time, and failure rates in clinical trials. Multiorgan human models utilize many aspects of currently available technologies including self-organized spherical 3D human organoids, microfabricated 3D human organ chips, and 3D bioprinted human organ constructs to mimic key structural and functional properties of human organs. They enable precise control of multicellular activities, extracellular matrix (ECM) compositions, spatial distributions of cells, architectural organizations of ECM, and environmental cues. Thus, engineered human organs can provide the microstructures and biological functions of target organs and advantageously substitute multiscaled drug-testing platforms including the current in vitro molecular assays, cell platforms, and in vivo models. This review provides an overview of advanced innovative designs based on the three main technologies used for organ construction leading to single and multiorgan systems useable for drug development. Current technological challenges and future perspectives are also discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Modeling the Dynamics and Export of Dissolved Organic Matter in the Northeastern U.S. Continental Shelf

NASA Technical Reports Server (NTRS)

Druon, J.N.; Mannino, A.; Signorini, Sergio R.; McClain, Charles R.; Friedrichs, M.; Wilkin, J.; Fennel, K.

2009-01-01

Continental shelves are believed to play a major role in carbon cycling due to their high productivity. Particulate organic carbon (POC) burial has been included in models as a carbon sink, but we show here that seasonally produced dissolved organic carbon (DOC) on the shelf can be exported to the open ocean by horizontal transport at similar rates (1-2 mol C/sq m/yr) in the southern U.S. Mid-Atlantic Bight (MAB). The dissolved organic matter (DOM) model imbedded in a coupled circulation-biogeochemical model reveals a double dynamics: the progressive release of dissolved organic nitrogen (DON) in the upper layer during summer increases the regenerated primary production by 30 to 300%, which, in turns ; enhances the DOC production mainly from phytoplankton exudation in the upper layer and solubilization of particulate organic matter (POM) deeper in the water column. This analysis suggests that DOM is a key element for better representing the ecosystem functioning and organic fluxes in models because DOM (1) is a major organic pool directly related to primary production, (2) decouples partially the carbon and nitrogen cycles (through carbon excess uptake, POM solubilization and DOM mineralization) and (3) is intimately linked to the residence time of water masses for its distribution and export.

Scalable printed electronics: an organic decoder addressing ferroelectric non-volatile memory

PubMed Central

Ng, Tse Nga; Schwartz, David E.; Lavery, Leah L.; Whiting, Gregory L.; Russo, Beverly; Krusor, Brent; Veres, Janos; Bröms, Per; Herlogsson, Lars; Alam, Naveed; Hagel, Olle; Nilsson, Jakob; Karlsson, Christer

2012-01-01

Scalable circuits of organic logic and memory are realized using all-additive printing processes. A 3-bit organic complementary decoder is fabricated and used to read and write non-volatile, rewritable ferroelectric memory. The decoder-memory array is patterned by inkjet and gravure printing on flexible plastics. Simulation models for the organic transistors are developed, enabling circuit designs tolerant of the variations in printed devices. We explain the key design rules in fabrication of complex printed circuits and elucidate the performance requirements of materials and devices for reliable organic digital logic. PMID:22900143

Self-organized pattern formation at organic-inorganic interfaces during deposition: Experiment versus modeling

NASA Astrophysics Data System (ADS)

Szillat, F.; Mayr, S. G.

2011-09-01

Self-organized pattern formation during physical vapor deposition of organic materials onto rough inorganic substrates is characterized by a complex morphological evolution as a function of film thickness. We employ a combined experimental-theoretical study using atomic force microscopy and numerically solved continuum rate equations to address morphological evolution in the model system: poly(bisphenol A carbonate) on polycrystalline Cu. As the key ingredients for pattern formation, (i) curvature and interface potential driven surface diffusion, (ii) deposition noise, and (iii) interface boundary effects are identified. Good agreement of experiments and theory, fitting only the Hamaker constant and diffusivity within narrow physical parameter windows, corroborates the underlying physics and paves the way for computer-assisted interface engineering.

Functional Coupling of Human Microphysiology Systems: Intestine, Liver, Kidney Proximal Tubule, Blood-Brain Barrier and Skeletal Muscle

PubMed Central

Vernetti, Lawrence; Gough, Albert; Baetz, Nicholas; Blutt, Sarah; Broughman, James R.; Brown, Jacquelyn A.; Foulke-Abel, Jennifer; Hasan, Nesrin; In, Julie; Kelly, Edward; Kovbasnjuk, Olga; Repper, Jonathan; Senutovitch, Nina; Stabb, Janet; Yeung, Catherine; Zachos, Nick C.; Donowitz, Mark; Estes, Mary; Himmelfarb, Jonathan; Truskey, George; Wikswo, John P.; Taylor, D. Lansing

2017-01-01

Organ interactions resulting from drug, metabolite or xenobiotic transport between organs are key components of human metabolism that impact therapeutic action and toxic side effects. Preclinical animal testing often fails to predict adverse outcomes arising from sequential, multi-organ metabolism of drugs and xenobiotics. Human microphysiological systems (MPS) can model these interactions and are predicted to dramatically improve the efficiency of the drug development process. In this study, five human MPS models were evaluated for functional coupling, defined as the determination of organ interactions via an in vivo-like sequential, organ-to-organ transfer of media. MPS models representing the major absorption, metabolism and clearance organs (the jejunum, liver and kidney) were evaluated, along with skeletal muscle and neurovascular models. Three compounds were evaluated for organ-specific processing: terfenadine for pharmacokinetics (PK) and toxicity; trimethylamine (TMA) as a potentially toxic microbiome metabolite; and vitamin D3. We show that the organ-specific processing of these compounds was consistent with clinical data, and discovered that trimethylamine-N-oxide (TMAO) crosses the blood-brain barrier. These studies demonstrate the potential of human MPS for multi-organ toxicity and absorption, distribution, metabolism and excretion (ADME), provide guidance for physically coupling MPS, and offer an approach to coupling MPS with distinct media and perfusion requirements. PMID:28176881

Crisis in Context Theory: An Ecological Model

ERIC Educational Resources Information Center

Myer, Rick A.; Moore, Holly B.

2006-01-01

This article outlines a theory for understanding the impact of a crisis on individuals and organizations. Crisis in context theory (CCT) is grounded in an ecological model and based on literature in the field of crisis intervention and on personal experiences of the authors. A graphic representation denotes key components and premises of CCT,…

Assessment of important SPECIATE Profiles in EPA’s Emissions Modeling Platform and Current Data Gaps (US EPA 2017 International Emissions Inventory Conference)

EPA Science Inventory

The US Environmental Protection Agency (EPA)’s SPECIATE database contains speciation profiles for both particulate matter (PM) and volatile organic compounds (VOCs) that are key inputs for creating speciated emission inventories for air quality modeling. The objective of th...

Key Planning Factors for Recovery from a Biological Terrorism Incident

DTIC Science & Technology

2012-08-30

Goals, this document identifies key technical planning areas that may be used to inform subsequent FEMA response and recovery guidance documents. The...expressed herein do not necessarily state or reflect those of their respective organizations or the US Government. The modeling and analysis provided by...responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would

Sustaining Culture Change: Experiences in the Green House Model.

PubMed

Bowers, Barbara; Nolet, Kimberly; Jacobson, Nora

2016-02-01

To describe conditions that influence how Green House (GH) organizations are sustaining culture change principles and practices in a sample of GH skilled nursing homes. Primary data were collected at 11 skilled nursing GH organizations from 2012 to 2014. These organizations have adopted the comprehensive and prescriptive GH model of culture change. To develop an understanding of sustainability from the perspective of staff who are immersed in GH daily work, grounded theory qualitative methods were used. Data were collected using semi-structured interviews with 166 staff and observation of house meetings and daily operations. Data were analyzed using grounded dimensional analysis. Organizations varied in their ability to sustain GH principles and practices. An organization's approach to problem solving was central to sustaining the model. Key conditions influenced reinforcement or erosion of GH principles and practices. Reinforcing the GH model requires a highly skilled team of staff with the ability to frequently and collaboratively solve both mundane and complex problems in ways that are consistent with the GH model. This raises questions about the type of human resources practices and policy supports that could assist organizations in sustaining culture change. © Health Research and Educational Trust.

Simulation of wheat growth and development based on organ-level photosynthesis and assimilate allocation.

PubMed

Evers, J B; Vos, J; Yin, X; Romero, P; van der Putten, P E L; Struik, P C

2010-05-01

Intimate relationships exist between form and function of plants, determining many processes governing their growth and development. However, in most crop simulation models that have been created to simulate plant growth and, for example, predict biomass production, plant structure has been neglected. In this study, a detailed simulation model of growth and development of spring wheat (Triticum aestivum) is presented, which integrates degree of tillering and canopy architecture with organ-level light interception, photosynthesis, and dry-matter partitioning. An existing spatially explicit 3D architectural model of wheat development was extended with routines for organ-level microclimate, photosynthesis, assimilate distribution within the plant structure according to organ demands, and organ growth and development. Outgrowth of tiller buds was made dependent on the ratio between assimilate supply and demand of the plants. Organ-level photosynthesis, biomass production, and bud outgrowth were simulated satisfactorily. However, to improve crop simulation results more efforts are needed mechanistically to model other major plant physiological processes such as nitrogen uptake and distribution, tiller death, and leaf senescence. Nevertheless, the work presented here is a significant step forwards towards a mechanistic functional-structural plant model, which integrates plant architecture with key plant processes.

Epoxide pathways improve model predictions of isoprene markers and reveal key role of acidity in aerosol formation.

PubMed

Pye, Havala O T; Pinder, Robert W; Piletic, Ivan R; Xie, Ying; Capps, Shannon L; Lin, Ying-Hsuan; Surratt, Jason D; Zhang, Zhenfa; Gold, Avram; Luecken, Deborah J; Hutzell, William T; Jaoui, Mohammed; Offenberg, John H; Kleindienst, Tadeusz E; Lewandowski, Michael; Edney, Edward O

2013-10-01

Isoprene significantly contributes to organic aerosol in the southeastern United States where biogenic hydrocarbons mix with anthropogenic emissions. In this work, the Community Multiscale Air Quality model is updated to predict isoprene aerosol from epoxides produced under both high- and low-NOx conditions. The new aqueous aerosol pathways allow for explicit predictions of two key isoprene-derived species, 2-methyltetrols and 2-methylglyceric acid, that are more consistent with observations than estimates based on semivolatile partitioning. The new mechanism represents a significant source of organic carbon in the lower 2 km of the atmosphere and captures the abundance of 2-methyltetrols relative to organosulfates during the simulation period. For the parametrization considered here, a 25% reduction in SOx emissions effectively reduces isoprene aerosol, while a similar reduction in NOx leads to small increases in isoprene aerosol.

Microporoelastic Modeling of Organic-Rich Shales

NASA Astrophysics Data System (ADS)

Khosh Sokhan Monfared, S.; Abedi, S.; Ulm, F. J.

2014-12-01

Organic-rich shale is an extremely complex, naturally occurring geo-composite. The heterogeneous nature of organic-rich shale and its anisotropic behavior pose grand challenges for characterization, modeling and engineering design The intricacy of organic-rich shale, in the context of its mechanical and poromechanical properties, originates in the presence of organic/inorganic constituents and their interfaces as well as the occurrence of porosity and elastic anisotropy, at multiple length scales. To capture the contributing mechanisms, of 1st order, responsible for organic-rich shale complex behavior, we introduce an original approach for micromechanical modeling of organic-rich shales which accounts for the effect of maturity of organics on the overall elasticity through morphology considerations. This morphology contribution is captured by means of an effective media theory that bridges the gap between immature and mature systems through the choice of system's microtexture; namely a matrix-inclusion morphology (Mori-Tanaka) for immature systems and a polycrystal/granular morphology for mature systems. Also, we show that interfaces play a role on the effective elasticity of mature, organic-rich shales. The models are calibrated by means of ultrasonic pulse velocity measurements of elastic properties and validated by means of nanoindentation results. Sensitivity analyses using Spearman's Partial Rank Correlation Coefficient shows the importance of porosity and Total Organic Carbon (TOC) as key input parameters for accurate model predictions. These modeling developments pave the way to reach a "unique" set of clay properties and highlight the importance of depositional environment, burial and diagenetic processes on overall mechanical and poromechanical behavior of organic-rich shale. These developments also emphasize the importance of understanding and modeling clay elasticity and organic maturity on the overall rock behavior which is of critical importance for a practical rock physics model that accounts for time dependent phenomena which can be employed for seismic inversion.

A mathematical model for adaptive transport network in path finding by true slime mold.

PubMed

Tero, Atsushi; Kobayashi, Ryo; Nakagaki, Toshiyuki

2007-02-21

We describe here a mathematical model of the adaptive dynamics of a transport network of the true slime mold Physarum polycephalum, an amoeboid organism that exhibits path-finding behavior in a maze. This organism possesses a network of tubular elements, by means of which nutrients and signals circulate through the plasmodium. When the organism is put in a maze, the network changes its shape to connect two exits by the shortest path. This process of path-finding is attributed to an underlying physiological mechanism: a tube thickens as the flux through it increases. The experimental evidence for this is, however, only qualitative. We constructed a mathematical model of the general form of the tube dynamics. Our model contains a key parameter corresponding to the extent of the feedback regulation between the thickness of a tube and the flux through it. We demonstrate the dependence of the behavior of the model on this parameter.

Decision support systems and the healthcare strategic planning process: a case study.

PubMed

Lundquist, D L; Norris, R M

1991-01-01

The repertoire of applications that comprises health-care decision support systems (DSS) includes analyses of clinical, financial, and operational activities. As a whole, these applications facilitate developing comprehensive and interrelated business and medical models that support the complex decisions required to successfully manage today's health-care organizations. Kennestone Regional Health Care System's use of DSS to facilitate strategic planning has precipitated marked changes in the organization's method of determining capital allocations. This case study discusses Kennestone's use of DSS in the strategic planning process, including profiles of key DSS modeling components.

Carolina Care at University of North Carolina Health Care: Implementing a Theory-Driven Care Delivery Model Across a Healthcare System.

PubMed

Tonges, Mary; Ray, Joel D; Herman, Suzanne; McCann, Meghan

2018-04-01

Patient satisfaction is a key component of healthcare organizations' performance. Providing a consistent, positive patient experience across a system can be challenging. This article describes an organization's approach to achieving this goal by implementing a successful model developed at the flagship academic healthcare center across an 8-hospital system. The Carolina Care at University of North Carolina Health Care initiative has resulted in substantive qualitative and quantitative benefits including higher patient experience scores for both overall rating and nurse communication.

Modality-based organization of ascending somatosensory axons in the direct dorsal column pathway.

PubMed

Niu, Jingwen; Ding, Long; Li, Jian J; Kim, Hyukmin; Liu, Jiakun; Li, Haipeng; Moberly, Andrew; Badea, Tudor C; Duncan, Ian D; Son, Young-Jin; Scherer, Steven S; Luo, Wenqin

2013-11-06

The long-standing doctrine regarding the functional organization of the direct dorsal column (DDC) pathway is the "somatotopic map" model, which suggests that somatosensory afferents are primarily organized by receptive field instead of modality. Using modality-specific genetic tracing, here we show that ascending mechanosensory and proprioceptive axons, two main types of the DDC afferents, are largely segregated into a medial-lateral pattern in the mouse dorsal column and medulla. In addition, we found that this modality-based organization is likely to be conserved in other mammalian species, including human. Furthermore, we identified key morphological differences between these two types of afferents, which explains how modality segregation is formed and why a rough "somatotopic map" was previously detected. Collectively, our results establish a new functional organization model for the mammalian direct dorsal column pathway and provide insight into how somatotopic and modality-based organization coexist in the central somatosensory pathway.

Communication-oriented person-organization fit as a key factor of job-seeking behaviors: millennials' social media use and attitudes toward organizational social media policies.

PubMed

Cho, Jaehee; Park, Dong Jin; Ordonez, Zoa

2013-11-01

The main goal of this study was to assess how the millennial generation perceives companies that have different social media policies and how such perception influences key variables for job-seeking behaviors, including perceived person-organization fit (POF), organizational attraction, and job pursuit intention. Results from a univariate general linear model and path analysis supported all of the established hypotheses. In particular, the results revealed that millennials perceived higher POF for a company with organizational policies supporting employees' social media use. Further, organizational attractiveness significantly mediated the relationship between communication-oriented POF and job pursuit intention.

Disclosure, Apology, and Offer Programs: Stakeholders' Views of Barriers to and Strategies for Broad Implementation

PubMed Central

Bell, Sigall K; Smulowitz, Peter B; Woodward, Alan C; Mello, Michelle M; Duva, Anjali Mitter; Boothman, Richard C; Sands, Kenneth

2012-01-01

Context The Disclosure, Apology, and Offer (DA&O) model, a response to patient injuries caused by medical care, is an innovative approach receiving national attention for its early success as an alternative to the existing inherently adversarial, inefficient, and inequitable medical liability system. Examples of DA&O programs, however, are few. Methods Through key informant interviews, we investigated the potential for more widespread implementation of this model by provider organizations and liability insurers, defining barriers to implementation and strategies for overcoming them. Our study focused on Massachusetts, but we also explored themes that are broadly generalizable to other states. Findings We found strong support for the DA&O model among key stakeholders, who cited its benefits for both the liability system and patient safety. The respondents did not perceive any insurmountable barriers to broad implementation, and they identified strategies that could be pursued relatively quickly. Such solutions would permit a range of organizations to implement the model without legislative hurdles. Conclusions Although more data are needed about the outcomes of DA&O programs, the model holds considerable promise for transforming the current approach to medical liability and patient safety. PMID:23216427

Disclosure, apology, and offer programs: stakeholders' views of barriers to and strategies for broad implementation.

PubMed

Bell, Sigall K; Smulowitz, Peter B; Woodward, Alan C; Mello, Michelle M; Duva, Anjali Mitter; Boothman, Richard C; Sands, Kenneth

2012-12-01

The Disclosure, Apology, and Offer (DA&O) model, a response to patient injuries caused by medical care, is an innovative approach receiving national attention for its early success as an alternative to the existing inherently adversarial, inefficient, and inequitable medical liability system. Examples of DA&O programs, however, are few. Through key informant interviews, we investigated the potential for more widespread implementation of this model by provider organizations and liability insurers, defining barriers to implementation and strategies for overcoming them. Our study focused on Massachusetts, but we also explored themes that are broadly generalizable to other states. We found strong support for the DA&O model among key stakeholders, who cited its benefits for both the liability system and patient safety. The respondents did not perceive any insurmountable barriers to broad implementation, and they identified strategies that could be pursued relatively quickly. Such solutions would permit a range of organizations to implement the model without legislative hurdles. Although more data are needed about the outcomes of DA&O programs, the model holds considerable promise for transforming the current approach to medical liability and patient safety. © 2012 Milbank Memorial Fund.

The Derivation of Sink Functions of Wheat Organs using the GREENLAB Model

PubMed Central

Kang, Mengzhen; Evers, Jochem B.; Vos, Jan; de Reffye, Philippe

2008-01-01

Background and Aims In traditional crop growth models assimilate production and partitioning are described with empirical equations. In the GREENLAB functional–structural model, however, allocation of carbon to different kinds of organs depends on the number and relative sink strengths of growing organs present in the crop architecture. The aim of this study is to generate sink functions of wheat (Triticum aestivum) organs by calibrating the GREENLAB model using a dedicated data set, consisting of time series on the mass of individual organs (the ‘target data’). Methods An experiment was conducted on spring wheat (Triticum aestivum, ‘Minaret’), in a growth chamber from, 2004 to, 2005. Four harvests were made of six plants each to determine the size and mass of individual organs, including the root system, leaf blades, sheaths, internodes and ears of the main stem and different tillers. Leaf status (appearance, expansion, maturity and death) of these 24 plants was recorded. With the structures and mass of organs of four individual sample plants, the GREENLAB model was calibrated using a non-linear least-square-root fitting method, the aim of which was to minimize the difference in mass of the organs between measured data and model output, and to provide the parameter values of the model (the sink strengths of organs of each type, age and tiller order, and two empirical parameters linked to biomass production). Key Results and Conclusions The masses of all measured organs from one plant from each harvest were fitted simultaneously. With estimated parameters for sink and source functions, the model predicted the mass and size of individual organs at each position of the wheat structure in a mechanistic way. In addition, there was close agreement between experimentally observed and simulated values of leaf area index. PMID:18045794

FORest canopy atmosphere transfer (FORCAsT) 1.0: a 1-D model of biosphere-atmosphere chemical exchange

NASA Astrophysics Data System (ADS)

Ashworth, K.; Chung, S. H.; Griffin, R. J.; Chen, J.; Forkel, R.; Bryan, A. M.; Steiner, A. L.

2015-07-01

Biosphere-atmosphere interactions play a critical role in governing atmospheric composition, mediating the concentration of key species such as ozone and aerosol, thereby influencing air quality and climate. The exchange of reactive trace gases and their oxidation products (both gas and particle phase) is of particular importance in this process. The FORCAsT (FORest Canopy AtmoSphere Transfer) one-dimensional model is developed to study the emission, deposition, chemistry and transport of volatile organic compounds (VOCs) and their oxidation products in the atmosphere within and above the forest canopy. We include an equilibrium partitioning scheme, making FORCAsT one of the few canopy models currently capable of simulating the formation of secondary organic aerosols (SOA) from VOC oxidation in a forest environment. We evaluate the capability of FORCAsT to reproduce observed concentrations of key gas-phase species and report modeled SOA concentrations within and above a mixed forest at the University of Michigan Biological Station (UMBS) during the Community Atmosphere-Biosphere Interactions Experiment (CABINEX) field campaign in summer 2009. We examine the impact of two different gas-phase chemical mechanisms on modelled concentrations of short-lived primary emissions, such as isoprene and monoterpenes, and their oxidation products. While the two chemistry schemes perform similarly under high-NOx conditions, they diverge at the low levels of NOx at UMBS. We identify peroxy radical and alkyl nitrate chemistry as the key causes of the differences, highlighting the importance of this chemistry in understanding the fate of biogenic VOCs (bVOCs) for both the modelling and measurement communities.

FORest Canopy Atmosphere Transfer (FORCAsT) 1.0: a 1-D model of biosphere-atmosphere chemical exchange

NASA Astrophysics Data System (ADS)

Ashworth, K.; Chung, S. H.; Griffin, R. J.; Chen, J.; Forkel, R.; Bryan, A. M.; Steiner, A. L.

2015-11-01

Biosphere-atmosphere interactions play a critical role in governing atmospheric composition, mediating the concentrations of key species such as ozone and aerosol, thereby influencing air quality and climate. The exchange of reactive trace gases and their oxidation products (both gas and particle phase) is of particular importance in this process. The FORCAsT (FORest Canopy Atmosphere Transfer) 1-D model is developed to study the emission, deposition, chemistry and transport of volatile organic compounds (VOCs) and their oxidation products in the atmosphere within and above the forest canopy. We include an equilibrium partitioning scheme, making FORCAsT one of the few canopy models currently capable of simulating the formation of secondary organic aerosols (SOAs) from VOC oxidation in a forest environment. We evaluate the capability of FORCAsT to reproduce observed concentrations of key gas-phase species and report modeled SOA concentrations within and above a mixed forest at the University of Michigan Biological Station (UMBS) during the Community Atmosphere-Biosphere Interactions Experiment (CABINEX) field campaign in the summer of 2009. We examine the impact of two different gas-phase chemical mechanisms on modelled concentrations of short-lived primary emissions, such as isoprene and monoterpenes, and their oxidation products. While the two chemistry schemes perform similarly under high-NOx conditions, they diverge at the low levels of NOx at UMBS. We identify peroxy radical and alkyl nitrate chemistry as the key causes of the differences, highlighting the importance of this chemistry in understanding the fate of biogenic VOCs (bVOCs) for both the modelling and measurement communities.

A Roy Model of Social Interactions. NBER Working Paper No. 16880

ERIC Educational Resources Information Center

Cicala, Steve; Fryer, Roland G., Jr.; Spenkuch, Jorg L.

2011-01-01

We develop a Roy model of social interactions in which individuals sort into peer groups based on comparative advantage. Two key results emerge: First, when comparative advantage is the guiding principle of peer group organization, the effect of moving a student into an environment with higher-achieving peers depends on where in the ability…

Toward a Community School: A Model for Organizing Community Based Educational Support Services. Publication Series No. 10.

ERIC Educational Resources Information Center

Bartelt, David W.

This paper focuses on how to develop a community-based educational intervention when community apathy is present, or where the isolation between school and community makes partnership more difficult. The key elements for this model are three steps: (1) determining the school-community relationship, establishing that a condition of isolation…

Modeling Global Soil Carbon and Soil Microbial Carbon by Integrating Microbial Processes into the Ecosystem Process Model TRIPLEX-GHG

DOE PAGES

Wang, Kefeng; Peng, Changhui; Zhu, Qiuan; ...

2017-09-28

Microbial physiology plays a critical role in the biogeochemical cycles of the Earth system. However, most traditional soil carbon models are lacking in terms of the representation of key microbial processes that control the soil carbon response to global climate change. In this study, the improved process-based model TRIPLEX-GHG was developed by coupling it with the new MEND (Microbial-ENzyme-mediated Decomposition) model to estimate total global soil organic carbon (SOC) and global soil microbial carbon. The new model (TRIPLEX-MICROBE) shows considerable improvement over the previous version (TRIPLEX-GHG) in simulating SOC. We estimated the global soil carbon stock to be approximately 1195more » Pg C, with 348 Pg C located in the high northern latitudes, which is in good agreement with the well-regarded Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). We also estimated the global soil microbial carbon to be 21 Pg C, similar to the 23 Pg C estimated. We found that the microbial carbon quantity in the latitudinal direction showed reversions at approximately 30°N, near the equator and at 25°S. A sensitivity analysis suggested that the tundra ecosystem exhibited the highest sensitivity to a 1°C increase or decrease in temperature in terms of dissolved organic carbon (DOC), microbial biomass carbon (MBC) and mineral-associated organic carbon (MOC). Furthermore, our work represents the first step towards a new generation of ecosystem process models capable of integrating key microbial processes into soil carbon cycles.« less

Modeling Global Soil Carbon and Soil Microbial Carbon by Integrating Microbial Processes into the Ecosystem Process Model TRIPLEX-GHG

NASA Astrophysics Data System (ADS)

Wang, Kefeng; Peng, Changhui; Zhu, Qiuan; Zhou, Xiaolu; Wang, Meng; Zhang, Kerou; Wang, Gangsheng

2017-10-01

Microbial physiology plays a critical role in the biogeochemical cycles of the Earth system. However, most traditional soil carbon models are lacking in terms of the representation of key microbial processes that control the soil carbon response to global climate change. In this study, the improved process-based model TRIPLEX-GHG was developed by coupling it with the new MEND (Microbial-ENzyme-mediated Decomposition) model to estimate total global soil organic carbon (SOC) and global soil microbial carbon. The new model (TRIPLEX-MICROBE) shows considerable improvement over the previous version (TRIPLEX-GHG) in simulating SOC. We estimated the global soil carbon stock to be approximately 1195 Pg C, with 348 Pg C located in the high northern latitudes, which is in good agreement with the well-regarded Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). We also estimated the global soil microbial carbon to be 21 Pg C, similar to the 23 Pg C estimated by Xu et al. (2014). We found that the microbial carbon quantity in the latitudinal direction showed reversions at approximately 30°N, near the equator and at 25°S. A sensitivity analysis suggested that the tundra ecosystem exhibited the highest sensitivity to a 1°C increase or decrease in temperature in terms of dissolved organic carbon (DOC), microbial biomass carbon (MBC), and mineral-associated organic carbon (MOC). However, our work represents the first step toward a new generation of ecosystem process models capable of integrating key microbial processes into soil carbon cycles.

Modeling Global Soil Carbon and Soil Microbial Carbon by Integrating Microbial Processes into the Ecosystem Process Model TRIPLEX-GHG

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

Wang, Kefeng; Peng, Changhui; Zhu, Qiuan

Microbial physiology plays a critical role in the biogeochemical cycles of the Earth system. However, most traditional soil carbon models are lacking in terms of the representation of key microbial processes that control the soil carbon response to global climate change. In this study, the improved process-based model TRIPLEX-GHG was developed by coupling it with the new MEND (Microbial-ENzyme-mediated Decomposition) model to estimate total global soil organic carbon (SOC) and global soil microbial carbon. The new model (TRIPLEX-MICROBE) shows considerable improvement over the previous version (TRIPLEX-GHG) in simulating SOC. We estimated the global soil carbon stock to be approximately 1195more » Pg C, with 348 Pg C located in the high northern latitudes, which is in good agreement with the well-regarded Harmonized World Soil Database (HWSD) and the Northern Circumpolar Soil Carbon Database (NCSCD). We also estimated the global soil microbial carbon to be 21 Pg C, similar to the 23 Pg C estimated. We found that the microbial carbon quantity in the latitudinal direction showed reversions at approximately 30°N, near the equator and at 25°S. A sensitivity analysis suggested that the tundra ecosystem exhibited the highest sensitivity to a 1°C increase or decrease in temperature in terms of dissolved organic carbon (DOC), microbial biomass carbon (MBC) and mineral-associated organic carbon (MOC). Furthermore, our work represents the first step towards a new generation of ecosystem process models capable of integrating key microbial processes into soil carbon cycles.« less

The group employed model as a foundation for health care delivery reform.

PubMed

Minott, Jenny; Helms, David; Luft, Harold; Guterman, Stuart; Weil, Henry

2010-04-01

With a focus on delivering low-cost, high-quality care, several organizations using the group employed model (GEM)-with physician groups whose primary and specialty care physicians are salaried or under contract-have been recognized for creating a culture of patient-centeredness and accountability, even in a toxic fee-for-service environment. The elements that leaders of such organizations identify as key to their success are physician leadership that promotes trust in the organization, integration that promotes teamwork and coordination, governance and strategy that drive results, transparency and health information technology that drive continual quality improvement, and a culture of accountability that focuses providers on patient needs and responsibility for effective care and efficient use of resources. These organizations provide important lessons for health care delivery system reform.

Optical Measurements and Modeling to Estimate Concentrations and Fluxes of Organic Matter in the Southern Ocean

NASA Technical Reports Server (NTRS)

Stramski, Dariusz; Mitchell, B. Greg; Marra, John W. (Technical Monitor)

2001-01-01

This project was a collaboration between two Principal Investigators, Dr. Dariusz Stramski and Dr. Greg Mitchell of Scripps Institution of Oceanography, University of California San Diego. Our overall goal was to conduct optical measurements and modeling to estimate concentrations of organic matter in the Southern Ocean in support of the U.S. JGOFS Process Study in this region. Key variables and processes of high relevance to accomplish the JGOFS goals include time and space resolution of phytoplankton pigments, particulate organic carbon, and the formation and export of organic carbon. Our project focused on establishing the fundamental relationships for parameterization of these variables and processes in terms of the optical properties of seawater, and developing understanding of why the Southern Ocean differs from other low-latitude systems, or has differentiation within. Our approach builds upon historical observations that optical properties provide a useful proxy for key reservoirs of organic matter such as chlorophyll alpha (Chl) and particulate organic carbon (POC) concentrations, which are of relevance to the JGOFS objectives. We carried out detailed studies of in situ and water sample optical properties including spectral reflectance, absorption, beam attenuation, scattering, and backscattering coefficients. We evaluated the ability to estimate Chl from the spectral reflectance (ocean color) in the Southern Ocean. We examined relationships between the ocean optical properties and particulate organic carbon. We developed, for the first time, an algorithm for estimating particulate organic carbon concentration in the surface ocean from satellite imagery of ocean color. With this algorithm, we obtained maps of POC distribution in the Southern Ocean showing the seasonal progression of POC in the austral spring-summer season. We also developed a semianalytical reflectance model for the investigated polar waters based on our field measurements of absorption and backscattering coefficients and Chl-dependent parameterizations of these coefficients. With this model, libraries of expected reflectance spectra for various chlorophyll concentrations can be generated with high spectral resolution for specific oceanic regions. In addition, our semianalytical reflectance model provided insight into the mechanisms which drive the empirical relationships between the ocean color and chlorophyll concentration. Our optical approach to the study of pigment and carbon concentrations will be directly relevant to development of system models and long-term monitoring of the Southern Ocean.

Spinal cord regeneration: lessons for mammals from non-mammalian vertebrates.

PubMed

Lee-Liu, Dasfne; Edwards-Faret, Gabriela; Tapia, Víctor S; Larraín, Juan

2013-08-01

Unlike mammals, regenerative model organisms such as amphibians and fish are capable of spinal cord regeneration after injury. Certain key differences between regenerative and nonregenerative organisms have been suggested as involved in promoting this process, such as the capacity for neurogenesis and axonal regeneration, which appear to be facilitated by favorable astroglial, inflammatory and immune responses. These traits provide a regenerative-permissive environment that the mammalian spinal cord appears to be lacking. Evidence for the regenerative nonpermissive environment in mammals is given by the fact that they possess neural stem/progenitor cells, which transplanted into permissive environments are able to give rise to new neurons, whereas in the nonpermissive spinal cord they are unable to do so. We discuss the traits that are favorable for regeneration, comparing what happens in mammals with each regenerative organism, aiming to describe and identify the key differences that allow regeneration. This comparison should lead us toward finding how to promote regeneration in organisms that are unable to do so. Copyright © 2013 Wiley Periodicals, Inc.

APOL1 Oligomerization as the Key Mediator of Kidney Disease in African Americans

DTIC Science & Technology

2015-10-01

INVESTIGATOR: Dr. David Friedman CONTRACTING ORGANIZATION: Beth Israel Deaconess Medical Center Boston, MA 02215 REPORT DATE: October 2015 TYPE OF...ORGANIZATION REPORT NUMBER Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 9. SPONSORING / MONITORING AGENCY NAME(S) AND...different APOL1 genotype with interferon stimulation, then look for oligomer formation in our APOL1 transgenic zebrafish and mouse models, and lastly test

Land Cover Land Use Change and Soil Organic Carbon under Climate Variability in the Semi-Arid West African Sahel (1960-2050)

ERIC Educational Resources Information Center

Dieye, Amadou M.

2016-01-01

Land Cover Land Use (LCLU) change affects land surface processes recognized to influence climate change at local, national and global levels. Soil organic carbon is a key component for the functioning of agro-ecosystems and has a direct effect on the physical, chemical and biological characteristics of the soil. The capacity to model and project…

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control.

PubMed

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease.

Spatial and Functional Organization of Pig Trade in Different European Production Systems: Implications for Disease Prevention and Control

PubMed Central

Relun, Anne; Grosbois, Vladimir; Sánchez-Vizcaíno, José Manuel; Alexandrov, Tsviatko; Feliziani, Francesco; Waret-Szkuta, Agnès; Molia, Sophie; Etter, Eric Marcel Charles; Martínez-López, Beatriz

2016-01-01

Understanding the complexity of live pig trade organization is a key factor to predict and control major infectious diseases, such as classical swine fever (CSF) or African swine fever (ASF). Whereas the organization of pig trade has been described in several European countries with indoor commercial production systems, little information is available on this organization in other systems, such as outdoor or small-scale systems. The objective of this study was to describe and compare the spatial and functional organization of live pig trade in different European countries and different production systems. Data on premise characteristics and pig movements between premises were collected during 2011 from Bulgaria, France, Italy, and Spain, which swine industry is representative of most of the production systems in Europe (i.e., commercial vs. small-scale and outdoor vs. indoor). Trade communities were identified in each country using the Walktrap algorithm. Several descriptive and network metrics were generated at country and community levels. Pig trade organization showed heterogeneous spatial and functional organization. Trade communities mostly composed of indoor commercial premises were identified in western France, northern Italy, northern Spain, and north-western Bulgaria. They covered large distances, overlapped in space, demonstrated both scale-free and small-world properties, with a role of trade operators and multipliers as key premises. Trade communities involving outdoor commercial premises were identified in western Spain, south-western and central France. They were more spatially clustered, demonstrated scale-free properties, with multipliers as key premises. Small-scale communities involved the majority of premises in Bulgaria and in central and Southern Italy. They were spatially clustered and had scale-free properties, with key premises usually being commercial production premises. These results indicate that a disease might spread very differently according to the production system and that key premises could be targeted to more cost-effectively control diseases. This study provides useful epidemiological information and parameters that could be used to design risk-based surveillance strategies or to more accurately model the risk of introduction or spread of devastating swine diseases, such as ASF, CSF, or foot-and-mouth disease. PMID:26870738

Mechanistic simulation of normal-tissue damage in radiotherapy—implications for dose-volume analyses

NASA Astrophysics Data System (ADS)

Rutkowska, Eva; Baker, Colin; Nahum, Alan

2010-04-01

A radiobiologically based 3D model of normal tissue has been developed in which complications are generated when 'irradiated'. The aim is to provide insight into the connection between dose-distribution characteristics, different organ architectures and complication rates beyond that obtainable with simple DVH-based analytical NTCP models. In this model the organ consists of a large number of functional subunits (FSUs), populated by stem cells which are killed according to the LQ model. A complication is triggered if the density of FSUs in any 'critical functioning volume' (CFV) falls below some threshold. The (fractional) CFV determines the organ architecture and can be varied continuously from small (series-like behaviour) to large (parallel-like). A key feature of the model is its ability to account for the spatial dependence of dose distributions. Simulations were carried out to investigate correlations between dose-volume parameters and the incidence of 'complications' using different pseudo-clinical dose distributions. Correlations between dose-volume parameters and outcome depended on characteristics of the dose distributions and on organ architecture. As anticipated, the mean dose and V20 correlated most strongly with outcome for a parallel organ, and the maximum dose for a serial organ. Interestingly better correlation was obtained between the 3D computer model and the LKB model with dose distributions typical for serial organs than with those typical for parallel organs. This work links the results of dose-volume analyses to dataset characteristics typical for serial and parallel organs and it may help investigators interpret the results from clinical studies.

Seven Key Principles of Program and Project Success: A Best Practices Survey

NASA Technical Reports Server (NTRS)

Bilardo, Vincent J.; Korte, John J.; Dankhoff, Walter; Langan, Kevin; Branscome, Darrell R.; Fragola, Joseph R.; Dugal, Dale J.; Gormley, Thomas J.; Hammond, Walter E.; Hollopeter, James J.;

Distribution and fate of selected oxygenated organic species in the troposphere and lower stratosphere over the Atlantic

NASA Astrophysics Data System (ADS)

Singh, H.; Chen, Y.; Tabazadeh, A.; Fukui, Y.; Bey, I.; Yantosca, R.; Jacob, D.; Arnold, F.; Wohlfrom, K.; Atlas, E.; Flocke, F.; Blake, D.; Blake, N.; Heikes, B.; Snow, J.; Talbot, R.; Gregory, G.; Sachse, G.; Vay, S.; Kondo, Y.

2000-02-01

A large number of oxygenated organic chemicals (peroxyacyl nitrates, alkyl nitrates, acetone, formaldehyde, methanol, methylhydroperoxide, acetic acid and formic acid) were measured during the 1997 Subsonic Assessment (SASS) Ozone and Nitrogen Oxide Experiment (SONEX) airborne field campaign over the Atlantic. In this paper, we present a first picture of the distribution of these oxygenated organic chemicals (Ox-organic) in the troposphere and the lower stratosphere, and assess their source and sink relationships. In both the troposphere and the lower stratosphere, the total atmospheric abundance of these oxygenated species (ΣOx-organic) nearly equals that of total nonmethane hydrocarbons (ΣNMHC), which have been traditionally measured. A sizable fraction of the reactive nitrogen (10-30%) is present in its oxygenated organic form. The organic reactive nitrogen fraction is dominated by peroxyacetyl nitrate (PAN), with alkyl nitrates and peroxypropionyl nitrate (PPN) accounting for <5% of total NOy. Comparison of observations with the predictions of the Harvard three-dimensional global model suggests that in many key areas (e.g., formaldehyde and peroxides) substantial differences between measurements and theory are present and must be resolved. In the case of CH3OH, there appears to be a large mismatch between atmospheric concentrations and estimated sources, indicating the presence of major unknown removal processes. Instrument intercomparisons as well as disagreements between observations and model predictions are used to identify needed improvements in key areas. The atmospheric chemistry and sources of this group of chemicals is poorly understood even though their fate is intricately linked with upper tropospheric NOx and HOx cycles.

Applying business management models in health care.

PubMed

Trisolini, Michael G

2002-01-01

Most health care management training programmes and textbooks focus on only one or two models or conceptual frameworks, but the increasing complexity of health care organizations and their environments worldwide means that a broader perspective is needed. This paper reviews five management models developed for business organizations and analyses issues related to their application in health care. Three older, more 'traditional' models are first presented. These include the functional areas model, the tasks model and the roles model. Each is shown to provide a valuable perspective, but to have limitations if used in isolation. Two newer, more 'innovative' models are next discussed. These include total quality management (TQM) and reengineering. They have shown potential for enabling dramatic improvements in quality and cost, but have also been found to be more difficult to implement. A series of 'lessons learned' are presented to illustrate key success factors for applying them in health care organizations. In sum, each of the five models is shown to provide a useful perspective for health care management. Health care managers should gain experience and training with a broader set of business management models.

[Barriers to the normalization of telemedicine in a healthcare system model based on purchasing of healthcare services using providers' contracts].

PubMed

Roig, Francesc; Saigí, Francesc

2011-01-01

Despite the clear political will to promote telemedicine and the large number of initiatives, the incorporation of this modality in clinical practice remains limited. The objective of this study was to identify the barriers perceived by key professionals who actively participate in the design and implementation of telemedicine in a healthcare system model based on purchasing of healthcare services using providers' contracts. We performed a qualitative study based on data from semi-structured interviews with 17 key informants belonging to distinct Catalan health organizations. The barriers identified were grouped in four areas: technological, organizational, human and economic. The main barriers identified were changes in the healthcare model caused by telemedicine, problems with strategic alignment, resistance to change in the (re)definition of roles, responsibilities and new skills, and lack of a business model that incorporates telemedicine in the services portfolio to ensure its sustainability. In addition to suitable management of change and of the necessary strategic alignment, the definitive normalization of telemedicine in a mixed healthcare model based on purchasing of healthcare services using providers' contracts requires a clear and stable business model that incorporates this modality in the services portfolio and allows healthcare organizations to obtain reimbursement from the payer. 2010 SESPAS. Published by Elsevier Espana. All rights reserved.

Integrating 'omic' data and biogeochemical modeling: the key to understanding the microbial regulation of matter cycling in soil

NASA Astrophysics Data System (ADS)

Pagel, Holger; Kandeler, Ellen; Seifert, Jana; Camarinha-Silva, Amélia; Kügler, Philipp; Rennert, Thilo; Poll, Christian; Streck, Thilo

2016-04-01

Matter cycling in soils and associated soil functions are intrinsically controlled by microbial dynamics. It is therefore crucial to consider functional traits of microorganisms in biogeochemical models. Tremendous advances in 'omic' methods provide a plethora of data on physiology, metabolic capabilities and ecological life strategies of microorganisms in soil. Combined with isotopic techniques, biochemical pathways and transformations can be identified and quantified. Such data have been, however, rarely used to improve the mechanistic representation of microbial dynamics in soil organic matter models. It is the goal of the Young Investigator Group SoilReg to address this challenge. Our general approach is to tightly integrate experiments and biochemical modeling. NextGen sequencing will be applied to identify key functional groups. Active microbial groups will be quantified by measurements of functional genes and by stable isotope probing methods of DNA and proteins. Based on this information a biogeochemical model that couples a mechanistic representation of microbial dynamics with physicochemical processes will be set up and calibrated. Sensitivity and stability analyses of the model as well as scenario simulations will reveal the importance of intrinsic and extrinsic controls of organic matter turnover. We will demonstrate our concept and present first results of two case studies on pesticide degradation and methane oxidation.

Growth and resilience of pioneering nonprofit human service organizations: a cross-case analysis of organizational histories.

PubMed

Kimberlin, Sara E; Schwartz, Sara L; Austin, Michael J

2011-01-01

Knowledge of organizational history is important for recognizing patterns in effective management and understanding how organizations respond to internal and external challenges. This cross-case analysis of 12 histories of pioneering nonprofit human service organizations contributes an important longitudinal perspective on organizational history, complementing the cross-sectional case studies that dominate the existing research on nonprofit organizations. The literature on organizational growth, including lifecycle models and growth management, is reviewed, along with the literature on organizational resilience. Based on analysis of the 12 organizational histories, a conceptual model is presented that synthesizes key factors in the areas of leadership, internal operations, and external relations that influence organizational growth and resilience to enable nonprofit organizations to survive and thrive over time. Both cross-sectional and longitudinal examples from the organizational histories illustrate the conceptual map. The paper concludes with a discussion of directions for future research on nonprofit organizational history.

Organic semiconductor density of states controls the energy level alignment at electrode interfaces

PubMed Central

Oehzelt, Martin; Koch, Norbert; Heimel, Georg

2014-01-01

Minimizing charge carrier injection barriers and extraction losses at interfaces between organic semiconductors and metallic electrodes is critical for optimizing the performance of organic (opto-) electronic devices. Here, we implement a detailed electrostatic model, capable of reproducing the alignment between the electrode Fermi energy and the transport states in the organic semiconductor both qualitatively and quantitatively. Covering the full phenomenological range of interfacial energy level alignment regimes within a single, consistent framework and continuously connecting the limiting cases described by previously proposed models allows us to resolve conflicting views in the literature. Our results highlight the density of states in the organic semiconductor as a key factor. Its shape and, in particular, the energy distribution of electronic states tailing into the fundamental gap is found to determine both the minimum value of practically achievable injection barriers as well as their spatial profile, ranging from abrupt interface dipoles to extended band-bending regions. PMID:24938867

It's time to swim! Zebrafish and the circadian clock.

PubMed

Vatine, Gad; Vallone, Daniela; Gothilf, Yoav; Foulkes, Nicholas S

2011-05-20

The zebrafish represents a fascinating model for studying key aspects of the vertebrate circadian timing system. Easy access to early embryonic development has made this species ideal for investigating how the clock is first established during embryogenesis. In particular, the molecular basis for the functional development of the zebrafish pineal gland has received much attention. In addition to this dedicated clock and photoreceptor organ, and unlike the situation in mammals, the clocks in zebrafish peripheral tissues and even cell lines are entrainable by direct exposure to light thus providing unique insight into the function and evolution of the light input pathway. Finally, the small size, low maintenance costs and high fecundity of this fish together with the availability of genetic tools make this an attractive model for forward genetic analysis of the circadian clock. Here, we review the work that has established the zebrafish as a valuable clock model organism and highlight the key questions that will shape the future direction of research. Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Perspectives of Community- and Faith-Based Organizations about Partnering with Local Health Departments for Disasters

PubMed Central

Stajura, Michael; Glik, Deborah; Eisenman, David; Prelip, Michael; Martel, Andrea; Sammartinova, Jitka

2012-01-01

Public health emergency planners can better perform their mission if they develop and maintain effective relationships with community- and faith-based organizations in their jurisdictions. This qualitative study presents six themes that emerged from 20 key informant interviews representing a wide range of American community- and faith-based organizations across different types of jurisdictions, organizational types, and missions. This research seeks to provide local health department public health emergency planners with tools to assess and improve their inter-organizational community relationships. The themes identified address the importance of community engagement, leadership, intergroup dynamics and communication, and resources. Community- and faith-based organizations perceive that they are underutilized or untapped resources with respect to public health emergencies and disasters. One key reason for this is that many public health departments limit their engagement with community- and faith-based organizations to a one-way “push” model for information dissemination, rather than engaging them in other ways or improving their capacity. Beyond a reprioritization of staff time, few other resources would be required. From the perspective of community- and faith-based organizations, the quality of relationships seems to matter more than discrete resources provided by such ties. PMID:22851942

Interstellar Grains: 50 Years On

NASA Astrophysics Data System (ADS)

Wickramasinghe, N. Chandra

2011-12-01

Our understanding of the nature of interstellar grains has evolved considerably over the past half century with the present author and Fred Hoyle being intimately involved at several key stages of progress. The currently fashionable graphite-silicate-organic grain model has all its essential aspects unequivocally traceable to original peer-reviewedpublicationsbytheauthorand/orFredHoyle. Theprevailingreluctancetoaccepttheseclear-cut priorities may be linked to our further work that argued for interstellar grains and organics to have a biological provenance - a position perceived as heretical. The biological model, however, continues to provide a powerful unifying hypothesis for a vast amount of otherwise disconnected and disparate astronomical data.

Computational Design of Functionalized Metal–Organic Framework Nodes for Catalysis

PubMed Central

2017-01-01

Recent progress in the synthesis and characterization of metal–organic frameworks (MOFs) has opened the door to an increasing number of possible catalytic applications. The great versatility of MOFs creates a large chemical space, whose thorough experimental examination becomes practically impossible. Therefore, computational modeling is a key tool to support, rationalize, and guide experimental efforts. In this outlook we survey the main methodologies employed to model MOFs for catalysis, and we review selected recent studies on the functionalization of their nodes. We pay special attention to catalytic applications involving natural gas conversion. PMID:29392172

Developing Learning Environments: Challenges for Theory, Research and Practice.

ERIC Educational Resources Information Center

Iles, Paul

1994-01-01

Key challenges in development of learning organizations, promotion of learning culture, enhancement of learning processes, and development of learning communities are appropriateness of current models for interdisciplinary teams; whether valuing diversity enhances effectiveness; how global human resource development affects domestic; and what…

Modeling Exponential Population Growth

ERIC Educational Resources Information Center

McCormick, Bonnie

2009-01-01

The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

Spatiotemporal Data Organization and Application Research

NASA Astrophysics Data System (ADS)

Tan, C.; Yan, S.

2017-09-01

Organization and management of spatiotemporal data is a key support technology for intelligence in all fields of the smart city. The construction of a smart city cannot be realized without spatiotemporal data. Oriented to support intelligent applications this paper proposes an organizational model for spatiotemporal data, and details the construction of a spatiotemporal big data calculation, analysis, and service framework for highly efficient management and intelligent application of spatiotemporal data for the entire data life cycle.

Organization and Dynamics of Receptor Proteins in a Plasma Membrane.

PubMed

Koldsø, Heidi; Sansom, Mark S P

2015-11-25

The interactions of membrane proteins are influenced by their lipid environment, with key lipid species able to regulate membrane protein function. Advances in high-resolution microscopy can reveal the organization and dynamics of proteins and lipids within living cells at resolutions <200 nm. Parallel advances in molecular simulations provide near-atomic-resolution models of the dynamics of the organization of membranes of in vivo-like complexity. We explore the dynamics of proteins and lipids in crowded and complex plasma membrane models, thereby closing the gap in length and complexity between computations and experiments. Our simulations provide insights into the mutual interplay between lipids and proteins in determining mesoscale (20-100 nm) fluctuations of the bilayer, and in enabling oligomerization and clustering of membrane proteins.

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatiotemporal Network Dynamics.

PubMed

Hendrickson, Phillip J; Yu, Gene J; Song, Dong; Berger, Theodore W

2016-01-01

This paper describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust nonrandom pattern of spiking best described as a spatiotemporal "clustering." To identify the network property or properties responsible for generating such firing "clusters," we progressively eliminated from the model key mechanisms, such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatiotemporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: topography-dependent clusters of granule cell activity as "functional units" or "channels" that organize the processing of entorhinal signals. This modeling study also reveals for the first time how a global signal processing feature of a neural network can evolve from one of its underlying structural characteristics.

A Million-Plus Neuron Model of the Hippocampal Dentate Gyrus: Critical Role for Topography in Determining Spatio-Temporal Network Dynamics

PubMed Central

Hendrickson, Phillip J.; Yu, Gene J.; Song, Dong; Berger, Theodore W.

2016-01-01

Goal This manuscript describes a million-plus granule cell compartmental model of the rat hippocampal dentate gyrus, including excitatory, perforant path input from the entorhinal cortex, and feedforward and feedback inhibitory input from dentate interneurons. Methods The model includes experimentally determined morphological and biophysical properties of granule cells, together with glutamatergic AMPA-like EPSP and GABAergic GABAA-like IPSP synaptic excitatory and inhibitory inputs, respectively. Each granule cell was composed of approximately 200 compartments having passive and active conductances distributed throughout the somatic and dendritic regions. Modeling excitatory input from the entorhinal cortex was guided by axonal transport studies documenting the topographical organization of projections from subregions of the medial and lateral entorhinal cortex, plus other important details of the distribution of glutamatergic inputs to the dentate gyrus. Information contained within previously published maps of this major hippocampal afferent were systematically converted to scales that allowed the topographical distribution and relative synaptic densities of perforant path inputs to be quantitatively estimated for inclusion in the current model. Results Results showed that when medial and lateral entorhinal cortical neurons maintained Poisson random firing, dentate granule cells expressed, throughout the million-cell network, a robust, non-random pattern of spiking best described as spatio-temporal “clustering”. To identify the network property or properties responsible for generating such firing “clusters”, we progressively eliminated from the model key mechanisms such as feedforward and feedback inhibition, intrinsic membrane properties underlying rhythmic burst firing, and/or topographical organization of entorhinal afferents. Conclusion Findings conclusively identified topographical organization of inputs as the key element responsible for generating a spatio-temporal distribution of clustered firing. These results uncover a functional organization of perforant path afferents to the dentate gyrus not previously recognized: topography-dependent clusters of granule cell activity as “functional units” or “channels” that organize the processing of entorhinal signals. This modeling study also reveals for the first time how a global signal processing feature of a neural network can evolve from one of its underlying structural characteristics. PMID:26087482

Successful Implementation of New Technology Using an Interdepartmental Collaborative Approach.

PubMed

Tetef, Sue

2017-06-01

The implementation of new technology is vital to the success of health care organizations. New technology provides health care organizations an opportunity to obtain new patients, increase revenue, and stay competitive. In 2014, a union hospital in Southern California successfully implemented a bronchial thermoplasty program. To implement this new technology, the administration created a strategy, identified financial risks and benefits, created an implementation model, established a plan based on Lewin's change model and Roger's diffusion of innovations theory, and recognized adult learning needs through an interdepartmental, open communication, and collaborative approach. In addition, the implementation of the bronchial thermoplasty program allowed the organization to meet the goals, mission, and vision of the organization, which is key to remaining viable and marketable. Copyright © 2016 American Society of PeriAnesthesia Nurses. Published by Elsevier Inc. All rights reserved.

IT vendor selection model by using structural equation model & analytical hierarchy process

NASA Astrophysics Data System (ADS)

Maitra, Sarit; Dominic, P. D. D.

2012-11-01

Selecting and evaluating the right vendors is imperative for an organization's global marketplace competitiveness. Improper selection and evaluation of potential vendors can dwarf an organization's supply chain performance. Numerous studies have demonstrated that firms consider multiple criteria when selecting key vendors. This research intends to develop a new hybrid model for vendor selection process with better decision making. The new proposed model provides a suitable tool for assisting decision makers and managers to make the right decisions and select the most suitable vendor. This paper proposes a Hybrid model based on Structural Equation Model (SEM) and Analytical Hierarchy Process (AHP) for long-term strategic vendor selection problems. The five steps framework of the model has been designed after the thorough literature study. The proposed hybrid model will be applied using a real life case study to assess its effectiveness. In addition, What-if analysis technique will be used for model validation purpose.

Diversity, competition, extinction: the ecophysics of language change.

PubMed

Solé, Ricard V; Corominas-Murtra, Bernat; Fortuny, Jordi

2010-12-06

As indicated early by Charles Darwin, languages behave and change very much like living species. They display high diversity, differentiate in space and time, emerge and disappear. A large body of literature has explored the role of information exchanges and communicative constraints in groups of agents under selective scenarios. These models have been very helpful in providing a rationale on how complex forms of communication emerge under evolutionary pressures. However, other patterns of large-scale organization can be described using mathematical methods ignoring communicative traits. These approaches consider shorter time scales and have been developed by exploiting both theoretical ecology and statistical physics methods. The models are reviewed here and include extinction, invasion, origination, spatial organization, coexistence and diversity as key concepts and are very simple in their defining rules. Such simplicity is used in order to catch the most fundamental laws of organization and those universal ingredients responsible for qualitative traits. The similarities between observed and predicted patterns indicate that an ecological theory of language is emerging, supporting (on a quantitative basis) its ecological nature, although key differences are also present. Here, we critically review some recent advances and outline their implications and limitations as well as highlight problems for future research.

Diversity, competition, extinction: the ecophysics of language change

PubMed Central

Solé, Ricard V.; Corominas-Murtra, Bernat; Fortuny, Jordi

2010-01-01

As indicated early by Charles Darwin, languages behave and change very much like living species. They display high diversity, differentiate in space and time, emerge and disappear. A large body of literature has explored the role of information exchanges and communicative constraints in groups of agents under selective scenarios. These models have been very helpful in providing a rationale on how complex forms of communication emerge under evolutionary pressures. However, other patterns of large-scale organization can be described using mathematical methods ignoring communicative traits. These approaches consider shorter time scales and have been developed by exploiting both theoretical ecology and statistical physics methods. The models are reviewed here and include extinction, invasion, origination, spatial organization, coexistence and diversity as key concepts and are very simple in their defining rules. Such simplicity is used in order to catch the most fundamental laws of organization and those universal ingredients responsible for qualitative traits. The similarities between observed and predicted patterns indicate that an ecological theory of language is emerging, supporting (on a quantitative basis) its ecological nature, although key differences are also present. Here, we critically review some recent advances and outline their implications and limitations as well as highlight problems for future research. PMID:20591847

Better Care Teams: A Stepwise Skill Reinforcement Model.

PubMed

Christopher, Beth-Anne; Grantner, Mary; Coke, Lola A; Wideman, Marilyn; Kwakwa, Francis

2016-06-01

The Building Healthy Urban Communities initiative presents a path for organizations partnering to improve patient outcomes with continuing education (CE) as a key component. Components of the CE initiative included traditional CE delivery formats with an essential element of adaptability and new methods, with rigorous evaluation over time that included evaluation prior to the course, immediately following the CE session, 6 to 8 weeks after the CE session, and then subsequent monthly "testlets." Outcome measures were designed to allow for ongoing adaptation of content, reinforcement of key learning objectives, and use of innovative concordant testing and retrieval practice techniques. The results after 1 year of programming suggest the stepwise skill reinforcement model is effective for learning and is an efficient use of financial and human resources. More important, its design is one that could be adopted at low cost by organizations willing to work in close partnership. J Contin Educ Nurs. 2016;47(6):283-288. Copyright 2016, SLACK Incorporated.

Surgeon Participation in Early Accountable Care Organizations.

PubMed

Resnick, Matthew J; Graves, Amy J; Buntin, Melinda B; Richards, Michael R; Penson, David F

2018-03-01

We aimed to characterize the landscape of surgeon participation in early accountable care organizations (ACOs) and to identify specialty-, organization-, and market-specific factors associated with ACO participation. Despite rapid deployment of alternative payment models (APMs), little is known about the prevalence of surgeon participation, and key drivers behind surgeon participation in APMs. Using data from SK&A, a research firm, we evaluated the near universe of US practices to characterize ACO participation among 125,425 US surgeons in 2015. We fit multivariable logistic regression models to characterize key drivers of ACO participation, and more specifically, the interaction between ACO affiliation and organizational structure. Of 125,425 US surgeons, 27,956 (22.3%) participated in at least 1 ACO program in 2015. We observed heterogeneity in participation by subspecialty, with trauma and transplant reporting the highest rate of ACO enrollment (36% for both) and plastic surgeons reporting the lowest (12.9%) followed by ophthalmology (16.0%) and hand (18.6%). Surgeons in group practices and integrated systems were more likely to participate relative to those practicing independently (aOR 1.57, 95% CI 1.50, 1.64; aOR 4.87, 95% CI 4.68, 5.07, respectively). We observed a statistically significant interaction (P <0.001) between surgical specialty and practice organization. Model-derived predicted probabilities revealed that, within each specialty, surgeons in integrated health systems had the highest predicted probabilities of ACO and those practicing independently generally had the lowest. We observed considerable variation in ACO enrollment among US surgeons, mediated at least in part by differences in practice organization. These data underscore the need for development of frameworks to characterize the strategic advantages and disadvantages associated with APM participation.

Model of the Dynamic Construction Process of Texts and Scaling Laws of Words Organization in Language Systems

PubMed Central

Li, Shan; Lin, Ruokuang; Bian, Chunhua; Ma, Qianli D. Y.

2016-01-01

Scaling laws characterize diverse complex systems in a broad range of fields, including physics, biology, finance, and social science. The human language is another example of a complex system of words organization. Studies on written texts have shown that scaling laws characterize the occurrence frequency of words, words rank, and the growth of distinct words with increasing text length. However, these studies have mainly concentrated on the western linguistic systems, and the laws that govern the lexical organization, structure and dynamics of the Chinese language remain not well understood. Here we study a database of Chinese and English language books. We report that three distinct scaling laws characterize words organization in the Chinese language. We find that these scaling laws have different exponents and crossover behaviors compared to English texts, indicating different words organization and dynamics of words in the process of text growth. We propose a stochastic feedback model of words organization and text growth, which successfully accounts for the empirically observed scaling laws with their corresponding scaling exponents and characteristic crossover regimes. Further, by varying key model parameters, we reproduce differences in the organization and scaling laws of words between the Chinese and English language. We also identify functional relationships between model parameters and the empirically observed scaling exponents, thus providing new insights into the words organization and growth dynamics in the Chinese and English language. PMID:28006026

Model of the Dynamic Construction Process of Texts and Scaling Laws of Words Organization in Language Systems.

PubMed

Li, Shan; Lin, Ruokuang; Bian, Chunhua; Ma, Qianli D Y; Ivanov, Plamen Ch

2016-01-01

Scaling laws characterize diverse complex systems in a broad range of fields, including physics, biology, finance, and social science. The human language is another example of a complex system of words organization. Studies on written texts have shown that scaling laws characterize the occurrence frequency of words, words rank, and the growth of distinct words with increasing text length. However, these studies have mainly concentrated on the western linguistic systems, and the laws that govern the lexical organization, structure and dynamics of the Chinese language remain not well understood. Here we study a database of Chinese and English language books. We report that three distinct scaling laws characterize words organization in the Chinese language. We find that these scaling laws have different exponents and crossover behaviors compared to English texts, indicating different words organization and dynamics of words in the process of text growth. We propose a stochastic feedback model of words organization and text growth, which successfully accounts for the empirically observed scaling laws with their corresponding scaling exponents and characteristic crossover regimes. Further, by varying key model parameters, we reproduce differences in the organization and scaling laws of words between the Chinese and English language. We also identify functional relationships between model parameters and the empirically observed scaling exponents, thus providing new insights into the words organization and growth dynamics in the Chinese and English language.

Organic chemistry on solid surfaces

NASA Astrophysics Data System (ADS)

Ma, Zhen; Zaera, Francisco

2006-07-01

Chemistry on solid surfaces is central to many areas of practical interest such as heterogeneous catalysis, tribology, electrochemistry, and materials processing. With the development of many surface-sensitive analytical techniques in the past decades, great advances have been possible in our understanding of such surface chemistry at the molecular level. Earlier studies with model systems, single crystals in particular, have provided rich information about the adsorption and reaction kinetics of simple inorganic molecules. More recently, the same approach has been expanded to the study of the surface chemistry of relatively complex organic molecules, in large measure in connection with the selective synthesis of fine chemicals and pharmaceuticals. In this report, the chemical reactions of organic molecules and fragments on solid surfaces, mainly on single crystals of metals but also on crystals of metal oxides, carbides, nitrides, phosphides, sulfides and semiconductors as well as on more complex models such as bimetallics, alloys, and supported particles, are reviewed. A scheme borrowed from the organometallic and organic chemistry literature is followed in which key examples of representative reactions are cited first, and general reactivity trends in terms of both the reactants and the nature of the surface are then identified to highlight important mechanistic details. An attempt has been made to emphasize recent advances, but key earlier examples are cited as needed. Finally, correlations between surface and organometallic and organic chemistry, the relevance of surface reactions to applied catalysis and materials functionalization, and some promising future directions in this area are briefly discussed.

Skull Development, Ossification Pattern, and Adult Shape in the Emerging Lizard Model Organism Pogona vitticeps: A Comparative Analysis With Other Squamates.

PubMed

Ollonen, Joni; Da Silva, Filipe O; Mahlow, Kristin; Di-Poï, Nicolas

2018-01-01

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution.

Skull Development, Ossification Pattern, and Adult Shape in the Emerging Lizard Model Organism Pogona vitticeps: A Comparative Analysis With Other Squamates

PubMed Central

Ollonen, Joni; Da Silva, Filipe O.; Mahlow, Kristin; Di-Poï, Nicolas

2018-01-01

The rise of the Evo-Devo field and the development of multidisciplinary research tools at various levels of biological organization have led to a growing interest in researching for new non-model organisms. Squamates (lizards and snakes) are particularly important for understanding fundamental questions about the evolution of vertebrates because of their high diversity and evolutionary innovations and adaptations that portrait a striking body plan change that reached its extreme in snakes. Yet, little is known about the intricate connection between phenotype and genotype in squamates, partly due to limited developmental knowledge and incomplete characterization of embryonic development. Surprisingly, squamate models have received limited attention in comparative developmental studies, and only a few species examined so far can be considered as representative and appropriate model organism for mechanistic Evo-Devo studies. Fortunately, the agamid lizard Pogona vitticeps (central bearded dragon) is one of the most popular, domesticated reptile species with both a well-established history in captivity and key advantages for research, thus forming an ideal laboratory model system and justifying his recent use in reptile biology research. We first report here the complete post-oviposition embryonic development for P. vitticeps based on standardized staging systems and external morphological characters previously defined for squamates. Whereas the overall morphological development follows the general trends observed in other squamates, our comparisons indicate major differences in the developmental sequence of several tissues, including early craniofacial characters. Detailed analysis of both embryonic skull development and adult skull shape, using a comparative approach integrating CT-scans and gene expression studies in P. vitticeps as well as comparative embryology and 3D geometric morphometrics in a large dataset of lizards and snakes, highlights the extreme adult skull shape of P. vitticeps and further indicates that heterochrony has played a key role in the early development and ossification of squamate skull bones. Such detailed studies of embryonic character development, craniofacial patterning, and bone formation are essential for the establishment of well-selected squamate species as Evo-Devo model organisms. We expect that P. vitticeps will continue to emerge as a new attractive model organism for understanding developmental and molecular processes underlying tissue formation, morphology, and evolution. PMID:29643813

Development and application of a soil organic matter-based soil quality index in mineralized terrane of the Western US

USGS Publications Warehouse

Blecker, S.W.; Stillings, Lisa L.; Amacher, M.C.; Ippolito, J.A.; DeCrappeo, N.M.

2013-01-01

Soil quality indices provide a means of distilling large amounts of data into a single metric that evaluates the soil’s ability to carry out key ecosystem functions. Primarily developed in agroecosytems, then forested ecosystems, an index using the relation between soil organic matter and other key soil properties in more semi-arid systems of the Western US impacted by different geologic mineralization was developed. Three different sites in two different mineralization types, acid sulfate and Cu/Mo porphyry in California and Nevada, were studied. Soil samples were collected from undisturbed soils in both mineralized and nearby unmineralized terrane as well as waste rock and tailings. Eight different microbial parameters (carbon substrate utilization, microbial biomass-C, mineralized-C, mineralized-N and enzyme activities of acid phosphatase, alkaline phosphatase, arylsulfatase, and fluorescein diacetate) along with a number of physicochemical parameters were measured. Multiple linear regression models between these parameters and both total organic carbon and total nitrogen were developed, using the ratio of predicted to measured values as the soil quality index. In most instances, pooling unmineralized and mineralized soil data within a given study site resulted in lower model correlations. Enzyme activity was a consistent explanatory variable in the models across the study sites. Though similar indicators were significant in models across different mineralization types, pooling data across sites inhibited model differentiation of undisturbed and disturbed sites. This procedure could be used to monitor recovery of disturbed systems in mineralized terrane and help link scientific and management disciplines.

Predicting Trophic Interactions and Habitat Utilization in the California Current Ecosystem

DTIC Science & Technology

2015-09-30

spatial and temporal distribution of key marine organisms over multiple trophic levels, and (2) natural and anthropogenic variability in ecosystem...areas of climate modeling in upwelling regions (E. Curchitser), physical-biological modeling in the CCLME (J. Fiechter and C. Edwards), data...optimal growth conditions). By comparing interannual changes in fat depot against EOF modes for environmental variability (i.e., SST) and prey

A Model for Occupational Safety and Health Intervention Diffusion to Small Businesses

PubMed Central

Sinclair, Raymond C.; Cunningham, Thomas R.; Schulte, Paul A.

2015-01-01

Background Smaller businesses differ from their larger counterparts in having higher rates of occupational injuries and illnesses and fewer resources for preventing those losses. Intervention models developed outside the United States have addressed the resource deficiency issue by incorporating intermediary organizations such as trade associations. Methods This paper extends previous models by using exchange theory and by borrowing from the diffusion of innovations model. It emphasizes that occupational safety and health (OSH) organizations must understand as much about intermediary organizations as they do about small businesses. OSH organizations (“initiators”) must understand how to position interventions and information to intermediaries as added value to their relationships with small businesses. Examples from experiences in two midwestern states are used to illustrate relationships and types of analyses implied by the extended model. Results The study found that intermediary organizations were highly attuned to providing smaller businesses with what they want, including OSH services. The study also found that there are opinion leader organizations and individual champions within intermediaries who are key to decisions and actions about OSH programming. Conclusions The model places more responsibility on both initiators and intermediaries to develop and market interventions that will be valued in the competitive small business environment where the resources required to adopt each new business activity could always be used in other ways. The model is a candidate for empirical validation, and it offers some encouragement that the issue of sustainable OSH assistance to small businesses might be addressed. PMID:24115112

Towards a paradigm shift in the modeling of soil organic carbon decomposition for earth system models

NASA Astrophysics Data System (ADS)

He, Yujie

Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon dynamics and climate. However, these models often predict a wide range of soil carbon responses and their formulations have lagged behind recent soil science advances, omitting key biogeochemical mechanisms. In contrast, recent mechanistically-based biogeochemical models that explicitly account for microbial biomass pools and enzyme kinetics that catalyze soil carbon decomposition produce notably different results and provide a closer match to recent observations. However, a systematic evaluation of the advantages and disadvantages of the microbial models and how they differ from empirical, first-order formulations in soil decomposition models for soil organic carbon is still needed. This dissertation consists of a series of model sensitivity and uncertainty analyses and identifies dominant decomposition processes in determining soil organic carbon dynamics. Poorly constrained processes or parameters that require more experimental data integration are also identified. This dissertation also demonstrates the critical role of microbial life-history traits (e.g. microbial dormancy) in the modeling of microbial activity in soil organic matter decomposition models. Finally, this study surveys and synthesizes a number of recently published microbial models and provides suggestions for future microbial model developments.

BRACHIAL EFFLUX OF HYDROPHOBIC ORGANIC COMPOUNDS BY RAINBOW TROUT (ONCORHYNCHUS MYKISS)

EPA Science Inventory

Data on the branchial elimination of hydrophobic compounds has been suggested as key information in the development of PBTK models for fish. The hypothesis is that branchial efflux of high log Kow compounds proceeds to an equilibrium between the afferent blood and expired water. ...

High Throughput Exposure Modeling of Semi-Volatile Chemicals in Articles of Commerce (SOT)

EPA Science Inventory

Chemical components of consumer products and articles of commerce such as carpet and clothing are key drivers of exposure in the near-field environment. These chemicals include semi-volatile organic compounds (SVOCs), some of which have been shown to alter endocrine functionality...

Teaching Reading Sourcebook, Second Edition

ERIC Educational Resources Information Center

Honig, Bill; Diamond, Linda; Gutlohn, Linda

2008-01-01

The "Teaching Reading Sourcebook, Second Edition" is a comprehensive reference about reading instruction. Organized according to the elements of explicit instruction (what? why? when? and how?), the "Sourcebook" includes both a research-informed knowledge base and practical sample lesson models. It teaches the key elements of an effective reading…

[On the issue of organization of consultative medical care on hospital stage].

PubMed

2011-01-01

The study picked out several groups of in-demand specialties of consulting physicians. It is proposed to elaborate specific model of hospital consultative medical care providing the possibility of counseling by the most in-demand specialists already on the level of admission department. The key target is to avoid the involvement of less in-demand specialists at the expense of organization the specialized consultative crew on the basis on emergency medical care.

Hugh's book and Krogh's animals: biodiversity and textbook examples in teaching.

PubMed

Robischon, Marcel

2014-09-01

The medieval simile of the world as a book seems to anticipate modern notions of biodiversity as a key to insights and learning. This thought is translated into the practice of research in the August Krogh principle, which provides argumentative support for researchers who dare to venture beyond the range of commonly used models by choosing a new experimental organism for a particular scientific question. Established model organisms often hold high exploratory power to the researcher yet little explanatory power to the student, in particular when represented in a secondary source. This essay puts forward the suggestion that Krogh's principle applies to the use of organisms as instructional models and textbook examples too and encourages educators to continuously venture beyond established illustrative teaching examples in a continuous exploration of the "book of the world" and the "treasure house of nature." Copyright © 2014 The American Physiological Society.

Hugh's book and Krogh's animals: biodiversity and textbook examples in teaching

PubMed Central

2014-01-01

The medieval simile of the world as a book seems to anticipate modern notions of biodiversity as a key to insights and learning. This thought is translated into the practice of research in the August Krogh principle, which provides argumentative support for researchers who dare to venture beyond the range of commonly used models by choosing a new experimental organism for a particular scientific question. Established model organisms often hold high exploratory power to the researcher yet little explanatory power to the student, in particular when represented in a secondary source. This essay puts forward the suggestion that Krogh's principle applies to the use of organisms as instructional models and textbook examples too and encourages educators to continuously venture beyond established illustrative teaching examples in a continuous exploration of the “book of the world” and the “treasure house of nature.” PMID:25179607

Second Generation Crop Yield Models Review

NASA Technical Reports Server (NTRS)

Hodges, T. (Principal Investigator)

1982-01-01

Second generation yield models, including crop growth simulation models and plant process models, may be suitable for large area crop yield forecasting in the yield model development project. Subjective and objective criteria for model selection are defined and models which might be selected are reviewed. Models may be selected to provide submodels as input to other models; for further development and testing; or for immediate testing as forecasting tools. A plant process model may range in complexity from several dozen submodels simulating (1) energy, carbohydrates, and minerals; (2) change in biomass of various organs; and (3) initiation and development of plant organs, to a few submodels simulating key physiological processes. The most complex models cannot be used directly in large area forecasting but may provide submodels which can be simplified for inclusion into simpler plant process models. Both published and unpublished models which may be used for development or testing are reviewed. Several other models, currently under development, may become available at a later date.

International summit on integrated environmental modeling

USGS Publications Warehouse

Gaber, Noha; Geller, Gary; Glynn, Pierre; Laniak, Gerry; Voinov, Alexey; Whelan, Gene; Roger, Moore; Hughes, Andrew

2013-01-01

This report describes the International Summit on Integrated Environmental Modeling (IEM), held in Reston, VA, on 7th-9th December 2010. The meeting brought together 57 scientists and managers from leading US and European government and non-governmental organizations, universities and companies together with international organizations convened over a number of years, including: the US Environmental Protection Agency (USEPA) workshop on Collaborative Approaches to Integrated Modeling: Better Integration for Better Decisionmaking (December, 2008); the AGU Fall Meeting, San Francisco (December 2009); and the International Congress on Environmental Modeling and Software (July 2010). From these meetings there is now recognition that many separate communities are involved in developing IEM. The aim of the Summit was to bring together two key groupings, the US and Europe, with the intention of creating a community open to all.

Impact and cost-effectiveness of current and future tuberculosis diagnostics: the contribution of modelling

PubMed Central

Houben, R.; Cohen, T.; Pai, M.; Cobelens, F.; Vassall, A.; Menzies, N. A.; Gomez, G. B.; Langley, I.; Squire, S. B.; White, R.

2014-01-01

SUMMARY The landscape of diagnostic testing for tuberculosis (TB) is changing rapidly, and stakeholders need urgent guidance on how to develop, deploy and optimize TB diagnostics in a way that maximizes impact and makes best use of available resources. When decisions must be made with only incomplete or preliminary data available, modelling is a useful tool for providing such guidance. Following a meeting of modelers and other key stakeholders organized by the TB Modelling and Analysis Consortium, we propose a conceptual framework for positioning models of TB diagnostics. We use that framework to describe modelling priorities in four key areas: Xpert® MTB/RIF scale-up, target product profiles for novel assays, drug susceptibility testing to support new drug regimens, and the improvement of future TB diagnostic models. If we are to maximize the impact and cost-effectiveness of TB diagnostics, these modelling priorities should figure prominently as targets for future research. PMID:25189546

Administrative decision making: a stepwise method.

PubMed

Oetjen, Reid M; Oetjen, Dawn M; Rotarius, Timothy

2008-01-01

Today's health care organizations face tremendous challenges and fierce competition. These pressures impact the decisions that managers must execute on any given day, not to mention the ever-present constraints of time, personnel, competencies, and finances. The importance of making quality and informed decisions cannot be underestimated. Traditional decision making methods are inadequate for today's larger, more complex health care organizations and the rapidly changing health care environment. As a result, today's health care managers and their teams need new approaches to making decisions for their organizations. This article examines the managerial decision making process and offers a model that can be used as a decision making template to help managers successfully navigate the choppy health care seas. The administrative decision making model will enable health care managers and other key decision makers to avoid the common pitfalls of poor decision making and guide their organizations to success.

Growth-coupled overproduction is feasible for almost all metabolites in five major production organisms

NASA Astrophysics Data System (ADS)

von Kamp, Axel; Klamt, Steffen

2017-06-01

Computational modelling of metabolic networks has become an established procedure in the metabolic engineering of production strains. One key principle that is frequently used to guide the rational design of microbial cell factories is the stoichiometric coupling of growth and product synthesis, which makes production of the desired compound obligatory for growth. Here we show that the coupling of growth and production is feasible under appropriate conditions for almost all metabolites in genome-scale metabolic models of five major production organisms. These organisms comprise eukaryotes and prokaryotes as well as heterotrophic and photoautotrophic organisms, which shows that growth coupling as a strain design principle has a wide applicability. The feasibility of coupling is proven by calculating appropriate reaction knockouts, which enforce the coupling behaviour. The study presented here is the most comprehensive computational investigation of growth-coupled production so far and its results are of fundamental importance for rational metabolic engineering.

Recovery and Resilience After a Nuclear Power Plant Disaster: A Medical Decision model for Managing an Effective, Timely, and Balanced Response

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

Coleman, C. Norman; Blumenthal, Daniel J.

2013-05-01

Based on experiences in Tokyo responding to the Fukushima Daiichi nuclear power plant crisis, a real-time, medical decision model is presented by which to make key health-related decisions given the central role of health and medical issues in such disasters. Focus is on response and recovery activities that are safe, timely, effective, and well-organized. This approach empowers on-site decision makers to make interim decisions without undue delay using readily available and high-level scientific, medical, communication, and policy expertise. Key features of this approach include ongoing assessment, consultation, information, and adaption to the changing conditions. This medical decision model presented ismore » compatible with the existing US National Response Framework structure.« less

Interstellar Grains: 50 Years on

NASA Astrophysics Data System (ADS)

Wickramasinghe, N. C.

Our understanding of the nature of interstellar grains has evolved considerably over the past half century with the present author and Fred Hoyle being intimately involved at several key stages of progress. The currently fashionable graphite-silicate-organic grain model has all its essential aspects unequivocally traceable to original peer-reviewed publications by the author and/or Fred Hoyle. The prevailing reluctance to accept these clear-cut priorities may be linked to our further work that argued for interstellar grains and organics to have a biological provenance -- a position perceived as heretical. The biological model, however, continues to provide a powerful unifying hypothesis for a vast amount of otherwise disconnected and disparate astronomical data.

Development of a Short Form of the Abridged Big Five-Dimensional Circumplex Model to Aid with the Organization of Personality Traits.

PubMed

Bucher, Meredith A; Samuel, Douglas B

2018-02-01

Although there has been widespread consensus on the use of the Five-Factor Model (FFM) of general personality functioning in personality research, there are various, diverse models of the lower order traits of the FFM domains. Given the usefulness of these finer grained traits, it is imperative to integrate facets proposed across a variety of models and eventually reach consensus on the lower level traits of the FFM. Due to its depth and coverage, the Abridged Big Five-Dimensional Circumplex (AB5C) model potentially provides a useful framework for organizing various faceted models due to its conceptual organization and inclusiveness. The only measure of this model-the IPIP-AB5C-has shown promise, but is limited by its length (i.e., 485 items). This study developed an abbreviated version of the IPIP-AB5C using an iterative process including item response theory methods. The shorter version maintained key features of the long form including a factor structure that matched the full form as well as facets that correlated in expected ways with other FFM measures. Building on this support, the short form was used to contextualize and organize the facets from 2 commonly used measures.

Mutant mice: experimental organisms as materialised models in biomedicine.

PubMed

Huber, Lara; Keuck, Lara K

2013-09-01

Animal models have received particular attention as key examples of material models. In this paper, we argue that the specificities of establishing animal models-acknowledging their status as living beings and as epistemological tools-necessitate a more complex account of animal models as materialised models. This becomes particularly evident in animal-based models of diseases that only occur in humans: in these cases, the representational relation between animal model and human patient needs to be generated and validated. The first part of this paper presents an account of how disease-specific animal models are established by drawing on the example of transgenic mice models for Alzheimer's disease. We will introduce an account of validation that involves a three-fold process including (1) from human being to experimental organism; (2) from experimental organism to animal model; and (3) from animal model to human patient. This process draws upon clinical relevance as much as scientific practices and results in disease-specific, yet incomplete, animal models. The second part of this paper argues that the incompleteness of models can be described in terms of multi-level abstractions. We qualify this notion by pointing to different experimental techniques and targets of modelling, which give rise to a plurality of models for a specific disease. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modeling a molecular initiating event to population effects: A case study of aromatase inhibition in fathead minnows

EPA Science Inventory

An adverse outcome pathway (AOP) conceptually links a molecular initiating event with measureable key events at higher levels of biological organization that ultimately result in an adverse outcome. Development of an AOP requires experimental data and scientific expertise to ide...

Collective (Team) Learning Process Models: A Conceptual Review

ERIC Educational Resources Information Center

Knapp, Randall

2010-01-01

Teams have become a key resource for learning and accomplishing work in organizations. The development of collective learning in specific contexts is not well understood, yet has become critical to organizational success. The purpose of this conceptual review is to inform human resource development (HRD) practice about specific team behaviors and…

Planning and Partnerships for the Renewal of Urban Neighborhoods

ERIC Educational Resources Information Center

Sterrett, Stephen A.

2009-01-01

Urban universities are a key resource for municipal government, businesses, community organizations, and citizens to foster partnerships for successful renewal of distressed urban neighborhoods. From its experience over the past decade, the Ohio State University has created a successful model for engagement with its neighborhoods and the City of…

Uncovering the Dark Energy of Aging.

PubMed

Melov, Simon

2016-10-26

A medically relevant understanding of aging requires an appreciation for how time degrades specific, healthy features of individual organisms over the course of their lives. Zach Pincus and colleagues make a key step in this direction, using C. elegans as a model system. Copyright © 2016 Elsevier Inc. All rights reserved.

Exploring the Use of Multimedia Fate and Bioaccumulation Models to Calculate Trophic Magnification Factors (TMFs)

EPA Science Inventory

The trophic magnification factor (TMF) is considered to be a key metric for assessing the bioaccumulation potential of organic chemicals in food webs. Fugacity is an equilibrium criterion and thus reflects the relative thermodynamic status of a chemical in the environment and in ...

Ecosystem-scale VOC fluxes during an extreme drought in a broad-leaf temperate forest of the Missouri Ozarks (central USA)

EPA Science Inventory

Considerable amounts and varieties of biogenic volatile organic compounds (BVOCs) are exchanged between vegetation and the surrounding air. These BVOCs play key ecological and atmospheric roles that must be adequately represented for accurately modeling the coupled biosphere-atmo...

42: DESIGNING A DASHBOARD FOR EVALUATION THE BUSINESS-IT ALIGNMENT STRATEGIES IN HOSPITALS ORGANIZATIONS

PubMed Central

piri, Zakieh; Raef, Behnaz; moftian, Nazila; dehghani, Mohamad; khara, Rouhallah

2017-01-01

Background and aims Business-IT Alignment Evaluation is One of the most important issues that managers should monitor and make decisions about it. Dashboard software combines data and graphical indicators to deliver at-a-glance summaries of information for users to view the state of their business and quickly respond. The aim of this study was to design a dashboard to assess the business-IT alignment strategies for hospitals organizations in Tehran University of Medical Sciences. Methods This is a functional-developmental study. Initially, we searched related databases (PubMed and ProQuest) to determine the key performance indicators of business-IT alignment for selecting the best model for dashboard designing. After selecting the Luftman model, the key indicators were extracted for designing the dashboard model. In the next stage, an electronic questionnaire was designed based on extracted indicators. This questionnaire sends to Hospital managers and IT administrators. Collected data were analyzed by Excel 2015 and displayed in dashboard page. Results The number of key performance indicators was 39. After recognition the technical requirements the dashboard was designed in Excel. The overall business-IT alignment rate in hospitals was 3.12. Amir-aalam hospital has the highest business-IT alignment rate (3.55) and vali-asr hospital has the lowest business-IT alignment rat (2.80). Conclusion Using dashboard software improves the alignment and reduces the time and energy compared with doing this process manually.

Regression models evaluating THMs, HAAs and HANs formation upon chloramination of source water collected from Yangtze River Delta Region, China.

PubMed

Lin, Jiajia; Chen, Xi; Ansheng, Zhu; Hong, Huachang; Liang, Yan; Sun, Hongjie; Lin, Hongjun; Chen, Jianrong

2018-09-30

Present study aimed to generate multiple regression models to estimate the formation of trihalomethanes (THMs), haloacetonitriles (HANs) and haloacetic acids (HAAs) during chloramination of source water obtained from Yangtze River Delta Region, China. The results showed that the regression models for trichloromethane (TCM), dichloroacetonitrile (DCAN), dichloroacetic acid (DCAA), dihaloacetic acids (DHAAs), 5 HAAs species regulated by U.S. EPA (HAA 5 ) and total haloacetic acids (HAA 9 ) have good evaluation ability (prediction accuracy reached 81-94%), while the models for total haloacetonitriles (HAN 4 ), trichloroacetic acid (TCAA), trihaloacetic acids (THAAs) and total trihalomethanes (THM 4 ), they appeared relative low prediction accuracy (58-72%). For THMs, dissolved organic nitrogen (DON) was their key organic precursor, yet for HAN, DHAAs and THAAs, UVA 254 played the dominant role. The other key factors influencing DBP formation included the bromide (THM 4 , DHAAs and HAA 9 ), reaction time (DCAN, HAN 4 ), chloramine dose (TCM, DCAA, TCAA, HAA 5 and THAAs). These results provided important information for water works to optimize the water treatment process to control DBPs, and give an evaluating method for DBPs levels when estimating the health risks related with DBP exposure during chloramination. Copyright © 2018 Elsevier Inc. All rights reserved.

Structural, Thermodynamic, and Functional Mechanisms of Adaptations WrbA and AdoMetDC Proteins in Extremophilic Organisms

DTIC Science & Technology

2007-08-15

thermophilic ) and low (psychrophilic). A model protein used in this study, S- adenosyl-methionine decarboxylase (AdoMetDC), is a key enzyme in the polyamine...experimental characterization of the thermophilic AdoMtDC from Termatoga maritima. The processing of TmAdoMetDC that leads to catalytically active enzyme is... thermophilic organisms. One of the open questions of structural biology is the understanding of the mechanisms by which enzymes adapt to extreme temperatures

Hippo Pathway in Organ Size Control, Tissue Homeostasis, and Cancer

PubMed Central

Yu, Fa-Xing; Zhao, Bin; Guan, Kun-Liang

2015-01-01

Two decades of studies in multiple model organisms have established the Hippo pathway as a key regulator of organ size and tissue homeostasis. By inhibiting YAP and TAZ transcription co-activators, the Hippo pathway regulates cell proliferation, apoptosis, and stemness in response to a wide range of extracellular and intracellular signals, including cell-cell contact, cell polarity, mechanical cues, ligands of G-protein coupled receptors, and cellular energy status. Dysregulation of the Hippo pathway exerts a significant impact on cancer development. Further investigation of the functions and regulatory mechanisms of this pathway will help uncovering the mystery of organ size control and identify new targets for cancer treatment. PMID:26544935

Evidence-based management of ambulatory electronic health record system implementation: an assessment of conceptual support and qualitative evidence.

PubMed

McAlearney, Ann Scheck; Hefner, Jennifer L; Sieck, Cynthia; Rizer, Milisa; Huerta, Timothy R

2014-07-01

While electronic health record (EHR) systems have potential to drive improvements in healthcare, a majority of EHR implementations fall short of expectations. Shortcomings in implementations are often due to organizational issues around the implementation process rather than technological problems. Evidence from both the information technology and healthcare management literature can be applied to improve the likelihood of implementation success, but the translation of this evidence into practice has not been widespread. Our objective was to comprehensively study and synthesize best practices for managing ambulatory EHR system implementation in healthcare organizations, highlighting applicable management theories and successful strategies. We held 45 interviews with key informants in six U.S. healthcare organizations purposively selected based on reported success with ambulatory EHR implementation. We also conducted six focus groups comprised of 37 physicians. Interview and focus group transcripts were analyzed using both deductive and inductive methods to answer research questions and explore emergent themes. We suggest that successful management of ambulatory EHR implementation can be guided by the Plan-Do-Study-Act (PDSA) quality improvement (QI) model. While participants did not acknowledge nor emphasize use of this model, we found evidence that successful implementation practices could be framed using the PDSA model. Additionally, successful sites had three strategies in common: 1) use of evidence from published health information technology (HIT) literature emphasizing implementation facilitators; 2) focusing on workflow; and 3) incorporating critical management factors that facilitate implementation. Organizations seeking to improve ambulatory EHR implementation processes can use frameworks such as the PDSA QI model to guide efforts and provide a means to formally accommodate new evidence over time. Implementing formal management strategies and incorporating new evidence through the PDSA model is a key element of evidence-based management and a crucial way for organizations to position themselves to proactively address implementation and use challenges before they are exacerbated. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Organizational models of educational technology in U.S. and Canadian medical schools.

PubMed

Souza, Kevin H; Kamin, Carol; O'Sullivan, Patricia; Moses, Anna; Heestand, Diane

2008-07-01

To examine the organizational structure of educational technology units within U.S. and Canadian medical schools in order to (1) identify organization models that support educational technology, (2) describe key attributes of these models, and (3) discuss the strengths and challenges associated with these models. The authors distributed a survey to 88 schools that had previously provided information on their educational technology services and infrastructure. The authors developed the survey through a series of pilots and, then, from the data for each respondent school, created concept maps, which were used to identify organizational models. The authors conducted analyses to determine differences among models. The authors coded the comments about organizational models and identified themes. The authors received adequate data for analysis from 61 schools (69%). Four models for educational technology organizations emerged: (1) centralized units located in the school of medicine, (2) centralized units located at the health science center, (3) centralized units at the comprehensive university, and (4) no centralized unit (Dispersed Model). The majority (75%) of schools relied on some type of centralized organization. Whereas few organization attributes proved to be statistically significant, the centralized models have more resources devoted to educational technology and a closer alignment with the academic mission than the Dispersed Model. Medical schools primarily use central models. The authors recommend that schools structuring their educational technology resources consider exploration of a central model because of its focused use of resources to improve teaching and learning.

Global distribution of secondary organic aerosol particle phase state

NASA Astrophysics Data System (ADS)

Shiraiwa, M.; Li, Y., Sr.; Tsimpidi, A.; Karydis, V.; Berkemeier, T.; Pandis, S. N.; Lelieveld, J.; Koop, T.; Poeschl, U.

2016-12-01

Secondary organic aerosols (SOA) account for a large fraction of submicron particles in the atmosphere and play a key role in aerosol effects on climate, air quality and public health. The formation and aging of SOA proceed through multiple steps of chemical reaction and mass transport in the gas and particle phases, which is challenging for the interpretation of field measurements and laboratory experiments as well as accurate representation of SOA evolution in atmospheric aerosol models. SOA particles can adopt liquid, semi-solid and amorphous solid (glassy) phase states depending on chemical composition, relative humidity and temperature. The particle phase state is crucial for various atmospheric gas-particle interactions, including SOA formation, heterogeneous and multiphase reactions and ice nucleation. We found that organic compounds with a wide variety of functional groups fall into molecular corridors, characterized by a tight inverse correlation between molar mass and volatility. Based on the concept of molecular corridors, we develop a method to estimate glass transition temperatures based on the molar mass and molecular O:C ratio of SOA components, which is a key property for determination of particle phase state. We use the global chemistry climate model EMAC with the organic aerosol module ORACLE to predict the atmospheric SOA phase state. For the planetary boundary layer, global simulations indicate that SOA is mostly liquid in tropical and polar air with high relative humidity, semi-solid in the mid-latitudes, and solid over dry lands. We find that in the middle and upper troposphere (>500 hPa) SOA should be mostly in a glassy solid phase state. Thus, slow diffusion of water, oxidants, and organic molecules could kinetically limit gas-particle interactions of SOA in the free and upper troposphere, promote ice nucleation and facilitate long-range transport of reactive and toxic organic pollutants embedded within SOA.

The policy context of patient centered medical homes: perspectives of primary care providers.

PubMed

Alexander, Jeffrey A; Cohen, Genna R; Wise, Christopher G; Green, Lee A

2013-01-01

Interest in the patient centered medical home (PCMH) model has increased significantly in recent years. Despite this attention, information is limited regarding the influence of policy context on implementation of the PCMH model. Using comparative, qualitative data, we identify several key policy impediments to PCMH implementation, and propose practical guidelines for addressing these issues. Qualitative, semi-structured in-person interviews with representatives of physician organizations and primary care practices pursuing PCMH. Practitioners and staff at 16 physician practices in Michigan, as well as key leaders of physician organizations. We identified five primary policy issues cited by physicians and physician organization leaders as most impactful on their efforts to adopt PCMH: misalignment of current reimbursement schemes, administrative burden, conflicting criteria for PCMH designation, workforce policy issues, and uncertainty of health care reform. These policies were largely seen as barriers to their ability to implement PCMH. Providers' motivation to embrace PCMH, and their level of confidence regarding the results of such change, are greatly influenced by their perception of the external environment and the control they believe they have over this environment. Having policies in place that shape the path to PCMH in a manner that makes it as easy as possible for providers to accomplish the desired changes could well make the difference in whether successful transformation is achieved.

Enhancing population pharmacokinetic modeling efficiency and quality using an integrated workflow.

PubMed

Schmidt, Henning; Radivojevic, Andrijana

2014-08-01

Population pharmacokinetic (popPK) analyses are at the core of Pharmacometrics and need to be performed regularly. Although these analyses are relatively standard, a large variability can be observed in both the time (efficiency) and the way they are performed (quality). Main reasons for this variability include the level of experience of a modeler, personal preferences and tools. This paper aims to examine how the process of popPK model building can be supported in order to increase its efficiency and quality. The presented approach to the conduct of popPK analyses is centered around three key components: (1) identification of most common and important popPK model features, (2) required information content and formatting of the data for modeling, and (3) methodology, workflow and workflow supporting tools. This approach has been used in several popPK modeling projects and a documented example is provided in the supplementary material. Efficiency of model building is improved by avoiding repetitive coding and other labor-intensive tasks and by putting the emphasis on a fit-for-purpose model. Quality is improved by ensuring that the workflow and tools are in alignment with a popPK modeling guidance which is established within an organization. The main conclusion of this paper is that workflow based approaches to popPK modeling are feasible and have significant potential to ameliorate its various aspects. However, the implementation of such an approach in a pharmacometric organization requires openness towards innovation and change-the key ingredient for evolution of integrative and quantitative drug development in the pharmaceutical industry.

Current reinforcement model reproduces center-in-center vein trajectory of Physarum polycephalum.

PubMed

Akita, Dai; Schenz, Daniel; Kuroda, Shigeru; Sato, Katsuhiko; Ueda, Kei-Ichi; Nakagaki, Toshiyuki

2017-06-01

Vein networks span the whole body of the amoeboid organism in the plasmodial slime mould Physarum polycephalum, and the network topology is rearranged within an hour in response to spatio-temporal variations of the environment. It has been reported that this tube morphogenesis is capable of solving mazes, and a mathematical model, named the 'current reinforcement rule', was proposed based on the adaptability of the veins. Although it is known that this model works well for reproducing some key characters of the organism's maze-solving behaviour, one important issue is still open: In the real organism, the thick veins tend to trace the shortest possible route by cutting the corners at the turn of corridors, following a center-in-center trajectory, but it has not yet been examined whether this feature also appears in the mathematical model, using corridors of finite width. In this report, we confirm that the mathematical model reproduces the center-in-center trajectory of veins around corners observed in the maze-solving experiment. © 2017 Japanese Society of Developmental Biologists.

Organ donation and Islam-challenges and opportunities.

PubMed

Sharif, Adnan

2012-09-15

The issue of organ donation in Islam has been debated for decades, with most religious authorities sanctioning both living-organ and deceased-organ donation. However, disquiet among the Islamic community on the compatibility of organ donation with their faith remains, especially in relation to deceased-organ donation. This remains a topical, controversial, and challenging component of organ procurement at both local and international levels. In this article, I will explore Islamic arguments both for and against organ donation, in the context of both living-donor and deceased-donor models. By discussing both practical and philosophical perspectives, the aim is to facilitate discussion on how best to achieve consensus on this issue by driving the debate forward in an open and all-encompassing manner. Although every attempt should be made to achieve consensus among key Muslim opinion makers (individuals, authorities, and institutions), encouraging personalized decision making by intellectual effort should be the goal to achieve genuine informed consent.

Prosomeric organization of the hypothalamus in an elasmobranch, the catshark Scyliorhinus canicula

PubMed Central

Santos-Durán, Gabriel N.; Menuet, Arnaud; Lagadec, Ronan; Mayeur, Hélène; Ferreiro-Galve, Susana; Mazan, Sylvie; Rodríguez-Moldes, Isabel; Candal, Eva

2015-01-01

The hypothalamus has been a central topic in neuroanatomy because of its important physiological functions, but its mature organization remains elusive. Deciphering its embryonic and adult organization is crucial in an evolutionary approach of the organization of the vertebrate forebrain. Here we studied the molecular organization of the hypothalamus and neighboring telencephalic domains in a cartilaginous fish, the catshark, Scyliorhinus canicula, focusing on ScFoxg1a, ScShh, ScNkx2.1, ScDlx2/5, ScOtp, and ScTbr1 expression profiles and on the identification α-acetylated-tubulin-immunoreactive (ir), TH-ir, 5-HT-ir, and GFAP-ir structures by means of immunohistochemistry. Analysis of the results within the updated prosomeric model framework support the existence of alar and basal histogenetic compartments in the hypothalamus similar to those described in the mouse, suggesting the ancestrality of these subdivisions in jawed vertebrates. These data provide new insights into hypothalamic organization in cartilaginous fishes and highlight the generality of key features of the prosomeric model in jawed vertebrates. PMID:25904850

Convective Propagation Characteristics Using a Simple Representation of Convective Organization

NASA Astrophysics Data System (ADS)

Neale, R. B.; Mapes, B. E.

2016-12-01

Observed equatorial wave propagation is intimately linked to convective organization and it's coupling to features of the larger-scale flow. In this talk we a use simple 4 level model to accommodate vertical modes of a mass flux convection scheme (shallow, mid-level and deep). Two paradigms of convection are used to represent convective processes. One that has only both random (unorganized) diagnosed fluctuations of convective properties and one with organized fluctuations of convective properties that are amplified by previously existing convection and has an explicit moistening impact on the local convecting environment We show a series of model simulations in single-column, 2D and 3D configurations, where the role of convective organization in wave propagation is shown to be fundamental. For the optimal choice of parameters linking organization to local atmospheric state, a broad array of convective wave propagation emerges. Interestingly the key characteristics of propagating modes are the low-level moistening followed by deep convection followed by mature 'large-scale' heating. This organization structure appears to hold firm across timescales from 5-day wave disturbances to MJO-like wave propagation.

New animal models of cystic fibrosis: what are they teaching us?

PubMed Central

Keiser, Nicholas W.; Engelhardt, John F.

2013-01-01

Purpose of review Cystic fibrosis is the first human genetic disease to benefit from the directed engineering of three different species of animal models (mice, pigs, and ferrets). Recent studies on the cystic fibrosis pig and ferret models are providing new information about the pathophysiology of cystic fibrosis in various organ systems. Additionally, new conditional cystic fibrosis transmembrane conductance regulator (CFTR) knockout mice are teaching unexpected lessons about CFTR function in surprising cellular locations. Comparisons between these animal models and the human condition are key to dissecting the complexities of disease pathophysiology in cystic fibrosis. Recent findings Cystic fibrosis pigs and ferrets have provided new models to study the spontaneous development of disease in the lung and pancreas, two organs that are largely spared overt spontaneous disease in cystic fibrosis mice. New cystic fibrosis mouse models are now interrogating CFTR functions involved in growth and inflammation at an organ-based level using conditional knockout technology. Together, these models are providing new insights on the human condition. Summary Basic and clinical cystic fibrosis research will benefit greatly from the comparative pathophysiology of cystic fibrosis mice, pigs, and ferrets. Both similarities and differences between these three cystic fibrosis models will inform pathophysiologically important mechanisms of CFTR function in humans and aid in the development of both organ-specific and general therapies for cystic fibrosis. PMID:21857224

Modeling of Tool-Tissue Interactions for Computer-Based Surgical Simulation: A Literature Review

PubMed Central

Misra, Sarthak; Ramesh, K. T.; Okamura, Allison M.

2009-01-01

Surgical simulators present a safe and potentially effective method for surgical training, and can also be used in robot-assisted surgery for pre- and intra-operative planning. Accurate modeling of the interaction between surgical instruments and organs has been recognized as a key requirement in the development of high-fidelity surgical simulators. Researchers have attempted to model tool-tissue interactions in a wide variety of ways, which can be broadly classified as (1) linear elasticity-based, (2) nonlinear (hyperelastic) elasticity-based finite element (FE) methods, and (3) other techniques that not based on FE methods or continuum mechanics. Realistic modeling of organ deformation requires populating the model with real tissue data (which are difficult to acquire in vivo) and simulating organ response in real time (which is computationally expensive). Further, it is challenging to account for connective tissue supporting the organ, friction, and topological changes resulting from tool-tissue interactions during invasive surgical procedures. Overcoming such obstacles will not only help us to model tool-tissue interactions in real time, but also enable realistic force feedback to the user during surgical simulation. This review paper classifies the existing research on tool-tissue interactions for surgical simulators specifically based on the modeling techniques employed and the kind of surgical operation being simulated, in order to inform and motivate future research on improved tool-tissue interaction models. PMID:20119508

Resolving Microzooplankton Functional Groups In A Size-Structured Planktonic Model

NASA Astrophysics Data System (ADS)

Taniguchi, D.; Dutkiewicz, S.; Follows, M. J.; Jahn, O.; Menden-Deuer, S.

2016-02-01

Microzooplankton are important marine grazers, often consuming a large fraction of primary productivity. They consist of a great diversity of organisms with different behaviors, characteristics, and rates. This functional diversity, and its consequences, are not currently reflected in large-scale ocean ecological simulations. How should these organisms be represented, and what are the implications for their biogeography? We develop a size-structured, trait-based model to characterize a diversity of microzooplankton functional groups. We compile and examine size-based laboratory data on the traits, revealing some patterns with size and functional group that we interpret with mechanistic theory. Fitting the model to the data provides parameterizations of key rates and properties, which we employ in a numerical ocean model. The diversity of grazing preference, rates, and trophic strategies enables the coexistence of different functional groups of micro-grazers under various environmental conditions, and the model produces testable predictions of the biogeography.

Validation of systems biology derived molecular markers of renal donor organ status associated with long term allograft function.

PubMed

Perco, Paul; Heinzel, Andreas; Leierer, Johannes; Schneeberger, Stefan; Bösmüller, Claudia; Oberhuber, Rupert; Wagner, Silvia; Engler, Franziska; Mayer, Gert

2018-05-03

Donor organ quality affects long term outcome after renal transplantation. A variety of prognostic molecular markers is available, yet their validity often remains undetermined. A network-based molecular model reflecting donor kidney status based on transcriptomics data and molecular features reported in scientific literature to be associated with chronic allograft nephropathy was created. Significantly enriched biological processes were identified and representative markers were selected. An independent kidney pre-implantation transcriptomics dataset of 76 organs was used to predict estimated glomerular filtration rate (eGFR) values twelve months after transplantation using available clinical data and marker expression values. The best-performing regression model solely based on the clinical parameters donor age, donor gender, and recipient gender explained 17% of variance in post-transplant eGFR values. The five molecular markers EGF, CD2BP2, RALBP1, SF3B1, and DDX19B representing key molecular processes of the constructed renal donor organ status molecular model in addition to the clinical parameters significantly improved model performance (p-value = 0.0007) explaining around 33% of the variability of eGFR values twelve months after transplantation. Collectively, molecular markers reflecting donor organ status significantly add to prediction of post-transplant renal function when added to the clinical parameters donor age and gender.

Chemistry of transuranium elements in salt-base repository

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

Borkowski, Marian; Reed, Donald T; Lucchini, Jean - Francois

2010-12-02

The mobility and potential release of actinides into the accessible environment continues to be the key performance assessment concern of nuclear repositories. Actinide, in particular plutonium speciation under the wide range of conditions that can exist in the subsurface is complex and depends strongly on the coupled effects of redox conditions, inorganic/organic complexation, and the extent/nature of aggregation. Understanding the key factors that define the potential for actinide migration is, in this context, an essential and critical part of making and sustaining a licensing case for a nuclear repository. Herein we report on recent progress in a concurrent modeling andmore » experimental study to determine the speciation of plutonium, uranium and americium in high ionic strength Na-CI-Mg brines. This is being done as part of the ongomg recertification effort m the Waste Isolation Pilot Plant (WIPP). The oxidation-state specific solubility of actinides were established in brine as function of pC{sub H+}, brine composition and the presence and absence of organic chelating agents and carbonate. An oxidation-state invariant analog approach using Nd{sup 3+} and Th{sup 4+} was used for An{sup 3+} and An{sup 4+} respectively. These results show that organic ligands and hydrolysis are key factors for An(III) solubility, hydrolysis at pC{sub H+} above 8 is predominate for An(IV) and carbonates are the key factor for U(VI) solubility. The effect of high ionic strength and brine components measured in absence of carbonates leads to measurable increased in overall solubility over analogous low ionic strength groundwater. Less is known about the bioreduction of actinides by halo-tolerant microorganisms, but there is now evidence that bioreduction does occur and is analogous, in many ways, to what occurs with soil bacteria. Results of solubility studies that focus on Pitzer parameter corrections, new species (e.g. borate complexation), and the thermodynamic parameters for modeling are discussed.« less

Key ingredients of anti-stigma programs for health care providers: a data synthesis of evaluative studies.

PubMed

Knaak, Stephanie; Modgill, Geeta; Patten, Scott B

2014-10-01

As part of its ongoing effort to combat stigma against mental illness among health care providers, the Mental Health Commission of Canada partnered with organizations conducting anti-stigma interventions. Our objective was to evaluate program effectiveness and to better understand what makes some programs more effective than others. Our paper reports the elements of these programs found to be most strongly associated with favourable outcomes. Our study employed a multi-phased, mixed-methods design. First, a grounded theory qualitative study was undertaken to identify key program elements. Next, each program (n = 22) was coded according to the presence or absence of the identified key program ingredients. Then, random-effects, meta-regression modelling was used to examine the association between program outcomes and the key ingredients. The qualitative analysis led to a 6-ingredient model of key program elements. Results of the quantitative analysis showed that programs that included all 6 of these ingredients performed significantly better than those that did not. Individual analyses of each of the 6 ingredients showed that including multiple forms of social contact and emphasizing recovery were characteristics of the most effective programs. The results provide a validation of a 6-ingredient model of key program elements for anti-stigma programming for health care providers. Emphasizing recovery and including multiple types of social contact are of particular importance for maximizing the effectiveness of anti-stigma programs for health care providers.

Use of multiple regression models to evaluate the formation of halonitromethane via chlorination/chloramination of water from Tai Lake and the Qiantang River, China.

PubMed

Hong, Huachang; Qian, Lingya; Xiong, Yujing; Xiao, Zhuoqun; Lin, Hongjun; Yu, Haiying

2015-01-01

The deterioration of water quality, especially organic pollution in Tai Lake and the Qiantang River, have recently received attention in China. The objectives of this study were to evaluate the formation of halonitromethanes (HNMs) using multiple regression models for chlorination and chloramination and to identify the key factors that influence the formation of HNMs in Tai Lake and the Qiantang River. The results showed that the total formation of HNMs (T-HNMs) during chlorination and chloramination could be described using the following models: (1) [Formula: see text] =(10)(5.267)(DON)(6.645)(Br(-))(0.737)(DOC)(-)(5.537)(Cl2)(0.333)(t)(0.165) (R(2)=0.974, p<0.01, n=33), and (2) T-HNMNH2Cl=(10)(-)(2.481)(Cl2)(0.451)(NO2(-))(0.382)(Br(-))(0.630)(t)(0.640)(Temp)(0.581) (R(2)=0.961, p<0.05, n=33), respectively. The key factors that influenced the T-HNM yields during chlorination were dissolved organic nitrogen (DON), bromide and dissolved organic carbon (DOC). The nitrite and bromide concentrations and the reaction time mainly affected the T-HNM yields during chloramination. Additional analysis indicated that the bromine incorporation factors (BIFs) for trihalogenated HNMs generally decreased as the chlorine/chloramine dose, temperature and reaction time decreased and increased as the bromide concentration increased. Copyright © 2014 Elsevier Ltd. All rights reserved.

Stochastic models for plant microtubule self-organization and structure.

PubMed

Eren, Ezgi C; Dixit, Ram; Gautam, Natarajan

2015-12-01

One of the key enablers of shape and growth in plant cells is the cortical microtubule (CMT) system, which is a polymer array that forms an appropriately-structured scaffolding in each cell. Plant biologists have shown that stochastic dynamics and simple rules of interactions between CMTs can lead to a coaligned CMT array structure. However, the mechanisms and conditions that cause CMT arrays to become organized are not well understood. It is prohibitively time-consuming to use actual plants to study the effect of various genetic mutations and environmental conditions on CMT self-organization. In fact, even computer simulations with multiple replications are not fast enough due to the spatio-temporal complexity of the system. To redress this shortcoming, we develop analytical models and methods for expeditiously computing CMT system metrics that are related to self-organization and array structure. In particular, we formulate a mean-field model to derive sufficient conditions for the organization to occur. We show that growth-prone dynamics itself is sufficient to lead to organization in presence of interactions in the system. In addition, for such systems, we develop predictive methods for estimation of system metrics such as expected average length and number of CMTs over time, using a stochastic fluid-flow model, transient analysis, and approximation algorithms tailored to our problem. We illustrate the effectiveness of our approach through numerical test instances and discuss biological insights.

Dietary restriction decreases coenzyme Q and ubiquinol potentially via changes in gene expression in the model organism C. elegans.

PubMed

Fischer, Alexandra; Klapper, Maja; Onur, Simone; Menke, Thomas; Niklowitz, Petra; Döring, Frank

2015-05-06

Dietary restriction (DR) is a robust intervention that extends both health span and life span in many organisms. Ubiquinol and ubiquinone represent the reduced and oxidized forms of coenzyme Q (CoQ). CoQ plays a central role in energy metabolism and functions in several cellular processes including gene expression. Here we used the model organism Caenorhabditis elegans to determine level and redox state of CoQ and expression of genes in response to DR. We found that DR down-regulates the steady-state expression levels of several evolutionary conserved genes (i.e. coq-1) that encode key enzymes of the mevalonate and CoQ-synthesizing pathways. In line with this, DR decreases the levels of total CoQ and ubiquinol. This CoQ-reducing effect of DR is obvious in adult worms but not in L4 larvae and is also evident in the eat-2 mutant, a genetic model of DR. In conclusion, we propose that DR reduces the level of CoQ and ubiquinol via gene expression in the model organism C. elegans. © 2015 International Union of Biochemistry and Molecular Biology.

Determining Competencies for Frontline Sales Managers in For-Profit Organizations

ERIC Educational Resources Information Center

Busch, Tina Killough

2012-01-01

Practice in the sales profession and current competency research indicate salesperson competence is key to organizational competitive advantage. With models of selling evolving to respond to the marketplace, there are changes in the competency requirements and roles people must play for future success, resulting in the emergence of new kinds of…

Global How?--Linking Practice to Theory: A Competency Model for Training Global Learning Facilitators

ERIC Educational Resources Information Center

Büker, Gundula; Schell-Straub, Sigrid

2017-01-01

Global learning facilitators from civil society organizations (CSOs) design and enrich educational processes in formal and non-formal educational settings. They need to be empowered through adequate training opportunities in global learning (GL) contexts. The project Facilitating Global Learning--Key Competences from Members of European CSOs (FGL)…

Collaborative School Improvement: An Integrated Model for Educational Leaders.

ERIC Educational Resources Information Center

Perry, Eleanor A.

A systematic way to create collaborative school improvement is provided. The currently expanding role of administrators as staff developers is explored; 10 strategies are listed for the principal to use as a key player in staff development. Two specific organization development problem-solving strategies, Situation-Target-Plan (S-T-P) and Force…

Functional Imaging and Optogenetics in Drosophila

PubMed Central

Simpson, Julie H.; Looger, Loren L.

2018-01-01

Understanding how activity patterns in specific neural circuits coordinate an animal’s behavior remains a key area of neuroscience research. Genetic tools and a brain of tractable complexity make Drosophila a premier model organism for these studies. Here, we review the wealth of reagents available to map and manipulate neuronal activity with light. PMID:29618589

Managing the Organizational Culture of Rural Schools: Creating Environments for Human Development.

ERIC Educational Resources Information Center

Steinhoff, Carl R.; Owens, Robert G.

The factors of people, technology, structure, and task provide a sociotechnical model for understanding the essential elements of schools as organizations. Schools can be understood as cultures and managed as such. Effective schools focus on a task-oriented organizational culture that meaningfully involves all participants in the key elements of…

Beyond meaningful use: getting meaningful value from IT.

PubMed

Fortin, Jason; Zywiak, Walt

2010-02-01

The HITECH provisions of ARRA include financial incentives for providers to demonstrate meaningful use of certified EHR technology. However, to maximize the value of IT under new payment models, provider organizations will need to go beyond meaningful use criteria in three key areas: Delivering high-quality care. Ensuring coordinated care. Integrating financial systems.

Identification and Functional Prediction of Large Intergenic Noncoding RNAs (lincRNAs) in Rainbow Trout (Oncorhynchus mykiss)

USDA-ARS?s Scientific Manuscript database

Long noncoding RNAs (lncRNAs) have been recognized in recent years as key regulators of diverse cellular processes. Genome-wide large-scale projects have uncovered thousands of lncRNAs in many model organisms. Large intergenic noncoding RNAs (lincRNAs) are lncRNAs that are transcribed from intergeni...

Multiscale digital Arabidopsis predicts individual organ and whole-organism growth.

PubMed

Chew, Yin Hoon; Wenden, Bénédicte; Flis, Anna; Mengin, Virginie; Taylor, Jasper; Davey, Christopher L; Tindal, Christopher; Thomas, Howard; Ougham, Helen J; de Reffye, Philippe; Stitt, Mark; Williams, Mathew; Muetzelfeldt, Robert; Halliday, Karen J; Millar, Andrew J

2014-09-30

Understanding how dynamic molecular networks affect whole-organism physiology, analogous to mapping genotype to phenotype, remains a key challenge in biology. Quantitative models that represent processes at multiple scales and link understanding from several research domains can help to tackle this problem. Such integrated models are more common in crop science and ecophysiology than in the research communities that elucidate molecular networks. Several laboratories have modeled particular aspects of growth in Arabidopsis thaliana, but it was unclear whether these existing models could productively be combined. We test this approach by constructing a multiscale model of Arabidopsis rosette growth. Four existing models were integrated with minimal parameter modification (leaf water content and one flowering parameter used measured data). The resulting framework model links genetic regulation and biochemical dynamics to events at the organ and whole-plant levels, helping to understand the combined effects of endogenous and environmental regulators on Arabidopsis growth. The framework model was validated and tested with metabolic, physiological, and biomass data from two laboratories, for five photoperiods, three accessions, and a transgenic line, highlighting the plasticity of plant growth strategies. The model was extended to include stochastic development. Model simulations gave insight into the developmental control of leaf production and provided a quantitative explanation for the pleiotropic developmental phenotype caused by overexpression of miR156, which was an open question. Modular, multiscale models, assembling knowledge from systems biology to ecophysiology, will help to understand and to engineer plant behavior from the genome to the field.

Some key features in the evolution of self psychology and psychoanalysis.

PubMed

Fosshage, James L

2009-04-01

Psychoanalysis, as every science and its application, has continued to evolve over the past century, especially accelerating over the last 30 years. Self psychology has played a constitutive role in that evolution and has continued to change itself. These movements have been supported and augmented by a wide range of emergent research and theory, especially that of cognitive psychology, infant and attachment research, rapid eye movement and dream research, psychotherapy research, and neuroscience. I present schematically some of what I consider to be the key features of the evolution of self psychology and their interconnection with that of psychoanalysis at large, including the revolutionary paradigm changes, the new epistemology, listening/experiencing perspectives, from narcissism to the development of the self, the new organization model of transference, the new organization model of dreams, and the implicit and explicit dimensions of analytic work. I conclude with a focus on the radical ongoing extension of the analyst's participation in the analytic relationship, using, as an example, the co-creation of analytic love, and providing several brief clinical illustrations. The leading edge question guiding my discussion is "How does analytic change occur?"

Creating a Partnering Community Aimed to Foster Climate Literacy in the Southeastern United States

NASA Astrophysics Data System (ADS)

Rutherford, D.; McNeal, K. S.; Smith, R.; Hare, D.; Nair, U. S.

2011-12-01

The Climate Literacy Partnership in the Southeast (CLiPSE) is a part of the Climate Change Education Program supported by the National Science Foundation (http://CLiPSE-project.org). The established CLiPSE partnership is dedicated to improving climate literacy in the southeast through crafting a shared vision and strategic plan among stakeholders that promotes scientific formal and informal educational resources, materials and programs; a diverse network of key partnering organizations throughout the Southeastern United States (SE US); and effective public dialogues that address diverse learners and audiences and supports learning of climate, climate change, and its relevance upon human and environmental systems. The CLiPSE project has been successful in creating partnerships with more than fifty key stakeholders that stem from a few key publics such as agriculture, education, leisure, religious organizations, and culturally diverse communities. These key publics in the SE US frequently consist of individuals that place great trust in local, private efforts, and CLiPSE has realized the importance of the role of the partnering organizations in providing information through a trusted source. A second unique characteristic of the SE US is the predominately conservative and Protestant citizenry in the region. Working with and through these communities enhances climate change education outreach to this citizenry. The CLiPSE project rests on solid climate science and learning science research in order to formulate an effective plan with desired learning outcomes of critical thinking and civil conversation through effective communication strategies. This paper will present the CLiPSE model in reaching the key publics that traditionally hold ideologies that are traditionally perceived as incompatible with climate change science. We will present the strategies utilized to bring together experts and researchers in climate science, learning science, and social science with practitioners and leaders of key stakeholder groups to formulate a shared climate change education plan in the SE US that is uniquely formatted for each target audience. We will also share what we have learned from interacting with the leaders of our partnering organizations in crafting effective messages for their audiences and addressing learners' affective and cognitive domains.

Crypt dynamics and colorectal cancer: advances in mathematical modelling.

PubMed

van Leeuwen, I M M; Byrne, H M; Jensen, O E; King, J R

2006-06-01

Mathematical modelling forms a key component of systems biology, offering insights that complement and stimulate experimental studies. In this review, we illustrate the role of theoretical models in elucidating the mechanisms involved in normal intestinal crypt dynamics and colorectal cancer. We discuss a range of modelling approaches, including models that describe cell proliferation, migration, differentiation, crypt fission, genetic instability, APC inactivation and tumour heterogeneity. We focus on the model assumptions, limitations and applications, rather than on the technical details. We also present a new stochastic model for stem-cell dynamics, which predicts that, on average, APC inactivation occurs more quickly in the stem-cell pool in the absence of symmetric cell division. This suggests that natural niche succession may protect stem cells against malignant transformation in the gut. Finally, we explain how we aim to gain further understanding of the crypt system and of colorectal carcinogenesis with the aid of multiscale models that cover all levels of organization from the molecular to the whole organ.

Quantifying the degradation of organic matter in marine sediments: A review and synthesis

NASA Astrophysics Data System (ADS)

Arndt, Sandra; Jørgensen, B. B.; LaRowe, D. E.; Middelburg, J. J.; Pancost, R. D.; Regnier, P.

2013-08-01

Quantifying the rates of biogeochemical processes in marine sediments is essential for understanding global element cycles and climate change. Because organic matter degradation is the engine behind benthic dynamics, deciphering the impact that various forces have on this process is central to determining the evolution of the Earth system. Therefore, recent developments in the quantitative modeling of organic matter degradation in marine sediments are critically reviewed. The first part of the review synthesizes the main chemical, biological and physical factors that control organic matter degradation in sediments while the second part provides a general review of the mathematical formulations used to model these processes and the third part evaluates their application over different spatial and temporal scales. Key transport mechanisms in sedimentary environments are summarized and the mathematical formulation of the organic matter degradation rate law is described in detail. The roles of enzyme kinetics, bioenergetics, temperature and biomass growth in particular are highlighted. Alternative model approaches that quantify the degradation rate constant are also critically compared. In the third part of the review, the capability of different model approaches to extrapolate organic matter degradation rates over a broad range of temporal and spatial scales is assessed. In addition, the structure, functions and parameterization of more than 250 published models of organic matter degradation in marine sediments are analyzed. The large range of published model parameters illustrates the complex nature of organic matter dynamics, and, thus, the limited transferability of these parameters from one site to another. Compiled model parameters do not reveal a statistically significant correlation with single environmental characteristics such as water depth, deposition rate or organic matter flux. The lack of a generic framework that allows for model parameters to be constrained in data-poor areas seriously limits the quantification of organic matter degradation on a global scale. Therefore, we explore regional patterns that emerge from the compiled more than 250 organic matter rate constants and critically discuss them in their environmental context. This review provides an interdisciplinary view on organic matter degradation in marine sediments. It contributes to an improved understanding of global patterns in benthic organic matter degradation, and helps identify outstanding questions and future directions in the modeling of organic matter degradation in marine sediments.

Controls on the spatial variability of key soil properties: comparing field data with a mechanistic soilscape evolution model

NASA Astrophysics Data System (ADS)

Vanwalleghem, T.; Román, A.; Giraldez, J. V.

2016-12-01

There is a need for better understanding the processes influencing soil formation and the resulting distribution of soil properties. Soil properties can exhibit strong spatial variation, even at the small catchment scale. Especially soil carbon pools in semi-arid, mountainous areas are highly uncertain because bulk density and stoniness are very heterogeneous and rarely measured explicitly. In this study, we explore the spatial variability in key soil properties (soil carbon stocks, stoniness, bulk density and soil depth) as a function of processes shaping the critical zone (weathering, erosion, soil water fluxes and vegetation patterns). We also compare the potential of a geostatistical versus a mechanistic soil formation model (MILESD) for predicting these key soil properties. Soil core samples were collected from 67 locations at 6 depths. Total soil organic carbon stocks were 4.38 kg m-2. Solar radiation proved to be the key variable controlling soil carbon distribution. Stone content was mostly controlled by slope, indicating the importance of erosion. Spatial distribution of bulk density was found to be highly random. Finally, total carbon stocks were predicted using a random forest model whose main covariates were solar radiation and NDVI. The model predicts carbon stocks that are double as high on north versus south-facing slopes. However, validation showed that these covariates only explained 25% of the variation in the dataset. Apparently, present-day landscape and vegetation properties are not sufficient to fully explain variability in the soil carbon stocks in this complex terrain under natural vegetation. This is attributed to a high spatial variability in bulk density and stoniness, key variables controlling carbon stocks. Similar results were obtained with the mechanistic soil formation model MILESD, suggesting that more complex models might be needed to further explore this high spatial variability.

Organ-on-a-chip: development and clinical prospects toward toxicity assessment with an emphasis on bone marrow.

PubMed

Kim, Jeehye; Lee, Hanna; Selimović, Šeila; Gauvin, Robert; Bae, Hojae

2015-05-01

Conventional approaches for toxicity evaluation of drugs and chemicals, such as animal tests, can be impractical due to the large experimental scale and the immunological differences between species. Organ-on-a-chip models have recently been recognized as a prominent alternative to conventional toxicity tests aiming to simulate the human in vivo physiology. This review focuses on the organ-on-a-chip applications for high-throughput screening of candidate drugs against toxicity, with a particular emphasis on bone-marrow-on-a-chip. Studies in which organ-on-a-chip models have been developed and utilized to maximize the efficiency and predictability in toxicity assessment are introduced. The potential of these devices to replace tests of acute systemic toxicity in animals, and the challenges that are inherent in simulating the human immune system are also discussed. As a promising approach to overcome the limitations, we further focus on an in-depth analysis of the development of bone-marrow-on-a-chip that is capable of simulating human immune responses against external stimuli due to the key roles of marrow in immune systems with hematopoietic activities. Owing to the complex interactions between hematopoietic stem cells and marrow microenvironments, precise control of both biochemical and physical niches that are critical in maintenance of hematopoiesis remains a key challenge. Thus, recently developed bone-marrow-on-a-chip models support immunogenicity and immunotoxicity testing in long-term cultivation with repeated antigen stimulation. In this review, we provide an overview of clinical studies that have been carried out on bone marrow transplants in patients with immune-related diseases and future aspects of clinical and pharmaceutical application of bone-marrow-on-a-chip.

Quantifying the effect of organic aerosol aging and intermediate-volatility emissions on regional-scale aerosol pollution in China

PubMed Central

Zhao, Bin; Wang, Shuxiao; Donahue, Neil M.; Jathar, Shantanu H.; Huang, Xiaofeng; Wu, Wenjing; Hao, Jiming; Robinson, Allen L.

2016-01-01

Secondary organic aerosol (SOA) is one of the least understood constituents of fine particles; current widely-used models cannot predict its loadings or oxidation state. Recent laboratory experiments demonstrated the importance of several new processes, including aging of SOA from traditional precursors, aging of primary organic aerosol (POA), and photo-oxidation of intermediate volatility organic compounds (IVOCs). However, evaluating the effect of these processes in the real atmosphere is challenging. Most models used in previous studies are over-simplified and some key reaction trajectories are not captured, and model parameters are usually phenomenological and lack experimental constraints. Here we comprehensively assess the effect of organic aerosol (OA) aging and intermediate-volatility emissions on regional-scale OA pollution with a state-of-the-art model framework and experimentally constrained parameters. We find that OA aging and intermediate-volatility emissions together increase OA and SOA concentrations in Eastern China by about 40% and a factor of 10, respectively, thereby improving model-measurement agreement significantly. POA and IVOCs both constitute over 40% of OA concentrations, and IVOCs constitute over half of SOA concentrations; this differs significantly from previous apportionment of SOA sources. This study facilitates an improved estimate of aerosol-induced climate and health impacts, and implies a shift from current fine-particle control policies. PMID:27350423

Multiplexed measurement of protein diffusion in Caenorhabditis elegans embryos with SPIM-FCS

NASA Astrophysics Data System (ADS)

Struntz, Philipp; Weiss, Matthias

2016-02-01

Quantifying the diffusion behavior of proteins in different environments, e.g. on cellular membranes, is a key step in uncovering the vital action of protein networks in living organisms. While several established techniques for local diffusion measurements exist, the life sciences are currently in need of a multiplexed, i.e. spatially parallelized, data acquisition that allows for obtaining diffusion maps with high spatiotemporal resolution. Following this demand, the combination of camera-based single-plane illumination microscopy (SPIM) and fluorescence correlation spectroscopy (FCS) has recently emerged as a promising approach. So far, SPIM-FCS has mainly been used to assess the diffusion of soluble particles and proteins in vitro and in culture cells, but due to a particularly low photobleaching and -toxicity the method is also well applicable to developmental organisms. Here, we have probed the performance of SPIM-FCS on an established developmental model organism, the small nematode Caenorhabditis elegans. In particular, we have quantified the diffusion of the peripheral membrane protein PLC1δ 1 in the embryo’s cytoplasm and on the plasma membrane. As a result, we were able to derive diffusion maps of PLC1δ 1 in both compartments in multiple individuals, showing the spatially varying diffusion coefficients across the embryo. Our data also report on the dissociation kinetics of PLC1δ 1 from the plasma membrane, hence underlining that SPIM-FCS can be used to explore key features of peripheral membrane proteins in fragile developmental model organisms.

Simulation and Modeling Efforts to Support Decision Making in Healthcare Supply Chain Management

PubMed Central

Lazarova-Molnar, Sanja

2014-01-01

Recently, most healthcare organizations focus their attention on reducing the cost of their supply chain management (SCM) by improving the decision making pertaining processes' efficiencies. The availability of products through healthcare SCM is often a matter of life or death to the patient; therefore, trial and error approaches are not an option in this environment. Simulation and modeling (SM) has been presented as an alternative approach for supply chain managers in healthcare organizations to test solutions and to support decision making processes associated with various SCM problems. This paper presents and analyzes past SM efforts to support decision making in healthcare SCM and identifies the key challenges associated with healthcare SCM modeling. We also present and discuss emerging technologies to meet these challenges. PMID:24683333

[Roles of organic acid metabolism in plant adaptation to nutrient deficiency and aluminum toxicity stress].

PubMed

Wang, Jianfei; Shen, Qirong

2006-11-01

Organic acids not only act as the intermediates in carbon metabolism, but also exert key roles in the plant adaptation to nutrient deficiency and metal stress and in the plant-microbe interactions at root-soil interface. From the viewpoint of plant nutrition, this paper reviewed the research progress on the formation and physiology of organic acids in plant, and their functions in nitrogen metabolism, phosphorus and iron uptake, aluminum tolerance, and soil ecology. New findings in the membrane transport of organic acids and the biotechnological manipulation of organic acids in transgenic model were also discussed. This novel perspectives of organic acid metabolism and its potential manipulation might present a possibility to understand the fundamental aspects of plant physiology, and lead to the new strategies to obtain crop varieties better adapted to environmental and metal stress.

Strongly exchange-coupled triplet pairs in an organic semiconductor

NASA Astrophysics Data System (ADS)

Weiss, Leah R.; Bayliss, Sam L.; Kraffert, Felix; Thorley, Karl J.; Anthony, John E.; Bittl, Robert; Friend, Richard H.; Rao, Akshay; Greenham, Neil C.; Behrends, Jan

2017-02-01

From biological complexes to devices based on organic semiconductors, spin interactions play a key role in the function of molecular systems. For instance, triplet-pair reactions impact operation of organic light-emitting diodes as well as photovoltaic devices. Conventional models for triplet pairs assume they interact only weakly. Here, using electron spin resonance, we observe long-lived, strongly interacting triplet pairs in an organic semiconductor, generated via singlet fission. Using coherent spin manipulation of these two-triplet states, we identify exchange-coupled (spin-2) quintet complexes coexisting with weakly coupled (spin-1) triplets. We measure strongly coupled pairs with a lifetime approaching 3 μs and a spin coherence time approaching 1 μs, at 10 K. Our results pave the way for the utilization of high-spin systems in organic semiconductors.

Management, leadership, and user control in self-advocacy: an english case study.

PubMed

Tilley, Elizabeth

2013-12-01

This paper presents findings from a qualitative research project on an English self-advocacy organization. In light of recent political and economic developments that have threatened the sustainability of a number of self-advocacy groups for people with intellectual disability, I seek to explore how one particular organization managed to survive and grow. In particular, the paper explores themes of management, leadership, and user control, linking these to external perceptions about self-advocacy organizations. The organization in my study developed an "interdependent" governance model based on key organizational roles for nondisabled advisors and self-advocates, which proved popular with external funders. Despite the organization's notable achievements, its success raises questions for the wider self-advocacy movement, notably how leadership capacity can be developed among self-advocates.

Organic and Inorganic Carbon in the Rio Tinto (Spain) Deep Subsurface System: a Possible Model for Subsurface Carbon and Lithoautotrophs on Mars.

NASA Astrophysics Data System (ADS)

Bonaccorsi, R.; Stoker, C. R.; MARTE Science Team

2007-12-01

The subsurface is the key environment for searching for life on planets lacking surface life. Subsurface ecosystems are of great relevance to astrobiology including the search for past/present life on Mars. Conditions on the Martian surface do not support biological activity but the subsurface might preserve organics and host subsurface life [1]. A key requirement for the analysis of subsurface samples on Mars is the ability to characterize organic vs. inorganic carbon pools. This information is needed to determine if the sample contains organic material of biological origin and/ or to establish if pools of inorganic carbon can support subsurface biospheres. The Mars Analog Rio Tinto Experiment (MARTE) performed deep drilling of cores i.e., down to 165-m depth, in a volcanically-hosted-massive-sulfide deposit at Rio Tinto, Spain, which is considered an important analog of the Sinus Meridiani site on Mars. Results from MARTE suggest the existence of a relatively complex subsurface life including aerobic and anaerobic chemoautotrophs, and strict anaerobic methanogens sustained by Fe and S minerals in anoxic conditions, which is an ideal model analog for a deep subsurface Martian environment. We report here on the distribution of organic (C-org: 0.01-0.3Wt% and inorganic carbon (IC = 0.01-7.0 Wt%) in a subsurface rock system including weathered/oxidized i.e., gossan, and unaltered pyrite stockwork. Cores were analyzed from 3 boreholes (BH-4, BH-7, and BH-8) that penetrated down to a depth of ~165 m into massive sulfide. Nearsurface phyllosilicate rich-pockets contain the highest amounts of organics (0.3Wt%) [2], while the deeper rocks contain the highest amount of carbonates. Assessing the amount of C pools available throughout the RT subsurface brings key insight on the type of trophic system sustaining its microbial ecosystem (i.e., heterotrophs vs. autotrophs) and the biogeochemical relationships that characterize a new type of subsurface biosphere at RT. This potentially novel biosphere on Earth could be used as a model to test for extant and extinct life on Mars. Furthermore, having found carbonates in an hyperacidic system (pH ~2.3) brings new insights on the possible occurrence of deep carbonates deposits under low-pH condition on Mars. [1] Boston, P.J., et al., 1992. Icarus 95,300-308; Bonaccorsi, Stoker and Sutter, 2007 Accepted with review in Astrobiology.

A 3-D mathematical model to identify organ-specific risks in rats during thermal stress.

PubMed

Rakesh, Vineet; Stallings, Jonathan D; Helwig, Bryan G; Leon, Lisa R; Jackson, David A; Reifman, Jaques

2013-12-01

Early prediction of the adverse outcomes associated with heat stress is critical for effective management and mitigation of injury, which may sometimes lead to extreme undesirable clinical conditions, such as multiorgan dysfunction syndrome and death. Here, we developed a computational model to predict the spatiotemporal temperature distribution in a rat exposed to heat stress in an attempt to understand the correlation between heat load and differential organ dysfunction. The model includes a three-dimensional representation of the rat anatomy obtained from medical imaging and incorporates the key mechanisms of heat transfer during thermoregulation. We formulated a novel approach to estimate blood temperature by accounting for blood mixing from the different organs and to estimate the effects of the circadian rhythm in body temperature by considering day-night variations in metabolic heat generation and blood perfusion. We validated the model using in vivo core temperature measurements in control and heat-stressed rats and other published experimental data. The model predictions were within 1 SD of the measured data. The liver demonstrated the greatest susceptibility to heat stress, with the maximum temperature reaching 2°C higher than the measured core temperature and 95% of its volume exceeding the targeted experimental core temperature. Other organs also attained temperatures greater than the core temperature, illustrating the need to monitor multiple organs during heat stress. The model facilitates the identification of organ-specific risks during heat stress and has the potential to aid in the development of improved clinical strategies for thermal-injury prevention and management.

Perception of prescription medicine sample packs among Australian professional, government, industry, and consumer organizations, based on automated textual analysis of one-on-one interviews.

PubMed

Kyle, Greg J; Nissen, Lisa; Tett, Susan

2008-12-01

Prescription medicine samples provided by pharmaceutical companies are predominantly newer and more expensive products. The range of samples provided to practices may not represent the drugs that the doctors desire to have available. Few studies have used a qualitative design to explore the reasons behind sample use. The aim of this study was to explore the opinions of a variety of Australian key informants about prescription medicine samples, using a qualitative methodology. Twenty-three organizations involved in quality use of medicines in Australia were identified, based on the authors' previous knowledge. Each organization was invited to nominate 1 or 2 representatives to participate in semistructured interviews utilizing seeding questions. Each interview was recorded and transcribed verbatim. Leximancer v2.25 text analysis software (Leximancer Pty Ltd., Jindalee, Queensland, Australia) was used for textual analysis. The top 10 concepts from each analysis group were interrogated back to the original transcript text to determine the main emergent opinions. A total of 18 key interviewees representing 16 organizations participated. Samples, patient, doctor, and medicines were the major concepts among general opinions about samples. The concept drug became more frequent and the concept companies appeared when marketing issues were discussed. The Australian Pharmaceutical Benefits Scheme and cost were more prevalent in discussions about alternative sample distribution models, indicating interviewees were cognizant of budgetary implications. Key interviewee opinions added richness to the single-word concepts extracted by Leximancer. Participants recognized that prescription medicine samples have an influence on quality use of medicines and play a role in the marketing of medicines. They also believed that alternative distribution systems for samples could provide benefits. The cost of a noncommercial system for distributing samples or starter packs was a concern. These data will be used to design further research investigating alternative models for distribution of samples.

Characterization Of Dissolved Organic Mattter In The Florida Keys Ecosystem

NASA Astrophysics Data System (ADS)

Adams, D. G.; Shank, G. C.

2009-12-01

Over the past few decades, Scleractinian coral populations in the Florida Keys have increasingly experienced mortality due to bleaching events as well as microbial mediated illnesses such as black band and white band disease. Such pathologies seem to be most correlated with elevated sea surface temperatures, increased UV exposures, and shifts in the microbial community living on the coral itself. Recent studies indicate that corals’ exposure to UV in the Florida Keys is primarily controlled by the concentration of CDOM (Chromophoric Dissolved Organic Matter) in the water column. Further, microbial community alterations may be linked to changes in concentration and chemical composition of the larger DOM (Dissolved Organic Matter) pool. Our research characterized the spatial and temporal properties of DOM in Florida Bay and along the Keys ecosystems using DOC analyses, in-situ water column optical measurements, and spectral analyses including absorbance and fluorescence measurements. We analyzed DOM characteristics along transects running from the mouth of the Shark River at the southwest base of the Everglades, through Florida Bay, and along near-shore Keys coastal waters. Two 12 hour time-series samplings were also performed at the Seven-Mile Bridge, the primary Florida Bay discharge channel to the lower Keys region. Photo-bleaching experiments showed that the chemical characteristics of the DOM pool are altered by exposure to solar radiation. Results also show that DOC (~0.8-5.8 mg C/L) and CDOM (~0.5-16.5 absorbance coefficient at 305nm) concentrations exhibit seasonal fluctuations in our study region. EEM analyses suggest seasonal transitions between primarily marine (summer) and terrestrial (winter) sources along the Keys. We are currently combining EEM-PARAFAC analysis with in-situ optical measurements to model changes in the spectral properties of DOM in the water column. Additionally, we are using stable δ13C isotopic analysis to further characterize DOM sources. Information generated by our study will provide a valuable data set for better understanding DOM bio-geochemical dynamics along the Florida Keys ecosystem and information for future studies linking DOM and the coral community.

Integration of biotic ligand models (BLM) and bioaccumulation kinetics into a mechanistic framework for metal uptake in aquatic organisms.

PubMed

Veltman, Karin; Huijbregts, Mark A J; Hendriks, A Jan

2010-07-01

Both biotic ligand models (BLM) and bioaccumulation models aim to quantify metal exposure based on mechanistic knowledge, but key factors included in the description of metal uptake differ between the two approaches. Here, we present a quantitative comparison of both approaches and show that BLM and bioaccumulation kinetics can be merged into a common mechanistic framework for metal uptake in aquatic organisms. Our results show that metal-specific absorption efficiencies calculated from BLM-parameters for freshwater fish are highly comparable, i.e. within a factor of 2.4 for silver, cadmium, copper, and zinc, to bioaccumulation-absorption efficiencies for predominantly marine fish. Conditional affinity constants are significantly related to the metal-specific covalent index. Additionally, the affinity constants of calcium, cadmium, copper, sodium, and zinc are significantly comparable across aquatic species, including molluscs, daphnids, and fish. This suggests that affinity constants can be estimated from the covalent index, and constants can be extrapolated across species. A new model is proposed that integrates the combined effect of metal chemodynamics, as speciation, competition, and ligand affinity, and species characteristics, as size, on metal uptake by aquatic organisms. An important direction for further research is the quantitative comparison of the proposed model with acute toxicity values for organisms belonging to different size classes.

Segmenting the thoracic, abdominal and pelvic musculature on CT scans combining atlas-based model and active contour model

NASA Astrophysics Data System (ADS)

Zhang, Weidong; Liu, Jiamin; Yao, Jianhua; Summers, Ronald M.

2013-03-01

Segmentation of the musculature is very important for accurate organ segmentation, analysis of body composition, and localization of tumors in the muscle. In research fields of computer assisted surgery and computer-aided diagnosis (CAD), muscle segmentation in CT images is a necessary pre-processing step. This task is particularly challenging due to the large variability in muscle structure and the overlap in intensity between muscle and internal organs. This problem has not been solved completely, especially for all of thoracic, abdominal and pelvic regions. We propose an automated system to segment the musculature on CT scans. The method combines an atlas-based model, an active contour model and prior segmentation of fat and bones. First, body contour, fat and bones are segmented using existing methods. Second, atlas-based models are pre-defined using anatomic knowledge at multiple key positions in the body to handle the large variability in muscle shape. Third, the atlas model is refined using active contour models (ACM) that are constrained using the pre-segmented bone and fat. Before refining using ACM, the initialized atlas model of next slice is updated using previous atlas. The muscle is segmented using threshold and smoothed in 3D volume space. Thoracic, abdominal and pelvic CT scans were used to evaluate our method, and five key position slices for each case were selected and manually labeled as the reference. Compared with the reference ground truth, the overlap ratio of true positives is 91.1%+/-3.5%, and that of false positives is 5.5%+/-4.2%.

Nitrogen cycling models and their application to forest harvesting

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

Johnson, D.W.; Dale, V.H.

1986-01-01

The characterization of forest nitrogen- (N-) cycling processes by several N-cycling models (FORCYTE, NITCOMP, FORTNITE, and LINKAGES) is briefly reviewed and evaluated against current knowledge of N cycling in forests. Some important processes (e.g., translocation within trees, N dynamics in decaying leaf litter) appear to be well characterized, whereas others (e.g., N mineralization from soil organic matter, N fixation, N dynamics in decaying wood, nitrification, and nitrate leaching) are poorly characterized, primarily because of a lack of knowledge rather than an oversight by model developers. It is remarkable how well the forest models do work in the absence of datamore » on some key processes. For those systems in which the poorly understood processes could cause major changes in N availability or productivity, the accuracy of model predictions should be examined. However, the development of N-cycling models represents a major step beyond the much simpler, classic conceptual models of forest nutrient cycling developed by early investigators. The new generation of computer models will surely improve as research reveals how key nutrient-cycling processes operate.« less

Numerical study on electronic and optical properties of organic light emitting diodes.

PubMed

Kim, Kwangsik; Hwang, Youngwook; Won, Taeyoung

2013-08-01

In this paper, we present a finite element method (FEM) study of space charge effects in organic light emitting diodes. Our model includes a Gaussian density of states to account for the energetic disorder in organic semiconductors and the Fermi-Dirac statistics to account for the charge hopping process between uncorrelated sites. The physical model cover all the key physical processes in OLEDs, namely charge injection, transport and recombination, exciton diffusion, transfer and decay as well as light coupling, and thin-film-optics. The exciton model includes generation, diffusion, and energy transfer as well as annihilation. We assumed that the light emission originates from oscillating and thus embodied as excitons and embedded in a stack of multilayer. The out-coupled emission spectrum has been numerically calculated as a function of viewing angle, polarization, and dipole orientation. We discuss the accumulation of charges at internal interfaces and their signature in the transient response as well as the electric field distribution.

Comparative Model Evaluation Studies of Biogenic Trace Gas Fluxes in Tropical Forests

NASA Technical Reports Server (NTRS)

Potter, C. S.; Peterson, David L. (Technical Monitor)

1997-01-01

Simulation modeling can play a number of important roles in large-scale ecosystem studies, including synthesis of patterns and changes in carbon and nutrient cycling dynamics, scaling up to regional estimates, and formulation of testable hypotheses for process studies. Recent comparative studies have shown that ecosystem models of soil trace gas exchange with the atmosphere are evolving into several distinct simulation approaches. Different levels of detail exist among process models in the treatment of physical controls on ecosystem nutrient fluxes and organic substrate transformations leading to gas emissions. These differences are is in part from distinct objectives of scaling and extrapolation. Parameter requirements for initialization scalings, boundary conditions, and time-series driven therefore vary among ecosystem simulation models, such that the design of field experiments for integration with modeling should consider a consolidated series of measurements that will satisfy most of the various model requirements. For example, variables that provide information on soil moisture holding capacity, moisture retention characteristics, potential evapotranspiration and drainage rates, and rooting depth appear to be of the first order in model evaluation trials for tropical moist forest ecosystems. The amount and nutrient content of labile organic matter in the soil, based on accurate plant production estimates, are also key parameters that determine emission model response. Based on comparative model results, it is possible to construct a preliminary evaluation matrix along categories of key diagnostic parameters and temporal domains. Nevertheless, as large-scale studied are planned, it is notable that few existing models age designed to simulate transient states of ecosystem change, a feature which will be essential for assessment of anthropogenic disturbance on regional gas budgets, and effects of long-term climate variability on biosphere-atmosphere exchange.

Antioxidants that protect mitochondria reduce interleukin-6 and oxidative stress, improve mitochondrial function, and reduce biochemical markers of organ dysfunction in a rat model of acute sepsis

PubMed Central

Lowes, D. A.; Webster, N. R.; Murphy, M. P.; Galley, H. F.

2013-01-01

Background Sepsis-induced organ failure is the major cause of death in critical care units, and is characterized by a massive dysregulated inflammatory response and oxidative stress. We investigated the effects of treatment with antioxidants that protect mitochondria (MitoQ, MitoE, or melatonin) in a rat model of lipopolysaccharide (LPS) plus peptidoglycan (PepG)-induced acute sepsis, characterized by inflammation, mitochondrial dysfunction and early organ damage. Methods Anaesthetized and ventilated rats received an i.v. bolus of LPS and PepG followed by an i.v. infusion of MitoQ, MitoE, melatonin, or saline for 5 h. Organs and blood were then removed for determination of mitochondrial and organ function, oxidative stress, and key cytokines. Results MitoQ, MitoE, or melatonin had broadly similar protective effects with improved mitochondrial respiration (P<0.002), reduced oxidative stress (P<0.02), and decreased interleukin-6 levels (P=0.0001). Compared with control rats, antioxidant-treated rats had lower levels of biochemical markers of organ dysfunction, including plasma alanine amino-transferase activity (P=0.02) and creatinine concentrations (P<0.0001). Conclusions Antioxidants that act preferentially in mitochondria reduce mitochondrial damage and organ dysfunction and decrease inflammatory responses in a rat model of acute sepsis. PMID:23381720

Self-organization of network dynamics into local quantized states.

PubMed

Nicolaides, Christos; Juanes, Ruben; Cueto-Felgueroso, Luis

2016-02-17

Self-organization and pattern formation in network-organized systems emerges from the collective activation and interaction of many interconnected units. A striking feature of these non-equilibrium structures is that they are often localized and robust: only a small subset of the nodes, or cell assembly, is activated. Understanding the role of cell assemblies as basic functional units in neural networks and socio-technical systems emerges as a fundamental challenge in network theory. A key open question is how these elementary building blocks emerge, and how they operate, linking structure and function in complex networks. Here we show that a network analogue of the Swift-Hohenberg continuum model-a minimal-ingredients model of nodal activation and interaction within a complex network-is able to produce a complex suite of localized patterns. Hence, the spontaneous formation of robust operational cell assemblies in complex networks can be explained as the result of self-organization, even in the absence of synaptic reinforcements.

A Genome-Scale Metabolic Reconstruction of Mycoplasma genitalium, iPS189

PubMed Central

Suthers, Patrick F.; Dasika, Madhukar S.; Kumar, Vinay Satish; Denisov, Gennady; Glass, John I.; Maranas, Costas D.

2009-01-01

With a genome size of ∼580 kb and approximately 480 protein coding regions, Mycoplasma genitalium is one of the smallest known self-replicating organisms and, additionally, has extremely fastidious nutrient requirements. The reduced genomic content of M. genitalium has led researchers to suggest that the molecular assembly contained in this organism may be a close approximation to the minimal set of genes required for bacterial growth. Here, we introduce a systematic approach for the construction and curation of a genome-scale in silico metabolic model for M. genitalium. Key challenges included estimation of biomass composition, handling of enzymes with broad specificities, and the lack of a defined medium. Computational tools were subsequently employed to identify and resolve connectivity gaps in the model as well as growth prediction inconsistencies with gene essentiality experimental data. The curated model, M. genitalium iPS189 (262 reactions, 274 metabolites), is 87% accurate in recapitulating in vivo gene essentiality results for M. genitalium. Approaches and tools described herein provide a roadmap for the automated construction of in silico metabolic models of other organisms. PMID:19214212

A Bayesian generative model for learning semantic hierarchies

PubMed Central

Mittelman, Roni; Sun, Min; Kuipers, Benjamin; Savarese, Silvio

2014-01-01

Building fine-grained visual recognition systems that are capable of recognizing tens of thousands of categories, has received much attention in recent years. The well known semantic hierarchical structure of categories and concepts, has been shown to provide a key prior which allows for optimal predictions. The hierarchical organization of various domains and concepts has been subject to extensive research, and led to the development of the WordNet domains hierarchy (Fellbaum, 1998), which was also used to organize the images in the ImageNet (Deng et al., 2009) dataset, in which the category count approaches the human capacity. Still, for the human visual system, the form of the hierarchy must be discovered with minimal use of supervision or innate knowledge. In this work, we propose a new Bayesian generative model for learning such domain hierarchies, based on semantic input. Our model is motivated by the super-subordinate organization of domain labels and concepts that characterizes WordNet, and accounts for several important challenges: maintaining context information when progressing deeper into the hierarchy, learning a coherent semantic concept for each node, and modeling uncertainty in the perception process. PMID:24904452

Septin Organization and Functions in Budding Yeast

PubMed Central

Glomb, Oliver; Gronemeyer, Thomas

2016-01-01

The septins are a conserved family of GTP-binding proteins present in all eukaryotic cells except plants. They were originally discovered in the baker's yeast Saccharomyces cerevisiae that serves until today as an important model organism for septin research. In yeast, the septins assemble into a highly ordered array of filaments at the mother bud neck. The septins are regulators of spatial compartmentalization in yeast and act as key players in cytokinesis. This minireview summarizes the recent findings about structural features and cell biology of the yeast septins. PMID:27857941

A model for occupational safety and health intervention diffusion to small businesses.

PubMed

Sinclair, Raymond C; Cunningham, Thomas R; Schulte, Paul A

2013-12-01

Smaller businesses differ from their larger counterparts in having higher rates of occupational injuries and illnesses and fewer resources for preventing those losses. Intervention models developed outside the United States have addressed the resource deficiency issue by incorporating intermediary organizations such as trade associations. This paper extends previous models by using exchange theory and by borrowing from the diffusion of innovations model. It emphasizes that occupational safety and health (OSH) organizations must understand as much about intermediary organizations as they do about small businesses. OSH organizations ("initiators") must understand how to position interventions and information to intermediaries as added value to their relationships with small businesses. Examples from experiences in two midwestern states are used to illustrate relationships and types of analyses implied by the extended model. The study found that intermediary organizations were highly attuned to providing smaller businesses with what they want, including OSH services. The study also found that there are opinion leader organizations and individual champions within intermediaries who are key to decisions and actions about OSH programming. The model places more responsibility on both initiators and intermediaries to develop and market interventions that will be valued in the competitive small business environment where the resources required to adopt each new business activity could always be used in other ways. The model is a candidate for empirical validation, and it offers some encouragement that the issue of sustainable OSH assistance to small businesses might be addressed. Am. J. Ind. Med. 56:1442-1451, 2013. Published 2013. This article is a U.S. Government work and is in the public domain in the USA. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.

Identifying a key physical factor sensitive to the performance of Madden-Julian oscillation simulation in climate models

NASA Astrophysics Data System (ADS)

Kim, Go-Un; Seo, Kyong-Hwan

2018-01-01

A key physical factor in regulating the performance of Madden-Julian oscillation (MJO) simulation is examined by using 26 climate model simulations from the World Meteorological Organization's Working Group for Numerical Experimentation/Global Energy and Water Cycle Experiment Atmospheric System Study (WGNE and MJO-Task Force/GASS) global model comparison project. For this, intraseasonal moisture budget equation is analyzed and a simple, efficient physical quantity is developed. The result shows that MJO skill is most sensitive to vertically integrated intraseasonal zonal wind convergence (ZC). In particular, a specific threshold value of the strength of the ZC can be used as distinguishing between good and poor models. An additional finding is that good models exhibit the correct simultaneous convection and large-scale circulation phase relationship. In poor models, however, the peak circulation response appears 3 days after peak rainfall, suggesting unfavorable coupling between convection and circulation. For an improving simulation of the MJO in climate models, we propose that this delay of circulation in response to convection needs to be corrected in the cumulus parameterization scheme.

Evidence in the learning organization

PubMed Central

Crites, Gerald E; McNamara, Megan C; Akl, Elie A; Richardson, W Scott; Umscheid, Craig A; Nishikawa, James

2009-01-01

Background Organizational leaders in business and medicine have been experiencing a similar dilemma: how to ensure that their organizational members are adopting work innovations in a timely fashion. Organizational leaders in healthcare have attempted to resolve this dilemma by offering specific solutions, such as evidence-based medicine (EBM), but organizations are still not systematically adopting evidence-based practice innovations as rapidly as expected by policy-makers (the knowing-doing gap problem). Some business leaders have adopted a systems-based perspective, called the learning organization (LO), to address a similar dilemma. Three years ago, the Society of General Internal Medicine's Evidence-based Medicine Task Force began an inquiry to integrate the EBM and LO concepts into one model to address the knowing-doing gap problem. Methods During the model development process, the authors searched several databases for relevant LO frameworks and their related concepts by using a broad search strategy. To identify the key LO frameworks and consolidate them into one model, the authors used consensus-based decision-making and a narrative thematic synthesis guided by several qualitative criteria. The authors subjected the model to external, independent review and improved upon its design with this feedback. Results The authors found seven LO frameworks particularly relevant to evidence-based practice innovations in organizations. The authors describe their interpretations of these frameworks for healthcare organizations, the process they used to integrate the LO frameworks with EBM principles, and the resulting Evidence in the Learning Organization (ELO) model. They also provide a health organization scenario to illustrate ELO concepts in application. Conclusion The authors intend, by sharing the LO frameworks and the ELO model, to help organizations identify their capacities to learn and share knowledge about evidence-based practice innovations. The ELO model will need further validation and improvement through its use in organizational settings and applied health services research. PMID:19323819

Higher Education Institution Branding as a Component of Country Branding in Ghana: Renaming Kwame Nkrumah University of Science and Technology

ERIC Educational Resources Information Center

Williams, Robert, Jr.; Osei, Collins; Omar, Maktoba

2012-01-01

As Higher Education Institutions (HEI) become more marketised and increasingly promotionalised, brand building gains in intensity and names become increasingly important. This conceptual paper plans to explore the application of the Renaming Process Model which depicts the key components that impact the organization brand renaming process,…

Sample Language of Modified Contract Elements from Existing CBAs, MOUs, or EWAs to Support Turnaround

ERIC Educational Resources Information Center

Mass Insight Education (NJ1), 2011

2011-01-01

Organized by the key conditions areas for turnaround, "People, Program, Time and Money," this tool offers sample language for each contract element to serve as a model for modifications from a traditional CBA that may support a district's turnaround efforts. Sample language is offered from existing provisions in district-wide collective bargaining…

Wiki or Word? Evaluating Tools for Collaborative Writing and Editing

ERIC Educational Resources Information Center

Dishaw, Mark; Eierman, Michael A.; Iversen, Jakob H.; Philip, George C.

2011-01-01

Businesses and other organizations are relying increasingly on virtual teams to perform a range of business activities. A key challenge in utilizing virtual teams is to support collaboration among team members who are separated by distance and/or time. In this paper we use a research model based on a combination of the Technology Acceptance Model…

Taking a Broader View: Using Institutional Research's Natural Qualities for Transformation

ERIC Educational Resources Information Center

Leimer, Christina

2009-01-01

Many authors (Kezar, 2005; Duke, 2002; Keeling, Underhile, and Wall, 2007; Matier, Sidle, and Hurst, 1994) propose a new model of higher education organizations or a style of decision making whose central component is collaboration. This key characteristic helps make full use of all of the institution's resources to increase the likelihood that it…

Optical Models for Remote Sensing of Colored Dissolved Organic Matter Absorption and Salinity in New England, Middle Atlantic and Gulf Coast Estuaries USA

EPA Science Inventory

In estuarine and nearshore ecosystems, salinity levels, along with temperature, control water column stratification, the types and locations of plants and animals, and the flocculation of particles. Salinity is also a key factor when monitoring water quality variables (e.g., diss...

Black Political Socialization and Political Change: The Black Panther Party Platform as a "Model" of Radical Political Socialization

ERIC Educational Resources Information Center

McLemore, Leslie Burl

1975-01-01

Considers the potential impact of black revolutionary nationalism--cultural and military--upon the social patterns of black people, arguing that a racial, cultural, and military approach through black organizations with a highly developed system of communications holds the key to black salvation in America. (Author/JM)

Succession planning: securing the future.

PubMed

Bolton, Julia; Roy, Wendy

2004-12-01

Succession planning is an essential business strategy for healthcare organizations, given the impending retirement of the huge Baby Boomer cohort of experienced nurses. It ensures that there will be qualified candidates when key vacancies occur. The authors describe the critical elements of a succession plan and suggest ways to implement them. The model can be applied to leadership and clinical positions.

A biomonitor for tracking changes in the availability of lakewater cadmium over space and time

USGS Publications Warehouse

Hare, L.; Tessier, A.; Croteau, M.-N.

2008-01-01

Determining the exposure of organisms to contaminants is a key component of Ecological Risk Assessments (ERAs). Effective estimates of exposure consider not only the total concentrations of contaminants in an organism's surroundings but also the availability of the contaminants to organisms. Contaminant availability can be inferred from mechanistic models and verified by measurements of contaminant concentrations in organisms. We evaluated the widespread lake-dwelling insect Chaoborus as a potential biomonitor for use in exposure assessments for three metals: cadmium (Cd), copper (Cu), and zinc (Zn). We show that larvae of this midge maintain constant their concentrations of the essential metals Cu and Zn and thus cannot be used to monitor them. In contrast, larval Cd concentrations varied widely both among lakes and in a given lake over time. We were able to relate these variations in biomonitor Cd to changes in lakewater Cd and pH using the Free Ion Activity Model (FIAM). Our results suggest that Chaoborus larvae could be used as an effective tool for estimating the Cd exposure of organisms in lakes for the purposes of ERAs.

Regulatory neutrality is essential to establishing a level playing field for accountable care organizations.

PubMed

Bacher, Gary E; Chernew, Michael E; Kessler, Daniel P; Weiner, Stephen M

2013-08-01

Accountable care organizations (ACOs) are among the most widely discussed models for encouraging movement away from fee-for-service payment arrangements. Although ACOs have the potential to slow health spending growth and improve quality of care, regulating them poses special challenges. Regulations, particularly those that affect both ACOs and Medicare Advantage plans, could inadvertently favor or disfavor certain kinds of providers or payers. Such favoritism could drive efficient organizations from the market and thus increase costs or reduce quality of and access to care. To avoid this type of outcome, we propose a general principle: Regulation of ACOs should strive to preserve a level playing field among different kinds of organizations seeking the same cost, quality, and access objectives. This is known as regulatory neutrality. We describe the implications of regulatory neutrality in four key areas: antitrust, financial solvency regulation, Medicare governance requirements, and Medicare payment models. We also discuss issues relating to short-term versus long-term perspectives--to promote the goal of regulatory neutrality and allow the most efficient organizations to prevail in the marketplace.

service line analytics in the new era.

PubMed

Spence, Jay; Seargeant, Dan

2015-08-01

To succeed under the value-based business model, hospitals and health systems require effective service line analytics that combine inpatient and outpatient data and that incorporate quality metrics for evaluating clinical operations. When developing a framework for collection, analysis, and dissemination of service line data, healthcare organizations should focus on five key aspects of effective service line analytics: Updated service line definitions. Ability to analyze and trend service line net patient revenues by payment source. Access to accurate service line cost information across multiple dimensions with drill-through capabilities. Ability to redesign key reports based on changing requirements. Clear assignment of accountability.

Defining the conserved internal architecture of a protein kinase.

PubMed

Kornev, Alexandr P; Taylor, Susan S

2010-03-01

Protein kinases constitute a large protein family of important regulators in all eukaryotic cells. All of the protein kinases have a similar bilobal fold, and their key structural features have been well studied. However, the recent discovery of non-contiguous hydrophobic ensembles inside the protein kinase core shed new light on the internal organization of these molecules. Two hydrophobic "spines" traverse both lobes of the protein kinase molecule, providing a firm but flexible connection between its key elements. The spine model introduces a useful framework for analysis of intramolecular communications, molecular dynamics, and drug design. Published by Elsevier B.V.

Evolution and regulation of complex life cycles: a brown algal perspective.

PubMed

Cock, J Mark; Godfroy, Olivier; Macaisne, Nicolas; Peters, Akira F; Coelho, Susana M

2014-02-01

The life cycle of an organism is one of its fundamental features, influencing many aspects of its biology. The brown algae exhibit a diverse range of life cycles indicating that transitions between life cycle types may have been key adaptive events in the evolution of this group. Life cycle mutants, identified in the model organism Ectocarpus, are providing information about how life cycle progression is regulated at the molecular level in brown algae. We explore some of the implications of the phenotypes of the life cycle mutants described to date and draw comparisons with recent insights into life cycle regulation in the green lineage. Given the importance of coordinating growth and development with life cycle progression, we suggest that the co-option of ancient life cycle regulators to control key developmental events may be a common feature in diverse groups of multicellular eukaryotes. Copyright © 2013 Elsevier Ltd. All rights reserved.

Data warehouse model for monitoring key performance indicators (KPIs) using goal oriented approach

NASA Astrophysics Data System (ADS)

Abdullah, Mohammed Thajeel; Ta'a, Azman; Bakar, Muhamad Shahbani Abu

2016-08-01

The growth and development of universities, just as other organizations, depend on their abilities to strategically plan and implement development blueprints which are in line with their vision and mission statements. The actualizations of these statements, which are often designed into goals and sub-goals and linked to their respective actors are better measured by defining key performance indicators (KPIs) of the university. The proposes ReGADaK, which is an extended the GRAnD approach highlights the facts, dimensions, attributes, measures and KPIs of the organization. The measures from the goal analysis of this unit serve as the basis of developing the related university's KPIs. The proposed data warehouse schema is evaluated through expert review, prototyping and usability evaluation. The findings from the evaluation processes suggest that the proposed data warehouse schema is suitable for monitoring the University's KPIs.

TTI CM/AQ evaluation model user`s guide and workshop training materials. Interim research report, September 1993-August 1996

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

NONE

1995-08-01

The TTI CM/AQ Evaluation Model evaluates potential projects based on the following criteria: eligibility, travel impacts, emission impacts, and cost-effectiveness. To compare independent projects within a region during the decision process for CM/AQ funding, each project evaluated with this model is given an overall score based on the project`s effects for the criteria listed above. Training workshops were held by TTI in the first quarter of 1995 to teach metropolitan planning organization, state department of transportation, and regional air quality organization staff how to use this model. Basics of sketch-planning applications were also taught. The DRCOG and TTI CM/AQ Evaluationmore » Models represent significant steps toward the development of analytical methodologies for selecting projects for CM/AQ funding. Because the needs of nonattainment and attainment areas change over time, this model is particularly useful as key evaluation criteria can be modified to reflect the changing needs of a metropolitan area.« less

Whole-mount in situ hybridization in the rotifer Brachionus plicatilis representing a basal branch of lophotrochozoans.

PubMed

Boell, Louis A; Bucher, Gregor

2008-08-01

In order to broaden the comparative scope of evolutionary developmental biology and to refine our picture of animal macroevolution, it is necessary to establish new model organisms, especially from previously underrepresented groups, like the Lophotrochozoa. We have established the culture and protocols for molecular developmental biology in the rotifer species Brachionus plicatilis Müller (Rotifera, Monogononta). Rotifers are nonsegmented animals with enigmatic basal position within the lophotrochozoans and marked by several evolutionary novelties like the wheel organ (corona), the median eye, and the nonpaired posterior foot. The expression of Bp-Pax-6 is shown using whole-mount in situ hybridization. The inexpensive easy culture and experimental tractability of Brachionus as well as the range of interesting questions to which it holds the key make it a promising addition to the "zoo" of evo-devo model organisms.

Developing criteria to establish Trusted Digital Repositories

USGS Publications Warehouse

Faundeen, John L.

2017-01-01

This paper details the drivers, methods, and outcomes of the U.S. Geological Survey’s quest to establish criteria by which to judge its own digital preservation resources as Trusted Digital Repositories. Drivers included recent U.S. legislation focused on data and asset management conducted by federal agencies spending $100M USD or more annually on research activities. The methods entailed seeking existing evaluation criteria from national and international organizations such as International Standards Organization (ISO), U.S. Library of Congress, and Data Seal of Approval upon which to model USGS repository evaluations. Certification, complexity, cost, and usability of existing evaluation models were key considerations. The selected evaluation method was derived to allow the repository evaluation process to be transparent, understandable, and defensible; factors that are critical for judging competing, internal units. Implementing the chosen evaluation criteria involved establishing a cross-agency, multi-disciplinary team that interfaced across the organization. 

Direct and indirect impacts of crop-livestock organization on mixed crop-livestock systems sustainability: a model-based study.

PubMed

Sneessens, I; Veysset, P; Benoit, M; Lamadon, A; Brunschwig, G

2016-11-01

Crop-livestock production is claimed more sustainable than specialized production systems. However, the presence of controversial studies suggests that there must be conditions of mixing crop and livestock productions to allow for higher sustainable performances. Whereas previous studies focused on the impact of crop-livestock interactions on performances, we posit here that crop-livestock organization is a key determinant of farming system sustainability. Crop-livestock organization refers to the percentage of the agricultural area that is dedicated to each production. Our objective is to investigate if crop-livestock organization has both a direct and an indirect impact on mixed crop-livestock (MC-L) sustainability. In that objective, we build a whole-farm model parametrized on representative French sheep and crop farming systems in plain areas (Vienne, France). This model permits simulating contrasted MC-L systems and their subsequent sustainability through the following indicators of performance: farm income, production, N balance, greenhouse gas (GHG) emissions (/kg product) and MJ consumption (/kg product). Two MC-L systems were simulated with contrasted crop-livestock organizations (MC20-L80: 20% of crops; MC80-L20: 80% of crops). A first scenario - constraining no crop-livestock interactions in both MC-L systems - permits highlighting that crop-livestock organization has a significant direct impact on performances that implies trade-offs between objectives of sustainability. Indeed, the MC80-L20 system is showing higher performances for farm income (+44%), livestock production (+18%) and crop GHG emissions (-14%) whereas the MC20-L80 system has a better N balance (-53%) and a lower livestock MJ consumption (-9%). A second scenario - allowing for crop-livestock interactions in both MC20-L80 and MC80-L20 systems - stated that crop-livestock organization has a significant indirect impact on performances. Indeed, even if crop-livestock interactions permit improving performances, crop-livestock organization influences the capacity of MC-L systems to benefit from crop-livestock interactions. As a consequence, we observed a decreasing performance trade-off between MC-L systems for farm income (-4%) and crop GHG emissions (-10%) whereas the gap increases for nitrogen balance (+23%), livestock production (+6%) - MJ consumption (+16%) - GHG emissions (+5%) and crop MJ consumption (+5%). However, the indirect impact of crop-livestock organization doesn't reverse the trend of trade-offs between objectives of sustainability determined by the direct impact of crop-livestock organization. As a conclusion, crop-livestock organization is a key factor that has to be taken into account when studying the sustainability of mixed crop-livestock systems.

A Framework for Considering Comprehensibility in Modeling

PubMed Central

Gleicher, Michael

2016-01-01

Abstract Comprehensibility in modeling is the ability of stakeholders to understand relevant aspects of the modeling process. In this article, we provide a framework to help guide exploration of the space of comprehensibility challenges. We consider facets organized around key questions: Who is comprehending? Why are they trying to comprehend? Where in the process are they trying to comprehend? How can we help them comprehend? How do we measure their comprehension? With each facet we consider the broad range of options. We discuss why taking a broad view of comprehensibility in modeling is useful in identifying challenges and opportunities for solutions. PMID:27441712

Bioavailability of xenobiotics in the soil environment.

PubMed

Katayama, Arata; Bhula, Raj; Burns, G Richard; Carazo, Elizabeth; Felsot, Allan; Hamilton, Denis; Harris, Caroline; Kim, Yong-Hwa; Kleter, Gijs; Koedel, Werner; Linders, Jan; Peijnenburg, J G M Willie; Sabljic, Aleksandar; Stephenson, R Gerald; Racke, D Kenneth; Rubin, Baruch; Tanaka, Keiji; Unsworth, John; Wauchope, R Donald

2010-01-01

It is often presumed that all chemicals in soil are available to microorganisms, plant roots, and soil fauna via dermal exposure. Subsequent bioaccumulation through the food chain may then result in exposure to higher organisms. Using the presumption of total availability, national governments reduce environmental threshold levels of regulated chemicals by increasing guideline safety margins. However, evidence shows that chemical residues in the soil environment are not always bioavailable. Hence, actual chemical exposure levels of biota are much less than concentrations present in soil would suggest. Because "bioavailability" conveys meaning that combines implications of chemical sol persistency, efficacy, and toxicity, insights on the magnitude of a chemicals soil bioavailability is valuable. however, soil bioavailability of chemicals is a complex topic, and is affected by chemical properties, soil properties, species exposed, climate, and interaction processes. In this review, the state-of-art scientific basis for bioavailability is addressed. Key points covered include: definition, factors affecting bioavailability, equations governing key transport and distributive kinetics, and primary methods for estimating bioavailability. Primary transport mechanisms in living organisms, critical to an understanding of bioavailability, also presage the review. Transport of lipophilic chemicals occurs mainly by passive diffusion for all microorganisms, plants, and soil fauna. Therefore, the distribution of a chemical between organisms and soil (bioavailable proportion) follows partition equilibrium theory. However, a chemical's bioavailability does not always follow partition equilibrium theory because of other interactions with soil, such as soil sorption, hysteretic desorption, effects of surfactants in pore water, formation of "bound residue", etc. Bioassays for estimating chemical bioavailability have been introduced with several targeted endpoints: microbial degradation, uptake by higher plants and soil fauna, and toxicity to organisms. However, there bioassays are often time consuming and laborious. Thus, mild extraction methods have been employed to estimate bioavailability of chemicals. Mild methods include sequential extraction using alcohols, hexane/water, supercritical fluids (carbon dioxide), aqueous hydroxypropyl-beta-cyclodextrin extraction, polymeric TENAX beads extraction, and poly(dimethylsiloxane)-coated solid-phase microextraction. It should be noted that mild extraction methods may predict bioavailability at the moment when measurements are carried out, but not the changes in bioavailability that may occur over time. Simulation models are needed to estimate better bioavailability as a function of exposure time. In the past, models have progressed significantly by addressing each group of organisms separately: microbial degradation, plant uptake via evapotranspiration processes, and uptake of soil fauna in their habitat. This approach has been used primarily because of wide differences in the physiology and behaviors of such disparate organisms. However, improvement of models is badly needed, Particularly to describe uptake processes by plant and animals that impinge on bioavailability. Although models are required to describe all important factors that may affect chemical bioavailability to individual organisms over time (e.g., sorption/desorption to soil/sediment, volatilization, dissolution, aging, "bound residue" formation, biodegradation, etc.), these models should be simplified, when possible, to limit the number of parameters to the practical minimum. Although significant scientific progress has been made in understanding the complexities in specific methodologies dedicated to determining bioavailability, no method has yet emerged to characterized bioavailability across a wide range of chemicals, organisms, and soils/sediments. The primary aim in studying bioavailability is to define options for addressing bioremediation or environmental toxicity (risk assessment), and that is unlikely to change. Because of its importance in estimating research is needed to more comprehensively address the key environmental issue of "bioavailability of chemicals in soil/sediment."

Role of conceptual models in a physical therapy curriculum: application of an integrated model of theory, research, and clinical practice.

PubMed

Darrah, Johanna; Loomis, Joan; Manns, Patricia; Norton, Barbara; May, Laura

2006-11-01

The Department of Physical Therapy, University of Alberta, Edmonton, Alberta, Canada, recently implemented a Master of Physical Therapy (MPT) entry-level degree program. As part of the curriculum design, two models were developed, a Model of Best Practice and the Clinical Decision-Making Model. Both models incorporate four key concepts of the new curriculum: 1) the concept that theory, research, and clinical practice are interdependent and inform each other; 2) the importance of client-centered practice; 3) the terminology and philosophical framework of the World Health Organization's International Classification of Functioning, Disability, and Health; and 4) the importance of evidence-based practice. In this article the general purposes of models for learning are described; the two models developed for the MPT program are described; and examples of their use with curriculum design and teaching are provided. Our experiences with both the development and use of models of practice have been positive. The models have provided both faculty and students with a simple, systematic structured framework to organize teaching and learning in the MPT program.

A study of factors affecting the adoption of server virtualization technology

NASA Astrophysics Data System (ADS)

Lu, Hsin-Ke; Lin, Peng-Chun; Chiang, Chang-Heng; Cho, Chien-An

2018-04-01

It has become a trend that worldwide enterprises and organizations apply new technologies to improve their operations; besides, it has higher cost and less flexibility to construct and manage traditional servers, therefore the current mainstream is to use server virtualization technology. However, from these new technology organizations will not necessarily get the expected benefits because each one has its own level of organizational complexity and abilities to accept changes. The researcher investigated key factors affecting the adoption of virtualization technology through two phases. In phase I, the researcher reviewed literature and then applied the dimensions of "Information Systems Success Model" (ISSM) to generalize the factors affecting the adoption of virtualization technology to be the preliminary theoretical framework and develop a questionnaire; in phase II, a three-round Delphi Method was used to integrate the opinions of experts from related fields which were then gradually converged in order to obtain a stable and objective questionnaire of key factors so that these results were expected to provide references for organizations' adoption of server virtualization technology and future studies.

To the bottom of carbon processing at the seafloor: towards integration of geological, geochemical and ecological concepts (Vladimir Ivanovich Vernadsky Medal Lecture)

NASA Astrophysics Data System (ADS)

Middelburg, Jack J.

2017-04-01

Marine sediments are a habitat for organisms, govern the partitioning of material being buried or recycled, and act as filter for the paleorecord. Processes in the surface sediment layer determine whether carbon is recycled within the biosphere (short-term cycle) or transferred to the geosphere (long-term cycle) and as such it function as key interface in the System Earth. Scientists from various disciplines with their own interests, paradigms and techniques have studied this pivotal role of the seafloor in processing material deposited. Marine geologists and paleoceanographers study sediments with the primary aim to extract information on past environmental conditions using down-core measurements of substances delivered to the seafloor and that have survived the processing at the seafloor. Biogeochemists quantify the fate of material delivered, in particular how much of the material is eventually buried and when and in what form is the remaining recycled to the water column, because recycling of key nutrients (e.g. N, P, Si, Fe) sustain primary production. Organic geochemists investigate how organic matter delivered to the seafloor is degraded, transformed or preserved using changes in the composition at the molecular level. Ecologists focus on the organisms, i.e. the actors consuming, producing and transporting the material deposited. Although these disciplines often study the same material, e.g. organic matter delivered to the seafloor, they focus on different aspect ignoring key concepts, findings and approaches from other disciplines. For example, ecologists and biogeochemist studying carbon flow at the seafloor normally ignore detailed molecular information available from organic geochemistry. Bioturbation, particle transport and mixing at the seafloor, is often ignored by paleocanographers, and biogeochemists have developed advanced transport-reaction models in which the actors, the animals, mix the particles but do so without consuming organic matter, their food. Here I present existing views on organic carbon processing at the seafloor, discuss where they agree and disagree and aim to arrive at an integrated view of carbon processing at the seafloor that is consistent with recent views within the organic geochemical, sediment geochemical, ecological and microbiological communities.

Salient features of the ciliated organ of asymmetry

PubMed Central

Amack, Jeffrey D.

2014-01-01

Many internal organs develop distinct left and right sides that are essential for their functions. In several vertebrate embryos, motile cilia generate an asymmetric fluid flow that plays an important role in establishing left-right (LR) signaling cascades. These ‘LR cilia’ are found in the ventral node and posterior notochordal plate in mammals, the gastrocoel roof plate in amphibians and Kupffer’s vesicle in teleost fish. I consider these transient ciliated structures as the ‘organ of asymmetry’ that directs LR patterning of the developing embryo. Variations in size and morphology of the organ of asymmetry in different vertebrate species have raised questions regarding the fundamental features that are required for LR determination. Here, I review current models for how LR asymmetry is established in vertebrates, discuss the cellular architecture of the ciliated organ of asymmetry and then propose key features of this organ that are critical for orienting the LR body axis. PMID:24481178

Integrative analysis of the Caenorhabditis elegans genome by the modENCODE project.

PubMed

Gerstein, Mark B; Lu, Zhi John; Van Nostrand, Eric L; Cheng, Chao; Arshinoff, Bradley I; Liu, Tao; Yip, Kevin Y; Robilotto, Rebecca; Rechtsteiner, Andreas; Ikegami, Kohta; Alves, Pedro; Chateigner, Aurelien; Perry, Marc; Morris, Mitzi; Auerbach, Raymond K; Feng, Xin; Leng, Jing; Vielle, Anne; Niu, Wei; Rhrissorrakrai, Kahn; Agarwal, Ashish; Alexander, Roger P; Barber, Galt; Brdlik, Cathleen M; Brennan, Jennifer; Brouillet, Jeremy Jean; Carr, Adrian; Cheung, Ming-Sin; Clawson, Hiram; Contrino, Sergio; Dannenberg, Luke O; Dernburg, Abby F; Desai, Arshad; Dick, Lindsay; Dosé, Andréa C; Du, Jiang; Egelhofer, Thea; Ercan, Sevinc; Euskirchen, Ghia; Ewing, Brent; Feingold, Elise A; Gassmann, Reto; Good, Peter J; Green, Phil; Gullier, Francois; Gutwein, Michelle; Guyer, Mark S; Habegger, Lukas; Han, Ting; Henikoff, Jorja G; Henz, Stefan R; Hinrichs, Angie; Holster, Heather; Hyman, Tony; Iniguez, A Leo; Janette, Judith; Jensen, Morten; Kato, Masaomi; Kent, W James; Kephart, Ellen; Khivansara, Vishal; Khurana, Ekta; Kim, John K; Kolasinska-Zwierz, Paulina; Lai, Eric C; Latorre, Isabel; Leahey, Amber; Lewis, Suzanna; Lloyd, Paul; Lochovsky, Lucas; Lowdon, Rebecca F; Lubling, Yaniv; Lyne, Rachel; MacCoss, Michael; Mackowiak, Sebastian D; Mangone, Marco; McKay, Sheldon; Mecenas, Desirea; Merrihew, Gennifer; Miller, David M; Muroyama, Andrew; Murray, John I; Ooi, Siew-Loon; Pham, Hoang; Phippen, Taryn; Preston, Elicia A; Rajewsky, Nikolaus; Rätsch, Gunnar; Rosenbaum, Heidi; Rozowsky, Joel; Rutherford, Kim; Ruzanov, Peter; Sarov, Mihail; Sasidharan, Rajkumar; Sboner, Andrea; Scheid, Paul; Segal, Eran; Shin, Hyunjin; Shou, Chong; Slack, Frank J; Slightam, Cindie; Smith, Richard; Spencer, William C; Stinson, E O; Taing, Scott; Takasaki, Teruaki; Vafeados, Dionne; Voronina, Ksenia; Wang, Guilin; Washington, Nicole L; Whittle, Christina M; Wu, Beijing; Yan, Koon-Kiu; Zeller, Georg; Zha, Zheng; Zhong, Mei; Zhou, Xingliang; Ahringer, Julie; Strome, Susan; Gunsalus, Kristin C; Micklem, Gos; Liu, X Shirley; Reinke, Valerie; Kim, Stuart K; Hillier, LaDeana W; Henikoff, Steven; Piano, Fabio; Snyder, Michael; Stein, Lincoln; Lieb, Jason D; Waterston, Robert H

2010-12-24

We systematically generated large-scale data sets to improve genome annotation for the nematode Caenorhabditis elegans, a key model organism. These data sets include transcriptome profiling across a developmental time course, genome-wide identification of transcription factor-binding sites, and maps of chromatin organization. From this, we created more complete and accurate gene models, including alternative splice forms and candidate noncoding RNAs. We constructed hierarchical networks of transcription factor-binding and microRNA interactions and discovered chromosomal locations bound by an unusually large number of transcription factors. Different patterns of chromatin composition and histone modification were revealed between chromosome arms and centers, with similarly prominent differences between autosomes and the X chromosome. Integrating data types, we built statistical models relating chromatin, transcription factor binding, and gene expression. Overall, our analyses ascribed putative functions to most of the conserved genome.

Laboratory Experiments and Modeling for Interpreting Field Studies of Secondary Organic Aerosol Formation Using an Oxidation Flow Reactor

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

Jimenez, Jose-Luis

2016-02-01

This grant was originally funded for deployment of a suite of aerosol instrumentation by our group in collaboration with other research groups and DOE/ARM to the Ganges Valley in India (GVAX) to study aerosols sources and processing. Much of the first year of this grant was focused on preparations for GVAX. That campaign was cancelled due to political reasons and with the consultation with our program manager, the research of this grant was refocused to study the applications of oxidation flow reactors (OFRs) for investigating secondary organic aerosol (SOA) formation and organic aerosol (OA) processing in the field and laboratorymore » through a series of laboratory and modeling studies. We developed a gas-phase photochemical model of an OFR which was used to 1) explore the sensitivities of key output variables (e.g., OH exposure, O 3, HO 2/OH) to controlling factors (e.g., water vapor, external reactivity, UV irradiation), 2) develop simplified OH exposure estimation equations, 3) investigate under what conditions non-OH chemistry may be important, and 4) help guide design of future experiments to avoid conditions with undesired chemistry for a wide range of conditions applicable to the ambient, laboratory, and source studies. Uncertainties in the model were quantified and modeled OH exposure was compared to tracer decay measurements of OH exposure in the lab and field. Laboratory studies using OFRs were conducted to explore aerosol yields and composition from anthropogenic and biogenic VOC as well as crude oil evaporates. Various aspects of the modeling and laboratory results and tools were applied to interpretation of ambient and source measurements using OFR. Additionally, novel measurement methods were used to study gas/particle partitioning. The research conducted was highly successful and details of the key results are summarized in this report through narrative text, figures, and a complete list of publications acknowledging this grant.« less

Le management des projets scientifiques

NASA Astrophysics Data System (ADS)

Perrier, Françoise

2000-12-01

We describe in this paper a new approach for the management of scientific projects. This approach is the result of a long reflexion carried out within the MQDP (Methodology and Quality in the Project Development) group of INSU-CNRS, and continued with Guy Serra. Our reflexion was initiated with the study of the so-called `North-American Paradigm' which was, initially considered as the only relevant management model. Through our active participation in several astrophysical projects we realized that this model could not be applied to our laboratories without major modifications. Therefore, step-by-step, we have constructed our own methodology, using to the fullest human potential resources existing in our research field, their habits and skills. We have also participated in various working groups in industrial and scientific organisms for the benefits of CNRS. The management model presented here is based on a systemic and complex approach. This approach lets us describe the multiple aspects of a scientific project specially taking into account the human dimension. The project system model includes three major interconnected systems, immersed within an influencing and influenced environment: the `System to be Realized' which defines scientific and technical tasks leading to the scientific goals, the `Realizing System' which describes procedures, processes and organization, and the `Actors' System' which implements and boosts all the processes. Each one exists only through a series of successive models, elaborated at predefined dates of the project called `key-points'. These systems evolve with time and under often-unpredictable circumstances and the models have to take it into account. At these key-points, each model is compared to reality and the difference between the predicted and realized tasks is evaluated in order to define the data for the next model. This model can be applied to any kind of projects.

Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants

PubMed Central

Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

2013-01-01

Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless “bending number” B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies. PMID:23236182

Unifying model of shoot gravitropism reveals proprioception as a central feature of posture control in plants.

PubMed

Bastien, Renaud; Bohr, Tomas; Moulia, Bruno; Douady, Stéphane

2013-01-08

Gravitropism, the slow reorientation of plant growth in response to gravity, is a key determinant of the form and posture of land plants. Shoot gravitropism is triggered when statocysts sense the local angle of the growing organ relative to the gravitational field. Lateral transport of the hormone auxin to the lower side is then enhanced, resulting in differential gene expression and cell elongation causing the organ to bend. However, little is known about the dynamics, regulation, and diversity of the entire bending and straightening process. Here, we modeled the bending and straightening of a rod-like organ and compared it with the gravitropism kinematics of different organs from 11 angiosperms. We show that gravitropic straightening shares common traits across species, organs, and orders of magnitude. The minimal dynamic model accounting for these traits is not the widely cited gravisensing law but one that also takes into account the sensing of local curvature, what we describe here as a graviproprioceptive law. In our model, the entire dynamics of the bending/straightening response is described by a single dimensionless "bending number" B that reflects the ratio between graviceptive and proprioceptive sensitivities. The parameter B defines both the final shape of the organ at equilibrium and the timing of curving and straightening. B can be estimated from simple experiments, and the model can then explain most of the diversity observed in experiments. Proprioceptive sensing is thus as important as gravisensing in gravitropic control, and the B ratio can be measured as phenotype in genetic studies.

Developing and maintaining state-wide adolescent pregnancy prevention coalitions: a preliminary investigation.

PubMed

Nezlek, J B; Galano, J

1993-09-01

This paper presents the results of a study of state-wide adolescent pregnancy prevention coalitions. Key informants in five states throughout the southern United States were given semi-structured interviews regarding the adolescent pregnancy prevention coalitions in their states. From these interviews and other documents, conclusions were drawn regarding the nature and importance of the environments within which these coalitions operate, the universe of activities in which coalitions engage, and the stages of development of these coalitions. Katz and Kahn's model of social organizations served as the basis for understanding coalitions in terms of these three considerations. Future research should consider the utility of organizational models that can explain more fully the organization--committee hybrid structure that tends to characterize these coalitions.

A DNA-Inspired Encryption Methodology for Secure, Mobile Ad Hoc Networks

NASA Technical Reports Server (NTRS)

Shaw, Harry

2012-01-01

Users are pushing for greater physical mobility with their network and Internet access. Mobile ad hoc networks (MANET) can provide an efficient mobile network architecture, but security is a key concern. A figure summarizes differences in the state of network security for MANET and fixed networks. MANETs require the ability to distinguish trusted peers, and tolerate the ingress/egress of nodes on an unscheduled basis. Because the networks by their very nature are mobile and self-organizing, use of a Public Key Infra structure (PKI), X.509 certificates, RSA, and nonce ex changes becomes problematic if the ideal of MANET is to be achieved. Molecular biology models such as DNA evolution can provide a basis for a proprietary security architecture that achieves high degrees of diffusion and confusion, and resistance to cryptanalysis. A proprietary encryption mechanism was developed that uses the principles of DNA replication and steganography (hidden word cryptography) for confidentiality and authentication. The foundation of the approach includes organization of coded words and messages using base pairs organized into genes, an expandable genome consisting of DNA-based chromosome keys, and a DNA-based message encoding, replication, and evolution and fitness. In evolutionary computing, a fitness algorithm determines whether candidate solutions, in this case encrypted messages, are sufficiently encrypted to be transmitted. The technology provides a mechanism for confidential electronic traffic over a MANET without a PKI for authenticating users.

Transgenic approaches to altering carbon and nitrogen partitioning in whole plants: assessing the potential to improve crop yields and nutritional quality

DOE PAGES

Yadav, Umesh P.; Ayre, Brian G.; Bush, Daniel R.

2015-04-22

The principal components of plant productivity and nutritional value, from the standpoint of modern agriculture, are the acquisition and partitioning of organic carbon (C) and nitrogen (N) compounds among the various organs of the plant. The flow of essential organic nutrients among the plant organ systems is mediated by its complex vascular system, and is driven by a series of transport steps including export from sites of primary assimilation, transport into and out of the phloem and xylem, and transport into the various import-dependent organs. Manipulating C and N partitioning to enhance yield of harvested organs is evident in themore » earliest crop domestication events and continues to be a goal for modern plant biology. Research on the biochemistry, molecular and cellular biology, and physiology of C and N partitioning has now matured to an extent that strategic manipulation of these transport systems through biotechnology are being attempted to improve movement from source to sink tissues in general, but also to target partitioning to specific organs. These nascent efforts are demonstrating the potential of applied biomass targeting but are also identifying interactions between essential nutrients that require further basic research. In this review, we summarize the key transport steps involved in C and N partitioning, and discuss various transgenic approaches for directly manipulating key C and N transporters involved. In addition, we propose several experiments that could enhance biomass accumulation in targeted organs while simultaneously testing current partitioning models.« less

Transgenic approaches to altering carbon and nitrogen partitioning in whole plants: assessing the potential to improve crop yields and nutritional quality

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

Yadav, Umesh P.; Ayre, Brian G.; Bush, Daniel R.

The principal components of plant productivity and nutritional value, from the standpoint of modern agriculture, are the acquisition and partitioning of organic carbon (C) and nitrogen (N) compounds among the various organs of the plant. The flow of essential organic nutrients among the plant organ systems is mediated by its complex vascular system, and is driven by a series of transport steps including export from sites of primary assimilation, transport into and out of the phloem and xylem, and transport into the various import-dependent organs. Manipulating C and N partitioning to enhance yield of harvested organs is evident in themore » earliest crop domestication events and continues to be a goal for modern plant biology. Research on the biochemistry, molecular and cellular biology, and physiology of C and N partitioning has now matured to an extent that strategic manipulation of these transport systems through biotechnology are being attempted to improve movement from source to sink tissues in general, but also to target partitioning to specific organs. These nascent efforts are demonstrating the potential of applied biomass targeting but are also identifying interactions between essential nutrients that require further basic research. In this review, we summarize the key transport steps involved in C and N partitioning, and discuss various transgenic approaches for directly manipulating key C and N transporters involved. In addition, we propose several experiments that could enhance biomass accumulation in targeted organs while simultaneously testing current partitioning models.« less

Development of polyparameter linear free energy relationship models for octanol-air partition coefficients of diverse chemicals.

PubMed

Jin, Xiaochen; Fu, Zhiqiang; Li, Xuehua; Chen, Jingwen

2017-03-22

The octanol-air partition coefficient (K OA ) is a key parameter describing the partition behavior of organic chemicals between air and environmental organic phases. As the experimental determination of K OA is costly, time-consuming and sometimes limited by the availability of authentic chemical standards for the compounds to be determined, it becomes necessary to develop credible predictive models for K OA . In this study, a polyparameter linear free energy relationship (pp-LFER) model for predicting K OA at 298.15 K and a novel model incorporating pp-LFERs with temperature (pp-LFER-T model) were developed from 795 log K OA values for 367 chemicals at different temperatures (263.15-323.15 K), and were evaluated with the OECD guidelines on QSAR model validation and applicability domain description. Statistical results show that both models are well-fitted, robust and have good predictive capabilities. Particularly, the pp-LFER model shows a strong predictive ability for polyfluoroalkyl substances and organosilicon compounds, and the pp-LFER-T model maintains a high predictive accuracy within a wide temperature range (263.15-323.15 K).

Molecular mechanisms of floral organ specification by MADS domain proteins.

PubMed

Yan, Wenhao; Chen, Dijun; Kaufmann, Kerstin

2016-02-01

Flower development is a model system to understand organ specification in plants. The identities of different types of floral organs are specified by homeotic MADS transcription factors that interact in a combinatorial fashion. Systematic identification of DNA-binding sites and target genes of these key regulators show that they have shared and unique sets of target genes. DNA binding by MADS proteins is not based on 'simple' recognition of a specific DNA sequence, but depends on DNA structure and combinatorial interactions. Homeotic MADS proteins regulate gene expression via alternative mechanisms, one of which may be to modulate chromatin structure and accessibility in their target gene promoters. Copyright © 2015 Elsevier Ltd. All rights reserved.

The application of supply chain management principles to emergency management logistics: An empirical study.

PubMed

Peterson, Matthew R; Young, Richard R; Gordon, Gary A

2016-01-01

Key elements of supply chain theory remain relevant to emergency management (EM) logistics activities. The Supply Chain Operations Reference model can also serve as a useful template for the planning, organizing, and execution of EM logistics. Through a series of case studies (developed through intensive survey of organizations and individuals responsible for EM), the authors identified the extent supply chain theory is being adopted and whether the theory was useful for emergency logistics managers. The authors found several drivers that influence the likelihood of an organization to implement elements of supply chain management: the frequency of events, organizational resources, population density, range of events, and severity of the disaster or emergency.

Experimental Models to Study the Role of Microbes in Host-Parasite Interactions.

PubMed

Hahn, Megan A; Dheilly, Nolwenn M

2016-01-01

Until recently, parasitic infections have been primarily studied as interactions between the parasite and the host, leaving out crucial players: microbes. The recent realization that microbes play key roles in the biology of all living organisms is not only challenging our understanding of host-parasite evolution, but it also provides new clues to develop new therapies and remediation strategies. In this paper we provide a review of promising and advanced experimental organismal systems to examine the dynamic of host-parasite-microbe interactions. We address the benefits of developing new experimental models appropriate to this new research area and identify systems that offer the best promises considering the nature of the interactions among hosts, parasites, and microbes. Based on these systems, we identify key criteria for selecting experimental models to elucidate the fundamental principles of these complex webs of interactions. It appears that no model is ideal and that complementary studies should be performed on different systems in order to understand the driving roles of microbes in host and parasite evolution.

A comparison of newborn stylized and tomographic models for dose assessment in paediatric radiology

NASA Astrophysics Data System (ADS)

Staton, R. J.; Pazik, F. D.; Nipper, J. C.; Williams, J. L.; Bolch, W. E.

2003-04-01

Establishment of organ doses from diagnostic and interventional examinations is a key component to quantifying the radiation risks from medical exposures and for formulating corresponding dose-reduction strategies. Radiation transport models of human anatomy provide a convenient method for simulating radiological examinations. At present, two classes of models exist: stylized mathematical models and tomographic voxel models. In the present study, organ dose comparisons are made for projection radiographs of both a stylized and a tomographic model of the newborn patient. Sixteen separate radiographs were simulated for each model at x-ray technique factors typical of newborn examinations: chest, abdomen, thorax and head views in the AP, PA, left LAT and right LAT projection orientation. For AP and PA radiographs of the torso (chest, abdomen and thorax views), the effective dose assessed for the tomographic model exceeds that for the stylized model with per cent differences ranging from 19% (AP abdominal view) to 43% AP chest view. In contrast, the effective dose for the stylized model exceeds that for the tomographic model for all eight lateral views including those of the head, with per cent differences ranging from 9% (LLAT chest view) to 51% (RLAT thorax view). While organ positioning differences do exist between the models, a major factor contributing to differences in effective dose is the models' exterior trunk shape. In the tomographic model, a more elliptical shape is seen thus providing for less tissue shielding for internal organs in the AP and PA directions, with corresponding increased tissue shielding in the lateral directions. This observation is opposite of that seen in comparisons of stylized and tomographic models of the adult.

Representative Sinusoids for Hepatic Four-Scale Pharmacokinetics Simulations

PubMed Central

Schwen, Lars Ole; Schenk, Arne; Kreutz, Clemens; Timmer, Jens; Bartolomé Rodríguez, María Matilde; Kuepfer, Lars; Preusser, Tobias

2015-01-01

The mammalian liver plays a key role for metabolism and detoxification of xenobiotics in the body. The corresponding biochemical processes are typically subject to spatial variations at different length scales. Zonal enzyme expression along sinusoids leads to zonated metabolization already in the healthy state. Pathological states of the liver may involve liver cells affected in a zonated manner or heterogeneously across the whole organ. This spatial heterogeneity, however, cannot be described by most computational models which usually consider the liver as a homogeneous, well-stirred organ. The goal of this article is to present a methodology to extend whole-body pharmacokinetics models by a detailed liver model, combining different modeling approaches from the literature. This approach results in an integrated four-scale model, from single cells via sinusoids and the organ to the whole organism, capable of mechanistically representing metabolization inhomogeneity in livers at different spatial scales. Moreover, the model shows circulatory mixing effects due to a delayed recirculation through the surrounding organism. To show that this approach is generally applicable for different physiological processes, we show three applications as proofs of concept, covering a range of species, compounds, and diseased states: clearance of midazolam in steatotic human livers, clearance of caffeine in mouse livers regenerating from necrosis, and a parameter study on the impact of different cell entities on insulin uptake in mouse livers. The examples illustrate how variations only discernible at the local scale influence substance distribution in the plasma at the whole-body level. In particular, our results show that simultaneously considering variations at all relevant spatial scales may be necessary to understand their impact on observations at the organism scale. PMID:26222615

Electron Transport Modeling of Molecular Nanoscale Bridges Used in Energy Conversion Schemes

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

Dunietz, Barry D

2016-08-09

The goal of the research program is to reliably describe electron transport and transfer processes at the molecular level. Such insight is essential for improving molecular applications of solar and thermal energy conversion. We develop electronic structure models to study (1) photoinduced electron transfer and transport processes in organic semiconducting materials, and (2) charge and heat transport through molecular bridges. We seek fundamental understanding of key processes, which lead to design new experiments and ultimately to achieve systems with improved properties.

Learning Organisations--Reengineering Schools for Life Long Learning.

ERIC Educational Resources Information Center

O'Sullivan, Fergus

1997-01-01

Examines some key ideas behind the learning organization and explains why the concept is so powerful in contemporary contexts. Identifies various types of learning organizations, and suggests an analytical technique for relating styles of organizational learning to the environmental context. The key to becoming a learning organization is…

Shale Gas Petrophysical Models: an evaluation of contrasting approaches and assumptions

NASA Astrophysics Data System (ADS)

Inwood, Jennifer; Lovell, Mike; Davies, Sarah; Fishwick, Stewart; Taylor, Kevin

2015-04-01

Shale gas refers to fine-grained formations, or mudstones, where organic matter has matured sufficiently to produce predominantly gas, but that gas has not migrated any significant distance and hence the source rock is effectively the reservoir. Due to the success of shale gas extraction in the USA, many European countries are assessing their potential resources. A key uncertainty in evaluating the resource is the estimation of gas in place and most models are based on North American plays. However, it would seem that no single model to date can confidently predict the gas in place for a 'new' shale formation. Shale gas is frequently characterized by two distinct gas components: free gas is able to move and occupies the pores, while adsorbed gas is fixed onto organic surfaces and held in place by pressure. There are a number of different published methodologies that attempt to take account for this complicated distribution of gas within the rock ranging from models where the importance of the adsorbed gas is assumed to be negligible to those where all gas is assumed to exist within the organic pores and none within the mineral pore spaces. Models that assume both components are important and occupy adjacent volumes need to consider how to separate out the two to avoid double counting. Due to the heterogeneity of mudstones the most appropriate model may vary downhole as well as across adjacent wells. In this pilot study we consider the underlying assumptions and categorize models dependent on the deterministic or probabilistic approach used. We use an initial dataset from North America to test and compare a number of different approaches before expanding the analysis to further formations that span a range of geological and petrophysical characteristics. We then review and evaluate the models, identifying key variables and, where possible, determining their importance through sensitivity analysis. This work aims to establish guidelines for selecting the most appropriate petrophysical model for evaluating the gas in place in a shale gas play, and as such provides a more informed understanding of this petrophysical maze for both specialists and non-specialists.

Stability of ecological industry chain: an entropy model approach.

PubMed

Wang, Qingsong; Qiu, Shishou; Yuan, Xueliang; Zuo, Jian; Cao, Dayong; Hong, Jinglan; Zhang, Jian; Dong, Yong; Zheng, Ying

2016-07-01

A novel methodology is proposed in this study to examine the stability of ecological industry chain network based on entropy theory. This methodology is developed according to the associated dissipative structure characteristics, i.e., complexity, openness, and nonlinear. As defined in the methodology, network organization is the object while the main focus is the identification of core enterprises and core industry chains. It is proposed that the chain network should be established around the core enterprise while supplementation to the core industry chain helps to improve system stability, which is verified quantitatively. Relational entropy model can be used to identify core enterprise and core eco-industry chain. It could determine the core of the network organization and core eco-industry chain through the link form and direction of node enterprises. Similarly, the conductive mechanism of different node enterprises can be examined quantitatively despite the absence of key data. Structural entropy model can be employed to solve the problem of order degree for network organization. Results showed that the stability of the entire system could be enhanced by the supplemented chain around the core enterprise in eco-industry chain network organization. As a result, the sustainability of the entire system could be further improved.

Farm Animal Models of Organic Dust Exposure and Toxicity: Insights and Implications for Respiratory Health

PubMed Central

McClendon, Chakia J.; Gerald, Carresse L.; Waterman, Jenora T.

2016-01-01

Purpose of review Modern food animal production is a major contributor to the global economy, owing to advanced intensive indoor production facilities aimed at increasing market readiness and profit. Consequences of these advances are accumulation of dusts, gases and microbial products that diminish air quality within production facilities. Chronic inhalation exposure contributes to onset and exacerbation of respiratory symptoms and diseases in animals and workers. This article reviews literature regarding constituents of farm animal production facility dusts; animal responses to production building and organic dust exposure, and the effect of chronic inhalation exposure on pulmonary oxidative stress and inflammation. Recent findings –Porcine models of production facility and organic dust exposures reveal striking similarities to observations of human cells, tissues and clinical data. Oxidative stress plays a key role in mediating respiratory diseases in animals and humans, and enhancement of antioxidant levels through nutritional supplements can improve respiratory health. Summary – Pigs are well adapted to the exposures common to swine production buildings and thus serve as excellent models for facility workers. Insight for understanding mechanisms governing organic dust associated respiratory diseases may come from parallel comparisons between farmers and the animals they raise. PMID:25636160

The Barley Phytomer

PubMed Central

Forster, Brian P.; Franckowiak, Jerome D.; Lundqvist, Udda; Lyon, Jackie; Pitkethly, Ian; Thomas, William T. B.

2007-01-01

Background and Aims Morphological mutants have been useful in elucidating the phytomeric structure of plants. Recently described mutants have shed new light on the ontogeny (development of plant structures) and the phytomeric system of barley (Hordeum vulgare). Since the current model for barley phytomers was not adequate to explain the nature of some mutants, a new model is proposed. Methods New phytomer mutants were detected by visual assessment of mutant families in the Optic barley mutation grid population. This was done at various growth stages using laboratory, glasshouse and field screens. Simple explanations were adopted to account for aberrant phytomer phenotypes and a thesis for a new phytomer model was developed. Key Results and Conclusions A barley phytomer model is presented, in which the origins of vegetative and generative structures can be explained by a single repeating phytomer unit. Organs on the barley plant are divided into two classes, single or paired, depending on their origin. Paired structures are often fused together to create specific organs. The model can be applied to wheat (Triticum aestivum) and related grasses. PMID:17901062

Economic Model For a Return on Investment Analysis of United States Government High Performance Computing (HPC) Research and Development (R & D) Investment

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

Joseph, Earl C.; Conway, Steve; Dekate, Chirag

This study investigated how high-performance computing (HPC) investments can improve economic success and increase scientific innovation. This research focused on the common good and provided uses for DOE, other government agencies, industry, and academia. The study created two unique economic models and an innovation index: 1 A macroeconomic model that depicts the way HPC investments result in economic advancements in the form of ROI in revenue (GDP), profits (and cost savings), and jobs. 2 A macroeconomic model that depicts the way HPC investments result in basic and applied innovations, looking at variations by sector, industry, country, and organization size. Amore » new innovation index that provides a means of measuring and comparing innovation levels. Key findings of the pilot study include: IDC collected the required data across a broad set of organizations, with enough detail to create these models and the innovation index. The research also developed an expansive list of HPC success stories.« less

Implementation of eMental Health care: viewpoints from key informants from organizations and agencies with eHealth mandates.

PubMed

Wozney, Lori; Newton, Amanda S; Gehring, Nicole D; Bennett, Kathryn; Huguet, Anna; Hartling, Lisa; Dyson, Michele P; McGrath, Patrick

2017-06-02

The use of technology such as computers, tablets, and smartphones to improve access to and the delivery of mental health care (eMental Health care) is growing worldwide. However, despite the rapidly expanding evidence base demonstrating the efficacy of eMental Health care, its implementation in clinical practice and health care systems remains fragmented. To date, no peer-reviewed, key-informant studies have reported on the perspectives of decision-makers concerned with whether and how to implement eMental Health care. From September to November 2015, we conducted 31 interviews with key informants responsible for leadership, policy, research, and/ or information technology in organizations influential in the adoption of technology for eMental Health care. Deductive and inductive thematic analyses of transcripts were conducted using the Behavior Change Wheel as an organizing framework. Frequency and intensity effect sizes were calculated for emerging themes to further explore patterns within the data. Key informant responses (n = 31) representing 6 developed countries and multiple organizations showed consensus on common factors impacting implementation: individual and organizational capacities (e.g., computer literacy skills [patients and providers], knowledge gaps about cyber security, limited knowledge of available services); motivational drivers of technology-based care (e.g., extending care, data analytics); and opportunities for health systems to advance eMental Health care implementation (e.g., intersectoral research, rapid testing cycles, sustainable funding). Frequency effect sizes showed strong associations between implementation and credibility, knowledge, workflow, patient empowerment, electronic medical record (EMR) integration, sustained funding and intersectoral networks. Intensity effect sizes showed the highest concentration of statements (>10% of all comments) related to funding, credibility, knowledge gaps, and patient empowerment. This study provides previously unavailable information about key informant perspectives on eMental Health care implementation. The themes that emerged, namely the need to intensify intersectoral research, measure/monitor readiness to implement, define cost-utility benchmarks, raise awareness about available technologies, and test assumptions that 'proven' technologies will be easily integrated can inform the design and evaluation of eMental Health care implementation models.

A probabilistic model of debris-flow delivery to stream channels, demonstrated for the Coast Range of Oregon, USA

Treesearch

Daniel J. Miller; Kelly M. Burnett

2008-01-01

Debris flows are important geomorphic agents in mountainous terrains that shape channel environments and add a dynamic element to sediment supply and channel disturbance. Identification of channels susceptible to debris-flow inputs of sediment and organic debris, and quantification of the likelihood and magnitude of those inputs, are key tasks for characterizing...

Music as the Representative of the World Picture, the Phenomenon of Culture

ERIC Educational Resources Information Center

Kossanova, Aigul Sh.; Yermanov, Zhanat R.; Bekenova, Aizhan S.; Julmukhamedova, Aizhan A.; Takezhanova, Roza Ph.; Zhussupova, Saule S.

2016-01-01

The purpose of this article is to the study of music as a representative of the picture of the world nomadic culture. With a systemic organization, rich expressive means, music reflects the diversity of the world in its complex, subtle and profound manifestations being the artistic value, key world modeling element. Music can satisfy the aesthetic…

Ciona intestinalis as a Marine Model System to Study Some Key Developmental Genes Targeted by the Diatom-Derived Aldehyde Decadienal

PubMed Central

Lettieri, Anna; Esposito, Rosaria; Ianora, Adrianna; Spagnuolo, Antonietta

2015-01-01

The anti-proliferative effects of diatoms, described for the first time in copepods, have also been demonstrated in benthic invertebrates such as polychaetes, sea urchins and tunicates. In these organisms PUAs (polyunsaturated aldehydes) induce the disruption of gametogenesis, gamete functionality, fertilization, embryonic mitosis, and larval fitness and competence. These inhibitory effects are due to the PUAs, produced by diatoms in response to physical damage as occurs during copepod grazing. The cell targets of these compounds remain largely unknown. Here we identify some of the genes targeted by the diatom PUA 2-trans-4-trans-decadienal (DD) using the tunicate Ciona intestinalis. The tools, techniques and genomic resources available for Ciona, as well as the suitability of Ciona embryos for medium-to high-throughput strategies, are key to their employment as model organisms in different fields, including the investigation of toxic agents that could interfere with developmental processes. We demonstrate that DD can induce developmental aberrations in Ciona larvae in a dose-dependent manner. Moreover, through a preliminary analysis, DD is shown to affect the expression level of genes involved in stress response and developmental processes. PMID:25789602

Assessing Soil Organic C Stability at the Continental Scale: An Analysis of Soil C and Radiocarbon Profiles Across the NEON Sites

NASA Astrophysics Data System (ADS)

Heckman, K. A.; Gallo, A.; Hatten, J. A.; Swanston, C.; McKnight, D. M.; Strahm, B. D.; Sanclements, M.

2017-12-01

Soil carbon stocks have become recognized as increasingly important in the context of climate change and global C cycle modeling. As modelers seek to identify key parameters affecting the size and stability of belowground C stocks, attention has been drawn to the mineral matrix and the soil physiochemical factors influenced by it. Though clay content has often been utilized as a convenient and key explanatory variable for soil C dynamics, its utility has recently come under scrutiny as new paradigms of soil organic matter stabilization have been developed. We utilized soil cores from a range of National Ecological Observatory Network (NEON) experimental plots to examine the influence of physicochemical parameters on soil C stocks and turnover, and their relative importance in comparison to climatic variables. Soils were cored at NEON sites, sampled by genetic horizon, and density separated into light fractions (particulate organics neither occluded within aggregates nor associated with mineral surfaces), occluded fractions (particulate organics occluded within aggregates), and heavy fractions (organics associated with mineral surfaces). Bulk soils and density fractions were measured for % C and radiocarbon abundance (as a measure of C stability). Carbon and radiocarbon abundances were examined among fractions and in the context of climatic variables (temperature, precipitation, elevation) and soil physiochemical variables (% clay and pH). No direct relationships between temperature and soil C or radiocarbon abundances were found. As a whole, soil radiocarbon abundance in density fractions decreased in the order of light>heavy>occluded, highlighting the importance of both surface sorption and aggregation to the preservation of organics. Radiocarbon abundance was correlated with pH, with variance also grouping by dominate vegetation type. Soil order was also identified as an important proxy variable for C and radiocarbon abundance. Preliminary results suggest that both integrative proxies as well as physicochemical properties may be needed to account for variation in soil C abundance and stability at the continental scale.

Modelling Lean and Green Supply Chain

NASA Astrophysics Data System (ADS)

Duarte, Susana Carla Vieira Lino Medina

The success of an organization depends on the effective control of its supply chain. It is important to recognize new opportunities for organization and its supply chain. In the last few years the approach to lean, agile, resilient and green supply chain paradigms has been addressed in the scientific literature. Research in this field shows that the integration of these concepts revealed some contradictions among so many paradigms. This thesis is mainly focused on the lean and green approaches. Thirteen different management frameworks, embodied in awards, standards and tools were studied to understand if they could contribute for the modelling process of a lean and green approach. The study reveals a number of categories that are common in most management frameworks, providing adequate conditions for a lean and green supply chain transformation. A conceptual framework for the evaluation of a lean and green organization`s supply chain was proposed. The framework considers six key criteria, namely, leadership, people, strategic planning, stakeholders, processes and results. It was proposed an assessment method considering a criteria score for each criterion. The purpose is to understand how lean and green supply chain can be compatible, using principles, practices, techniques or tools (i.e. elements) that support both, a lean and a green approach, in all key criteria. A case study in the automotive upstream supply chain was performed to understand more deeply if the elements proposed for the conceptual framework could be implemented in a real-scenario. Based on the conceptual framework and the case study, a roadmap to achieve a lean-green transformation is presented. The proposed roadmap revealed its contribution to the understanding on how and when an organization`s supply chain should apply the lean and green elements. This study is relevant to practice, as it may assist managers in the adoption of a lean and green supply chain approach, giving insights for the implementation of a hybrid supply chain.

Low-Temperature Alkaline pH Hydrolysis of Oxygen-Free Titan Tholins: Carbonates' Impact.

PubMed

Brassé, Coralie; Buch, Arnaud; Coll, Patrice; Raulin, François

2017-01-01

Titan, the largest moon of Saturn, is one of the key planetary objects in the field of exobiology. Its dense, nitrogen-rich atmosphere is the site of important organic chemistry. This paper focuses on the organic aerosols produced in Titan's atmosphere that play an important role in atmospheric and surface processes and in organic chemistry as it applies to exobiological interests. To produce reliable laboratory analogues of these aerosols, we developed, tested, and optimized a device for the synthesis of clean tholins. The potential chemical evolution of Titan aerosols at Titan's surface has been studied, in particular, the possible interaction between aerosols and putative ammonia-water cryomagma. Modeling of the formation of Saturn's atmosphere has permitted the characterization of a composition of salts in the subsurface ocean and cryolava. From this new and original chemical composition, a laboratory study of several hydrolyses of tholins was carried out. The results obtained show the formation of many organic compounds, among them, species identified only in the presence of salts. In addition, a list of potential precursors of these compounds was established, which could provide a database for research of the chemical composition of tholins and/or aerosols of Titan. Key Words: Titan tholins-Titan aerosols-Hydrolysis-Carbonates-Titan's surface. Astrobiology 17, 8-26.

Detection and Classification of Live and Dead Escherichia coli by Laser-Induced Breakdown Spectroscopy

PubMed Central

Sivakumar, P.; Fernández-Bravo, A.; Taleh, L.; Biddle, J.F.

2015-01-01

Abstract A common goal for astrobiology is to detect organic materials that may indicate the presence of life. However, organic materials alone may not be representative of currently living systems. Thus, it would be valuable to have a method with which to determine the health of living materials. Here, we present progress toward this goal by reporting on the application of laser-induced breakdown spectroscopy (LIBS) to study characteristics of live and dead cells using Escherichia coli (E. coli) strain K12 cells as a model organism since its growth and death in the laboratory are well understood. Our goal is to determine whether LIBS, in its femto- and/or nanosecond forms, could ascertain the state of a living organism. E. coli strain K12 cells were grown, collected, and exposed to one of two types of inactivation treatments: autoclaving and sonication. Cells were also kept alive as a control. We found that LIBS yields key information that allows for the discrimination of live and dead E. coli bacteria based on ionic shifts reflective of cell membrane integrity. Key Words: E. coli—Trace elements—Live and dead cells—Laser-induced breakdown spectroscopy—Atomic force microscopy. Astrobiology 15, 144–153. PMID:25683088

Discrimination of Active and Weakly Active Human BACE1 Inhibitors Using Self-Organizing Map and Support Vector Machine.

PubMed

Li, Hang; Wang, Maolin; Gong, Ya-Nan; Yan, Aixia

2016-01-01

β-secretase (BACE1) is an aspartyl protease, which is considered as a novel vital target in Alzheimer`s disease therapy. We collected a data set of 294 BACE1 inhibitors, and built six classification models to discriminate active and weakly active inhibitors using Kohonen's Self-Organizing Map (SOM) method and Support Vector Machine (SVM) method. Each molecular descriptor was calculated using the program ADRIANA.Code. We adopted two different methods: random method and Self-Organizing Map method, for training/test set split. The descriptors were selected by F-score and stepwise linear regression analysis. The best SVM model Model2C has a good prediction performance on test set with prediction accuracy, sensitivity (SE), specificity (SP) and Matthews correlation coefficient (MCC) of 89.02%, 90%, 88%, 0.78, respectively. Model 1A is the best SOM model, whose accuracy and MCC of the test set were 94.57% and 0.98, respectively. The lone pair electronegativity and polarizability related descriptors importantly contributed to bioactivity of BACE1 inhibitor. The Extended-Connectivity Finger-Prints_4 (ECFP_4) analysis found some vitally key substructural features, which could be helpful for further drug design research. The SOM and SVM models built in this study can be obtained from the authors by email or other contacts.

Key Factors in the Success of an Organization's Information Security Culture: A Quantitative Study and Analysis

ERIC Educational Resources Information Center

Pierce, Robert E.

2012-01-01

This research study reviewed relative literature on information security and information security culture within organizations to determine what factors potentially assist an organization in implementing, integrating, and maintaining a successful organizational information security culture. Based on this review of literature, five key factors were…

Application of a framework for extrapolating chemical effects ...

EPA Pesticide Factsheets

Cross-species extrapolation of toxicity data from limited surrogate test organisms to all wildlife with potential of chemical exposure remains a key challenge in ecological risk assessment. A number of factors affect extrapolation, including the chemical exposure, pharmacokinetics, life-stage, and pathway similarities/differences. Here we propose a framework using a tiered approach for species extrapolation that enables a transparent weight-of-evidence driven evaluation of pathway conservation (or lack thereof) in the context of adverse outcome pathways. Adverse outcome pathways describe the linkages from a molecular initiating event, defined as the chemical-biomolecule interaction, through subsequent key events leading to an adverse outcome of regulatory concern (e.g., mortality, reproductive dysfunction). Tier 1 of the extrapolation framework employs in silico evaluations of sequence and structural conservation of molecules (e.g., receptors, enzymes) associated with molecular initiating events or upstream key events. Such evaluations make use of available empirical and sequence data to assess taxonomic relevance. Tier 2 uses in vitro bioassays, such as enzyme inhibition/activation, competitive receptor binding, and transcriptional activation assays to explore functional conservation of pathways across taxa. Finally, Tier 3 provides a comparative analysis of in vivo responses between species utilizing well-established model organisms to assess departure from

Comparison of AIHA ISO 9001-based occupational health and safety management system guidance document with a manufacturer's occupational health and safety assessment instrument.

PubMed

Dyjack, D T; Levine, S P; Holtshouser, J L; Schork, M A

1998-06-01

Numerous manufacturing and service organizations have integrated or are considering integration of their respective occupational health and safety management and audit systems into the International Organization for Standardization-based (ISO) audit-driven Quality Management Systems (ISO 9000) or Environmental Management Systems (ISO 14000) models. Companies considering one of these options will likely need to identify and evaluate several key factors before embarking on such efforts. The purpose of this article is to identify and address the key factors through a case study approach. Qualitative and quantitative comparisons of the key features of the American Industrial Hygiene Association ISO-9001 harmonized Occupational Health and Safety Management System with The Goodyear Tire & Rubber Co. management and audit system were conducted. The comparisons showed that the two management systems and their respective audit protocols, although structured differently, were not substantially statistically dissimilar in content. The authors recommend that future studies continue to evaluate the advantages and disadvantages of various audit protocols. Ideally, these studies would identify those audit outcome measures that can be reliably correlated with health and safety performance.

Creating a nursing strategic planning framework based on evidence.

PubMed

Shoemaker, Lorie K; Fischer, Brenda

2011-03-01

This article describes an evidence-informed strategic planning process and framework used by a Magnet-recognized public health system in California. This article includes (1) an overview of the organization and its strategic planning process, (2) the structure created within nursing for collaborative strategic planning and decision making, (3) the strategic planning framework developed based on the organization's balanced scorecard domains and the new Magnet model, and (4) the process undertaken to develop the nursing strategic priorities. Outcomes associated with the structure, process, and key initiatives are discussed throughout the article. Copyright © 2011 Elsevier Inc. All rights reserved.

Revealing Long-Range Interconnected Hubs in Human Chromatin Interaction Data Using Graph Theory

NASA Astrophysics Data System (ADS)

Boulos, R. E.; Arneodo, A.; Jensen, P.; Audit, B.

2013-09-01

We use graph theory to analyze chromatin interaction (Hi-C) data in the human genome. We show that a key functional feature of the genome—“master” replication origins—corresponds to DNA loci of maximal network centrality. These loci form a set of interconnected hubs both within chromosomes and between different chromosomes. Our results open the way to a fruitful use of graph theory concepts to decipher DNA structural organization in relation to genome functions such as replication and transcription. This quantitative information should prove useful to discriminate between possible polymer models of nuclear organization.

Leveraging biomedical ontologies and annotation services to organize microbiome data from Mammalian hosts.

PubMed

Sarkar, Indra Neil

2010-11-13

A better understanding of commensal microbiotic communities ("microbiomes") may provide valuable insights to human health. Towards this goal, an essential step may be the development of approaches to organize data that can enable comparative hypotheses across mammalian microbiomes. The present study explores the feasibility of using existing biomedical informatics resources - especially focusing on those available at the National Center for Biomedical Ontology - to organize microbiome data contained within large sequence repositories, such as GenBank. The results indicate that the Foundational Model of Anatomy and SNOMED CT can be used to organize greater than 90% of the bacterial organisms associated with 10 domesticated mammalian species. The promising findings suggest that the current biomedical informatics infrastructure may be used towards the organizing of microbiome data beyond humans. Furthermore, the results identify key concepts that might be organized into a semantic structure for incorporation into subsequent annotations that could facilitate comparative biomedical hypotheses pertaining to human health.

Elucidating secondary organic aerosol from diesel and gasoline vehicles through detailed characterization of organic carbon emissions

PubMed Central

Gentner, Drew R.; Isaacman, Gabriel; Worton, David R.; Chan, Arthur W. H.; Dallmann, Timothy R.; Davis, Laura; Liu, Shang; Day, Douglas A.; Russell, Lynn M.; Wilson, Kevin R.; Weber, Robin; Guha, Abhinav; Harley, Robert A.; Goldstein, Allen H.

2012-01-01

Emissions from gasoline and diesel vehicles are predominant anthropogenic sources of reactive gas-phase organic carbon and key precursors to secondary organic aerosol (SOA) in urban areas. Their relative importance for aerosol formation is a controversial issue with implications for air quality control policy and public health. We characterize the chemical composition, mass distribution, and organic aerosol formation potential of emissions from gasoline and diesel vehicles, and find diesel exhaust is seven times more efficient at forming aerosol than gasoline exhaust. However, both sources are important for air quality; depending on a region’s fuel use, diesel is responsible for 65% to 90% of vehicular-derived SOA, with substantial contributions from aromatic and aliphatic hydrocarbons. Including these insights on source characterization and SOA formation will improve regional pollution control policies, fuel regulations, and methodologies for future measurement, laboratory, and modeling studies. PMID:23091031

Elucidating secondary organic aerosol from diesel and gasoline vehicles through detailed characterization of organic carbon emissions.

PubMed

Gentner, Drew R; Isaacman, Gabriel; Worton, David R; Chan, Arthur W H; Dallmann, Timothy R; Davis, Laura; Liu, Shang; Day, Douglas A; Russell, Lynn M; Wilson, Kevin R; Weber, Robin; Guha, Abhinav; Harley, Robert A; Goldstein, Allen H

2012-11-06

Emissions from gasoline and diesel vehicles are predominant anthropogenic sources of reactive gas-phase organic carbon and key precursors to secondary organic aerosol (SOA) in urban areas. Their relative importance for aerosol formation is a controversial issue with implications for air quality control policy and public health. We characterize the chemical composition, mass distribution, and organic aerosol formation potential of emissions from gasoline and diesel vehicles, and find diesel exhaust is seven times more efficient at forming aerosol than gasoline exhaust. However, both sources are important for air quality; depending on a region's fuel use, diesel is responsible for 65% to 90% of vehicular-derived SOA, with substantial contributions from aromatic and aliphatic hydrocarbons. Including these insights on source characterization and SOA formation will improve regional pollution control policies, fuel regulations, and methodologies for future measurement, laboratory, and modeling studies.

Caenorhabditis elegans: nature and nurture gift to nematode parasitologists.

PubMed

Salinas, Gustavo; Risi, Gastón

2017-12-06

The free-living nematode Caenorhabditis elegans is the simplest animal model organism to work with. Substantial knowledge and tools have accumulated over 50 years of C. elegans research. The use of C. elegans relating to parasitic nematodes from a basic biology standpoint or an applied perspective has increased in recent years. The wealth of information gained on the model organism, the use of the powerful approaches and technologies that have advanced C. elegans research to parasitic nematodes and the enormous success of the omics fields have contributed to bridge the divide between C. elegans and parasite nematode researchers. We review key fields, such as genomics, drug discovery and genetics, where C. elegans and nematode parasite research have convened. We advocate the use of C. elegans as a model to study helminth metabolism, a neglected area ready to advance. How emerging technologies being used in C. elegans can pave the way for parasitic nematode research is discussed.

MOlecular MAterials Property Prediction Package (MOMAP) 1.0: a software package for predicting the luminescent properties and mobility of organic functional materials

NASA Astrophysics Data System (ADS)

Niu, Yingli; Li, Wenqiang; Peng, Qian; Geng, Hua; Yi, Yuanping; Wang, Linjun; Nan, Guangjun; Wang, Dong; Shuai, Zhigang

2018-04-01

MOlecular MAterials Property Prediction Package (MOMAP) is a software toolkit for molecular materials property prediction. It focuses on luminescent properties and charge mobility properties. This article contains a brief descriptive introduction of key features, theoretical models and algorithms of the software, together with examples that illustrate the performance. First, we present the theoretical models and algorithms for molecular luminescent properties calculation, which includes the excited-state radiative/non-radiative decay rate constant and the optical spectra. Then, a multi-scale simulation approach and its algorithm for the molecular charge mobility are described. This approach is based on hopping model and combines with Kinetic Monte Carlo and molecular dynamics simulations, and it is especially applicable for describing a large category of organic semiconductors, whose inter-molecular electronic coupling is much smaller than intra-molecular charge reorganisation energy.

St. Michael's Improvement Program - A Collaborative Approach to Sustainable Cost Savings.

PubMed

Trafford, Anne; Jane, Danielle

2017-01-01

In response to a challenging financial environment and increasing patient demand, St. Michael's Hospital needed to find long-term sustainable solutions to continue to provide high-quality patient care and invest in key priorities. By conducting Operational Reviews in focused areas, the hospital achieved $7.4 million of in-year savings in the first year, found standardizations, process efficiencies and direct cost savings that positioned itself for success in future funding models. Initiatives were grounded in evidence and relied heavily on the effective execution by the leadership, front-line staff and physicians. As organizations face similar challenges, this journey can provide key learnings.

Process maturity progress at Motorola Cellular Systems Division

NASA Technical Reports Server (NTRS)

Borgstahl, Ron; Criscione, Mark; Dobson, Kim; Willey, Allan

1994-01-01

We believe that the key success elements are related to our recognition that Software Process Improvement (SPI) can and should be organized, planned, managed, and measured as if it were a project to develop a new process, analogous to a software product. We believe that our process improvements have come as the result of these key elements: use of a rigorous, detailed requirements set (Capability Maturity Model, CMM); use of a robust, yet flexible architecture (IEEE 1074); use of a SPI project, resourced and managed like other work, to produce the specifications and implement them; and development of both internal and external goals, with metrics to support them.

Proposed Core Competencies and Empirical Validation Procedure in Competency Modeling: Confirmation and Classification.

PubMed

Baczyńska, Anna K; Rowiński, Tomasz; Cybis, Natalia

2016-01-01

Competency models provide insight into key skills which are common to many positions in an organization. Moreover, there is a range of competencies that is used by many companies. Researchers have developed core competency terminology to underline their cross-organizational value. The article presents a theoretical model of core competencies consisting of two main higher-order competencies called performance and entrepreneurship. Each of them consists of three elements: the performance competency includes cooperation, organization of work and goal orientation, while entrepreneurship includes innovativeness, calculated risk-taking and pro-activeness. However, there is lack of empirical validation of competency concepts in organizations and this would seem crucial for obtaining reliable results from organizational research. We propose a two-step empirical validation procedure: (1) confirmation factor analysis, and (2) classification of employees. The sample consisted of 636 respondents (M = 44.5; SD = 15.1). Participants were administered a questionnaire developed for the study purpose. The reliability, measured by Cronbach's alpha, ranged from 0.60 to 0.83 for six scales. Next, we tested the model using a confirmatory factor analysis. The two separate, single models of performance and entrepreneurial orientations fit quite well to the data, while a complex model based on the two single concepts needs further research. In the classification of employees based on the two higher order competencies we obtained four main groups of employees. Their profiles relate to those found in the literature, including so-called niche finders and top performers. Some proposal for organizations is discussed.

Mouse Models of Neurodevelopmental Disease of the Basal Ganglia and Associated Circuits

PubMed Central

Pappas, Samuel S.; Leventhal, Daniel K.; Albin, Roger L.; Dauer, William T.

2014-01-01

This chapter focuses on neurodevelopmental diseases that are tightly linked to abnormal function of the striatum and connected structures. We begin with an overview of three representative diseases in which striatal dysfunction plays a key role—Tourette syndrome and obsessive-compulsive disorder, Rett's syndrome, and primary dystonia. These diseases highlight distinct etiologies that disrupt striatal integrity and function during development, and showcase the varied clinical manifestations of striatal dysfunction. We then review striatal organization and function, including evidence for striatal roles in online motor control/action selection, reinforcement learning, habit formation, and action sequencing. A key barrier to progress has been the relative lack of animal models of these diseases, though recently there has been considerable progress. We review these efforts, including their relative merits providing insight into disease pathogenesis, disease symptomatology, and basal ganglia function. PMID:24947237

Fungal model systems and the elucidation of pathogenicity determinants

PubMed Central

Perez-Nadales, Elena; Almeida Nogueira, Maria Filomena; Baldin, Clara; Castanheira, Sónia; El Ghalid, Mennat; Grund, Elisabeth; Lengeler, Klaus; Marchegiani, Elisabetta; Mehrotra, Pankaj Vinod; Moretti, Marino; Naik, Vikram; Oses-Ruiz, Miriam; Oskarsson, Therese; Schäfer, Katja; Wasserstrom, Lisa; Brakhage, Axel A.; Gow, Neil A.R.; Kahmann, Regine; Lebrun, Marc-Henri; Perez-Martin, José; Di Pietro, Antonio; Talbot, Nicholas J.; Toquin, Valerie; Walther, Andrea; Wendland, Jürgen

2014-01-01

Fungi have the capacity to cause devastating diseases of both plants and animals, causing significant harvest losses that threaten food security and human mycoses with high mortality rates. As a consequence, there is a critical need to promote development of new antifungal drugs, which requires a comprehensive molecular knowledge of fungal pathogenesis. In this review, we critically evaluate current knowledge of seven fungal organisms used as major research models for fungal pathogenesis. These include pathogens of both animals and plants; Ashbya gossypii, Aspergillus fumigatus, Candida albicans, Fusarium oxysporum, Magnaporthe oryzae, Ustilago maydis and Zymoseptoria tritici. We present key insights into the virulence mechanisms deployed by each species and a comparative overview of key insights obtained from genomic analysis. We then consider current trends and future challenges associated with the study of fungal pathogenicity. PMID:25011008

The epicurean fly: using Drosophila melanogaster to study metabolism.

PubMed

Bharucha, Kamal N

2009-02-01

In this review, the utility of Drosophila melanogaster as a model organism for research in metabolism will be demonstrated. Importantly, many metabolic pathways are conserved in both man and the fly. Recent work has highlighted that these conserved molecular pathways have the potential to give rise to similar phenotypes. For example, it has proven possible to generate obese and diabetic Drosophila; conversely, genetic manipulation can also generate lean and hypoglycemic phenotypes. From conserved circulating hormones to key enzymes, the fly is host to a variety of homologous, metabolically active signaling mechanisms. The world of Drosophila research has not only a rich history of developing techniques for exquisite genetic manipulation, but also continues to develop genetic methodologies at an exciting rate. Many of these techniques add to the cadre of experimental tools available for the use of the fly as a model organism for studying carbohydrate and lipid homeostasis. This review is written for the pediatric-scientist with little background in Drosophila, with the goal of relaying the potential of this model organism for contributing to a better understanding of diseases affecting today's children.

Self-organized phenomena of pedestrian counterflow through a wide bottleneck in a channel

NASA Astrophysics Data System (ADS)

Dong, Li-Yun; Lan, Dong-Kai; Li, Xiang

2016-09-01

The pedestrian counterflow through a bottleneck in a channel shows a variety of flow patterns due to self-organization. In order to reveal the underlying mechanism, a cellular automaton model was proposed by incorporating the floor field and the view field which reflects the global information of the studied area and local interactions with others. The presented model can well reproduce typical collective behaviors, such as lane formation. Numerical simulations were performed in the case of a wide bottleneck and typical flow patterns at different density ranges were identified as rarefied flow, laminar flow, interrupted bidirectional flow, oscillatory flow, intermittent flow, and choked flow. The effects of several parameters, such as the size of view field and the width of opening, on the bottleneck flow are also analyzed in detail. The view field plays a vital role in reproducing self-organized phenomena of pedestrian. Numerical results showed that the presented model can capture key characteristics of bottleneck flows. Project supported by the National Basic Research Program of China (Grant No. 2012CB725404) and the National Natural Science Foundation of China (Grant Nos. 11172164 and 11572184).

Behavioral Design Teams: The Next Frontier in Clinical Delivery Innovation?

PubMed

Robertson, Ted; Darling, Matthew; Leifer, Jennifer; Footer, Owen; Gordski, Dani

2017-11-01

A deep understanding of human behavior is critical to designing effective health care delivery models, tools, and processes. Currently, however, few mechanisms exist to systematically apply insights about human behavior to improve health outcomes. Behavioral design teams (BDTs) are a successful model for applying behavioral insights within an organization. Already operational within government, this model can be adapted to function in a health care setting. To explore how BDTs could be applied to clinical care delivery and review models for integrating these teams within health care organizations. Interviews with experts in clinical delivery innovation and applied behavioral science, as well as leaders of existing government BDTs. BDTs are most effective when they enjoy top-level executive support, are co-led by a domain expert and behavioral scientist, collaborate closely with key staff and departments, have access to data and IT support, and operate a portfolio of projects. BDTs could be embedded in health care organizations in multiple ways, including in or just below the CEO’s office, within a quality improvement unit, or within an internal innovation center. When running a portfolio, BDTs achieve a greater number and diversity of insights at lower costs. They also become a platform for strategic learning and scaling.

Using GOMS models and hypertext to create representations of medical procedures for online display

NASA Technical Reports Server (NTRS)

Gugerty, Leo; Halgren, Shannon; Gosbee, John; Rudisill, Marianne

1991-01-01

This study investigated two methods to improve organization and presentation of computer-based medical procedures. A literature review suggested that the GOMS (goals, operators, methods, and selecton rules) model can assist in rigorous task analysis, which can then help generate initial design ideas for the human-computer interface. GOMS model are hierarchical in nature, so this study also investigated the effect of hierarchical, hypertext interfaces. We used a 2 x 2 between subjects design, including the following independent variables: procedure organization - GOMS model based vs. medical-textbook based; navigation type - hierarchical vs. linear (booklike). After naive subjects studies the online procedures, measures were taken of their memory for the content and the organization of the procedures. This design was repeated for two medical procedures. For one procedure, subjects who studied GOMS-based and hierarchical procedures remembered more about the procedures than other subjects. The results for the other procedure were less clear. However, data for both procedures showed a 'GOMSification effect'. That is, when asked to do a free recall of a procedure, subjects who had studies a textbook procedure often recalled key information in a location inconsistent with the procedure they actually studied, but consistent with the GOMS-based procedure.

From clinical integration to accountable care.

PubMed

Shields, Mark

2011-01-01

Four key challenges to reforming health care organizations can be addressed by a clinical integration model patterned after Advocate Physician Partners (APP). These challenges are: predominance of small group practices, dominant fee-for-service reimbursement methods, weaknesses of the traditional hospital medical staff structure and a need to partner with commercial insurance companies. APP has demonstrated teamwork between 3800 physicians and hospitals to improve quality, patient safety and cost-effectiveness. Building on this model, an innovative contract with Blue Cross Blue Shield of Illinois serves as a prototype for a commercial Accountable Care Organization. For this contract to succeed, APP must outperform the market competition. To accomplish this, APP has implemented strategies to reduce readmissions, avoid unnecessary admissions and emergency room visits, expand primary care access, and enhance quality and patient safety.

Towards a functional organization of episodic memory in the medial temporal lobe

PubMed Central

Eichenbaum, Howard; Sauvage, Magdalena; Fortin, Norbert; Komorowski, Robert; Lipton, Paul

2011-01-01

Here we describe a model of medial temporal lobe organization in which parallel “what” and “where” processing streams converge within the hippocampus to represent events in the spatio-temporal context in which they occurred; this circuitry also mediates the retrieval of context from event cues and vice versa, which are prototypes of episodic recall. Evidence from studies in animals are reviewed in support of this model, including experiments that distinguish characteristics of episodic recollection from familiarity, neuropsychological and recording studies that have identified a key role for the hippocampus in recollection and in associating events with the context in which they occurred, and distinct roles for parahippocampal region areas in separate “what” and “where” information processing that contributes to recollective and episodic memory. PMID:21810443

Identification of Modules in Protein-Protein Interaction Networks

NASA Astrophysics Data System (ADS)

Erten, Sinan; Koyutürk, Mehmet

In biological systems, most processes are carried out through orchestration of multiple interacting molecules. These interactions are often abstracted using network models. A key feature of cellular networks is their modularity, which contributes significantly to the robustness, as well as adaptability of biological systems. Therefore, modularization of cellular networks is likely to be useful in obtaining insights into the working principles of cellular systems, as well as building tractable models of cellular organization and dynamics. A common, high-throughput source of data on molecular interactions is in the form of physical interactions between proteins, which are organized into protein-protein interaction (PPI) networks. This chapter provides an overview on identification and analysis of functional modules in PPI networks, which has been an active area of research in the last decade.

Transitioning From Volume to Value: A Strategic Approach to Design and Implementation.

PubMed

Randazzo, Geralyn; Brown, Zenobia

2016-01-01

As the health care delivery system migrates toward a model based on value rather than volume, nursing leaders play a key role in assisting in the design and implementation of new models of care to support this transition. This article provides an overview of one organization's approach to evolve in the direction of value while gaining the experience needed to scope and scale cross-continuum assets to meet this growing demand. This article outlines the development and deployment of an organizational structure, information technology integration, clinical implementation strategies, and tools and metrics utilized to evaluate the outcomes of value-based programs. Experience in Bundled Payments for Care Improvement program is highlighted. The outcomes and lessons learned are incorporated for those interested in advancing value-based endeavors in their own organizations.

Evaluation of a Postdischarge Call System Using the Logic Model.

PubMed

Frye, Timothy C; Poe, Terri L; Wilson, Marisa L; Milligan, Gary

2018-02-01

This mixed-method study was conducted to evaluate a postdischarge call program for congestive heart failure patients at a major teaching hospital in the southeastern United States. The program was implemented based on the premise that it would improve patient outcomes and overall quality of life, but it had never been evaluated for effectiveness. The Logic Model was used to evaluate the input of key staff members to determine whether the outputs and results of the program matched the expectations of the organization. Interviews, online surveys, reviews of existing patient outcome data, and reviews of publicly available program marketing materials were used to ascertain current program output. After analyzing both qualitative and quantitative data from the evaluation, recommendations were made to the organization to improve the effectiveness of the program.

Towards a functional organization of episodic memory in the medial temporal lobe.

PubMed

Eichenbaum, Howard; Sauvage, Magdalena; Fortin, Norbert; Komorowski, Robert; Lipton, Paul

2012-08-01

Here we describe a model of medial temporal lobe organization in which parallel "what" and "where" processing streams converge within the hippocampus to represent events in the spatio-temporal context in which they occurred; this circuitry also mediates the retrieval of context from event cues and vice versa, which are prototypes of episodic recall. Evidence from studies in animals are reviewed in support of this model, including experiments that distinguish characteristics of episodic recollection from familiarity, neuropsychological and recording studies that have identified a key role for the hippocampus in recollection and in associating events with the context in which they occurred, and distinct roles for parahippocampal region areas in separate "what" and "where" information processing that contributes to recollective and episodic memory. Copyright © 2011 Elsevier Ltd. All rights reserved.

General practices as emergent research organizations: a qualitative study into organizational development.

PubMed

Macfarlane, Fraser; Shaw, Sara; Greenhalgh, Trisha; Carter, Yvonne H

2005-06-01

An increasing proportion of research in primary care is locally undertaken in designated research practices. Capacity building to support high quality research at these grass roots is urgently needed and is a government priority. There is little previously published research on the process by which GP practices develop as research organizations or on their specific support needs at organizational level. Using in-depth qualitative interviews with 28 key informants in 11 research practices across the UK, we explored their historical accounts of the development of research activity. We analysed the data with reference to contemporary theories of organizational development. Participants identified a number of key events and processes, which allowed us to produce a five-phase model of practice development in relation to research activity (creative energy, concrete planning, transformation/differentiation, consolidation and collaboration). Movement between these phases was not linear or continuous, but showed emergent and adaptive properties in which specific triggers and set-backs were often critical. This developmental model challenges previous categorical taxonomies of research practices. It forms a theory-driven framework for providing appropriate support at the grass roots of primary care research, based on the practice's phase of development and the nature of external triggers and potential setbacks. Our findings have important implications for the strategic development of practice-based research in the UK, and could serve as a model for the wider international community.

Application of Bayesian inference to the study of hierarchical organization in self-organized complex adaptive systems

NASA Astrophysics Data System (ADS)

Knuth, K. H.

2001-05-01

We consider the application of Bayesian inference to the study of self-organized structures in complex adaptive systems. In particular, we examine the distribution of elements, agents, or processes in systems dominated by hierarchical structure. We demonstrate that results obtained by Caianiello [1] on Hierarchical Modular Systems (HMS) can be found by applying Jaynes' Principle of Group Invariance [2] to a few key assumptions about our knowledge of hierarchical organization. Subsequent application of the Principle of Maximum Entropy allows inferences to be made about specific systems. The utility of the Bayesian method is considered by examining both successes and failures of the hierarchical model. We discuss how Caianiello's original statements suffer from the Mind Projection Fallacy [3] and we restate his assumptions thus widening the applicability of the HMS model. The relationship between inference and statistical physics, described by Jaynes [4], is reiterated with the expectation that this realization will aid the field of complex systems research by moving away from often inappropriate direct application of statistical mechanics to a more encompassing inferential methodology.

Application of game-like simulations in the Spanish Transplant National Organization.

PubMed

Borro-Escribano, B; Martínez-Alpuente, I; Blanco, A Del; Torrente, J; Fernández-Manjón, B; Matesanz, R

2013-01-01

Twenty years ago, the Spanish National Transplant Organization (NTO) started a management and organizational system, known as the Spanish Model, that has allowed the NTO to occupy a privileged world position regarding deceased donation rates, which have been 33-35 donors per million population in recent years. One of the key elements of this model is its instructional approach. Two years ago, the NTO started the project "educ@nt" in close collaboration with the e-UCM research group of the University Complutense of Madrid to support and maximize its successful professional training system. As a result, 3 game-like simulations have been developed representing the different procedural steps of the suprahospital level of the transplantation process. These simulations represent the donor and organ evaluation, the allocation of organs applying the corresponding geographic and clinical criteria, and the logistics of transportation. Simulations are based on 10 representative teaching cases that help students become familiar with the most common cases arriving in the NTO. For the 2nd consecutive year, these simulations have been used in different courses around Spain. Copyright © 2013 Elsevier Inc. All rights reserved.

Organic memristive device as key element for neuromorphic networks

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

Erokhin, Victor

Organic memristive device has three important properties allowing to consider it as a key element of neuromorphic systems. First, its electrical properties are somehow similar to those of synapses. Second, it can be easily transferred into an oscillator. Third, organic nature of the devices allow to assemble them into stochastic 3D networks capable to learning and adaptations.

Molecular regulation of the mitosis/meiosis decision in multicellular organisms.

PubMed

Kimble, Judith

2011-08-01

A major step in the journey from germline stem cell to differentiated gamete is the decision to leave the mitotic cell cycle and begin progression through the meiotic cell cycle. Over the past decade, molecular regulators of the mitosis/meiosis decision have been discovered in most of the major model multicellular organisms. Historically, the mitosis/meiosis decision has been closely linked with controls of germline self-renewal and the sperm/egg decision, especially in nematodes and mice. Molecular explanations of those linkages clarify our understanding of this fundamental germ cell decision, and unifying themes have begun to emerge. Although the complete circuitry of the decision is not known in any organism, the recent advances promise to impact key issues in human reproduction and agriculture.

21st Century Cell Culture for 21st Century Toxicology.

PubMed

Pamies, David; Hartung, Thomas

2017-01-17

There is no good science in bad models. Cell culture is especially prone to artifacts. A number of novel cell culture technologies have become more broadly available in the 21st century, which allow overcoming limitations of traditional culture and are more physiologically relevant. These include the use of stem-cell derived human cells, cocultures of different cell types, scaffolds and extracellular matrices, perfusion platforms (such as microfluidics), 3D culture, organ-on-chip technologies, tissue architecture, and organ functionality. The physiological relevance of such models is further enhanced by the measurement of biomarkers (e.g., key events of pathways), organ specific functionality, and more comprehensive assessment cell responses by high-content methods. These approaches are still rarely combined to create microphysiological systems. The complexity of the combination of these technologies can generate results closer to the in vivo situation but increases the number of parameters to control, bringing some new challenges. In fact, we do not argue that all cell culture needs to be that sophisticated. The efforts taken are determined by the purpose of our experiments and tests. If only a very specific molecular target to cell response is of interest, a very simple model, which reflects this, might be much more suited to allow standardization and high-throughput. However, the less defined the end point of interest and cellular response are, the better we should approximate organ- or tissue-like culture conditions to make physiological responses more probable. Besides these technologic advances, important progress in the quality assurance and reporting on cell cultures as well as the validation of cellular test systems brings the utility of cell cultures to a new level. The advancement and broader implementation of Good Cell Culture Practice (GCCP) is key here. In toxicology, this is a major prerequisite for meaningful and reliable results, ultimately supporting risk assessment and product development decisions.

Characterizing and sourcing ambient PM2.5 over key emission regions in China II: Organic molecular markers and CMB modeling

NASA Astrophysics Data System (ADS)

Zhou, Jiabin; Xiong, Ying; Xing, Zhenyu; Deng, Junjun; Du, Ke

2017-08-01

From November 2012 to July 2013, a sampling campaign was completed for comprehensive characterization of PM2.5 over four key emission regions in China: Beijing-Tianjin-Hebei (BTH), Yangzi River Delta (YRD), Pearl River Delta (PRD), and Sichuan Basin (SB). A multi-method approach, adopting different analytical and receptor modeling methods, was employed to determine the relative abundances of region-specific air pollution constituents and contributions of emission sources. This paper is focused on organic molecular marker based source apportionment using chemical mass balance (CMB) receptor modeling. Analyses of the organic molecular markers revealed that vehicle emission, coal combustion, biomass burning, meat cooking and natural gas combustion were the major contributors to organic carbon (OC) in PM2.5. The vehicle emission dominated the sources contributing to OC in spring at four sampling sites. During wintertime, the coal combustion had highest contribution to OC at BTH site, while the major source contributing to OC at YRD and PRD sites was vehicle emission. In addition, the relative contributions of different emission sources to PM2.5 mass at a specific location site and in a specific season revealed seasonal and spatial variations across all four sampling locations. The largest contributor to PM2.5 mass was secondary sulfate (14-17%) in winter at the four sites. The vehicle emission was found to be the major source (14-21%) for PM2.5 mass at PRD site. The secondary ammonium has minor variation (4-5%) across the sites, confirming the influences of regional emission sources on these sites. The distinct patterns of seasonal and spatial variations of source apportionment observed in this study were consistent with the findings in our previous paper based upon water-soluble ions and carbonaceous fractions. This makes it essential for the local government to make season- and region-specific mitigation strategies for abating PM2.5 pollution in China.

Organics in the atmosphere: From air pollution to biogeochemical cycles and climate (Vilhelm Bjerknes Medal)

NASA Astrophysics Data System (ADS)

Kanakidou, Maria

2016-04-01

Organics are key players in the biosphere-atmosphere-climate interactions. They have also a significant anthropogenic component due to primary emissions or interactions with pollution. The organic pool in the atmosphere is a complex mixture of compounds of variable reactivity and properties, variable content in C, H, O, N and other elements depending on their origin and their history in the atmosphere. Multiphase atmospheric chemistry is known to produce organic acids with high oxygen content, like oxalic acid. This water soluble organic bi-acid is used as indicator for cloud processing and can form complexes with atmospheric Iron, affecting Iron solubility. Organics are also carriers of other nutrients like nitrogen and phosphorus. They also interact with solar radiation and with atmospheric water impacting on climate. In line with this vision for the role of organics in the atmosphere, we present results from a global 3-dimensional chemistry-transport model on the role of gaseous and particulate organics in atmospheric chemistry, accounting for multiphase chemistry and aerosol ageing in the atmosphere as well as nutrients emissions, atmospheric transport and deposition. Historical simulations and projections highlight the human impact on air quality and atmospheric deposition to the oceans. The results are put in the context of climate change. Uncertainties and implications of our findings for biogeochemical and climate modeling are discussed.

"One man's trash is another man's treasure": exploring economic and moral subtexts of the "organ shortage" problem in public views on organ donation.

PubMed

Schicktanz, S; Schweda, M

2009-08-01

The debate over financial incentives and market models for organ procurement represents a key trend in recent bioethics. In this paper, we wish to reassess one of its central premises-the idea of organ shortage. While the problem is often presented as an objective statistical fact that can be taken for granted, we will take a closer look at the underlying framework expressed in the common rhetoric of "scarcity", "shortage" or "unfulfilled demand". On the basis of theoretical considerations as well as a socioempirical examination of public attitudes, we will argue that this rhetoric has an economic subtext that imbues the debate with normative premises that have far-reaching social and ethical consequences and need to be made explicit and discussed.

Academic service partnerships: organizational efficiency and efficacy between organizations.

PubMed

Fetsch, Susan H; DeBasio, Nancy O

2011-01-01

Two leading nursing organizations, the Greater Kansas City Area Collegiate Nurse Educators and the Kansas City Area Nurse Executives, represent the Kansas City metropolitan area nursing programs and area employers. These two organizations have been engaged in collaborative workforce planning and strategy development around key nursing issues for over 25 years. This model of collaboration is unique in that the partnership is between organizations representing 17 nursing programs and 28 hospitals. The collaborative partnership has enhanced organizational efficiency and efficacy between the groups, which has directly benefited the organizational members. Most importantly, it has had a transformative impact on both nursing education and professional practice in the Kansas City metropolitan area. This article describes the evolution of the partnership and the collaborative work that has led to the accomplishment of mutual goals. Copyright © 2011 Elsevier Inc. All rights reserved.

Developing an Enterprise Systems Appropriation Model in the Public Sector: A Case Study of Implementing Payroll System Replacement (PAYSERV) at the New York State Office of the State Comptroller

ERIC Educational Resources Information Center

Kamya, Moses M.

2009-01-01

This dissertation examines an enterprise system appropriation process applying structuration theory and adaptive structuration theory (AST). The key research questions are: (1) what structures emerge from the implementation of enterprise information technology (EIT); (2) how do enterprise technologies and existing organization structures influence…

Characteristics of Information Agencies (Libraries) and Information Agents (Librarians) in Highly Productive Computer Software and Services Companies: The Key to Growth and Survival?

ERIC Educational Resources Information Center

Carroll, Margaret Aby; Chandler, Yvonne J.

This study examines whether an analysis of characteristics of libraries or information centers and librarians in highly productive companies yields operational models and standards that can improve their efficiency and effectiveness and their parent organization's productivity. Data was collected using an e-mail survey instrument sent to 500 large…

Low-cost housing design and provision: A case study of Kenya

NASA Astrophysics Data System (ADS)

Kabo, Felichism W.

Shelter is as basic a human need as food and water. Today, many people in Third World countries live in sub-standard housing, or lack shelter altogether. Prior research addresses either one of two housing dimensions: broader provision processes, or specific aspects of design. This dissertation is an effort at addressing both dimensions, the underlying premise being that their inter-connectedness demands an integrative approach. More specifically, this dissertation is a combined strategy case study of housing design and provision in Kenya, a sub-Saharan African country with serious shelter problems. A majority of Kenya's urban population lives in slums or squatter settlements. This dissertation covers four major areas of housing design and provision in Kenya: building materials, user preferences for building materials and housing designs, interior layouts, and the organizational context of the housing sector. These four areas are theoretically unified by Canter's (1977) model of place. Each of the first three areas (housing design) relates to one or more of the three domains in the model. The fourth area (housing provision) pertains to the model's context and framework. The technical building materials research reveals the feasibility of making low-cost materials (soil-cements) with satisfactory engineering performance. The research in preference for building materials reveals that the two independent variables, soil and mix, have a significant effect on potential users' ratings. The housing preference study reveals that of the four independent variables, design and type had a significant effect on potential users' ratings, while materials and construction method did not have a significant effect. The interior layout studies reveal important associations between spatial configurations and a key space (the kitchen), and between configuration and conceptualizations of living, cooking, and sleeping spaces. The findings from the studies of preferences and interior layouts are then synthesized in the development of a low-cost housing prototype. Lastly, analysis of the organizational context reveals notable links between nominal housing-related responsibilities, and the potential power and influence of key organizations. The potential effects of the spatial context on housing organizations are also explored. Later, the key organizations are restructured to address shortcomings identified at the organizational and sectoral levels.

Genome-enabled Modeling of Microbial Biogeochemistry using a Trait-based Approach. Does Increasing Metabolic Complexity Increase Predictive Capabilities?

NASA Astrophysics Data System (ADS)

King, E.; Karaoz, U.; Molins, S.; Bouskill, N.; Anantharaman, K.; Beller, H. R.; Banfield, J. F.; Steefel, C. I.; Brodie, E.

2015-12-01

The biogeochemical functioning of ecosystems is shaped in part by genomic information stored in the subsurface microbiome. Cultivation-independent approaches allow us to extract this information through reconstruction of thousands of genomes from a microbial community. Analysis of these genomes, in turn, gives an indication of the organisms present and their functional roles. However, metagenomic analyses can currently deliver thousands of different genomes that range in abundance/importance, requiring the identification and assimilation of key physiologies and metabolisms to be represented as traits for successful simulation of subsurface processes. Here we focus on incorporating -omics information into BioCrunch, a genome-informed trait-based model that represents the diversity of microbial functional processes within a reactive transport framework. This approach models the rate of nutrient uptake and the thermodynamics of coupled electron donors and acceptors for a range of microbial metabolisms including heterotrophs and chemolithotrophs. Metabolism of exogenous substrates fuels catabolic and anabolic processes, with the proportion of energy used for cellular maintenance, respiration, biomass development, and enzyme production based upon dynamic intracellular and environmental conditions. This internal resource partitioning represents a trade-off against biomass formation and results in microbial community emergence across a fitness landscape. Biocrunch was used here in simulations that included organisms and metabolic pathways derived from a dataset of ~1200 non-redundant genomes reflecting a microbial community in a floodplain aquifer. Metagenomic data was directly used to parameterize trait values related to growth and to identify trait linkages associated with respiration, fermentation, and key enzymatic functions such as plant polymer degradation. Simulations spanned a range of metabolic complexities and highlight benefits originating from simulations including a larger number of organisms that more appropriately reflect the in situ microbial community.

Multi-scale modeling of the CD8 immune response

NASA Astrophysics Data System (ADS)

Barbarroux, Loic; Michel, Philippe; Adimy, Mostafa; Crauste, Fabien

2016-06-01

During the primary CD8 T-Cell immune response to an intracellular pathogen, CD8 T-Cells undergo exponential proliferation and continuous differentiation, acquiring cytotoxic capabilities to address the infection and memorize the corresponding antigen. After cleaning the organism, the only CD8 T-Cells left are antigen-specific memory cells whose role is to respond stronger and faster in case they are presented this very same antigen again. That is how vaccines work: a small quantity of a weakened pathogen is introduced in the organism to trigger the primary response, generating corresponding memory cells in the process, giving the organism a way to defend himself in case it encounters the same pathogen again. To investigate this process, we propose a non linear, multi-scale mathematical model of the CD8 T-Cells immune response due to vaccination using a maturity structured partial differential equation. At the intracellular scale, the level of expression of key proteins is modeled by a delay differential equation system, which gives the speeds of maturation for each cell. The population of cells is modeled by a maturity structured equation whose speeds are given by the intracellular model. We focus here on building the model, as well as its asymptotic study. Finally, we display numerical simulations showing the model can reproduce the biological dynamics of the cell population for both the primary response and the secondary responses.

Multi-scale modeling of the CD8 immune response

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

Barbarroux, Loic, E-mail: loic.barbarroux@doctorant.ec-lyon.fr; Ecole Centrale de Lyon, 36 avenue Guy de Collongue, 69134 Ecully; Michel, Philippe, E-mail: philippe.michel@ec-lyon.fr

During the primary CD8 T-Cell immune response to an intracellular pathogen, CD8 T-Cells undergo exponential proliferation and continuous differentiation, acquiring cytotoxic capabilities to address the infection and memorize the corresponding antigen. After cleaning the organism, the only CD8 T-Cells left are antigen-specific memory cells whose role is to respond stronger and faster in case they are presented this very same antigen again. That is how vaccines work: a small quantity of a weakened pathogen is introduced in the organism to trigger the primary response, generating corresponding memory cells in the process, giving the organism a way to defend himself inmore » case it encounters the same pathogen again. To investigate this process, we propose a non linear, multi-scale mathematical model of the CD8 T-Cells immune response due to vaccination using a maturity structured partial differential equation. At the intracellular scale, the level of expression of key proteins is modeled by a delay differential equation system, which gives the speeds of maturation for each cell. The population of cells is modeled by a maturity structured equation whose speeds are given by the intracellular model. We focus here on building the model, as well as its asymptotic study. Finally, we display numerical simulations showing the model can reproduce the biological dynamics of the cell population for both the primary response and the secondary responses.« less

Interactions between soil thermal and hydrological dynamics in the response of Alaska ecosystems to fire disturbance

USGS Publications Warehouse

Yi, Shuhua; McGuire, A. David; Harden, Jennifer; Kasischke, Eric; Manies, Kristen L.; Hinzman, Larry; Liljedahl, Anna K.; Randerson, J.; Liu, Heping; Romanovsky, Vladimir E.; Marchenko, Sergey S.; Kim, Yongwon

2009-01-01

Soil temperature and moisture are important factors that control many ecosystem processes. However, interactions between soil thermal and hydrological processes are not adequately understood in cold regions, where the frozen soil, fire disturbance, and soil drainage play important roles in controlling interactions among these processes. These interactions were investigated with a new ecosystem model framework, the dynamic organic soil version of the Terrestrial Ecosystem Model, that incorporates an efficient and stable numerical scheme for simulating soil thermal and hydrological dynamics within soil profiles that contain a live moss horizon, fibrous and amorphous organic horizons, and mineral soil horizons. The performance of the model was evaluated for a tundra burn site that had both preburn and postburn measurements, two black spruce fire chronosequences (representing space-for-time substitutions in well and intermediately drained conditions), and a poorly drained black spruce site. Although space-for-time substitutions present challenges in model-data comparison, the model demonstrates substantial ability in simulating the dynamics of evapotranspiration, soil temperature, active layer depth, soil moisture, and water table depth in response to both climate variability and fire disturbance. Several differences between model simulations and field measurements identified key challenges for evaluating/improving model performance that include (1) proper representation of discrepancies between air temperature and ground surface temperature; (2) minimization of precipitation biases in the driving data sets; (3) improvement of the measurement accuracy of soil moisture in surface organic horizons; and (4) proper specification of organic horizon depth/properties, and soil thermal conductivity.

From conflict to partnership: growing collaboration between police and NGOs in countries with concentrated epidemics among key populations.

PubMed

Thomson, Nicholas; Riley, Diane; Bergenstrom, Anne; Carpenter, Jenae; Zelitchenko, Alex

2016-01-01

Between September 2012 and December 2015, a series of national and regional consultations, aimed at resolving a persistent dynamic of conflict between law enforcement agencies (LEAs) and civil society organizations (CSOs) working on issues of access to HIV services in high-priority countries for people who use drugs have been organized by the HIV/AIDS Section of the United Nations Office on Drugs and Crime, the Joint United Nations Programme on HIV/AIDS, the Law Enforcement and HIV Network (LEAHN) and other international organizations. The aim of these consultations has been to understand, at a national and regional level, the key points of tension between police and CSOs and how to overcome these tensions to enhance access to and uptake of services by key populations, including people who inject drugs, sex workers, men who have sex with men and transgenders. This commentary briefly describes the methods, process, content and key outcomes of these consultations held across diverse number of countries and regions, including Africa, South East Asia, South Asia, Central Asia, Eastern Europe and Latin America. While the context varies, this paper highlights that there are commonalities that drive a persistent dynamic of conflict and therefore also common methods for resolution of conflict and forging partnerships. Both policing and CSOs have key sectoral responsibilities and reform agendas to implement to ensure that as an individual agency they are able to meet their obligations as partners in the HIV response. Using the key outcomes of discussions and recommendations from these consultations and drawing on existing literature, the objective of this paper is to present a preliminary model that roadmaps the critical path from resolution of conflict to partnership between LEAs and CSOs. This paper seeks to highlight that critical resources are required to support ongoing development and harnessing of partnerships between LEAs and CSOs and argues that these resources should not just come from global HIV funding mechanisms but should be part of a more mainstreamed security sector reform agenda that understands the mutual benefits that programming for human rights-based policing reform would have on HIV, development and security.

From conflict to partnership: growing collaboration between police and NGOs in countries with concentrated epidemics among key populations

PubMed Central

Thomson, Nicholas; Riley, Diane; Bergenstrom, Anne; Carpenter, Jenae; Zelitchenko, Alex

2016-01-01

Introduction Between September 2012 and December 2015, a series of national and regional consultations, aimed at resolving a persistent dynamic of conflict between law enforcement agencies (LEAs) and civil society organizations (CSOs) working on issues of access to HIV services in high-priority countries for people who use drugs have been organized by the HIV/AIDS Section of the United Nations Office on Drugs and Crime, the Joint United Nations Programme on HIV/AIDS, the Law Enforcement and HIV Network (LEAHN) and other international organizations. The aim of these consultations has been to understand, at a national and regional level, the key points of tension between police and CSOs and how to overcome these tensions to enhance access to and uptake of services by key populations, including people who inject drugs, sex workers, men who have sex with men and transgenders. This commentary briefly describes the methods, process, content and key outcomes of these consultations held across diverse number of countries and regions, including Africa, South East Asia, South Asia, Central Asia, Eastern Europe and Latin America. Discussion While the context varies, this paper highlights that there are commonalities that drive a persistent dynamic of conflict and therefore also common methods for resolution of conflict and forging partnerships. Both policing and CSOs have key sectoral responsibilities and reform agendas to implement to ensure that as an individual agency they are able to meet their obligations as partners in the HIV response. Using the key outcomes of discussions and recommendations from these consultations and drawing on existing literature, the objective of this paper is to present a preliminary model that roadmaps the critical path from resolution of conflict to partnership between LEAs and CSOs. Conclusions This paper seeks to highlight that critical resources are required to support ongoing development and harnessing of partnerships between LEAs and CSOs and argues that these resources should not just come from global HIV funding mechanisms but should be part of a more mainstreamed security sector reform agenda that understands the mutual benefits that programming for human rights–based policing reform would have on HIV, development and security. PMID:27435718

Regulation mechanisms in mixed and pure culture microbial fermentation.

PubMed

Hoelzle, Robert D; Virdis, Bernardino; Batstone, Damien J

2014-11-01

Mixed-culture fermentation is a key central process to enable next generation biofuels and biocommodity production due to economic and process advantages over application of pure cultures. However, a key limitation to the application of mixed-culture fermentation is predicting culture product response, related to metabolic regulation mechanisms. This is also a limitation in pure culture bacterial fermentation. This review evaluates recent literature in both pure and mixed culture studies with a focus on understanding how regulation and signaling mechanisms interact with metabolic routes and activity. In particular, we focus on how microorganisms balance electron sinking while maximizing catabolic energy generation. Analysis of these mechanisms and their effect on metabolism dynamics is absent in current models of mixed-culture fermentation. This limits process prediction and control, which in turn limits industrial application of mixed-culture fermentation. A key mechanism appears to be the role of internal electron mediating cofactors, and related regulatory signaling. This may determine direction of electrons towards either hydrogen or reduced organics as end-products and may form the basis for future mechanistic models. © 2014 Wiley Periodicals, Inc.

Key-lock colloids in a nematic liquid crystal.

PubMed

Silvestre, Nuno M; Tasinkevych, M

2017-01-01

The Landau-de Gennes free energy is used to study theoretically the effective interaction of spherical "key" and anisotropic "lock" colloidal particles. We assume identical anchoring properties of the surfaces of the key and of the lock particles, and we consider planar degenerate and perpendicular anchoring conditions separately. The lock particle is modeled as a spherical particle with a spherical dimple. When such a particle is introduced into a nematic liquid crystal, it orients its dimple at an oblique angle θ_{eq} with respect to the far field director n_{∞}. This angle depends on the depth of the dimple. Minimization results show that the free energy of a pair of key and lock particles exhibits a global minimum for the configuration when the key particle is facing the dimple of the lock colloidal particle. The preferred orientation ϕ_{eq} of the key-lock composite doublet relative to n_{∞} is robust against thermal fluctuations. The preferred orientation θ_{eq}^{(2)} of the dimple particle in the doublet is different from the isolated situation. This is related to the "direct" interaction of defects accompanying the key particle with the edge of the dimple. We propose that this nematic-amplified key-lock interaction can play an important role in self-organization and clustering of mixtures of colloidal particles with dimple colloids present.

Analyzing the contributions of a government-commissioned research project: a case study.

PubMed

Hegger, Ingrid; Janssen, Susan W J; Keijsers, Jolanda F E M; Schuit, Albertine J; van Oers, Hans A M

2014-02-05

It often remains unclear to investigators how their research contributes to the work of the commissioner. We initiated the 'Risk Model' case study to gain insight into how a Dutch National Institute for Public Health and the Environment (RIVM) project and its knowledge products contribute to the commissioner's work, the commissioner being the Health Care Inspectorate. We aimed to identify the alignment efforts that influenced the research project contributions. Based on the literature, we expected interaction between investigators and key users to be the most determining factor for the contributions of a research project. In this qualitative case study, we analyzed the alignment efforts and contributions in the Risk Model project by means of document analysis and interviews according to the evaluation method Contribution Mapping. Furthermore, a map of the research process was drafted and a feedback session was organized. After the feedback session with stakeholders discussing the findings, we completed the case study report. Both organizations had divergent views on the ownership of the research product and the relationship between RIVM and the Inspectorate, which resulted in different expectations. The RIVM considered the use of the risk models to be problematic, but the inspectors had a positive opinion about its contributions. Investigators, inspectors, and managers were not aware of these remarkably different perceptions. In this research project, we identified six relevant categories of both horizontal alignment efforts (between investigators and key users) as well as vertical alignment efforts (within own organization) that influenced the contributions to the Inspectorate's work. Relevant alignment efforts influencing the contributions of the project became manifest at three levels: the first level directly relates to the project, the second to the organizational environment, and the third to the formal and historical relationship between the organizations. Both external and internal alignments influence the contributions of a research project. Based on the findings, we recommend that research institutes invest in a reflective attitude towards the social aspects of research projects at all levels of the organization and develop alignment strategies to enhance the contributions of research.

Construction and analysis of a modular model of caspase activation in apoptosis

PubMed Central

Harrington, Heather A; Ho, Kenneth L; Ghosh, Samik; Tung, KC

2008-01-01

Background A key physiological mechanism employed by multicellular organisms is apoptosis, or programmed cell death. Apoptosis is triggered by the activation of caspases in response to both extracellular (extrinsic) and intracellular (intrinsic) signals. The extrinsic and intrinsic pathways are characterized by the formation of the death-inducing signaling complex (DISC) and the apoptosome, respectively; both the DISC and the apoptosome are oligomers with complex formation dynamics. Additionally, the extrinsic and intrinsic pathways are coupled through the mitochondrial apoptosis-induced channel via the Bcl-2 family of proteins. Results A model of caspase activation is constructed and analyzed. The apoptosis signaling network is simplified through modularization methodologies and equilibrium abstractions for three functional modules. The mathematical model is composed of a system of ordinary differential equations which is numerically solved. Multiple linear regression analysis investigates the role of each module and reduced models are constructed to identify key contributions of the extrinsic and intrinsic pathways in triggering apoptosis for different cell lines. Conclusion Through linear regression techniques, we identified the feedbacks, dissociation of complexes, and negative regulators as the key components in apoptosis. The analysis and reduced models for our model formulation reveal that the chosen cell lines predominately exhibit strong extrinsic caspase, typical of type I cell, behavior. Furthermore, under the simplified model framework, the selected cells lines exhibit different modes by which caspase activation may occur. Finally the proposed modularized model of apoptosis may generalize behavior for additional cells and tissues, specifically identifying and predicting components responsible for the transition from type I to type II cell behavior. PMID:19077196

Explaining Work Exhaustion From a Coping Theory Perspective: Roles of Techno-Stressors and Technology-Specific Coping Strategies.

PubMed

Gaudioso, Fulvio; Turel, Ofir; Galimberti, Carlo

2015-01-01

The purpose of this study is to theoretically develop and empirically examine a general coping theory model which explicates the indirect effects of key job-related techno-stressors on job exhaustion. Through this study, we show that techno-stress creators are detrimental to employee well-being and should be treated accordingly. Specifically, we first argue that key techno-stress creators on the job, namely techno-invasion and techno-overload, drive unpleasant states such as work-family conflict and distress. Next, we rely on general coping theory and argue that people respond to these states differently, but with both adaptive and maladaptive technology-specific coping strategies. Adaptive coping behaviors are argued to ultimately reduce work exhaustion, and maladaptive coping strategies are argued to increase it. The proposed model was tested and validated with structural equation modeling techniques applied to self-reported data obtained from a sample of 242 employees of a large organization in the United States. Implications for theory and practice are discussed.

Perceived Barriers and Facilitators to Integrating HIV Prevention and Treatment with Cross-Sex Hormone Therapy for Transgender Women in Lima, Peru.

PubMed

Reisner, Sari L; Perez-Brumer, Amaya G; McLean, Sarah A; Lama, Javier R; Silva-Santisteban, Alfonso; Huerta, Leyla; Sanchez, Jorge; Clark, Jesse L; Mimiaga, Matthew J; Mayer, Kenneth H

2017-12-01

Transgender women (TW) represent a vulnerable population at increased risk for HIV infection in Peru. A mixed-methods study with 48 TW and 19 healthcare professionals was conducted between January and February 2015 to explore barriers and facilitators to implementing a model of care that integrates HIV services with gender-affirmative medical care (i.e., hormone therapy) in Lima, Peru. Perceived acceptability of the integrated care model was high among TW and healthcare professionals alike. Barriers included stigma, lack of provider training or Peruvian guidelines regarding optimal TW care, and service delivery obstacles (e.g., legal documents, spatial placement of clinics, hours of operation). The hiring of TW staff was identified as a key facilitator for engagement in health care. Working in partnership with local TW and healthcare provider organizations is critical to overcoming existing barriers to successful implementation of an integrated HIV services and gender-affirmative medical care model for this key population in Peru.

Computing by robust transience: How the fronto-parietal network performs sequential category-based decisions

PubMed Central

Chaisangmongkon, Warasinee; Swaminathan, Sruthi K.; Freedman, David J.; Wang, Xiao-Jing

2017-01-01

Summary Decision making involves dynamic interplay between internal judgements and external perception, which has been investigated in delayed match-to-category (DMC) experiments. Our analysis of neural recordings shows that, during DMC tasks, LIP and PFC neurons demonstrate mixed, time-varying, and heterogeneous selectivity, but previous theoretical work has not established the link between these neural characteristics and population-level computations. We trained a recurrent network model to perform DMC tasks and found that the model can remarkably reproduce key features of neuronal selectivity at the single-neuron and population levels. Analysis of the trained networks elucidates that robust transient trajectories of the neural population are the key driver of sequential categorical decisions. The directions of trajectories are governed by network self-organized connectivity, defining a ‘neural landscape’, consisting of a task-tailored arrangement of slow states and dynamical tunnels. With this model, we can identify functionally-relevant circuit motifs and generalize the framework to solve other categorization tasks. PMID:28334612

The Evolving MCART Multimodal Imaging Core: Establishing a protocol for Computed Tomography and Echocardiography in the Rhesus macaque to perform longitudinal analysis of radiation-induced organ injury

PubMed Central

de Faria, Eduardo B.; Barrow, Kory R.; Ruehle, Bradley T.; Parker, Jordan T.; Swartz, Elisa; Taylor-Howell, Cheryl; Kieta, Kaitlyn M.; Lees, Cynthia J.; Sleeper, Meg M.; Dobbin, Travis; Baron, Adam D.; Mohindra, Pranshu; MacVittie, Thomas J.

2015-01-01

Computed Tomography (CT) and Echocardiography (EC) are two imaging modalities that produce critical longitudinal data that can be analyzed for radiation-induced organ-specific injury to the lung and heart. The Medical Countermeasures Against Radiological Threats (MCART) consortium has a well-established animal model research platform that includes nonhuman primate (NHP) models of the acute radiation syndrome and the delayed effects of acute radiation exposure. These models call for a definition of the latency, incidence, severity, duration, and resolution of different organ-specific radiation-induced subsyndromes. The pulmonary subsyndromes and cardiac effects are a pair of inter-dependent syndromes impacted by exposure to potentially lethal doses of radiation. Establishing a connection between these will reveal important information about their interaction and progression of injury and recovery. Herein, we demonstrate the use of CT and EC data in the rhesus macaque models to define delayed organ injury thereby establishing: a) consistent and reliable methodology to assess radiation-induced damage to the lung and heart, b) an extensive database in normal age-matched NHP for key primary and secondary endpoints, c) identified problematic variables in imaging techniques and proposed solutions to maintain data integrity and d) initiated longitudinal analysis of potentially lethal radiation-induced damage to the lung and heart. PMID:26425907

Organ-on-a-Chip Systems: Microengineering to Biomimic Living Systems.

PubMed

Zheng, Fuyin; Fu, Fanfan; Cheng, Yao; Wang, Chunyan; Zhao, Yuanjin; Gu, Zhongze

2016-05-01

"Organ-on-a-chip" systems integrate microengineering, microfluidic technologies, and biomimetic principles to create key aspects of living organs faithfully, including critical microarchitecture, spatiotemporal cell-cell interactions, and extracellular microenvironments. This creative platform and its multiorgan integration recapitulating organ-level structures and functions can bring unprecedented benefits to a diversity of applications, such as developing human in vitro models for healthy or diseased organs, enabling the investigation of fundamental mechanisms in disease etiology and organogenesis, benefiting drug development in toxicity screening and target discovery, and potentially serving as replacements for animal testing. Recent advances in novel designs and examples for developing organ-on-a-chip platforms are reviewed. The potential for using this emerging technology in understanding human physiology including mechanical, chemical, and electrical signals with precise spatiotemporal controls are discussed. The current challenges and future directions that need to be pursued for these proof-of-concept studies are also be highlighted. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The growth, characterization, and application of highly ordered small molecule semiconducting thin films

NASA Astrophysics Data System (ADS)

Lunt, Richard Royal, III

Organic semiconductors have gained tremendous attention recently as their use in field effect transistors, sensors, solar cells, lasers, and organic light emitting diodes have been demonstrated, offering the potential for low-cost alternatives. Since renewable energy remains one the greatest challenges of the 21st century, the possibility for low-cost and flexible organic photovoltaics is particularly exciting. In the first part of this thesis, we demonstrate a route to the controlled growth of oriented crystalline films through organic vapor-phase deposition (OVPD), in conjunction with organic-inorganic, and organic-organic quasi-epitaxy. This method for producing highly ordered crystalline thin-film heterostructures combines the control of film growth with the electronic properties expected to approach that of organic single crystals, making them potentially useful for high efficiency organic thin-film devices and solar cells. We further demonstrate OVPD as a method for the deposition of large-scale organic electronics with low material waste, a key ability in fulfilling the promise of low-cost organic devices. The second part of this thesis is focused on understanding factors that govern energy (i.e. exciton) transport. The two single most important and fundamental properties of organic semiconductors are the transport of charge and energy. While charge mobility has been extensively studied and convincingly linked to the degree of crystalline order and orientation, the principles governing energy transport, i.e. exciton migration, in this class of materials and the subsequent connection to crystalline properties still remain ambiguous. Therefore, we aim to understand key aspects governing exciton motion in organic materials to better engineer materials, film morphologies, and film architectures for organic electronics with improved performance. To this end, we have developed a new method for measuring exciton diffusion and characterize a range of archetypal organic compounds. We then derive a simple theoretical model that provides insight into the control of exciton migration in organic systems through changes in both crystal orientation (anisotropy) and degree of crystalline order, which is crucial for the management of energy transport in a wide range of important organic electronic devices.

Human effects on ecological connectivity in aquatic ecosystems: Integrating scientific approaches to support management and mitigation.

PubMed

Crook, David A; Lowe, Winsor H; Allendorf, Frederick W; Erős, Tibor; Finn, Debra S; Gillanders, Bronwyn M; Hadwen, Wade L; Harrod, Chris; Hermoso, Virgilio; Jennings, Simon; Kilada, Raouf W; Nagelkerken, Ivan; Hansen, Michael M; Page, Timothy J; Riginos, Cynthia; Fry, Brian; Hughes, Jane M

2015-11-15

Understanding the drivers and implications of anthropogenic disturbance of ecological connectivity is a key concern for the conservation of biodiversity and ecosystem processes. Here, we review human activities that affect the movements and dispersal of aquatic organisms, including damming of rivers, river regulation, habitat loss and alteration, human-assisted dispersal of organisms and climate change. Using a series of case studies, we show that the insight needed to understand the nature and implications of connectivity, and to underpin conservation and management, is best achieved via data synthesis from multiple analytical approaches. We identify four key knowledge requirements for progressing our understanding of the effects of anthropogenic impacts on ecological connectivity: autecology; population structure; movement characteristics; and environmental tolerance/phenotypic plasticity. Structuring empirical research around these four broad data requirements, and using this information to parameterise appropriate models and develop management approaches, will allow for mitigation of the effects of anthropogenic disturbance on ecological connectivity in aquatic ecosystems. Copyright © 2015 Elsevier B.V. All rights reserved.

Experimental platform for intra-uterine needle placement procedures

NASA Astrophysics Data System (ADS)

Madjidi, Yashar; Haidegger, Tamás.; Ptacek, Wolfgang; Berger, Daniel; Kirisits, Christian; Kronreif, Gernot; Fichtinger, Gabor

2013-03-01

A framework has been investigated to enable a variety of comparative studies in the context of needle-based gynaecological brachytherapy. Our aim was to create an anthropomorphic phantom-based platform. The three main elements of the platform are the organ model, needle guide, and needle drive. These have been studied and designed to replicate the close environment of brachytherapy treatment for cervical cancer. Key features were created with the help of collaborating interventional radio-oncologists and the observations made in the operating room. A phantom box, representing the uterus model, has been developed considering available surgical analogies and operational limitations, such as organs at risk. A modular phantom-based platform has been designed and prototyped with the capability of providing various boundary conditions for the target organ. By mimicking the female pelvic floor, this framework has been used to compare a variety of needle insertion techniques and configurations for cervical and uterine interventions. The results showed that the proposed methodology is useful for the investigation of quantifiable experiments in the intraabdominal and pelvic regions.

Whole-mount in situ hybridization in the Rotifer Brachionus plicatilis representing a basal branch of lophotrochozoans

PubMed Central

Boell, Louis A.

2008-01-01

In order to broaden the comparative scope of evolutionary developmental biology and to refine our picture of animal macroevolution, it is necessary to establish new model organisms, especially from previously underrepresented groups, like the Lophotrochozoa. We have established the culture and protocols for molecular developmental biology in the rotifer species Brachionus plicatilis Müller (Rotifera, Monogononta). Rotifers are nonsegmented animals with enigmatic basal position within the lophotrochozoans and marked by several evolutionary novelties like the wheel organ (corona), the median eye, and the nonpaired posterior foot. The expression of Bp-Pax-6 is shown using whole-mount in situ hybridization. The inexpensive easy culture and experimental tractability of Brachionus as well as the range of interesting questions to which it holds the key make it a promising addition to the “zoo” of evo-devo model organisms. Electronic supplementary material The online version of this article (doi:10.1007/s00427-008-0234-z) contains supplementary material, which is available to authorized users. PMID:18594859

Safety climate and culture: Integrating psychological and systems perspectives.

PubMed

Casey, Tristan; Griffin, Mark A; Flatau Harrison, Huw; Neal, Andrew

2017-07-01

Safety climate research has reached a mature stage of development, with a number of meta-analyses demonstrating the link between safety climate and safety outcomes. More recently, there has been interest from systems theorists in integrating the concept of safety culture and to a lesser extent, safety climate into systems-based models of organizational safety. Such models represent a theoretical and practical development of the safety climate concept by positioning climate as part of a dynamic work system in which perceptions of safety act to constrain and shape employee behavior. We propose safety climate and safety culture constitute part of the enabling capitals through which organizations build safety capability. We discuss how organizations can deploy different configurations of enabling capital to exert control over work systems and maintain safe and productive performance. We outline 4 key strategies through which organizations to reconcile the system control problems of promotion versus prevention, and stability versus flexibility. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Unraveling the mechanisms of synapse formation and axon regeneration: the awesome power of C. elegans genetics.

PubMed

Jin, YiShi

2015-11-01

Since Caenorhabditis elegans was chosen as a model organism by Sydney Brenner in 1960's, genetic studies in this organism have been instrumental in discovering the function of genes and in deciphering molecular signaling network. The small size of the organism and the simple nervous system enable the complete reconstruction of the first connectome. The stereotypic developmental program and the anatomical reproducibility of synaptic connections provide a blueprint to dissect the mechanisms underlying synapse formation. Recent technological innovation using laser surgery of single axons and in vivo imaging has also made C. elegans a new model for axon regeneration. Importantly, genes regulating synaptogenesis and axon regeneration are highly conserved in function across animal phyla. This mini-review will summarize the main approaches and the key findings in understanding the mechanisms underlying the development and maintenance of the nervous system. The impact of such findings underscores the awesome power of C. elegans genetics.

The wing and the eye: a parsimonious theory for scaling and growth control?

PubMed

Romanova-Michaelides, Maria; Aguilar-Hidalgo, Daniel; Jülicher, Frank; Gonzalez-Gaitan, Marcos

2015-01-01

How a developing organ grows and patterns to its final shape is an important question in developmental biology. Studies of growth and patterning in the Drosophila wing imaginal disc have identified a key player, the morphogen Decapentaplegic (Dpp). These studies provided insights into our understanding of growth control and scaling: expansion of the Dpp gradient correlated with the growth of the tissue. A recent report on growth of a Drosophila organ other than the wing, the eye imaginal disc, prompts a reconsideration of our models of growth control. Despite striking differences between the two, the Dpp gradient scales with the target tissues of both organs and the growth of both the wing and the eye is controlled by Dpp. The goal of this review is to discuss whether a parsimonious model of scaling and growth control can explain the relationship between the Dpp gradient and growth in these two different developmental systems. © 2015 Wiley Periodicals, Inc.

A New Model for Self-organized Dynamics and Its Flocking Behavior

NASA Astrophysics Data System (ADS)

Motsch, Sebastien; Tadmor, Eitan

2011-09-01

We introduce a model for self-organized dynamics which, we argue, addresses several drawbacks of the celebrated Cucker-Smale (C-S) model. The proposed model does not only take into account the distance between agents, but instead, the influence between agents is scaled in term of their relative distance. Consequently, our model does not involve any explicit dependence on the number of agents; only their geometry in phase space is taken into account. The use of relative distances destroys the symmetry property of the original C-S model, which was the key for the various recent studies of C-S flocking behavior. To this end, we introduce here a new framework to analyze the phenomenon of flocking for a rather general class of dynamical systems, which covers systems with non-symmetric influence matrices. In particular, we analyze the flocking behavior of the proposed model as well as other strongly asymmetric models with "leaders". The methodology presented in this paper, based on the notion of active sets, carries over from the particle to kinetic and hydrodynamic descriptions. In particular, we discuss the hydrodynamic formulation of our proposed model, and prove its unconditional flocking for slowly decaying influence functions.

Physiologically Based Pharmacokinetic Modeling of Therapeutic Proteins.

PubMed

Wong, Harvey; Chow, Timothy W

2017-09-01

Biologics or therapeutic proteins are becoming increasingly important as treatments for disease. The most common class of biologics are monoclonal antibodies (mAbs). Recently, there has been an increase in the use of physiologically based pharmacokinetic (PBPK) modeling in the pharmaceutical industry in drug development. We review PBPK models for therapeutic proteins with an emphasis on mAbs. Due to their size and similarity to endogenous antibodies, there are distinct differences between PBPK models for small molecules and mAbs. The high-level organization of a typical mAb PBPK model consists of a whole-body PBPK model with organ compartments interconnected by both blood and lymph flows. The whole-body PBPK model is coupled with tissue-level submodels used to describe key mechanisms governing mAb disposition including tissue efflux via the lymphatic system, elimination by catabolism, protection from catabolism binding to the neonatal Fc (FcRn) receptor, and nonlinear binding to specific pharmacological targets of interest. The use of PBPK modeling in the development of therapeutic proteins is still in its infancy. Further application of PBPK modeling for therapeutic proteins will help to define its developing role in drug discovery and development. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Identification of key micro-organisms involved in Douchi fermentation by statistical analysis and their use in an experimental fermentation.

PubMed

Chen, C; Xiang, J Y; Hu, W; Xie, Y B; Wang, T J; Cui, J W; Xu, Y; Liu, Z; Xiang, H; Xie, Q

2015-11-01

To screen and identify safe micro-organisms used during Douchi fermentation, and verify the feasibility of producing high-quality Douchi using these identified micro-organisms. PCR-denaturing gradient gel electrophoresis (DGGE) and automatic amino-acid analyser were used to investigate the microbial diversity and free amino acids (FAAs) content of 10 commercial Douchi samples. The correlations between microbial communities and FAAs were analysed by statistical analysis. Ten strains with significant positive correlation were identified. Then an experiment on Douchi fermentation by identified strains was carried out, and the nutritional composition in Douchi was analysed. Results showed that FAAs and relative content of isoflavone aglycones in verification Douchi samples were generally higher than those in commercial Douchi samples. Our study indicated that fungi, yeasts, Bacillus and lactic acid bacteria were the key players in Douchi fermentation, and with identified probiotic micro-organisms participating in fermentation, a higher quality Douchi product was produced. This is the first report to analyse and confirm the key micro-organisms during Douchi fermentation by statistical analysis. This work proves fermentation micro-organisms to be the key influencing factor of Douchi quality, and demonstrates the feasibility of fermenting Douchi using identified starter micro-organisms. © 2015 The Society for Applied Microbiology.

Dairy calf management-A comparison of practices and producer attitudes among conventional and organic herds.

PubMed

Pempek, J A; Schuenemann, G M; Holder, E; Habing, G G

2017-10-01

Dairy calves are at high risk for morbidity and mortality early in life. Understanding producer attitudes is important for implementation of best management practices to improve calf health. The objectives of this study were to evaluate usage frequency and producer attitudes on key calf management practices between conventional and organic dairy operations. A cross-sectional survey was mailed to conventional and organic dairy producers in Ohio and Michigan that included questions on cow-calf separation, colostrum management, and vaccination use. The overall survey response rate was 49% (727/1,488); 449 and 172 conventional and organic producer respondents, respectively, were included in the final analysis. Binary, cumulative, and multinomial logistic regression models were used to test differences within and between herd types for management practices and producer attitudes. The majority of conventional (64%, 279/439) producers reported separating the calf from the dam 30 min to 6 h after birth. More organic (34%, 56/166) than conventional (18%, 80/439) producers reported separation 6 to 12 h after birth, and organic producers were more likely to agree time before separation is beneficial. Few conventional (10%, 44/448) and organic (3%, 5/171) producers reported measuring colostrum quality. Most conventional producers (68%, 304/448) hand-fed the first feeding of colostrum, whereas the majority of organic producers (38%, 69/171) allowed calves to nurse colostrum. Last, 44% (188/430) of conventional producers reported vaccinating their calves for respiratory disease, compared with 14% (22/162) of organic producers; organic producers were more likely to perceive vaccines as ineffective and harmful to calf health. Thus, the usage frequency and perceived risks and benefits of calf management practices vary considerably between conventional and organic dairy producers. These findings provide helpful information to understand decision making at the herd level regarding key calf management and health practices, regardless of production systems. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Stochasticity and organization of tropical convection: Role of stratiform heating in the simulation of MJO in an aquaplanet coarse resolution GCM using a stochastic multicloud parameterization

NASA Astrophysics Data System (ADS)

Khouider, B.; Majda, A.; Deng, Q.; Ravindran, A. M.

2015-12-01

Global climate models (GCMs) are large computer codes based on the discretization of the equations of atmospheric and oceanic motions coupled to various processes of transfer of heat, moisture and other constituents between land, atmosphere, and oceans. Because of computing power limitations, typical GCM grid resolution is on the order of 100 km and the effects of many physical processes, occurring on smaller scales, on the climate system are represented through various closure recipes known as parameterizations. The parameterization of convective motions and many processes associated with cumulus clouds such as the exchange of latent heat and cloud radiative forcing are believed to be behind much of uncertainty in GCMs. Based on a lattice particle interacting system, the stochastic multicloud model (SMCM) provide a novel and efficient representation of the unresolved variability in GCMs due to organized tropical convection and the cloud cover. It is widely recognized that stratiform heating contributes significantly to tropical rainfall and to the dynamics of tropical convective systems by inducing a front-to-rear tilt in the heating profile. Stratiform anvils forming in the wake of deep convection play a central role in the dynamics of tropical mesoscale convective systems. Here, aquaplanet simulations with a warm pool like surface forcing, based on a coarse-resolution GCM , of ˜170 km grid mesh, coupled with SMCM, are used to demonstrate the importance of stratiform heating for the organization of convection on planetary and intraseasonal scales. When some key model parameters are set to produce higher stratiform heating fractions, the model produces low-frequency and planetary-scale Madden Julian oscillation (MJO)-like wave disturbances while lower to moderate stratiform heating fractions yield mainly synoptic-scale convectively coupled Kelvin-like waves. Rooted from the stratiform instability, it is conjectured here that the strength and extent of stratiform downdrafts are key contributors to the scale selection of convective organizations perhaps with mechanisms that are in essence similar to those of mesoscale convective systems.

Policy model for space economy infrastructure

NASA Astrophysics Data System (ADS)

Komerath, Narayanan; Nally, James; Zilin Tang, Elizabeth

2007-12-01

Extraterrestrial infrastructure is key to the development of a space economy. Means for accelerating transition from today's isolated projects to a broad-based economy are considered. A large system integration approach is proposed. The beginnings of an economic simulation model are presented, along with examples of how interactions and coordination bring down costs. A global organization focused on space infrastructure and economic expansion is proposed to plan, coordinate, fund and implement infrastructure construction. This entity also opens a way to raise low-cost capital and solve the legal and public policy issues of access to extraterrestrial resources.

Bayesian Decision Support

NASA Astrophysics Data System (ADS)

Berliner, M.

2017-12-01

Bayesian statistical decision theory offers a natural framework for decision-policy making in the presence of uncertainty. Key advantages of the approach include efficient incorporation of information and observations. However, in complicated settings it is very difficult, perhaps essentially impossible, to formalize the mathematical inputs needed in the approach. Nevertheless, using the approach as a template is useful for decision support; that is, organizing and communicating our analyses. Bayesian hierarchical modeling is valuable in quantifying and managing uncertainty such cases. I review some aspects of the idea emphasizing statistical model development and use in the context of sea-level rise.

Interorganizational Systems Adoption: A Socio-Technical Perspective

NASA Astrophysics Data System (ADS)

Bunker, Deborah; Kautz, Karlheinz; Pyne, Clayton

This paper discusses a case study of an electronic data interchange (EDI) interorganizational system (IOS) adoption project between two organizations (ProvideCo and BuildCo) highlighting that IOS adoption is not only technological in nature and orientation but that organizational factors also play their part. As a result of the case analysis and key findings, an interorganizational collaboration model (Barratt 2004) is amended to explain and highlight the effect of organizational factors on IOS adoption. The amended model includes the relationship of technology (IOS) adoption to cross-functional collaborative activities and risk, power, opportunism, and trust.

Comparative endocrinology in the 21st century

USGS Publications Warehouse

Denver, R.J.; Hopkins, P.M.; McCormick, S.D.; Propper, C.R.; Riddiford, L.; Sower, S.A.; Wingfield, J.C.

2009-01-01

Hormones coordinate developmental, physiological, and behavioral processes within and between all living organisms. They orchestrate and shape organogenesis from early in development, regulate the acquisition, assimilation, and utilization of nutrients to support growth and metabolism, control gamete production and sexual behavior, mediate organismal responses to environmental change, and allow for communication of information between organisms. Genes that code for hormones; the enzymes that synthesize, metabolize, and transport hormones; and hormone receptors are important targets for natural selection, and variation in their expression and function is a major driving force for the evolution of morphology and life history. Hormones coordinate physiology and behavior of populations of organisms, and thus play key roles in determining the structure of populations, communities, and ecosystems. The field of endocrinology is concerned with the study of hormones and their actions. This field is rooted in the comparative study of hormones in diverse species, which has provided the foundation for the modern fields of evolutionary, environmental, and biomedical endocrinology. Comparative endocrinologists work at the cutting edge of the life sciences. They identify new hormones, hormone receptors and mechanisms of hormone action applicable to diverse species, including humans; study the impact of habitat destruction, pollution, and climatic change on populations of organisms; establish novel model systems for studying hormones and their functions; and develop new genetic strains and husbandry practices for efficient production of animal protein. While the model system approach has dominated biomedical research in recent years, and has provided extraordinary insight into many basic cellular and molecular processes, this approach is limited to investigating a small minority of organisms. Animals exhibit tremendous diversity in form and function, life-history strategies, and responses to the environment. A major challenge for life scientists in the 21st century is to understand how a changing environment impacts all life on earth. A full understanding of the capabilities of organisms to respond to environmental variation, and the resilience of organisms challenged by environmental changes and extremes, is necessary for understanding the impact of pollution and climatic change on the viability of populations. Comparative endocrinologists have a key role to play in these efforts.

Self-Organization Processes at the Intracellular Level

NASA Astrophysics Data System (ADS)

Ponce Dawson, Silvina

2003-03-01

In spite of their relatively small sizes, cells are incredibly complex objects in which various sorts of self-organizing processes occur. Cell division is an example of a process that nearly all cells undergo in which a concerted sequence of events takes place. What are the signals that tell the cell to move along this sequence? Clearly, this is a self-organized process. Microtubules (long polymers that are part of the cytoskeleton) and calcium signals play a major role during cell division. In this course we will focus on some features of microtubule dynamics and calcium signals that are amenable to modeling. In both of these biological systems, behaviors at a single molecule level are key determinants of the self-organized dynamics that is observed at larger scales. Thus, the modeling of these systems presents interesting challenges which require novel strategies. Their study may not only provide answers for biologically motivated questions, but is also a natural setting in which the transition between particle-like and mean-field models can be explored. In this course we will first give a brief biological introduction on the structure of eukaryotic cells, microtubule dynamics and intracellular calcium signals. We will then describe some of the models that have been presented in the literature and discuss the spatio-temporal dynamics that they predict, comparing them with observed behaviors in vitro or in vivo. We will end with a discussion on the virtues and limitations of the various modeling strategies described.

Testing the Nanoparticle-Allostatic Cross Adaptation-Sensitization Model for Homeopathic Remedy Effects

PubMed Central

Bell, Iris R.; Koithan, Mary; Brooks, Audrey J.

2012-01-01

Key concepts of the Nanoparticle-Allostatic Cross-Adaptation-Sensitization (NPCAS) Model for the action of homeopathic remedies in living systems include source nanoparticles as low level environmental stressors, heterotypic hormesis, cross-adaptation, allostasis (stress response network), time-dependent sensitization with endogenous amplification and bidirectional change, and self-organizing complex adaptive systems. The model accommodates the requirement for measurable physical agents in the remedy (source nanoparticles and/or source adsorbed to silica nanoparticles). Hormetic adaptive responses in the organism, triggered by nanoparticles; bipolar, metaplastic change, dependent on the history of the organism. Clinical matching of the patient’s symptom picture, including modalities, to the symptom pattern that the source material can cause (cross-adaptation and cross-sensitization). Evidence for nanoparticle-related quantum macro-entanglement in homeopathic pathogenetic trials. This paper examines research implications of the model, discussing the following hypotheses: Variability in nanoparticle size, morphology, and aggregation affects remedy properties and reproducibility of findings. Homeopathic remedies modulate adaptive allostatic responses, with multiple dynamic short- and long-term effects. Simillimum remedy nanoparticles, as novel mild stressors corresponding to the organism’s dysfunction initiate time-dependent cross-sensitization, reversing the direction of dysfunctional reactivity to environmental stressors. The NPCAS model suggests a way forward for systematic research on homeopathy. The central proposition is that homeopathic treatment is a form of nanomedicine acting by modulation of endogenous adaptation and metaplastic amplification processes in the organism to enhance long-term systemic resilience and health. PMID:23290882

How desert varnish forms?

NASA Astrophysics Data System (ADS)

Perry, Randall S.; Kolb, Vera M.; Lynne, Bridget Y.; Sephton, Mark A.; Mcloughlin, Nicola; Engel, Michael H.; Olendzenski, Lorraine; Brasier, Martin; Staley, James T., Jr.

2005-09-01

Desert varnish is a black, manganese-rich rock coating that is widespread on Earth. The mechanism underlying its formation, however, has remained unresolved. We present here new data and an associated model for how desert varnish forms, which substantively challenges previously accepted models. We tested both inorganic processes (e.g. clays and oxides cementing coatings) and microbial methods of formation. Techniques used in this preliminary study include SEM-EDAX with backscatter, HRTEM of focused ion beam prepared (FIB) wafers and several other methods including XRPD, Raman spectroscopy, XPS and Tof-SIMS. The only hypothesis capable of explaining a high water content, the presence of organic compounds, an amorphous silica phase (opal-A) and lesser quantities of clays than previously reported, is a mechanism involving the mobilization and redistribution of silica. The discovery of silica in desert varnish suggests labile organics are preserved by interaction with condensing silicic acid. Organisms are not needed for desert varnish formation but Bacteria, Archaea, Eukarya, and other organic compounds are passively incorporated and preserved as organominerals. The rock coatings thus provide useful records of past environments on Earth and possibly other planets. Additionally this model also helps to explain the origin of key varnish and rock glaze features, including their hardness, the nature of the "glue" that binds heterogeneous components together, its layered botryoidal morphology, and its slow rate of formation.

Understanding Care Integration from the Ground Up: Five Organizing Constructs that Shape Integrated Practices.

PubMed

Cohen, Deborah J; Balasubramanian, Bijal A; Davis, Melinda; Hall, Jennifer; Gunn, Rose; Stange, Kurt C; Green, Larry A; Miller, William L; Crabtree, Benjamin F; England, Mary Jane; Clark, Khaya; Miller, Benjamin F

2015-01-01

To provide empirical evidence on key organizing constructs shaping practical, real-world integration of behavior health and primary care to comprehensively address patients' medical, emotional, and behavioral health needs. In a comparative case study using an immersion-crystallization approach, a multidisciplinary team analyzed data from observations of practice operations, interviews, and surveys of practice members, and implementation diaries. Practices were drawn from 2 studies of practices attempting to integrate behavioral health and primary care: Advancing Care Together, a demonstration project of 11 practices located in Colorado, and the Integration Workforce Study, a study of 8 practices across the United States. We identified 5 key organizing constructs influencing integration of primary care and behavioral health: 1) Integration REACH (the extent to which the integration program was delivered to the identified target population), 2) establishment of continuum of care pathways addressing the location of care across the range of patient's severity of illness, 3) approach to patient transitions: referrals or warm handoffs, 4) location of the integration workforce, and 5) participants' mental model for integration. These constructs intertwine within an organization's historic and social context to produce locally adapted approaches to integrating care. Contextual factors, particularly practice type, influenced whether specialty mental health and substance use services were colocated within an organization. Interaction among 5 organizing constructs and practice context produces diverse expressions of integrated care. These constructs provide a framework for understanding how primary care and behavioral health services can be integrated in routine practice. © Copyright 2015 by the American Board of Family Medicine.

Building groundwater modeling capacity in Mongolia

USGS Publications Warehouse

Valder, Joshua F.; Carter, Janet M.; Anderson, Mark T.; Davis, Kyle W.; Haynes, Michelle A.; Dorjsuren Dechinlhundev,

2016-06-16

Ulaanbaatar, the capital city of Mongolia (fig. 1), is dependent on groundwater for its municipal and industrial water supply. The population of Mongolia is about 3 million people, with about one-half the population residing in or near Ulaanbaatar (World Population Review, 2016). Groundwater is drawn from a network of shallow wells in an alluvial aquifer along the Tuul River. Evidence indicates that current water use may not be sustainable from existing water sources, especially when factoring the projected water demand from a rapidly growing urban population (Ministry of Environment and Green Development, 2013). In response, the Government of Mongolia Ministry of Environment, Green Development, and Tourism (MEGDT) and the Freshwater Institute, Mongolia, requested technical assistance on groundwater modeling through the U.S. Army Corps of Engineers (USACE) to the U.S. Geological Survey (USGS). Scientists from the USGS and USACE provided two workshops in 2015 to Mongolian hydrology experts on basic principles of groundwater modeling using the USGS groundwater modeling program MODFLOW-2005 (Harbaugh, 2005). The purpose of the workshops was to bring together representatives from the Government of Mongolia, local universities, technical experts, and other key stakeholders to build in-country capacity in hydrogeology and groundwater modeling.A preliminary steady-state groundwater-flow model was developed as part of the workshops to demonstrate groundwater modeling techniques to simulate groundwater conditions in alluvial deposits along the Tuul River in the vicinity of Ulaanbaatar. ModelMuse (Winston, 2009) was used as the graphical user interface for MODFLOW for training purposes during the workshops. Basic and advanced groundwater modeling concepts included in the workshops were groundwater principles; estimating hydraulic properties; developing model grids, data sets, and MODFLOW input files; and viewing and evaluating MODFLOW output files. A key to success was developing in-country technical capacity and partnerships with the Mongolian University of Science and Technology; Freshwater Institute, Mongolia, a non-profit organization; United Nations Educational, Scientific and Cultural Organization (UNESCO); the Government of Mongolia; and the USACE.

Organic Nitrate Contribution to New Particle Formation and Growth in Secondary Organic Aerosols from α-Pinene Ozonolysis.

PubMed

Berkemeier, Thomas; Ammann, Markus; Mentel, Thomas F; Pöschl, Ulrich; Shiraiwa, Manabu

2016-06-21

The chemical kinetics of organic nitrate production during new particle formation and growth of secondary organic aerosols (SOA) were investigated using the short-lived radioactive tracer (13)N in flow-reactor studies of α-pinene oxidation with ozone. Direct and quantitative measurements of the nitrogen content indicate that organic nitrates accounted for ∼40% of SOA mass during initial particle formation, decreasing to ∼15% upon particle growth to the accumulation-mode size range (>100 nm). Experiments with OH scavengers and kinetic model results suggest that organic peroxy radicals formed by α-pinene reacting with secondary OH from ozonolysis are key intermediates in the organic nitrate formation process. The direct reaction of α-pinene with NO3 was found to be less important for particle-phase organic nitrate formation. The nitrogen content of SOA particles decreased slightly upon increase of relative humidity up to 80%. The experiments show a tight correlation between organic nitrate content and SOA particle-number concentrations, implying that the condensing organic nitrates are among the extremely low volatility organic compounds (ELVOC) that may play an important role in the nucleation and growth of atmospheric nanoparticles.

Modeling of crude oil biodegradation using two phase partitioning bioreactor.

PubMed

Fakhru'l-Razi, A; Peyda, Mazyar; Ab Karim Ghani, Wan Azlina Wan; Abidin, Zurina Zainal; Zakaria, Mohamad Pauzi; Moeini, Hassan

2014-01-01

In this work, crude oil biodegradation has been optimized in a solid-liquid two phase partitioning bioreactor (TPPB) by applying a response surface methodology based d-optimal design. Three key factors including phase ratio, substrate concentration in solid organic phase, and sodium chloride concentration in aqueous phase were taken as independent variables, while the efficiency of the biodegradation of absorbed crude oil on polymer beads was considered to be the dependent variable. Commercial thermoplastic polyurethane (Desmopan®) was used as the solid phase in the TPPB. The designed experiments were carried out batch wise using a mixed acclimatized bacterial consortium. Optimum combinations of key factors with a statistically significant cubic model were used to maximize biodegradation in the TPPB. The validity of the model was successfully verified by the good agreement between the model-predicted and experimental results. When applying the optimum parameters, gas chromatography-mass spectrometry showed a significant reduction in n-alkanes and low molecular weight polycyclic aromatic hydrocarbons. This consequently highlights the practical applicability of TPPB in crude oil biodegradation. © 2014 American Institute of Chemical Engineers.

Summary of development of 70 MW class model superconducting generator--research and development of superconducting for electric power application

NASA Astrophysics Data System (ADS)

Oishi, Ikuo; Nishijima, Kenichi

2002-03-01

A 70 MW class superconducting model generator was designed, manufactured, and tested from 1988 to 1999 as Phase I, which was Japan's national project on applications of superconducting technologies to electric power apparatuses that was commissioned by NEDO as part of New Sunshine Program of AIST and MITI. Phase II then is now being carried out by almost same organization as Phase I. With the development of the 70 MW class superconducting model generator, technologies for a 200 MW class pilot generator were established. The world's largest output (79 MW), world's longest continuous operation (1500 h), and other sufficient characteristics were achieved on the 70 MW class superconducting model generator, and key technologies of design and manufacture required for the 200 MW class pilot generator were established. This project contributed to progress of R&D of power apparatuses. Super-GM has started the next project (Phase II), which shall develop the key technologies for larger-capacity and more-compact machine and is scheduled from 2000 to 2003. Phase II shall be the first step for commercialization of superconducting generator.

Microfabrication of human organs-on-chips.

PubMed

Huh, Dongeun; Kim, Hyun Jung; Fraser, Jacob P; Shea, Daniel E; Khan, Mohammed; Bahinski, Anthony; Hamilton, Geraldine A; Ingber, Donald E

2013-11-01

'Organs-on-chips' are microengineered biomimetic systems containing microfluidic channels lined by living human cells, which replicate key functional units of living organs to reconstitute integrated human organ-level pathophysiology in vitro. These microdevices can be used to test efficacy and toxicity of drugs and chemicals, and to create in vitro models of human disease. Thus, they potentially represent low-cost alternatives to conventional animal models for pharmaceutical, chemical and environmental applications. Here we describe a protocol for the fabrication, microengineering and operation of these microfluidic organ-on-chip systems. First, microengineering is used to fabricate a multilayered microfluidic device that contains two parallel elastomeric microchannels separated by a thin porous flexible membrane, along with two full-height, hollow vacuum chambers on either side; this requires ∼3.5 d to complete. To create a 'breathing' lung-on-a-chip that mimics the mechanically active alveolar-capillary interface of the living human lung, human alveolar epithelial cells and microvascular endothelial cells are cultured in the microdevice with physiological flow and cyclic suction applied to the side chambers to reproduce rhythmic breathing movements. We describe how this protocol can be easily adapted to develop other human organ chips, such as a gut-on-a-chip lined by human intestinal epithelial cells that experiences peristalsis-like motions and trickling fluid flow. Also, we discuss experimental techniques that can be used to analyze the cells in these organ-on-chip devices.

The evaluation and enhancement of quality, environmental protection and seaport safety by using FAHP

NASA Astrophysics Data System (ADS)

Tadic, Danijela; Aleksic, Aleksandar; Popovic, Pavle; Arsovski, Slavko; Castelli, Ana; Joksimovic, Danijela; Stefanovic, Miladin

2017-02-01

The evaluation and enhancement of business processes in any organization in an uncertain environment presents one of the main requirements of ISO 9000:2008 and has a key effect on competitive advantage and long-term sustainability. The aim of this paper can be defined as the identification and discussion of some of the most important business processes of seaports and the performances of business processes and their key performance indicators (KPIs). The complexity and importance of the treated problem call for analytic methods rather than intuitive decisions. The existing decision variables of the considered problem are described by linguistic expressions which are modelled by triangular fuzzy numbers (TFNs). In this paper, the modified fuzzy extended analytic hierarchy process (FAHP) is proposed. The assessment of the relative importance of each pair of performances and their key performance indicators are stated as a fuzzy group decision-making problem. By using the modified fuzzy extended analytic hierarchy process, the fuzzy rank of business processes of a seaport is obtained. The model is tested through an illustrative example with real-life data, where the obtained data suggest measures which should enhance business strategy and improve key performance indicators. The future improvement is based on benchmark and knowledge sharing.

Leveraging organismal biology to forecast the effects of climate change.

PubMed

Buckley, Lauren B; Cannistra, Anthony F; John, Aji

2018-04-26

Despite the pressing need for accurate forecasts of ecological and evolutionary responses to environmental change, commonly used modelling approaches exhibit mixed performance because they omit many important aspects of how organisms respond to spatially and temporally variable environments. Integrating models based on organismal phenotypes at the physiological, performance and fitness levels can improve model performance. We summarize current limitations of environmental data and models and discuss potential remedies. The paper reviews emerging techniques for sensing environments at fine spatial and temporal scales, accounting for environmental extremes, and capturing how organisms experience the environment. Intertidal mussel data illustrate biologically important aspects of environmental variability. We then discuss key challenges in translating environmental conditions into organismal performance including accounting for the varied timescales of physiological processes, for responses to environmental fluctuations including the onset of stress and other thresholds, and for how environmental sensitivities vary across lifecycles. We call for the creation of phenotypic databases to parameterize forecasting models and advocate for improved sharing of model code and data for model testing. We conclude with challenges in organismal biology that must be solved to improve forecasts over the next decade.acclimation, biophysical models, ecological forecasting, extremes, microclimate, spatial and temporal variability.

Voltage Amplifier Based on Organic Electrochemical Transistor.

PubMed

Braendlein, Marcel; Lonjaret, Thomas; Leleux, Pierre; Badier, Jean-Michel; Malliaras, George G

2017-01-01

Organic electrochemical transistors (OECTs) are receiving a great deal of attention as amplifying transducers for electrophysiology. A key limitation of this type of transistors, however, lies in the fact that their output is a current, while most electrophysiology equipment requires a voltage input. A simple circuit is built and modeled that uses a drain resistor to produce a voltage output. It is shown that operating the OECT in the saturation regime provides increased sensitivity while maintaining a linear signal transduction. It is demonstrated that this circuit provides high quality recordings of the human heart using readily available electrophysiology equipment, paving the way for the use of OECTs in the clinic.

Tools for Detecting Causality in Space Systems

NASA Astrophysics Data System (ADS)

Johnson, J.; Wing, S.

2017-12-01

Complex systems such as the solar and magnetospheric envivonment often exhibit patterns of behavior that suggest underlying organizing principles. Causality is a key organizing principle that is particularly difficult to establish in strongly coupled nonlinear systems, but essential for understanding and modeling the behavior of systems. While traditional methods of time-series analysis can identify linear correlations, they do not adequately quantify the distinction between causal and coincidental dependence. We discuss tools for detecting causality including: granger causality, transfer entropy, conditional redundancy, and convergent cross maps. The tools are illustrated by applications to magnetospheric and solar physics including radiation belt, Dst (a magnetospheric state variable), substorm, and solar cycle dynamics.

Genes, isotopes, and ecosystem biogeochemistry. Dissecting methane flux at the leading edge of global change

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

Saleska, Scott; Rich, Virginia; Tyson, Gene

This project integrates across three fields (microbiology, biogeochemistry, and modeling) to understand the mechanisms of methane cycling in thawing permafrost. We have made substantial progress in each area, and in cross-cutting interdisciplinary synthesis. Large releases of CH 4 from thawing permafrost to the atmosphere, a strong positive feedback to global warming, are plausible but little is known about the controls on such release. Our project (“IsoGenie”) addresses the key question: What is the interplay of microbial communities and soil organic matter composition in the decomposition of organic C to CH 4 across a permafrost thaw gradient?

Examining organic carbon transport by the Orinoco River using SeaWiFS imagery

NASA Astrophysics Data System (ADS)

López, Ramón; Del Castillo, Carlos E.; Miller, Richard L.; Salisbury, Joseph; Wisser, Dominik

2012-09-01

The Orinoco River is the fourth largest in the world in terms of water discharge and organic carbon export to the ocean. River export of organic carbon is a key component of the carbon cycle and the global carbon budget. Here, we examined the seasonal transport of organic carbon by the Orinoco River into the eastern Caribbean using the conservative relationship of colored dissolved organic matter (CDOM) and dissolved organic carbon (DOC) in low salinity coastal waters influenced by river plumes. In situ measurements of CDOM absorption, DOC, and salinity were used to develop an empirical model for DOC concentration at the Orinoco River Plume. Satellite remote sensing reflectances were used with empirical models to determine DOC and Particulate organic carbon (POC) river transport. Our estimates of CDOM and DOC significantly correlated with in situ measurements and were within the expected ranges for the river. Total organic carbon transport by the Orinoco River during the period of 1998 to 2010 was 7.10 ×1012 g C y-1, from 5.29 × 1012 g C y-1 of DOC and 1.81 × 1012 g C y-1 of POC, representing ˜6% increase to previous published estimates. The variability in organic carbon transport responded to the seasonality in river flow more than to changes in organic carbon concentration in the river. Our results corroborate that is possible to estimate organic carbon transport using ocean color data at global scales. This is needed to reduce the uncertainties of land-ocean carbon fluxes.

Barriers to Offering Vasectomy at Publicly Funded Family Planning Organizations in Texas.

PubMed

White, Kari; Campbell, Anthony; Hopkins, Kristine; Grossman, Daniel; Potter, Joseph E

2017-05-01

Few publicly funded family planning clinics in the United States offer vasectomy, but little is known about the reasons this method is not more widely available at these sources of care. Between February 2012 and February 2015, three waves of in-depth interviews were conducted with program administrators at 54 family planning organizations in Texas. Participants described their organization's vasectomy service model and factors that influenced how frequently vasectomy was provided. Interview transcripts were coded and analyzed using a theme-based approach. Service models and barriers to providing vasectomy were compared by organization type (e.g., women's health center, public health clinic) and receipt of Title X funding. Two thirds of organizations did not offer vasectomy on-site or pay for referrals with family planning funding; nine organizations frequently provided vasectomy. Organizations did not widely offer vasectomy because they could not find providers that would accept the low reimbursement for the procedure or because they lacked funding for men's reproductive health care. Respondents often did not perceive men's reproductive health care as a service priority and commented that men, especially Latinos, had limited interest in vasectomy. Although organizations of all types reported barriers, women's health centers and Title X-funded organizations more frequently offered vasectomy by conducting tailored outreach to men and vasectomy providers. A combination of factors operating at the health systems and provider level influence the availability of vasectomy at publicly funded family planning organizations in Texas. Multilevel approaches that address key barriers to vasectomy provision would help organizations offer comprehensive contraceptive services.

Recent advances in understanding secondary organic aerosols: implications for global climate forcing

NASA Astrophysics Data System (ADS)

Shrivastava, Manish

2017-04-01

Anthropogenic emissions and land-use changes have modified atmospheric aerosol concentrations and size distributions over time. Understanding pre-industrial conditions and changes in organic aerosol due to anthropogenic activities is important because these features 1) influence estimates of aerosol radiative forcing and 2) can confound estimates of the historical response of climate to increases in greenhouse gases (e.g. the 'climate sensitivity'). Secondary organic aerosol (SOA), formed in the atmosphere by oxidation of organic gases, often represents a major fraction of global submicron-sized atmospheric organic aerosol. Over the past decade, significant advances in understanding SOA properties and formation mechanisms have occurred through measurements, yet current climate models typically do not comprehensively include all important processes. This presentation is based on a US Department of Energy Atmospheric Systems Research sponsored workshop, which highlighted key SOA processes overlooked in climate models that could greatly affect climate forcing estimates. We will highlight the importance of processes that influence the growth of SOA particles to sizes relevant for clouds and radiative forcing, including: formation of extremely low-volatility organics in the gas-phase; isoprene epoxydiols (IEPOX) multi-phase chemistry; particle-phase oligomerization; and physical properties such as viscosity. We also highlight some of the recently discovered important processes that involve interactions between natural biogenic emissions and anthropogenic emissions such as effects of sulfur and NOx emissions on SOA. We will present examples of integrated model-measurement studies that relate the observed evolution of organic aerosol mass and number with knowledge of particle properties such as volatility and viscosity. We will also highlight the importance of continuing efforts to rank the most influential SOA processes that affect climate forcing, but are often missing in climate models. Ultimately, gas- and particle-phase chemistry processes that capture the dynamic evolution of number and mass concentrations of SOA particles need to be accurately and efficiently represented in regional and global atmospheric chemistry-climate models.

Individual heterogeneity generating explosive system network dynamics.

PubMed

Manrique, Pedro D; Johnson, Neil F

2018-03-01

Individual heterogeneity is a key characteristic of many real-world systems, from organisms to humans. However, its role in determining the system's collective dynamics is not well understood. Here we study how individual heterogeneity impacts the system network dynamics by comparing linking mechanisms that favor similar or dissimilar individuals. We find that this heterogeneity-based evolution drives an unconventional form of explosive network behavior, and it dictates how a polarized population moves toward consensus. Our model shows good agreement with data from both biological and social science domains. We conclude that individual heterogeneity likely plays a key role in the collective development of real-world networks and communities, and it cannot be ignored.

Phylogeny of the Genus Drosophila

PubMed Central

O’Grady, Patrick M.; DeSalle, Rob

2018-01-01

Understanding phylogenetic relationships among taxa is key to designing and implementing comparative analyses. The genus Drosophila, which contains over 1600 species, is one of the most important model systems in the biological sciences. For over a century, one species in this group, Drosophila melanogaster, has been key to studies of animal development and genetics, genome organization and evolution, and human disease. As whole-genome sequencing becomes more cost-effective, there is increasing interest in other members of this morphologically, ecologically, and behaviorally diverse genus. Phylogenetic relationships within Drosophila are complicated, and the goal of this paper is to provide a review of the recent taxonomic changes and phylogenetic relationships in this genus to aid in further comparative studies. PMID:29716983

Architecture and Key Techniques of Augmented Reality Maintenance Guiding System for Civil Aircrafts

NASA Astrophysics Data System (ADS)

hong, Zhou; Wenhua, Lu

2017-01-01

Augmented reality technology is introduced into the maintenance related field for strengthened information in real-world scenarios through integration of virtual assistant maintenance information with real-world scenarios. This can lower the difficulty of maintenance, reduce maintenance errors, and improve the maintenance efficiency and quality of civil aviation crews. Architecture of augmented reality virtual maintenance guiding system is proposed on the basis of introducing the definition of augmented reality and analyzing the characteristics of augmented reality virtual maintenance. Key techniques involved, such as standardization and organization of maintenance data, 3D registration, modeling of maintenance guidance information and virtual maintenance man-machine interaction, are elaborated emphatically, and solutions are given.

Individual heterogeneity generating explosive system network dynamics

NASA Astrophysics Data System (ADS)

Manrique, Pedro D.; Johnson, Neil F.

2018-03-01

Individual heterogeneity is a key characteristic of many real-world systems, from organisms to humans. However, its role in determining the system's collective dynamics is not well understood. Here we study how individual heterogeneity impacts the system network dynamics by comparing linking mechanisms that favor similar or dissimilar individuals. We find that this heterogeneity-based evolution drives an unconventional form of explosive network behavior, and it dictates how a polarized population moves toward consensus. Our model shows good agreement with data from both biological and social science domains. We conclude that individual heterogeneity likely plays a key role in the collective development of real-world networks and communities, and it cannot be ignored.

Integrating Cellular Metabolism into a Multiscale Whole-Body Model

PubMed Central

Krauss, Markus; Schaller, Stephan; Borchers, Steffen; Findeisen, Rolf; Lippert, Jörg; Kuepfer, Lars

2012-01-01

Cellular metabolism continuously processes an enormous range of external compounds into endogenous metabolites and is as such a key element in human physiology. The multifaceted physiological role of the metabolic network fulfilling the catalytic conversions can only be fully understood from a whole-body perspective where the causal interplay of the metabolic states of individual cells, the surrounding tissue and the whole organism are simultaneously considered. We here present an approach relying on dynamic flux balance analysis that allows the integration of metabolic networks at the cellular scale into standardized physiologically-based pharmacokinetic models at the whole-body level. To evaluate our approach we integrated a genome-scale network reconstruction of a human hepatocyte into the liver tissue of a physiologically-based pharmacokinetic model of a human adult. The resulting multiscale model was used to investigate hyperuricemia therapy, ammonia detoxification and paracetamol-induced toxication at a systems level. The specific models simultaneously integrate multiple layers of biological organization and offer mechanistic insights into pathology and medication. The approach presented may in future support a mechanistic understanding in diagnostics and drug development. PMID:23133351

The secondary drying and the fate of organic solvents for spray dried dispersion drug product.

PubMed

Hsieh, Daniel S; Yue, Hongfei; Nicholson, Sarah J; Roberts, Daniel; Schild, Richard; Gamble, John F; Lindrud, Mark

2015-05-01

To understand the mechanisms of secondary drying of spray-dried dispersion (SDD) drug product and establish a model to describe the fate of organic solvents in such a product. The experimental approach includes characterization of the SDD particles, drying studies of SDD using an integrated weighing balance and mass spectrometer, and the subsequent generation of the drying curve. The theoretical approach includes the establishment of a Fickian diffusion model. The kinetics of solvent removal during secondary drying from the lab scale to a bench scale follows Fickian diffusion model. Excellent agreement is obtained between the experimental data and the prediction from the modeling. The diffusion process is dependent upon temperature. The key to a successful scale up of the secondary drying is to control the drying temperature. The fate of primary solvents including methanol and acetone, and their potential impurity such as benzene can be described by the Fickian diffusion model. A mathematical relationship based upon the ratio of diffusion coefficient was established to predict the benzene concentration from the fate of the primary solvent during the secondary drying process.

Organic Crystal Engineering of Thermosetting Cyanate Ester Monomers: Influence of Structure on Melting Point

DTIC Science & Technology

2016-05-27

often discussed in the field of thermosetting materials, crystal engineering1-4 plays a key role in facilitating the successful utilization of these...not to alter the desirable properties of the polymerized networks. Fortunately, the field of crystal engineering provides examples where even very...Chickos and Acree.26 For molecular modeling, methods ranging from atomistic simulations with semi-empirical force fields to density functional

Computational Modeling and Simulation of Developmental ...

EPA Pesticide Factsheets

SYNOPSIS: The question of how tissues and organs are shaped during development is crucial for understanding human birth defects. Data from high-throughput screening assays on human stem cells may be utilized predict developmental toxicity with reasonable accuracy. Other types of models are necessary, however, for mechanism-specific analysis because embryogenesis requires precise timing and control. Agent-based modeling and simulation (ABMS) is an approach to virtually reconstruct these dynamics, cell-by-cell and interaction-by-interaction. Using ABMS, HTS lesions from ToxCast can be integrated with patterning systems heuristically to propagate key events This presentation to FDA-CFSAN will update progress on the applications of in silico modeling tools and approaches for assessing developmental toxicity.

Proposed Core Competencies and Empirical Validation Procedure in Competency Modeling: Confirmation and Classification

PubMed Central

Baczyńska, Anna K.; Rowiński, Tomasz; Cybis, Natalia

2016-01-01

Competency models provide insight into key skills which are common to many positions in an organization. Moreover, there is a range of competencies that is used by many companies. Researchers have developed core competency terminology to underline their cross-organizational value. The article presents a theoretical model of core competencies consisting of two main higher-order competencies called performance and entrepreneurship. Each of them consists of three elements: the performance competency includes cooperation, organization of work and goal orientation, while entrepreneurship includes innovativeness, calculated risk-taking and pro-activeness. However, there is lack of empirical validation of competency concepts in organizations and this would seem crucial for obtaining reliable results from organizational research. We propose a two-step empirical validation procedure: (1) confirmation factor analysis, and (2) classification of employees. The sample consisted of 636 respondents (M = 44.5; SD = 15.1). Participants were administered a questionnaire developed for the study purpose. The reliability, measured by Cronbach’s alpha, ranged from 0.60 to 0.83 for six scales. Next, we tested the model using a confirmatory factor analysis. The two separate, single models of performance and entrepreneurial orientations fit quite well to the data, while a complex model based on the two single concepts needs further research. In the classification of employees based on the two higher order competencies we obtained four main groups of employees. Their profiles relate to those found in the literature, including so-called niche finders and top performers. Some proposal for organizations is discussed. PMID:27014111

Mechanochemical Symmetry Breaking in Hydra Aggregates

PubMed Central

Mercker, Moritz; Köthe, Alexandra; Marciniak-Czochra, Anna

2015-01-01

Tissue morphogenesis comprises the self-organized creation of various patterns and shapes. Although detailed underlying mechanisms are still elusive in many cases, an increasing amount of experimental data suggests that chemical morphogen and mechanical processes are strongly coupled. Here, we develop and test a minimal model of the axis-defining step (i.e., symmetry breaking) in aggregates of the Hydra polyp. Based on previous findings, we combine osmotically driven shape oscillations with tissue mechanics and morphogen dynamics. We show that the model incorporating a simple feedback loop between morphogen patterning and tissue stretch reproduces a wide range of experimental data. Finally, we compare different hypothetical morphogen patterning mechanisms (Turing, tissue-curvature, and self-organized criticality). Our results suggest the experimental investigation of bigger (i.e., multiple head) aggregates as a key step for a deeper understanding of mechanochemical symmetry breaking in Hydra. PMID:25954896

Cultural models of self and social class disparities at organizational gateways and pathways.

PubMed

Townsend, Sarah Sm; Truong, Mindy

2017-12-01

Attaining a college degree has traditionally been assumed to be key to upward social and professional mobility. However, college graduates from working-class backgrounds achieve less career success in professional, white-collar workplaces compared to those from middle-class backgrounds. Using a cultural models approach, we examine how the independent cultural beliefs and practices promoted by professional organizations disadvantage people from working-class backgrounds, who espouse interdependent beliefs and practices. Our review illustrates how this disadvantage can manifest in two ways. First, despite relative equality in objective qualifications, it can occur at organizational gateways (e.g., interview and hiring decisions). Second, even after people from working-class backgrounds gain access to an organization, it can occur along organizational pathways (e.g., performance evaluations and assignment to high-profile tasks). Copyright © 2017. Published by Elsevier Ltd.

Giant plasma membrane vesicles: models for understanding membrane organization.

PubMed

Levental, Kandice R; Levental, Ilya

2015-01-01

The organization of eukaryotic membranes into functional domains continues to fascinate and puzzle cell biologists and biophysicists. The lipid raft hypothesis proposes that collective lipid interactions compartmentalize the membrane into coexisting liquid domains that are central to membrane physiology. This hypothesis has proven controversial because such structures cannot be directly visualized in live cells by light microscopy. The recent observations of liquid-liquid phase separation in biological membranes are an important validation of the raft hypothesis and enable application of the experimental toolbox of membrane physics to a biologically complex phase-separated membrane. This review addresses the role of giant plasma membrane vesicles (GPMVs) in refining the raft hypothesis and expands on the application of GPMVs as an experimental model to answer some of key outstanding problems in membrane biology. Copyright © 2015 Elsevier Inc. All rights reserved.

Cancer models in C. elegans

PubMed Central

Kirienko, Natalia V.; Mani, Kumaran; Fay, David S.

2013-01-01

Although now dogma, the idea that non-vertebrate organisms such as yeast, worms, and flies could inform, and in some cases even revolutionize, our understanding of oncogenesis in humans was not immediately obvious. Aided by the conservative nature of evolution and the persistence of a cohort of devoted researchers, the role of model organisms as a key tool in solving the cancer problem has, however, become widely accepted. In this review, we focus on the nematode Caenorhabditis elegans and its diverse and sometimes surprising contributions to our understanding of the tumorigenic process. Specifically, we discuss findings in the worm that address a well-defined set of processes known to be deregulated in cancer cells including cell cycle progression, growth factor signaling, terminal differentiation, apoptosis, the maintenance of genome stability, and developmental mechanisms relevant to invasion and metastasis. PMID:20175192

The Influence of Leadership in Implementing Management Systems

NASA Astrophysics Data System (ADS)

Nae, Ilie; Solomon, Gheorghe; Severin, Irina

2014-12-01

This paper presents a new perspective of the implementation of Management Systems within organizations in order to increase the success rate. The objective is to analyse how the leadership could influence positively or negatively the implementation, according to the leadership approach chosen. It offers a method to analyse the maturity of the leadership for any organization, based on existing leadership models, completing these models with specificities of a Management System. The Maturity Grid is extended to key elements of the Organizational Leadership: Strategic Planning, Process and Performance. The results expected are to change the current understanding of leadership during a Management System implementation(leadership seen as a principle) to an active leadership, implemented at organizational level. It propose an alternative of the classic management approach, to a Performance Management approach, that integrates naturally the leadership in all processes and methods

Turbulent transport measurements in a model of GT-combustor

NASA Astrophysics Data System (ADS)

Chikishev, L. M.; Gobyzov, O. A.; Sharaborin, D. K.; Lobasov, A. S.; Dulin, V. M.; Markovich, D. M.; Tsatiashvili, V. V.

2016-10-01

To reduce NOx formation modern industrial power gas-turbines utilizes lean premixed combustion of natural gas. The uniform distribution of local fuel/air ratio in the combustion chamber plays one of the key roles in the field of lean combustion to prevent thermo-acoustic pulsations. Present paper reports on simultaneous Particle Image Velocimetry and acetone Planar Laser Induced Fluorescence measurements in a cold model of GT-combustor to investigate mixing processes which are relevant to the organization of lean premixed combustion. Velocity and passive admixture pulsations correlations were measured to verify gradient closer model, which is often used in Reynolds-Averaged Navier-Stokes (RANS) simulation of turbulent mixing.

New Frontiers in Language Evolution and Development.

PubMed

Oller, D Kimbrough; Dale, Rick; Griebel, Ulrike

2016-04-01

This article introduces the Special Issue and its focus on research in language evolution with emphasis on theory as well as computational and robotic modeling. A key theme is based on the growth of evolutionary developmental biology or evo-devo. The Special Issue consists of 13 articles organized in two sections: A) Theoretical foundations and B) Modeling and simulation studies. All the papers are interdisciplinary in nature, encompassing work in biological and linguistic foundations for the study of language evolution as well as a variety of computational and robotic modeling efforts shedding light on how language may be developed and may have evolved. Copyright © 2016 Cognitive Science Society, Inc.

A model for reducing health care employee turnover.

PubMed

Nowak, Paul; Holmes, Gary; Murrow, Jim

2010-01-01

Explaining the rationale as to why employees leave their jobs has led to many different strategies to retain employees. The model presented here seeks to explain why employees choose to stay or to leave their place of employment. The information from the analysis will provide managers with well-tested tools to reduce turnover and to ascertain what employees value from their work environment in order to help the organization to retain those employees. The model identifies key factors that management can utilize to provide barriers to exit and retain professional employees in their health care units. Recommendations are provided that reward loyalty and build barriers to exit.

Nutrition in primary health care: using a Delphi process to design new interdisciplinary services.

PubMed

Brauer, Paula; Dietrich, Linda; Davidson, Bridget

2006-01-01

A modified Delphi process was used to identify key features of interdisciplinary nutrition services, including provider roles and responsibilities for Ontario Family Health Networks (FHNs), a family physician-based type of primary care. Twenty-three representatives from interested professional organizations, including three FHN demonstration sites, completed a modified Delphi process. Participants reviewed evidence from a systematic literature review, a patient survey, a costing analysis, and key informant interview results before undertaking the Delphi process. Statements describing various options for services were developed at an in-person meeting, which was followed by two rounds of e-mail questionnaires. Teleconference discussions were held between rounds. An interdisciplinary model with differing and complementary roles for health care providers emerged from the process. Additional key features addressing screening for nutrition problems, health promotion and disease prevention, team collaboration, planning and evaluation, administrative support, access to care, and medical directives/delegated acts were identified. Under the proposed model, the registered dietitian is the team member responsible for managing all aspects of nutrition services, from needs assessment to program delivery, as well as for supporting all providers' nutrition services. The proposed interdisciplinary nutrition services model merits evaluation of cost, effectiveness, applicability, and sustainability in team-based primary care service settings.

Estimation of design space for an extrusion-spheronization process using response surface methodology and artificial neural network modelling.

PubMed

Sovány, Tamás; Tislér, Zsófia; Kristó, Katalin; Kelemen, András; Regdon, Géza

2016-09-01

The application of the Quality by Design principles is one of the key issues of the recent pharmaceutical developments. In the past decade a lot of knowledge was collected about the practical realization of the concept, but there are still a lot of unanswered questions. The key requirement of the concept is the mathematical description of the effect of the critical factors and their interactions on the critical quality attributes (CQAs) of the product. The process design space (PDS) is usually determined by the use of design of experiment (DoE) based response surface methodologies (RSM), but inaccuracies in the applied polynomial models often resulted in the over/underestimation of the real trends and changes making the calculations uncertain, especially in the edge regions of the PDS. The completion of RSM with artificial neural network (ANN) based models is therefore a commonly used method to reduce the uncertainties. Nevertheless, since the different researches are focusing on the use of a given DoE, there is lack of comparative studies on different experimental layouts. Therefore, the aim of present study was to investigate the effect of the different DoE layouts (2 level full factorial, Central Composite, Box-Behnken, 3 level fractional and 3 level full factorial design) on the model predictability and to compare model sensitivities according to the organization of the experimental data set. It was revealed that the size of the design space could differ more than 40% calculated with different polynomial models, which was associated with a considerable shift in its position when higher level layouts were applied. The shift was more considerable when the calculation was based on RSM. The model predictability was also better with ANN based models. Nevertheless, both modelling methods exhibit considerable sensitivity to the organization of the experimental data set, and the use of design layouts is recommended, where the extreme values factors are more represented. Copyright © 2016 Elsevier B.V. All rights reserved.

Three-Dimensional Genome Organization and Function in Drosophila

PubMed Central

Schwartz, Yuri B.; Cavalli, Giacomo

2017-01-01

Understanding how the metazoan genome is used during development and cell differentiation is one of the major challenges in the postgenomic era. Early studies in Drosophila suggested that three-dimensional (3D) chromosome organization plays important regulatory roles in this process and recent technological advances started to reveal connections at the molecular level. Here we will consider general features of the architectural organization of the Drosophila genome, providing historical perspective and insights from recent work. We will compare the linear and spatial segmentation of the fly genome and focus on the two key regulators of genome architecture: insulator components and Polycomb group proteins. With its unique set of genetic tools and a compact, well annotated genome, Drosophila is poised to remain a model system of choice for rapid progress in understanding principles of genome organization and to serve as a proving ground for development of 3D genome-engineering techniques. PMID:28049701

Groundwater–surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover

PubMed Central

Stegen, James C.; Fredrickson, James K.; Wilkins, Michael J.; Konopka, Allan E.; Nelson, William C.; Arntzen, Evan V.; Chrisler, William B.; Chu, Rosalie K.; Danczak, Robert E.; Fansler, Sarah J.; Kennedy, David W.; Resch, Charles T.; Tfaily, Malak

2016-01-01

Environmental transitions often result in resource mixtures that overcome limitations to microbial metabolism, resulting in biogeochemical hotspots and moments. Riverine systems, where groundwater mixes with surface water (the hyporheic zone), are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. Here, to investigate the coupling among groundwater–surface water mixing, microbial communities and biogeochemistry, we apply ecological theory, aqueous biogeochemistry, DNA sequencing and ultra-high-resolution organic carbon profiling to field samples collected across times and locations representing a broad range of mixing conditions. Our results indicate that groundwater–surface water mixing in the hyporheic zone stimulates heterotrophic respiration, alters organic carbon composition, causes ecological processes to shift from stochastic to deterministic and is associated with elevated abundances of microbial taxa that may degrade a broad suite of organic compounds. PMID:27052662

Groundwater-surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover.

PubMed

Stegen, James C; Fredrickson, James K; Wilkins, Michael J; Konopka, Allan E; Nelson, William C; Arntzen, Evan V; Chrisler, William B; Chu, Rosalie K; Danczak, Robert E; Fansler, Sarah J; Kennedy, David W; Resch, Charles T; Tfaily, Malak

2016-04-07

Environmental transitions often result in resource mixtures that overcome limitations to microbial metabolism, resulting in biogeochemical hotspots and moments. Riverine systems, where groundwater mixes with surface water (the hyporheic zone), are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. Here, to investigate the coupling among groundwater-surface water mixing, microbial communities and biogeochemistry, we apply ecological theory, aqueous biogeochemistry, DNA sequencing and ultra-high-resolution organic carbon profiling to field samples collected across times and locations representing a broad range of mixing conditions. Our results indicate that groundwater-surface water mixing in the hyporheic zone stimulates heterotrophic respiration, alters organic carbon composition, causes ecological processes to shift from stochastic to deterministic and is associated with elevated abundances of microbial taxa that may degrade a broad suite of organic compounds.

Optimizing learning in healthcare: how Island Health is evolving to learn at the speed of change.

PubMed

Gottfredson, Conrad; Stroud, Carol; Jackson, Mary; Stevenson, R Lynn; Archer, Jana

2014-01-01

Healthcare organizations are challenged with constrained resources and increasing service demands by an aging population with complex care needs. Exponential growth in competency requirements also challenges staff's ability to provide quality patient care. How can a healthcare organization support its staff to learn "at or above the speed of change" while continuing to provide the quality patient care? Island Health is addressing this challenge by transforming its traditional education model into an innovative, evidence-based learning and performance support approach. Implementation of the methodology is yielding several lessons learned, both for the internal Learning and Performance Support team, and for what it takes to bring a new way of doing business into an organization. A key result is that this approach is enabling the organization to be more responsive in helping staff gain and maintain competencies.

Lingering representations of stimuli influence recall organization

PubMed Central

Chan, Stephanie C.Y.; Applegate, Marissa C.; Morton, Neal W; Polyn, Sean M.; Norman, Kenneth A.

2017-01-01

Several prominent theories posit that information about recent experiences lingers in the brain and organizes memories for current experiences, by forming a temporal context that is linked to those memories at encoding. According to these theories, if the thoughts preceding an experience X resemble the thoughts preceding an experience Y, then X and Y should show an elevated probability of being recalled together. We tested this prediction by using multi-voxel pattern analysis (MVPA) of fMRI data to measure neural evidence for lingering processing of preceding stimuli. As predicted, memories encoded with similar lingering thoughts about the category of preceding stimuli were more likely to be recalled together. Our results demonstrate that the “fading embers” of previous stimuli help to organize recall, confirming a key prediction of computational models of episodic memory. PMID:28132858

A university and health care organization partnership to prepare nurses for evidence-based practice.

PubMed

Missal, Bernita; Schafer, Beth Kaiser; Halm, Margo A; Schaffer, Marjorie A

2010-08-01

This article describes a partnership model between a university and health care organizations for teaching graduate nursing research from a framework of evidence-based practice. Nurses from health care organizations identified topics for graduate students to search the literature and synthesize evidence for guiding nursing practice. Nurse educators mentored graduate students in conducting critical appraisals of the literature. Students learned how to search for the evidence, summarize the existing research findings, and translate the findings into practice recommendations. Through presenting and discussing their findings with key stakeholders, students learned how nurses planned to integrate the evidence into practice. Nurses used the evidence-based results to improve their practice in the two partner hospitals. The partnership stimulated action for further inquiry into best practices.

Household Energy Consumption: Community Context and the Fuelwood Transition*

PubMed Central

Link, Cynthia F.; Axinn, William G.; Ghimire, Dirgha J.

2012-01-01

We examine the influence of community context on change over time in households’ use of non-wood fuels. Our theoretical framework builds on sociological concepts in order to study energy consumption at the micro-level. The framework emphasizes the importance of nonfamily organizations and services in the local community as determinants of the transition from use of fuelwood to use of alternative fuels. We use multilevel longitudinal data on household fuel choice and community context from rural Nepal to provide empirical tests of our theoretical model. Results reveal that increased exposure to nonfamily organizations in the local community increases the use of alternative fuels. The findings illustrate key features of human impacts on the local environment and motivate greater incorporation of social organization into research on environmental change. PMID:23017795

Topological structure dynamics revealing collective evolution in active nematics

PubMed Central

Shi, Xia-qing; Ma, Yu-qiang

2013-01-01

Topological defects frequently emerge in active matter like bacterial colonies, cytoskeleton extracts on substrates, self-propelled granular or colloidal layers and so on, but their dynamical properties and the relations to large-scale organization and fluctuations in these active systems are seldom touched. Here we reveal, through a simple model for active nematics using self-driven hard elliptic rods, that the excitation, annihilation and transportation of topological defects differ markedly from those in non-active media. These dynamical processes exhibit strong irreversibility in active nematics in the absence of detailed balance. Moreover, topological defects are the key factors in organizing large-scale dynamic structures and collective flows, resulting in multi-spatial temporal effects. These findings allow us to control the self-organization of active matter through topological structures. PMID:24346733

Molecular Regulation of the Mitosis/Meiosis Decision in Multicellular Organisms

PubMed Central

Kimble, Judith

2011-01-01

A major step in the journey from germline stem cell to differentiated gamete is the decision to leave the mitotic cell cycle and begin progression through the meiotic cell cycle. Over the past decade, molecular regulators of the mitosis/meiosis decision have been discovered in most of the major model multicellular organisms. Historically, the mitosis/meiosis decision has been closely linked with controls of germline self-renewal and the sperm/egg decision, especially in nematodes and mice. Molecular explanations of those linkages clarify our understanding of this fundamental germ cell decision, and unifying themes have begun to emerge. Although the complete circuitry of the decision is not known in any organism, the recent advances promise to impact key issues in human reproduction and agriculture. PMID:21646377

The effect of long-term changes in plant inputs on soil carbon stocks

NASA Astrophysics Data System (ADS)

Georgiou, K.; Li, Z.; Torn, M. S.

2017-12-01

Soil organic carbon (SOC) is the largest actively-cycling terrestrial reservoir of C and an integral component of thriving natural and managed ecosystems. C input interventions (e.g., litter removal or organic amendments) are common in managed landscapes and present an important decision for maintaining healthy soils in sustainable agriculture and forestry. Furthermore, climate and land-cover change can also affect the amount of plant C inputs that enter the soil through changes in plant productivity, allocation, and rooting depth. Yet, the processes that dictate the response of SOC to such changes in C inputs are poorly understood and inadequately represented in predictive models. Long-term litter manipulations are an invaluable resource for exploring key controls of SOC storage and validating model representations. Here we explore the response of SOC to long-term changes in plant C inputs across a range of biomes and soil types. We synthesize and analyze data from long-term litter manipulation field experiments, and focus our meta-analysis on changes to total SOC stocks, microbial biomass carbon, and mineral-associated (`protected') carbon pools and explore the relative contribution of above- versus below-ground C inputs. Our cross-site data comparison reveals that divergent SOC responses are observed between forest sites, particularly for treatments that increase C inputs to the soil. We explore trends among key variables (e.g., microbial biomass to SOC ratios) that inform soil C model representations. The assembled dataset is an important benchmark for evaluating process-based hypotheses and validating divergent model formulations.

Privacy protection in HealthGrid: distributing encryption management over the VO.

PubMed

Torres, Erik; de Alfonso, Carlos; Blanquer, Ignacio; Hernández, Vicente

2006-01-01

Grid technologies have proven to be very successful in tackling challenging problems in which data access and processing is a bottleneck. Notwithstanding the benefits that Grid technologies could have in Health applications, privacy leakages of current DataGrid technologies due to the sharing of data in VOs and the use of remote resources, compromise its widespreading. Privacy control for Grid technology has become a key requirement for the adoption of Grids in the Healthcare sector. Encrypted storage of confidential data effectively reduces the risk of disclosure. A self-enforcing scheme for encrypted data storage can be achieved by combining Grid security systems with distributed key management and classical cryptography techniques. Virtual Organizations, as the main unit of user management in Grid, can provide a way to organize key sharing, access control lists and secure encryption management. This paper provides programming models and discusses the value, costs and behavior of such a system implemented on top of one of the latest Grid middlewares. This work is partially funded by the Spanish Ministry of Science and Technology in the frame of the project Investigación y Desarrollo de Servicios GRID: Aplicación a Modelos Cliente-Servidor, Colaborativos y de Alta Productividad, with reference TIC2003-01318.

Toughening mechanisms in bioinspired multilayered materials.

PubMed

Askarinejad, Sina; Rahbar, Nima

2015-01-06

Outstanding mechanical properties of biological multilayered materials are strongly influenced by nanoscale features in their structure. In this study, mechanical behaviour and toughening mechanisms of abalone nacre-inspired multilayered materials are explored. In nacre's structure, the organic matrix, pillars and the roughness of the aragonite platelets play important roles in its overall mechanical performance. A micromechanical model for multilayered biological materials is proposed to simulate their mechanical deformation and toughening mechanisms. The fundamental hypothesis of the model is the inclusion of nanoscale pillars with near theoretical strength (σth ~ E/30). It is also assumed that pillars and asperities confine the organic matrix to the proximity of the platelets, and, hence, increase their stiffness, since it has been previously shown that the organic matrix behaves more stiffly in the proximity of mineral platelets. The modelling results are in excellent agreement with the available experimental data for abalone nacre. The results demonstrate that the aragonite platelets, pillars and organic matrix synergistically affect the stiffness of nacre, and the pillars significantly contribute to the mechanical performance of nacre. It is also shown that the roughness induced interactions between the organic matrix and aragonite platelet, represented in the model by asperity elements, play a key role in strength and toughness of abalone nacre. The highly nonlinear behaviour of the proposed multilayered material is the result of distributed deformation in the nacre-like structure due to the existence of nano-asperities and nanopillars with near theoretical strength. Finally, tensile toughness is studied as a function of the components in the microstructure of nacre.

Toughening mechanisms in bioinspired multilayered materials

PubMed Central

Askarinejad, Sina; Rahbar, Nima

2015-01-01

Outstanding mechanical properties of biological multilayered materials are strongly influenced by nanoscale features in their structure. In this study, mechanical behaviour and toughening mechanisms of abalone nacre-inspired multilayered materials are explored. In nacre's structure, the organic matrix, pillars and the roughness of the aragonite platelets play important roles in its overall mechanical performance. A micromechanical model for multilayered biological materials is proposed to simulate their mechanical deformation and toughening mechanisms. The fundamental hypothesis of the model is the inclusion of nanoscale pillars with near theoretical strength (σth ~ E/30). It is also assumed that pillars and asperities confine the organic matrix to the proximity of the platelets, and, hence, increase their stiffness, since it has been previously shown that the organic matrix behaves more stiffly in the proximity of mineral platelets. The modelling results are in excellent agreement with the available experimental data for abalone nacre. The results demonstrate that the aragonite platelets, pillars and organic matrix synergistically affect the stiffness of nacre, and the pillars significantly contribute to the mechanical performance of nacre. It is also shown that the roughness induced interactions between the organic matrix and aragonite platelet, represented in the model by asperity elements, play a key role in strength and toughness of abalone nacre. The highly nonlinear behaviour of the proposed multilayered material is the result of distributed deformation in the nacre-like structure due to the existence of nano-asperities and nanopillars with near theoretical strength. Finally, tensile toughness is studied as a function of the components in the microstructure of nacre. PMID:25551150

Risk factors, sequential organ failure assessment and model for end-stage liver disease scores for predicting short term mortality in cirrhotic patients admitted to intensive care unit.

PubMed

Cholongitas, E; Senzolo, M; Patch, D; Kwong, K; Nikolopoulou, V; Leandro, G; Shaw, S; Burroughs, A K

2006-04-01

Prognostic scores in an intensive care unit (ICU) evaluate outcomes, but derive from cohorts containing few cirrhotic patients. To evaluate 6-week mortality in cirrhotic patients admitted to an ICU, and to compare general and liver-specific prognostic scores. A total of 312 consecutive cirrhotic patients (65% alcoholic; mean age 49.6 years). Multivariable logistic regression to evaluate admission factors associated with survival. Child-Pugh, Model for End-stage Liver Disease (MELD), Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores were compared by receiver operating characteristic curves. Major indication for admission was respiratory failure (35.6%). Median (range) Child-Pugh, APACHE II, MELD and SOFA scores were 11 (5-15), 18 (0-44), 24 (6-40) and 11 (0-21), respectively; 65% (n = 203) died. Survival improved over time (P = 0.005). Multivariate model factors: more organs failing (FOS) (<3 = 49.5%, > or =3 = 90%), higher FiO(2), lactate, urea and bilirubin; resulting in good discrimination [area under receiver operating characteristic curve (AUC) = 0.83], similar to SOFA and MELD (AUC = 0.83 and 0.81, respectively) and superior to APACHE II and Child-Pugh (AUC = 0.78 and 0.72, respectively). Cirrhotics admitted to ICU with > or =3 failing organ systems have 90% mortality. The Royal Free model discriminated well and contained key variables of organ function. SOFA and MELD were better predictors than APACHE II or Child-Pugh scores.

An "age"-structured model of hematopoietic stem cell organization with application to chronic myeloid leukemia.

PubMed

Roeder, Ingo; Herberg, Maria; Horn, Matthias

2009-04-01

Previously, we have modeled hematopoietic stem cell organization by a stochastic, single cell-based approach. Applications to different experimental systems demonstrated that this model consistently explains a broad variety of in vivo and in vitro data. A major advantage of the agent-based model (ABM) is the representation of heterogeneity within the hematopoietic stem cell population. However, this advantage comes at the price of time-consuming simulations if the systems become large. One example in this respect is the modeling of disease and treatment dynamics in patients with chronic myeloid leukemia (CML), where the realistic number of individual cells to be considered exceeds 10(6). To overcome this deficiency, without losing the representation of the inherent heterogeneity of the stem cell population, we here propose to approximate the ABM by a system of partial differential equations (PDEs). The major benefit of such an approach is its independence from the size of the system. Although this mean field approach includes a number of simplifying assumptions compared to the ABM, it retains the key structure of the model including the "age"-structure of stem cells. We show that the PDE model qualitatively and quantitatively reproduces the results of the agent-based approach.

Hot kinetic model as a guide to improve organic photovoltaic materials.

PubMed

Sosorev, Andrey Yu; Godovsky, Dmitry Yu; Paraschuk, Dmitry Yu

2018-01-31

The modeling of organic solar cells (OSCs) can provide a roadmap for their further improvement. Many OSC models have been proposed in recent years; however, the impact of the key intermediates from photons to electricity-hot charge-transfer (CT) states-on the OSC efficiency is highly ambiguous. In this study, we suggest an analytical kinetic model for OSC that considers a two-step charge generation via hot CT states. This hot kinetic model allowed us to evaluate the impact of different material parameters on the OSC performance: the driving force for charge separation, optical bandgap, charge mobility, geminate recombination rate, thermalization rate, average electron-hole separation distance in the CT state, dielectric permittivity, reorganization energy and charge delocalization. In contrast to a widespread trend of lowering the material bandgap, the model predicts that this approach is only efficient along with improvement of the other material properties. The most promising ways to increase the OSC performance are decreasing the reorganization energy, i.e., an energy change accompanying CT from the donor molecule to the acceptor, increasing the dielectric permittivity and charge delocalization. The model suggests that there are no fundamental limitations that can prevent achieving the OSC efficiency above 20%.

The Evolution of Sulfide in Shallow Aquatic Ecosystem Sediments: An Analysis of the Roles of Sulfate, Organic Carbon, and Iron and Feedback Constraints Using Structural Equation Modeling

NASA Astrophysics Data System (ADS)

Pollman, C. D.; Swain, E. B.; Bael, D.; Myrbo, A.; Monson, P.; Shore, M. D.

2017-11-01

The generation of elevated concentrations of sulfide in sediment pore waters that are toxic to rooted macrophytes is problematic in both marine and freshwaters. In marine waters, biogeochemical conditions that lead to toxic levels of sulfide generally relate to factors that affect oxygen dynamics or the sediment iron concentration. In freshwaters, increases in surface water sulfate have been implicated in decline of Zizania palustris (wild rice), which is important in wetlands across the Great Lakes region of North America. We developed a structural equation (SE) model to elucidate key variables that govern the evolution of sulfide in pore waters in shallow aquatic habitats that are potentially capable of supporting wild rice. The conceptual basis for the model is the hypothesis that dissimilatory sulfate reduction is limited by the availability of both sulfate and total organic carbon (TOC) in the sediment. The conceptual model also assumes that pore water sulfide concentrations are constrained by the availability of pore water iron and that sediment iron supports the supply of dissolved iron to the pore water. A key result from the SE model is that variations in three external variables (sulfate, sediment TOC, and sediment iron) contribute nearly equally to the observed variations in pore water sulfide. As a result, management efforts to mitigate against the toxic effects of pore water sulfide on macrophytes such as wild rice should approach defining a protective sulfate threshold as an exercise tailored to the geochemistry of each site that quantitatively considers the effects of ambient concentrations of sediment Fe and TOC.

Environmental impact and risk assessments and key factors contributing to the overall uncertainties.

PubMed

Salbu, Brit

2016-01-01

There is a significant number of nuclear and radiological sources that have contributed, are still contributing, or have the potential to contribute to radioactive contamination of the environment in the future. To protect the environment from radioactive contamination, impact and risk assessments are performed prior to or during a release event, short or long term after deposition or prior and after implementation of countermeasures. When environmental impact and risks are assessed, however, a series of factors will contribute to the overall uncertainties. To provide environmental impact and risk assessments, information on processes, kinetics and a series of input variables is needed. Adding problems such as variability, questionable assumptions, gaps in knowledge, extrapolations and poor conceptual model structures, a series of factors are contributing to large and often unacceptable uncertainties in impact and risk assessments. Information on the source term and the release scenario is an essential starting point in impact and risk models; the source determines activity concentrations and atom ratios of radionuclides released, while the release scenario determine the physico-chemical forms of released radionuclides such as particle size distribution, structure and density. Releases will most often contain other contaminants such as metals, and due to interactions, contaminated sites should be assessed as a multiple stressor scenario. Following deposition, a series of stressors, interactions and processes will influence the ecosystem transfer of radionuclide species and thereby influence biological uptake (toxicokinetics) and responses (toxicodynamics) in exposed organisms. Due to the variety of biological species, extrapolation is frequently needed to fill gaps in knowledge e.g., from effects to no effects, from effects in one organism to others, from one stressor to mixtures. Most toxtests are, however, performed as short term exposure of adult organisms, ignoring sensitive history life stages of organisms and transgenerational effects. To link sources, ecosystem transfer and biological effects to future impact and risks, a series of models are usually interfaced, while uncertainty estimates are seldom given. The model predictions are, however, only valid within the boundaries of the overall uncertainties. Furthermore, the model predictions are only useful and relevant when uncertainties are estimated, communicated and understood. Among key factors contributing most to uncertainties, the present paper focuses especially on structure uncertainties (model bias or discrepancies) as aspects such as particle releases, ecosystem dynamics, mixed exposure, sensitive life history stages and transgenerational effects, are usually ignored in assessment models. Research focus on these aspects should significantly reduce the overall uncertainties in the impact and risk assessment of radioactive contaminated ecosystems. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assessment of the Simulated Molecular Composition with the GECKO-A Modeling Tool Using Chamber Observations for α-Pinene.

NASA Astrophysics Data System (ADS)

Aumont, B.; Camredon, M.; Isaacman-VanWertz, G. A.; Karam, C.; Valorso, R.; Madronich, S.; Kroll, J. H.

2016-12-01

Gas phase oxidation of VOC is a gradual process leading to the formation of multifunctional organic compounds, i.e., typically species with higher oxidation state, high water solubility and low volatility. These species contribute to the formation of secondary organic aerosols (SOA) viamultiphase processes involving a myriad of organic species that evolve through thousands of reactions and gas/particle mass exchanges. Explicit chemical mechanisms reflect the understanding of these multigenerational oxidation steps. These mechanisms rely directly on elementary reactions to describe the chemical evolution and track the identity of organic carbon through various phases down to ultimate oxidation products. The development, assessment and improvement of such explicit schemes is a key issue, as major uncertainties remain on the chemical pathways involved during atmospheric oxidation of organic matter. An array of mass spectrometric techniques (CIMS, PTRMS, AMS) was recently used to track the composition of organic species during α-pinene oxidation in the MIT environmental chamber, providing an experimental database to evaluate and improve explicit mechanisms. In this study, the GECKO-A tool (Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere) is used to generate fully explicit oxidation schemes for α-pinene multiphase oxidation simulating the MIT experiment. The ability of the GECKO-A chemical scheme to explain the organic molecular composition in the gas and the condensed phases is explored. First results of this model/observation comparison at the molecular level will be presented.

Key Response Planning Factors for the Aftermath of Nuclear Terrorism

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

Buddemeier, B R; Dillon, M B

Despite hundreds of above-ground nuclear tests and data gathered from Hiroshima and Nagasaki, the effects of a ground-level, low-yield nuclear detonation in a modern urban environment are still the subject of considerable scientific debate. Extensive review of nuclear weapon effects studies and discussions with nuclear weapon effects experts from various federal agencies, national laboratories, and technical organizations have identified key issues and bounded some of the unknowns required to support response planning for a low-yield, ground-level nuclear detonation in a modern U.S. city. This study, which is focused primarily upon the hazards posed by radioactive fallout, used detailed fallout predictionsmore » from the advanced suite of three-dimensional (3-D) meteorology and plume/fallout models developed at Lawrence Livermore National Laboratory (LLNL), including extensive global Key Response Planning Factors for the Aftermath of Nuclear Terrorism geographical and real-time meteorological databases to support model calculations. This 3-D modeling system provides detailed simulations that account for complex meteorology and terrain effects. The results of initial modeling and analysis were presented to federal, state, and local working groups to obtain critical, broad-based review and feedback on strategy and messaging. This effort involved a diverse set of communities, including New York City, National Capitol Regions, Charlotte, Houston, Portland, and Los Angeles. The largest potential for reducing casualties during the post-detonation response phase comes from reducing exposure to fallout radiation. This can be accomplished through early, adequate sheltering followed by informed, delayed evacuation.B The response challenges to a nuclear detonation must be solved through multiple approaches of public education, planning, and rapid response actions. Because the successful response will require extensive coordination of a large number of organizations, supplemented by appropriate responses by local responders and the general population within the hazard zones, regional planning is essential to success. The remainder of this Executive Summary provides summary guidance for response planning in three areas: (1) Public Protection Strategy details the importance of early, adequate shelter followed by informed evacuation. (2) Responder Priorities identify how to protect response personnel, perform regional situational assessment, and support public safety. (3) Key Planning Considerations refute common myths and provide important information on planning how to respond in the aftermath of nuclear terrorism.« less

Barriers to Offering Vasectomy at Publicly Funded Family Planning Organizations in Texas

PubMed Central

White, Kari; Campbell, Anthony; Hopkins, Kristine; Grossman, Daniel; Potter, Joseph E.

2017-01-01

Few publicly funded family planning clinics in the United States offer vasectomy, but little is known about the reasons this method is not more widely available at these sources of care. Between February 2012 and February 2015, three waves of in-depth interviews were conducted with program administrators at 54 family planning organizations in Texas. Participants described their organization’s vasectomy service model and factors that influenced how frequently vasectomy was provided. Interview transcripts were coded and analyzed using a theme-based approach. Service models and barriers to providing vasectomy were compared by organization type (e.g., women’s health center, public health clinic) and receipt of Title X funding. Two thirds of organizations did not offer vasectomy on-site or pay for referrals with family planning funding; nine organizations frequently provided vasectomy. Organizations did not widely offer vasectomy because they could not find providers that would accept the low reimbursement for the procedure or because they lacked funding for men’s reproductive health care. Respondents often did not perceive men’s reproductive health care as a service priority and commented that men, especially Latinos, had limited interest in vasectomy. Although organizations of all types reported barriers, women’s health centers and Title X-funded organizations more frequently offered vasectomy by conducting tailored outreach to men and vasectomy providers. A combination of factors operating at the health systems and provider level influence the availability of vasectomy at publicly funded family planning organizations in Texas. Multilevel approaches that address key barriers to vasectomy provision would help organizations offer comprehensive contraceptive services. PMID:28413942

Loops determine the mechanical properties of mitotic chromosomes

NASA Astrophysics Data System (ADS)

Zhang, Yang; Heermann, Dieter W.

2013-03-01

In mitosis, chromosomes undergo a condensation into highly compacted, rod-like objects. Many models have been put forward for the higher-order organization of mitotic chromosomes including radial loop and hierarchical folding models. Additionally, mechanical properties of mitotic chromosomes under different conditions were measured. However, the internal organization of mitotic chromosomes still remains unclear. Here we present a polymer model for mitotic chromosomes and show how chromatin loops play a major role for their mechanical properties. The key assumption of the model is the ability of the chromatin fibre to dynamically form loops with the help of binding proteins. Our results show that looping leads to a tight compaction and significantly increases the bending rigidity of chromosomes. Moreover, our qualitative prediction of the force elongation behaviour is close to experimental findings. This indicates that the internal structure of mitotic chromosomes is based on self-organization of the chromatin fibre. We also demonstrate how number and size of loops have a strong influence on the mechanical properties. We suggest that changes in the mechanical characteristics of chromosomes can be explained by an altered internal loop structure. YZ gratefully appreciates funding by the German National Academic Foundation (Studienstiftung des deutschen Volkes) and support by the Heidelberg Graduate School for Mathematical and Computational Methods in the Sciences (HGS MathComp).

The development and evaluation of a succession planning programme in nursing, in Australia.

PubMed

Brunero, Scott; Kerr, Suzie; Jastrzab, Grazyna

2009-07-01

This study reports on a locally organized model of succession planning in a 550-bed general hospital. Within healthcare, succession planning has traditionally been considered for people at the executive director level and little research has been published with nurses working at the clinical level. A succession planning model was developed from the literature and through a process of consultation with senior staff. The model was then evaluated from a customer satisfaction, programme progress, effective placement and organizational results perspectives. Nurses who were successful in obtaining a new role were surveyed after 6 weeks in the position. Descriptive statistics, including numbers of placements and types of positions filled, were recorded. A checklist for conducting a programme evaluation of succession planning was also used. Twenty-five nurses participated, with 31 positions succeeded to. Nurses reported positively that the programme was beneficial, increased their sense of career planning and gave them a greater understanding of their career pathway. The succession planning programme provided an opportunity for the organization to identify new leaders. The study outcomes have identified potential improvements to the way succession planning is conducted at the hospital. Nurse Managers are in key positions to develop effective succession planning models. This study offers a process for managers to develop effective succession planning programmes within their organization.

TAD-free analysis of architectural proteins and insulators.

PubMed

Mourad, Raphaël; Cuvier, Olivier

2018-03-16

The three-dimensional (3D) organization of the genome is intimately related to numerous key biological functions including gene expression and DNA replication regulations. The mechanisms by which molecular drivers functionally organize the 3D genome, such as topologically associating domains (TADs), remain to be explored. Current approaches consist in assessing the enrichments or influences of proteins at TAD borders. Here, we propose a TAD-free model to directly estimate the blocking effects of architectural proteins, insulators and DNA motifs on long-range contacts, making the model intuitive and biologically meaningful. In addition, the model allows analyzing the whole Hi-C information content (2D information) instead of only focusing on TAD borders (1D information). The model outperforms multiple logistic regression at TAD borders in terms of parameter estimation accuracy and is validated by enhancer-blocking assays. In Drosophila, the results support the insulating role of simple sequence repeats and suggest that the blocking effects depend on the number of repeats. Motif analysis uncovered the roles of the transcriptional factors pannier and tramtrack in blocking long-range contacts. In human, the results suggest that the blocking effects of the well-known architectural proteins CTCF, cohesin and ZNF143 depend on the distance between loci, where each protein may participate at different scales of the 3D chromatin organization.

Protective effect of Korean Red Ginseng against chemotherapeutic drug-induced premature catagen development assessed with human hair follicle organ culture model

PubMed Central

Keum, Dong In; Pi, Long-Quan; Hwang, Sungjoo Tommy; Lee, Won-Soo

2015-01-01

Background Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects for patients undergoing chemotherapy. This study evaluated the protective effect of Korean Red Ginseng (KRG) on CIA in a well-established in vitro human hair follicle organ culture model as it occurs in vivo. Methods We examined whether KRG can prevent premature hair follicle dystrophy in a human hair follicle organ culture model during treatment with a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC). Results 4-HC inhibited human hair growth, induced premature catagen development, and inhibited proliferation and stimulated apoptosis of hair matrix keratinocytes. In addition, 4-HC increased p53 and Bax protein expression and decreased Bcl2 protein expression. Pretreatment with KRG protected against 4-HC-induced hair growth inhibition and premature catagen development. KRG also suppressed 4-HC-induced inhibition of matrix keratinocyte proliferation and stimulation of matrix keratinocyte apoptosis. Moreover, KRG restored 4-HC-induced p53 and Bax/Bcl2 expression. Conclusion Overall, our results indicate that KRG may protect against 4-HC-induced premature catagen development through modulation of p53 and Bax/Bcl2 expression. PMID:27158238

Transimulation - protein biosynthesis web service.

PubMed

Siwiak, Marlena; Zielenkiewicz, Piotr

2013-01-01

Although translation is the key step during gene expression, it remains poorly characterized at the level of individual genes. For this reason, we developed Transimulation - a web service measuring translational activity of genes in three model organisms: Escherichia coli, Saccharomyces cerevisiae and Homo sapiens. The calculations are based on our previous computational model of translation and experimental data sets. Transimulation quantifies mean translation initiation and elongation time (expressed in SI units), and the number of proteins produced per transcript. It also approximates the number of ribosomes that typically occupy a transcript during translation, and simulates their propagation. The simulation of ribosomes' movement is interactive and allows modifying the coding sequence on the fly. It also enables uploading any coding sequence and simulating its translation in one of three model organisms. In such a case, ribosomes propagate according to mean codon elongation times of the host organism, which may prove useful for heterologous expression. Transimulation was used to examine evolutionary conservation of translational parameters of orthologous genes. Transimulation may be accessed at http://nexus.ibb.waw.pl/Transimulation (requires Java version 1.7 or higher). Its manual and source code, distributed under the GPL-2.0 license, is freely available at the website.

Protective effect of Korean Red Ginseng against chemotherapeutic drug-induced premature catagen development assessed with human hair follicle organ culture model.

PubMed

Keum, Dong In; Pi, Long-Quan; Hwang, Sungjoo Tommy; Lee, Won-Soo

2016-04-01

Chemotherapy-induced alopecia (CIA) is one of the most distressing side effects for patients undergoing chemotherapy. This study evaluated the protective effect of Korean Red Ginseng (KRG) on CIA in a well-established in vitro human hair follicle organ culture model as it occurs in vivo. We examined whether KRG can prevent premature hair follicle dystrophy in a human hair follicle organ culture model during treatment with a key cyclophosphamide metabolite, 4-hydroperoxycyclophosphamide (4-HC). 4-HC inhibited human hair growth, induced premature catagen development, and inhibited proliferation and stimulated apoptosis of hair matrix keratinocytes. In addition, 4-HC increased p53 and Bax protein expression and decreased Bcl2 protein expression. Pretreatment with KRG protected against 4-HC-induced hair growth inhibition and premature catagen development. KRG also suppressed 4-HC-induced inhibition of matrix keratinocyte proliferation and stimulation of matrix keratinocyte apoptosis. Moreover, KRG restored 4-HC-induced p53 and Bax/Bcl2 expression. Overall, our results indicate that KRG may protect against 4-HC-induced premature catagen development through modulation of p53 and Bax/Bcl2 expression.

Facilitators and barriers to implementing electronic referral and/or consultation systems: a qualitative study of 16 health organizations.

PubMed

Tuot, Delphine S; Leeds, Kiren; Murphy, Elizabeth J; Sarkar, Urmimala; Lyles, Courtney R; Mekonnen, Tekeshe; Chen, Alice H M

2015-12-19

Access to specialty care remains a challenge for primary care providers and patients. Implementation of electronic referral and/or consultation (eCR) systems provides an opportunity for innovations in the delivery of specialty care. We conducted key informant interviews to identify drivers, facilitators, barriers and evaluation metrics of diverse eCR systems to inform widespread implementation of this model of specialty care delivery. Interviews were conducted with leaders of 16 diverse health care delivery organizations between January 2013 and April 2014. A limited snowball sampling approach was used for recruitment. Content analysis was used to examine key informant interview transcripts. Electronic referral systems, which provide referral management and triage by specialists, were developed to enhance tracking and operational efficiency. Electronic consultation systems, which encourage bi-directional communication between primary care and specialist providers facilitating longitudinal virtual co-management, were developed to improve access to specialty expertise. Integrated eCR systems leverage both functionalities to enhance the delivery of coordinated, specialty care at the population level. Elements of successful eCR system implementation included executive and clinician leadership, established funding models for specialist clinician reimbursement, and a commitment to optimizing clinician workflows. eCR systems have great potential to streamline access to and enhance the coordination of specialty care delivery. While different eCR models help solve different organizational challenges, all require institutional investments for successful implementation, such as funding for program management, leadership and clinician incentives.

Understanding soil erosion impacts in temperate agroecosystems: bridging the gap between geomorphology and soil ecology using nematodes as a model organism

NASA Astrophysics Data System (ADS)

Baxter, C.; Rowan, J. S.; McKenzie, B. M.; Neilson, R.

2013-11-01

Soil is a key asset of natural capital, providing a myriad of goods and ecosystem services that sustain life through regulating, supporting and provisioning roles, delivered by chemical, physical and biological processes. One of the greatest threats to soil is accelerated erosion, which raises a natural process to unsustainable levels, and has downstream consequences (e.g.~economic, environmental and social). Global intensification of agroecosystems is a recognised major cause of soil erosion which, in light of predicted population growth and increased demand for food security, will continue or increase. Transport and redistribution of biota by soil erosion has hitherto been ignored and thus is poorly understood. With the move to sustainable intensification this is a key knowledge gap that needs to be addressed. Here we highlight the erosion-energy and effective-erosion-depth continuum in soils, differentiating between different forms of soil erosion, and argue that nematodes are an appropriate model taxa to investigate impacts of erosion on soil biota across scales. We review the different known mechanisms of soil erosion that impact on soil biota in general, and nematodes in particular, and highlight the few detailed studies, primarily from tropical regions, that have considered soil biota. Based on the limited literature and using nematodes as a model organism we outline future research priorities to initially address the important interrelationships between soil erosion processes and soil biota.

Creating infrastructure supportive of evidence-based nursing practice: leadership strategies.

PubMed

Newhouse, Robin P

2007-01-01

Nursing leadership is the cornerstone of successful evidence-based practice (EBP) programs within health care organizations. The key to success is a strategic approach to building an EBP infrastructure, with allocation of appropriate human and material resources. This article indicates the organizational infrastructure that enables evidence-based nursing practice and strategies for leaders to enhance evidence-based practice using "the conceptual model for considering the determinants of diffusion, dissemination, and implementation of innovations in health service delivery and organization." Enabling EBP within organizations is important for promoting positive outcomes for nurses and patients. Fostering EBP is not a static or immediate outcome, but a long-term developmental process within organizations. Implementation requires multiple strategies to cultivate a culture of inquiry where nurses generate and answer important questions to guide practice. Organizations that can enable the culture and build infrastructure to help nurses develop EBP competencies will produce a professional environment that will result in both personal growth for their staff and improvements in quality that would not otherwise be possible.

Social dynamics within decomposer communities lead to nitrogen retention and organic matter build-up in soils

PubMed Central

Kaiser, Christina; Franklin, Oskar; Richter, Andreas; Dieckmann, Ulf

2015-01-01

The chemical structure of organic matter has been shown to be only marginally important for its decomposability by microorganisms. The question of why organic matter does accumulate in the face of powerful microbial degraders is thus key for understanding terrestrial carbon and nitrogen cycling. Here we demonstrate, based on an individual-based microbial community model, that social dynamics among microbes producing extracellular enzymes (‘decomposers') and microbes exploiting the catalytic activities of others (‘cheaters') regulate organic matter turnover. We show that the presence of cheaters increases nitrogen retention and organic matter build-up by downregulating the ratio of extracellular enzymes to total microbial biomass, allowing nitrogen-rich microbial necromass to accumulate. Moreover, increasing catalytic efficiencies of enzymes are outbalanced by a strong negative feedback on enzyme producers, leading to less enzymes being produced at the community level. Our results thus reveal a possible control mechanism that may buffer soil CO2 emissions in a future climate. PMID:26621582

The relationship between metal toxicity and biotic ligand binding affinities in aquatic and soil organisms: a review.

PubMed

Ardestani, Masoud M; van Straalen, Nico M; van Gestel, Cornelis A M

2014-12-01

The biotic ligand model (BLM) is a theoretical, potentially mechanistic approach to assess metal bioavailability in soil and aquatic systems. In a BLM, toxicity is linked to the fraction of biotic ligand occupied, which in turn, depends on the various components of the solution, including activity of the metal. Bioavailability is a key factor in determining toxicity and uptake of metals in organisms. In this study, the present status of BLM development for soil and aquatic organisms is summarized. For all species and all metals, toxicity was correlated with the conditional biotic ligand binding constants. For almost all organisms, values for Ag, Cu, and Cd were higher than those for Zn and Ni. The constants derived for aquatic systems seem to be equally valid for soil organisms, but in the case of soils, bioavailability from the soil solution is greatly influenced by the presence of the soil solid phase. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implementing high-performance work practices in healthcare organizations: qualitative and conceptual evidence.

PubMed

McAlearney, Ann Scheck; Robbins, Julie; Garman, Andrew N; Song, Paula H

2013-01-01

Studies across industries suggest that the systematic use of high-performance work practices (HPWPs) may be an effective but underused strategy to improve quality of care in healthcare organizations. Optimal use of HPWPs depends on how they are implemented, yet we know little about their implementation in healthcare. We conducted 67 key informant interviews in five healthcare organizations, each considered to have exemplary work practices in place and to deliver high-quality care, as part of an extensive study of HPWP use in healthcare. We analyzed interview transcripts inductively and deductively to examine why and how organizations implement HPWPs. We used an evidence-based model of complex innovation adoption to guide our exploration of factors that facilitate HPWP implementation. We found considerable variability in interviewees' reasons for implementing HPWPs, including macro-organizational (strategic level) and micro-organizational (individual level) reasons. This variability highlighted the complex context for HPWP implementation in many organizations. We also found that our application of an innovation implementation model helped clarify and categorize facilitators of HPWP implementation, thus providing insight on how these factors can contribute to implementation effectiveness. Focusing efforts on clarifying definitions, building commitment, and ensuring consistency in the application of work practices may be particularly important elements of successful implementation.

Operationalizing the Learning Health Care System in an Integrated Delivery System

PubMed Central

Psek, Wayne A.; Stametz, Rebecca A.; Bailey-Davis, Lisa D.; Davis, Daniel; Darer, Jonathan; Faucett, William A.; Henninger, Debra L.; Sellers, Dorothy C.; Gerrity, Gloria

2015-01-01

Introduction: The Learning Health Care System (LHCS) model seeks to utilize sophisticated technologies and competencies to integrate clinical operations, research and patient participation in order to continuously generate knowledge, improve care, and deliver value. Transitioning from concept to practical application of an LHCS presents many challenges but can yield opportunities for continuous improvement. There is limited literature and practical experience available in operationalizing the LHCS in the context of an integrated health system. At Geisinger Health System (GHS) a multi-stakeholder group is undertaking to enhance organizational learning and develop a plan for operationalizing the LHCS system-wide. We present a framework for operationalizing continuous learning across an integrated delivery system and lessons learned through the ongoing planning process. Framework: The framework focuses attention on nine key LHCS operational components: Data and Analytics; People and Partnerships; Patient and Family Engagement; Ethics and Oversight; Evaluation and Methodology; Funding; Organization; Prioritization; and Deliverables. Definitions, key elements and examples for each are presented. The framework is purposefully broad for application across different organizational contexts. Conclusion: A realistic assessment of the culture, resources and capabilities of the organization related to learning is critical to defining the scope of operationalization. Engaging patients in clinical care and discovery, including quality improvement and comparative effectiveness research, requires a defensible ethical framework that undergirds a system of strong but flexible oversight. Leadership support is imperative for advancement of the LHCS model. Findings from our ongoing work within the proposed framework may inform other organizations considering a transition to an LHCS. PMID:25992388

The use of BLT humanized mice to investigate the immune reconstitution of the gastrointestinal tract.

PubMed

Wahl, Angela; Victor Garcia, J

2014-08-01

The gastrointestinal (GI) track represents an important battlefield where pathogens first try to gain entry into a host. It is also a universe where highly diverse and ever changing inhabitants co-exist in an exceptional equilibrium without parallel in any other organ system of the body. The gut as an organ has its own well-developed and fully functional immune organization that is similar and yet different in many important ways to the rest of the immune system. Both a compromised and an overactive immune system in the gut can have dire and severe consequences to human health. It has therefore been of great interest to develop animal models that recapitulate key aspects of the human condition to better understand the interplay of the host immune system with its friends and its foes. However, reconstitution of the GI tract in humanized mice has been difficult and highly variable in different systems. A better molecular understanding of the development of the gut immune system in mice has provided critical cues that have been recently used to develop novel humanized mouse models that fully recapitulate the genesis and key functions of the gut immune system of humans. Of particular interest is the presence of human gut-associated lymphoid tissue (GALT) aggregates in the gut of NOD/SCID BLT humanized mice that demonstrate the faithful development of bona fide human plasma cells capable of migrating to the lamina propria and producing human IgA1 and IgA2. Copyright © 2014 Elsevier B.V. All rights reserved.

Ultrathin Polymer Membranes with Patterned, Micrometric Pores for Organs-on-Chips.

PubMed

Pensabene, Virginia; Costa, Lino; Terekhov, Alexander Y; Gnecco, Juan S; Wikswo, John P; Hofmeister, William H

2016-08-31

The basal lamina or basement membrane (BM) is a key physiological system that participates in physicochemical signaling between tissue types. Its formation and function are essential in tissue maintenance, growth, angiogenesis, disease progression, and immunology. In vitro models of the BM (e.g., Boyden and transwell chambers) are common in cell biology and lab-on-a-chip devices where cells require apical and basolateral polarization. Extravasation, intravasation, membrane transport of chemokines, cytokines, chemotaxis of cells, and other key functions are routinely studied in these models. The goal of the present study was to integrate a semipermeable ultrathin polymer membrane with precisely positioned pores of 2 μm diameter in a microfluidic device with apical and basolateral chambers. We selected poly(l-lactic acid) (PLLA), a transparent biocompatible polymer, to prepare the semipermeable ultrathin membranes. The pores were generated by pattern transfer using a three-step method coupling femtosecond laser machining, polymer replication, and spin coating. Each step of the fabrication process was characterized by scanning electron microscopy to investigate reliability of the process and fidelity of pattern transfer. In order to evaluate the compatibility of the fabrication method with organs-on-a-chip technology, porous PLLA membranes were embedded in polydimethylsiloxane (PDMS) microfluidic devices and used to grow human umbilical vein endothelial cells (HUVECS) on top of the membrane with perfusion through the basolateral chamber. Viability of cells, optical transparency of membranes and strong adhesion of PLLA to PDMS were observed, thus confirming the suitability of the prepared membranes for use in organs-on-a-chip devices.

Iron-Mediated Oxidation of Methoxyhydroquinone under Dark Conditions: Kinetic and Mechanistic Insights.

PubMed

Yuan, Xiu; Davis, James A; Nico, Peter S

2016-02-16

Despite the biogeochemical significance of the interactions between natural organic matter (NOM) and iron species, considerable uncertainty still remains as to the exact processes contributing to the rates and extents of complexation and redox reactions between these important and complex environmental components. Investigations on the reactivity of low-molecular-weight quinones, which are believed to be key redox active compounds within NOM, toward iron species, could provide considerable insight into the kinetics and mechanisms of reactions involving NOM and iron. In this study, the oxidation of 2-methoxyhydroquinone (MH2Q) by ferric iron (Fe(III)) under dark conditions in the absence and presence of oxygen was investigated within a pH range of 4-6. Although Fe(III) was capable of stoichiometrically oxidizing MH2Q under anaerobic conditions, catalytic oxidation of MH2Q was observed in the presence of O2 due to further cycling between oxygen, semiquinone radicals, and iron species. A detailed kinetic model was developed to describe the predominant mechanisms, which indicated that both the undissociated and monodissociated anions of MH2Q were kinetically active species toward Fe(III) reduction, with the monodissociated anion being the key species accounting for the pH dependence of the oxidation. The generated radical intermediates, namely semiquinone and superoxide, are of great importance in reaction-chain propagation. The kinetic model may provide critical insight into the underlying mechanisms of the thermodynamic and kinetic characteristics of metal-organic interactions and assist in understanding and predicting the factors controlling iron and organic matter transformation and bioavailability in aquatic systems.

Hybrid Modeling of Cell Signaling and Transcriptional Reprogramming and Its Application in C. elegans Development.

PubMed

Fertig, Elana J; Danilova, Ludmila V; Favorov, Alexander V; Ochs, Michael F

2011-01-01

Modeling of signal driven transcriptional reprogramming is critical for understanding of organism development, human disease, and cell biology. Many current modeling techniques discount key features of the biological sub-systems when modeling multiscale, organism-level processes. We present a mechanistic hybrid model, GESSA, which integrates a novel pooled probabilistic Boolean network model of cell signaling and a stochastic simulation of transcription and translation responding to a diffusion model of extracellular signals. We apply the model to simulate the well studied cell fate decision process of the vulval precursor cells (VPCs) in C. elegans, using experimentally derived rate constants wherever possible and shared parameters to avoid overfitting. We demonstrate that GESSA recovers (1) the effects of varying scaffold protein concentration on signal strength, (2) amplification of signals in expression, (3) the relative external ligand concentration in a known geometry, and (4) feedback in biochemical networks. We demonstrate that setting model parameters based on wild-type and LIN-12 loss-of-function mutants in C. elegans leads to correct prediction of a wide variety of mutants including partial penetrance of phenotypes. Moreover, the model is relatively insensitive to parameters, retaining the wild-type phenotype for a wide range of cell signaling rate parameters.

Self-organized synchronization of digital phase-locked loops with delayed coupling in theory and experiment

PubMed Central

Wetzel, Lucas; Jörg, David J.; Pollakis, Alexandros; Rave, Wolfgang; Fettweis, Gerhard; Jülicher, Frank

2017-01-01

Self-organized synchronization occurs in a variety of natural and technical systems but has so far only attracted limited attention as an engineering principle. In distributed electronic systems, such as antenna arrays and multi-core processors, a common time reference is key to coordinate signal transmission and processing. Here we show how the self-organized synchronization of mutually coupled digital phase-locked loops (DPLLs) can provide robust clocking in large-scale systems. We develop a nonlinear phase description of individual and coupled DPLLs that takes into account filter impulse responses and delayed signal transmission. Our phase model permits analytical expressions for the collective frequencies of synchronized states, the analysis of stability properties and the time scale of synchronization. In particular, we find that signal filtering introduces stability transitions that are not found in systems without filtering. To test our theoretical predictions, we designed and carried out experiments using networks of off-the-shelf DPLL integrated circuitry. We show that the phase model can quantitatively predict the existence, frequency, and stability of synchronized states. Our results demonstrate that mutually delay-coupled DPLLs can provide robust and self-organized synchronous clocking in electronic systems. PMID:28207779

Blue light reduces organ injury from ischemia and reperfusion

PubMed Central

Yuan, Du; Collage, Richard D.; Huang, Hai; Zhang, Xianghong; Kautza, Benjamin C.; Lewis, Anthony J.; Zuckerbraun, Brian S.; Tsung, Allan; Angus, Derek C.; Rosengart, Matthew R.

2016-01-01

Evidence suggests that light and circadian rhythms profoundly influence the physiologic capacity with which an organism responds to stress. However, the ramifications of light spectrum on the course of critical illness remain to be determined. Here, we show that acute exposure to bright blue spectrum light reduces organ injury by comparison with bright red spectrum or ambient white fluorescent light in two murine models of sterile insult: warm liver ischemia/reperfusion (I/R) and unilateral renal I/R. Exposure to bright blue light before I/R reduced hepatocellular injury and necrosis and reduced acute kidney injury and necrosis. In both models, blue light reduced neutrophil influx, as evidenced by reduced myeloperoxidase (MPO) within each organ, and reduced the release of high-mobility group box 1 (HMGB1), a neutrophil chemotactant and key mediator in the pathogenesis of I/R injury. The protective mechanism appeared to involve an optic pathway and was mediated, in part, by a sympathetic (β3 adrenergic) pathway that functioned independent of significant alterations in melatonin or corticosterone concentrations to regulate neutrophil recruitment. These data suggest that modifying the spectrum of light may offer therapeutic utility in sterile forms of cellular injury. PMID:27114521

[Groundwater organic pollution source identification technology system research and application].

PubMed

Wang, Xiao-Hong; Wei, Jia-Hua; Cheng, Zhi-Neng; Liu, Pei-Bin; Ji, Yi-Qun; Zhang, Gan

2013-02-01

Groundwater organic pollutions are found in large amount of locations, and the pollutions are widely spread once onset; which is hard to identify and control. The key process to control and govern groundwater pollution is how to control the sources of pollution and reduce the danger to groundwater. This paper introduced typical contaminated sites as an example; then carried out the source identification studies and established groundwater organic pollution source identification system, finally applied the system to the identification of typical contaminated sites. First, grasp the basis of the contaminated sites of geological and hydrogeological conditions; determine the contaminated sites characteristics of pollutants as carbon tetrachloride, from the large numbers of groundwater analysis and test data; then find the solute transport model of contaminated sites and compound-specific isotope techniques. At last, through groundwater solute transport model and compound-specific isotope technology, determine the distribution of the typical site of organic sources of pollution and pollution status; invest identified potential sources of pollution and sample the soil to analysis. It turns out that the results of two identified historical pollution sources and pollutant concentration distribution are reliable. The results provided the basis for treatment of groundwater pollution.

Coalescent Theory Analysis of Population Collapse and Recovery in a Neutral Evolution Model

NASA Astrophysics Data System (ADS)

King, Dawn; Bahar, Sonya

As we move through the Anthropocene Epoch, human-driven climate change is predicted to accelerate extinction risk in the near future. Therefore, understanding basic underlying mechanisms of population loss and recovery could be paramount to saving key species in changing ecosystems. Here, we present an evolutionary model that investigates the dynamics of population collapse and recovery following a simulated mass extinction. Previously, we have shown that nonequilibrium, continuous phase transitions of the directed percolation universality class occur as a function of two different control parameters: the mutability, μ, which dictates how phenotypically different an offspring can be from its parent, and the death probability, δ, which probabilistically removes organisms within each generation. Here, we characterize the phylogenetic tree structures at two levels of biological organization--the organism and species level. Using methods from coalescent theory, we examine the phylogenetic tree structures at, and above, criticality, by considering common descent. The times to most recent common ancestor show phase transition behavior, as well as scale-free branching behavior at both levels of organization. We further examine these genealogical structures pre- and post-extinction. This research was supported by funding from the James S. McDonnell Foundation.

First-Principles Modeling of the Initial Stages of Organic Solvent Decomposition on Li xMn 2O 4 (100) Surfaces [First principles modeling of Mn(II) migration to and dissolution from Li xMn 2O 4 (100) surfaces

DOE PAGES

Leung, Kevin

2012-04-13

Density functional theory and ab initio molecular dynamics simulations are applied to investigate the migration of Mn(II) ions to above-surface sites on spinel Li xMn 2O 4 (100) surfaces, the subsequent Mn dissolution into the organic liquid electrolyte, and the detrimental effects on anode solid electrolyte interphase (SEI) passivating films after Mn(II) ions diffuse through the separator. The dissolution mechanism proves complex; the much-quoted Hunter disproportionation of Mn(III) to form Mn(II) is necessary but far from sufficient. Key steps that facilitate Mn(II) ion migration include concerted liquid/solid-state motions, proton-induced weakening of Mn-O bonds forming mobile OH - surface groups; andmore » chemical reactions of adsorbed decomposed organic fragments. Mn(II) lodged between the inorganic Li 2CO 3 and organic lithium ethylene dicarbonate (LEDC) anode SEI component facilitates electrochemical reduction and decomposition of LEDC. These findings help inform future design of protective coatings, electrolytes, additives, and interfaces.« less

Prediction of anaerobic biodegradability and bioaccessibility of municipal sludge by coupling sequential extractions with fluorescence spectroscopy: towards ADM1 variables characterization.

PubMed

Jimenez, Julie; Gonidec, Estelle; Cacho Rivero, Jesús Andrés; Latrille, Eric; Vedrenne, Fabien; Steyer, Jean-Philippe

2014-03-01

Advanced dynamic anaerobic digestion models, such as ADM1, require both detailed organic matter characterisation and intimate knowledge of the involved metabolic pathways. In the current study, a methodology for municipal sludge characterization is investigated to describe two key parameters: biodegradability and bioaccessibility of organic matter. The methodology is based on coupling sequential chemical extractions with 3D fluorescence spectroscopy. The use of increasingly strong solvents reveals different levels of organic matter accessibility and the spectroscopy measurement leads to a detailed characterisation of the organic matter. The results obtained from testing 52 municipal sludge samples (primary, secondary, digested and thermally treated) showed a successful correlation with sludge biodegradability and bioaccessibility. The two parameters, traditionally obtained through the biochemical methane potential (BMP) lab tests, are now obtain in only 5 days compared to the 30-60 days usually required. Experimental data, obtained from two different laboratory scale reactors, were used to validate the ADM1 model. The proposed approach showed a strong application potential for reactor design and advanced control of anaerobic digestion processes. Copyright © 2013 Elsevier Ltd. All rights reserved.

The Role of Ultrahigh Resolution Fourier Transform Mass Spectrometry (FT-MS) in Astrobiology-Related Research: Analysis of Meteorites and Tholins.

PubMed

Somogyi, Árpád; Thissen, Roland; Orthous-Daunay, Francois-Régis; Vuitton, Véronique

2016-03-24

It is an important but also a challenging analytical problem to understand the chemical composition and structure of prebiotic organic matter that is present in extraterrestrial materials. Its formation, evolution and content in the building blocks ("seeds") for more complex molecules, such as proteins and DNA, are key questions in the field of exobiology. Ultrahigh resolution mass spectrometry is one of the best analytical techniques that can be applied because it provides reliable information on the chemical composition and structure of individual components of complex organic mixtures. Prebiotic organic material is delivered to Earth by meteorites or generated in laboratories in simulation (model) experiments that mimic space or atmospheric conditions. Recent representative examples for ultrahigh resolution mass spectrometry studies using Fourier-transform (FT) mass spectrometers such as Orbitrap and ion cyclotron resonance (ICR) mass spectrometers are shown and discussed in the present article, including: (i) the analysis of organic matter of meteorites; (ii) modeling atmospheric processes in ICR cells; and (iii) the structural analysis of laboratory made tholins that might be present in the atmosphere and surface of Saturn's largest moon, Titan.

The Role of Ultrahigh Resolution Fourier Transform Mass Spectrometry (FT-MS) in Astrobiology-Related Research: Analysis of Meteorites and Tholins

PubMed Central

Somogyi, Árpád; Thissen, Roland; Orthous-Daunay, Francois-Régis; Vuitton, Véronique

2016-01-01

It is an important but also a challenging analytical problem to understand the chemical composition and structure of prebiotic organic matter that is present in extraterrestrial materials. Its formation, evolution and content in the building blocks (“seeds”) for more complex molecules, such as proteins and DNA, are key questions in the field of exobiology. Ultrahigh resolution mass spectrometry is one of the best analytical techniques that can be applied because it provides reliable information on the chemical composition and structure of individual components of complex organic mixtures. Prebiotic organic material is delivered to Earth by meteorites or generated in laboratories in simulation (model) experiments that mimic space or atmospheric conditions. Recent representative examples for ultrahigh resolution mass spectrometry studies using Fourier-transform (FT) mass spectrometers such as Orbitrap and ion cyclotron resonance (ICR) mass spectrometers are shown and discussed in the present article, including: (i) the analysis of organic matter of meteorites; (ii) modeling atmospheric processes in ICR cells; and (iii) the structural analysis of laboratory made tholins that might be present in the atmosphere and surface of Saturn’s largest moon, Titan. PMID:27023520

Evolutionary cell biology: functional insight from "endless forms most beautiful".

PubMed

Richardson, Elisabeth; Zerr, Kelly; Tsaousis, Anastasios; Dorrell, Richard G; Dacks, Joel B

2015-12-15

In animal and fungal model organisms, the complexities of cell biology have been analyzed in exquisite detail and much is known about how these organisms function at the cellular level. However, the model organisms cell biologists generally use include only a tiny fraction of the true diversity of eukaryotic cellular forms. The divergent cellular processes observed in these more distant lineages are still largely unknown in the general scientific community. Despite the relative obscurity of these organisms, comparative studies of them across eukaryotic diversity have had profound implications for our understanding of fundamental cell biology in all species and have revealed the evolution and origins of previously observed cellular processes. In this Perspective, we will discuss the complexity of cell biology found across the eukaryotic tree, and three specific examples of where studies of divergent cell biology have altered our understanding of key functional aspects of mitochondria, plastids, and membrane trafficking. © 2015 Richardson et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

CALM: Complex Adaptive System (CAS)-Based Decision Support for Enabling Organizational Change

NASA Astrophysics Data System (ADS)

Adler, Richard M.; Koehn, David J.

Guiding organizations through transformational changes such as restructuring or adopting new technologies is a daunting task. Such changes generate workforce uncertainty, fear, and resistance, reducing morale, focus and performance. Conventional project management techniques fail to mitigate these disruptive effects, because social and individual changes are non-mechanistic, organic phenomena. CALM (for Change, Adaptation, Learning Model) is an innovative decision support system for enabling change based on CAS principles. CALM provides a low risk method for validating and refining change strategies that combines scenario planning techniques with "what-if" behavioral simulation. In essence, CALM "test drives" change strategies before rolling them out, allowing organizations to practice and learn from virtual rather than actual mistakes. This paper describes the CALM modeling methodology, including our metrics for measuring organizational readiness to respond to change and other major CALM scenario elements: prospective change strategies; alternate futures; and key situational dynamics. We then describe CALM's simulation engine for projecting scenario outcomes and its associated analytics. CALM's simulator unifies diverse behavioral simulation paradigms including: adaptive agents; system dynamics; Monte Carlo; event- and process-based techniques. CALM's embodiment of CAS dynamics helps organizations reduce risk and improve confidence and consistency in critical strategies for enabling transformations.

A mathematical framework for modelling cambial surface evolution using a level set method

PubMed Central

Sellier, Damien; Plank, Michael J.; Harrington, Jonathan J.

2011-01-01

Background and Aims During their lifetime, tree stems take a series of successive nested shapes. Individual tree growth models traditionally focus on apical growth and architecture. However, cambial growth, which is distributed over a surface layer wrapping the whole organism, equally contributes to plant form and function. This study aims at providing a framework to simulate how organism shape evolves as a result of a secondary growth process that occurs at the cellular scale. Methods The development of the vascular cambium is modelled as an expanding surface using the level set method. The surface consists of multiple compartments following distinct expansion rules. Growth behaviour can be formulated as a mathematical function of surface state variables and independent variables to describe biological processes. Key Results The model was coupled to an architectural model and to a forest stand model to simulate cambium dynamics and wood formation at the scale of the organism. The model is able to simulate competition between cambia, surface irregularities and local features. Predicting the shapes associated with arbitrarily complex growth functions does not add complexity to the numerical method itself. Conclusions Despite their slenderness, it is sometimes useful to conceive of trees as expanding surfaces. The proposed mathematical framework provides a way to integrate through time and space the biological and physical mechanisms underlying cambium activity. It can be used either to test growth hypotheses or to generate detailed maps of wood internal structure. PMID:21470972

A Large-Scale, High-Resolution Hydrological Model Parameter Data Set for Climate Change Impact Assessment for the Conterminous US

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

Oubeidillah, Abdoul A; Kao, Shih-Chieh; Ashfaq, Moetasim

2014-01-01

To extend geographical coverage, refine spatial resolution, and improve modeling efficiency, a computation- and data-intensive effort was conducted to organize a comprehensive hydrologic dataset with post-calibrated model parameters for hydro-climate impact assessment. Several key inputs for hydrologic simulation including meteorologic forcings, soil, land class, vegetation, and elevation were collected from multiple best-available data sources and organized for 2107 hydrologic subbasins (8-digit hydrologic units, HUC8s) in the conterminous United States at refined 1/24 (~4 km) spatial resolution. Using high-performance computing for intensive model calibration, a high-resolution parameter dataset was prepared for the macro-scale Variable Infiltration Capacity (VIC) hydrologic model. The VICmore » simulation was driven by DAYMET daily meteorological forcing and was calibrated against USGS WaterWatch monthly runoff observations for each HUC8. The results showed that this new parameter dataset may help reasonably simulate runoff at most US HUC8 subbasins. Based on this exhaustive calibration effort, it is now possible to accurately estimate the resources required for further model improvement across the entire conterminous United States. We anticipate that through this hydrologic parameter dataset, the repeated effort of fundamental data processing can be lessened, so that research efforts can emphasize the more challenging task of assessing climate change impacts. The pre-organized model parameter dataset will be provided to interested parties to support further hydro-climate impact assessment.« less

Research on the key technologies of 3D spatial data organization and management for virtual building environments

NASA Astrophysics Data System (ADS)

Gong, Jun; Zhu, Qing

2006-10-01

As the special case of VGE in the fields of AEC (architecture, engineering and construction), Virtual Building Environment (VBE) has been broadly concerned. Highly complex, large-scale 3d spatial data is main bottleneck of VBE applications, so 3d spatial data organization and management certainly becomes the core technology for VBE. This paper puts forward 3d spatial data model for VBE, and the performance to implement it is very high. Inherent storage method of CAD data makes data redundant, and doesn't concern efficient visualization, which is a practical bottleneck to integrate CAD model, so An Efficient Method to Integrate CAD Model Data is put forward. Moreover, Since the 3d spatial indices based on R-tree are usually limited by their weakness of low efficiency due to the severe overlap of sibling nodes and the uneven size of nodes, a new node-choosing algorithm of R-tree are proposed.

A unified model of Grignard reagent formation.

PubMed

Shao, Yunqi; Liu, Zhen; Huang, Pan; Liu, Boping

2018-04-25

Grignard reagents are among the most fundamental reagents in organic synthesis, yet studies have hitherto failed to fully explain the selectivity and kinetics of Grignard reagent formation (GRF). The present study provides new insights into the intermediates and pathways of GRF using density functional theory (DFT) calculations. Potential energy surfaces of RX dissociation along different directions reveal the origin of configuration retention of alkenyl and aromatic halides. Radical intermediates participate solely in the dissociation stage, and depend on the geometry of the reactant halide. Dissociation of organic halides yields stabilized surface anions, and the rest of the reaction is ionic in nature. MgX+/RMg+ were proposed as the key intermediates of Mg leaving from the surface in the self-activation of GRF, which explains the accelerated kinetics upon addition of RMgX or MgX2. The intermediacy of the cations was supported by a simple electrochemical experiment. To the best of our knowledge, this is the first unified ionic model (I-model) developed for resolving the controversial issues of GRF.

A prototypic mathematical model of the human hair cycle.

PubMed

Al-Nuaimi, Yusur; Goodfellow, Marc; Paus, Ralf; Baier, Gerold

2012-10-07

The human hair cycle is a complex, dynamic organ-transformation process during which the hair follicle repetitively progresses from a growth phase (anagen) to a rapid apoptosis-driven involution (catagen) and finally a relative quiescent phase (telogen) before returning to anagen. At present no theory satisfactorily explains the origin of the hair cycle rhythm. Based on experimental evidence we propose a prototypic model that focuses on the dynamics of hair matrix keratinocytes. We argue that a plausible feedback-control structure between two key compartments (matrix keratinocytes and dermal papilla) leads to dynamic instabilities in the population dynamics resulting in rhythmic hair growth. The underlying oscillation consists of an autonomous switching between two quasi-steady states. Additional features of the model, namely bistability and excitability, lead to new hypotheses about the impact of interventions on hair growth. We show how in silico testing may facilitate testing of candidate hair growth modulatory agents in human HF organ culture or in clinical trials. Copyright © 2012 Elsevier Ltd. All rights reserved.

Groundwater–surface water mixing shifts ecological assembly processes and stimulates organic carbon turnover

DOE PAGES

Stegen, James C.; Fredrickson, James K.; Wilkins, Michael J.; ...

2016-04-07

Environmental transition zones are associated with geochemical gradients that overcome energy limitations to microbial metabolism, resulting in biogeochemical hot spots and moments. Riverine systems where groundwater mixes with surface water (the hyporheic zone) are spatially complex and temporally dynamic, making development of predictive models challenging. Spatial and temporal variations in hyporheic zone microbial communities are a key, but understudied, component of riverine biogeochemical function. To investigate the coupling among groundwater-surface water mixing, microbial communities, and biogeochemistry we applied ecological theory, aqueous biogeochemistry, DNA sequencing, and ultra-high resolution organic carbon profiling to field samples collected across times and locations representing amore » broad range of mixing conditions. Mixing of groundwater and surface water resulted in a shift from transport-driven stochastic dynamics to a deterministic microbial structure associated with elevated biogeochemical rates. While the dynamics of the hyporheic make predictive modeling a challenge, we provide new knowledge that can improve the tractability of such models.« less

Patients-people-place: developing a framework for researching organizational culture during health service redesign and change.

PubMed

Gale, Nicola K; Shapiro, Jonathan; McLeod, Hugh S T; Redwood, Sabi; Hewison, Alistair

2014-08-20

Organizational culture is considered by policy-makers, clinicians, health service managers and researchers to be a crucial mediator in the success of implementing health service redesign. It is a challenge to find a method to capture cultural issues that is both theoretically robust and meaningful to those working in the organizations concerned. As part of a comparative study of service redesign in three acute hospital organizations in England, UK, a framework for collecting data reflective of culture was developed that was informed by previous work in the field and social and cultural theory. As part of a larger mixed method comparative case study of hospital service redesign, informed by realist evaluation, the authors developed a framework for researching organisational culture during health service redesign and change. This article documents the development of the model, which involved an iterative process of data analysis, critical interdisciplinary discussion in the research team, and feedback from staff in the partner organisations. Data from semi-structured interviews with 77 key informants are used to illustrate the model. In workshops with NHS partners to share and debate the early findings of the study, organizational culture was identified as a key concept to explore because it was perceived to underpin the whole redesign process. The Patients-People-Place framework for studying culture focuses on three thematic areas ('domains') and three levels of culture in which the data could be organised. The framework can be used to help explain the relationship between observable behaviours and cultural artefacts, the values and habits of social actors and the basic assumptions underpinning an organization's culture in each domain. This paper makes a methodological contribution to the study of culture in health care organizations. It offers guidance and a practical approach to investigating the inherently complex phenomenon of culture in hospital organizations. The Patients-People-Place framework could be applied in other settings as a means of ensuring the three domains and three levels that are important to an organization's culture are addressed in future health service research.

48 CFR 970.5203-3 - Contractor's organization.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Officer a chart showing the names, duties, and organization of key personnel (see 48 CFR 952.215-70) to be... employee competency, conduct, and integrity and shall be responsible for taking such disciplinary action... work under the contract. This includes the right to direct the Contractor to remove its most senior key...

48 CFR 970.5203-3 - Contractor's organization.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Officer a chart showing the names, duties, and organization of key personnel (see 48 CFR 952.215-70) to be... employee competency, conduct, and integrity and shall be responsible for taking such disciplinary action... work under the contract. This includes the right to direct the Contractor to remove its most senior key...

48 CFR 970.5203-3 - Contractor's organization.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Officer a chart showing the names, duties, and organization of key personnel (see 48 CFR 952.215-70) to be... employee competency, conduct, and integrity and shall be responsible for taking such disciplinary action... work under the contract. This includes the right to direct the Contractor to remove its most senior key...

48 CFR 970.5203-3 - Contractor's organization.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Officer a chart showing the names, duties, and organization of key personnel (see 48 CFR 952.215-70) to be... employee competency, conduct, and integrity and shall be responsible for taking such disciplinary action... work under the contract. This includes the right to direct the Contractor to remove its most senior key...

Structural Model of the Bilitranslocase Transmembrane Domain Supported by NMR and FRET Data.

PubMed

Roy Choudhury, Amrita; Sikorska, Emilia; van den Boom, Johannes; Bayer, Peter; Popenda, Łukasz; Szutkowski, Kosma; Jurga, Stefan; Bonomi, Massimiliano; Sali, Andrej; Zhukov, Igor; Passamonti, Sabina; Novič, Marjana

2015-01-01

We present a 3D model of the four transmembrane (TM) helical regions of bilitranslocase (BTL), a structurally uncharacterized protein that transports organic anions across the cell membrane. The model was computed by considering helix-helix interactions as primary constraints, using Monte Carlo simulations. The interactions between the TM2 and TM3 segments have been confirmed by Förster resonance energy transfer (FRET) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy, increasing our confidence in the model. Several insights into the BTL transport mechanism were obtained by analyzing the model. For example, the observed cis-trans Leu-Pro peptide bond isomerization in the TM3 fragment may indicate a key conformational change during anion transport by BTL. Our structural model of BTL may facilitate further studies, including drug discovery.

Keys to successful organ procurement: An experience-based review of clinical practices at a high-performing health-care organization

PubMed Central

Wojda, Thomas R.; Stawicki, Stanislaw P.; Yandle, Kathy P.; Bleil, Maria; Axelband, Jennifer; Wilde-Onia, Rebecca; Thomas, Peter G.; Cipolla, James; Hoff, William S.; Shultz, Jill

2017-01-01

Organ procurement (OP) from donors after brain death and circulatory death represents the primary source of transplanted organs. Despite favorable laws and regulations, OP continues to face challenges for a number of reasons, including institutional, personal, and societal barriers. This focused review presents some of the key components of a successful OP program at a large, high-performing regional health network. This review focuses on effective team approaches, aggressive resuscitative strategies, optimal communication, family support, and community outreach efforts. PMID:28660162

Assessment and improvement of biotransfer models to cow's milk and beef used in exposure assessment tools for organic pollutants.

PubMed

Takaki, Koki; Wade, Andrew J; Collins, Chris D

2015-11-01

The aim of this study was to assess and improve the accuracy of biotransfer models for the organic pollutants (PCBs, PCDD/Fs, PBDEs, PFCAs, and pesticides) into cow's milk and beef used in human exposure assessment. Metabolic rate in cattle is known as a key parameter for this biotransfer, however few experimental data and no simulation methods are currently available. In this research, metabolic rate was estimated using existing QSAR biodegradation models of microorganisms (BioWIN) and fish (EPI-HL and IFS-HL). This simulated metabolic rate was then incorporated into the mechanistic cattle biotransfer models (RAIDAR, ACC-HUMAN, OMEGA, and CKow). The goodness of fit tests showed that RAIDAR, ACC-HUMAN, OMEGA model performances were significantly improved using either of the QSARs when comparing the new model outputs to observed data. The CKow model is the only one that separates the processes in the gut and liver. This model showed the lowest residual error of all the models tested when the BioWIN model was used to represent the ruminant metabolic process in the gut and the two fish QSARs were used to represent the metabolic process in the liver. Our testing included EUSES and CalTOX which are KOW-regression models that are widely used in regulatory assessment. New regressions based on the simulated rate of the two metabolic processes are also proposed as an alternative to KOW-regression models for a screening risk assessment. The modified CKow model is more physiologically realistic, but has equivalent usability to existing KOW-regression models for estimating cattle biotransfer of organic pollutants. Copyright © 2015. Published by Elsevier Ltd.

Accurate prediction of the refractive index of polymers using first principles and data modeling

NASA Astrophysics Data System (ADS)

Afzal, Mohammad Atif Faiz; Cheng, Chong; Hachmann, Johannes

Organic polymers with a high refractive index (RI) have recently attracted considerable interest due to their potential application in optical and optoelectronic devices. The ability to tailor the molecular structure of polymers is the key to increasing the accessible RI values. Our work concerns the creation of predictive in silico models for the optical properties of organic polymers, the screening of large-scale candidate libraries, and the mining of the resulting data to extract the underlying design principles that govern their performance. This work was set up to guide our experimentalist partners and allow them to target the most promising candidates. Our model is based on the Lorentz-Lorenz equation and thus includes the polarizability and number density values for each candidate. For the former, we performed a detailed benchmark study of different density functionals, basis sets, and the extrapolation scheme towards the polymer limit. For the number density we devised an exceedingly efficient machine learning approach to correlate the polymer structure and the packing fraction in the bulk material. We validated the proposed RI model against the experimentally known RI values of 112 polymers. We could show that the proposed combination of physical and data modeling is both successful and highly economical to characterize a wide range of organic polymers, which is a prerequisite for virtual high-throughput screening.

Spatial organization of the budding yeast genome in the cell nucleus and identification of specific chromatin interactions from multi-chromosome constrained chromatin model.

PubMed

Gürsoy, Gamze; Xu, Yun; Liang, Jie

2017-07-01

Nuclear landmarks and biochemical factors play important roles in the organization of the yeast genome. The interaction pattern of budding yeast as measured from genome-wide 3C studies are largely recapitulated by model polymer genomes subject to landmark constraints. However, the origin of inter-chromosomal interactions, specific roles of individual landmarks, and the roles of biochemical factors in yeast genome organization remain unclear. Here we describe a multi-chromosome constrained self-avoiding chromatin model (mC-SAC) to gain understanding of the budding yeast genome organization. With significantly improved sampling of genome structures, both intra- and inter-chromosomal interaction patterns from genome-wide 3C studies are accurately captured in our model at higher resolution than previous studies. We show that nuclear confinement is a key determinant of the intra-chromosomal interactions, and centromere tethering is responsible for the inter-chromosomal interactions. In addition, important genomic elements such as fragile sites and tRNA genes are found to be clustered spatially, largely due to centromere tethering. We uncovered previously unknown interactions that were not captured by genome-wide 3C studies, which are found to be enriched with tRNA genes, RNAPIII and TFIIS binding. Moreover, we identified specific high-frequency genome-wide 3C interactions that are unaccounted for by polymer effects under landmark constraints. These interactions are enriched with important genes and likely play biological roles.

Latitudinal Variations of Auroral-Zone Ionization Distribution.

DTIC Science & Technology

1983-02-01

CONTRACT OR GRANT NUMBER(s) Robert M. Robinson F49620-80-C-0014 Roland T. Tsunoda 9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM ELEMENT , PROJECT...scanned. A. Auroral Zone Ionospheric Conductivity A key element in modelling the magnetosphere-ionosphere circuit is the auroral zone ionospheric...while the maximum conductivity for the evening eastward electro- jet was less than 20 mho in our data set . In other words, both the south- ward field and

Hydrologic Drivers of Soil Organic Carbon Erosion and Burial: Insights from a Spatially-explicit Model of a Degraded Landscape at the Calhoun Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Dialynas, Y. G.; Bras, R. L.; Richter, D. D., Jr.

2017-12-01

Soil erosion and burial of organic material may constitute a substantial sink of atmospheric CO2. Attempts to quantify impacts of soil erosion on the soil-atmosphere C exchange are limited by difficulties in accounting for the fate of eroded soil organic carbon (SOC), a key factor in estimating of the net effect of erosion on the C cycle. Processes that transport SOC are still inadequately represented in terrestrial carbon (C) cycle models. This study investigates hydrologic controls on SOC redistribution across the landscape focusing on dynamic feedbacks between watershed hydrology, soil erosional processes, and SOC burial. We use tRIBS-ECO (Triangulated Irregular Network-based Real-time Integrated Basin Simulator-Erosion and Carbon Oxidation), a spatially-explicit model of SOC dynamics coupled with a physically-based hydro-geomorphic model. tRIBS-ECO systematically accounts for the fate of eroded SOC across the watershed: Rainsplash erosion and sheet erosion redistribute SOC from upland sites to depositional environments, altering depth-dependent soil biogeochemical properties in diverse soil profiles. Eroded organic material is transferred with sediment and can be partially oxidized upon transport, or preserved from decomposition by burial. The model was applied in the Calhoun Critical Zone Observatory (CZO), a site that is recovering from some of the most serious agricultural erosion in North America. Soil biogeochemical characteristics at multiple soil horizons were used to initialize the model and test performance. Remotely sensed soil moisture data (NASA SMAP) were used for model calibration. Results show significant rates of hydrologically-induced burial of SOC at the Calhoun CZO. We find that organic material at upland eroding soil profiles is largely mobilized by rainsplash erosion. Sheet erosion mainly drives C transport in lower elevation clayey soils. While SOC erosion and deposition rates declined with recent reforestation at the study site, the erosional potential of the degraded landscape remains significant.

Executive Thinking and Decision Skills: A Characterization and Implications for Training

DTIC Science & Technology

1990-10-01

operates, and to find ways to foster this development. Marvin Minsky (1986) has drawn an analogy between the mind and a bureaucratic organization...frames (cf. Anderson, 1980; Minsky , 1975). Similar to scripts, frames are expectancy-driven organizers of knowledge. Scripts focus more on goal and plan...be called intelligent. The key to intelligence, maintains Minsky , is in how these interactions are organized. One of Minsky’s key theoretical tenets

The approach to detection and application of the company’s technological competences to form a business-model

NASA Astrophysics Data System (ADS)

Chursin, A. A.; Kashirin, A. I.; Strenalyuk, V. V.; Semenov, A. S.; Ostrovskaya, A. A.; Kokuytseva, T. V.

2018-02-01

The most important condition for increasing the competitiveness of business is the formation, retention, and development of key competences of the organization, which reflect the competitive advantage. This problem is especially urgent for high-tech industries, which are the most sensitive to all kinds of changes and innovations. The ways of applying the company’s technological competences to form a business model, the proper form of competence description and analysis on the example of the company “Teplolux” are considered. The following from is recommended to use in IT solutions for competence databases.

100 years of Drosophila research and its impact on vertebrate neuroscience: a history lesson for the future.

PubMed

Bellen, Hugo J; Tong, Chao; Tsuda, Hiroshi

2010-07-01

Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience.

Understanding Cooperative Chirality at the Nanoscale

NASA Astrophysics Data System (ADS)

Yu, Shangjie; Wang, Pengpeng; Govorov, Alexander; Ouyang, Min

Controlling chirality of organic and inorganic structures plays a key role in many physical, chemical and biochemical processes, and may offer new opportunity to create technology applications based on chiroptical effect. In this talk, we will present a theoretical model and simulation to demonstrate how to engineer nanoscale chirality in inorganic nanostructures via synergistic control of electromagnetic response of both lattice and geometry, leading to rich tunability of chirality at the nanoscale. Our model has also been applied to understand recent materials advancement of related control with excellent agreement, and can elucidate physical origins of circular dichroism features in the experiment.

100 years of Drosophila research and its impact on vertebrate neuroscience: a history lesson for the future

PubMed Central

Bellen, Hugo J; Tong, Chao; Tsuda, Hiroshi

2014-01-01

Discoveries in fruit flies have greatly contributed to our understanding of neuroscience. The use of an unparalleled wealth of tools, many of which originated between 1910–1960, has enabled milestone discoveries in nervous system development and function. Such findings have triggered and guided many research efforts in vertebrate neuroscience. After 100 years, fruit flies continue to be the choice model system for many neuroscientists. The combinational use of powerful research tools will ensure that this model organism will continue to lead to key discoveries that will impact vertebrate neuroscience. PMID:20383202

NEMA, a functional-structural model of nitrogen economy within wheat culms after flowering. II. Evaluation and sensitivity analysis.

PubMed

Bertheloot, Jessica; Wu, Qiongli; Cournède, Paul-Henry; Andrieu, Bruno

2011-10-01

Simulating nitrogen economy in crop plants requires formalizing the interactions between soil nitrogen availability, root nitrogen acquisition, distribution between vegetative organs and remobilization towards grains. This study evaluates and analyses the functional-structural and mechanistic model of nitrogen economy, NEMA (Nitrogen Economy Model within plant Architecture), developed for winter wheat (Triticum aestivum) after flowering. NEMA was calibrated for field plants under three nitrogen fertilization treatments at flowering. Model behaviour was investigated and sensitivity to parameter values was analysed. Nitrogen content of all photosynthetic organs and in particular nitrogen vertical distribution along the stem and remobilization patterns in response to fertilization were simulated accurately by the model, from Rubisco turnover modulated by light intercepted by the organ and a mobile nitrogen pool. This pool proved to be a reliable indicator of plant nitrogen status, allowing efficient regulation of nitrogen acquisition by roots, remobilization from vegetative organs and accumulation in grains in response to nitrogen treatments. In our simulations, root capacity to import carbon, rather than carbon availability, limited nitrogen acquisition and ultimately nitrogen accumulation in grains, while Rubisco turnover intensity mostly affected dry matter accumulation in grains. NEMA enabled interpretation of several key patterns usually observed in field conditions and the identification of plausible processes limiting for grain yield, protein content and root nitrogen acquisition that could be targets for plant breeding; however, further understanding requires more mechanistic formalization of carbon metabolism. Its strong physiological basis and its realistic behaviour support its use to gain insights into nitrogen economy after flowering.

Estimation of soil clay and organic matter using two quantitative methods (PLSR and MARS) based on reflectance spectroscopy

NASA Astrophysics Data System (ADS)

Nawar, Said; Buddenbaum, Henning; Hill, Joachim

2014-05-01

A rapid and inexpensive soil analytical technique is needed for soil quality assessment and accurate mapping. This study investigated a method for improved estimation of soil clay (SC) and organic matter (OM) using reflectance spectroscopy. Seventy soil samples were collected from Sinai peninsula in Egypt to estimate the soil clay and organic matter relative to the soil spectra. Soil samples were scanned with an Analytical Spectral Devices (ASD) spectrometer (350-2500 nm). Three spectral formats were used in the calibration models derived from the spectra and the soil properties: (1) original reflectance spectra (OR), (2) first-derivative spectra smoothened using the Savitzky-Golay technique (FD-SG) and (3) continuum-removed reflectance (CR). Partial least-squares regression (PLSR) models using the CR of the 400-2500 nm spectral region resulted in R2 = 0.76 and 0.57, and RPD = 2.1 and 1.5 for estimating SC and OM, respectively, indicating better performance than that obtained using OR and SG. The multivariate adaptive regression splines (MARS) calibration model with the CR spectra resulted in an improved performance (R2 = 0.89 and 0.83, RPD = 3.1 and 2.4) for estimating SC and OM, respectively. The results show that the MARS models have a great potential for estimating SC and OM compared with PLSR models. The results obtained in this study have potential value in the field of soil spectroscopy because they can be applied directly to the mapping of soil properties using remote sensing imagery in arid environment conditions. Key Words: soil clay, organic matter, PLSR, MARS, reflectance spectroscopy.

Characteristics of health care organizations associated with learning and development: lessons from a pilot study.

PubMed

Nyström, Monica

2009-01-01

Characteristics of health care organizations associated with an ability to learn from experiences and to develop and manage change were explored in this study. Understanding of these characteristics is necessary to identify factors influencing success in learning from the past and achieving future health care quality objectives. A literature review of the quality improvement, strategic organizational development and change management, organizational learning, and microsystems fields identified 20 organizational characteristics, grouped under (a) organizational systems, (b) key actors, and (c) change management processes. Qualitative methods, using interviews, focus group reports, and archival records, were applied to find associations between identified characteristics and 6 Swedish health care units externally evaluated as delivering high-quality care. Strong support for a characteristic was defined as units having more than 4 sources describing the characteristic as an important success factor. Eighteen characteristics had strong support from at least 2 units. The strongest evidence was found for the following: (i) key actors have long-term commitment, provide support, and make sense of ambiguous situations; (ii) organizational systems encourage employee commitment, participation, and involvement; and (iii) change management processes are employed systematically. Based on the results, a new model of "characteristics associated with learning and development in health care organizations" is proposed.

High-rate, High Temperature Acetotrophic Methanogenesis Governed by a Three Population Consortium in Anaerobic Bioreactors

PubMed Central

Ho, Dang; Jensen, Paul; Gutierrez-Zamora, Maria-Luisa; Beckmann, Sabrina; Manefield, Mike; Batstone, Damien

2016-01-01

A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65°C), but this capability had not been linked to any key organisms. This study combined RNA–stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65°C, and fed with 13-C labelled and 12C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on 13C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65°C), acetoclastic Methanosarcina (55 to 60°C) and hydrogenotrophic Methanothermobacter (60 to 65°C). The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55°C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures. PMID:27490246

High-rate, High Temperature Acetotrophic Methanogenesis Governed by a Three Population Consortium in Anaerobic Bioreactors.

PubMed

Ho, Dang; Jensen, Paul; Gutierrez-Zamora, Maria-Luisa; Beckmann, Sabrina; Manefield, Mike; Batstone, Damien

2016-01-01

A combination of acetate oxidation and acetoclastic methanogenesis has been previously identified to enable high-rate methanogenesis at high temperatures (55 to 65°C), but this capability had not been linked to any key organisms. This study combined RNA-stable isotope probing on 13C-labelled acetate and 16S amplicon sequencing to identify the active micro-organisms involved in high-rate methanogenesis. Active biomass was harvested from three bench-scale thermophilic bioreactors treating waste activated sludge at 55, 60 and 65°C, and fed with 13-C labelled and 12C-unlabelled acetate. Acetate uptake and cumulative methane production were determined and kinetic parameters were estimated using model-based analysis. Pyrosequencing performed on 13C- enriched samples indicated that organisms accumulating labelled carbon were Coprothermobacter (all temperatures between 55 and 65°C), acetoclastic Methanosarcina (55 to 60°C) and hydrogenotrophic Methanothermobacter (60 to 65°C). The increased relative abundance of Coprothermobacter with increased temperature corresponding with a shift to syntrophic acetate oxidation identified this as a potentially key oxidiser. Methanosarcina likely acts as both a hydrogen utilising and acetoclastic methanogen at 55°C, and is replaced by Methanothermobacter as a hydrogen utiliser at higher temperatures.

Understanding the primary emissions and secondary formation of gaseous organic acids in the oil sands region of Alberta, Canada

NASA Astrophysics Data System (ADS)

Liggio, John; Moussa, Samar G.; Wentzell, Jeremy; Darlington, Andrea; Liu, Peter; Leithead, Amy; Hayden, Katherine; O'Brien, Jason; Mittermeier, Richard L.; Staebler, Ralf; Wolde, Mengistu; Li, Shao-Meng

2017-07-01

Organic acids are known to be emitted from combustion processes and are key photochemical products of biogenic and anthropogenic precursors. Despite their multiple environmental impacts, such as on acid deposition and human-ecosystem health, little is known regarding their emission magnitudes or detailed chemical formation mechanisms. In the current work, airborne measurements of 18 gas-phase low-molecular-weight organic acids were made in the summer of 2013 over the oil sands region of Alberta, Canada, an area of intense unconventional oil extraction. The data from these measurements were used in conjunction with emission retrieval algorithms to derive the total and speciated primary organic acid emission rates, as well as secondary formation rates downwind of oil sands operations. The results of the analysis indicate that approximately 12 t day-1 of low-molecular-weight organic acids, dominated by C1-C5 acids, were emitted directly from off-road diesel vehicles within open pit mines. Although there are no specific reporting requirements for primary organic acids, the measured emissions were similar in magnitude to primary oxygenated hydrocarbon emissions, for which there are reporting thresholds, measured previously ( ≈ 20 t day-1). Conversely, photochemical production of gaseous organic acids significantly exceeded the primary sources, with formation rates of up to ≈ 184 t day-1 downwind of the oil sands facilities. The formation and evolution of organic acids from a Lagrangian flight were modelled with a box model, incorporating a detailed hydrocarbon reaction mechanism extracted from the Master Chemical Mechanism (v3.3). Despite evidence of significant secondary organic acid formation, the explicit chemical box model largely underestimated their formation in the oil sands plumes, accounting for 39, 46, 26, and 23 % of the measured formic, acetic, acrylic, and propionic acids respectively and with little contributions from biogenic VOC precursors. The model results, together with an examination of the carbon mass balance between the organic acids formed and the primary VOCs emitted from oil sands operations, suggest the existence of significant missing secondary sources and precursor emissions related to oil sands and/or an incomplete mechanistic and quantitative understanding of how they are processed in the atmosphere.

Registered dietitian nutritionists bring value to emerging health care delivery models.

PubMed

Jortberg, Bonnie T; Fleming, Michael O

2014-12-01

Health care in the United States is the most expensive in the world; however, most citizens do not receive quality care that is comprehensive and coordinated. To address this gap, the Institute for Healthcare Improvement developed the Triple Aim (ie, improving population health, improving the patient experience, and reducing costs), which has been adopted by patient-centered medical homes and accountable care organizations. The patient-centered medical home and other population health models focus on improving the care for all people, particularly those with multiple morbidities. The Joint Principles of the Patient-Centered Medical Home, developed by the major primary care physician organizations in 2007, recognizes the key role of the multidisciplinary team in meeting the challenge of caring for these individuals. Registered dietitian nutritionists (RDNs) bring value to this multidisciplinary team by providing care coordination, evidence-based care, and quality-improvement leadership. RDNs have demonstrated efficacy for improvements in outcomes for patients with a wide variety of medical conditions. Primary care physicians, as well as several patient-centered medical home and population health demonstration projects, have reported the benefits of RDNs as part of the integrated primary care team. One of the most significant barriers to integrating RDNs into primary care has been an insufficient reimbursement model. Newer innovative payment models provide the opportunity to overcome this barrier. In order to achieve this integration, the Academy of Nutrition and Dietetics and RDNs must fully understand and embrace the opportunities and challenges that the new health care delivery and payment models present, and be prepared and empowered to lead the necessary changes. All stakeholders within the health care system need to more fully recognize and embrace the value and multidimensional role of the RDN on the multidisciplinary team. The Academy's Patient-Centered Medical Home/Accountable Care Organizations Workgroup Report provides a framework for the Academy, its members, and key partners to use to achieve this goal. Copyright © 2014 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Acute Radiation Risk and BRYNTRN Organ Dose Projection Graphical User Interface

NASA Technical Reports Server (NTRS)

Cucinotta, Francis A.; Hu, Shaowen; Nounu, Hateni N.; Kim, Myung-Hee

2011-01-01

The integration of human space applications risk projection models of organ dose and acute radiation risk has been a key problem. NASA has developed an organ dose projection model using the BRYNTRN with SUM DOSE computer codes, and a probabilistic model of Acute Radiation Risk (ARR). The codes BRYNTRN and SUM DOSE are a Baryon transport code and an output data processing code, respectively. The risk projection models of organ doses and ARR take the output from BRYNTRN as an input to their calculations. With a graphical user interface (GUI) to handle input and output for BRYNTRN, the response models can be connected easily and correctly to BRYNTRN. A GUI for the ARR and BRYNTRN Organ Dose (ARRBOD) projection code provides seamless integration of input and output manipulations, which are required for operations of the ARRBOD modules. The ARRBOD GUI is intended for mission planners, radiation shield designers, space operations in the mission operations directorate (MOD), and space biophysics researchers. BRYNTRN code operation requires extensive input preparation. Only a graphical user interface (GUI) can handle input and output for BRYNTRN to the response models easily and correctly. The purpose of the GUI development for ARRBOD is to provide seamless integration of input and output manipulations for the operations of projection modules (BRYNTRN, SLMDOSE, and the ARR probabilistic response model) in assessing the acute risk and the organ doses of significant Solar Particle Events (SPEs). The assessment of astronauts radiation risk from SPE is in support of mission design and operational planning to manage radiation risks in future space missions. The ARRBOD GUI can identify the proper shielding solutions using the gender-specific organ dose assessments in order to avoid ARR symptoms, and to stay within the current NASA short-term dose limits. The quantified evaluation of ARR severities based on any given shielding configuration and a specified EVA or other mission scenario can be made to guide alternative solutions for attaining determined objectives set by mission planners. The ARRBOD GUI estimates the whole-body effective dose, organ doses, and acute radiation sickness symptoms for astronauts, by which operational strategies and capabilities can be made for the protection of astronauts from SPEs in the planning of future lunar surface scenarios, exploration of near-Earth objects, and missions to Mars.

Can Process Understanding Help Elucidate The Structure Of The Critical Zone? Comparing Process-Based Soil Formation Models With Digital Soil Mapping.

NASA Astrophysics Data System (ADS)

Vanwalleghem, T.; Román, A.; Peña, A.; Laguna, A.; Giráldez, J. V.

2017-12-01

There is a need for better understanding the processes influencing soil formation and the resulting distribution of soil properties in the critical zone. Soil properties can exhibit strong spatial variation, even at the small catchment scale. Especially soil carbon pools in semi-arid, mountainous areas are highly uncertain because bulk density and stoniness are very heterogeneous and rarely measured explicitly. In this study, we explore the spatial variability in key soil properties (soil carbon stocks, stoniness, bulk density and soil depth) as a function of processes shaping the critical zone (weathering, erosion, soil water fluxes and vegetation patterns). We also compare the potential of traditional digital soil mapping versus a mechanistic soil formation model (MILESD) for predicting these key soil properties. Soil core samples were collected from 67 locations at 6 depths. Total soil organic carbon stocks were 4.38 kg m-2. Solar radiation proved to be the key variable controlling soil carbon distribution. Stone content was mostly controlled by slope, indicating the importance of erosion. Spatial distribution of bulk density was found to be highly random. Finally, total carbon stocks were predicted using a random forest model whose main covariates were solar radiation and NDVI. The model predicts carbon stocks that are double as high on north versus south-facing slopes. However, validation showed that these covariates only explained 25% of the variation in the dataset. Apparently, present-day landscape and vegetation properties are not sufficient to fully explain variability in the soil carbon stocks in this complex terrain under natural vegetation. This is attributed to a high spatial variability in bulk density and stoniness, key variables controlling carbon stocks. Similar results were obtained with the mechanistic soil formation model MILESD, suggesting that more complex models might be needed to further explore this high spatial variability.

Developmental models for estimating ecological responses to environmental variability: structural, parametric, and experimental issues.

PubMed

Moore, Julia L; Remais, Justin V

2014-03-01

Developmental models that account for the metabolic effect of temperature variability on poikilotherms, such as degree-day models, have been widely used to study organism emergence, range and development, particularly in agricultural and vector-borne disease contexts. Though simple and easy to use, structural and parametric issues can influence the outputs of such models, often substantially. Because the underlying assumptions and limitations of these models have rarely been considered, this paper reviews the structural, parametric, and experimental issues that arise when using degree-day models, including the implications of particular structural or parametric choices, as well as assumptions that underlie commonly used models. Linear and non-linear developmental functions are compared, as are common methods used to incorporate temperature thresholds and calculate daily degree-days. Substantial differences in predicted emergence time arose when using linear versus non-linear developmental functions to model the emergence time in a model organism. The optimal method for calculating degree-days depends upon where key temperature threshold parameters fall relative to the daily minimum and maximum temperatures, as well as the shape of the daily temperature curve. No method is shown to be universally superior, though one commonly used method, the daily average method, consistently provides accurate results. The sensitivity of model projections to these methodological issues highlights the need to make structural and parametric selections based on a careful consideration of the specific biological response of the organism under study, and the specific temperature conditions of the geographic regions of interest. When degree-day model limitations are considered and model assumptions met, the models can be a powerful tool for studying temperature-dependent development.

[Key content and formulation of national Chinese materia medica resources survey at county level].

PubMed

Lu, Jian-Wei; Zhang, Xiao-Bo; Li, Hai-Tao; Guo, Lan-Ping; Zhao, Run-Huai; Zhang, Ben-Gang; Sun, Li-Ying; Huang, Lu-Qi

2013-08-01

According to National Census for Water, National Population Census, National Land and Resources Survey, and work experience of experimental measures for national Chinese materia medica resources(CMMR) survey,the national CMMR survey at the county level is the key point of whole survey, that includes organization and management, field survey, sorting data three key links. Organization and management works of national CMMR survey needs to finish four key contents, there are definite goals and tasks, practicable crew, preparation directory, and security assurance. Field survey works of the national CMMR survey needs to finish five key contents, there are preparation works for field survey, the choice of the key survey area (samples), fill in the questionnaire, video data collection, specimen and other physical collection. Sorting data works of the national CMMR survey needs to finish tree key contents, there are data, specimen and census results.

Studies on kinetics of water quality factors to establish water transparency model in Neijiang River, China.

PubMed

Li, Ronghui; Pan, Wei; Guo, Jinchuan; Pang, Yong; Wu, Jianqiang; Li, Yiping; Pan, Baozhu; Ji, Yong; Ding, Ling

2014-05-01

The basis for submerged plant restoration in surface water is to research the complicated dynamic mechanism of water transparency. In this paper, through the impact factor analysis of water transparency, the suspended sediment, dissolved organic matter, algae were determined as three main impactfactors for water transparency of Neijiang River in Eastern China. And the multiple regression equation of water transparency and sediment concentration, permanganate index, chlorophyll-a concentration was developed. Considering the complicated transport and transformation of suspended sediment, dissolved organic matter and algae, numerical model of them were developed respectively for simulating the dynamic process. Water transparency numerical model was finally developed by coupling the sediment, water quality, and algae model. These results showed that suspended sediment was a key factor influencing water transparency of Neijiang River, the influence of water quality indicated by chemical oxygen demand and algal concentration indicated by chlorophyll a were indeterminate when their concentrations were lower, the influence was more obvious when high concentrations are available, such three factors showed direct influence on water transparency.

Incorporating water table dynamics in climate modeling: 1. Water table observations and equilibrium water table simulations

NASA Astrophysics Data System (ADS)

Fan, Ying; Miguez-Macho, Gonzalo; Weaver, Christopher P.; Walko, Robert; Robock, Alan

2007-05-01

Soil moisture is a key participant in land-atmosphere interactions and an important determinant of terrestrial climate. In regions where the water table is shallow, soil moisture is coupled to the water table. This paper is the first of a two-part study to quantify this coupling and explore its implications in the context of climate modeling. We examine the observed water table depth in the lower 48 states of the United States in search of salient spatial and temporal features that are relevant to climate dynamics. As a means to interpolate and synthesize the scattered observations, we use a simple two-dimensional groundwater flow model to construct an equilibrium water table as a result of long-term climatic and geologic forcing. Model simulations suggest that the water table depth exhibits spatial organization at watershed, regional, and continental scales, which may have implications for the spatial organization of soil moisture at similar scales. The observations suggest that water table depth varies at diurnal, event, seasonal, and interannual scales, which may have implications for soil moisture memory at these scales.

Human 3D vascularized organotypic microfluidic assays to study breast cancer cell extravasation

PubMed Central

Jeon, Jessie S.; Bersini, Simone; Gilardi, Mara; Dubini, Gabriele; Charest, Joseph L.; Moretti, Matteo; Kamm, Roger D.

2015-01-01

A key aspect of cancer metastases is the tendency for specific cancer cells to home to defined subsets of secondary organs. Despite these known tendencies, the underlying mechanisms remain poorly understood. Here we develop a microfluidic 3D in vitro model to analyze organ-specific human breast cancer cell extravasation into bone- and muscle-mimicking microenvironments through a microvascular network concentrically wrapped with mural cells. Extravasation rates and microvasculature permeabilities were significantly different in the bone-mimicking microenvironment compared with unconditioned or myoblast containing matrices. Blocking breast cancer cell A3 adenosine receptors resulted in higher extravasation rates of cancer cells into the myoblast-containing matrices compared with untreated cells, suggesting a role for adenosine in reducing extravasation. These results demonstrate the efficacy of our model as a drug screening platform and a promising tool to investigate specific molecular pathways involved in cancer biology, with potential applications to personalized medicine. PMID:25524628

PyramidalExplorer: A New Interactive Tool to Explore Morpho-Functional Relations of Human Pyramidal Neurons.

PubMed

Toharia, Pablo; Robles, Oscar D; Fernaud-Espinosa, Isabel; Makarova, Julia; Galindo, Sergio E; Rodriguez, Angel; Pastor, Luis; Herreras, Oscar; DeFelipe, Javier; Benavides-Piccione, Ruth

2015-01-01

This work presents PyramidalExplorer, a new tool to interactively explore and reveal the detailed organization of the microanatomy of pyramidal neurons with functionally related models. It consists of a set of functionalities that allow possible regional differences in the pyramidal cell architecture to be interactively discovered by combining quantitative morphological information about the structure of the cell with implemented functional models. The key contribution of this tool is the morpho-functional oriented design that allows the user to navigate within the 3D dataset, filter and perform Content-Based Retrieval operations. As a case study, we present a human pyramidal neuron with over 9000 dendritic spines in its apical and basal dendritic trees. Using PyramidalExplorer, we were able to find unexpected differential morphological attributes of dendritic spines in particular compartments of the neuron, revealing new aspects of the morpho-functional organization of the pyramidal neuron.

PyramidalExplorer: A New Interactive Tool to Explore Morpho-Functional Relations of Human Pyramidal Neurons

PubMed Central

Toharia, Pablo; Robles, Oscar D.; Fernaud-Espinosa, Isabel; Makarova, Julia; Galindo, Sergio E.; Rodriguez, Angel; Pastor, Luis; Herreras, Oscar; DeFelipe, Javier; Benavides-Piccione, Ruth

2016-01-01

This work presents PyramidalExplorer, a new tool to interactively explore and reveal the detailed organization of the microanatomy of pyramidal neurons with functionally related models. It consists of a set of functionalities that allow possible regional differences in the pyramidal cell architecture to be interactively discovered by combining quantitative morphological information about the structure of the cell with implemented functional models. The key contribution of this tool is the morpho-functional oriented design that allows the user to navigate within the 3D dataset, filter and perform Content-Based Retrieval operations. As a case study, we present a human pyramidal neuron with over 9000 dendritic spines in its apical and basal dendritic trees. Using PyramidalExplorer, we were able to find unexpected differential morphological attributes of dendritic spines in particular compartments of the neuron, revealing new aspects of the morpho-functional organization of the pyramidal neuron. PMID:26778972

The Process for the Formulation of the International Telehealth Position Statement for Occupational Therapy

PubMed Central

JACOBS, KAREN; CASON, JANA; MCCULLOUGH, ANN

2015-01-01

The World Federation of Occupational Therapists (WFOT) consists of 84 member organizations representing over 420,000 occupational therapists internationally (WFOT, 2014). In 2014, WFOT published the WFOT Telehealth Position Statement on the use of telehealth in occupational therapy. The process for the formulation of the official document involved reviewing WFOT member organizations’ telehealth position statements and data collected from a survey sent to member organizations’ delegates in April 2014. Qualitative data from 39 countries yielded factors to consider in five key areas: licensure/registration requirements, the cost of technology, privacy and security, reimbursement/payment models, and other issues (e.g., need for collaboration/transfer of knowledge, client selection, provider competencies, standard of care). The WFOT Telehealth Position Statement addressed each of these areas. The collaborative effort resulting in the development of the WFOT Telehealth Position Statement serves as a model for other international organizations. PMID:27563380

Human 3D vascularized organotypic microfluidic assays to study breast cancer cell extravasation.

PubMed

Jeon, Jessie S; Bersini, Simone; Gilardi, Mara; Dubini, Gabriele; Charest, Joseph L; Moretti, Matteo; Kamm, Roger D

2015-01-06

A key aspect of cancer metastases is the tendency for specific cancer cells to home to defined subsets of secondary organs. Despite these known tendencies, the underlying mechanisms remain poorly understood. Here we develop a microfluidic 3D in vitro model to analyze organ-specific human breast cancer cell extravasation into bone- and muscle-mimicking microenvironments through a microvascular network concentrically wrapped with mural cells. Extravasation rates and microvasculature permeabilities were significantly different in the bone-mimicking microenvironment compared with unconditioned or myoblast containing matrices. Blocking breast cancer cell A3 adenosine receptors resulted in higher extravasation rates of cancer cells into the myoblast-containing matrices compared with untreated cells, suggesting a role for adenosine in reducing extravasation. These results demonstrate the efficacy of our model as a drug screening platform and a promising tool to investigate specific molecular pathways involved in cancer biology, with potential applications to personalized medicine.

The Biology of Aging: Citizen Scientists and Their Pets as a Bridge Between Research on Model Organisms and Human Subjects.

PubMed

Kaeberlein, M

2016-03-01

A fundamental goal of research into the basic mechanisms of aging is to develop translational strategies that improve human health by delaying the onset and progression of age-related pathology. Several interventions have been discovered that increase life span in invertebrate organisms, some of which have similar effects in mice. These include dietary restriction and inhibition of the mechanistic target of rapamycin by treatment with rapamycin. Key challenges moving forward will be to assess the extent to which these and other interventions improve healthy longevity and increase life span in mice and to develop practical strategies for extending this work to the clinic. Companion animals may provide an optimal intermediate between laboratory models and humans. By improving healthy longevity in companion animals, important insights will be gained regarding human aging while improving the quality of life for people and their pets. © The Author(s) 2015.

Improvised Nuclear Device Case Study

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

Buddemeier, Brooke; Suski, Nancy

2011-07-12

Reducing the casualties of catastrophic terrorist attacks requires an understanding of weapons of mass destruction (WMD) effects, infrastructure damage, atmospheric dispersion, and health effects. The Federal Planning Guidance for Response to a Nuclear Detonation provides the strategy for response to an improvised nuclear device (IND) detonation. The supporting science developed by national laboratories and other technical organizations for this document significantly improves our understanding of the hazards posed by such an event. Detailed fallout predictions from the advanced suite of three-dimensional meteorology and plume/fallout models developed at Lawrence Livermore National Laboratory, including extensive global geographical and real-time meteorological databases tomore » support model calculations, are a key part of response planning. This presentation describes the methodology and results to date, including visualization aids developed for response organizations. These products have greatly enhanced the community planning process through first-person points of view and description of the dynamic nature of the event.« less

Standing variation in spatially growing populations

NASA Astrophysics Data System (ADS)

Fusco, Diana; Gralka, Matti; Kayser, Jona; Hallatschek, Oskar

Patterns of genetic diversity not only reflect the evolutionary history of a species but they can also determine the evolutionary response to environmental change. For instance, the standing genetic diversity of a microbial population can be key to rescue in the face of an antibiotic attack. While genetic diversity is in general shaped by both demography and evolution, very little is understood when both factors matter, as e.g. for biofilms with pronounced spatial organization. Here, we quantitatively explore patterns of genetic diversity by using microbial colonies and well-mixed test tube populations as antipodal model systems with extreme and very little spatial structure, respectively. We find that Eden model simulations and KPZ theory can remarkably reproduce the genetic diversity in microbial colonies obtained via population sequencing. The excellent agreement allows to draw conclusions on the resilience of spatially-organized populations and to uncover new strategies to contain antibiotic resistance.

The Impact Of Medicare ACOs On Improving Integration And Coordination Of Physical And Behavioral Health Care.

PubMed

Fullerton, Catherine A; Henke, Rachel M; Crable, Erika L; Hohlbauch, Andriana; Cummings, Nicholas

2016-07-01

The accountable care organization (ACO) model holds the promise of reducing costs and improving the quality of care by realigning payment incentives to focus on health outcomes instead of service volume. One key to managing the total cost of care is improving care coordination for and treatment of people with behavioral health disorders. We examined qualitative data from ninety organizations participating in Medicare ACO demonstration programs from 2012 through 2015 to determine whether and how they focused on behavioral health care. These ACOs had mixed degrees of engagement in improving behavioral health care for their populations. The biggest challenges included a lack of behavioral health care providers, data availability, and sustainable financing models. Nonetheless, we found substantial interest in integrating behavioral health care into primary care across a majority of the ACOs. Project HOPE—The People-to-People Health Foundation, Inc.

A strategy for tissue self-organization that is robust to cellular heterogeneity and plasticity.

PubMed

Cerchiari, Alec E; Garbe, James C; Jee, Noel Y; Todhunter, Michael E; Broaders, Kyle E; Peehl, Donna M; Desai, Tejal A; LaBarge, Mark A; Thomson, Matthew; Gartner, Zev J

2015-02-17

Developing tissues contain motile populations of cells that can self-organize into spatially ordered tissues based on differences in their interfacial surface energies. However, it is unclear how self-organization by this mechanism remains robust when interfacial energies become heterogeneous in either time or space. The ducts and acini of the human mammary gland are prototypical heterogeneous and dynamic tissues comprising two concentrically arranged cell types. To investigate the consequences of cellular heterogeneity and plasticity on cell positioning in the mammary gland, we reconstituted its self-organization from aggregates of primary cells in vitro. We find that self-organization is dominated by the interfacial energy of the tissue-ECM boundary, rather than by differential homo- and heterotypic energies of cell-cell interaction. Surprisingly, interactions with the tissue-ECM boundary are binary, in that only one cell type interacts appreciably with the boundary. Using mathematical modeling and cell-type-specific knockdown of key regulators of cell-cell cohesion, we show that this strategy of self-organization is robust to severe perturbations affecting cell-cell contact formation. We also find that this mechanism of self-organization is conserved in the human prostate. Therefore, a binary interfacial interaction with the tissue boundary provides a flexible and generalizable strategy for forming and maintaining the structure of two-component tissues that exhibit abundant heterogeneity and plasticity. Our model also predicts that mutations affecting binary cell-ECM interactions are catastrophic and could contribute to loss of tissue architecture in diseases such as breast cancer.

Generic features of the wealth distribution in ideal-gas-like markets.

PubMed

Mohanty, P K

2006-07-01

We provide an exact solution to the ideal-gas-like models studied in econophysics to understand the microscopic origin of Pareto law. In these classes of models the key ingredient necessary for having a self-organized scale-free steady-state distribution is the trading or collision rule where agents or particles save a definite fraction of their wealth or energy and invest the rest for trading. Using a Gibbs ensemble approach we could obtain the exact distribution of wealth in this model. Moreover we show that in this model (a) good savers are always rich and (b) every agent poor or rich invests the same amount for trading. Nonlinear trading rules could alter the generic scenario observed here.

Engaging blind and partially sighted stakeholders in transformational change.

PubMed

Pearson, Victoria

2016-09-01

For non-profit organizations in the disability sector, engaging stakeholders with disabilities on matters of strategic planning is both a responsibility and an expectation. As part of our current strategic plan, which calls for organizational and systemic transformation, the Canadian National Institute for the Blind (CNIB) has engaged blind and partially sighted stakeholders alongside other interest groups to build and advocate for a more holistic model of vision healthcare and rehabilitation. This article describes the CNIB's multi-year process, including early-stage consultations, collaborative strategy development, and political advocacy and shares our organization's key success factors and learnings in creating meaningful, mutually beneficial engagement. © 2016 The Canadian College of Health Leaders.

Mechanisms of perceptual organization provide auto-zoom and auto-localization for attention to objects

PubMed Central

Mihalas, Stefan; Dong, Yi; von der Heydt, Rüdiger; Niebur, Ernst

2011-01-01

Visual attention is often understood as a modulatory field acting at early stages of processing, but the mechanisms that direct and fit the field to the attended object are not known. We show that a purely spatial attention field propagating downward in the neuronal network responsible for perceptual organization will be reshaped, repositioned, and sharpened to match the object's shape and scale. Key features of the model are grouping neurons integrating local features into coherent tentative objects, excitatory feedback to the same local feature neurons that caused grouping neuron activation, and inhibition between incompatible interpretations both at the local feature level and at the object representation level. PMID:21502489

Application research on temporal GIS in the transportation information management system

NASA Astrophysics Data System (ADS)

Wang, Wei; Qin, Qianqing; Wang, Chao

2006-10-01

The application, development and key matters of applying spatio-temporal GIS to traffic information management system are discussed in this paper by introducing the development of spatio-temporal database, current models of spatio-temporal data, traits of traffic information management system. This paper proposes a method of organizing spatio-temporal data taking road object changes into consideration, and describes its data structure in 3 aspects, including structure of spatio-temporal object, organizing method spatio-temporal data and storage means of spatio-temporal data. Trying to manage types of spatio-temporal data involved in traffic system, such as road information, river information, railway information, social and economical data, and etc, uniformly, efficiently and with low redundancy.

Quantification of landfill methane using modified Intergovernmental Panel on Climate Change's waste model and error function analysis.

PubMed

Govindan, Siva Shangari; Agamuthu, P

2014-10-01

Waste management can be regarded as a cross-cutting environmental 'mega-issue'. Sound waste management practices support the provision of basic needs for general health, such as clean air, clean water and safe supply of food. In addition, climate change mitigation efforts can be achieved through reduction of greenhouse gas emissions from waste management operations, such as landfills. Landfills generate landfill gas, especially methane, as a result of anaerobic degradation of the degradable components of municipal solid waste. Evaluating the mode of generation and collection of landfill gas has posted a challenge over time. Scientifically, landfill gas generation rates are presently estimated using numerical models. In this study the Intergovernmental Panel on Climate Change's Waste Model is used to estimate the methane generated from a Malaysian sanitary landfill. Key parameters of the model, which are the decay rate and degradable organic carbon, are analysed in two different approaches; the bulk waste approach and waste composition approach. The model is later validated using error function analysis and optimum decay rate, and degradable organic carbon for both approaches were also obtained. The best fitting values for the bulk waste approach are a decay rate of 0.08 y(-1) and degradable organic carbon value of 0.12; and for the waste composition approach the decay rate was found to be 0.09 y(-1) and degradable organic carbon value of 0.08. From this validation exercise, the estimated error was reduced by 81% and 69% for the bulk waste and waste composition approach, respectively. In conclusion, this type of modelling could constitute a sensible starting point for landfills to introduce careful planning for efficient gas recovery in individual landfills. © The Author(s) 2014.

Towards integrated modelling of soil organic carbon cycling at landscape scale

NASA Astrophysics Data System (ADS)

Viaud, V.

2009-04-01

Soil organic carbon (SOC) is recognized as a key factor of the chemical, biological and physical quality of soil. Numerous models of soil organic matter turnover have been developed since the 1930ies, most of them dedicated to plot scale applications. More recently, they have been applied to national scales to establish the inventories of carbon stocks directed by the Kyoto protocol. However, only few studies consider the intermediate landscape scale, where the spatio-temporal pattern of land management practices, its interactions with the physical environment and its impacts on SOC dynamics can be investigated to provide guidelines for sustainable management of soils in agricultural areas. Modelling SOC cycling at this scale requires accessing accurate spatially explicit input data on soils (SOC content, bulk density, depth, texture) and land use (land cover, farm practices), and combining both data in a relevant integrated landscape representation. The purpose of this paper is to present a first approach to modelling SOC evolution in a small catchment. The impact of the way landscape is represented on SOC stocks in the catchment was more specifically addressed. This study was based on the field map, the soil survey, the crop rotations and land management practices of an actual 10-km² agricultural catchment located in Brittany (France). RothC model was used to drive soil organic matter dynamics. Landscape representation in the form of a systematic regular grid, where driving properties vary continuously in space, was compared to a representation where landscape is subdivided into a set of homogeneous geographical units. This preliminary work enabled to identify future needs to improve integrated soil-landscape modelling in agricultural areas.

Lingering representations of stimuli influence recall organization.

PubMed

Chan, Stephanie C Y; Applegate, Marissa C; Morton, Neal W; Polyn, Sean M; Norman, Kenneth A

2017-03-01

Several prominent theories posit that information about recent experiences lingers in the brain and organizes memories for current experiences, by forming a temporal context that is linked to those memories at encoding. According to these theories, if the thoughts preceding an experience X resemble the thoughts preceding an experience Y, then X and Y should show an elevated probability of being recalled together. We tested this prediction by using multi-voxel pattern analysis (MVPA) of fMRI data to measure neural evidence for lingering processing of preceding stimuli. As predicted, memories encoded with similar lingering thoughts about the category of preceding stimuli were more likely to be recalled together. Our results demonstrate that the "fading embers" of previous stimuli help to organize recall, confirming a key prediction of computational models of episodic memory. Copyright © 2017 Elsevier Ltd. All rights reserved.

Addressing Social Determinants Of Health Through Medical-Legal Partnerships.

PubMed

Regenstein, Marsha; Trott, Jennifer; Williamson, Alanna; Theiss, Joanna

2018-03-01

The US health care system needs effective tools to address complex social and environmental issues that perpetuate health inequities, such as food insecurity, education and employment barriers, and substandard housing conditions. The medical-legal partnership is a collaborative intervention that embeds civil legal aid professionals in health care settings to address seemingly intractable social problems that contribute to poor health outcomes and health disparities. More than three hundred health care organizations are home to medical-legal partnerships. This article draws upon national survey data and field research to identify three models of the medical-legal partnership that health care organizations have adopted and the core elements of infrastructure that they share. Financing and commitment from health care organizations are key considerations for sustaining and scaling up the medical-legal partnership as a health equity intervention.

Endocytosis and Signaling during Development

PubMed Central

Bökel, Christian

2014-01-01

The development of multicellular organisms relies on an intricate choreography of intercellular communication events that pattern the embryo and coordinate the formation of tissues and organs. It is therefore not surprising that developmental biology, especially using genetic model organisms, has contributed significantly to the discovery and functional dissection of the associated signal-transduction cascades. At the same time, biophysical, biochemical, and cell biological approaches have provided us with insights into the underlying cell biological machinery. Here we focus on how endocytic trafficking of signaling components (e.g., ligands or receptors) controls the generation, propagation, modulation, reception, and interpretation of developmental signals. A comprehensive enumeration of the links between endocytosis and signal transduction would exceed the limits of this review. We will instead use examples from different developmental pathways to conceptually illustrate the various functions provided by endocytic processes during key steps of intercellular signaling. PMID:24591521

Particle size studies to reveal crystallization mechanisms of the metal organic framework HKUST-1 during sonochemical synthesis.

PubMed

Armstrong, Mitchell R; Senthilnathan, Sethuraman; Balzer, Christopher J; Shan, Bohan; Chen, Liang; Mu, Bin

2017-01-01

Systematic studies of key operating parameters for the sonochemical synthesis of the metal organic framework (MOF) HKUST-1(also called CuBTC) were performed including reaction time, reactor volume, sonication amplitude, sonication tip size, solvent composition, and reactant concentrations analyzed through SEM particle size analysis. Trends in the particle size and size distributions show reproducible control of average particle sizes between 1 and 4μm. These results along with complementary studies in sonofragmentation and temperature control were conducted to compare these results to kinetic crystal growth models found in literature to develop a plausible hypothetical mechanism for ultrasound-assisted growth of metal-organic-frameworks composed of a competitive mechanism including constructive solid-on-solid (SOS) crystal growth and a deconstructive sonofragmentation. Copyright © 2016 Elsevier B.V. All rights reserved.

Spatial and Temporal Variability of Solar Ultraviolet Exposure of Coral Assemblages in the Florida Keys: Importance of Colored Dissolved Organic Matter

EPA Science Inventory

Solar UV radiation can have deleterious effects on coral assemblages in tropical and subtropical marine environments. We present evidence that UV exposure of coral reefs in the Florida Keys is controlled primarily by chromophoric dissolved organic matter (CDOM) in waters overlyin...

Analyzing the Effectiveness of the Self-organized Public-Key Management System on MANETs under the Lack of Cooperation and the Impersonation Attacks

NASA Astrophysics Data System (ADS)

da Silva, Eduardo; Dos Santos, Aldri Luiz; Lima, Michele N.; Albini, Luiz Carlos Pessoa

Among the key management schemes for MANETs, the Self-Organized Public-Key Management System (PGP-Like) is the main chaining-based key management scheme. It is fully self-organized and does not require any certificate authority. Two kinds of misbehavior attacks are considered to be great threats to PGP-Like: lack of cooperation and impersonation attacks. This work quantifies the impact of such attacks on the PGP-Like. Simulation results show that PGP-Like was able to maintain its effectiveness when submitted to the lack of cooperation attack, contradicting previously theoretical results. It correctly works even in the presence of more than 60% of misbehaving nodes, although the convergence time is affected with only 20% of misbehaving nodes. On the other hand, PGP-Like is completely vulnerable to the impersonation attack. Its functionality is affected with just 5% of misbehaving nodes, confirming previously theoretical results.

Advances and perspectives in in vitro human gut fermentation modeling.

PubMed

Payne, Amanda N; Zihler, Annina; Chassard, Christophe; Lacroix, Christophe

2012-01-01

The gut microbiota is a highly specialized organ containing host-specific assemblages of microbes whereby metabolic activity directly impacts human health and disease. In vitro gut fermentation models present an unmatched opportunity of performing studies frequently challenged in humans and animals owing to ethical concerns. Multidisciplinary systems biology analyses supported by '-omics' platforms remain widely neglected in the field of in vitro gut fermentation modeling but are key to advancing the significance of these models. Model-driven experimentation using a combination of in vitro gut fermentation and in vitro human cell models represent an advanced approach in identifying complex host-microbe interactions and niches central to gut fermentation processes. The aim of this review is to highlight the advances and challenges exhibited by in vitro human gut fermentation modeling. Copyright © 2011 Elsevier Ltd. All rights reserved.

Recovery and resilience after a nuclear power plant disaster: a medical decision model for managing an effective, timely, and balanced response.

PubMed

Coleman, C Norman; Blumenthal, Daniel J; Casto, Charles A; Alfant, Michael; Simon, Steven L; Remick, Alan L; Gepford, Heather J; Bowman, Thomas; Telfer, Jana L; Blumenthal, Pamela M; Noska, Michael A

2013-04-01

Resilience after a nuclear power plant or other radiation emergency requires response and recovery activities that are appropriately safe, timely, effective, and well organized. Timely informed decisions must be made, and the logic behind them communicated during the evolution of the incident before the final outcome is known. Based on our experiences in Tokyo responding to the Fukushima Daiichi nuclear power plant crisis, we propose a real-time, medical decision model by which to make key health-related decisions that are central drivers to the overall incident management. Using this approach, on-site decision makers empowered to make interim decisions can act without undue delay using readily available and high-level scientific, medical, communication, and policy expertise. Ongoing assessment, consultation, and adaption to the changing conditions and additional information are additional key features. Given the central role of health and medical issues in all disasters, we propose that this medical decision model, which is compatible with the existing US National Response Framework structure, be considered for effective management of complex, large-scale, and large-consequence incidents.